733 research outputs found

    On Resilient Behaviors in Computational Systems and Environments

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    The present article introduces a reference framework for discussing resilience of computational systems. Rather than a property that may or may not be exhibited by a system, resilience is interpreted here as the emerging result of a dynamic process. Said process represents the dynamic interplay between the behaviors exercised by a system and those of the environment it is set to operate in. As a result of this interpretation, coherent definitions of several aspects of resilience can be derived and proposed, including elasticity, change tolerance, and antifragility. Definitions are also provided for measures of the risk of unresilience as well as for the optimal match of a given resilient design with respect to the current environmental conditions. Finally, a resilience strategy based on our model is exemplified through a simple scenario.Comment: The final publication is available at Springer via http://dx.doi.org/10.1007/s40860-015-0002-6 The paper considerably extends the results of two conference papers that are available at http://ow.ly/KWfkj and http://ow.ly/KWfgO. Text and formalism in those papers has been used or adapted in the herewith submitted pape

    A method for exploratory repeated-measures analysis applied to a breast-cancer screening study

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    When a model may be fitted separately to each individual statistical unit, inspection of the point estimates may help the statistician to understand between-individual variability and to identify possible relationships. However, some information will be lost in such an approach because estimation uncertainty is disregarded. We present a comparative method for exploratory repeated-measures analysis to complement the point estimates that was motivated by and is demonstrated by analysis of data from the CADET II breast-cancer screening study. The approach helped to flag up some unusual reader behavior, to assess differences in performance, and to identify potential random-effects models for further analysis.Comment: Published in at http://dx.doi.org/10.1214/11-AOAS481 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

    East Asia and the global/transatlantic/Western crisis

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    This paper introduces the special collection on East Asia and the Global Crisis. After justifying why a focus on East Asia is appropriate, it draws out the main themes that run through the individual contributions. These are the extent to which the region is decoupling from the global economy (or the West), the increasing legitimacy of statist alternatives to neoliberal development strategies, and the impact of crises on the definition of ―region‖ and the functioning of regional institutions and governance mechanisms

    Effectively Mapping Linguistic Abstractions for Message-passing Concurrency to Threads on the Java Virtual Machine

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    Efficient mapping of message passing concurrency (MPC) abstractions to Java Virtual Machine (JVM) threads is critical for performance, scalability, and CPU utilization; but tedious and time consuming to perform manually. In general, this mapping cannot be found in polynomial time, but we show that by exploiting the local characteristics of MPC abstractions and their communication patterns this mapping can be determined effectively. We describe our MPC abstraction to thread mapping technique, its realization in two frameworks (Panini and Akka), and its rigorous evaluation using several benchmarks from representative MPC frameworks. We also compare our technique against four default mapping techniques: thread-all, round-robin-task-all, random-task-all and work-stealing. Our evaluation shows that our mapping technique can improve the performance by 30%-60% over default mapping techniques. These improvements are due to a number of challenges addressed by our technique namely: i) balancing the computations across JVM threads, ii) reducing the communication overheads, iii) utilizing information about cache locality, and iv) mapping MPC abstractions to threads in a way that reduces the contention between JVM threads

    Fetal alcohol spectrum disorder: development of concensus referral criteria for specialist diagnostic assessment in Australia

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    Background: Fetal alcohol spectrum disorder (FASD) is known to be under-recognised in Australia. The use of standard methods to identify when to refer individuals who may have FASD for specialist assessment could help improve the identification of this disorder. The purpose of this study was to develop referral criteria for use in Australia. Method: An online survey about FASD screening and diagnosis in Australia, which included 23 statements describing criteria for referral for fetal alcohol syndrome (FAS) and FASD based on published recommendations for referral in North America, was sent to 139 health professionals who had expertise or involvement in FASD screening or diagnosis. Survey findings and published criteria for referral were subsequently reviewed by a panel of 14 investigators at a consensus development workshop where criteria for referral were developed.Results: Among the 139 health professionals who were sent the survey, 103 (74%) responded, and 90 (65%) responded to the statements on criteria for referral. Over 80% of respondents agreed that referral for specialist evaluation should occur when there is evidence of significant prenatal alcohol exposure, defined as 7 or more standard drinks per week and at least 3 standard drinks on any one day, and more than 70% agreed with 13 of the16 statements that described criteria for referral other than prenatal alcohol exposure. Workshop participants recommended five independent criteria for referral: confirmed significant prenatal alcohol exposure; microcephaly and confirmed prenatal alcohol exposure; 2 or more significant central nervous system (CNS) abnormalities and confirmed prenatal alcohol exposure; 3 characteristic FAS facial anomalies; and 1 characteristic FAS facial anomaly, growth deficit and 1 or more CNS abnormalities .Conclusion: Referral criteria recommended for use in Australia are similar to those recommended in North America. There is a need to develop resources to raise awareness of these criteria among health professionals and evaluate their feasibility, acceptability and capacity to improve the identification of FASD in Australia

    Titania coating of mesoporous silica nanoparticles for improved biocompatibility and drug release within blood vessels

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    Blood vessel disease is a major contributor to cardiovascular morbidity and mortality and is hallmarked by dysfunction of the lining endothelial cells (ECs). These cells play a significant role in vascular homeostasis, through the release of mediators to control vessel diameter, hence tissue perfusion. Mesoporous silica nanoparticles (MSNs) can be used as potential drug delivery platforms for vasodilator drugs. Here, using an ex vivo model of vascular function, we examine the use of titania coating for improved biocompatibility and release dynamics of MSN loaded sodium nitroprusside (SNP). MSNs (95 ± 23 nm diameter; pore size 2.7 nm) were synthesised and fully characterised. They were loaded with SNP and coated with titania (TiO2), using the magnetron sputtering technique. Pre-constricted aortic vessels were exposed to drug loaded MSNs (at 1.96 × 1012 MSN mL−1) and the time course of vessel dilation observed, in real time. Exposure of viable vessels to MSNs lead to their internalization into the cytoplasm of ECs, while TiMSNs were also observed in the elastic lamina and smooth muscle cell layers. We demonstrate that titania coating of MSNs significantly improves their biocompatibility and alters the dynamics of drug release. A slow and more sustained relaxation was evident after uptake of TiMSN-SNP, in comparison to uncoated MSN-SNP (rate of dilation was 0.08% per min over a 2.5 h period). The use of titania coated MSNs for drug delivery to the vasculature may be an attractive strategy for therapeutic clinical intervention in cardiovascular disease

    Promoting students’ interest through culturally sensitive curricula in higher education

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    Previous studies have emphasized culturally sensitive curricula in the context of enhancing minoritized students’ education. We examined the relationship between second-year higher education students’ perceptions of the cultural sensitivity of their curriculum and both majoritized and minoritized students’ interest in their course. A total of 286 (228 F) students rated the cultural sensitivity of their curriculum on six scales using a revised version of the Culturally Sensitive Curricula Scales (CSCS-R), the perceived quality of their relationships with teachers, and their interest. The CSCS-R widened the construct with two new scales and showed better reliability. Ethnic minority students (n = 99) perceived their curriculum as less culturally sensitive than White students (n = 182), corroborating previous findings. Black students perceived their curriculum as less culturally sensitive than Asian students. There were no significant differences between ethnic minority and White students on interest or perceived quality of relationships with teachers. Five dimensions of cultural sensitivity (Diversity Represented, Positive Depictions, Challenge Power, Inclusive Classroom Interactions, Culturally Sensitive Assessments) and perceived quality of relationships with teachers predicted interest. Ethnicity did not. Ensuring curricula and assessments represent diversity positively, challenge power and are inclusive may support students’ interest while reflecting an increasingly diverse society

    SARS-CoV-2 (COVID-19) infection in pregnant women: characterization of symptoms and syndromes predictive of disease and severity through real-time, remote participatory epidemiology

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    Objective: To test whether pregnant and non-pregnant women differ in COVID-19 symptom profile and severity. To extend previous investigations on hospitalized pregnant women to those who did not require hospitalization. Design: Observational study prospectively collecting longitudinal (smartphone application interface) and cross-sectional (web-based survey) data. Setting:Community-based self-participatory citizen surveillance in the United Kingdom, Sweden and the United States of America. Population: Two female community-based cohorts aged 18-44 years. The discovery cohort was drawn from 1,170,315 UK, Sweden and USA women (79 pregnant tested positive) who self-reported status and symptoms longitudinally via smartphone. The replication cohort included 1,344,966 USA women (134 pregnant tested positive) who provided cross-sectional self-reports. Methods: Pregnant and non-pregnant were compared for frequencies of symptoms and events, including SARS-CoV-2 testing and hospitalization rates. Multivariable regression was used to investigate symptoms severity and comorbidity effects. Results: Pregnant and non-pregnant women positive for SARS-CoV-2 infection were not different in syndromic severity. Pregnant were more likely to have received testing than non-pregnant, despite reporting fewer symptoms. Pre-existing lung disease was most closely associated with the syndromic severity in pregnant hospitalized women. Heart and kidney diseases and diabetes increased risk. The most frequent symptoms among all non-hospitalized women were anosmia [63% pregnant, 92% non-pregnant] and headache [72%, 62%]. Cardiopulmonary symptoms, including persistent cough [80%] and chest pain [73%], were more frequent among pregnant women who were hospitalized. Conclusions: Symptom characteristics and severity were comparable among pregnant and non-pregnant women, except for gastrointestinal symptoms. Consistent with observations in non-pregnant populations, lung disease and diabetes were associated with increased risk of more severe SARS-CoV-2 infection during pregnancy. Tweetable abstract: Pregnancy with SARS-CoV-2 has no higher risk of severe symptoms. Underlying lung disease or cardiac condition can increase risk. Competing Interest Statement: ATC previously served as an investigator on a clinical trial of diet and lifestyle using a separate mobile application that was supported by Zoe Global Ltd. Clinical Trial -- Funding Statement: This work was supported by Zoe Global. The Department of Twin Research receives grants from the Wellcome Trust (212904/Z/18/Z) and Medical Research Council/British Heart Foundation Ancestry and Biological Informative Markers for Stratification of Hypertension (AIMHY; MR/M016560/1), and support from the European Union, the Chronic Disease Research Foundation, Zoe Global, the NIHR Clinical Research Facility and the Biomedical Research Centre (based at Guys and St Thomas NHS Foundation Trust in partnership with Kings College London). The School of Biomedical Engineering & Imaging Science and Center for Medical Engineering at Kings College London receive grants from the Wellcome/EPSRC Centre for Medical Engineering [WT 203148/Z/16/Z]. E.M. is funded by the Skills Development Scheme of the Medical Research Council UK. C.M.A. is funded by NIDDK K23 DK120899 and the Boston Childrens Hospital Office of Faculty Development Career Development Award. CHS is supported by an Alzheimers Society Junior fellowship (AS-JF-17-011). W.M., J.S.B. and A.T.C. are supported by the Massachusetts Consortium on Pathogen Readiness (MassCPR) and Mark and Lisa Schwartz
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