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This manuscript compiles both theoretical and experimental information on contact freezing with the aim to better understand this potentially important but still not well quantified heterogeneous freezing mode. There is no complet...
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This manuscript compiles both theoretical and experimental information on contact freezing with the aim to better understand this potentially important but still not well quantified heterogeneous freezing mode. There is no complete theory that describes contact freezing and how the energy barrier has to be overcome to nucleate an ice crystal by contact freezing. Experiments on contact freezing conducted using the cold plate technique indicate that it can initiate ice formation at warmer temperatures than immersion freezing. Additionally, a qualitative difference in the freezing temperatures between contact and immersion freezing has been found using different instrumentation and different ice nuclei. There is a lack of data on collision rates in most of the reported data, which inhibits a quantitative calculation of the freezing efficiencies. Thus, new or modified instrumentation to study contact nucleation in the laboratory and in the field are needed to identify the conditions at which contact nucleation could occur in the atmosphere. Important questions concerning contact freezing and its potential role for ice cloud formation and climate are also summarized.
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Context: Grey Literature (GL) recently has grown in Software Engineering (SE) research since the increased use of online communication channels by software engineers. However, there is still a limited understanding of how SE resea...
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Context: Grey Literature (GL) recently has grown in Software Engineering (SE) research since the increased use of online communication channels by software engineers. However, there is still a limited understanding of how SE research is taking advantage of GL. Objective: This research aimed to understand how SE researchers use GL in their secondary studies. Methods: We conducted a tertiary study of studies published between 2011 and 2018 in high-quality software engineering conferences and journals. We then applied qualitative and quantitative analysis to investigate 446 potential studies. Results: From the 446 selected studies, 126 studies cited GL but only 95 of those used GL to answer a specific research question representing almost 21% of all the 446 secondary studies. Interestingly, we identified that few studies employed specific search mechanisms and used additional criteria for assessing GL. Moreover, by the time we conducted this research, 49% of the GL URLs are not working anymore. Based on our findings, we discuss some challenges in using GL and potential mitigation plans. Conclusion: In this paper, we summarized the last 10 years of software engineering research that uses GL, showing that GL has been essential for bringing practical new perspectives that are scarce in traditional literature. By drawing the current landscape of use, we also raise some awareness of related challenges (and strategies to deal with them).
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Context Systematic reviews can provide useful knowledge for software engineering practice, by aggregating and synthesising empirical studies related to a specific topic.
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Many researchers adopting systematic reviews (SRs) have also published papers discussing problems with the SR methodology and suggestions for improving it. Since guidelines for SRs in software engineering (SE) were last updated in...
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Many researchers adopting systematic reviews (SRs) have also published papers discussing problems with the SR methodology and suggestions for improving it. Since guidelines for SRs in software engineering (SE) were last updated in 2007, we believe it is time to investigate whether the guidelines need to be amended in the light of recent research. Objective: To identify, evaluate and synthesize research published by software engineering researchers concerning their experiences of performing SRs and their proposals for improving the SR process. Method: We undertook a systematic review of papers reporting experiences of undertaking SRs and/or discussing techniques that could be used to improve the SR process. Studies were classified with respect to the stage in the SR process they addressed, whether they related to education or problems faced by novices and whether they proposed the use of textual analysis tools. Results: We identified 68 papers reporting 63 unique studies published in SE conferences and journals between 2005 and mid-2012. The most common criticisms of SRs were that they take a long time, that SE digital libraries are not appropriate for broad literature searches and that assessing the quality of empirical studies of different types is difficult. Conclusion: We recommend removing advice to use structured questions to construct search strings and including advice to use a quasi-gold standard based on a limited manual search to assist the construction of search stings and evaluation of the search process. Textual analysis tools are likely to be useful for inclusion/exclusion decisions and search string construction but require more stringent evaluation. SE researchers would benefit from tools to manage the SR process but existing tools need independent validation. Quality assessment of studies using a variety of empirical methods remains a major problem.
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Background and purpose: Cohort studies are one of the best types of observational studies in investigating the causal relationship, diseases etiology, and determining the incidence and natural history of diseases. In recent decade...
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Background and purpose: Cohort studies are one of the best types of observational studies in investigating the causal relationship, diseases etiology, and determining the incidence and natural history of diseases. In recent decades cohort studies played a major role in identification of environmental, cardiovascular and cancers risk factors. Considering the important role of cohort studies in public health, this study aimed to review population based cohort studies in Iran. Materials and methods: In this review article, Pubmed and Scopus databases and Iranian population based cohort studies websites were searched. Keywords included cohort, population based cohort, and Iran. Results: Six population based cohort studies running in Iran were found including Tehran Lipid and Glucose Study, Golestan and Isfahan Cohort Studies, Shahroud Eye Cohort Study, Amirkola Health and Ageing Project, and KERCADR study. The first population based cohort study in Iran was Tehran Lipid and Glucose Study which began in 1997. We also found other cohorts with various follow up time from months to years on diseased people, pregnant women, infants and specific occupational groups. Also, some historical cohorts such as Sradasht cohort study were found. Conclusion: Several historical cohorts and six population based cohort studies were launched in different places in Iran. The oldest (Tehran Lipid and Glucose Study) is being conducted for 18 years. These studies have relatively good variety in terms of population, diversity of exposure and research objectives and can play a prominent role in production of knowledge which will be very important in evidence based policy making in public health.
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OBJECTIVE: The objective of the study was to describe characteristics and outcomes of a review of multisite perinatal studies by individual institutional review boards (IRBs) and identify barriers and opportunities for streamlined IRB review.
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OBJECTIVE: The objective of the study was to describe characteristics and outcomes of a review of multisite perinatal studies by individual institutional review boards (IRBs) and identify barriers and opportunities for streamlined IRB review.
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Background: The Federal Joint Committee (Gemeinsamer Bundesausschuss) assigns the highest evidence level of Ia to systematic reviews of randomized controlled trials in evaluating the benefit of therapeutic interventions. Contradic...
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Background: The Federal Joint Committee (Gemeinsamer Bundesausschuss) assigns the highest evidence level of Ia to systematic reviews of randomized controlled trials in evaluating the benefit of therapeutic interventions. Contradictory results among randomized and non-randomized studies may not always be caused by the study design.
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Background and Objective: In view of the growth of published articles, there is an increasing need for studies that summarize scientific research. An increasingly common review is a "methodology scoping review,"which provides a su...
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Background and Objective: In view of the growth of published articles, there is an increasing need for studies that summarize scientific research. An increasingly common review is a "methodology scoping review,"which provides a summary of existing analytical methods, techniques and software that have been proposed or applied in research articles to address an analytical problem or further an analytical approach. However, guidelines for their design, implementation, and reporting are limited.
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A mixed studies review (MSR) is a type of literature review that includes qualitative, quantitative, and mixed methods studies. This form of literature review is popular since it can provide a rich understanding of complex health ...
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A mixed studies review (MSR) is a type of literature review that includes qualitative, quantitative, and mixed methods studies. This form of literature review is popular since it can provide a rich understanding of complex health interventions and programs. However, conducting a MSR can be challenging since it combines several study designs. A wiki toolkit was developed to provide MSR-specific guidance and suggest tips and tools for planning, conducting and reporting MSR. The toolkit is structured according to eight stages for conducting a systematic review: (1) formulate a review question, (2) define eligibility criteria, (3) select sources of information, (4) identify potentially relevant studies, (5) select relevant studies, (6) appraise the quality of studies, (7) extract data, and (8) synthesize included studies. The toolkit includes examples, tips for searching studies with diverse designs, existing tools for searching, selecting and appraising, synthesis designs, and a template for proposals and reports. This toolkit is presented as a wiki, which allows users to collaboratively modify the content and provides continuous updates on the science of MSR. It is hoped that this wiki toolkit will be useful to all users and contribute to creating a network of people interested in MSR.
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