1,514 research outputs found
Multi-Party Trust Computation in Decentralized Environments
In this paper, we describe a decentralized privacy-preserving protocol for securely casting trust ratings in distributed reputation systems. Our protocol allows n participants to cast their votes in a way that preserves the privacy of individual values against both internal and external attacks. The protocol is coupled with an extensive theoretical analysis in which we formally prove that our protocol is resistant to collusion against as many as n-1 corrupted nodes in the semi-honest model. The behavior of our protocol is tested in a real P2P network by measuring its communication delay and processing overhead. The experimental results uncover the advantages of our protocol over previous works in the area; without sacrificing security, our decentralized protocol is shown to be almost one order of magnitude faster than the previous best protocol for providing anonymous feedback
Alexandre Yersin's explorations (1892-1894) in French Indochina before the discovery of the plague bacillus.
Alexandre Yersin, the great French discoverer of yersinia pestis, was a keen explorer of unknown lands. At the age of 30, a member of the French Colonial Health service, he set off to fulfil his intimate dream and explore other continents. For almost two years and three long expeditions, he journeyed through widely unknown regions in the province of the French Indochina, in southeast Asia, territories of Vietnam, Cambodia and Laos. This article presents vignettes from his explorations. During his difficult travels, he carefully planned and noted his itineraries; designed new routes, but also observed and recorded sociodemographic and environmental data and unidentified diseases. The immature science of late 19th century geography had the strength to allure such an influential medical figure and place him among the early medical geographers. His journeys, observations and recordings brought to Yersin great experience, and he made his most important scientific contributions after he had concluded his explorations
Good Sleep Quality Improves the Relationship Between Pain and Depression Among Individuals With Chronic Pain
Individuals with chronic pain often experience co-existing sleep problems and depression-related states. Chronic pain, sleep problems, and depression interrelate, and have been shown to exacerbate one another, which negatively impacts quality of life. This study explored the relationships between pain severity, pain interference, sleep quality, and depression among individuals with chronic pain. Secondly, we tested whether sleep quality may moderate the relationship between pain and depression. A cross-sectional survey was completed by 1,059 adults with non-malignant chronic pain conditions (Mage 43 years, 88% identified as women) and collected measures related to pain severity, pain interference, sleep quality and depression. Multiple regression analyses found that pain severity, pain interference and sleep quality are all significantly associated with depression. Secondly, moderated regression analyses revealed that sleep quality moderates the relationship between pain interference and depression among individuals with chronic pain such that good sleep quality attenuates the effect of pain interference on depression, and poor sleep quality amplifies the effect of pain interference on depression. These findings suggest that sleep quality may be a relevant therapeutic target for individuals with chronic pain and co-existing depression
Refurbishment of a Victorian terraced house for energy efficiency
The impacts of global warming are now obvious. The international community has committed itself to reduce CO2 emissions, the main contributor to the greenhouse effect, both at international and national levels. In the Kyoto Protocol signed in 1997, countries have committed to reduce their greenhouse gases emissions below their 1990 levels by the period 2008-2012. The UK specifically should reduce those emissions by 12.5%. Format reason, the UK has introduced a package of policies, which promote not only the use of renewable energy resources, but most importantly the reduction in energy use, with energy efficiency. Refurbishment of existing houses has and will contribute to the reduction of energy consumption. A Victorian mid-terraced house was studied in this report, and different refurbishment measures were tested, using two software programmes: TAS and SAP. The targets were to achieve certain levels of thermal comfort, to comply with the Building Regulation for building thermal elements and to achieve a high SAP rating. Then, the cost of each measure was calculated and its CO2 emissions were compared. Heat losses were mainly through the walls and roof. Roof and mainly wall refurbishment measures reduce the heating loads the most. Ground floor insulation does not contribute to the reduction of the heating loads, on the contrary it has detrimental effect in summer, where the cooling effect coming from the ground is being reduced. Window replacement achieves a very good performance in summer resulting in the reduction of overheating. Wall and roof insulation increase the SAP rating the most, between the building elements, but boiler replacement and upgrading of heating controls increase it more. According to the SAP rating, CO2 annual emissions are reduced the most by boiler replacement and then by wall and roof. The results given by the two softwares concerning which measure is more leads more to energy efficiency, are the same. Finally, if the measures which lead to the best energy performance are combined together, then the house could cut its energy bills by half, and could have 70% reduction in CO2 emissions
Low power general purpose loop acceleration for NDP applications
Modern processor architectures face a throughput scaling problem as the performance bottleneck shifts from the core pipeline to the data transfer operations between the dynamic random access memory (DRAM) and the processor chip. To address such issue researchers have proposed the near-data processing (NDP) paradigm in which the instruction execution is moved to the DRAM die thus, lowering the data movement between the processor and the DRAM. Previous NDP works focus on specific application types and thus the general purpose application execution paradigm is neglected. In this work we propose an NDP methodology for low power general purpose loop acceleration. For this reason we design and implement a hardware loop accelerator from the ground up to improve the throughput and lower the power consumption of general purpose loops. We adopt a novel loop scheduling approach which enables the loop accelerator to take advantage of the dataflow parallelism of the executing loop and we implement our design on the logic layer of a hybrid memory cube (HMC) DRAM. Post-layout simulations demonstrate an average speedup factor of 20.5x when executing kernels from various scientific fields while the energy consumption is reduced by a factor of 9.3x over the host CPU execution
The Impact of the COVID-19 Pandemic on Students’ Mental Health and Sleep in Saudi Arabia
BACKGROUND: Mental health problems are prevalent among university students in Saudi Arabia. This study aimed to investigate the impact of the COVID-19 pandemic on university students’ mental health and sleep in Saudi Arabia. Method: A total of 582 undergraduate students from Saudi Arabia aged between 18 and 45 years old (M = 20.91, SD = 3.17) completed a cross-sectional online questionnaire measuring depression, anxiety, stress, resilience, and insomnia during the COVID-19 pandemic (2020). Analysis included an independent samples t-test, one-way ANOVA, and Hierarchical regression analysis. RESULTS: Undergraduate students reported high levels of depression, anxiety, and perceived stress and low levels of resilience (p < 0.001) during the pandemic. In addition, students reported experiencing insomnia. A hierarchical regression analysis indicated that lower resilience, high levels of insomnia, having a pre-existing mental health condition, and learning difficulties (such as dyslexia, dyspraxia, or dyscalculia) were significantly associated with high levels of depression and stress. In addition, lower resilience, a high level of insomnia, and pre-existing mental health conditions were significantly associated with high levels of anxiety. Finally, a lower level of psychological resilience and a high level of insomnia were significantly associated with increased levels of depression, anxiety and stress within university students. CONCLUSION: This study has provided evidence that a lower level of psychological resilience and insomnia were associated with mental health problems among undergraduate students in Saudi Arabia, thus enhancing psychological resilience and interventions to support sleep and mental health are vital to support student well-being outcomes throughout the pandemic
Acute impact of a national lockdown during the COVID-19 pandemic on wellbeing outcomes among individuals with chronic pain
Changes to wellbeing in a community- based sample of 638 adults with non-malignant chronic pain were assessed during a period of mandated lockdown measures in the UK to control the COVID-19 outbreak. Participants completed an online survey pre-lockdown and were followed up during lockdown. Multivariate analysis demonstrate that decreased ability to self-manage, restricted access to healthcare and increased dependence on others were associated with negative wellbeing outcomes related to sleep, anxiety and depression. Essential but nonurgent services are required during periods of lockdown to maintain independence and self-management in order to preserve wellbeing in this population
Theoretical Findings and Measurements on Planning a UHF RFID System inside a Room
This paper investigates the problem of improving the identification performance of a UHF RFID system inside a room. We assume static reader, passive tags and availability of commodity antennas. A ray-tracing propagation model is developed that includes multipath in 3D space. It is found that careful selection of reader antenna placement and tilting must be performed to control destructive interference effects. Furthermore, 3D coverage performance gains on the order of 10% are observed by implementing tags’ diversity. A device that successfully manipulates destructive interference is introduced. All theoretical findings are verified by measurements. Finally, a method to perform propagation measurements with commodity RFID hardware is demonstrated
Sleep and Cognition in Children with Fetal Alcohol Spectrum Disorders (FASD) and Children with Autism Spectrum Disorders (ASD)
Children with Fetal Alcohol Spectrum Disorders (FASD) and Autism Spectrum Disorders (ASD) experience significantly higher rates of sleep disturbances than their typically developing peers. However, little is known about the association between sleep and the cognitive phenotype in these clinical populations. Structural damage affecting cortical and subcortical connectivity occurs as a result of prenatal alcohol exposure in children with FASD, whilst it is believed an abundance of short-range connectivity explains the phenotypic manifestations of childhood ASD. These underlying neural structural and connectivity differences manifest as cognitive patterns, with some shared and some unique characteristics between FASD and ASD. This is the first study to examine sleep and its association with cognition in individuals with FASD, and to compare sleep in individuals with FASD and ASD. We assessed children aged 6–12 years with a diagnosis of FASD (n = 29), ASD (n = 21), and Typically Developing (TD) children (n = 46) using actigraphy (CamNTech Actiwatch 8), digit span tests of working memory (Weschler Intelligence Scale), tests of nonverbal mental age (MA; Ravens Standard Progressive Matrices), receptive vocabulary (British Picture Vocabulary Scale), and a choice reaction time (CRT) task. Children with FASD and ASD presented with significantly shorter total sleep duration, lower sleep efficiency, and more nocturnal wakings than their TD peers. Sleep was significantly associated with scores on the cognitive tests in all three groups. Our findings support the growing body of work asserting that sleep is significant to cognitive functioning in these neurodevelopmental conditions; however, more research is needed to determine cause and effect
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