Food Habits of Deer in the Black Hills

This study was conducted in two parts for Master of Science theses by the senior authors of Parts I and II. The study in the Northem Black Hills (Part I) was completed in 1968. Principal and preferred foods were determined for the winter and summer and a pasture study was conducted to measure production and utilization of foods in a typical aspen stand during the summer months. The study in the Southern Black Hills (Part II) was made in 1968 and 1969. Objectives were to determine the principal plants used by mule and white-tailed deer in fall, winter and summer. The utility of the point-analysis technique for measuring rumen contents was evaluated and the technique was applied to rumen contents examined. The studies were supported by the South Dakota Department of Game, Fish and Parks under Federal Aid Project W-75-R through the South Dakota Cooperative Wildlife Research Unit (South Dakota State University, the Bureau of Sport Fisheries and Wildlife, the South Dakota Department of Game, Fish and Parks and the Wildlife Management Institute, cooperating). Special acknowledgement is extended to the personnel of the Wildlife Habitat Project, Rocky Mountain Forest and Range Experiment Station Rapid City, for their assistance in both studies. Dr. Donald Dietz, Project Leader, and Harold E. Messner, Range Technician, were particularly helpful in the development of techniques for analysis of rumen content and the equipment used for the point-analysis method described in Part II. The assistance of William Hepworth, Director of Technical Research, Wyoming Game and Fish Department, in securing the two deer used in the pasture study described in Part I is gratefully acknowledged

Characterization of Clostridium difficile isolates using capillary gel electrophoresis-based PCR ribotyping

We have developed a Clostridium difficile PCR ribotyping method based on capillary gel electrophoresis and have compared it with conventional PCR ribotyping. A total of 146 C. difficile isolates were studied: five isolates were reference strains (PCR ribotypes 001, 014, 017, 027 and 053); 141 were clinical isolates comprising 39 Austrian PCR ribotypes collected in the period 2006–2007 at 25 Austrian healthcare facilities. Capillary gel electrophoresis yielded up to 11 fragments per isolate and 47 ribotype patterns. All but one of the five PCR ribotypes of reference strains were clearly reflected in the chromatograms of capillary-based typing. Capillary gel electrophoresis divided 24 isolates belonging to PCR ribotype type 014 into seven subgroups, whereas subtyping the same isolates using multiple-locus variable-number tandem-repeat analysis yielded three unrelated subgroups, without obvious correlation to sr subgroups. Using a web-based software program (http://webribo.ages.at), we were able to correctly identify these 014 isolates by simply allocating the seven subgroup patterns to one ribotype, i.e. to PCR ribotype 014. We consider capillary gel electrophoresis-based PCR ribotyping to be a way of overcoming the problems associated with inter-laboratory comparisons of typing results, while at the same time substantially diminishing the hands-on time for PCR ribotyping

Model Cortical Association Fields Account for the Time Course and Dependence on Target Complexity of Human Contour Perception

Can lateral connectivity in the primary visual cortex account for the time dependence and intrinsic task difficulty of human contour detection? To answer this question, we created a synthetic image set that prevents sole reliance on either low-level visual features or high-level context for the detection of target objects. Rendered images consist of smoothly varying, globally aligned contour fragments (amoebas) distributed among groups of randomly rotated fragments (clutter). The time course and accuracy of amoeba detection by humans was measured using a two-alternative forced choice protocol with self-reported confidence and variable image presentation time (20-200 ms), followed by an image mask optimized so as to interrupt visual processing. Measured psychometric functions were well fit by sigmoidal functions with exponential time constants of 30-91 ms, depending on amoeba complexity. Key aspects of the psychophysical experiments were accounted for by a computational network model, in which simulated responses across retinotopic arrays of orientation-selective elements were modulated by cortical association fields, represented as multiplicative kernels computed from the differences in pairwise edge statistics between target and distractor images. Comparing the experimental and the computational results suggests that each iteration of the lateral interactions takes at least ms of cortical processing time. Our results provide evidence that cortical association fields between orientation selective elements in early visual areas can account for important temporal and task-dependent aspects of the psychometric curves characterizing human contour perception, with the remaining discrepancies postulated to arise from the influence of higher cortical areas

The Effect of Retirement on Cognition: Evidence from the Irish Marriage Bar

This study empirically investigates the relationship between retirement du- ration and cognition among older Irish women using microdata collected in the third wave of The Irish Longitudinal Study on Ageing. Ordinary least squares (OLS) regression estimates indicate that the longer an individual has been retired, the lower the cognitive functioning, with other factors thought to affect cognition held constant (e.g., age, education, and early-life socioeconomic conditions). However, retirement is potentially endogenous with respect to cognition because cognition may affect deci- sions relating to retiring. If so, the OLS estimates will be biased. To test for this possibility, instrumental variable (IV) estimation is used. This method requires an IV that is highly correlated with retirement duration but not correlated with cognition. The instrument used in this study is based on the so-called marriage bar, the legal require- ment that women leave paid employment upon getting married, which took effect in Ireland in the 1930s and was abolished only in the 1970s. The IV regression estimates, along with formal statistical tests, provide no evidence in support of the view that cognition affects retirement decisions. The finding of a small negative effect of retirement duration on cognition is robust to alternative empirical specifications. These findings are discussed in the wider context of the effects of work-like and work-related activities on cognition