639 research outputs found

    An introduction to spectral distances in networks (extended version)

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    Many functions have been recently defined to assess the similarity among networks as tools for quantitative comparison. They stem from very different frameworks - and they are tuned for dealing with different situations. Here we show an overview of the spectral distances, highlighting their behavior in some basic cases of static and dynamic synthetic and real networks

    Kant's problem of causality and the ding-an-sich

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    Teaching health justice and reimagining narratives of place through community-driven science practices

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    This study explores how a biology teacher from a summer science program engaged high school students of color in a three-week science unit exploring community health at the intersection of history, race, place, and power. The goal of this study is to better understand what community-driven science looks like in a science classroom when a health equity unit is guided by a biology teacher who engages the socio-historical, political, and relational aspects of community structure and agency. Using student and instructor interviews, program observations, and student artifacts, I examine how the instructor\u27s positioning as a Black woman scientist shaped her goals and vision and the instructional and pedagogical resources made available during the unit. In addition, I explore how engaging in community-driven science practices during the unit such as critical inquiry and data analysis supported students\u27 sense making about community health and the possibilities they imagined for their communities. Findings illuminate how engaging community health at the intersection of history, race, place, and power shaped engagement in community-driven science practices and supported student sense making in ways that surfaced challenges, tensions, and opportunities for disrupting and reimagining community narratives. Further, finding highlight the importance of an instructor\u27s lived experiences and pedagogical vision in supporting emergent forms of student agency and place remaking, and generating possibilities for community healing and hope

    Stability Indicators in Network Reconstruction

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    The number of algorithms available to reconstruct a biological network from a dataset of high-throughput measurements is nowadays overwhelming, but evaluating their performance when the gold standard is unknown is a difficult task. Here we propose to use a few reconstruction stability tools as a quantitative solution to this problem. We introduce four indicators to quantitatively assess the stability of a reconstructed network in terms of variability with respect to data subsampling. In particular, we give a measure of the mutual distances among the set of networks generated by a collection of data subsets (and from the network generated on the whole dataset) and we rank nodes and edges according to their decreasing variability within the same set of networks. As a key ingredient, we employ a global/local network distance combined with a bootstrap procedure. We demonstrate the use of the indicators in a controlled situation on a toy dataset, and we show their application on a miRNA microarray dataset with paired tumoral and non-tumoral tissues extracted from a cohort of 241 hepatocellular carcinoma patients

    Interpretation of the Pattern in Rate Ratios Across Strata

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    The pattern in the ratio of disease rates over strata is a summary statistic used to describe the changing risk of disease in one group relative to another. While patterns of the ratios of disease rates over strata appear to correspond to specific changes in disease rates, plots of the disease rates over strata seem to contradict the information yielded by the ratios. For example, if disease rates from populations A and B have identical rates of decline (parallel lines), the difference in the rates (A - B) at each strata remains constant, while the ratio of the rates (AIB) increases over strata. Through simple algebraic manipulation, one can show that the pattern of the rate ratio is a function of the rate difference relative to the endemic disease rate. Thus, rather than describing the behavior of the disease rates, ratio patterns reflect the importance of exposure relative to the disease rate in the unexposed population

    Postsynaptic α1-Adrenergic vasoconstriction is impaired in young patients with vasovagal syncope and is corrected by nitric oxide synthase inhibition

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    BACKGROUND: Syncope is a sudden transient loss of consciousness and postural tone with spontaneous recovery; the most common form is vasovagal syncope (VVS). During VVS, gravitational pooling excessively reduces central blood volume and cardiac output. In VVS, as in hemorrhage, impaired adrenergic vasoconstriction and venoconstriction result in hypotension. We hypothesized that impaired adrenergic responsiveness because of excess nitric oxide can be reversed by reducing nitric oxide. METHODS AND RESULTS: We recorded cardiopulmonary dynamics in supine syncope patients and healthy volunteers (aged 15-27 years) challenged with a dose-response using the α1-agonist phenylephrine (PE), with and without the nitric oxide synthase inhibitor N(G)-monomethyl-L-arginine, monoacetate salt (L-NMMA). Systolic and diastolic pressures among control and VVS were the same, although they increased after L-NMMA and saline+PE (volume and pressor control for L-NMMA). Heart rate was significantly reduced by L-NMMA (P<0.05) for control and VVS compared with baseline, but there was no significant difference in heart rate between L-NMMA and saline+PE. Cardiac output and splanchnic blood flow were reduced by L-NMMA for control and VVS (P<0.05) compared with baseline, while total peripheral resistance increased (P<0.05). PE dose-response for splanchnic flow and resistance were blunted for VVS compared with control after saline+PE, but enhanced after L-NMMA (P<0.001). Postsynaptic α1-adrenergic vasoconstrictive impairment was greatest in the splanchnic vasculature, and splanchnic blood flow was unaffected by PE. Forearm and calf α1-adrenergic vasoconstriction were unimpaired in VVS and unaffected by L-NMMA. CONCLUSIONS: Impaired postsynaptic α1-adrenergic vasoconstriction in young adults with VVS can be corrected by nitric oxide synthase inhibition, demonstrated with our use of L-NMMA

    WHOSE HISTORY?: EXPANDING PLACE-BASED INITIATIVES THROUGH OPEN COLLABORATION

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    This chapter is the case study of a collaboration between the University of Texas Rio Grande Valley’s Teaching & Learning Program and the University Library’s Special Collections. The collaboration, Whose History? uses place-based education (PBE) as the pedagogical underpinning of a multi-stage project of student-developed research, creation, and teaching. While PBE underpins the project, “openness” is the framework around which Whose History? is built. Teaching & Learning undergraduate students, referred to hereafter as teacher-candidates, use special collections resources to conduct research into regional history and culture, and then create open lesson plans from their findings. Select teacher-candidates teach their lesson plans in area classrooms, and exemplary lesson plans are published online as open educational resources, with project facilitators guiding Special Collections and Teaching & Learning student workers through the OER creation process
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