1,878 research outputs found

    Shore-level size gradients in Tegula funebralis (A. Adams) : seasonal changes influenced by interaction of predator preference and prey behavior

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    Aspects of the Pisaster-Tegula interaction are re-examined. Reproductive portions of T. funebrallis populations are shown to be immune to seastar predation through a combination of predator preference for larger snails and a withdrawal behavior that favors the escape of smaller snails after capture by a seastar . Experimental addition of p. ochraaceus in winter causes changes in the intertidal distribution of T. funebralis similar to those observed during the summer increase in seastar numbers. It is suggested that these results supplant the hypothesis that lowered prereproductive mortality influences formation and maintenance of vertical size gradients in the lower intertidal

    Antipsychotic Adherence Patterns and Health Care Utilization and Costs Among Patients Discharged After a Schizophrenia-Related Hospitalization

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    This study aimed to assess antipsychotic adherence patterns and all-cause and schizophrenia-related health care utilization and costs sequentially during critical clinical periods (i.e., before and after schizophrenia-related hospitalization) among Medicaid-enrolled patients experiencing a schizophrenia-related hospitalization

    Intelligent Camera Control Using Behavior Trees

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    Automatic camera systems produce very basic animations for virtual worlds. Users often view environments through two types of cameras: a camera that they control manually, or a very basic automatic camera that follows their character, minimizing occlusions. Real cinematography features much more variety producing more robust stories. Cameras shoot establishing shots, close-ups, tracking shots, and bird’s eye views to enrich a narrative. Camera techniques such as zoom, focus, and depth of field contribute to framing a particular shot. We present an intelligent camera system that automatically positions, pans, tilts, zooms, and tracks events occurring in real-time while obeying traditional standards of cinematography. We design behavior trees that describe how a single intelligent camera might behave from low-level narrative elements assigned by “smart events”. Camera actions are formed by hierarchically arranging behavior sub-trees encapsulating nodes that control specific camera semantics. This approach is more modular and particularly reusable for quickly creating complex camera styles and transitions rather then focusing only on visibility. Additionally, our user interface allows a director to provide further camera instructions, such as prioritizing one event over another, drawing a path for the camera to follow, and adjusting camera settings on the fly.We demonstrate our method by placing multiple intelligent cameras in a complicated world with several events and storylines, and illustrate how to produce a well-shot “documentary” of the events constructed in real-time

    Regulation of the subcellular distribution of key cellular RNA-processing factors during permissive human cytomegalovirus infection

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    Alternative splicing and polyadenylation of human cytomegalovirus (HCMV) immediate-early (IE) pre-mRNAs are temporally regulated and rely on cellular RNA-processing factors. This study examined the location and abundance of essential RNA-processing factors, which affect alternative processing of UL37 IE pre-mRNAs, during HCMV infection. Serine/threonine protein kinase 1 (SRPK1) phosphorylates serine/arginine-rich proteins, necessary for pre-spliceosome commitment. It was found that HCMV infection progressively increased the abundance of cytoplasmic SRPK1, which is regulated by subcellular partitioning. The essential polyadenylation factor CstF-64 was similarly increased in abundance, albeit in the nucleus, proximal to and within viral replication compartments (VRCs). In contrast, the location of polypyrimidine tract-binding protein (PTB), known to adversely affect splicing of HCMV major IE RNAs, was temporally regulated during infection. PTB co-localized with CstF-64 in the nucleus at IE times. By early times, PTB was detected in punctate cytoplasmic sites of some infected cells. At late times, PTB relocalized to the nucleus, where it was notably excluded from HCMV VRCs. Moreover, HCMV infection induced the formation of nucleolar stress structures, fibrillarin-containing caps, in close proximity to its VRCs. PTB exclusion from HCMV VRCs required HCMV DNA synthesis and/or late gene expression, whereas the regulation of SRPK1 subcellular distribution did not. Taken together, these results indicated that HCMV increasingly regulates the subcellular distribution and abundance of essential RNA-processing factors, thereby altering their ability to affect the processing of viral pre-mRNAs. These results further suggest that HCMV infection selectively induces sorting of nucleolar and nucleoplasmic components

    Automated group assignment in large phylogenetic trees using GRUNT: GRouping, Ungrouping, Naming Tool

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    <p>Abstract</p> <p>Background</p> <p>Accurate taxonomy is best maintained if species are arranged as hierarchical groups in phylogenetic trees. This is especially important as trees grow larger as a consequence of a rapidly expanding sequence database. Hierarchical group names are typically manually assigned in trees, an approach that becomes unfeasible for very large topologies.</p> <p>Results</p> <p>We have developed an automated iterative procedure for delineating stable (monophyletic) hierarchical groups to large (or small) trees and naming those groups according to a set of sequentially applied rules. In addition, we have created an associated ungrouping tool for removing existing groups that do not meet user-defined criteria (such as monophyly). The procedure is implemented in a program called GRUNT (GRouping, Ungrouping, Naming Tool) and has been applied to the current release of the Greengenes (Hugenholtz) 16S rRNA gene taxonomy comprising more than 130,000 taxa.</p> <p>Conclusion</p> <p>GRUNT will facilitate researchers requiring comprehensive hierarchical grouping of large tree topologies in, for example, database curation, microarray design and pangenome assignments. The application is available at the greengenes website <abbrgrp><abbr bid="B1">1</abbr></abbrgrp>.</p

    Searching for the Kuhnian moment : the Black-Scholes-Merton formula and the evolution of modern finance theory

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    The Black-Scholes-Merton formula has been put to widespread use by options traders because it provides a means of calculating the theoretically 'correct' price of stock options. Traders can therefore see whether the market price of stock options undervalues or overvalues them compared with their hypothetical Black-Scholes-Merton price, before choosing to buy or sell options accordingly. As a consequence of this close relationship between options pricing theory and options pricing practice, a strong performativity loop was activated, whereby market prices quickly converged on the hypothetical Black-Scholes-Merton prices following the dissemination of the formula. The theory has therefore had significant real-world effects, but how should we characterize the initial instinct to derive the theory from a philosophy of science perspective? The two books under review suggest that a Kuhnian reading of the advancement of scientific knowledge might well be the most appropriate. But, on closer inspection, it becomes clear that the publication of the Black-Scholes-Merton formula should not be seen as a Kuhnian moment with paradigm-shaping attributes. It is shown that, at most, the formula acts as an important exemplar which, via its use in the training of options pricing theorists and options pricing practitioners, reinforces the entrenchment of finance theory within the orthodox economics worldview

    Virtually Real, But Not Quite There: Social and Economic Barriers to Meeting Virtual Reality’s True Potential for Mental Health

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    7 pagesStrategies to mitigate the spread of COVID-19, namely quarantine and social distancing protocols, have exposed a troubling paradox: mandated isolation meant to preserve well-being has inadvertently contributed to its decline. Prolonged isolation has been associated with widespread loneliness and diminished mental health, with effects compounded by limited face-to-face access to clinical and social support systems. While remote communication technologies (e.g., video chat) can connect individuals with healthcare providers and social networks, remote technologies might have limited effectiveness in clinical and social contexts. In this review, we articulate the promise of Virtual Reality as a conduit to clinical resources and social connection. Furthermore, we outline various social and economic factors limiting the virtual reality industry’s ability to maximize its potential to address mental health issues brought upon by the pandemic. These barriers are delineated across five dimensions: sociocultural, content, affordability, supply chain, and equitable design. After examining potential short- and long-term solutions to these hurdles, we outline potential avenues for applied and theoretical research seeking to validate these solutions. Through this evaluation we seek to (a) emphasize virtual reality’s capacity to improve mental health by connecting communities to clinical and social support systems, (b) identify socioeconomic barriers preventing users from accessing these systems through virtual reality, and (c) discuss solutions that ensure these systems can be equitably accessed via changes to existing and future virtual reality infrastructures

    Compassion fade and the challenge of environmental conservation

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    Compassion shown towards victims often decreases as the number of individuals in need of aid increases, identifiability of the victims decreases, and the proportion of victims helped shrinks. Such “compassion fade” may hamper individual-level and collective responses to pressing large-scale crises. To date, research on compassion fade has focused on humanitarian challenges; thus, it remains unknown whether and to what extent compassion fade emerges when victims are non-human others. Here we show that compassion fade occurs in the environmental domain, but only among non-environmentalists. These findings suggest that compassion fade may challenge our collective ability and willingness to confront the major environmental problems we face, including climate change. The observed moderation effect of environmental identity further indicates that compassion fade may present a significant psychological barrier to building broad public support for addressing these problems. Our results highlight the importance of bringing findings from the field of judgment and decision making to bear on pressing societal issues

    Discovery of soft and hard X-ray time lags in low-mass AGNs

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    The scaling relations between the black hole (BH) mass and soft lag properties for both active galactic nuclei (AGNs) and BH X-ray binaries (BHXRBs) suggest the same underlying physical mechanism at work in accreting BH systems spanning a broad range of mass. However, the low-mass end of AGNs has never been explored in detail. In this work, we extend the existing scaling relations to lower-mass AGNs, which serve as anchors between the normal-mass AGNs and BHXRBs. For this purpose, we construct a sample of low-mass AGNs (MBH<3×106MM_{\rm BH}<3\times 10^{6} M_{\rm \odot}) from the XMM-Newton archive and measure frequency-resolved time delays between the soft (0.3-1 keV) and hard (1-4 keV) X-ray emissions. We report that the soft band lags behind the hard band emission at high frequencies [1.32.6]×103\sim[1.3-2.6]\times 10^{-3} Hz, which is interpreted as a sign of reverberation from the inner accretion disc in response to the direct coronal emission. At low frequencies ([38]×104\sim[3-8]\times 10^{-4} Hz), the hard band lags behind the soft band variations, which we explain in the context of the inward propagation of luminosity fluctuations through the corona. Assuming a lamppost geometry for the corona, we find that the X-ray source of the sample extends at an average height and radius of 10rg\sim 10r_{\rm g} and 6rg\sim 6r_{\rm g}, respectively. Our results confirm that the scaling relations between the BH mass and soft lag amplitude/frequency derived for higher-mass AGNs can safely extrapolate to lower-mass AGNs, and the accretion process is indeed independent of the BH mass.Comment: 11 pages, 5 figures, 4 tables, Published in MNRA
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