2,002 research outputs found

    Relief of the Dma1-mediated checkpoint requires Dma1 autoubiquitination and dynamic localization

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    © 2018 Jones, Chen, et al. Chromosome segregation and cell division are coupled to prevent aneuploidy and cell death. In the fission yeast Schizosaccharomyces pombe, the septation initiation network (SIN) promotes cytokinesis, but upon mitotic checkpoint activation, the SIN is actively inhibited to prevent cytokinesis from occurring before chromosomes have safely segregated. SIN inhibition during the mitotic checkpoint is mediated by the E3 ubiquitin ligase Dma1. Dma1 binds to the CK1-phosphorylated SIN scaffold protein Sid4 at the spindle pole body (SPB), and ubiquitinates it. Sid4 ubiquitination antagonizes the SPB localization of the Polo-like kinase Plo1, the major SIN activator, so that SIN signaling is delayed. How this checkpoint is silenced once spindle defects are resolved has not been clear. Here we establish that Dma1 transiently leaves SPBs during anaphase B due to extensive autoubiquitination. The SIN is required for Dma1 to return to SPBs later in anaphase. Blocking Dma1 removal from SPBs by permanently tethering it to Sid4 prevents SIN activation and cytokinesis. Therefore, controlling Dma1’s SPB dynamics in anaphase is an essential step in S. pombe cell division and the silencing of the Dma1-dependent mitotic checkpoint

    Early life social and ecological determinants of global DNA methylation in wild spotted hyenas

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    Environmental factors early in life can have lasting influence on the development and phenotypes of animals, but the underlying molecular modifications remain poorly understood. We examined cross‐sectional associations among early life socioecological factors and global DNA methylation in 293 wild spotted hyenas (Crocuta crocuta) in the Masai Mara National Reserve, Kenya, grouped according to three age classes (cub, subadult and adult). Explanatory variables of interest included annual maternal rank based on outcomes of dyadic agonistic interactions, litter size, wild ungulate prey density and anthropogenic disturbance in the year each hyena was born based on counts of illegal livestock in the Reserve. The dependent variable of interest was global DNA methylation, assessed via the LUminometric Methylation Assay, which provides a percentage methylation value calculated at CCGG sites across the genome. Among cubs, we observed approximately 2.75% higher CCGG methylation in offspring born to high‐ than low‐ranking mothers. Among cubs and subadults, higher anthropogenic disturbance corresponded with greater %CCGG methylation. In both cubs and adults, we found an inverse association between prey density measured before a hyena was 3 months old and %CCGG methylation. Our results suggest that maternal rank, anthropogenic disturbance and prey availability early in life are associated with later life global DNA methylation. Future studies are required to understand the extent to which these DNA methylation patterns relate to adult phenotypes and fitness outcomes.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151897/1/mec15174_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151897/2/mec15174.pd

    Clinical Presentation and Treatment of Early-Onset Behavior Disorders: The Role of Parent Emotion Regulation, Emotion Socialization, and Family Income

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    Parent emotion regulation and socialization have been linked to various aspects of child functioning. In the case of early-onset behavior disorders in particular, parent emotion regulation may be an important correlate of the coercive cycle implicated in early-onset behavior disorders thus, symptom presentation at baseline. Further, emotion socialization may be complicated by a pattern of parent-child interactions in which both supportive or unsupportive parenting behaviors in response to behavioral dysregulation may increase vulnerability for problem behavior in the future. Some work suggests standard Behavioral Parent Training may impact parent emotion regulation and socialization. Still little is known, however, about how such processes may vary by family income, which is critical given the overrepresentation of low-income children in statistics on early-onset behavior disorders. This study explored parent emotion regulation, socialization, and family income in a sample of socioeconomically diverse treatment-seeking families of young (3–8 years old) children. Findings suggest relations between parental emotion regulation, socialization, and child behavior although the pattern of associations differed at baseline and post-treatment and varied by family income. Clinical implications and future directions are discussed

    Patterns of predation and meat-eating by chacma baboons in an Afromontane environment

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    Meat-eating among non-human primates has been well documented but its prevalence among Afromontane baboons is understudied. In this study we report the predatory and meat-eating behaviours of a habituated group of gray-footed chacma baboons (Papio ursinus griseipes) living in an Afromontane environment in South Africa. We calculated a vertebrate-eating rate of 1 every 78.5 hours, increasing to 58.1 hours when unsuccessful predation attempts were included. A key food source was young antelopes, particularly bushbuck (Tragelaphus scriptus), which were consumed once every 115 observation hours. Similar to other baboon research sites, predations seemed mostly opportunistic, adult males regularly scrounged and monopolised prey, there was no evidence they used an active kill bite, and active sharing was absent. This is the first baboon study to report predation of rock python (Python sebae) eggs and likely scavenging of a leopard (Panthera pardus) kill (bushbuck) cached in a tree. We also describe several scramble kleptoparasitism events, tolerating active defence from antelope parents, and the baboons inhibiting public information about predations. In the latter case, baboons with meat often hid beyond the periphery of the group, reducing the likelihood of scrounging by competitors. This often led to prey carcasses being discarded without being fully exploited and potentially providing resources to scavengers. We also highlight the absence of encounters with numerous species, suggesting the baboons are a key component of several species’ landscapes of fear. Given these findings it seems likely that their ecological role in the Soutpansberg has been undervalued, and such conclusions may also hold for other baboon populations

    High Temperature Treatment of Diamond Particles Toward Enhancement of Their Quantum Properties

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    Fluorescence of the negatively charged nitrogen-vacancy (NV-) center of diamond is sensitive to external electromagnetic fields, lattice strain, and temperature due to the unique triplet configuration of its spin states. Their use in particulate diamond allows for the possibility of localized sensing and magnetic-contrast-based differential imaging in complex environments with high fluorescent background. However, current methods of NV(-)production in diamond particles are accompanied by the formation of a large number of parasitic defects and lattice distortions resulting in deterioration of the NV(-)performance. Therefore, there are significant efforts to improve the quantum properties of diamond particles to advance the field. Recently it was shown that rapid thermal annealing (RTA) at temperatures much exceeding the standard temperatures used for NV(-)production can efficiently eliminate parasitic paramagnetic impurities and, as a result, by an order of magnitude improve the degree of hyperpolarization of(13)C via polarization transfer from optically polarized NV(-)centers in micron-sized particles. Here, we demonstrate that RTA also improves the maximum achievable magnetic modulation of NV(-)fluorescence in micron-sized diamond by about 4x over conventionally produced diamond particles endowed with NV-. This advancement can continue to bridge the pathway toward developing nano-sized diamond with improved qualities for quantum sensing and imaging

    A World-Volume Perspective on the Recombination of Intersecting Branes

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    We study brane recombination for supersymmetric configurations of intersecting branes in terms of the world-volume field theory. This field theory contains an impurity, corresponding to the degrees of freedom localized at the intersection. The Higgs branch, on which the impurity fields condense, consists of vacua for which the intersection is deformed into a smooth calibrated manifold. We show this explicitly using a superspace formalism for which the calibration equations arise naturally from F- and D-flatness.Comment: References adde

    Common sleep disorders in pregnancy: a review

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    In this review, we provide a comprehensive overview of common sleep disorders during pregnancy, including their characterization, prevalence, risk factors, and possible contribution to maternal and fetal outcomes. We conducted a quasi-systematic literature search of the MEDLINE database and identified 744 studies from 1991 through 2021, inclusive, that met our inclusion criteria. We synthesized the existing literature on sleep disorders during pregnancy and highlighted controversies, research gaps, and needed clinical developments. Our review covers a range of sleep disorders, including insomnia, obstructive sleep apnea, restless legs syndrome, and circadian rhythm disorders. We discuss the prevalence of these disorders in pregnancy and their potential impact on maternal and fetal health outcomes. We also explore the relationship between sleep disorders, pre-pregnancy comorbidities such as obesity, and pregnancy-related conditions such as gestational diabetes mellitus and preeclampsia. In addition to summarizing the existing literature on sleep disorders during pregnancy, we also highlight opportunities for further research in this area. We suggest that future studies should strive to employ validated and objective measurement tools for sleep disorders and prioritize utilization of longitudinal methods with participant follow-up through postpartum, mid-life, menopause, and beyond. We also put forward investigation into the impact of circadian rhythm disruption on reproductive physiology and early pregnancy outcomes as an area of important work. Overall, our review provides valuable insights on sleep and reproduction and into common sleep disorders during pregnancy and their potential impact on maternal and fetal health outcomes
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