5,437 research outputs found

    Frontoparietal representations of task context support the flexible control of goal-directed cognition.

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    Cognitive control allows stimulus-response processing to be aligned with internal goals and is thus central to intelligent, purposeful behavior. Control is thought to depend in part on the active representation of task information in prefrontal cortex (PFC), which provides a source of contextual bias on perception, decision making, and action. In the present study, we investigated the organization, influences, and consequences of context representation as human subjects performed a cued sorting task that required them to flexibly judge the relationship between pairs of multivalent stimuli. Using a connectivity-based parcellation of PFC and multivariate decoding analyses, we determined that context is specifically and transiently represented in a region spanning the inferior frontal sulcus during context-dependent decision making. We also found strong evidence that decision context is represented within the intraparietal sulcus, an area previously shown to be functionally networked with the inferior frontal sulcus at rest and during task performance. Rule-guided allocation of attention to different stimulus dimensions produced discriminable patterns of activation in visual cortex, providing a signature of top-down bias over perception. Furthermore, demands on cognitive control arising from the task structure modulated context representation, which was found to be strongest after a shift in task rules. When context representation in frontoparietal areas increased in strength, as measured by the discriminability of high-dimensional activation patterns, the bias on attended stimulus features was enhanced. These results provide novel evidence that illuminates the mechanisms by which humans flexibly guide behavior in complex environments

    The mobile emergency recovery intervention trial (MERIT): Protocol for a 3-year mixed methods observational study of mobile recovery outreach teams in Nevada's emergency departments.

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    BACKGROUND: The Substance Abuse and Mental Health Administration awarded State Targeted Response grants to support states' efforts to address the opioid epidemic. In Nevada, one component of this grant was mobile recovery outreach teams (MROTs) that utilized peer recovery support specialists to provide care for qualifying patients in emergency departments (EDs). The Mobile Emergency Recovery Intervention Trial (MERIT) is a mixed methods study to assess the feasibility/acceptability and effectiveness of the MROT intervention. This protocol mainly describes the R33 research activities and outcomes. The full protocol can be found protocols.io. METHODS: Data will be derived from state-level data sets containing de-identified emergency department visits, substance use disorder treatment records, and mortality files; in-person mixed methods interviews; participant observation; and self-report process evaluation forms. Primary outcomes include Medication Assisted Treatment (MAT) initiation and non-fatal overdose; secondary outcomes include MAT retention and fatal overdose. Quantitative hypotheses will be tested using generalized linear mixed effects models, Bayesian hierarchical models, and marginal Cox models. Qualitative interview data will be analyzed using an inductive thematic analysis procedure. DISCUSSION: It is impossible to conduct a randomized controlled trial of the effectiveness of the MROTs, given the ethical and logistical considerations of this intervention.This study's innovative design employs a mixed methods formative phase to examine feasibility and acceptability, and a quasi-experimental outcomes evaluation phase employing advanced statistical methods to mitigate bias and suggest causal inference regarding the effectiveness of the MROTs.Innovative interventions have been deployed in many states; evidence regarding their effectiveness is lacking, but critical to informing an effective public health response to the opioid epidemic

    Ternary Syndrome Decoding with Large Weight

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    The Syndrome Decoding problem is at the core of many code-based cryptosystems. In this paper, we study ternary Syndrome Decoding in large weight. This problem has been introduced in the Wave signature scheme but has never been thoroughly studied. We perform an algorithmic study of this problem which results in an update of the Wave parameters. On a more fundamental level, we show that ternary Syndrome Decoding with large weight is a really harder problem than the binary Syndrome Decoding problem, which could have several applications for the design of code-based cryptosystems

    Extracardiac 18F-florbetapir imaging in patients with systemic amyloidosis: more than hearts and minds

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    PURPOSE: 18F-Florbetapir has been reported to show cardiac uptake in patients with systemic light-chain amyloidosis (AL). This study systematically assessed uptake of 18F-florbetapir in patients with proven systemic amyloidosis at sites outside the heart. METHODS: Seventeen patients with proven cardiac amyloidosis underwent 18F-florbetapir PET/CT imaging, 15 with AL and 2 with transthyretin amyloidosis (ATTR). Three patients had repeat scans. All patients had protocolized assessment at the UK National Amyloidosis Centre including imaging with 123I-serum amyloid P component (SAP). 18F-Florbetapir images were assessed for areas of increased tracer accumulation and time-uptake curves in terms of standardized uptake values (SUVmean) were produced. RESULTS: All 17 patients showed 18F-florbetapir uptake at one or more extracardiac sites. Uptake was seen in the spleen in 6 patients (35%; 6 of 9, 67%, with splenic involvement on 123I-SAP scintigraphy), in the fat in 11 (65%), in the tongue in 8 (47%), in the parotids in 8 (47%), in the masticatory muscles in 7 (41%), in the lungs in 3 (18%), and in the kidney in 2 (12%) on the late half-body images. The 18F-florbetapir spleen retention index (SRI) was calculated. SRI >0.045 had 100% sensitivity/sensitivity (in relation to 123I-SAP splenic uptake, the current standard) in detecting splenic amyloid on dynamic imaging and a sensitivity of 66.7% and a specificity of 100% on the late half-body images. Intense lung uptake was seen in three patients, one of whom had lung interstitial infiltration suggestive of amyloid deposition on previous high-resolution CT. Repeat imaging showed a stable appearance in all three patients suggesting no early impact of treatment response. CONCLUSION: 18F-Florbetapir PET/CT is a promising tool for the detection of extracardiac sites of amyloid deposition. The combination of uptake in the heart and uptake in the spleen on 18F-florbetapir PET/CT, a hallmark of AL, suggests that this tracer holds promise as a screening tool for AL

    Sectoral specialisation in the EU a macroeconomic perspective

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    This paper analyses trends in sectoral specialisation in the EU and concludes the following: 1) The European production structure appears more homogenous than that of the US. 2) While sectoral specialisation has shown a slight increase in some smaller euro area countries towards the end-1990s, it is too early to detect any potential impact of EMU. 3) Despite some changes in sectoral composition, the business cycles of euro area countries became more synchronised over the 1990s, which may be seen as reassuring from the point of view of the single monetary policy. 4) Sectoral re-allocation accounts for as much as 50% of the increase in labour productivity growth in business sector services in the euro area. 5) The slowdown of European labour productivity growth relative to the US since the mid-1990s is explained by a stronger performance in the US wholesale and retail trade, financial intermediation and high-tech manufacturing sectors.

    Asymmetry to symmetry transition of Fano line-shape: Analytical derivation

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    An analytical derivation of Fano line-shape asymmetry ratio has been presented here for a general case. It is shown that Fano line-shape becomes less asymmetric as \q is increased and finally becomes completely symmetric in the limiting condition of q equal to infinity. Asymmetry ratios of Fano line-shapes have been calculated and are found to be in good consonance with the reported expressions for asymmetry ratio as a function of Fano parameter. Application of this derivation is also mentioned for explanation of asymmetry to symmetry transition of Fano line-shape in quantum confined silicon nanostructures.Comment: 3 figures, Latex files, Theoretica

    Training emergency services’ dispatchers to recognise stroke: an interrupted time-series analysis

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    Background: Stroke is a time-dependent medical emergency in which early presentation to specialist care reduces death and dependency. Up to 70% of all stroke patients obtain first medical contact from the Emergency Medical Services (EMS). Identifying ‘true stroke’ from an EMS call is challenging, with over 50% of strokes being misclassified. The aim of this study was to evaluate the impact of the training package on the recognition of stroke by Emergency Medical Dispatchers (EMDs). Methods: This study took place in an ambulance service and a hospital in England using an interrupted time-series design. Suspected stroke patients were identified in one week blocks, every three weeks over an 18 month period, during which time the training was implemented. Patients were included if they had a diagnosis of stroke (EMS or hospital). The effect of the intervention on the accuracy of dispatch diagnosis was investigated using binomial (grouped) logistic regression. Results: In the Pre-implementation period EMDs correctly identified 63% of stroke patients; this increased to 80% Post-implementation. This change was significant (p=0.003), reflecting an improvement in identifying stroke patients relative to the Pre-implementation period both the During-implementation (OR=4.10 [95% CI 1.58 to 10.66]) and Post-implementation (OR=2.30 [95% CI 1.07 to 4.92]) periods. For patients with a final diagnosis of stroke who had been dispatched as stroke there was a marginally non-significant 2.8 minutes (95% CI −0.2 to 5.9 minutes, p=0.068)reduction between Pre- and Post-implementation periods from call to arrival of the ambulance at scene. Conclusions: This is the first study to develop, implement and evaluate the impact of a training package for EMDs with the aim of improving the recognition of stroke. Training led to a significant increase in the proportion of stroke patients dispatched as such by EMDs; a small reduction in time from call to arrival at scene by the ambulance also appeared likely. The training package has been endorsed by the UK Stroke Forum Education and Training, and is free to access on-line

    BIOGEOGRAFIA DOS MANGUEZAIS

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    Os manguezais são ecossistemas localizados entre o mar e a terra firme, ao longo de boa parte dos litorais tropicais e subtropicais de todo o mundo. Este ecossistema, sujeito à influência de diversos fatores geoecológicos, em especial à hidrodinâmica flúvio-marinha, possui uma imensa importância para a biota de diversos ambientes, especialmente para os organismos marinhos, que encontram nele abrigo, local para reprodução, descanso e alimentação. Além da variada função ecológica, os manguezais também são importantes para o próprio homem, fornecendo-o recursos alimentares, madeira e proteção contra algumas catástrofes naturais, como tsunamis. Por outro lado, os manguezais são destruídos no mundo inteiro pela ação antrópica, que disputa com este ecossistema o valorizado espaço costeiro. Sob esta perspectiva, este trabalho buscou, através de uma revisão bibliográfica básica, trazer de maneira sucinta algumas das características destes ecossistemas costeiros, através de um enfoque biogeográfico e ecológico, bem como a sua importância ecológica, benefícios que oferece ao homem e as ameaças deste aos manguezais. Palavras-chave: Manguezais. Biogeografia. Ecologia. Biogeography of mangroves Mangroves ecosystems are located between sea and land, along much of coastal tropical and subtropical regions around the world. This ecosystem, subject to the influence of several geoecological factors, the fluvial-marine hydrodinamic particularly, has an immense importance to the biota of the several environments, especially for marine organisms, which find him shelter for reproduction, rest and feeding. Besides the varied ecological function, mangroves are important also for man, providing food resources, wood and some protection against natural disasters, such as tsunamis. Furthermore, the mangroves are destroyed worldwide by human action, that this dispute with the valued ecosystem space on the coastal environment. From this perspective, this study searched, through of the basic review bring some of characteristics of the ecosystem, during a biogeographical and ecological focus as well as their ecological importance, benefits and offers to the man, and the human threats to mangroves. Key words: Mangroves. Biogeography. Ecology
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