7440 research outputs found
Sort by
Cascading attacks against smart grid using control command disaggregation and services
No full textIn this paper, we propose new types of cascading attacks against smart grid that use control command disaggregation and core smart grid services. Although there have been tremendous research efforts in injection attacks against the smart grid, to our knowledge most studies focus on false meter data injection, and false command and false feedback injection attacks have been scarcely investigated. In addition, control command disaggregation has not been addressed from a security point of view, in spite of the fact that it is becoming one of core concepts in the smart grid and hence analysing its security implications is crucial to the smart grid security. Our cascading attacks use false control command, false feedback or false meter data injection, and cascade the effects of such injections throughout the smart grid subsystems and components. Our analysis and evaluation results show that the proposed attacks can cause serious service disruptions in the smart grid. The evaluation has been performed on a widely used smart grid simulation platform.6 page(s
Dynamic competition between large-scale functional networks differentiates fear conditioning and extinction in humans
No full textThe high evolutionary value of learning when to respond to threats or when to inhibit previously learned associations after changing threat contingencies is reflected in dedicated networks in the animal and human brain. Recent evidence further suggests that adaptive learning may be dependent on the dynamic interaction of meta-stable functional brain networks. However, it is still unclear which functional brain networks compete with each other to facilitate associative learning and how changes in threat contingencies affect this competition. The aim of this study was to assess the dynamic competition between large-scale networks related to associative learning in the human brain by combining a repeated differential conditioning and extinction paradigm with independent component analysis of functional magnetic resonance imaging data. The results (i) identify three task-related networks involved in initial and sustained conditioning as well as extinction, and demonstrate that (ii) the two main networks that underlie sustained conditioning and extinction are anti-correlated with each other and (iii) the dynamic competition between these two networks is modulated in response to changes in associative contingencies. These findings provide novel evidence for the view that dynamic competition between large-scale functional networks differentiates fear conditioning from extinction learning in the healthy brain and suggest that dysfunctional network dynamics might contribute to learning-related neuropsychiatric disorders.6 page(s
Prevention of low back pain : a systematic review and meta-analysis
No full textImportance: Existing guidelines and systematic reviews lack clear recommendations for prevention of low back pain (LBP). Objective: To investigate the effectiveness of interventions for prevention of LBP. Data sources: MEDLINE, EMBASE, Physiotherapy Evidence Database Scale, and Cochrane Central Register of Controlled Trials from inception to November 22, 2014. Study selection: Randomized clinical trials of prevention strategies for nonspecific LBP. Data extraction and synthesis: Two independent reviewers extracted data and assessed the risk of bias. The Physiotherapy Evidence Database Scale was used to evaluate the risk-of-bias. The Grading of Recommendations Assessment, Development, and Evaluation system was used to describe the quality of evidence. Main outcomes and measures: The primary outcome measurewas an episode of LBP, and the secondary outcome measure was an episode of sick leave associated with LBP.We calculated relative risks (RRs) and 95% CIs using random-effects models. Results: The literature search identified 6133 potentially eligible studies; of these, 23 published reports (on 21 different randomized clinical trials including 30 850 unique participants) met the inclusion criteria. With results presented as RRs (95% CIs), there was moderate-quality evidence that exercise combined with education reduces the risk of an episode of LBP (0.55 [0.41-0.74]) and low-quality evidence of no effect on sick leave (0.74 [0.44-1.26]). Low-to very low-quality evidence suggested that exercise alone may reduce the risk of both an LBP episode (0.65 [0.50-0.86]) and use of sick leave (0.22 [0.06-0.76]). For education alone, there was moderate-to very low-quality evidence of no effect on LBP (1.03 [0.83-1.27]) or sick leave (0.87 [0.47-1.60]). There was low-to very low-quality evidence that back belts do not reduce the risk of LBP episodes (1.01 [0.71-1.44]) or sick leave (0.87 [0.47-1.60]). There was low-quality evidence of no protective effect of shoe insoles on LBP (1.01 [0.74-1.40]). Conclusion and relevance: The current evidence suggests that exercise alone or in combination with education is effective for preventing LBP. Other interventions, including education alone, back belts, and shoe insoles, do not appear to prevent LBP. Whether education, training, or ergonomic adjustments prevent sick leave is uncertain because the quality of evidence is low.10 page(s
Evolving eating disorder psychopathology : conceptualising muscularity-oriented disordered eating
No full textEating disorders, once thought to be largely confined to females, are increasingly common in males. However, the presentation of disordered eating among males is often distinct to that observed in females and this diversity is not accommodated in current classification schemes. Here, we consider the diagnostic and clinical challenges presented by these distinctive presentations.2 page(s
Dux ludens : Eleonora de Toledo, Cosimo I de' Medici, and games of chance in the ducal household of mid-sixteenth-century Florence
No full textHigh-stakes gambling was a widespread pastime in the courts of early modern Europe and the Medici court in Florence enjoyed a particular notoriety for it in the middle decades of the sixteenth century. Using insights from the sociological writings of Johan Huizinga, Erving Goffman, and Clifford Geertz, this article explores the meaning and significance of games of chance in the ducal household, focusing specifically on the gambling habits of the duke and duchess, Cosimo I de' Medici and Eleonora de Toledo. It argues that play in the Medici court was always more than simple diversion and that the ducal couple used gambling to demonstrate their self-control, fortitude, and suitability for governance. Play, the article suggests, was a constitutive element of court culture in early modern Europe.23 page(s
Enhancing the impact of cross-sector partnerships
No full textThis paper addresses the topic of this special symposium issue: how to enhance the impact of cross-sector partnerships. The paper takes stock of two related discussions: the discourse in cross-sector partnership research on how to assess impact and the discourse in impact assessment research on how to deal with more complex organizations and projects. We argue that there is growing need and recognition for cross-fertilization between the two areas. Cross-sector partnerships are reaching a paradigmatic status in society, but both research and practice need more thorough evidence of their impacts and of the conditions under which these impacts can be enhanced. This paper develops a framework that should enable a constructive interchange between the two research areas, while also framing existing research into more precise categories that can lead to knowledge accumulation. We address the preconditions for such a framework and discuss how the constituent parts of this framework interact. We distinguish four different pathways or impact loops that refer to four distinct orders of impact. The paper concludes by applying these insights to the four papers included in this special issue.17 page(s
Interannual modulation of subtropical Atlantic boreal summer dust variability by ENSO
No full textDust variability in the climate system has been studied for several decades, yet there remains an incomplete understanding of the dynamical mechanisms controlling interannual and decadal variations in dust transport. The sparseness of multi-year observational datasets has limited our understanding of the relationship between climate variations and atmospheric dust. We use available in situ and satellite observations of dust and a century-length fully coupled Community Earth System Model (CESM) simulation to show that the El Niño-Southern Oscillation (ENSO) exerts a control on North African dust transport during boreal summer. In CESM, this relationship is stronger over the dusty tropical North Atlantic than near Barbados, one of the few sites having a multi-decadal observed record. During strong La Niña summers in CESM, a statistically significant increase in lower tropospheric easterly wind is associated with an increase in North African dust transport over the Atlantic. Barbados dust and Pacific SST variability are only weakly correlated in both observations and CESM, suggesting that other processes are controlling the cross-basin variability of dust. We also use our CESM simulation to show that the relationship between downstream North African dust transport and ENSO fluctuates on multidecadal timescales and is associated with a phase shift in the North Atlantic Oscillation. Our findings indicate that existing observations of dust over the tropical North Atlantic are not extensive enough to completely describe the variability of dust and dust transport, and demonstrate the importance of global models to supplement and interpret observational records.15 page(s
Nitrogen nanoinclusions in milky diamonds from Juina area, Mato Grosso State, Brazil
No full textA unique set of diamonds with a ‘milky’ optical appearance from the Rio Soriso placer deposit in the Juina area, Mato Grosso, Brazil was studied by combined transmission electron microscopy (TEM) and fourier transform infrared (FTIR) spectroscopy. The main characteristics of the studied samples are large numbers of randomly distributed {111}-faceted octahedral defect nanostructures. The dislocation densities of the focused ion beam (FIB) foils are generally low. Dislocation loops are observed only around larger inclusions. The inclusion size shows a bimodal distribution and spreads around values of 20 and 200 nm. Electron energy-loss spectroscopy (EELS) and energy-dispersive X-ray (EDX) spectroscopy mapping of both subsets yield high nitrogen contents for all sealed inclusions. In cases where the nanoinclusions touch the surface of the FIB section no nitrogen signal could be detected, indicating the loss of a fluid or gas phase as the carrier of nitrogen. FTIR mapping of the same regions showed a strong correlation between structurally bound nitrogen, hydrogen and the abundance of nanoinclusions. We propose that the most likely phase included in these nanoinclusions is NH₃. These nanoinclusions could be the result of a high-temperature episode or of long residence times at shallower depths and lower temperatures. Thus they might represent the last stage of the nitrogen aggregation, or they may be syngenetic trapped NH-bearing source fluids.11 page(s
From crypsis to mimicry : changes in colour and the configuration of the visual system during ontogenetic habitat transitions in a coral reef fish
No full textAnimals often change their habitat throughout ontogeny; yet, the triggers for habitat transitions and how these correlate with developmental changes - e.g. physiological, morphological and behavioural - remain largely unknown. Here, we investigated how ontogenetic changes in body coloration and of the visual system relate to habitat transitions in a coral reef fish. Adult dusky dottybacks, Pseudochromis fuscus, are aggressive mimics that change colour to imitate various fishes in their surroundings; however, little is known about the early life stages of this fish. Using a developmental time series in combination with the examination of wild-caught specimens, we revealed that dottybacks change colour twice during development: (i) nearly translucent cryptic pelagic larvae change to a grey camouflage coloration when settling on coral reefs; and (ii) juveniles change to mimic yellow- or brown-coloured fishes when reaching a size capable of consuming juvenile fish prey. Moreover, microspectrophotometric (MSP) and quantitative real-time PCR (qRT-PCR) experiments show developmental changes of the dottyback visual system, including the use of a novel adult-specific visual gene (RH2 opsin). This gene is likely to be co-expressed with other visual pigments to form broad spectral sensitivities that cover the medium-wavelength part of the visible spectrum. Surprisingly, the visual modifications precede changes in habitat and colour, possibly because dottybacks need to first acquire the appropriate visual performance before transitioning into novel life stages.14 page(s
Can we predict those with osteoarthritis who will worsen following a chronic disease management program?
No full textObjective: To identify predictors of worsening symptoms and overall health of the treated hip or knee joint following 26 weeks of a nonsurgical chronic disease management program for hip and knee osteoarthritis (OA) and to examine the consistency of these predictors across 3 definitions of worsening. Methods: This prospective cohort study followed 539 participants of the program for 26 weeks. The 3 definitions of worsening included symptomatic worsening based on change in the Western Ontario and McMaster Universities Osteoarthritis Index Global score (WOMAC-G) measuring pain, stiffness, and function; a transition scale that asked about overall health of the treated hip or knee joint; and a composite outcome including both. Multivariate logistic regression models were constructed for the 3 definitions of worsening. Results: Complete data were available for 386 participants: mean age was 66.3 years, 69% were female, 85% reported knee joint pain as primary symptom (signal joint), 46% were waitlisted for total joint arthroplasty (TJA). TJA waitlist status, signal joint, 6-Minute Walk Test (6MWT), depressive symptoms, pain, and age were independently associated with at least 1 definition of worsening. TJA waitlist status and 6MWT remained in the multivariate models for the transition and composite definitions of worsening. Conclusion: Participants reporting worsening on the transition scale did not consistently meet the WOMAC-G definition of worsening symptoms. TJA waitlist status was predictive of the composite definition of worsening, a trend apparent for the transition definition. However, variables that predict worsening remain largely unknown. Further research is required to direct comprehensive and targeted management of patients with hip and knee OA.10 page(s