936 resultados para Scientific research methodologies


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In vertebrates, early brain development takes place at the expanded anterior end of the neural tube, which is filled with embryonic cerebrospinal fluid (E-CSF). We have recently identified a transient blood-CSF barrier that forms between embryonic days E3 and E4 in chick embryos and that is responsible for the transport of proteins and control of E-CSF homeostasis, including osmolarity. Here we examined the presence of glucose transporter GLUT-1 as well the presence of caveolae-structural protein Caveolin1 (CAV-1) in the embryonic blood-CSF barrier which may be involved in the transport of glucose and of proteins, water and ions respectively across the neuroectoderm. In this paper we demonstrate the presence of GLUT-1 and CAV-1 in endothelial cells of blood vessels as well as in adjacent neuroectodermal cells, located in the embryonic blood-CSF barrier. In blood vessels, these proteins were detected as early as E4 in chick embryos and E12.7 in rat embryos, i.e. the point at which the embryonic blood-CSF barrier acquires this function. In the neuroectoderm of the embryonic blood-CSF barrier, GLUT-1 was also detected at E4 and E12.7 respectively, and CAV-1 was detected shortly thereafter in both experimental models. These experiments contribute to delineating the extent to which the blood-CSF embryonic barrier controls E-CSF composition and homeostasis during early stages of brain development in avians and mammals. Our results suggest the regulation of glucose transport to the E-CSF by means of GLUT-1 and also suggest a mechanism by which proteins are transported via transcellular routes across the neuroectoderm, thus reinforcing the crucial role of E-CSF in brain development.

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A range of different language systems for nursing diagnosis, interventions and outcomes are currently available. Nursing terminologies are intended to support nursing practice but they have to be evaluated. This study aims to assess the results of an expert survey to establish the face validity of a nursing interface terminology. The study applied a descriptive design with a cross-sectional survey strategy using a written questionnaire administered to expert nurses working in hospitals. Sample size was estimated at 35 participants. The questionnaire included topics related to validity and reliability criteria for nursing controlled vocabularies described in the literature. Mean global score and criteria scoring at least 7 were considered main outcome measures. The analysis included descriptive statistics with a confidence level of 95%. The mean global score was 8.1. The mean score for the validity criteria was 8.4 and 7.8 for reliability and applicability criteria. Two of the criteria for reliability and applicability evaluation did not achieve minimum scores. According to the experts" responses, this terminology meets face validity, but that improvements are required in some criteria and further research is needed to completely demonstrate its metric properties.

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Tutkimuksen tavoitteena on analysoida laskentatoimen kauppatieteellisiä väitöskirjatutkimuksia vuosilta 1985-1999. Väitöskirjoista tutkitaan: missä yliopistoissa ne on tehty, ketkä tutkimuksia ovat tehneet, mitä on tutkittu ja mitä tutkimusmetodologiaa on käytetty. Lisäksi suoritetaan vertailua edellisiin vuosikymmeniin sekä USA:n ja Euroopan tutkimuksiin. Tutkimusote on nomoteettinen. Laskentatoimen väitöskirjat vuosilta 1985-1999 luokitellaan ja analysoidaan tutkimusten aihepiirin, tutkimusotteen ja tutkimusten ongelma-alueen perusteella. Analyyseistä saatuja tiivistettyjä tuloksia vertaillaan Juha ja Salme Näsin (1985) vuosien 1940-1984 laskentatoimen väitöskirjojen tutkimustuloksiin. Lopputuloksena todetaan, että vuosien 1985-1999 väitöskirjatutkimusten aihepiirit ovat keskittyneet johdon päätöksentekoon, väitöskirjojen tutkimusotteissa nomoteettinen tutkimusote on menettänyt johtoasemansa toiminta-analyyttisella tutkimusotteelle sekä ongelma-alueidensa perusteella väitöskirjat ovat suuntautuneet yrityksen taloudelliseen toimintaan.

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Although abundant in the number of individuals, the Atlantic salmon may be considered as a threatened species in many areas of its native distribution range. Human activities such as building of power plant dams, offshore overfishing, pollution, clearing of riverbeds for timber floating and badly designed stocking regimes have diminished the distribution of Atlantic salmon. As a result of this, many of the historical populations both in Europe and northern America have gone extinct or are severely depressed. In fact, only 1% of Atlantic salmon existing today are of natural origin, the rest being farmed salmon. All of this has lead to a vast amount of research and many restoration programmes aiming to bring Atlantic salmon back to rivers from where it has vanished. However, many of the restoration programmes conducted thus far have been unsuccessful due to inadequate scientific research or lack of its implementation, highlighting the fact that more research is needed to fully understand the biology of this complex species. The White and Barents Seas in northwest Russia are among the last regions in Europe where Atlantic salmon populations are still stable, thus forming an important source of biodiversity for the entire European region. Salmon stocks from this area are also of immense economic and social importance for the local people in the form of fishing tourism. The main aim of this thesis was to elucidate the post-glacial history and population genetic structure of north European and particularly northwest Russian Atlantic salmon, both of which are aspects of great importance for the management and conservation of the species. Throughout the whole thesis, these populations were studied by utilizing microsatellites as the main molecular tool. One of the most important discoveries of the thesis was the division of Atlantic salmon from the White and Barents Seas into four separate clusters, which has not been observed in previous studies employing nuclear markers although is supported by mtDNA studies. Populations from the western Barents Sea clustered together with the northeast Atlantic populations into a clearly distinguishable group while populations from the White Sea and eastern Barents Sea were separated into three additional groups. This has important conservation implications as this thesis clearly indicates that conservation of populations from all of the observed clusters is warranted in order to conserve as much of the genetic diversity as possible in this area. The thesis also demonstrates how differences in population life histories within a species, migratory behaviour in this case, and in their phylogeographic origin affect the genetic characteristics of populations, namely diversity and divergence levels. The anadromous populations from the Atlantic Ocean, White Sea and Barents Sea possessed higher levels of genetic diversity than the anadromous populations form the Baltic Sea basin. Among the non-anadromous populations the result was the opposite: the Baltic freshwater populations were more variable. This emphasises the importance of taking the life history of a population into consideration when developing conservation strategies: due to the limited possibilities for new genetic diversity to be generated via gene flow, it is expected that freshwater Atlantic salmon populations would be more vulnerable to extinction following a population crash and thus deserve a high conservation status. In the last chapter of this thesis immune relevant marker loci were developed and screened for signatures of natural selection along with loci linked to genes with other functions or no function at all. Also, a novel landscape genomics method, which combines environmental information with molecular data, was employed to investigate whether immune relevant markers displayed significant correlations to various environmental variables more frequently than other loci. Indications of stronger selection pressure among immune-relevant loci compared to non-immune relevant EST-linked loci was found but further studies are needed to evaluate whether it is a common phenomenon in Atlantic salmon.

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Abstract: Qualitative literature review as a method and a social scientific research approach

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The purpose of this research is to explore the variability on the soil thermal conductivity -λ- after a prescribe fire, and to assess the effects of the ashes on the heat transfer once it"s were incorporated into the soil matrix. Sampling plot was located in the Montgrí Massif (NE of Spain). A set of 42 soil samples between surface and 5 cm depth was collected before and after the fire. To characterize the soil chemical and physical variables were analyzed. To determine the vari-ability on the soil λ a dry-out curve per scenario (before and after fire) was determined. SoilRho® method based on ASTM D-5334-08 which was validated by LabFerrer was used. Soil thermal conductivity has shown changes in their values. Indeed, in all moisture scenarios the values of soil λ decreased after soil was burnt. The critical point in the rela-tionship ϴ (λ) for the soil after fire which always was stronger than soil before to be burnt. Soil with"white" ashes showed a high thermal conductivity. An X-Ray diffractometry analysis allowed to clarify and to verify these results. To sum up, we could say that thermal conductivity presents changes when the scenario changes, i.e. before and after to be burnt. On the other hand, the volume of ashes incorporated on the soil increased the differences between no burnt and burnt soil, showing even some improvements on the heat transfer when water content started to govern the process.

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AIM: In the past few years, spectacular progress in neuroscience has led to the emergence of a new interdisciplinary field, the so-called "neurolaw" whose goal is to explore the effects of neuroscientific discoveries on legal proceedings and legal rules and standards. In the United States, a number of neuroscientific researches are designed specifically to explore legally relevant topics and a case-law has already been developed. In Europe, neuroscientific evidence is increasingly being used in criminal courtrooms, as part of psychiatric testimony, nourishing the debate about the legal implications of brain research in psychiatric-legal settings. Though largely debated, up to now the use of neuroscience in legal contexts had not specifically been regulated by any legislation. In 2011, with the new bioethics law, France has become the first country to admit by law the use of brain imaging in judicial expertise. According to the new law, brain imaging techniques can be used only for medical purposes, or scientific research, or in the context of judicial expertise. This study aims to give an overview of the current state of the neurolaw in the US and Europe, and to investigate the ethical issues raised by this new law and its potential impact on the rights and civil liberties of the offenders. METHOD: An overview of the emergence and development of "neurolaw" in the United States and Europe is given. Then, the new French law is examined in the light of the relevant debates in the French parliament. Consequently, we outline the current tendencies in Neurolaw literature to focus on assessments of responsibility, rather than dangerousness. This tendency is analysed notably in relation to the legal context relevant to criminal policies in France, where recent changes in the legislation and practice of forensic psychiatry show that dangerousness assessments have become paramount in the process of judicial decision. Finally, the potential interpretations of neuroscientific data introduced into psychiatric testimonies by judges are explored. RESULTS: The examination of parliamentary debates showed that the new French law allowing neuroimaging techniques in judicial expertise was introduced in the aim to provide a legal framework that would protect the subject against potential misuses of neuroscience. The underlying fear above all, was that this technology be used as a lie detector, or as a means to predict the subject's behaviour. However, the possibility of such misuse remains open. Contrary to the legislator's wish, the defendant is not fully guaranteed against uses of neuroimaging techniques in criminal courts that would go against their interests and rights. In fact, the examination of the recently adopted legislation in France shows that assessments of dangerousness and of risk of recidivism have become central elements of the criminal policy, which makes it possible, if not likely that neuroimaging techniques be used for the evaluation of the dangerousness of the defendant. This could entail risks for the latter, as judges could perceive neuroscientific data as hard evidence, more scientific and reliable than the soft data of traditional psychiatry. If such neuroscientific data are interpreted as signs of potential dangerousness of a subject rather than as signs of criminal responsibility, defendants may become subjected to longer penalties or measures aiming to ensure public safety in the detriment of their freedom. CONCLUSION: In the current context of accentuated societal need for security, the judge and the expert-psychiatrist are increasingly asked to evaluate the dangerousness of a subject, regardless of their responsibility. Influenced by this policy model, the judge might tend to use neuroscientific data introduced by an expert as signs of dangerousness. Such uses, especially when they subjugate an individual's interest to those of society, might entail serious threats to an individual's freedom and civil liberties.

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Objective: The purpose of this study was to identify the influence of readiness of change for physical activity (PA), sociodemographic factors, lifestyle and physical activity status (PAS) on perceived barriers among Spanish university students. Participants: Seven hundred and seventy two (n = 772) men and women ages 17 - 39 at a north-west regional university in Spain participated in the study. Methods: The International Physical Activity Questionnaire, the States of Change for Physical Activity Behaviour Questionnaire and the Self-perceived Barriers for Physical Activity Questionnaire were used. Description, correlation and multiple regression analyses were completed. Results: Participants self-perceived low average-score barriers (2.6 ± 1.4 over 10.0). The 3-higher scores barriers corresponded to “too much work”; “lack of time for exercise” and “laziness”. Gender, PAS and self-perceived health were shown to be associated with perceived barriers. Conclusions: University institutions should consider those factors that predict barriers to PA to develop effective intervention programs.

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The study examines partner selection criteria and the life cycle impacts on them. The target is to define the relevant criteria that should be applied in case of a partnership. In this context partnership means strategic supplier relationship. It is also examined how these criteria change on the different stages of the product and business life cycle. The empirical part is a description of developing Criteria selection tool in the case company. The study is conducted as a qualitative research using constructive and action research methodologies. The Criteria selection tool is a MS Excel workbook, giving the relevant set of supplier criteria depending on the business case. The most essential criteria, the tool will suggest for partner suppliers, are related to strategic fit, development potential and collaborative aspects. On the early stages of the life cycles the criteria related to research and development and growth potential are significant. On the late stages of the life cycles cost reduction potential becomes very important.

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The impact factor of scientific journals has been used to evaluate them, as well as the quality of scientific research. This parameter was recently used by CAPES as an important criterion for the evaluation of Brazilian postgraduate courses. The main objective of this paper is to show how impact factor is calculated and to discuss its importance and limitations, with special emphasis on chemistry journals.

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Natural products have been utilized by humans since ancient times and the relief and cure of their diseases was the first purpose for using natural products in medicine. The history of the oriental and occidental civilizations is very rich in examples of the utilization of natural products in medicine and health care. Chinese traditional medicine is one of the most important examples of how natural products can be efficient in the treatment of diseases, and it points to the importance of scientific research on natural products, concerning the discovery of new active chemical entities. The complexity, chemical diversity and biological properties of natural products always fascinated people, and during the last 200 years, this led to the discovery of important new drugs. In the last 30 years, the development of new bioassay techniques, biotechnology methods, bio-guided phytochemical studies, automated high throughput screening and high performance analytical methods, have introduced new concepts and possibilities of rational drug design and drug discovery. In this context, natural products have played an important and decisive role in the development of modern medicinal chemistry.

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A continuous random variable is expanded as a sum of a sequence of uncorrelated random variables. These variables are principal dimensions in continuous scaling on a distance function, as an extension of classic scaling on a distance matrix. For a particular distance, these dimensions are principal components. Then some properties are studied and an inequality is obtained. Diagonal expansions are considered from the same continuous scaling point of view, by means of the chi-square distance. The geometric dimension of a bivariate distribution is defined and illustrated with copulas. It is shown that the dimension can have the power of continuum.

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Brazilian science is evolving rapidly and steadly in the last 10 years, reaching the 15º place in the international ranking. Research in nanotechnology is following a similar way generating new scientific and technological knowledge in several frontiers but specially in the interfaces of two or more areas, where Chemistry is consolidating itself as a central science. In this context, the supramolecular approach is a very promissing one because it allows the build-up of a chemical inteligence using all the sistematized knowledge for the design and development of new nanomaterials and products. The great challenge of Chemistry is not decrease the dimensionality of the materials but instead find ways to increase the dimensionality and structural complexity keeping strict control on the interactions between the components, in order to generate materials with new properties and functionalities. Unfortunately, the current vigorous advancement of scientific research has not been followed by the transformation of such know-how into patents and produts. Therefore much efforts should be devoted to build a national science and technology program, joining all the segments of the society involved in the technological development (university, institutes of technological research, industry and government) in order to promote the furtherance of the Brazilian technological base. Only in this way it is possible to evolve to a technological society capable to transform the scientific knowledge into wealthy, thus sustaining the socioeconomic development of the country.

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Quimica Nova and the Journal of the Brazilian Chemical Society are two examples of successful initiatives taken by the Brazilian Chemical Society (SBQ - Sociedade Brasileira de Química), and may serve as models for the scientific societies of developing countries. Pillars of the SBQ, these two periodicals are undeniable demonstrations that idealism, utopia and dignity are the essential ingredients for transforming dreams into reality. Few believed that the Brazilian chemical community would one day have, as it does today, two scientific research periodicals indexed in the principal international data banks.

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This research studied children who had been diagnosed with Multisystem Developmental Disorder (MSDD) (NC, 2002) under the Diagnostic Classifications of Mental Health and Developmental Disorders of Infancy and Early Childhood (DC: 0 - 3). They all showed, to a varying degree, difficulties in relating to others, play, affective interaction and severe delay in developing communication skills. Some studies have observed continuity in the diagnosis of autism during the first years of life. The objective of this study is to analyse the development of infants with MSDD whose diagnosis of autism was not confirmed. We also attempted to verify any possible psychomotor developmental differences based on, or related to, the severity and typology (B and C) of the MSDD. To enable us to do this we carried out a 3-year follow-up during which we assessed the infants (n = 15) and their parents. They are 2 - 4 years old. Results showed that type B children did present a greater impairment of psychomotor development in assessment tests. However, we did not observe any correlation between the degree of severity of the initial symptoms and later diagnoses. Conclusion: although our sample is small, we can conclude that there isn’t a clear evolution in the diagnosis, but we have found significant differences in the symptomatology between the type B and C