956 resultados para micro and small enterprises
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Connexins are transmembrane proteins that form gap junction- and hemi-channels. Once inserted into the membrane, hemi-channels (connexons) allow for diffusion of ions and small molecules (<1kDa) between the extracellular space and the cytosol. Gap junction channels allow diffusion of similar molecules between the cytoplasms of adjacent cells. The expression and function of connexins in blood vessels has been intensely studied in the last few decades. In contrast, only a few studies paid attention to lymphatic vessels; convincing in vivo data with respect to expression patterns of lymphatic connexins and their functional roles have only recently begun to emerge. Interestingly, mutations in connexin genes have been linked to diseases of lymphatic vasculature, most notably primary and secondary lymphedema. This review summarizes the available data regarding lymphatic connexins. More specifically it addresses (i) early studies aimed at presence of gap junction-like structures in lymphatic vessels, (ii) more recent studies focusing on lymphatic connexins using genetically engineered mice, and (iii) results of clinical studies that have reported lymphedema-linked mutations in connexin genes.
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The identification of a distinct syndrome, designated eosinophilic oesophagitis (EoE), with its own clinical and histopathological characteristics, was first described in the early 1990s. Meanwhile intense research has uncovered many molecular, immunological and clinical aspects of this chronic-inflammatory disorder. This article focuses exclusively on basic and clinical insights of EoE gathered during the last few years. Regarding aetiopathogenesis it has become clear that EoE is a food-triggered disease with milk and wheat as the dominant culprit food categories. However, it is still debated whether a disturbed mucosal integrity allowing allergens to cross the mucosal barrier, or changes in wheat and milk manufacturing might induce these inflammatory responses. Furthermore, basic science and clinical studies have accordingly confirmed that a chronic eosinophilic inflammation leads to a remodelling of the oesophagus with micro- and macro-morphological alterations, ending in a strictured oesophagus with impaired function. Fortunately, long-term therapeutic trials, using either topical corticosteroids or dietary allergen avoidance, have demonstrated that this sequela can be prevented or even reversed. This finding is of clinical relevance as it supports the initiation of a consistent anti-inflammatory therapy. Nevertheless, EoE is still an enigmatic disease and the long list of unanswered questions will certainly stimulate further research.
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Institutional and organizational variety is increasingly characterizing advanced economic systems. While traditional economic theories have focused almost exclusively on profit-maximizing (i.e., for-profit) enterprises and on publicly-owned organizations, the increasing relevance of non-profit organizations, and especially of social enterprises, requires scientists to reflect on a new comprehensive economic approach for explaining this organizational variety. This paper examines the main limitations of the orthodox and institutional theories and asserts the need for creating and testing a new theoretical framework, which considers the way in which diverse enterprises pursue their goals, the diverse motivations driving actors and organizations, and the different learning patterns and routines within organizations. The new analytical framework proposed in the paper draws upon recent developments in the theories of the firm, mainly of an evolutionary and behavioral kind. The firm is interpreted as a coordination mechanism of economic activity, and one whose objectives need not coincide with profit maximization. On the other hand, economic agents driven by motivational complexity and intrinsic, non-monetary motivation play a crucial role in forming firm activity over and above purely monetary and financial objectives. The new framework is thought to be particularly suitable to correctly interpret the emergence and role of nontraditional organizational and ownership forms that are not driven by the profit motive (non-profit organizations), mainly recognized in the legal forms of cooperative firms, non-profit organizations and social enterprises. A continuum of organizational forms ranging from profit making activities to public benefit activities, and encompassing mutual benefit organizations as its core constituent, is envisaged and discussed.
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Many firms around the world are managed and partially owned by entrepreneurs. These entrepreneurs hold under diversified portfolios and, therefore, bear idiosyncratic risk in addition to systematic risk. To compensate the additional risk borne, they extract private benefits. In this paper, we analyse how an entrepreneur's overconfidence affects the market performance of the firm, through the channel of private benefits. We show that two dimensions of overconfidence, namely overestimation of future cash-flows and underestimation of idiosyncratic risk (called miscalibration), have opposite effects on the private benefits extracted by the entrepreneur. As a consequence, firms managed and partially owned by overconfident entrepreneurs can deliver overperformance or underperformance, depending on the prevalence of overestimation or miscalibration of the beliefs of the entrepreneur.
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In this study we investigated the effect of medial temporal lobe epilepsy (MTLE) on the global characteristics of brain connectivity estimated by topological measures. We used DSI (Diffusion Spectrum Imaging) to construct a connectivity matrix where the nodes represents the anatomical ROIs and the edges are the connections between any pair of ROIs weighted by the mean GFA/FA values. A significant difference was found between the patient group vs control group in characteristic path length, clustering coefficient and small-worldness. This suggests that the MTLE network is less efficient compared to the network of the control group.
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Cancer genomes frequently contain somatic copy number alterations (SCNA) that can significantly perturb the expression level of affected genes and thus disrupt pathways controlling normal growth. In melanoma, many studies have focussed on the copy number and gene expression levels of the BRAF, PTEN and MITF genes, but little has been done to identify new genes using these parameters at the genome-wide scale. Using karyotyping, SNP and CGH arrays, and RNA-seq, we have identified SCNA affecting gene expression ('SCNA-genes') in seven human metastatic melanoma cell lines. We showed that the combination of these techniques is useful to identify candidate genes potentially involved in tumorigenesis. Since few of these alterations were recurrent across our samples, we used a protein network-guided approach to determine whether any pathways were enriched in SCNA-genes in one or more samples. From this unbiased genome-wide analysis, we identified 28 significantly enriched pathway modules. Comparison with two large, independent melanoma SCNA datasets showed less than 10% overlap at the individual gene level, but network-guided analysis revealed 66% shared pathways, including all but three of the pathways identified in our data. Frequently altered pathways included WNT, cadherin signalling, angiogenesis and melanogenesis. Additionally, our results emphasize the potential of the EPHA3 and FRS2 gene products, involved in angiogenesis and migration, as possible therapeutic targets in melanoma. Our study demonstrates the utility of network-guided approaches, for both large and small datasets, to identify pathways recurrently perturbed in cancer.
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INTRODUCTION: Squamous-cell carcinoma of the head and neck (SCCHN) remains a challenging clinical problem, due to the persistent high rate of local and distant failures and the occurrence of secondary primaries. For locally advanced SCCHN, a combination of chemotherapy (CT), radiation or surgery is often used, but there are limitations, which may reduce compliance. Molecular targeted therapies, namely anti-EGFR treatments, are in development with the aim of improving clinical outcomes and mitigating treatment-related toxicities. AREAS COVERED: This review provides an overview of early investigational drugs that target EGFR for the treatment of SCCHN and discusses the ongoing trials in this domain. EXPERT OPINION: Targeted therapies are increasingly used in oncology, especially in SCCHN. Cetuximab has demonstrated a significant improvement in the treatment outcome, both as a curative treatment in combination with radiation therapy and as a palliative treatment in combination with CT; however, it failed to show any benefit in combination with concomitant chemoradiotherapy. Presently, there are many new agents, including monoclonal antibodies and small-molecule tyrosine kinase inhibitors, which are either currently under investigation for or which warrant further investigation for treating SCCHN. The discovery of predictive factors that help to identify patients most likely to respond to EGFR inhibitors as well as patient-customized therapies would help to improve patient outcomes in the future.
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Literature on sex occupational segregation has typically focused on the micro and macro determinants of it, on mobility patterns over the life course, on implications of segregation and mobility for gender inequalities. Rarely the link between sex-type occupations and women’s risk of labour market interruptions over family formation has been explored. In this piece of work we shall analyse whether women who are working in the female-dominated, male-dominated or integrated occupations have more or less chances to remain attached to the labour market, controlling for qualifications, class, sector and contract positions. By drawing from ECHP, and comparing Italy, Spain, Denmark and the UK, we shall in particular see whether such connection varies across countries with different institutional and cultural configurations.We find that, ceteris paribus, only in the UK the sex-composition of an occupation matters: women in female occupations are more likely to move to inactivity than women in mixed or male occupations. In the other countries considered the main cleavages lie elsewhere. In Italy what matters most is the sector of employment (public vs. private). In Spain the sector is relevant too, but also social class and the type of contract held (permanent vs. temporary). In Denmark women’s transitions to inactivity are largely independent of human capital and job characteristics.
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We offer new evidence on multi-level determinants of the gender division of housework. Using data from the 2004 European Social Survey (ESS) for 26 European, we study the micro and macro-level factors which increase the likelihood of men doing an equal or greater share of housework than their female partners. A sample of 11,915 young men and women is analysed with a multi-level logistic regression in order to test at individual level the classic relative-income, time-availability and gender-role values, and a new couple conflict hypothesis. At individual level we find significant relationships between relative resources, values, couple's disagreement, and the division of housework which support more economic dependency than "doing gender" perspectives. At the macro-level, we find important composition effects and also support for gender empowerment, family model and social stratification explanations of cross-country differences.
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This paper investigates the micro and macro-level factors affecting the empirical association between occupational sex-composition and individual earnings. This is done in two analytical steps using data from the second round of the European Social Survey. In a first step, country-fixed-effects regressions are used to test the extent to which job-specialization, gender attitudes and the relative supply of domestic work can account for the impact of occupational sex-composition on earnings. In accordance with previous research, it is found that all these micro-level variables have a significant effect on the analyzed association, yet only job-specialization can explain it away by itself. In a second analytical step, macro-level interactions are tested under the hypothesis that defamilialization policies reduce the pay-offs of sphere specialization by sex, generating incentives for all types of women to invest in the labor market. Empirical results suggest that gender attitudes and the relative supply of housework are much more loosely associated to earning in social-democratic and former communist societies than in conservative or liberal regimes. This finding is interpreted as consistent with the defamilialization hypothesis.
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Recent studies at high magnetic fields using the phase of gradient-echo MR images have shown the ability to unveil cortical substructure in the human brain. To investigate the contrast mechanisms in phase imaging, this study extends, for the first time, phase imaging to the rodent brain. Using a 14.1 T horizontal bore animal MRI scanner for in vivo micro-imaging, images with an in-plane resolution of 33 microm were acquired. Phase images revealed, often more clearly than the corresponding magnitude images, hippocampal fields, cortical layers (e.g. layer 4), cerebellar layers (molecular and granule cell layers) and small white matter structures present in the striatum and septal nucleus. The contrast of the phase images depended in part on the orientation of anatomical structures relative to the magnetic field, consistent with bulk susceptibility variations between tissues. This was found not only for vessels, but also for white matter structures, such as the anterior commissure, and cortical layers in the cerebellum. Such susceptibility changes could result from variable blood volume. However, when the deoxyhemoglobin content was reduced by increasing cerebral blood flow (CBF) with a carbogen breathing challenge, contrast between white and gray matter and cortical layers was not affected, suggesting that tissue cerebral blood volume (and therefore deoxyhemoglobin) is not a major source of the tissue phase contrast. We conclude that phase variations in gradient-echo images are likely due to susceptibility shifts of non-vascular origin.
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Este trabalho apresenta um estudo qualitativo, desenvolvido através de pesquisa exploratória, bibliográfica e de campo, feito a trezentos e noventa e nove empreendedores e empresários da Ilha de Santiago, tendo em consideração o cenário económico actual e a preocupação à volta do sector privado. Procurou-se através de pesquisa junto às empresas activas, e cujo número de pessoas ao seu serviço não ultrapassa vinte, identificar três pontos fundamentais relacionados com os empreendedores: investigar os factores que levaram as pessoas a tornarem-se empreendedores; investigar as características principais do empreendedor de sucesso; identificar as características imprescindíveis para se atingir o sucesso empresarial relacionadas com o conhecimento, competências, atitude e talento, sequenciadas por ordem de importância. Para um melhor entendimento destas questões foi utilizado um referencial teórico que aborda o empreendedorismo. A pesquisa de campo foi realizada através de utilização de questionários – entrevistas às empresas estabelecidas nesta ilha, e o método de recolha de dados foi o de entrevista directa. Os resultados obtidos mostraram que os empreendedores enfatizam a importância dos factores comportamentais no sucesso das pequenas e médias empresas e evidenciaram que os factores mais significativos e limitativos do sucesso dos empreendedores no Município da Praia, ilha de Santiago, se referem ao ambiente interno do negócio. Considerando todos estes factores e de acordo com as pesquisas desenvolvidas e analisadas, este trabalho recolheu informações específicas dos empreendedores de sucesso da ilha de Santiago e que podem ser úteis para os que almejam o sucesso empresarial e para eventuais programas de capacitação e formação empreendedora na ilha. This work presents a qualitative study developed through exploratory, bibliographic and field research to three hundred and ninety nine managers and entrepreneurs from Santiago Island, taking into consideration the present economical scenario and main concerns linked to private sector. Through a research in active enterprises and whose staff number doesn’t exceed twenty, the goal was to identify three main issues related to entrepreneurs: look into the factors that encouraged people to become entrepreneurs; examine the main characteristics of a successful entrepreneur and identify, sequenced by order of importance, the most critical characteristics related to knowledge, skills, attitude and talent, that allow entrepreneurial success achievement. For a better understanding of these questions, a theoretical approach to entrepreneurship was exploited. Field research was carried on through the use of questionnaires in enterprises located in Praia, and the data collection method was direct interviews. Results obtained showed that entrepreneurs emphasize the importance of behavioral factors in the success of small and medium enterprises and they evidenced that the most significant and restrictive factors of entrepreneurs’ success in Santiago Island are related to internal business environment. Considering these factors, and according to research developed and analyzed, the work has collected specific information of successful entrepreneurs in Santiago that can be useful for those, in the island, who seek entrepreneurial success and for eventual capacity building and entrepreneurial training programs.
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Este trabalho apresenta um estudo qualitativo, desenvolvido através de pesquisa exploratória, bibliográfica e de campo, feito a trezentos e noventa e nove empreendedores e empresários da Ilha de Santiago, tendo em consideração o cenário económico actual e a preocupação à volta do sector privado. Procurou-se através de pesquisa junto às empresas activas, e cujo número de pessoas ao seu serviço não ultrapassa vinte, identificar três pontos fundamentais relacionados com os empreendedores: investigar os factores que levaram as pessoas a tornarem-se empreendedores; investigar as características principais do empreendedor de sucesso; identificar as características imprescindíveis para se atingir o sucesso empresarial relacionadas com o conhecimento, competências, atitude e talento, sequenciadas por ordem de importância. Para um melhor entendimento destas questões foi utilizado um referencial teórico que aborda o empreendedorismo. A pesquisa de campo foi realizada através de utilização de questionários – entrevistas às empresas estabelecidas nesta ilha, e o método de recolha de dados foi o de entrevista directa. Os resultados obtidos mostraram que os empreendedores enfatizam a importância dos factores comportamentais no sucesso das pequenas e médias empresas e evidenciaram que os factores mais significativos e limitativos do sucesso dos empreendedores no Município da Praia, ilha de Santiago, se referem ao ambiente interno do negócio. Considerando todos estes factores e de acordo com as pesquisas desenvolvidas e analisadas, este trabalho recolheu informações específicas dos empreendedores de sucesso da ilha de Santiago e que podem ser úteis para os que almejam o sucesso empresarial e para eventuais programas de capacitação e formação empreendedora na ilha. This work presents a qualitative study developed through exploratory, bibliographic and field research to three hundred and ninety nine managers and entrepreneurs from Santiago Island, taking into consideration the present economical scenario and main concerns linked to private sector. Through a research in active enterprises and whose staff number doesn’t exceed twenty, the goal was to identify three main issues related to entrepreneurs: look into the factors that encouraged people to become entrepreneurs; examine the main characteristics of a successful entrepreneur and identify, sequenced by order of importance, the most critical characteristics related to knowledge, skills, attitude and talent, that allow entrepreneurial success achievement. For a better understanding of these questions, a theoretical approach to entrepreneurship was exploited. Field research was carried on through the use of questionnaires in enterprises located in Praia, and the data collection method was direct interviews. Results obtained showed that entrepreneurs emphasize the importance of behavioral factors in the success of small and medium enterprises and they evidenced that the most significant and restrictive factors of entrepreneurs’ success in Santiago Island are related to internal business environment. Considering these factors, and according to research developed and analyzed, the work has collected specific information of successful entrepreneurs in Santiago that can be useful for those, in the island, who seek entrepreneurial success and for eventual capacity building and entrepreneurial training programs.
Resumo:
Objective To associate the territory of identity with the production of care within a PCC focusing on children and adolescents with drug abuse and their institutional identity. Method We used the “ process tracing methodology” in four research categories: focus groups, characterization of professionals, observing the everyday and interviewing two members of emblematic cases of the service. Results territory of identity of the institution, which operates the production of care is crossed by the difficulty of dealing with the complexity brought by the users and the performance of the PCC network. This paper is also permeated by different conceptions of care and small problematization of these issues in collective spaces of service. Conclusion The discussion in focus groups and other devices can be powerful resources to reframe the meaning of care and identity of collective service.
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Whirligig beetles (Gyrinidae) inhabit water surfaces and possess unique eyes which are split into the overwater and underwater parts. In this study we analyze the micro- and nanostructure of the split eyes of two Gyrinidae beetles genera, Gyrinus and Orectochilus. We find that corneae of the overwater ommatidia are covered with maze-like nanostructures, while the corneal surface of the underwater eyes is smooth. We further show that the overwater nanostructures possess no anti-wetting, but the anti-reflective properties with the spectral preference in the range of 450-600 nm. These findings illustrate the adaptation of the corneal nanocoating of the two halves of an insect's eye to two different environments. The novel natural anti-reflective nanocoating we describe may find future technological applications.