Early haemorrhage control and minimizing the time to definitive care have long been the cornerstones of therapy for patients exsanguinating from non-compressible haemorrhage (NCH) after penetrating injuries, as only basic treatment could be provided on scene. However, more recently, advanced on-scene treatments such as the transfusion of blood products, resuscitative thoracotomy (RT) and resuscitative endovascular balloon occlusion of the aorta (REBOA) have become available in a small number of pre-hospital critical care teams. Although these advanced techniques are included in the current traumatic cardiac arrest algorithm of the European Resuscitation Council (ERC), published in 2021, clear guidance on the practical application of these techniques in the pre-hospital setting is scarce. This paper provides a scoping review on how these advanced techniques can be incorporated into practice for the resuscitation of patients exsanguinating from NCH after penetrating injuries, based on available literature and the collective experience of several helicopter emergency medical services (HEMS) across Europe who have introduced these advanced resuscitation interventions into routine practice. Trauma is a major cause of death and disability worldwide in all age groups , 2. PeneWhile minimizing the time to definitive care remains a priority, advanced pre-hospital interventions such as blood product administration , 11, resThe revised traumatic cardiac arrest algorithm of the European Resuscitation Council (ERC) published in 2021  mentionsThis paper aims to provide a scoping review on when advanced techniques such as blood product transfusion, RT and REBOA can be utilized in the pre-hospital setting for the resuscitation of patients with NCH due to non-ballistic penetrating injuries, based on available literature and the collective experience of several helicopter emergency medical services (HEMS) across Europe who have introduced these advanced resuscitation interventions into routine practice.The primary treatment goal for all patients with NCH in the pre-hospital setting is to maintain or restore adequate coronary  perfusion until definitive  haemorrhage control can be achieved. Blood product transfusion, RT and REBOA can be used to facilitate cardiac resuscitation to achieve this goal in patients who are otherwise unlikely to survive the pre-hospital phase of care.how both techniques should be applied, as this has been described in detail previously [when each of these techniques should be considered in patients with a traumatic cardiac arrest  or patients with a profound haemorragic shock (second section) as a result of NCH from non-ballistic penetrating injuries.While blood transfusion may restore effective circulating volume, aortic occlusion by RT or REBOAs’ mechanism of action is to augment proximal diastolic blood pressure (and therefore coronary perfusion)  and resueviously , 22. In When patients present in TCA Fig.  after noAt all times, decision-making must continue in an efficient manner: time should not be wasted establishing monitoring for this purpose if it is not already in place. If there is any doubt about timings, a rapid point of care ultrasonography (POCUS) (to confirm if organized cardiac activity is present) can contribute to decision-making when there is reasonable doubt about the time of arrest in the absence of an organized rhythm, but no time should be wasted doing this when an organized rhythm is present .Current ERC guidelines  suggest When patients suffer from isolated penetrating injury to the chest resulting in a TCA, RT offers the opportunity to relieve a cardiac tamponade and to obtain haemorrhage control by direct treatment of intrathoracic injuries. For this purpose, the clamshell technique maximizes exposure to facilitate identification and treatment of injuries , 30, 31.When penetrating injuries are located below the diaphragm and the patient is in TCA, both RT and REBOA can be considered. If RT is performed, it is with the aim of occluding the descending aorta by manual compression (or by cross-clamping) as a pre-laparotomy rescue manoeuvre . AlternaOne of the key challenges of REBOA in patients in TCA is the cannulation of the common femoral artery. Although previous studies have shown the feasibility of intra-arrest cannulation in patients who had suffered a medical arrest –38, cannEpigastric injuries are particularly challenging to pre-hospital care providers, as they are at the junction of the abdominal and thoracic cavity. In these instances, rapid POCUS in addition to clinical assessment can help the pre-hospital clinician to decide whether to proceed with RT or with REBOA . If a taWhen there are multiple penetrating injuries of both chest and abdomen/groin, an informed decision needs to be made about the most likely source of bleeding causing the TCA , 41. ThiExternal cardiac massage is often of limited benefit where cardiac arrest is due to hypovolemia or a tamponade, as it relies on the passive filling of the heart during the recoil phase after each compression . During Standard resuscitation doses of adrenaline at fixed intervals should be avoided as no survival benefit has been demonstrated in patients with a hypovolemic cardiac arrest . If exte47.To maximize chances of ROSC optimal quality CPR, especially cardiac massage, should be provided. Transporting patients in-arrest to hospital will compromise this quality and is therefore not preferable when the advanced treatments as described have already been delivered on scene. When ROSC is obtained, rapid transfer to definitive  care is warranted for all patients. Distal perfusion should be restored as soon as possible after a period of heart and volume resuscitation, as prolonged complete aortic occlusion is unsurvivable due to the distal ischaemia created . The actAlthough a diagnosis of hypovolemic shock due to blood loss should be assumed in all patients presenting in shock with penetrating injuries, other causes of shock, such as tension pneumothorax or a pericardial tamponade, may also exist, especially when thoracic or epigastric injuries are present and should be treated according to existing recommendations .The primary treatment goal for patients presenting with profound hypovolemic shock due to NCH after penetrating injuries is to maintain adequate cerebral and coronary perfusion and to prevent deterioration of hypovolemic shock into cardiac arrest before definitive haemorrhage control has been obtained. Both volume resuscitation and haemorrhage control are important to achieve this.The evidence base guiding the indications and timing of pre-hospital volume replacement to maintain adequate coronary and cerebral perfusion in the pre-hospital setting is poor. Although a degree of hypotension is often accepted, and beneficial effects on outcome have been reported for permissive hypotension in the past , the effWhen volume replacement is initiated, this should ideally be done utilizing a 1:1 ratio of PRBC’s and FFP’s (or freeze-dried plasma) to limit coagulopathy –52. WholThe response to volume resuscitation should be monitored closely. Patients with haemorrhagic shock often demonstrate large variation in non-invasive blood pressure readings and automated readings tend to overestimate pressures . Additio2, tachy- or bradycardia and altered level of consciousness are present [Injured patients in extremis exsanguinating from NCH due to penetrating injuries may benefit from pre-hospital REBOA in addition to volume resuscitation when their injuries are situated below the level of the diaphragm to prevent them from dying before they reach definitive care . However present . There a present –59. Howe present .Determination of the appropriate zone for REBOA (I or III) is based on anatomical location of the injuries and presenting physiology: penetrating injuries in the upper thigh, groin, or buttock are amenable to zone III REBOA, whereas for abdominal and flank penetrating injuries, the balloon is deployed in zone I . In thesOnce the balloon is inflated, rapid transfer to a hospital with full trauma resuscitation capabilities is a priority. Titrated deflation (P-REBOA) and/or relocation of the balloon from zone I to zone III should be considered on route to hospital if injury location and physiology allow. If REBOA is not feasible in an exsanguinating patient, because of inability to cannulate the femoral vessels, pre-hospital RT with aortic occlusion can be considered in patients who are about to arrest.1/2Keo) such as ketamine are preferable [Pre-hospital emergency anaesthesia (PHEA) of hypotensive patients with penetrating injuries carries a significant risk, as it prolongs scene time, and previous studies have shown that PHEA in hypotensive trauma patients is associated with an increased in-hospital mortality . This iseferable . SometimServices that have adopted advanced techniques are rapidly developing experience on which groups of patients may benefit from them and how techniques can be adapted to facilitate delivery. There are some key questions that remain unanswered.Historically, the penetrating trauma literature suggested that short scene time and fast transport to hospital defined effective pre-hospital management , and pre47, is investigating this in patients with exsanguinating sub-diaphragmatic haemorrhage and imminent risk of hypovolemic cardiac arrest, or recent hypovolemic cardiac arrest. The results of these studies will hopefully provide some direction on the future treatment of patients in full cardiac arrest after subdiaphragmatic injuries.At present, experience with REBOA for patients in TCA with subdiaphragmatic injuries is limited. If advanced pre-hospital interventions at all are provided to these patients, the most likely interventions is a RT. Pre-hospital survival rates of this specific cohort are unavailable, but from in-hospital studies we know that reported survival rates of this patient group of RT patients are extremely poor . REBOA iWhen the decision has been made to convey the patient to hospital, the most suitable available transport modality should be chosen. In urban areas with short distances to trauma centers, this will usually be a ground ambulance. For patients attended in rural areas, the decision may be more complex and may depend on many factors, such as available resources, weather, injuries identified and anticipated clinical course. Although helicopter transport may contribute to a shorter time to definitive care and has been shown to be associated with an improved survival after major trauma in general , a surviIt is important to note that the pre-hospital response (both for patients in full cardiac arrest and for patients in profound shock) should always be adapted based on the expertise available. This covers seniority, training and the number of clinicians in a team required to deliver interventions in a timely fashion. Advanced interventions as described in this paper can only be provided in a system with ample opportunities to train and maintain skills. They mandate a system of rigorous clinical government, to deploy these techniques safely, especially as the evidence base behind many of the techniques described is still small. Even in the hands of well-trained providers, these interventions have the potential to delay scene times and may come with significant  complications , 17. ThePre-hospital resuscitation of patients in extremis due to NCH from non-ballistic injuries is dependent on available resources. Although minimizing scene time is important, several advanced pre-hospital interventions can be provided to a select group of exsanguinating patients in the pre-hospital setting in order to improve their chances of survival. Research studies as well as the experience gained from the adoption of these advanced resuscitation interventions by some pre-hospital services provide guidance on the future resuscitation of this patient group.


Human and other genomes encode tens of thousands of long noncoding RNAs (lncRNAs), the vast majority of which remain uncharacterised. High-throughput functional screening methods, notably those based on pooled CRISPR-Cas perturbations, promise to unlock the biological significance and biomedical potential of lncRNAs. Such screens are based on libraries of single guide RNAs (sgRNAs) whose design is critical for success. Few off-the-shelf libraries are presently available, and lncRNAs tend to have cell-type-specific expression profiles, meaning that library design remains in the hands of researchers. Here we introduce the topic of pooled CRISPR screens for lncRNAs and guide readers through the three key steps of library design: accurate annotation of transcript structures, curation of optimal candidate sets, and design of sgRNAs. This review is a starting point and reference for researchers seeking to design custom CRISPR screening libraries for lncRNAs. The number of annotated long noncoding RNA (lncRNA) genes has grown dramatically in the past decade thanks to next-generation sequencing (NGS). However, our ability to functionally characterise these genes has failed to keep pace, meaning that the vast majority of lncRNAs are of unknown biological or disease relevance  face a number of barriers when applied to lncRNAs. First among these is that RNA interference (RNAi) is often ineffective for lncRNAs, possibly due to the latter’s relative enrichment in the nucleus  afford versatile and highly scalable perturbations in the laboratory via direct targeting of the lncRNA gene itself . Our understanding of the sequence and genomic features determining these properties continues to evolve.This Review aims to highlight the main aspects of an optimal high-throughput lncRNA screen and will cover these principle topics: evolution of lncRNA screen technologies, and the three steps of screening library design: gene annotation, candidate selection, and sgRNA design.LncRNAs are defined as RNA transcripts longer than 200 nt that are not translated into proteins  ; CRISPR-based perturbations; and ASOs Fig. a–c. HereEarly approaches to screen lncRNAs came from RNAi, which had a long history in PCG screening , can be targeted to the gene locus or the RNA product, displays reduced off-target effects, and most importantly, can be conveniently scaled to high throughputs  consists of a 20 nt variable RNA sequence or “spacer”, which recognises by homology a specific genomic site followed by a protospacer adjacent motif (PAM) , which is a non-templated method that repairs breaks but often introduces untemplated insertions and deletions (indels) at the repair site , one may achieve gene activation (CRISPRa) or inhibition (CRISPRi)  , a coverage of 100–1000 individual cells per sgRNA sequence, and 100 s of NGS reads per sgRNA . These considerations are further complicated by the fact that oncogenes are frequently amplified in tumours, meaning that phenotypic effects of targeting oncogenic lncRNAs may be a mixture of both specific and non-specific effects. To our knowledge, this issue remains to be satisfactorily resolved, apart from careful validation by ASOs or other DSB-independent perturbations. Differential expression can also be used as a method for selection. For example, when screening for lncRNAs involved in cancer development, tumor samples can be compared against its healthy counterpart to find tumour-upregulated lncRNAs  lncRNAs might be targeted, so as to avoid perturbation of a nearby PCG. In this case a minimum distance from the TSS of lncRNAs to the nearest PCG can be applied as a filter.Many lncRNAs have been associated with diseases. Several online databases have compiled such lncRNAs, and may be used as a valuable filter for candidate selection . A summary of these tools can be found in Table CRISPR perturbation efficiency is directly linked to sgRNA design. Improved designs will increase the performance of the screen and avoid false negatives. The 20 nt sgRNA spacer sequence will dictate the on-target activity and the number of possible off-target regions  has led to its rapid adoption over RNAi-based approaches. As the volume of CRISPR data increases, further improvements are likely in aspects such as sgRNA on-target and off-target activity.Space constraints meant that we could not discuss an upcoming variation of CRISPR screening based on direct RNA perturbation with Cas13 and other enzymes (Anton et al. The practicality and versatility of CRISPR screening makes it capable of identifying lncRNAs mediating a wide variety of cellular processes in healthy and diseased biological contexts. We expect that as annotations improve and screen components become standardised, this approach will become increasingly widely used to identify molecular components and therapeutic targets among the tens of thousands of uncharacterised lncRNA genes.


Elder abuse continues to grow as a national issue with significant gaps in standards for identifying victims. The emergency department provides an opportune setting for affected older adults to report abuse privately, but traditional screening methods may miss certain types of elder abuse when there are no visible signs of abuse. Community resources and reporting methods may not be known or can be stigmatized, therefore creating a challenging scenario for victims of abuse to navigate without fear. The VOICES Elder Abuse Intervention (EAI) is a unique self-administrated tablet-based tool with an automated digital coach that combines major components of screening, educational content, and brief psychoeducational interviewing to empower the older adults and encourage self-identification and self-reporting of abuse. The digital format of the tool allows this EAI to be integrated within an existing elder abuse workflow protocol in the emergency department, rather than replacing it entirely. We will discuss our completed study that included  participants over the age of 60, which suggests that patients find the EAI user-friendly and easy to use. For example, 93% of participants agreed that VOICES was appropriate for learning about abuse, and 94% agreed that using VOICES was very easy to use. Informed by these findings, we plan to adapt and evaluate VOICES EAI for use in other older adult populations and healthcare settings.


There is a developing body of research that suggests that there may be distinct categories of patients that can explain the relationship between psychosis and antisocial behaviours. Specifically, three pathways of offending, antisocial behaviour and psychosis have been described and there is an evolving empirical evidence base to suggest that these pathways are aetiologically distinct. Firstly, there is a pathway for early-start offenders, which have been identified as those with psychosis preceded by Conduct Disorder (SZ + CD). Secondly, a group that start to display antisocial behaviours in parallel to the onset of psychosis (SZ-AS). The third group involves those with a long history of a psychotic disorder and no history of antisocial behaviours, who will present to services following a first conviction for non-violent or violent crime (SZ). The authors hypothesise that each typology will utilise services differently throughout the clinical trajectory. This pilot study aimed to (i) examine the concurrent validity of the antisocial behaviour and psychosis typologies, and (ii) examine differences in the service utilisation patterns of patients between these groups.The sample consisted of adult male patients admitted to low and medium secure forensic hospitals within the Northwest of England. A total of 90 patients were used.A categorisation checklist was developed, and the typology of patients determined from data collected from electronic health records. Data were collected on patient demographics, psychiatric diagnosis, aetiological factors, and service utilisation. Two researchers reviewed the data and determined the typology. Statistical analysis aimed to assess the difference in aetiological variables between the typologies and examine the relationship with how each typology utilised services.This study provided further evidence of distinguishing characteristics emphasising typology heterogeneity.The CD-SZ group were more likely to have utilised mental health services <18 years , and to have used services preceding a diagnosis of psychosis . Following the onset of a psychotic disorder, the AS-SZ and SZ groups had a higher proportion that used general adult psychiatry services (p = 0.031), with CD-SZ coming in to contact with forensic psychiatry services and criminal justice services earlier and more frequently.This study demonstrates that each typology has a different clinical trajectory through mental health services. This provides further empirical evidence towards different clinical typologies and trajectories of individuals with psychosis and anti-social behaviour. Understanding more about how these typologies utilise services will enable clinicians to introduce interventions help develop effective management plans that address the distinct characteristics of each typology of offender with psychosis.


While the impact of neighborhood characteristics on access to social capital is well established, less is known about how neighborhood landscape design interventions play a role in shaping access to this resource and how this varies across the life course. In this study we examined the association between age and perceived impact of recently installed neighborhood block-scale green infrastructure (GI) on frequency of social interactions with neighbors. We also examined age variation in how alternative GI designs were perceived , and how these perceptions were associated with the anticipated impact on frequency of neighbor interactions. Data are from the Neighborhood, environment, and water research collaborations for green infrastructure (NEW-GI) project based in Detroit, MI. Four neighborhood GI interventions were installed in two Detroit neighborhoods in 2016. Surveys were conducted with residents living around the interventions in 2017-18 (n=171), and in nearby neighborhoods (n=145). Age was significantly associated with perceived impact of the landscape interventions on frequency of social interactions with neighbors. Specifically, older adults were significantly more likely to report that the landscape interventions that they were most familiar with resulted in increased frequency of interactions with their neighbors. Further, design alternatives perceived as more well cared for were anticipated to result in greater increases in the frequency of interactions with neighbors among older compared to younger adults. Results suggest neighborhood landscape interventions can improve access to social capital particularly among older adults, and perceptions of landscape care play a role in this process.


Manual scavengers, or ‘Safai Karamcharis’, as they are known in India, are sanitation workers who manually clean human waste for a living and face considerable occupational health risks. They are subject to deep-seated, caste-based stigma associated with their perceived ‘caste impurity’ and lack of cleanliness, which result both in consistently dangerous substandard working conditions and lack of social mobility, with women facing greater hardships. The COVID-19 pandemic has further exacerbated their plight. Despite the considerable efforts of social advocates, organised movements and government institutions, reforms and criminalisation have produced mixed results and campaigners remain divided on whether banning manual scavenging is an effective solution. This article reviews the history of attempts to address scavenging in India. Starting in the colonial period and ending with the current government’s Swachh Bharat Mission, it highlights how attempts to deal with scavenging via quick-fix solutions like legal bans criminalising their employment, infrastructure upgrades or paternalistic interventions have either failed to resolve issues or exacerbated scavengers’ situation by pushing long-standing problems out of view. It argues that meaningful progress depends on abandoning top-down modes of decision-making, addressing the underlying sociocultural and infrastructural factors that perpetuate the ill health and social conditions of manual scavengers, collecting data on the true extent of scavenging, and investing in and providing political agency to communities themselves. According to labour standards, Indian Manual Scavengers face considerable social stigma and occupational health risks.Laws banning manual scavenging have not eradicated manual scavenging in India.Skill upgradation schemes, sanitation infrastructure development and social welfare measures for manual scavengers have been attempted over the years by several governments in India.Despite various substantive reports, government and municipal agencies deny the existence and employment of manual scavenging.Across Indian cultures and communities, sanitation work has been the responsibility of the lowest castes.This paper assesses the impact of these reforms on Safai Karamcharis and their communities. Following an overview of the significant health costs communities incur, we conduct a historical survey of legal arrangements from ca. 1900 onwards. We draw on published literature in peer-reviewed journals in medicine, humanities and social sciences. We complement this review of published academic material by analysing newspaper reports, grey or non-academic literature (mostly from between 1990 and 2021), legal and policy documents, and detailed accounts of the experiences of the workers themselves to create a multiperspective analysis of the extent and evolution of Safai Karamcharis’ legal and social status.Our findings highlight that shifting political priorities, technocratic optimism, paternalism (defined here as top-down restrictions on the freedoms of subordinate peoples under a governance structure that simultaneously provides limited protection and support), and neoliberal attempts to serve market-based supply and demand of scavenging labour, have repeatedly prioritised quick-fix legal and technological solutions over structural interventions. We argue that improvement of Safai Karamcharis’ situation depends not only on upgrading sanitary infrastructure, but also on empowering communities by collecting data on the true extent of scavenging and ending their economic, sociocultural and political obfuscation.Manual scavenging is an extremely dangerous occupation. According to the Press Trust of India, 115 manual scavengers died while cleaning sewers and septic tanks in 2019.8Gender plays a significant role in the degree of occupational health risk that scavengers face. Women reportedly comprise over 95% of all manual scavengers in India and tend to be charged with cleaning human excreta from dry latrines as it is the lowest paid job.11dal (an important source of protein in India) and other foods after handling faeces all day. Despite thorough washing of hands, a female scavenger stated that her own hands and nails repulsed her, claiming “Cleaning the shit of these people is bad enough. I don’t want to put that in my mouth.”13Occupation-related poor nutrition may exacerbate health problems. Scavengers also report an aversion to eating Scavenging communities face additional secondary health risks by directly or indirectly exposing family members to pathogens via touch or food preparation.15The disproportionate mortality and morbidity faced by scavenging communities has deep roots in Indian society and history. Understanding the extent of these roots as well as political path dependencies created by previous administrations’ attempts to address scavengers’ plight is important when it comes to developing more robust interventions moving forward. Looking back at the past century of reform efforts, what emerges is a complicated history in which a long-term mix of socioeconomic, cultural and biological precarity has only ever been partially addressed by regulatory interventions.chaturvarna), which sees the role of Karamcharis as providing an essential community service by taking up ‘polluting’ work and allowing members of higher castes to maintain their purity. This concept of service includes aspects of social and spatial segregation such as expectations for Karamcharis to mark themselves, announce their presence and physically exclude themselves from areas designated for ‘purer’ members of society to avoid ‘polluting’ vital elements such as air or water.23The caste system in India has long divided communities into a distinct social hierarchy based on concepts of cleanliness embedded in Hindu philosophy.The deep-rooted cultural and social discrimination against manual scavengers has been exacerbated by a long history of using scavengers to compensate for deficient sanitation infrastructure. During the colonial era, sanitary and public hygiene interventions were frequently piecemeal, lacklustre and concentrated on British residences and cantonment areas.30Resistance by scavengers, including strikes in Bombay, Delhi and Haridwar, was met with punitive legislation like the Municipal Act of 1900 in Haridwar, which specified that hereditary sweepers could be fined for neglecting to clean private residences or required to forfeit rights to cleaning the building.32This binary logic of simultaneously acknowledging the need for manual scavenging and disciplining scavenging communities accelerated during the first half of the 20th century. Some states tried to stifle scavenger agency by restricting collective action with laws like the Punjab Municipal Act No. 3 of 1911 or the Uttar Pradesh Act No. 2 of 1916, which remain in place to this day. Meanwhile, leading figures within Congress tried to reconcile nationalist ideals of democratic enfranchisement with an idealised paternalist vision of the caste system.dalit himself.37During the interwar period, Mahatma Gandhi repeatedly described India’s caste system as an organic hierarchy underpinning the smooth running of society in which all factions played an important role and should be respected and developed.Clashes about the status of scavengers and how to improve their condition continued after Independence. Driven by activist protest and government attempts to gain electoral favour, a series of expert commissions were installed. Resulting reports recommended a mix of technological interventions and social reforms, which were intended to reduce the need for scavenging and turn it into a regulated service with employee protections. Results were mixed.38 39et al’sIn 1949, the Government of Bombay’s Barve Committee enquired into the living conditions of local scavengers and minimum wages.During the late 1960s, the newly formed ‘All India Safai Mazdoor (Cleaning Workers) Congress’ and its various political affiliations launched campaigns for renewed action. Spurred by labour movements and the shift towards emphasising antipoverty measures under the new Congress Leader Indira Gandhi in 1968–69, the National Commission on Labour recommended comprehensive legislation to regulate the working conditions of ‘sweepers and scavengers’ alongside effective enforcement.employment of manual scavengers rather than manual scavenging itself.42In view of these failings, 1990s Indian governments changed tack by moving away from paternalist measures designed to protect scavengers with legal safeguards to market-based interventions aiming to serve the supply and demand dynamics perpetuating the scavenging sector. In 1993, the Rao administration tried to address both the supply and demand for scavenging labour by outlawing the employment of manual scavengers with the Employment of Manual Scavengers and Construction of Dry Latrines (Prohibition) Act.Neither illegalisation nor incentivisation succeeded. By targeting employers and failing to address the lack of regular water sources driving ongoing reliance on dry latrines, the 1993 Act did not end demand, but drove it underground. Meanwhile, deep-seated caste and socioeconomic deprivation meant that manual scavengers continued to provide labour to unblock drains and clean latrines, but now lacked legal protection. Cloaked in the language of ‘liberation’ and ‘development’, the new economic schemes failed to address the structural barriers preventing Karamcharis from accessing the reskilling schemes promised by the government. Literacy requirements, bureaucratic hurdles and the need for authorisation by local governments meant that many applications for loans and self-employment projects failed or were never attempted.44With 1990s reforms stalling, the new millennium saw NGOs and courts emerge as drivers of change. Lawsuits challenged the legal status quo and highlighted how pushing scavenging underground had obfuscated rather than solved problems. Grassroots data gathered among manual scavenging communities on otherwise hidden activities proved vital in both defining the goals of legal action and forcing government authorities to address existing gaps in official data collection.Jan Sahas began a campaign to inform and encourage manual scavengers to leave the practice of their own volition with activist and legal support.Rashtriya Garima Abhiyan , the organised effort saw approximately 15 000 manual scavenging women boycott their work and enter alternative employment. Parallel surveys significantly improved public understanding of the health and safety risks incurred by manual scavenging communities,11Beginning in 2002, a coalition of 30 non-profit volunteer organisations led by the group In 2003, Bezwada Wilson, founder of the non-profit Safai Karamchari Andolan and a member of a manual scavenging caste community, tried to force official recognition of ongoing problems by petitioning the Supreme Court for measures to protect manual scavengers across India.Court proceedings revealed deeply flawed estimates regarding the total number of manual scavengers. Analysis of the 15th Census of India (2011) indicated that millions of households still had dry latrines with entire communities openly defecating, requiring workers to manually scavenge after them. This number far exceeded decades-old official estimates of between 400,000 and 500,000 scavengers.Although the PEMSR Act of 2013 has been the backbone of many appeals, institutional reforms and advocacy movements, scavenging and caste-based discrimination persist. According to recent reports, there have been no convictions under the 2013 law.46While the mixed outcomes of the PEMSR Act highlight the limits of legal reform alone, the parallel intensification of technocratic initiatives to improve India’s sanitary infrastructure has similarly failed to resolve the challenge of manual scavenging. In 2014, the newly elected government under Narendra Modi announced an ambitious Swachh Bharat Mission (SBM) or Abhiyan (‘Clean India Campaign’) to eradicate open defecation by building approximately 10.4 million toilets for individuals and 50.8 million community toilets nationwide. Toilet designs chosen were either pit latrines, which collect human faeces in a hole in the ground, or pour-flush latrines, which manually or mechanically use water to push faeces to a collection unit.54Given the failure of legislation, technocratic investments and piecemeal executive interventions to resolve the structural barriers faced by scavengers, pressure for further action continues to emanate from Indian NGOs, international organisations and India’s judiciary. In 2019, the World Bank and others issued a critical report on the criminalisation of manual sanitation work.56As the long list of only partially successful—and occasionally counterproductive—reform efforts shows, it is unlikely that manual scavenging will disappear from India anytime soon. Successive administrations have tried to solve problems with quick fixes like review committees, retraining, outlawing employment and calling for more data. However, there has been little political appetite to address the underlying environmental conditions, entrenched social attitudes, economic precarity and gender biases that have been driving manual scavenging and the marginalisation of scavenging communities. Although it would be wrong to romanticise the paternalist worker protection offered by post-Independence administrations, the increasing neoliberalisation of India’s economy and concomitant focus on labour competition have exacerbated the condition of low-cost, lower-caste workers.18In the absence of an overarching strategy of tackling the identified structural conditions, headlines of scavengers’ deaths spark explosive yet fleeting outrage before returning to the margins of public awareness. Meanwhile, reformers themselves remain divided about the basic question of whether to reformalise or continue to outlaw manual scavenging. In 2020, the judiciary tabled an amendment to the 2013 PEMSR Act, which mandated the development of sanitation technology, while also introducing stricter punishments for offenders.1In the absence of agreement on how to proceed, scavengers remain stuck in a dangerous state of legal limbo, which has been further exacerbated by the COVID-19 pandemic. Recent reports reveal that the highest percentage of cleaning staff who died of COVID-19 in Delhi consisted of municipal sanitation workers tasked with cleaning streets and handling contaminated material from health centres.Zeitgeist, officials employed various strategies to deal with the vicious cycle of demand for manual scavenging due to inadequate sanitary infrastructure and its supply through caste-based labour pools. During the colonial period, British and municipal authorities allowed discriminatory ‘traditional’ practices to continue and expand. Scavenging communities’ attempts to assert agency were met with crackdowns. Following Independence, political acknowledgement of scavengers’ plight sat uneasily with a romanticisation of caste-based notions of Safai Karamcharis’ service to higher castes. A series of paternalist interventions attempted to formalise and regulate work practices not only remained ineffective due to lack of investment and enforcement, but also continued to lock communities into a broader exploitative setting. The 1990s reformers moved away from this paternalistic model of reform and instead followed contemporary neoliberal thinking by attempting to tackle scavenging as an issue of supply and demand. Demand was made illegal, while supply was to be dried out via retraining. What might have been promising policies and schemes, however, tottered due to apathetic enforcement, failure to make support schemes accessible to scavenging communities and the obfuscation of scavengers from official statistics. Since 2013, the most recent wave of legislative reform and technological investment in sanitary infrastructure has gone some way towards reducing the need for scavenging, but has failed to eliminate it or address the entrenched discrimination scavenging communities face.This article does not make for light reading—nor is it meant to. Looking back on 120 years of attempts to regulate manual scavenging in India reveals a fundamental tension in addressing the entangled problems of caste-based discrimination and dangerous labour conditions. The interconnection between caste station and impurity has perpetuated an apathy among the public towards manual scavengers and an indifference towards their occupational safety and well-being. Depending on the political In many ways, the Swachh Bharat Mission’s official logo of Gandhi’s spectacles perfectly symbolises the ongoing disenfranchisement of scavengers. For over a century, Safai Karamcharis have variously been prosecuted, ‘protected,’ ‘liberated’ or seemingly ‘made redundant’ via technology. However, Karamcharis largely remain spoken for by political elites, yet continue to fight for the agency to speak for themselves.Regardless of which party leads India over the next decades, manual scavenging and the wider provision of sanitation and sanitary labour need to be seen not as paternalist or purely market-based policy problems, but as collaboration with affected communities requiring an amalgamation of technical, environmental, social and cultural interventions. In view of ongoing demand for sanitary labour, reforms not only need to end exploitative informal employment of scavengers—especially by public bodies—but also address the desires and needs of the broader sanitation worker communities for accessible, safe and dignified housing and working conditions, as well as affordable healthcare, insurance, employee benefits and children’s education. A nationwide census and record of all manual scavengers as well as surveys of scavengers’ aspirations alongside proper representation in decision-making bodies are important first steps towards achieving a more participatory form of engagement.


Social medicine (SM) is an emerging field that includes the study of the social determinants of health (SDoH), which include addressing health disparities, cultural competency, service, and population health.20As the scope and practice of emergency medicine (EM) is intimately tied with SM, there has been a recent focus on incorporating SM curricula into existing residency programs to better care for the underserved patients who often rely on the emergency department (ED).To address this gap, we aimed to develop and evaluate an SM elective where EM residents learn from experience. We sought to understand the impact of this type of curriculum on residents’ attitudes toward and self-reported ability to care for vulnerable populations.This study received approval from the institutional review board. From July 2018–2019, all 73 residents at our EM residency program were invited to participate in experiential two-week electives focused on patients from seven vulnerable subpopulations: persons experiencing substance use disorders; experiencing homelessness; having been seen at a border health clinic; seeking asylum, facing primary care access barriers; having been involved in the Violence Intervention Program (VIP), or involved with the carceral system. Participation was voluntary. Experiences were coordinated with community-based organizations (CBO) and tailored to the resident’s interest and prior exposure.The SM curriculum was developed by a task force of ED faculty, residents, community-engaged faculty, and linked CBOs that were active in addressing SDoH from the ED in a multidisciplinary perspective. Partnerships were built on prior connections with CBOs and existing linkages between the department and the community. Faculty reached out to CBOs already interacting with ED care, such as on-campus VIPs, and established more robust and defined routes of resident involvement in programming for a two-week elective period. Care was taken in working with CBOs to ensure that resident involvement would not be onerous to their staff or disrupt workflow and that the task force incorporated an approach beneficial to their service delivery whenever possible. Content expert faculty who helped with development of electives included the director of the street medicine program, sociology research faculty working with vulnerable populations in needle-exchange settings, the director of addiction medicine for the medical center, the faculty directors of the Keck University of Southern California Human Rights Asylum Clinic, the director of the urgent care clinic and outpatient clinic care coordination, and a trauma surgery faculty member who serves on the board of the violence intervention CBO. The main faculty member developing and coordinating the curriculum development (TS) was fellowship trained in community-based research methods and SM, and has experience with a previous SM curriculum development at another program.In addition to resident educational experience, the task force valued solidarity with CBOs and benefit to patients as primary goals. The curriculum was driven by CBOs that were activated, interested, and willing to provide learning opportunities for residents. We recognized that residents were present to learn from the CBOs; thus, the intention was to not overwhelm CBOs with extra tasks. Finally, we also favored CBOs who had already been involved in providing services in the ED with the intention of maximizing the overlap of patients between CBOs and the ED.Objectives were to expose residents to CBOs working with these specific populations with the goal of better understanding the structural vulnerability of these populations. These rotations exposed residents to services provided by the CBO and how those services can be incorporated into the care of these patients in the ED. For example, for VIP, residents observed and assisted the community partner with service provision including job placement, peer counseling, and tattoo removal, and subsequently learned how to better incorporate referrals during routine ED care. This strategy used the expertise of the CBO while extending ED care to incorporate a community perspective. Sample activities from each experience are listed in We invited participants to complete a voluntary, anonymous, post-rotation electronic survey exploring changes in their attitudes and competence . Items w29Of the 38 residents who participated, 22 completed the survey (58%). Participants reported increased understanding, satisfaction, empathy, perceived responsibility, and perceived competence towards working with vulnerable populations after their elective . Any refFirst, participants reported increased understanding of the healthcare challenges faced by vulnerable populations. One participant offered that their carceral health elective:…definitely narrowed the gap in knowledge, significantly, as far as understanding their experience in the jails. I got to go to this space where my patients come to me from. How often do you ever get to do that and understand their perspectives and their experience from like directly going into the place…and seeing it? (Participant #5)Participants commented on the increased sense of empathy that came from their experience. Participants also reported perceived increased confidence and clinical competence when caring for these patients, as the experiences “made it easier to come back and work in the setting that I was working in and be able to bring lessons from both to each place.” (Participant #7) Participants noted that the elective provided a sense of rejuvenation, as “it re-inspired some of those folks or at least made those conversations a bigger part of every shift.” (Participant #7) The SM elective also was integral in career development. One participant voiced, “I’d like to be involved in health system development or community outreach or something at least part time for my career.” (Participant #2)Finally, participants offered suggestions for future iterations of the elective, such as a hybrid curriculum, including formalized didactic lectures. Most participants also requested a more longitudinal experience to “keep the momentum going longer.” (Participant #6) One participant also voiced that “a social EM, formalized curriculum should be a mandatory part of training in this program that happens early on in residency because I think it really does impact the type of care and follow-up that we provide to our patients.” (Participant #2)While the results of our SM curriculum suggest that it positively impacted residents’ attitudes and informed their care of vulnerable populations, several limitations exist. Although the construct of partnership with CBOs is generalizable, the exact CBOs with which we worked vary geographically and demographically, which may limit reproducibility. Our innovation also involved a single institution and medical specialty, which may further limit its generalizability. Individuals who completed the surveys are susceptible to varying levels of response bias. Our qualitative findings are limited by the small sample size of resident interviews, whose voluntary participation may also introduce selection bias.Despite these limitations, our experiential SM curriculum positively impacted residents’ attitudes and informed their care of vulnerable populations. It also empowered residents in addressing SDoH on shift. Given the pervasive impact of the SDoH in the practice of EM, it may be useful for residency program leaders to integrate experiential electives into residency curricula. Future research may include community-based participatory research methods with existing CBOs to understand the perceived attitudes, challenges, and opportunities that CBOs have in facilitating and receiving hand-off of patients from clinical providers. Resident practice patterns in referring and linking patients to care beyond the ED should also be examined as well. Resident performance milestones consistent with current Accreditation Council for Graduate Medical Education guidelines  could also be examined in existing residency-specific evaluation avenues. Finally, as this was a preliminary and foundational study, patient-centered outcomes were not studied and are important to examine in future iterations.


Production activities drive the replacement of original habitats with artificial ones, leading to new bird assemblages. In this study, we assessed if anthropogenic habitats acted as environmental filters causing functional redundancy or as promoters of functional divergence, depending on the biome. We also investigated if functional patterns derived from phylogenetic convergence or clustering. For this purpose, we computed the standardized effect sizes (SES) for avian functional and phylogenetic diversity using null models and compared the SES values among tree plantations, urban settlements (US), cattle pastures (CP), crop fields (CF) and natural habitats from two biomes: grassland and forest. We used generalized least squares models to test if functional and phylogenetic SES indicated functional redundancy or divergence, and phylogenetic convergence or clustering. We found functional redundancy in grassland and functional divergence in forest associated with environmental filtering and competitive exclusion, respectively. In grassland, functional structure was not associated with a clear phylogenetic pattern, while in forest functional divergence was caused by evolutionary convergence in CF and CP and conservation in US. The prevalences of functional redundancy and functional divergence patterns and their associated predominant mechanism of community assembly were found to depend on the biome and the regional species pool. Abiotic conditions and resources may operate as a selective force against species unable to enter or persist in a community. Thus, environmental filtering is usually the predominant mechanism underlying assembly processes in anthropogenic habitats3. Species that persist in a given habitat exhibit tolerance to environmental conditions, which is determined by the functional trait composition of the community. As a result, co-existing species in the regional pool are functionally more similar than expected by chance 4.The intensification of production activities induces the replacement of original habitats by anthropogenic ones worldwide, leading to the formation of new community assemblages with varying relative abundances in different biomes. In highly modified environments  abiotic constraints are the main factor determining species establishment6. For example, the loss of native taxonomic and functional diversity is greater for land uses involving drastic changes in vegetation structure than for those preserving it9. In this regard, anthropogenic habitats such as crop fields, tree plantations and cattle pastures may show different environmental filters according to the biome.The resulting species and functional trait composition in communities from anthropogenic habitats may vary in response to land use across biomes, as it can alter the natural environmental filters imposed on the different species from the regional species pool10 reported that, in grassland, land conversion into tree plantations or urbanized areas led to higher loss of native bird species than conversion into cattle pastures and some types of agricultural lands. Likewise, Vaccaro and Bellocq11 found that open habitat types and tree plantations were the worst and best habitats for the conservation of bird species and functional trait assemblages of the native forest, respectively. In regard to biomes, environmental similarity between anthropogenic and native habitats has been emphasized as a key factor for preserving the taxonomic and functional diversity of bird assemblages in tropical forests13 and grasslands14.Studies conducted by our research group addressed the effect of different types of anthropogenic habitats located in contrasting biomes on bird species and functional trait assemblages. Results indicated a greater loss of native diversity in habitats that were environmentally different from their natural habitat. Thus, Vaccaro et al.In our previous studies mentioned above, some issues remain unexplored. Therefore, in this work we deepen the understanding of processes and factors underlying bird community assembly in distinct anthropogenic habitat types located in contrasting biomes. To this aim, we addressed the question of whether anthropogenic habitats act as environmental filters leading to functional redundancy, or as promoters of functional divergence, depending on the biome.15. Here, we considered phylogenetic diversity, which is defined as the amount of evolutionary history represented in the species of a particular community16. It is used as a complement to taxonomic and functional diversities in community ecology studies on assembly processes18. Phylogenetically diverse communities are likely to be more resilient to environmental changes and to better preserve unique lineages19. As a result of environmental filtering, phylogenetic structure within communities may reflect either phylogenetic clustering or evenness depending on whether ecologically relevant traits are phylogenetically conserved or convergent20. Phylogenetic clustering occurs when species have a tendency to retain ancestral ecological characteristics allowing them to cope with environmental constraints 21. The phylogenetic structure is characterized by the co-occurrence of more closely related species than expected by chance. Moreover, environmental filtering can generate a uniform phylogenetic structure (phylogenetic evenness) if species share important traits to habitat specialization by evolutionary convergence 24. The quantification of functional and phylogenetic structures of assemblages in anthropogenic habitats allows us to identify factors associated with environmental filtering  or competitive exclusion25. This will depend on the biome where the land use type is located because species pools and the structure of assemblages in contrasting biomes such as forests and grasslands are expected to be shaped by different ecological, evolutionary and historical mechanisms26.The inclusion of several attributes of biological communities in studies focused on the formation of assemblages in anthropogenic habitats provides meaningful information for more efficient conservation planningThe purpose of this study was to test the existence of functional redundancy in different anthropogenic habitat types, which is the pattern predicted by the environmental filtering hypothesis when environmental filters are the main community assembly drivers. Taking into account that the transformation level of anthropogenic habitats depends on the biome, in this study we included four anthropogenic habitat types  and natural habitats in two contrasting biomes: grassland and forest. Under the environmental filtering hypothesis, we expected a higher functional redundancy in habitat types showing a simpler vegetation structure than that found in the natural habitat , due to the loss of specialist species. In line with this reasoning, we predict the occurrence of functional divergence in anthropogenic habitats with structural or environmental dimensions that were absent in the original environment , due to the inclusion of species with new traits. Furthermore, we tested whether functional redundancy or divergence are due to phylogenetic evenness or phylogenetic clustering, since these imply different consequences for species assemblages in terms of traits favoring species persistence in anthropogenic habitats. For example, environmental filtering will have a more negative effect on phylogenetic clustering  than on phylogenetic evenness (presence of species from different lineages).We analyzed the occurrence of functional redundancy or divergence in bird assemblages from different anthropogenic habitat types located in two contrasting biomes to determine the potential mechanisms driving their formation. Moreover, we studied the phylogenetic structure of bird assemblages to identify phylogenetic clustering or evenness (overdispersion). For this purpose, we used null models to estimate the standardized effect sizes (SES) associated with functional and phylogenetic diversity of avian communities in anthropogenic habitat types and natural habitats. Data were obtained from birds sampled in natural habitats (NH) and four types of anthropogenic habitats , crop field (CF), tree plantation (TP) and urban settlement (US) located in the grassland and forest). We selected 27 study sites in the grassland comprising six sites per anthropogenic habitat type and three NHs, and 22 sites in the forest consisting of five CPs, five CFs, five TPs, four USs and three NHs Fig. .Figure 128. These were the Pampean grassland and the subtropical Atlantic Forest  in South America  at all observation points during the 5-min period to ensure a reliable identification and to account for differences in visual detectability between habitat types36.Bird surveys were carried out in 2014 and 2015 during the breeding season (September to November), using the point-count technique with a fixed 50-m radius38. We estimated species abundance at each study site by pooling the results obtained from the 10 observation points. Abundance data were used to build two site-by-species matrices for each biome: one including all species recorded and the other the regional species pool. The species in the regional pool were extracted from the regional species pool matrix (see below).After the field work, birds' identification was accomplished by comparing our 490 bird songs recorded with published recordings39 so that all traits were treated as categorical, and each category was binary. Each trait category was assigned 0 or 1 depending on whether it was present or not10. All trait categories were mutually exclusive (only one category of each trait was 1), except for diet, foraging substrate and nesting habitat. The resulting matrix for each biome was used to generate the regional species pool matrix. For the Grassland matrix, we selected species showing functional traits related to grassland or open habitats, such as foraging on the ground or nesting in grasses. For the Forest matrix, we considered species that use trees or shrubs for nesting, foraging or hiding.To determine functional diversity, we first created a species-by-trait matrix separately for each biome. To construct this matrix we selected ecological traits  and life-history traits , making a total of 11 traits 40 to create two phylogenetic trees for each biome: one for all species recorded and the other for the regional species pool. The consensus trees were obtained with the "consensus.edges" function in the R "phytools" package42.To estimate phylogenetic diversity, we used a global phylogeny of birds  using the “mpd” function in the “picante” package of R44. This function uses functional and phylogenetic mpd matrices as inputs to functional and phylogenetic SES, respectively. SES describes the difference between functional or phylogenetic distances in the community observed (mpd.obs) and the mean of null communities created with the randomization method (mpd.rand.mean), divided by the standard deviation of functional or phylogenetic distances in the null data (mpd.rand.sd). The randomization method used for null communities was ‘taxa.labels’, which shuffles distance matrix labels across all included in the distance matrix43. We used matrices of all the species recorded in each habitat type to estimate the functional and phylogenetic mpd.obs. Conversely, we used the regional species pool matrices to estimate the functional and phylogenetic mpd in null communities , because these species are expected to occur if the biome is not altered. We calculated a single SES value per site.To analyze functional and phylogenetic structures, we computed the standardized effect sizes (SES) for avian functional and phylogenetic diversity using null models and compared the SES values among habitat types for the two biomes. The SES values were estimated using the “ses.mpd” function in the “picante” package of R45. In case of heteroscedasticity, we used the “varIdent” function with “nlme” package, which allows different variances per treatment. Then, with the “emmeans” function in the “emmeans” package46 we computed estimated marginal means for the specified factor  using the linear model as input (gls). The “emmeans” function allowed obtaining 95% confidence intervals (CI) for SES estimations of habitat types in each biome. Thus, we corroborated if zero was included in those CIs. Negative values of functional SES  indicate that species are more similar in terms of functional traits than expected by chance , suggesting that environmental filtering is the predominant assembly process. Conversely, positive values  indicate that species are less similar than expected by chance , suggesting a possible competitive exclusion among assemblages47. With respect to phylogenetic structures, positive phylogenetic SES values indicate a greater phylogenetic distance between co-occurring species than expected by chance (phylogenetic evenness or overdispersion), while negative SES values may imply a smaller phylogenetic distance between species than expected (phylogenetic clustering). Additionally, with “emmeans” function we compared mean SES values between habitat types through Tukey multiple comparisons.We fitted generalized least squares (gls) models with SESs values (response) and habitat type (factor), with both functional and phylogenetic values in each biome. Models were fitted using the “gls” function in the “nlme” R packageColumba livia (Rock pigeon) and Passer domesticus (House sparrow). In TP, there were species using trees or shrubs for foraging or nesting, such as Leptotila verreauxi (White-tipped dove), Colaptes melanochloros (Green-barred woodpecker) and Lepidocolaptes angustirostris (Narrow-billed woodcreeper) , Guira guira (Guira Cuckoo), Sturnella superciliaris (White-browed Meadowlark), Ammodramus humeralis (Grassland Sparrow), and Rhynchotus rufescens (Red-winged Tinamou). The House sparrow was dominant in US , such as In the Grassland, all habitat types showed similar mean functional diversity, except for US, which had the lowest functional mean mpd. Urban settlements and CP exhibited the lowest and the highest phylogenetic mean mpd, respectively. In the Forest, CF showed the lowest functional and phylogenetic mean mpd, and TP and NH the highest ones, respectively Table .Table 1In the Grassland, the functional SES values of all habitat types were significantly lower than zero, except for those of NH and US Fig. , indicatIn the Forest, functional SES was significantly lower than zero only in NH, showing functional redundancy, and significantly positive in CF and TP, indicating functional divergence. Functional SES of CP and US did not differ significantly from zero Fig. . When coOur results revealed that factors involved in bird community assembly in anthropogenic habitats depend on the biome in which they are located. In Grassland, most anthropogenic habitat types showed functional redundancy, suggesting that environmental filtering was the main driver for community assembly. Conversely, functional divergence was the dominant pattern in the Forest, pointing to competitive exclusion as the major driving factor. As we expected, we found a tendency  toward greater functional redundancy in open habitats in the Grassland. In the Forest, contrary to our expectations, these habitat types showed functional divergence. Although functional divergence was not found in urban settlements and tree plantations in the Grassland, there was a tendency toward low functional redundancy. In Grassland, functional patterns do not appear to be associated with phylogenetic structures that reflect an evolutionary pattern of traits. In the Forest, functional divergence was probably caused by evolutionary trait convergence in crop fields and cattle pastures, and trait conservation in urban settlements.48, who proposed that the long-term land-use history in Switzerland contributed to filter out breeding birds with strong nesting-site fidelity. It is possible that the highly disturbed habitats in the Pampean region prevent the occurrence of grassland specialists50. We assume that that the current regional pool of bird species in the Pampean grasslands is the result of environmental filters caused by land-use changes since the seventeenth century51, when livestock was first introduced from Europe. Filloy and Bellocq52 found that many bird species in the Pampean region showed no response to the spatial agricultural gradient suggesting that they were tolerant to changes in land-use over time. However, in the present study functional redundancy was lower in urban settlements and, less evident, in tree plantations than in open habitats. Such result is consistent with what we expected, as these habitats include new resources such as shrubs, trees, flower plants and buildings. These provide a higher variety of food items and nesting substrates favoring the presence of species with traits different from those of species adapted to open habitats. This is in agreement with the study of Concepcion et al.48 in urban environments and supports our hypothesis that the incorporation of structural or environmental features into the native habitat favors the occurrence of new species with different traits. These are typically characterized by having a wide range of requirements54 and do not necessarily belong to the regional species pool.In the Grassland, bird assemblages in cattle pastures, tree plantations and crop fields showed functional redundancy, while a tendency toward this pattern was observed in urban settlements and natural habitats. These results may indicate that environmental filtering was the primary driver of community assembly, and possibly even in natural habitats. Similar results were reported by Concepción et al.55. It is possible that, on the one hand, environmental filtering may have selected for species with traits inherited from a common ancestor . On the other hand, phylogenetically distant species sharing similar traits may have also been selected . Cavender-Bares et al.20 stated that environmental filtering may cause phylogenetic clustering if the ecologically important trait is highly conserved, but it may also drive phylogenetic overdispersion if other traits important to habitat specialization are labile. Therefore, despite our results indicated random phylogenetic assembly of species, phylogenetic structures may have resulted from a combination of processes.The habitat types of the Grassland showed random phylogenetic structures, suggesting that the formation of bird assemblages was not related to evolutionary conservation or convergence of characters. However, assemblies formed by environmental filtering are expected to exhibit phylogenetic clustering or evenness47. Our results could be due to the predominance of strong competitors bearing novel characteristics. Open habitats, for example, can act as novel ecosystems56 allowing the presence of extra-regional species with different traits. Surprisingly, bird assemblages in the native forests  were characterized by functional redundancy. These results are in accordance with those of Vaccaro and Bellocq11, who, for these same sites, found lower and higher functional diversity in natural habitats and tree plantations, respectively, than in other habitat types. Tree plantations exhibited functional divergence probably because they harbored not only species with traits similar to those inhabiting the native forest57, but also generalist species that forage and nest in a variety of environments11. Tree plantations are generally unsuitable for native forest birds59, while extra-regional species possess traits that enable them to take advantage of the resources available not only in these habitat types but also in open habitats.In the Forest we found evidence of functional divergence in bird assemblages of tree plantations and crop fields and, less evident, of cattle pastures. This indicates a prevalence of competitive exclusion driving community assembly26 proposed that farmland bird assemblages are composed of very dissimilar species because limiting similarity precludes the co-existence of functionally redundant taxa. Phylogenetic overdispersion could be associated with environmental filtering if ecologically relevant traits are phylogenetically convergent55. Therefore, the bird assemblage found in crop fields and cattle pastures in the Forest may also reflect an early stage of environmental filtering in which functional redundancy would become apparent with time. In the case of tree plantations, the combined result of functional divergence and random phylogenetic structure with a tendency toward clustering may be associated with competitive exclusion if there had been evolutionary convergence55; it means that there are species with different traits because they are strong competitors. Finally, urban settlements revealed a random functional pattern but a clustering phylogenetic structure. If we assume that phylogeny represents functional differences in species assemblage composition60 and urbanization leads to the loss of traits61, then phylogenetic clustering results from environmental filtering selection of closely related species that share similar niches63. The study of Sol et al.64 reported that exotic species did not compensate for the loss of phylogenetic diversity related to urbanization. Since we did not detect functional redundancy to support environmental filtering, phylogenetic clustering may be a result of competitive exclusion20. In conclusion, except for urban settlements, competitive exclusion seems to play a more relevant role than environmental filtering in the process of bird assembly in anthropogenic habitats within the Forest; this process appeared to be more evident in the open habitats, which may act as sinks of novel, highly competitive species.Our results in the Forest may reflect evolutionary trait convergence in crop fields and cattle pastures and evolutionary trait conservation in urban settlements and, less evident, in tree plantations. The combined results of functional divergence and phylogenetic overdispersion in open habitats seem to be consistent with the evolutionary conservation of traits associated with niche occupancy. This suggests the predominance of species interactions (competitive exclusion) over environmental filtering in the process of community assembly. García-Navas and Thuiller66, here we provide evidence that the predominant pattern (and its associated mechanism of community assembly) depends on the biome and the regional species pool. For example, bird assemblages in crop fields or cattle pastures exhibited functional redundancy in one context (grassland) but functional divergence in another (forest). In the Grassland, species of the regional pool may be characterized as using open habitats and being able to coexist with each other due to the long-term history of land use in the region. In the Forest, for example, open habitats allow the presence of species with different traits and belonging to different phylogenetic lineages that did not occur before in the biome. Prevalences of functional redundancy or divergence do not ensure that the process of community assembly was driven by environmental filtering or competitive exclusion. In fact, these patterns could be attributed to new environments where assemblages are still in an early stage of development. For instance, although in most anthropogenic habitat types in the Forest we found functional divergence, this pattern could be associated with competitive exclusion or an early stage of environmental filtering in assemblage formation. Finally, it is worth noting that functional redundancy or divergence do not necessarily imply a worse or better situation for the conservation of native bird species, respectively. Regional contexts, traits and phylogenetic structures associated with these patterns must be considered for a deeper understanding of the factors driving community assembly in anthropogenic habitats.The prevalences of functional redundancy and functional divergence patterns and their associated main mechanism of community assembly depend on the biome and the regional species pool. In contrast to previous studies showing that land uses lead to functional redundancySupplementary Information 1.Supplementary Information 2.


Advances in medical imaging have redefined the practice of vascular surgery. Current training programs for vascular surgery do not incorporate formal training in vascular imaging other than in duplex ultrasound when a physician is undergoing the vascular interpretation certification process. Yet imaging modalities and techniques have grown exponentially in the adjacent fields of interventional radiology, interventional and diagnostic cardiology, and neuroradiology, so much so that advanced imaging fellowships have been established in these fields. This article reviews the current state of vascular imaging training, identifies gaps in the current training regimen, and proposes an advanced vascular imaging fellowship for the future. Duplex ultrasound now has a formalized curriculum through the Registered Physician in Vascular Interpretation certification process, which is required to become board certified in vascular surgery. However, vascular surgeons have no role in the interpretation of other imaging modalities, and many feel uncomfortable interpreting magnetic resonance imaging (MRI), which has ultimately limited its clinical use due to the limited training vascular surgeons receive in MRI. The inability to understand, post-process, and interpret images may inhibit the growth of the vascular surgery specialty if surgeons feel unable to keep up with state-of-the-art imaging techniques that deliver the best possible care.1 The purpose of this review is to discuss the current state of training in vascular imaging, identify gaps in knowledge and training, and propose an advanced vascular imaging fellowship for the future.Advances in medical imaging have redefined the practice of vascular surgery. The trend towards minimally invasive procedures, which rely heavily on guidance from imaging modalities, has improved patients’ recovery times and outcomes. However, no formal training is available in multimodal vascular imaging and the advances that exist.Figure 1). The goal was to train the next generation of vascular specialists to become experts in vascular diagnostics, medical therapies, endovascular training, and open surgery.2345 This change in the training paradigm recognized the fact that general and vascular surgery skill sets diverged with the increased use of laparoscopic and fluoroscopic techniques, respectively. However, it is challenging to understand the vascular specialist’s role and differentiate it from specialties such as interventional cardiology and interventional radiology. Traditional training often invokes “The Law of the Instrument,” arguing that “if your only tool is a hammer, everything looks like a nail”; in this context, vascular specialists have the unique ability to personalize treatment for patients in order to offer both open and endovascular treatments. At the same time, this argument fails to address the fact that vascular surgeons have limited their “tools” by not keeping pace with the multimodal imaging that dictates most vascular care today.In 2006, the Accreditation Council for Graduate Medical Education (ACGME) started the first integrated 0+5 vascular surgery residency programs to address the changing scope of vascular surgery and rebrand the specialty to encompass the holistic care of vascular patients , positron emission tomography perfusion imaging, and more. Improved diagnostics propelled the cardiology specialty as a whole as clinicians developed a new understanding of the structure and function of the heart and vessels. By comparison, vascular surgery has not seen similar growth in imaging techniques, and the lack of training has limited the specialty as a whole from integrating and developing new imaging modalities into clinical practice.5The ability to understand and interpret imaging is critical to treating patients with vascular disease. Cardiology has shown how dedicated training in advanced imaging has had the synergistic effect of giving cardiologists more information to treat patients while also improving the imaging modalities themselves.Figure 1).1 For example, in the curriculum for the 5-year integrated vascular surgery residency training program at Houston Methodist Hospital, first-year residents have 1 month of CT or interventional radiology training and 1 month of duplex ultrasound training. They also have a 1-month interventional neurology rotation in the third year. These 1-month rotations help residents gain exposure to more types of cases and disciplines. However, a month is typically not enough time to gain the necessary understanding and knowledge to accurately interpret multimodal imaging modalities. Apart from these dedicated 3 months, residents learn to interpret images throughout their training in case conferences and day-to-day clinical activities that require a cursory knowledge of CT angiography and x-ray angiography. Ultrasound education is the exception, because the Registered Physician in Vascular Interpretation qualification, which requires ultrasound training, is a prerequisite for vascular surgery certification. Ultrasound interpretation has become a key competency in vascular surgery and highlights the value of gaining the necessary training to interpret vascular imaging.456While some degree of variability exists in the curriculum for integrated 0+5 vascular surgery residencies across the country, dedicated imaging training is not typically a focus  techniques. CMR has changed the standard of care for cardiology patients and is now considered the gold standard for morphologic assessment of the heart and ventricular function.4Appropriate patient selection is the cornerstone of optimal vascular care. Patient age, comorbidities, and clinical exam inform management, but the final decision of whether to intervene either endovascularly or via traditional open surgery hinges on imaging. Typically noninvasive vascular lab studies are reviewed first, followed by cross-sectional imaging with CT angiography and at times intraprocedural x-ray angiography.1112Most vascular surgeons use standard clinical imaging modalities to plan procedures. However, the captured data contains a wealth of knowledge that benefits from awareness of post-processing to aid procedural planning. Most vascular surgeons have some degree of familiarity with sizing an endograft using centerline software such as TeraRecon (TeraRecon Inc.) or syngo.via .Figure 3 shows the cinematic rendering of a patient prior to open repair of a thoracoabdominal aortic aneurysm. This post-processing technique allows surgeons to select the optimal intercostal to enter the chest cavity and also provides information about the angles and locations of vital branch vessels that require individual bypass grafts or reimplantation .1113 Though patient position affects the accuracy of the rendered images, surgeons nevertheless gain pertinent information to help plan open operations and optimize their approach.Although not used routinely, three-dimensional (3D) image post-processing software for planning open surgical procedures could offer important information. For example, “cinematic rendering” is a visualization tool that enables photo-realistic 3D visualization of vessels and surrounding tissue. Developed by Siemens Healthineers and still only approved for research purposes, this tool illustrates the potential for improving open surgical planning. This technique allows the user to scroll back and forth through layers of the body and from skin to muscle/soft tissue to visceral structures and bones. This enables surgeons to effectively plan their procedure and mentally rehearse the steps of complex exposures. 14 Even x-ray angiography, which is a routine modality used in vascular surgery, has specific training gaps. For example, there is no formalized curriculum for radiation safety, and practices vary significantly in terms of adherence to “as low as reasonably achieved” (ALARA) guiding principles.515 One way of reducing radiation for complex procedures is to use intraoperative image fusion with preoperative cross-sectional imaging using 2D or 3D image registration for guidance. Typically, this process involves registering preoperative CT angiography with intraoperative x-ray angiography, and its use in vascular surgery is limited primarily to large vessels of the aorta and major branches. However, interventional neuroradiology and interventional radiology routinely use CT guidance or rotational angiography with registration for small vessels, and some centers use time-resolved CT angiograms (4D CTA) in the operating room.16 By training with these other specialties, vascular surgeons can expand their toolbox to perform procedures precisely under image guidance. Registration and intraprocedural image guidance are likely to be safer for patients by reducing radiation, which is ultimately safer for the operating physician as well.Multimodal intraoperative imaging is playing a larger role in vascular procedures. In addition to using x-ray angiography, vascular surgeons typically use duplex ultrasound for arterial access and completion studies after carotid or bypass surgery. Use of intravascular imaging during vascular procedures also is increasing. Intravascular ultrasound (IVUS) is now the standard of care when intervening on aortic dissections to differentiate true and false lumens and is recognized as the gold standard imaging modality for venous interventions. Understanding IVUS and interpretation is taught informally during procedures, but other intravascular modalities such as optical coherence tomography (OCT) typically are not used.81217 The Society for Vascular Surgery has established specific duplex ultrasound criteria to indicate when to intervene prophylactically. However, thoracic aortic disease cannot be imaged by ultrasound and requires CT angiography for surveillance on a lifelong basis. This poses risks of additional radiation and potential renal impairment with repeated studies over a lifetime. Furthermore, there are no universally accepted anatomic criteria for the management of uncomplicated type B dissections or when to intervene. An estimated 20% to 55% of medically managed type B dissections will develop aneurysmal degeneration at 5 years, but there are no established imaging findings indicating who is most at risk.8 The risk of aneurysmal degeneration is related to the pressure and flow within the true and false lumen and fenestrations between, but these dynamic features are not captured on traditional CT angiograms. Four-dimensional flow with MRI enables the visualization and quantification of complex flow patterns , and this modality, in particular, is showing promise in evaluating predictive factors to determine who would benefit most from prophylactic thoracic endovascular repair.171819 False lumen pressures and the identification and hemodynamic measurements of small flap fenestrations may prove useful in patient selection as well as optimal placement of thoracic endografts in the future.1220 Therefore, select CMR fellowship programs are needed to provide training on how to interpret these images, the basics of image post-processing, and research opportunities to improve these techniques in the future.Surveillance with duplex ultrasound is an established method for evaluating many conditions. Pertinent examples include surveying peripheral bypass grafts and endovascular repairs for abdominal aortic aneurysms at regular intervals.2 Some of the imaging fellowships available are research focused, supporting academic advancement that also may further motivate individuals, especially with the growing need for publications required to gain academic appointment.3 Research-based specialization and courses in a specific modality are the current practices for specializing in vascular imaging. Much like the American College of Cardiology (ACC) establishing a consensus statement emanating from the Core Cardiology Training Symposium (COCATS) to standardize cardiology training, we recommend that the vascular surgery board and professional organizations such as the Society for Vascular Surgery and the European Society for Vascular Surgery establish a similar statement to standardize advanced vascular imaging training.4 According to the 2021 ACC advanced training statement on vascular medicine, Level III training pertains to advanced knowledge in diagnostic and therapeutic modalities for evaluating and managing vascular disease that enables one to direct a vascular laboratory, train others, and conduct advanced research in vascular medicine.5 However, the COCATS 4 Task Force 9 report did not provide detailed guidelines for Level III training in vascular medicine; rather, it described it in broad terms to provide context for trainees and clarify that these advanced competencies are not covered during the cardiovascular fellowship.1921The path we propose to expand learning opportunities is similar to advanced imaging fellowships in cardiology. These 1-to-2-year programs focus on cardiac MRI, CT, and echocardiography.5 By instituting an advanced imaging fellowship, we could train future vascular specialists to lead and direct labs with the complete spectrum of imaging modalities. However, the current limitation to establishing a vascular imaging fellowship is the lack of vascular surgeons with expertise in using imaging modalities such as CT or MRI, especially compared with the fields of cardiology or interventional radiology. Therefore, to overcome such limitations, we propose a team that includes faculty members from other disciplines such as cardiology, radiology, and neurology. An interdisciplinary team would enable the next generation of vascular specialists to read and interpret the various imaging modalities that would be applicable in both academic centers and private practice clinics .2223Given the increasing burden of vascular diseases, it is critical that trainees in cardiovascular medicine receive advanced training in vascular medicine.Furthermore, an interdisciplinary team would allow the different specialists to demonstrate how to read, interpret, and post-process the relevant modalities. Cone-beam CT training could be done by vascular surgeons and interventional radiologists, and interventional cardiologists could provide IVUS/OCT training. Transcranial Doppler training could be provided by vascular surgeons and vascular neurologists, whereas training in CT and MRI reading and interpretation could be done by radiologists and cardiologists. Interventional cardiologists have proven the utility of noninvasive diagnostic imaging such as CT fractional flow reserve for evaluating coronary artery disease, and image fusion with cone-beam CT and fluoroscopy is being used for intraprocedural guidance. Interventional radiologists use MRI and ultrasound fusion for targeted biopsies. By harnessing the experience of different specialties, advanced vascular imaging fellows can apply these techniques to their own practice. In addition, an interdisciplinary approach would train fellows to think outside the box and optimize imaging to improve delivery of care.Figure 7 illustrates the importance of an interdisciplinary team and the collaboration needed to train vascular specialists who are knowledgeable in all applicable imaging modalities.By working with and learning from different specialists, vascular trainees can learn to apply the same techniques to their patients and continue the vascular surgery paradigm of personalized treatment plans. Our proposed advanced vascular imaging fellowship could equip fellows with all the core competencies required to screen, diagnose, and care for vascular patients while also enabling them to train future generations of vascular specialists. Similar to the COCATS diagram, An advanced vascular imaging fellowship could enable fellows to be trained with all the core competencies required to:screen, diagnose, and care for vascular patients;learn the different imaging techniques and apply them in novel ways to treat patients; andapply a team-based approach in treating patients.


Chordomas are a locally invasive, low-grade, CNS malignancy that are primarily found in the skull base, spine, and sacrum. They are thought to be derived from notochordal remnants and remain a significant clinical challenge due to their local invasiveness, resistance to chemoradiation, and difficulty in achieving a complete resection. Adjuvant therapy such as proton beam therapy is critical in preventing recurrence in patients who are at high risk, however this treatment is associated with increased risk of complication. Currently, intraoperative observation and imaging findings are used to determine recurrence and success of gross total resection. These methods can be unreliable due to limited operative view, bony and soft tissue involvement, and complex post-operative changes on MRI. Earlier detection of incomplete resection or recurrence will allow for earlier ability to intervene and potentially improve patient outcomes. Circulating-tumor DNA (ctDNA) is cell-free DNA that is released by tumor cells as they undergo cellular turn-over. Monitoring ctDNA has been shown to be more sensitive at predicting residual tumor than imaging in numerous solid malignancies. Furthermore, ctDNA could be detected earlier in peripheral blood as opposed to imaging changes, allowing for earlier intervention. In this review, we intend to give a brief overview of the current state of molecular diagnosis for skull base chordomas. We will then discuss current advances in the utilization of ctDNA for the management of CNS pathologies such as glioblastoma (GBM) and brain metastases. We will also discuss the role ctDNA has in the management of non-CNS pathologies such as osteosarcoma and Ewing sarcoma (EWS). Finally, we will discuss potential implications of ctDNA monitoring for chordoma management. Chordomas are low grade tumors that reside primarily in the sacral region, skull base, or within the vertebral bodies. Known to primarily affect patients that are 40-75 years of age, this tumor accounts for approximately 3% of all bone tumors, and roughly 300 new cases of chordoma are diagnosed in the United States each year , 2.Derived from remnants of the notochord, these tumors are very slow growing yet locally invasive, enabling this tumor to have a higher recurrence rate compared to other low grade CNS tumors. Specific genes that are known to contribute to the formation of chordomas include the mTOR signaling pathway, a deficiency in the PTEN pathway, and the brachyury gene, among others –5. DeletThe centerpiece of treatment for skull base chordomas is surgical resection, however, total en bloc resection of this tumor is often challenging as it is often difficult to achieve negative margins. Surgical outcomes for this disease are difficult to determine as outcomes are often determined through intra-operative observation as well as post-operative imaging, however these methods of assessment are often inaccurate due to both the presence of unresected microscopic disease, as well as the presence of significant post-operative changes.While patients can undergo adjuvant radiation therapy for this disease, this treatment modality is associated with significant risks . Studiesvia liquid biopsy and analyzed to determine whether a tumor is recurring, as well as to establish a mutational profile for the lesion which can be exploited via targeted therapies.Cell-free DNA (cfDNA) are DNA fragments that can be found in the blood, CSF, or other bodily fluids, that are derived from different cell populations within the body. A subtype of cfDNA is circulating-tumor DNA (ctDNA) which are DNA fragments that have been released into the blood stream from a tumor. It has been well established that tumors are often highly vascularized as tumors need an increased blood supply to continue their growth and proliferation. As tumors grow, their cells undergo apoptosis/necrosis and these cells release their DNA into the blood stream which is often adjacent to the lesion . This ctIn this review, we intend to highlight how ctDNA technology is currently being used in clinical studies to monitor for tumor recurrence in patients diagnosed with brain metastases, glioblastoma (GBM), as well as osteosarcoma and Ewing sarcoma (EWS). In addition to highlighting whether this monitoring of recurrence improved patient outcomes, we will also highlight genomic findings that were gleaned from these studies. Finally, we will share our reasons for why we believe the field should consider incorporating ctDNA monitoring into the management of patients diagnosed with skull base chordomas.The current methods used for diagnosing skull base chordomas are quite limited as fine-needle aspiration or core needle biopsy are the preferred methods of diagnosis prior to surgical resection. However, these methods pose a concern for tumor seeding . Until rvia conventional imaging studies  or droplet digital polymerase chain reaction (ddPCR) . With thDespite the either absent or extremely low levels of plasma-derived ctDNA associated with exclusive intracranial lesions, it has been shown that ctDNA is present in cerebrospinal fluid (CSF) of brain tumor patients . Given CA prospective study of 21 consecutive patients with non-small cell lung cancer (NSCLC) and brain metastasis also confirmed the specificity of CSF-derived ctDNA over plasma-derived ctDNA in detecting genetic abnormalities specific to brain metastases . The stuAnother case in a HER2-positive metastatic breast cancer patient with brain metastases also confirms CSF-derived ctDNA’s ability to harbor clinically relevant genomic alterations in patients with CNS metastases, making it an effective tool in tracking tumor evolution . BaselinGBM is one of the most common primary brain tumors and boasts an average life expectancy of just 15-18 months after initial diagnosis. The standard of care for GBM includes maximal surgical resection and chemoradiation therapy, however, despite these measures, patient survival remains poor. One of the major challenges associated with GBM management is monitoring for tumor recurrence as patients often undergo radiation therapy following surgical resection and it is often difficult to differentiate between tumor recurrence and radiation necrosis. This often requires patients to undergo a tumor biopsy which is highly invasive.ctDNA has been a useful tool in the management of patients with GBM as it has enabled physicians to establish a mutational profile for one’s tumor. A study by Bettegowda and colleagues, was able to use ctDNA to detect IDH1, EGFR, TP53 and PTEN mutations in a subset of patients diagnosed with high- and low-grade gliomas . Howevervia ctDNA analysis had an improved response and time till progression following treatment with alkylating agents  are the second most common type of primary bone cancer and are rarely found in individuals over the age of 30 . In contctDNA has proven to be a valuable tool in the management of patients diagnosed with osteosarcoma or EWS. In a study by Shulman and colleagues, ctDNA was detected in 53% and 57% of plasma samples from patients with newly diagnosed EWS and osteosarcoma respectively . In patiIn a study by Krumbholz and colleagues, the authors demonstrate that ctDNA levels in treatment naïve patients are correlated with event-free and OS in patients diagnosed with EWS . Like ShIn addition to serving as a valuable predictor of patient survival and highlighting patient response to treatment, ctDNA can reveal complex chromosomal rearrangements. In the study by Shah and colleagues, the research team was able to identify a novel EWSR1-PKNOX2 translocation in a EWS patient’s plasma at the time of their relapse . This trIn this review we have highlighted cancers of the CNS where ctDNA technology has demonstrated success in determining disease recurrence and/or allowed for the further understanding of tumor genetics Table 1.Few studies have utilized ctDNA in the management of chordoma, however, a study by Zuccato and colleagues revealed that chordomas have different subtypes based on their DNA methylation profiles . The resThere are many potential benefits ctDNA may provide should it be incorporated into the management of those diagnosed with chordomas. In CNS and non-CNS cancers discussed throughout this manuscript, ctDNA has been used to glean valuable tumor genetic information. Given that tumor genetics impacts chordoma invasiveness and risk of recurrence, analysis of genetic information from ctDNA may aid in determining whether patients should undergo radiation therapy, which has risks of complication . Additiovia conventional imaging studies due to anatomical changes following surgical resection as well as the slow growing nature of chordomas (via peripheral biopsy.There are major challenges in determining chordoma recurrence hordomas . ctDNA hSF performed a review of the literature, wrote the manuscript, and is the first author. CD contributed to the writing of the manuscript and created the table included in the manuscript. XZ, SH, SA, PG, CS, EW, and GZ provided their expertise on the clinical aspects of the manuscript. GZ supervised the writing of the manuscript. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.