917 resultados para Local linearization approach
Resumo:
Epileptic seizures are due to the pathological collective activity of large cellular assemblies. A better understanding of this collective activity is integral to the development of novel diagnostic and therapeutic procedures. In contrast to reductionist analyses, which focus solely on small-scale characteristics of ictogenesis, here we follow a systems-level approach, which combines both small-scale and larger-scale analyses. Peri-ictal dynamics of epileptic networks are assessed by studying correlation within and between different spatial scales of intracranial electroencephalographic recordings (iEEG) of a heterogeneous group of patients suffering from pharmaco-resistant epilepsy. Epileptiform activity as recorded by a single iEEG electrode is determined objectively by the signal derivative and then subjected to a multivariate analysis of correlation between all iEEG channels. We find that during seizure, synchrony increases on the smallest and largest spatial scales probed by iEEG. In addition, a dynamic reorganization of spatial correlation is observed on intermediate scales, which persists after seizure termination. It is proposed that this reorganization may indicate a balancing mechanism that decreases high local correlation. Our findings are consistent with the hypothesis that during epileptic seizures hypercorrelated and therefore functionally segregated brain areas are re-integrated into more collective brain dynamics. In addition, except for a special sub-group, a highly significant association is found between the location of ictal iEEG activity and the location of areas of relative decrease of localised EEG correlation. The latter could serve as a clinically important quantitative marker of the seizure onset zone (SOZ).
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Structured cardiac rehabilitation goes back to the late 1960s also in Switzerland and in the beginning was only available in rehabilitation clinics. In 1972 the first ambulatory rehabilitation programs became available to patients in Zurich and Bern. In the following years, in addition to the increasing number of rehabilitation centers for inpatients, more and more ambulatory rehabilitation programs were developed, especially in the larger Midlands population area in German and French-speaking Switzerland. In 1985 the Swiss Working Group of Cardiac Rehabilitation (SAKR) was initiated as an official working group of the Swiss Society of Cardiology and one of its first tasks was to establish a list of the institutions for cardiac rehabilitation in Switzerland. At that time there were 42 rehabilitation programs for a population of approx. 6.5 million, 21 for inpatients and 21 ambulatory; however, 90% of the patients were in inpatient programs. In 1992 the SAKR group defined the quality criteria which were to be applied for official recognition of institutions for cardiac rehabilitation in Switzerland. Due to these criteria, plus the fact that an increasing number of rehabilitation clinics in the mountains had been closed down, the number of inpatient rehabilitation centers decreased from 21 to 11 between 1989 and 2011, whereas the number of ambulatory programs increased from 21 to 51. The ambulatory rehabilitation centers are partially organized by local medical groups; however, most have integrated their activities into the local hospitals. The trend shows a developing preference for ambulatory rehabilitation. More and more elderly, polymorbid patients, however, will still need care in inpatient programs.
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This project considered the second stage of transforming local administration and public service management to reflect democratic forms of government. In Hungary in the second half of the 1990s more and more public functions delegated to local governments have been handed over to the private or civil sectors. This has led to a relative decrease of municipal functions but not of local governments' responsibilities, requiring them to change their orientation and approach to their work so as to be effective in their new roles of managing these processes rather than traditional bureaucratic administration. Horvath analysed the Anglo-Saxon, French and German models of self-government, identifying the differing aspects emphasised in increasing the private sector's role in the provision of public services, and the influence that this process has on the system of public administration. He then highlighted linkages between actors and local governments in Hungary, concluding that the next necessary step is to develop institutional mechanisms, financial incentives and managerial practices to utilise the full potential of this process. Equally important is the need for conscious avoidance of restrictive barriers and unintended consequences, and for local governments to confront the social conflicts that have emerged in parallel with privatisation. A further aspect considered was a widening of the role of functional governance at local level in the field of human services. A number of different special purpose bodies have been set up in Hungary, but the results of their work are unclear and Horvath feels that this institutionalisation of symbiosis is not the right path in Hungary today. He believes that the change from local government to local governance will require the formulation of specific public policy, the relevance of which can be proven by processes supported with actions.
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This was an exploratory study that aimed to gain a rough understanding of the possible ways of implementing community development. The study was carried out between October 1998 and August 1999 in Lupeni, in the Jiu Valley, which is a mining area facing major decline following the government's decision to restructure the mining industry. Against a background of the history of sociology and its insights into the development of the community concept and its theoretical, methodological and practical significance, an analysis was carried out on four levels relevant to the community development approach: social participation, citizens' level of dependency on the state, and membership and the sense of belonging to the local and national community. A needs analysis approach using questionnaires, in-depth interviews and the Delphi approach took into consideration all those actors who could play important roles in local development: local authorities, representatives of local organisations (schools, trade unions, local associations, churches), and local residents.
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Many efforts have been made in Ethiopia to mitigate land degradation, particularly soil erosion, through both local and newly introduced soil and water conservation (SWC) practices. However, the strict focus on soil erosion and conservation does not necessarily lead to satisfactory results. If SWC is effective in reducing erosion but is at the same time too costly and unacceptable to land users, sooner or later it will disappear and its positive effects will also be lost. This book therefore suggests to follow the broader approach of Sustainable Land Management (SLM), which aims at ecological soundness, economic viability and social acceptability, and thus places SWC in a more holistic framework that is closer to farmers’ reality.
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PURPOSE: Malignant glial brain tumors consistently overexpress neurokinin type 1 receptors. In classic seed-based brachytherapy, one to several rigid (125)I seeds are inserted, mainly for the treatment of small low-grade gliomas. The complex geometry of rapidly proliferating high-grade gliomas requires a diffusible system targeting tumor-associated surface structures to saturate the tumor, including its margins. EXPERIMENTAL DESIGN: We developed a new targeting vector by conjugating the chelator 1,4,7,10-tetraazacyclododecane-1-glutaric acid-4,7,10-triacetic acid to Arg(1) of substance P, generating a radiopharmaceutical with a molecular weight of 1,806 Da and an IC(50) of 0.88 +/- 0.34 nmol/L. Cell biological studies were done with glioblastoma cell lines. neurokinin type-1 receptor (NK1R) autoradiography was done with 58 tumor biopsies. For labeling, (90)Y was mostly used. To reduce the "cross-fire effect" in critically located tumors, (177)Lut and (213)Bi were used instead. In a pilot study, we assessed feasibility, biodistribution, and early and long-term toxicity following i.t. injection of radiolabeled 1,4,7,10-tetraazacyclododecane-1-glutaric acid-4,7,10-triacetic acid substance P in 14 glioblastoma and six glioma patients of WHO grades 2 to 3. RESULTS: Autoradiography disclosed overexpression of NK1R in 55 of 58 gliomas of WHO grades 2 to 4. Internalization of the peptidic vector was found to be specific. Clinically, the radiopharmeutical was distributed according to tumor geometry. Only transient toxicity was seen as symptomatic radiogenic edema in one patient (observation period, 7-66 months). Disease stabilization and/or improved neurologic status was observed in 13 of 20 patients. Secondary resection disclosed widespread radiation necrosis with improved demarcation. CONCLUSIONS: Targeted radiotherapy using diffusible peptidic vectors represents an innovative strategy for local control of malignant gliomas, which will be further assessed as a neoadjuvant approach.
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We propose a method for diagnosing confounding bias under a model which links a spatially and temporally varying exposure and health outcome. We decompose the association into orthogonal components, corresponding to distinct spatial and temporal scales of variation. If the model fully controls for confounding, the exposure effect estimates should be equal at the different temporal and spatial scales. We show that the overall exposure effect estimate is a weighted average of the scale-specific exposure effect estimates. We use this approach to estimate the association between monthly averages of fine particles (PM2.5) over the preceding 12 months and monthly mortality rates in 113 U.S. counties from 2000-2002. We decompose the association between PM2.5 and mortality into two components: 1) the association between “national trends” in PM2.5 and mortality; and 2) the association between “local trends,” defined as county-specificdeviations from national trends. This second component provides evidence as to whether counties having steeper declines in PM2.5 also have steeper declines in mortality relative to their national trends. We find that the exposure effect estimates are different at these two spatio-temporalscales, which raises concerns about confounding bias. We believe that the association between trends in PM2.5 and mortality at the national scale is more likely to be confounded than is the association between trends in PM2.5 and mortality at the local scale. If the association at the national scale is set aside, there is little evidence of an association between 12-month exposure to PM2.5 and mortality.
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Advances in information technology and global data availability have opened the door for assessments of sustainable development at a truly macro scale. It is now fairly easy to conduct a study of sustainability using the entire planet as the unit of analysis; this is precisely what this work set out to accomplish. The study began by examining some of the best known composite indicator frameworks developed to measure sustainability at the country level today. Most of these were found to value human development factors and a clean local environment, but to gravely overlook consumption of (remote) resources in relation to nature’s capacity to renew them, a basic requirement for a sustainable state. Thus, a new measuring standard is proposed, based on the Global Sustainability Quadrant approach. In a two‐dimensional plot of nations’ Human Development Index (HDI) vs. their Ecological Footprint (EF) per capita, the Sustainability Quadrant is defined by the area where both dimensions satisfy the minimum conditions of sustainable development: an HDI score above 0.8 (considered ‘high’ human development), and an EF below the fair Earth‐share of 2.063 global hectares per person. After developing methods to identify those countries that are closest to the Quadrant in the present‐day and, most importantly, those that are moving towards it over time, the study tackled the question: what indicators of performance set these countries apart? To answer this, an analysis of raw data, covering a wide array of environmental, social, economic, and governance performance metrics, was undertaken. The analysis used country rank lists for each individual metric and compared them, using the Pearson Product Moment Correlation function, to the rank lists generated by the proximity/movement relative to the Quadrant measuring methods. The analysis yielded a list of metrics which are, with a high degree of statistical significance, associated with proximity to – and movement towards – the Quadrant; most notably: Favorable for sustainable development: use of contraception, high life expectancy, high literacy rate, and urbanization. Unfavorable for sustainable development: high GDP per capita, high language diversity, high energy consumption, and high meat consumption. A momentary gain, but a burden in the long‐run: high carbon footprint and debt. These results could serve as a solid stepping stone for the development of more reliable composite index frameworks for assessing countries’ sustainability.
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Spacecraft formation flying navigation continues to receive a great deal of interest. The research presented in this dissertation focuses on developing methods for estimating spacecraft absolute and relative positions, assuming measurements of only relative positions using wireless sensors. The implementation of the extended Kalman filter to the spacecraft formation navigation problem results in high estimation errors and instabilities in state estimation at times. This is due tp the high nonlinearities in the system dynamic model. Several approaches are attempted in this dissertation aiming at increasing the estimation stability and improving the estimation accuracy. A differential geometric filter is implemented for spacecraft positions estimation. The differential geometric filter avoids the linearization step (which is always carried out in the extended Kalman filter) through a mathematical transformation that converts the nonlinear system into a linear system. A linear estimator is designed in the linear domain, and then transformed back to the physical domain. This approach demonstrated better estimation stability for spacecraft formation positions estimation, as detailed in this dissertation. The constrained Kalman filter is also implemented for spacecraft formation flying absolute positions estimation. The orbital motion of a spacecraft is characterized by two range extrema (perigee and apogee). At the extremum, the rate of change of a spacecraft’s range vanishes. This motion constraint can be used to improve the position estimation accuracy. The application of the constrained Kalman filter at only two points in the orbit causes filter instability. Two variables are introduced into the constrained Kalman filter to maintain the stability and improve the estimation accuracy. An extended Kalman filter is implemented as a benchmark for comparison with the constrained Kalman filter. Simulation results show that the constrained Kalman filter provides better estimation accuracy as compared with the extended Kalman filter. A Weighted Measurement Fusion Kalman Filter (WMFKF) is proposed in this dissertation. In wireless localizing sensors, a measurement error is proportional to the distance of the signal travels and sensor noise. In this proposed Weighted Measurement Fusion Kalman Filter, the signal traveling time delay is not modeled; however, each measurement is weighted based on the measured signal travel distance. The obtained estimation performance is compared to the standard Kalman filter in two scenarios. The first scenario assumes using a wireless local positioning system in a GPS denied environment. The second scenario assumes the availability of both the wireless local positioning system and GPS measurements. The simulation results show that the WMFKF has similar accuracy performance as the standard Kalman Filter (KF) in the GPS denied environment. However, the WMFKF maintains the position estimation error within its expected error boundary when the WLPS detection range limit is above 30km. In addition, the WMFKF has a better accuracy and stability performance when GPS is available. Also, the computational cost analysis shows that the WMFKF has less computational cost than the standard KF, and the WMFKF has higher ellipsoid error probable percentage than the standard Measurement Fusion method. A method to determine the relative attitudes between three spacecraft is developed. The method requires four direction measurements between the three spacecraft. The simulation results and covariance analysis show that the method’s error falls within a three sigma boundary without exhibiting any singularity issues. A study of the accuracy of the proposed method with respect to the shape of the spacecraft formation is also presented.
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Depending on tumor burden, hepatic function and patients' performance status, hepatocellular carcinoma is treated by surgery, local procedures, systemic therapy or palliation. The majority of patients are diagnosed at a stage where local therapy is the treatment of choice. Recently, the multikinase inhibitor sorafenib was found to improve the survival of patients with advanced hepatocellular carcinoma and conserved liver function. In this manuscript, we summarize the experimental evidence supporting the combination of a systemic targeted therapy with a local therapy. We also discuss the pros and cons of different schedules of combining such treatments. We conclude that there is enough of a theoretical argument to design clinical trials testing this strategy.
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Metanephric adenoma (MA) is a rare renal neoplasm present at any age. Usually, a total nephrectomy is performed. Some successful partial nephrectomies or selective tumor resections are described in adults but not in children. We present here the case of a 15-month-old boy, the youngest patient yet to be reported with an MA. We performed a local resection of the tumor. Today, 2 1/2 years after surgery, we can document a favorable clinical course and normal ultrasound findings in the follow-up of the operated kidney. This case gives further evidence that organ-sparing resection of MA is feasible in selected cases. A close clinical and ultrasound follow-up is mandatory for this approach.
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In the Andean highlands, indigenous environmental knowledge is currently undergoing major changes as a result of various external and internal factors. As in other parts of the world, an overall process of erosion of local knowledge can be observed. In response to this trend, some initiatives that adopt a biocultural approach aim at actively strengthening local identities and revalorizing indigenous environmental knowledge and practices, assuming that such practices can contribute to more sustainable management of biodiversity. However, these initiatives usually lack a sound research basis, as few studies have focused on the dynamics of indigenous environmental knowledge in the Andes and on its links with biodiversity management. Against this background, the general objective of this research project was to contribute to the understanding of the dynamics of indigenous environmental knowledge in the Andean highlands of Peru and Bolivia by investigating how local medicinal knowledge is socially differentiated within rural communities, how it is transformed, and which external and internal factors influence these transformation processes. The project adopted an actor-oriented perspective and emphasized the concept of knowledge dialogue by analyzing the integration of traditional and formal medicinal systems within family therapeutic strategies. It also aimed at grasping some of the links between the dynamics of medicinal knowledge and the types of land use systems and biodiversity management. Research was conducted in two case study areas of the Andes, both Quechua-speaking and situated in comparable agro-ecological production belts - Pitumarca District, Department of Cusco (Southern Peruvian Highlands) and the Tunari National Park, Department of Cochabamba (Bolivian inner-Andean valleys). In each case study area, the land use systems and strategies of 18 families from two rural communities, their environmental knowledge related to medicine and to the local therapeutic flora, and an appreciation of the dynamics of this knowledge were assessed. Data were collected through a combination of disciplinary and participatory action-research methods. It was mostly analyzed using qualitative methods, though some quantitative ethnobotanical methods were also used. In both case studies, traditional medicine still constitutes the preferred option for the families interviewed, independently of their age, education level, economic status, religion, or migration status. Surprisingly and contrary to general assertions among local NGOs and researchers, results show that there is a revival of Andean medicine within the younger generation, who have greater knowledge of medicinal plants than the previous one, value this knowledge as an important element of their way of life and relationship with “Mother Earth” (Pachamama), and, at least in the Bolivian case, prefer to consult the traditional healer rather than go to the health post. Migration to the urban centres and the Amazon lowlands, commonly thought to be an important factor of local medicinal knowledge loss, only affects people’s knowledge in the case of families who migrate over half of the year or permanently. Migration does not influence the knowledge of medicinal plants or the therapeutic strategies of families who migrate temporarily for shorter periods of time. Finally, economic status influences neither the status of people’s medicinal knowledge, nor families’ therapeutic strategies, even though the financial factor is often mentioned by practitioners and local people as the main reason for not using the formal health system. The influence of the formal health system on traditional medicinal knowledge varies in each case study area. In the Bolivian case, where it was only introduced in the 1990s and access to it is still very limited, the main impact was to give local communities access to contraceptive methods and to vaccination. In the Peruvian case, the formal system had a much greater impact on families’ health practices, due to local and national policies that, for instance, practically prohibit some traditional practices such as home birth. But in both cases, biomedicine is not considered capable of responding to cultural illnesses such as “fear” (susto), “bad air” (malviento), or “anger” (colerina). As a consequence, Andean farmers integrate the traditional medicinal system and the formal one within their multiple therapeutic strategies, reflecting an inter-ontological dialogue between different conceptions of health and illness. These findings reflect a more general trend in the Andes, where indigenous communities are currently actively revalorizing their knowledge and taking up traditional practices, thus strengthening their indigenous collective identities in a process of cultural resistance.
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In the Peruvian Andes, a long history of interaction between the local populations and their natural environment has led to extraordinary levels of agrobiodiversity. However, in sharp contrast with this biological wealth, Andean indigenous populations live under most precarious conditions. Moreover, natural resources are undergoing severe degradation processes and local knowledge about biodiversity management is under serious pressure. Against this background, the BioAndes Programme is developing initiatives based on a biocultural approach that aim at fostering biodiversity through the enhancement of cultural processes. On the basis of intercultural dialogue, joint learning and capacity development, and transdisciplinary action-research, indigenous communities, development practitioners, and researchers strive for the creation of innovative ways to contribute to more sustainable economic, socio-cultural, and political valorization of Andean biodiversity. Project activities are diverse and range from the cultivation, transformation, and commercialization of organic Andean fruits in San Marcos, Cajamarca Department, to the recuperation of natural dying techniques for alpaca wool and traditional weaving in Pitumarca, Cusco Department, and the promotion of responsible ecotourism in both regions. Based on the projects’ first two-years of experience, the following lessons learnt will be presented and discussed: 1. The economic valorization and commercialization of local products can be a powerful tool for the revival and innovation of eroded know-how; at the same time it contributes to the strengthening of local identities, in parallel with the empowerment of marginalized groups such as smallholders and women. 2. Such initiatives are only successful when they are embedded within activities that go beyond the focus on local products and seek the valorization of the entire natural and cultural landscape (e.g. through the promotion of agrotourism and local gastronomy, more sustainable management of local resources including the restoration of ecosystems, and the realization of inventories of local agrobiodiversity and the knowledge related to it). 3. The sustainability of these initiatives, which are often externally induced, is conditioned by the ability of local actors to acquire ownership of projects and access to the knowledge required to carry them out, which also means developing the personal and institutional capacities for handling the whole chain from production to commercialization. 4. The confrontation of different economic rationalities and their underlying worldviews that occur when local or indigenous people integrate into the market economy implies the need for a dialogical co-production of knowledge and collective action by local people, experts from NGOs, and political authorities in order to better control the conditions relating to the market economy. The valorization of local agrobiodiversity shows much potential for enhancing natural and cultural diversity in Southern countries, but only when local communities can participate in the shaping of the conditions under which this happens. Such activities should be designed in the mid- to long-term as part of social learning processes that are carefully embedded in the local context. Supporting institutions play a crucial role in these processes, but should see themselves only as facilitators, while ensuring that control and ownership remain with the local actors.
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Change, be it socio-cultural, political, institutional, technological, economic or ecological motivates local communities and farming families to mobilise and increase their innovation potential in order to create ways of life and production that match their own visions and priorities. In spite of the growing recognition of the potential of local innovations, they are hardly being integrated into development plans and projects; as a consequence, their diffusion within and between communities is limited. therefore interactive and participatory methods for supporting and strengthening the innovative potential of local actors are valuable inputs for sustainable rural development. the article presents an approach to promote local innovations.
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A key challenge for land change science in general and research on swidden agriculture in particular, is linking land cover information to human–environment interactions over larger spatial areas. In Lao PDR, a country facing rapid and multi-level land change processes, this hinders informed policy- and decision-making. Crucial information on land use types and people involved is still lacking. This article proposes an alternative approach for the description of landscape mosaics. Instead of analyzing local land use combinations, we studied land cover mosaics at a meso-level of spatial scale and interpreted these in terms of human–environmental interactions. These landscape mosaics were then overlaid with population census data. Results showed that swidden agricultural landscapes, involving 17% of the population, dominate 29% of the country, while permanent agricultural landscapes involve 74% of the population in 29% of the territory. Forests still form an important component of these landscape mosaics.