Performance of Some Ridge Parameters for Probit Regression: with Application on Swedish Job Search Data

In ridge regression the estimation of the ridge parameter is an important issue. This paper generalizes some methods for estimating the ridge parameter for probit ridge regression (PRR) model based on the work of Kibria et al. (2011). The performance of these new estimators are judged by calculating the mean square error (MSE) using Monte Carlo simulations. In the design of the experiment we chose to vary the sample size and the number of regressors. Furthermore, we generate explanatory variables that are linear combinations of other regressors, which is a common situation in economics. In an empirical application regarding Swedish job search data we also illustrate the benefits of the new method.probit regression; maximum likelihood; multicollinearity; ridge regression; MSE; job search

Faktorer som påverkar teknikkonsulters intention att stanna hos eller säga upp sig från sin arbetsgivare

Syftet med uppsatsen var att i ett svenskt konsultföretag undersöka förhållanden i teknikkonsulters arbete vilka arbetsgivaren antas kunna påverka, som kan ha samband med intention att stanna hos respektive säga upp sig från arbetsgivaren. I en kvalitativ intervjustudie (n=9) identi-fierades följande typer av förhållanden: arbetsuppgifternas egenskaper, de arbetsrelaterade relationerna, arbetsrelaterade belöningar, yttre faktorer samt uppsägningsprocessen. Utifrån intervjuresultaten och tidigare forskning genomfördes en enkätstudie (n=54). En principalkomponentanalys identi-fierade fyra faktorer. Korrelationsanalyser och regressionsanalyser visade att upplevelsen av att vara önskad av arbetsgivaren var en faktor som sam-varierade med och förklarade intentioner att stanna hos respektive säga upp sig från sin arbetsgivare

Pathogenic Potential to Humans of Bovine Escherichia coli O26, Scotland

Escherichia coli O26 and O157 have similar overall prevalences in cattle in Scotland, but in humans, Shiga toxin–producing E. coli O26 infections are fewer and clinically less severe than E. coli O157 infections. To investigate this discrepancy, we genotyped E. coli O26 isolates from cattle and humans in Scotland and continental Europe. The genetic background of some strains from Scotland was closely related to that of strains causing severe infections in Europe. Nonmetric multidimensional scaling found an association between hemolytic uremic syndrome (HUS) and multilocus sequence type 21 strains and confirmed the role of stx<sub>2</sub> in severe human disease. Although the prevalences of E. coli O26 and O157 on cattle farms in Scotland are equivalent, prevalence of more virulent strains is low, reducing human infection risk. However, new data on E. coli O26–associated HUS in humans highlight the need for surveillance of non-O157 enterohemorrhagic E. coli and for understanding stx<sub>2</sub> phage acquisition

Act therefore to be a virago of the Lord: Eleventh Century Ecclesiastical Reform and New Forms and Perceptions of Lay Female Religiosity

Despite the extensive scholarship on the eleventh and twelfth century ecclesiastical reform movement, the roles that lay noblewomen played within the reform have often been overlooked. This thesis focuses on the correspondence between lay noblewomen across Europe and clerical reformers, chronicle excerpts, and several vitae of women from this period in order to study laywomen's participation in all aspects of the reform movement. An analysis of these sources points to the emergence of a new perception of lay female religiosity, one built upon the belief in a politically and socially active female agent of the Christian Church who could use her position in her family and her rank as a member of the nobility to influence and support the efforts of the reform movement. This thesis contributes to the growing scholarship focusing on the role of gender in medieval religious history, and suggests that the importance of women within the reform dynamic was greater and more complex than hitherto suspected.Master of Art

Escherichia coli O157 Infection and Secondary Spread, Scotland, 1999–2008

To determine the proportion of Escherichia coli O157 cases in Scotland attributable to secondary spread, we analyzed data obtained through entire-population enhanced surveillance. We identified 11% of cases as secondary. Secondary cases in single households were younger than secondary cases in outbreaks affecting >1 household and had similar risk for hemolytic uremic syndrome

Primary and secondary cases in Escherichia coli O157 outbreaks: a statistical analysis

<p>Abstract</p> <p>Background</p> <p>Within outbreaks of <it>Escherichia coli </it>O157 (<it>E. coli </it>O157), at least 10–15% of cases are thought to have been acquired by secondary transmission. However, there has been little systematic quantification or characterisation of secondary outbreak cases worldwide. The aim of this study was to characterise secondary outbreak cases, estimate the overall proportion of outbreak cases that were the result of secondary transmission and to analyse the relationships between primary and secondary outbreak cases by mode of transmission, country and median age.</p> <p>Methods</p> <p>Published data was obtained from 90 confirmed <it>Escherichia coli </it>O157 outbreaks in Great Britain, Ireland, Scandinavia, Canada, the United States and Japan, and the outbreaks were described in terms of modes of primary and secondary transmission, country, case numbers and median case age. Outbreaks were tested for statistically significant differences in the number of ill, confirmed, primary and secondary cases (analysis of variance and Kruskal-Wallis) and in the rate of secondary cases between these variables (Generalised Linear Models).</p> <p>Results</p> <p>The outbreaks had a median of 13.5 confirmed cases, and mean proportion of 0.195 secondary cases. There were statistically significant differences in the numbers of ill, confirmed, primary and secondary cases between modes of primary transmission (p < 0.021), and in primary and secondary cases between median age categories (p < 0.039) and modes of secondary transmission (p < 0.001).</p> <p>Secondary case rates differed statistically significantly between modes of secondary and primary transmission and median age categories (all p < 0.001), but not between countries (p = 0.23). Statistically significantly higher rates of secondary transmission were found in outbreaks with a median age <6 years and those with secondary transmission via person to person spread in nurseries. No statistically significant interactions were found between country, mode of transmission and age category.</p> <p>Conclusion</p> <p>Our analyses indicated that ~20% of <it>E. coli </it>O157 outbreak cases were the result of secondary spread, and that this spread is significantly influenced by age and modes of primary and secondary transmission, but not country. In particular, the results provide further data emphasising the importance of simple but effective preventive strategies, such as handwashing, that can reduce the risk of secondary spread, particularly amongst young children in nurseries.</p

Motor Habits in Visuo-manual Tracking: Manifestation of an Unconscious Short-Term Motor Memory?

Normal subjects were tested in short, repetitive trials of a tracking task, with an identical shape of target movement being used throughout one session. Analysis of the net error curves (pursuit minus target movement) revealed that subjects regularly exhibit a remoteness effect: neighbouring trials were more similar than distant ones. The effect is demonstrated to be stronger in the absence of visual cues, and was found to be absent in a patient with complete loss of proprioception when he was performing without visual feedback as well. The results are discussed in terms of a short term memory store contributing to unconscious movement habits in tracking. This may represent part of the motor learning process working together with conscious visuo-motor control mechanisms. Its function is probably related to the acquisition of automatic movements