36 resultados para laser beam beyond the diffraction limits
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This article has been written as a comment to Dr Thomas and Dr Baker's article "Teaching an adult brain new tricks: A critical review of evidence for training-dependent structural plasticity in humans". We deliberately expand on the key question about the biological substrates underlying use-dependent brain plasticity rather than reiterating the authors' main points of criticism already addressed in more general way by previous publications in the field. The focus here is on the following main issues: i) controversial brain plasticity findings in voxel-based morphometry studies are partially due to the strong dependency of the widely used T1-weighted imaging protocol on varying magnetic resonance contrast contributions; ii) novel concepts in statistical analysis allow one to directly infer topological specificity of structural brain changes associated with plasticity. We conclude that iii) voxel-based quantification of relaxometry derived parameter maps could provide a new perspective on use-dependent plasticity by characterisation of brain tissue property changes beyond the estimation of volume and cortical thickness changes. In the relevant sections we respond to the concerns raised by Dr Thomas and Dr Baker from the perspective of the proposed data acquisition and analysis strategy.
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OBJECTIVE: To identify characteristics of consultations that do not conform to the traditionally understood communication 'dyad', in order to highlight implications for medical education and develop a reflective 'toolkit' for use by medical practitioners and educators in the analysis of consultations. DESIGN: A series of interdisciplinary research workshops spanning 12 months explored the social impact of globalisation and computerisation on the clinical consultation, focusing specifically on contemporary challenges to the clinician-patient dyad. Researchers presented detailed case studies of consultations, taken from their recent research projects. Drawing on concepts from applied sociolinguistics, further analysis of selected case studies prompted the identification of key emergent themes. SETTING: University departments in the UK and Switzerland. PARTICIPANTS: Six researchers with backgrounds in medicine, applied linguistics, sociolinguistics and medical education. One workshop was also attended by PhD students conducting research on healthcare interactions. RESULTS: The contemporary consultation is characterised by a multiplicity of voices. Incorporation of additional voices in the consultation creates new forms of order (and disorder) in the interaction. The roles 'clinician' and 'patient' are blurred as they become increasingly distributed between different participants. These new consultation arrangements make new demands on clinicians, which lie beyond the scope of most educational programmes for clinical communication. CONCLUSIONS: The consultation is changing. Traditional consultation models that assume a 'dyadic' consultation do not adequately incorporate the realities of many contemporary consultations. A paradox emerges between the need to manage consultations in a 'super-diverse' multilingual society, while also attending to increasing requirements for standardised protocol-driven approaches to care prompted by computer use. The tension between standardisation and flexibility requires addressing in educational contexts. Drawing on concepts from applied sociolinguistics and the findings of these research observations, the authors offer a reflective 'toolkit' of questions to ask of the consultation in the context of enquiry-based learning.
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With the dramatic increase in the volume of experimental results in every domain of life sciences, assembling pertinent data and combining information from different fields has become a challenge. Information is dispersed over numerous specialized databases and is presented in many different formats. Rapid access to experiment-based information about well-characterized proteins helps predict the function of uncharacterized proteins identified by large-scale sequencing. In this context, universal knowledgebases play essential roles in providing access to data from complementary types of experiments and serving as hubs with cross-references to many specialized databases. This review outlines how the value of experimental data is optimized by combining high-quality protein sequences with complementary experimental results, including information derived from protein 3D-structures, using as an example the UniProt knowledgebase (UniProtKB) and the tools and links provided on its website ( http://www.uniprot.org/ ). It also evokes precautions that are necessary for successful predictions and extrapolations.
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Transparency is now seen as a key tool of democratic governance. The European Union's commitment to transparency is now at the centre of a crucial debate between the Commission and the Parliament on the future of citizen's right of access to information. This article presents the main characteristics of the current regime and questions the pertinence of the proposed changes in light of the international drive at modernising access to information laws and the attempt at identifying the ̳proper limits of transparency'. The questions raised range from the identification of what can be accessed to the definition of exemption and the protection of competing interests.
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Cette thèse doctorale étudie le rôle de la citoyenneté Suisse et le modèle libérale de l'Etat social dans la production du racisme institutionnel au sein des services sociaux en Suisse. Cette thèse pose la question comment le régime de la citoyenneté Suisse rend possible et contraint les travailleurs sociaux à racialiser et discriminer leur clients avec des différences culturelles alors que les normes de l'aide sociale (normes de CSIAS) ne prévoient pas des traitements différentialistes selon la culture ou l'origine. Le modèle théorique du racisme institutionnel développé se passe sur une approche néo- institutionaliste et des ethnie and racial studies, prenant en compte le niveau individuel, collectif et institutionnel. En incluant ces deux approches, on dépasse le déterminisme des structuralistes dans les études sur le racisme institutionnel. Cette recherche qualitative montre que les travailleurs sociaux utilisent les ressources de la citoyenneté Suisse, de l'Etat social Suisse et leur expériences personnelles quand ils interagissent avec des clients. En plus, cette thèse démontre que le workfare logique en combinaison avec l'idée de l'assimilation culturelle rend possible la production d'un discours sur la nécessité de mériter d'être un membre de la communauté nationale et d'accéder à l'aide sociale. Cette compréhension néo-libérale de la citoyenneté renforce et légitime les travailleurs sociaux de racialiser et pratiquer la discrimination à l'égard de leurs clients et les rend incapable de développer une réflexivité critique. Toutefois, cette thèse montre également que les travailleurs sociaux produisent du travail social interculturel s'ils ont pu développer une telle réflexivité critique dans les institutions de l'aide sociale qui mettent en avant une conception "individuelle" de l'aide sociale.-Cette thèse vise à aller au-delà du silence qui constitue les débats publiques et la recherche sur le racisme au sein des institutions publiques en Suisse. - This thesis questions the role of the Swiss citizenship regime and the Swiss liberal social welfare model in the production of institutional racism in social services in Switzerland. Considering the absence of intercultural formal guidelines in the norms of social welfare (SKOS norms), this research investigates how the Swiss citizenship regime constrains and enables social workers to racialise and discriminate against their clients with cultural differences. This thesis develops a model of institutional racism, taking into account ethnic and racial studies and a neo-institutionalist approach on institutions, addressing the individual, collective and institutional level. In this framework, this thesis allows to overcome the structuralist determinism in the studies on institutional racism. Based on a qualitative inquiry, this research shows that social workers use the resources from the Swiss citizenship regime, social welfare model and their personal experiences when they interact with their clients. This study also shows that the workfare logic in combination with the idea of cultural assimilation enables to produce a discourse on deserving social welfare and earning membership to the national community. This neo-liberal citizenship understanding reinforces and legitimises social workers to racialise and discriminate against their clients and hinders them to develop critical reflexivity. However, this thesis also shows that social workers are able to produce intercultural social work when they could develop such a reflexivity in social services with an "individual" social welfare conceptions. This thesis aims to go beyond a persisting silence regarding public debates and research on racism in public institutions in Switzerland.
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BACKGROUND: Port-wine stains (PWS) are malformations of capillaries in 0.3% of newborn children. The treatment of choice is by pulsed dye LASER (PDL), and requires several sessions. The efficacy of this treatment is at present evaluated on the basis of clinical inspection and of digital photographs taken throughout the treatment. LASER-Doppler imaging (LDI) is a noninvasive method of imaging the perfusion of the tissues by the microcirculatory system (capillaries). The aim of this paper is to demonstrate that LDI allows a quantitative, numerical evaluation of the efficacy of the PDL treatment of PWS. METHOD: The PDL sessions were organized according to the usual scheme, every other month, from September 1, 2012, to September 30, 2013. LDI imaging was performed at the start and at the conclusion of the PDL treatment, and simultaneously on healthy skin in order to obtain reference values. The results evidenced by LDI were analyzed according to the "Wilcoxon signed-rank" test before and after each session, and in the intervals between the three PDL treatment sessions. RESULTS: Our prospective study is based on 20 new children. On average, the vascularization of the PWS was reduced by 56% after three laser sessions. Compared with healthy skin, initial vascularization of PWS was 62% higher than that of healthy skin at the start of treatment, and 6% higher after three sessions. During the 2 months between two sessions, vascularization of the capillary network increased by 27%. CONCLUSION: This study shows that LDI can demonstrate and measure the efficacy of PDL treatment of PWS in children. The figures obtained when measuring the results by LDI corroborate the clinical assessments and may allow us to refine, and perhaps even modify, our present use of PDL and thus improve the efficacy of the treatment.
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Mental illnesses have long been perceived as the exclusive consequence of abnormalities in neuronal functioning. Until recently, the role of glial cells in the pathophysiology of mental diseases has largely been overlooked. However recently, multiple lines of evidence suggest more diverse and significant functions of glia with behavior-altering effects. The newly ascribed roles of astrocytes, oligodendrocytes and microglia have led to their examination in brain pathology and mental illnesses. Indeed, abnormalities in glial function, structure and density have been observed in postmortem brain studies of subjects diagnosed with mental illnesses. In this review, we discuss the newly identified functions of glia and highlight the findings of glial abnormalities in psychiatric disorders. We discuss these preclinical and clinical findings implicating the involvement of glial cells in mental illnesses with the perspective that these cells may represent a new target for treatment.
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This paper examines the explanation of commercial crises offered by William Huskisson in 1810 in the wake of the debate on the Bullion Report. Huskisson argued that the suspension of convertibility made it possible to extend issues of paper currency beyond its proper limits. Such an expansion, being in the interest of all parties concerned, would actually take place and stimulate excessive speculations, which would eventually prove unsustainable and bring generalized ruin and distress. Although some elements of this explanations were not new (having been anticipated by writers sucha as James Currie in 1793, William Roscoe in 1793, William Anderson in 1797 and an anonymous in 1796), Huskisson's explanation is more systematic and better organized, and his emphasis on the endogenous character of the crisis and on the instability of the dynamics of trade and credit makes it an interesting foreshadower of the theories of crises that were advanced half a century later.
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To compare autofluorescence (AF) images obtained with the confocal scanning laser ophthalmoscope (using the Heidelberg retina angiograph; HRA) and the modified Topcon fundus camera, in a routine clinical setting. A prospective comparative study conducted at the Jules-Gonin Eye Hospital. Fifty-six patients from the medical retina clinic. All patients had complete ophthalmic slit-lamp and fundus examinations, colour and red-free fundus photography, AF imaging with both instruments, and fluorescein angiography. Cataract and fixation were graded clinically. AF patterns were analyzed for healthy and pathological features. Differences of image noise were analyzed by cataract grading and fixation. A total of 105 eyes were included. AF patterns discovered by the retina angiograph and the fundus camera images, respectively, were a dark optic disc in 72 % versus 15 %, a dark fovea in 92 % versus 4 %, sub- and intraretinal fluid visible as hyperautofluorescence on HRA images only, lipid exudates visible as hypoautofluorescence on HRA images only. The same autofluorescent pattern was found on both images for geographic atrophy, retinal pigment changes, drusen and haemorrhage. Image noise was significantly associated with the degree of cataract and/or poor fixation, favouring the fundus camera. Images acquired by the fundus camera before and after fluorescein angiography were identical. Fundus AF images differ according to the technical differences of the instruments used. Knowledge of these differences is important not only for correctly interpreting images, but also for selecting the most appropriate instrument for the clinical situation.
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Resection of lung metastases from colorectal cancer (CRC) is increasingly performed with a curative intent. This strategy was made possible in the 1990s by the development of new chemotherapeutic approaches, improved surgical techniques and better imaging modalities. However, evidence-based data showing clinical benefits of lung metastasectomy in this setting are nonexistent, and there are no prospective randomized trials to support the routine performance of these procedures for stage IV CRC. Current evidence suggests that resection of pulmonary metastases in combination with new cytotoxic agents, such as oxaliplatin, irinotecan and bevacizumab, may result in prolonged survival for many, and cure for a small minority of CRC patients who experienced tumor spread beyond the limits of the abdomen. This review focuses on the results of surgical management of CRC patients with lung metastases: we report the outcome of published series according to the presence or the absence of liver metastasis (and hepatic resection) prior to lung resection.
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OBJECTIVE: To determine the means and the reference intervals of the quantitative morphometric parameters of femoroacetabular impingement (FAI) in normal hips with high-resolution computed tomography (CT). METHODS: We prospectively included 94 adult individuals who underwent CT for thoracic, abdominal or urologic pathologies. Patients with a clinical history of hip pathology and/or with osteoarthritis on CT were excluded. We calculated means and 95 % reference intervals for imaging signs of cam-type (alpha angle at 90° and 45° and femoral head-neck offset) and pincer-type impingement (acetabular version angle, lateral centre-edge angle and acetabular index). RESULTS: The 95 % reference interval limits were all far beyond the abnormal thresholds found in the literature for cam-type and to a lesser extent for pincer-type FAI. The upper limits of the reference intervals for the alpha angles (at 90°/45°) were 68°/83° (men) and 69°/84° (women), compared to thresholds from the literature (50°, 55° or 60°). Reference intervals were similar between genders for cam-type parameters, and slightly differed for pincer-type. CONCLUSION: The 95 % reference intervals of morphometric measurements of FAI in asymptomatic hips were beyond the abnormal thresholds, which was especially true for cam-type FAI. Our results suggest the need for redefining the current morphometric parameters used in the diagnosis of FAI. KEY POINTS: ? 95 % reference intervals limits of FAI morphotype were beyond currently defined thresholds. ? Reference intervals of pincer-type morphotype measurements were close to current definitions. ? Reference intervals of cam-type morphotype measurements were far beyond the current definitions. ? Current morphometric definitions of cam-type morphotype should be used with care.
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The purpose of this study is to analyze the retina and choroid response following krypton laser photocoagulation. Ninety-two C57BL6/Sev129 and 32 C57BL/6J, 5-6-week-old mice received one single krypton (630 nm) laser lesion: 50 microm, 0.05 s, 400 mW. On the following day, every day thereafter for 1 week and every 2-3 days for the following 3 weeks, serial sections throughout the lesion were systematically collected and studied. Immunohistology using specific markers or antibodies for glial fibrillary acidic protein (GFAP) (astrocytes, glia and Muller's cells), von Willebrand (vW) (vascular endothelial cells), TUNEL (cells undergoing caspase dependent apoptosis), PCNA (proliferating cell nuclear antigen) p36, CD4 and F4/80 (infiltrating inflammatory and T cells), DAPI (cell nuclei) and routine histology were carried out. Laser confocal microscopy was also performed on flat mounts. Temporal and spatial observations of the created photocoagulation lesions demonstrate that, after a few hours, activated glial cells within the retinal path of the laser beam express GFAP. After 48 h, GFAP-positive staining was also detected within the choroid lesion center. "Movement" of this GFAP-positive expression towards the lasered choroid was preceded by a well-demarcated and localized apoptosis of the retina outer nuclear layer cells within the laser beam path. Later, death of retinal outer nuclear cells and layer thinning at this site was followed by evagination of the inner nuclear retinal layer. Funneling of the entire inner nuclear and the thinned outer nuclear layers into the choroid lesion center was accompanied by "dragging" of the retinal capillaries. Thus, from days 10 to 14 after krypton laser photocoagulation onward, well-formed blood capillaries (of retinal origin) were observed within the lesion. Only a few of the vW-positive capillary endothelial cells stained also for PCNA p36. In the choroid, dilatation of the vascular bed occurred at the vicinity of the photocoagulation site and around it. Confocal microscopy demonstrates that the vessels throughout the path lesion are located within the neuroretina while in the choroid (after separation of the neural retina) only GFAP-positive but no lectin-positive cells can be seen. The involvement of infiltrating inflammatory cells in these remodeling and healing processes remained minimal throughout the study period. During the 4 weeks following krypton laser photocoagulation in the mouse eye, processes of wound healing and remodeling appear to be driven by cells (and vessels) originating from the retina.