Abnormal negative feedback processing in first episode schizophrenia: evidence from an oculomotor rule switching task

Background. Previous studies have shown that patients with schizophrenia are impaired on executive tasks, where positive and negative feedbacks are used to update task rules or switch attention. However, research to date using saccadic tasks has not revealed clear deficits in task switching in these patients. The present study used an oculomotor ‘ rule switching ’ task to investigate the use of negative feedback when switching between task rules in people with schizophrenia. Method. A total of 50 patients with first episode schizophrenia and 25 healthy controls performed a task in which the association between a centrally presented visual cue and the direction of a saccade could change from trial to trial. Rule changes were heralded by an unexpected negative feedback, indicating that the cue-response mapping had reversed. Results. Schizophrenia patients were found to make increased errors following a rule switch, but these were almost entirely the result of executing saccades away from the location at which the negative feedback had been presented on the preceding trial. This impairment in negative feedback processing was independent of IQ. Conclusions. The results not only confirm the existence of a basic deficit in stimulus–response rule switching in schizophrenia, but also suggest that this arises from aberrant processing of response outcomes, resulting in a failure to appropriately update rules. The findings are discussed in the context of neurological and pharmacological abnormalities in the conditions that may disrupt prediction error signalling in schizophrenia

An Evaluation of Selected Aspects of the Student Teaching Program in Physical Education at Utah State University

This study was an attempt to determine through a survey of opinions to what extent the objectives, methods and procedures were effectively being accomplished in the professional preparation of student teachers in physical education at Utah State University. A questionnaire was developed and administered to student teachers who were currently completing their student teaching experience, and mailed to graduates who had completed their preparation program between 1966 and 1971. The areas surveyed, the pre-student teaching preparation, the assistance given by the university supervisor and the assistance rendered by the cooperating teacher were for the most part found to be adequate according to a majority of the opinions returned. The areas considered to be below adequate in the preparation program regarding the pre-student teacher preparation were items involving the school services and how they affect the student teaching assignment, techniques in self-disciplining student groups, communicating with parents, understanding social and cultural background of students and general techniques of discipline. The assistance provided by the university supervisor was considered be low adequate in the areas related to extra duties expected of teachers, fostering an understanding of a full year program, and locating and utilizing teaching materials. The cooperating teacher assistance was considered below adequate in areas regarding opportunities to observe other teachers in the school, developing teaching materials, selecting appropriate media for methods used, working professionally with other colleagues, and providing teaching situations that would link theory with practice. The supervisory assistance, according to a comparison of male and female opinion, seems to indicate that the university supervisor responsible for the male student teachers experienced a more effective accomplishment. The male cooperating teachers were found to be more effective in many of the areas considered than were the female cooperating teachers

Consumer dissatisfaction and market performance / BEBR No. 377

Includes bibliographical references (leaves [18-19])

Second Overtone Pulsators Among Delta Scuti Stars

We investigate the modal stability of stellar models at masses and luminosity levels corresponding to post main sequence luminous delta scuti pulsators. The envelope models have been computed at fixed mass value, luminosity level and chemical composition (Y=0.28, Z=0.02). According to a nonlinear approach to radial oscillations the present investigation predicts the occurrence of stable second overtone pulsators for the first time. The shape of both light and velocity curves are presented and discussed, providing a useful tool for the identification of second overtone pulsators among the known groups of radially pulsating stars. The period ratios of mixed mode pulsators obtained by perturbing the first and the second overtone radial eigenfunctions are in agreement with observative values. Finally, the physical structure and the dynamical properties of second overtone pulsators are discussed in detail. The role played by the nodal lines in the destabilization of second overtone pulsators is also pointed out.Comment: 20 pages, 11 Postscript figures, uses aaspp4.sty and tighten.st

Removal Efficiencies in Full-scale Biotrickling Filters used to clean Pig House Exhaust Air

In this study, we tested the performance and perspectives of four full-scale biotrickling filters based on Leca® (Light Expanded Clay Aggregates), a mechanically stable, non-degradable filter media, known to absorb odorous compounds such as H2S and methanethiol. The four filters varied in: filter thickness, carrying media, and the presence of dust filters. Biological Leca® filters were found to be capable of reducing NH3, H2S and odour by up to 96%, 80% and 78%, respectively. Clogging was observed to occur after approximately 100 days, but the installation of a dust filter successfully eliminated this problem

Swath Mapping Data Management Within the National Oceanic and Atmospheric Administration

In 1983, the United States proclaimed the establishment of a maritime Exclusive Economic Zone (EEZ) extending beyond the territorial sea to a distance of 200 nautical miles from its coastline. The proclamation reserved for the U.S. the sovereign right to explore for, exploit, conserve, and manage all natural resources within this new 3.4 million square nautical mile territory, an area roughly 1.2 times the total U.S. land mass. In order to help determine the characteristics and resources of the U.S. EEZ, a detailed program was developed to systematically map the entire area using multi-beam swath sounding systems. The program is under the direction of the National Oceanic and Atmospheric Administration (NOAA), United States Department of Commerce. Field operations commenced in early 1984 as two NOAA ships, equipped with advanced bathymetric swath mapping and precision navigation capabilities, began surveying off the coast of central California. Two additional ships have been added since and, to date, 36,000 square nautical miles of bathymetric mapping have been completed, a product of 95,000 lineal nautical miles of swath sounding. With such an enormous amount of data produced by swath mapping systems, the necessity for a comprehensive data management program was recognized early in the project. This paper describes the two-level data management system that has evolved, the lower level utilized aboard NOAA ships that acquire and initially process swath data, and the upper level employed by the Ocean Mapping Section, which is responsible for receiving, verifying, final processing and archiving all bathymetric swath data

Global and regional cortical thinning in first-episode psychosis patients: relationships with clinical and cognitive features

BackgroundThe thickness of the cortical mantle is a sensitive measure for identifying alterations in cortical structure. We aimed to explore whether first episode schizophrenia patients already show a significant cortical thinning and whether cortical thickness anomalies may significantly influence clinical and cognitive features.MethodWe investigated regional changes in cortical thickness in a large and heterogeneous sample of schizophrenia spectrum patients (n=142) at their first break of the illness and healthy controls (n=83). Magnetic resonance imaging brain scans (1.5 T) were obtained and images were analyzed by using BRAINS2. The contribution of sociodemographic, cognitive and clinical characterictics was investigated.ResultsPatients showed a significant total cortical thinning (F=17.55, d=−0.62, p0.53). No significant group × gender interactions were observed (all p’s>0.15). There were no significant associations between the clinical and pre-morbid variables and cortical thickness measurements (all r’s<0.12). A weak significant negative correlation between attention and total (r=−0.24, p=0.021) and parietal cortical thickness (r=−0.27, p=0.009) was found in patients (thicker cortex was associated with lower attention). Our data revealed a similar pattern of cortical thickness changes related to age in patients and controls.ConclusionsCortical thinning is independent of gender, age, age of onset and duration of the illness and does not seem to significantly influence clinical and functional symptomatology. These findings support a primary neuro-development disorder affecting the normal cerebral cortex development in schizophrenia

Novel mutation in CCBE 1 as a cause of recurrent hydrops fetalis from Hennekam lymphangiectasia-lymphedema syndrome-1.

Whole exome sequencing (WES) was used to determine the etiology of recurrent hydrops fetalis in this case of Hennekam lymphangiectasia-lymphedema syndrome-1. WES is a useful approach for diagnosing rare single-gene conditions with nonspecific phenotypes and should be considered early in the diagnostic process of investigating fetal abnormalities