Thyroid nodules are extremely common and the vast majority are non-malignant; therefore the accurate discrimination of a benign lesion from malignancy is challenging. Ultrasound (US) characterisation has become the key component of many thyroid nodule guidelines and is primarily based on the detection of key features by high-resolution US. The thyroid imager should be familiar with the strengths and limitations of this modality and understand the technical factors that create and alter the imaging characteristics. Specific advances in high-resolution US are discussed with reference to individual features of thyroid cancer and benign disease. Potential roles for three-dimensional thyroid ultrasound and computer-aided diagnosis are also considered. The second section provides an overview of current evidence regarding thyroid ultrasound elastography (USE). USE is a novel imaging technique that quantifies tissue elasticity (stiffness) non-invasively and has potential utility because cancers cause tissue stiffening. In recent years, there has been much research into the value of thyroid USE for distinguishing benign and malignant nodules. Preliminary findings from multiple pilot studies and meta-analyses are promising and suggest that USE can augment the anatomical detail provided by high-resolution US. However, a definite role remains controversial and is discussed.• High-resolution US characterises thyroid nodules by demonstration of specific anatomical features• Technical advances heavily influence the key US features of thyroid nodules• Most papillary carcinomas appear stiffer than benign thyroid nodules on US elastography (USE)• Thyroid USE is controversial because of variation in the reported accuracies for malignancy• Combined grey-scale US/USE may lower the FNAC rate in benign nodules US characteristics that carry a high negative predictive value for malignancy enable an evidence-based decision not to investigate further, allowing unnecessary FNAC and/or surgery to be avoided in a very large population. Many of these key thyroid nodule features are heavily dependent on recent advances in high-resolution ultrasound technology and are therefore altered and influenced by US machine settings. In an era of wider US use by different groups , the high-resolution features of thyroid disease—and the technical factors, which create and alter these valuable signs—must be familiar to the operator.Ultrasound (US) examination of the neck is a commonly performed investigation and thyroid nodules are a highly prevalent finding. As the vast majority of nodules are non-malignant, the accurate discrimination of a benign from cancerous lesion is an important and challenging feature of thyroid US. Whilst single US features remain of limited accuracy, constellations of findings enable thyroid nodules to be accurately stratified on a ‘risk-of-malignancy’ basis and form the basis of several guidelines , 2. ImagUS elastography (USE) is a recent technological advance that measures tissue elasticity or stiffness properties objectively and has been available in recent years on many state-of-the-art clinical US machines. USE is classified as diagnostic ultrasound and is safe, non-invasive and requires no costly consumables. Importantly, USE can be performed in real-time alongside conventional sonography, providing objective stiffness data that can be used to influence clinical decisions during US examinations. The clinical potential of USE relies on the same principles as clinical palpation, namely that processes such as malignancy and fibrosis alter elasticity. Numerous clinical applications of USE are under investigation at different body sites. To date, over 100 preliminary studies on USE for thyroid nodules for malignancy have been published, with promising but controversial results, as will be discussed.This article will focus on two aspects of thyroid ultrasound: first, technical advances in high-resolution US are discussed with relevance to specific features of thyroid cancer, benign disease and emerging developments. The second part of the article provides a concise overview of the current role of elastography and how elasticity imaging may supplement high-resolution ultrasound in the pursuit of accurate thyroid nodule assessment.TM, Philips) than older crystals. Improving the source piezoelectric material enables the effective bandwidth of the probe to be used more efficiently and uniformly than was previously possible , 7925, 7Current and future directions of USEGiven the aforementioned sources of operator influence, practical challenges and artefacts, establishing a high reproducibility of thyroid USE is an important objective. An early report of strain USE had disappointing reproducibility results ; howeverAccording to recently published guidelines from the European Federation of Societies of Ultrasound in Medicine and Biology (EFSUMB): “elastography is an additional tool for thyroid lesion differentiation” and “based on expert opinion, elastography may be used to guide follow-up of lesions negative for malignancy at FNAC” . This caAlthough controversial, USE shows promise as an adjunct to conventional US for reliable identification of benignity in a select group of nodules on the initial US examination as well as those with non-diagnostic or indeterminate cytological results following FNAC. Even if these indications are validated in future studies, several issues will still need to be addressed before USE can be accepted widely in routine practice. USE technologies should be robust and simple to apply by the range of health care professionals who perform thyroid US routinely. The specific strengths and limitations of each USE technology including artefacts need to be catalogued systematically. While it is acknowledged that USE technologies are proprietary and their outputs may not be interchangeable, there should be greater standardisation of thyroid USE, for example by unifying nodule-grading systems and elastogram chromatic scales. Fortunately, USE technologies are continually improving including with respect to measurement precision and quality assurance, which should augment their diagnostic accuracies and reliabilities. Ideally, with advances in CAD software, a nodule’s grey scale and elastographic features could be analysed automatically and converted into a single estimate of its malignant risk. There are still some hurdles to overcome although, at the current pace of promising research and technological advances, USE may well become a valuable complementary technique for evaluating thyroid nodules in the near future.Innovative advances in high-resolution ultrasound now enable detailed anatomical characterisation and accurate differentiation of benign from malignant disease. Ultrasound has become the core component of thyroid nodule guidelines, but it is important that the key technological aspects of the modality are understood and that challenges and limitations remain with the technique. The large evidence base for ultrasound elastography indicates that the assessment of nodule stiffness can improve the imaging evaluation of thyroid lesions and potentially avoids unnecessary FNAC/surgery for benign nodules, particularly if integrated with US classification. The potential for 3D and CEUS in thyroid nodule US has not yet been realised, but the emergence of these novel approaches is an illustration of the huge strides that have been made in the underlying ultrasound technology.


The exponential growth in world population is feeding a steadily increasing global need for arable farmland, a resource that is already in high demand. This trend has led to increased farming on subprime arid and semi-arid lands, where limited availability of water and a host of environmental stresses often severely reduce crop productivity. The conventional approach to mitigating the abiotic stresses associated with arid climes is to breed for stress-tolerant cultivars, a time and labor intensive venture that often neglects the complex ecological context of the soil environment in which the crop is grown. In recent years, studies have attempted to identify microbial symbionts capable of conferring the same stress-tolerance to their plant hosts, and new developments in genomic technologies have greatly facilitated such research. Here, we highlight many of the advantages of these symbiont-based approaches and argue in favor of the broader recognition of crop species as ecological niches for a diverse community of microorganisms that function in concert with their plant hosts and each other to thrive under fluctuating environmental conditions. Climate change and an increasing world population are predicted to drastically increase the global need for arable farmland, a resource that is already in high demand . With thThis large expansion in agricultural output will require both improvements in crop yield as well as the cultivation of additional farmland. One direct effect of this trend will be the steadily increasing prevalence of farming on marginal, arid, and semi-arid lands, especially in the developing world . Even wiThe historical approach to mitigate the negative effects of abiotic stresses on crop yield has been the creation of stress-tolerant cultivars . ConventIn recent years, plant-associated microbial communities have received considerable attention for their ability to confer many of the same benefits to crop productivity and stress resistance as have been achieved through plant breeding programs . It is nIn this article, we will highlight some of the advantages associated with symbiont-based approaches to increasing crop resistance to abiotic stress, with a focus on engineering increased tolerance to drought, which is the most critical and prevalent factor for crop production in many parts of the world . We presThe success of plant biotechnology programs has helped the world’s food supply keep pace with the increasing rate of population growth . Novel cTo avoid the time and labor costs associated with conventional breeding, some researchers have turned to generation of transgenic lines for producing varietals with improved plant growth regulators, antioxidants, organic osmolytes or other factors capable of increasing drought tolerance . UnfortuBoth the conventional breeding and genetic engineering based approaches may rely too heavily on the assumption that plants function as autonomous organisms regulated solely by their genetic code and cellular physiology , althougFigure 1). First, microbial symbionts are frequently capable of conferring stress tolerance to a wide variety of diverse plant hosts, and many PGPM can confer benefits to both monocots and dicot crop species (Achromobacter piechaudii, isolated from dry riverbeds of southern Israel, was capable of increasing salt and drought resistance in both pepper and tomato (Compared with methods for directly engineering stress tolerance into the host described above, symbiont-based approaches to improving stress tolerance offer some clear advantages ( species . The bacd tomato . Using oArabidopsis plants in symbiosis with Paenibacillus polymyxa have increased drought tolerance as well as improved resistance to pathogen attack (Piriformospora indica have both increased resistance to Fusarium and Blumeria infections and increased salt tolerance. These examples of microbes conferring multiple benefits are likely due to the fact that many symbionts exert their influence over the plant host through manipulating plant hormone pathways (Secondly, PGPM frequently confer more than one type of abiotic and/or biotic stress tolerance , and cron attack . Waller pathways  and thatpathways .Thirdly, plant-associated microbial species represent a vast reservoir of genetic information that has coevolved with their hosts under natural environmental conditions. These microbes can add genetic flexibility to the adaptation of comparatively sessile and longer-lived plants . The conMicrobial species with plant-growth promoting capabilities are both numerous and easier to characterize now than ever before. A considerable fraction of endophytes isolated from crops appear to have measurable effects on host fitness . Two recStenotrophomonas rhizophila, a recent study identified spermidine as a novel PGPM regulator of plant abiotic stress (As more and more genomes from PGPM become available, our ability to identify the shared genetic components or metabolites that are responsible for conferring specific abiotic stress advantages increases. Through a transcriptomic analysis of the symbiosis between oilseed rape and c stress . Identifc stress . Recentlc stress .Bacillus subtilus was shown to be the result of tissue specific modulation of the expression of the Arabidopsis Na+/K+ transporter, HKT1 (Arabidopsis as a result of inoculation with P. polymyxa was related to strong upregulation of the host gene ERD15 (Investigation of the mechanisms by which PGPM confer stress-tolerance to their plant hosts is another avenue for identifying targets for direct transgenic manipulation of stress response in crops. Recent technological advances in cell-type specific transcriptomics , combineer, HKT1 . Similarne ERD15 .Finally, there is a need for rethinking modern agronomic practices in light of our current understanding of the importance of host-associated microbial communities for plant productivity and health. Current large-scale agricultural systems rely heavily on monoculture cropping systems, in many cases without between-season crop rotation, which has been shown to lead to the build up of specialized plant pathogens, increased disease incidence, and decreased yield . ResearcAs with the plant-breeding and transgenic approaches to engineering stress-resistance in tomorrow’s crops, there are of course challenges associated with symbiont based strategies that will need to be overcome. One potential challenge will be detangling synergistic and antagonistic effects of different microorganisms within the plant microbiome . ResearcAgriculture currently accounts for 70% of human fresh water use, and in many parts of the world this rate of water consumption exceeds local regeneration rates, leading to unsustainable reliance on underground aquifers that are rapidly depleting . Given tIn the future, there is a need for more collaboration between the host-focused and symbiont-focused approaches to mitigating abiotic stress in crop plants. Medical science has in recent years undergone a profound restructuring of its understanding of the microbiome housed within the body and its impact on human health . There iThe 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.


Plants represent a safe, efficacious and inexpensive production platform by which to provide vaccines and other therapeutic proteins to the world’s poor. Plant virus expression vector technology has rapidly become one of the most popular methods to express pharmaceutical proteins in plants. This review discusses several of the state-of-the-art plant expression systems based upon geminiviruses that have been engineered for vaccine production. An overview of the advantages of these small, single-stranded DNA viruses is provided and comparisons are made with other virus expression systems. Advances in the design of several different geminivirus vectors are presented in this review, and examples of vaccines and other biologics generated from each are described. Over the past twenty years, great advances have been made in the construction and generation of plant-derived vaccines. Vaccines and other biopharmaceutical proteins produced from plants are safe, efficacious, and can be easily scaled up for mass production. Plant-made vaccines may provide a select advantage for specific demands that may not be readily addressed through conventional vaccine production. These range from providing inexpensive vaccines for the world’s poor who reside in developing countries to stockpiling vaccines against pandemic infectious diseases and even to generating plant made biologics for the field of personalized medicine ,2.Initially, vaccines and other pharmaceutical proteins were generated from transgenic plants, however, recent advances in plant virus molecular biology have yielded an alternative means of transiently expressing proteins through the use of virus expression vectors which are engineered to be delivery vehicles. Plant virus expression vectors offer many advantages for foreign protein expression over stably transformed plants; these include greater expression levels over a short period of time, the ability to generate proteins which may impede plant growth, as well as reduced biocontainment issues and related public perception concerns related to genetically modified crops. The deletion of virus movement and coat proteins disables plant to plant movement of virus expression vectors, and as a result, the possibility of pharmaceutical proteins being transmitted to weedy relatives is greatly reduced. Conversely, stable transgenic lines have the advantage of providing a permanent genetic resource which lacks significant variation in foreign protein expression and can be stored as seed .Agrobacterium is also frequently used as a means to introduce virus vectors to plants ..cis-actiIt has been suggested that geminiviruses originate from a common ancestor along with other small, circular, single-stranded DNA viruses of related genomes, including nanoviruses, circoviruses and cycloviruses. This group of viruses infect a diverse array of organisms, ranging from plants and mammals to birds, fish and insects ,8. The cGeminiviruses replicate via a rolling circle mechanism and use a replication initiator protein, Rep, that initiates replication at a highly conserved stem-loop structure located between two major open reading frames of the genome. The replication strategy of geminiviruses has been reviewed extensively and will be only briefly described here ,18. FollBegomoviruses and Curtoviruses, and betaC1, which is encoded by betasatellites that are associated with a number of begomoviruses ..N. benthet al., (2013), have developed a technology based on the mastrevirus Tobacco yellow dwarf virus (TYDV) that offers an interesting new twist on previous geminivirus expression vector constructs  requires the presence of the helper viruses tomato leaf curl virus (ToLCV) or beet severe curly top virus (BSCTV). An expression vector was engineered from this betasatellite by replacing the βC1 ORF with segments of either the CaMV 35S or the petunia ChsA promoter. The authors showed that they could silence reporter gene activities in transgenic plants expressing by 35SGUS and in nontransgenic petunia plants expressing ChsA by supplying this betasatellite in the presence of helper virus .Recently, the Bean yellow dwarf geminivirus vector has been used to deliver sequence-specific nucleases and DNA repair templates to facilitate homologous repair of double-stranded breaks within plant sequences ,51. RepaPlant virus expression vectors have been engineered to function as rapid, inexpensive and robust platforms for vaccine production. The implications of this and other technologies related to molecular pharming in plants are substantial. Geminivirus vectors offer select advantages over plant RNA virus expression vectors, for example, they are able to function in a much broader range of plants, and thus provide more choices of the production system to be used. Geminiviruses lack the stability issues that their RNA virus vector counterparts experience . Geminiv


Brain changes in schizophrenia evolve along a dynamic trajectory, emerging before disease onset and proceeding with ongoing illness. Recent investigations have focused attention on functional brain interactions, with experimental imaging studies supporting the disconnection hypothesis of schizophrenia. These studies have revealed a broad spectrum of abnormalities in brain connectivity in patients, particularly for connections integrating the frontal cortex. A critical point is that brain connectivity abnormalities, including altered resting state connectivity within the fronto-parietal (FP) network, are already observed in non-help-seeking individuals with psychotic-like experiences. If we consider psychosis as a continuum, with individuals with psychotic-like experiences at the lower and psychotic patients at the upper ends, individuals with psychotic-like experiences represent a key population for investigating the validity of putative biomarkers underlying the onset of psychosis. This paper selectively addresses the role played by FP connectivity in the psychosis continuum, which includes patients with chronic psychosis, early psychosis, clinical high risk, genetic high risk, as well as the general population with psychotic experiences. We first discuss structural connectivity changes among the FP pathway in each domain in the psychosis continuum. This may provide a basis for us to gain an understanding of the subsequent changes in functional FP connectivity. We further indicate that abnormal FP connectivity may arise from glutamatergic disturbances of this pathway, in particular from abnormal NMDA receptor-mediated plasticity. In the second part of this paper we propose some concepts for further research on the use of network connectivity in the classification of the psychosis continuum. These concepts are consistent with recent efforts to enhance the role of data in driving the diagnosis of psychiatric spectrum diseases. Almost two decades ago, it was proposed that the pathophysiology of psychosis is more closely related to abnormal functional integration between specific brain regions rather than to changes in local brain activity , which can be compared with model comparison procedures. Both of these approaches,—model-based investigations of effective connectivity and more global data-driven correlation approaches across the whole brain with graph theory—have already demonstrated network connectivity abnormalities in psychosis  derived from structural or functional MRI. Graph theory analysis has emerged as a very helpful approach to infer complex network properties of the brain from a more global perspective. In this framework, brain networks can be understood as graphs that are composed of nodes representing neural elements, such as neurons or brain regions, that are linked by edges denoting structural  or functional connections. Their topological properties or patterns of connectivity can be expressed by a variety of parameters, such as node degree, clustering coefficient, path length, connection density, or modularity  studies of the resting state have shown reduced FP connectivity in chronic psychotic patients –dependent synaptic plasticity  . Within this perspective, it has been shown that functional connectivity from the prefrontal cortex to thalamus and nucleus accumbens correlated positively with prefrontal glutamate concentrations. The correlations involving prefrontal glutamate and prefrontal-related functional connectivity were mirrored by correlations with structural connectivity , which have already been applied in early psychosis detection (Koutsouleris et al., Brain imaging may provide a powerful tool to improve the specificity and validity of an early diagnosis and to sustain preventive intervention prior to the onset of illness (Fusar-Poli et al., The Review Editor Dr. Kroken declares that, despite having collaborated with the author Paolo Fusar-Poli, the review process was handled objectively and no conflict of interest exists. 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.


An unprecedented number of Ebola virus infections among healthcare workers and patients have raised questions about our understanding of Ebola virus transmission. Here, we explore different routes of Ebola virus transmission between people, summarizing the known epidemiological and experimental data. From this data, we expose important gaps in Ebola virus research pertinent to outbreak situations. We further propose experiments and methods of data collection that will enable scientists to fill these voids in our knowledge about the transmission of Ebola virus. The 2014 outbreak of Ebola virus disease (EVD) in West Africa has claimed more lives than all previous EVD outbreaks combined [Zaire ebolavirus, one of five species of viruses in the genus Ebolavirus, has been identified as the etiological agent of the 2014 outbreak of Ebola virus disease (EVD). In humans, EBOV has been found in variety of bodily fluids, including saliva, blood, breast milk, stool, and semen [Ebola virus (EBOV), species nd semen . There and semen . InfectiAssessing the potential routes of EBOV transmission, the United States Centers for Disease Control and Prevention (CDC) has communicated the scientific consensus that EBOV spreads only through direct contact with mucous membranes or through broken skin with infected blood or bodily fluids, contaminated objects such as needles, and contact with infected animals . AdditioOur knowledge about human-to-human EBOV transmission is based mainly on epidemiological evidence from previous outbreaks . While aAirborne or aerosol transmission of a virus occurs when small, virus-laden droplets evaporate before settling on surfaces, leaving behind infectious droplet nuclei that can travel long distances. The small droplets that can form these droplet nuclei are often called aerosols, but aerosols are also generally defined as any small liquid or solid particles that are suspended in air . In ordeCurrently no data exist for whether EBOV forms droplet nuclei. EBOV particles have been found in human alveoli , yet it While there is no evidence of airborne transmission of EBOV in humans, experiments in NHPs have shed light on this mode of infection. Early experiments examining routes of infection of EBOV demonstrated that the virus could be aerosolized to small droplet or droplet nuclei size, and cause lethal disease in rhesus macaques after inhalation of at least 400 pfu . More reResearchers have also tested the stability of mechanically generated aerosols (1–3 µm diameter) that contain EBOV. These stability studies have shown that 99% of the initial virus decays after 104 min at 50%–55% relative humidity and 19–25 degrees Celsius [Ebolavirus, Reston virus, indirectly infected naïve NHPs in distant cages [Initial concerns about the possibility of aerosol transmission of EBOV were raised when NHPs infected with another virus in the genus nt cages . Indirecnt cages ,9. Howevnt cages .Overall, differences in experimental design make it difficult to know what we can infer from these experiments about traditional airborne transmission. Measures such as the plexiglass barrier may prevent the exchange of droplets, but they may also impede aerosols. Furthermore, all EBOV transmission experiments take place in biosafety level 4 (BSL-4) laboratories that have pressure driven airflow, which could interfere with the path of the virus in the air. In order to definitely prove or disprove the possibility of EBOV airborne transmission in NHPs, rigorous experimental design is necessary to make sure droplet or fomite transmission cannot occur, while a positive control must also demonstrate that aerosol transmission is possible in the experimental setup.Droplet transmission, or large droplet transmission, refers to contact with infectious droplets that do not evaporate or travel long distances. Although these droplets do travel through the air, they are defined differently from aerosols that evaporate in the air to form droplet nuclei. While some viruses are not stable as droplet nuclei, they may remain stable inside droplets and can infect individuals exposed to them. It has been generally assumed that droplet transmission can occur up to a meter from an infected individual, but this varies depending on the droplet size, environment, and stability of the virus . EBOV-coOther ways that EBOV-containing droplets and aerosols could be created are through aerosol-generating procedures (AGPs). Known AGPs in clinical settings are those that stimulate coughing or involve the manipulation of the patient’s airway, including activities such as intubation, manual ventilation, and broncoscopy. Although health care workers may not perform AGPs in ETUs, it is possible that those working in hospital settings could generate EBOV aerosols when using AGPs to treat an EVD patient.Additional AGPs include spraying and pressure washing infected materials. For example, the previously mentioned indirect EBOV infections in NHPs are believed to have occurred from activities done by the researchers, such as pressure washing cages, or from activities by the NHPs themselves that could have formed EBOV-containing droplets that infected other animals. Although such AGPs might not occur outside of a laboratory setting, it would be helpful to experimentally determine the types of research and clinical activities that generate infectious EBOV droplets and aerosols. Air sampling while washing the cages of EBOV infected animals or when intubating an infected animal could reveal whether these activities generate EBOV droplets or aerosols. Additionally, this sampling could be performed during other experiments, thereby limiting the use of animals.Experimentally testing the stability of the virus in bodily fluids such as vomit, saliva, stool, and blood could help us determine how long EBOV can persist in droplets generated from infected patients. Similar environmental stability experiments to those we described for small aerosols could also be done with large droplets to determine how factors such as temperature, humidity, and particle diameter influence the viability of EBOV. By determining the viability of the virus in different size aerosols and droplets, we could better predict the range and modes of EBOV transmission. Additionally, conducting air sampling in Ebola treatment units (ETUs) could reveal whether EBOV aerosols or droplets are generated by patients. These data could inform us whether personal protective equipment (PPE) guidelines and protective behaviors in ETUs are sufficient. For example, the CDC currently recommends that healthcare workers wear a minimum of a face shield, surgical mask, gown, and two pairs of gloves when working with EBOV patients and that a purifying respirator (PAPR) or N95 respirator be used during an AGP with an EVD patient . HoweverA fomite refers to any surface that a pathogen is able to persist on, and fomite transmission can occur when an individual comes into contact with that infected surface. Potential routes of EBOV fomite transmission include touching objects such as bed sheets or gurneys that have been in contact with EBOV patients or other surfaces contaminated with EBOV-containing bodily fluids.10 after 5.9 days when placed on glass and in the dark at 24 °C and 40% relative humidity [Little is known about the stability of EBOV on surfaces. One experiment showed that EBOV viral load is reduced by 4 loghumidity . Anotherhumidity . Both poFurther experiments testing the stability of EBOV on surfaces found in outbreak locations and in tropical conditions could determine whether EBOV persists in the environment and if it is possible to acquire infection through contact with contaminated surfaces. In these laboratory experiments it is also important to accurately mimic the conditions one would find in real outbreak settings. While previous studies tested the stability of EBOV in dried guinea pig sera and cell culture media at low temperature and humidity, it would be insightful to test the stability of EBOV in dried human bodily fluids and at a higher temperature and humidity.In addition to experimentally testing the stability and viability of EBOV in human bodily fluids, both as liquid and dried on different surfaces, it would be useful to test the limits of EBOV stability in other environments, such as water. Because of the reduced public health infrastructure in countries afflicted by EVD outbreaks, it is common to find open sewage canals or waste-containing buckets. Because EBOV is shed in feces and other bodily secretions that come into contact with water, it would be helpful to know how long the virus is stable in water. Contaminated water could come into contact with the eyes, nose, or mouth of individuals, leading to possible infection through contact with mucous membranes.Flaviviridae, persists for 19–30 days in water [Other viruses that are also shed in vomit and diarrhea can cause infection among people who come into contact with sewage contaminated water . Many ofin water . Yet HIVin water . In factin water . TherefoMany biological factors could influence the stability of EBOV, such as whether the virus is cell-associated or protected by organic matter such as fecal waste. Because there are so many permutations for testing the virus in different environments and at varying temperatures, humidities, pH’s, and salinities, it is most reasonable to test the virus in conditions that one is likely to find in outbreak settings. Designing experiments that accurately simulate the environments where one might encounter EBOV, such as on clinical surfaces, corpses, and disposed waste, and are at the same temperature and humidity as outbreak locations, would provide the environmental boundaries for EBOV transmission.Of all the possible modes of transmission, direct contact with bodily fluids remains the most likely way of transmitting EBOV between people. Circumstantial evidence from previous outbreaks, epidemiological data, and experiments in NHPs all demonstrate that contact with EBOV infected fluids via mucous membranes, injection, or open wounds can lead to infection.The use of unsterilized needles was linked to the spread of EBOV in hospital wards during the first recorded EVD outbreak in the Democratic Republic of the Congo in 1976 . AccidenDespite contact with bodily fluids being a confirmed route of EBOV transmission, it is not clear when and which fluids contain infectious virus. EBOV has been isolated from blood, saliva, breast milk and semen , while ROne limitation of sampling the viral load in patients is that we may be missing asymptomatic or subclinical infected individuals. These asymptomatic individuals may have been recently infected and are in the pre-clinical stages of EVD, or they may have been infected for a while and have not developed any symptoms, remaining subclinical. EBOV replication has been identified in patients who never developed any symptoms after being exposed to the virus , but it While evidence from previous outbreaks has enabled public health personnel to make informed decisions during the current outbreak, we do not have a complete understanding of all of the potential routes of EBOV transmission. If we continue to piece together our understanding of transmission from primarily epidemiological data, we will miss understanding the biological phenomena that lead to transmission events.Fortunately, BSL-4 research facilities are ideally equipped to help answer these underlying questions about EBOV environmental stability and transmission. Experiments testing different modes of transmission in animal models and the limits of EBOV viability in different environments could answer many of the remaining questions about EBOV transmission, such as whether the virus can undergo droplet or fomite transmission.As we consider the current EBOV epidemic in regards to potential outbreaks of other viral diseases, it is important to think about how both epidemiology and experimental research can be used together to inform our understanding of virus transmission. Epidemiology allows us to infer how transmission is occurring on a population level, while experiments enable researchers to determine the biological limits of transmission. Therefore, the experiments that we propose for EBOV could also be used to fill gaps in our knowledge about other viruses as well.In summary, sparse epidemiological and experimental evidence exist for mechanisms of EBOV transmission between people. Currently we know that humans shed the virus in a variety of bodily fluids, are infected by multiple routes, and only need a small amount of virus for infection. This creates a high risk of exposure, so all infection control measures must be followed rigorously in order to prevent further infections. From epidemiological evidence it appears that these infections primarily occur through direct contact with bodily fluids, yet more indirect modes of EBOV transmission have yet to be thoroughly studied experimentally. While contact with bodily fluids from EVD patients remains the most likely route of transmission, further experiments regarding the generation of EBOV in the respiratory tract and during AGPs, as well as the stability of EBOV in droplets and on surfaces, could help us define all routes of infection and improve infection control policies.


Selective internal radiation therapy (SIRT) is a promising treatment modality for advanced hepatocellular carcinoma or metastatic liver cancer. SIRT is usually well tolerated. However, in most patients, SIRT will result in a (temporary) decreased liver function. Occasionally patients develop radioembolization-induced liver disease (REILD). In case of a high tumor burden of the liver, it could be beneficial to perform SIRT in two sessions enabling the primary untreated liver segments to guarantee liver function until function in the treated segments has recovered or functional hypertrophy has occurred. Clinically used liver function tests provide evidence of only one of the many liver functions, though all of them lack the possibility of assessment of segmental  liver function. Hepatobiliary scintigraphy (HBS) has been validated as a tool to assess total and regional liver function in liver surgery. It is also used to assess segmental liver function before and after portal vein embolization. HBS is considered as a valuable quantitative liver function test enabling assessment of segmental liver function recovery after regional intervention and determination of future remnant liver function. We present two cases in which HBS was used to monitor total and regional liver function in a patient after repeated whole liver SIRT complicated with REILD and a patient treated unilaterally without complications. Average disease control ranges from 70 to 90% or even higher and SIRT is usually very well tolerated  is a form of brachytherapy in which intra-arterially injected olerated –3. Patieolerated .Severe side-effects of SIRT are not common after radioembolization. Several rather mild procedure-related symptoms may ensue including fatigue 54–61%), abdominal pain (23–56%), nausea and vomiting (20–32%), and low-grade fever (3–12%) that usually last only a few hours . REILD has been recently distinguished from other liver toxicity diseases, such as radiation-induced liver disease (RILD) which is seen after external beam radiation, by the research group of Bilbao et al. . REILD iIn clinical practice, we assume that SIRT will probably result in a (temporary) decreased liver function or occasional REILD. To minimize this risk, one can perform SIRT in two sessions enabling the primary untreated liver segments to guarantee liver function until function in the treated segments has recovered. At this moment, changes in the regional liver function after SIRT are unknown. The timing of the second SIRT-session is crucial as, if performed too early , it may cause the same complications as when performed in one session. In order to improve the current SIRT strategy, we need to investigate the changes in regional liver function after SIRT.The liver is responsible for a spectrum of functions including the uptake, metabolism, conjugation, and excretion of various endogenous and foreign substances. Most of the different functions of the liver are performed by hepatocytes but to a smaller degree by other liver cells. The substrates, by-products, or final products of those processes can be used to estimate liver function. However, few of the tests used in everyday clinical practice truly measure liver function. They rather provide an indirect evidence of only one of the liver’s many processes.Categorization schemes are based either on laboratory findings entirely or the combination of laboratory and clinical findings. The approach is to either stratify patients into groups with increasing degree of dysfunction or to calculate a score that reflects severity of liver dysfunction. The most widely used system today in adults is the model for end-stage liver disease (MELD) scoring system that uses the International Normalized Ratio (INR) in combination with serum bilirubin and serum creatinin values to predict survival . AnotherThe indocyanine green (ICG) clearance test was initially devised for the measurement of blood flow and later found clinical application in the assessment of liver function by yielding a measurement of functional hepatocyte mass. It is now the most widely used quantitative liver function test in clinical use in the setting of liver surgery. ICG is exclusively removed by the liver and excreted into the bile without intrahepatic conjugation. Elimination is dependent on hepatic blood flow, cellular uptake, and biliary excretion. The disappearance of ICG from the blood reflects the liver’s capacity to transport organic anions and metabolize drugs providing an indirect measurement of global liver function. A limitation is that ICG clearance test reflects global liver function, but it does not take into account regional variations in liver quality that may occur .99mTc-mebrofenin hepatobiliary scintigraphy (HBS). 99mTc-mebrofenin is a hepatic specific lidocaine analog and is transported to the liver bound to albumin and dissociates from albumin in the hepatic space of Disse from where it is taken up by the hepatocytes. Subsequently, mebrofenin is excreted into the bile canaliculi without prior biotransformation. The hepatic uptake represents one of the main hepatic processes and the use of 99mTc-mebrofenin HBS for preoperative assessment of liver function in patients undergoing liver surgery was first described by Erdogan et al. In 54 patients scheduled for liver resection, the Mebrofenin uptake rate (MUR) strongly correlated with the ICG clearance test (2) for both categories of patients  function. In this relatively small patient study, preoperatively estimated FRL function correlated well with actual remnant liver function 1 day after resection . A recenfunction . The resfunction . The uptFor liver surgery, HBS has been validated as a tool to assess total and regional liver function, and is performed routinely in our patients before major liver resection . It is a99mTc-mebrofenin HBS a suitable quantitative liver function test to monitor regional liver function changes after SIRT. The effect of SIRT observed 4–6 weeks after the procedure is performed. HBS is performed before and 6 weeks after SIRT in order to measure the changes in the treated and non-treated lobes. If our hypothesis is correct and SIRT does cause decrease in liver function in the treated segments and (hyper)function in the untreated segments, HBS can be used as a monitoring tool in order to determine the timing of the second SIRT session.In this light, we consider The two case examples presented here illustrate the possible role of total and regional functional imaging of the liver. Both patients were treated with SIR-Spheres for HCC in a salvage setting. Immediately before and 6 weeks after the SIRT, liver function was measured with HBS as described elsewhere .It is shown that HBS is able to depict relative and absolute change in regional liver function in non-affected liver segments.Case 1: Multifocal HCC, SIRT whole liver treatment twice Figures .Case 2: Multifocal HCC, SIRT right-sided liver segments Figure .Hepatobiliary scintigraphy is able to give insight into relative liver function before SIRT and depict relative and absolute change in regional liver function in non-affected liver segments after SIRT. This could be of importance in risk stratification of patients before the first treatment or timing of subsequent treatment.Roelof J. Bennink, Kasia Cieslak, Heinz-Josef klümpen, and Thomas van Gulik were involved in study design, implementation, analysis, and manuscript preparation. Otto van Delden and Krijn van Lienden were involved in radioembolization, angiographic analysis, and manuscript preparation. Peter Jansen was involved in study design, clinical care, and manuscript preparation.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.


Major Histocompatibility Complex (MHC) genes code for proteins involved in the incitation of the adaptive immune response in vertebrates, which is achieved through binding oligopeptides (antigens) of pathogenic origin. Across vertebrate species, substitutions of amino acids at sites responsible for the specificity of antigen binding (ABS) are positively selected. This is attributed to pathogen-driven balancing selection, which is also thought to maintain the high polymorphism of MHC genes, and to cause the sharing of allelic lineages between species. However, the nature of this selection remains controversial. We used individual-based computer simulations to investigate the roles of two phenomena capable of maintaining MHC polymorphism: heterozygote advantage and host-pathogen arms race (Red Queen process). Our simulations revealed that levels of MHC polymorphism were high and driven mostly by the Red Queen process at a high pathogen mutation rate, but were low and driven mostly by heterozygote advantage when the pathogen mutation rate was low. We found that novel mutations at ABSs are strongly favored by the Red Queen process, but not by heterozygote advantage, regardless of the pathogen mutation rate. However, while the strong advantage of novel alleles increased the allele turnover rate, under a high pathogen mutation rate, allelic lineages persisted for a comparable length of time under Red Queen and under heterozygote advantage. Thus, when pathogens evolve quickly, the Red Queen is capable of explaining both positive selection and long coalescence times, but the tension between the novel allele advantage and persistence of alleles deserves further investigation. Major Histocompatibility Complex (MHC) proteins, responsible for presenting antigens to lymphocytes and thus fundamental to immune response are highly diverse. This diversity, is due to extremely high polymorphism of genes that encode MHC. MHC genes are the paradigm for the positive selection whereby novel MHC alleles are strongly favored by natural selection. This positive selection is widely assumed to be driven by advantage of individuals that are heterozygous at MHC loci and thus are considered to bind wider spectrum of pathogen-derived antigens. In contrast, our simulations showed that novel mutations in MHC are strongly favored by frequency-dependent selection arising from host-pathogen coevolution (the Red Queen process), but not by heterozygote advantage. Our results challenge the predominating view on the processes driving the evolution of MHC genes. Major histocompatibility complex (MHC) genes code for proteins involved in antigen presentation and initiation of the T-cell-mediated specific immune responses; these genes are the most polymorphic known in vertebrates. Because of its function in pathogen recognition, this high polymorphism is thought to be maintained by some form of balancing selection that is imposed by pathogens. Two mechanisms of balancing selection are most often mentioned: heterozygote advantage, whereby heterozygous individuals gain superior resistance by being able to present a wider range of antigens , and RedRemarkably, the majority of polymorphism at MHC genes is located at the amino-acid residues that encode the Antigen Binding Sites ABSs; ,5, consiBoth frequency dependence and heterozygote advantage can potentially favor novel alleles that arise by mutation. Such alleles are initially rare, and as such should be favored by negative frequency-dependent selection, but because of the low initial frequency they will occur in heterozygotes. However, the relative roles of these two mechanisms in shaping MHC evolution are far from being understood [reviewed in −4), intermediate (1∙10−3) and high  . Thus, o−3), but some common MHC alleles were nevertheless quite successful at pathogen recognition . We chose these rates because they were effective in exerting selection on host genotypes , pathogens are unable to adapt to host genotypes fast enough, so that the level of polymorphism is low for both heterozygote advantage and frequency-dependent selection [−2), effectively random pathogen genotypes are produced and the variation in fitness between host genotypes is negligible [see figure 3 in −5 [−4 per 20aa antigen.Haploid pathogens reproduce asexually, such that the genotypes of the offspring and parents were identical except for mutations. We simulated random point mutations in pathogens, i.e. each bit of an antigen could change to the reverse in each generation. We derived populations using three different pathogen mutation rates: 2∙10election . At rate 3 in −5  which giFor each of the three considered pathogen mutation rates, we simulated scenarios that included the two primary mechanisms thought to act on the evolution of the MHC: heterozygote advantage and host-pathogen coevolution (Red Queen process), following the framework of Ejsmond et al. . Here weFor all scenarios, simulations were initiated with populations of hosts and pathogens (or hosts only in the Drift scenario) that contained randomly generated genes and antigens; thus host polymorphism was maximal at the outset (see Table B in 6) pairs of alleles in a population. Because these simulations were very time-consuming, we ran three replicates for each scenario for 40 000 host generations. This was enough for many lineages to reach coalescence at the low and intermediate mutation rates  with populations of 2500 hosts, in which we recorded the history of ancestry for all alleles. Then, starting from the last generation, we traced back the alleles’ history to find the common ancestor for any pair of alleles. We recorded the proportion of such coalescence events, as well as the coalescence time (expressed in number of generations). The analysis was performed for all .All simulations were performed with Matlab 7.9  and the the results of our computer simulations are available from the Zenodo open digital repository Click here for additional data file.S2 Appendix(PDF)Click here for additional data file.


Health care professionals (HCPs) are able to make effective decisions regarding patient care through the use of systematically developed clinical practice guidelines (CPGs). These recommendations are especially important in a cancer health care context as patients are exposed to a multitude of interdisciplinary HCPs offering high-quality care throughout diagnosis, treatment, survivorship and palliative care. Although a large number of CPGs targeted towards cancer are widely disseminated, it is unknown whether implementation strategies targeting the use of these guidelines are effective in effecting HCP behaviour and patient outcomes in the cancer care context. The purpose of this systematic review will be to determine the effectiveness of different CPG dissemination and implementation interventions on HCPs’ behaviour and patient outcomes in the cancer health care context.Five electronic databases  will be searched to include all studies examining the dissemination and/or implementation of CPGs in a cancer care setting targeting all HCPs. CPG implementation strategies will be included if the CPGs were systematically developed . The studies will be limited to randomized controlled trials, controlled clinical trials and quasi-experimental  studies. Two independent reviewers will assess articles for eligibility, data extraction and quality appraisal.The aim of this review is to inform cancer care health care professionals and policymakers about evidence-based implementation strategies that will allow for effective use of CPGs.CRD42015019331PROSPERO The online version of this article (doi:10.1186/s13643-015-0100-9) contains supplementary material, which is available to authorized users. Clinical practice guidelines (CPGs)—‘systematically developed statements to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances’ —provide The cancer health care context is unique as a number of medical and allied HCPs are involved in different stages of the cancer care continuum , and have to function as a multidisciplinary team to provide optimal care , 8. FurtThis systematic review is informed by reviews that synthesized literature examining the effectiveness of guideline dissemination and implementation interventions on medical  and alliStudies will be selected according to the criteria outlined below.Peer-reviewed and published experimental  and quasi-experimental  studies will be included in the search. We will exclude cross-sectional, cohort, qualitative only, retrospective, and case studies, as well as any studies without primary data . Unpublished data, abstracts and conference proceedings will also be excluded.Studies examining the dissemination and/or implementation of CPGs among medically qualified  and allied HCPs  who work within the cancer care context will be included. Studies evaluating the introduction of CPGs targeting patients, the general public, or hospital administrators or policymakers (who are not HCPs themselves), without targeting HCPs, will be excluded.Guidelines, clinical guidelines, practice guidelines, guidance, advice, recommendations, expert opinion and consensus statements will be considered under the ‘CPG’ umbrella if the study reports that they were systematically developed . All CPG dissemination and implementation interventions/strategies will be included and classified according to the Mazza taxonomy . The MazWithin each study, separate comparisons will be made for the following: (1) single intervention vs. no-intervention control; (2) single intervention vs. control that receives some intervention; (3) multifaceted intervention vs. no-intervention control; and (4) multifaceted intervention vs. control that receives some intervention.The primary outcome will be an objective measure of HCP behaviour in line with the CPG recommendation . Secondary outcomes will include patient outcomes  resulting from dissemination and use of the CPG by HCPs.There will be no restrictions by length of follow-up of outcomes; however, maintenance of outcomes will be noted in final manuscript.To be included in the review, the dissemination and/or implementation strategies must have been implemented in any cancer setting or context related to cancer care.We will search MEDLINE (OVID interface), EMBASE (OVID interface), PsycINFO (OVID interface), CINAHL, and the Cochrane Controlled Trials Register. The literature search will be limited to the English language (given resources are not available for translation) and human subjects. To exclusively capture studies that were not previously included in last systematic review of the effectiveness of dissemination and implementation strategies for CPGs among medical HCPs , the litA search strategy will be built based on the EPOC Group strategy  and prevLiterature search results will be uploaded to EndNote X7 reference management software. References will be de-duplicated by comparing citation details, such as author names, year of publication, article title, and journal. Two reviewers will independently screen titles and abstracts of the de-duplicated bibliographic records. Full texts of records passing the title and abstract screening level will be retrieved and examined independently by the two reviewers according to the eligibility criteria above. Disagreements at both screening levels will be resolved through discussion. A PRISMA flow chart will outline the study selection process and reasons for exclusions.A data extraction form will be created based on the data collection checklist used for Grimshaw and colleagues’  review; The Cochrane Collaboration tool for assessing the risk of bias  will be The Cochrane Risk of Bias Assessment Tool for Non-Randomized Studies of Interventions  will be Risk of bias will be determined for all studies by one reviewer (RC), and then verified by a second reviewer (JRT). Disagreements will be resolved by discussion.Due to the anticipated heterogeneity in study outcomes and comparator (c.f. ) across A comprehensive review of the effectiveness of CPG dissemination and implementation strategies in the cancer care context does not yet exist in the literature. Previous reviews examining the effectiveness of CPG implementation interventions have either examined medical HCPs  or allie


Improving Bayesian Reasoning: What Works and Why offers more than its editors had bargained for or its title suggests. Many papers offer methodological and conceptual insights that should help readers understand the psychology of Bayesian reasoning as practiced in cognitive science.This edited collection was motivated by an interest in understanding how to improve Bayesian reasoning. In that sense, the book before you is pragmatically and prescriptively oriented. Several of the papers address that challenge and some pick up on the important question of why certain factors work as well as they do. However, The book is comprised of 23 papers by 48 authors. The contributions are ordered by type: 10 original research articles first, followed by three reviews and 10 shorter essays. Foregoing an attempt to summarize each contribution in sufficient detail, let us simply draw out some observations about the collection.This collection extends the base of original research on Bayesian reasoning in many important ways. Several papers offer further empirical evidence of the advantage of using visualized natural frequencies to communicate statistical information. Hoffrage et al.  show thawhere and why by showing that grid representations of natural frequencies facilitate Bayesian reasoning more strongly in medical patients with low numeracy, and that representational effects on reasoning are mediated by metacognitive judgment calibration. Hafenbrädl and Hoffrage (Other contributions identify where facilitative factors have their greatest impact. For instance, Hoffrage et al.  find thaHoffrage  go even Hoffrage  observe uncertain deductions using coherence-based Bayesian metrics such as probabilistic validity. These papers capture the fundamental insight that, even in deduction, most arguments consist of uncertain premises from which uncertain conclusions are drawn.The study of deduction had long been associated with reasoning from certain premises to certain conclusions. Yet Evans et al.  and CruzFinally, the contribution by Douven and Schupbach  is pragmThe articles in this category draw out several dominant themes. First, the debate over natural frequencies vs. nested sets is passé. Although disagreement over the merits of the evolutionary account within which the original natural-frequency arguments were put forth linger, there is wide consensus that natural-frequency formats improve Bayesian performance by clarifying nested-set relations, which confers both representational and computational benefits (Brase and Hill, Second, there has been a move away from the dual-systems account that emphasized System 1 sources of Bayesian error (Barbey and Sloman, Whereas, most papers in this collection focus on Bayesian reasoners' performance, two refocus our attention on Bayesian communication by experts. Navarrete et al.  make us Finally, several papers in this collection take the literature to task. Mandel  and McNaHowever, attention to problems that have a temporal component is not lacking in this collection: Tubau et al.  provide We hope readers will find this book informative, thought provoking, and of practical value.Both authors wrote the manuscript.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.


Significant reductions in the extent of acute injury in the CNS can be achieved by exposure to different preconditioning stimuli, but the duration of the induced protective phenotype is typically short-lasting, and thus is deemed as limiting its clinical applicability. Extending the period over which such adaptive epigenetic changes persist – in effect, expanding conditioning’s “therapeutic window” – would significantly broaden the potential applications of such a treatment approach in patients. The frequency of the conditioning stimulus may hold the key. While transient (1–3 days) protection against CNS ischemic injury is well established preclinically following a single preconditioning stimulus, repetitively presenting preconditioning stimuli extends the duration of ischemic tolerance by many weeks. Moreover, repetitive intermittent postconditioning enhances post-ischemic recovery metrics and improves long-term survival. Intermittent conditioning is also efficacious for preventing or delaying injury in preclinical models of chronic neurodegenerative disease, and for promoting long-lasting functional improvements in a number of other pathologies as well. Although the detailed mechanisms underlying these protracted kinds of neuroplasticity remain largely unstudied, accumulating empirical evidence supports the contention that all of these adaptive phenotypes are epigenetically mediated. Going forward, additional preclinical demonstrations of the ability to induce sustained beneficial phenotypes that reduce the burden of acute and chronic neurodegeneration, and experimental interrogations of the regulatory constructs responsible for these epigenetic responses, will accelerate the identification of not only efficacious but also practical, adaptive epigenetics-based treatments for individuals with neurological disease. It is now widely established that organisms, tissues, and cells respond to sublethal stressors by a transient augmentation in their innate capacity to resist injury. That low doses of a harmful stimulus can promote beneficial responses forms the basis of hormesis theory , but onlSignificant progress has been made in preclinical models that advance our understanding of the molecular and genetic mechanisms underlying ischemic tolerance in the CNS –9. Many Against this backdrop, I explore herein the contention that, as a result of epigenetics-based changes in gene expression, the duration of injury resistance following a stress stimulus can be increased quite significantly based on specific manipulations of the “dose” of the conditioning stimulus. Further interrogation of how best to establish protracted therapeutic windows of innate neuroprotection will provide some of the most valuable opportunities for multiplying the clinical potential of conditioning to prevent and treat both acute and chronic neurological disease.Throughout most of its history at both the bench and in the clinic, the conditioning/tolerance field has evolved based on a fundamental, implicit definition of the very phenomenon we have come to understand: A transient, but robust, reduction in injury from acute ischemia can be realized if the tissue is preconditioned “X” hours prior to the lethal ischemic insult. For the aforementioned delayed phase of conditioning, the words “transient” and “X” in this definition have been understood to be ~8–48 h, essentially bookending the “therapeutic window” for treatment. Similarly, for postconditioning, preclinical protocols typically involve conditioning shortly after the ischemic event, as well as performing relatively early assessments of efficacy based largely on lesion quantification. Few studies have examined whether the duration of tolerance resulting from pre- or post-conditioning can be extended secondary to manipulating the “dose” of the conditioning treatment, or the related possibility that repetitive postconditioning during recovery can not only reduce injury but concomitantly enhance one or more long-term stroke recovery metrics; both of these advances would portend powerful clinical implications. In dose–response parlance, if the goal is to invoke a protracted response or prolonged period of tolerance to a given dose of conditioning, and if the given period of tolerance currently appears time-limited, then a closer examination of the conditioning dose is required to achieve this desired response. This has not really happened in any systematic sense; rather, we were quick to adopt the general assumption that the only type of tolerance is one defined by a short therapeutic window.Every stimulus can be defined by at least three parameters: magnitude, duration, and frequency. Until the advent of postconditioning by instituting cycles of brief ischemia during early reperfusion, the vast majority of preconditioning paradigms for stroke have historically involved a single stimulus  of a specific duration and magnitude that set into motion tolerance-signaling cascades; in the field of myocardial ischemia, repetitive preconditioning treatments have been explored , but notIn fact, stimulus frequency is critical not only for determining the duration of the phenotypic change induced but also for its cumulative ability to promote an adaptive response, in contrast to the potential impotence of a single exposure or the potential injury resulting from multiple exposures combined as one or administered too closely together. Indeed, evidence emerging not only in the field of conditioning but across other dimensions of biology as well indicates that the frequency of the presented stimulus may be the key dose feature with respect to generating a beneficial, adaptive response instead of a harmful, maladaptive response . Exercise represents one example of benefit-inducing repetitive conditioning ; moreoveWith respect to stimulus frequency influencing the duration of the resultant phenotype, examples can be found in the conditioning literature that either strongly hint at such a possibility or support it directly. For example, the therapeutic window for myocardial ischemic tolerance resulting from a single hypoxic challenge was extended significantly if intermittent mild hypoxia is used as the conditioning stimulus , 24. SimDespite the above caveats, because most heart attacks and strokes are unpredictable, the inherent clinical advantage of postconditioning relative to preconditioning still generates considerable translational excitement. Progress might be accelerated if postconditioning protocols move beyond cyclical interruptions of early reperfusion to assessments of the benefits accruing from more protracted, repetitive treatments, and if long-term survival rates and functional metrics of post-stroke recovery become the more standard endpoints. Indeed, in cardiac ischemia, repeated remote postconditioning improved long-term survival relative to both a single preconditioning challenge and to an even lower frequency of repetitive remote postconditioning . IntentiThat distinct patterns of “continuous” but intermittent conditioning treatments provide protracted periods of protection against stroke and other acute neurological disorders implies that the slow and progressive neuronal death that defines neurodegenerative disease might also be significantly impacted by a similar therapeutic strategy. Evidence from the hormesis field that repeated presentations of low-dose stressors extend beneficial, prevention-, and/or recovery-promoting effects in preclinical models of more chronic cardiovascular, immunological, metastatic, and other non-neurological and non-psychological pathologies, as well as in human studies , supportAs alluded to above, the idea that repetitive stress conditioning can trigger and possibly maintain long-lasting phenotypic change in the CNS actually derives strong historical support from the neuropsychology and behavior fields, which provide rich examples of sustained plasticity within and across age groups, and ideal opportunities for considering stress along a negative–positive continuum, with distress anchoring one end and “eustress” anchoring the other . For insThe molecular basis of the many adaptive responses to repeated stress highlighted thus far is predictably complex, given the relative permanence of the resultant phenotype. Many studies have sought to characterize the beneficial phenotypes, finding evidence for increased neurogenesis , changesThe ischemia-tolerant phenotype resulting from a pre- or post-conditioning stimulus is, by definition, an epigenetic response, but only recently have we begun to directly recognize it as such –70. GenoA rapidly evolving subfield of epigenetics extends the aforementioned phenomenon of even life-long phenotypic change within an individual to the transmission of adaptive or maladaptive phenotypes from parents to their offspring. Epigenetic inheritance, or transgenerational epigenetics, provides a mechanistic foundation for Lamarck’s notion that the effects of environment and/or experience could be inherited by, and thus benefit, one’s immediate offspring – known as “soft inheritance” in Lamarck’s day. This phenomenon is not inconsistent with Darwinian evolutionary theory, given the selection pressure inherent in preserving adaptive phenotypic variation if it increases fitness when resources and/or other environmental stress levels change; but it does carry the important implication that random DNA mutations are not the sole driving force of evolution. In transgenerational epigenetics, gene expression is altered, not genetic inheritance; environment becomes heredity. At least in theory, this suggests the possibility of obtaining desired phenotypes in offspring that prevent or reduce disease burden and/or enhance vitality by therapeutically manipulating epigenetic regulatory systems in their parents. Conditioning across generations might seem at first blush to represent an implausible extension of tolerance’s therapeutic window. However, while the vast majority of preclinical studies have focused on the germline linking of adverse or dysfunctional behavioral changes in an individual to life experiences of their parents or grandparents –78, a smDespite the discovery of the robustness of endogenous cytoprotection almost 25 years ago, the thousands of published preclinical successes, and even the dozens of efficacious studies in humans, the time-limited therapeutic window that has inadvertently come to define conditioning-based responses continues to constrain its acceptance as a viable therapeutic strategy, even for acute tissue injury. However, given the accumulating evidence supporting long-lasting, epigenetics-mediated changes in phenotype in the CNS and other tissues secondary to repetitive stress, perhaps it is time to shelf the assumption that conditioning-induced tolerance is “transient,” reevaluate our assumptions about the defining features of tolerance, and in so doing open new doors regarding its full clinical destiny. As scientists and physicians, capturing the ability to leverage sustained, beneficial phenotypic changes capable of providing protracted periods of resilience to acute and chronic neurological injury should be our next collective goal.The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


An important part of male infertility of unknown etiology may be attributed to various environmental and occupational exposures to toxic substances, such as lead. The reproductive effects of lead are complex and appear to involve multiple pathways, not all of which are fully understood. It is still unclear, for example, if male reproductive issues in lead-exposed persons are mostly related to the disruption of reproductive hormones, whether the problems are due to the lead’s direct effects on the gonads, or both? This question has been difficult to answer, because lead, especially at high levels, may adversely affect many human organs. Although lead can potentially reduce male fertility by decreasing sperm count and motility, inducing abnormal morphology and affecting functional parameters; not all studies have been able to clearly demonstrate such findings. In addition, research has shown that the blood-testis barrier can protect testicular cells from direct exposure to high levels of blood lead. For these reasons and considering the wide spectrum of lead toxicity on reproductive hormones, the present review suggests that lead’s main influence on male reproduction probably occurs by altering the reproductive hormonal axis and the hormonal control on spermatogenesis, rather than by a direct toxic effect on the seminiferous tubules of the testes. As blood lead concentrations below the currently accepted worker protection standard may still adversely affect male fertility, future studies should aim to establish more concrete links between lead exposure  and subsequent male infertility. Research should also pay more attention to lead’s effects on reducing male fertility rates based on not only hormonal axis alteration, but also on the changes in sperm characteristic among exposed subjects. Many industrial chemicals are known to have a negative impact on human reproduction -3, parti Experimental animal studies, mainly in rats, have also reported that lead is an active element responsible for male reproductive parameter imbalances , 15. On Because human sperm count, normal morphology and functions appear to be in decline  increasing attention has been paid to male reproductive problems in recent years . On the SpermatogenesisThe most frequent causes of male infertility are associated with spermatogenesis. Because it is relatively easy to conduct, non-invasive and inexpensive to perform, semen analysis  is one of the first laboratory tests commonly performed for infertile couples. Studies on occupationally lead-exposed men have shown multiple sperm parameters being affected as seminal plasma or blood lead concentrations rise, usually at levels of >40μg/dl, but sometimes even at levels of <10μg/dl. For instance, reductions in sperm count and sperm concentration or density , 26, decMany studies on reproductive system of male animals have documented lead as a toxicant for testicular tissue and functions -34 such Macroscopic changes in accessory sex organs such as diminished weight of testes, seminal vesicles, epididymis, and ventral prostate have been demonstrated in various studies using experimental animals , 40. MicSperm functional parametersSuccessful fertilization of an ovum by spermatozoa depends not only on sperm count and morphology but is also relevant to functional parameters. Lead has been shown to incur detectable negative effects on blood, semen and/or spermatozoa quality in workers, such as inducing prolonged liquefaction time and decreasing sperm motility . It has On the other hand, concomitantly, significant improvements in the number of motile sperm has been reported after mean blood lead decreased from 42 µg/dl to 20 µg/dl among the lead factories workers . ReducedTwo studies of mice and one of rats, have shown that there may be a dose-dependent decrease in the number of sperm attaching to ova , reducinHormonal disruptionReproductive hormones play an important and complicated role in the regulation of spermatogenesis and sperm development. The results of experimental studies in rats have shown that the effects of lead involve multiple sites on male reproductive hormones although the most important part of these disorders probably occurs in the hypothalamic-pituitary-testosterone (HPT) axis , 57. ForAnother study on male rats administered lead acetate in water showed a dose-related increase in GnRH mRNA and no effects on the serum concentrations of hypothalamic GnRH or LH, suggesting there may be a compensatory mechanism in the HPT axis . In addiTestosterone, the main male sex hormone, is formed and secreted by Leyding cells in testes in response to stimulation by of LH. Semen lead concentrations at a mean of 2 µg/dl have been reported to be inversely related to serum testosterone among occupationally-exposed men . Suppression of testicular testosterone levels and increasing steroid binding globulin levels related to increased duration of exposure to lead has been also demonstrated among mice exposed to lead for 30 days . The supThese findings suggest that it might involve other hormonal and/or hormonal feedback pathway(s) than disruption of testosterone secretion in the reproductive hormonal axis by lead, such as a lack of reflex in response to plasma testosterone, direct inhibitory androgen biosynthesis in Leydig cells , or defeOn the other hand, due to imbalances in the HPT hormonal axis induced by lead exposure, pituitary cells release inappropriate levels of LH and change the steroid negative feedback loop , usuallyOn the other hand, inappropriate inhibin B overproduction in excessively lead exposed subjects may be induced by a Cell of Sertoli dysfunction, which suggests spermatogenesis impairment . On the Mechanisms of lead reproductive toxicityReactive Oxygen Species (ROS), an issue which has been paid more attention recently. ROS inhibits the production of sulfhydryl antioxidants, inhibits enzyme reactions, damages nucleic acids and inhibits DNA repair, as well as initiating lipid peroxidation in cellular membranes. Lead induces oxidative stress and promotes the generation of hydrogen peroxide  as they may still adversely affect male fertility . As such, occupational health surveillance must continue to include the assessment of adverse effects on the reproductive system of lead-exposed workers, particularly those with significant environmental exposures. Because laboratory findings cannot definitively ascertain fertility status, this review suggests that future studies should aim to establish more concrete links between lead’s effects on reproductive dysfunctions and reduced fertility rates; not only changes in hormonal or sperm characteristics among lead-exposed subjects.


In Europe, there is evidence of the effect of the global financial crisis and austerity measures on vulnerable people’s health: increasing risky health behaviours, difficulties accessing health care and poorer mental, maternal and child health.Europe has a substantial burden of infectious diseases in vulnerable groups with social and economic disadvantages. In the past two decades this region has received more than 3.5 million Latin American immigrants, with a predominance of young-to-middle aged women, many of whom are undocumented.Chagas disease transmission through congenital and unscreened blood and organ donations has been identified in several European countries. Italy and Spain, two countries severely hit by the economic crisis, host the largest Latin American communities at risk and have reported the highest number of Chagas cases.Despite evidence of the economic and health benefits of introducing targeted screening and treatment strategies among risk groups, Chagas disease-related health needs remain largely unmet in Europe. It is estimated that 90% of infected persons living in Europe have yet to be identified.Europe’s current economic crisis and subsequent austerity measures have been significantly affecting the management of Chagas disease. Since 2008, several European countries have been cutting health and social services for vulnerable immigrants. Spain, for example, issued a Royal Decree in 2012 severely restricting access to preventive and primary health care for undocumented immigrants.As a result of the decreasing economic opportunities in the countries most affected – notably Italy, Portugal and Spain – immigrants have been moving to other European countries or going back to their countries of origin.While most infected immigrants initially lived in Spain – where effective responses to Chagas disease have been developed over the last decade – some immigrants have recently moved to other European countries, with few or no Chagas-disease programmes, thus raising the likelihood of further transmission.Therefore, there is a need for European countries to implement evidence-based public health and clinical interventions to optimize Chagas-disease management and control in Europe in the context of current migration patterns.The community at highest risk is that of the Bolivians who accounted for the majority of the 4290 cases identified in Europe up to 2009.While developing specialized vertical Chagas-disease programmes might entail major financial and organizational constraints, integrating them into existing primary health care programmes targeting immigrants is likely to be the most effective strategy.Improving awareness, ensuring that diagnostic facilities are available and developing capacities to orientate patients towards the best treatment options within such settings (including paediatric and gynaecology and obstetrics facilities) would help identify cases early and reduce the risk of transmission.Primary care represents the optimal setting for providing an effective and global approach to the whole family. Close collaboration between primary and specialized care services has proven beneficial for fostering the optimal conditions to provide treatment in the safest conditions.Chagas-disease patients frequently present concomitant noncommunicable diseases, requiring regular contact with primary-care services, highlighting the need for comprehensive, primary care-based patient management.Strong coordination and effective communication between health institutions providing services for immigrants across Europe would allow for better continuity of care as immigrants move. Benefits include reducing the risk of loss to follow-up of newborns undergoing the months-long multi-stage diagnostic procedure to identify congenital transmission from infected mothers and improving the post-treatment clinical follow-up of all cases.http://www.findechagas.com), they have been effective in raising awareness, spreading information and facilitating contacts between communities and health systems in areas with Chagas disease burden. Strengthening community-based intervention with the support of immigrants’ organizations may therefore harness benefits in terms of effectiveness of screening and transmission-control programmes in communities that are often hard to reach.Chagas disease is deeply embedded in social, economic and cultural factors, which also affect immigrant communities’ health behaviour. Immigrants might not engage with programmes for different reasons. These could include lack of awareness, fear of stigma and deportation, or negative messages about the disease. In recent years, organizations of Chagas-disease patients have sprung up in Latin America, North America and Europe. As a part of the international federation of associations of people affected by Chagas disease , a single or a limited number of reference centres would be sufficient to process all samples at little extra cost.Economic factors may reduce public health and clinical capacities to address Chagas disease and increase immigrants’ vulnerability. However, the experience gained during the past decade in Europe in Chagas disease management can be used to design optimal control strategies in newly-affected countries.


Emotion and Aging: Evidence from Brain and Behavior takes a step into uncovering emotional aging considering both brain and behavioral processes. The contributions featured in this issue adopt innovative theoretical perspectives and use novel methodological approaches to target a variety of topics that can be categorized into three overarching questions: How do cognition and emotion interact in aging in brain and behavior? What are behavioral and brain-related moderators of emotional aging? Does emotion-regulatory success as reflected in brain and behavior change with age? In this perspective paper we discuss theoretical innovation, methodological approach, and scientific advancement of the 13 papers in the context of the broader literature on emotional aging. We conclude by reflecting on topics untouched and future directions to take.Emotions play a central role in every human life from the moment we are born until we die. They prepare the body for action, highlight what should be noticed and remembered, and guide decisions and actions. As emotions are central to daily functioning, it is important to understand how aging affects perception, memory, experience, as well as regulation of emotions. The Frontiers research topic  Emotions play a central role throughout human life. They highlight what is important and guide actions. As emotions are central to daily functioning, it is important to understand how aging affects them. An early scientific view argued that aging led to a deterioration of emotional function. This theory, represented by Carl Jung, claimed that old age is a period in life when people feel emotional sameness and the aging emotional landscape was described as bleached and barren. However, current psychological research shows that emotion is relatively unaffected by aging or even improves with age, in contrast to most cognitive functions . For exaHow do cognition and emotion interact in aging in brain and behavior? (2) What are behavioral and brain-related moderators of emotional aging? (3) Does emotion-regulatory success as reflected in brain and behavior change with age? Within those overarching questions, different emotion-related phenomena  will be addressed.The current Frontiers research topic takes a step into this direction. It comprises novel theoretical and methodological approaches and presents exciting new findings. The contributions evolve around three broader questions that have only recently received attention in the literature on emotional aging and answers to which will inform affective science research: (1) In the following, we will summarize the contributions. We will illustrate how they increase scientific understanding of emotional aging. In particular, we will emphasize how adoption of diverse theoretical and methodological approaches allow for a multi-faceted study of emotional aging and we will lay out how adopting an aging brain-behavior prespective increases understanding of cognition–emotion interactions, moderators of emotion processing, and emotion-regulatory success. We will conclude by raising topics not yet covered for exploration in future research.The research topic presents novel theoretical perspectives on emotional aging. Two of these are featured in perspective papers as summarized next. Other approaches are embedded in the context of the empirical paper contributions and integrated in the discussion below.Complementing lifespan theories of developmental regulation that define negative affect and positive affect broadly e.g., , KunzmanThe ability to read facial emotions in others declines with age . FölsterThis issue is characterized by a wide selection of methodological approaches, reflecting the complexity of the emotional aging phenomenon. Employed approaches are experience sampling , subjectA growing number of studies are targeting cognition–emotion interactions. The majority of these studies examine behavioral age-related change . Still lIn Emotional content of information should affect working memory pronouncedly in older adults, given increased emotion orientation  and presIn Mechanisms underlying age deficits in the ability to read emotions in others are not well understood yet. The literature discusses age-related change in visual processing, brain structure and function, hormones, and neurotransmitters as possible explanations . RecentlIn response to critique that the majority of studies on emotion perception use photographs of prototypic facial expressions  and examPeople show similar facial expressions in disparate situations. Parkinson’s disease is associated with reduced emotional expressivity . In a clEmotion regulation refers to promotion of helpful emotions while managing harmful emotions . ApproprLow-arousing negative stimuli engage controlled processes , while hSuccessful cognitive reappraisal recruits brain areas involved in working memory  and is mThe work discussed in this perspective paper provides novel insights into the study of emotional aging, providing responses to pressing research questions. However, various topics remain untouched, offering opportunities for exciting future research moving forward in this domain of inquiry. All articles in this issue adopted a cross-sectional approach. Longitudinal, lifespan research will allow examination of gradual quantitative and qualitative emotional change over the life-cycle, allowing to draw a comprehensive picture of emotional development. With one exception , all papThe 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.