1,231 research outputs found

    To fight or fly: Law Brothers auto accessories

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    This case describes the stiff competition faced by Law Brothers, a pioneer in the car accessories industry. The negative financial result during the past few years had forced the company to struggle for possible solutions. The company had to consider alternative ways to grow the business, diversify or merge with the other players to remain relevant in the industry. This case is suitable for undergraduate and postgraduate courses in strategic management, entrepreneurship and marketing

    Magnetar-like X-ray Bursts from an Anomalous X-ray Pulsar

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    Anomalous X-ray Pulsars (AXPs) are a class of rare X-ray pulsars whose energy source has been perplexing for some 20 years. Unlike other, better understood X-ray pulsars, AXPs cannot be powered by rotation or by accretion from a binary companion, hence the designation ``anomalous.'' AXP rotational and radiative properties are strikingly similar to those of another class of exotic objects, the Soft Gamma Repeaters (SGRs). However, the defining property of SGRs, namely their low-energy gamma-ray and X-ray bursts, have heretofore not been seen in AXPs. SGRs are thought to be ``magnetars,'' young neutron stars powered by the decay of an ultra-high magnetic field. The suggestion that AXPs are magnetars has been controversial. Here we report the discovery, from the direction of AXP 1E 1048-5937, of two X-ray bursts that have many properties similar to those of SGR bursts. These events imply a close relationship between AXPs and SGRs, with both being magnetars.Comment: 14 pages, 2 figures, accepted for publication in Nature. Note: The content of this paper is embargoed until 1900 hrs London time / 1400 US Eastern Time on Sept 1

    Differential expression analysis with global network adjustment

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    <p>Background: Large-scale chromosomal deletions or other non-specific perturbations of the transcriptome can alter the expression of hundreds or thousands of genes, and it is of biological interest to understand which genes are most profoundly affected. We present a method for predicting a gene’s expression as a function of other genes thereby accounting for the effect of transcriptional regulation that confounds the identification of genes differentially expressed relative to a regulatory network. The challenge in constructing such models is that the number of possible regulator transcripts within a global network is on the order of thousands, and the number of biological samples is typically on the order of 10. Nevertheless, there are large gene expression databases that can be used to construct networks that could be helpful in modeling transcriptional regulation in smaller experiments.</p> <p>Results: We demonstrate a type of penalized regression model that can be estimated from large gene expression databases, and then applied to smaller experiments. The ridge parameter is selected by minimizing the cross-validation error of the predictions in the independent out-sample. This tends to increase the model stability and leads to a much greater degree of parameter shrinkage, but the resulting biased estimation is mitigated by a second round of regression. Nevertheless, the proposed computationally efficient “over-shrinkage” method outperforms previously used LASSO-based techniques. In two independent datasets, we find that the median proportion of explained variability in expression is approximately 25%, and this results in a substantial increase in the signal-to-noise ratio allowing more powerful inferences on differential gene expression leading to biologically intuitive findings. We also show that a large proportion of gene dependencies are conditional on the biological state, which would be impossible with standard differential expression methods.</p> <p>Conclusions: By adjusting for the effects of the global network on individual genes, both the sensitivity and reliability of differential expression measures are greatly improved.</p&gt

    Incidence of Anaemia Due To Hookworm Infestation in Patients Attending Murtala Muhammad Specialist Hospital, Kano, Nigeria

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    A study on the incidence of anaemia due to hookworm infestation was carried out among patients attending Murtala Muhanmmad Specialist Hospital in Kano metropolis between December 2010 and January 2011. Out of the 200 stool samples examined by formol-ether concentration technique, only 1 (0.5%) was found to be positive for the hookworm infection and the anaemia status of the positive patient was negative as determined using haematocrit technique. Therefore, this study presented a very low incidence of the infection and the anaemic status obtained from the hookworm positive patient showed that the infection is not severe. The reason for the low incidence of the hookworm infection in this study could be attributed to strict personal and community hygiene, improved sanitary conditions, better awareness, proper disposal of sewage and less availability of breeding habitats for the hookworm larvae in the area. Therefore, more emphasis should be laid on personal and community hygiene in order to remain healthy and free from this kind of infection among other measures.Keywords: Anaemia, hookworm, hospital, community hygien

    Does antenatal care attendance prevent anemia in pregnancy at term?

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    Background: Anemia in pregnancy is one of the public health problems in the developed and developing world. If uncontrolled it is a major indirect cause of maternal and perinatal morbidity and mortality. This is worst in settings with poor prenatal practices. Quality prenatal interventions therefore are expected to prevent or ameliorate this disorder in pregnancy. Nigerian scientific literatures are full of data on anemia in pregnancy, but few of them are on the influence of prenatal care on maternal anemia. This study, therefore, sought to appraise the role of antenatal care (ANC) services in the prevention of anemia in pregnancy at term in Nigerian women.Objectives: The aim was to estimate the prevalence of anemia at first antenatal visit and determine if antenatal attendance prevents anemia at term among prenatal Nigerian women. To measure the hematocrit levels at booking and at term respectively and compare the proportion anemic at booking with the proportion anemic at term.Materials and Methods: A retrospective cross‑sectional comparative study of 3442 prenatal women in a mission hospital in South‑South Nigeria from 2009 to 2013. Venous blood hematocrit was estimated from each woman at booking and at term, and the prevalence of anemia for the two periods were compared.Results: There were 1205 subjects with hematocrit of below 33% at booking, an anemia prevalence of 32.2% at booking in this population. At term or delivery at term 736 (21.4% odds ratio [OR] =2.3, P < 0.0001) of the 1052 subjects that fulfilled the study criteria had their anemia corrected, a 69.9% prevention, while 316 (9.2%, OR = 0.43, P < 0.0001) persisted despite their antenatal attendance. The subjects were similar in most of the confounding factors like parity, social class, mean age, body mass index and gestational age at delivery (P value: all > 0.05).Conclusion: The prevalence of anemia in pregnancy is still high in our setting. Quality ANC appeared a valuable preventive intervention that should be made widely available, accessible and affordable to all pregnant women.Key words: Antenatal care, anemia prevention, South‑South Nigeria, term pregnanc

    Therapeutic role of glucogalactan polysaccharide extracted from Agaricus bisporus on trimethyltin chloride induced neuropathy in rats

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    Trimethyltin (TMT) chloride induces limbic system neuro-degeneration, resulting in behavioral alterations like cognitive deficits. This study investigates the effect of glucogalactan polysaccharide (GA) extract, which was purified from the roots of Agaricus bisporus mushroom, on trimethyltin chloride (TMT) induced neuropathy in rats. Adult male rats (200 ±10 g) were divided into four groups that were fed with basal diet throughout the experiment (28 days). The first group (G I) was control group, the second group (GII) was treated with 300 mg/kg BW GA intraperitoneally (i.p.) daily for 28 day. The third group (GIII) was administered i.p. with 8.0 mg TMT /kg body weight (BW), and the fourth (G IV) was treated like the third group and was injected with GA 300 mg/kg BW daily for 28 day after 48 h of TMT. Many bioactive compounds, which were found in GA did not cause any changes in the second group compared to normal control group. The results reveal that GA given 48 h after TMT treatment has excellent neuropathy effect, lowers the average of MDA, HSP70, homocystein and the neurotransmitters in brain tissue homogenate; they were markedly reduced by the administration of GA to almost normal levels. Neurotransmitters and nitric oxide were significantly increased in the group given GA treatment compared to TMT group. The comet assay for DNA revealed that, TMT induced statistically significant (P<0.05) increase in the mean value of the tail length and tail moment of the rats. They significantly decreased after GA treatment, suggesting alleviated oxidative stress mediated by TMT. GA administered TMT-treated rats had improved brain histology, diminished level of MDA and nitric oxide (NO) in brain tissue and enhanced total antioxidant capacity in serum compared to TMT group. It could be concluded that GA plays a positive role in the improvement of brain function after TMT-induced neuropathy. Taken together, our results suggest that GA will be useful in developing strategies for protecting nervous system and improving the brain.Keywords: Trimethyltin, neuro-degeneration, Agaricusbisporus, glucogalactan

    Preliminary Phytochemical Screening and Antimicrobial Activities of Some Medicinal Plants Used In Ebiraland

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    Dried leaves of Abrus precatorius, Desmodium ramosissimum, Scoparia dulcis and aerial parts of Phyllanthus amarus used in folkloric medicine of Ebiraland were extracted with hexane, methanol and water sequentially using soxhlet apparatus. The extracts were screened for antimicrobial activities against Bacillus subtilis, E. coli, Pseudomonas aeruginosa, Salmonella typhi, Staphylococcus aureus and Candida albicans using the agar-cup diffusion protocol. All the extracts except the hexane extract of Abrus precatorius were active against at least two of the test microorganisms at the highest concentration of 100 mg/ml used in this study. The aqueous and methanolic extracts of Phyllanthus amarus were active against all the test microorganisms. The methanolic extract of Phyllanthus amarus also showed a broad spectrum of activity with a minimum inhibitory concentration (M.I.C.) of 1.56 mg/ml against all the test microorganisms. The extracts were also screened for secondary metabolites and the result indicated the presence of alkaloids, saponins, tannins and terpenoids. The results of this investigation, appears to justify the ethnomedicinal uses of these plants for the traditional treatment of infectious diseases. However, further investigation is required to obtain more information on their antimicrobial potentials and also to isolate their bioactive compounds. Keywords: Medicinal plants, antimicrobial activity, minimum inhibitory concentration, phytochemical screening

    Comparative studies on Khaya. A. Juss (Meliaceae) in Nigeria

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    Comparative phytochemical, microscopical and chemomicroscopical studies were carried out on the genus Khaya with the aim of obtaining useful characters for the identification and delimitation of species boundaries. Tannins and saponins were present in all the species while phenols were detected in all except K. grandifoliola. Protein and anthraquinones were present in the bark of all the species. Carbohydrate is present in all the species except in the bark of K. ivoriensis. Flavonoids and phlobatannins were absent in all the taxa. Microscopical examination of the powdered bark revealed different types and shapes of lignified sclereids, abundant distribution of prismatic calcium oxalate crystals, druses, lignified cork-cells, fibres, medullary rays and parenchyma cells which may contain starch grain

    Activated Magnetospheres of Magnetars

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    Like the solar corona, the external magnetic field of magnetars is twisted by surface motions of the star. The twist energy is dissipated over time. We discuss the theory of this activity and its observational status. (1) Theory predicts that the magnetosphere tends to untwist in a peculiar way: a bundle of electric currents (the "j-bundle") is formed with a sharp boundary, which shrinks toward the magnetic dipole axis. Recent observations of shrinking hot spots on magnetars are consistent with this behavior. (2) Continual discharge fills the j-bundle with electron-positron plasma, maintaining a nonthermal corona around the neutron star. The corona outside a few stellar radii strongly interacts with the stellar radiation and forms a "radiatively locked" outflow with a high e+- multiplicity. The locked plasma annihilates near the apexes of the closed magnetic field lines. (3) New radiative-transfer simulations suggest a simple mechanism that shapes the observed X-ray spectrum from 0.1 keV to 1 MeV: part of the thermal X-rays emitted by the neutron star are reflected from the outer corona and then upscattered by the inner relativistic outflow in the j-bundle, producing a beam of hard X-rays.Comment: 23 pages, 7 figures; review chapter in the proceedings of ICREA Workshop on the High-Energy Emission from Pulsars and Their Systems, Sant Cugat, Spain, April 201

    EEG changes and neuroimaging abnormalities in relevance to severity of autism

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    Background: Autism is currently viewed as a genetically determined neurodevelopmental disorder although its defi nite underlying etiology remains to be established.Aim of the Study: Our purpose was to assess autism related morphologicalneuroimaging changes of the brain and EEG abnormalities in correlation to the degree of disease severity.Patients and Methods: Seventeen cases with classic autism, 13 males and 4 females were included in the study. Severity of the disease was assessed both clinically and by Childhood Autism Rating Scale (CARS). MRI changes and EEG abnormalities were detected in seven patients, mostly severely and moderately affected.Results: Hypoplasia of cerebellar vermian lobules is the most replicated MRI abnormality in our patients (18%). Periventricular white matter dysmyelination is detected in 12% of studied cases. 29% of the cases have EEG abnormalities. Head circumference above 97th centiles is detected in 18% of cases. The increased head circumference, when in combination with EEG abnormalities, positively correlates with the degree of disease severity. Conclusion: Although, no defi nite correlation could be established between the studied parameters and disease severity, most patients in the present study who exhibited MRI abnormality, EEG changes and/or increased head circumference (H.C) manifested severe form of autism. The absence of correlation may be attributed to lack of statistical power, resulting from small sample size. However, the correlation was not solidly excluded therefore, the recommendation of further neuroradiological evaluation as well as the implementation ofnewer techniques, might help future elucidating the etiology of autism.Keywords: Autism, MRI, EEG, brain development
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