Quality of life and general health in patients with temporomandibular disorders

The aim of this study was to associate minor psychiatric disorders (general health) and quality of life with temporomandibular disorders (TMD) in patients diagnosed with different TMD classifications and subclassifications with varying levels of severity. Among 150 patients reporting TMD symptoms, 43 were included in the present study. Fonseca's anamnestic index was used for initial screening while axis I of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC-TMD) was used for TMD diagnosis (muscle-related, joint-related or muscle and joint-related). Minor psychiatric disorders were evaluated through the General Health Questionnaire (GHQ) and quality of life was assessed using the World Health Organization Quality Of Life-Brief Version (WHOQOL-BREF). An association was found between minor psychiatric disorders and TMD severity, except for stress. A stronger association was found with mild TMD. Considering TMD classifications and severity together, only the item "death wish" from the GHQ was related to severe muscle-related TMD (p = 0.049). For quality of life, an association was found between disc displacement with reduction and social domain (p = 0.01). Physical domains were associated with TMD classifications and severity and the association was stronger for muscle and joint-related TMD (p = 0.37) and mild TMD (p = 0.042). It was concluded that patients with TMD require multiple focuses of attention since psychological indicators of general health and quality of life are likely associated with dysfunction.

A Study of How Economic Attitudes Are Shaped by Environmental Shocks and Life Experiences

Social attitudes, attitudes toward financial risk and attitudes toward deferred gratification are thought to influence many important economic decisions over the life-course. In economic theory, these attitudes are key components in diverse models of behavior, including collective action, saving and investment decisions and occupational choice. The relevance of these attitudes have been confirmed empirically. Yet, the factors that influence them are not well understood. This research evaluates how these attitudes are affected by large disruptive events, namely, a natural disaster and a civil conflict, and also by an individual-specific life event, namely, having children.

By implementing rigorous empirical strategies drawing on rich longitudinal datasets, this research project advances our understanding of how life experiences shape these attitudes. Moreover, compelling evidence is provided that the observed changes in attitudes are likely to reflect changes in preferences given that they are not driven just by changes in financial circumstances. Therefore the findings of this research project also contribute to the discussion of whether preferences are really fixed, a usual assumption in economics.

In the first chapter, I study how altruistic and trusting attitudes are affected by exposure to the 2004 Indian Ocean tsunami as long as ten years after the disaster occurred. Establishing a causal relationship between natural disasters and attitudes presents several challenges as endogenous exposure and sample selection can confound the analysis. I take on these challenges by exploiting plausibly exogenous variation in exposure to the tsunami and by relying on a longitudinal dataset representative of the pre-tsunami population in two districts of Aceh, Indonesia. The sample is drawn from the Study of the Tsunami Aftermath and Recovery (STAR), a survey with data collected both before and after the disaster and especially designed to identify the impact of the tsunami. The altruistic and trusting attitudes of the respondents are measured by their behavior in the dictator and trust games. I find that witnessing closely the damage caused by the tsunami but without suffering severe economic damage oneself increases altruistic and trusting behavior, particularly towards individuals from tsunami affected communities. Having suffered severe economic damage has no impact on altruistic behavior but may have increased trusting behavior. These effects do not seem to be caused by the consequences of the tsunami on people’s financial situation. Instead they are consistent with how experiences of loss and solidarity may have shaped social attitudes by affecting empathy and perceptions of who is deserving of aid and trust.

In the second chapter, co-authored with Ryan Brown, Duncan Thomas and Andrea Velasquez, we investigate how attitudes toward financial risk are affected by elevated levels of insecurity and uncertainty brought on by the Mexican Drug War. To conduct our analysis, we pair the Mexican Family Life Survey (MxFLS), a rich longitudinal dataset ideally suited for our purposes, with a dataset on homicide rates at the month and municipality-level. The homicide rates capture well the overall crime environment created by the drug war. The MxFLS elicits risk attitudes by asking respondents to choose between hypothetical gambles with different payoffs. Our strategy to identify a causal effect has two key components. First, we implement an individual fixed effects strategy which allows us to control for all time-invariant heterogeneity. The remaining time variant heterogeneity is unlikely to be correlated with changes in the local crime environment given the well-documented political origins of the Mexican Drug War. We also show supporting evidence in this regard. The second component of our identification strategy is to use an intent-to-treat approach to shield our estimates from endogenous migration. Our findings indicate that exposure to greater local-area violent crime results in increased risk aversion. This effect is not driven by changes in financial circumstances, but may be explained instead by heightened fear of victimization. Nonetheless, we find that having greater economic resources mitigate the impact. This may be due to individuals with greater economic resources being able to avoid crime by affording better transportation or security at work.

The third chapter, co-authored with Duncan Thomas, evaluates whether attitudes toward deferred gratification change after having children. For this study we also exploit the MxFLS, which elicits attitudes toward deferred gratification (commonly known as time discounting) by asking individuals to choose between hypothetical payments at different points in time. We implement a difference-in-difference estimator to control for all time-invariant heterogeneity and show that our results are robust to the inclusion of time varying characteristics likely correlated with child birth. We find that becoming a mother increases time discounting especially in the first two years after childbirth and in particular for those women without a spouse at home. Having additional children does not have an effect and the effect for men seems to go in the opposite direction. These heterogeneous effects suggest that child rearing may affect time discounting due to generated stress or not fully anticipated spending needs.

Mellanchefers upplevelser av psykosocial arbetsmiljö inom distributions- och logistikverksamhet – en pendling mellan hög aktivitet och låg stress?

Forskarnas genuina intresse för den psykosociala arbetsmiljön med koppling mellanchefer gav upphov till att dyka djupare inom området och belysa centrala delar i form av krav, kontroll och socialt stöd. Framåtskridandet går mot en ökad medvetenhet kring den psykosociala arbetsmiljön, då ohälsan i arbetslivet ökar och Arbetsmiljöverkets nya föreskrift om organisatorisk och social arbetsmiljö är i fokus. I linje med en ökad medvetenhet som sker kring den psykosociala arbetsmiljön vill vi rikta ett särskilt fokus till mellanchefer som bör ha en förmåga att hantera krav både uppifrån och ned. Studien har främst utgått från Robert Karaseks och Töres Theorells Krav – kontroll – stödmodellen. Syftet är att undersöka mellanchefers upplevelse med fokus på den psykosociala arbetsmiljön i ett privat företag inom distributions- och logistikverksamhet. Metoden har bestått av en kvalitativ metod i form av en fallstudie där semistrukturerade intervjuer ligger som grund med åtta respondenter ifrån distributionscentret. Resultatet uppvisar att mellancheferna har en hög grad av inflytande, upplevelsen av arbetskrav varierar men i koppling till befattningen är kraven rimliga. Det sociala stödet upplevs som bra på arbetsplatsen och anses av funktionscheferna som en viktig och central del i arbetet. Slutsatser som har uppnåtts är att funktionscheferna har rimliga krav och upplever en bra nivå av kontroll i arbetet, men att ha en alltför hög kontroll i arbetet kan leda till negativ stress. En balans i pendlingen mellan aktiva arbeten och lågstressarbeten anses vara en fördel för att bevara en god psykosocial arbetsmiljö. Detta för att motverka de negativa effekterna som kan uppstå av att befinna sig inom varje komponent för länge. I studien har det påvisats att företaget anses ha en god psykosocial arbetsmiljö och därmed kan ses som ett gott exempel i arbetslivet.

Stress e Emergência Médica: níveis e factores de stress em profissionais de emergência pré–hospitalar

O stress é a doença da actualidade, devido à exigência e à pressão emocional que o meio pode exercer sobre todas as pessoas, quer no seu ambiente pessoal quer no ambiente profissional. O termo stress serve cada vez mais como justificação ou forma de expressão de irritações, mal-estar físico e mental, cansaço, ansiedade e depressões. Todavia torna-se pertinente percebermos a evolução do stress enquanto conceito e enquanto doença. Neste trabalho contextualizamos o stress no âmbito da Emergência Pré – Hospitalar, explorando-o, avaliando-o e analisando-o, de modo a podermos perceber os níveis de stress e de que forma os Profissionais de Emergência a ele estão sujeitos. Considerando a base teórica deste estudo definimos, como objectivo geral do trabalho, a avaliação de níveis e factores de stress percepcionados pelos profissionais de emergência médica e como objectivos específicos do estudo a descrever e caracterizar, a nível da região centro, os indivíduos que desempenham funções na emergência préhospitalar, verificar a percepção dos mesmos no que respeita ao stress na sua vida profissional, conhecer como percepcionam os níveis de stress em situações profissionais de emergência e identificar a sua percepção no que concerne aos níveis de stress diário no seu quotidiano. Com estes objectivos, utilizamos uma amostra de 184 profissionais de Emergência Médica divididos por quatro profissões [Médicos, Enfermeiros, Técnicos de Ambulância de Emergência (TAE) e Operadores de Central de Emergência Médica(OPCEM)], com idades compreendidas entre os 20 e os 56 anos. Realizámos ainda um estudo descritivo explorando os questionários de stress no INEM (Instituto Nacional de Emergência Médica) e o Questionário de Vulnerabilidade do Stress com variáveis do estudo demográfico. Podemos concluir que o stress está presente nas actividades de emergência. A sua presença relaciona-se, por um lado, com uma maior ou menor discriminação dos factores stressantes e, por outro, numa maior ou menor centração no sujeito, nomeadamente, um maior perfeccionismo e intolerância à frustração que se apresentam como distressantes para a actividade profissional de emergência. Os aspectos estudados permitem-nos clarificar o sentido e a utilidade do conceito, a sua operacionalidade e a sua importância nos profissionais de emergência. / Stress is the disease of our time, due to the requirement and emotional pressure that the media can have on all people, both in their personal environment and in the professional environment. The word stress increasingly serves as a justification or form of expression of irritation, physical discomfort and mental fatigue, anxiety and depression. However it is pertinent to realize the evolution of stress as a concept and as a disease. In this work, we contextualize under the stress of the Pre - Hospital Emergency, exploring it, assessing it and analyzing it, so you can see the stress levels and how the Emergency Professionals are subject to it. Whereas the theoretical basis of this study as a strategic objective of the work, the assessment of levels and stress factors perceived by medical emergency professionals and specific objectives of the study description and characterization, the level of the center, individuals who perform functions in pre-hospital emergency, check their perception with regard to the stress in your life, know how they experience the stress levels of professionals in emergency situations and identify the perceptions of individuals regarding the levels of daily stress in their daily lives. For this we used a sample of 184 professionals of Medical Emergency divided by four professions [(Doctors, Nurses, Technicians Ambulance Emergency (TAE), Operators of Emergency Medical Center (OPCEM)], aged 20 to 56 years. We conducted a descriptive study also exploring the questionnaires of stress in INEM(National Institute of Medical Emergency) and Vulnerability Questionnaire Stress with variables of the study population. We can conclude that stress is present in emergency activities. Its presence is related to, first, with more or less stressful factors of discrimination and, secondly, a greater or lesser concentration on the subject, in particular, greater perfectionism and intolerance to frustration that stand as unstressed for the activity of emergency professionals. The areas studied will clarify the meaning and usefulness of the concept, its operation and its importance in day-to-day occupation of emergency.

Validação do Youth Quality of Life Instrument para a população portuguesa: YQOL-R

É incontornável o estatuto que o conceito de qualidade de vida assume hoje na prática e políticas de saúde pública. Na infância e adolescência é ainda escassa a investigação, tornando-se crucial o desenvolvimento de instrumentos de qualidade vida relacionada com a saúde validados para esta população. O presente trabalho tem como objetivo fundamental analisar as qualidades psicométricas e validar a versão portuguesa do Youth Quality of Life (YQOL-R) (Patrick, et al., 2002). A amostra é constituída por 507 adolescentes, com idades compreendidas entre os 12 e os 19 anos, a frequentar o 3º ciclo do ensino básio e ensino secundário de escolas públicas do ensino regular. Para além do citado instrumento a validar, os jovens preencheram também, para a análise da validade convergente e divergente, o Kidscreen-27 (Gaspar & Matos, 2008) e a Escala da Depressão, Ansiedade e Stresse (EADS-21) (Pais-Ribeiro, Honrado & Leal, 2004). Os resultados mostram que o YQOL-R apresenta uma estrutura fatorial de quatro fatores, semelhantes à versão original americana (individual, relações sociais, ambiente e qualidade de vida em geral). Possui uma boa consistência interna e uma adequada estabilidade temporal. Mostrou correlações significativas e no sentido esperado com as variáveis em estudo. Foram igualmente encontradas diferenças de género em relação à qualidade de vida, sendo os rapazes a reportarem em média níveis mais elevados de perceção da qualidade de vida, comparativamente às raparigas. Futuros estudos devem ser realizados em amostras clínicas para confirmação dos dados. Não obstante esta limitação, o presente estudo contribuiu para a disponibilização de um novo instrumento para avaliação da qualidade de vida em crianças e adolescentes, o qual evidenciou boas propriedade psicométricas, apoiando, assim empiricamente, a sua utilização nas práticas de saúde e investigação em amostras da comunidade. / Nowadays, it´s unavoidable the status that, the concept of quality of life assumes in practices and politics of public health. In childhood and adolescence it´s weak the investigation but it´s crucial the development of instruments of quality of life related to health validated to this population. The present work has an important aim, it´s analyze the psychometric qualities and validate the Portuguese version of Youth Quality of Life (YQOL-R) (Patrick, et al., 2002). The sample consists of 507 adolescents, aged between 12 and 19 years old and they attend the 3 rd cycle of basic education and secondary education schools in villages of regular education. Apart from that instrument, teenagers fill in, also, to the analysis convergent and divergent, the Kidscreen-27 (Gaspar & Matos, 2008) and the Depression, Anxiety and Stress Scale (EADS-21) (Pais-Ribeiro, Honrado & Leal, 2004). The results show that the YQOL-R presents a factorial structure with four factors similar to original American version (individual, social relations, environment and general quality of life), presenting a good internal consistence and an adequate temporal stability. Substantial correlations showed and in the expected way with the variables in study. Have been found differences of gender related to quality of life, boys reported on average higher levels of quality of life perception, comparatively to the girls. Future studies must be performed in clinical samples to confirm the findings. In spite of this restriction, the actual study contributes to providing a new instrument to evaluate the quality of life in children and adolescents, this evidenced good psychometric properties, supported empirically its application in heath practices and investigation in community samples.

Equilíbrios Difíceis: stress laboral, equilíbrio trabalho/família e diferenças de género entre os colaboradores de uma empresa de tecnologias da informação

O stress é não apenas inerente para o ser humano, como indispensável para a sua sobrevivência. À medida que as sociedades humanas evoluíram, assim também se alteraram as principais fontes de stress. Actualmente o stress organizacional é uma das principais áreas de investigação, bem como as suas relações com a família e a vida pessoal. Em foco estão ainda as variáveis individuais que servem como moderadoras da experiência de stress, como o coping e o suporte social. Neste trabalho procurou-se conhecer os níveis de stress experienciados pelos colaboradores da Cisco Systems Lda, identificando diferenças de género e entre os tipos de trabalho. Pretendeu-se ainda relacionar o stress no trabalho com o equilíbrio trabalho/família, equlíbrio vida pessoal/trabalho, suporte social e coping. Através de um estudo não experimental transversal, descritivo/descritivo correlacional, com 42 sujeitos, utilizando o PMI – Pressure Management Indicator, foi possível identificar quatro factores, com α a partir de 0,531 para as variáveis moderadoras ate 0,904 para as variáveis stressoras. Os trabalhadores da amostra trabalham em média 49,7 horas por semana, apontando como principal razão “para que o trabalho seja feito”; 31,7% consideram estar a sofrer de pressão negativa iniciada há mais de 3 meses. Estão muito satisfeitos com a organização, mas sentem pressão devido ao volume de trabalho, ao relacionamento interpessoal e às dificuldades em desligar do trabalho quando em casa, fazendo uso de estratégias focadas no problema e de suporte social. Existem diferenças estatisticamente significativas entre homens e mulheres nas subescalas “Estado de espírito” e “Nível de confiança”, indicando níveis mais altos de segurança e satisfação com o seu estado mental para o grupo dos homens. No que respeita aos tipos de trabalho, foi possível identificar diferenças entre as categorias Sénior gerência/profissional e Manual/hábil nas subescalas “Nível de energia”, “Volume de trabalho” e “Equilíbrio vida/trabalho”. Existe correlação positiva entre as variáveis stressoras e a subescala “Equilíbrio trabalho/família” (r=0,890; p<0,000) e entre as variáveis stressoras e a escala de Coping (r=0,748; p<0,000), sugerindo que níveis de stress elevados interferem com a vida familiar e conduzem a maior utilização das estratégias de coping. Apesar das políticas de recursos humanos da empresa no sentido de promover a conciliação entre trabalho e vida pessoal e familiar, há ainda margem para intervir e melhorar. / Stress is not only inherent to the human being, it’s essential to survival. As the humans societies evolved, so did the major sources of stress. These days, organizational stress is one of the main areas of research, as it is it’s relation with family and personal life. Under the spotlight are also individual variables that moderate the stress experience, such as coping and social support. With this paper, we intended to know the levels of stress experienced by the workers of Cisco Systems Lda, identifying gender and work type differences. We were also intending to relate work stress with home/work balance, life/work balance, social support and coping. Using a cross sectional correlational study, with n=42, using the PMI, we were able to identify four factors, with α starting on 0,531 for moderator variables to 0,904 for stressor variables. The workers on this sample work an average of 49,7 hours per week, naming “to get the job done” as the main reason for it. 31,7% consider to be suffering from negative pressure that started more than 3 months ago. They are very satisfied with the organization, but feel pressure due to workload, interpersonal relationship and the difficulties in switching off from work when at home. They use mostly Problem focus strategies and social support.There are statically significative differences between men and women in the subscales “State of mind” and “Confidence level”, which indicate higher levels of security and satisfaction with their state of mind for men. Regarding work types, we were able to identify differences between senior Management and Manual categories on subscales “Energy level”, “Workload” and “Life/work balance”. There is a positive correlation between stressor variables and the subscales “Home/work balance” (r=0,890; p<0,000) and between stressor variables and Coping scale (r=0,748; p<0,000), suggesting that high levels of stress interfere with family life and lead to higher use of coping mechanisms. Despite the company’s human resources policies to promote the balance between work and personal and family life, there is still place to intervene and improve.

Relação entre Vulnerabilidade ao Stress e Estratégias de Coping: estudo de caso numa empresa de venda a retalho da Região Centro do País

As situações indutoras de stress são uma constante imutável no dia-a-dia do ser humano e quando esta perturbação não é gerida de forma adequada, acarreta graves prejuízos na saúde dos indivíduos refletindo-se em diversas áreas das suas vidas nomeadamente no trabalho. O presente estudo tem como finalidade identificar a relação entre o stress e as estratégias de coping e perceber se os indivíduos com vulnerabilidade ao stress diferem dos indivíduos sem stress no que concerne às estratégias de coping utilizadas. A vulnerabilidade ao stress foi medida pela escala 23QVS, enquanto as estratégias de coping foram avaliadas pelo Inventário de Resolução de Problemas (IRP), tendo sido, ainda, utilizado um questionário sociodemográfico. A amostra foi composta por 62 trabalhadores de uma empresa de venda a retalho com idades compreendidas entre os 20 e os 44 anos (M=32,02 DP=5,770). Os resultados obtidos revelaram que a vulnerabilidade ao stress se correlaciona de forma negativa e altamente significativa com as estratégias de coping e que indivíduos com e sem vulnerabilidade ao stress não diferem quanto ao uso destas estratégias. / The stress-induction situations are a constant unchanging in human being life, and if this disturbance is not managed adequately can be harmful to the health of individuals and reflected in many areas of their lives including their work. The present study aims to analyze the relationship between stress and coping strategies, and understand if individuals with stress vulnerability differs from individuals without stress in respect to the use of coping strategies. Stress vulnerability was measured by the 23QVS scale and coping strategies by the Inventário de Resolução de Problemas – IRP (Inventory of Problem Solving), and we also used a sociodemographic questionnaire. The sample consisted of 62 workers of a retailing company with ages between 20 and 40 years old (M = 32,02; DP = 5,770). Our research studies reveal that stress vulnerability correlates negatively and highly with coping strategies, and individuals with and without stress vulnerability not differ in the use of these strategies.

Suporte, Stress e Solidão: um estudo sobre o apoio offline e online percecionado pelas mães portuguesas

Uma “rede social” diz respeito a uma estrutura constituída por pessoas ou organizações que partilham interesses, motivações e valores comuns. Um ponto partilhado pelos diversos tipos de rede social é a troca de informações, conhecimentos, interesses e esforços na tentativa de atingir objectivos comuns, muitas vezes potencializando forças e recursos em situações de crise. Recentemente tem-se ouvido falar bastante deste conceito aplicado à internet. A maternidade constitui, por si só, um momento de crise na vida de cada família e de cada mulher, requerendo adaptações e mudanças. O estudo realizado teve o intuito de avaliar o suporte online e offline (denominando-se essas ligações de redes sociais), no caso específico de assuntos ligados à maternidade. Pretendeu-se verificar também se existia uma correlação entre estes tipos de suporte e os níveis de stress e solidão sentidos pelas mães. Por último, aferiu-se ainda a influência que a idade dos filhos teria nesta adesão a grupos de suporte à maternidade, no Facebook. Este estudo teve uma amostra constituída por 170 mulheres (mães), estando as suas idades compreendidas entre os 25 e os 62 anos. Os resultados revelaram que apesar de não haver diferenças estatisticamente significativas entre o apoio online e offline, as mulheres que pertencem a grupos do Facebook tendem a sentir mais suporte por parte das plataformas de suporte disponíveis. Constatou-se ainda que não existem diferenças significativas entre os níveis de solidão e stress, entre mães que pertencem a grupos e mães que não pertencem. Foi interessante verificar que as mulheres com filhos mais novos (faixa etária dos 0-4 anos) têm uma presença mais significativa em grupos de apoio à maternidade, no Facebook. Pensamos que isso se deve às dúvidas e ao stresse gerado por um primeiro filho ou pela introdução de mais um filho no núcleo familiar, nos primeiros anos em que tal ocorre, procurando por isso mais activamente grupos que ajudem como rede de suporte, para partilhas, apoio emocional e esclarecimento de dúvidas. / A “social network” refers to a structure formed by individuals or organisations that share interests, motivations and common values. A feature shared by several types of social network is the exchange of information, knowledge, interests and efforts, in an attempt to achieve common goals, often potentiating strengths and resources in crisis situations. Recently, we have heard of this concept applied to the internet. Motherhood is, by itself, a moment of crisis in the life of every family and every woman, requiring adaptations and changes. This study aimed to assess online and offline supports (being these connections themselves denominated social networks), in the specific case of motherhood-related issues. It was also intended to confirm whether there was a correlation between these types of support and stress and loneliness levels sensed by mothers. Finally, it was evaluated as well the influence that the children’s age would have on this adherence to motherhood support groups on Facebook. This study had a sample of 170 women (mothers), with ages between 25 and 62 years. The results showed that, although there are no statistically significant differences between the online and offline support, women who belong to Facebook groups tend to feel more support from the available support platforms. It was shown as well that there are no significant differences between loneliness and stress levels among mothers who belong to groups and mothers who do not belong to those groups. It was interesting to find that women with young children (aged 0-4 years old) have a more significant presence in motherhood support groups on Facebook. We think that this is due to the doubts and the stress generated by a first child or the introduction of another child in the household, therefore making sense that they seek, in the early years of the child’s life, groups that help as a support network, for shares, emotional support and answering questions.

Influence of grinding operations on surface integrity and chloride induced stress corrosion cracking of stainless steels

Stainless steels were developed in the early 20th century and are used where both the mechanical properties of steels and corrosion resistance are required. There is continuous research to allow stainless steel components to be produced in a more economical way and be used in more harsh environments. A necessary component in this effort is to correlate the service performance with the production processes. The central theme of this thesis is the mechanical grinding process.  This is commonly used for producing stainless steel components, and results in varied surface properties that will strongly affect their service life. The influence of grinding parameters including abrasive grit size, machine power and grinding lubricant were studied for 304L austenitic stainless steel (Paper II) and 2304 duplex stainless steel (Paper I). Surface integrity was proved to vary significantly with different grinding parameters. Abrasive grit size was found to have the largest influence. Surface defects (deep grooves, smearing, adhesive/cold welding chips and indentations), a highly deformed surface layer up to a few microns in thickness and the generation of high level tensile residual stresses in the surface layer along the grinding direction were observed as the main types of damage when grinding stainless steels. A large degree of residual stress anisotropy is interpreted as being due to mechanical effects dominating over thermal effects. The effect of grinding on stress corrosion cracking behaviour of 304L austenitic stainless steel in a chloride environment was also investigated (Paper III). Depending on the surface conditions, the actual loading by four-point bend was found to deviate from the calculated value using the formula according to ASTM G39 by different amounts. Grinding-induced surface tensile residual stress was suggested as the main factor to cause micro-cracks initiation on the ground surfaces. Grinding along the loading direction was proved to increase the susceptibility to chloride-induced SCC, while grinding perpendicular to the loading direction improved SCC resistance. The knowledge obtained from this work can provide a reference for choosing appropriate grinding parameters when fabricating stainless steel components; and can also be used to help understanding the failure mechanism of ground stainless steel components during service.

Stressful Life Events and their Trajectories among Midlife Women: Observations from the Seattle Midlife Women's Health Study

Thesis (Ph.D.)--University of Washington, 2016-08

Resource use and greenhouse gas emissions from grain-finishing beef cattle in seven Australian feedlots: a life cycle assessment

Grain finishing of cattle has become increasingly common in Australia over the past 30 years. However, interest in the associated environmental impacts and resource use is increasing and requires detailed analysis. In this study we conducted a life cycle assessment (LCA) to investigate impacts of the grain-finishing stage for cattle in seven feedlots in eastern Australia, with a particular focus on the feedlot stage, including the impacts from producing the ration, feedlot operations, transport, and livestock emissions while cattle are in the feedlot (gate-to-gate). The functional unit was 1 kg of liveweight gain (LWG) for the feedlot stage and results are included for the full supply chain (cradle-to-gate), reported per kilogram of liveweight (LW) at the point of slaughter. Three classes of cattle produced for different markets were studied: short-fed domestic market (55–80 days on feed), mid-fed export (108–164 days on feed) and long-fed export (>300 days on feed). In the feedlot stage, mean fresh water consumption was found to vary from 171.9 to 672.6 L/kg LWG and mean stress-weighted water use ranged from 100.9 to 193.2 water stress index eq. L/kg LWG. Irrigation contributed 57–91% of total fresh water consumption with differences mainly related to the availability of irrigation water near the feedlot and the use of irrigated feed inputs in rations. Mean fossil energy demand ranged from 16.5 to 34.2 MJ lower heating values/kg LWG and arable land occupation from 18.7 to 40.5 m2/kg LWG in the feedlot stage. Mean greenhouse gas (GHG) emissions in the feedlot stage ranged from 4.6 to 9.5 kg CO2-e/kg LWG (excluding land use and direct land-use change emissions). Emissions were dominated by enteric methane and contributions from the production, transport and milling of feed inputs. Linear regression analysis showed that the feed conversion ratio was able to explain >86% of the variation in GHG intensity and energy demand. The feedlot stage contributed between 26% and 44% of total slaughter weight for the classes of cattle fed, whereas the contribution of this phase to resource use varied from 4% to 96% showing impacts from the finishing phase varied considerably, compared with the breeding and backgrounding. GHG emissions and total land occupation per kilogram of LWG during the grain finishing phase were lower than emissions from breeding and backgrounding, resulting in lower life-time emissions for grain-finished cattle compared with grass finishing.

Life without complex I: proteome analyses of an Arabidopsis mutant lacking the mitochondrial NADH dehydrogenase complex

The mitochondrial NADH dehydrogenase complex (complex I) is of particular importance for the respiratory chain in mitochondria. It is the major electron entry site for the mitochondrial electron transport chain (mETC) and therefore of great significance for mitochondrial ATP generation. We recently described an Arabidopsis thaliana double-mutant lacking the genes encoding the carbonic anhydrases CA1 and CA2, which both form part of a plant-specific 'carbonic anhydrase domain' of mitochondrial complex I. The mutant lacks complex I completely. Here we report extended analyses for systematically characterizing the proteome of the ca1ca2 mutant. Using various proteomic tools, we show that lack of complex I causes reorganization of the cellular respiration system. Reduced electron entry into the respiratory chain at the first segment of the mETC leads to induction of complexes II and IV as well as alternative oxidase. Increased electron entry at later segments of the mETC requires an increase in oxidation of organic substrates. This is reflected by higher abundance of proteins involved in glycolysis, the tricarboxylic acid cycle and branched-chain amino acid catabolism. Proteins involved in the light reaction of photosynthesis, the Calvin cycle, tetrapyrrole biosynthesis, and photorespiration are clearly reduced, contributing to the significant delay in growth and development of the double-mutant. Finally, enzymes involved in defense against reactive oxygen species and stress symptoms are much induced. These together with previously reported insights into the function of plant complex I, which were obtained by analysing other complex I mutants, are integrated in order to comprehensively describe 'life without complex I'.

Predictors of stress and depressive mood in portuguese middle-aged women

This cross-sectional study investigates the predictors of psychological symptoms-stress and depressive mood-in a sample of middle-aged women. A community sample of 1,003 women filled in the questionnaires and instruments, which included the Depression, Anxiety and Stress Scales and the Life Events Survey; sociodemographic, health, and menopause-related and lifestyle information was also collected. Structural equation modeling was used to build the model that had stress and depressive mood as dependent variables. Health status (both physical and psychological), recent life events, income and menopausal phase were significantly associated with the frequency of stress and depressive symptoms. Additionally, educational level and parity were also significant predictors of depressive mood. This study emphasizes that psychological symptoms occurrence in midlife depends not only on personal variables (such as health and menopausal status) but also on contextual ones (including recent stressful events) that can be a strong influence on how middle-aged women feel.

Nitrogen vs argon: what is the most effective atmosphere for shelf-life extension of buckler sorrel leaves?

Buckler sorrel (Rumex induratus Boiss. & Reut.) is an underutilized leafy vegetable with peculiar sensory properties and potential as a gourmet food. In the food industry, different packaging methods have been used for shelf-life extension, but it is important to know how the quality of minimally processed vegetable is affected by these treatments. Recently, nitrogen and argon have been used for food packaging. Nitrogen is low soluble in water and other food constituents and does not support the growth of aerobic microbes. In turn, argon is biochemically active and appears to interfere with enzymatic oxygen receptor sites. In this study, modified atmospheres enriched with nitrogen and argon were evaluated for shelf-life extension of buckler sorrel leaves. Wild samples were gathered in Bragança, Portugal, considering local consumers’ sites and criteria. Healthy and undamaged leaves were selected, rinsed in tap water, and a portion was immediately analyzed (non-stored control). The remaining fresh material was packaged in polyethylene bags under nitrogen- and argon-enriched atmospheres and a conventional control atmosphere (air). All packaged samples were stored at 4 ºC for 12 days and then analyzed. The headspace gas composition was monitored during storage. Different quality attributes were evaluated, including visual (colour), nutritional (macronutrients, individual sugars and fatty acids) and bioactive (hydrophilic and lipophilic molecules and antioxidant properties) parameters. Different statistical tools were used; the one-way analysis of variance (ANO VA) was applied for analyse the differences among treatments and a linear discriminant analysis (LDA ) was used to evaluate the effects on the overall postharvest quality. The argon-enriched atmosphere better prevent the samples yellowing. The proximate composition did not change significantly during storage. Samples in control atmosphere revealed higher protein and ash contents and lower levels of lipids. The non-stored control samples presented the higher amounts of fructose, glucose and trehalose. The storage time increased the palmitic acid levels and decreased the content in α-linolenic and linoleic acids. The γ- e δ-tocopherols were higher after the 12 days of cold storage. Probably, the synthesis of these lipophilic compounds was a plant strategy to fight against the abiotic stress induced by storage. Higher levels of total phenolics and flavonoids and increased reducing power and β-carotene bleaching inhibition capacity were also found in the stored control samples. Once again, this result may be attributed to the intrinsic plant-protection mechanisms. Overall, the argon atmosphere was more suitable for quality preservation and shelf-life extension of buckler sorrel.

A Social Cognitive Approach to Coping with Acculturative Stress in International Students

The present study employed a cross-sectional design to test a model of coping with acculturative stress in an international student sample. Drawing from Lent’s (2004) social cognitive model of restorative well-being, several direct and mediated paths were hypothesized to predict (negatively) acculturative stress and (positively) life satisfaction. Behavioral acculturation and behavioral enculturation (Kim & Omizo, 2006) were also examined as predictors of coping with acculturative stress among international students. Using a self-report survey, participants’ ratings of acculturative stress, life satisfaction, social support, behavioral acculturation, behavioral enculturation, and coping self-efficacy were assessed. The results revealed that the variables of the model explained 16% of the variance in acculturative stress and 27% of the variance in life satisfaction. A final model, including the use of modification indices, provided good fit to the data. Findings also suggested that coping self-efficacy was a direct predictor of acculturative stress, and that behavioral acculturation and coping self-efficacy were direct predictors of students’ life satisfaction. Limitations, future research, and practical implications are discussed.