No description available.

In the current investigation, we modified the high Go low No-Go Sustained Attention to Response Task (SART) by replacing the single response on Go trials with a dual response (dual response SART or DR SART). In three experiments a total of 80 participants completed the SART and versions of the DR SART in which response probabilities varied from 50-50, through 70-30 to 90-10. The probability of No-Go withhold stimuli was .11 in all experiments. Using a dynamic utility based model proposed by Peebles and Bothell (2004) we predicted that the 50-50 DR-SART would dramatically reduce commission errors. Additionally, the model predicted that the probability of commission errors to be an increasing function of response frequency. Both predictions were confirmed. Although the increasing rate of commission errors with response probability can also be accommodated by the rationale originally proposed for the SART by its creators (Robertson, Manly, Andrade, Baddeley, & Yiend, 1997) the fact that the current DR SART results and SART findings in general can be accommodated by a utility model without need for any attention processes is a challenge to views that ascribe commission errors to lapses of sustained attention.

Uppsatsen syfte var att undersöka effekten av koffeinintag på mental uthållighet. Hypotesen var att koffein skulle förbättra mental uthållighet på ett statistiskt signifikant vis. 34 individer rekryterades genom ett bekvämlighetsurval. SART (Sustained Attention to Response Task) användes för att mäta mental uthållighet före och efter intag av 180 mg koffein. Resultat på SART visade en signifikant minskning i antal fel gjorda, men inte i responstid. Det påvisades även en signifikant korrelation mellan ålder och responstid där äldre individer uppvisade en längre responstid före och efter koffeinintag. De förbättrade resultaten på SART efter koffeinintag är i linje med annan koffeinforskning och studien ger ytterligare stöd till att koffein förbättrar mental uthållighet. Metodologiska brister i form av en eventuell förväntanseffekt, intag av B-vitaminer i samband med koffeinintag, okontrollerade motivationsfaktorer, och eventuellt andra oidentifierade confounding variabler i undersökningen gör att vi inte med fullständig säkerhet kan tillskriva den signifikanta förbättringen i mental uthållighet till enbart koffein. / The purpose of this study was to examine the effects of caffeine on sustained attention. The working hypothesis was that caffeine would increase sustained attention in a significant way. 34 individuals were recruited by way of a convenience sample. SART (Sustained Attention to Response Task) was used to measure sustained attention before and after ingestion of 180 mg of caffeine. Results of SART showed a significant decrease in the number of errors made, but not in response time after caffeine ingestion. The study also showed a significant correlation between age and response time, in which older adults took a longer time to respond before and after caffeine ingestion. The improved results of SART after caffeine ingestion are in line with other caffeine studies and provide further support to the notion that caffeine improves sustained attention. Methodological shortcomings in shape of an eventual expectancy effect, intake of B vitamins in conjunction with caffeine intake, uncontrolled motivational factors and other eventual unidentified confounding variables makes it so that we can't ascribe the significant improvement in sustained attention to only caffeine with absolute certainty.

No description available.

Sexual Assault Nurse Examiners (SANE) are nurses that provide forensic examination and crisis intervention to victims of sexual assault. The training required to receive SANE certification ensures that SANE nurses are 1educated to provide thorough examinations and compassionate care to sexual assault victims. A SANE often works on a Sexual Assault Response/Resource Team (SART) which combines the efforts of law enforcement, detectives, victim advocates, and healthcare providers to provide a rapid response to the sexual assault victim. Proper evidence collection and a maintained chain of custody provide support for the conviction and if the evidence is obtained inaccurately the examination may be inadmissible in court. Even though SANEs can provide quality nursing care, many facilities lack trained SANEs to perform sexual assault examinations. Accurate data is crucial to support the need for facilities to implement a SANE program. This review and synthesis of literature examines the quality of forensic examinations performed by SANEs, conviction rates, and psychological well being of victims examined by SANEs. Research studies examined in this review suggest that SANE examinations are more complete and contribute to higher conviction rates then examinations performed by non-SANEs, however a combined SANE and SART intervention results in the highest level of victim participation. The research also suggests that the psychological well being of victims is improved with SANE intervention, however more evidence is needed

No description available.

There have been increased efforts to develop methods for improving attention across a range of tasks including those assessing sustained attention. Using a variety of techniques, researchers have reported modest reductions in errors on sustained attention tasks. However, published reports often have not documented changes in response times (RTs) that might accompany error reductions, which is problematic given that the error reductions could be mediated by a slowing strategy (i.e., speed-accuracy trade-off). In three studies, I explored the effects of speed-accuracy trade-offs in a sustained attention task (The Sustained Attention to Response Task; SART). In Study 1, I examined the effects of changing SART instructions from the double-edged "be fast and accurate" to the more conceptually accurate goal of maintaining high accuracy by responding slowly and carefully, and found that instructions to respond slowly and accurately resulted in both significantly longer RTs and fewer SART errors. In Studies 2 and 3, I developed a modified version of the SART that allowed me to experimentally manipulate RTs and found that errors were a systematic function of manipulated differences in RT independent of individual differences in response strategies. The results of these experiments indicate that it is possible that any technique that alters RT might indirectly alter error rates independently of improvements in sustained attention. I therefore conclude that investigators need to carefully attend to, control for, and report any changes in RT that accompany improvements in accuracy of performance, or alternatively employ tasks controlling for RT.

There have been increased efforts to develop methods for improving attention across a range of tasks including those assessing sustained attention. Using a variety of techniques, researchers have reported modest reductions in errors on sustained attention tasks. However, published reports often have not documented changes in response times (RTs) that might accompany error reductions, which is problematic given that the error reductions could be mediated by a slowing strategy (i.e., speed-accuracy trade-off). In three studies, I explored the effects of speed-accuracy trade-offs in a sustained attention task (The Sustained Attention to Response Task; SART). In Study 1, I examined the effects of changing SART instructions from the double-edged "be fast and accurate" to the more conceptually accurate goal of maintaining high accuracy by responding slowly and carefully, and found that instructions to respond slowly and accurately resulted in both significantly longer RTs and fewer SART errors. In Studies 2 and 3, I developed a modified version of the SART that allowed me to experimentally manipulate RTs and found that errors were a systematic function of manipulated differences in RT independent of individual differences in response strategies. The results of these experiments indicate that it is possible that any technique that alters RT might indirectly alter error rates independently of improvements in sustained attention. I therefore conclude that investigators need to carefully attend to, control for, and report any changes in RT that accompany improvements in accuracy of performance, or alternatively employ tasks controlling for RT.

In this thesis, we present ProxiSART, a flexible proximal framework for robust 3D cone beam tomographic reconstruction based on the Simultaneous Algebraic Reconstruction Technique (SART). We derive the proximal operator for the SART algorithm and use it for minimizing the data term in a proximal algorithm. We show the flexibility of the framework by plugging in different powerful regularizers, and show its robustness in achieving better reconstruction results in the presence of noise and using fewer projections. We compare our framework to state-of-the-art methods and existing popular software tomography reconstruction packages, on both synthetic and real datasets, and show superior reconstruction quality, especially from noisy data and a small number of projections.

<p>A computerized tomography scan enables the visualization of an object interior without opening it up. This technique is used in many fields e.g. in medical imaging, geology, and industry. To obtain information about an object, exterior measurements by means of X-rays are performed. Then, to reconstruct an image of the object’s interior, image-reconstructions methods are applied. The problem of reconstructing images from measurements of X-ray radiation belongs to the class of inverse problems. A class of important methods for inverse problems is Algebraic Reconstruction Techniques (ART). The performance of these methods depends on the choice of a relaxation parameter.</p> <p>In this thesis, we compare numerically various ART methods, namely Kaczmarz, symmetric Kaczmarz, randomized Kaczmarz and simultaneous ART. We perform an extensive numerical investigation of the behaviour of these methods, and in particular, study how they perform with respect to this relaxation parameter. We propose a simple heuristic for finding a good relaxation parameter for each of these methods. Comparisons of the new proposed strategy with a previously proposed one shows that our strategy has a slightly better performance in terms of relative error, relative residual and image discrepancy of the reconstructed image. Both strategies showed relatively close numerical results, but interestingly enough, for different values of this parameter.</p> / Master of Computer Science (MCS)