Introduction of sensor spectral response into image fusion methods. Application to wavelet-based methods

Usual image fusion methods inject features from a high spatial resolution panchromatic sensor into every low spatial resolution multispectral band trying to preserve spectral signatures and improve spatial resolution to that of the panchromatic sensor. The objective is to obtain the image that would be observed by a sensor with the same spectral response (i.e., spectral sensitivity and quantum efficiency) as the multispectral sensors and the spatial resolution of the panchromatic sensor. But in these methods, features from electromagnetic spectrum regions not covered by multispectral sensors are injected into them, and physical spectral responses of the sensors are not considered during this process. This produces some undesirable effects, such as resolution overinjection images and slightly modified spectral signatures in some features. The authors present a technique which takes into account the physical electromagnetic spectrum responses of sensors during the fusion process, which produces images closer to the image obtained by the ideal sensor than those obtained by usual wavelet-based image fusion methods. This technique is used to define a new wavelet-based image fusion method.

Deviant trajectories of cortical maturation in 22q11.2 deletion syndrome (22q11DS): a cross-sectional and longitudinal study.

22q11.2 deletion syndrome (22q11DS) is associated with an increased susceptibility to develop schizophrenia. Despite a large body of literature documenting abnormal brain structure in 22q11DS, cerebral changes associated with brain maturation in 22q11DS remained largely unexplored. To map cortical maturation from childhood to adulthood in 22q11.2 deletion syndrome, we used cerebral MRI from 59 patients with 22q11DS, aged 6 to 40, and 80 typically developing controls; three year follow-up assessments were also available for 32 patients and 31 matched controls. Cross-sectional cortical thickness trajectories during childhood and adolescence were approximated in age bins. Repeated-measures were also conducted with the longitudinal data. Within the group of patients with 22q11DS, exploratory measures of cortical thickness differences related to COMT polymorphism, IQ, and schizophrenia were also conducted. We observed deviant trajectories of cortical thickness changes with age in patients with 22q11DS. In affected preadolescents, larger prefrontal thickness was observed compared to age-matched controls. Afterward, we observed greater cortical loss in 22q11DS with a convergence of cortical thickness values by the end of adolescence. No compelling evidence for an effect of COMT polymorphism on cortical maturation was observed. Within 22q11DS, significant differences in cortical thickness were related to cognitive level in children and adolescents, and to schizophrenia in adults. Deviant trajectories of cortical thickness from childhood to adulthood provide strong in vivo cues for a defect in the programmed synaptic elimination, which in turn may explain the susceptibility of patients with 22q11DS to develop psychosis.

Measures of health and disease in Africa: are current methods giving us useful information about trends in cardiovascular diseases?

An enormous burst of interest in the public health burden from chronic disease in Africa has emerged as a consequence of efforts to estimate global population health. Detailed estimates are now published for Africa as a whole and each country on the continent. These data have formed the basis for warnings about sharp increases in cardiovascular disease (CVD) in the coming decades. In this essay we briefly examine the trajectory of social development on the continent and its consequences for the epidemiology of CVD and potential control strategies. Since full vital registration has only been implemented in segments of South Africa and the island nations of Seychelles and Mauritius - formally part of WHO-AFRO - mortality data are extremely limited. Numerous sample surveys have been conducted but they often lack standardization or objective measures of health status. Trend data are even less informative. However, using the best quality data available, age-standardized trends in CVD are downward, and in the case of stroke, sharply so. While acknowledging that the extremely limited available data cannot be used as the basis for inference to the continent, we raise the concern that general estimates based on imputation to fill in the missing mortality tables may be even more misleading. No immediate remedies to this problem can be identified, however bilateral collaborative efforts to strength local educational institutions and governmental agencies rank as the highest priority for near term development.

Identification of psychological dysfunctions and eating disorders in obese women seeking weight loss: cross-sectional study.

Objective. The aim of this study is to analyse associations between eating behaviour and psychological dysfunctions in treatment-seeking obese patients and identify parameters for the development of diagnostic tools with regard to eating and psychological disorders. Design and Methods. Cross-sectional data were analysed from 138 obese women. Bulimic Investigatory Test of Edinburgh and Eating Disorder Inventory-2 assessed eating behaviours. Beck Depression Inventory II, Spielberger State-Trait Anxiety Inventory, form Y, Rathus Assertiveness Schedule, and Marks and Mathews Fear Questionnaire assessed psychological profile. Results. 61% of patients showed moderate or major depressive symptoms and 77% showed symptoms of anxiety. Half of the participants presented with a low degree of assertiveness. No correlation was found between psychological profile and age or anthropometric measurements. The prevalence and severity of depression, anxiety, and assertiveness increased with the degree of eating disorders. The feeling of ineffectiveness explained a large degree of score variance. It explained 30 to 50% of the variability of assertiveness, phobias, anxiety, and depression. Conclusion. Psychological dysfunctions had a high prevalence and their severity is correlated with degree of eating disorders. The feeling of ineffectiveness constitutes the major predictor of the psychological profile and could open new ways to develop screening tools.

The prediction of speed and incline in outdoor running in humans using accelerometry.

PURPOSE: To explore whether triaxial accelerometric measurements can be utilized to accurately assess speed and incline of running in free-living conditions. METHODS: Body accelerations during running were recorded at the lower back and at the heel by a portable data logger in 20 human subjects, 10 men, and 10 women. After parameterizing body accelerations, two neural networks were designed to recognize each running pattern and calculate speed and incline. Each subject ran 18 times on outdoor roads at various speeds and inclines; 12 runs were used to calibrate the neural networks whereas the 6 other runs were used to validate the model. RESULTS: A small difference between the estimated and the actual values was observed: the square root of the mean square error (RMSE) was 0.12 m x s(-1) for speed and 0.014 radiant (rad) (or 1.4% in absolute value) for incline. Multiple regression analysis allowed accurate prediction of speed (RMSE = 0.14 m x s(-1)) but not of incline (RMSE = 0.026 rad or 2.6% slope). CONCLUSION: Triaxial accelerometric measurements allows an accurate estimation of speed of running and incline of terrain (the latter with more uncertainty). This will permit the validation of the energetic results generated on the treadmill as applied to more physiological unconstrained running conditions.

Treatment of penile carcinoma: to cut or not to cut?

PURPOSE: The aim of this study was to assess the outcome in patients with penile cancer. METHODS AND MATERIALS: A total of 60 patients with penile carcinoma were included. Of the patients, 45 (n = 27) underwent surgery, and 51 underwent definitive (n = 29) or postoperative (n = 22) radiotherapy (RT). Median follow-up was 62 months. RESULTS: Median time to locoregional relapse was 14 months. Local failure was observed in 3 of 23 patients (13%) treated with surgery with or without postoperative RT vs. in 19 of 33 patients (56%) given organ-sparing treatment (p = 0.0008). Of 22 local failures, 16 (73%) were salvaged with surgery. Of the 33 patients treated with definitive RT (n = 29) and the 4 patients refusing RT after excisional biopsy, local control was obtained with organ preservation in 13 (39%). In the remaining 20, 4 patients with local failure underwent salvage conservatively, resulting in an ultimate penis preservation rate of 17 of 33 (52%) patients treated with definitive RT. The 5-year and 10-year probability of surviving with an intact penis was 43% and 26%, respectively. There was no survival difference between the patients treated with definitive RT and primary surgery (56% vs. 53%; p = 0.16). In multivariate analysis, independent factors influencing survival were N-classification and pathologic grade. Surgery was the only independent predictor for better local control. CONCLUSION: Based on our study findings, in patients with penile cancer, local control is superior with surgery. However, there is no difference in survival between patients treated with surgery and those treated with definitive RT, with 52% organ preservation.

Novel methods improve prediction of species' distributions from occurrence data

Prediction of species' distributions is central to diverse applications in ecology, evolution and conservation science. There is increasing electronic access to vast sets of occurrence records in museums and herbaria, yet little effective guidance on how best to use this information in the context of numerous approaches for modelling distributions. To meet this need, we compared 16 modelling methods over 226 species from 6 regions of the world, creating the most comprehensive set of model comparisons to date. We used presence-only data to fit models, and independent presence-absence data to evaluate the predictions. Along with well-established modelling methods such as generalised additive models and GARP and BIOCLIM, we explored methods that either have been developed recently or have rarely been applied to modelling species' distributions. These include machine-learning methods and community models, both of which have features that may make them particularly well suited to noisy or sparse information, as is typical of species' occurrence data. Presence-only data were effective for modelling species' distributions for many species and regions. The novel methods consistently outperformed more established methods. The results of our analysis are promising for the use of data from museums and herbaria, especially as methods suited to the noise inherent in such data improve.

Crescent and star shapes of members of the Chlamydiales order: impact of fixative methods.

Members of the Chlamydiales order all share a biphasic lifecycle alternating between small infectious particles, the elementary bodies (EBs) and larger intracellular forms able to replicate, the reticulate bodies. Whereas the classical Chlamydia usually harbours round-shaped EBs, some members of the Chlamydia-related families display crescent and star-shaped morphologies by electron microscopy. To determine the impact of fixative methods on the shape of the bacterial cells, different buffer and fixative combinations were tested on purified EBs of Criblamydia sequanensis, Estrella lausannensis, Parachlamydia acanthamoebae, and Waddlia chondrophila. A linear discriminant analysis was performed on particle metrics extracted from electron microscopy images to recognize crescent, round, star and intermediary forms. Depending on the buffer and fixatives used, a mixture of alternative shapes were observed in varying proportions with stars and crescents being more frequent in C. sequanensis and P. acanthamoebae, respectively. No tested buffer and chemical fixative preserved ideally the round shape of a majority of bacteria and other methods such as deep-freezing and cryofixation should be applied. Although crescent and star shapes could represent a fixation artifact, they certainly point towards a diverse composition and organization of membrane proteins or intracellular structures rather than being a distinct developmental stage.

Bacterial contamination of platelet concentrates: pathogen detection and inactivation methods

Whereas the reduction of transfusion related viral transmission has been a priority during the last decade, bacterial infection transmitted by transfusion still remains associated to a high morbidity and mortality, and constitutes the most frequent infectious risk of transfusion. This problem especially concerns platelet concentrates because of their favorable bacterial growth conditions. This review gives an overview of platelet transfusion-related bacterial contamination as well as on the different strategies to reduce this problem by using either bacterial detection or inactivation methods.

Effect of collection and preprocessing methods on neutrophil elastase plasma concentrations.

OBJECTIVES: Elevated plasma levels of the elastase alpha 1-proteinase inhibitor complex (E-alpha 1 PI) have been proposed as a marker of bacterial infection and neutrophil activation. Liberation of elastase from neutrophils after collection of blood may cause falsely elevated results. Collection methods have not been validated for critically ill neonates and children. We evaluated the influence of preanalytical methods on E-alpha 1 PI results including the recommended collection into EDTA tubes. DESIGN AND METHODS: First, we compared varying acceleration speeds and centrifugation times. Centrifugation at 1550 g for 3 min resulted in reliable preparation of leukocyte free plasma. Second, we evaluated all collection tubes under consideration for absorption of E-alpha 1 PI. Finally, 12 sets of samples from healthy adults and 42 sets obtained from critically ill neonates and children were distributed into the various sampling tubes. Samples were centrifuged within 15 min of collection and analyzed with a new turbidimetric assay adapted to routine laboratory analyzers. RESULTS: One of the two tubes containing a plasma-cell separation gel absorbed 22.1% of the E-alpha 1 PI content. In the remaining tubes without absorption of E-alpha 1 PI no differences were observed for samples from healthy adult patients. However, in samples from critically ill neonates or children, significantly higher results were obtained for plain Li-heparin tubes (mean = 183 micrograms/L), EDTA tubes (mean = 93 micrograms/L), and citrate tubes (mean = 88.5 micrograms/L) than for the Li-hep tube with cell-plasma separation gel and no absorption of E-alpha 1 PI (mean = 62.4 micrograms/L, p < 0.01). CONCLUSION: Contrary to healthy adults, E-alpha 1 PI results in plasma samples from critically ill neonates and children depend on the type of collection tube.

Plaque characteristics and arterial remodeling in coronary and peripheral arterial systems.

BACKGROUND: Few studies have examined plaque characteristics among multiple arterial beds in vivo. The purpose of this study was to compare the plaque morphology and arterial remodeling between coronary and peripheral arteries using gray-scale and radiofrequency intravascular ultrasound (IVUS) at clinical presentation. METHODS AND RESULTS: IVUS imaging was performed in 68 patients with coronary and 93 with peripheral artery lesions (29 carotid, 50 renal, and 14 iliac arteries). Plaques were classified as fibroatheroma (VH-FA) (further subclassified as thin-capped [VH-TCFA] and thick-capped [VH-ThCFA]), fibrocalcific plaque (VH-FC) and pathological intimal thickening (VH-PIT). Plaque rupture (13% of coronary, 7% of carotid, 6% of renal, and 7% of iliac arteries; P = NS) and VH-TCFA (37% of coronary, 24% of carotid, 16% of renal, and 7% of iliac arteries; P = 0.02) were observed in all arteries. Compared with coronary arteries, VH-FA was less frequently observed in renal (P < 0.001) and iliac arteries (P < 0.006). Lesions with positive remodeling demonstrated more characteristics of VH-FA in coronary (84% vs. 25%, P < 0.001), carotid (72% vs. 20%, P = 0.001), and renal arteries (42% vs. 4%, P = 0.001) compared with those with intermediate/negative remodeling. There was positive relationship between remodeling index and percent necrotic area in all four arteries. CONCLUSIONS: Atherosclerotic plaque phenotypes were heterogeneous among four different arteries; renal and iliac arteries had more stable phenotypes compared with coronary artery. In contrast, the associations of remodeling pattern with plaque phenotype and composition were similar among the various arterial beds.

A prospective study of predictors of poststroke depression.

OBJECTIVE: To investigate the association between early depressive behavior after stroke onset and occurrence of poststroke depression (PSD) at 3- and 12-month follow-up evaluations. METHODS: The study prospectively included 273 patients with first-ever single uncomplicated ischemic stroke. In the stroke unit, nurses scored crying, overt sadness, and apathy daily using an observational method to include patients with comprehension deficits. The Barthel Index was used to assess disability. Follow-up evaluation at months 3 and 12 included psychiatric assessment based on the Diagnostic and Statistical Manual of Mental Disorders, 4th edition. RESULTS: Crying (19.8%), overt sadness (50.5%), and apathy (47.6%) were observed. Of the patients observed crying, 4 showed pathologic crying, 19 emotionalism, and 12 catastrophic reactions. Crying and overt sadness, but not apathy, were associated with a subjective experience of depression (p < 0.05). Thirty of 52 (58%) patients observed crying, 12 of 19 (63%) patients with emotionalism, and 5 of 12 (41%) patients with catastrophic reactions developed PSD within the first year. Multiple logistic regression analysis showed that only severe functional disability (odds ratio [OR], 4.31; 95% CI, 2.41 to 7.69), crying behaviors (OR, 2.66; 95% CI, 1.35 to 5.27), and an age <68 years (OR, 2.32; 95% CI, 1.30 to 4.13) were (p < 0.05) predictors of late PSD development (13% of the variance). CONCLUSIONS: In the stroke unit, crying and overt sadness are more reliable indicators of depressed mood than apathy. In patients with first-ever stroke, crying behaviors soon after stroke, a younger age, and severe disability are predictors of poststroke depression occurrence within the first year after stroke onset.

A program for the computation of power and determination of sample size in hierarchical experimental designs.

We have devised a program that allows computation of the power of F-test, and hence determination of appropriate sample and subsample sizes, in the context of the one-way hierarchical analysis of variance with fixed effects. The power at a fixed alternative is an increasing function of the sample size and of the subsample size. The program makes it easy to obtain the power of F-test for a range of values of sample and subsample sizes, and therefore the appropriate sizes based on a desired power. The program can be used for the 'ordinary' case of the one-way analysis of variance, as well as for hierarchical analysis of variance with two stages of sampling. Examples are given of the practical use of the program.

Termination of Atrial Fibrillation by Catheter Ablation can be Successfully Predicted from Baseline ECG

Purpose Multiple organization indices (OIs) have been used to predict the outcome of stepwise catheter ablation (step-CA) in long-standing persistent AF (pers-AF), however with limited success. Our study aims at developing innovative OIs from baseline (BL, before ablation) ECG in order to predict the outcome of step-CA. Methods Fourteen consecutive patients (pts) (60±5 y, AF duration 21±9 m) underwent a step-CA consisting in pulmonary veins isolation, left atrial (LA) defragmentation and linear ablations, and right atrial (RA) ablations if non terminated. Chest lead V6 was placed in the back (V6b). After QRST cancellation from chest leads V1 to V6b, two OIs were computed to quantify the harmonic components of ECG atrial activity: 1) phase difference variance (PD) between the AF harmonic components as a measure of AF regularity, and 2) adaptive OI (AOI) evaluating the time evolution of the AF harmonic components. Both indices were compared to classical ones: a spectrum-based OI (SOI) and ECG AF cycle length (AFCL). Results Pers-AF was terminated into sinus rhythm or atrial tachycardia in 10/14 pts during step-CA, 8 during LA (LT), 2 during RA (RT) ablation, and 4 were non terminated (NT). The figure shows that LT was best separated from RT/NT before ablation by AOI computed on lead V1 (A) and PD from lead V6b (B) as compared to SOI and AFCL respectively. Conclusion Our results suggest that adaptive OIs computed before ablation perform better than classical OIs for separating LT from RT/NT pts. These findings are indicative of a higher baseline organization in LT pts that could be used to select candidates for the restoration of sinus rhythm by step-CA.

Quality of care and survival of haemodialysed patients in western Switzerland.

BACKGROUND: Many factors affect survival in haemodialysis (HD) patients. Our aim was to study whether quality of clinical care may affect survival in this population, when adjusted for demographic characteristics and co-morbidities. METHODS: We studied survival in 553 patients treated by chronic HD during March 2001 in 21 dialysis facilities in western Switzerland. Indicators of quality of care were established for anaemia control, calcium and phosphate product, serum albumin, pre-dialysis blood pressure (BP), type of vascular access and dialysis adequacy (spKt/V) and their baseline values were related to 3-year survival. The modified Charlson co-morbidity index (including age) and transplantation status were also considered as a predictor of survival. RESULTS: Three-year survival was obtained for 96% of the patients; 39% (211/541) of these patients had died. The 3-year survival was 50, 62 and 69%, respectively, in patients who had 0-2, 3 and >or=4 fulfilled indicators of quality of care (test for linear trend, P < 0.001). In a Cox multivariate analysis model, the absence of transplantation, a higher modified Charlson's score, decreased fulfilment of indicators of good clinical care and low pre-dialysis systolic BP were independent predictors of death. CONCLUSION: Good clinical care improves survival in HD patients, even after adjustment for availability of transplantation and co-morbidities.