<p>Deposition remains the most common form of waste disposal in many parts of the world. As a terminus of the products consumed in our society a landfill may contain virtually all sorts of man-made chemicals. Despite this, the harmfulness of landfill leachate has not been extensively evaluated in feral organisms in the environment. In a leachate-contaminated lake, Molnbyggen, in Sweden, our studies reported a low percent of sexually mature (SM) female perch (<i>Perca fluviatilis</i>) that had decreased plasma androgen levels, decreased brain aromatase activity, distinctive sores and fin erosion. The impairments were attributed to unidentified compound(s) present in the leachate. In one out of four other investigated leachate-contaminated lakes, the low percent of SM female perch had reduced plasma sex steroid levels and similar sores as perch in Molnbyggen. The biochemical mechanism causing the disorders was investigated in order to establish a connection between the impairments and possible causative compound(s). Plasma levels of progesterone and 17α-hydroxyprogesterone were unaffected. Ovarian 17,20-lyase activity was decreased while levels of biliary steroid conjugates and hepatic testosterone UDP-glucuronosyltransferase activity did not differ between exposed and reference SM fish. Furthermore, the decreased brain aromatase activity seems to be a secondary effect; possibly a result of low substrate availability. Altogether, this suggests a possible disruption in the synthesis of androgens, knowledge that could be used as a tool in biomarker-directed fractionation studies to pinpoint compound(s). Molnbyggen sediment extracts decreased the testosterone and estradiol concentrations in whole-body homogenates of zebrafish (<i>Danio rerio</i>) after a three week exposure period. This suggests that compound(s) with the potency to alter endocrine function are present in the sediment. Although the first steps have been taken towards identifying compound(s) responsible for this kind of reproductive impairments, they still remain unidentified. Measures have to be taken to identify harmful chemicals in our society, to reduce their number, and to minimise their uncontrolled dispersal.</p>

Disruption is something that we must negotiate as part of our everyday lives. The context of disruption can vary in nature from being positive to being negative in nature. However, the emotional effects of the disruption have not been investigated in the social psychological literature. This study utilizes structuralized ritualization affect theory of social exchange, attribution theory, and the theory of relational cohesion in order to investigate the effects of disruption on the overall positive emotion of the actors involved and their feelings of cohesiveness with regard to their group.

Industrial and domestic sewage effluents have been found to cause reproductive disorders in wild fish, often as a result of the interference of compounds in the effluents with the endocrine system. This thesis describes laboratory-based exposure experiments and a field survey that were conducted with juveniles of the three-spined stickleback, Gasterosteus aculeatus. This small teleost is a common fish in Swedish coastal waters and was chosen as an alternative to non-native test species commonly used in endocrine disruption studies, which allows the comparison of field data with results from laboratory experiments. The aim of this thesis was to elucidate 1) if genetic sex determination and differentiation can be disturbed by natural and synthetic steroid hormones and 2) whether this provides an endpoint for the detection of endocrine disruption, 3) to evaluate the applicability of specific estrogen- and androgen-inducible marker proteins in juvenile three-spined sticklebacks, 4) to investigate whether estrogenic and/or androgenic endocrine disrupting activity can be detected in effluents from Swedish pulp mills and domestic sewage treatment plants and 5) whether such activity can be detected in coastal waters receiving these effluents. Laboratory exposure experiments found juvenile three-spined sticklebacks to be sensitive to water-borne estrogenic and androgenic steroid substances. Intersex – the co-occurrence of ovarian and testicular tissue in gonads – was induced by 17β-estradiol (E2), 17α-ethinylestradiol (EE2), 17α-methyltestosterone (MT) and 5α-dihydrotestosterone (DHT). The first two weeks after hatching was the phase of highest sensitivity. MT was ambivalent by simultaneously eliciting masculinizing and feminizing effects. When applying a DNA-based method for genetic sex identification, it was found that application of MT only during the first two weeks after hatching caused total and apparently irreversible development of testis in genetic females. E2 caused gonad type reversal from male to female. E2 and EE2 induced vitellogenin - the estrogen-responsive yolk precursor protein, while DHT and MT induced spiggin – the androgen-responsive glue protein of the stickleback. None of the effluents from two pulp mills and two domestic sewage treatment plants had any estrogenic or androgenic activity. Juvenile three-spined sticklebacks were collected during four subsequent summers at the Swedish Baltic Sea coast in recipients of effluents from pulp mills and a domestic sewage treatment plant as well as remote reference sites. No sings of endocrine disruption were observed at any site, when studying gonad development or marker proteins, except for a deviation of sex ratios at a reference site. The three-spined stickleback – with focus on the juvenile stage – was found to be a sensitive species suitable for the study of estrogenic and androgenic endocrine disruption.

Deposition remains the most common form of waste disposal in many parts of the world. As a terminus of the products consumed in our society a landfill may contain virtually all sorts of man-made chemicals. Despite this, the harmfulness of landfill leachate has not been extensively evaluated in feral organisms in the environment. In a leachate-contaminated lake, Molnbyggen, in Sweden, our studies reported a low percent of sexually mature (SM) female perch (Perca fluviatilis) that had decreased plasma androgen levels, decreased brain aromatase activity, distinctive sores and fin erosion. The impairments were attributed to unidentified compound(s) present in the leachate. In one out of four other investigated leachate-contaminated lakes, the low percent of SM female perch had reduced plasma sex steroid levels and similar sores as perch in Molnbyggen. The biochemical mechanism causing the disorders was investigated in order to establish a connection between the impairments and possible causative compound(s). Plasma levels of progesterone and 17α-hydroxyprogesterone were unaffected. Ovarian 17,20-lyase activity was decreased while levels of biliary steroid conjugates and hepatic testosterone UDP-glucuronosyltransferase activity did not differ between exposed and reference SM fish. Furthermore, the decreased brain aromatase activity seems to be a secondary effect; possibly a result of low substrate availability. Altogether, this suggests a possible disruption in the synthesis of androgens, knowledge that could be used as a tool in biomarker-directed fractionation studies to pinpoint compound(s). Molnbyggen sediment extracts decreased the testosterone and estradiol concentrations in whole-body homogenates of zebrafish (Danio rerio) after a three week exposure period. This suggests that compound(s) with the potency to alter endocrine function are present in the sediment. Although the first steps have been taken towards identifying compound(s) responsible for this kind of reproductive impairments, they still remain unidentified. Measures have to be taken to identify harmful chemicals in our society, to reduce their number, and to minimise their uncontrolled dispersal.

No description available.

The literature reviewed on lot-sizing models with random yields is limited to certain random occurrences such as day to day administrative errors, minor machine repairs and random supply due to faulty delivery of parts. In reality however, the manufacturing industry faces other risks that are non random in nature. One example would be yield discrepancies caused by non random triggers such as a change in the production process, product or material. Yield uncertainties of these types are temporary in nature and usually pertain until the system stabilizes. One way of reducing the implications of such events is to have additional batches processed earlier in the production that can absorb the risk associated with the event. In this thesis, this particular approach is referred to as the <i>anticipatory batch insertion</i> to mitigate perceived risk. This thesis presents an exploratory study to analyze the performance of batch insertion under various scenarios. The scenarios are determined by sensitivity of products, schedule characteristics and magnitude of risks associated with causal triggers such as a process change. The results indicate that the highest return from batch insertion can be expected when there are slightly loose production schedules, high volumes of sensitive products are produced, there are high costs associated with the risks, and the risks can be predicted with some degree of certainty.

The literature reviewed on lot-sizing models with random yields is limited to certain random occurrences such as day to day administrative errors, minor machine repairs and random supply due to faulty delivery of parts. In reality however, the manufacturing industry faces other risks that are non random in nature. One example would be yield discrepancies caused by non random triggers such as a change in the production process, product or material. Yield uncertainties of these types are temporary in nature and usually pertain until the system stabilizes. One way of reducing the implications of such events is to have additional batches processed earlier in the production that can absorb the risk associated with the event. In this thesis, this particular approach is referred to as the <i>anticipatory batch insertion</i> to mitigate perceived risk. This thesis presents an exploratory study to analyze the performance of batch insertion under various scenarios. The scenarios are determined by sensitivity of products, schedule characteristics and magnitude of risks associated with causal triggers such as a process change. The results indicate that the highest return from batch insertion can be expected when there are slightly loose production schedules, high volumes of sensitive products are produced, there are high costs associated with the risks, and the risks can be predicted with some degree of certainty.

Disruption is something that we must negotiate as part of our everyday lives. The context of disruption can vary in nature from being positive to being negative in nature. However, the emotional effects of the disruption have not been investigated in the social psychological literature. This study utilizes structuralized ritualization affect theory of social exchange, attribution theory, and the theory of relational cohesion in order to investigate the effects of disruption on the overall positive emotion of the actors involved and their feelings of cohesiveness with regard to their group.

Endocrine disrupting chemicals (EDCs) are a class of environmental toxicants, of both natural and synthetic origin, that interfere with normal endocrine function. Exposure to EDCs during susceptible periods of development, particularly embryogenesis, can result in profound neurological and reproductive deficits. While the impact of developmental exposure to EDCs on reproductive function and behavior has been much studied, the underlying mechanisms responsible for these observed effects are not well understood. The goal of the research detailed in this dissertation is to elucidate the cellular and molecular targets by which a representative class of EDCs, polychlorinated biphenyls (PCBs), disrupts normal reproductive neuroendocrine function. My specific hypothesis is that PCBs cause changes in sexually dimorphic brain regions underlying sex-specific reproductive physiology and behavior through the perturbation of normal developmental apoptosis, with long-term consequences for reproductive success. The studies detailed herein focus on three areas which contribute to an understanding of the effects of PCBs on neuroendocrine reproductive function: (1) the in vitro effects of PCBs on a neuroendocrine cell line, (2) developmental effects of PCBs on the gestationally exposed F1 generation, and (3) the physiological consequences of these developmental alterations for adult reproductive function. In the first section of this dissertation, the neurotoxic and endocrine disrupting effects of PCBs on a representative developing neuroendocrine cell model, the GT1-7 GnRH cell line, are investigated in time- and dose-response experiments. Treatment and dose-dependent effects are observed for GnRH peptide concentrations, cell viability, apoptotic and necrotic cell death, and caspase activation. In general, GnRH peptide levels are suppressed by high doses and longer durations of PCBs, and elevated at low doses and shorter time points. The suppression of GnRH peptide levels was partially reversed in cultures co-treated with the estrogen receptor antagonist ICI 182,780. All PCBs tested reduced viability and increased both apoptotic and necrotic cell death. The second section of this dissertation examines whether prenatal PCB exposure alters normal neuroendocrine development in the F1 generation, including sexual differentiation of the brain. Disruption of hypothalamic development is detectable as early as the day after birth (postnatal day (P) 1), as indicated by abnormal programmed cell death, and alterations in neuroendocrine gene and protein expression. The third section discusses the physiological impact of developmental PCB exposure on reproductive maturation and adult neuroendocrine function. Pubertal onset is advanced and estrous cyclicity irregular in PCB endocrine-disrupted females. Furthermore, sexual differentiation of female neuroendocrine systems is masculinized/defeminized. Collectively, these results suggest that the disrupted sexual differentiation of the POA can be detected as early as the day after birth, effects that may underlie the adult reproductive phenotype. / text

In a world economy where globalization reaches almost every corner, the need for a company to attain flexibility has acquired tremendous importance to remain competitive and profitable. This Thesis would present the importance of flexibility in times of uncertain conditions (natural and socio-economic), it would present an analysis of the struggle of Toyota Motors Manufacturing Texas and one of its on-site suppliers Futaba Industrial Texas “FIT” to attain Manufacturing Flexibility through different economic crisis and a natural disaster presenting its strategies to mitigate economic losses and cope with the turbulent environment by developing robust systems. / text