274 research outputs found

    Future humidity trends over the western United States in the CMIP5 global climate models and variable infiltration capacity hydrological modeling system

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    Global climate models predict relative humidity (RH) in the western US will decrease at a rate of about 0.1–0.6 percentage points per decade, albeit with seasonal differences (most drying in spring and summer), geographical variability (greater declines in the interior), stronger reductions for greater anthropogenic radiative forcing, and notable spread among the models. Although atmospheric moisture content increases, this is more than compensated for by higher air temperatures, leading to declining RH. Fine-scale hydrological simulations driven by the global model results should reproduce these trends. It is shown that the MT-CLIM meteorological algorithms used by the Variable Infiltration Capacity (VIC) hydrological model, when driven by daily Tmin, Tmax, and precipitation (a configuration used in numerous published studies), do not preserve the original global model\u27s humidity trends. Trends are biased positive in the interior western US, so that strong RH decreases are changed to weak decreases, and weak decreases are changed to increases. This happens because the MT-CLIM algorithms VIC incorporates infer an overly large positive trend in atmospheric moisture content in this region, likely due to an underestimate of the effect of increasing aridity on RH. The result could downplay the effects of decreasing RH on plants and wildfire. RH trends along the coast have a weak negative bias due to neglect of the ocean\u27s moderating influence. A numerical experiment where the values of Tdew are altered to compensate for the RH error suggests that eliminating the atmospheric moisture bias could, in and of itself, decrease runoff up to 14% in high-altitude regions east of the Sierra Nevada and Cascades, and reduce estimated Colorado River runoff at Lees Ferry up to 4% by the end of the century. It could also increase the probability of large fires in the northern and central US Rocky Mountains by 13 to 60%

    Leadership experiences of internal medicine residents: A needs assessment for leadership curricula

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    PURPOSE: Leadership development during medical training is critical. Accrediting bodies strongly recommend and residents desire leadership training. However, limited needs assessment data exist regarding trainee perceptions of and experiences with leadership training. Our objective is to describe residents\u27 perceptions of leadership and desires for leadership training with the goal of informing effective curricular development. PATIENTS AND METHODS: In 2019 a trained qualitative interviewer conducted semi-structured interviews with volunteer second-year categorical internal medicine residents recruited via email across four institutions. Interviews were audio-recorded, transcribed, and inductively coded by two independent coders. After adjudicating discrepancies, coders synthesized codes into broader themes. Final thematic analysis was triangulated with the entire author group. RESULTS: Fourteen residents were interviewed (50% female). Few reported prior leadership training. Thematic analysis yielded six main themes. First, residents perceive leadership to be related to formal, assigned, hierarchical roles. Second, residents identify their own leadership primarily in the inpatient clinical setting. Third, residents identify clinical competence, emotional intelligence, and communication as important skills for effective leadership. Fourth, residents struggle to identify where leadership is currently being taught. Fifth, residents desire additional leadership development. Finally, residents prefer well-labeled, interactive methods for leadership development. CONCLUSION: Although residents desire leadership development, these skills are not often explicitly taught, labeled, or assessed. Curriculum developers may consider explicitly contextualizing leadership training within an everyday leadership framework, dovetailing leadership coaching with daily teaching workflow and feedback structures, and implementing faculty development initiatives to allow for appropriate feedback and assessment of these skills

    Homing Guidance Using Spatially Quantized Signals

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    This paper considers homing guidance for a vehicle with a single omnidirectional receiver traveling to a stationary, omnidirectional transmitting beacon by using spatially quantized signal strength measurements. Two homing strategies are presented, and simulations are performed for cases with signal noise and vehicle turn rate limits. The first strategy is the Oyler strategy, which adapts a sliding mode controller and observer from the previous work. The second strategy is based on constant heading changes (CHCs) each time a range increment is detected, and this strategy is shown to be sufficient for homing. This study also discusses a signal filter designed to improve the homing controllers' performance. Performance metrics are developed for strategy evaluation and parameter optimization. The performance of each guidance strategy is shown through simulations for a variety of conditions. The Oyler strategy guides the vehicle to the beacon more efficiently than the constant heading change strategy, but it comes with a slight penalty in success rate

    Hierarchical reasoning game theory based approach for evaluation and testing of autonomous vehicle control systems

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    A hierarchical game theoretic decision making framework is exploited to model driver decisions and interactions in traffic. In this paper, we apply this framework to develop a simulator to evaluate various existing autonomous driving algorithms. Specifically, two algorithms, based on Stackelberg policies and decision trees, are quantitatively compared in a traffic scenario where all the human-driven vehicles are modeled using the presented game theoretic approach. © 2016 IEEE

    Multilevel human secondary lymphoid immune system compartmentalization revealed by complementary imaging approaches.

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    Secondary human lymphoid tissue immune reactions take place in a highly coordinated environment with compartmentalization representing a fundamental feature of this organization. In situ profiling methodologies are indispensable for the understanding of this compartmentalization. Here, we propose a complementary experimental approach aiming to reveal different aspects of this process. The analysis of human tonsils, using a combination of single cell phenotypic analysis based on flow cytometry and multiplex imaging and mass spectrometry-based methodologies, revealed a compartmentalized organization at the cellular and molecular levels. More specifically, the skewed distribution of highly specialized immune cell subsets and relevant soluble mediators was accompanied by a compartmentalized localization of several lipids across different anatomical areas of the tonsillar tissue. The performance of such combinatorial experimental approaches could lead to the identification of novel in situ interactions and molecular targets for the in vivo manipulation of lymphoid organ, particularly the germinal center, immune reactions

    Differential expression of synaptophysin and synaptoporin during pre- and postnatal development of the hippocampal network

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    The closely related synaptic vesicle membrane proteins synaptophysin and synaptoporin are abundant in the hippocampal formation of the adult rat. But the prenatal hippocampal formation contains only synaptophysin, which is first detected at embryonic day 17 (E17) in perikarya and axons of the pyramidal neurons. At E21 synaptophysin immunoreactivity extends into the apical dendrites of these cells and in newly formed terminals contacting these dendrites. The transient presence of synaptophysin in axons and dendrites suggests a functional involvement of synaptophysin in fibre outgrowth of developing pyramidal neurons. Synaptoporin expression parallels the formation of dentate granule cell synaptic contacts with pyramidal neurons: the amount of hippocampal synaptoporin, determined in immunoblots and by synaptoporin immunostaining of developing mossy fibre terminals, increases during the first postnatal week. Moreover, in the adult, synaptoporin is found exclusively in the mossy fibre terminals present in the hilar region of the dentate gyrus and the regio inferior of the cornu ammonis. In contrast, synaptophysin is present in all synaptic fields of the hippocampal formation, including the mossy fibre terminals, where it colocalizes with synaptoporin in the same boutons. Our data indicate that granule neuron terminals differ from all other terminals of the hippocampal formation by the presence of both synaptoporin and synaptophysin. This difference, observed in the earliest synaptic contacts in the postnatal hippocampus and persisting into adult life, suggests distinct functions of synaptoporin in these nerve terminals

    Carbon‐Enriched Amorphous Hydrogenated Boron Carbide Films for Very‐Low‐k Interlayer Dielectrics

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    A longstanding challenge in ultralarge‐scale integration has been the continued improvement in low‐dielectric‐constant (low‐k) interlayer dielectric materials and other specialized layers in back‐end‐of‐the‐line interconnect fabrication. Modeled after the success of carbon‐containing organosilicate materials, carbon‐enriched amorphous hydrogenated boron carbide (a‐BxC:Hy) films are grown by plasma‐enhanced chemical vapor deposition from ortho‐carborane and methane. These films contain more extraicosahedral sp3 hydrocarbon groups than nonenriched a‐BxC:Hy films, as revealed by FTIR and NMR spectroscopy, and also exhibit lower dielectric constants than their nonenriched counterparts, notably due to low densities combined with a low distortion and orientation contribution to the total polarizability. Films with dielectric constant as low as 2.5 are reported with excellent electrical stability (leakage current of 10−9 A cm−2 at 2 MV cm−1 and breakdown voltage of >6 MV cm−1), good thermal conductivity of 0.31 ± 0.03 W m−1 K−1, and high projected Young’s modulus of 12 ± 3 GPa. These properties rival those of leading SiOC:H materials, and position a‐BxC:Hy as an important complement to traditional Si‐based materials to meet the complex needs of next‐generation interconnect fabrication.Carbon‐enriched amorphous hydrogenated boron carbide films are demonstrated with dielectric constant (k) as low as 2.5—attributed to low densities combined with network‐rigidifying CH2 bridging groups—as well as excellent electrical, thermal, and mechanical properties, rivaling those of state‐of‐the‐art silicon‐based low‐k dielectric materials.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141869/1/aelm201700116_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141869/2/aelm201700116.pd

    Rapid Microsatellite Identification from Illumina Paired-End Genomic Sequencing in Two Birds and a Snake

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    Identification of microsatellites, or simple sequence repeats (SSRs), can be a time-consuming and costly investment requiring enrichment, cloning, and sequencing of candidate loci. Recently, however, high throughput sequencing (with or without prior enrichment for specific SSR loci) has been utilized to identify SSR loci. The direct “Seq-to-SSR” approach has an advantage over enrichment-based strategies in that it does not require a priori selection of particular motifs, or prior knowledge of genomic SSR content. It has been more expensive per SSR locus recovered, however, particularly for genomes with few SSR loci, such as bird genomes. The longer but relatively more expensive 454 reads have been preferred over less expensive Illumina reads. Here, we use Illumina paired-end sequence data to identify potentially amplifiable SSR loci (PALs) from a snake (the Burmese python, Python molurus bivittatus), and directly compare these results to those from 454 data. We also compare the python results to results from Illumina sequencing of two bird genomes (Gunnison Sage-grouse, Centrocercus minimus, and Clark's Nutcracker, Nucifraga columbiana), which have considerably fewer SSRs than the python. We show that direct Illumina Seq-to-SSR can identify and characterize thousands of potentially amplifiable SSR loci for as little as $10 per sample – a fraction of the cost of 454 sequencing. Given that Illumina Seq-to-SSR is effective, inexpensive, and reliable even for species such as birds that have few SSR loci, it seems that there are now few situations for which prior hybridization is justifiable
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