Global change profoundly alters biological communities and increases species extinction rates. Recent reports show that odonate species (dragonflies and damselflies) are declining globally, however, odonates can also respond strongly to climate and land use change through shifts in range and phenology - i.e., the timing of life history events. Understanding how and when species respond to rapid environmental change is critical to address conservation risks in a timely way. I assembled a dataset of ~2 million odonate records between 1901 and 2021 and investigated a series of research questions about odonate persistence within historically occupied regions, how species respond across continents, and mechanisms leading to these responses. I discovered that non-target effects of pesticides interacted with temperature increases, leading to higher rates of odonate declines across the United States. Species with greater capacities in shifting their range northward may be more robust to impacts of global change (Chapter 2). Converging across Europe and North America, stronger range limit shifts were associated with stronger shifts in emergence phenology towards earlier spring dates, even though land use histories are highly divergent among regions. It is temperature variability and range geography, determinants of habitat conditions to which species are exposed, rather than ecological traits, that facilitated or hindered range shifts (Chapter 3). Temperature variability interacted with pesticide applications to hinder persistence or establishment in new areas that were otherwise climatically suitable, providing further evidence of impacts of extreme weather to insect declines. Tests of methods commonly used to predict species' distributions under future climate change (Species Distribution Models) revealed that species most likely to decline were also less likely to be well modeled, in terms of their temporal transferability (Chapter 4). This work deepens knowledge of spatial and temporal interspecific variation in species distributions as humans continue to reshape the Earth's ecosystems and climatic processes. This thesis can help improve species-specific conservation planning for species that decline in the face of anthropogenic activities.

Large wildfires in California cause significant socioecological impacts, and half of the federal funds for fire suppression are spent each year in California. Future fire activity is projected to increase with climate change, but predictions are uncertain because humans can modulate or even override climatic effects on fire activity. Here we test the hypothesis that changes in socioecological systems from the Native American to the current period drove shifts in fire activity and modulated fire-climate relationships in the Sierra Nevada. We developed a 415-y record (1600-2015 CE) of fire activity by merging a treering-based record of Sierra Nevada fire history with a 20th-century record based on annual area burned. Large shifts in the fire record corresponded with socioecological change, and not climate change, and socioecological conditions amplified and buffered fire response to climate. Fire activity was highest and fire-climate relationships were strongest after Native American depopulation-following mission establishment (ca. 1775 CE)-reduced the self-limiting effect of Native American burns on fire spread. With the Gold Rush and EuroAmerican settlement (ca. 1865 CE), fire activity declined, and the strong multidecadal relationship between temperature and fire decayed and then disappeared after implementation of fire suppression (ca. 1904 CE). The amplification and buffering of fire-climate relationships by humans underscores the need for parameterizing thresholds of human-vs. climate-driven fire activity to improve the skill and value of fire-climate models for addressing the increasing fire risk in California.

The aim of this study was to understand how assistant nurses in the care of elderly experiences partial shifts. It was based on six different semi-structured interviews with assistant nurses in the elderly care and then analyzed. It is a qualitative research of subjective thoughts and experiences from assistant nurses. The study shows that the assistant nurses experienced dissatisfaction with the work environment due partial shifts and low fact of influence on the schedule. The assistant nurses complained of deficiencies in care of the elderly, which ought to be correlated with the structure of partial shifts and the lack of energy and patience that brings with it. On the other hand some participants could find positive aspects of partial shifts regarding time to rest and be there for the caretakers. The impact of the private life was palpable, and despite some aspects to have time to rest, the work-life balance was hard to fulfill and all assistant nurses with schedules containing partial shifts on the weekdays wanted a schedule without it.

The thesis examine strategic shifts in big trading company. The company trades with steel. The strategic shifts are analysed and evaluated. The recommendations are made on the basis of analysis. The thesis is devided in two parts. First part is theoretical, second part is practical. The base of theoretical part is aimed at the theory of strategy and strategic operating. Practical part introduces the company and describes the shifts. In conclusion is the evaluation and the recommendations.

Made available in DSpace on 2016-03-22T17:26:13Z (GMT). No. of bitstreams: 1 rosane feij.pdf: 333568 bytes, checksum: 8103e781de169d7b65675b610abcfafc (MD5) Previous issue date: 2008-12-19 / The present study aimed at investigating the world of private security workers, in the city of Pelotas-RS, in the year of 2008, refering to the relationship between work shifts (day and night) and the possible occurence of stress, since night shift work may lead to a worse performance of labor tasks and cause more labor accidents. The accomplished study of tranversal type was based on security service companies which were selected from aleatory sample, proportionally to the number of security workers. The defined sample were 223 security workers, from which 19 did not belong to any known companies. However, only a total of 56 security workers from the 13 selected companies answered the study questionnaire. Research data showed a 40-hour work week schedule, approximately. The security workers who labored from 41 to 47 hours showed a percentage of stress of 60%. From the security workers interviewed, 71,4% did not labor in another place, and the 28,6% who did, developed different activities. A total of 69,6% of the interviewees attended qualifying courses, while the other 30,4%, who had not attended any complementing courses, showed a percentage of 58,8% of stress. The research results indicate that 53,6% of security workers labor at night, showing a higher proportion of stress compared to the ones who labor during the day / O presente estudo objetivou uma investigação sobre o universo dos trabalhadores do setor de segurança privada, na cidade de Pelotas-RS, no ano de 2008, referente às relações entre os turnos de trabalho (diurno e noturno) e a possível ocorrência de estresse, pois a jornada noturna pode provocar um prejuízo no desempenho das tarefas laborais e ocasionar mais acidentes de trabalho. O estudo realizado é do tipo transversal, com base nas empresas de serviços de vigilância e as empresas foram selecionadas por amostragem aleatória e proporcional ao número de vigilantes em cada uma. A amostra definida foi de 223 vigilantes. Entretanto, somente um total de 56 vigilantes das 13 empresas selecionadas, responderam aos questionários do estudo (LIPP e MEQ). Dados da pesquisa mostram uma carga horária semanal de trabalho com uma média de 40 h. Os vigilantes que trabalham de 41 a 47 h apresentam um percentual de estresse de 60,0%. Dos vigilantes entrevistados, 71,4% não trabalham em outro local, e os 28,6% que trabalham em outros lugares desenvolvem atividades variadas. Um total de 69,6% dos entrevistados realizou cursos de qualificação, constatando-se que os outros 30,4%, sem nenhum curso de reciclagem, apresentam um percentual de 58,8% de estresse. Os resultados da pesquisa apontam que 53,6% dos vigilantes trabalham no turno da noite, apresentando maior proporção de estresse do que aqueles que trabalham de dia

This thesis investigates the effect that variation in employment between industries has had on the depth of recession faced by Metropolitan Statistical Areas (MSAs) in the United States. This analysis is limited to the previous two national recessions. I use regression analysis to find that increases in variation in employment has a significant effect on the maximum increase in unemployment rate in MSAs after controlling for relevant MSA characteristics. In this framework I also find that increases in education could mitigate the negative effects of this variation. I include several other measures of depth of recession including the fall in economic conditions and length for real GDP to recover to its pre-recession levels. I find that the measure of variation is significant in explaining falls in the economic conditions, but not so in explaining the length it takes for each MSA to recover its real GDP.

One of the aims of this study is to identify shifts of cohesion in translation from Spanish into English, with a view to validating Blum-Kulka's proposal that explication is a universal strategy in translation. The study uses the translation work of ten advanced translation students using narrative texts of approximately 250 words in length. Some of these students are native speakers of Spanish and others native speakers of English. Another aim of the study is to examine how cohesive devices are deployed across an ability range of students and to establish whether there are systematic differences in their deployment. The study will also attempt to establish whether the levels of language competence of informants account for specific shifts of cohesion in translation and whether certain shifts of cohesion are motivated by the style of the source and target texts. / Master of Arts (Hons)

The green turtle, Chelonia mydas, is a circumglobal species that exhibits several important developmental or ontogenetic shifts throughout its life history. The first major shift occurs when juvenile turtles migrate from pelagic habitat, where they forage as omnivores, to coastal neritic habitat, where they become primarily herbivores, foraging on algae and seagrass. Anecdotal evidence and gut-content analyses suggest that juvenile green turtles in south Texas bays, such as the lower Laguna Madre and Aransas Bay, undergo an additional ontogenetic shift during this important life history stage. Evidence from stable isotope analysis (SIA) of scute tissues of green turtles from Texas' lower Laguna Madre and Aransas Bay supports an intermediate stage between this species' shift from pelagic waters to seagrass beds in neritic waters; this additional shift comprises an initial recruitment of post-pelagic juveniles to jetty habitat located on the channel passes Gulf-ward of adjacent bays before subsequently recruiting to seagrass beds in these bays. Examination of stable carbon ([delta]¹³C) and nitrogen ([delta]¹⁵N) isotopes in microlayers of scute tissue from several size classes of green turtles from the lower Laguna Madre and Aransas Bay was used to confirm the occurrence of two ontogenetic shifts. Smaller green turtles (< 35 cm SCL) exhibited more depleted [delta]¹³C signatures and more enriched [delta]¹⁵N signatures, consistent with jetty habitat, compared to those of larger counterparts (> 45 cm SCL) that displayed enriched [delta]¹³C signatures and depleted ¹⁵N signatures, consistent with seagrass habitat. Changes in the isotopic composition between these size classes indicate distinct shifts in diet. Post-pelagic juveniles first recruit to jetty habitat and forage primarily on algae, before subsequently shifting to seagrass beds and foraging primarily on seagrass. These findings indicate the use of a characteristic sequence of distinct habitats by multiple life history stages of green turtles in Texas bays, a conclusion with broad management implications for this endangered species.

As in many service organizations, hospitals use a variety of shift types when scheduling nurse resources. In general, the operational decisions of workforce planning can be divided into two interrelated problems: (1) midterm planning in terms of shift assignments for up to six weeks at a time, and (2) the short-term daily adjustment of schedules. Individual nurse profiles are a function of a unit's skill requirements, labor laws, and other qualifications, and are results of the long-term planning decision. At the midterm level, the goal is to match nurse resources with the expected workload over the planning horizon. Rosters are designed to maximize personnel preferences as well as minimize cost. To investigate this problem, a large-scale integer program model was developed and solved with two methodologies. The first is based on Lagrangian Relaxation based heuristic, which uses a combination of subgradient optimization and Bundle methods, with variable fixing strategy and IP-based heuristic. The second methodology is a branch-and-price algorithm that makes use of several new branching rules, an extremely effective rounding heuristic, a dual bound procedure, and specialized aggregation scheme. To extend the algorithms to solve different levels of nursing skills, a downgrading strategy is used by giving scheduling priorities to higher level of worker. The midterm schedules provide a blueprint for the monthly work assignments of the staff. Because of absenteeism and unpredicted demand fluctuations, though, a hospital-wide reallocation of resources is needed on a daily basis. While the overall goal is to ensure adequate coverage at minimize cost, a secondary goal is to minimize changes to the assigned rosters. Nevertheless, to allow more flexibility, nurses are permitted to work in several units during a shift rather than just their home unit. An IP-based column generation methodology was developed to solve this problem and applied within a rolling horizon framework. The idea is to consider 24 hours at a time, but implement the results for only the first 8 hours. All algorithms were tested on data obtained from a 400-bed US hospital. The results show an order-of-magnitude improvement over current approaches in terms of solution quality and computation times. / text

Abrupt and persistent reconfiguration of ecosystem’s structure and function has been observed on a wide variety of ecosystems worldwide. While scientist believe that such phenomena could become more common and severe in the near future, little is known about the patterns of regime shifts’ causes and consequences for human well-being. This thesis aims to assess global patterns of regime shifts in social-ecological systems. A framework for comparing regime shifts has been developed as well as a public forum for discussing knowledge about regime shifts, namely the regime shift database. The most common drivers and expected impacts on ecosystem services have been identified by studying the qualitative topology of causal networks as well as the statistical properties that explain their emergent patters. Given that long time series data for ecosystems monitoring is rather sparse, and experimenting with ecosystems at the scales required to understand their feedback dynamics is rarely an option; we also proposed an indirect computationally based method for monitoring changes in ecosystem services. I hope the results here presented offer useful guidance for managers and policy makers on how to prioritize drivers or impacts of regime shifts: one take home message is that well-understood variables are not necessary the ones where most managerial efforts need to be taken. I also hope the scientific community rigorously criticize our results, but also acknowledge that when doing theoretical or empirical work, our methods tend to ignore the multi-causal nature of regime shifts. By bringing back multi-causality to the scientific debate, I hope our results offer new avenues for hypothesis exploration and theory development on the human endeavour of understanding Nature. / Transiciones críticas o cambios de régimen en ecosistemas se definen como reconfiguraciones abruptas de su estructura y función. Estos cambios, en ocasiones inesperados, se han documentado en una gran variedad de ecosistemas en todo el planeta. Algunos científicos proponen que en el futuro cercano dichos fenómenos pueden volverse más frecuentes y severos. Sin embargo, sabemos muy poco sobre las causas y consecuencias potenciales para el bienestar humano. El objetivo de esta tesis es evaluar patrones globales de cambios de régimen en sistemas socio-ecológicos. Un marco conceptual para comparar cambios de régimen y un foro público de discusión sobre el estado del arte en su conocimiento fue desarrollado en la base de datos virtual www.regimeshifts.org. Las causas más comunes y los impactos en servicios ecosistémicos más esperados han sido identificados estudiando las propiedades topológicas de redes causales, así como las propiedades estadísticas que explican sus propiedades emergentes. Dado que experimentar con ecosistemas a la escala adecuada para capturar sus mecanismos causales generalmente no es una opción, y dado que la disponibilidad de datos de largo plazo necesarios para monitorear cambios de régimen son la excepción y no la regla, proponemos un método indirecto computacional para monitorear cambios en servicios ecosistémicos. Espero que los resultados sean de utilidad para actores encargados del diseño de políticas o del manejo de ecosistemas, especialmente espero que ofrezcan una guía sobre cómo priorizar causas y consecuencias de estos cambios de régimen: una lección clave es que las variables que mejor entendemos o las que más monitoreamos no son necesariamente aquellas en las que debemos enfocar las estrategias de manejo. También espero que la comunidad científica critique con rigor nuestros resultados, pero a su vez reconozca que tanto el trabajo empírico y teórico como los métodos que comúnmente se utilizan para estudiar cambios de régimen tienden a ignorar su naturaleza multi-causal. Al enfatizar la diversidad de sus causas, espero que los resultados ofrezcan nuevas posibilidades para la exploración de hipótesis y el desarrollo de teorías para entender mejor la Naturaleza. / Abrupt och ihållande omkonfigurering av ekosystems struktur och funktion har observerats i en mängd olika ekosystem världen över. Forskning visar på att dessa fenomen antas bli vanligare och allvarligare inom vår närmsta framtid. Kunskapen kring dessa s.k. regimskiften är dock bristfällig, framförallt kring dess konsekvenser för mänskligt välbefinnande. Denna avhandling syftar till att bedöma globala mönster av regimskiften. Ett ramverk för att jämföra regimskiften, samt ett offentligt forum, “the regime shifts database”, för att främja diskussion och sprida kunskap om regimskiften, har utvecklats. De mest förekommande drivkrafter och effekter på ekosystemtjänster har identifierats genom att studera kvalitativa topologiska och kausala nätverk, samt de statistiska egenskaperna som förklarar deras framväxande mönster. Då långvariga tidsserier av ekosystemövervakning är få, och då de experiment som krävs för att förstå regimskiftens återkopplingsdynamik sällan är möjliga, föreslås också en indirekt beräkningsmetod för övervakning av förändringar i ekosystemtjänster. Resultaten från denna avhandling ämnar ger värdefull vägledning för beslutsfattare om prioriteringsordningen mellan olika typer av drivkrafter och effekter av regimskiften. En viktig slutsats är att gedigen kunskap om en viss variabel inte nödvändigtvis ger området där insatser bör tillsättas. Vidare, genom att föra tillbaka multi-kausalitet till den vetenskapliga debatten, erbjuder avhandlingen nya vägar för hypotesprövning och teoriutveckling inom vår gemensamma strävan att förstå Naturen. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 2: Manuscript. Paper 4: Manuscript.</p>