4,512 research outputs found
On Kant's first insight into the problem of space dimensionality and its physical foundations
In this article it is shown that a careful analysis of Kant's "Thoughts on
the True Estimation of Living Forces" leads to a conclusion that does not match
the usually accepted interpretation of Kant's reasoning in 1747, according to
which the Young Kant supposedly establishes a relationship between the
tridimensionality of space and Newton's law of universal gravitation. Indeed,
it is argued that this text does not yield a satisfactory explanation of space
dimensionality, actually restricting itself to justify the tridimensionality of
extension.Comment: 14 page
As veias abertas da América Latina
Em 1971 é publicada a obra da autoria de Eduardo Galeano, As Veias Abertas da América
Latina. Inicialmente em espanhol, a obra rapidamente se disseminou e obteve tradução em
diversos idiomas. O livro conta a história da constante exploração por parte do Imperialismo,
primeiramente Europeu e posteriormente Norte-Americano, da América Latina desde os
primórdios da Humanidade até à actualidade
Human Resource Management Practices and Organisational Citizenship Behaviour: What is the relationship?
This study aims to provide additional empirical evidence on the impact of Human Resource
Management Practices (HRMP) on Organizational Citizenship Behaviors (OCB). To this end
it was hypothesized: HRMPs have a significant and positive effect on OCBs. A total of 525
participants, employees in different organisations in Portugal, participated in this study. The
results revealed a significant and positive effect of HRMPs on OCBs. However, of the seven
HRMPs only Performance Appraisal showed a significant effect on OCB.info:eu-repo/semantics/publishedVersio
Developing a RDF4J frontend
Dissertação de mestrado integrado em Engenharia InformáticaA few years ago, data was not shared and kept isolated, preventing communication
between datasets. Currently, we have more significant data volumes, and in a world where
everything is connected, our data is now also following this trend.
Data model focus changed from a square structure like the relational model to a model
centered on the relations. Knowledge graphs are the new paradigm to represent and manage
this new kind of information structure.
Along with the new paradigm, graph databases emerged to support the new requirements.
Despite the increasing interest in the field, only a few native solutions are available. Most
are under a commercial license, and the open-source options have very basic or outdated
interfaces, and because of that, they are a little distant for most end-users.
In this thesis, we introduce the Open Web Ontobud and discuss its design and develop ment. Ontobud is a Web Application aimed at improving the interface for one of the most
fascinating and influential frameworks in this area: RDF4J. RDF4J is a Java framework to
deal with RDF triple storage, management, and query.
Open Web Ontobud is an open-source RDF4J web frontend created to reduce the gap
between end-users and the RDF4J backend. We created a web interface that enables users
with a basic knowledge of OWL and SPARQL to explore ontologies via resource tables or
graphs and extract information from them with SPARQL queries. The interface aims to
remain intuitive, providing tooltips and help when needed, as well as some statistical data
in a readily available form.
Despite the frontend being the main focus, a backend and two databases are also used for
a total of four components in the framework. For the best deployment experience, Docker
was used for its simplicity, allowing deployment in just a few commands. Each component
has a dedicated image, following a modular design and allowing them to be executed on
separate machines if desired.No passado, dados não era partilhada e permanecia isolada, impedindo comunicação
entre datasets. Atualmente, temos maiores volumes de dados e num mundo onde tudo está
interligado, os nossos dados também seguem essa tendência.
O foco de modelo de dados alterou de uma estrutura quadrada, como o modelo relacional,
para um modelo centrado em relações. Grafos de Conhecimento são o novo paradigma para
a representação e manipulação desta nova estrutura de dados.
Com o novo paradigma, bases de dados de grafos emergiram para suportar as novas
necessidades. Apesar do aumento de interesse neste campo, apenas algumas soluções
nativas estão disponíveis. A maioria requere uma licença comercial, e as opções open-source
são interfaces básicas ou desatualizadas, e por consequência, distantes a muitos utilizadores.
Nesta tese introduzimos o Open Web Ontobud e discutimos o seu design e desenvolvi mento. O Ontobud é uma aplicação Web direcionada ao melhoramento da interface de
uma das mais fascinantes e influentes frameworks nesta área: o RDF4J. O RDF4J é uma
framework em Java para guardar, manipular e inquirir grafos RDF.
Open Web Ontobud é um open-source web frontend para o RDF4J criado para diminuir
a separação entre os utilizadores e o RDF4J backend. Nós criamos uma interface web que
permite utilizadores com conhecimento básico de OWL e SPARQL explorar ontologias
através de tabelas de recursos ou grafos, e inquirir informação com queries SPARQL. O
objetivo da interface é ser intuitiva, com tooltips e ajuda quando necessário, bem como
alguma informação de estatísticas numa forma facilmente acessível.
Apesar do frontend ser o foco principal, o backend e duas bases de dados também são
utilizadas, para um total de quatro componentes nesta framework. Para a melhor experiência
de inicialização utilizamos Docker pela sua simplicidade, permitindo inicialização em poucos
comandos. Cada componente tem uma imagem dedicada, seguindo um design modular e
permitindo cada componente ser executada em máquinas separadas se necessário
The effect of heteroscedasticity on bayesian variable selection
Mestrado em Econometria Aplicada e PrevisãoNesta dissertação estudamos o efeito da heterocedasticidade na seleção bayesiana de variáveis. Através de um estudo de simulação, e utilizando dois conjuntos de dados reais, avaliamos os efeitos de introduzir heteroscedasticidade numa regressão linear, bem como o efeito de transformar dados heterocedásticos em homocedásticos. Analisando as variáveis selecionadas, probabilidades de inclusão e medidas de performance preditiva, concluimos que a seleção bayesiana de variáveis é robusta à heterocedasticidade, mas é possível obter melhor perfomance preditiva se a estrutura de variância dos erros for tomada em conta.This dissertation aims to study the effect of heteroscedasticity on Bayesian Variable Selection. It employs a simulation study, using two distinct datasets, to evaluate the effects of introducing heteroscedasticity in a linear regression, and whether transforming an heteroscedastic dataset into an homoscedastic one results in any considerable differences. We look at the variables selected, inclusion probabilities and performance measures. We find Bayesian Variable Selection to be robust to heteroscedasticity, although a better predictive performance may be attained if we take the error variance's structure explicitly into account.info:eu-repo/semantics/publishedVersio
Organizational Commitment as a reducer of Turnover Intentions: which component (affective, calculative and normative) is the best predictor?
This study aims to provide additional empirical evidence on the effect of the three components
of organizational commitment on turnover intentions. To this end, we hypothesized that organizational commitment (affective, calculative, and normative) has a significant and negative
effect on turnover intentions. A total of 302 participants, employees in different organizations
in Portugal, participated in this study. The results revealed a significant and negative effect of
affective commitment (AC) and normative commitment (NC) on turnover intentions. Of the
three components, affective commitment is the one with the strongest association.info:eu-repo/semantics/publishedVersio
Medicinal Plants in Pregnancy and Lactation: Perception of the Health Risk and Practical Educational Group in Araraquara, São Paulo State, Brazil
The use of medicinal plants among pregnant women and lactating is a common practice in diverse countries.
However, many medicinal plants are contraindicated during pregnancy and lactating, due to various adverse effects,
such as teratogenic, embryotoxic and abortive effects, exposing these women, their fetus and babies to health
unknown risks. Thus, the purpose of this commentary, was to analyze the perception about the use of medicinal
plants by pregnant women and lactating registered in the "baby on board" NGO, Araraquara, São Paulo state,
Brazil, between 2010 at 2013. The group was constituted by 48 women, between the first and last trimester of
pregnancy or whilst breastfeeding. Information was collected during group meetings by oral interview, using a
questionnaire, as script. The nature of the study was a qualitative analysis. The results were based on reports about
the use of medicinal plants by pregnant women during group meetings: use, indication of use, knowledge about
risks. All participants received written and oral information about the study and they gave a written informed consent.
The use of medicinal plants is a reality among pregnant and lactating women of the "baby on board" NGO. They
reported that they feel that "natural" products are not harmful for their health. The primary information sources for the
majority of women about medicinal plants during pregnancy are family, neighbors and herbalists. The plants most
cited were: senna, chamomile, boldo, lemon balm, lemon grass. They were used mainly for: nausea, heartburn,
indigestion, flatulence, intestinal and abdominal pain, anxiety, intestinal constipation and low milk production. The
pregnant and lactating women lacked knowledge about the health risks of the use of medicinal plants and herbal
medicines in pregnancy and lactation. They also reported difficulties in clarifying some questions about the use of
medicinal plants with their doctors. The results of the present study showed that educative actions about the rational
use of medicinal plants in pregnancy and breastfeeding could be part of the operating protocols to promote the
maternal and child health programs in Araraquara. Thus, our results also suggest the importance of creating
institutionalized places, to the implementation of continued education programs about rational use of medicinal
plants in pregnancy and lactation. These targeted programs are not only for health professionals, but also for
community members, pregnant women and breastfeeding. Our results pointed out the importance of guidance of
doctors and healthcare professionals on the scientific studies about medicinal plants and herbal medicines and the
risk/benefit of using herbs during pregnancy. Finally, it is noted the importance of the health professionals to inform
women of childbearing on risks to their health, as well as on possibilities of utilization of herbs during fertile period,
giving special attention to the potential risk of self-medication
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