Anaxyrus houstonensis). NIR spectra (N = 396) were collected from live A. houstonensis individuals (N = 132), and distinct spectral patterns between males and females were identified using chemometrics. Linear discriminant analysis (PCA-LDA) classified the spectra from each biological sex with accuracy ≥ 98% in the calibration and internal validation datasets and 94% in the external validation process. Through the use of NIRS, we have determined that unique spectral signatures can be holistically captured in the skin of male and female anurans, bringing to light the possibility of further application of this technique for juveniles and sexually monomorphic species, whose sex designation is important for breeding-related decisions.Biological sex is one of the more critically important physiological parameters needed for managing threatened animal species because it is crucial for informing several of the management decisions surrounding conservation breeding programs. Near-infrared spectroscopy (NIRS) is a non-invasive technology that has been recently applied in the field of wildlife science to evaluate various aspects of animal physiology and may have potential as an in vivo technique for determining biological sex in live amphibian species. This study investigated whether NIRS could be used as a rapid and non-invasive method for discriminating biological sex in the endangered Houston toad ( Amphibians are the most threatened group of vertebrate taxa, with over 40% of species showing dramatic population declines and well over 100 species having gone extinct in the last several decades ,3. The pSex identification is critical for informing management decisions surrounding captive breeding programs, such as breeding pair selection, maintenance of an appropriate sex ratio, avoidance of inbreeding among tank mates, management and transfer of juveniles for the purpose of optimizing genetic diversity, and informing practitioners on what reproductive technologies should be applied for propagating the species of interest. For example, the reproductive hormone regimens  used to induce spermiation in males and ovulation in females are often sex-specific and should therefore be tailored to the individual’s sex ,9,10. HoLithobates sevosus), white-bellied frogs , orange-bellied frogs, (Geocrinia vitellina), and Maud Island frogs (Leiopelma pakeka) has previously been determined through the assessment of testosterone and estrone ratios via urinary and fecal hormone analyses [While some methods for determining the biological sex of monomorphic species and juveniles have been developed, most of these technologies are costly, labor-intensive, and/or limited in their application. For example, the biological sex of dusky gopher frogs  is a portable, non-destructive, biophotonic tool that functions by measuring the biochemical properties of a given sample. When light energy is applied to a sample, the chemical bonds vibrate at specific wavelengths and frequencies that are characteristic of the chemical constituents comprising the tested material . NIRS meThe porous nature of amphibian skin allows for the direct application of NIRS technologies in vivo . The skiAnaxyrus houstonensis) is an endangered anuran species endemic to the plains of Central Texas [A. houstonensis exhibits marked dimorphism during the breeding season, making it possible to assign biological sex to individuals. Males are easily identifiable as they possess nuptial pads and black throat sacs, and produce distinct mating calls during the breeding season, signaled by increased precipitation in the early spring months [A. houstonensis may serve as a model of known dimorphism to provide a ‘proof of principle’ for NIRS analysis to discriminate sex in a living animal system. Although these sex-specific traits are present both during and outside the breeding months for A. houstonensis adults, such traits may be less pronounced or absent in individuals until they reach sexual maturity [The Houston toad  in excess during the breeding season . NIRS, aA. houstonensis individuals from the Fort Worth Zoo  were selected for this study based on the age and visual assessment of male phenotypic characteristics  or presence of eggs in females, which was identified through ultrasound imaging [A. houstonensis were housed in 18” × 26” × 15” containers with up to four same-sex adults in each group. Each enclosure was illuminated with a 10.0 Reptibulb UVB light and placed on a slight incline to create a land–water environment, where a hide box with sphagnum moss comprised the dry side and water was allowed to pool at the bottom. Enclosures were flushed daily with reconstituted reverse osmosis water and cleaned weekly. A. houstonensis were seasonally conditioned to promote natural hibernation behavior from October to January by gradually lowering the temperature from room temperature to 13 °C. For the rest of the year, the toads were kept at 28 °C. Sexually mature  imaging . Experim®) reference spectrum was captured between each individual. NIR reflectance spectra (λ = 350–2500 nm) were collected from adult females  and males  using a portable spectrophotometer, the ASD FieldSpec® 3 Indico®Pro , and a 2 cm diameter low-powered plant contact probe. Live individuals had their ventral sides blotted dry with a sterile Kimwipe™, and spectral data were collected in triplicate for each individual by placing the contact probe on the abdomen, superior to the cloaca . Mathematical pretreatments of Standard Normal Variate (SNV), linear de-trending, and first derivative Savitzky–Golay  were applied to the spectral database prior to principal component analysis (PCA) and linear discriminant analysis (PCA-LDA).To develop the prediction models, a balanced dataset with equal numbers of spectra from males and females was created by randomly sorting spectra into an 80:20 calibration/validation distribution  to test for mathematical pre-processing and avoid modeling bias. Chemometrics was applied to the near-infrared range of 700–2000 nm using the program UnscramblerPCA was utilized to visualize the trends and outliers present in the spectral database. PCA on the mean-centered matrix was obtained by full (leave-one-out) cross-validation and algorithm-singular value decomposition (SVD). PCA was applied before the LDA to reduce the dimensionality of the spectral database. The PCA-LDA model using the Mahalanobis method was generated with the top-down approach for PC selection. The results from the PCA-LDA calibration are reported in the confusion matrix, and the percent (%) accuracy was calculated to evaluate its performance. The generated PCA-LDA model was tested on the internal validation set and an external validation set containing 36 females and 6 males. Females were assessed by ultrasound immediately after the NIR spectral data were collected, and ultrasound grades were also incorporated post hoc in the PCA scores plot to evaluate females of varying reproductive states with consideration of male scores. Ultrasound data were collected for each female using a 0–5 grading scale adapted from Graham et al. , where 0Upon inspection of the raw and transformed spectral data, visually distinct patterns differentiating males and females were observed . Major d2 influence plot generated by the PCA indicated that no outliers were present in the spectral dataset. The PCA scores plot A revealePost-hoc examination of the PCA scores plot, including ultrasound grades, indicated that the spectra of females exhibiting low ultrasound grades  were clustered within the positive quadrant of PC-2, while females exhibiting high ultrasound grades  were present across both the positive and negative quadrants of PC-2. Furthermore, four out of 36 females in the external validation dataset were misclassified as males, with two of these individuals being non-gravid females and the other two being gravid females. A. houstonensis were accurately classified in 99.1 ± 0.0%, 98.1 ± 2.6%, and 94.0 ± 8.5% of the calibration, internal validation, and external validation datasets, respectively. The high percentage of classification between both sexes was also observed in the PCA-LDA plot  were clustered in close proximity to spectra from males, which may have contributed to their misclassification as males in the validation process; overall, we observed that non-gravid females were more likely to be classified as males compared to gravid females, indicating that males and non-gravid females are less dissimilar than males and gravid females. Altogether, these data reveal that not only do male and female A. houstonensis differ with regard to their chemical profiles, but females of varying follicular developmental stages also appear distinguishable from one another, such that females trend further away from males in their chemical spectra as they progress in follicular state. The ability of NIRS to accurately detect biochemical differences between sexes as well as in females with varying degrees of gravidity provides novel insight into their underlying reproductive state. Previous research in mammal species, including red deer (Cervus elaphus), fallow deer (Dama dama), giant pandas (Ailuropoda melanoleuca), alpacas (Lama pacos), and several livestock species, has also demonstrated the utility of NIRS as an analytical technique to assist in the management decisions surrounding breeding programs [The PCA-LDA prediction model successfully classified programs ,37,38,39Eurycea cirrigera, Burger, pers comm). Additionally, exogenous hormone-induced gametogenesis is useful for determining biological sex, but it can only be applied to sexually mature individuals and has the potential to result in nonresponders [Although biological sex identification is possible through the observance of sex-specific morphological traits and breeding behaviors in many adult amphibian species, such traits may be absent or imperceptible in sexually monomorphic species, immature juveniles, small animals, and individuals outside of the mating season . As opposponders  , 100% in tiger salamanders (Ambystoma tigrinum), and 92.7% in giant Chinese salamanders (Andrias davidianus) for the external validation process [Lithobates sevosa) [Anaxyrus fowleri), and 97.5% in Colorado boreal toads (Anaxyrus boreas) [Preliminary results from our lab demonstrating NIRS as a novel method to discriminate sex in amphibians have thus far been evaluated in a limited number of caudate and anuran species ,31,43. F sevosa) , 98.4% i boreas) . Althoug boreas) ,45. It iLeiopelma pakeka) and hellbender salamanders , exhibit no reliable indicators of sexual dimorphism prior to sexual maturity, which may take several years to reach and even then may only be expressed during their respective mating seasons [Future research should investigate whether NIRS can be used on more species as a sex-discriminatory tool, especially for monomorphic amphibian species, immature individuals, and individuals outside of the breeding season who do not exhibit sex-specific traits. For example, numerous amphibians, such as leiopelmatid frogs  or for evaluating the sexual maturation of females. Considering that amphibians represent the most threatened class of vertebrates, methods to detect and assess crucial physiological information are needed to effectively inform the management decisions concerning at-risk populations. As NIRS is a non-invasive, cost-effective tool capable of generating a robust throughput of chemical information, it may benefit wildlife conservation managers to partner with experts in specific management situations where knowledge of physiological factors  is needed to make reliable, on-the-ground decisions.


Ocular allergy is a localised form of allergy occurring on the surface of the eye and surrounding tissues. Typical signs and symptoms of ocular allergy include itching, redness, swelling of the eyelids and inflammation. Emerging studies on ocular allergy have shown that tears collected from ocular allergy sufferers show significantly different protein contents than in healthy populations. Differences in protein contents in tear samples have been hypothesised to be caused by a number of allergy-mediated factors, including long-term inflammation and eye-rubbing. Excessive eye-rubbing due to allergy-associated itch has also been shown to have significant effects on the physical shape of the eye, thereby potentially causing progressive vision problems in ocular allergy sufferers. This review aims to summarise and explore recent findings in ocular allergy protein research. This is to help determine which ocular surface proteins differ between ocular allergy sufferers and healthy controls, and the role each protein may play in the underlying chemistry of ocular allergy. Additionally, potential benefits of expanding the current pool of research into ocular surface proteins in ocular allergy sufferers in terms of diagnosis and treatment of the condition is discussed.Ocular allergy is an immunoglobulin E-mediated Type I hypersensitivity reaction localised to the ocular surface and surrounding tissues. Primary signs and symptoms of ocular allergy include itching, redness, irritation and inflammation. Eye-rubbing caused by itching has been shown to alter ocular surface protein concentrations in conditions linked to ocular allergy such as keratoconus. In keratoconus, the cornea begins to thin and sag over time, leading to progressive vision loss and blindness in severe conditions. Due to the high incidence of ocular allergy sufferers rubbing their eyes in response to symptoms of itching, the protein landscape of the ocular surface may be significantly altered. Differential protein expression caused by long-term inflammation and eye-rubbing may lead to subsequent changes in ocular surface structure and function over time. This review aims to summarise and explore the findings of current ocular allergy proteome research conducted using techniques such as gel electrophoresis, mass spectrometry and lab-on-a-chip proteomics. Proteins of interest for this review include differentially expressed immunoglobulins, mucins, functional proteins, enzymes and proteins with previously uncharacterised roles in ocular allergy. Additionally, potential applications of this research are addressed in terms of diagnostics, drug development and future research prospects. The current proteomic landscape of the ocular surface in ocular allergy outlines a compelling narrative, potentially linking ocular allergy to increased concentrations of inflammatory and immune defence proteins compared to normal ocular surface conditions. Ocular allergy is a localised subset of immunoglobulin E (IgE)-mediated allergy (Type I hypersensitivity), whereby specific IgE antibodies are raised against allergic molecules from sources such as pollen, animal dander and fungal spores, upon initial exposure ,2. When When considering the full scope of signs and symptoms experienced by ocular allergy sufferers, a clear pattern emerges of prolonged itchiness and inflammation due to the allergy-induced release of histamine, leading to excessive eye-rubbing . If expep = 0.001) [p-values for relationship between ocular symptoms and poor sleep were significant in two categories pertaining to sleep problems , sleep disturbance (p = 0.19), sleep shortness of breath or with headache (p = 0.19) and sleep somnolence (p = 0.15) [The impacts of ocular allergy on daily quality of life have been thoroughly researched in recent years. Namely, a study by Stull et al. in 2009 outlined the significance of ocular allergy on daily life . Patient= 0.001) . Similar= 0.001) ,9. The s= 0.001) . The p-v = 0.15) . Additio = 0.15) ,11. In o = 0.15) ,12. An aBiomarkers are proteomic, genetic or lipidomic characteristics unique to and indicative of a particular biochemical process or pathological pathway . ClinicaResearch into lipid and gene biomarkers of ocular allergy has been previously limited due to lack of sufficient analytical techniques, however protein biomarkers have emerged as an exciting and promising new field of research in recent years ,19,20,21Human tears are a compelling sample type as they are a great source of proteins collected directly from the ocular surface using non-invasive techniques . Human tHuman tear samples gathered by microcapillary collection should be limited to volumes below 60 μL, as greater volumes have been associated with excessive watering, potentially due to introduced ocular stress . TypicalProteins extracted from human tear samples have traditionally been quantified using a combination of different methods reliant on the goals of the study. Methods such as SDS-PAGE are often coupled with MS to identify protein contents from within trypsin-digested gel segments with high accuracy. The placement of protein bands within a sample can be used to identify protein constituents and show if sample degradation has occurred . SDS-PAGMS is a far more advanced method, capable of identifying proteins within a sample to increasing specificity and accuracy as high throughput technology develops over time; as a result of these technological advancements, progressively lower sample volumes are required for MS analysis, with some recent publications using volumes as low as 5 μL to identify protein contents of tear samples from healthy participants . 2: 0.81 ± 0.17) [The specificity and accuracy of MS proteome analysis has greatly increased over the last 16 years. MS analysis of tear samples in subjects with no ocular conditions occurred as early as 2005, with a paper written by Li et al. citing the identification of 54 proteins in the tears of one individual . Just 7  ± 0.17) . This pr ± 0.17) . This pr ± 0.17) . As timeThe use of LC–MS has also been documented in a 2017 paper on comparative protein analysis between healthy controls, dry eye sufferers and meibomian-gland dysfunction sufferers . This stAn emerging “lab-on-a-chip” automated electrophoresis technology (AET) has also recently gained popularity in ocular allergy tear analysis studies despite primarily being used with other sample types such as blood, sputum and buccal cells ,36,37,38Multiple recent proteomic studies using human tears have carried out analysis with the AET due to the speed, reproducibility and accuracy of this assay ,39,40,41A number of tear proteome studies on keratoconus patients have uncovered a pattern of irregular protein expression occurring on the ocular surface. Proteins of altered expression in keratoconus may have roles in surface tension stabilisation, pro-secretion and mitogenesis, or antimicrobial activity or be merely involved in cellular infrastructure ,43,44,45There does not appear to be much consistency in terms of increased or decreased expression of proteins in ocular allergy sufferers compared to healthy subjects. This is perhaps because current ocular allergy tear proteomics research is limited as the field is still relatively new. Baseline protein characterisations have only just begun to be developed with a consistent methodology and significant sample size. Lack of comparative values and standardised techniques reduce the validity of findings pertaining to specific ocular surface conditions, and thus additional healthy participant studies must be carried out prior to commencing ocular allergy research.Three of the proteins shown in Limited available studies in ocular allergy have identified a number of potential diagnostic biomarkers and drug targets in human tears. Proteins such as lactoferrin and IgA were reportedly increased in ocular allergy , as wereThe antigen–antibody complex forms by binding of allergens to IgE on mast cell surfaces, which triggers mast cell activation and then tryptase is released via degranulation . A 2018 Other potential contributing factors to protein expression inconsistencies between ocular allergy studies on ocular allergy sufferers compared to healthy controls shown in Other allergy-associated mediators are granule molecules released by mast cells that directly stimulate inflammation, redness and irritation on the ocular surface ,80,81. TO-glycosylation. This mesh of O-glycoproteins not only protect mucins from proteolytic enzymes, but are also responsible for their rigid, extended conformation [Mucins are high molecular weight, heavily glycosylated proteins that are the major macromolecular constituents of the mucus layer of all the major tracts of the human body, including the ocular surface . Mucin pormation . As thesMucins are classified into two categories, based on their location relative to the cell surface—secreted mucins are entirely extracellular as they are secreted by mucus-producing secretory cells and cell-surface  mucins that are anchored to the cell via a transmembrane domain ,84,85,86The normal regulatory tear film in healthy subjects may be affected by individual characteristics such as age and sex. Sex-linked differences in ocular surface composition have not been well documented in ocular allergy, however, have been noted in healthy participants . Sex-assAge has been shown to be an extraneous variable in protein expression on the ocular surface; it has been previously reported that the protein eotaxin increases with age . ExpressBiomarkers such as proteins and mucins expressed on the ocular surface can be used to update modern therapeutics for ocular allergy. Characterisation of protein and mucin biomarkers of ocular allergy may allow for clinical diagnosis of ‘at-risk’ patients and thus the implementation of earlier intervention strategies. Early intervention will lead to reduced symptoms of itchiness and thus less frequent rubbing of eyes, in turn protecting the cornea from long-term irreversible damage. Current therapeutics for ocular allergy include antihistamines, eosinophil inhibitors, mast-cell stabilisers and nasal corticosteroids for those individuals who seek symptomatic relief in a timely manner. However, those who avoid seeking medical attention may pursue instant relief, alleviating the most common symptom of itch by rubbing their eyes. The initial relief caused by eye rubbing may delay treatment even further, however, as it may lead to increased mechanical stress, and therefore upregulated reactionary protein expression. This perpetuates the symptom cycle on the ocular surface. The true impacts of eye-rubbing on the ocular surface have not yet been researched at the molecular, genetic or cellular level, despite being linked to cornea-altering conditions such as keratoconus . AllergyEmerging sales trends of OTC pharmaceutical drugs used to symptomatically treat allergy expose a pattern of unmonitored self-treatment of common allergic conditions such as allergic rhinitis (hay fever) and ocular allergy—thus presenting an attempt by patients to take control and improve upon a reduced quality of life with OTC drugs. Australian cumulative wholesale costs of OTC anti-allergic drugs has more than doubled from 1991 to 2010, showing an increase from $108 million annually to $226 million . These OAdditionally, patients may be over-exposing their eyes to treatments or preservatives found in some of these eye drops that could be harmful if used in excess or not according to directions. It is thereby pertinent that large-scale proteomics studies of human tears be conducted to provide a comparative standard for investigating the potential irritation caused by unmonitored treatments. Biomarker research may also characterise new drug targets that directly implicate ocular allergy biopathways, thus preventing symptom presentation on the ocular surface altogether.A combination of clinical screening measures such as questionnaires, physical ocular surface assessments and biochemical tests would be the most effective way to treat the individual. Underutilised and post-symptomatic diagnostic methods for ocular allergy may lead to treatments being implemented too late, therefore greatly impacting the daily quality of life of sufferers. Early detection using biochemical and clinical methods in conjunction would therefore lead to fewer downstream adverse effects of eye-rubbing on the cornea. Symptoms may gradually worsen without appropriate management, as research has shown that OTC medications may cause patients to develop an increasing tolerance that decreases drug efficacy in the long-term . In orde


Septic shock is a medical emergency that represents one of the most important underlying causes for presentation to the Emergency Department. Sepsis is defined as organ dysfunction, life-threatening event caused by a deregulated inflammatory host response to infection, with a mortality risk ranging from 10 to 40%. Early sepsis identification is the cornerstone of management and diagnostic imaging can play a pivotal role in this clinical context. The choice of imaging modality depends on several factors, associated with the clinical condition and the presence or absence of localising signs and symptoms. The diagnostic accuracy of contrast-enhanced total-body CT has been well established during septic shock, allowing for a rapid, panoramic, and detailed study of multiple body areas, simultaneously. The aim of this article is to illustrate the controversial CT hypoperfusion complex in patients with septic shock, characterised by the following imaging features: decreased enhancement of the viscera; increased mucosal enhancement; luminal dilation of the small bowel; mural thickening and fluid-filled loops of the small bowel; the halo sign and flattening of the inferior vena cava; reduced aortic diameter; peripancreatic oedema; abnormal parenchymal perfusion; and other controversial findings that are variably associated with each other and reversible during the early stages. Increasing physicians’ awareness of the significance of these findings could prompt alternative approaches to the early assessment and management of septic shock. In this perspective, CT imaging represents a useful tool for a complete, rapid and detailed diagnosis of clinically suspected septic shock, which can be used to improve patient outcomes. Sepsis is a life-threatening event with a mortality risk ranging from 10 to 40%.Early patient recognition is a cornerstone of sepsis management.Total-body CT imaging plays a pivotal role in septic shock condition.CT hypoperfusion complex recognition may facilitate early diagnosis improving treatment planning in septic shock patients. Septic shock qualifies as a medical emergency and represents one of the most important causes for presentation to the Emergency Department (ED). Sepsis refers to life-threatening organ dysfunction caused by a deregulated host response to infection –4. AccorEscherichia coli, Klebsiella pneumoniae, Enterobacter spp., Acinetobacter baumannii, and Pseudomonas aeruginosa) or nosocomial gram-positive cocci (Staphylococcus aureus and coagulase-negative Staphylococcus) cocci, and septic shock most often occurs in immunocompromised patients and in those with chronic and debilitating diseases. Antimicrobial-resistant bacteria, such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci, are often detected in septic patients with nosocomial infections. Invasive candidiasis and other uncommon pathogens should be considered in particular conditions, such as in neutropenic patients .Fig.Fig23].FParenchymal signs include abnormal pancreatic enhancement, associated with peripancreatic fluid, the hypoperfusion of the spleen and liver and the abnormal perfusion of the adrenal glands, kidneys and thyroid.Shock pancreas appears as an abnormal, post-contrast attenuation, with higher than normal density values (20 HU greater than the liver and spleen) and the presence of peripancreatic low-density fluid (< 20 HU), often in combination with mesenteric and other retroperitoneal fluid collections, at an incidence rate of up to 44% Figs. . This phThe spleen is among the most vulnerable abdominal organs to hypotensive shock and often shows extremely decreased enhancement in early-phase CT Figs. c–d. The Hepatic enhancement is typically heterogeneous during hypotensive shock complex. A reduction in hepatic enhancement (25 HU less than the spleen) is thought to be significant due to oedema Fig. c 23]. T. T23]. TAbnormal renal perfusion typically manifests as an increased and prolonged parenchymal enhancement Fig. ; howeverThe bilateral hyperenhancement of the adrenal gland is more common in paediatric cases than in adults and can also present in combination with acute adrenal haemorrhage, which most commonly affects the right side unilaterally, with a homogeneous increase in the size of the gland and the associated suffusion of fat around the adrenal gland Figs. a, 9. BilThe thyroid gland, in the absence of direct damage, presents an increase sized, heterogeneous contrast hyperenhancement, similar to a multinodular gland, with the presence of low-density fluid surrounding the thyroid (5–10 HU) Fig. . ThyroidThe presence of ascites correlates with multiorgan dysfunction and is a non-specific sign .In previously published studies, CT hypoperfusion complex has been almost exclusively focused on trauma-induced hypotensive shock and only few studies correlated these signs with prognosis. Some studies have suggested that flattering of IVC, shock bowel, impaired renal enhancement and splenic hypoperfusion are the most suggestive signs of hypoperfusion complex, strongly correlated with a poor prognosis although in a series of trauma-related hypovolemic shock –26, 31.


Hybrid magnetic resonance (MR)-Linac systems have recently been introduced into clinical practice. The systems allow online adaption of the treatment plan with the aim of compensating for interfractional anatomical changes. The aim of this study was to evaluate the dose volume histogram (DVH)-based dosimetric benefits of online adaptive MR-guided radiotherapy (oMRgRT) across different tumor entities and to investigate which subgroup of plans improved the most from adaption.Fifty patients treated with oMRgRT for five different tumor entities  were included in this retrospective analysis. Various target volume  and organs at risk (OAR) related DVH parameters were compared between the dose distributions before and after plan adaption.98%) were found for the liver , lung , and abdominal lymph nodes  subgroups. Regarding OAR sparing, the largest median OAR dose reduction during plan adaption was found for the pancreas subgroup (-87.0%). However, in the pancreas subgroup an optimal GTV coverage was not always achieved because sparing of OARs was prioritized.All subgroups clearly benefited from online plan adaption in terms of improved PTV coverage. For the liver, lung and abdominal lymph nodes cases, a consistent improvement in GTV coverage was found, while many fractions of the prostate subgroup showed acceptable CTV coverage even before plan adaption. The largest median improvements in GTV near-minimum dose (DWith online plan adaptation, it was possible to achieve significant improvements in target volume coverage and OAR sparing for various tumor entities and account for interfractional anatomical changes. Various inter- and intra-fractional anatomical changes in patient anatomy pose a major challenge for the safe and successful treatment application in modern ablative image-guided radiotherapy (RT). Typical examples of such changes in patient geometry are different organ fillings of bladder, stomach or rectum, breathing-related motion, peristalsis, cardiac motion, tumor response (shrinkage), or organ and patient weight changes . NumerouThese types of anatomical changes occur on various time-scales, ranging from seconds to weeks, and can potentially be accounted for via tumor-tracking or gating techniques and plan adaption strategies . AlthougOverall, 50 patients treated between 01/2020 and 11/2021 were included in this retrospective analysis. All patients were treated for one out of five different tumor entities, which are typical indications for oMRgRT . Ten patients per entity were randomly selected from all patients of the respective subgroups, who successfully completed their RT treatment in the given period. Table The mean percentage of adapted fractions per patient was 86% (range 15% to 100%) and 79% of all fractions were adapted in total. Table The oMRgRT workflow was similar to that described by Bohoudi et al. . For iniFor tumor tracking via a 2D bSSFP cine MRI sequence, the tracking structure was propagated onto a 2D cine MRI slice and a gating ROI was created by expansion of the tracking structure. These structures were subsequently used for online beam gating. All patients in which the target volume showed a breathing-related motion were treated using a breath-hold technique (mostly deep inspiration breath hold). However, patients treated with a free breathing approach  were also treated using the automated gating function in order to ensure that the target was positioned within tolerance boundaries during treatment application.All baseline plans were validated dosimetrically with an ionization chamber and/or diode detector array  prior to the first fraction.98% = near minimum dose, PTV D95%, PTV D50% = median dose, PTV D2% = near maximum dose) and the mean PTV dose (PTV Dmean). All parameters were also reported for the GTV. In prostate cases, the CTV was reported, as no GTV was defined. Furthermore, the volume of the PTV (VPTV) was extracted. Out of usually multiple, patient-specific OAR constraints prescribed in the TPS, three OAR constraints were chosen for OARs, which were closest to the PTV and as a result received the highest maximum dose values. Only OAR constraints were chosen, which were related to structures that were updated . The individual OAR dose constraints (near maximum dose or dose-to-volume constraints) depend on the dose prescription and the individual case and were defined by a senior physician based on the applicable guidelines.Several dose volume histogram (DVH) parameters were extracted from the TPS for the predicted (non-adapted) and re-optimized scenarios for all fractions: the dose to 98%, 95%, 50% and 2% of the volume of the PTV , the number of segments, the number of Monitor Units (MU) and the number of beams were read out from treatment plan documentation files Table ; ResultsFirst the OAR related DVH parameters for the predicted and re-optimized doses of each adapted fraction were compared.98% and D95% dose values were normalized to the prescribed dose (PD) for non-homogenous stereotactic prescriptions (65% or 80% prescription isodose PI) or 0.95 × PD for homogenous prescriptions (95% PI). The D50% and Dmean dose values were normalized to the PD. The D2% was normalized to PD/PI (thus PD/0.8 for a prescription to the 80% isodose) for stereotactic prescriptions or to PD for homogenous prescriptions. Since all normalization factors depend solely on the planning aim for the PTV, these factors may differ between patients but the same factors are applied to all fractions of a single patient. The dose normalization was done to achieve comparable data for the generation of analysis figures. Statistical analysis or the calculation of percent changes of dose values is not affected by this normalization. Statistical analysis of the DVH-based parameters was performed via paired Wilcoxon signed-rank test. A significance level of α = 5% was used.Second, the same comparison was made for target volume  related DVH parameters. These parameters were systematically compared pairwise to quantify the DVH-based dosimetric benefit of online plan adaption for each subgroup separately. Primary dosimetric endpoints were chosen as follows: increase in GTV  or CTV (prostate cases) D98%, increase in GTV or CTV D95%, increase in GTV mean dose, reduction in OAR exposure. The GTV (or CTV) near-minimum parameters (D98% and D95%) were chosen because underdose (e.g. dose drop at the surface or cold spots) within the GTV/CTV are likely to affect the local control (LC). The GTV (or CTV in prostate cases) mean dose was chosen because there is evidence for a predictive value of this parameter in terms of improved LC in liver  and lungCharacteristics of the online adapted plans are shown in Table 95% improved by more than 10.0% and the duodenum D50% was reduced by about one third.Figure p-values and median percent changes are shown in the first row of Table Figure 98% and D95% for the PTV and GTV/CTV when comparing the re-optimized with the predicted doses  and GTV D2% (lung). When looking at the boxplots  and mean (Dmean) doses show an inverse behaviour. For these values, slight median increases were found in most cases, except for the pancreas subgroup, where no significant changes were found for PTV D50%, GTV D50% and GTV Dmean  before plan adaption was worse compared to lung and prostate but was comparable to lymph nodes and pancreas. One reason might be that less complex shaped (sphere-like) targets, as small lung lesions  and so was the mean number of segments (26), indicating easy-to-adapt, simple treatment plans.For lung cases, the initial PTV coverage of the predicted base plan was better compared to liver, but could still be significantly improved and resulted in a near-optimal PTV coverage after plan adaption. The initial GTV coverage was similar to that of liver, but could still be significantly improved. With 84.4% of all fractions adapted, lung showed similar adaption rates as lymph node cases. Regarding OAR sparing and change of PTV near-maximum doses, similar findings were made as for the liver subgroup. The mean PTV volume of lung cases was the smallest of all subgroups  in GTV D5% Table . A largeGy of duodenum, stomach and bowel was reduced on average by more than 80% respectively  GTV coverage was acceptable, some cases were observed where sufficient GTV coverage could not be achieved, even after plan adaption, because sparing of OARs was prioritized. This can be seen in Fig. ly Table . WithoutFor most prostate cases, the initial PTV and especially the CTV coverage were acceptable. In only a few fractions very insufficient initial target volume coverage was found Fig. . For the98% and D95%). In addition, a large portion of fractions (> 82%) required re-optimization in all three subgroups, indicating that most of these fractions can be significantly improved by online plan adaption. Since small values of GTV D98% and D95% indicate insufficient GTV coverage, these indices can be considered the most predictive  in terms of improved tumor control probability (TCP) and possibly LC when comparing non-adapted and online adapted fractions. However, it remains unclear if the significant increases in GTV near-minimum and mean doses will translate into a detectable improved LC.All subgroups clearly benefited from online plan adaption in terms of improved PTV coverage. The improved target dose varied between the different tumor entities. To estimate the absolute dose changes of the target volumes achieved by online plan adaption, it is possible to multiply the total prescribed dose of any dose prescription Table  with theIn addition to the significantly improved GTV coverage in the liver, lung and abdominal lymph nodes subgroups when using plan adaption, these subgroups might also largely benefit from the breath-hold and automated beam gating capabilities of the oMRgRT system, since no internal target volume concept is needed. An internal target volume concept would increase the total irradiated volume , especiaIt was found for pancreas, that the plan adaption capabilities were largely used to reduce OAR doses to an acceptable level. Although the re-optimized GTV coverage was acceptable in most cases, the improvement in GTV coverage via online plan adaption was not as large as in the other subgroups, as OAR sparing was prioritized. In contrast, in the prostate subgroup, only 69.4% of all fractions were considered for re-optimization. For most of these fractions, the initial CTV coverage was quite good but could still be slightly improved when adapted. Ultimately, few fractions were found, where the initial PTV and CTV coverage was unacceptable. For these fractions, online re-optimization resulted in an excellent CTV coverage. In summary, for prostate cases, the benefit of online re-optimization was found to be not as systematic as for the liver, lung, abdominal lymph nodes and pancreas cases. In each subgroup, at least one of the primary dosimetric endpoints defined under “98% or D95%. In the same study only small increases in mean BED inside the PTV and GTV were found, which is also in accordance with our findings of PTV and GTV Dmean. El Bared et al. [To the best of our knowledge, up to now, no attempt has been made to quantify the influence of MR-guided online plan adaption on DVH-related parameters and systemically compare the results between multiple subgroups with different tumor entities typically treated on integrated MR-Linac systems. Our intent was to provide information for a more informed decision making when assigning patients to the (still very limited access) MR-Linac. Henke et al.  analyzedd et al.  evaluated et al.  found a d et al.  analyzedd et al.  artificiAll subgroups clearly benefited from online plan adaption in terms of improved PTV coverage. Moreover, for the liver, lung and abdominal lymph node cases, a systematic improvement in GTV coverage was found, resulting in excellent target coverage after re-optimization in most fractions. In combination with the breath-hold-based technique, these subgroups can fully exploit the potential of oMRgRT systems. In the pancreatic cancer subgroup, online plan adaption resulted in largely decreased OAR doses but the target coverage could not always be improved due to the limiting OAR constraints. While many fractions of the prostate subgroup could, in theory, also be effectively treated without plan adaption, most fractions still showed improved PTV coverage and few fractions even showed large CTV coverage improvements after online plan re-optimization.


Pseudois nayaur) in Baima Snow Mountain is found to exhibit a distinctive bimodal distribution along elevation gradient contrasting the unimodal distributions of most species. The first distributional peak of Himalaya blue sheep was in scree habitat around 4100 m a.s.l., while the second peak was in the dry-hot valley around 2600 m. Geographic separation from the original population along elevation suggested that population at lower elevation could be a separate species ecologically, or a taxa ongoing differentiation. Invasive species Opuntia ficus-indica, which colonized the region six hundred years ago, may have formed new foraging niche to support population at lower elevation. Our results suggested conservation measures should pay attention to taxa ongoing differentiation, and consider the possible active effect of biological invasion.The Himalaya blue sheep (Pseudois nayaur) and its co-existence with other ground animal communities along a slope of Baima Snow Mountain, southwest China. The results show that Himalaya blue sheep exhibited a distinctive bimodal distribution along the elevation gradient contrasting the unimodal distributions found for the other ungulates in Baima snow mountain. A first distributional peak was represented by a population habituating in scree habitat around 4100 m, and a second peak was found in the dry-hot valley around 2600 m. The two distinct populations co-existed with disparate animal communities and these assemblages were similar both in the dry and rainy seasons. The extremely low abundance of blue sheep observed in the densely forested belt at mid-elevation indicates that vegetation rather than temperature is responsible for such segregation. The low-elevation population relied highly on Opuntia ficus-indica, an invasive cactus species that colonized the region six hundred years ago, as food resource. Being the only animal that developed a strategy to feed on this spiky plant, we suggest invasive species may have formed new foraging niche to support blue sheep population in lower elevation hot-dry river valleys, resulting in the geographic separation from the original population and a potential morphological differentiation, as recorded. These findings emphasize the important conservation values of role of ecological functions to identify different taxa, and conservation values of apparent similar species of different ecological functions.The elevational range where montane species live is a key factor of spatial niche partitioning, because the limits of such ranges are influenced by interspecies interaction, abiotic stress, and dispersal barriers. At the regional scale, unimodal distributions of single species along the elevation gradient have often been reported, while discontinuous patterns, such as bimodal distributions, and potential ecological implications have been rarely discussed. Here, we used extensive camera trap records to reveal the elevation distribution of Himalaya blue sheep ( Understanding the mechanisms underlying the formation of vertical niche partitioning and the elevational distribution of montane biodiversity is a critical aspect in ecology and biogeography, providing basic references for conservation ,2. Both Pseudois nayaur), is a mountain ungulate endemic to the Pan-Himalaya area [Pseudois schaeferi) [The bharal, also known as blue sheep  ,15. Mitohaeferi) . HoweverOpuntia ficus-indica, was the main food resource consumed by blue sheep of the Jinsha valley on Baima Snow Mountain, especially during the winter season [Blue sheep prefer open vegetation  and avoir season . Based oMoschus chrysogaster), dwarf musk deer (Moschus berezovskii), Chinese goral (Naemorhedus griseus), Chinese serow (Capricornis milneedwardsii), and tufted deer  co-exist. With the collected records, we assess the distribution patterns of the identified species and analyze the community co-existence of blue sheep in different vegetation types and elevations. We also review the elevational range of blue sheep species across other regions where the blue sheep occur. We predict that the blue sheep of BSM will show a particularly discontinued distribution along the elevation owing to the presence of suitable but divergent habitat at both low and high elevation, separated by an unsuitable densely vegetated belt. We also expect differences in their co-existence with other animal communities occurring in divergent habitats.Here, we survey the distribution of blue sheep and other ground animals by installing camera traps in different vegetation types distributed between 2000 and 4700 m. on Baima Snow Mountain area (BSM), southwest China. In this region, several montane species co-exist, including five additional ungulate species, namely, alpine musk deer  and coniferous forests  are found between 2600 and 4200 m, while alpine shrubs  and scree are usually above 4000 m [The study was conducted on the eastern slope of southern Baima Snow Mountain National Nature Reserve  stations , active Camera days for each camera were counted from the date of deployment until the date of the last photo. Consecutive captures for the same individuals or species  at the same station were considered as independent observations (IO) when separated by at least a one-hour interval. The relative abundance index (RAI) of each species was defined as the number of IO per 100 camera days . The RAI of each ground species in each camera trap were plotted along the elevation gradient to reveal their vertical distribution. The ungulate community structure and composition in each station with different elevation and vegetation type were assessed using Nonmetric Multi-dimensional Scaling ordination (NMDS) . The NMDPseudois nayaur” or “Pseudois schaeferi”. Only the publications that provided sufficient elevation information of the species were included, and redundant records  were excluded.We searched the Google Scholar database with the key words “Blue sheep” or “Bharal” or “A total of 60 species were identified from the collected records, including 41 birds and 19 mammals . AccordiThe RAI of blue sheep were higher in the valley shrubs, followed by alpine screes and meadows, while those in forest and alpine shrub were much lower . Along tThe Chinese goral shared the habitat with the blue sheep population at low elevation, showing a unimodal elevational distribution. Chinese serow and Tufted deer showed similar patterns, with their peaks were around 3000 to 4000 m, while the Alpine musk deer was mostly observed at a slightly higher elevation. We excluded alpine musk deer because of the low data collected. Species showed a similar pattern in dry and rainy seasons .The NMDS community ordination analysis for the full data-set produced a two-dimensional solution (stress = 0.06). The NMDS plots showed separated community compositions according to vegetation types . In partA total of 10 studies focusing on blue sheep distribution in four regions were collected . Most ofThe results of elevational distribution of blue sheep populations in several regions and other ungulates in BSM showed a general tendency to a unimodal distribution along the elevation gradient. However, our focus blue sheep population in BSM presented a peculiar bimodal distribution, with peaks at lower and higher elevations and a void at mid-elevation, where densely forested areas are found. This discontinuous elevational distribution is consistent with our hypothesis. Although the study was not conducted throughout a whole year, we were able to reveal a similar pattern in both dry and rainy season. Such kind of distribution pattern has also been reported in Batang, located at the west bank of the Jinsha river (a section of the Yangzi) . The absCactus in Yunnan Province can be traced to more than six hundred years ago when Cactus was used as ornamental flowers or fences [Cactus is a widely used fodder in Latin America and Africa as a buffer food lacking fiber and nitrogen [O. ficus-indica’ [In general, invasive species have a negative impact on the biodiversity of the affected areas, creating niche displacement, competitive exclusion, or predation ,29. Hower fences . Cactus nitrogen . Grove [nitrogen  once poi-indica’ . The horCactus. Most of the previous studies based on molecular biology argued that the low-elevation population was not an isolated species, leading to its removal from the IUCN Red List of Threatened Species. However, when considering their different ecological functions and their geographically separated, population at lower elevation should be treated as a separate species. Moreover, speciation is a long-time process, conservation perspective should consider on those taxa under ongoing ecological differentiation.Biological species, defined by their phylogenetic relationships , are usuPseudois nayaur) results from climatic, food resources, and plant invasion processes. Invasive species do not always decrease regional biodiversity as generally supposed, but can promote speciation by providing new foraging niches. Conservation biology should put emphasis on those taxa owning functional differentiation.The discontinuous distribution along the elevation gradient of the Himalaya blue sheep (


Infection of peripheral arterial vascular grafts and stent-grafts represents a complex surgical scenario, with a number of proposed management strategies. Surgical removal of infected material with adjunctive arterial reconstruction is often required. However, surgical removal is often difficult and complex. This case study demonstrates an infected Viabahn stent-graft between the external iliac artery and the superficial femoral artery, with arterial autolysis of the common femoral artery and proximal superficial femoral artery, in which a hybrid technique combining remote endarterectomy and surgical debridement was used to remove the infected stent-graft. Clinical experience dictates that radical excision of infected material and extra-anatomical bypass in a noninfected field is the treatment of choice.A 71-year-old woman, with a history of hypertension, dyslipidemia, hypothyroidism, and morbid obesity (body mass index 40), initially presented with one-block calf claudication and nocturnal rest pain of the right leg. Angiography demonstrated heavy calcification within the right external iliac (EIA), common femoral (CFA), and profunda arteries (PFA), and occlusion from the origin of the superficial femoral artery (SFA) to popliteal artery. A femoropopliteal in situ bypass with iliofemoral endarterectomy, extended profundoplasty, and bovine pericardial patch  arterioplasty was performed. The saphenous vein graft originated from the bovine patch. She was discharged on oral antibiotics given her high risk for wound infection.She presented 1 month later with infection and bleeding in the right inguinal incision. Angiography demonstrated a patent graft, and computed tomography suggested an infected hematoma. This was initially treated with intravenous (IV) antibiotics. However, secondary to hemorrhage from the groin, she underwent emergency excision of the infected pseudoaneurysm and bovine patch via a right flank retroperitoneal incision to control the inflow external iliac artery; she then underwent vein patch arterioplasty of the CFA and PFA, excision of the proximal portion of the previous femoropopliteal bypass due to sepsis, and reconstruction of the right femoropopliteal bypass using the left long saphenous vein. Because of extensive sepsis and debridement, a full thickness skin, fat, and muscle flap was rotated from the anterior thigh to the right groin. The patient bled postoperatively, necessitating stenting grafting of the right CFA into the right PFA using a 10 mm × 100 mm Viabahn  stent graft, which occluded her femoral-to-popliteal bypass.Staphylococcus aureus. The patient was reluctant to undergo further surgery. After negative blood cultures, a 10 mm × 150 mm Viabahn graft was deployed extending from the EIA into the previously placed graft, thereby excluding a large false aneurysm proximal to the original stent graft. She was discharged and remained on a continuous 2-year course of IV antibiotics due to a chronically draining sinus in the right groin, and positive Escherichia coli, Enterobacter cloacae, methicillin-resistant S. aureus, and Klebsiella pneumonia cultures. Despite ongoing antibiotics, eventually the Viabahn graft eroded the overlying skin and was visible in the right groin . Using a vertical incision from the lower anterior abdominal wall to the right thigh, the PFA (at the level of the second perforating muscular branch) and proximal CFA were exposed, and vascular control was obtained. The CFA and proximal PFA were autolyzed by sepsis, and only the stent-graft remained . SimultaAfter confirming occlusion of the right EIA via angiography, the distal profunda femoris was clamped and the stent graft was transected. Using sharp dissection, the distal portion of the stent graft was excised to the mid-profunda. Attention was then directed proximally. Direct moderate traction on the transected end of the stent-graft did not dislodge it. An EndoRE remote endarterectomy device (LeMaitre Vascular) was placed around the exposed graft, similar to an intimal core during remote endarterectomy  and 3. TPostoperatively, the patient had minor wound sepsis. The patient has been followed yearly for 4.5 years with duplex scanning of the patent cross-femoral venous bypass. She has had full wound healing and remains asymptomatic.,Although uncommon, peripheral extra-anatomical graft and endovascular stent-graft infection can create complex surgical scenarios with significant patient morbidity. Incidence of infected peripheral bare-metal stents is estimated at 1 in 10,000,,,,,Arterial infection can cause arterial destruction in the absence of foreign material; however, the presence of foreign material further predisposes ongoing arterial suppuration and degradation.Remote endarterectomy has been shown to be safe for the management of peripheral arterial disease, though with variable results.Given the formidable operative morbidity and mortality associated with stent infections, a hybrid surgical technique was employed in this case. Accordingly, retroperitoneal exposure was avoided, fluoroscopy-guided remote endarterectomy reduced surgical invasiveness in a high-risk patient, and removal of infected prosthetic material promoted wound healing. The treatment principles for management of infected covered stents in peripheral arteries mirror those of infected aortic endografts of the abdominal aorta—surgical explantation of the infected graft.


FDR = 0.022) and processing speed . SVD burden accounted for between 4 and 5% of variance in declines of general cognitive ability and processing speed. After accounting for the covariance between tests of processing speed and general cognitive ability, only SVD’s association with greater decline in general cognitive ability remained significant, prior to FDR correction . Our findings do not support the notion that SVD has a specific association with declining processing speed, independent of decline in general cognitive ability (which captures the variance shared across domains of cognitive ability). The association between SVD burden and declining general cognitive ability supports the notion of SVD as a diffuse, whole-brain disease and suggests that trials monitoring SVD-related cognitive changes should consider domain-specific changes in the context of overall, general cognitive decline.Slowed processing speed is considered a hallmark feature of cognitive decline in cerebral small vessel disease (SVD); however, it is unclear whether SVD’s association with slowed processing might be due to its association with overall declining general cognitive ability. We quantified the total MRI-visible SVD burden of 540 members of the Lothian Birth Cohort 1936 . Using latent growth curve modelling, we tested associations between total SVD burden at mean age 73 and changes in general cognitive ability, processing speed, verbal memory and visuospatial ability, measured at age 73, 76, 79 and 82. Covariates included age, sex, vascular risk and childhood cognitive ability. In the fully adjusted models, greater SVD burden was associated with greater declines in general cognitive ability (standardised β: −0.201; 95% CI: ; p Cerebral small vessel disease (SVD) is a major cause of cognitive impairment in older adults. It causes ~25% of all strokes and is the second most common cause of dementia after Alzheimer’s disease, either on its own or through mixed pathologies , 2. CausCurrent consensus statements suggest that SVD is associated with declining processing speed and executive function, alongside relative preservation of memory and language abilities , 7. HoweTo date, most studies investigating the relationship between SVD brain changes and cognitive decline have focused on individual radiological markers of SVD. WMH are the most frequently investigated SVD marker, perhaps due to their prevalence which is estimated at 64–94% in 82 year olds . Recent To improve the fidelity of SVD burden quantification, two previous studies (one using the same sample as the present study) utilised continuous neuroimaging variables to construct continuous SVD burden scores , 20. In Longitudinal associations between SVD burden and declines in specific domains of cognitive ability, independent of their associations with general cognitive ability, have yet to be examined. Here, in a sample of relatively healthy older individuals, we investigate associations between total MRI-visible SVD burden at age 73 and longitudinal cognitive decline between the ages of 73 and 82, a period that coincides with a substantial increase in dementia risk . Using gn = 1091), 73 (n = 866), 76 (n = 697), 79 (n = 550) and 82 (n = 431) years. The present study includes neuroimaging data from Waves 2, and cognitive data from Waves 2–5 of the LBC1936 (there was no MRI at Wave 1). Wave 2 MRI data were unusable for 51 of the 731 participants who underwent neuroimaging. Images belonging to a further 140 participants exhibited noise or motion artefacts that precluded the computational quantification of PVS, which due to the small size of the PVS (<3 mm), is highly sensitive to such artefacts. Therefore, the remaining 540 participants constitute the baseline sample of this study , a longitudinal study of cognitive, brain and general ageing . In brieThe neuroimaging protocol for the LBC1936 has been published previously . Brieflyhttps://sourceforge.net/projects/bric1936/. All slices of all scans were checked by a trained observer and manually corrected, if necessary, to ensure that no true WMH had been omitted and to avoid including erroneous tissues in the WMH. PVS were computationally segmented in the native T2W space in the centrum semiovale using a recently validated technique [As previously reported, we used confirmatory factor analysis (CFA) to construct a latent variable representing total MRI-visible SVD burden at baseline (Wave 2 of the LBC1936 ). This lechnique , 27 and echnique . Cerebraechnique . A randoProcessing speed was measured using Digit Symbol Substitution and Symbol Search from the Wechsler Adult Intelligence Scale-III (WAIS-III UK ) and twoMemory consisted of Verbal Paired Associates  and Logical Memory  from the Wechsler Memory Scale-III UK (WMS-III UK ), and BaVisuospatial ability included Block Design and Matrix Reasoning (WAIS-III UK) and Spatial Span .Participants completed the same series of cognitive tests at each wave of data collection, in the same location, administered using the same instructions. According to previous work examining their correlational structure , we grouOur measure of general cognitive ability encompassed each of the above-mentioned tests. The Moray House Test Number 12 (MHT), a 71-item test of general cognitive ability, was also administered at the age of 11 as part of the Scottish Mental Survey 1947. In this study, we use the raw MHT score, which can range from 0–76 and subsequently refer to this variable as childhood cognitive ability.We included age in years, sex, vascular risk and childhood cognitive ability in all models, in a stepwise manner. Vascular risk variables included self-reported history of hypertension (yes/no); diabetes mellitus (yes/no); smoking status (ever/never); blood-derived glycated haemoglobin ; blood-derived total cholesterol (mmol/l); and systolic and diastolic blood pressure (average of six readings: three seated and three standing), which were measured by trained nurses. We observed very little change in vascular risk variables over the four waves of testing  within a SEM framework , as has Next, we specified linear regressions between baseline (Wave 2) SVD burden (independent variable) and the latent intercepts and slopes (Waves 2–5) of general cognitive ability, processing speed, memory and visuospatial ability (dependent variables). This was carried out in separate hierarchical FoC models: one for general cognitive ability, and one for each cognitive domain. Importantly, it should be noted that at this stage the cognitive domains will contain any variance actually attributable to general cognitive ability (i.e. common across cognitive domains). Associations between SVD burden and latent cognitive intercepts approximate the cross-sectional associations that we reported previously . TherefoPrevious analyses in the LBC1936 have estimated that general cognitive ability explains ~50% of the variability in the decline of individual test scores between the ages of 70 and 76, and up to 70% of variability in their decline between 70 and 79 , 40. OwiOf the radiological markers of SVD examined here, WMH are the most regularly associated with poorer cognitive abilities. It is plausible, therefore, that any associations between the SVD burden variable and cognitive factors could largely be driven WMH. To test whether this was the case, we repeated the hierarchical FoC analyses with WMH/TIV in the place of SVD burden as the predictor variable. As an indication of the relative utility of total SVD burden and WMH/TIV as predictors of cognitive outcomes, we examined the magnitude of standardised effect sizes and confidence intervals of models specifying WMH/TIV, and those of models specifying total SVD burden as the predictor.As absolute fit indices are unavailable when using maximum likelihood to estimate models including binary measures, we assessed the fit of models specifying total SVD burden as the predictor (binary measures of lacunes and microbleeds contribute to the latent SVD variable) against a less-restrictive neighbouring model  using the likelihood ratio test statistic calculated as follows: −2 × (loglikelihood of the less-restrictive model − loglikelihood of full model). For models specifying WMH/TIV as the predictor, model fit was assessed using four absolute fit indices: Root Mean Square Error of Approximation , Comparative Fit Index , Tucker-Lewis Index , and Standardised Root Mean Square Residual .p-values for multiple comparisons using the False Discovery Rate adjustment  associations between total SVD burden and the intercept and slopes of cognitive change from hierarchical FoC models; (2) associations between WMH/TIV and the intercept and slopes of cognitive change from hierarchical FoC models; (3) associations between total SVD burden and the intercept and slopes of cognitive change from bifactor models.All analyses were carried out in MPlus version 8.4  and wereent (FDR ), with pent . In standard deviation units, the declines per year were: −0.13  for general cognitive ability, −0.16 for processing speed, −0.005 for memory and −0.08 for visuospatial ability.We first modelled the mean change in general cognitive ability, processing speed, memory and visuospatial ability between the ages of 73 and 82 in separate hierarchical FoC models. Note that, at this stage, the cognitive domains will still contain any variance due to general cognitive ability. Table p = 0.015; pFDR = 0.022) and processing speed , but not with verbal memory or visuospatial ability . In line with our previously reported results [FDR ≤ 0.022; for full results see Table The key analyses in this study were associations between total SVD burden and trajectories of general cognitive ability, processing speed, verbal memory and visuospatial ability. Note that in the hierarchical FoC models, the domains still contain any variance due to general cognitive ability. After the inclusion of covariates, total SVD burden was negatively associated with the slope of general cognitive ability . We found no significant associations between total SVD burden and the slopes of any other cognitive variables  in the bifactor model. In terms of SVD-cognitive intercept associations, total SVD burden was associated with the intercept of general cognitive ability only, but this association became non-significant after the inclusion of covariates and adjustment for FDR  and processing speed . Effect sizes of these models were 0.052 and 0.046 standard deviations smaller  than models specifying total SVD burden as the predictor, and confidence intervals from models using different predictors overlapped substantially. Differences in effect size magnitudes were more pronounced for the total SVD-cognitive intercept associations; effect sizes of models with WMH/TIV as the predictor were between 0.105 and 0.117 standard deviations smaller than models with total SVD burden as the predictor. Overlap between confidence intervals of these models was present but more modest than for slopes.Finally, we tested whether the associations observed between SVD burden and cognitive decline were likely driven by the contribution of WMH to the SVD burden score. We re-ran the hierarchical FoC models with WMH/TIV in the place of total SVD burden as the predictor (for results see Tables p = 0.008), but became non-significant after FDR correction (pFDR = 0.085). In contrast, in the bifactor model the negative association between total SVD burden and declining processing speed was non-significant both prior to and following FDR correction . We were cautious in our use of FDR correction; smaller p-values in the bifactor models were heavily penalised due to the large number of p-values included in the correction. In addition to the non-zero-containing confidence intervals for this association, the overall results from this bifactor model suggest that SVD burden’s association with declining processing speed might be accounted for by overall decline in general cognitive ability. By overlooking the shared variance among domain-specific cognitive tests, previously observed associations between radiological markers of SVD and decline in domain-specific abilities could be an artefact of the relationship between SVD markers and declining general cognitive ability. Alongside these main results, in the hierarchical FoC models we observed associations between total SVD burden and the initial levels of general cognitive ability, processing speed, verbal memory and visuospatial ability at the age of 73. These results are in line with our previous analyses that used only cross-sectional data from age 73 [In this longitudinal study of 540 community-dwelling older adults, we investigated associations between the total MRI-visible burden of cerebral SVD and the nine-year trajectory of cognitive abilities between the ages of 73 and 82. We found associations between greater SVD burden and greater decline in both general cognitive ability and processing speed, after accounting for age, sex, vascular risk and childhood cognitive ability. We then separated the variance in cognitive test scores attributable to domain-specific abilities and to general cognitive ability (using a bifactor model), to test SVD’s relationship with declining processing speed, independent of the influence of general cognitive decline. In the fully adjusted bifactor model, the association between greater SVD burden and declining general cognitive ability was nominally significant , were medium sized (standardised betas were −0.201 and −0.222 respectively) . These rThat SVD burden appears to be associated with an overall decline in general cognitive ability  is consistent with the pattern of non-pathological, age-related cognitive decline. Previous studies have estimated that the majority of the variance in age-related decline across domain-specific cognitive abilities is shared, and that the proportion of shared variance increases with age (up to 70% by the age of 85) , 38. ThiThe potential association between SVD burden and overall decline in general cognitive ability also supports the notion of SVD as a diffuse, whole-brain disease that disrupts or ‘disconnects’ regions of the brain that sub-serve our cognitive abilities , 50. DifTo test whether associations between total MRI-visible SVD burden and cognitive outcomes were driven primarily by the contribution of WMH burden to the total SVD burden variable, we re-ran our hierarchical FoC models specifying WMH volume as the predictor. WMH volume was associated with the intercept of all cognitive factors, however, the magnitudes of effect sizes of these models were smaller  than those from models specifying SVD burden as the predictor. This suggests that total SVD burden could be a more powerful predictor of cognitive performance cross-sectionally than WMH burden alone. Interestingly, this was not the case when modelling cognitive decline; differences between the effect sizes of models specifying total SVD burden vs. WMH/TIV as the predictor of decline in cognitive outcomes appeared to be more modest . Whereas incorporating measurements of PVS, lacunes and microbleeds alongside WMH in a single SVD burden score appears to strengthen the prediction of cognitive outcomes cross-sectionally, doing so may provide limited predictive power beyond that of WMH volume alone in associations with cognitive change between the ages of 73 and 82. WMH on neuroimaging represent heterogenous changes in the underlying brain tissue and cerebral microvasculature, ranging from alterations in water content and the build-up of perivascular oedema, which can resolve over time, to demyelination and axonal degeneration, which likely cannot , as one This study benefits from the availability of multiple waves of in-depth cognitive testing in a relatively large sample of individuals, over almost a decade of time. In-depth biological and clinical phenotyping in the LBC1936 also enabled us to account for a broad range of vascular risk variables. A further strength of the LBC1936 is the availability of a measure of childhood cognitive ability. By including childhood cognitive ability as a covariate in our models, we were able to eliminate its confounding effects on associations between SVD burden and later life cognitive abilities. Our study also has several limitations. Members of the LBC1936 are self-selecting, so represent a generally healthy, well-educated and highly motivated sample and mostly have a mild, non-clinical presentation of SVD. The main effect of this is probably a slight lowering of true effect sizes . It coulIn this study we observed associations between the total MRI-visible burden of SVD and decline in general cognitive ability. The association we observed between SVD burden and decline in processing speed appears to be due to the overarching association between SVD burden and declining cognitive ability more generally. When monitoring SVD-related cognitive decline, trials of treatments or interventions for SVD should carry out an in-depth measure of general cognitive ability (i.e. as opposed to a brief screening instrument) alongside assessments of any specific cognitive domain that is of particular interest. In doing so, any domain-specific cognitive changes can be examined in the context of declining general cognitive ability.Supplementary Tables S1-S7