1,352 research outputs found
Analysis of matrilin function in knockout mice and knockdown zebrafish
The matrilins are non-collagenous extracellular matrix proteins that form a subbranch of the superfamily of proteins containing VWA domains. Four matrilins are present in mammals, matrilin-1, -2, -3 and �4. The matrilins contain one or two VWA domains which are connected by a varying number of EGF-like domains, followed by a C-terminal a-helical coiled-coil domain. Matrilins serve as adaptors in the assembly of supramolecular structures in the extracellular matrix, but it is not known if this role is static or dynamic in nature. The in vivo functions of matrilins remain unclear and need to be elucidated in detail, in particular to understand the role of matrilins in inherited disease. Mutations in the gene encoding human matrilin-3 lead to autosomal dominant skeletal disorders, such as multiple epiphyseal dysplasia (MED), which is characterized by short stature and early onset osteoarthritis, and bilateral hereditary microepiphyseal dysplasia, a variant form of MED characterized by pain in the hip and knee joints. In addition, a mutation in the first EGF-like domain of matrilin-3 has been linked to hand osteoarthritis in the Icelandic population. Matrilin-3 null mice and matrilin-1/-3 double deficient mice were characterized. Homozygous matrilin-3 mutant mice appear normal, are fertile, and show no obvious skeletal malformations. Histological and ultrastructural analyses reveal an endochondral bone formation indistinguishable from that of wildtype animals. Northern blot, immunohistochemical, and biochemical analyses showed no compensatory upregulation of any other member of the matrilin family. In matrilin-1/-3 double null mice, biochemical analyses revealed a molecular phenotype in which the amount of matrilin-4 protein is increased and the band patterns of matrilin-3 and -4 are altered. The upregulation of matrilin-4 is likely to represent a compensatory mechanism. Altogether, the findings suggest functional redundancy among matrilins in mammals and demonstrate that the phenotypes of MED-like disorders are not caused by the absence of matrilin-3, but are likely to be due to dominant negative effects of the mutant proteins. The zebrafish is a well established model organism for the study of vertebrate development. The matrilins are present in neither Drosophila nor in C. elegans and the zebrafish is therefore among the simplest organisms which express matrilins. Highly conserved orthologues, matrilin-1, -3a, -3b and �4, are present in zebrafish, while the matrilin-2 gene is missing. The temporal and spatial expression of zebrafish matrilins was characterized. Zebrafish matrilin-1 was found not only in skeletal tissue but also in notochord and intestine. Matrilin-3a expression is restricted to skeletal tissues, while the expression pattern of matrilin-3b has not yet been elucidated due to the lack of a specific antibody. Nevertheless, RT-PCR analysis reveals that matrilin-3b is expressed at 24 hpf and, interestingly, splice variants of matrilin-3b containing a proline- and serine/threonine-rich domain are found only in embryos but not in adult fish, indicating that this new domain probably has an important function during zebrafish development. Similar to in mammals, matrilin-4 is the earliest and most widely expressed matrilin in zebrafish. Matrilin-4 is strongly expressed already at 24 hpf and is present in the skeletal tissues, soft connective tissues and nervous tissues. Morpholino antisense oligonucleotides were used to knockdown matrilins expressed in zebrafish. Malformations were seen at all the doses used and the phenotypes matched to the tissue distribution of the respective matrilin. Injection of matrilin-1 or matrilin-4 morpholinos give curled body shape, smaller eyes or a truncated body axis depending on dosage. The matrilin-3a knockdown embryos showed a serious skeletal phenotype
MSSM Anatomy of the Polarization Puzzle in B --> phi K* Decays
We analyze the polarization puzzle in the Minimal
Supersymmetric Standard Model (MSSM) including the neutral Higgs boson (NHB)
contributions. To calculate the non-factorizable contributions to hadronic
matrix elements of operators, we have used the QCD factorization framework to
the order. It is shown that the recent experimental results of the
polarization fractions in decays, which are difficult to be
explained in SM, could be explained in MSSM if there are flavor non-diagonal
squark mass matrix elements of 2nd and 3rd generations, which also satisfy all
relevant constraints from known experiments (, etc.). We have shown
in details that the experimental results can be accommodated with the flavor
non-diagonal mass insertion of chirality RL, RL+LR, RR, or LL+ RR when the NHB
contributions as well as corrections of hadronic matrix
elements of operators are included. However the branching ratios for the decay
are smaller than the experimental measurements.Comment: 15 pages, 5 figures, minor revision and references adde
Processing and Utilization of Bio-Flocculant from Dent Corn in Food Wastewater
In the present research, native starch was prepared from dent corn (Zea mays L.) and the prepared native starch was modified by phosphorylation to get biodegradable bio-flocculants. The processed modified starch bio-flocculants were applied in the treatment of food wastewater. The physico-chemical properties of dent corn such as protein, fiber, fat, moisture, carbohydrate and ash contents were determined by AOAC (2000) method. The physico-chemical characteristics of native starch and modified starch (bio-flocculants) such as iodine test, bulk density, the degree of substitution, swelling power, amylose and amylopectin contents were determined. The flocculation efficiency of the processed bio-flocculants by using ferric laurate suspension and the optimal transmission percentage was investigated. The properties of food wastewater such as pH, colour, turbidity, total solids, dissolved solids and suspended solids before and after treatment with processes bio-flocculants were also determined
Using artificial intelligence to study the impact of jobseekers\u27 Facebook profile pictures on recruiters’ interview decision
Previous research has shown that jobseekers’ information on Facebook influences recruiters’ decision-making. This study extends previous research by using artificial intelligence to study the impact of jobseekers\u27 Facebook profile pictures sharing on recruiters\u27 decision-making during the pandemics.
For most people, Facebook is an integral part of everyday life. Facebook allows its jobseekers to interact with passive and active jobseekers in a low-cost and relatively easy way. Facebook is a useful business tool for companies and individuals to promote their brands, personal image and personality types. Jobseekers are one of the largest groups of Facebook jobseekers. Smart business recruiters and recruiters are using many tools and strategies to find the best Jobseekers on Facebook. Jobseekers’ Facebook profile pictures sharing has been a topic of interest to searchers in recent years.
This study collected data from 500 Jobseekers\u27 Facebook profile pictures and recruited 50 recruiters. The results show that the jobseekers\u27 Facebook profile pictures are positively correlated with recruiters\u27 interview decisions during the pandemic. This study uses artificial intelligence to judge the personality traits of jobseekers based on Facebook profile pictures and examines the impact of jobseekers\u27 Facebook profile pictures and recruiters’ interview decisions
How much do school teachers know about childhood asthma in Ilesa, Nigeria?
Background: Childhood asthma is affected by events and conditions of the school environment. Teachers as de-facto caregivers of children with asthma have a major role to play in ensuring good asthma control in school. This study set out to determine the level of knowledge of school teacher about childhood asthma and factors influencing this knowledge.Methods: Four secondary schools (two private and two public) in Ilesa, South West Nigeria were selected by multistage sampling method. All the teachers in these schools were required to fill a self -administered questionnaire incorporating a validated 40-item asthma knowledge questions. Factors associated with the level of knowledge were determined appropriately.Results: A total of 132 teacher (M: F = 1:2) participated in the study with 85 (64.4%) from private school. The mean (SD) age of the teachers was 38.0 (9.1) years and median (IQR) years in teaching service was 7.0 (5.0 to 15.0) years. Majority (56.1%) of the teachers had university education while only 7 (5.3%) had a post graduate degree. The mean (SD) score of the 40 item questions was 21.5 (7.2) and majority (51.5%) had poor asthma knowledge (score < 22). Poorer knowledge was observed in questions related to the nature and management of childhood asthma than triggers and manifestations. No significant correlation was found between knowledge and age, teaching experience and qualifications (p > 0.05). However, teachers with previous training about childhood asthma had relatively good knowledge about the condition. (p <0.05)Conclusion: The level of knowledge about childhood asthma among school teachers in Ilesa is poor particularly as regards to nature and management of the disease. We advocate for training of school teachers about common childhood conditions including asthma to ensure optimal symptoms control in school.Keywords: Childhood asthma, Knowledge, School teacher
The Relationship between Coenzyme Q10, Oxidative Stress, and Antioxidant Enzymes Activities and Coronary Artery Disease
A higher oxidative stress may contribute to the pathogenesis of coronary artery disease (CAD). The purpose of this study was to investigate the relationship between coenzyme Q10 concentration and lipid peroxidation, antioxidant enzymes activities and the risk of CAD. Patients who were identified by cardiac catheterization as having at least 50% stenosis of one major coronary artery were assigned to the case group (n = 51). The control group (n = 102) comprised healthy individuals with normal blood biochemical values. The plasma coenzyme Q10, malondialdehyde (MDA) and antioxidant enzymes activities (catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx)) were measured. Subjects with CAD had significant lower plasma coenzyme Q10, CAT and GPx activities and higher MDA and SOD levels compared to those of the control group. The plasma coenzyme Q10 was positively correlated with CAT and GPx activities and negatively correlated with MDA and SOD. However, the correlations were not significant after adjusting for the potential confounders of CAD with the exception of SOD. A higher level of plasma coenzyme Q10 (≥0.52 μmol/L) was significantly associated with reducing the risk of CAD. Our results support the potential cardioprotective impact of coenzyme Q10
Expansion and evolution of insect GMC oxidoreductases
BackgroundThe GMC oxidoreductases comprise a large family of diverse FAD enzymes that share a homologous backbone. The relationship and origin of the GMC oxidoreductase genes, however, was unknown. Recent sequencing of entire genomes has allowed for the evolutionary analysis of the GMC oxidoreductase family. ResultsAlthough genes that encode enzyme families are rarely linked in higher eukaryotes, we discovered that the majority of the GMC oxidoreductase genes in the fruit fly (D. melanogaster), mosquito (A. gambiae), honeybee (A. mellifera), and flour beetle (T. castaneum) are located in a highly conserved cluster contained within a large intron of the flotillin-2 (Flo-2) gene. In contrast, the genomes of vertebrates and the nematode C. elegans contain few GMC genes and lack a GMC cluster, suggesting that the GMC cluster and the function of its resident genes are unique to insects or arthropods. We found that the development patterns of expression of the GMC cluster genes are highly complex. Among the GMC oxidoreductases located outside of the GMC gene cluster, the identities of two related enzymes, glucose dehydrogenase (GLD) and glucose oxidase (GOX), are known, and they play major roles in development and immunity. We have discovered that several additional GLD and GOX homologues exist in insects but are remotely similar to fungal GOX. ConclusionWe speculate that the GMC oxidoreductase cluster has been conserved to coordinately regulate these genes for a common developmental or physiological function related to ecdysteroid metabolism. Furthermore, we propose that the GMC gene cluster may be the birthplace of the insect GMC oxidoreductase genes. Through tandem duplication and divergence within the cluster, new GMC genes evolved. Some of the GMC genes have been retained in the cluster for hundreds of millions of years while others might have transposed to other regions of the genome. Consistent with this hypothesis, our analysis indicates that insect GOX and GLD arose from a different ancestral GMC gene than that of fungal GOX
Genomic variation and adaptation in Africa: implications for human evolutionary history and disease
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