353 research outputs found

    Effects of motor preparation and spatial attention on corticospinal excitability in a delayed-response paradigm

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    The preparation of motor responses during the delay period of an instructed delay task is associated with sustained neural firing in the primate premotor cortex. It remains unclear how and when such preparation-related premotor activity influences the motor output system. In this study, we tested modulation of corticospinal excitability using single-pulse transcranial magnetic stimulation (TMS) during a delayed-response task. At the beginning of the delay interval participants were either provided with no information, spatial attentional information concerning location but not identity of an upcoming imperative stimulus, or information regarding the upcoming response. Behavioral data indicate that participants used all information available to them. Only when information concerning the upcoming response was provided did corticospinal excitability show differential modulation for the effector muscle compared to other task-unrelated muscles. We conclude that modulation of corticospinal excitability reflects specific response preparation, rather than non-specific event preparation

    Remotely Operated Train for Inspection and Measurement in CERN's LHC Tunnel

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    Personnel access to the LHC tunnel will be restricted to varying extents during the life of the machine due to radiation and cryogenic hazards. For this reason a remotely operated modular inspection train, (TIM) running on the LHC tunnel’s overhead monorail has been developed. In order to be compatible with the LHC personnel access system, a small section train that can pass through small openings at the top of sector doors has now been produced. The basic train can be used for remote visual inspection; additional modules give the capability of carrying out remote measurement of radiation levels, environmental conditions around the tunnel, and even remote measurement of the precise position of machine elements such as collimators. The paper outlines the design, development and operation of the equipment including preparation of the infrastructure. Key features of the trains are described along with future developments and intervention scenarios

    Forget-me-some: General versus special purpose models in a hierarchical probabilistic task

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    Humans build models of their environments and act according to what they have learnt. In simple experimental environments, such model-based behaviour is often well accounted for as if subjects are ideal Bayesian observers. However, more complex probabilistic tasks require more sophisticated forms of inference that are sufficiently computationally and statistically taxing as to demand approximation. Here, we study properties of two approximation schemes in the context of a serial reaction time task in which stimuli were generated from a hierarchical Markov chain. One, pre-existing, scheme was a generically powerful variational method for hierarchical inference which has recently become popular as an account of psychological and neural data across a wide swathe of probabilistic tasks. A second, novel, scheme was more specifically tailored to the task at hand. We show that the latter model fit significantly better than the former. This suggests that our subjects were sensitive to many of the particular constraints of a complex behavioural task. Further, the tailored model provided a different perspective on the effects of cholinergic manipulations in the task. Neither model fit the behaviour on more complex contingencies that competently. These results illustrate the benefits and challenges that come with the general and special purpose modelling approaches and raise important questions of how they can advance our current understanding of learning mechanisms in the brain

    Genetic predisposition in patients undergoing cardiopulmonary bypass surgery is associated with an increase of inflammatory cytokines

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    Objective: Cardiopulmonary bypass (CPB) surgery induces a transient rise in pro-inflammatory cytokines typically released by activated monocytes. The E4 variant of apolipoprotein E is a recognized risk factor for atherosclerosis. It has recently been shown that apolipoprotein E affects monocyte functions in vitro and leads to higher levels of median lipoprotein (a) in humans. The aim of the study is to investigate if the E4 genetic variant of apolipoprotein E affects cytokine release after CPB surgery. Methods: 22 patients were operated on with standard coronary artery bypass grafting. Concentrations of interleukin 8 (IL-8) and tumor necrosis factor (TNF-α) were measured by automated Immulite immunoassay at regular intervals within 48 h after surgery. Total apparent cytokine outputs were calculated as area under the curve. Results are expressed as mean±standard deviation and compared by unpaired t-test. Results: In the presented patient population 6 (27%) carried the E4 allele. Sixteen (63%) showed no E4 allele. Mean cross clamp time (CCT) was 56.2±13.5 min versus 55.7±12.1 min and CPB time was 91.8±17.5 versus 93.5±15.7 min. No statistical difference between E4-carriers and E4 non-carriers regarding CCT and CPB was observed. The total amount of IL-8 and TNF-α was higher in patients carrying the E4 genetic variant of apolipoprotein E in comparison to E4 non-carriers (Pâ‰Ș0.08, Pâ‰Ș0.039). Conclusion: The presence of the E4 allele is associated with increased release of IL-8 and TNF-α after CBP surgery. The preoperative determination of E4 in patients undergoing cardiac surgery may lead to additional perioperative measures for the treatment of an increased systemic inflammatory respons

    Adaptive deep brain stimulation for Parkinson's disease demonstrates reduced speech side effects compared to conventional stimulation in the acute setting.

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    Deep brain stimulation (DBS) for Parkinson's disease (PD) is currently limited by costs, partial efficacy and surgical and stimulation-related side effects. This has motivated the development of adaptive DBS (aDBS) whereby stimulation is automatically adjusted according to a neurophysiological biomarker of clinical state, such as ÎČ oscillatory activity (12–30 Hz). aDBS has been studied in parkinsonian primates and patients and has been reported to be more energy efficient and effective in alleviating motor symptoms than conventional DBS (cDBS) at matched amplitudes

    Identification of the Sex Pheromone of a Protected Species, the Spanish Moon Moth Graellsia isabellae

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    Sex attractant pheromones are highly sensitive and selective tools for detecting and monitoring populations of insects, yet there has been only one reported case of pheromones being used to monitor protected species. Here, we report the identification and synthesis of the sex pheromone of a protected European moth species, Graellsia isabellae (Lepidoptera: Saturniidae), as the single component, (4E,6E,11Z)-hexadecatrienal. In preliminary field trials, lures loaded with this compound attracted male moths from populations of this species at a number of widely separated field sites in France, Switzerland, and Spain, clearly demonstrating the utility of pheromones in sampling potentially endangered insect species

    Incomplete evidence that increasing current intensity of tDCS boosts outcomes

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    BACKGROUND: Transcranial direct current stimulation (tDCS) is investigated to modulate neuronal function by applying a fixed low-intensity direct current to scalp. OBJECTIVES: We critically discuss evidence for a monotonic response in effect size with increasing current intensity, with a specific focus on a question if increasing applied current enhance the efficacy of tDCS. METHODS: We analyzed tDCS intensity does-response from different perspectives including biophysical modeling, animal modeling, human neurophysiology, neuroimaging and behavioral/clinical measures. Further, we discuss approaches to design dose-response trials. RESULTS: Physical models predict electric field in the brain increases with applied tDCS intensity. Data from animal studies are lacking since a range of relevant low-intensities is rarely tested. Results from imaging studies are ambiguous while human neurophysiology, including using transcranial magnetic stimulation (TMS) as a probe, suggests a complex state-dependent non-monotonic dose response. The diffusivity of brain current flow produced by conventional tDCS montages complicates this analysis, with relatively few studies on focal High Definition (HD)-tDCS. In behavioral and clinical trials, only a limited range of intensities (1-2 mA), and typically just one intensity, are conventionally tested; moreover, outcomes are subject brain-state dependent. Measurements and models of current flow show that for the same applied current, substantial differences in brain current occur across individuals. Trials are thus subject to inter-individual differences that complicate consideration of population-level dose response. CONCLUSION: The presence or absence of simple dose response does not impact how efficacious a given tDCS dose is for a given indication. Understanding dose-response in human applications of tDCS is needed for protocol optimization including individualized dose to reduce outcome variability, which requires intelligent design of dose-response studies

    Structures and processes necessary for providing effective home treatment to severely mentally ill persons: a naturalistic study

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    Background: Home treatment for severely mentally ill persons is becoming increasingly popular. This research aims to identify structures and processes in home treatment that impact on patient-related outcomes. Methods: We analysed 17 networks that provide home treatment to severely mentally ill persons using a naturalistic approach. The networks were similar with regard to central components of home treatment such as case management, 24 h crisis hotline and home visits, but differed in all other aspects such as the multidisciplinary teams, time spent with patients, etc. To determine treatment outcome, patients’ psychosocial functioning was measured using the Health of the Nation Outcome Scales (HoNOS). Structures and processes were assessed using claims data and questionnaires answered by the different networks. Primary outcome was highlighted by the change in HoNOS scores from the start of home treatment compared with 6 months later. We sought to explain this outcome through patient and network characteristics using regression analysis. Data on 3,567 patients was available. Results: On average, psychosocial functioning improved by 0.84 across networks between t0 and t1. There were more similarities than differences between the networks with regard to the structures and processes that we tested. A univariate regression analysis found staff’s prior experience in mental health care and the effort that they invested in their work correlated positively with patient outcome. This needs to be interpreted under considering that univariate analysis does not show causal relationship. A high case load per case manager, increased and longer patient contact and more family intervention were correlated with worse patient outcome, probably indicating that sicker patients receive more care and intervention. Conclusion: Home treatment networks succeed in delivering care tailored to the needs of patients. In order to improve the quality of care in home treatment, this study suggests employing experienced staff who is ready to invest more effort in their patients. Further research needs to consider a longer follow-up time

    Genetic predisposition in patients undergoing cardiopulmonary bypass surgery is associated with an increase of inflammatory cytokines

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    Objective: Cardiopulmonary bypass (CPB) surgery induces a transient rise in pro-inflammatory cytokines typically released by activated monocytes. The E4 variant of apolipoprotein E is a recognized risk factor for atherosclerosis. It has recently been shown that apolipoprotein E affects monocyte functions in vitro and leads to higher levels of median lipoprotein (a) in humans. The aim of the study is to investigate if the E4 genetic variant of apolipoprotein E affects cytokine release after CPB surgery. Methods: 22 patients were operated on with standard coronary artery bypass grafting. Concentrations of interleukin 8 (IL-8) and tumor necrosis factor (TNF-α) were measured by automated Immulite immunoassay at regular intervals within 48 h after surgery. Total apparent cytokine outputs were calculated as area under the curve. Results are expressed as mean±standard deviation and compared by unpaired t-test. Results: In the presented patient population 6 (27%) carried the E4 allele. Sixteen (63%) showed no E4 allele. Mean cross clamp time (CCT) was 56.2±13.5 min versus 55.7±12.1 min and CPB time was 91.8±17.5 versus 93.5±15.7 min. No statistical difference between E4-carriers and E4 non-carriers regarding CCT and CPB was observed. The total amount of IL-8 and TNF-α was higher in patients carrying the E4 genetic variant of apolipoprotein E in comparison to E4 non-carriers (Pâ‰Ș0.08, Pâ‰Ș0.039). Conclusion: The presence of the E4 allele is associated with increased release of IL-8 and TNF-α after CBP surgery. The preoperative determination of E4 in patients undergoing cardiac surgery may lead to additional perioperative measures for the treatment of an increased systemic inflammatory respons

    Magnet Acceptance and Allocation at the LHC Magnet Evaluation Board

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    The normal and superconducting magnets for the LHC ring have been carefully examined to insure that each of about 1900 assemblies is suitable for the operation in the accelerator. Hardware experts and accelerator physicists have contributed to this work that consisted in magnet acceptance, and sorting according to geometry, field quality and quench level. This paper gives a description of the magnet approval mechanism that has been running since four years, reporting in a concise summary the main results achieved
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