917 resultados para Diffuse reflection


Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper presents reflexions about statistical considerations on illicit drug profiling and more specifically about the calculation of threshold for determining of the seizure are linked or not. The specific case of heroin and cocaine profiling is presented with the necessary details on the target profiling variables (major alkaloids) selected and the analytical method used. Statistical approach to compare illicit drug seizures is also presented with the introduction of different scenarios dealing with different data pre-treatment or transformation of variables.The main aim consists to demonstrate the influence of data pre-treatment on the statistical outputs. A thorough study of the evolution of the true positive rate (TP) and the false positive rate (FP) in heroin and cocaine comparison is then proposed to investigate this specific topic and to demonstrate that there is no universal approach available and that the calculations have to be revaluate for each new specific application.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A high-resolution three-dimensional (3-D) seismic reflection survey was conducted in Lake Geneva, near the city of Lausanne, Switzerland, as part of a project for developing such seismic techniques. Using a single 48-channel streamer, the 3-D site with an area of 1200 m x 600 m was surveyed in 10 days. A variety of complex geologic structures (e.g. thrusts, folds, channel-fill) up to similar to150 m below the water bottom were obtained with a 15 in.(3) water gun. The 3-D data allowed the construction of an accurate velocity model and the distinction of five major seismic facies within the Lower Freshwater Molasse (Aquitanian) and the Quaternary sedimentary units. Additionally, the Plateau Molasse (PM) and Subalpine Molasse (SM) erosional surface, "La Paudeze" thrust fault (PM-SM boundary) and the thickness of Quaternary sediments were accurately delineated in 3-D.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This is the third report to be published by the Department of Health and Children under the Springboard Initiative. It is written to promote understanding and appreciation of the role of a fathers in family life. Download the Report here

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Severe mucocutaneous (MCL) and diffuse (DCL) forms of American cutaneous leishmaniasis (ACL) are infrequent in Venezuela. Chemotherapy produces only transitory remission in DCL, and occasional treatment failures are observed in MCL. We have evaluated therapy with an experimental vaccine in patients with severe leishmaniasis. Four patients with MCL and 3 with early DCL were treated with monthly intradermal injections of a vaccine containing promastigotes of Leishmania (Viannia) braziliensis killed by pasteurization and viable Bacillus Calmette- Guerin. Clinical and immunological responses were evaluated. Integrity of protein constituents in extracts of pasteurized promastigotes was evaluated by gel electrophoresis. Complete remission of lesions occurred after 5-9 injections in patients with MCL or 7-10 injections in patients with early DCL. DCL patients developed positive skin reactions, average size 18.7 mm. All have been free of active lesions for at least 10 months. Adverse effects of the vaccine were limited to local reactivity to BCG at the injection sites and fever in 2 patients. Extracts of pasteurized and fresh promastigotes did not reveal differences in the integrity of protein components detectable by gel electrophoresis. Immunotherapy with this modified vaccine offers an effective, safe option for the treatment of patients who do not respond to immunotherapy with vaccine containing autoclaved parasites or to chemotherapy .

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Violence and aggression in human drinking society, either physical, psychological, sexual or resulting from neglect are not only debilitating both for the victim and the offender but extremely prevalent and pervasive. While being on the frontline to identify and rate auto- and hetero aggressive behaviour risk, the general health practitioner remains keen to protect his special relationship. When a history of violent behaviour becomes apparent, discernment must be thoroughly assessed and a critical exploration of its larger impact on family, children, co-workers and everyday fellow citizen should become compulsory.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Research has demonstrated that landscape or watershed scale processes can influence instream aquatic ecosystems, in terms of the impacts of delivery of fine sediment, solutes and organic matter. Testing such impacts upon populations of organisms (i.e. at the catchment scale) has not proven straightforward and differences have emerged in the conclusions reached. This is: (1) partly because different studies have focused upon different scales of enquiry; but also (2) because the emphasis upon upstream land cover has rarely addressed the extent to which such land covers are hydrologically connected, and hence able to deliver diffuse pollution, to the drainage network However, there is a third issue. In order to develop suitable hydrological models, we need to conceptualise the process cascade. To do this, we need to know what matters to the organism being impacted by the hydrological system, such that we can identify which processes need to be modelled. Acquiring such knowledge is not easy, especially for organisms like fish that might occupy very different locations in the river over relatively short periods of time. However, and inevitably, hydrological modellers have started by building up piecemeal the aspects of the problem that we think matter to fish. Herein, we report two developments: (a) for the case of sediment associated diffuse pollution from agriculture, a risk-based modelling framework, SCIMAP, has been developed, which is distinct because it has an explicit focus upon hydrological connectivity; and (b) we use spatially distributed ecological data to infer the processes and the associated process parameters that matter to salmonid fry. We apply the model to spatially distributed salmon and fry data from the River Eden, Cumbria, England. The analysis shows, quite surprisingly, that arable land covers are relatively unimportant as drivers of fry abundance. What matters most is intensive pasture, a land cover that could be associated with a number of stressors on salmonid fry (e.g. pesticides, fine sediment) and which allows us to identify a series of risky field locations, where this land cover is readily connected to the river system by overland flow. (C) 2010 Elsevier B.V. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Introduction: L'ossification du ligament commun vertébral postérieur (LCVP) est une hyperostose prédominant au rachis cervical, associée à différentes pathologies constructrices comme l'arthrose, la maladie de Forestier (ou DISH : Diffuse Idiopathic Squeletal Hyperostosis) ou les spondylarthrites (1). Nous rapportons le cas d'une patiente avec ossification cervicale du LCVP, avec coexistence de DISH et de spondylarthrite.Observation: Patiente de 55 ans, d'origine Irakienne, qui présente depuis l'âge de 40 ans des lombalgies et des talalgies attribuées initialement à un métier physique. En 2008, apparait une cervicobrachialgie C6 gauche. L'IRM cervicale retrouve plusieurs hernies discales (C5-C6 et C6-C7 gauches) avec un canal cervical étroit constitutionnel et une ossification du LCVP cervical. Cette ossification est attribuée à un DISH (Figure1). L'échec du traitement conservateur de la névralgie et la menace neurologique de l'ossification du LCVP conduisent en 2010 à une laminectomie C3-C6 avec fixation postérieure (figure 2). En 2011, la patiente consulte en raison de la persistance de cette névralgie, ainsi que pour des lombalgies inflammatoires. La coexistence de ces symptômes inflammatoires et de l'ossification du LCVP nous incite à réaliser une IRM des sacroiliaques qui retrouve une sacroiliite bilatérale (figure 3). Le diagnostic de spondylarthrite HLA B27 négative est retenu devant l'association des signes cliniques et radiologiques. L'étiologie précise quant à l'origine de l'ossification du LCVP reste incertaine, néanmoins un traitement spécifique de la spondylarthopathie est proposé.Discussion: L'ossification du ligament vertébral commun postérieur est une hyperostose dont les principales causes sont le DISH et les spondylarthrites. On retrouve une ossification du ligament commun vertébral, qu'il soit lombaire, cervical ou dorsal, dans 10 à 50 % des DISH, et 3.5 à 30% des spondylarthrites. 4 types d'ossification du LCVP sont décrites : continue, segmentaire, mixte ou circonscrite. Selon Resnick, le DISH se différencie de la spondylarthrite par la présence d'ossifications antérolatérales d'au moins 4 vertèbres contigües sans érosion des sacroiliaques. Cependant on retrouve dans la littérature quelques cas décrivant la coexistence des 2 pathologies. Récemment, Kim et al. Ont rapporté un cas similaire à notre patiente, avec ossification du LCVP cervical et coexistence de DISH et de spondylarthrite (2).Conclusion: Devant la présence d'une ossification du ligament vertébral commun postérieur cervical, il convient de rechercher des signes de DISH et de spondylarthrite, car leur coexistence est possible. La prévalence exacte de cette association reste encore à déterminer.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Over the past decade, significant interest has been expressed in relating the spatial statistics of surface-based reflection ground-penetrating radar (GPR) data to those of the imaged subsurface volume. A primary motivation for this work is that changes in the radar wave velocity, which largely control the character of the observed data, are expected to be related to corresponding changes in subsurface water content. Although previous work has indeed indicated that the spatial statistics of GPR images are linked to those of the water content distribution of the probed region, a viable method for quantitatively analyzing the GPR data and solving the corresponding inverse problem has not yet been presented. Here we address this issue by first deriving a relationship between the 2-D autocorrelation of a water content distribution and that of the corresponding GPR reflection image. We then show how a Bayesian inversion strategy based on Markov chain Monte Carlo sampling can be used to estimate the posterior distribution of subsurface correlation model parameters that are consistent with the GPR data. Our results indicate that if the underlying assumptions are valid and we possess adequate prior knowledge regarding the water content distribution, in particular its vertical variability, this methodology allows not only for the reliable recovery of lateral correlation model parameters but also for estimates of parameter uncertainties. In the case where prior knowledge regarding the vertical variability of water content is not available, the results show that the methodology still reliably recovers the aspect ratio of the heterogeneity.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We present first results on a method enabling mechanical scanning-free tomography with submicrometer axial resolution by multiple-wavelength digital holographic microscopy. By sequentially acquiring reflection holograms and summing 20 wavefronts equally spaced in spatial frequency in the 485-670 nm range, we are able to achieve a slice-by-slice tomographic reconstruction with a 0.6-1 mum axial resolution in a biological medium. The method is applied to erythrocytes investigation to retrieve the cellular membrane profile in three dimensions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

PURPOSE: Studies of diffuse large B-cell lymphoma (DLBCL) are typically evaluated by using a time-to-event approach with relapse, re-treatment, and death commonly used as the events. We evaluated the timing and type of events in newly diagnosed DLBCL and compared patient outcome with reference population data. PATIENTS AND METHODS: Patients with newly diagnosed DLBCL treated with immunochemotherapy were prospectively enrolled onto the University of Iowa/Mayo Clinic Specialized Program of Research Excellence Molecular Epidemiology Resource (MER) and the North Central Cancer Treatment Group NCCTG-N0489 clinical trial from 2002 to 2009. Patient outcomes were evaluated at diagnosis and in the subsets of patients achieving event-free status at 12 months (EFS12) and 24 months (EFS24) from diagnosis. Overall survival was compared with age- and sex-matched population data. Results were replicated in an external validation cohort from the Groupe d'Etude des Lymphomes de l'Adulte (GELA) Lymphome Non Hodgkinien 2003 (LNH2003) program and a registry based in Lyon, France. RESULTS: In all, 767 patients with newly diagnosed DLBCL who had a median age of 63 years were enrolled onto the MER and NCCTG studies. At a median follow-up of 60 months (range, 8 to 116 months), 299 patients had an event and 210 patients had died. Patients achieving EFS24 had an overall survival equivalent to that of the age- and sex-matched general population (standardized mortality ratio [SMR], 1.18; P = .25). This result was confirmed in 820 patients from the GELA study and registry in Lyon (SMR, 1.09; P = .71). Simulation studies showed that EFS24 has comparable power to continuous EFS when evaluating clinical trials in DLBCL. CONCLUSION: Patients with DLBCL who achieve EFS24 have a subsequent overall survival equivalent to that of the age- and sex-matched general population. EFS24 will be useful in patient counseling and should be considered as an end point for future studies of newly diagnosed DLBCL.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND The role of re-treatment with rituximab in aggressive B-cell lymphomas still needs to be defined. This study evaluated the influence of prior exposure to rituximab on response rates and survival in patients with diffuse large B-cell lymphoma treated with rituximab plus etoposide, cytarabine, cisplatinum and methylprednisolone (R-ESHAP). DESIGN AND METHODS We retrospectively analyzed 163 patients with relapsed or refractory diffuse large B-cell lymphoma who received R-ESHAP as salvage therapy with a curative purpose. Patients were divided into two groups according to whether rituximab had been administered (n=94, "R+" group) or not (n=69, "R-" group) prior to R-ESHAP. RESULTS Response rates were significantly higher in the R- group in the univariate but not in the multivariate analysis. In the analysis restricted to the R+ group, we observed very low complete remission and overall response rates in patients with primary refractory disease (8% and 33%, respectively), as compared to those in patients who were in first partial remission (41% and 86%) or who had relapsed disease (50% and 75%) (p<0.01 in both cases). Overall, 60% and 65% of patients in the R+ and R- groups, respectively, underwent stem-cell transplantation after the salvage therapy. With a median follow-up of 29 months (range, 6-84), patients in the R+ group had significantly worse progression-free survival (17% vs. 57% at 3 years, p<0.0001) and overall survival (38% v 67% at 3 years, p=0.0005) than patients in the R- group. Prior exposure to rituximab was also an independent adverse prognostic factor for both progression-free survival (RR: 2.0; 95% CI: 1.2-3.3, p=0.008) and overall survival (RR: 2.2; 95% CI: 1.3-3.9, p=0.004). CONCLUSIONS R-ESHAP was associated with a high response rate in patients who were not refractory to upfront rituximab-based chemotherapy. However, the survival outcome was poor for patients previously exposed to rituximab, as compared to in those who had not previously been treated with rituximab.