211 resultados para Stochastic Differential Utility
Resumo:
Reaching a consensus in terms of interchangeability and utility (i.e., disease detection/monitoring) of a medical device is the eventual aim of repeatability and agreement studies. The aim of the tolerance and relative utility indices described in this report is to provide a methodology to compare change in clinical measurement noise between different populations (repeatability) or measurement methods (agreement), so as to highlight problematic areas. No longitudinal data are required to calculate these indices. Both indices establish a metric of least to most effected across all parameters to facilitate comparison. If validated, these indices may prove useful tools when combining reports and forming the consensus required in the validation process for software updates and new medical devices.
Resumo:
Recent literature evidences differential associations of personal and general just-world beliefs with constructs in the interpersonal domain. In line with this research, we examine the respective relationships of each just-world belief with the Five-Factor and the HEXACO models of personality in one representative sample of the working population of Switzerland and one sample of the general US population, respectively. One suppressor effect was observed in both samples: Neuroticism and emotionality was positively associated with general just-world belief, but only after controlling for personal just-world belief. In addition, agreeableness was positively and honesty-humility negatively associated with general just-world belief but unrelated to personal just-world belief. Conscientiousness was consistently unrelated to any of the just-world belief and extraversion and openness to experience revealed unstable coefficients across studies. We discuss these points in light of just-world theory and their implications for future research taking both dimensions into account.
Resumo:
Foliar shade triggers rapid growth of specific structures that facilitate access of the plant to direct sunlight. In leaves of many plant species, this growth response is complex because, although shade triggers the elongation of petioles, it reduces the growth of the lamina. How the same external cue leads to these contrasting growth responses in different parts of the leaf is not understood. Using mutant analysis, pharmacological treatment and gene expression analyses, we investigated the role of PHYTOCHROME INTERACTING FACTOR7 (PIF7) and the growth-promoting hormone auxin in these contrasting leaf growth responses. Both petiole elongation and lamina growth reduction are dependent on PIF7. The induction of auxin production is both necessary and sufficient to induce opposite growth responses in petioles vs lamina. However, these contrasting growth responses are not caused by different auxin concentrations in the two leaf parts. Our work suggests that a transient increase in auxin levels triggers tissue-specific growth responses in different leaf parts. We provide evidence suggesting that this may be caused by the different sensitivity to auxin in the petiole vs the blade and by tissue-specific gene expression.
Resumo:
The goal of this study was to investigate the performance of 3D synchrotron differential phase contrast (DPC) imaging for the visualization of both macroscopic and microscopic aspects of atherosclerosis in the mouse vasculature ex vivo. The hearts and aortas of 2 atherosclerotic and 2 wild-type control mice were scanned with DPC imaging with an isotropic resolution of 15 μm. The coronary artery vessel walls were segmented in the DPC datasets to assess their thickness, and histological staining was performed at the level of atherosclerotic plaques. The DPC imaging allowed for the visualization of complex structures such as the coronary arteries and their branches, the thin fibrous cap of atherosclerotic plaques as well as the chordae tendineae. The coronary vessel wall thickness ranged from 37.4 ± 5.6 μm in proximal coronary arteries to 13.6 ± 3.3 μm in distal branches. No consistent differences in coronary vessel wall thickness were detected between the wild-type and atherosclerotic hearts in this proof-of-concept study, although the standard deviation in the atherosclerotic mice was higher in most segments, consistent with the observation of occasional focal vessel wall thickening. Overall, DPC imaging of the cardiovascular system of the mice allowed for a simultaneous detailed 3D morphological assessment of both large structures and microscopic details.
Resumo:
Ample evidence indicates that inhibitory control (IC), a key executive component referring to the ability to suppress cognitive or motor processes, relies on a right-lateralized fronto-basal brain network. However, whether and how IC can be improved with training and the underlying neuroplastic mechanisms remains largely unresolved. We used functional and structural magnetic resonance imaging to measure the effects of 2 weeks of training with a Go/NoGo task specifically designed to improve frontal top-down IC mechanisms. The training-induced behavioral improvements were accompanied by a decrease in neural activity to inhibition trials within the right pars opercularis and triangularis, and in the left pars orbitalis of the inferior frontal gyri. Analyses of changes in brain anatomy induced by the IC training revealed increases in grey matter volume in the right pars orbitalis and modulations of white matter microstructure in the right pars triangularis. The task-specificity of the effects of training was confirmed by an absence of change in neural activity to a control working memory task. Our combined anatomical and functional findings indicate that differential patterns of functional and structural plasticity between and within inferior frontal gyri enhanced the speed of top-down inhibition processes and in turn IC proficiency. The results suggest that training-based interventions might help overcoming the anatomic and functional deficits of inferior frontal gyri manifesting in inhibition-related clinical conditions. More generally, we demonstrate how multimodal neuroimaging investigations of training-induced neuroplasticity enable revealing novel anatomo-functional dissociations within frontal executive brain networks. Hum Brain Mapp 36:2527-2543, 2015. © 2015 Wiley Periodicals, Inc.
Resumo:
Background. Molecular tests for breast cancer (BC) risk assessment are reimbursed by health insurances in Switzerland since the beginning of year 2015. The main current role of these tests is to help oncologists to decide about the usefulness of adjuvant chemotherapy in patients with early stage endocrine-sensitive and human epidermal growth factor receptor 2 (HER2)-negative BC. These gene expression signatures aim at predicting the risk of recurrence in this subgroup. One of them (OncotypeDx/OT) also predicts distant metastases rate with or without the addition of cytotoxic chemotherapy to endocrine therapy. The clinical utility of these tests -in addition to existing so-called "clinico-pathological" prognostic and predictive criteria (e.g. stage, grade, biomarkers status)-is still debated. We report a single center one year experience of the use of one molecular test (OT) in clinical decision making. Methods. We extracted from the CHUV Breast Cancer Center data base the total number of BC cases with estrogen-receptor positive (ER+), HER2-negative early breast cancer (node negative (pN0) disease or micrometastases in up to 3 lymph nodes) operated between September 2014 and August 2015. For the cases from this group in which a molecular test had been decided by the tumor board, we collected the clinicopathologic parameters, the initial tumor board decision, and the final adjuvant systemic therapy decision. Results. A molecular test (OT) was done in 12.2% of patients with ER + HER2 negative early BC. The median age was 57.4 years and the median invasive tumor size was 1.7 cm. These patients were classified by ODX testing (Recurrence Score) into low-, intermediate-, and high risk groups, respectively in 27.2%, 63.6% and 9% of cases. Treatment recommendations changed in 18.2%, predominantly from chemotherapyendocrine therapy to endocrine treatment alone. Of 8 patients originally recommended chemotherapy, 25% were recommended endocrine treatment alone after receiving the Recurrence Score result. Conclusions. Though reimbursed by health insurances since January 2015, molecular tests are used moderately in our institution as per the decision of the multidisciplinary tumor board. It's mainly used to obtain a complementary confirmation supporting the decision of no chemotherapy. The OncotypeDx Recurrence Score results were in the intermediate group in 66% of the 9 tested cases but contributed to avoid chemotherapy in 2 patients during the last 12 months.
Resumo:
Bark beetle outbreaks have a devastating effect on economically important forests worldwide, thus requiring extensive application of management control strategies. The presence of unmanaged protected areas in close proximity to managed forests can instigate concerns that bark beetle infestations may spread from unmanaged into managed stands. We studied the impact of differential management of forest stands on the dispersal dynamics of the European spruce bark beetle, Ips typographus, making use of inferential population genetics on mitochondrial and nuclear genomes. Bayesian inferences of migration rates and a most parsimonious dispersal tree show that outgoing gene flow was consistently higher from managed to unmanaged areas. Reason for that is likely the thorough removal of potential breeding material in managed forests and thus the dispersal of the base stock beetles from these areas to unmanaged areas where breeding material is available. Our study suggests that the potential threat posed by unmanaged to managed forests in regard to I. typographus infestation needs to be carefully re-considered.
Resumo:
INTRODUCTION: The aim of this study was to test the diagnostic value of cerebrospinal fluid (CSF) beta-amyloid (Aβ1-42), phosphorylated tau, and total tau (tau) to discriminate Alzheimer's disease (AD) dementia from other forms of dementia. METHODS: A total of 675 CSF samples collected at eight memory clinics were obtained from healthy controls, AD dementia, subjective memory impairment, mild cognitive impairment, vascular dementia, Lewy body dementia (LBD), fronto-temporal dementia (FTD), depression, or other neurological diseases. RESULTS: CSF Aβ1-42 showed the best diagnostic accuracy among the CSF biomarkers. At a sensitivity of 85%, the specificity to differentiate AD dementia against other diagnoses ranged from 42% (for LBD, 95% confidence interval or CI = 32-62) to 77% (for FTD, 95% CI = 62-90). DISCUSSION: CSF Aβ1-42 discriminates AD dementia from FTD, but shows significant overlap with other non-AD forms of dementia, possibly reflecting the underlying mixed pathologies.