3,733 research outputs found
The characterization of organic monolayers at gold surfaces using scanning tunneling microscopy and atomic force microscopy: Correlation with macrostructural properties
Monolayer films formed by the self-assembly of organothiols at epitaxially grown Au(111) films at mica were examined in air using scanning tunneling (STM) and atomic force microscopies (AFM). n-Alkanethiolate monolayers exhibit a hexagonal packing arrangement with nearest-neighbor and next-nearest-neighbor spacings of approximately 0.50 nm and 0.87 nm, respectively, as revealed by both STM and AFM. This arrangement is consistent with the (√3 x √3)R30° adlayer structure at Au(111), confirming the results of previous macroscopic studies. The STM reveals the structure of the Au-bound sulfur. In contrast, the AFM details the structure at the monolayer/air interface, revealing that the order at the Au-S interface is retained up to the monolayer/air interface. The investigation of the self-assembled CF[subscript]3(CF[subscript]2)[subscript]7(CH[subscript]2)[subscript]2 SH monolayer at Au(111) by AFM reveals a (2 x 2) adlayer structure, with nearest-neighbor and next-nearest-neighbor spacings of 0.58 ± 0.02 nm and 1.0 ± 0.02 nm, respectively. This arrangement is consistent with the larger van der Waals diameter of the fluorinated chain versus the alkane chain. The coverage of this fluorinated thiolate monolayer, as determined from the electrochemical reductive desorption, is (6.3 ± 0.8) x 10[superscript]-10 mol/cm[superscript]2, a value consistent with the expected 0.25 monolayer coverage of the (2 x 2) adlayer structure at Au(111). Infrared reflection spectroscopic (IRS) data also confirm this structure. Upon prolonged exposure to air (\u3e2 days), the thiolate species is oxidized to elemental sulfur in the forms of cyclooctasulfur (cyclo-S[subscript]8) and other allotropes. The STM investigation reveals the appearance of square structures on aged thiolate monolayers. The dimensions of these squares (0.40-0.50 nm per side) are close to those of cyclo-S[subscript]8. Electrochemical reductive desorption experiments also reveal a change in the surface species with time, with a second desorption wave appearing. The importance of these microscopic characterizations is examined in the context of molecular level descriptions that have recently been developed from macroscopic characterization studies of these monolayers
Saliência de papéis e stresse profissional numa amostra de professores : comparações inter-geracionais
Tese de mestrado, Psicologia (Secção de Psicologia dos Recursos Humanos, do Trabalho e das Organizações), Universidade de Lisboa, Faculdade de Psicologia, 2012A presente investigação insere-se no âmbito do estudo da saliência de papéis e do stresse profissional, com o objectivo de comparar três gerações: a Geração Baby Boomer, a Geração X e a Geração Y. A amostra é constituída por 68 professores do ensino básico e secundário. Os instrumentos utilizados foram o Inventário sobre a Saliência das Actividades e o Inventário sobre o Stresse Profissional. Os resultados obtidos parecem indiciar a inexistência de diferenças inter-geracionais entre os professores, no que diz respeito à saliência de papéis e ao stresse profissional. Ressalva-se, porém, que a participação na actividade estudo é significativamente mais elevada na Geração Baby Boomer, comparativamente à Geração X e, ao nível do stresse profissional os acontecimentos burocráticos são considerados mais stressantes e mais frequentes na Geração Baby Boomer face à Geração Y.This investigation is inserted under the study of role salience and occupational stress, in order to compare three generations: the Baby Boomer Generation, Generation X and Generation Y. The sample consists of 68 teachers of elementary and secondary education. The instruments used were the Survey on the Role Salience and Job Stress Survey. The results obtained appear to indicate the absence of intergenerational differences between the teachers respecting to the role salience and occupational stress. However, is important to note that participation in the activity study is significantly higher in the Baby Boomer Generation, compared to Generation X and at occupational stress level the bureaucratic events are considered more stressful and more frequent at Baby Boomer Generation face Generation Y
Modelos de supervisão/regulação bancária: enquadramento internacional e desenvolvimentos mais recentes
Mestrado em Contabilidade e Análise FinanceiraEsta investigação centra-se na temática “Modelos de Supervisão/Regulação bancária: Enquadramento internacional e desenvolvimentos mais recentes ”, apresentando uma abordagem teórica dos modelos de Supervisão / Regulação adoptados pelos governos, enquadrando-os no actual contexto de crise financeira, aferindo as suas fragilidades, mas também abordando as principais reformas na sua estrutura e funcionamento.
As origens e desenvolvimentos da crise financeira vieram demonstrar debilidades nos modelos de supervisão/regulação demasiado assentes na auto-regulação e na mera disciplina de mercado. Para evitar novas crises é necessária uma maior cooperação em termos de partilha de informação entre as entidades de supervisão, assim como atribuir aos reguladores/supervisores, de modo concertado, poderes acrescidos para que possam actuar de modo mais eficaz nos mercados. No entanto, é necessário reconhecer que, por mais que se supervisione e se aperfeiçoem os quadros regulatórios, nada substituirá o comportamento responsável, tanto por parte de quem investe como por parte de quem gere esse investimento.
Assim, esta crise deve ser encarada também como uma oportunidade para implementar importantes reformas no sistema financeiro. Nesta perspectiva, este estudo focou-se nos dois exercícios de stress test realizados à banca europeia, os quais evidenciaram que todos os bancos portugueses participantes se situaram acima do limiar para o rácio de capital previsto.
Para melhor se avaliarem os resultados obtidos foi colocada a questão de saber em que medida a adequação de fundos próprios, por parte das instituições financeiras, contribui para a estabilidade do sistema financeiro, tendo-se concluído que quanto maior for o rácio de solvabilidade maior será a capacidade dos bancos fazerem face a eventuais choques económico-financeiros.This research focuses on the theme “Models of Supervision / Banking Regulation: International framework and recent developments”, presenting a theoretical model of supervision / regulation adopted by governments, framing them in the current context of financial crisis, gauging their weaknesses, but also addressing key reforms in its structure and operation.
The beginning and developments of the financial crisis have demonstrated weaknesses in the models of supervision / regulation too much based on a simple self-regulation and market discipline. To avoid further crises it’s necessary a greater cooperation in terms of sharing information between supervisors, as well as to give regulators / supervisors in a concerted fashion, increased powers to enable them to act more effectively on world markets. Nevertheless, we must recognize that, however much they oversee and improve regulatory frameworks, nothing will replace the responsible behavior by those who invest as by those who manage the investment.
So, this crisis should be seen also as an opportunity to implement major reforms in the financial system. In this perspective, this study focused on two exercise stress tests for European banks, which showed that all the portuguese participants stood above the threshold for the ratio of capital expected.
For better evaluate the results obtained was put the question of knowing in what way the own funds adequacy, for financial institutions, contributes to the stability of the financial system, it was concluded that the higher the solvency ratio greater banks' ability to cope with economic and financial eventual shocks
Apoio social, saúde mental e bem-estar em idosos institucionalizados e não institucionalizados
Contexto: o envelhecimento bem-sucedido está associado a três grandes
grupos de condições: baixa probabilidade de ter doenças; manutenção de um
elevado nível funcional (físico e cognitivo); e, conservação do empenho social e
bem-estar, o que reforça a ideia de que o apoio social e o bem-estar são
variantes fundamentais na saúde mental, em particular, na população idosa
(fontaine, 2000).
Objetivo(s): o presente estudo tem como objetivo caraterizar a saúde
mental, o bem-estar e o apoio social de idosos institucionalizados e não
institucionalizados.
metodologia: participaram 100 idosos (50 institucionalizados e 50
não institucionalizados) com idades iguais ou superiores a 65
anos, residentes no grande porto. Os dados foram recolhidos com recurso a
um questionário sociodemográfico, à versão portuguesa da escala de bemestar
mental de warwick-edinburgh (wemwbs), à escala continuum de saúde
mental (mhc-sf) e à escala de rede de apoio social de lubben (lsns-6). O
tratamento dos dados foi realizado com recurso ao programa estatístico spss,
versão 24.
Resultados: verificou-se uma relação positiva entre bem-estar, saúde mental e
apoio social, sugerindo que globalmente os idosos que apresentam maior bemestar,
apresentam também níveis mais elevados de saúde mental e têm
perceção de apoio social mais elevado. Em termos do impacto da
institucionalização constatou-se que são os idosos Institucionalizados,
concretamente as mulheres, que apresentam níveis mais baixos de bem-Estar,
saúde mental e apoio social. Ainda a destacar que níveis mais baixos de bemestar
e saúde mental nos idosos solteiros ou divorciados, em comparação com
os viúvos ou casados, sobretudo nos idosos institucionalizados. Nos idosos não
institucionalizados o ter descendência representou um papel importante, uma
vez que estes apresentaram níveis mais elevados de bem-estar, saúde mental
e suporte social, em particular ao nível da família.
Conclusões: em termos globais este estudo indica o impacto menos positivo
que a institucionalização pode ter ao nível da saúde mental na população
idosa. Os dados parecem também sublinhar a relevância do apoio social
enquanto variável associada ao bem-estar e saúde mental dando assim importantes pistas para a intervenção biopsicossocial com esta população.info:eu-repo/semantics/publishedVersio
Toxicological effects of a pharmaceutical, simvastatin, in Gammarus locusta: histopathological evaluation
Dissertação para obtenção do Grau de Mestre em
Engenharia do AmbientePharmaceuticals and their derivatives are considered emerging organic contaminants of aquatic ecosystems, mostly by inputs from domestic and hospital effluents. The toxicological risk associated to these substances results essentially from their ability to act on a specific metabolic process. These substances have been revealed toxic to aquatic organisms as well as to the human populations that depend on these ecosystems. However, the toxicity of pharmaceuticals in the environment is not yet well known, such as for simvastatin, which is a human drug used for the treatment of high levels of cholesterol. The amphipod Gammarus locusta is a species with high ecological relevance and high importance in toxicological studies, both acute and chronic. However, histopathological appraisals on these organisms are almost absent. Gammarus locusta (newborn) were exposed to a chronic assay with a broad range of sublethal concentrations of simvastatin. At the end of their life cycle, males and females were subjected to a histopathological evaluation using histochemical techniques for light bright-field and fluorescence microscopy, considering the hepatopancreas as the main target-organ. The comparison between the control treatment and the organisms exposed to several concentrations of the pharmaceutical permitted the selection and evaluation of qualitative and quantitative histopathological biomarkers. The results show non-monotonic dose-response curves that support the physiological alterations on the hepatopancreas epithelium reflecting alterations in the metabolism of carbohydrates, enzymatic activity and lipid storage. However, no evidence of severe lesions in this and other organs could be related to exposure. Females presented a higher ability to react to the pharmaceutical than males, when exposed to the lower concentrations of simvastatin. This can be connected with the higher energy reserves of females, associated in part to their reproductive functions. In conclusion, simvastatin affects amphipod metabolism that is responsible by alterations on cellular structures of the hepatopancreas, revealing thus more important physiological alterations than direct damage induced by the pharmaceutical
Feline leishmaniasis: a review
Abstract
According to the World Health Organization (WHO), Leishmaniasis’ endemic areas have spread
and the prevalence of the disease has increased, as well as the number of reported cases.
Europe is one of the most affected continents concerning the risk of re-emergency of this
zoonosis.
Feline Leishmaniasis (FeL) was for the first time described in Algeria, 1912. The significance of
the cat as a reservoir of Leishmania and not simply an alternative host seems to be gaining
ground, mainly because: i) cats can present increased seropositivity between serology analysis;
ii) cats can be infected during some months and thus are available for sand flies; iii) cats
transmit the Leishmania agent in a competent form.
Furthermore, cats have behavioral characteristics that contribute to the infection by Leishmania
infantum, and as such, FeL has been reported worldwide. When clinical signs of FeL are
present, they are usually cutaneous, with unspecific dermatological changes, that frequently
occur in other feline diseases and if not diagnosed can contribute to an underestimation of the
actual occurrence of the disease in cats. The low seroprevalence titers along with the commonly
asymptomatic infection in cats can further contribute to the underestimation of FeL occurrence.
This work aims to bring up to date the current status of FeL infection worldwide. It comprises a
review of the most recent case reports and surveillance studies. Although currently limited, the
most relevant and recent information on the parasite, vector, epidemiology, pathology, and
immune response is presented, as well as available diagnostic and treatment strategies. The
knowledge of the epidemiological and immunopathological features of FeL, in some aspects so
different from the Canine Leishmaniasis (CanL), can be used as a tool in an attempt to prevent
infection and decrease the hazard that FeL can embody for both humans and cats
Contextos de vida: desafios e concretizações
Relatório de atividade profissional de
mestrado integrado em Psicologia (área de especialização em Psicologia Escolar e da Educação)Resumo: Este relatório de atividade profissional tem como objetivo descrever um conjunto de
atividades para evidenciar o percurso profissional enquanto psicóloga, nos últimos doze anos,
na área da Psicologia Escolar e da Educação. Apresentam-se as atividades desenvolvidas num
agrupamento escolar e no contexto da formação profissional, inserida em projetos de cariz
educativo. Nas atividades apresentadas, descrevem-se as funções e papéis desempenhados
como psicóloga escolar e da educação e respetivas competências desenvolvidas e adquiridas.
Procedemos igualmente a uma reflexão pessoal acerca do papel e competências do psicólogo
na área da Psicologia Escolar e da Educação, no contexto escolar e educativo, limitações,
contexto profissional, ética, carreira.Abstract: The aim of this professional activity report is to describe a series of activities to
highlight the professional career path as a psychologist, in the last twelve years, in the field of
School and Educational Psychology. The activities which were undertaken in a school
grouping and in the context of vocational training, inserted in projects oriented towards
education, are presented. The functions and roles performed as a school and educational
psychologist and respective skills which were developed and acquired are described in the
exposed activities. Equally, we proceed to make a personal reflection about the role and skills
of a psychologist in the field of School and Educational Psychology in the school and
educational context, limitations, professional context, ethics and career
Elder abuse: a mini review
There is an increasing interest in social, clinical, and public health research on elder abuse. Recent studies show a wide prevalence range of figures because studies employ different populations, measures, and definitions of abuse. The prevalence rate of elderly people abuse is between 2% and 44%. It is one of the most hidden modes of interfamily conflict, and the strategies of recognition of this problem as a social and global phenomenon are still meager. The lack of adequate guidelines related to this major public health issue make it difficult to early evaluate and recognize elderly abuse, as its often confused with the aging process. For these reasons, healthcare professionals should be more aware to this issue, to screen elderly abuse and to develop strategies to early detect the risk factors for elder abuse.info:eu-repo/semantics/publishedVersio
O PASSADO PRESENTE: a política de assistência social e os rebatimentos no trabalho profissional
RESUMO: Neste trabalho realizo uma análise da política de assistência social no Brasil levando em consideração os determinantes estruturais e conjunturais da sociabilidade burguesa, revelando o espectro do passado no presente e as implicações no trabalho do (a) assistente social nesta política pública. Neste sentido, o trabalho foi estruturado buscando desmistificar a forma etapista de apreender a história ao realizar um movimento de avançar e resgatar estes traços na história dialeticamente
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