Environmental change is a major threat to marine ecosystems worldwide. Understanding the key biological processes and environmental factors mediating spatial and temporal species' responses to habitat alterations underpins our ability to forecast impacts on marine ecosystems under any range of scenarios. This is especially important for calcifying species, many of which have both a high climate sensitivity and disproportionately strong ecological impacts in shaping marine communities. Although geographic patterns of calcifiers' sensitivity to environmental changes are defined by interacting multiple abiotic and biotic stressors, local adaptation, and acclimation, knowledge on species' responses to disturbance is derived largely from short- and medium-term laboratory and field experiments. Therefore, little is known about the biological mechanisms and key drivers in natural environments that shape regional differences and long-term variations in species vulnerability to global changes. In this thesis, I examined natural variations in shell characteristics, both morphology and biomineralisation, under heterogeneous environmental conditions i) across large geographical scales, spanning a 30° latitudinal range (3,334 km), and ii) over historical times, using museum collections (archival specimens from 1904 to 2016 at a single location), in mussels of the genus Mytilus. The aim was to observe whether plasticity in calcareous shell morphology, production, and composition mediates spatial and temporal patterns of resistance to climate change in these critical foundation species. For the morphological analyses, the combined use of new statistical methods and multiple study systems at various geographical scales allowed the uncoupling of the contribution of development, genetic status, and environmental factors to shell morphology. I found salinity had the strongest effect on the latitudinal patterns of Mytilus shape. Temperature and food supply, however, were the main predictor of mussel shape heterogeneity. My results suggest the potential of shell shape plasticity in Mytilus as a powerful indicator of rapid environmental changes. I found decreasing shell calcification towards high latitudes. Salinity was the best predictor of regional differences in shell deposition, and its mineral and organic composition. In polar, low-salinity environments, the production of calcite and organic shell layers was increased, while aragonite deposition was enhanced under temperate, higher-salinity regimes. Interacting strong effects of decreasing salinity and increasing food availability on compositional shell plasticity predict the deposition of a thicker external organic layer (periostracum) at high latitudes under forecasted future conditions. This response potential of Mytilus shell suggests an enhanced protection of temperate mussels from predators and a strong capacity for increased resistance of polar and subpolar individuals to dissolving water conditions. Analyses of museum specimens indicated increasing shell calcification during the last century. Deposition of individual shell layers was more closely related to temporal changes in the variability of key environmental drivers than to alterations of mean habitat conditions. Calcitic layer and periostracum showed marked responses to alterations of biotic conditions, suggesting the potential of mussels to trade-off between the deposition of calcareous and organic layers as a compensatory response to strategy-specific predation pressure. These changes in biomineralisation indicated a marked resistance to environmental change over the last century in a species predicted to be vulnerable, and how locally heterogeneous environments and predation levels can have a stronger effect on Mytilus responses than global environmental trends. My work illustrates that biological mechanisms and local conditions, driving plastic responses to the spatial and temporal structure of multiple abiotic and biotic stressors, can define geographic and temporal patterns of unforeseen species resistance to global environmental change.

Background: Inadequate foetal growth cannot be remedied postnatally, leading to severe consequences for neonatal and adult development. Furthermore, sexual dimorphism in placental development has been suggested in humans although this remains poorly investigated in the pig. Hypotheses: Intrauterine Growth Restriction (IUGR) occurs due to aberrant conceptus attachment, which leads to alterations in angiogenesis and vascularity of the feto-maternal interface. Altered gene expression and vascularity will be observed at the feto-maternal interface in male foetuses compared to female foetuses. Increased apoptosis and decreased proliferation will be observed in the feto-maternal interface associated with the lightest foetuses compared to the closest to mean litter weight (CTMLW) foetuses. Aims: This thesis aimed to investigate the association between foetal size and sex and: integrin signalling; apoptotic and proliferation pathways; umbilical arterial (UA) blood flow; and angiogenesis and vascularity at the feto-maternal interface. This was performed by the collection of placental and endometrial samples associated with conceptuses or foetuses of different size (lightest and CTMLW) and sex at gestational day (GD) 18, 30, 45, 60 and 90. Conclusion This thesis has presented novel findings of associations between foetal size and sex, and placental and endometrial integrin signalling, apoptosis and proliferation, and angiogenesis and vascularity. Currently, this is the first suggestion in the literature that foetal size, and more intriguingly foetal sex, may have a strong influence on the activity of the endometrium. The mechanisms behind these findings warrant further investigation. Switches in the direction of differences at the feto-maternal interface between foetuses of different size were observed throughout gestation, notably between GD45 and 60, highlighting the dynamic nature of the feto-maternal interface and suggesting this as a potential window that could be manipulated by the industry to attempt to rescue the postnatal phenotype of IUGR piglets.

Chez les pollinisateurs sociaux, comme l'abeille domestique (Apis mellifera L.) et le bourdon terrestre (Bombus terrestris L.), mes deux modèles d'étude, différents individus sont spécialisés dans différentes tâches. Il est admis que différents types de comportement de butinage contribuent à une optimisation des performances de la colonie. Actuellement, les populations de pollinisateurs sont exposées à des stress environnementaux, qui sont connus pour perturber le comportement des individus en visant directement leur cognition. Il est ainsi crucial de mieux comprendre comment les colonies d'abeilles et de bourdons maintiennent une activité de butinage efficace, et quels sont les effets de stress environnementaux sur les butineuses. Dans cette thèse, j'ai donc examiné les différentes stratégies de butinage pour différentes sources de nourriture, pollen et nectar, et les variabilités interindividuelles dans le comportement de butinage. Je me suis aussi intéressé à l'impact de stress tels que les pesticides sur l'efficacité de butinage. J'ai utilisé la technologie RFID pour suivre le comportement des abeilles tout au long de leur vie. J'ai trouvé que les colonies d'abeilles et de bourdons reposent sur un petit groupe d'individus très actifs qui fournissent la majorité de la nourriture pour la colonie. Chez les abeilles, ces individus très actifs sont aussi plus efficaces pour collecter nectar et pollen. J'ai aussi identifié l'existence de différentes stratégies pour la collecte de pollen ou de nectar. Ensuite, j'ai pu montrer que les bourdons ont des différences interindividuelles très marquées dans un test de navigation, une tâche cruciale dans le comportement de butinage. Finalement, j'ai testé l'effet néfaste de pesticides sur l'apprentissage visuel chez l'abeille. Cette thèse a pour but de mieux comprendre les causes de vulnérabilité des pollinisateurs aux stress environnementaux. Mes résultats soulignent le besoin de considérer la diversité comportementale comme une adaptation des espèces de pollinisateurs sociaux, mais aussi comme une potentielle cause de vulnérabilité de la colonie vis-à-vis des stress. / In social insects, such as bees, different individuals specialise in the collection of different resources, and it is assumed that natural behavioural variability among foragers contributes to a self-organised optimisation of colony performance. Currently, bee populations are facing an increasing number of environmental stressors, known to disturb the behaviour of individuals, presumably upon their impact on cognitive capacities. Hence it is important to learn more about how stressors impact on individual foraging behaviour to understand how a colony maintains effective nutrition and development. In this thesis in cognitive ecology, I examined the different foraging strategies for the different macronutrient sources, pollen and nectar, and the inter-individual variation in bee foraging performance. I also looked at how stressors, such as pesticides, can impact on bee foraging efficiency. I compared two social Hymenoptera that vary in their level of social complexity: the European honey bee (Apis mellifera L.) and the buffed-tailed bumblebee (Bombus terrestris L.). I used Radio Frequency Identification (RFID) to automatically track the foraging behaviour of bees throughout their life. I found that honey bee and bumblebee colonies rely on a subset of very active bees to supply the whole colony needs. In honey bees, these foragers are more efficient and collect more pollen. I also identified different strategies for pollen or nectar collection in both species. Using manipulative experiments, I then showed that bees exhibit consistent inter-individual different behaviours in a spatial learning task and that pesticides impair visual learning. My thesis aims at better explaining the causes of vulnerability of pollinators to sublethal pesticides and other environmental stressors. The results highlight the need for considering behavioural diversity as an adaptation for social insects, as well as a potential dimension of colony-level vulnerability to environmental stressors that can impair the whole colony nutritional balance.

In recent years, School-Based Agricultural Education has been facing a shortage of secondary teachers, due in part to low retention rates of these valuable educators. In light of this shortage, a multitude of research has been conducted throughout the country on challenges faced by agricultural educators, some as indicators of intent to leave the profession. This thesis sought to synthesize the research conducted on job satisfaction, retention, and attrition of School-Based Agricultural Educators order to identify prevalent problems facing these teachers which may contribute to the decision to leave the classroom. From the research, seven themes emerged as job-related factors contributing to agriculture teacher job satisfaction, retention, and attrition: Work-Life Balance, Workload, Time Management, Student Discipline, Administrative Support, Salary, and Student Motivation.

Prior research has indicated higher risk of suicide for farmers and identified depression and anxiety as mental health concerns, though the majority of research was conducted in the 1980s-1990s. In today’s economic, social, and political climate, farmers are exposed to situations and stressors reminiscent of the 1980s Farm Crisis. An added risk is the aging workforce of farmers, as age-related conditions can make farming even riskier. This study investigated the mental health of a subset of American farmers by exploring farm-related stressors, coping mechanisms, and mental health outcomes. Dispositional mindfulness was explored as a specific coping mechanism. Participants (N = 158) were recruited through in-person and online surveys. All participants were farmers in the United States at the time of the study, with the majority farming in the state of Kentucky (48.7%). Participants were predominantly female (55.4%), White (98.1%), married (77.1%), and multi-generation farmers (69.2%). Participants completed measures of farm stress, general stress, depressive and anxious symptoms, coping, resilience, and dispositional mindfulness. Hierarchical linear regressions and moderation analyses were used to examine study aims. Results showed that farmers in this sample experience rates of depressive symptoms 1.5 times to 4.5 times higher than the national population, as well as rates of anxiety symptoms 1.5 times higher than the national population. Results also revealed that farmers with higher levels of farm stress are at a higher risk for anxious and depressive symptomology. Age appeared to be a protective factor, as older farmers reported the lowest levels of farm stress. Being a female was associated with higher farm stress. Regarding coping, over half of farmers endorsed using “planning” as the top strategy for coping with farm-related stressors. Farmers higher in dispositional mindfulness had better mental health ratings and lower farm stress. Further results and implications of the findings are discussed.

Fathers face difficulties when taking on the single parent role, including having to prove their ability to care for their children alone. Existing research does not address issues concerning single fathers and the stressors they experience in raising their children. This study addresses these issues and helps researchers understand single fathers by using a qualitative approach to understand their perception of parenting. Fourteen participants from New York City participated in semi-structured interviews to elicit information about this phenomenon. This study focused on experiences the men have while being a single parent, the impact of living in New York City on single fathers parenting, and helpful services for single fathers. After completion of the interviews, each discussion was input into the memos section of Nvivo for use in the analysis phase. Interviews were separated into descriptive nodes addressing each area of interest. Data was then dissected into subnodes, which assisted in determining the themes, represented by participant responses. The last analysis step included the establishment of important ideas for each of the three research questions. The findings show fathers experience stressors when being a single parent as they identified childcare, the absence of the child's mother, finances, housing, medical insurance, and communication issues as stress factors. Surprisingly, a majority of the participants felt living in New York positively impacted their parenting. Although a majority of the participants identified stress as part of their parenting experience, all the fathers identified services as a practical tool to help them improve their parenting. Several implications for positive social change after completing this research study include helping providers understand the needs of this population, and identifying the need for support to help improve parenting for this population.

Lowered academic achievement and premature departure from high school continue to plague the educational system, creating the need for greater insight into experiences affecting students' classroom performance. Much is known about academic achievement; however, less research has focused on the role of familial attachment on premature departure from high school. Guided by attachment theory, the purpose of this interpretative phenomenological study was to gain insight into General Education Diploma (GED) students' familial attachment experiences influencing premature departure from high school. The research questions focused on GED students' primary caregiver and educational experiences. Participants (n = 14) consisted of current or previous GED students 18-30 years of age. Data were gathered from semistructured interviews and a Life Map used to capture expression of feelings through symbols. Interview transcriptions were hand-coded by bracketing words and phrases for composite textual descriptions. Data interpretations were bolstered by committee member checking and participants' review of extracted data. Findings revealed a close connection between the types of attachment formed with primary caregivers and early departure from high school, but participants were more strongly influenced by external influences such as relationship conflicts, health crises, domestic violence, abuse, loss, and paternal abandonment. This study offers insight to educators, counselors, and those within the criminal justice system on these students' emotional and mental needs.

Above-ground biomass was allometrically estimated to quantify the amount of mangrove species in selected quadrats of Xuan Thuy National Park. Physicochemical properties of surrounding waters and soils were measured and treated stochastically by correlational analysis with estimated biomass values. Correlation results suggested that qualities of surrounding waters and soils are not the principal inhibitors of mangrove growth in Xuan Thuy. The available historical records infer that the main factor of mangrove loss in the past lay on land reclamation for shrimp aquaculture. In addition, results of correlation analysis showed geographical coincidence of mangrove fragmentation with influence area of water channeling used for aquaculture activities. Furthermore, the distribution of anomalous values of metals concentration was corresponding with anthropological activities associated to clam aquaculture and sand extraction. Based on the aforementioned analysis and the information on anthropological activities in the buffer zone of Xuan Thuy, were provided basic information on inherent environmental stressors of ecosystems in Xuan Thuy National Park. / Sinh khối trên mặt đất đã được ước tính theo phương pháp tương quan sinh trưởng để đưa ra số lượng các loài đước trong các mẫu vuông được lựa chọn tại Vườn quốc gia Xuân Thủy. Các đặc tính hóa-lí của những vùng nước và đất xung quanh đã được đo đạc và xử lí ngẫu nhiên bằng cách phân tích tương quan với những giá trị sinh khối ước tính. Kết quả tương quan cho thấy rằng chất lượng nước và đất xung quanh không phải là những thước đo chính cho tốc độ phát triển cây đước ở Xuân Thủy. Những ghi chép cũ đã kết luận rằng việc sử dụng đất để nuôi tôm là tác nhân chính dẫn tới suy giảm loài đước trong quá khứ. Bên cạnh đó, kết quả phân tích tương quan cho thấy sựtrùng hợp về mặt địa lý giữa sự phân mảnh của loài đước và những vùng nước bị ảnh hưởng do việc nuôi trồng thủy sản. Hơn nữa, sự phân bố bất thường của các giá trị đo mức độ tập trung kim loại cũng tương ứng với các hoạt động nuôi trồng thủy sản và khai thác cát của con người. Những phân tích nêu trên và nghiên cứu về hoạt động của con người tại vùng đệm của Xuân Thủy sẽ cung cấp những thông tin cơ bản về những mối đe dọa môi trường hệ sinh thái tại Vườn Quốc Gia Xuân Thủy.

Tyrimo tikslas - nustatyti patiriamų patyčių darbe, psichosocialinių stresorių darbe ir darbuotojų subjektyviai vertinamos sveikatos sąsajas. Tyrime dalyvavo 167 vieno didžiojo Lietuvos miesto įmonės, susijusios su prekių gamyba, darbuotojos moterys. Patiriamoms patyčioms darbe įvertinti buvo naudojamas Patikslintas negatyvių veiksmų klausimynas (NAQ-R) (Einarsen, Hoel, Notelaers, 2009). Klausimynas sudarytas iš 22 klausimų. Psichosocialinius stresorius darbe įvertinti buvo naudojamas trumpasis klausimynas įvertinti psichosocialinius rizikos veiksnius (SIMPH) (Notelares, De Witte, Van Veldhoven, &Vermunt, 2007). Klausimynas sudarytas iš 36 klausimų. Darbuotojų subjektyviai vertinamai sveikatai įvertinti buvo naudojamas klausimynas, kurį sudaro 20 klausimų, susijusisų su nusiskundimais sveikata (Smith, Johal, Wadsworth et al., 2000). Tyrimo metu buvo atlikta faktorinė analizė ir išskirti šeši faktoriai, iš kurių penki buvo naudoti duomenų analizėje (nusiskundimai, susiję su peršalimu, su nuovargiu ir stresu, galvos ir nugaros skausmai, nusiskundimais, susiję su virškinimo ir kvėpavimo sistema). Taip pat buvo įtrauktas klausimas apie asmens subjektyvų savo sveikatos vertinimą – „Kaip įvertintumėte savo bendrą sveikatos būklę?“ (McDowell, 2006). Tyrimo rezultatai parodė, kad tam tikri psichosocialiniai stresoriai darbe yra susiję su patyčiomis darbe, taip pat su nusiskundimais sveikata ir prasčiau subjektyviai vertinama darbuotojų sveikata bei vyresniu amžiumi. Dažniau... [toliau žr. visą tekstą] / The aim of the study was to assess the relationships among women‘s bullying at work, psychosocial stressors at work and subjectively assessed health. The subjects of the study were 167 women who work in an organization related to production of goods in one of the biggest cities of Lithuania. For the assessment of bullying at work, Negative Acts Questionnaire-Revised (NAQ-R) was used (Einarsen, Hoel, Notelaers, 2009). It consists of 22 items. For the assessment of psychosocial stressors at work, Short Inventory to Monitor Psychosocial Hazards (SIMPH) was used (Notelares, De Witte, Van Veldhoven, &Vermunt, 2007). It consists of 36 items. The questionnaire of health symptoms was used for the assessment of subjective health (Smith, Johal, Wadsworth et al., 2000). It consists of 20 items. Factor analysis was done, six factors were developed, five factors were used for the further data analysis. Factors were named as follows: symptoms of cold, symptoms of tiredness and stress, headaches and back pain, symptoms of the digestive system and symptoms of the respiratory system, an additional question was used: „In general, how would you rate your overall health now?“. The results of the study showed that some psychosocial stressors at work are related to bullying at work, health symptoms, lower assessment of subjective health, and older age. More frequent bullying at work is related to some health symptoms, lower assessment of subjective health, also older age and lower education level... [to full text]

Tyrimo tikslai - įvertinti psichosocialinių stresorių išreikštumą darbuotojų grupėse atsižvelgiant į sociademografinius rodiklius ir nustatyti psichosocialinių stresorių darbe ir psichologinio atsparumo ryšį su darbuotojų sveikatai palankiu elgesiu. Tyrimo metodas - anketinė apklausa. Darbuotojų psichosocialiniams stresoriams nustatyti naudotas ilgasis COPSOQ II (2004-2005) klausimynas. Nustatant darbuotojų psichologinį atsparumą, panaudota dispozicinio psichologinio atsparumo skalė (angl. Dispositional Resilience Scale, DRS15-R, Bartone, 2007). Tyrime dalyvavo 151 biuro darbuotojai, kurių amžius yra nuo 23 iki 55 metų. Tyrimo rezultatai atskleidė, jog darbuotojų psichosocialinių stresorių vertinimas skiriasi skirtingose socialinėse demografinėse grupėse: darbuotojai vyrai labiau nei moterys linkę teigti, kad darbe turi dirbti dideliu tempu; vyresni darbuotojai labiau nei jaunesni patiria nesaugumo jausmą dėl darbo vietos, jaučia didesnį darbo-šeimos disbalansą ir konfliktą. Kuo labiau darbuotojai subjektyviai vertina, kad darbo vietoje patiria didelį darbo krūvį, jų darbas reikalauja daug kognityvinių resursų, kuo labiau jie linkę manyti, kad turi slėpti savo emocijas darbo vietoje ir patiria didesni darbo-šeimos vaidmenų pusiausvyros konfliktą, mažiau jaučia savo įtaką darbo vietoje, mažesnes vystymosi galimybes, turi mažesnį darbo prasmės pojūtį, mažiau jaučiasi patenkinti savo atlygiu už darbą, mažiau aiškiai suvokia savo vaidmenį organizacijoje, prasčiau vertina... [toliau žr. visą tekstą] / The aims of the study were to assess the severity of psychosocial stressors employee groups according to sociodemographic indicators and to assess the relationship of psychosocial stressors at work employees‘ hardiness and health-promoting behaviour. Methodological instrument – questionnaire. It was used The Copenhagen Psychosocial questionnaire COPSOQ II (2004-2005) to determine psychosocial stressors of employees. It was used Dispositional Resilience Scale, DRS15-R, Bartone, 2007 to determine psychological resistance of employees. The subjects of the study were 151 of different gender, educational level, age (from 23 to 55), length. The research results have shown that psychosocial stressors of employees is differ in different social demographic groups: man employees are more as women employees tend to suggest an opinion that the rate of work is high: older employees more as young suffer insecurity about working place, feel bigger work-family imbalance and conflict. The more subjective the employees that work at a significant workload, they require a great deal of cognitive resources, the more they tend to believe that they have to hide their emotions in the workplace and are more work-family conflict, less feel their influence in the workplace, lower development opportunities, have lower sense of the meaning of work, the less feel satisfied with their rewards for the work, less understand their role clarity in the organization, value worse the quality of leadership, feel... [to full text]