71 resultados para 1556
Resumo:
Equipped with state-of-the-art smartphones and mobile devices, today's highly interconnected urban population is increasingly dependent on these gadgets to organize and plan their daily lives. These applications often rely on current (or preferred) locations of individual users or a group of users to provide the desired service, which jeopardizes their privacy; users do not necessarily want to reveal their current (or preferred) locations to the service provider or to other, possibly untrusted, users. In this paper, we propose privacy-preserving algorithms for determining an optimal meeting location for a group of users. We perform a thorough privacy evaluation by formally quantifying privacy-loss of the proposed approaches. In order to study the performance of our algorithms in a real deployment, we implement and test their execution efficiency on Nokia smartphones. By means of a targeted user-study, we attempt to get an insight into the privacy-awareness of users in location-based services and the usability of the proposed solutions.
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This multi-phase study examined the influence of retrieval processes on children’s metacognitive processes in relation to and in interaction with achievement level and age. First, N = 150 9/10- and 11/12-year old high and low achievers watched an educational film and predicted their test performance. Children then solved a cloze test regarding the film content including answerable and unanswerable items and gave confidence judgments to every answer. Finally, children withdrew answers that they believed to be incorrect. All children showed adequate metacognitive processes before and during test taking with 11/12- year-olds outperforming 9/10-year-olds when considering characteristics of on-going retrieval processes. As to the influence of achievement level, high compared to low achievers proved to be more accurate in their metacognitive monitoring and controlling. Results suggest that both cognitive resources (operationalized through achievement level) and mnemonic experience (assessed through age) fuel metacognitive development. Nevertheless, when facing higher demands regarding retrieval processes, experience seems to play the more important role.
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In the present study, associations between executive functioning, metacognition, and self-perceived competence in the context of early academic outcomes were examined. A total of 209 children attending first grade were initially assessed in terms of their executive functioning and academic self-concept. One year later, children’s executive functioning, academic self-concept, metacognitive monitoring and control, as well as their achievement in mathematics and literacy were evaluated. Structural equation modeling revealed that executive functioning was significantly related to metacognitive control, both cross-sectionally and longitudinally, and that self-concept was substantially associated with metacognitive monitoring, both cross-sectionally and longitudinally. Individual differences in executive functioning and metacognitive control were significantly related to academic outcomes, with metacognitive control appearing to yield a more circumscribed influence on academic outcomes (only literacy) compared to executive functioning (literacy and mathematics).
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BACKGROUND Contour augmentation around early-placed implants (Type 2 placement) using autogenous bone chips combined with deproteinized bovine bone mineral (DBBM) and a collagen barrier membrane has been documented to predictably provide esthetically satisfactory clinical outcomes. In addition, recent data from cone beam computed tomography studies have shown the augmented volume to be stable long-term. However, no human histologic data are available to document the tissue reactions to this bone augmentation procedure. METHODS Over an 8-year period, 12 biopsies were harvested 14 to 80 months after implant placement with simultaneous contour augmentation in 10 patients. The biopsies were subjected to histologic and histomorphometric analysis. RESULTS The biopsies consisted of 32.0% ± 9.6% DBBM particles and 40.6% ± 14.6% mature bone. 70.3% ± 14.5% of the DBBM particle surfaces were covered with bone. On the remaining surface, multinucleated giant cells with varying intensity of tartrate-resistant acid phosphatase staining were regularly present. No signs of inflammation were visible, and no tendency toward a decreasing volume fraction of DBBM over time was observed. CONCLUSIONS The present study confirms previous findings that osseointegrated DBBM particles do not tend to undergo substitution over time. This low substitution rate may be the reason behind the clinically and radiographically documented long-term stability of contour augmentation using a combination of autogenous bone chips, DBBM particles, and a collagen membrane.
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This study focuses on relations between 7- and 9-year-old children’s and adults’ metacognitive monitoring and control processes. In addition to explicit confidence judgments (CJ), data for participants’ control behavior during learning and recall as well as implicit CJs were collected with an eye-tracking device (Tobii 1750). Results revealed developmental progression in both accuracy of implicit and explicit monitoring across age groups. In addition, efficiency of learning and recall strategies increases with age, as older participants allocate more fixation time to critical information and less time to peripheral or potentially interfering information. Correlational analyses, recall performance, metacognitive monitoring, and controlling indicate significant interrelations between all of these measures, with varying patterns of correlations within age groups. Results are discussed in regard to the intricate relationship between monitoring and recall and their relation to performance.
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Backspatter from wounds caused by contact shots against a biological target had before been shown to be propelled into firearms' barrels where they can persist and be retrieved from as relevant forensic evidence. Herein, that insight was applied to the investigation of a case of multiple familial homicide with a firearm. Samples of backspatter were collected from the firearm using DNA-free swabs. DNA was extracted from the swabs, and 16 STR systems were PCR-amplified to generate DNA profiles of all victims shot by the firearm. The quality of the resulting DNA profiles was sufficient to exclude the perpetrator as donor and to differentiate the three closely related victims thereby proving that all three victims had been shot by the same firearm from very close or contact distance. A key insight gained from this case was that not only a firearms' barrel inside but other inner surfaces may be charged with profilable DNA.
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Histopathologic determination of tumor regression provides important prognostic information for locally advanced gastroesophageal carcinomas after neoadjuvant treatment. Regression grading systems mostly refer to the amount of therapy-induced fibrosis in relation to residual tumor or the estimated percentage of residual tumor in relation to the former tumor site. Although these methods are generally accepted, currently there is no common standard for reporting tumor regression in gastroesophageal cancers. We compared the application of these 2 major principles for assessment of tumor regression: hematoxylin and eosin-stained slides from 89 resection specimens of esophageal adenocarcinomas following neoadjuvant chemotherapy were independently reviewed by 3 pathologists from different institutions. Tumor regression was determined by the 5-tiered Mandard system (fibrosis/tumor relation) and the 4-tiered Becker system (residual tumor in %). Interobserver agreement for the Becker system showed better weighted κ values compared with the Mandard system (0.78 vs. 0.62). Evaluation of the whole embedded tumor site showed improved results (Becker: 0.83; Mandard: 0.73) as compared with only 1 representative slide (Becker: 0.68; Mandard: 0.71). Modification into simplified 3-tiered systems showed comparable interobserver agreement but better prognostic stratification for both systems (log rank Becker: P=0.015; Mandard P=0.03), with independent prognostic impact for overall survival (modified Becker: P=0.011, hazard ratio=3.07; modified Mandard: P=0.023, hazard ratio=2.72). In conclusion, both systems provide substantial to excellent interobserver agreement for estimation of tumor regression after neoadjuvant chemotherapy in esophageal adenocarcinomas. A simple 3-tiered system with the estimation of residual tumor in % (complete regression/1% to 50% residual tumor/>50% residual tumor) maintains the highest reproducibility and prognostic value.
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Spanish Abstract: El presente trabajo analiza los posibles efectos que generaría en la regulación internacional de la inversión extranjera, el acuerdo de un capítulo de inversiones en el Acuerdo de Asociación Transpacífico (TPP), actualmente en negociaciones, sobre la base de la información disponible a la fecha. El artículo aborda cuatro aspectos que presentan especial importancia dada la divergencia de intereses entre algunos de los Estados negociadores: el ámbito de protección de la inversión extranjera; las normas sobre transparencia de los regímenes de inversión y sus disputas; la irrupción de entidades estatales como inversionistas extranjeros; y la solución de controversias a través del arbitraje inversionista-Estado. El autor concluye que en comparación a la actual fragmentación regulatoria de la que dan cuenta los acuerdos internacionales de inversión suscritos por los países negociadores del TPP, la incorporación de un capítulo de inversiones en ese Acuerdo es una oportunidad para avanzar en la convergencia de la regulación sobre inversión extranjera, tanto en materia de estándares sustantivos de protección de la inversión como en la mejora del arbitraje inversionista-Estado como mecanismo de solución de controversias.
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This paper analyzes the main features of Chilean trade and investment treaties, examining if there is a Chilean pattern in the regulation of trade and investment flows or if it is influenced by agreements signed by Chile with developed countries. The article also examines if there are differences between the treaties signed by Chile and other “Southern” developing countries and those negotiated with “Northern” developed economies, and if sustainable development concerns are part of the negotiations of trade and investment agreements by Chile.
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PURPOSE The goal of this study was to investigate whether different computed tomography (CT) energy levels could supply additional information for the differentiation of dental materials for forensic investigations. METHODS Nine different commonly used restorative dental materials were investigated in this study. A total of 75 human third molars were filled with the restorative dental materials and then scanned using the forensic reference phantom in singlesource mode. The mean Hounsfield unit values and standard deviations (SDs) of each material were calculated at 120, 80 and 140 kVp. RESULTS Most of the dental materials could be differentiated at 120 kVp. We found that greater X-ray density of a material resulted in higher SDs and that the material volume could influence the measurements. CONCLUSION Differentiation of dental materials in CT was possible in many cases using single-energy CT scans at 120 kVp. Because of the number of dental restorative materials available and scanner and scan parameter dependence, as well as the CT imaging artifacts, the identification (in contrast to differentiation) was problematic.
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Forensic radiology is a new subspecialty that has arisen worldwide in the field of forensic medicine. Postmortem computed tomography (PMCT) and, to a lesser extent, PMCT angiography (PMCTA), are established imaging methods that have replaced dated conventional X-ray images in morgues. However, these methods have not been standardized for postmortem imaging. Therefore, this article outlines the main approach for a recommended standard protocol for postmortem cross-sectional imaging that focuses on unenhanced PMCT and PMCTA. This review should facilitate the implementation of a high-quality protocol that enables standardized reporting in morgues, associated hospitals or private practices that perform forensic scans to provide the same quality that clinical scans provide in court.