118 resultados para Directly modulated feedback
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Animal work implicates the brain-derived neurotrophic factor (BDNF) in function of the ventral striatum (VS), a region known for its role in processing valenced feedback. Recent evidence in humans shows that BDNF Val66Met polymorphism modulates VS activity in anticipation of monetary feedback. However, it remains unclear whether the polymorphism impacts the processing of self-attributed feedback differently from feedback attributed to an external agent. In this study, we emphasize the importance of the feedback attribution because agency is central to computational accounts of the striatum and cognitive accounts of valence processing. We used functional magnetic resonance imaging and a task, in which financial gains/losses are either attributable to performance (self-attributed, SA) or chance (externally-attributed, EA) to ask whether BDNF Val66Met polymorphism predicts VS activity. We found that BDNF Val66Met polymorphism influenced how feedback valence and agency information were combined in the VS and in the right inferior frontal junction (IFJ). Specifically, Met carriers' VS response to valenced feedback depended on agency information, while Val/Val carriers' VS response did not. This context-specific modulation of valence effectively amplified VS responses to SA losses in Met carriers. The IFJ response to SA losses also differentiated Val/Val from Met carriers. These results may point to a reduced allocation of attention and altered motivational salience to SA losses in Val/Val compared to Met carriers. Implications for major depressive disorder are discussed.
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BACKGROUND Receptor activator of NF-κB ligand (RANKL) is expressed as either surface (hRANKL1, hRANKL2) or soluble (hRANKL3) form. RANKL is involved in multifaceted processes of immunoregulation and bone resorption such as they occur in rheumatoid arthritis (RA). Interestingly, activated basophils, which are effector cells in allergic inflammation, contribute to the progress of collagen-induced arthritis (CIA), a mouse model for RA. Here, we investigate under which conditions human basophils express RANKL. METHODS Among other stimuli, basophils were cultured with IL-3 alone. Alternatively, as a secondary stimulus, IgER-dependent or IgER-independent agents were added simultaneously either with IL-3 or after prolonged IL-3 culturing. Expression of RANKL protein and mRNA was analyzed by flow cytometry, ELISA, and real-time PCR. A coculture system was applied to investigate biological activity of basophil-derived RANKL. RESULTS We show that in human basophils, IL-3 but no other stimulus induces de novo expression of soluble and surface RANKL, of which the latter enhances survival of MoDC. Upon simultaneous stimulation, IgER cross-linking reduces surface RANKL expression, while IgER-independent stimuli have no effect. This is in contrast to consecutive stimulation, as triggering with both IgER-dependent and IgER-independent stimuli enhances RANKL expression, particularly in its soluble form. Real-time PCR analysis shows that RANKL expression is mainly regulated at the mRNA level. CONCLUSION This study identifies IL-3 as a potent inducer of RANKL expression in human basophils, suggesting them to interact with bone physiology and activation of immune cells. IgER-dependent and IgER-independent stimuli modulate the IL-3-mediated RANKL expression in a time- and stimulus-dependent fashion.
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Current models of sales force strategy imply formidable information processing demands, which leads us to take a cognitive approach to studying the issue of sales force strategy. We focus on how top-level executives use mental models of sales force performance to simplify the issue of sales force strategy. We interviewed 74 senior executives responsible for their firms’ selling function using the repertory grid approach, as this methodology has been shown to be particularly effective at uncovering the collective cognitive maps on which executives’ decisions and behaviors are based. Executives identified a broad set of 37 strategic concepts that they felt distinguish the sales force efforts of directly competing companies. A second set of sales executives classified the 37 concepts into capabilities, resources, and organizational context concepts. Based on the classification results and feedback from both sets of executives, we developed research propositions for examining sales force strategy and provide directions for future research.
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The H19 lncRNA has been implicated in development and growth control and is associated with human genetic disorders and cancer. Acting as a molecular sponge, H19 inhibits microRNA (miRNA) let-7. Here we report that H19 is significantly decreased in muscle of human subjects with type-2 diabetes and insulin resistant rodents. This decrease leads to increased bioavailability of let-7, causing diminished expression of let-7 targets, which is recapitulated in vitro where H19 depletion results in impaired insulin signaling and decreased glucose uptake. Furthermore, acute hyperinsulinemia downregulates H19, a phenomenon that occurs through PI3K/AKT-dependent phosphorylation of the miRNA processing factor KSRP, which promotes biogenesis of let-7 and its mediated H19 destabilization. Our results reveal a previously undescribed double-negative feedback loop between sponge lncRNA and target miRNA that contributes to glucose regulation in muscle cells.
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BACKGROUND Efficiently performed basic life support (BLS) after cardiac arrest is proven to be effective. However, cardiopulmonary resuscitation (CPR) is strenuous and rescuers' performance declines rapidly over time. Audio-visual feedback devices reporting CPR quality may prevent this decline. We aimed to investigate the effect of various CPR feedback devices on CPR quality. METHODS In this open, prospective, randomised, controlled trial we compared three CPR feedback devices (PocketCPR, CPRmeter, iPhone app PocketCPR) with standard BLS without feedback in a simulated scenario. 240 trained medical students performed single rescuer BLS on a manikin for 8min. Effective compression (compressions with correct depth, pressure point and sufficient decompression) as well as compression rate, flow time fraction and ventilation parameters were compared between the four groups. RESULTS Study participants using the PocketCPR performed 17±19% effective compressions compared to 32±28% with CPRmeter, 25±27% with the iPhone app PocketCPR, and 35±30% applying standard BLS (PocketCPR vs. CPRmeter p=0.007, PocketCPR vs. standard BLS p=0.001, others: ns). PocketCPR and CPRmeter prevented a decline in effective compression over time, but overall performance in the PocketCPR group was considerably inferior to standard BLS. Compression depth and rate were within the range recommended in the guidelines in all groups. CONCLUSION While we found differences between the investigated CPR feedback devices, overall BLS quality was suboptimal in all groups. Surprisingly, effective compression was not improved by any CPR feedback device compared to standard BLS. All feedback devices caused substantial delay in starting CPR, which may worsen outcome.
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Warum Feedback? Feedback geben bedeutet nicht nur zu urteilen oder zu bewerten. Es vermittelt auch einen Einblick in die Grenzen des Lernenden. Ohne diesen Einblick können Lernende keine Fortschritte machen oder Schwierigkeiten meistern – oder sicher sein, was sie gut machen.
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BACKGROUND AND PURPOSE: In stroke patients, neglect diagnostic is often performed by means of paper-pencil cancellation tasks. These tasks entail static stimuli, and provide no information concerning possible changes in the severity of neglect symptoms when patients are confronted with motion. We therefore aimed to directly contrast the cancellation behaviour of neglect patients under static and dynamic conditions. Since visual field deficits often occur in neglect patients, we analysed whether the integrity of the optic radiation would influence cancellation behaviour. METHODS: Twenty-five patients with left spatial neglect after right-hemispheric stroke were tested with a touchscreen cancellation task, once when the evenly distributed targets were stationary, and once when the identic targets moved with constant speed on a random path. The integrity of the right optic radiation was analysed by means of a hodologic probabilistic approach. RESULTS: Motion influenced the cancellation behaviour of neglect patients, and the direction of this influence (i.e., an increase or decrease of neglect severity) was modulated by the integrity of the right optic radiation. In patients with an intact optic radiation, the severity of neglect significantly decreased in the dynamic condition. Conversely, in patients with damage to the optic radiation, the severity of neglect significantly increased in the dynamic condition. CONCLUSION: Motion may influence neglect in stroke patients. The integrity of the optic radiation may be a predictor of whether motion increases or decreases the severity of neglect symptoms.
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Eco-driving has well-known positive effects on fuel economy and greenhouse-gas emissions. Moreover, eco-driving reduces road-traffic noise, which is a serious threat to the health and well-being of many people. We investigated the psychological predictors of the adoption of eco-driving from the perspective of road-traffic noise abatement. The data came from 890 car drivers who participated in a longitudinal survey over four months. Specifically, we tested the effects of the intention to prevent road-traffic noise, variables derived from the theory of planned behavior (social norm, perceived behavioral control, and attitude), and variables derived from the health action process approach (implementation intention, maintenance self-efficacy, and action control) on the intention to practice eco-driving and on eco-driving behavior. The intention to prevent road-traffic noise was not linked to the intention to practice eco-driving. The strongest predictors of the intention to practice eco-driving were attitude and perceived behavioral control. The strongest predictor of eco-driving behavior was action control. The link between behavioral intention and behavior was weak, indicating that drivers have difficulties putting their intention to practice eco-driving into action. Therefore, intervention efforts should directly address and support the transition from intention to behavior. This could be accomplished by providing reminders, which help to maintain behavioral intention, and by providing behavior feedback, which helps car drivers to monitor their behavior.
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Motivated by conflicting evidence in the literature, we re-assessed the role of facial feedback when detecting quantitative or qualitative changes in others’ emotional expressions. Fifty-three healthy adults observed self-paced morph sequences where the emotional facial expression either changed quantitatively (i.e., sad-to-neutral, neutral-to-sad, happy-to-neutral, neutral-to-happy) or qualitatively (i.e. from sad to happy, or from happy to sad). Observers held a pen in their own mouth to induce smiling or frowning during the detection task. When morph sequences started or ended with neutral expressions we replicated a congruency effect: Happiness was perceived longer and sooner while smiling; sadness was perceived longer and sooner while frowning. Interestingly, no such congruency effects occurred for transitions between emotional expressions. These results suggest that facial feedback is especially useful when evaluating the intensity of a facial expression, but less so when we have to recognize which emotion our counterpart is expressing.
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The International Surface Pressure Databank (ISPD) is the world's largest collection of global surface and sea-level pressure observations. It was developed by extracting observations from established international archives, through international cooperation with data recovery facilitated by the Atmospheric Circulation Reconstructions over the Earth (ACRE) initiative, and directly by contributing universities, organizations, and countries. The dataset period is currently 1768–2012 and consists of three data components: observations from land stations, marine observing systems, and tropical cyclone best track pressure reports. Version 2 of the ISPD (ISPDv2) was created to be observational input for the Twentieth Century Reanalysis Project (20CR) and contains the quality control and assimilation feedback metadata from the 20CR. Since then, it has been used for various general climate and weather studies, and an updated version 3 (ISPDv3) has been used in the ERA-20C reanalysis in connection with the European Reanalysis of Global Climate Observations project (ERA-CLIM). The focus of this paper is on the ISPDv2 and the inclusion of the 20CR feedback metadata. The Research Data Archive at the National Center for Atmospheric Research provides data collection and access for the ISPDv2, and will provide access to future versions.
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STUDY OBJECTIVES Sleep deprivation (SDp) performed before stroke induces an ischemic tolerance state as observed in other forms of preconditioning. As the mechanisms underlying this effect are not well understood, we used DNA oligonucleotide microarray analysis to identify the genes and the gene-pathways underlying SDp preconditioning effects. DESIGN Gene expression was analyzed 3 days after stroke in 4 experimental groups: (i) SDp performed before focal cerebral ischemia (IS) induction; (ii) SDp performed before sham surgery; (iii) IS without SDp; and (iv) sham surgery without SDp. SDp was performed by gentle handling during the last 6 h of the light period, and ischemia was induced immediately after. SETTINGS Basic sleep research laboratory. MEASUREMENTS AND RESULTS Stroke induced a massive alteration in gene expression both in sleep deprived and non-sleep deprived animals. However, compared to animals that underwent ischemia alone, SDp induced a general reduction in transcriptional changes with a reduction in the upregulation of genes involved in cell cycle regulation and immune response. Moreover, an upregulation of a new neuroendocrine pathway which included melanin concentrating hormone, glycoprotein hormones-α-polypeptide and hypocretin was observed exclusively in rats sleep deprived before stroke. CONCLUSION Our data indicate that sleep deprivation before stroke reprogrammed the signaling response to injury. The inhibition of cell cycle regulation and inflammation are neuroprotective mechanisms reported also for other forms of preconditioning treatment, whereas the implication of the neuroendocrine function is novel and has never been described before. These results therefore provide new insights into neuroprotective mechanisms involved in ischemic tolerance mechanisms.
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PURPOSE Standard dose of external beam radiotherapy seems to be insufficient for satisfactory control of loco-regionally advanced cervical cancer. Aim of our study is to evaluate the outcome as well as early and chronic toxicities in patients with loco-regionally advanced cervical cancer, treated with dose escalated intensity modulated radiotherapy (IMRT) combined with cisplatin chemotherapy. MATERIAL AND METHODS Thirty-nine patients with cervical carcinoma FIGO stage IB2 - IVA were treated with curative intent between 2006 and 2010. The dose of 50.4 Gy was prescribed to the elective pelvic nodal volume. Primary tumors < 4 cm in diameter (n = 6; 15.4 %) received an external beam radiotherapy (EBRT) boost of 5.4 Gy, primary tumors > 4 cm in diameter (n = 33; 84.6 %) received an EBRT boost of 9 Gy. Patients with positive lymph nodes detected with (18)FDG-PET/CT (n = 22; 56.4 %) received a boost to a total dose of 59.4 - 64.8 Gy. The para-aortic region was included in the radiation volume in 8 (20.5 %) patients and in 5 (12.8 %) patients the para-aortic macroscopic lymph nodes received an EBRT boost. IMRT was followed with a 3D planned high dose rate intrauterine brachytherapy given to 36 (92.3 %) patients with a total dose ranging between 15-18 Gy in three fractions (single fraction: 4-6.5 Gy). Patients without contraindications (n = 31/79.5 %) received concomitantly a cisplatin-based chemotherapy (40 mg/kg) weekly. Toxicities were graded according to the common terminology criteria for adverse events (CTCAE v 4.0). RESULTS Mean overall survival for the entire cohort was 61.1 months (±3.5 months). Mean disease free survival was 47.2 months (±4.9 months) and loco-regional disease free survival was 55.2 months (±4.4 months). 65 % of patients developed radiotherapy associated acute toxicities grade 1, ca. 30 % developed toxicities grade 2 and just two (5.2 %) patients developed grade 3 toxicities, one acute diarrhea and one acute cystitis. 16 % of patients had chronic toxicities grade 1, 9 % grade 2 and one patient (2.6 %) toxicities grade 3 in the form of vaginal dryness. CONCLUSION Dose escalated IMRT appears to have a satisfactory outcome with regards to mean overall survival, disease free and loco-regional disease free survival, whereas the treatment-related toxicities remain reasonably low.