Temperature dependence of the average electron-hole pair creation energy in Al0.8Ga0.2As

The temperature dependence of the average energy consumed in the creation of an electron-hole pair in the wide bandgap compound semiconductor Al 0.8Ga0.2As is reported following X-ray measurements made using an Al0.8Ga0.2As photodiode diode coupled to a low-noise charge-sensitive preamplifier operating in spectroscopic photon counting mode. The temperature dependence is reported over the range of 261 K-342 K and is found to be best represented by the equation ε AlGaAs 7.327-0.0077 T, where εAlGaAs is the average electron-hole pair creation energy in eV and T is the temperature in K. © 2013 © 2013 Author(s)

MS

thesisA descriptive correlation methodology was used to investigate the relationship between the type of severity of menstrual discomforts experienced by a sample of undergraduate women and the amount of physical exercise in which they participate A questionnaire, developed and pilot-tested by the investigator, was administered to 150 women between the ages of 18 and 25 years who were enrolled in classes at The University of Utah. Analysis of data was completed by use of the Statistical Package for the Social Sciences at The University of Utah Computer Center. Frequency distribution and measures of central tendency, Chi-square correlations, Spearman correlation coefficients, and Pearson product-moment correlation coefficients were employed to answer research questions dealing with menstrual discomforts and physical exercise. Of the total sample, 98.7% reported experiencing one or more symptoms associated with their periods. This percentage approximated findings of previous studies (Loevsky, 1978). The most common discomforts seen in the sample, as a whole, were abdominal swelling, abdominal cramping, irritability, and weight gain. The most frequent symptoms reported only before the onset of the period were weight gain, acne, and irritability. Those most commonly reported during the period were abdominal cramping, low backache, abdominal swelling, and diarrhea. Those symptoms most frequently experience, both before and during the period, were abdominal swelling, irritability, and abdominal cramping. Of 150 subjects, 96.7% reported participating in one or more physical activities. The most common activities were walking, individualized program (e.g., calisthenics, stretching, and weight training), and jogging. The results of the study generally support literatures which suggest an association between increasing amounts of physical exercise and a decreasing incidence of menstrual discomforts. The total amount of exercise per week was demonstrated to be negatively correlated (p<.022) with the occurrence of discomforts categorized as pain symptoms (abdominal cramping, low backache, breast tenderness, leg discomfort, and other pain. Of the women who reported training for competition in sporting events, the majority experienced favorable effects associated with the physical activity (43.8% reported less severe symptoms, and 25% experienced no symptoms during the time they were training). Women in the general sample reported favorable effects from increased activity (excluding sports training) in relation to their menstrual symptoms. Of 141 respondents, 39.7% reported symptoms as being less sever during the months when they were more active, while 19% reported experiencing not symptoms during more active months. A higher frequency of symptoms were found in women whose menarche occurred between the ages of 9 and 13 years, than in those who started menstruating between the ages of 14 and 18. A significant negative correlation was noted between age at menarche and severity of symptoms (as age of menarche decreased, severity of symptoms increased). Results suggest that increased frequency of symptoms is associated with irregularity in the menstrual cycle, as proposed by Romney et al. (1975). Greater frequency and severity of symptoms, as well as an increased amount of flow during the period were noted in the presence of increasing irregularity of periods. A significant positive relationship was demonstrated between the incidence of vomiting and increasing irregularity of periods. Five significant relationships were noted in regards to the amount of flow during periods: (1) weight gain and increasing flow, (2) diarrhea and increasing flow, (3) vomiting and increasing flow, (4) other pain and increasing flow, and (5) increasing severity and increasing flow

Bonus babies? The impact of paid parental leave on fertility intentions

Paid parental leave has become an increasingly important part of family policy in OECD countries: by 2004 on average over a year of leave paid at 59% of average wages was provided. Australia’s Paid Parental Leave (PPL) scheme was introduced in 2011 and provides 18 weeks of leave paid at the full time minimum wage for the primary carer of a child. Prior to the scheme, federal and state legislation provided paid maternity leave for most state and federal employees. We estimate the effect of access to paid parental leave on women’s fertility desires and intentions by exploiting the differential impact of the scheme for women working in the public and private sectors. We find that the announcement of the scheme had no impact on fertility desires or intentions at the extensive margin but that, conditional on intending to have at least one (more) child, the number of children intended increases by 0.28, a 13% increase. This effect is driven by highly educated women who do not already have children. As it has been shown that fertility intentions predict fertility outcomes, these results suggest that even modest paid parental leave programs can increase the fertility of working women and so moderate the declines in fertility rates seen in many developed countries

Intelligent Bio-Environments: Exploring Fuzzy Logic Approaches to the Honeybee Crisis

Project in collaboration with the Institute of Energy and Sustainable Development (IESD)This paper presents an overview of how fuzzy logic can be employed to model intelligent bio-environments. It explores how non-invasive monitoring techniques, combined with sensor fusion, can be used to generate a warning signal if a critical event within the natural environment is on the horizon. The honeybee hive is presented as a specific example of an intelligent bio-environment that unfortunately, under certain indicative circumstances, can fail within the natural world. This is known as Colony Collapse Disorder (CCD). The paper describes the design of a fuzzy logic methodology that utilizes input from non-invasive beehive monitoring systems, combining data from dedicated sensors and other disparate sources. An overview is given of two fuzzy logic approaches that are being explored in the context of the beehive; a fuzzy logic system and an Adaptive Neuro-Fuzzy Inference System (ANFIS)

11β-hydroxysteroid dehydrogenase glucocorticoid metabolism within the lung and its influence on macrophage function in the acute respiratory distress syndrome

The acute respiratory distress syndrome (ARDS) is an important cause of respiratory failure in critically ill patients characterised by severe inflammation within the lungs. This inflammation is limited by anti-­inflammatory glucocorticoid hormones released from the hypothalamus-pituitary-adrenal (HPA) system. This thesis reports a series of investigations into glucocorticoid concentrations and glucocorticoid metabolism within the lungs of patients with ARDS. It also contains an investigation into a potential biomarker for ARDS. Our study of glucocorticoid concentrations in alveolar epithelial lining fluid showed increased cortisol concentrations within the lungs at onset of ARDS. These concentrations have a positive relationship with critical illness severity indices, but negative relationships with alveolar permeability and alveolar neutrophil counts. In peripheral tissues cortisone and cortisol are inter-converted by iso-­enzymes of 11β-­hydroxysteroid dehydrogenase (11β-­HSD). We have shown that healthy primary resident alveolar macrophages increase their production of active cortisol by the oxo-­reduction of inactive cortisone in response to inflammatory stimuli. Alveolar macrophages are responsible for the removal of spent and apoptotic inflammatory cells, failure of this process causes further inflammation. We have shown that glucocorticoids increase the rate of uptake of apoptotic cells by alveolar macrophages, and that macrophage 11β-HSD production of cortisol increases this process. We have shown however that alveolar macrophages extracted from patients with established ARDS have decreased 11β-HSD oxo-reductase activity. This decreased conversion of cortisone to cortisol will cause a diminished response to the anti-inflammatory signal of the HPA system. The implications of this are that they will have a limited capacity to up-­regulate efferocytosis and a diminished anti-­inflammatory potential. The receptor for advanced glycation end-­products (RAGE) is a potential biomarker in ARDS. We have shown that RAGE concentrations in plasma and BALF had excellent diagnostic compatibility with ARDS diagnostic criteria. The use of a threshold RAGE concentration could assure pulmonary inflammation in future investigations

An Intuitive Solution to the Problem of Induction

The subject of this essay is the classical problem of induction, which is sometimes attributed to David Hume and called “the Humean Problem of Induction.” Here, I examine a certain sort of Neo-Aristotelian solution to the problem, which appeals to the concept of natural kinds in its response to the inductive skeptic. This position is most notably represented by Howard Sankey and Marc Lange. The purpose of this paper is partly destructive and partly constructive. I raise two questions. The first is: Are the natural kind solutions to the problem successful? The first thesis of this paper is that they are not, and I will show how and why they fail. And the second question I raise here is: Is there nonetheless some alternative Neo-Aristotelian solution to the problem which is successful and can overcome the shortcomings endemic to the Sankey-Lange account? The second thesis is that there is, and I’ll attempt to sketch one. My stance here may be summarized by saying that, while I agree with Sankey and Lange that the problem of induction can be adequately resolved, and while I am on the whole sympathetic with the Aristotelian spirit of their account(s), I am, for all that, dissatisfied with the letter of them. Nothing short of a more thoroughgoing Aristotelianism about the epistemology of induction will do

God’s Place in Logical Space

It has been argued recently that classical theism and Lewisian modal realism are incompatible theses. The most substantial argument to this effect takes the form of a trilemma. It argues that no sense can be made of God’s being a necessary being in the modal realistic picture, on pain of, among other things, modal collapse. The question of this essay is: Is that so? My goal here is to detail the reasons that have been offered in support of this contention and then defend the coherence of theistic modal realism from the trilemma. I call my reply to the argument an “Anselmian-Thomistic” defense, since it appeals to resources from classical medieval philosophy, especially from Anselm and Aquinas