Frontal Lobe Function and Performance Monitoring following Total Sleep Deprivation

Imaging studies have shown reduced frontal lobe resources following total sleep deprivation (TSD). The anterior cingulate cortex (ACC) in the frontal region plays a role in performance monitoring and cognitive control; both error detection and response inhibition are impaired following sleep loss. Event-related potentials (ERPs) are an electrophysiological tool used to index the brain's response to stimuli and information processing. In the Flanker task, the error-related negativity (ERN) and error positivity (Pe) ERPs are elicited after erroneous button presses. In a Go/NoGo task, NoGo-N2 and NoGo-P3 ERPs are elicited during high conflict stimulus processing. Research investigating the impact of sleep loss on ERPs during performance monitoring is equivocal, possibly due to task differences, sample size differences and varying degrees of sleep loss. Based on the effects of sleep loss on frontal function and prior research, it was expected that the sleep deprivation group would have lower accuracy, slower reaction time and impaired remediation on performance monitoring tasks, along with attenuated and delayed stimulus- and response-locked ERPs. In the current study, 49 young adults (24 male) were screened to be healthy good sleepers and then randomly assigned to a sleep deprived (n = 24) or rested control (n = 25) group. Participants slept in the laboratory on a baseline night, followed by a second night of sleep or wake. Flanker and Go/NoGo tasks were administered in a battery at 1O:30am (i.e., 27 hours awake for the sleep deprivation group) to measure performance monitoring. On the Flanker task, the sleep deprivation group was significantly slower than controls (p's <.05), but groups did not differ on accuracy. No group differences were observed in post-error slowing, but a trend was observed for less remedial accuracy in the sleep deprived group compared to controls (p = .09), suggesting impairment in the ability to take remedial action following TSD. Delayed P300s were observed in the sleep deprived group on congruent and incongruent Flanker trials combined (p = .001). On the Go/NoGo task, the hit rate (i.e., Go accuracy) was significantly lower in the sleep deprived group compared to controls (p <.001), but no differences were found on false alarm rates (i.e., NoGo Accuracy). For the sleep deprived group, the Go-P3 was significantly smaller (p = .045) and there was a trend for a smaller NoGo-N2 compared to controls (p = .08). The ERN amplitude was reduced in the TSD group compared to controls in both the Flanker and Go/NoGo tasks. Error rate was significantly correlated with the amplitude of response-locked ERNs in control (r = -.55, p=.005) and sleep deprived groups (r = -.46, p = .021); error rate was also correlated with Pe amplitude in controls (r = .46, p=.022) and a trend was found in the sleep deprived participants (r = .39, p =. 052). An exploratory analysis showed significantly larger Pe mean amplitudes (p = .025) in the sleep deprived group compared to controls for participants who made more than 40+ errors on the Flanker task. Altered stimulus processing as indexed by delayed P3 latency during the Flanker task and smaller amplitude Go-P3s during the Go/NoGo task indicate impairment in stimulus evaluation and / or context updating during frontal lobe tasks. ERN and NoGoN2 reductions in the sleep deprived group confirm impairments in the monitoring system. These data add to a body of evidence showing that the frontal brain region is particularly vulnerable to sleep loss. Understanding the neural basis of these deficits in performance monitoring abilities is particularly important for our increasingly sleep deprived society and for safety and productivity in situations like driving and sustained operations.

An Electrophysiological Investigation into the Role of Cognitive Control in the Attentional Blink

Accuracy at reporting a second-target (T2) is reduced if it is presented within approximately 500 ms of the first target (T1) – an attentional blink (AB). Early models explained the AB in terms of attentional limitations creating a processing bottleneck such that T2 processing would be impaired while T1 processing was ongoing. Theoretical models of the AB have more recently been expanded to include the role of cognitive control. In this dissertation I propose that cognitive control, defined as the optimization of information processing in order to achieve goals, is maladapted to the dual-task conditions of the AB task in that cognitive control optimizes the T1 goal, due to its temporal proximity, at the cost of T2. I start with the concept that the role of cognitive control is to serve goals, and that how goals are conceived of and the degree of motivation associated with those goals will determine whether cognitive control will create the condition that cause the AB. This leads to the hypothesis that electrophysiological measures of cognitive control and the degree of attentional investment resulting from cognitive control modulate the AB and explain individual differences in the AB. In a series of four studies feedback-related N2 amplitude, (reflecting individual differences in the strength of cognitive control), and event-related and resting alpha frequency oscillatory activity (reflecting degree of attentional investment), are used to explain both intra- and inter-individual variability in performance on the AB task. Results supported the hypothesis that stronger cognitive control and greater attentional investment are associated with larger AB magnitudes. Attentional investment, as measured by alpha frequency oscillations, and cognitive control, as measured by the feedback-related N2, did not relate to each other as hypothesized. It is proposed that instead of a measure of attentional investment alone, alpha frequency oscillatory activity actually reflects control over information processing over time, in other words the timing of attention. With this conceptualization, various aspects of cognitive control, either related to the management of goals (feedback-related N2) or the management of attention over time to meet goals, explain variability in the AB.

A research capacity strengthening project for infectious diseases in Honduras: experience and lessons learned

Background: In Honduras, research capacity strengthening (RCS) has not received sufficient attention, but an increase in research competencies would enable local scientists to advance knowledge and contribute to national priorities, including the Millennium Development Goals (MDGs). Objective: This project aimed at strengthening research capacity in infectious diseases in Honduras, focusing on the School of Microbiology of the National Autonomous University of Honduras (UNAH). The primary objective was the creation of a research-based graduate program for the continued training of researchers. Parallel objectives included institutional strengthening and the facilitation of partnerships and networks. Methods: Based on a multi-stakeholder consultation, an RCS workplan was designed and undertaken from 2007 to 2012. Due to unexpected adverse circumstances, the first 2 years were heavily dedicated to implementing the project's flagship, an MSc program in infectious and zoonotic diseases (MEIZ). In addition, infrastructure improvements and demand-driven continuing education opportunities were facilitated; biosafety and research ethics knowledge and practices were enhanced, and networks fostering collaborative work were created or expanded. Results: The project coincided with the peak of UNAH's radical administrative reform and an unprecedented constitutional crisis. Challenges notwithstanding, in September 2009, MEIZ admitted the first cohort of students, all of whom undertook MDG-related projects graduating successfully by 2012. Importantly, MEIZ has been helpful in expanding the School of Microbiology's traditional etiology-based, disciplinary model to infectious disease teaching and research. By fulfilling its objectives, the project contributed to a stronger research culture upholding safety and ethical values at the university. Conclusions: The resources and strategic vision afforded by the project enhanced UNAH's overall research capacity and its potential contribution to the MDGs. Furthermore, increased research activity and the ensuing improvement in performance indicators at the prime Honduran research institution invoke the need for a national research system in Honduras.

An fMRI study of emotional episodic memory in schizophrenia : effects of diagnosis and sex

La schizophrénie est une psychopathologie largement hétérogène caractérisée entre autres par d’importantes défaillances dans le fonctionnement cognitif et émotionnel. En effet, par rapport à la population générale, forte proportion de ces individus présentent une mémoire déficitaire pour les événements émotionnels. À ce jour, le peu d’études qui se sont penchées sur la mémoire émotionnelle épisodique dans la schizophrénie, ont uniquement mis l’emphase sur l'effet de la valence des stimuli (c’est-à-dire le caractère agréable ou désagréable du stimulus). Toutefois, aucune n’a investigué spécifiquement l’intensité de la réaction aux stimuli (c’est-à-dire une faible par rapport à une forte réaction) malgré quantité de preuves faisant montre, dans la population générale, de différents processus de mémoire émotionnelle pour des stimuli suscitant une forte réaction par rapport à ceux évoquant une faible réponse. Ce manque est d’autant plus flagrant étant donné le nombre d’études ayant rapporté un traitement et un encodage atypiques des émotions spécifiquement au niveau de l’intensité de la réponse subjective chez des patients atteints de schizophrénie. Autre fait important, il est étonnant de constater l’absence de recherches sur les différences de sexe dans la mémoire émotionnelle étant donné l’ensemble des divergences entre hommes et femmes atteints de schizophrénie au niveau de la prévalence, de l’âge de diagnostic, de la manifestation clinique, de l’évolution de la maladie, de la réponse au traitement et des structures cérébrales. Pour pallier à ces lacunes, ce mémoire a évalué : (1) l’effet de la valence des stimuli et de l'intensité de la réaction émotionnelle au niveau des fonctions cérébrales correspondant à la mémoire émotionnelle chez des patients atteints de schizophrénie comparativement à des participants sains; et (2) les possibles différences de sexe dans les processus cérébraux impliqués dans la mémoire émotionnelle chez des patients atteints de schizophrénie par rapport à des volontaires sains. Ainsi, la première étude a comparé les activations cérébrales de patients atteints de schizophrénie par rapport à des participants sains au cours d’une tâche de mémoire émotionnelle dont les stimuli variaient à la fois au niveau de la valence et de l'intensité de la réaction subjective. 37 patients atteints de schizophrénie ainsi que 37 participants en bonne santé ont effectué cette tâche de mémoire émotionnelle lors d’une session d’imagerie par résonance magnétique fonctionnelle (IRMf). Pour toutes les conditions étudiées (images négatives, positives, de faible et de forte intensité), le groupe atteint de schizophrénie a performé significativement moins bien que les volontaires sains. Comparativement aux sujets sains, ils ont montré moins d’activations cérébrales dans les régions limbiques et préfrontales lors de la reconnaissance des images négatives, mais ont présenté un patron d'activations similaire à celui des participants sains lors de la reconnaissance des images chargées positivement (activations observées dans le cervelet, le cortex temporal et préfrontal). Enfin, indépendamment de la valence des stimuli, les deux groupes ont démontré une augmentation des activations cérébrales pour les images de forte intensité par rapport à celles de plus faible intensité. La seconde étude a quant à elle exploré les différences de sexe potentielles au niveau des activations cérébrales associées à la mémoire émotionnelle dans la schizophrénie et dans la population en général. Nous avons comparé 41 patients atteints de schizophrénie (20 femmes) à 41 participants en bonne santé (19 femmes) alors qu’ils effectuaient la même tâche de mémoire émotionnelle mentionnée plus haut. Or, pour cette étude, nous nous sommes concentrés sur les conditions suivantes : la reconnaissance d’images positives, négatives et neutres. Nous n'avons pas observé de différences entre les hommes et les femmes au niveau des performances à la tâche de mémoire pour aucune des conditions. En ce qui a trait aux données de neuroimagerie, comparativement aux femmes en bonne santé, celles atteintes de schizophrénie ont montré une diminution des activations cérébrales dans les régions corticales du système limbique (p. ex. cortex cingulaire moyen) et dans les régions sous-corticales (p. ex. amygdale) lors de la reconnaissance d'images négatives. Pour ce qui est de la condition positive, elles ont présenté, comparativement au groupe de femmes saines, des diminutions d’activations spécifiquement dans le cervelet ainsi que dans le gyrus frontal inférieur et moyen. Les hommes atteints de schizophrénie, eux, ont montré une augmentation d’activations par rapport aux hommes sains dans le gyrus préfrontal médian lors de la reconnaissance des stimuli négatifs ; ainsi que dans les régions pariétales, temporales et limbiques lors de la reconnaissance des stimuli positifs. Dans un autre ordre d’idées, notre analyse corrélationnelle a mis en évidence, chez les femmes, un lien significatif entre l’activité cérébrale et les symptômes au cours de la mémoire des stimuli positifs, alors que chez les hommes atteints schizophrénie, ce lien a été observé au cours de la mémoire des stimuli négatifs. Bref, l’ensemble de nos résultats suggère, chez les patients atteints de schizophrénie, un fonctionnement cérébral atypique spécifiquement lors de la reconnaissance d’images négatives, mais un fonctionnement intact lors de la reconnaissance de stimuli positifs. De plus, nous avons mis en évidence la présence de différences de sexe dans les activations cérébrales associées à la mémoire épisodique émotionnelle soulignant ainsi l'importance d’étudier séparément les hommes et les femmes atteints de schizophrénie dans le cadre de recherches sur les plans cognitif et émotionnel.

"A Most Weird Dialectic of Inversion" : revolutionary fraternity, sexuality and translation in Pierre Vallières and Eldridge Cleaver

Dans ce mémoire de maîtrise, il s'agit d'examiner le rôle du genre, de la sexualité et de la traduction dans les rapports entre deux mouvements nationalistes. D'abord, nous examinerons les représentations de la famille véchiulées dans l'autobiographie du membre du Front de libération du Québec Pierre Vallières (1938-1998), Les Nègres blancs d'Amérique. Ensuite, nous nous pencherons sur l'analyse du genre et de la sexualité contenue dans Soul on Ice, un recueil de textes écrits par le nationaliste noir Eldridge Cleaver (1933-1998). Dans les deux cas, la question de la violence révolutionnaire tiendra lieu de fil conducteur. Enfin, dans le troisième chapitre, nous relirons la traduction anglaise de Vallières, White Niggers of America, signée par Joan Pinkham. Cette relecture nous fournira l'occasion à la fois de comprendre et de critiquer, à partir de la perspective établie par la pensée de Cleaver au sujet de la masculinité noire dans une société régie par la suprématie blanche, comment Vallières essaie de bâtir des réseaux de solidarité internationaux et interraciaux entre les hommes. Dans notre conclusion, nous réunirons ces trois textes par le biais du sujet de l'internationalisme, en nous servant de la théorie queer, de la traductologie et des données biographiques pour résumer les résultats de nos recherches.

Analysis of resource use efficiency of the spinning mills in Kerala

This thesis discusses the factors which influence the productive and financial performance of the spinning mills in Kerala. The study will also help to assess the effect of ongoing reforms in the industrial sector in India. The main objective of the study is to identify and analyse the factors affecting the efficiency of the spinning mills. The unique feature of the study is that it compares the performance of private sector in relation to its public counterparts and also performance of small sector in relation to medium sector. The study is carried out with reference to the relative performance of differmills in Kerala and to identify the sources of differences in performance. The study covers twenty one spinning mills in Kerala, of which ten are in the private sector, four under NTC, three under co—operat;ive sector and four under KSTC.Measured in terms of firm-size fifteen belong to small size with a spindleage of less than 26,000 and six are in the medium size with a spindleage of 26,000 to 50,0OO.1 The period of study is 1982-83 to 1991-92. Hence, only those companies, of which data of 10 years upto 1991-92 wereavailable, are taken for study.

A study on the performance of flexible pavements on mature soil subgrades

The country has witnessed tremendous increase in the vehicle population and increased axle loading pattern during the last decade, leaving its road network overstressed and leading to premature failure. The type of deterioration present in the pavement should be considered for determining whether it has a functional or structural deficiency, so that appropriate overlay type and design can be developed. Structural failure arises from the conditions that adversely affect the load carrying capability of the pavement structure. Inadequate thickness, cracking, distortion and disintegration cause structural deficiency. Functional deficiency arises when the pavement does not provide a smooth riding surface and comfort to the user. This can be due to poor surface friction and texture, hydro planning and splash from wheel path, rutting and excess surface distortion such as potholes, corrugation, faulting, blow up, settlement, heaves etc. Functional condition determines the level of service provided by the facility to its users at a particular time and also the Vehicle Operating Costs (VOC), thus influencing the national economy. Prediction of the pavement deterioration is helpful to assess the remaining effective service life (RSL) of the pavement structure on the basis of reduction in performance levels, and apply various alternative designs and rehabilitation strategies with a long range funding requirement for pavement preservation. In addition, they can predict the impact of treatment on the condition of the sections. The infrastructure prediction models can thus be classified into four groups, namely primary response models, structural performance models, functional performance models and damage models. The factors affecting the deterioration of the roads are very complex in nature and vary from place to place. Hence there is need to have a thorough study of the deterioration mechanism under varied climatic zones and soil conditions before arriving at a definite strategy of road improvement. Realizing the need for a detailed study involving all types of roads in the state with varying traffic and soil conditions, the present study has been attempted. This study attempts to identify the parameters that affect the performance of roads and to develop performance models suitable to Kerala conditions. A critical review of the various factors that contribute to the pavement performance has been presented based on the data collected from selected road stretches and also from five corporations of Kerala. These roads represent the urban conditions as well as National Highways, State Highways and Major District Roads in the sub urban and rural conditions. This research work is a pursuit towards a study of the road condition of Kerala with respect to varying soil, traffic and climatic conditions, periodic performance evaluation of selected roads of representative types and development of distress prediction models for roads of Kerala. In order to achieve this aim, the study is focused into 2 parts. The first part deals with the study of the pavement condition and subgrade soil properties of urban roads distributed in 5 Corporations of Kerala; namely Thiruvananthapuram, Kollam, Kochi, Thrissur and Kozhikode. From selected 44 roads, 68 homogeneous sections were studied. The data collected on the functional and structural condition of the surface include pavement distress in terms of cracks, potholes, rutting, raveling and pothole patching. The structural strength of the pavement was measured as rebound deflection using Benkelman Beam deflection studies. In order to collect the details of the pavement layers and find out the subgrade soil properties, trial pits were dug and the in-situ field density was found using the Sand Replacement Method. Laboratory investigations were carried out to find out the subgrade soil properties, soil classification, Atterberg limits, Optimum Moisture Content, Field Moisture Content and 4 days soaked CBR. The relative compaction in the field was also determined. The traffic details were also collected by conducting traffic volume count survey and axle load survey. From the data thus collected, the strength of the pavement was calculated which is a function of the layer coefficient and thickness and is represented as Structural Number (SN). This was further related to the CBR value of the soil and the Modified Structural Number (MSN) was found out. The condition of the pavement was represented in terms of the Pavement Condition Index (PCI) which is a function of the distress of the surface at the time of the investigation and calculated in the present study using deduct value method developed by U S Army Corps of Engineers. The influence of subgrade soil type and pavement condition on the relationship between MSN and rebound deflection was studied using appropriate plots for predominant types of soil and for classified value of Pavement Condition Index. The relationship will be helpful for practicing engineers to design the overlay thickness required for the pavement, without conducting the BBD test. Regression analysis using SPSS was done with various trials to find out the best fit relationship between the rebound deflection and CBR, and other soil properties for Gravel, Sand, Silt & Clay fractions. The second part of the study deals with periodic performance evaluation of selected road stretches representing National Highway (NH), State Highway (SH) and Major District Road (MDR), located in different geographical conditions and with varying traffic. 8 road sections divided into 15 homogeneous sections were selected for the study and 6 sets of continuous periodic data were collected. The periodic data collected include the functional and structural condition in terms of distress (pothole, pothole patch, cracks, rutting and raveling), skid resistance using a portable skid resistance pendulum, surface unevenness using Bump Integrator, texture depth using sand patch method and rebound deflection using Benkelman Beam. Baseline data of the study stretches were collected as one time data. Pavement history was obtained as secondary data. Pavement drainage characteristics were collected in terms of camber or cross slope using camber board (slope meter) for the carriage way and shoulders, availability of longitudinal side drain, presence of valley, terrain condition, soil moisture content, water table data, High Flood Level, rainfall data, land use and cross slope of the adjoining land. These data were used for finding out the drainage condition of the study stretches. Traffic studies were conducted, including classified volume count and axle load studies. From the field data thus collected, the progression of each parameter was plotted for all the study roads; and validated for their accuracy. Structural Number (SN) and Modified Structural Number (MSN) were calculated for the study stretches. Progression of the deflection, distress, unevenness, skid resistance and macro texture of the study roads were evaluated. Since the deterioration of the pavement is a complex phenomena contributed by all the above factors, pavement deterioration models were developed as non linear regression models, using SPSS with the periodic data collected for all the above road stretches. General models were developed for cracking progression, raveling progression, pothole progression and roughness progression using SPSS. A model for construction quality was also developed. Calibration of HDM–4 pavement deterioration models for local conditions was done using the data for Cracking, Raveling, Pothole and Roughness. Validation was done using the data collected in 2013. The application of HDM-4 to compare different maintenance and rehabilitation options were studied considering the deterioration parameters like cracking, pothole and raveling. The alternatives considered for analysis were base alternative with crack sealing and patching, overlay with 40 mm BC using ordinary bitumen, overlay with 40 mm BC using Natural Rubber Modified Bitumen and an overlay of Ultra Thin White Topping. Economic analysis of these options was done considering the Life Cycle Cost (LCC). The average speed that can be obtained by applying these options were also compared. The results were in favour of Ultra Thin White Topping over flexible pavements. Hence, Design Charts were also plotted for estimation of maximum wheel load stresses for different slab thickness under different soil conditions. The design charts showed the maximum stress for a particular slab thickness and different soil conditions incorporating different k values. These charts can be handy for a design engineer. Fuzzy rule based models developed for site specific conditions were compared with regression models developed using SPSS. The Riding Comfort Index (RCI) was calculated and correlated with unevenness to develop a relationship. Relationships were developed between Skid Number and Macro Texture of the pavement. The effort made through this research work will be helpful to highway engineers in understanding the behaviour of flexible pavements in Kerala conditions and for arriving at suitable maintenance and rehabilitation strategies. Key Words: Flexible Pavements – Performance Evaluation – Urban Roads – NH – SH and other roads – Performance Models – Deflection – Riding Comfort Index – Skid Resistance – Texture Depth – Unevenness – Ultra Thin White Topping

Technical and scale efficiency of cassava production system in Delta State, Nigeria: an application of Two-Stage DEA approach

The present study examines the level of pure technical and scale efficiencies of cassava production system including its sub-processes (that is production and processing stages) of 278 cassava farmers/processors from three regions of Delta State, Nigeria by applying Two-Stage Data Envelopment Analysis (DEA) approach. Results reveal that pure technical efficiency (PTE) is significantly lower at the production stage 0.41 vs 0.55 for the processing stage, but scale efficiency (SE) is high at both stages (0.84 and 0.87), implying that productivity can be improved substantially by reallocation of resources and adjusting operation size. The socio-economic determinants exert differential impacts on PTE and SE at each stage. Overall, education, experience and main occupation as farmer significantly improve SE while subsistence pressure reduces it. Extension contact significantly improves SE at the processing stage but reduces PTE and SE overall. Inverse size-PTE and size-SE relationships exist in cassava production system. In other words, large/medium farms are technically and scale inefficient. Gender gap exists in performance. Male farmers are technically efficient at processing stage but scale inefficient overall. Farmers in northern region are technically efficient. Investments in education, extension services and infrastructure are suggested as policy options to improve the cassava sector in Nigeria.

Attentional Selection in Object Recognition

A key problem in object recognition is selection, namely, the problem of identifying regions in an image within which to start the recognition process, ideally by isolating regions that are likely to come from a single object. Such a selection mechanism has been found to be crucial in reducing the combinatorial search involved in the matching stage of object recognition. Even though selection is of help in recognition, it has largely remained unsolved because of the difficulty in isolating regions belonging to objects under complex imaging conditions involving occlusions, changing illumination, and object appearances. This thesis presents a novel approach to the selection problem by proposing a computational model of visual attentional selection as a paradigm for selection in recognition. In particular, it proposes two modes of attentional selection, namely, attracted and pay attention modes as being appropriate for data and model-driven selection in recognition. An implementation of this model has led to new ways of extracting color, texture and line group information in images, and their subsequent use in isolating areas of the scene likely to contain the model object. Among the specific results in this thesis are: a method of specifying color by perceptual color categories for fast color region segmentation and color-based localization of objects, and a result showing that the recognition of texture patterns on model objects is possible under changes in orientation and occlusions without detailed segmentation. The thesis also presents an evaluation of the proposed model by integrating with a 3D from 2D object recognition system and recording the improvement in performance. These results indicate that attentional selection can significantly overcome the computational bottleneck in object recognition, both due to a reduction in the number of features, and due to a reduction in the number of matches during recognition using the information derived during selection. Finally, these studies have revealed a surprising use of selection, namely, in the partial solution of the pose of a 3D object.

Passive Dynamics in the Control of Gymnastic Maneuvers

The control of aerial gymnastic maneuvers is challenging because these maneuvers frequently involve complex rotational motion and because the performer has limited control of the maneuver during flight. A performer can influence a maneuver using a sequence of limb movements during flight. However, the same sequence may not produce reliable performances in the presence of off-nominal conditions. How do people compensate for variations in performance to reliably produce aerial maneuvers? In this report I explore the role that passive dynamic stability may play in making the performance of aerial maneuvers simple and reliable. I present a control strategy comprised of active and passive components for performing robot front somersaults in the laboratory. I show that passive dynamics can neutrally stabilize the layout somersault which involves an "inherently unstable" rotation about the intermediate principal axis. And I show that a strategy that uses open loop joint torques plus passive dynamics leads to more reliable 1 1/2 twisting front somersaults in simulation than a strategy that uses prescribed limb motion. Results are presented from laboratory experiments on gymnastic robots, from dynamic simulation of humans and robots, and from linear stability analyses of these systems.

Brief neuropsychological assessment of adults post-stroke in the left hemisphere

The neuropsychological assessment investigates cognitive deficits to improve the diagnosis, the prognosis and the rehabilitation of patients. In Brazil, stroke is a major cause of hospitalization and the leading cause of mortality and disability. The stroke in the left hemisphere (LH) is associated with different degrees of loss of language and other cognitive impairments, for example, in the memory. We compared the performance in brief neuropsychological tasks of the left hemisphere poststroke patients, without moderate or severe aphasia, with healthy controls. A list of 135 patients was selected based on inclusion criteria. The study included 15 patients with left stroke, paired by sex, age and education to 30 neurologically healthy adults. The data resulting from application of the Neupsilin Brief Neuropsychological Assessment Instrument were analyzed with the nonparametric Mann-Whitney U. Adults with LH stroke showed a significant reduction in performance when compared to healthy controls on language, working memory and ideomotor praxis, results also found in other studies of patients with left hemisphere stroke

Measuring sustained superior performance at the firm level

This paper proposes a two-dimensional Strategic Performance Measure (SPM) to evaluate the achievement of sustained superior performance. This proposal builds primarily on the fact that, under the strategic management perspective, a firm's prevalent objective is the pursuit of sustained superior performance. Three basic conceptual dimensions stem from this objective: relativity, sign dependence, and dynamism. These are the foundations of the SPM, which carries out a separate evaluation of the attained superior performance and of its sustainability over time. In contrast to existing measures of performance, the SPM provides: (i) a dynamic approach by considering the progress or regress in performance over time, and (ii) a cardinal measurement of performance differences and its changes over time. The paper also proposes an axiomatic framework that a measure of strategic performance should comply with to be theoretically and managerially sound. Finally, an empirical illustration of the Spanish banking sector during 1987-1999 is herein provided by discussing some relevant case

Perception and cognition in deaf children

This dissertation examines conceptual functioning of hearing impaired persons. Specifically the study addresses perceptual and conceptual functioning in both deaf and hearing children and whether there is a difference in performance as a function of hearing status, as attributable to age differences, or as a function of the school environment.

Prediction of global and local model quality in CASP8 using the ModFOLD server

The development of effective methods for predicting the quality of three-dimensional (3D) models is fundamentally important for the success of tertiary structure (TS) prediction strategies. Since CASP7, the Quality Assessment (QA) category has existed to gauge the ability of various model quality assessment programs (MQAPs) at predicting the relative quality of individual 3D models. For the CASP8 experiment, automated predictions were submitted in the QA category using two methods from the ModFOLD server-ModFOLD version 1.1 and ModFOLDclust. ModFOLD version 1.1 is a single-model machine learning based method, which was used for automated predictions of global model quality (QMODE1). ModFOLDclust is a simple clustering based method, which was used for automated predictions of both global and local quality (QMODE2). In addition, manual predictions of model quality were made using ModFOLD version 2.0-an experimental method that combines the scores from ModFOLDclust and ModFOLD v1.1. Predictions from the ModFOLDclust method were the most successful of the three in terms of the global model quality, whilst the ModFOLD v1.1 method was comparable in performance to other single-model based methods. In addition, the ModFOLDclust method performed well at predicting the per-residue, or local, model quality scores. Predictions of the per-residue errors in our own 3D models, selected using the ModFOLD v2.0 method, were also the most accurate compared with those from other methods. All of the MQAPs described are publicly accessible via the ModFOLD server at: http://www.reading.ac.uk/bioinf/ModFOLD/. The methods are also freely available to download from: http://www.reading.ac.uk/bioinf/downloads/.

Age-related decline in the ability to decode emotional prosody: primary or secondary phenomenon?

Emotion processing deficits can cause catastrophic damage to a person's ability to interact socially. While it is known that older adults have difficulty identifying facial emotions, it is still not clear whether this difficulty extends to identification of the emotion conveyed by prosody. This study investigated whether the ability of older adults to decode emotional prosody falls below that of young adults after controlling for loss of hearing sensitivity and key features of cognitive ageing. Apart from frontal lobe load, only verbal IQ was associated with the age-related reduction in performance displayed by older participants, but a notable deficit existed after controlling for its effects. It is concluded that older adults may indeed have difficulty deducing the emotion conveyed by prosody, and that while this difficulty can be exaggerated by some aspects of cognitive ageing, it is primary in origin.