72 research outputs found
Everyday legitimacy and international administration: global governance and local legitimacy in Kosovo
International administrations are a very specific form of statebuilding. This paper examines the limits illustrated by the experience in Kosovo. Here, the international administration faced the same requirements of any legitimate, Liberal government, but without the checks and balances normally associated with Liberal governance. Thus, the international administration was granted full authority and the power thereby associated, but without the legitimacy upon which the Liberal social contract rests. The state-building agenda put forth came to be seen as more exogenous, reinforcing the delegitimization process. This paper will specifically address the influence of the Weberian approach to legitimacy on the statebuilding literature, as well as its limits. It will then propose other possible avenues for statebuilding, more in line with a wider understanding of legitimacy and intervention
Artificial intelligence for classification of temporal lobe epilepsy with ROI-level MRI data: A worldwide ENIGMA-Epilepsy study
Artificial intelligence has recently gained popularity across different medical fields to aid in the detection of diseases based on pathology samples or medical imaging findings. Brain magnetic resonance imaging (MRI) is a key assessment tool for patients with temporal lobe epilepsy (TLE). The role of machine learning and artificial intelligence to increase detection of brain abnormalities in TLE remains inconclusive. We used support vector machine (SV) and deep learning (DL) models based on region of interest (ROI-based) structural (n = 336) and diffusion (n = 863) brain MRI data from patients with TLE with (âlesionalâ) and without (ânon-lesionalâ) radiographic features suggestive of underlying hippocampal sclerosis from the multinational (multi-center) ENIGMA-Epilepsy consortium. Our data showed that models to identify TLE performed better or similar (68â75%) compared to models to lateralize the side of TLE (56â73%, except structural-based) based on diffusion data with the opposite pattern seen for structural data (67â75% to diagnose vs. 83% to lateralize). In other aspects, structural and diffusion-based models showed similar classification accuracies. Our classification models for patients with hippocampal sclerosis were more accurate (68â76%) than models that stratified non-lesional patients (53â62%). Overall, SV and DL models performed similarly with several instances in which SV mildly outperformed DL. We discuss the relative performance of these models with ROI-level data and the implications for future applications of machine learning and artificial intelligence in epilepsy care
The ENIGMA-Epilepsy working group: Mapping disease from large data sets
Epilepsy is a common and serious neurological disorder, with many different constituent conditions characterized by their electro clinical, imaging, and genetic features. MRI has been fundamental in advancing our understanding of brain processes in the epilepsies. Smallerâscale studies have identified many interesting imaging phenomena, with implications both for understanding pathophysiology and improving clinical care. Through the infrastructure and concepts now wellâestablished by the ENIGMA Consortium, ENIGMAâEpilepsy was established to strengthen epilepsy neuroscience by greatly increasing sample sizes, leveraging ideas and methods established in other ENIGMA projects, and generating a body of collaborating scientists and clinicians to drive forward robust research. Here we review published, current, and future projects, that include structural MRI, diffusion tensor imaging (DTI), and resting state functional MRI (rsfMRI), and that employ advanced methods including structural covariance, and eventâbased modeling analysis. We explore age of onsetâ and durationârelated features, as well as phenomenaâspecific work focusing on particular epilepsy syndromes or phenotypes, multimodal analyses focused on understanding the biology of disease progression, and deep learning approaches. We encourage groups who may be interested in participating to make contact to further grow and develop ENIGMAâEpilepsy
White matter abnormalities across different epilepsy syndromes in adults: an ENIGMA-Epilepsy study
The epilepsies are commonly accompanied by widespread abnormalities in cerebral white matter. ENIGMA-Epilepsy is a large quantitative brain imaging consortium, aggregating data to investigate patterns of neuroimaging abnormalities in common epilepsy syndromes, including temporal lobe epilepsy, extratemporal epilepsy, and genetic generalized epilepsy. Our goal was to rank the most robust white matter microstructural differences across and within syndromes in a multicentre sample of adult epilepsy patients. Diffusion-weighted MRI data were analysed from 1069 healthy controls and 1249 patients: temporal lobe epilepsy with hippocampal sclerosis (nâ=â599), temporal lobe epilepsy with normal MRI (nâ=â275), genetic generalized epilepsy (nâ=â182) and non-lesional extratemporal epilepsy (nâ=â193). A harmonized protocol using tract-based spatial statistics was used to derive skeletonized maps of fractional anisotropy and mean diffusivity for each participant, and fibre tracts were segmented using a diffusion MRI atlas. Data were harmonized to correct for scanner-specific variations in diffusion measures using a batch-effect correction tool (ComBat). Analyses of covariance, adjusting for age and sex, examined differences between each epilepsy syndrome and controls for each white matter tract (Bonferroni corrected at Pâ<â0.001). Across âall epilepsiesâ lower fractional anisotropy was observed in most fibre tracts with small to medium effect sizes, especially in the corpus callosum, cingulum and external capsule. There were also less robust increases in mean diffusivity. Syndrome-specific fractional anisotropy and mean diffusivity differences were most pronounced in patients with hippocampal sclerosis in the ipsilateral parahippocampal cingulum and external capsule, with smaller effects across most other tracts. Individuals with temporal lobe epilepsy and normal MRI showed a similar pattern of greater ipsilateral than contralateral abnormalities, but less marked than those in patients with hippocampal sclerosis. Patients with generalized and extratemporal epilepsies had pronounced reductions in fractional anisotropy in the corpus callosum, corona radiata and external capsule, and increased mean diffusivity of the anterior corona radiata. Earlier age of seizure onset and longer disease duration were associated with a greater extent of diffusion abnormalities in patients with hippocampal sclerosis. We demonstrate microstructural abnormalities across major association, commissural, and projection fibres in a large multicentre study of epilepsy. Overall, patients with epilepsy showed white matter abnormalities in the corpus callosum, cingulum and external capsule, with differing severity across epilepsy syndromes. These data further define the spectrum of white matter abnormalities in common epilepsy syndromes, yielding more detailed insights into pathological substrates that may explain cognitive and psychiatric co-morbidities and be used to guide biomarker studies of treatment outcomes and/or genetic research
Topographic divergence of atypical cortical asymmetry and atrophy patterns in temporal lobe epilepsy
Temporal lobe epilepsy, a common drug-resistant epilepsy in adults, is primarily a limbic network disorder associated with predominant unilateral hippocampal pathology. Structural MRI has provided an in vivo window into whole-brain grey matter structural alterations in temporal lobe epilepsy relative to controls, by either mapping (i) atypical inter-hemispheric asymmetry; or (ii) regional atrophy. However, similarities and differences of both atypical asymmetry and regional atrophy measures have not been systematically investigated. Here, we addressed this gap using the multisite ENIGMA-Epilepsy dataset comprising MRI brain morphological measures in 732 temporal lobe epilepsy patients and 1418 healthy controls. We compared spatial distributions of grey matter asymmetry and atrophy in temporal lobe epilepsy, contextualized their topographies relative to spatial gradients in cortical microstructure and functional connectivity calculated using 207 healthy controls obtained from Human Connectome Project and an independent dataset containing 23 temporal lobe epilepsy patients and 53 healthy controls and examined clinical associations using machine learning. We identified a marked divergence in the spatial distribution of atypical inter-hemispheric asymmetry and regional atrophy mapping. The former revealed a temporo-limbic disease signature while the latter showed diffuse and bilateral patterns. Our findings were robust across individual sites and patients. Cortical atrophy was significantly correlated with disease duration and age at seizure onset, while degrees of asymmetry did not show a significant relationship to these clinical variables. Our findings highlight that the mapping of atypical inter-hemispheric asymmetry and regional atrophy tap into two complementary aspects of temporal lobe epilepsy-related pathology, with the former revealing primary substrates in ipsilateral limbic circuits and the latter capturing bilateral disease effects. These findings refine our notion of the neuropathology of temporal lobe epilepsy and may inform future discovery and validation of complementary MRI biomarkers in temporal lobe epilepsy.11Nsciescopu
Precision glass molding: Cost efficient production of glass-optics with spectral range from 180nm ultraviolet to 13ÎŒm thermal infrared
Precision Glass Molding (PGM) is a manufacturing method which enables cost efficient production of highly complex glass optics in medium to high quantities. The produced glass optics can be intended for applications in a spectral range from 180 nm ultraviolet to 13 Όm thermal infrared. However, it is necessary to choose the glass type according to their intended task and wavelength domain. Typical glass types used for PGM are low Tg optical glasses. Fused silica and chalcogenide glasses expand applications to UV and IR. The use of different glass types entails a variation of the necessary temperature range in which the glass can be processed. The processing temperature of these glasses varies between 200 and 1400 °C. To ensure an economical processing, mold materials and mold manufacturing technologies are varied according to the task at hand. The application of PVD thin film coatings is one of the methods commonly used for prolonging the molds service lifetime. However, the specific coating has to be selected suitable for the glass type and mold material. To illustrate the differences in molding optical grade low Tg glass, fused silica and chalcogenide glass a representative process chain for PGM is described and peculiarities for each glass category is presented in regards to the state of the art. Finally an outlook on ongoing and future issues for applied research in the filed of PGM is given
An investigation on effectiveness of temperature treatment for fluorineâbased reactive plasma jet machining of NâBK7Âź
In this study, a fluorine-based reactive plasma jet is investigated as a promising tool for ultraprecise surface machining of N-BK7Âź. Plasma-generated particles react with an N-BK7 surface to create volatile and nonvolatile compounds. The desorption of volatile compounds results in an etched surface, whereas nonvolatile compounds form a residual layer in the etched area, causing unpredictable effects on the etching rate. Surface temperature treatment is proposed to improve the machining procedure with respect to deterministic material removal, leading to predictable results. It is shown that, at an elevated surface temperature, the residual layer properties are modified in favor of improved etching performance. The etching behavior of N-BK7 is compared with fused silica to verify the optimality of the obtained results
Replicative manufacturing of complex lighting optics by non-isothermal glass molding
The advantages of LED lighting, especially its energy efficiency and the long service life have led to a wide distribution of LED technology in the world. However, in order to make fully use of the great potential that LED lighting offers, complex optics are required to distribute the emitted light from the LED efficiently. Nowadays, many applications use polymer optics which can be manufactured at low costs. However, due to ever increasing luminous power, polymer optics reach their technological limits. Due to its outstanding properties, especially its temperature resistance, resistance against UV radiation and its long term stability, glass is the alternative material of choice for the use in LED optics. This research is introducing a new replicative glass manufacturing approach, namely non-isothermal glass molding (NGM) which is able to manufacture complex lighting optics in high volumes at competitive prices. The integration of FEM simulation at the early stage of the process development is presented and helps to guarantee a fast development cycle. A coupled thermo-mechanical model is used to define the geometry of the glass preform as well as to define the mold surface geometry. Furthermore, simulation is used to predict main process outcomes, especially in terms of resulting form accuracy of the molded optics. Experiments conducted on a commercially available molding machine are presented to validate the developed simulation model. Finally, the influence of distinct parameters on important process outcomes like form accuracy, surface roughness, birefringence, etc. is discussed
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