排序方式： 共有69条查询结果，搜索用时 15 毫秒
61.
Rico Illing Corinna Burkart Daniel Pfitzner Dirk Jungmann Larysa Baraban Gianaurelio Cuniberti 《Biomicrofluidics》2016,10(2)
Precise analysis of the aquatic cells and their responses to the toxic chemicals, i.e., water disinfective agents, is of crucial importance due to their role in the ecosystem. We demonstrate the application of the droplets based millifluidic tool for isolating and longtime monitoring of single Paramecium tetraurelia cells using a large number of water-in-oil emulsion droplets. Due to the automated monitoring of the fluorescence signal, the droplets containing cells are distinguished from the empty reservoirs. A viability indicator is used to follow the metabolic dynamic of the cells in every single droplet. Finally, we perform ecotoxicity tests in droplets, exposing the encapsulated paramecia cells to silver nitrate for determination of EC50 levels, and compare the output with the conventional microtiter plate assay. 相似文献
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Efficiency differences of finnish senior secondary schools: An application of DEA and Tobit analysis 总被引：1，自引：0，他引：1
We studied efficiency differences among Finnish senior secondary schools by Data Envelopment Analysis (DEA). Four model variants were used. Average efficiencies in the most extensive models were 82–84 per cent. When parents' educational level was treated as an additional input, average efficiency increased to 91 per cent. The efficiency rankings of schools changed to some extent when simplest quantitative inputs and outputs were augmented by measures of teacher quality and national matriculation examination results. As a second stage after DEA analysis, we explained the degree of inefficiency (100-efficiency score) by a statistical Tobit model. Schools with small classes and heterogenous student bodies were inefficient whereas school size did not affect efficiency. Surprisingly, private schools were inefficient relative to public schools. When parents' educational level was only included in the Tobit model, it affected efficiency positively. 相似文献
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Sabina Semiz Tanja Dujic Adlija Causevic 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2013,23(2):154-171
Type 2 diabetes mellitus (T2DM) is a worldwide epidemic with considerable health and economic consequences. T2DM patients are often treated with more than one drug, including oral antidiabetic drugs (OAD) and drugs used to treat diabetic complications, such as dyslipidemia and hypertension. If genetic testing could be employed to predict treatment outcome, appropriate measures could be taken to treat T2DM more efficiently. Here we provide a review of pharmacogenetic studies focused on OAD and a role of common drug-metabolizing enzymes (DME) and drug-transporters (DT) variants in therapy outcomes. For example, genetic variations of several membrane transporters, including SLC22A1/2 and SLC47A1/2 genes, are implicated in the highly variable glycemic response to metformin, a first-line drug used to treat newly diagnosed T2DM. Furthermore, cytochrome P450 (CYP) enzymes are implicated in variation of sulphonylurea and meglitinide metabolism. Additional variants related to drug target and diabetes risk genes have been also linked to interindividual differences in the efficacy and toxicity of OAD. Thus, in addition to promoting safe and cost-effective individualized diabetes treatment, pharmacogenomics has a great potential to complement current efforts to optimize treatment of diabetes and lead towards its effective and personalized care. 相似文献
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The aim of the present study was to gather information from athletes and doping control officials about their satisfaction and acceptance concerning the accomplishment of the doping control system (DCS) in Germany. 761 high elite athletes and 101 doping control officers took part in a written survey. Special attention was given to the subjective estimation of knowledge about the DCS as well as to their experiences during doping controls (DC) and on the whereabouts system.Three quarters of the responding athletes stated to have control experience; many of them were controlled several times a year. The majority of athletes confirmed to be familiar with the sampling procedure. But every second mentioned deficits regarding their rights during the collection or the functioning of the whereabouts system. Athletes and control officials evaluated their communication and coordination among each other mainly positive. By the majority of athletes, control officials’ attitude was judged to be friendly and open minded and their behavior neutral and discreet. A strong and internationally comparable accomplishment of the DCS was demanded especially from athletes belonging to higher testing pools. Doping control officials appreciated athletes’ generally high willingness to cooperate and, predominantly, felt well instructed for their duty. 相似文献
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Intergenerational transmission of gender segregation: How parents’ occupational field affects gender differences in field of study choices 
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下载免费PDF全文 Maaike van der Vleuten Eva Jaspers Ineke Maas Tanja van der Lippe 《British Educational Research Journal》2018,44(2):294-318
The study explores how parents’ occupational field affects gender differences in educational fields. On the one hand, the theory of direct transfer predicts that adolescents enter fields similar to those of their parents because of intergenerational transmission of occupation‐specific resources and that adolescents are more likely to draw upon the resources provided by the higher‐status parent. On the other hand, the theory of sex‐role learning predicts that boys and girls are more likely to choose more gender‐stereotypical fields of study because they learn ‘appropriate’ gender‐role behaviour from their parents’ occupational field and that boys are more likely to learn this behaviour from their father and girls from their mother. We use longitudinal data collected from adolescents and their parents in the Netherlands (N = 2,497) and tested our hypotheses using multiple‐group structural equation modelling and multinomial regression analyses. In line with sex‐role learning, results show that especially mothers who are employed in a more feminine occupational field influence their daughters to enter a more feminine field of study (health, biology, agriculture and veterinary) and their sons to enter a more masculine field of study (science and technology). Mothers’ occupational field therefore not only influences girls’ field of study, but also boys’. This study highlights the role of horizontal characteristics when examining which field of study adolescents enter. Contrary to the stratification literature, which primarily focuses on fathers, this study concludes that mothers play a more important role in gender differences in fields of study. 相似文献
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Tanja Oosthuyse Joanne A. McVeigh Lisa K. Micklesfield 《European Journal of Sport Science》2017,17(2):231-240
Low magnitude bone-loading sports may benefit bone structure and strength in the exercised limbs. This study compared peripheral quantitative computed tomography measures of radial and tibial diaphyseal strength (strength–strain index, SSI), structure (total area (ToA) and cortical area (CoA), density (CoD) and thickness (CT), and circumferences), muscle cross-sectional area (MCSA) and strength (one-repetition maximum, 1-RM) in male endurance athletes taking part in (i) non-weight-bearing and non-impact sports: swimmers (SWIM, n?=?13) and road cyclists (RC, n?=?10), (ii) non-weight-bearing, impact sport: mountain bikers (MB, n?=?10), (iii) weight bearing and impact sport: runners (RUN, n?=?9). All athlete groups were also compared to sedentary controls (CON, n?=?10). Arm MCSA, 1-RM and radial bone size and strength tended to be greater in SWIM than CON and/or RC (ToA, %difference ±?95%CI, SWIM-CON: 14.6%?±?12.7%; SWIM-RC: 12.9%?±?10.7%) but not different to MB and RUN. RUN had bigger tibial CoA than CON, SWIM and RC (CoA, RUN-CON: 12.1%?±?10.7%; RUN-SWIM: 10.9%?±?9.4%; RUN-RC: 15.8%?±?9.5%) without marked changes in tibial strength indices, lower-limb MCSA or 1-RM. Both MB and RC failed to display any difference in tibial indices, lower-limb MCSA and 1-RM compared to CON. In swimmers, the bone structure and strength of the primary exercised limbs, the arms, is greater than controls and road cyclists. Conversely, although runners experience impact and weight-bearing loading, tibial structure is greater without a substantial difference in tibial strength compared to controls and non-impact sports. Failure to observe a difference in tibial indices in MB and RC compared to controls is unexpected. 相似文献
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Karen D. Wang Jade Maï Cock Tanja Käser Engin Bumbacher 《British journal of educational technology : journal of the Council for Educational Technology》2023,54(1):192-221
Technology-based, open-ended learning environments (OELEs) can capture detailed information of students' interactions as they work through a task or solve a problem embedded in the environment. This information, in the form of log data, has the potential to provide important insights about the practices adopted by students for scientific inquiry and problem solving. How to parse and analyse the log data to reveal evidence of multifaceted constructs like inquiry and problem solving holds the key to making interactive learning environments useful for assessing students' higher-order competencies. In this paper, we present a systematic review of studies that used log data generated in OELEs to describe, model and assess scientific inquiry and problem solving. We identify and analyse 70 conference proceedings and journal papers published between 2012 and 2021. Our results reveal large variations in OELE and task characteristics, approaches used to extract features from log data and interpretation models used to link features to target constructs. While the educational data mining and learning analytics communities have made progress in leveraging log data to model inquiry and problem solving, multiple barriers still exist to hamper the production of representative, reproducible and generalizable results. Based on the trends identified, we lay out a set of recommendations pertaining to key aspects of the workflow that we believe will help the field develop more systematic approaches to designing and using OELEs for studying how students engage in inquiry and problem-solving practices.
Practitioner notes
What is already known about this topic- Research has shown that technology-based, open-ended learning environments (OELEs) that collect users' interaction data are potentially useful tools for engaging students in practice-based STEM learning.
- More work is needed to identify generalizable principles of how to design OELE tasks to support student learning and how to analyse the log data to assess student performance.
- We identified multiple barriers to the production of sufficiently generalizable and robust results to inform practice, with respect to: (1) the design characteristics of the OELE-based tasks, (2) the target competencies measured, (3) the approaches and techniques used to extract features from log files and (4) the models used to link features to the competencies.
- Based on this analysis, we can provide a series of specific recommendations to inform future research and facilitate the generalizability and interpretability of results:
- Making the data available in open-access repositories, similar to the PISA tasks, for easy access and sharing.
- Defining target practices more precisely to better align task design with target practices and to facilitate between-study comparisons.
- More systematic evaluation of OELE and task designs to improve the psychometric properties of OELE-based measurement tasks and analysis processes.
- Focusing more on internal and external validation of both feature generation processes and statistical models, for example with data from different samples or by systematically varying the analysis methods.
- Using the framework of evidence-centered assessment design, we have identified relevant criteria for organizing and evaluating the diverse body of empirical studies on the topic and that policy makers and practitioners can use for their own further examinations.
- This paper identifies promising research and development areas on the measurement and assessment of higher-order constructs with process data from OELE-based tasks that government agencies and foundations can support.
- Researchers, technologists and assessment designers might find useful the insights and recommendations for how OELEs can enhance science assessment through thoughtful integration of learning theories, task design and data mining techniques.