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Response Control (response + control)
Selected AbstractsTuned mass dampers for response control of torsional buildingsEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 4 2002Mahendra P. Singh Abstract This paper presents an approach for optimum design of tuned mass dampers for response control of torsional building systems subjected to bi-directional seismic inputs. Four dampers with fourteen distinct design parameters, installed in pairs along two orthogonal directions, are optimally designed. A genetic algorithm is used to search for the optimum parameter values for the four dampers. This approach is quite versatile as it can be used with different design criteria and definitions of seismic inputs. It usually provides a globally optimum solution. Several optimal design criteria, expressed in terms of performance functions that depend on the structural response, are used. Several sets of numerical results for a torsional system excited by random and response spectrum models of seismic inputs are presented to show the effectiveness of the optimum designs in reducing the system response. Copyright © 2002 John Wiley & Sons, Ltd. [source] Cognitive response control in writer's crampEUROPEAN JOURNAL OF NEUROLOGY, Issue 6 2001D. Berg Disturbances of the motor and sensory system as well as an alteration of the preparation of movements have been reported to play a role in the pathogenesis of dystonias. However, it is unclear whether higher aspects of cortical , like cognitive , functions are also involved. Recently, the NoGo-anteriorization (NGA) elicited with a visual continuous performance test (CPT) during recording of a 21-channel electroencephalogram has been proposed as an electrophysiological standard-index for cognitive response control. The NGA consists of a more anterior location of the positive area of the brain electrical field associated with the inhibition (NoGo-condition) compared with that of the execution (Go-condition) of a prepared motor response in the CPT. This response control paradigm was applied in 16 patients with writer's cramp (WC) and 14 age matched healthy controls. Topographical analysis of the associated event-related potentials revealed a significant (P < 0.05) NGA effect for both patients and controls. Moreover, patients with WC showed a significantly higher global field power value (P < 0.05) in the Go-condition and a significantly higher difference-amplitude (P < 0.05) in the NoGo-condition. A source location analysis with the low resolution electromagnetic tomography (LORETA) method demonstrated a hypoactivity for the Go-condition in the parietal cortex of the right hemisphere and a hyperactivity in the NoGo-condition in the left parietal cortex in patients with WC compared with healthy controls. These results indicate an altered response control in patients with WC in widespread cortical brain areas and therefore support the hypothesis that the pathogenesis of WC is not restricted to a pure sensory-motor dysfunction. [source] Independent component analysis of erroneous and correct responses suggests online response controlHUMAN BRAIN MAPPING, Issue 9 2010Sven Hoffmann Abstract After errors in reaction tasks, a sharp negative wave emerges in the event-related potential (ERP), the error (related) negativity (Ne or ERN). However, also after correct trials, an Ne-like wave is seen, called CRN or Nc, which is much smaller than the Ne. This study tested the hypothesis whether Ne and Nc reflect the same functional process, and whether this process is linked to online response control. For this purpose, independent component analysis (ICA) was utilized with the EEG data of two types of reaction tasks: a flanker task and a mental rotation task. To control for speed-accuracy effects, speed and accuracy instructions were balanced in a between subjects design. For both tasks ICA and dipole analysis revealed one component (Ne-IC) explaining most of the variance for the difference between correct and erroneous trials. The Ne-IC showed virtually the same features as the raw postresponse ERP, being larger for erroneous compared to correct trials and for the flanker than for the rotation task. In addition, it peaked earlier for corrected than for uncorrected errors. The results favor the hypothesis that Ne and Nc reflect the same process, which is modulated by response correctness and type of task. On the basis of the literature and the present results, we assume that this process induces online response control, which is much stronger in error than correct trials and with direct rather than indirect stimulus response mapping. Hum Brain Mapp, 2010. © 2010 Wiley-Liss, Inc. [source] Cytokine profiling of pulmonary aspergillosisINTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 4 2006H. Sambatakou Summary Aspergillus fumigatus is ubiquitous and yet causes invasive, chronic and allergic disease of the lung. Chronic cavitary pulmonary aspergillosis (CCPA) is a slowly destructive form of pulmonary aspergillosis, without immunocompromise. We hypothesized that CCPA cytokine gene polymorphisms would differ from patients with allergic bronchopulmonary aspergillosis (ABPA) and uninfected controls. We have profiled functional cytokine gene polymorphisms for interleukin (IL)-10, IL-15, transforming growth factors (TGF)-,1, tumour necrosis factor (TNF)-, and interferon (IFN)-, in patients with CCPA (n = 24) who were compared with other forms of aspergillosis (mostly ABPA) (n = 15) and with ethnically matched controls (n = 65,330). Results are described with reference to the high-producing genotype in each case. Susceptibility to aspergillosis (all patients compared with normal controls) was associated with higher frequency of the IL-15 +13689*A allele (OR = 2.37, P = 0.0028) and A/A genotype (,2 = 10.31, P < 0.001), with a lower frequency of the TNF-,,308*A/A genotype (,2 = 11.05, P < 0.01). Within the aspergillosis patients, CCPA is associated with lower frequency of the IL-10 ,1082*G allele (OR = 0.38, P = 0.0006) and G/G genotype (,2 = 22.45, P < 0.001) and with a lower frequency of the TGF-,1 +869 *T allele (OR +0.42, P < 0.0029) and T/T genotype (,2 = 17.82, P < 0.001) compared with non-CCPA patients and normal controls. Patients infected with Aspergillus appear to be higher producers of IL-15, a Th2-promoting cytokine, and lower producers of TNF-,, a cytokine central in protective responses. CCPA occurs in patients who are genetically lower producers of both IL-10 and TGF-,1. As these cytokines are regulatory and anti-inflammatory, CCPA may be a consequence of poor inflammatory response control in the lung. [source] Resisting recently acted-on cues: Compatibility of Go/NoGo responses to response history modulates (frontal P3) event-related potentialsPSYCHOPHYSIOLOGY, Issue 1 2007Antonio L. Freitas Abstract Using event-related potentials to investigate compatibility between past and present cue,response interactions, an experiment combined elements of selective-attention and Go/NoGo tasks. In the selective-attention part of each trial, participants responded to one of two visible numerical digits. Immediately afterward, in the Go/NoGo part of each trial, one of the same two digits appeared, with participants required to press the corresponding key on Go trials and to withhold responding on NoGo trials. Higher-amplitude anterior P3 responses on NoGo than on Go trials emerged when participants withheld responding to a recently selected cue but were greatly diminished when participants withheld responding to a recently ignored cue. The findings suggest that episodic traces of past Go/NoGo responses guide future action decisions, such that increased response control is needed to overcome bias to respond to recently acted-on NoGo cues. [source] Segmented post-column analyte addition; a concept for continuous response control of liquid chromatography/mass spectrometry peaks affected by signal suppression/enhancementRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 5 2005Anton Kaufmann A novel technique, "segmented post-column analyte addition", is proposed to visualize and compensate signal suppression/enhancement effects in electrospray ionization tandem mass spectrometry (ESI-MS/MS). Instead of delivering a constant flow of analyte solution between the liquid chromatography (LC) column exit and the ESI interface into the eluent resulting from LC separation of analyte-free matrix in order to determine retention time widows in which suppression/enhancement is unimportant (King et al., J. Am. Soc. Mass Spectrom. 2000; 11: 942), segmented packets of analyte-containing solvent and analyte-free solvent were infused into an LC eluent resulting from separation of an analyte-containing sample. The obtained, superimposed, periodic spikes are much narrower than the analyte peak eluting from the column. The height of the spikes is affected by signal suppression phenomena to the same extent as the analyte signal, and hence variations of the spike height can be used to correct the peak area of analyte peaks affected by signal suppression/enhancement. Copyright © 2005 John Wiley & Sons, Ltd. [source] Performance variability, impulsivity errors and the impact of incentives as gender-independent endophenotypes for ADHDTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 2 2010Henrik Uebel Background:, Attention-deficit hyperactivity disorder (ADHD) is one of the most common and highly heritable child psychiatric disorders. There is strong evidence that children with ADHD show slower and more variable responses in tasks such as Go/Nogo tapping aspects of executive functions like sustained attention and response control which may be modulated by motivational factors and/or state-regulation processes. The aim of this study was (1) to determine if these executive functions may constitute an endophenotype for ADHD; (2) to investigate for the first time whether known modulators of these executive functions may also be familial; and (3) to explore whether gender has an impact on these measures. Methods:, Two hundred and five children with ADHD combined type, 173 nonaffected biological siblings and 53 controls with no known family history of ADHD were examined using a Go/Nogo task in the framework of a multi-centre study. Performance-measures and modulating effects of event-rate and incentives were examined. Shared familial effects on these measures were assessed, and the influence of gender was tested. Results:, Children with ADHD responded more slowly and variably than nonaffected siblings or controls. Nonaffected siblings showed intermediate scores for reaction-time variability, false alarms and omission errors under fast and slow event-rates. A slower event-rate did not lead to reduced performance specific to ADHD. In the incentive condition, mean reaction-times speeded up and became less variable only in children with ADHD and their nonaffected siblings, while accuracy was improved in all groups. Males responded faster, but also committed more false alarms. There were no interactions of group by gender. Conclusions:, Reaction-time variability and accuracy parameters could be useful neuropsychological endophenotypes for ADHD. Performance-modulating effects of incentives suggested a familially driven motivational dysfunction which may play an important role on etiologic pathways and treatment approaches for ADHD. The effects of gender were independent of familial effects or ADHD-status, which in turn suggests that the proposed endophenotypes are independent of gender. [source] | |||||||||||||