726 research outputs found

    Preliminary Test Results for Full Scale Drilled Shaft Under Cyclic Lateral Loading

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    Preliminary results are presented of a field testing program for a full-scale, large diameter cast-in-drilled-hole (CIDH) shaft/column under cyclic lateral loading. The shaft was extensively instrumented to enable high precision, redundant section curvature measurements, measurements of pressure at the soil-shaft interface around the shaft perimeter, and in situ measurements of concrete quality. The principal objective of the testing was to characterize the soil-shaft interaction across a wide displacement range to gain insight into the adequacy of existing design guidelines (which are based principally on the testing of small diameter piles) for the large diameter shafts commonly used to support highway bridges in California. Also of interest is the failure mechanism of the shaft-column, since most previous tests of large-diameter shaft-columns do not test the column to large levels of ductility. This testing was only recently completed, and reduction and interpretation of the data is ongoing as of this writing. This paper presents preliminary results of the overall specimen performance across the full range of tested displacements. Details of the soil-shaft interaction remain under study, and are not presented here

    Human development and climate affect hibernation in a large carnivore with implications for human–carnivore conflicts

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    1. Expanding human development and climate change are dramatically altering habitat conditions for wildlife. While the initial response of wildlife to changing environmental conditions is typically a shift in behavior, little is known about the effects of these stressors on hibernation behavior, an important life-history trait that can subsequently affect animal physiology, demography, interspecific interactions and human-wildlife interactions. Given future trajectories of land use and climate change, it is important that wildlife professionals understand how animals that hibernate are adapting to altered landscape conditions so that management activities can be appropriately tailored. 2. We investigated the influence of human development and weather on hibernation in black bears (Ursus americanus), a species of high management concern, whose behavior is strongly tied to natural food availability, anthropogenic foods around development and variation in annual weather conditions. Using GPS collar data from 131 den events of adult female bears (n = 51), we employed fine-scale, animal-specific habitat information to evaluate the relative and cumulative influence of natural food availability, anthropogenic food and weather on the start, duration and end of hibernation. 3. We found that weather and food availability (both natural and human) additively shaped black bear hibernation behavior. Of the habitat variables we examined, warmer temperatures were most strongly associated with denning chronology, reducing the duration of hibernation and expediting emergence in the spring. Bears appeared to respond to natural and anthropogenic foods similarly, as more natural foods, and greater use of human foods around development, both postponed hibernation in the fall and decreased its duration. 4. Synthesis and applications. Warmer temperatures and use of anthropogenic food subsides additively reduced black bear hibernation, suggesting that future changes in climate and land use may further alter bear behavior and increase the length of their active season. We speculate that longer active periods for bears will result in subsequent increases in human–bear conflicts and human-caused bear mortalities. These metrics are commonly used by wildlife agencies to index trends in bear populations, but have the potential to be misleading when bear behavior dynamically adapts to changing environmental conditions, and should be substituted with reliable demographic methods

    Feasibility and effectiveness of a telehealth service delivery model for treating childhood posttraumatic stress: A community-based, open pilot trial of trauma-focused cognitive-behavioral therapy

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    © 2020 American Psychological Association. Telepsychotherapy (also referred to as telehealth or telemental health), the use of videoconferencing to deliver psychotherapy services, offers an innovative way to address significant gaps in access to care and is being used to deliver a variety of treatments for youth. Although recent research has supported the effectiveness of telehealth delivery of a variety of interventions for children, the literature has focused very little on childhood posttraumatic stress disorder. This pilot study examined the feasibility and potential effectiveness of trauma-focused cognitive- behavioral therapy (TF-CBT) delivered via telepsychotherapy in community-based locations of either schools or patient homes. Telepsychotherapy treatment was delivered to 70 traumaexposed youth in 7 underserved communities. Of these, 88.6% completed a full course of TF-CBT and 96.8% of these treatment completers no longer met diagnostic criteria for a trauma-related disorder at posttreatment. Results demonstrated clinically meaningful symptom change posttreatment, with large effect sizes evident for both youthand caregiver-reported reduction in posttraumatic stress disorder symptoms. The results observed in this pilot evaluation are promising and provide preliminary evidence of the feasibility and effectiveness of this novel treatment format. The COVID-19 global pandemic has resulted in an unprecedented need to rethink how mental health services are delivered, which is particularly applicable to high base rate conditions related to posttraumatic stress. Given the existing network of nationally certified TF-CBT therapists, and many international TF-CBT therapists, these findings suggest the potential for providing effective and accessible telepsychotherapy intervention during this public health crisis (as well as those that will occur in the future)

    Collective consciousness and its pathologies: Understanding the failure of AIDS control and treatment in the United States

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    We address themes of distributed cognition by extending recent formal developments in the theory of individual consciousness. While single minds appear biologically limited to one dynamic structure of linked cognitive submodules instantiating consciousness, organizations, by contrast, can support several, sometimes many, such constructs simultaneously, although these usually operate relatively slowly. System behavior remains, however, constrained not only by culture, but by a developmental path dependence generated by organizational history, in the context of market selection pressures. Such highly parallel multitasking – essentially an institutional collective consciousness – while capable of reducing inattentional blindness and the consequences of failures within individual workspaces, does not eliminate them, and introduces new characteristic malfunctions involving the distortion of information sent between workspaces and the possibility of pathological resilience – dysfunctional institutional lock-in. Consequently, organizations remain subject to canonical and idiosyncratic failures analogous to, but more complicated than, those afflicting individuals. Remediation is made difficult by the manner in which pathological externalities can write images of themselves onto both institutional function and corrective intervention. The perspective is applied to the failure of AIDS control and treatment in the United States

    Impaired Glucose Tolerance and Insulin Resistance Are Associated With Increased Adipose 11β-Hydroxysteroid Dehydrogenase Type 1 Expression and Elevated Hepatic 5α-Reductase Activity

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    OBJECTIVE—The precise molecular mechanisms contributing to the development of insulin resistance, impaired glucose tolerance (IGT), and type 2 diabetes are largely unknown. Altered endogenous glucocorticoid metabolism, including 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), which generates active cortisol from cortisone, and 5α-reductase (5αR), which inactivates cortisol, has been implicated

    Using surface integrals for checking the Archimedes' law of buoyancy

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    A mathematical derivation of the force exerted by an \emph{inhomogeneous} (i.e., compressible) fluid on the surface of an \emph{arbitrarily-shaped} body immersed in it is not found in literature, which may be attributed to our trust on Archimedes' law of buoyancy. However, this law, also known as Archimedes' principle (AP), does not yield the force observed when the body is in contact to the container walls, as is more evident in the case of a block immersed in a liquid and in contact to the bottom, in which a \emph{downward} force that \emph{increases with depth} is observed. In this work, by taking into account the surface integral of the pressure force exerted by a fluid over the surface of a body, the general validity of AP is checked. For a body fully surrounded by a fluid, homogeneous or not, a gradient version of the divergence theorem applies, yielding a volume integral that simplifies to an upward force which agrees to the force predicted by AP, as long as the fluid density is a \emph{continuous function of depth}. For the bottom case, this approach yields a downward force that increases with depth, which contrasts to AP but is in agreement to experiments. It also yields a formula for this force which shows that it increases with the area of contact.Comment: 15 pages, 3 figures, accepted for publication in "Eur. J. Phys." (10/20/2011

    Antibodies in healthcare personnel following severe acute respiratory syndrome coronavirus virus 2 (SARS-CoV-2) infection

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    In a prospective cohort of healthcare personnel (HCP), we measured severe acute respiratory syndrome coronavirus virus 2 (SARS-CoV-2) nucleocapsid IgG antibodies after SARS-CoV-2 infection. Among 79 HCP, 68 (86%) were seropositive 14-28 days after their positive PCR test, and 54 (77%) of 70 were seropositive at the 70-180-day follow-up. Many seropositive HCP (95%) experienced an antibody decline by the second visit
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