910 research outputs found
Molecular and biological characterization of Trichogramma turkestanica
Parasitoids of Trichogramma (Hymenoptera: Trichogrammatidae) parasitize the eggs of many species of Lepidoptera and have been used for the biological control of numerous pest species. We collected this parasitoid from Taif governorate, KSA in summer of 2009. It is difficult to differentiate between Trichogramma species because of their small size and lack of differences in morphological characters. Therefore, different molecular markers were employed to characterize this species, including direct amplification of the internal transcribed spacer 2 (ITS2) of ribosomal DNA and by restriction fragment length polymorphism followed by sequencing. The results show that ITS2 region is 491 bp and indicated that this is a new stain of Trichogramma. We named this strain TaifKSA. From the tested restriction enzymes, only EcoRI and PstI cut the PCR product of ITS2 region. We compared the biological characteristics of the strain under investigation with other commercial strain (SQG) of the same species and no significant differences between them have been shown.Key words: Trichogramma turkestanica, TaifKSA, molecular identification, internal transcribed spacer 2 (ITS2), restriction enzymes, biological characteristics
Common MEFV mutations in Egyptian patients with familial Mediterranean fever
Background: Familial Mediterranean fever (FMF) which is an autosomal recessive condition that primarily affect population of the Mediterranean basin. If undiagnosed effectively and treated with colchicine for life it may lead to serious consequences in terms of renal amyloidosis and renal failure. Objectives: We aim to check for the presence of FMF mutations in clinically suspected Egyptian patients, as an important step for family counseling and case management. Subjects and Methods: The study is a pilot study to check for the presence of FMF mutations among suspected cases (24 cases) from Sharkia Governorate. The control subjects (24) were selected from healthy volunteers. We examined FMF mutations by PCR technique for MEFV gene analysis in order to establish a diagnosis of FMF by examining two mutations, M694V and E148Q. Results: We found 58.3% (14/24 cases) of cohort were positive for M694V mutation, and all cohort were negative for E148Q mutation. The normal controls were negative for previous two mutations. Conclusions: PCR technique provides a rapid, reliable, cost-effective, noninvasive, and sensitive test for establishing a diagnosis of FMF in symptomatic patients and also provides a rational basis for medical and genetic counseling of FMF patients and their families.Key Words: FMF, MEFV, mutations, Egypt
Materials-to-applications evaluation framework: assessing memristor technologies for neural network implementations
Practical needs in technology capability assessment for extremely low-energy neuromorphic computing is addressed via a novel development/analysis concept integrating atomic-level material modeling, statistical simulations of charge transport in a device material stack and verification of the modeling scheme against measurements emulating circuitry operation conditions for applications in specific neural networks (NN). This multi-scale concept - from materials to applications - directly links materials to their electrical properties, and the latter to NN algorithms. Such link enables identifying structural features controlling device characteristics and the range of operation conditions delivering performance targets for a given technology implementation. In comparison to widely employed memristor analyses primarily based on TCAD-type methodology with adjustable phenomenological parameters, the proposed approach allows to deliver feedback on favorable material compositions and cell architecture/dimensions to modify memristor fabrication process. Implementation of this technology evaluation approach to carbon nanotube (CNT) memristors enables identifying structural and operation conditions delivering optimal performance ahead of actual circuitry fabrication
Ethnic Inequalities in Mortality: The Case of Arab-Americans
BACKGROUND: Although nearly 112 million residents of the United States belong to a non-white ethnic group, the literature about differences in health indicators across ethnic groups is limited almost exclusively to Hispanics. Features of the social experience of many ethnic groups including immigration, discrimination, and acculturation may plausibly influence mortality risk. We explored life expectancy and age-adjusted mortality risk of Arab-Americans (AAs), relative to non-Arab and non-Hispanic Whites in Michigan, the state with the largest per capita population of AAs in the US. METHODOLOGY/PRINCIPAL FINDINGS: Data were collected about all deaths to AAs and non-Arab and non-Hispanic Whites in Michigan between 1990 and 2007, and year 2000 census data were collected for population denominators. We calculated life expectancy, age-adjusted all-cause, cause-specific, and age-specific mortality rates stratified by ethnicity and gender among AAs and non-Arab and non-Hispanic Whites. Among AAs, life expectancies among men and women were 2.0 and 1.4 years lower than among non-Arab and non-Hispanic White men and women, respectively. AA men had higher mortality than non-Arab and non-Hispanic White men due to infectious diseases, chronic diseases, and homicide. AA women had higher mortality than non-Arab and non-Hispanic White women due to chronic diseases. CONCLUSIONS/SIGNIFICANCE: Despite better education and higher income, AAs have higher age-adjusted mortality risk than non-Arab and non-Hispanic Whites, particularly due to chronic diseases. Features specific to AA culture may explain some of these findings
Hydrogen-induced rupture of strained SiβO bonds in amorphous silicon dioxide
Using ab initio modeling we demonstrate that H atoms can break strained SiβO bonds in continuous amorphous silicon dioxide (a-SiO(2)) networks, resulting in a new defect consisting of a threefold-coordinated Si atom with an unpaired electron facing a hydroxyl group, adding to the density of dangling bond defects, such as E' centers. The energy barriers to form this defect from interstitial H atoms range between 0.5 and 1.3 eV. This discovery of unexpected reactivity of atomic hydrogen may have significant implications for our understanding of processes in silica glass and nanoscaled silica, e.g., in porous low-permittivity insulators, and strained variants of a-SiO(2)
Functional modelling of a novel mutation in <em>BBS5</em>
Background: Bardet-Biedl syndrome (BBS) is an autosomal recessive ciliopathy disorder with 18 known causative genes (BBS1-18). The primary clinical features are renal abnormalities, rod-cone dystrophy, post-axial polydactyly, learning difficulties, obesity and male hypogonadism.Results: We describe the clinical phenotype in three Saudi siblings in whom we have identified a novel mutation in exon 12 of BBS5 (c.966dupT; p.Ala323CysfsX57). This single nucleotide duplication creates a frame shift results in a predicted elongated peptide. Translation blocking Morpholino oligonucleotides were used to create zebrafish bbs5 morphants. Morphants displayed retinal layering defects, abnormal cardiac looping and dilated, cystic pronephric ducts with reduced cilia expression. Morphants also displayed significantly reduced dextran clearance via the pronephros compared to wildtype embryos, suggesting reduced renal function in morphants. The eye, kidney and heart defects reported in morphant zebrafish resemble the human phenotype of BBS5 mutations. The pathogenicity of the novel BBS5 mutation was determined. Mutant mRNA was unable to rescue pleiotropic phenotypes of bbs5 morphant zebrafish and in cell culture we demonstrate a mislocalisation of mutant BBS5 protein which fails to localise discretely with the basal body.Conclusions: We conclude that this novel BBS5 mutation has a deleterious function that accounts for the multisystem ciliopathy phenotype seen in affected human patients. \ua9 2014 Al-Hamed et al.; licensee BioMed Central Ltd
Suicide among Arab-Americans
BACKGROUND: Arab-American (AA) populations in the US are exposed to discrimination and acculturative stress-two factors that have been associated with higher suicide risk. However, prior work suggests that socially oriented norms and behaviors, which characterize recent immigrant ethnic groups, may be protective against suicide risk. Here we explored suicide rates and their determinants among AAs in Michigan, the state with the largest proportion of AAs in the US. METHODOLOGY/PRINCIPAL FINDINGS: ICD-9/10 underlying cause of death codes were used to identify suicide deaths from among all deaths in Michigan between 1990 and 2007. Data from the 2000 U.S. Census were collected for population denominators. Age-adjusted suicide rates among AAs and non-ethnic whites were calculated by gender using the direct method of standardization. We also stratified by residence inside or outside of Wayne County (WC), the county with the largest AA population in the state. Suicide rates were 25.10 per 100,000 per year among men and 6.40 per 100,000 per year among women in Michigan from 1990 to 2007. AA men had a 51% lower suicide rate and AA women had a 33% lower rate than non-ethnic white men and women, respectively. The suicide rate among AA men in WC was 29% lower than in all other counties, while the rate among AA women in WC was 20% lower than in all other counties. Among non-ethnic whites, the suicide rate in WC was higher compared to all other counties among both men (12%) and women (16%). CONCLUSIONS/SIGNIFICANCE: Suicide rates were higher among non-ethnic white men and women compared to AA men and women in both contexts. Arab ethnicity may protect against suicide in both sexes, but more so among men. Additionally, ethnic density may protect against suicide among Arab-Americans
Abundant Human DNA Contamination Identified in Non-Primate Genome Databases
During routine screens of the NCBI databases using human repetitive elements we discovered an unlikely level of nucleotide identity across a broad range of phyla. To ascertain whether databases containing DNA sequences, genome assemblies and trace archive reads were contaminated with human sequences, we performed an in depth search for sequences of human origin in non-human species. Using a primate specific SINE, AluY, we screened 2,749 non-primate public databases from NCBI, Ensembl, JGI, and UCSC and have found 492 to be contaminated with human sequence. These represent species ranging from bacteria (B. cereus) to plants (Z. mays) to fish (D. rerio) with examples found from most phyla. The identification of such extensive contamination of human sequence across databases and sequence types warrants caution among the sequencing community in future sequencing efforts, such as human re-sequencing. We discuss issues this may raise as well as present data that gives insight as to how this may be occurring
Arthroscopic washout of the ankle for septic arthritis in a three-month-old boy
There is no report of athroscopic treatment for septic arthritis of the ankle in infants. We report a case of successful management of septic arthritis of the ankle in a three-month-old boy by arthroscopic washout. Arthroscopic washout may be a useful treatment for septic arthritis in young infants when performed early after onset
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