817 resultados para kalevala - folk poetry - history of research
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The genus Prunus L. is large and economically important. However, phylogenetic relationships within Prunus at low taxonomic level, particularly in the subgenus Amygdalus L. s.l., remain poorly investigated. This paper attempts to document the evolutionary history of Amygdalus s.l. and establishes a temporal framework, by assembling molecular data from conservative and variable molecular markers. The nuclear s6pdh gene in combination with the plastid trnSG spacer are analyzed with bayesian and maximum likelihood methods. Since previous phylogenetic analysis with these markers lacked resolution, we additionally analyzed 13 nuclear SSR loci with the δµ2 distance, followed by an unweighted pair group method using arithmetic averages algorithm. Our phylogenetic analysis with both sequence and SSR loci confirms the split between sections Amygdalus and Persica, comprising almonds and peaches, respectively. This result is in agreement with biogeographic data showing that each of the two sections is naturally distributed on each side of the Central Asian Massif chain. Using coalescent based estimations, divergence times between the two sections strongly varied when considering sequence data only or combined with SSR. The sequence-only based estimate (5 million years ago) was congruent with the Central Asian Massif orogeny and subsequent climate change. Given the low level of differentiation within the two sections using both marker types, the utility of combining microsatellites and data sequences to address phylogenetic relationships at low taxonomic level within Amygdalus is discussed. The recent evolutionary histories of almond and peach are discussed in view of the domestication processes that arose in these two phenotypically-diverging gene pools: almonds and peaches were domesticated from the Amygdalus s.s. and Persica sections, respectively. Such economically important crops may serve as good model to study divergent domestication process in close genetic pool.
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Odontoid fractures are the most common cervical fractures in the adult population. They represent 9 to 18 % of all cervical fractures and the type II is the most common. The incidence of neurologic deficits (ND) in odontoid fractures varies between 3 to 25%. A recent study showed that patients with ND had a mortality rate increased by 4.72 times and a complication rate higher of 1.18 times. The most common complication in patients with ND was respiratory distress8. Surprisingly, although type II odontoid fractures are frequent cervical fractures, their natural history has been poorly described. Surgery for odontoid fractures is well described. However, there are so far guidelines based on class II and class III evidence only regarding indications for surgery and regarding surgical techniques. The class II guidelines recommend to consider surgical stabilization and fusion for type II odontoid in patients over 50 years of age. The class III recommendations are to first manage non-displaced odontoid type II fracture with external immobilization and that translation of 5mm or more is associated with a high rate of non- union with the conservative treatment and should be treated surgically.
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The challenges posed by the assessment of distance learning is a topic that requires, on the one hand, evolution with new trends and, on the other improving evaluative processes, to promote good practices. This demand becomes more imperative when we are dealing with a formativescenario based on distance assessment of competence-based learning.The Open University of Catalonia has begun to work with these formative tools, promoting new practices for online education. A very clear example of these educational practices is the assessment of research competences using the e-portfolio system. To meet this aim a profound and solid process has been developed over recent years, with the intention of making this tool an assessment alternative, and providing the opportunity to use it in a formative context. The objective is to study its strengths and limitations keeping in mind the final goal of offering the higher education community a validated assessment system.
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This work highlights and analyzes the citations and co-citations by different authors, countries and institutions in series of researches on biofuel. These relations represent a knowledge map which shows the areas of research by different countries and authors. The contributions of different institutions were also shown. With this knowledge map developed, areas of research that still need more attention as well as the most important studies were highlighted. The software used for this analysis is Citespace which is developed by Chaomei Chen. Sources of information are articles retrieved from ISI Web of Science. Biofuel as a renewable form of energy is discussed. Its sources, types, methods of production, effects, market, and producers were discussed. Also plans and strategies that aim at boosting world biofuel market were listed as well as recent researches on it. Knowledge mapping, its types and methods as well as the method and software used for the analysis were also discussed.
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The scale of research and development (R&D), and other technological activities, and the way in which the available resources are managed and organized at the enterprise and national level contribute to the rate of technological change in a country. A well organized national innovation system can be a powerful engine of progress, whereas a lack of interaction between institutions results in the slowing down of technological change, thereby diminishing its contribution to economic growth and welfare. The research object of this thesis is Australia’s national innovation system and the state of R&D in Australia. In order to establish an overall picture of the situation and to be able to make recommendations for future development, the general level of R&D activity and the main performers and funders of R&D within the system are analyzed. The framework policies supporting R&D and prevalent dynamics between different actors and sectors are of specific interest of the research. The findings reveal that the Australian culture is not a culture of research and innovation and that the main challenge is building a coherent system with strong domestic and international linkages.
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Cryoscopy is considered one of the foundations of the modern theory of solutions and of physical chemistry. This paper shows in order the first regularities pointed out by several scientists on the subject, in the first chapter of its birth as a scientific discipline. The study is focused on the identification of the different steps that helped, first qualitatively and then quantitatively, to adjust the different classes of possible solutions, including those that formed hydrates, to a basic formulation that the French scientist François-Marie Raoult would later generalize in the law that bears his name.
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The formulation of the so-called law of rectilinear diameter for the determination of the critical volume of substances in the concluding decades of the nineteenth century became in a very useful and acceptably exact alternative tool for researchers in the field of critical phenomena. Its corresponding original expression, and even those of its early few modifications, were so mathematically simple that their use did not limit to exclusively contribute to remove the by then experimental obstacle for the estimating of this critical parameter, but also extended along several decades in the increasing applications of the principle of corresponding states.
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Background: Celiac disease is a lifelong, gluten-sensitive, autoimmune-mediated chronic enteropathy, tightly associated with risk alleles at the HLA class II genes. Aims: This study was carried out as a part of the population-based Type 1 Diabetes Prediction and Prevention (DIPP) Project. The first aim was to study the natural history of celiac disease-associated antibodies before the diagnosis of celiac disease was made. The second aim was to describe when and in which order celiac disease-associated and type 1 diabetes-associated antibodies appeared in children with genetic risk for both diseases. Subjects and Methods: Antibodies against tissue transglutaminase (TGA) and other celiac disease-associated antibodies were measured in serum samples collected at 3- to 12-month intervals of children at genetic risk for celiac disease who participated in the DIPP project. Celiac disease was confirmed by duodenal biopsy. Type 1 diabetes-associated antibodies were measured in all samples that had been collected. Overt disease was diagnosed according to World Health Organization criteria. Follow-up continued until a diagnosis of type 1 diabetes or until the end of a defined follow-up period. Results: TGA appeared in children at genetic risk for celiac disease only after the first year of life, but anti-gliadin antibodies often emerged significantly earlier, at age 6 months. The data show that spontaneous disappearance of celiac disease-associated antibodies, transient or persisting, is a common phenomenon, at least in prepubertal children. In children with genetic susceptibility to type 1 diabetes and celiac disease, celiac disease-associated antibodies usually develop earlier than the type 1 diabetes-associated antibodies. Conclusions: The transient nature of celiac disease-associated antibodies emphasizes the significance of establishing seropositivity repeatedly in screening detected celiac disease before gastroscopy and duodenal biopsy are considered and emphasized the importance of duodenal biopsy for diagnosing celiac disease.
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The aim of this study is to gain a better understanding of the structure and the deformation history of a NW-SE trending regional, crustal-scale shear structure in the Åland archipelago, SW Finland, called the Sottunga-Jurmo shear zone (SJSZ). Approaches involving e.g. structural geology, geochronology, geochemistry and metamorphic petrology were utilised in order to reconstruct the overall deformation history of the study area. The study therefore describes several features of the shear zone including structures, kinematics and lithologies within the study area, the ages of the different deformation phases (ductile to brittle) within the shear zone, as well as some geothermobarometric results. The results indicate that the SJSZ outlines a major crustal discontinuity between the extensively migmatized rocks NE of the shear zone and the unmigmatised, amphibolite facies rocks SW of the zone. The main SJSZ shows overall dextral lateral kinematics with a SW-side up vertical component and deformation partitioning into pure shear and simple shear dominated deformation styles that was intensified toward later stages of the deformation history. The deformation partitioning resulted in complex folding and refolding against the SW margin of the SJSZ, including conical and sheath folds, and in a formation of several minor strike-slip shear zones both parallel and conjugate to the main SJSZ in order to accommodate the regional transpressive stresses. Different deformation phases within the study area were dated by SIMS (zircon U-Pb), ID-TIMS (titanite U-Pb) and 40Ar/39Ar (pseudotachylyte wholerock) methods. The first deformation phase within the ca. 1.88 Ga rocks of the study area is dated at ca. 1.85 Ga, and the shear zone was reactivated twice within the ductile regime (at ca. 1.83 Ga and 1.79 Ga), during which the strain was successively increasingly partitioned into the main SJSZ and the minor shear zones. The age determinations suggest that the orogenic processes within the study area did not occur in a temporal continuum; instead, the metamorphic zircon rims and titanites show distinct, 10-20 Ma long breaks in deformation between phases of active deformation. The results of this study further imply slow cooling of the rocks through 600-700ºC so that at 1.79 Ga, 2 the temperature was still at least 600ºC. The highest recorded metamorphic pressures are 6.4-7.1 kbar. At the late stages or soon after the last ductile phase (ca. 1.79 Ga), relatively high-T mylonites and ultramylonites were formed, witnessing extreme deformation partitioning and high strain rates. After the rocks reached lower amphibolite facies to amphibolite-greenschist facies transitional conditions (ca. 500-550ºC), they cooled rapidly, probably due to crustal uplift and exhumation. The shear zone was reactivated at least once within the semi-brittle to brittle regime between ca. 1.79 Ga and 1.58 Ga, as evidenced by cataclasites and pseudotachylytes. In summary, the results of this study suggest that the Sottunga-Jurmo shear zone (and the South Finland shear zone) defines a major crustal discontinuity, and played a central role in accommodating the regional stresses during and after the Svecofennian orogeny.
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The aim of this study is to explore how a new concept appears inscientific discussion and research, how it diffuses to other fields and out of the scientific communities, and how the networks are formed around the concept. Text and terminology take the interest of a reader in the digital environment. Texts create networks where the terminology used is dependent on the ideas, viewsand paradigms of the field. This study is based mainly on bibliographic data. Materials for bibliometric studies have been collected from different databases. The databases are also evaluated and their quality and coverage are discussed. The thesauri of those databases that have been selected for a more in depth study have also been evaluated. The material selected has been used to study how long and in which ways an innovative publication, which can be seen as a milestone in a specific field, influences the research. The concept that has been chosen as a topic for this research is Social Capital, because it has been a popular concept in different scientific fields as well as in everyday speech and the media. It seemed to be a `fashion concept´ that appeared in different situations at the Millennium. The growth and diffusion of social capital publications has been studied. The terms connected with social capital in different fields and different stages of the development have also been analyzed. The methods that have been used in this study are growth and diffusion analysis, content analysis, citation analysis, coword analysis and cocitation analysis. One method that can be used tounderstand and to interpret results of these bibliometric studies is to interview some key persons, who are known to have a gatekeeper position in the diffusion of the concept. Thematic interviews with some Finnish researchers and specialists that have influenced the diffusion of social capital into Finnish scientificand social discussions provide background information. iv The Milestone Publications on social capital have been chosen and studied. They give answers to the question "What is Social Capital?" By comparing citations to Milestone Publications with the growth of all social capital publications in a database, we can drawconclusions about the point at which social capital became generally approved `tacit knowledge´. The contribution of the present study lies foremost in understanding the development of network structures around a new concept that has diffused in scientific communities and also outside them. The network means both networks of researchers, networks of publications and networks of concepts that describe the research field. The emphasis has been on the digital environment and onthe socalled information society that we are now living in, but in this transitional stage, the printed publications are still important and widely used in social sciences and humanities. The network formation is affected by social relations and informal contacts that push new ideas. This study also gives new information about using different research methods, like bibliometric methods supported by interviews and content analyses. It is evident that interpretation of bibliometric maps presupposes qualitative information and understanding of the phenomena under study.
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Tämän tutkimusraportin suomenkielinen versio on osoitteessa: http://urn.fi/URN:ISBN:978-951-29-4509-2
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Added engraved title page: The history of Lapland.