4,802 research outputs found

    Parent Interaction In Primetime Family Themed Television Portrayals: A Replication And Extension Of Dail And Way\u27s (1985) Content Analysis

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    This research is a replication and extension of Dail and Way’s (1985) content analysis identifying parent interactions portrayed in family oriented prime time network television programs. Family structure, parent role, child rearing, and child responses were coded from five episodes each of eight different programs from 2014-2015 television season. The programs presented parent roles more often than child rearing, while mothers were found in child rearing more often than fathers. Traditional family structures were most prevalent with fewer single parent households and a new presence of same-sex parents. Mothers and fathers were still portrayed stereotypically, but children’s responses were more realistic and further reinforced traditional gender roles. Child responses reinforced traditional and rejected non-traditional parent interactions according to the parents’ sex, partnership, and occupation

    Automatic interpretation of oblique ionograms

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    We present an algorithm for the identification of trace characteristics of oblique ionograms allowing determination of the Maximum Usable Frequency (MUF) for communication between the transmitter and receiver. The algorithm automatically detects and rejects poor quality ionograms. We performed an exploratory test of the algorithm using data from a campaign of oblique soundings between Rome, Italy (41.90 N, 12.48 E) and Chania, Greece (35.51 N, 24.01 E) and also between Kalkarindji, Australia (17.43 S, 130.81 E) and Culgoora, Australia (30.30 S, 149.55 E). The success of these tests demonstrates the applicability of the method to ionograms recorded by different ionosondes in various helio and geophysical conditions

    Scientific review on the ionospheric absorption and research prospects of a Complex Eikonal model for one-layer ionosphere

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    Thepresent paper conducts a scientific review on ionospheric absorption, extrapolating the research prospects of a complex eikonal model for one-layer ionosphere. As regards the scientific review, here a quasi-longitudinal (QL) approximation for nondeviative absorption is deduced which is more refined than the corresponding equation reported by Davies (1990). As regards the research prospects, a complex eikonal model for one-layer ionosphere is analyzed in depth here, already discussed by Settimi et al. (2013). A simple formula is deduced for a simplified problem. A flat, layered ionospheric medium is considered, without any horizontal gradient. The authors prove that the QL nondeviative amplitude absorption according to the complex eikonal model is more accurate than Rawer’s theory (1976) in the range of middle critical frequencies

    Nonlinear diffusion & thermo-electric coupling in a two-variable model of cardiac action potential

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    This work reports the results of the theoretical investigation of nonlinear dynamics and spiral wave breakup in a generalized two-variable model of cardiac action potential accounting for thermo-electric coupling and diffusion nonlinearities. As customary in excitable media, the common Q10 and Moore factors are used to describe thermo-electric feedback in a 10-degrees range. Motivated by the porous nature of the cardiac tissue, in this study we also propose a nonlinear Fickian flux formulated by Taylor expanding the voltage dependent diffusion coefficient up to quadratic terms. A fine tuning of the diffusive parameters is performed a priori to match the conduction velocity of the equivalent cable model. The resulting combined effects are then studied by numerically simulating different stimulation protocols on a one-dimensional cable. Model features are compared in terms of action potential morphology, restitution curves, frequency spectra and spatio-temporal phase differences. Two-dimensional long-run simulations are finally performed to characterize spiral breakup during sustained fibrillation at different thermal states. Temperature and nonlinear diffusion effects are found to impact the repolarization phase of the action potential wave with non-monotone patterns and to increase the propensity of arrhythmogenesis

    Sub-lethal 5-fluorouracil dose challenges planarian stem cells promoting transcriptional profile changes in the pluripotent sigma-class neoblasts

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    Under physiological conditions, the complex planarian neoblast system is a composite of hierarchically organized stem cell sub-populations with sigma-class neoblasts, including clonogenic neoblasts, endowed with larger self-renewal and differentiation capabilities, thus generating all the other sub-populations and dominating the regenerative process. This complex system responds to differentiated tissue demands, ensuring a continuous cell turnover in a way to replace aged specialized cells and maintain tissue functionality. Potency of the neoblast system can be appreciated under challenging conditions in which these stem cells are massively depleted and the few remaining repopulate the entire body, ensuring animal resilience. These challenging conditions offer the possibility to deepen the relationships among different neoblast sub-populations, allowing to expose uncanonical properties that are negligible under physiological conditions. In this paper, we employ short, sub-lethal 5-fluorouracil treatment to specifically affect proliferating cells passing through the S phase and demonstrate that S-phase slowdown triggers a shift in the transcriptional profile of sigma neoblasts, which reduces the expression of their hallmark sox-P1. Later, some cells reactivate sox-P1 expression, suggesting that some neoblasts in the earlier steps of commitment could modulate their expression profile, reacquiring a wider differentiative potential

    Phosphorus fractionation chemistry across the Great Plains

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    The SGS-LTER research site was established in 1980 by researchers at Colorado State University as part of a network of long-term research sites within the US LTER Network, supported by the National Science Foundation. Scientists within the Natural Resource Ecology Lab, Department of Forest and Rangeland Stewardship, Department of Soil and Crop Sciences, and Biology Department at CSU, California State Fullerton, USDA Agricultural Research Service, University of Northern Colorado, and the University of Wyoming, among others, have contributed to our understanding of the structure and functions of the shortgrass steppe and other diverse ecosystems across the network while maintaining a common mission and sharing expertise, data and infrastructure.Includes bibliographical references.Phosphorus is one of the three important plant nutrients found in soils and has been used with great success as an index for soil and ecosystem development (Aguilar et al., 1988; Honeycutt et al., 1990; Vitousek et al., 2004). In general, phosphorus is has minimal solubility in soil because it participates in a number of secondary reactions after release from primary minerals as a result of weathering. Studies of the biogeochemical cycling of P in humid ecosystems has led to important insights about soil and ecosystem development. Arid and semi-arid ecosystems have largely been ignored under the assumption that chemical transformations are minimal. We conducted research on the biogeochemistry of P along a bioclimatic gradient in grassland ecosystems of the Great Plains. The overall goal of our research is to use a systematic approach to characterize and further quantify the P transformations in biogeographically diverse grassland ecosystems. Identifying P quantities originally contained in central Great Plains soil will allow us to assess 1) the relative importance of P in the biogeochemical behavior of grassland soils, 2) help us quantify the degree of chemical weathering in semi-arid-humid grassland ecosystems, and 3) elucidate cultural use and potential productivity of these ecosystems prior to use of commercial fertilizers. We sampled soils along a bioclimatic gradient that represent three grassland ecosystems, namely, the shortgrass steppe, the mixed-grass prairie, and the tallgrass prairie in eastern Kansas. The soils were collected from sites studied within the Long-Term Ecological Research Program in areas that had not been used for agricultural practices other than grazing. We conducted a sequential extraction procedure to identify the following P fractions: soluble, Al-bound, Fe-bound, occluded, and Ca-bound. Our results suggest that soluble P is generally below detection limits at these sites, illustrating the high turnover rate of available P in these undisturbed systems. The Al-bound fraction was variable across all sites. The Fe-bound P contributed to the total P fraction only from the mixed grass and tall grass prairies. The occluded P fraction was greatest in the shortgrass steppe, decreased dramatically as mean annual and primary production increase from west to east.NSF Grant No. 0217631

    Ceftolozane-tazobactam combination therapy compared to ceftolozane-tazobactam monotherapy for the treatment of severe infections: A systematic review and meta-analysis

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    Ceftolozane-tazobactam (C/T) is a combination of an advanced-generation cephalosporin (ceftolozane) with a β-lactamase inhibitor (tazobactam). It is approved for the treatment of compli-cated urinary-tract/intra-abdominal infections and hospital-acquired/ventilator-associated pneumo-nia. This systematic review and meta-analysis (registered prospectively on PROSPERO, no. CRD42019134099, on 20 January 2020) aimed to evaluate the effectiveness of C/T combination therapy compared to C/T monotherapy for the treatment of severe infections and to describe the prevalence of microorganisms in the included studies. We retrieved literature from PubMed, EMBASE, and CENTRAL, until 26 November 2020. Eligible studies were both randomised trials and nonrandomised studies with a control group, published in the English language and peer-reviewed journals. The primary outcome was all-cause mortality; secondary outcomes were (i) clinical improvement and (ii) microbiological cure. Eight nonrandomised studies were included in the qualitative synthesis: Seven retrospective cohort studies and one case-control study. The meta-analysis of the four studies evaluating all-cause mortality (in total 148 patients: 87 patients treated with C/T alone and 61 patients treated with C/T combination therapy) showed a significant reduction of mortality in patients receiving C/T combination therapy, OR: 0.31, 95% CI: 0.10–0.97, p = 0.045. Conversely, the meta-analysis of the studies evaluating clinical improvement and microbiological cure showed no differences in C/T combination therapy compared to C/T monotherapy. The most consistent data come from the analysis of the clinical improvement, n = 391 patients, OR: 0.97, 95% CI: 0.54–1.74, p = 0.909. In 238 of the 391 patients included (60.8%), C/T was used for the treatment of infections caused by Pseudomonas aeruginosa

    Rationale and evidence on the use of tocilizumab in COVID-19: a systematic review

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    Background: Tocilizumab is an IL-6 receptor-blocking agent proposed for the treatment of severe COVID-19. The aim of this systematic review was to describe the rationale for the use of tocilizumab for the treatment of COVID-19 and to summarize the available evidence regarding its efficacy and safety. Methods: MEDLINE, PubMed, EMBASE, pre-print repositories (bioRxiv and medRxiv) and two trial Registries were searched for studies on the use of tocilizumab in COVID-19 or SARS-CoV-2 infection, viral pneumonia, and/or sepsis until 20th June 2020. Results: We identified 3 indirect pre-clinical studies and 28 clinical studies including 5776 patients with COVID-19 (13 with a comparison group, 15 single-arm). To date, no randomized trials have been published. We retrieved no studies at low risk of bias. Forty-five ongoing studies were retrieved from trial registries. Conclusions: There is insufficient evidence regarding the clinical efficacy and safety of tocilizumab in patients with COVID-19. Its use should be considered experimental, requiring ethical approval and clinical trial oversight
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