72 research outputs found
The First Murchison Widefield Array low-frequency radio observations of cluster scale non-thermal emission: the case of Abell 3667
We present the first Murchison Widefield Array observations of the well-known cluster of galaxies Abell 3667 (A3667) between 105 and 241 MHz. A3667 is one of the best known examples of a galaxy cluster hosting a double radio relic and has been reported to contain a faint radio halo and bridge. The origin of radio haloes, relics and bridges is still unclear, however galaxy cluster merger seems to be an important factor. We clearly detect the north-west (NW) and south-east radio relics in A3667 and find an integrated flux density at 149 MHz of 28.1 ± 1.7 and 2.4 ± 0.1 Jy, respectively, with an average spectral index, between 120 and 1400 MHz, of −0.9 ± 0.1 for both relics. We find evidence of a spatial variation in the spectral index across the NW relic steepening towards the centre of the cluster, which indicates an ageing electron population. These properties are consistent with higher frequency observations. We detect emission that could be associated with a radio halo and bridge. However, due to the presence of poorly sampled large-scale Galactic emission and blended point sources we are unable to verify the exact nature of these features
Consanguinity and reproductive health among Arabs
Consanguineous marriages have been practiced since the early existence of modern humans. Until now consanguinity is widely practiced in several global communities with variable rates depending on religion, culture, and geography. Arab populations have a long tradition of consanguinity due to socio-cultural factors. Many Arab countries display some of the highest rates of consanguineous marriages in the world, and specifically first cousin marriages which may reach 25-30% of all marriages. In some countries like Qatar, Yemen, and UAE, consanguinity rates are increasing in the current generation. Research among Arabs and worldwide has indicated that consanguinity could have an effect on some reproductive health parameters such as postnatal mortality and rates of congenital malformations. The association of consanguinity with other reproductive health parameters, such as fertility and fetal wastage, is controversial. The main impact of consanguinity, however, is an increase in the rate of homozygotes for autosomal recessive genetic disorders. Worldwide, known dominant disorders are more numerous than known recessive disorders. However, data on genetic disorders in Arab populations as extracted from the Catalogue of Transmission Genetics in Arabs (CTGA) database indicate a relative abundance of recessive disorders in the region that is clearly associated with the practice of consanguinity
Intramyocardial coronary arterial changes in rheumatic mitral valve disease
A retrospective analysis of intramyocardial coronary arterial changes was done in excised papillary muscles obtained at surgery in 46 cases with rheumatic mitral valve disease (RMVD). The findings were correlated with left ventricular function. Vessel wall thickening with obliteration of the lumen was found in 15 patients (32.6%) while adventitial and peri vascular fibrosis was found in 12 cases (26 %). Patients with microarteriopathy had significantly higher left ventricular and diastolic pressure (p < 0.05), lower ejection fraction (p < 0.001), and lower cardiac index (p < 0.01), as compared to patients with no microarteriopathy. The incidence of left ventricular dysfunction and surgical mortality was higher in patients with microarteriopathy (80 and 47%, respectively) than in those with normal microvasculature (26 and 13 %, respectively). As a test for predicting left ventricular dysfunction and surgical mortality a positive biopsy was moderately sensitive (sensitivity 60 and 64%, respectively) and highly specific (specificity 88 and 77%, respectively). Successful outcome after mitral valve replacement was correctly predicted by a negative biopsy result in 87% cases. We conclude that in RMVD, microarteriopathy is associated with left ventricular dysfunction and poor postoperative prognosis
Factor V Leiden mutation: An added risk in single ventricle palliation
We present the case report of a child with Factor V Leiden mutation who underwent Fontan procedure. Thromboembolism is a widely recognized complication of the Fontan procedure and its modifications. Factor V Leiden mutation, being a hypercoagulable state, posed a higher risk for thromboembolism in this child. Appropriate measures taken before and after surgery prevented postoperative coagulopathy
Discordant atrioventricular connection and concordant ventriculoarterial connection in situs inversus: isolated ventricular noninversion
A case of discordant atrioventricular (AV) connection and concordant ventriculoarterial (VA) connection (with aortomitral fibrous continuity and tricuspid pulmonary discontinuity) in situs inversus (I, D, I) is reported because of its rarity. This segmental combination with abnormally related great arteries in the absence of anomalies of venous connections and/or splenic anomalies is extremely rare
Automating image segmentation verification and validation by learning test oracles
An image segmentation algorithm delineates (an) object(s) of interest in an image. Its output is referred to as a segmentation. Developing these algorithms is a manual, iterative process involving repetitive verification and validation tasks. This process is time-consuming and depends on the availability of experts, who may be a scarce resource (e.g., medical experts). We propose a framework referred to as Image Segmentation Automated Oracle (ISAO) that uses machine learning to construct an oracle, which can then be used to automatically verify the correctness of image segmentations, thus saving substantial resources and making the image segmentation verification and validation task significantly more efficient. The framework also gives informative feedback to the developer as the segmentation algorithm evolves and provides a systematic means of testing different parametric configurations of the algorithm. During the initial learning phase, segmentations from the first few (optimally two) versions of the segmentation algorithm are manually verified by experts. The similarity of successive segmentations of the same images is also measured in various ways. This information is then fed to a machine learning algorithm to construct a classifier that distinguishes between consistent and inconsistent segmentation pairs (as determined by an expert) based on the values of the similarity measures associated with each segmentation pair. Once the accuracy of the classifier is deemed satisfactory to support a consistency determination, the classifier is then used to determine whether the segmentations that are produced by subsequent versions of the algorithm under test, are (in)consistent with already verified segmentations from previous versions. This information is then used to automatically draw conclusions about the correctness of the segmentations. We have successfully applied this approach to 3D segmentations of the cardiac left ventricle obtained from CT scans and have obtained promising results (accuracies of 95%). Even though more experiments are needed to quantify the effectiveness of the approach in real-world applications, ISAO shows promise in increasing the quality and testing efficiency of image segmentation algorithms
Use of isolated vegetable proteins in the treatment of protein malnutrition (Kwashiorkor)
Forty-five children with kwashiorkor aged one to five years were treated with three protein blends: Blend i, a mixture of isolated peanut and soy bean proteins and casein fortified with dl-methionine and 1-lysine. Blend ii, a mixture of 52 parts of peanut protein and 48 parts of skim milk powder. Blend iii, a mixture of 66.6 parts of peanut protein and 33.3 parts of skim milk powder. Each child in different groups received 30 gm. of protein daily from blends i, ii, iii or skim milk powder. The protein blends were readily digested by the children; diarrhea stopped in a shorter time in children receiving the protein blends than in those receiving skim milk powder. The different protein blends compared favorably with skim milk powder in their effectiveness in the treatment of kwashiorkor. The rate of regeneration of serum albumin with protein blend i and skim milk powder was significantly greater than that observed with protein blends ii and iii. The serum protein contents and albumin: globulin ratio were brought to normal levels after treatment with the different protein blends for a period of thirty days. The results indicate that a 2:1 blend of peanut protein isolate and skim milk powder can be used with considerable advantage in the treatment of kwashiorkor
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