Genetic variation and genetic diversity in chicken populations using microsatellite assay

Microsatellites are one of the recent markers widely used in gene marker studies, as they are abundant, co-~ominant, highly polymorphic and dispersed throughout the genome. Microsatellites are identified as reliable markers in chicken.(Romanov and Weigend 2001). Birds (212) representing 8 populations were utilized in the present study. Blood samples were collected from the Wbite Leghorn layer parent strains (WLH-IWD and WLHIWF) from AICRP on Poultry Breeding, Rajendranagar, the Babcock and the Vencobb commercial birds maintained at the Department of Poultry Science, College of Veterinary Science, Hyderabad, the Aseel from the backyards of farmers of West Godavari and Srikakukam districts and non-descript (desi) birds from adjoining areas of Rajendranagar. Three di-nucleotide microsatellite markers chosen randomly from the list recommended by the FAO (Cheng et al. 1995) and mapped either in Compton or East Lansing reference populations were genotyped. Blood samples (0.5-2.0 mVbird) were coUected into the vacutainers containing EDTA (5.4 mg) from the wing vein

An Image Statistics–Based Model for Fixation Prediction

The problem of predicting where people look at, or equivalently salient region detection, has been related to the statistics of several types of low-level image features. Among these features, contrast and edge information seem to have the highest correlation with the fixation locations. The contrast distribution of natural images can be adequately characterized using a two-parameter Weibull distribution. This distribution catches the structure of local contrast and edge frequency in a highly meaningful way. We exploit these observations and investigate whether the parameters of the Weibull distribution constitute a simple model for predicting where people fixate when viewing natural images. Using a set of images with associated eye movements, we assess the joint distribution of the Weibull parameters at fixated and non-fixated regions. Then, we build a simple classifier based on the log-likelihood ratio between these two joint distributions. Our results show that as few as two values per image region are already enough to achieve a performance comparable with the state-of-the-art in bottom-up saliency prediction

Evolution and Optimality of Similar Neural Mechanisms for Perception and Action during Search

A prevailing theory proposes that the brain's two visual pathways, the ventral and dorsal, lead to differing visual processing and world representations for conscious perception than those for action. Others have claimed that perception and action share much of their visual processing. But which of these two neural architectures is favored by evolution? Successful visual search is life-critical and here we investigate the evolution and optimality of neural mechanisms mediating perception and eye movement actions for visual search in natural images. We implement an approximation to the ideal Bayesian searcher with two separate processing streams, one controlling the eye movements and the other stream determining the perceptual search decisions. We virtually evolved the neural mechanisms of the searchers' two separate pathways built from linear combinations of primary visual cortex receptive fields (V1) by making the simulated individuals' probability of survival depend on the perceptual accuracy finding targets in cluttered backgrounds. We find that for a variety of targets, backgrounds, and dependence of target detectability on retinal eccentricity, the mechanisms of the searchers' two processing streams converge to similar representations showing that mismatches in the mechanisms for perception and eye movements lead to suboptimal search. Three exceptions which resulted in partial or no convergence were a case of an organism for which the targets are equally detectable across the retina, an organism with sufficient time to foveate all possible target locations, and a strict two-pathway model with no interconnections and differential pre-filtering based on parvocellular and magnocellular lateral geniculate cell properties. Thus, similar neural mechanisms for perception and eye movement actions during search are optimal and should be expected from the effects of natural selection on an organism with limited time to search for food that is not equi-detectable across its retina and interconnected perception and action neural pathways

Association of stroke lesion shape with newly detected atrial fibrillation - Results from the MonDAFIS study

Paroxysmal Atrial fibrillation (AF) is often clinically silent and may be missed by the usual diagnostic workup after ischemic stroke. We aimed to determine whether shape characteristics of ischemic stroke lesions can be used to predict AF in stroke patients without known AF at baseline. Lesion shape quantification on brain MRI was performed in selected patients from the intervention arm of the Impact of standardized MONitoring for Detection of Atrial Fibrillation in Ischemic Stroke (MonDAFIS) study, which included patients with ischemic stroke or TIA without prior AF. Multiple morphologic parameters were calculated based on lesion segmentation in acute brain MRI data. Multivariate logistic models were used to test the association of lesion morphology, clinical parameters, and AF. A stepwise elimination regression was conducted to identify the most important variables. A total of 755 patients were included. Patients with AF detected within 2 years after stroke (n = 86) had a larger overall oriented bounding box (OBB) volume (p = 0.003) and a higher number of brain lesion components (p = 0.008) than patients without AF. In the multivariate model, OBB volume (OR 1.72, 95%CI 1.29–2.35, p < 0.001), age (OR 2.13, 95%CI 1.52–3.06, p < 0.001), and female sex (OR 2.45, 95%CI 1.41–4.31, p = 0.002) were independently associated with detected AF. Ischemic lesions in patients with detected AF after stroke presented with a more dispersed infarct pattern and a higher number of lesion components. Together with clinical characteristics, these lesion shape characteristics may help in guiding prolonged cardiac monitoring after stroke

Not Available

Not AvailableMicrosatellites are one of the recent markers widely used in gene marker studies, as they are abundant, co-~ominant, highly polymorphic and dispersed throughout the genome. Microsatellites are identified as reliable markers in chicken.(Romanov and Weigend 2001). Birds (212) representing 8 populations were utilized in the present study. Blood samples were collected from the Wbite Leghorn layer parent strains (WLH-IWD and WLHIWF) from AICRP on Poultry Breeding, Rajendranagar, the Babcock and the Vencobb commercial birds maintained at the Department of Poultry Science, College of Veterinary Science, Hyderabad, the Aseel from the backyards of farmers of West Godavari and Srikakukam districts and non-descript (desi) birds from adjoining areas of Rajendranagar. Three di-nucleotide microsatellite markers chosen randomly from the list recommended by the FAO (Cheng et al. 1995) and mapped either in Compton or East Lansing reference populations were genotyped. Blood samples (0.5-2.0 mVbird) were coUected into the vacutainers containing EDTA (5.4 mg) from the wing vein.Not Availabl