Soft contact lenses monovision and stereopsis

This investigation was structured to determine whether any of three specific measures of stereopsis improved with time following fitting with the monovision technique. Measurements were taken on nine presbyopic subjects with their habitual prescription as a baseline finding, then repeated with their monovision correction at dispensing, and at 2-day, one-week, and two-week follow-up s. While adaptation was not demonstrated there was a mark ed difference in performance on stereo tests based on add power. Adds below + 1. 75 resulted in significantly better performance than for higher adds

Reviewing energy system modelling of decentralized energy autonomy

Research attention on decentralized autonomous energy systems has increased exponentially in the past three decades, as demonstrated by the absolute number of publications and the share of these studies in the corpus of energy system modelling literature. This paper shows the status quo and future modelling needs for research on local autonomous energy systems. A total of 359 studies are roughly investigated, of which a subset of 123 in detail. The studies are assessed with respect to the characteristics of their methodology and applications, in order to derive common trends and insights. Most case studies apply to middle-income countries and only focus on the supply of electricity in the residential sector. Furthermore, many of the studies are comparable regarding objectives and applied methods. Local energy autonomy is associated with high costs, leading to levelized costs of electricity of 0.41 $/kWh on average. By analysing the studies, many improvements for future studies could be identified: the studies lack an analysis of the impact of autonomous energy systems on surrounding energy systems. In addition, the robust design of autonomous energy systems requires higher time resolutions and extreme conditions. Future research should also develop methodologies to consider local stakeholders and their preferences for energy systems

Effects of dopamine D4 receptor antagonist on spontaneous alternation in rats

<p>Abstract</p> <p>Background</p> <p>The present study was a component of a series of studies scrutinising the neuroreceptor substrate of behavioural flexibility in a rat model. Spontaneous alternation paradigms model the natural tendency of rodents to spontaneously and flexibly shift between alternative spatial responses. In the study it was tested for the first time if the neurochemical substrate mediating spontaneous alternation behaviour includes the dopamine D₄receptor.</p> <p>Methods</p> <p>The acute effects of the highly selective dopamine D₄receptor antagonist L-745,870 on rats' performance in a spontaneous alternation paradigm in a T-maze were examined. The paradigm was a food-rewarded continuous trial procedure performed for 20 trials.</p> <p>Results</p> <p>The spontaneous alternation rate was not affected by the doses of the drug administered (0.02 mg/kg; 0.2 mg/kg; 2 mg/kg), but the position bias of the group receiving the highest L-745,870 dose (2 mg/kg) was significantly increased compared to the group that received the lowest dose (0.02 mg/kg). No significant effects on position bias were found compared to saline. The drug did not increase response perseveration.</p> <p>Conclusion</p> <p>The results show that the neural substrate mediating the spatial distribution of responses in the spontaneous alternation paradigm includes the D₄receptor. However, the statistically significant effect of L-745,870 on position bias was found comparing a high drug dose with a low drug dose, and not comparing the drug doses with saline. For the tested doses of L-745,870 the effect on position bias was not large enough to affect the alternation rate.</p

Spatial high-resolution socio-energetic data for municipal energy system analyses

Acknowledgements The authors gratefully acknowledge the financial support of the PhD College “Energy and Resource Efficiency” (ENRES), from the Federal State of Baden-Wuerttemberg, for funding the first author’s PhD studentship. The second author gratefully acknowledges the support of the Smart City Accelerator project (https://smartcitiesaccelerator.eu/about-smart-cities-accelerator/), which supported his contribution to this article. Furthermore, we acknowledge support by the KIT-Publication Fund of the Karlsruhe Institute of Technology. The usual disclaimer applies.Peer reviewedPublisher PD

O ACESSO E PERMANÊNCIA DOS PROFESSORES CONTRATADOS NAS INSTITUIÇÕES EDUCATIVAS: UMA ANÁLISE DE SUAS EXPERIÊNCIAS

Esta pesquisa teve como objetivo investigar os sentidos atribuídos pelos professores contratados ao seu trabalho docente a partir do seu ingresso, através de um contrato temporário, na rede pública de educação no município de Cariacica. Estudiosas como Gatti (2011) e Oliveira (2008) vêm analisando e discutindo as transformações pelas quais o trabalho docente vem passando e apontando a efetivação do contrato para o trabalho temporário como uma realidade nas redes educacionais. Na contemporaneidade, convivemos com os ajustes econômicos que passam a interferir nos modos de regulação no trabalho docente e passamos então a experimentar relações no trabalho com transitoriedade, em curto prazo de tempo, com vínculos precarizados e desenvolvendo uma performance em que o professor vai se adequando às regras para o alcance de uma vaga de trabalho. Assim, utilizando-se de um estudo exploratório nos propusemos a observar o cenário em que se circunscreve o recrutamento dos professores contratados e a analisar os documentos que legitimam o processo de contratação. A pesquisa se estendeu em três fases, a fim de que pudéssemos observar os modos como os candidatos se relacionam com o ingresso na educação pública por meio dos processos seletivos de contratação e na segunda e terceira fase, a partir das narrativas dos professores, procuramos evidenciar os desdobramentos no percurso do trabalho em curto prazo que se configuram neste universo de professores em designação temporária. A pesquisa evidenciou que os professores contratados passam por experiências de competição entre os pares para acessar uma vaga de trabalho; há uma fragilidade na acolhida destes professores nas unidades educativas e tensões vão se estabelecendo ao final do contrato, o que traz um sentimento de impotência diante das lógicas de contratação temporária que vão se naturalizando no trabalho docente

Credit-constrained in risky activities? The determinants of the capital stocks of micro and small firms in Western Africa

Micro and small enterprises (MSEs) in developing countries are typically considered to be severely credit constrained. Additionally, high business risks may partly explain why the capital stocks of MSEs remain low. This article analyzes the determinants of the capital stocks of MSEs in poor economies focusing on credit constraints and risk. The analysis is based on a unique, albeit cross‐sectional but backward‐looking, micro data set on MSEs covering the economic capitals of seven West‐African countries. The main result is that capital market imperfections indeed seem to explain an important part of the variation in capital stocks in the early lifetime of MSEs. Furthermore, the analyses show that risk plays a key role in capital accumulation. Risk‐averse individuals seem to adjust their initially low capital stocks upwards when enterprises grow older. MSEs in risky activities owned by wealthy individuals even seem to over‐invest when they start their business and subsequently adjust capital stocks downwards. As other firms simultaneously suffer from capital shortages, such behaviour may imply large inefficiencies

Constrained gazelles. High potentials in West Africa’s informal economy

The informal sector is typically characterised as being very heterogeneous and possibly composed of two clearly distinct segments, sometimes called the lower and upper tier. However, empirical evidence shows that even among lower tier entrepreneurs profitability can be quite high. We combine these findings and develop an innovative approach to identify what we call ‘constrained gazelles’, next to the well-known survivalists in the lower tier and growth-oriented top-performers in the upper tier. Our sample of informal entrepreneurs in seven West-African countries allows to link the relative size of these three groups to the structural and macroeconomic environment in these countries

Credit‐constrained in risky activities? The determinants of the capital stocks of micro and mall firms in Western Africa

Micro and small enterprises (MSEs) in developing countries are typically considered to be severely credit constrained. Additionally, high business risks may partly explain why the capital stocks of MSEs remain low. This article analyzes the determinants of the capital stocks of MSEs in poor economies focusing on credit constraints and risk. The analysis is based on a unique, albeit cross-sectional but backward‐looking, micro data set on MSEs covering the economic capitals of seven West‐African countries. The main result is that capital market imperfections indeed seem to explain an important part of the variation in capital stocks in the early lifetime of MSEs. Furthermore, the analyses show that risk plays a key role in capital accumulation. Risk-averse individuals seem to adjust their initially low capital stocks upwards when enterprises grow older. MSEs in risky activities owned by wealthy individuals even seem to over-invest when they start their business and subsequently adjust capital stocks downwards. As other firms simultaneously suffer from capital shortages, such behavior may imply large inefficiencies

Constrained firms, not subsistence activities: evidence on capital returns and accumulation in Peruvian microenterprises

We investigate the returns to capital and capital accumulation using panel data of Peruvian micro enterprises (MEs). Marginal returns to capital are found to be very high at low levels of capital, but rapidly decreasing at higher levels. The dynamic analyses of capital accumulation in MEs suggest that credit constraints explain a major part of the variation in firm growth. We find a very large positive effect of household non-business wealth on capital stocks of MEs. We also show a sizable effect of risk on accumulation and pronounced interactions between wealth and risk. The presented evidence is consistent with poorly endowed entrepreneurs who operate in imperfect capital markets and a very risky environment