The Tunisian Fertilizer Distribution System - Structural and Policy Considerations

Crop Production/Industries,

Impact of Brain-Derived Neurotrophic Factor Val66Met Polymorphism on Cortical Thickness and Voxel-Based Morphometry in Healthy Chinese Young Adults

BACKGROUND: Following voxel-based morphometry (VBM), brain-derived neurotrophic factor (BDNF) Val66Met polymorphism (rs6265) has been shown to affect human brain morphology in Caucasians. However, little is known about the specific role of the Met/Met genotype on brain structure. Moreover, the relationship between BDNF Val66Met polymorphism and Chinese brain morphology has not been studied. METHODOLOGY/PRINCIPAL FINDINGS: The present study investigated brain structural differences among three genotypes of BDNF (rs6265) for the first time in healthy young Chinese adults via cortical thickness analysis and VBM. Brain differences in Met carriers using another grouping method (combining Val/Met and Met/Met genotypes into a group of Met carriers as in most previous studies) were also investigated using VBM. Dual-approach analysis revealed less gray matter (GM) in the frontal, temporal, cingulate and insular cortices in the Met/Met group compared with the Val/Val group (corrected, P<0.05). Areas with less GM in the Val/Met group were included in the Met/Met group. VBM differences in Met carriers were only found in the middle cingulate cortex. CONCLUSIONS/SIGNIFICANCE: The current results indicated a unique pattern of brain morphologic differences caused by BDNF (rs6265) in young Chinese adults, in which the Met/Met genotype markedly affected the frontal, temporal, cingulate, and insular regions. The grouping method with Met carriers was not suitable to detect the genetic effect of BDNF Val66Met polymorphism on brain morphology, at least in the Chinese population, because it may hide some specific roles of Met/Met and Val/Met genotypes on brain structure

Studying neuroanatomy using MRI

The study of neuroanatomy using imaging enables key insights into how our brains function, are shaped by genes and environment, and change with development, aging, and disease. Developments in MRI acquisition, image processing, and data modelling have been key to these advances. However, MRI provides an indirect measurement of the biological signals we aim to investigate. Thus, artifacts and key questions of correct interpretation can confound the readouts provided by anatomical MRI. In this review we provide an overview of the methods for measuring macro- and mesoscopic structure and inferring microstructural properties; we also describe key artefacts and confounds that can lead to incorrect conclusions. Ultimately, we believe that, though methods need to improve and caution is required in its interpretation, structural MRI continues to have great promise in furthering our understanding of how the brain works

Tubedown-1 (Tbdn-1) suppression in oxygen-induced retinopathy and in retinopathy of prematurity

Purpose: Identification of unique proteins involved in retinopathy of prematurity (ROP) may facilitate new and more effective diagnostic tools and molecular-based treatments for ROP. Tubedown-1 (Tbdn-1), a novel homeostatic protein which copurifies with an acetyltransferase activity, is expressed in normal retinal endothelium and is specifically suppressed in retinal endothelial cells from patients with proliferative diabetic retinopathy. Furthermore, recent in vivo knockdown studies in mice have revealed that Tbdn-1 is important for retinal blood vessel homeostasis and for preventing retinal neovascularization in adults. The purpose of the present study was to determine if the expression pattern of Tbdn-1 is altered during oxygen-induced retinal neovascularization in mice and in a specimen of stage 3 human ROP. Methods: Specimens of oxygen-induced retinal neovascularization in mice, and a single specimen of active stage 3 ROP were studied by immunohistochemistry and digital image analysis using antibodies raised against Tbdn-1 and other blood vessel markers. Results: The pattern of Tbdn-1 expression during the course of oxygen-induced retinal neovascularization in mice suggests a regulating role in neonatal retinopathy. Retinal lesions from oxygen-induced retinal neovascularization in mice display suppression of retinal endothelial Tbdn-1 protein expression in conjunction with an increase in expression of proliferating cell nuclear antigen (a marker of proliferation) and α smooth muscle actin (a marker of myofibroblastic cells). Abnormal blood vessels within vitreoretinal neovascular lesions in a human specimen of active stage 3 ROP did not show Tbdn-1 protein expression. Conclusions: These results suggest that the loss of retinal endothelial Tbdn-1 expression may be a contributing factor in retinal blood vessel proliferation in ROP

Discriminative Analysis for Image-Based Studies

In this paper, we present a methodology for performing statistical analysis for image-based studies of differences between populations and describe our experience applying the technique in several different population comparison experiments. Unlike traditional analysis tools, we consider all features simultaneously, thus accounting for potential correlations between the features. The result of the analysis is a classifier function that can be used for labeling new examples and a map over the original features indicating the degree to which each feature participates in estimating the label for any given example. Our experiments include shape analysis of subcortical structures in schizophrenia, cortical thinning in healthy aging and Alzheimer’s disease and comparisons of fMRI activations in response to different visual stimuli