Abstract
We use the upgraded Giant Metrewave Radio Telescope (uGMRT) to measure scintillation arc properties in six bright canonical pulsars with simultaneous dual-frequency coverage. These ...observations, at frequencies from 300 to 750 MHz, allowed for detailed analysis of arc evolution across frequency and epoch. We perform more robust determinations of frequency dependence for arc curvature, scintillation bandwidth, and scintillation timescale, and comparison between arc curvature and pseudo-curvature than allowed by single-frequency-band-per-epoch measurements, which we find to agree with theory and previous literature. We find a strong correlation between arc asymmetry and arc curvature, which we have replicated using simulations, and attribute to a bias in the Hough transform approach to scintillation arc analysis. Possible evidence for an approximately week-long timescale over which a given scattering screen dominates signal propagation was found by tracking visible scintillation arcs in each epoch in PSR J1136+1551. The inclusion of a 155-minute observation allowed us to resolve the scale of scintillation variations on short timescales, which we find to be directly tied to the amount of interstellar medium sampled over the observation. Some of our pulsars showed either consistent or emerging asymmetries in arc curvature, indicating instances of refraction across their lines of sight. Significant features in various pulsars, such as multiple scintillation arcs in PSR J1136+1551 and flat arclets in PSR J1509+5531, that have been found in previous works, were also detected. The simultaneous multiple-band observing capability of the upgraded GMRT shows excellent promise for future pulsar scintillation work.
One of the most endangered vertebrates, the Devils Hole pupfish Cyprinodon diabolis, survives in a nearly impossible environment: a narrow subterranean fissure in the hottest desert on earth, Death ...Valley. This species became a conservation icon after a landmark 1976 US Supreme Court case affirming federal groundwater rights to its unique habitat. However, one outstanding question about this species remains unresolved: how long has diabolis persisted in this hellish environment? We used next-generation sequencing of over 13 000 loci to infer the demographic history of pupfishes in Death Valley. Instead of relicts isolated 2–3 Myr ago throughout repeated flooding of the entire region by inland seas as currently believed, we present evidence for frequent gene flow among Death Valley pupfish species and divergence after the most recent flooding 13 kyr ago. We estimate that Devils Hole was colonized by pupfish between 105 and 830 years ago, followed by genetic assimilation of pelvic fin loss and recent gene flow into neighbouring spring systems. Our results provide a new perspective on an iconic endangered species using the latest population genomic methods and support an emerging consensus that timescales for speciation are overestimated in many groups of rapidly evolving species.
Abstract
We simulate scattering delays from the interstellar medium to examine the effectiveness of three estimators in recovering these delays in pulsar timing data. Two of these estimators use the ...more traditional process of fitting autocorrelation functions to pulsar dynamic spectra to extract scintillation bandwidths, while the third estimator uses the newer technique of cyclic spectroscopy on baseband pulsar data to recover the interstellar medium’s impulse response function. We find that either fitting a Lorentzian or Gaussian distribution to an autocorrelation function or recovering the impulse response function from the cyclic spectrum are, on average, accurate in recovering scattering delays, although autocorrelation function estimators have a large variance, even at high signal-to-noise ratio (S/N). We find that, given sufficient S/N, cyclic spectroscopy is more accurate than both Gaussian and Lorentzian fitting for recovering scattering delays at specific epochs, suggesting that cyclic spectroscopy is a superior method for scattering estimation in high-quality data.
Deployment of mouse carcasses laced with acetaminophen has become a common management tool to control invasive brown tree snakes (
Boiga irregularis
; BTS) on Guam. Additionally, anticoagulant ...rodenticides may be used to control invasive rats (
Rattus
spp.) if their populations increase due to predator release in the wake of BTS eradication. However, there has been little research examining how scavengers on Guam could be incidentally exposed to toxicants by scavenging carcasses of animals that die from these population control strategies. Furthermore, there is a limited understanding of how the proliferation of invasive species on Guam has influenced the composition of the scavenger community. We investigated these topics by examining scavenger consumption of mouse, rat, and BTS carcasses on Guam in both a coastal and upland site during the wet (May–Aug 2016) and dry season (Jan–Apr 2017). We documented carcass consumption by 9 species, which scavenged 48% of carcasses. Interactions between season, habitat, and carcass type influenced probability of scavenging, and appeared to be driven by consumption by the two main scavenger species, BTS and cane toads (
Rhinella marina
), both of which are invasive on Guam. Baiting programs should consider the potential for toxin exposure to land crabs (
Coenobita
spp.,
Birgus latro
), native species that scavenged at every combination of carcass type, habitat, and season. Overall, 60% of scavenging events were attributed to species considered pests that are recent introductions to Guam. Invasive species on Guam are the primary scavengers of small vertebrate carrion, suggesting a substantial role in trophic dynamics that extends beyond predation.
Decreases in individuals' physical activity and increases in sedentary behavior and bodyweight have been reported during the COVID-19 pandemic. The present study assessed the ability of physical ...activity monitoring, which may promote physical activity and discourage sedentary behavior, to mitigate these negative outcomes. An evaluation of university samples (
= 404, 40.5 ± 15.4 years) of self-reported physical activity, sedentary behavior, and bodyweight prior to the closure of campus due to the pandemic in March of 2020 and again at the time of the survey administration (May-June 2020) during pandemic-related restrictions was performed. Participants also reported whether they did (
= 172) or did not (
= 232) regularly use physical activity monitoring technology. While physical activity was unchanged during the pandemic (
≥ 0.15), participants significantly increased sitting by 67.8 ± 156.6 min/day and gained 0.64 ± 3.5 kg from pre-campus to post-campus closure (
< 0.001). However, the use of activity monitoring did not moderate these changes. In conclusion, while physical activity was not affected, participants reported significant increases in sedentary behavior and bodyweight during the COVID-19 pandemic. These changes occurred regardless of whether participants regularly used physical activity monitoring or not.
Paxillin family proteins regulate intracellular signaling downstream of extracellular matrix adhesion. Tissue expression patterns and cellular functions of Paxillin proteins during embryo development ...remain poorly understood. Additionally, the evolution of this gene family has not been thoroughly investigated.
This report characterizes the evolution and expression of a novel Paxillin gene, called Paxillin-b, in Teleosts. Alignments indicate that Teleost Paxillin-a and Paxillin-b proteins are highly homologous to each other and to human Paxillin. Phylogenetic and synteny analyses suggest that these genes originated from the duplication of an ancestral Paxillin gene that was in a common ancestor of Teleosts and Tetrapods. Analysis of the spatiotemporal expression profiles of Paxillin-a and Paxillin-b using zebrafish revealed both overlapping and distinct domains for Paxillin-a and Paxillin-b during embryo development. Localization of zebrafish Paxillin orthologs expressed in mammalian cells demonstrated that both proteins localize to focal adhesions, similar to mammalian Paxillin. This suggests these proteins regulate adhesion-dependent processes in their endogenous tissues.
Paxillin-a and Paxillin-b were generated by duplication in Teleosts. These genes likely play similar roles as Paxillin genes in other organisms. This work provides a framework for functional investigation of Paxillin family members during development using the zebrafish as an in vivo model system.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The aim was to assess topics of interest and concerns among patients with inflammatory bowel diseases (IBD) who are active online.
Social media (SM) networks are a major communication tool for ...patients with IBD and health care professionals.
We performed an anonymized investigation of SM networks for IBD patients; I-a thematic analysis of patients' posts, II-an online survey advertised through Facebook and other popular SM networks throughout November 2019.
Analyzing 2133 posts (2014 to 2019) revealed 18 topics of interest. The online survey was completed by 534 respondents 63%-Crohn's disease, 56%-female, median age-38 years (interquartile range: 28.7 to 51.0). Most respondents (70%) were followed in referral centers, and 45% were receiving biological therapy. Respondents reported high satisfaction with IBD care and health care provider professionalism. The top 5 topics of interest were diet, lifestyle, complementary and alternative medicine, diagnostic test interpretation, and specialist referrals and reviews. Cluster analysis demonstrated that gender, income, and education level were associated with specific interest and concerns.
Patients' activity on SM is independent of their satisfaction with formal IBD care and rather reflects an ongoing need for information and support. These needs may be addressed both in clinical settings and through online tools.
Paxillin (Pxn) is a key adapter protein and signaling regulator at sites of cell-extracellular matrix (ECM) adhesion. Here, we investigated the role of Pxn during vertebrate development using the ...zebrafish embryo as a model system. We have characterized two Pxn genes, pxna and pxnb, in zebrafish that are maternally supplied and expressed in multiple tissues. Gene editing and antisense gene knockdown approaches were used to uncover Pxn functions during zebrafish development. While mutation of either pxna or pxnb alone did not cause gross embryonic phenotypes, double mutants lacking maternally supplied pxna or pxnb displayed defects in cardiovascular, axial, and skeletal muscle development. Transient knockdown of Pxn proteins resulted in similar defects. Irregular myotome shape and ECM composition were observed, suggesting an “inside-out” signaling role for Paxillin genes in the development of myotendinous junctions. Inhibiting non-muscle Myosin-II during somitogenesis altered the subcellular localization of Pxn protein and phenocopied pxn gene loss-of-function. This indicates that Paxillin genes are effectors of actomyosin contractility-driven morphogenesis of trunk musculature in zebrafish. Together, these results reveal new functions for Pxn during muscle development and provide novel genetic models to elucidate Pxn functions.
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•Zebrafish paxillin genes regulate heart, notochord and skeletal muscle development.•Maternally supplied Paxillin proteins have non-redundant roles during development.•Loss of Paxillin alters extracellular matrix composition of myotendinous junctions.•Actomyosin cytoskeletal contractility is required for Paxillin localization to developing somite boundaries.
Abstract Although research including biological concepts and variables has gained more prominence in sociology, progress assimilating the organ of experience, the brain, has been theoretically and ...technically challenging. Formal uptake and assimilation have thus been slow. Within psychology and neuroscience, the traditional brain, which has made brief appearances in sociological research, is a “bottom–up” processor in which sensory signals are passed up the neural hierarchy where they are eventually cognitively and emotionally processed, after which actions and responses are generated. In this paper, we introduce the Active Inference Framework (AIF), which casts the brain as a Bayesian “inference engine” that tests its “top–down” predictive models against “bottom–up” sensory error streams in its attempts to resolve uncertainty and make the world more predictable. After assembling and presenting key concepts in the AIF, we describe an integrated neuro-bio-social model that prioritizes the microsociological assertion that the scene of action is the situation, wherein brains enculturate. Through such social dynamics, enculturated brains share models of the world with one another, enabling collective realities that disclose the actions afforded in those times and places. We conclude by discussing this neuro-bio-social model within the context of exemplar sociological research areas, including the sociology of stress and health, the sociology of emotions, and cognitive cultural sociology, all areas where the brain has received some degree of recognition and incorporation. In each case, sociological insights that do not fit naturally with the traditional brain model emerge intuitively from the predictive AIF model, further underscoring the interconnections and interdependencies between these areas, while also providing a foundation for a probabilistic sociology.
Zusammenfassung Trotz der zunehmenden Prominenz einer biologische Konzepte und Variablen einbeziehenden Forschung in der Soziologie steht ein ähnlicher Fortschritt bei der Berücksichtigung unseres Erfahrungsorgans, des Gehirns, in die soziologische Forschung vor theoretischen und technischen Herausforderungen. Eine formale Umsetzung und Integration ging daher bisher nur langsam voran. In der Psychologie und in den Neurowissenschaften wurde das Gehirn traditionell als ein „Bottom-up“-Prozessor angesehen, bei dem sensorische Signale entlang der neuronalen Hierarchie in höhere Hirnregionen weitergeleitet werden, wo sie schließlich kognitiv und emotional verarbeitet und woraufhin Aktionen und Reaktionen generiert werden. Diese traditionelle Sicht auf das Gehirn wurde in der soziologischen Forschung vereinzelt aufgegriffen. In diesem Beitrag stellen wir das Active Inference Framework (AIF) vor, demzufolge das Gehirn eine Bayesianische „Inferenzmaschine“ ist, die ihre „Top-down“-Vorhersagemodelle anhand von „Bottom-up“-Wahrnehmungen von Vorhersagefehlern prüft, um Unsicherheiten zu beseitigen und die Welt berechenbarer zu machen. Nach einer Zusammenstellung und Einführung von Schlüsselkonzepten des AIF beschreiben wir ein integriertes neuro-bio-soziales Modell, das der mikrosoziologischen These folgt, dass die Situation der Schauplatz des Handelns ist, in der Gehirne sich enkulturieren. Durch solche sozialen Dynamiken teilen enkulturierte Hirne Modelle der Welt miteinander und ermöglichen so kollektive Realitäten, die für die Zeit und den Ort angemessene Handlungen nahelegen. Abschließend wird dieses neuro-bio-soziale Modell im Kontext exemplarischer soziologischer Forschungsfelder diskutiert, darunter die Stress- und Gesundheitssoziologie, die Emotionssoziologie und die kognitive Kultursoziologie – alles Bereiche, in denen die Rolle des Gehirns in gewissem Maße beachtet und einbezogen wurde. In jedem Fall ergeben sich soziologische Erkenntnisse, die nicht in das traditionelle Hirnmodell passen, intuitiv aus dem prädiktiven AIF-Modell. Es verweist auf Verbindungen und Abhängigkeiten zwischen diesen Forschungsfeldern und bietet gleichzeitig eine Grundlage für eine probabilistische Soziologie.
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