No description available.

Worldwide water distribution infrastructure system is old and deteriorating. A water system with its myriad appurtenances (including pumps and valves and tanks) is susceptible to hydraulic transients resulting in high and low pressure waves alternatively passing through the network. While both low and high pressure events structurally tax the already weak system, there is copious evidence indicating intrusion of contaminants into the drinking water pipes from the pipe's exterior environment due to low pressure events associated with water hammer phenomenon. These contaminants enter into the drinking water as the home plumbing system is a passive recipient from the water main. While the major (municipal) system is readily recognized as a vast infrastructure system of nearly 1,409,800 km of piping within the United States, the minor (plumbing) system that is at least 5 to 10 times larger is generally not well analyzed. In this study, an experimental plumbing rig was designed and implemented that replicates the range of pressures encountered in actual minor water distribution systems. This research addresses how a pressure transient triggered within a house and from municipal systems can impact the service line with a possible suction effect. Experimental results on low pressure events and the accompanying numerical modeling showed good agreement. The experiment also enabled visualization of the various pressure transient phenomena. It is demonstrated that hydraulic transients triggered from water mains result in low pressures events (up to -10 psig) in service lines which can allow possible intrusion of microbial and chemical contaminants at the service line. Structural integrity of service line and hydraulic integrity at water mains should be maintained to minimize any public health risks. In the USA, about 90% of residential drinking water plumbing systems use copper pipes. Pinhole leaks in copper plumbing pipes have become a nationwide concern because these leaks cause property damage, lower property values, and result in possibility of adversely affecting homeowners' insurance coverage. In addition, resulting mold damage may cause health concerns. This research also addresses the concerns of the affected homeowners by enabling them to decide on whether to continue to repair or replace their plumbing system, the factors to be considered in a replacement decision, and the type of material to use for replacement. Plastic pipes such as PEX (cross-linked polyethylene), CPVC (Chlorinated Polyvinyl Chloride), and copper are considered in present analysis. Other alternatives include an epoxy coating technique on the existing piping systems, without the need to tear into walls. Multiple attributes of a plumbing system including cost (material plus labor charges), taste and odor impacts, potential for corrosion, longevity of the pipe system, fire retardance, convenience of installation or replacement, plumber or general contractor's opinions or expertise, and proven record in the market are considered. Attributes and material rankings are formalized within the framework of the preference elicitation tools namely AHP (Analytical Hierarchical Process). Surveys are conducted with selected homeowners in pinhole leak prone area in Southeastern US Community to observe their revealed and stated preferences. Participants' overall preference tradeoffs are reported in addition to comparing their revealed and stated preferences. Health effects, taste and odor of water turned out to be the most important factors from the survey. In real life, however, homeowners were not well aware of these safety issues related with plumbing materials. It is recommended that water professionals should work on bridging the gap between public perception and research results related to major and minor systems. / Ph. D.

Emerging infectious diseases can exert strong selection on hosts to evolve resistance or tolerance to infection. However, it remains unknown whether the evolution of specific defense strategies against a novel pathogen influences host immune phenotypes more broadly, potentially affecting their ability to respond to other pathogens. In 1994 the bacterial pathogen, Mycoplasma gallisepticum (MG) jumped from poultry into house finches, causing severe conjunctivitis and reducing host survival. MG then spread across the continental United States, exerting strong selection on host populations and creating geographic variation in the degree of population co-evolutionary history with the pathogen. Prior work found that populations of house finches with longer histories of MG endemism have evolved tolerance and resistance to MG, and this evolution is associated with several immunological differences including reductions in pro-inflammatory immune responses. However, it remains unknown whether these immunological changes are limited to MG-specific defenses or whether broader immune responses differ between populations with distinct coevolutionary histories with MG. To examine possible effects of the evolution of host responses to MG, we used five immune assays to challenge house finches from four populations, ranging from no history of MG endemism to 20+ years of MG endemism. When challenged with phytohemagglutinin (PHA), populations differed significantly in the strength of wing web swelling, with populations with longer MG exposure (and thus the highest MG tolerance) on average exhibiting the weakest swelling response when mass differences were controlled for. However, detected population differences in wing web swelling were small, and population differences were absent for responses to four other immune assays that spanned components of the innate and adaptive immune system. Future work should examine whether the local inflammation that underlies swelling responses to PHA shares common immunological mechanisms with local inflammatory responses to MG, which may explain why populations with evolved tolerance to MG show slightly lower swelling responses in response to PHA. Overall, these results suggest that the evolution of MG tolerance may have minor downstream consequences for responses to certain antigens, with the potential to influence a host's ability to respond to novel pathogen challenges, but most components of the host immune system appear largely unaffected. / Master of Science / Emerging infectious diseases can have devasting effects on new host species. To reduce the cost of these pathogens, host species can evolve ways to eliminate infection (resistance) or reduce damage during infection (tolerance), which is often caused by the host's immune system itself. As populations evolve these disease strategies, it is likely that other aspects of the immune system will also be affected, potentially compromising the ability of hosts to respond to pathogens other than the ones they evolved defenses against. We examined what sort of trade-offs might arise as house finches evolved resistance and tolerance to a new deadly pathogen, Mycoplasma gallisepticum (MG). House finch populations in the mid-Atlantic were first exposed to the disease in 1994, and as the disease spread across the continental United States, different populations have been exposed for different periods of time. This created a gradient in whether certain populations have had long enough time with MG to evolve disease strategies. Populations that have been exposed to MG for longer appear to have evolved both resistance and tolerance, and tolerant populations show lower levels of inflammatory immune markers that can be associated with self-damage. Using house finches from four different populations (ranging from 25 years of exposure history to zero years of MG exposure history), we tested a variety of immune system components to examine what areas of the immune system might have been broadly affected by the evolution of resistance and tolerance. We hypothesized that birds from populations with evolved MG tolerance would also have a reduced inflammation response when stimulated with substances that mimic infection by something other than MG. Only one assay supported this hypothesis. Birds from populations that had been exposed to MG for a longer period of time (and thus had evolved MG tolerance) had a reduced swelling response following injection with a plant protein called phytohemagglutinin. However, there were no population differences observed with the other four assays, suggesting that evolving defenses against MG did not result in widespread immunological effects. This suggests that the evolution of host defenses against an emerging pathogen may not compromise that host's ability to respond effectively to other types of pathogens that they encounter in nature.

There is a gap between intention and action that people experience when faced with protecting their digital data privacy. Known as the privacy paradox, it is the idea that what a person says they believe (protecting their data privacy is paramount) is not reflective of how they act (relinquishing their data privacy). In other words, what people express about their data privacy is often in opposition to the frequency with which they relinquish their data privacy. The research intends to examine the privacy paradox and consists of two studies, one qualitative and one quantitative. First, focus groups were held, the outcome of which was an attempt at the creation of a typology of words and phrases that consumers use relative to their data privacy. Second, an experiment using Likert scales and Pareto-optimal choice-based conjoint analysis was created based on the typology created in study one, giving insight into what consumers feel are motivators towards protecting or relinquishing their data privacy. The contribution is filling a gap in the existing literature related to the privacy paradox through an analysis of behavior. / Business Administration/Marketing

No description available.

Made available in DSpace on 2016-06-02T19:52:16Z (GMT). No. of bitstreams: 1 DissLBC.pdf: 757320 bytes, checksum: ac46c58fc642c6337262637abfef3a65 (MD5) Previous issue date: 2006-02-21 / Universidade Federal de Sao Carlos / Nowadays, the countrys development is based on science, tecnology and inovation. Because of this, the society is demanding that the university, one of the most important sources of that resources, acts transfering the results of its researches to the market. There are several ways to transfer the tecnology from university to the industry. One of them, that is emerging as an important mechanism, is the creation of firms from results of researches generated in the university (the academic spin-offs). Therefore, in Brasil there are few studies about this mechanism of university-company cooperation. Indenting to improve this situation, the present study mains to exihibit the profile of academic spin-offs from Brazil, showing its characteristics, motivations, difficulties and the opinion of spin-off owners. The methodology used was the quantitative research and the data was collected through questionnaires sent to 33 spin-offs companies from 9 universities. One important result obtained shows that just three companies have university s patents. / Atualmente, o desenvolvimento dos países é baseado na ciência, tecnologia e inovação.Por causa disto, a sociedade está demandando que a universidade, uma das mais importante fonte destes recursos, aja transferindo os resultados de suas pesquisas para o mercado. Existem diversas maneiras de transferi-los para o setor empresarial. Uma delas, que está emergindo com um destaque relevante, é a criação de empresas a partir de resultados de pesquisas geradas nas universidades (spin-offs acadêmicos). Entretanto, no Brasil há poucos estudos sobre este tipo de mecanismo de cooperação universidade-empresa. Buscando melhorar esta situação, o presente estudo objetiva apresentar o perfil dos spin-offs acadêmicos brasileiros, mostrando suas características, motivações, dificuldades e a opinião dos sócios destas empresas. A metodologia usada foi a pesquisa quantitativa e os dados foram coletados através de questionários enviados a 33 spin-offs de 9 universidades. Um importante resultado obtido mostra que, apesar de serem oriundas do meio acadêmico, somente três empresas têm patentes licenciadas pelas universidades.

Submitted by Nadir Basilio (nadirsb@uninove.br) on 2016-06-06T20:18:36Z No. of bitstreams: 1 Roberta Manfron De Paula.pdf: 1643854 bytes, checksum: d93f309ade3f7e24170ba83cea16e858 (MD5) / Made available in DSpace on 2016-06-06T20:18:36Z (GMT). No. of bitstreams: 1 Roberta Manfron De Paula.pdf: 1643854 bytes, checksum: d93f309ade3f7e24170ba83cea16e858 (MD5) Previous issue date: 2015-08-18 / The main goal of this thesis was to understand the entrepreneur spin-offs phenomenon – that is, the new companies settled up by workers that drop of the companies where they worked previously in order to build up their own companies – as a start up to understand the impact of the genealogic effects in regional dynamics. This research describes a single scenario that can be very useful in an effort to understand what can cause people reasons to create new companies and so forth, identify the coming up of a cluster. In this direction, some research problems were settled: What is really known about spin-offs and what main books and theories have caused some impact on researches about spin-offs? Is it possible to observe what the genealogy features of a cluster not so sophisticated technologically saying and relatively recent in Brazil are? What are the features, on the settled industries, which are the so called mother companies that contribute to cause entrepreneur spin-offs? In order to do so, I performed three studies with distinct approaches. However, in the context, they explain and complement the goals and the research questions, consolidating the theories, contexts, genealogy and features of the mother firm in bringing up the entrepreneur spin-offs. The first study was about an analysis converging resources to bibliometric techniques and procedures about existing international literature. The sample about this study came up with 812 articles published in international journals. The analysis of citations and co-citations were used and complemented by a factorial analysis, providing a presentation of a structural and longitudinal component of the publications, which made easy to comprehend how the research has evolved among the years. The published studies allowed identifying the main theoretical frames that basis the spin-offs phenomenon, as well as, a group of interest variables to better understand the phenomenon. The second study aimed to identify the existence of entrepreneur spin-offs in a small Brazilian cluster – to which I focused on the knitting companies cluster in Monte Sião. This genealogy study came up with a sample of 232 companies, with data gathered through structured questionnaire. The third study, a statistical empiric one, was supported on data gathered through questionnaire, and came up with a sample of 103 companies. This study aimed to identify a group of features of the settled companies in order to verify which are the mother firms features able to generate new entrepreneur spin-offs. The main results of the three studies show that research on spin-offs phenomenon has evolved over the years to different scenarios, the analysis of cocitações have highlighted the theoretical ties that consolidate authors in certain research environments. It has been strongly highlighted the academic context favoring the generation of spin-offs through knowledge transfer, innovation and entrepreneurship. It was also identified the way was the seed companies, recognizing six different types of undertakings contained in the cluster, active mothers firms, inactive mothers firms, formal spin-offs, spin-offs of several mothers, informal spin-offs and traditional firms, complementing the results also confirm that it is possible by the attributes of mothers firms generate spin-offs entrepreneurs, thus validating the model.This thesis contributing in causing a global literature perspective about spin-offs, with special emphasis to the Theory of Cost Transaction, Theory of Agency, Resources Based View and its variant Knowledge based View. It also contributes to better understanding the entrepreneur spin-offs and the genealogic effects that provide nuances about the located concentrations of the companies. Presenting the genealogic tree of a cluster can inspire researchers to try to understand the relations among mother-companies and spin-offs to create new companies, so empowering a specific cluster. Finally, it contributes to identify the main factors to generate entrepreneur spin-offs through the attributes of the mother-firms. It is mainly interesting the fact that environments presenting low technologic resources and a small and medium companies dimension can also be prone to entrepreneur dynamics. / O propósito central desta tese foi entender o fenômeno de spin-offs empreendedoras – ou seja, das novas empresas que são criadas por trabalhadores que saem das empresas onde trabalham para constituir a sua própria empresa – sendo um ponto de partida para entender o impacto dos efeitos genealógicos nas dinâmicas regionais. Este estudo descreve um quadro singular, que pode ser útil no esforço para entender as motivações para criação de novas empresas e assim, identificar o surgimento de um cluster. A tese foi, assim, orientada pelos seguintes problemas de pesquisa. Qual o estoque de conhecimento acumulado sobre spin-offs e quais as principais obras e teorias utilizadas têm impactado nas pesquisas sobre spin-offs? Podemos observar como se caracteriza a genealogia de um cluster tecnologicamente pouco sofisticado e relativamente recente no Brasil? Quais os atributos, ou características, ao nível das empresas estabelecidas, que designamos por empresas-mães, que contribuem para a geração de spin-offs empreendedoras? Para o efeito realizei três estudos com abordagens distintas, mas que conjuntamente explicam e complementam os objetivos e a problemática de pesquisa, consolidando assim as teorias, contextos, genealogia e características das empresas mães na geração de spin-offs empreendedoras. O primeiro estudo consistiu numa análise, com recursos a técnicas e procedimentos bibliométricos, da literatura internacional existente. A amostra do estudo bibliométrico elucidou 812 artigos publicados em periódicos internacionais. As análises de citações e co-citações foram utilizadas e complementadas por análise fatorial, possibilitando assim apresentar um componente estrutural e longitudinal das publicações facilitando a compreensão de como a pesquisa evoluiu ao longo dos anos. Os estudos publicados proporcionaram identificar as principais correntes teóricas que sustentam o fenômeno spin-offs e um conjunto de variáveis de interesse para melhor entender o fenômeno. O segundo estudo buscou identificar a existência de spin-offs de carácter empreendedor num pequeno cluster brasileiro – recorri ao caso do cluster de malharias de Monte Sião. Este estudo de genealogia obteve uma amostra de 232 malharias, com dados coletados por questionário estruturado. O terceiro estudo, de natureza empírica estatística, foi sustentado em dados coletados por questionário, e alcançou uma amostra de 103 malharias. Este estudo visou identificar um conjunto de características das empresas estabelecidas de modo a aferir quais as características das empresas-mãe que potencializam a geração de novas spin-offs empreendedoras. Os principais resultados dos três estudos apontam que a pesquisa sobre o fenômeno spin-offs tem evoluído ao longo dos anos para cenários distintos, as análises de cocitações permitiram evidenciar os laços teóricos que consolidam autores em determinados ambientes de pesquisa. Tem-se fortemente evidenciado o contexto acadêmico favorecendo a geração de spin-offs por meio de transferência de conhecimento, inovação e empreendedorismo. Identificou-se também à forma como ocorreu a descendência das empresas, reconhecendo seis tipos diferentes de empresas constantes no cluster, empresas mães ativas, empresas mães inativas, spin-offs formais, spin-offs de várias mães, spin-offs informais e empresas tradicionais, complementando, os resultados também confirmam que é possível pelos atributos das empresas mães gerarem spin-offs empreendedoras, validando assim o modelo proposto. Esta tese contribui para proporcionar uma perspectiva global da literatura de spin-offs, onde se destacaram a Teoria dos Custos de Transação, Teoria da Agência, Visão Baseada em Recursos e sua variante Visão Baseada no Conhecimento. Também contribui para entender melhor as spin-offs empreendedoras e os efeitos genealógicos que matizam as concentrações localizadas de empresas. Apresentar a árvore genealógica de um cluster inspira pesquisadores buscar entender as relações entre empresas-mães e spin-offs para criação de novas empresas fortalecendo assim um determinado cluster. Finalmente, contribui para identificar os fatores relevantes para geração de spin-offs empreendedora a partir dos atributos das empresas-mães. É particularmente interessante à revelação de que em ambientes de baixa intensidade tecnológica, matizados por um tecido empresarial de média e pequena dimensão também é propício para dinâmicas empreendedoras.

Résumé : La reproduction entraîne des dépenses énergétiques importantes chez les femelles mammifères. Ces dépenses sont supposées diminuer l'énergie disponible pour d'autres traits positivement corrélés à l'aptitude phénotypique et augmenter les besoins d'alimentation. Toutefois, des différences individuelles dans la capacité d'acquisition et d'allocation peuvent masquer l'impact négatif de l'effort reproducteur. La manipulation expérimentale de l'effort reproducteur et le contrôle statistique des effets individuels sont deux approches puissantes et complémentaires mises en œuvre dans le cadre de mon étude afin de contrôler pour l'hétérogénéité individuelle. Elles ont permis de montrer clairement un coût de la reproduction chez le kangourou gris de l'Est (Macropus giganteus). Dans un premier temps, nous avons trouvé que le coût de la reproduction affectait le montant d'énergie alloué à certaines fonctions somatiques (CHAPITRE I). L'effort reproducteur diminuait le gain de masse et la croissance des jambes pour des intervalles de capture supérieurs à deux ans. Chez les femelles non manipulées, un effet négatif sur le gain de masse était aussi observable pour un intervalle inférieur à 3 ans. À l'échelle de deux événements successifs de reproduction, le gain de masse et dans une moindre mesure la croissance des bras, mais non des jambes diminuaient avec un effort reproducteur plus important à la précédente reproduction. Ensuite, nous avons démontré qu'il y avait un coût de la reproduction en terme de futur succès reproducteur (CHAPITRE II). Les individus dont l'effort reproducteur avait été diminué expérimentalement produisaient davantage de jeunes qui survivaient au stade 'LPY', âgés approximativement de 7 mois, que les femelles contrôles. Ils diminuaient également davantage leur taux de reproduction en allongeant l'intervalle entre les naissances, mais la survie au sevrage n'était pas affectée. Le CHAPITRE III montre que les femelles adaptaient leur comportement alimentaire en fonction de leur statut reproducteur. En comparaison avec les individus manipulés ou ayant perdu leur jeune, les femelles allaitantes augmentaient leur temps passé à s'alimenter durant la journée, l'intensité de leurs bouchées et de leur mastication sans impliquer de compromis avec la vigilance. Nous avons aussi découvert que la survie au sevrage du jeune précédent menait à une augmentation du taux de bouchées pour l'année en cours. Les CHAPITRES I et II ont mis en évidence l'effet non négligeable des différences individuelles sur la détection des coûts de la reproduction. En effet, en l'absence de manipulation expérimentale ou de contrôle statistique, aucun compromis n'était détecté autant en terme de croissance que de prochaine reproduction. Au contraire, des corrélations positives entre l'effort reproducteur et les autres traits ont été trouvées. Le CHAPITRE I suggérait notamment que cette variabilité du succès reproducteur était liée à l'hétérogénéité individuelle dans le gain de masse maternelle qui augmentait la survie du jeune. Dans le CHAPITRE II, une corrélation positive entre les probabilités d'avoir un 'LPY' lors de deux événements successifs de reproduction suggérait que certaines femelles étaient capables de mener à bien ou non leur reproduction, mais cela indépendamment de l'effort reproducteur précédent. Enfin dans le dernier CHAPITRE (III), l'effet aléatoire était significatif dans l'analyse de différents comportements d'alimentation, ce qui pourrait être lié aux différences de gain de masse des femelles présentées dans le CHAPITRE I. Certaines contraintes individuelles affectant le coût de la reproduction ont été identifiées. La masse et la condition corporelle augmentaient le succès reproducteur et diminuaient l'intervalle entre deux naissances successives (CHAPITRES I et II), mais contrairement à de précédentes études le comportement d'alimentation des femelles n'était pas affecté par leur masse (CHAPITRE III). L'âge des individus avait également une influence. Les jeunes femelles croissaient davantage, avaient aussi une prise alimentaire plus importante et subissaient un coût de reproduction supérieur. Ce dernier se traduisait par un taux d'échec plus élevé à la reproduction suivante si les jeunes femelles avaient eu un jeune l'année précédente (CHAPITRES I, II et III). Des contraintes environnementales fortes influençaient la reproduction des femelles. La croissance, le succès reproducteur, l'intervalle entre les naissances et les comportements d'alimentation variaient suivant le site et l'année d'étude. Le site du Promontory et l'année 2011 apparaissaient particulièrement limitants. En effet en 2011, le gain de masse et le succès reproducteur ont diminué et l'intervalle de naissance et la prise de nourriture pour les femelles allaitantes ont augmenté (CHAPITRE I,II et III). Nous cherchions également à mettre au jour une allocation différentielle des mères suivant le sexe de leur jeune. Si le coût supérieur d'avoir un mâle par rapport à une femelle était évident quant aux taux de bouchées (CHAPITRE III), il s'est avéré plus difficile à détecter sur d'autres traits. À Anglesea, les jeunes mères avaient moins de probabilité d'avoir un jeune qui atteigne le stade 'LPY' après avoir eu un fils qu'une fille (CHAPITRE II). Toutefois, des résultats contraires à nos attentes ont été trouvés, du moins au premier abord, sur la croissance et le succès reproducteur subséquent. Ainsi, les femelles qui avaient eu une fille perdaient davantage de masse (CHAPITRE I) et avaient généralement une probabilité moindre de produire un jeune qui atteigne le stade 'LPY' ou qui soit sevré par la suite (CHAPITRE II). En revanche, l'intervalle de naissance n'était pas différent suivant le sexe du jeune alors qu'il était fortement affecté par le coût de la reproduction démontré grâce à la manipulation, invoquant une autre explication qu'un coût supérieur des filles par rapport aux fils. En effet, les femelles qui étaient en mauvaise condition corporelle gagnaient de la masse quand elles produisaient une fille, mais pas un fils (CHAPITRE I). De surcroît, les jeunes mères avaient moins de chances de sevrer un jeune à l'événement de reproduction suivant si elles avaient eu un fils plutôt qu'une fille, et le succès reproducteur des mères des fils n'était plus différent de celui des mères des filles dans les années plus difficiles (CHAPITRE II). Enfin, les mères des fils augmentaient la quantité de nourriture ingérée si elles avaient sevré un jeune l'année précédente, mais les mères des filles la diminuaient. Ces différents résultats suggéraient fortement qu'un ajustement du sexe-ratio était utilisé quand les ressources individuelles ou environnementales contraignaient davantage la reproduction. En conclusion, pour limiter le décalage entre les besoins énergétiques et la disponibilité en nourriture, les femelles chez le kangourou gris de l'Est pourraient modifier l'allocation de leurs ressources à la reproduction en reportant la prochaine mise bas et en produisant un jeune du sexe le moins coûteux en accord avec les contraintes individuelles et environnementales. Ces résultats soulignent l'importance d'études avec un suivi individuel sur plusieurs années afin de pouvoir comprendre la variabilité des stratégies de reproduction et leurs conséquences sur la dynamique des populations. // Abstract : Reproduction in living beings, particularly in female mammals that produce milk, is costly, potentially involving trade-offs with life-history traits if resources are limited and an increase in foraging effort. Individual differences may, however, hide the negative effects of this cost on life-history traits. I used two powerful and complementary approaches, to deal with individual heterogeneity: experimental manipulation of reproductive effort and statistical control of individual effect. Using both approaches, I investigated the effect of presence, size and sex of young on growth, subsequent reproduction and individual foraging behaviours of females. I used data of tagged free-ranging eastern grey kangaroos (Macropus giganteus) collected over six years at five study sites in Victoria, Australia. There was a clear cost of reproduction. Reproductive effort decreased mass gain and limb growth for inter-capture intervals greater than two years. Over two successive reproductive events, mass gain and arm growth were reduced but leg growth was independent of reproductive effort (CHAPTER II).In addition, survival to Large Pouch Young ('LPY') stage, about 7 months of age, was higher and birth rate lower in manipulated compared to control females but survival to weaning was not affected (CHAPTER III). CHAPTER IV shows that lactating females cope with current reproductive costs by increasing ivtime spent foraging as well as bite and chewing rates without decreasing vigilance comparedto non lactating ones. Bite rate was also greater for females that weaned a young at the previous reproductive event. My study supports reproductive cost hypothesis while showing substantial individual differences. To limit mismatch between energetic needs and resource availability, females of eastern grey kangaroo could modify resource allocation to reproduction by delaying birth date of subsequent young and producing the less costly sex according to individual and environmental constrains. My thesis shows the importance of experimental approach and individual monitoring over multiple years to understand the diversity of reproductive strategies and their consequences in evolutionary ecology and population dynamic.

The trade-off between gametes and soma is central to life-history evolution. Oosorption has been proposed as a mechanism that can mediate this trade-off. When conditions are not conducive to successful reproduction, females are expected to be able to recoup nutrients from unfertilized oocytes and reinvest them into the somatic processes that promote survival and hence future reproduction. Although positive correlations between oocyte degradation and lifespan have been documented in oviparous insects, the adaptive significance of this process in species with more complex reproductive biology has not been explored. Oocyte degradation via apoptosis (programmed cell death) occurs in response to enforced virginity in females of the ovoviviparous cockroach, Nauphoeta cinerea. Observed apoptosis may represent oosorption, however, an alternative but not mutually exclusive argument is that oocyte apoptosis may represent oocyte ageing and clearance in order to maintain reproductive synchrony. The aim of this thesis was to test the hypothesis that the function of oocyte apoptosis is oosorption in N. cinerea. I found that in addition to enforced virginity, starvation induces oocyte apoptosis. However, the life history outcome following one form of stress is the opposite of the other. Hence, the functional role of oocyte apoptosis appears to be different depending on whether apoptosis is induced through starvation or age. Following a period of starvation-induced apoptosis females exhibit the increase in survival and future reproduction predicted by oosorption. Whereas, following a period of age-induced apoptosis females suffer fecundity and longevity cuts. However, age-induced apoptosis does not appear to simply be cellular ageing and clearance. In conjugation with age-induced apoptosis, ovariole number declines whilst the size of surviving oocytes increases. Hence, it appears that resources from sacrificed oocytes are being recycled into the survivors, and that this reinvestment in current reproduction trade-offs with future reproductive capacity. My thesis shows the importance of studying proximal mechanisms alongside more traditional measures of life history, as the relationship between isolated biological levels is not always clear.

Prior to Statement of Financial Accounting Standards No.121 (SFAS No.121): Accounting for the Impairment of Long-Lived Assets and Long-Lived Assets to Be Disposed Of, managers had substantial discretion concerning the amount and timing of reporting writedowns of long-lived assets. Moreover, the frequency and dollar amount of asset writedown announcements that led to a large “surprise” caused the Financial Accounting Standards Board (FASB) and the Securities and Exchange Commission (SEC) to consider the need for a new standard to guide the recording of impairment of long-lived assets. This study has two primary objectives. First, it investigates the effects of SFAS No.121 on asset impairment reporting, examining whether SFAS No.121 reduces the magnitude and restricts the timing of reporting asset writedowns. Second, the study compares the information content (surprise element) of the asset impairment loss announcement as measured by cumulative abnormal returns (CAR) before and after the issuance of SFAS No.121. The findings provide support for the hypothesis that the FASB's new accounting standard does not affect the magnitude of asset writedown losses. The findings also provide support for the hypothesis that SFAS No. 121 does not affect the management choice of the timing for reporting asset writedowns. In addition, the findings suggest that the market evaluates the asset writedown losses after the issuance of SFAS No. 121 as good news for “big bath” firms, while, for “income smoothing” firms, the market does not respond to the announcements of asset writedown losses either before or after the issuance of SFAS No. 121. The findings also suggest that, for “big bath” firms, the market perceives the announcement of asset impairment losses after the adoption of SFAS No. 121 as more credible relative to that before its issuance. This could be because the practice of reporting asset writedowns after the issuance of SFAS No. 121 is under the FASB's authoritative guidance, which brings consistency and comparability in asset impairment reporting.