942 resultados para Nature society relation


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The upconversion quantum yield (UCQY) is one of the most significant parameters for upconverter materials. A high UCQY is essential for a succesful integration of upconversion in many applications, such as harvesting of the solar radiation. However, little is known about which doping level of the rare-earth ions yields the highest UCQY in the different host lattices and what are the underlying causes. Here, we investigate which Er3+ doping yields the highest UCQY in the host lattices β-NaYF4 and Gd2O2S under 4I15/2 → 4I13/2 excitation. We show for both host lattices that the optimum Er3+ doping is not fixed and it actually decreases as the irradiance of the excitation increases. To find the optimum Er3+ doping for a given irradiance, we determined the peak position of the internal UCQY as a function of the average Er−Er distance. For this purpose, we used a fit on experimental data, where the average Er−Er distance was calculated from the Er3+ doping of the upconverter samples and the lattice parameters of the host materials. We observe optimum average Er−Er distances for the host lattices β-NaYF4 and Gd2O2S with differences <14% at the same irradiance levels, whereas the optimum Er3+ doping are around 2× higher for β-NaYF4 than for Gd2O2S. Estimations by extrapolation to higher irradiances indicate that the optimum average Er−Er distance converges to values around 0.88 and 0.83 nm for β-NaYF4 and Gd2O2S, respectively. Our findings point to a fundamental relationship and focusing on the average distance between the active rare-earth ions might be a very efficient way to optimize the doping of rare-earth ions with regard to the highest achievable UCQY.

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Background context Studies involving factor analysis (FA) of the items in the North American Spine Society (NASS) outcome assessment instrument have revealed inconsistent factor structures for the individual items. Purpose This study examined whether the factor structure of the NASS varied in relation to the severity of the back/neck problem and differed from that originally recommended by the developers of the questionnaire, by analyzing data before and after surgery in a large series of patients undergoing lumbar or cervical disc arthroplasty. Study design/setting Prospective multicenter observational case series. Patient sample Three hundred ninety-one patients with low back pain and 553 patients with neck pain completed questionnaires preoperatively and again at 3 to 6 and 12 months follow-ups (FUs), in connection with the SWISSspine disc arthroplasty registry. Outcome measures North American Spine Society outcome assessment instrument. Methods First, an exploratory FA without a priori assumptions and subsequently a confirmatory FA were performed on the 17 items of the NASS-lumbar and 19 items of the NASS-cervical collected at each assessment time point. The item-loading invariance was tested in the German version of the questionnaire for baseline and FU. Results Both NASS-lumbar and NASS-cervical factor structures differed between baseline and postoperative data sets. The confirmatory analysis and item-loading invariance showed better fit for a three-factor (3F) structure for NASS-lumbar, containing items on “disability,” “back pain,” and “radiating pain, numbness, and weakness (leg/foot)” and for a 5F structure for NASS-cervical including disability, “neck pain,” “radiating pain and numbness (arm/hand),” “weakness (arm/hand),” and “motor deficit (legs).” Conclusions The best-fitting factor structure at both baseline and FU was selected for both the lumbar- and cervical-NASS questionnaires. It differed from that proposed by the originators of the NASS instruments. Although the NASS questionnaire represents a valid outcome measure for degenerative spine diseases, it is able to distinguish among all major symptom domains (factors) in patients undergoing lumbar and cervical disc arthroplasty; overall, the item structure could be improved. Any potential revision of the NASS should consider its factorial structure; factorial invariance over time should be aimed for, to allow for more precise interpretations of treatment success.

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INTRODUCTION Even though arthroplasty of the ankle joint is considered to be an established procedure, only about 1,300 endoprostheses are implanted in Germany annually. Arthrodeses of the ankle joint are performed almost three times more often. This may be due to the availability of the procedure - more than twice as many providers perform arthrodesis - as well as the postulated high frequency of revision procedures of arthroplasties in the literature. In those publications, however, there is often no clear differentiation between revision surgery with exchange of components, subsequent interventions due to complications and subsequent surgery not associated with complications. The German Orthopaedic Foot and Ankle Association's (D. A. F.) registry for total ankle replacement collects data pertaining to perioperative complications as well as cause, nature and extent of the subsequent interventions, and postoperative patient satisfaction. MATERIAL AND METHODS The D. A. F.'s total ankle replacement register is a nation-wide, voluntary registry. After giving written informed consent, the patients can be added to the database by participating providers. Data are collected during hospital stay for surgical treatment, during routine follow-up inspections and in the context of revision surgery. The information can be submitted in paper-based or online formats. The survey instruments are available as minimum data sets or scientific questionnaires which include patient-reported outcome measures (PROMs). The pseudonymous clinical data are collected and evaluated at the Institute for Evaluative Research in Medicine, University of Bern/Switzerland (IEFM). The patient-related data remain on the register's module server in North Rhine-Westphalia, Germany. The registry's methodology as well as the results of the revisions and patient satisfaction for 115 patients with a two year follow-up period are presented. Statistical analyses are performed with SAS™ (Version 9.4, SAS Institute, Inc., Cary, NC, USA). RESULTS About 2½ years after the register was launched there are 621 datasets on primary implantations, 1,427 on follow-ups and 121 records on re-operation available. 49 % of the patients received their implants due to post-traumatic osteoarthritis, 27 % because of a primary osteoarthritis and 15 % of patients suffered from a rheumatic disease. More than 90 % of the primary interventions proceeded without complications. Subsequent interventions were recorded for 84 patients, which corresponds to a rate of 13.5 % with respect to the primary implantations. It should be noted that these secondary procedures also include two-stage procedures not due to a complication. "True revisions" are interventions with exchange of components due to mechanical complications and/or infection and were present in 7.6 % of patients. 415 of the patients commented on their satisfaction with the operative result during the last follow-up: 89.9 % of patients evaluate their outcome as excellent or good, 9.4 % as moderate and only 0.7 % (3 patients) as poor. In these three cases a component loosening or symptomatic USG osteoarthritis was present. Two-year follow-up data using the American Orthopedic Foot and Ankle Society Ankle and Hindfoot Scale (AOFAS-AHS) are already available for 115 patients. The median AOFAS-AHS score increased from 33 points preoperatively to more than 80 points three to six months postoperatively. This increase remained nearly constant over the entire two-year follow-up period. CONCLUSION Covering less than 10 % of the approximately 240 providers in Germany and approximately 12 % of the annually implanted total ankle-replacements, the D. A. F.-register is still far from being seen as a national registry. Nevertheless, geographical coverage and inclusion of "high-" (more than 100 total ankle replacements a year) and "low-volume surgeons" (less than 5 total ankle replacements a year) make the register representative for Germany. The registry data show that the number of subsequent interventions and in particular the "true revision" procedures are markedly lower than the 20 % often postulated in the literature. In addition, a high level of patient satisfaction over the short and medium term is recorded. From the perspective of the authors, these results indicate that total ankle arthroplasty - given a correct indication and appropriate selection of patients - is not inferior to an ankle arthrodesis concerning patients' satisfaction and function. First valid survival rates can be expected about 10 years after the register's start.

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Introduction Recruiting and retaining volunteers who are prepared to make a long-term commitment is a major problem for Swiss sports clubs. With the inclusion of external counselling for the change and systematisation of volunteer management, sports clubs have a possibility to develop and defuse problems in spite of existing barriers and gaps in knowledge. To what extent is external counselling for personnel problems effective? It is often observed that standardised counselling inputs lead to varying consequences for sports clubs. It can be assumed that external impulses are interpreted and transformed differently into the workings of the club. However, this cannot be solely attributed to the situational or structural conditions of the clubs. It is also important to consider the underlying decision-making processes of a club. According to Luhmann’s organisational sociological considerations (2000), organisations (sports clubs) have to be viewed as social systems consisting of (communicated) decisions. This means that organisations are continually reproduced by decision-making processes. All other (observable) factors such as an organisation’s goals, recruiting strategies, support schemes for volunteers etc., have to be seen as an outcome of the operation of prior organisational decisions. Therefore: How do decision-making processes in sports clubs work in the context of the implementation of external counselling? Theoretical Framework An examination of the actual situation in sports clubs shows that decisions frequently appear to be shaped by inconsistency, unexpected outcomes, and randomness (Amis & Slack, 2003). Therefore, it must be emphasised that these decisions cannot be analysed according to any rational decision-making model. Their specific structural characteristics only permit a limited degree of rationality – bounded rationality. Non-profit organisations in particular are shaped by a specific mode of decisionmaking that Cohen, March, and Olsen (1972) have called the “garbage can model”. As sport clubs can also be conceived as “organised anarchies”, this model seems to offer an appropriate approach to understanding their practices and analysing their decision-making processes. The key concept in the garbage can model is the assumption that decision-making processes in organisations consist of four “streams”: (a) problems, (b) actors, (c) decision-making opportunities, and (d) solutions. Method Before presenting the method of the analysis of the decision-making processes in sports clubs, the external counselling will be described. The basis of the counselling is generated by a sports clubs’ capability to change. Due to the specific structural characteristics and organisational principles, change processes in sports clubs often merge with barriers and restrictions. These need to be considered when developing counselling guidelines for a successful planning and realisation of change processes. Furthermore, important aspects of personnel management in sports clubs and especially volunteer management must be implied in order to elaborate key elements for the counselling to recruit new volunteers (e.g., approach, expectations). A counselling of four system-counselling workshops was conceptualised by considering these specific characteristics. The decision-making processes in the sports clubs were analysed during the counselling and the implementation process. A case study is designed with the appropriate methodological approach for such explorative research. The approach adopted for these single case analyses was oriented toward the research program of behavioural decision-making theory (garbage can model). This posits that in-depth insights into organisational decision-making processes can only be gained through relevant case studies of existing organisational situations (Skille, 2013). Before, during and after the intervention, questionnaires and guided interviews were conducted with the project teams of the twelve par-ticipating football clubs to assess the different components of the “streams” in the context of external counselling. These interviews have been analysed using content analysis following guidelines as for-mulated by Mayring (2010). Results The findings show that decision-making processes in football clubs occur differently in the context of external counselling. Different initial positions and problems are the triggers for these decision-making processes. Furthermore, the implementation of the solutions and the external counselling is highly dependent on the commitment of certain people as central players within the decision-mak-ing process. The importance of these relationships is confirmed by previous findings in regard to decision-making and change processes in sports clubs. The decision-making processes in sports clubs can be theoretically analysed using behavioural decision-making theory and the “garbage can model”. Bounded rationality characterises all “streams” of the decision-making processes. Moreo-ver, the decision-making process of the football clubs can be well illustrated in the framework, and the interplay of the different dimensions illustrates the different decision-making practices within the football clubs. References Amis, J., & Slack, T. (2003). Analysing sports organisations: Theory and practice. In B. Houlihan (Eds.), Sport & Society (pp. 201–217). London, England: Sage. Cohen, M.D., March, J.G., & Olsen, J.P. (1972). A garbage can model of organisational choice. Ad-ministrative Science Quarterly, 17, 1-25. Luhmann, N. (2000). Organisation und Entscheidung. Opladen: Westdeutscher Verlag. Mayring, P. (2010). Qualitative Inhaltsanalyse. Grundlagen und Techniken. Weinheim: Beltz. Skille, E. Å. (2013). Case study research in sport management: A reflection upon the theory of science and an empirical example. In S. Söderman & H. Dolles (Eds.), Handbook of research on sport and business (pp. 161–175). Cheltenham, England: Edward Elgar.

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The correspondence of the state of alignment of macromolecules in biomimetic materials and natural tissues is demonstrated by investigating a mechanism of electrical polarity formation: An in vitro grown biomimetic FAp/gelatin composite is investigated for its polar properties by second harmonic (SHGM) and scanning pyroelectric microscopy (SPEM). Hexagonal prismatic seed crystals formed in gelatin gels represent a monodomain polar state, due to aligned mineralized gelatin molecules. Later growth stages, showing dumbbell morphologies, develop into a bipolar state because of surface recognition by gelatin functionality: A reversal of the polar alignment of macromolecules, thus, takes place close to that basal plane of the seed. In natural hard tissues (teeth and bone investigated by SPEM) and the biomimetic FAp/gelatin composite, we find a surprising analogy in view of growth-induced states of polarity: The development of polarity in vivo and in vitro can be explained by a Markov-type mechanism of molecular recognition during the attachment of macromolecules.

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This paper presents a first exploration of the syntactic abilities of autistic children using the framework of truncation theory (Rizzi 1993-4, 2000). It is the first step of an ongoing research project aiming to (a) provide a complete map of syntax in autism, for such work has never been attempted from a sound linguistic perspective (b) develop a targeted remediation program to enhance syntactic abilities of autistic children. Recently, a growing body of work has emphasized the existence of a causal relation between the acquisition of complex syntax (embedding) and the development of a theory of mind (in normally-developing, deaf and autistic children). Early identification and remediation of syntactic deficits is therefore crucial not only to enhance cognitive abilites related to theory of mind, but also because of the critical period hypothesis for language acquisition.

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Research has shown that chance events affect careers but has not established the nature of their effects. Moreover, the relationship between chance and career decidedness is not well understood. The present study used a person-centered approach with latent profile analysis to examine 312 Swiss adolescents in their first year of vocational training. We identified five qualitatively differing profiles according to levels of perceived chance events and career decidedness: balanced scorers, undecided with mean chance, undecided with high chance, decided with chance, and decided without chance. The groups differed significantly in work motivation (i.e., occupational self-efficacy beliefs, perceived person-job fit, and work engagement). Decided adolescents reported more favorable work motivation regardless of their level of perceived chance events. The results imply that promoting decidedness remains a valuable goal in career counseling despite the occurrence of unpredicted events.

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When proposing primary control (changing the world to fit self)/secondary control (changing self to fit the world) theory, Weisz et al. (1984) argued for the importance of the “serenity to accept the things I cannot change, the courage to change the things I can” (p. 967), and the wisdom to choose the right control strategy that fits the context. Although the dual processes of control theory generated hundreds of empirical studies, most of them focused on the dichotomy of PC and SC, with none of these tapped into the critical concept: individuals’ ability to know when to use what. This project addressed this issue by using scenario questions to study the impact of situationally adaptive control strategies on youth well-being. To understand the antecedents of youths’ preference for PC or SC, we also connected PCSC theory with Dweck’s implicit theory about the changeability of the world. We hypothesized that youths’ belief about the world’s changeability impacts how difficult it was for them to choose situationally adaptive control orientation, which then impacts their well-being. This study included adolescents and emerging adults between the ages of 18 and 28 years (Mean = 20.87 years) from the US (n = 98), China (n = 100), and Switzerland (n = 103). Participants answered a questionnaire including a measure of implicit theories about the fixedness of the external world, a scenario-based measure of control orientation, and several measures of well-being. Preliminary analyses of the scenario-based control orientation measures showed striking cross-cultural similarity of preferred control responses: while for three of the six scenarios primary control was the predominately chosen control response in all cultures, for the other three scenarios secondary control was the predominately chosen response. This suggested that youths across cultures are aware that some situations call for primary control, while others demand secondary control. We considered the control strategy winning the majority of the votes to be the strategy that is situationally adaptive. The results of a multi-group structural equation mediation model with the extent of belief in a fixed world as independent variable, the difficulties of carrying out the respective adaptive versus non-adaptive control responses as two mediating variables and the latent well-being variable as dependent variable showed a cross-culturally similar pattern of effects: a belief in a fixed world was significantly related to higher difficulties in carrying out the normative as well as the non-normative control response, but only the difficulty of carrying out the normative control response (be it primary control in situations where primary control is normative or secondary control in situations where secondary control is normative) was significantly related to a lower reported well-being (while the difficulty of carrying out the non-normative response was unrelated to well-being). While previous research focused on cross-cultural differences on the choice of PC or SC, this study shed light on the universal necessity of applying the right kind of control to fit the situation.

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En la tesis se consideran los procesos de cambio conceptual, teórico y metodológico que modelaron el desarrollo de los estudios sociales de la ciencia desde su emergencia hasta la actualidad, con el objeto de analizar los alcances y límites de las perspectivas humanistas y poshumanistas en la comprensión del vínculo "humano-no humano". Los estudios sociales de la ciencia conforman un campo marginal tanto dentro de los estudios metacientíficos como de la disciplina que les dio origen: la sociología. Si bien en las últimas décadas éstos han dado lugar a un significativo progreso en la comprensión cualitativa y cuantitativa de la ciencia y la tecnología, al responder primordialmente a la inquietud empírico-comparativa de programas de investigación de corte institucionalista han tendido a relegar de sus agendas de investigación el análisis epistemológico de los modelos explicativos considerados. En este sentido, en su afán de dar cuenta del carácter social de la ciencia apenas si han reparado en los nexos que pueden establecerse entre la explicación social de la ciencia y la explicación científica de "lo social". Con el objeto de atender a ello la tesis analiza las implicancias epistemológicas, metodológicas y ontológicas del estudio social de la ciencia considerando a la relación "humano-máquina" o "humano-no humano" como un hilo de Ariadna en la identificación de rupturas y continuidades en la consideración del vínculo "ciencia-sociedad". Desde esta perspectiva se estudia la dinámica de cambio conceptual, teórico y/o metodológico que dio lugar a la emergencia y desarrollo del estudio social de la ciencia en relación con aquella que modeló al estudio científico de "lo social", se identifican los cambios epistemológicos, ontológicos y metodológicos que configuraron a la dimensión no humana como un tópico relevante, cuando no ineludible, en la explicación social de la ciencia, se examinan las implicancias de la incorporación de los objetos naturales y/o tecnológicos a los modelos explicativos del estudio social de la ciencia en el contexto de la crítica poshumanista a las teorías de la acción que han asumido al sujeto como epicentro del análisis, y se analiza el impacto de la mencionada crítica en términos de un reordenamiento de los vínculos entre el estudio social de la ciencia y el estudio científico de "lo social". De este modo se ofrece una faceta de los estudios sociales de la ciencia inadvertida por buena parte de la literatura especializada, más atenta a la confrontación de imágenes sociológicas y filosóficas de la ciencia en el contexto de la denominada "guerra de las ciencias" que a sus implicancias epistemológicas para el estudio científico de "lo social". Enfatizando así el anclaje disciplinar del estudio social de la ciencia no se suscribe una visión "internalista" del progreso epistémico, sino que, por el contrario, se sugiere que la simultánea consideración de factores disciplinares y extra disciplinares resulta una estrategia tan fructífera como innovadora para analizar un campo que, al extender el dominio de la explicación social al ámbito de los fenómenos físico-naturales, ha dado lugar a uno de los más complejos casos de interacción disciplinar.

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La educación en la Argentina está articulada bajo criterios sociales establecidos pero que son básicamente arbitrarios y sustentados en supuestos no demostrados que afirman que el conocimiento se construye a partir de ciertos contenidos y no de otros. Dichos criterios no han variado mayormente durante las últimas décadas y siguen utilizándose como plataforma inicial a partir de los cuales se articula la educación posterior del educando. Los sistemas de educación superior en América Latina sufren una crisis a raíz de la creciente internacionalización de las nuevas tecnologías de comunicación e información y de los reclamos de inclusión social de los sectores marginados, entre otras razones. Las tecnologías de compresión digital dan origen a un modelo educativo "en red" caracterizado por un funcionamiento no presencial, mediante el cual se produce la transformación del rol de la Universidad, como centro de descubrimiento y posesión del conocimiento, para convertirse en apenas una intermediaria en la búsqueda del saber y la información. Esta nueva modalidad de educación crece en la medida en que puede cubrir una demanda social de educación superior insatisfecha, conformada básicamente por adultos que trabajan, estudiantes de zonas alejadas de los centros educativos, extranjeros que carecen de opciones educativas y alumnos globalizados. Por ello, la educación virtual nace como una nueva respuesta a viejas demandas. La construcción de una sociedad planetaria y la convivencia del multiculturalismo, además de representar la expresión de sociedades abiertas, que quizás no dispongan de bases comunes de cohesión nacional, debe ser parte de un nuevo proyecto de solidaridad y confraternidad mundial.Resulta sumamente importante que las Universidades de América Latina defiendan su participación como tales en los mercados regionales mediante la adquisición de mayor flexibilidad, actualización y excelencia, para erigirse de esta manera como una opción comparativamente válida. Asimismo, creemos que la educación, entendida como todo el corpus del conocimiento que tiene una persona, no se construye de manera arbitraria sino, por el contrario, de manera selectiva de acuerdo a las posibilidades del educando; y es precisamente sobre la base de esta pormenorizada elección el sustento sobre el cual el alumno llega posteriormente a desarrollos intelectuales superiores. El objetivo del presente trabajo se centra en mostrar la importancia de índole social y política que tienen la flexibilización y la personalización en el currículum de estudios universitarios, al momento de observar el resultado final del ejercicio profesional del graduado. Desde este punto de vista, es fundamental que la elección de los contenidos del plan de estudios de la carrera universitaria estén a cargo del educando, con la dirección de una unidad académica, especialmente en relación con lo que hoy se conoce como "aprendizaje justo a tiempo". Dicho en otras palabras, solamente cuando el educando trasciende ese fundamento institucional e inicial de conocimientos para abrevar en otras fuentes, como las Artes, la Religión, la Filosofía, etc., puede relacionar y comparar conocimientos diferentes entre sí, pero cuya elección obedece fundamentalmente a criterios personales y no meramente institucionales

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The work has as objective to produce a look about what we can think as a long history of information, what we think out from the most remote times until its conversion to theástatusáof object of the Information Science (IS) in the second half of 20th century. Of theorical nature and keeping up itself by the literature in IS and in similar areas, a discussion is made about the concept of information to then to list names, happenings and theories that contributed in the passage of the domain of the daily life to the domain of the Science. From a distant past to the most recent happenings connected to the problem of the privacity of the citizens in the digital networks, it is verified in the history of information a closed relation with the power, reason that suggests the deepening of the studies in IS about the political and ethical issues in the contemporary society.