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Spinocerebellar ataxia type 7 (SCA7) is a progressive neurodegenerative disorder resulting from abnormal expansion of an uninterrupted polyglutamine (polyQ) repeat in its disease protein, ataxin-7 (ATXN7). ATXN7 is part of Spt-Ada-Gcn5 acetyltransferase (SAGA), an evolutionarily conserved transcriptional coactivation complex with critical roles in chromatin remodeling, cell signaling, neurodifferentiation, mitochondrial health and autophagy. SCA7 is dominantly inherited and characterized by genetic anticipation and high repeat-length instability. Patients with SCA7 experience progressive ataxia, atrophy, spasticity, and blindness. There is currently no cure for SCA7, and therapies are aimed at alleviating symptoms to increase quality of life. Here, we report novel Drosophila lines of SCA7 with polyQ repeats in wild-type and human disease patient range. We find that ATXN7 expression has age- and polyQ repeat length-dependent reduction in fruit fly survival and retinal instability, concomitant with increased ATXN7 protein aggregation. These new lines will provide important insight on disease progression that can be used in the future to identify therapeutic targets for SCA7 patients., (© 2024. The Author(s).)

The COVID-19 pandemic has highlighted the importance of understanding what contributes to individual variability in experiences of stress. Increases in stress related to the pandemic have been especially pronounced in parents, indicating a need for research examining what factors contribute to parents' perceptions of stress. Here, we assessed the relationship between parents' perceptions of stress, control, loneliness, and experiences of childhood trauma in two populations of caregivers. In Study 1, we examined the relationship between perceptions of stress, control, loneliness, and history of early stress, along with indices of socioeconomic risk and resting parasympathetic nervous systema activity, which has been linked to variability in perceptions of stress, in caregivers of young children. Perceived control, loneliness, childhood stress, and resting parasympathetic nervous system activity predicted caregivers' stress. In Study 2, we replicated these initial findings in a second sample of caregivers. Additionally, we examined how these processes change over time. Caregivers demonstrated significant changes in perceptions of control, loneliness, and stress, and changes in control and childhood trauma history were associated with changes in perceptions of stress. Together these results indicate the importance of assessing how caregivers perceive their environment when examining what contributes to increased risk for stress. Additionally, they suggest that caregivers' stress-related processes are malleable and provide insight into potential targets for interventions aimed at reducing parents' stress., (© 2023. Springer Nature Limited.)

The perennial western ragweed (Ambrosia psilostachya DC.) arrived from North America to Europe in the late nineteenth century and behaves invasive in its non-native range. Due to its efficient vegetative propagation via root suckers, A. psilostachya got naturalized in major parts of Europe forming extensive populations in Mediterranean coastal areas. The invasion history, the spreading process, the relationships among the populations as well as population structuring is not yet explored. This paper aims to give first insights into the population genetics of A. psilostachya in its non-native European range based on 60 sampled populations and 15 Simple Sequence Repeats (SSR). By AMOVA analysis we detected 10.4% of genetic variation occurring among (pre-defined) regions. These regions represent important harbors for trading goods from America to Europe that might have served as source for founder populations. Bayesian Clustering revealed that spatial distribution of genetic variation of populations is best explained by six groups, mainly corresponding to regions around important harbors. As northern populations show high degrees of clonality and lowest levels of within-population genetic diversity (mean H o  = 0.40 ± 0.09), they could preserve the initial genetic variation levels by long-lived clonal genets. In Mediterranean populations A. psilostachya expanded to millions of shoots. Some of those were obviously spread by sea current along the coast to new sites, where they initiated populations characterized by a lower genetic diversity. For the future, the invasion history in Europe might get clearer after consideration of North American source populations of western ragweed., (© 2023. The Author(s).)

Choices under risk often have consequences for ourselves and others. Yet, it is unclear how the other's identity (stranger, close friend, etc.) influences risky choices made on their behalf. In a mixed within and between subjects design, two participant groups made three series of risky economic decisions: for themselves, another person, or for both themselves and another person (i.e., shared outcomes). One group made choices involving a same-sex stranger (n = 29), the other made choices involving a same-sex close friend (n = 28). Hierarchical Bayesian estimation of computations underlying risky decision-making revealed that relative to choosing for themselves, people were more risk averse, loss averse, and consistent when choices involved another person. Partner identity was additionally crucial: people became risk neutral and more consistent when choosing for friends relative to strangers. These findings establish that the complexity of the social world is mirrored in its nuanced consequences for our choices., (© 2022. The Author(s).)

Current declines in terrestrial insect biomass and abundance have raised global concern for the fate of insects and the ecosystem services they provide. However, the ecological and economic contributions of many insects have yet to be quantified. Carrion-specializing invertebrates are important mediators of carrion decomposition; however, the role of their reproductive activities in facilitating this nutrient pulse into ecosystems is poorly understood. Here, we investigate whether insects that sequester carrion belowground for reproduction alter soil biotic and abiotic properties in North American temperate forests. We conducted a field experiment that measured soil conditions in control, surface carrion alone, and beetle-utilized carrion treatments. Our data demonstrate that Nicrophorus beetle reproduction and development results in changes in soil characteristics which are consistent with those observed in surface carrion decomposition alone. Carrion addition treatments increase soil labile C, DON and DOC, while soil pH and microbial C:N ratios decrease. This study demonstrates that the decomposition of carrion drives soil changes but suggests that the behaviors of insect scavengers play an important role in the release of carrion nutrients directly into the soil by sequestering carrion resources in the ecosystem where they were deposited.

Native livestock breeds, i.e. those autochthonous to a specific region, are locally adapted domesticated animals that conserve genetic resources, guaranty food security and provide agroecosystem services. Native breeds are largely threatened worldwide by agricultural intensification and rural areas abandonment processes related to recent changes in production schemes and planning. Yet, our gap of knowledge regarding livestock breed-environment relationships may prevent the design of successful conservation measures. In this work, we analyse the links between livestock diversity -i.e. richness of native breeds- and a selection of environmental factors that express at broad scales, with a temporal perspective. We compare native breeds distributional patterns before and after the agricultural intensification, in the context of land-use change in mainland Spain. Our results confirm the existence of strong associations between the distribution of native livestock breeds and environmental factors. These links, however, weaken for contemporary distributions. In fact, changes in breed distribution reflect a shift towards more productive environments. Finally, we found that the areas having higher breed richness are undergoing land abandonment processes. Succeeding in the conservation of threatened native breeds will require going beyond merely genetic and production-oriented views. Ecological and sociocultural perspectives should also be accounted for as global change processes are determinant for livestock agrobiodiversity.

Fear of the speculum and feelings of vulnerability during the gynecologic exams are two of the biggest barriers to cervical cancer screening for women. To address these barriers, we have developed a novel, low-cost tool called the Callascope to reimagine the gynecological exam, enabling clinician and self-imaging of the cervix without the need for a speculum. The Callascope contains a 2 megapixel camera and contrast agent spray mechanism housed within a form factor designed to eliminate the need for a speculum during contrast agent administration and image capture. Preliminary bench testing for comparison of the Callascope camera to a $20,000 high-end colposcope demonstrated that the Callascope camera meets visual requirements for cervical imaging. Bench testing of the spray mechanism demonstrates that the contrast agent delivery enables satisfactory administration and cervix coverage. Clinical studies performed at Duke University Medical Center, Durham, USA and in Greater Accra Regional Hospital, Accra, Ghana assessed (1) the Callascope's ability to visualize the cervix compared to the standard-of-care speculum exam, (2) the feasibility and willingness of women to use the Callascope for self-exams, and (3) the feasibility and willingness of clinicians and their patients to use the Callascope for clinician-based examinations. Cervix visualization was comparable between the Callascope and speculum (83% or 44/53 women vs. 100%) when performed by a clinician. Visualization was achieved in 95% (21/22) of women who used the Callascope for self-imaging. Post-exam surveys indicated that participants preferred the Callascope to a speculum-based exam. Our results indicate the Callascope is a viable option for clinician-based and self-exam speculum-free cervical imaging.Clinical study registration ClinicalTrials.gov https://clinicaltrials.gov/ct2/show/record/ NCT00900575, Pan African Clinical Trial Registry (PACTR) https://www.pactr.org/ PACTR201905806116817.

The adverse biological impact of orthopaedic wear debris currently limits the long-term safety of human joint replacement devices. We investigated the role of particle size, surface composition and donor variation in influencing the biological impact of silicon nitride as a bioceramic for orthopaedic applications. Silicon nitride particles were compared to the other commonly used orthopaedic biomaterials (e.g. cobalt-chromium and Ti-6Al-4V alloys). A novel biological evaluation platform was developed to simultaneously evaluate cytotoxicity, inflammatory cytokine release, oxidative stress, and genotoxicity potential of particles using peripheral blood mononuclear cells (PBMNCs) from individual human donors. Irrespective of the particle size, silicon nitride did not cause any adverse responses whereas cobalt-chromium wear particles caused donor-dependent cytotoxicity, TNF-α cytokine release, oxidative stress, and DNA damage in PBMNCs after 24 h. Despite being similar in size and morphology, silicon dioxide nanoparticles caused the release of significantly higher levels of TNF-α compared to silicon nitride nanoparticles, suggesting that surface composition influences the inflammatory response in PBMNCs. Ti-6Al-4V wear particles also released significantly elevated levels of TNF-α cytokine in one of the donors. This study demonstrated that silicon nitride is an attractive orthopaedic biomaterial due to its minimal biological impact on human PBMNCs.

Nonulosonic acids are found in the surface polysaccharides of many bacterial species and are often implicated in pathogenesis. Here, the structure of a novel 5,7-diacetamido-3,5,7,9-tetradeoxynon-2-ulosonic acid recovered from the capsular polysaccharide of a multiply antibiotic resistant Acinetobacter baumannii isolate was determined. The isolate carries a sugar synthesis module that differs by only a single gene from the module for the synthesis of 5,7-diacetamido-3,5,7,9-tetradeoxy-L-glycero-L-altro-non-2-ulosonic acid or 5,7-di-N-acetylacinetaminic acid, recently discovered in the capsule of another A. baumannii isolate. The new monosaccharide is the C8-epimer of acinetaminic acid (8eAci; 5,7-diacetamido-3,5,7,9-tetradeoxy-D-glycero-L-altro-non-2-ulosonic acid) and the C7-epimer of legionaminic acid. This monosaccharide had not previously been detected in a biological sample but had been synthesized chemically.

Land-use change and intensification threaten bee populations worldwide, imperilling pollination services. Global models are needed to better characterise, project, and mitigate bees' responses to these human impacts. The available data are, however, geographically and taxonomically unrepresentative; most data are from North America and Western Europe, overrepresenting bumblebees and raising concerns that model results may not be generalizable to other regions and taxa. To assess whether the geographic and taxonomic biases of data could undermine effectiveness of models for conservation policy, we have collated from the published literature a global dataset of bee diversity at sites facing land-use change and intensification, and assess whether bee responses to these pressures vary across 11 regions (Western, Northern, Eastern and Southern Europe; North, Central and South America; Australia and New Zealand; South East Asia; Middle and Southern Africa) and between bumblebees and other bees. Our analyses highlight strong regionally-based responses of total abundance, species richness and Simpson's diversity to land use, caused by variation in the sensitivity of species and potentially in the nature of threats. These results suggest that global extrapolation of models based on geographically and taxonomically restricted data may underestimate the true uncertainty, increasing the risk of ecological surprises.

The South Asian Monson (SAM) is one of the most intense climatic elements yet its initiation and variations are not well established. Dating the deposits of SAM wind-driven currents in IODP cores from the Maldives yields an age of 12. 9 Ma indicating an abrupt SAM onset, over a short period of 300 kyrs. This coincided with the Indian Ocean Oxygen Minimum Zone expansion as revealed by geochemical tracers and the onset of upwelling reflected by the sediment's content of particulate organic matter. A weaker 'proto-monsoon' existed between 12.9 and 25 Ma, as mirrored by the sedimentary signature of dust influx. Abrupt SAM initiation favors a strong influence of climate in addition to the tectonic control, and we propose that the post Miocene Climate Optimum cooling, together with increased continentalization and establishment of the bipolar ocean circulation, i.e. the beginning of the modern world, shifted the monsoon over a threshold towards the modern system.

The ability of primates, including humans, to maintain large social networks appears to depend on the ratio of the neocortex to the rest of the brain. However, observed human network size frequently exceeds predictions based on this ratio (e.g., "Dunbar's Number"), implying that human networks are too large to be cognitively managed. Here I show that humans adaptively use compression heuristics to allow larger amounts of social information to be stored in the same brain volume. I find that human adults can remember larger numbers of relationships in greater detail when a network exhibits triadic closure and kin labels than when it does not. These findings help to explain how humans manage large and complex social networks with finite cognitive resources and suggest that many of the unusual properties of human social networks are rooted in the strategies necessary to cope with cognitive limitations.