620 research outputs found

    “Forward-Thinking” in U.S. Biobanking

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    Aims: Do biobanks enact policies and plans that allow them to anticipate and respond to potential challenges? If a biobank has one such policy or plan, is it likely to have more? Using survey data from 456 U.S. biobanks, we assess four possible indicators of such “forward-thinking.

    The effect of time constraint on anticipation, decision making, and option generation in complex and dynamic environments

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    Researchers interested in performance in complex and dynamic situations have focused on how individuals predict their opponent(s) potential courses of action (i.e., during assessment) and generate potential options about how to respond (i.e., during intervention). When generating predictive options, previous research supports the use of cognitive mechanisms that are consistent with long-term working memory (LTWM) theory (Ericsson and Kintsch in Phychol Rev 102(2):211–245, 1995; Ward et al. in J Cogn Eng Decis Mak 7:231–254, 2013). However, when generating options about how to respond, the extant research supports the use of the take-the-first (TTF) heuristic (Johnson and Raab in Organ Behav Hum Decis Process 91:215–229, 2003). While these models provide possible explanations about how options are generated in situ, often under time pressure, few researchers have tested the claims of these models experimentally by explicitly manipulating time pressure. The current research investigates the effect of time constraint on option-generation behavior during the assessment and intervention phases of decision making by employing a modified version of an established option-generation task in soccer. The results provide additional support for the use of LTWM mechanisms during assessment across both time conditions. During the intervention phase, option-generation behavior appeared consistent with TTF, but only in the non-time-constrained condition. Counter to our expectations, the implementation of time constraint resulted in a shift toward the use of LTWM-type mechanisms during the intervention phase. Modifications to the cognitive-process level descriptions of decision making during intervention are proposed, and implications for training during both phases of decision making are discussed

    HIV-1 transgene expression in rats causes oxidant stress and alveolar epithelial barrier dysfunction

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    <p>Abstract</p> <p>Background</p> <p>HIV-infected individuals are at increased risk for acute and chronic airway disease even though there is no evidence that the virus can infect the lung epithelium. Although HIV-related proteins including gp120 and Tat can directly cause oxidant stress and cellular dysfunction, their effects in the lung are unknown. The goal of this study was to determine the effects of HIV-1 transgene expression in rats on alveolar epithelial barrier function. Alveolar epithelial barrier function was assessed by determining lung liquid clearance <it>in vivo </it>and alveolar epithelial monolayer permeability <it>in vitro</it>. Oxidant stress in the alveolar space was determined by measuring the glutathione redox couple by high performance liquid chromatography, and the expression and membrane localization of key tight junction proteins were assessed. Finally, the direct effects of the HIV-related proteins gp120 and Tat on alveolar epithelial barrier formation and tight junction protein expression were determined.</p> <p>Results</p> <p>HIV-1 transgene expression caused oxidant stress within the alveolar space and impaired epithelial barrier function even though there was no evidence of overt inflammation within the airways. The expression and membrane localization of the tight junction proteins zonula occludens-1 and occludin were decreased in alveolar epithelial cells from HIV-1 transgenic rats. Further, treating alveolar epithelial monolayers from wild type rats <it>in vitro </it>with recombinant gp120 or Tat for 24 hours reproduced many of the effects on zonula occludens-1 and occludin expression and membrane localization.</p> <p>Conclusion</p> <p>Taken together, these data indicate that HIV-related proteins cause oxidant stress and alter the expression of critical tight junction proteins in the alveolar epithelium, resulting in barrier dysfunction.</p

    Ranking Objections to Christian Theism: A Survey of Subjective Declarations and their Correlations with Expert Opinions

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    There have been numerous books written on the top objections to Christianity—sometimes stated as “common,” “major,” “frequent,” “every day,” “cultural,” “tough,” “difficult” objections. However, there is a dearth of behavioral studies in the literature that show how and given population ranks objections to Christianity. As such, the apologist has had to rely on expert opinions from the books that have been authored. These expert opinions are based on familiarity with the literature in the field and contact with laity from university, church, and other speaking engagements. The purpose of this study is to document trends in how people report the relative strength of objections to Christian theism.[1] We analyze whether these trends correlate with popular works of Christian apologists—our baseline for expert opinion. Further, we determine whether there are any statistically significant relationships between reported demographics, rankings, and attitudes. Summary of Results and Analysis. Subjective declarations of respondents of the questionnaire showed that most participants were either 18-24 (marginally more than 55-64 and 65-74), male (marginally more than female), had some college (marginally more than bachelor’s, master’s degrees), lived in a suburban community, or lived in the South. In comparing the expert opinion baseline with the aggregate survey ranking results, we see similar rankings between the objection that “God is unloving/immoral” and that the “Bible is not inerrant” (ranked by both as 1st and 2nd, respectively) at the higher end of the spectrum. We found that those identified as agnostic seem to have the closest potential correlation to expert opinion (baseline). The mean of their rankings produced four objections that closely approximated the baseline, one objection that was about one rank removed from the baseline, and three objections that were about two ranks from the baseline. For demographics and rankings, we found statistically significant relationships between religious identification and the objection “God does not exist” with those who identified as atheists, giving it an average ranking of 3.74 (on a scale of 1-13; 1 = highest, 13 = lowest). For demographics and attitudes, we found statistically significant relationships between religious identification and age, religious discussion importance, and attitude toward Christian theism. (See “Analysis” section.) [1] The study was done under the School of Divinity Department at Liberty University in compliance with Liberty University’s Internal Review Board (Research Ethics Office). IRB-FY21-22-12. Policy: Post-2018 Rule. Submitted 07-06-2021. Last approved 09-07-2021, no expiration date applicable

    Trials and Tribulations of Humanizing Mice for Cancer Research

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    Cancers are aggressive, evasive, and ruthless killers, claiming millions of lives every year. Cancers are heterogeneous and there is often no single, clearly defined problem as they harness and manipulate a multitude of fundamental mechanisms at the very essence of life. To investigate these mechanisms and vet potential interventive therapies, humanized mice offer a unique model as a prelude to the use of nanosecond pulse stimulation (NPS), a pulse power technology applying nanosecond duration, high electric field pulses, to ablate human tumors. Immunodeficient mouse strains, NSG and NSG-SGM3, were engrafted with human immune cells and human tumors, which would allow us to study the effects of NPS therapy on the human tumor and the human immune system, albeit not without trials and tribulations. Here we show that mice engrafted with human cord blood CD34+ hematopoietic stem cells (hCD34+ HSC) lack consistency in expansion and chimerism, or variety of immune cell types. Unfortunately, mice that developed the human immune system rejected the human tumors without treatment, while mice that rejected the immune system developed the human tumors. Therefore, we had mice with human immune systems and no tumor to treat, and mice with tumors to treat yet no immune system to study. In non-humanized mice, NPS induced complete tumor death in the patient derived mammary cancer xenograft (PDX) model, but not in the MDA-MB-231 VIM-RFP mammary cancer cell-derived xenograft (CDX) model. The absence of NPS elimination of the CDX is the only known NPS cancer failure and requires further study.https://digitalcommons.odu.edu/gradposters2021_gradschool/1000/thumbnail.jp

    Polarization transfer in wide-angle Compton scattering and single-pion photoproduction from the proton

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    Wide-angle exclusive Compton scattering and single-pion photoproduction from the proton have been investigated via measurement of the polarization transfer from a circularly polarized photon beam to the recoil proton. The wide-angle Compton scattering polarization transfer was analyzed at an incident photon energy of 3.7 GeV at a proton scattering angle of θpcm=70°. The longitudinal transfer KLL, measured to be 0.645±0.059±0.048, where the first error is statistical and the second is systematic, has the same sign as predicted for the reaction mechanism in which the photon interacts with a single quark carrying the spin of the proton. However, the observed value is ∼3 times larger than predicted by the generalized-parton-distribution-based calculations, which indicates a significant unknown contribution to the scattering amplitude

    Atomic-scale confinement of optical fields

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    In the presence of matter there is no fundamental limit preventing confinement of visible light even down to atomic scales. Achieving such confinement and the corresponding intensity enhancement inevitably requires simultaneous control over atomic-scale details of material structures and over the optical modes that such structures support. By means of self-assembly we have obtained side-by-side aligned gold nanorod dimers with robust atomically-defined gaps reaching below 0.5 nm. The existence of atomically-confined light fields in these gaps is demonstrated by observing extreme Coulomb splitting of corresponding symmetric and anti-symmetric dimer eigenmodes of more than 800 meV in white-light scattering experiments. Our results open new perspectives for atomically-resolved spectroscopic imaging, deeply nonlinear optics, ultra-sensing, cavity optomechanics as well as for the realization of novel quantum-optical devices

    Phytoplankton dynamics in relation to seasonal variability and upwelling and relaxation patterns at the mouth of Ria de Aveiro (West Iberian Margin) over a four-year period

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    From June 2004 to December 2007, samples were weekly collected at a fixed station located at the mouth of Ria de Aveiro (West Iberian Margin). We examined the seasonal and inter-annual fluctuations in composition and community structure of the phytoplankton in relation to the main environmental drivers and assessed the influence of the oceano-graphic regime, namely changes in frequency and intensity of upwelling events, over the dynamics of the phytoplankton assemblage. The samples were consistently handled and a final subset of 136 OTUs (taxa with relative abundance > 0.01%) was subsequently submitted to various multivariate analyses. The phytoplankton assemblage showed significant changes at all temporal scales but with an overriding importance of seasonality over longer-(inter-annual) or shorter-term fluctuations (upwelling-related). Sea-surface temperature, salinity and maximum upwelling index were retrieved as the main driver of seasonal change. Seasonal signal was most evident in the fluctuations of chlorophyll a concentration and in the high turnover from the winter to spring phytoplankton assemblage. The seasonal cycle of production and succession was disturbed by upwelling events known to disrupt thermal stratification and induce changes in the phytoplankton assemblage. Our results indicate that both the frequency and intensity of physical forcing were important drivers of such variability, but the outcome in terms of species composition was highly dependent on the available local pool of species and the timing of those events in relation to the seasonal cycle. We conclude that duration, frequency and intensity of upwelling events, which vary seasonally and inter-annually, are paramount for maintaining long-term phytoplankton diversity likely by allowing unstable coexistence and incorporating species turnover at different scales. Our results contribute to the understanding of the complex mechanisms of coastal phytoplankton dynamics in relation to changing physical forcing which is fundamental to improve predictability of future prospects under climate change.Portuguese Foundation for Science and Technology (FCT, Portugal) [SFRH/BPD/ 94562/2013]; FEDER funds; national funds; CESAM [UID/AMB/50017]; FCT/MEC through national funds; FEDERinfo:eu-repo/semantics/publishedVersio

    Intrinsic Terahertz Plasmons and Magnetoplasmons in Large Scale Monolayer Graphene

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    We show that in graphene epitaxially grown on SiC the Drude absorption is transformed into a strong terahertz plasmonic peak due to natural nanoscale inhomogeneities, such as substrate terraces and wrinkles. The excitation of the plasmon modifies dramatically the magneto-optical response and in particular the Faraday rotation. This makes graphene a unique playground for plasmon-controlled magneto-optical phenomena thanks to a cyclotron mass 2 orders of magnitude smaller than in conventional plasmonic materials such as noble metals.Comment: to appear in Nano Letter
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