3,353 research outputs found

    The State of Sustainable Research Software: Results from the Workshop on Sustainable Software for Science: Practice and Experiences (WSSSPE5.1)

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    This article summarizes motivations, organization, and activities of the Workshop on Sustainable Software for Science: Practice and Experiences (WSSSPE5.1) held in Manchester, UK in September 2017. The WSSSPE series promotes sustainable research software by positively impacting principles and best practices, careers, learning, and credit. This article discusses the Code of Conduct, idea papers, position papers, experience papers, demos, and lightning talks presented during the workshop. The main part of the article discusses the speed-blogging groups that formed during the meeting, along with the outputs of those sessions

    Multi-stage liquid/liquid extraction with a zaiput apparatus

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    Poorly separable liquid/liquid mixtures often pose a major challenge in pharmaceutical extraction. In particular, compounds containing a low difference of density are difficult to separate using mixer-settler setups. The Zaiput device can prove an advantage over present liquid/liquid extractors. The research work involves characterizing the Zaiput apparatus for liquid/liquid extraction of pharmaceutical compounds with the model solvent system toluene-water. The extraction efficiency was investigated for a solvent mixture containing toluene-acetone-water residence times. To evaluate the separation success, the outlet’s concentrations are measured via IR spectroscopy

    Selective Photocyclization of Amino Acids in Dipeptides

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    Amino acids in dipeptides which are substituted at the N-atom by a benzoylalkyl group can be selectively photocyclized via a triplet biradical. With valine as amino acid the cyclization leads mainly to one product out of eight possible isomers

    Radiological-pathological correlation in Alzheimer's disease : systematic review of antemortem MRI findings

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    Background: The standard method of ascertaining Alzheimer’s disease (AD) remains postmortem assessment of amyloid plaques and neurofibrillary degeneration. Vascular pathology, Lewy bodies, TDP-43, and hippocampal sclerosis are frequent comorbidities. There is therefore a need for biomarkers that can assess these aetiologies and provide a diagnosis in vivo. Objective: We conducted a systematic review of published radiological-pathological correlation studies to determine the relationship between antemortem magnetic resonance imaging (MRI) and neuropathological findings in AD. Methods: We explored PubMed in June-July 2015 using “Alzheimer’s disease” and combinations of radiological and pathological terms. After exclusion following screening and full-text assessment of the 552 extracted manuscripts, three others were added from their reference list. In fine, we report results based on 27 articles. Results: Independently of normal age-related brain atrophy, AD pathology is associated with whole-brain and hippocampal atrophy and ventricular expansion as observed on T1-weighted images. Moreover, cerebral amyloid angiopathy and cortical microinfarcts are also related to brain volume loss in AD. Hippocampal sclerosis and TDP-43 are respectively associated with hippocampal and medial temporal lobe atrophy. Brain volume loss correlates more strongly with tangles than with any other pathological finding. White matter hyperintensities observed on proton density, T2-weighted and FLAIR images are strongly related to vascular pathologies, but are also associated with other histological changes such as gliosis or demyelination. Discussion: Cerebral atrophy and white matter changes in the living brain reflect underlying neuropathology and may be detectable using antemortem MRI. In vivo MRI may therefore be an avenue for AD pathological staging

    Health indices for the evaluation and monitoring of health in children and adolescents in prevention and health promotion: a scoping review

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    BACKGROUND Health indicators are used in different settings to monitor health outcomes. Child and adolescent health is arguably one of the most important areas for the application of indices and indicators in prevention and health promotion. Although single health indicators may be better suited to display the complexity of the health status and its determinants, a selected set of indicators will still offer a complex picture. Therefore, it is argued that a group of indicators combined into an index may offer a pragmatic tool that is easier to use in order to inform stakeholders. METHODS A scoping review was conducted to identify and describe health indices that monitor and evaluate health of children and adolescents and to appraise the quality and value of the identified indices that may guide the further applications of these indices in particular settings. The three bibliographic databases MEDLINE, EMBASE and PsycINFO were searched and a double screening of titles and abstracts as well as double screening of full texts was performed. Indices contained in these studies were analysed in terms of focus and composition and evaluated in terms of quality criteria. RESULTS The scoping review identified 36 eligible studies with 18 health indices in six thematic categories. Of the identified indices, seven indices focus on anthropometrical variables, three indices focus on special aspects of newborns and five indices focus on oral health. One index assesses \textquotedblhealthy lifestyle\textquotedbl and one \textquotedblfunctional ability\textquotedbl whereas one index a combination of different aspects. Most indices are calculated by using primary health data. CONCLUSIONS Alone or in combination with single sets of indicators, indices in six major thematic domains may be used as pragmatic tools for monitoring children's and adolescents´ health and the evaluation of interventions in health promotion and prevention settings

    MATLAB/Octave function to evaluate time-domain signals according to the measurement bandwidth and average/peak detector of EMI test receivers

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    Electromagnetic emissions are often measured with EMI (electromagnetic emissions) test receivers or spectrum analyzers [1] that must be specifically set up regarding their measurement bandwidth, frequency step size and measurement time (e.g. [2] for automobiles). Additionally, the emissions must be evaluated by different measurement detectors (e.g. average or peak) that may all have individual limit lines like in [2]. EMI measurements can be done in frequency or in time domain [1]. Frequency-domain measurement devices sequentially apply the superheterodyne principle to the frequencies of interest [3]. Since the measurement time for each frequency may take up to several seconds, the total measurement time can become long and cumbersome [4]. To overcome this problem, the time-domain signal can be processed by using, e.g., fast Fourier transforms (FFTs) and further methods [4]. This principle can also be applied to evaluate time-domain simulation results according to EMC standards. There are numerous publications on this topic including, e.g., [4] and [5]. In this contribution, a MATLAB/Octave function is presented that evaluates time-domain signals according to EMC standards. This “virtual EMI test receiver” mimics actual EMI test receivers regarding their measurement bandwidth, frequency step and average/peak detection. Potential use cases include the EMC evaluation of oscilloscope measurements or simulation results. The developed function can be found in the MATLAB Central (https://mathworks.com/matlabcentral/) under the title “Virtual EMI test receiver” by Andreas Bendicks [6]. In the following section, the superheterodyne measurement principle is described that is mimicked by the virtual EMI test receiver. Afterward, the corresponding signal processing of the MATLAB/Octave function is explained. The precision of the MATLAB/Octave function is verified by comparing its results to the ones of an actual EMI test receiver. The work is closed by a conclusion and an outlook

    Testing the robustness of transmission network models to predict ectoparasite loads. One lizard, two ticks and four years

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    Open access under CC BY-NC-SA licenseAbstract We investigated transmission pathways for two tick species, Bothriocroton hydrosauri and Amblyomma limbatum, among their sleepy lizard (Tiliqua rugosa) hosts in a natural population in South Australia. Our aim was to determine whether a transmission network model continued to predict parasite load patterns effectively under varying ecological conditions. Using GPS loggers we identified the refuge sites used by each lizard on each day. We estimated infectious time windows for ticks that detached from a lizard in a refuge. Time windows were from the time when a detached tick molted and become infective, until the time it died from desiccation while waiting for a new host. Previous research has shown that A. limbatum molts earlier and survives longer than B. hydrosauri. We developed two transmission network models based on these differences in infective time windows for the two tick species. Directed edges were generated in the network if one lizard used a refuge that had previously been used by another lizard within the infectious time window. We used those models to generate values of network node in-strength for each lizard, a measure of how strongly connected an individual is to other lizards in the transmission network, and a prediction of infection risk for each host. The consistent correlations over time between B. hydrosauri infection intensity and network derived infection risk suggest that network models can be robust to environmental variation among years. However, the contrasting lack of consistent correlation in A. limbatum suggests that the utility of the same network models may depend on the specific biology of a parasite species

    Implementation of mercury biomonitoring in German adults using dried blood spot sampling in combination with direct mercury analysis

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    Venous blood is a preferred matrix for the determination of total mercury (Hg) in human biomonitoring but has some drawbacks such as the requirement for an uninterrupted cold chain for transport and storage and the need of medical personnel for sample collection. Therefore, we tested and implemented a simpler and less expensive method for measuring Hg in human blood using dried blood spots (DBS). For method development, we investigated the influence of different storage conditions (temperature, storage vessel, time) on DBS samples. For method validation, we compared DBS and venous blood and investigated whether DBS sampling is suitable for measuring Hg in the general population in countries with low Hg exposure such as Germany. Based on our results, we found that pre-cleaned glass tubes were most suitable for storage of DBS samples, as this allowed the samples to remain stable for at least 4~weeks even at high temperatures (40~°C). When comparing venous blood and DBS, a very good correlation (r = 0.95, p < 0.01, Spearman-Rho) and high precision of DBS (mean relative standard deviation 8.2% vs. 7.2% in venous blood samples) were observed. Comparing the recoveries of both matrices in different concentration ranges, the variation of the recoveries decreases with increasing Hg concentration. The mean recoveries also decreased with increasing Hg concentration. Overall, we found comparable results for DBS and venous~blood using direct Hg analysis. Furthermore, we demonstrated that DBS are suitable for Hg biomonitoring in the general population in Germany and improved the storage conditions for the DBS

    Relación entre la calidad de servicio y la fidelización de los clientes de la Financiera Compartamos en Nuevo Chimbote – 2019

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    El presente estudio tuvo como finalidad determinar la relación entre la calidad de servicio y la fidelización de los clientes de la entidad financiera de Compartamos en Nuevo Chimbote, 2019. La investigación se ejecutó a través del enfoque cuantitativo siendo el estudio de tipo no experimental, con un diseño correlacional, transversal, transaccioanl descriptivo. La población estuvo constituida por 1182 clientes y la muestra fue de 290 clientes. Se utilizó la técnica de la encuesta para ambas variables, con cuestionarios como instrumentos de recolección. Los resultados que se obtuvieron fueron analizados a través de los software EXCEL y SPSS, con la finalidad de lograr una buena coherencia e interpretación y presentación de los mismos. Se determinó con el coeficiente de correlación Rho Spearman que R = 0.460 (existiendo una relación positiva moderada) con nivel de significancia p = 0.00 siendo esto menor al 5% (p < 0.05). La calidad de servicio se relaciona con la fidelización de los clientes de la financiera Compartamos
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