Factors affecting airport route development activity and performance

Airports have become increasingly active in route development as a means of attracting, growing and retaining air services. However, little is known about the different levels of route development activity at airports, or the extent to which route development activity affects performance. Based on the findings of a survey of 124 airports worldwide, this study finds that larger airports are significantly more active than smaller airports. It also finds that private airports are more active than public airports, and that airports in Europe are more active than airports in other world regions, although differences according to ownership and location are not significant. Route development activity has a significant positive effect on performance. Factors associated with the airport business environment (market turbulence, competitive intensity, market growth and airport constraints) were not found to have a significant moderating effect on the relationship between route development activity and performance. However, two factors were found to have a significant direct effect on performance; market growth has a significant positive effect while airport constraints have a significant negative effect.

The Worsening of the employment and work conditions and its relationship to the self-perceived health in European working population. Relevance and effects of the latest socioeconomic crisis

The recent crisis of the capitalistic economic system has altered the working conditions and occupations in the European Union. The recession situation has accelerated trends and has brought transformations that have been observed before. Changes have not looked the same way in all the countries of the Union. The social occupation norms, labour relations models and the type of global welfare provision can help underline some of these inequalities. Poor working conditions can expose workers to situations of great risk. This is one of the basic assumptions of the theoretical models and analytical studies of the approach to the psychosocial work environment. Changes in working conditions of the population seems to be important to explain in the worst health states. To observe these features in the current period of economic recession it has made a comparative study of trend through the possibilities of the European Working Conditions Survey in the 2005 and 2010 editions. It has also set different multivariate logistic regression models to explore potential partnerships with the worst conditions of employment and work. It seems that the economic crisis has intensified changes in working conditions and highlighted the effects of those conditions on the poor health of the working population. This conclusion can’t be extended for all EU countries; some differences were observed in terms of global welfare models.

Socializing toddlers : autonomy-supportive parenting practices and potential risk factors

Selon la théorie de l’auto-détermination, l’autonomie est un besoin universel de base qui, lorsque soutenu, permet aux individus de mieux fonctionner et de vivre plus de bien-être psychologique (p. ex., Deci & Ryan, 2008). Le style parental des parents qui soutiennent l’autonomie de leur enfant est caractérisé par le soutien du fonctionnement autodéterminé de ce dernier. Sa définition traditionnelle inclut des pratiques telles qu’offrir des explications et des choix lors des requêtes, communiquer de l’empathie, et encourager les prises d’initiatives tout en minimisant l’utilisation d’un langage contrôlant (p. ex., Soenens et al., 2007). Les bénéfices d’un style parental qui soutient l’autonomie d’un enfant ont été bien documentés (p. ex., Grolnick, Deci, & Ryan, 1997), toutefois, peu d’études ont été effectuées auprès des bambins. Or, cette thèse visait à enrichir la littérature sur le « parentage » en explorant les pratiques soutenantes qui sont utilisées par des parents de bambins dans un contexte de socialisation (étude 1), ainsi qu’en examinant les facteurs qui peuvent brimer leur mise en pratique (étude 2). La première étude a examiné un grand nombre de pratiques de socialisation que les parents qui favorisent davantage le soutien à l’autonomie (SA) pourraient utiliser plus fréquemment lorsqu’ils font des demandes à leurs bambins. Cette étude nous a permis d’explorer comment les parents manifestent leur SA et si le SA dans ce type de contexte est associé à un plus grand niveau d’internalisation des règles. Des parents (N = 182) de bambins (M âge = 27.08 mois) ont donc été invités à rapporter la fréquence avec laquelle ils utilisent 26 pratiques potentiellement soutenantes lorsqu’ils demandent à leurs bambins de compléter des tâches importantes mais non intéressantes et de rapporter à quel point ils valorisent le SA. Huit pratiques ont été identifiées comme étant soutenantes: quatre façons de communiquer de l’empathie, donner des explications courtes, expliquer pourquoi la tâche est importante, décrire le problème de façon informative et neutre, et mettre en pratique le comportement désiré soi-même. De plus, l’ensemble des huit pratiques corrélait positivement avec le niveau d’internalisation des bambins, suggérant aussi que celles-ci représentent bien le concept du SA. Des études futures pourraient tenter de répliquer ces résultats dans des contextes potentiellement plus chargés ou ébranlants (p. ex., réagir face à des méfaits, avec des enfants souffrant de retard de développement). La deuxième étude a poursuivi l’exploration du concept du SA parental en examinant les facteurs qui influencent la fréquence d’utilisation des stratégies soutenantes dans des contextes de socialisation. Puisque la littérature suggère que le stress parental et le tempérament difficile des bambins (c.-à-d., plus haut niveau d’affectivité négative, plus faible niveau de contrôle volontaire/autorégulation, plus faible niveau de surgency) comme étant des facteurs de risque potentiels, nous avons exploré de quelle façon ces variables étaient associées à la fréquence d’utilisation des stratégies soutenantes. Les buts de l’étude étaient: (1) d’examiner comment le tempérament des bambins et le stress parental influençaient le SA parental, et (2) de vérifier si le stress parental médiait la relation possible entre le tempérament des bambins et le SA parental. Le même échantillon de parents a été utilisé. Les parents ont été invités à répondre à des questions portant sur le tempérament de leur enfant ainsi que sur leur niveau de stress. Les résultats ont démontré qu’un plus grand niveau d’affectivité négative était associé à un plus grand niveau de stress parental, qui à son tour prédisait moins de SA parental. De plus, le stress parental médiait la relation positive entre l’autorégulation du bambin et le SA parental. Des recherches futures pourraient évaluer des interventions ayant pour but d’aider les parents à préserver leur attitude soutenante durant des contextes de socialisation plus difficiles malgré certaines caractéristiques tempéramentales exigeantes des bambins, en plus du stress qu’ils pourraient vivre au quotidien.

Experiências de Combate e a sua Relação com a Sintomatologia Associada à Perturbação Pós-Stress Traumático em Veteranos da Guerra Colonial Portuguesa

Objectivos: O presente estudo avaliou a relação entre diversos aspectos objectivos e subjectivos inerentes às experiências de combate/guerra e sintomatologia associada à Perturbação Pós-Stress Traumático. Os instrumentos de auto-resposta utilizados na colheita dos dados foram analisados quanto às suas principais propriedades psicométricas. Métodos: A amostra foi composta por 105 combatentes da Guerra Colonial Portuguesa. Foram utilizados os seguintes instrumentos de avaliação: um questionário sóciodemográfico de auto-resposta para a caracterização da amostra, o Posttraumatic Stress Disorder Checklist (para militares), o Peritraumatic Dissociative Experiences Questionnaire, o Questionário de Experiências de Combate e duas escalas do Deployment Risk and Resilience Inventory, nomeadamente a Difficult Livings and Working Environment Scale e a Perceived Threat Scale. Resultados: O estudo das qualidades psicométricas dos instrumentos apresenta uma consistência interna superior a .86 e uma estabilidade temporal superior a .79. A análise factorial do Peritraumatic Dissociative Experiences Questionnaire apresenta bons valores na medida de Kaiser-Meyer-Olkin e no teste de esfericidade de Bartlett. Na rotação de Varimax é extraído um factor, predizendo a sua unidimensionalidade, que explica cerca de 70% da variância total do questionário. Os resultados relativos à validade divergentediscriminante indicam, por si só, que esta se apresenta de forma clara entre os instrumentos estudados (PCL-M, PDEQ, DLWES e PTS) no subgrupo com PTSD, com excepção da verificada entre o PCL-M e o PDEQ.. Quanto à validade de critério, constatam-se diferenças entre os subgrupos com e sem PTSD. Através do método da regressão linear múltipla, duas das seis variáveis têm, isoladamente, um peso preditivo significativo para a PTSD, nomeadamente a frequência de exposição a situações típicas e objectivas de combate/ guerra e os desconfortos diários durante a(s) comissão(ões). Ao considerarmos as variáveis no seu conjunto, aquelas que mais contribuem são a dissociação peritraumática e os desconfortos diários durante a(s) comissão(ões). Conclusão: Constata-se que os factores peritraumáticos em estudo desempenham um importante papel no desenvolvimento da sintomatologia inerente à PTSD. /

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.

Behavior of Granular Materials Under Triaxial Compression with Pulsating Deviator Stress, HR-131, Special Report

Behavior of granular material subjected to repeated load triaxial compression tests is characterized by a model based on rate process theory. Starting with the Arrhenius equation from chemical kinetics, the relationship of temperature, shear stress, normal stress and volume change to deformation rate is developed. The proposed model equation includes these factors as a product of exponential terms. An empirical relationship between deformation and the cube root of the number of stress applications at constant temperature and normal stress is combined with the rate equation to yield an integrated relationship of temperature, deviator stress, confining pressure and number of deviator stress applications to axial strain. The experimental program consists of 64 repeated load triaxial compression tests, 52 on untreated crushed stone and 12 on the same crushed stone material treated with 4% asphalt cement. Results were analyzed with multiple linear regression techniques and show substantial agreement with the model equations. Experimental results fit the rate equation somewhat better than the integrated equation when all variable quantities are considered. The coefficient of shear temperature gives the activation enthalpy, which is about 4.7 kilocalories/mole for untreated material and 39.4 kilocalories/mole for asphalt-treated material. This indicates the activation enthalpy is about that of the pore fluid. The proportionality coefficient of deviator stress may be used to measure flow unit volume. The volumes thus determined for untreated and asphalt-treated material are not substantially different. This may be coincidental since comparison with flow unit volumes reported by others indicates flow unit volume is related to gradation of untreated material. The flow unit volume of asphalt-treated material may relate to asphalt cement content. The proposed model equations provide a more rational basis for further studies of factors affecting deformation of granular materials under stress similar to that in pavement subjected to transient traffic loads.

Ansiedade, Stress, Depressão e Lapsos de Memória

Apesar de todos nós nos esquecermos, é comum atribuir-se os lapsos de memória às pessoas com idades avançadas. A evidência científica tem, no entanto, demonstrado que o esquecimento advém de uma multiplicidade de factores, como por exemplo, o excesso de trabalho, falta de descanso, entre outros. Neste estudo pretende-se saber se existe associação entre a tríade conceptual ansiedade, stress e depressão e os lapsos de memória, numa população em idade activa e com habilitações académicas de nível superior. A amostra é constituída por 68 professores que exercem a sua actividade profissional na Escola E.B. 2,3 de Cantanhede. A recolha dos dados foi efectuada recorrendo a: um questionário elaborado por nós, constituído por questões abertas e fechadas, uma Escala de Ansiedade, Depressão e Stress (EADS-21) e um Questionário de lapsos de memória (QLM). As análises estatísticas dos questionários foram efectuadas recorrendo ao programa informático SPSS (versão 15). As análises tiveram com objectivo final a testagem das hipóteses e tomaram em consideração a natureza métrica das variáveis. / In spite of all of we forget ourselves, it is common the lapses of memory are attributed to the persons with advanced ages. The scientific evidence has, however, when that the oblivion results from a multiplicity of factors was demonstrated, I eat for example, the excess of work, rest lack, between others. In this study one intends to know if there is association between the conceptual triad anxiety, stress and depression and the lapses of memory, in a population in active age and with academic competences of superior level. The sample is constituted by 68 teachers who practice his professional activity in the School E.B. 2,3 of Cantanhede. The gathering of the data was effectuated resorting to: a questionnaire prepared by us, constituted by questions open and shut, a Scale of Anxiety, Depression and Stress (EADS-21) and a Questionnaire of lapses of memory (QLM). The statistical analyses of the questionnaires were effectuated when there is resorting to the program informatics SPSS (version 15). The analyses had with final objective the testate of the hypotheses and took in consideration the metric nature of the variables.

Understanding the impact of different cheese-making strategies on Mozzarella cheese properties

Le fromage Mozzarella entre dans la composition de plusieurs mets populaires d’Amérique du Nord. L’aptitude de ce fromage à être râpé et ses propriétés caractéristiques de cuisson en font un ingrédient idéal. Ces qualités sont attribuées principalement aux propriétés physiques particulières de ce fromage sous certaines conditions de cisaillement et de température. Le but de ce projet était d’évaluer l’impact de différentes stratégies couramment mises en oeuvre dans l’industrie fromagère sur la composition, la microstructure et les propriétés physiques du fromage. Diverses stratégies ont été étudiées : les conditions de filage du caillé lors du procédé de « pasta filata », l’addition de protéines sériques dénaturées, le contrôle de la minéralisation et le vieillissement du fromage. Les résultats ont démontré que le contrôle de l’intensité mécanique et thermique fournie lors du filage permettait respectivement de réduire les pertes de solides et d’améliorer la répartition de la phase aqueuse dans la matrice fromagère. L’aptitude au râpage du fromage peut être optimisée en combinant l’utilisation de plusieurs stratégies dont la réduction du calcium colloïdal, un temps de vieillissement adéquat et un râpage à basse température. Par ailleurs, des changements aux facteurs mentionnés précédemment sont apportés lors de l’ajout de protéines sériques dénaturées, ces dernières ayant un impact sur la composition et la structure du fromage. Des modèles prédictifs de l’aptitude au râpage ont été développés en sélectionnant uniquement les descripteurs de composition et de texture pertinents. La perception sensorielle du fromage cuit sur pizza et les propriétés physiques du fromage fondu ont été considérablement influencées par l’évolution physico-chimique du fromage au cours du vieillissement. L’utilisation d’une nouvelle approche pour la caractérisation des propriétés rhéologiques du fromage fondu sous fortes contraintes a permis d’établir de bonnes relations avec les descripteurs sensoriels de texture. Ce travail a permis de valider l’hypothèse que l’utilisation d’une ou plusieurs stratégies simples et accessibles pouvait être mise de l’avant afin d’optimiser les propriétés physiques du fromage Mozzarella. Cela contribue à une meilleure compréhension des facteurs pouvant être contrôlés afin de développer des fromages avec des attributs spécifiques, lorsqu’utilisés comme ingrédient.

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.

Stress ocupacional e estratégias de coping em fisioterapeutas e terapeutas ocupacionais

Mestrado em Segurança e Higiene no Trabalho

Considerations in the use of high intensity leg cycle ergometry as a test of muscular performance

High intensity leg cycle ergometry is a widely used method of measuring muscular performance during maximal exercise. Until recently, it was deemed to be a predominantly lower body activity; however, there is now evidence to suggest that the upper body could be making a significant contribution to power output, as demonstrated by the intense electrical activity of the forearm musculature. As high intensity cycle ergometry often is used to measure performance in untrained cyclists it is important they are given at least two familiarisation trials to ensure results are both reliable and reproducible. In addition, diurnal variations exist during a single high intensity bout of exercise. It is likely these daily fluctuations are influenced by a number of biochemical and physiological variables. The purpose of this article is to outline factors that contribute to our interpretation of data following high intensity cycle ergometry.

Sub lethal mercuric chloride toxicity induced stress related alterations in the epithelial lining of foot of the freshwater mussel Lamellidens marginalis (Lamarck)

Sub lethal (0.2 ppm) mercuric chloride induced stress related histopathological alterations in the epithelial linings of foot (podium) of the edible freshwater mussel Lamellidens marginalis (Lamarck) were studied using histochemical techniques up to 60 days of exposure. The histomorphological changes were manifested only slowly and its intensity was somewhat proportional to the duration of exposure. The immediate response of the exposed mussels was the altered mucous secretion. There was a progressive incorporation of sulphated glycoproteins into the secretory contents of the mucous cells especially in the first half of the experiment. Marked histopathological changes including necrosis, appearance of pyknotic nuclei, sloughing of epithelial cells and appearance of non-tissue spaces, etc., started appearing during the later half of the experiment. The fag end of the experiment, which witnessed prominent histomorphological changes, was accompanied by highly decreased mucous secretion. KEYWORDS: heavy metal toxicity, mercuric chloride, Lamellidens marginalis, freshwater mussel, histopathology.

Investigation of properties affecting controlled release of macromolecules from PLGA microspheres

Poly(lactide-co-glycolide), or PLGA, microspheres offer a widely-studied biodegradable option for controlled release of therapeutics. An array of fabrication methodologies have been developed to produce these microspheres with the capacity to encapsulate therapeutics of various types; and produce microspheres of a wide range of sizes for different methods of delivery. The encapsulation, stability, and release profiles of therapeutic release based on physical and thermodynamic properties has also been studied and modeled to an extent. Much research has been devoted to tailoring formulations for improved therapeutic encapsulation and stability as well as selective release profiles. Despite the breadth of available research on PLGA microspheres, further analysis of fundamental principles regarding the microsphere degradation, formation, and therapeutic encapsulation is necessary. This work aims to examine additional fundamental principles related to PLGA microsphere formation and degradation from solvent-evaporation of preformed polymer. In particular, mapping the development of the acidic microenvironment inside the microsphere during degradation and erosion is discussed. Also, the effect of macromolecule size and conformation is examined with respect to microsphere diameter and PLGA molecular weight. Lastly, the effects of mechanical shearing and protein exposure to aqueous media during microsphere formation are examined. In an effort to better understand the acidic microenvironment development across the microsphere diameter, pH sensitive dye conjugated to protein that undergoes conformational change at different acidic pH values was encapsulated in PLGA microspheres of diameters ranging from 40 µm to 80 µm, and used in conjunction with fluorescence resonance energy transfer to measure the radial pH change in the microspheres. Qualitative analysis of confocal micrographs was used to correlate fluorescence intensity with pH value, and obtain the radial pH across the center of the microsphere. Therapeutic encapsulation and release from polymeric microspheres is governed by an interconnected variety of factors, including the therapeutic itself. The globular protein bovine serum albumin, and the elongated and significantly smaller enzyme, lysozyme, were encapsulated in PLGA microspheres ranging from 40 µm to 80 µm in diameter. The initial surface morphology upon microsphere formation, release profiles, and microsphere erosion characteristics were explored in an effort to better understand the effect of protein size, conformation, and known PLGA interaction on the formation and degradation of PLGA microspheres and macromolecule release, with respect to PLGA molecular weight and microsphere diameter. In addition to PLGA behavior and macromolecule behavior, the effect of mechanical stresses during fabrication was examined. Two similar solvent extraction techniques were compared for the fabrication of albumin loaded microspheres. In particular, the homogeneity of the microspheres as well as capacity to retain encapsulated albumin were compared. This preliminary study paves the way for a more rigorous treatment of the effect of mechanical forces present in popular microsphere fabrication. Several factors affecting protein release from PLGA microspheres are examined herein. The technique explored for spatial resolution of the pH inside the microsphere proved mildly effective in producing a reliable method of mapping microsphere pH changes. However, notable trends with respect to microsphere size, PLGA molecular weight, and microsphere porosity were observed. Proposed methods of improving spatial resolution of the acidic microenvironment are also provided. With respect to microsphere formation, studies showed that albumin and lysozyme had little effect on the internal homogeneity of the microsphere. Rather, ionic interactions with PLGA played a more significant role in the encapsulation and release of each macromolecule. Studies also showed that higher instances of mechanical stress led to less homogeneous microspheres with lower protein encapsulation. This suggests that perhaps instead of or in addition to modifying the microsphere formation formulation, the fabrication technique itself should be more closely considered in achieving homogeneous microspheres with desired loading.

Characterization of Non-linear Polymer Properties to Predict Process Induced Warpage and Residual Stress of Electronic Packages

Nonlinear thermo-mechanical properties of advanced polymers are crucial to accurate prediction of the process induced warpage and residual stress of electronics packages. The Fiber Bragg grating (FBG) sensor based method is advanced and implemented to determine temperature and time dependent nonlinear properties. The FBG sensor is embedded in the center of the cylindrical specimen, which deforms together with the specimen. The strains of the specimen at different loading conditions are monitored by the FBG sensor. Two main sources of the warpage are considered: curing induced warpage and coefficient of thermal expansion (CTE) mismatch induced warpage. The effective chemical shrinkage and the equilibrium modulus are needed for the curing induced warpage prediction. Considering various polymeric materials used in microelectronic packages, unique curing setups and procedures are developed for elastomers (extremely low modulus, medium viscosity, room temperature curing), underfill materials (medium modulus, low viscosity, high temperature curing), and epoxy molding compound (EMC: high modulus, high viscosity, high temperature pressure curing), most notably, (1) zero-constraint mold for elastomers; (2) a two-stage curing procedure for underfill materials and (3) an air-cylinder based novel setup for EMC. For the CTE mismatch induced warpage, the temperature dependent CTE and the comprehensive viscoelastic properties are measured. The cured cylindrical specimen with a FBG sensor embedded in the center is further used for viscoelastic property measurements. A uni-axial compressive loading is applied to the specimen to measure the time dependent Young’s modulus. The test is repeated from room temperature to the reflow temperature to capture the time-temperature dependent Young’s modulus. A separate high pressure system is developed for the bulk modulus measurement. The time temperature dependent bulk modulus is measured at the same temperatures as the Young’s modulus. The master curve of the Young’s modulus and bulk modulus of the EMC is created and a single set of the shift factors is determined from the time temperature superposition. The supplementary experiments are conducted to verify the validity of the assumptions associated with the linear viscoelasticity. The measured time-temperature dependent properties are further verified by a shadow moiré and Twyman/Green test.

Post-Traumatic Stress Disorder (PTSD) and Its relationship with perinatal bereavement: definitions, reactions, adjustments, and grief.

A small percentage of women present with diagnosed PTSD post childbirth; however, though this an area of increasing research and clinical interest generally, little is known about PTSD in relation to perinatal bereavement. Health professionals must however be aware of the mechanisms and models of loss following perinatal bereavement in order to identify potential mental health phenomena which may be implicated in the development of PTSD symptomology. Understanding the predictive factors which may give early warning signs is an important component of the clinical evidence base. This chapter discusses mechanisms, models, and risk factors in relation to perinatal bereavement and the development of PTSD.