Sclerosing epithelioid fibrosarcoma of bone with hybrid features: clinicopathologic, radiologic, and molecular analysis of three cases.

Sclerosing epithelioid fibrosarcoma (SEF) occurring as a primary bone tumor is exceptionally uncommon. Even more rare are cases of SEF that show morphologic overlap with low-grade fibromyxoid sarcoma (LGFMS). Such hybrid lesions arising within the bone have only rarely been reported in the literature. Due to their variegated histomorphology and non-specific radiologic features, these tumors may pose diagnostic difficulties. Herein we describe three molecularly confirmed primary bone cases of sclerosing epithelioid fibrosarcoma that demonstrated prominent areas showing the features of LGFMS and with areas resembling so-called hyalinizing spindle cell tumor with giant rosettes (HSCTGR). Two patients were female and one was male aged 26, 47, and 16, respectively. The tumors occurred in the femoral head, clavicle, and temporal bone. Imaging studies demonstrated relatively well-circumscribed radiolucent bone lesions with enhancement on MRI. Cortical breakthrough and soft tissue extension were present in one case. Histologically the tumors all demonstrated hyalinized areas with SEF-like morphology as well as spindled and myxoid areas with LGFMS-like morphology. Two cases demonstrated focal areas with rosette-like architecture as seen in HSCTGR. The tumors were all positive for MUC4 by immunohistochemistry and cytogenetics, fluorescence in-situ hybridization, and next-generation sequencing studies identified EWSR1 gene rearrangements confirming the diagnosis in all three cases.Hybrid SEF is exceedingly rare as a primary bone tumor and can be difficult to distinguish from other low-grade spindled and epithelioid lesions of bone. MUC4 positivity and identification of underlying EWSR1 gene rearrangements help support this diagnosis and exclude other tumor types.

Homemade Nucleic Acid Preservation Buffer Proves Effective in Preserving the Equine Faecal Microbiota over Time at Ambient Temperatures.

The equine faecal microbiota is often assessed as a proxy of the microbial community in the distal colon, where the microbiome has been linked to states of health and disease in the horse. However, the microbial community structure may change over time if samples are not adequately preserved. This study stored equine faecal samples from n = 10 horses in four preservation treatments at room temperature for up to 150 h and assessed the resulting impact on microbial diversity and the differential abundance of taxa. Treatments included "COLD" (samples packaged with a cool pack), "CLX" (2% chlorhexidine digluconate solution), "NAP" (nucleic acid preservation buffer), and "FTA" (Whatman FTA™ cards). The samples were assessed using 16S rRNA gene sequencing after storage for 0, 24, 72, and 150 h at room temperature under the different treatments. The results showed effective preservation of diversity and community structure with NAP buffer but lower diversity (p = 0.001) and the under-representation of Fibrobacterota in the FTA card samples. The NAP treatment inhibited the overgrowth of bloom taxa that occurred by 72 h at room temperature. The COLD, CLX, and NAP treatments were effective in preserving the faecal microbiota for up to 24 h at room temperature, and the CLX and NAP treatments improved the yield of Patescibacteria and Fibrobacterota in some cases. The cold and CLX treatments were ineffective in preventing community shifts that occurred by 72 h at room temperature. These findings demonstrate the suitability of the COLD, NAP, and CLX treatments for the room temperature storage of equine faeces for up to 24 h and of NAP buffer for up to 150 h prior to processing.

Confidence does not mediate a relationship between owner experience and likelihood of using weight management approaches for native ponies.

Native ponies are at increased risk of obesity and metabolic perturbations, such as insulin dysregulation (ID), a key risk factor for endocrinopathic laminitis. Management and feeding practices can be adapted to maintain healthy body condition and support metabolic health, but owners may inadvertently provide their ponies with inappropriate management leading to obesity and exacerbating risk of metabolic disease. Adoption of preventative weight management approaches (WMAs), including regular monitoring of body condition, providing appropriate preserved forage, promoting seasonal weight loss, and using exercise accordingly, are key in supporting native ponies' metabolic health. The factors influencing the adoption of WMAs, such as owners' experience and confidence, require exploration. The aim of the current study was to understand factors influencing owners' likelihood to undertake certain WMAs, to develop our understanding of suitable intervention targets. A total of 571 responses to an online cross-sectional questionnaire were analysed. Mediation analysis revealed that whilst long term (≥20 years) experience caring for native ponies was associated with owners increased, self-reported confidence in identifying disease and managing their native ponies, this did not translate to an increased likelihood of implementing WMAs. Conversely, respondents who managed ponies with dietary requirements related to obesity, laminitis, or equine metabolic syndrome were more likely to use WMAs related to feeding, seasonal weight management and exercise. Owner confidence was assessed and rejected as a mediator of the relationship between experience and WMA use. These results highlight the need for further work that elucidates the pathways leading owners to undertake action against obesity without the need for ponies to develop overt disease, as well as suggesting a need for long term managers of native ponies to update management practices with preventative care as the focus.

Evaluating the Effectiveness of the Housing First for Youth Intervention for Youth Experiencing Homelessness in Canada: Protocol for a Multisite, Mixed Methods Randomized Controlled Trial.

BACKGROUND: Emerging evidence at the international level suggests that the Housing First approach could improve the housing stability of young people experiencing homelessness. However, there is a dearth of literature in Canada on whether the Housing First intervention for young people experiencing homelessness can improve outcomes including housing stability, health and well-being, and access to complementary supports. Adapted from the original Housing First model, Housing First for Youth (HF4Y) was developed in Canada as a rights-based approach tailored specifically for young people aged 16 to 24 years who are experiencing or are at risk of homelessness. OBJECTIVE: The Making the Shift Youth Homelessness Social Innovation Lab is testing the effectiveness of the HF4Y intervention in Canada. The objective of this study is to determine whether the HF4Y model results in better participant-level outcomes than treatment-as-usual services for young people experiencing homelessness in 2 urban settings: Ottawa and Toronto, Ontario. Primary outcomes include housing stability, health and well-being, and complementary supports, and secondary outcomes include employment and educational attainment and social inclusion. METHODS: The HF4Y study used a multisite, mixed methods, randomized controlled trial research approach for data collection and analysis. Eligible participants included young people aged 16 to 24 years who were experiencing homelessness or housing precarity. The participants were randomly assigned to either the treatment-as-usual group or the housing first intervention group. Survey and interview data in Ottawa and Toronto, Ontario are being collected at multiple time points (3-6 months) over 4 years to capture a range of outcomes. Analytic strategies for quantitative data will include mixed-effects modeling for repeated measures and logistic models. A thematic analysis will be used to analyze qualitative data based on participants' narratives and life journeys through homelessness. Furthermore, program fidelity evaluations are conducted within each HF4Y program. These evaluations assess how well the intervention aligns with the HF4Y model and identify any areas that may require adjustments or additional support. RESULTS: The HF4Y study has received human participant research ethics approval from the Office of Research Ethics at York University. Recruitment was conducted between February 2018 and March 2020. Data collection is expected to be completed at both sites by March 2024. A preliminary analysis of the quantitative and qualitative data collected between baseline and 24 months is underway. CONCLUSIONS: This pilot randomized controlled trial is the first to test the effectiveness of the HF4Y intervention in Canada. The findings of this study will enhance our understanding of how to effectively deliver and scale up the HF4Y intervention, with the aim of continually improving the HF4Y model to promote better outcomes for youth. TRIAL REGISTRATION: International Standard Randomized Controlled Trial Number (ISRCTN) ISRCTN10505930; https://www.isrctn.com/ISRCTN10505930. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/46690.

Immune challenge affects reproductive behaviour in the guppy (Poecilia reticulata).

Immunocompetence and reproduction are among the most important determinants of fitness. However, energetic and metabolic constraints create conflict between these two life-history traits. While many studies have explored the relationship between immune activity and reproductive fitness in birds and mammals inoculated with bacterial endotoxin, very few have focused on fish. Fish have been neglected in this area due, in part, to the claim that they are largely resistant to the immune effects of endotoxins. However, the present study suggests that they are susceptible to significant effects with respect to reproductive behaviour. Here, we examined the reproductive behaviour of male guppies following exposure to bacterial lipopolysaccharides (LPS) in comparison to that of male guppies in a control treatment. Additionally, we investigated the responses of females to these males. We show that although immune challenge does not suppress general activity in male guppies, it significantly reduces mating effort. While females showed no difference in general activity as a function of male treatments, they did exhibit reduced group cohesion in the presence of LPS-exposed males. We discuss this in the context of sickness behaviours, social avoidance of immune-challenged individuals and the effects of mounting an immune response on reproductive behaviour.

Tumor-induced osteomalacia treated with T12 tumor resection.

Summary: Tumor-induced osteomalacia (TIO) is a rare form of osteomalacia caused by fibroblast growth factor-23 (FGF23)-secreting tumors. Most of these tumors are phosphaturic mesenchymal tumors (PMTs) typically involving soft tissue in the extremities and bone of the appendicular skeleton and cranium. We report the case of a 60-year-old woman with about 3 years of persistent bone pain and multiple fractures, initially diagnosed as osteoporosis, who was found to have hypophosphatemia with low 1,25-dihydroxyvitamin D and elevated alkaline phosphatase and inappropriately normal FGF23 consistent with TIO. Her symptoms improved with phosphate supplementation, vitamin D and calcitriol. 68Ga-DOTATATE imaging revealed a T12 vertebral body lesion confirmed on biopsy to be a PMT. She underwent resection of the PMT with resolution of TIO and increased bone density. This rare case of TIO secondary to a PMT of the thoracic spine highlights some of the common features of PMT-associated TIO and draws attention to PMT-associated TIO as a possible cause of unexplained persistent bone pain, a disease entity that often goes undiagnosed and untreated for years. Learning points: Tumor-induced osteomalacia (TIO) is typically caused by phosphaturic mesenchymal tumors (PMTs) that are usually found in the soft tissue of the extremities and bone of the appendicular skeleton/cranium and rarely in the spine. TIO may be misdiagnosed as osteoporosis or spondyloarthritis, and the correct diagnosis is often delayed for years. However, osteoporosis, in the absence of fracture, is not associated with bone pain. The hallmark of TIO is hypophosphatemia with inappropriately normal or low 1,25-dihydroxyvitamin D and elevated or inappropriately normal fibroblast growth factor-23 (FGF23) levels. In patients with unexplained persistent bone pain, a serum phosphate should be measured. Consider PMT-associated TIO as a potential cause of unexplained persistent bone pain and hypophosphatemia. PMTs express somatostatin receptors and may be identified with 68Ga-DOTATATE imaging. Complete surgical resection is the preferred treatment for spinal PMTs associated with TIO.

Estrogens and Progestins Cooperatively Shift Breast Cancer Cell Metabolism.

Metabolic reprogramming remains largely understudied in relation to hormones in estrogen receptor (ER) and progesterone receptor (PR) positive breast cancer. In this study, we investigated how estrogens, progestins, or the combination, impact metabolism in three ER and PR positive breast cancer cell lines. We measured metabolites in the treated cells using ultra-performance liquid chromatography coupled with mass spectrometry (UPLC-MS). Top metabolic processes upregulated with each treatment involved glucose metabolism, including Warburg effect/glycolysis, gluconeogenesis, and the pentose phosphate pathway. RNA-sequencing and pathway analysis on two of the cell lines treated with the same hormones, found estrogens target oncogenes, such as MYC and PI3K/AKT/mTOR that control tumor metabolism, while progestins increased genes associated with fatty acid metabolism, and the estrogen/progestin combination additionally increased glycolysis. Phenotypic analysis of cell energy metabolism found that glycolysis was the primary hormonal target, particularly for the progestin and estrogen-progestin combination. Transmission electron microscopy found that, compared to vehicle, estrogens elongated mitochondria, which was reversed by co-treatment with progestins. Progestins promoted lipid storage both alone and in combination with estrogen. These findings highlight the shift in breast cancer cell metabolism to a more glycolytic and lipogenic phenotype in response to combination hormone treatment, which may contribute to a more metabolically adaptive state for cell survival.

The genome organization of Neurospora crassa at high resolution uncovers principles of fungal chromosome topology.

The eukaryotic genome must be precisely organized for its proper function, as genome topology impacts transcriptional regulation, cell division, replication, and repair, among other essential processes. Disruptions to human genome topology can lead to diseases, including cancer. The advent of chromosome conformation capture with high-throughput sequencing (Hi-C) to assess genome organization has revolutionized the study of nuclear genome topology; Hi-C has elucidated numerous genomic structures, including chromosomal territories, active/silent chromatin compartments, Topologically Associated Domains, and chromatin loops. While low-resolution heatmaps can provide important insights into chromosomal level contacts, high-resolution Hi-C datasets are required to reveal folding principles of individual genes. Of particular interest are high-resolution chromosome conformation datasets of organisms modeling the human genome. Here, we report the genome topology of the fungal model organism Neurospora crassa at a high resolution. Our composite Hi-C dataset, which merges 2 independent datasets generated with restriction enzymes that monitor euchromatin (DpnII) and heterochromatin (MseI), along with our DpnII/MseI double digest dataset, provide exquisite detail for both the conformation of entire chromosomes and the folding of chromatin at the resolution of individual genes. Within constitutive heterochromatin, we observe strong yet stochastic internal contacts, while euchromatin enriched with either activating or repressive histone post-translational modifications associates with constitutive heterochromatic regions, suggesting intercompartment contacts form to regulate transcription. Consistent with this, a strain with compromised heterochromatin experiences numerous changes in gene expression. Our high-resolution Neurospora Hi-C datasets are outstanding resources to the fungal community and provide valuable insights into higher organism genome topology.

Self-organization and information transfer in Antarctic krill swarms.

Antarctic krill swarms are one of the largest known animal aggregations, and yet, despite being the keystone species of the Southern Ocean, little is known about how swarms are formed and maintained. Understanding the local interactions between individuals that provide the basis for these swarms is fundamental to knowing how swarms arise in nature, and what potential factors might lead to their breakdown. Here, we analysed the trajectories of captive, wild-caught krill in 3D to determine individual-level interaction rules and quantify patterns of information flow. Our results demonstrate that krill align with near neighbours and that they regulate both their direction and speed relative to the positions of groupmates. These results suggest that social factors are vital to the formation and maintenance of swarms. Furthermore, krill operate a novel form of collective organization, with measures of information flow and individual movement adjustments expressed most strongly in the vertical dimension, a finding not seen in other swarming species. This research represents a vital step in understanding the fundamentally important swarming behaviour of krill.

Rapid histological imaging of bone without microtome sectioning using nonlinear microscopy.

Tissue preparation for histologic evaluation of bone is particularly lengthy, limiting its use in intraoperative or intraprocedural histological evaluation. Nonlinear microscopy (NLM) is an optical sectioning microscopy method that can visualize pathology in freshly excised tissue without requiring physical microtome sectioning. This study describes a rapid protocol for NLM imaging of bone and associated cartilage. NLM imaging was performed on 71 specimens of normal bone as well as arthritic, malignant and inflammatory bone tissue from 40 patients who underwent joint replacement, amputation, bone marrow biopsy or autopsy. Specimens ranged in size from core needle biopsies to transections of entire femoral heads. Specimens were stained with acridine orange and sulforhodamine 101, nuclear and cytoplasmic/stromal fluorescent dyes, for 5 min, then rinsed for 30 s. NLM fluorescent images were displayed using colors analogous to hematoxylin and eosin (H&E) to facilitate interpretation. Pathologists examined NLM images of the specimens in real time by rapidly translating the specimen to areas of interest, similar to a standard transmission light microscope. By adjusting the NLM focus depth, images from a few-µm-thick layer could be obtained down to ~100 µm below the tissue surface, analogous to serial sectioning. Following real-time NLM imaging, the tissue was processed for conventional paraffin histology, and H&E slides were compared to recorded NLM images. Similarities and differences between NLM and paraffin H&E were assessed. NLM enabled visualization of normal bone architecture, including the lamellar matrix and osteocytes of trabecular bone, articular cartilage, as well as pathological bone features such osteoarthritis, osteomyelitis, and malignancy with an appearance resembling the paraffin H&E. Differences such as changes in cell border sharpness, cellular and nucleolar size, and color patterns were noted, suggesting that training is required for accurate evaluation of bone pathology with NLM. Irregular surface contours and debris generated by gross tissue preparation of bone can make some regions difficult to evaluate with NLM, but the ability to perform rapid three-dimensional translation and sub-surface imaging reduced these problems. NLM is a promising technique for rapid evaluation of bone pathology. Further studies assessing diagnostic performance are warranted.

The Study of Developmental Risk Factors for Early Fire Involvement.

Child fireplay may be regarded as developmentally appropriate, yet can negatively impact those who engage in it and those around them. This study discusses the mental health, fire-specific, and psychosocial risk factors of children who set fires. Fifty-seven caregivers reported on their children's demographics, firesetting behaviors, mental health symptoms, and family history. Children were aged 2-6 years and the majority were male. Most children used lighters and matches on paper and small objects. The majority of the children were motivated by curiosity. Children who set more fires had more externalizing symptoms, and were more likely to have accomplices, to have been exposed to firesetting media, and to have been disciplined or punished for their firesetting behaviors. The study identifies important psychosocial risk factors among young children who set fires. Given the long-term implications of firesetting, understanding firesetting in children will set the foundation of intervention and prevention models.

More Specialties, Fewer Problems: Using Collaborative Competency Between Infectious Diseases, Podiatry, and Pathology to Improve the Care of Patients with Diabetic Foot Osteomyelitis.

BACKGROUND: Diabetic foot osteomyelitis is a common infection where treatment involves multiple services, including infectious diseases, podiatry, and pathology. Despite its ubiquity in the hospital, consensus on much of its management is lacking. METHODS: Representatives from infectious diseases, podiatry, and pathology interested in quality improvement developed multidisciplinary institutional recommendations culminating in an educational intervention describing optimal diagnostic and therapeutic approaches to diabetic foot osteomyelitis (DFO). Knowledge acquisition was assessed by preintervention and postintervention surveys. Inpatients with forefoot DFO were retrospectively reviewed before and after intervention to assess frequency of recommended diagnostic and therapeutic maneuvers, including appropriate definition of surgical bone margins, definitive histopathology reports, and unnecessary intravenous antibiotics or prolonged antibiotic courses. RESULTS: A postintervention survey revealed significant improvements in knowledge of antibiotic treatment duration and the role of oral antibiotics in managing DFO. There were 104 consecutive patients in the preintervention cohort (April 1, 2018, to April 1, 2019) and 32 patients in the postintervention cohort (November 5, 2019, to March 1, 2020), the latter truncated by changes in hospital practice during the coronavirus disease 2019 pandemic. Noncategorizable or equivocal disease reports decreased from before intervention to after intervention (27.0% versus 3.3%, respectively; P = .006). We observed nonsignificant improvement in correct bone margin definition (74.0% versus 87.5%; P = .11), unnecessary peripherally inserted central catheter line placement (18.3% versus 9.4%; P = .23), and unnecessary prolonged antibiotics (21.9% versus 5.0%; P = .10). In addition, by working as an interdisciplinary group, many solvable misunderstandings were identified, and processes were adjusted to improve the quality of care provided to these patients. CONCLUSIONS: This quality improvement initiative regarding management of DFO led to improved provider knowledge and collaborative competency between these three departments, improvements in definitive pathology reports, and nonsignificant improvement in several other clinical endpoints. Creating collaborative competency may be an effective local strategy to improve knowledge of diabetic foot infection and may generalize to other common multidisciplinary conditions.

Advances in Analyzing the Breast Cancer Lipidome and Its Relevance to Disease Progression and Treatment.

Abnormal lipid metabolism is common in breast cancer with the three main subtypes, hormone receptor (HR) positive, human epidermal growth factor 2 (HER2) positive, and triple negative, showing common and distinct lipid dependencies. A growing body of studies identify altered lipid metabolism as impacting breast cancer cell growth and survival, plasticity, drug resistance, and metastasis. Lipids are a class of nonpolar or polar (amphipathic) biomolecules that can be produced in cells via de novo synthesis or acquired from the microenvironment. The three main functions of cellular lipids are as essential components of membranes, signaling molecules, and nutrient storage. The use of mass spectrometry-based lipidomics to analyze the global cellular lipidome has become more prevalent in breast cancer research. In this review, we discuss current lipidomic methodologies, highlight recent breast cancer lipidomic studies and how these findings connect to disease progression and therapeutic development, and the potential use of lipidomics as a diagnostic tool in breast cancer. A better understanding of the breast cancer lipidome and how it changes during drug resistance and tumor progression will allow informed development of diagnostics and novel targeted therapies.

Social context affects camouflage in a cryptic fish species.

Crypsis, or the ability to avoid detection and/or recognition, is an important and widespread anti-predator strategy across the animal kingdom. Many animals are able to camouflage themselves by adapting their body colour to the local environment. In particular, rapid changes in body colour are often critical to the survival of cryptic prey which rely on evading detection by predators. This is especially pertinent for animals subject to spatio-temporal variability in their environment, as they must adapt to acute changes in their visual surroundings. However, which features of the local environment are most relevant is not well understood. In particular, little is known about how social context interacts with other environmental stimuli to influence crypsis. Here, we use a common cryptic prey animal, the goby (Pseudogobius species 2) to examine how the presence and body colour of conspecifics influence the rate and extent to which gobies change colour. We find that solitary gobies change colour to match their background faster and to a greater extent than gobies in pairs. Further, we find that this relationship holds irrespective of the colour of nearby conspecifics. This study demonstrates the importance of social context in mediating colour change in cryptic animals.

Translation of mechanical strain to a scalable biomanufacturing process for acellular matrix production from full thickness porcine bladders.

Bladder acellular matrix has promising applications in urological and other reconstructive surgery as it represents a naturally compliant, non-immunogenic and highly tissue-integrative material. As the bladder fills and distends, the loosely-coiled bundles of collagen fibres in the wall become extended and orientate parallel to the lumen, resulting in a physical thinning of the muscular wall. This accommodating property can be exploited to achieve complete decellularisation of the full-thickness bladder wall by immersing the distended bladder through a series of hypotonic buffers, detergents and nucleases, but the process is empirical, idiosyncratic and does not lend itself to manufacturing scale up. In this study we have taken a mechanical engineering approach to determine the relationship between porcine bladder size and capacity, to define the biaxial deformation state of the tissue during decellularisation and to apply these principles to the design and testing of a scalable novel laser-printed flat-bed apparatus in order to achieve reproducible and full-thickness bladder tissue decellularisation. We demonstrate how the procedure can be applied reproducibly to fresh, frozen or twice-frozen bladders to render8×8 cm2patches of DNA-free acellular matrix suitable for surgical applications.

The Human Aspect of Horse Care: How the COVID-19 Pandemic Impacted the Wellbeing of Equestrian Industry Stakeholders.

During the lockdown phase of the COVID-19 pandemic, equestrian stakeholders faced a dilemma whereby they were required to balance caring for the welfare of horses with adapting to the restrictions imposed to protect public health. The present study investigated the impact of the pandemic on the wellbeing of a sample of industry stakeholders, including horse owners, equine veterinarians, farriers and welfare centre managers (n = 26) using a qualitative methodology. Findings from the interviews indicated that the mental health and wellbeing of veterinarians and horse owners was negatively affected by pandemic-related obstacles to communication and limitations to horse-owner interactions. However, this study also identified several positive outcomes for wellbeing during lockdown resulting from pro-social activities that were engaged with by horse owners to overcome social isolation, the separation of the community and loneliness. These findings provide accounts of ways in which those caring for horses might be challenged during national emergency scenarios, pointing to areas that would benefit from future mental health and wellbeing interventions.

COVID-19 impacts equine welfare: Policy implications for laminitis and obesity.

The COVID-19 pandemic continues to impact human health and welfare on a global level. In March 2020, stringent national restrictions were enforced in the UK to protect public health and slow the spread of the SARS-CoV-2 virus. Restrictions were likely to have resulted in collateral consequences for the health and welfare of horses and ponies, especially those at risk of obesity and laminitis and this issue warranted more detailed exploration. The current study utilised qualitative methodology to investigate the implications of COVID-19 related policies upon equine management and welfare with a focus on horses and ponies at risk of laminitis and obesity. Twenty-four interviews with five sub-groups of key equestrian welfare stakeholders in the UK were conducted between May and July of 2020 to understand the challenges facing equine welfare in the context of laminitis and obesity susceptible animals. Thematic analysis revealed lockdown-associated factors with the potential to compromise welfare of horses and ponies at risk of obesity and laminitis. These included: disparate information and guidance, difficulties enacting public health measures in yard environments, and horses having reduced exercise during the pandemic. Positive examples of clear and consistent information sharing by farriers were reported to have improved horse owner understanding of routine hoof care during lockdown. Analysis suggested that the recommendations for supporting the management-based needs of horses under reduced supervision were not clearly defined, or were not sufficiently disseminated, across the equine industry. These findings support the development of guidelines specific to the care of horses and ponies at risk of obesity and laminitis through collaborative input from veterinary and welfare experts, to reduce the negative impacts of future lockdown events in the UK.

Sexual differences in bone porosity, osteocyte density, and extracellular matrix organization due to osteoblastic-specific Bmp2 deficiency in mice.

Clinical studies have come to conflicting conclusions regarding BMP2 deficiency's link to regulating bone mass and increasing fracture risk. This may be due to the signaling protein having sex- or age-dependent effects. Previous pre-clinical studies have supported a role, but have not adequately determined the physical mechanism causing altered bulk material properties. This study investigated the physical effects of Bmp2 ablation from osteogenic lineage cells (Osx-Cre; Bmp2fl/fl) in 10- and 15-week-old male and female mice. Bones collected post-mortem were subjected to fracture toughness testing, reference point indentation testing, microCT, and histological analysis to determine the multi-scale relationships between mechanical/material behavior and collagen production, collagen organization, and bone architecture. BMP2-deficient bones were smaller, more brittle, and contained more lacunae-scale voids and cortical pores. The cellular density was significantly increased and there were material-level differences measured by reference point indentation, independently of collagen fiber alignment or organization. The disparities in bone size and in bone fracture toughness between genotypes were especially striking in males at 15-weeks-old. Together, this study suggests that there are sex- and age-dependent effects of BMP2 deficiency. The results from both sexes also warrant further investigation into BMP2 deficiency's role in osteoblasts' transition to osteocytes and overall bone porosity.

Social rank and not physiological capacity determines competitive success in zebrafish (Danio rerio).

Competition for resources shapes ecological and evolutionary relationships. Physiological capacities such as in locomotor performance can influence the fitness of individuals by increasing competitive success. Social hierarchy too can affect outcomes of competition by altering locomotor behaviour or because higher ranking individuals monopolize resources. Here, we tested the hypotheses that competitive success is determined by sprint performance or by social status. We show that sprint performance of individuals measured during escape responses (fast start) or in an accelerated sprint test did not correlate with realized sprint speed while competing for food within a social group of five fish; fast start and accelerated sprint speed were higher than realized speed. Social status within the group was the best predictor of competitive success, followed by realized speed. Social hierarchies in zebrafish are established within 7 days of their first encounter, and interestingly, there was a positive correlation between social status and realized speed 1 and 4 days after fish were placed in a group, but not after 7 days. These data indicate that physiological performance decreases in importance as social relationships are established. Also, maximal physiological capacities were not important for competitive success, but swimming speed changed with social context.