995 resultados para grim trigger strategies


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This paper attempts to review the literature on Gammarus and examine how it allocates its internal resources when producing eggs. There is an extensive literature on the fecundity of freshwater species but almost nothing is known about the sizes and energy contents of the eggs. More is known for saltwater species, in which the mean number of eggs per brood is inversely proportional to mean egg size and directly proportional to the female's body size. Theoretical aspects of egg size, numbers and reproductive effort are examined, along with the relation between sizes of eggs, broods and female body size. The reproductive effort and breeding cycles of both saltwater and freshwater species are reviewed, and reproductive strategies assessed.

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Pike, Esox lucius, are present in Loch Callater at their highest altitude and most extreme habitat in the British Isles, with subarctic winter conditions and extended winter ice-cover. The response of pike in this environment is slower growth, due to a shorter growing season and the low availability of forage fish, giving the poorest reported length-at-age for pike in the British Isles. All pike were mature or had spawned in the same year, with gravid ovaries in April and normal recovering ovaries in June-July. As in other lochs with few prey fishes, the larger pike ate small items such as invertebrates.

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Viruses possess very specific methods of targeting and entering cells. These methods would be extremely useful if they could also be applied to drug delivery, but little is known about the molecular mechanisms of the viral entry process. In order to gain further insight into mechanisms of viral entry, chemical and spectroscopic studies in two systems were conducted, examining hydrophobic protein-lipid interactions during Sendai virus membrane fusion, and the kinetics of bacteriophage λ DNA injection.

Sendai virus glycoprotein interactions with target membranes during the early stages of fusion were examined using time-resolved hydrophobic photoaffinity labeling with the lipid-soluble carbene generator3-(trifluoromethyl)-3-(m-^(125 )I] iodophenyl)diazirine (TID). The probe was incorporated in target membranes prior to virus addition and photolysis. During Sendai virus fusion with liposomes composed of cardiolipin (CL) or phosphatidylserine (PS), the viral fusion (F) protein is preferentially labeled at early time points, supporting the hypothesis that hydrophobic interaction of the fusion peptide at the N-terminus of the F_1 subunit with the target membrane is an initiating event in fusion. Correlation of the hydrophobic interactions with independently monitored fusion kinetics further supports this conclusion. Separation of proteins after labeling shows that the F_1 subunit, containing the putative hydrophobic fusion sequence, is exclusively labeled, and that the F_2 subunit does not participate in fusion. Labeling shows temperature and pH dependence consistent with a need for protein conformational mobility and fusion at neutral pH. Higher amounts of labeling during fusion with CL vesicles than during virus-PS vesicle fusion reflects membrane packing regulation of peptide insertion into target membranes. Labeling of the viral hemagglutinin/neuraminidase (HN) at low pH indicates that HN-mediated fusion is triggered by hydrophobic interactions, after titration of acidic amino acids. HN labeling under nonfusogenic conditions reveals that viral binding may involve hydrophobic as well as electrostatic interactions. Controls for diffusional labeling exclude a major contribution from this source. Labeling during reconstituted Sendai virus envelope-liposome fusion shows that functional reconstitution involves protein retention of the ability to undergo hydrophobic interactions.

Examination of Sendai virus fusion with erythrocyte membranes indicates that hydrophobic interactions also trigger fusion between biological membranes, and that HN binding may involve hydrophobic interactions as well. Labeling of the erythrocyte membranes revealed close membrane association of spectrin, which may play a role in regulating membrane fusion. The data show that hydrophobic fusion protein interaction with both artificial and biological membranes is a triggering event in fusion. Correlation of these results with earlier studies of membrane hydration and fusion kinetics provides a more detailed view of the mechanism of fusion.

The kinetics of DNA injection by bacteriophage λ. into liposomes bearing reconstituted receptors were measured using fluorescence spectroscopy. LamB, the bacteriophage receptor, was extracted from bacteria and reconstituted into liposomes by detergent removal dialysis. The DNA binding fluorophore ethidium bromide was encapsulated in the liposomes during dialysis. Enhanced fluorescence of ethidium bromide upon binding to injected DNA was monitored, and showed that injection is a rapid, one-step process. The bimolecular rate law, determined by the method of initial rates, revealed that injection occurs several times faster than indicated by earlier studies employing indirect assays.

It is hoped that these studies will increase the understanding of the mechanisms of virus entry into cells, and to facilitate the development of virus-mimetic drug delivery strategies.

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Notwithstanding advances in modern chemical methods, the selective installation of sterically encumbered carbon stereocenters, in particular all-carbon quaternary centers, remains an unsolved problem in organic chemistry. The prevalence of all-carbon quaternary centers in biologically active natural products and pharmaceutical compounds provides a strong impetus to address current limitations in the state of the art of their generation. This thesis presents four related projects, all of which share in the goal of constructing highly-congested carbon centers in a stereoselective manner, and in the use of transition-metal catalyzed alkylation as a means to address that goal.

The first research described is an extension of allylic alkylation methodology previously developed in the Stoltz group to small, strained rings. This research constitutes the first transition metal-catalyzed enantioselective α-alkylation of cyclobutanones. Under Pd-catalysis, this chemistry affords all–carbon α-quaternary cyclobutanones in good to excellent yields and enantioselectivities.

Next is described our development of a (trimethylsilyl)ethyl β-ketoester class of enolate precursors, and their application in palladium–catalyzed asymmetric allylic alkylation to yield a variety of α-quaternary ketones and lactams. Independent coupling partner synthesis engenders enhanced allyl substrate scope relative to allyl β-ketoester substrates; highly functionalized α-quaternary ketones generated by the union of our fluoride-triggered β-ketoesters and sensitive allylic alkylation coupling partners serve to demonstrate the utility of this method for complex fragment coupling.

Lastly, our development of an Ir-catalyzed asymmetric allylic alkylation of cyclic β-ketoesters to afford highly congested, vicinal stereocenters comprised of tertiary and all-carbon quaternary centers with outstanding regio-, diastereo-, and enantiocontrol is detailed. Implementation of a subsequent Pd-catalyzed alkylation affords dialkylated products with pinpoint stereochemical control of both chiral centers. The chemistry is then extended to include acyclic β-ketoesters and similar levels of selective and functional group tolerance are observed. Critical to the successful development of this method was the employment of iridium catalysis in concert with N-aryl-phosphoramidite ligands.

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Face à crescente procura por outras modalidades terapêuticas que abordam o ser humano de forma holística e a introdução das mesmas no SUS, torna-se muito importante a avaliação da efetividade e segurança dessas formas de cuidado. A Homeopatia faz parte deste conjunto de terapêuticas e, para sua avaliação, pode existir a necessidade de se valer de múltiplos instrumentos para abarcar os vários aspectos de uma resposta integral ao tratamento. Este trabalho teve como objetivo identificar e elaborar categorias de análises e instrumentos que permitam avaliar e mensurar a efetividade deste tratamento, bem como testá-los, considerando-se as características desta racionalidade. Foram levantados, na literatura nacional e internacional, trabalhos sobre efetividade do tratamento homeopático, em busca da definição do estado da arte mas também dos principais problemas, limitações e possibilidades dessas avaliações tendo em vista seu resultado integral. Finda esta etapa, a pesquisa destinou-se a elaboração, proposição e testagem de uma metodologia considerada mais adequada a avaliar o tratamento homeopático nesta perspectiva. Um estudo observacional foi realizado em serviço público homeopático no município de Juiz de Fora, com tratamento individualizado, no qual foi utilizada uma estratégia de avaliação composta por três componentes: (1) avaliação de qualidade de vida pelo instrumento SF-36; (2) análises em busca de objetivar e quantificar queixas clínicas e outros atributos de natureza subjetiva (sensação de bem-estar, sono, estado cognitivo e memória, vida sexual, sensação de felicidade) por meio da utilização de uma escala visual analógica (EVA), na mensuração da intensidade e de opções fechadas, a exemplo do SF-36, na estimativa da frequência desses aspectos e (3) entrevistas qualitativas por intermédio de questionário semiestruturado, com a finalidade de abordar questões relacionadas a biopatografia e mudança da atitude vital (como pacientes enfrentam os problemas do cotidiano, fatores deflagradores das queixas, como se sentem e como reagem, além de indagar seus projetos de vida e felicidade). A aplicação do questionário SF-36 apresentou algumas dificuldades de compreensão pelos participantes, talvez devido à baixa escolaridade dos entrevistados, mas mostrou-se útil à pesquisa, embora demonstre limitações na avaliação do aspecto integral do resultado da terapêutica analisada. O acompanhamento das queixas clínicas, sensação de bem-estar, sono e estado cognitivo e memória foram captados e mensurados de forma satisfatória tanto pela EVA (intensidade dos sintomas) quanto pelas respostas fechadas para medir a frequência. Situações como as avaliações da biopatografia e da sexualidade foram insuficientes para serem adequadamente avaliadas pelo pesquisador e o paciente somente. A participação do médico assistente poderia contribuir nestes casos. Questões mais abrangentes na avaliação da mudança na atitude vital, como reação diante de fatores desequilibrantes e projeto de vida e felicidade, necessitam de metodologia qualitativa até que se possa avançar nas pesquisas à espera de soluções futuras. A combinação dessas estratégias em estudos controlados, randomizados, com amostras de magnitude satisfatória, preferencialmente em rede e que explicitem as condições nas quais o atendimento homeopático ocorreu e como se chegou a cada prescrição, podem ter utilidade para a avaliação da efetividade da dimensão integral do tratamento homeopático.

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Background: Little is known about the types of 'sit less, move more' strategies that appeal to office employees, or what factors influence their use. This study assessed the uptake of strategies in Spanish university office employees engaged in an intervention, and those factors that enabled or limited strategy uptake. Methods: The study used a mixed method design. Semi-structured interviews were conducted with academics and administrators (n = 12; 44 +/- 12 mean SD age; 6 women) at three points across the five-month intervention, and data used to identify factors that influenced the uptake of strategies. Employees who finished the intervention then completed a survey rating (n = 88; 42 +/- 8 mean SD age; 51 women) the extent to which strategies were used [never (1) to usually (4)]; additional survey items (generated from interviewee data) rated the impact of factors that enabled or limited strategy uptake [no influence (1) to very strong influence (4)]. Survey score distributions and averages were calculated and findings triangulated with interview data. Results: Relative to baseline, 67% of the sample increased step counts post intervention (n = 59); 60% decreased occupational sitting (n = 53). 'Active work tasks' and 'increases in walking intensity' were the strategies most frequently used by employees (89% and 94% sometimes or usually utilised these strategies); 'walk-talk meetings' and ` lunchtime walking groups' were the least used (80% and 96% hardly ever or never utilised these strategies). 'Sitting time and step count logging' was the most important enabler of behaviour change (mean survey score of 3.1 +/- 0.8); interviewees highlighted the motivational value of being able to view logged data through visual graphics in a dedicated website, and gain feedback on progress against set goals. 'Screen based work' (mean survey score of 3.2 +/- 0.8) was the most significant barrier limiting the uptake of strategies. Inherent time pressures and cultural norms that dictated sedentary work practices limited the adoption of 'walk-talk meetings' and ` lunch time walking groups'. Conclusions: The findings provide practical insights into which strategies and influences practitioners need to target to maximise the impact of 'sit less, move more' occupational intervention strategies.

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[EN] The objective of this paper is to analyze the incubation strategies developed in the universities of Andalusia, a relatively low-income region of Spain, to promote the creation of university spin-offs. These strategies are also compared to the incubation models noted in the literature. The performance of the university spin-offs created and its relation to the incubation strategies developed by the university are also analysed. The analysis is based on data from a survey of nine public universities that carry out strategies for the promotion of university spin-offs. The result of the analysis shows that university spin-off incubation strategies in Andalusia present specific characteristics not covered by certain models that are well-known in the literature on innovation. Then, a new stage in the process of the university spin-off incubation is proposed. We consider it to be a pre-strategic stage to the academic spin-off incubation strategies. The analysis also finds certain environmental factors associated to those spin-offs promoted by Andalusian universities that achieve the highest level of performance. This result suggests that previous to making any decision involving investment into developing incubation strategies, universities should gauge whether they have sufficient resources and the possibilities of connecting with a Technology Park.

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A discussão sobre a gestão é recente no Brasil, particularmente no âmbito da administração pública. As diretrizes do SUS são importantes instrumentos indutores de mudanças e modernização da gestão, incluindo aspectos relativos à organização da assistência, como sua humanização e também a busca de maiores níveis de desempenho e responsabilidade institucional para com os resultados alcançados. Diversos autores vêm se debruçando sobre o tema gestão, porém qual o modelo de gestão que conseguiria combinar um papel ativo, de liderança e de coordenação para gestores com autonomia? O presente trabalho tem por objetivo analisar a prática gerencial nos serviços de saúde do município de Piraí, buscando compreender as dimensões sociais e intersubjetivas de tais práticas, tendo como principal fonte as narrativa de seus gerentes. O município possui um contexto político peculiar, com uma continuidade política desde 1993, adota uma política de gestão participativa na saúde com várias instâncias formais e pratica um investimento em saúde acima do preconizado pela Constituição Federal o que permite um investimento em estruturação e oferta de serviços públicos. Do ponto de vista metodológico, o estudo adotou a abordagem de narrativas de vida, focalizando a gestão como um mundo social e expressão dos processos presentes nas organizações e que atravessam o relato dos entrevistados. Foram entrevistados quatro gerentes de unidades de saúde do município de Piraí. A análise do material empírico teve como um de seus eixos o estudo do percurso profissional dos gerentes, especialmente os processos que os levaram à função gerencial. A contingência marca essas trajetórias que se desenrolam em um contexto em que não existe qualquer exigência quanto à formação gerencial. Outro eixo abordado são as práticas gerenciais onde são examinados os sentidos que o exercício da função gerencial tem para os sujeitos, como também as suas estratégias de trabalho. O exame das práticas gerenciais norteia-se pela análise das possibilidades e limites para desencadear processos de mudança. Os depoimentos apontam as características destas experiências de gestão, que procuram construir condições para processos de mudança, seja através das experiências anteriores dessas gerentes ou das estratégias de trabalho e do sistema gerencial que procuram desenvolver. Os projetos profissionais de três das quatro entrevistadas vão claramente se definindo no âmbito da gestão: se veem, não mais como profissionais de sua área de formação original (enfermeira, médica), mas acima de tudo como gestores, alimentados pelo reconhecimento de suas capacidades de mobilização e de desenvolvimento de mudanças relativas a outras realizações no campo da gestão.

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The purpose of the project is to improve our understanding about best management practices that can be utilized on diked managed wetlands in Suisun Marsh for reducing the occurrence of low dissolved oxygen (DO) and high methylmercury (MeHg) events associated primarily with fall flood-up practices. Low DO events are of concern because they can lead to undue stress and even mortality of sensitive aquatic organisms. Elevated MeHg levels are of concern because MeHg is a neurotoxin that bio-magnifies up the food chain and can cause deleterious effects to higher trophic level consumers such as piscivorous fish, birds, and mammals (including humans). This study involved two years (2007-2008) of intensive field data collection at two managed wetland sites in northwest Suisun Marsh and their surrounding tidal sloughs, an area with prior documented low DO events. In addition, the study collected limited soils and water quality field data and mapped vegetation for three managed wetland sites in the central interior of Suisun Marsh, for the purpose of examining whether wetlands at other locations exhibit characteristics that could indicate potential for similar concerns. In Year 1 of the study, the objective was to identify the baseline conditions in the managed wetlands and determine which physical management conditions could be modified for Year 2 to reduce low DO and MeHg production issues most effectively. The objective of Year 2 was to evaluate the effectiveness of these modified management actions at reducing production of low DO and elevated MeHg conditions within the managed wetlands and to continue improving understanding of the underlying biogeochemical processes at play. This Final Evaluation Memorandum examined a total of 19 BMPs, 14 involving modified water management operations and the remaining five involving modified soil and vegetation management practices. Some of these BMPs were previously employed and others have not yet been tested. For each BMP this report assesses its efficacy in improving water quality conditions and potential conflicts with wetland management. It makes recommendations for further study (either feasibility assessments or field testing) and whether to consider for future use. Certain previously used BMPs were found to be important contributors to poor water quality conditions and their continued use is not recommended. Some BMPs that could improve water quality conditions appear difficult to implement in regards to compatibility with wetland management; these BMPs require further elaboration and feasibility assessment to determine whether they should be field tested. In practice for any given wetland, there is likely a combination of BMPs that would together have the greatest potential to address the low DO and high MeHg water quality concerns. Consequently, this report makes no sweeping recommendations applicable to large groups of wetlands but instead promotes a careful consideration of factors at each wetland or small groups of wetlands and from that assessment to apply the most effective suite of BMPs. This report also identifies a number of recommended future actions and studies. These recommendations are geared toward improving the process understanding of factors that promote low DO and high MeHg conditions, the extent of these problems in Suisun Marsh, the regulatory basis for the DO standards for a large estuarine marsh, the economics of BMPs, and alternative approaches to BMPs on diked managed wetlands that may address the water quality issues. The most important of these recommendations is that future BMP implementation should be carried out within the context of rigorous scientific evaluation so as to gain the maximum improvement in how to manage these water quality issues in the diked managed wetlands of Suisun Marsh.

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O objetivo desta dissertação é analisar contos selecionados e o romance Under the Feet of Jesus da escritora chicana Helena María Viramontes, enfocando a apropriação de mitos astecas e lendas mexicanas protagonizados por figuras femininas, históricas ou míticas, como La Manlinche, La Llorona e The Hungry Woman. Esta re-visão crítica do passado tem um papel vital para as chicanas, reais e ficcionais, ao enfrentarem o domínio patriarcal, colonial e neocolonial. Devido à complexidade gerada pela ausência de linearidade narrativa, tanto nos contos como no romance, tornou-se necessária uma breve análise das estratégias narrativas a fim de ilustrar como tais estratégias estão intrinsecamente ligadas à apresentação fragmentada da vida dos trabalhadores migrantes. Foi igualmente indispensável examinar as demais práticas narrativas da autora tais como focalização, desconstrução, simultaneidade e justaposição, assim como o elo, por ela proposto em Under the Feet of Jesus, entre leitura, identidade, e engajamento com o mundo para promover a transformação social