11,920 research outputs found

    Traumatic brain injury: Age at injury influences dementia risk after TBI

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    Traumatic brain injury (TBI) is increasingly recognized as a risk factor for dementia. New data provide further support for this association and demonstrate the influence of age at injury and injury severity on dementia risk after TBI, revealing that even mild TBI increases dementia risk in those aged ≥65 years

    Laser Generation of Narrow Band Ultrasound

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    Laser based sensor systems to replace conventional piezoelectric contact transducers for ultrasonic testing continue under development for applications where contact with the specimen surface is undesirable or impossible. To date, such systems are considerably less sensitive than their piezoelectric counterparts. As a result, a great deal of effort has contributed to the development of a number of interferoroetric transducer systems to detect ultrasound. Increasingly, however, researchers have begun looking at laser ultrasonic sources to see what improvements might be made to enhance overall system sensitivity for laser generation and detection of ultrasound

    Optimising outcomes for complex trauma survivors: assessing the motivators, barriers and enablers for implementing trauma informed practice within a multidisciplinary health setting

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    Background: Complex trauma is a significant public health issue with detrimental health, interpersonal and psychological impacts, which can impede client recovery and result in multiple representations. ‘Trauma Informed Practice’ (TIP) is an evidence-based model which ensures safe and effective services for clients and staff. This study examines health professional’s use of TIP, and the motivators, enablers and barriers to implementation in a multidisciplinary setting. Methods: A mixed methods study with 24 front-line clinicians and managers within a community health setting in Australia. A purpose designed, expert validated TIP checklist was completed, followed by semi-structured focus groups. Survey data was reported using descriptive statistics. Focus group data was digitally recorded, transcribed and thematically analysed. Results: Ten key factors were identified motivating, restricting or enabling TIP implementation. Seven were organisational factors including supportive and informed management, flexibility of service models, levels of service demands, resource availability, education opportunities, good client outcomes, and reporting requirements. Philosophical approach, team orientation, and vicarious trauma/stress management were three individual professional factors. Critically, alignment in two ways was necessary for successful implementation, that is: in knowledge and understanding across organisational role levels - clinician, manager and executive; and, in professional philosophy and team orientation of individual clinicians. Conclusion: Providing TIP is essential for ensuring optimum client outcomes for trauma survivors and for maintaining workforce wellbeing. Although the increasing uptake to TIP is evident within the health setting, further attention is required to address the tension between service models focused on efficiently servicing whole populations and those attuned to effectively meeting the needs of high risk groups. A complex strategy to unite therapeutic and managerial goals is necessary if client, professional and organisational needs are to be effectively met

    Direct electronic measurement of the spin Hall effect

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    The generation, manipulation and detection of spin-polarized electrons in nanostructures define the main challenges of spin-based electronics[1]. Amongst the different approaches for spin generation and manipulation, spin-orbit coupling, which couples the spin of an electron to its momentum, is attracting considerable interest. In a spin-orbit-coupled system, a nonzero spin-current is predicted in a direction perpendicular to the applied electric field, giving rise to a "spin Hall effect"[2-4]. Consistent with this effect, electrically-induced spin polarization was recently detected by optical techniques at the edges of a semiconductor channel[5] and in two-dimensional electron gases in semiconductor heterostructures[6,7]. Here we report electrical measurements of the spin-Hall effect in a diffusive metallic conductor, using a ferromagnetic electrode in combination with a tunnel barrier to inject a spin-polarized current. In our devices, we observe an induced voltage that results exclusively from the conversion of the injected spin current into charge imbalance through the spin Hall effect. Such a voltage is proportional to the component of the injected spins that is perpendicular to the plane defined by the spin current direction and the voltage probes. These experiments reveal opportunities for efficient spin detection without the need for magnetic materials, which could lead to useful spintronics devices that integrate information processing and data storage.Comment: 5 pages, 4 figures. Accepted for publication in Nature (pending format approval

    A probabilistic analysis of argument cogency

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    This paper offers a probabilistic treatment of the conditions for argument cogency as endorsed in informal logic: acceptability, relevance, and sufficiency. Treating a natural language argument as a reason-claim-complex, our analysis identifies content features of defeasible argument on which the RSA conditions depend, namely: change in the commitment to the reason, the reason’s sensitivity and selectivity to the claim, one’s prior commitment to the claim, and the contextually determined thresholds of acceptability for reasons and for claims. Results contrast with, and may indeed serve to correct, the informal understanding and applications of the RSA criteria concerning their conceptual dependence, their function as update-thresholds, and their status as obligatory rather than permissive norms, but also show how these formal and informal normative approachs can in fact align

    Flavor-symmetry Breaking with Charged Probes

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    We discuss the recombination of brane/anti-brane pairs carrying D3D3 brane charge in AdS5×S5AdS_5 \times S^5. These configurations are dual to co-dimension one defects in the N=4{\cal N}=4 super-Yang-Mills description. Due to their D3D3 charge, these defects are actually domain walls in the dual gauge theory, interpolating between vacua of different gauge symmetry. A pair of unjoined defects each carry localized (2+1)(2+1) dimensional fermions and possess a global U(N)×U(N)U(N)\times U(N) flavor symmetry while the recombined brane/anti-brane pairs exhibit only a diagonal U(N). We study the thermodynamics of this flavor-symmetry breaking under the influence of external magnetic field.Comment: 21 pages, 10 figure

    Long-term efficacy and safety of dichlorphenamide for treatment of primary periodic paralysis

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    Introduction/Aim: Long-term efficacy and safety of dichlorphenamide (DCP) were characterized in patients with primary periodic paralysis (PPP). Methods: Patients with PPP in a double-blind, placebo-controlled study were randomly assigned to receive DCP 50 mg twice daily or placebo for 9 weeks, followed by a 52-week open-label DCP treatment phase (DCP/DCP and placebo/DCP populations). Efficacy (attack rate, severity-weighted attack rate) and safety were assessed in patients completing the study (61 weeks). In this post hoc analysis, efficacy and safety data were pooled from hyperkalemic and hypokalemic substudies. Results: Sixty-three adults (age, 19-76 years) completed the double-blind phase; 47 (74.6%) of these patients completed 61 weeks. There were median decreases in weekly attack and severity-weighted attack rates from baseline to week 61 (DCP/DCP [n = 25], −1.00 [P < .0001]; placebo/DCP [n = 20], −0.63 [P = .01] and DCP/DCP, −2.25 [P < .0001]; placebo/DCP, −1.69 [P = .01]). Relatively smaller median decreases in weekly attack and severity-weighted attack rates occurred from weeks 9 to 61 among patients receiving DCP continuously (n = 26; −0.14 [P = .1] and −0.24 [P = .09]) than among those switching from placebo to DCP after 9 weeks (n = 16; −1.04 [P = .049] and −2.72 [P = .08]). Common adverse events (AEs) were paresthesia and cognition-related events, which typically first occurred within 1 month of blinded treatment initiation and in rare cases led to treatment discontinuation. Dose reductions were frequently associated with common AE resolution. Discussion: One-year open-label DCP treatment after a 9-week randomized, controlled study confirmed long-term DCP remains safe and effective for chronic use. Tolerability issues (paresthesia, cognition-related AEs) were manageable in most patients

    Magnetized Domain Walls in the Deconfined Sakai-Sugimoto Model at Finite Baryon Density

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    The magnetized pure pion gradient (5Ï•\mathcal{5}\phi) phase in the deconfined Sakai-Sugimoto model is explored at zero and finite temperature. We found that the temperature has very small effects on the phase. The thermodynamical properties of the phase shows that the excitations behave like a scalar solitonic free particles. By comparing the free energy of the pion gradient phase to the competing multiquark-pion gradient (MQ-5Ï•\mathcal{5}\phi) phase, it becomes apparent that the pure pion gradient is less thermodynamically preferred than the MQ-5Ï•\mathcal{5}\phi phase. However, in the parameter space where the baryonic chemical potential is smaller than the onset value of the multiquark, the dominating magnetized nuclear matter is the pion gradient phase.Comment: 20 pages, 9 figure

    The age of anxiety? It depends where you look: changes in STAI trait anxiety, 1970–2010

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    Purpose Population-level surveys suggest that anxiety has been increasing in several nations, including the USA and UK. We sought to verify the apparent anxiety increases by looking for systematic changes in mean anxiety questionnaire scores from research publications. Methods We analyzed all available mean State–Trait Anxiety Inventory scores published between 1970 and 2010. We collected 1703 samples, representing more than 205,000 participants from 57 nations. Results Results showed a significant anxiety increase worldwide, but the pattern was less clear in many individual nations. Our analyses suggest that any increase in anxiety in the USA and Canada may be limited to students, anxiety has decreased in the UK, and has remained stable in Australia. Conclusions Although anxiety may have increased worldwide, it might not be increasing as dramatically as previously thought, except in specific populations, such as North American students. Our results seem to contradict survey results from the USA and UK in particular. We do not claim that our results are more reliable than those of large population surveys. However, we do suggest that mental health surveys and other governmental sources of disorder prevalence data may be partially biased by changing attitudes toward mental health: if respondents are more aware and less ashamed of their anxiety, they are more likely to report it to survey takers. Analyses such as ours provide a useful means of double-checking apparent trends in large population surveys

    Sum rules, plasma frequencies and Hall phenomenology in holographic plasmas

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    We study the AC optical and hall conductivities of Dp/Dq-branes intersections in the probe approximation and use sum-rules to study various associated transport coefficients. We determine that the presence of massive fundamental matter, as compared to massless fundamental matter described holographically by a theory with no dimensional defects, reduces the plasma frequency. We further show that this is not the case when the brane intersections include defects. We discuss in detail how to implement correctly the regularization of retarded Green's functions so that the dispersion relations are satisfied and the low energy behaviour of the system is physically realistic.Comment: 25 pages, 5 figures. v2.minor changes, published versio
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