185 research outputs found

    A Survey on Secure and Private Federated Learning Using Blockchain: Theory and Application in Resource-constrained Computing

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    Federated Learning (FL) has gained widespread popularity in recent years due to the fast booming of advanced machine learning and artificial intelligence along with emerging security and privacy threats. FL enables efficient model generation from local data storage of the edge devices without revealing the sensitive data to any entities. While this paradigm partly mitigates the privacy issues of users' sensitive data, the performance of the FL process can be threatened and reached a bottleneck due to the growing cyber threats and privacy violation techniques. To expedite the proliferation of FL process, the integration of blockchain for FL environments has drawn prolific attention from the people of academia and industry. Blockchain has the potential to prevent security and privacy threats with its decentralization, immutability, consensus, and transparency characteristic. However, if the blockchain mechanism requires costly computational resources, then the resource-constrained FL clients cannot be involved in the training. Considering that, this survey focuses on reviewing the challenges, solutions, and future directions for the successful deployment of blockchain in resource-constrained FL environments. We comprehensively review variant blockchain mechanisms that are suitable for FL process and discuss their trade-offs for a limited resource budget. Further, we extensively analyze the cyber threats that could be observed in a resource-constrained FL environment, and how blockchain can play a key role to block those cyber attacks. To this end, we highlight some potential solutions towards the coupling of blockchain and federated learning that can offer high levels of reliability, data privacy, and distributed computing performance

    Orange is the new green: exploring the restorative capacity of seasonal foliage in schoolyard trees

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    Urban schoolyard environments are increasingly characterized by a proliferation of hard surfaces with little if any greenery. Schoolyard “greening” initiatives are becoming increasingly popular; however, schoolyard designs often fail to realize their restorative potential. In this quasi-experimental study, a proposed schoolyard greening project was used to visualize alternative planting designs and seasonal tree foliage; these design alternatives were subsequently used as visual stimuli in a survey administered to children who will use the schoolyard to assess the perceived restorative capacity of different design features. The findings indicate that seasonal changes in tree foliage enhance the perceived restorative quality of schoolyard environments. Specifically, fall foliage colour, when compared to green foliage, is rated as being perceived to be equally restorative for children. Additionally, seasonal planting, including evergreen conifers, may enhance the restorative quality of the schoolyard especially when deciduous trees are leafless. Landscape design professionals, community-based organizations, and other decision-makers in schoolyard greening efforts should strategically consider their tree choices to maximize year-round support for healthy attention functioning in children through restoration

    Does Spin-Orbit Coupling Effect Favor Planar Structures for Small Platinum Clusters?

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    We have performed full-relativistic density functional theory calculations to study the geometry and binding energy of different isomers of free platinum clusters Ptn_{n} (n=46n=4-6) within the spin multiplicities from singlet to nonet. The spin-orbit coupling effect has been discussed for the minimum-energy structures, relative stabilities, vibrational frequencies, magnetic moments, and the highest occupied and lowest unoccupied molecular-orbital gaps. It is found in contrast to some of the previous calculations that 3-dimentional configurations are still lowest energy structures of these clusters, although spin-orbit effect makes some planar or quasi-planar geometries more stable than some other 3-dimentional isomers

    Challenge Demcare: management of challenging behaviour in dementia at home and in care homes:Development, evaluation and implementation of an online individualised intervention for care homes; and a cohort study of specialist community mental health care for families

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    Background: Dementia with challenging behaviour (CB) causes significant distress for caregivers and the person with dementia. It is associated with breakdown of care at home and disruption in care homes. Challenge Demcare aimed to assist care home staff and mental health practitioners who support families at home to respond effectively to CB. Objectives: To study the management of CB in care homes (ResCare) and in family care (FamCare). Following a conceptual overview, two systematic reviews and scrutiny of clinical guidelines, we (1) developed and tested a computerised intervention; (2) conducted a cluster randomised trial (CRT) of the intervention for dementia with CB in care homes; (3) conducted a process evaluation of implementation of the intervention; and (4) conducted a longitudinal observational cohort study of the management of people with dementia with CB living at home, and their carers. Review methods: Cochrane review of randomised controlled trials; systematic meta-ethnographic review of quantitative and qualitative studies. Design: ResCare – survey, CRT, process evaluation and stakeholder consultations. FamCare – survey, longitudinal cohort study, participatory development design process and stakeholder consultations. Comparative examination of baseline levels of CB in the ResCare trial and the FamCare study participants. Settings: ResCare – 63 care homes in Yorkshire. FamCare – 33 community mental health teams for older people (CMHTsOP) in seven NHS organisations across England. Participants: ResCare – 2386 residents and 861 staff screened for eligibility; 555 residents with dementia and CB; 277 ‘other’ residents; 632 care staff; and 92 staff champions. FamCare – every new referral (n = 5360) reviewed for eligibility; 157 patients with dementia and CB, with their carer; and 26 mental health practitioners. Stakeholder consultations – initial workshops with 83 practitioners and managers from participating organisations; and 70 additional stakeholders using eight group discussions and nine individual interviews. Intervention: An online application for case-specific action plans to reduce CB in dementia, consisting of e-learning and bespoke decision support care home and family care e-tools. Main outcome measures: ResCare – survey with the Challenging Behaviour Scale; measurement of CB with the Neuropsychiatric Inventory (NPI) and medications taken from prescriptions; implementation with thematic views from participants and stakeholders. FamCare – case identification from all referrals to CMHTsOP; measurement of CB with the Revised Memory and Behaviour Problems Checklist and NPI; medications taken from prescriptions; and thematic views from stakeholders. Costs of care calculated for both settings. Comparison of the ResCare trial and FamCare study participants used the NPI, Clinical Dementia Rating and prescribed medications. Results: ResCare – training with group discussion and decision support for individualised interventions did not change practice enough to have an impact on CB in dementia. Worksite e-learning opportunities were not readily taken up by care home staff. Smaller homes with a less hierarchical management appear more ready than others to engage in innovation. FamCare – home-dwelling people with dementia and CB are referred to specialist NHS services, but treatment over 6 months, averaging nine contacts per family, had no overall impact on CB. Over 60% of people with CB had mild dementia. Families bear the majority of the care costs of dementia with CB. A care gap in the delivery of post-diagnostic help for families supporting relatives with dementia and significant CB at home has emerged. Higher levels of CB were recorded in family settings; and prescribing practices were suboptimal in both care home and family settings. Limitations: Functionality of the software was unreliable, resulting in delays. This compromised the feasibility studies and undermined delivery of the intervention in care homes. A planned FamCare CRT could not proceed because of insufficient referrals. Conclusions: A Cochrane review of individualised functional analysis-based interventions suggests that these show promise, although delivery requires a trained dementia care workforce. Like many staff training interventions, our interactive e-learning course was well received by staff when delivered in groups with facilitated discussion. Our e-learning and decision support e-tool intervention in care homes, in its current form, without ongoing review of implementation of recommended action plans, is not effective at reducing CB when compared with usual care. This may also be true for staff training in general. A shift in priorities from early diagnosis to early recognition of dementia with clinically significant CB could bridge the emerging gap and inequities of care to families. Formalised service improvements in the NHS, to co-ordinate such interventions, may stimulate better opportunities for practice models and pathways. Separate services for care homes and family care may enhance the efficiency of delivery and the quality of research on implementation into routine care. Future work: There is scope for extending functional analysis-based interventions with communication and interaction training for carers. Our clinical workbooks, video material of real-life episodes of CB and process evaluation tool resources require further testing. There is an urgent need for evaluation of interventions for home-dwelling people with dementia with clinically significant CB, delivered by trained dementia practitioners. Realist evaluation designs may illuminate how the intervention might work, and for whom, within varying service contexts

    Causal effect of plasminogen activator inhibitor type 1 on coronary heart disease

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    Background--Plasminogen activator inhibitor type 1 (PAI-1) plays an essential role in the fibrinolysis system and thrombosis. Population studies have reported that blood PAI-1 levels are associated with increased risk of coronary heart disease (CHD). However, it is unclear whether the association reflects a causal influence of PAI-1 on CHD risk. Methods and Results--To evaluate the association between PAI-1 and CHD, we applied a 3-step strategy. First, we investigated the observational association between PAI-1 and CHD incidence using a systematic review based on a literature search for PAI-1 and CHD studies. Second, we explored the causal association between PAI-1 and CHD using a Mendelian randomization approach using summary statistics from large genome-wide association studies. Finally, we explored the causal effect of PAI-1 on cardiovascular risk factors including metabolic and subclinical atherosclerosis measures. In the systematic meta-analysis, the highest quantile of blood PAI-1 level was associated with higher CHD risk comparing with the lowest quantile (odds ratio=2.17; 95% CI: 1.53, 3.07) in an age- and sex-adjusted model. The effect size was reduced in studies using a multivariable-adjusted model (odds ratio=1.46; 95% CI: 1.13, 1.88). The Mendelian randomization analyses suggested a causal effect of increased PAI-1 level on CHD risk (odds ratio=1.22 per unit increase of log-transformed PAI-1; 95% CI: 1.01, 1.47). In addition, we also detected a causal effect of PAI-1 on elevating blood glucose and high-density lipoprotein cholesterol. Conclusions--Our study indicates a causal effect of elevated PAI-1 level on CHD risk, which may be mediated by glucose dysfunction

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

    Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

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    BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)

    The Verbal Behavior Of Bilinguals: The Effect Of Language Of Report Uponthe Thematic Apperception Test Stories Of Adult French Bilinguals.

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    PhDSocial psychologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/179220/2/0012571.pd

    La demande dans la famille : apprendre à être poli et à persuader

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    Ervin-Tripp Susan Moore, Vriet Claire. La demande dans la famille : apprendre à être poli et à persuader. In: Bulletin de psychologie, tome 46 n°409, 1992. La communication prélinguistique et linguistique – Représentation de l'enfance. pp. 51-59
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