3,241 research outputs found

    Heat transfer over a nonlinearly stretching sheet with non-uniform heat source and variable wall temperature

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    In this paper we study the flow and heat transfer characteristics of a viscous fluid over a nonlinearly stretching sheet in the presence of non-uniform heat source and variable wall temperature. A similarity transformation is used to transform the governing partial differential equations to a system of nonlinear ordinary differential equations. An efficient numerical shooting technique with a fourth-order Runge-Kutta scheme is used to obtain the solution of the boundary value problem. The effects of various parameters (such as the power law index n, the Prandtl number Pr, the wall temperature parameter λ, the space dependent heat source parameter A* and the temperature dependent heat source parameter B*) on the heat transfer characteristics are analyzed. The numerical results for the heat transfer coefficient (the Nusselt number) are presented for several sets of values of the parameters and are discussed. The results reveal many interesting behaviors that warrant further study on the effects of non-uniform heat source and the variable wall temperature on the heat transfer phenomena at the nonlinear stretching sheet. © 2011 Elsevier Ltd. All rights reserved.postprin

    Quality of life and the risk of contracting malaria by multivariate analysis in the Brazilian Amazon region

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    BACKGROUND: The incidence of malaria in the Amazon basin is closely related to social inequalities, given that precarious economic and socio-environmental conditions represent favourable factors for the transmission of the disease in tropical regions, such as the Brazilian state of Pará. In the present study, an association was found between the variation in a quality of life index (QLI), based on the socioeconomic differences between the municipalities of this state, and the risk of contracting malaria, based on the Annual Parasitic Index (API), with the primary objective of providing guidelines for the development of effective strategies for the control of the disease. METHODS: The API scores for the years between 2003 and 2011 were collected from the Brazilian Ministry of Health’s DATASUS database, and socioeconomic data for the 143 municipalities of Pará were obtained from the 2010 census. The data were analysed using multivariate factorial and correspondence techniques. RESULTS: The QLI was calculated for each municipality, of which, 69.23% were classified as having a poor or regular quality of life. The municipalities with poor QLI scores also presented moderate to high rates of malaria, with probabilities of 80.97% and 95.13%, respectively, while those with good QLI scores had low rates of malaria, with a probability of 79.24%. The results indicated a concentration of malaria in the south-west of the state of Pará, with an increase of 8.82% in the incidence of the disease over the study period, and the northeastern and Marajó mesoregions, where there was an increase of over 90%. In south-eastern Pará, by contrast, there was a marked reduction (78%) in the incidence of the disease, reflecting the heterogeneous distribution of malaria among the different municipalities and mesoregions of the state, especially those with moderate to high risk of transmission. CONCLUSIONS: These findings confirm that malaria is endemic to Pará and is typical of the state’s poorest areas, and that the distribution of the disease within the state indicates an intimate relationship with the living conditions of the population, affecting primarily the economically less privileged sectors of the society

    The effect of prolonged monocular occlusion on latent nystagmus in the treatment of amblyopia

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    We recorded eye movements in 5 patients with latent nystagmus (LN) before and after 2 days of occlusion of the better eye. The slow-phase speed of the nystagmus (SPS) was in general, before occlusion, lower when the better eye fixated but, after occlusion, lower when the worse eye fixated. However, the sum of SPS during right fixation and SPS during left fixation remained constant. Oscillopsia complaints gradually disappeared during the period of occlusion. These findings indicate that the difference between the SPS during fixation with the right eye and the SPS during fixation with the left eye in LN patients is caused by a compensatory drift that decreases LN during fixation with the better eye but increases LN during fixation with the worse eye. During occlusion, this compensatory drift changes its direction and magnitude slowly over days. Hence, occlusion of the better eye in children with amblyopia and LN should be prescribed only in days per week, not in hours per day

    Use of in Vitro HTS-Derived Concentration–Response Data as Biological Descriptors Improves the Accuracy of QSAR Models of in Vivo Toxicity

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    BackgroundQuantitative high-throughput screening (qHTS) assays are increasingly being used to inform chemical hazard identification. Hundreds of chemicals have been tested in dozens of cell lines across extensive concentration ranges by the National Toxicology Program in collaboration with the National Institutes of Health Chemical Genomics Center.ObjectivesOur goal was to test a hypothesis that dose–response data points of the qHTS assays can serve as biological descriptors of assayed chemicals and, when combined with conventional chemical descriptors, improve the accuracy of quantitative structure–activity relationship (QSAR) models applied to prediction of in vivo toxicity end points.MethodsWe obtained cell viability qHTS concentration–response data for 1,408 substances assayed in 13 cell lines from PubChem; for a subset of these compounds, rodent acute toxicity half-maximal lethal dose (LD50) data were also available. We used the k nearest neighbor classification and random forest QSAR methods to model LD50 data using chemical descriptors either alone (conventional models) or combined with biological descriptors derived from the concentration–response qHTS data (hybrid models). Critical to our approach was the use of a novel noise-filtering algorithm to treat qHTS data.ResultsBoth the external classification accuracy and coverage (i.e., fraction of compounds in the external set that fall within the applicability domain) of the hybrid QSAR models were superior to conventional models.ConclusionsConcentration–response qHTS data may serve as informative biological descriptors of molecules that, when combined with conventional chemical descriptors, may considerably improve the accuracy and utility of computational approaches for predicting in vivo animal toxicity end points

    Current whole-body MRI applications in the neurofibromatoses

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    ObjectivesThe Response Evaluation in Neurofibromatosis and Schwannomatosis (REiNS) International Collaboration Whole-Body MRI (WB-MRI) Working Group reviewed the existing literature on WB-MRI, an emerging technology for assessing disease in patients with neurofibromatosis type 1 (NF1), neurofibromatosis type 2 (NF2), and schwannomatosis (SWN), to recommend optimal image acquisition and analysis methods to enable WB-MRI as an endpoint in NF clinical trials.MethodsA systematic process was used to review all published data about WB-MRI in NF syndromes to assess diagnostic accuracy, feasibility and reproducibility, and data about specific techniques for assessment of tumor burden, characterization of neoplasms, and response to therapy.ResultsWB-MRI at 1.5T or 3.0T is feasible for image acquisition. Short tau inversion recovery (STIR) sequence is used in all investigations to date, suggesting consensus about the utility of this sequence for detection of WB tumor burden in people with NF. There are insufficient data to support a consensus statement about the optimal imaging planes (axial vs coronal) or 2D vs 3D approaches. Functional imaging, although used in some NF studies, has not been systematically applied or evaluated. There are no comparative studies between regional vs WB-MRI or evaluations of WB-MRI reproducibility.ConclusionsWB-MRI is feasible for identifying tumors using both 1.5T and 3.0T systems. The STIR sequence is a core sequence. Additional investigation is needed to define the optimal approach for volumetric analysis, the reproducibility of WB-MRI in NF, and the diagnostic performance of WB-MRI vs regional MRI

    LINGKUNGAN BISNIS PETERNAK SAPI PERAH TERHADAP POSITIONING KOPERASI SERTA IMPLIKASINYA PADA KINERJA PEMASARAN (Studi Pada Pelaku Usaha Bisnis Sapi Perah di Provinsi Jawa Barat)

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    Latar Belakang : Dalam perspektif bisnis, peternak sapi perah memiliki peluang yang tinggi, mengingat susu sapi sebagai kebutuhan setiap manusia untuk memenuhi kebutuhan nutrisi tubuh, tetapi total kebutuhan nasional untuk produksi susu tahun 2018 sekitar 4,5 juta ton per tahun hanya dipenuhi dari produksi lokal hanya sebesar 18% (920 ton) atau sekitar 82% kebutuhan susu dipenuhi dengan impor. Di sisi lain menunjukan bahwa jumlah populasi sapi perah di Indonesia terus turun. Sampai 2016, jumlah populasi sapi tercatat 291.183 ekor, jauh berkurang dibandingkan 2013 sebanyak 438.745 ekor atau berkurang sebanyak 33%. Angka ini juga sejalan dengan penurunan jumlah peternak di Indonesia. Pada 2016, jumlah peternak yang tergabung dalam koperasi mencapai 96.355 orang, turun dibandingkan 2013 sebanyak 102.726 orang, atau berkurang sekitar 7%. Permasalahan pokok dalam penelitian ini ialah kinerja pemasaran pada peternak sapi perah di provinsi Jawa Barat, hal ini didasarkan oleh lingkungan bisnis terhadap positioning koperasi dalam memenuhi layanan kepada anggota koperasi Tujuan : Hasil penelitian secara deskriftif lingkungan bisnis dan positioning koperasi memberikan kontribusi terhadap kinerja pemasaran peternak sapi perah di provinsi Jawa Barat. Walaupun dalam pelaksanaannya secara umum belum sepenuhnya didasarkan atas aspek-aspek lingkungan bisnis dan posisi koperasi sebagai wadah bahgi para peternak sapi perah. Metode : Metode penelitian ini adalah metode survey sebagai upaya mengumpulkan informasi dari responden dengan menggunakan angket, hal ini dimaksudkan untuk menguji jawaban rasional sehingga dapat menjelaskan fenomena yang menjadi masalah, dengan model analisis SEM (Structural Equation Modelling). Hasil Penelitian : Hasil penelitian secara simultan menunjukan bahwa lingkungan bisnis eksternal dan internal besar pengaruhnya terhadap positioning koperasi sebesar 40,4% sedangkan epsilonnya 18,7 %. Sementara pengaruh lingkungan bisniseksternal terhadap positioning koperas sebesar 82% sementara pengaruh lingkungan bisnis internal terhadap positioning koperasi sebesar 17%. Hal ini menunjukan bahwa lingkungan peternak sapi perah di provinis Jawa Barat memiliki ketergantungan yang sangat kuat terhdap lingkungan bisnis eksternal, dibanding terhdap lingkungan bisnis internal. Adapun postioning koperasi memberikan pengearuh terhadap kinerja pemasaran sebesar 93% dengan epsilon 13,5%. Dengan demikian lingkungan bisnis dan positioning koperasi dapat dijadikan indikator yang diharapkan dapat untuk memperbaiki kinerja pemasaran peternak sapi perah di provinsi Jawa Barat. Kata Kunci : Lingkungan Bisnis Eksternal, Lingkungan Bisnis Internal, Positioning Koperasi dan Kinerja Pemasara

    Different types of FC Îł -receptors are involved in anti-Lewis Y antibody induced effector functions in vitro

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    Stimulation of monocytes by interaction of monoclonal antibodies (mAbs) with Fc gamma receptors (FcγRs) results in the activation of various monocyte effector functions. In the present investigation we show that the anti-Lewis Y (LeY) anti-tumour mAb ABL 364 and its mouse/human IgG1 chimaera induce both antibody-dependent cellular cytotoxicity (ADCC) and the release of tumour necrosis factor α (TNF-α) during mixed culture of monocytes with LeY+SKBR5 breast cancer cells in vitro. Although anti-LeY mAb-mediated TNF-α release paralleled ADCC activity, cytokine release required a higher concentration of sensitizing mAb than the induction of cytolysis. The determination of the FcγR classes involved in the induction of the distinct effector functions showed that anti-LeY mAb-induced cytolysis was triggered by interaction between anti-LeY mAbs and FcγRI. In contrast, mAb-induced TNF-α release mainly depended on the activation of monocyte FcγRII. Neutralization of TNF-α showed no influence on monocyte ADCC activity towards SKBR5 target cells. Our data indicate an independent regulation of anti-LeY mAb induced effector functions of ADCC and TNF-α release which seemed to be triggered by activation of different types of FcγR. © 2000 Cancer Research Campaig

    Acute myocardial infarction, associated with the use of a synthetic adamantyl-cannabinoid: a case report

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    BACKGROUND: “Legal highs” are novel psychoactive substances that have evaded statutory control. Synthetic cannabinoid compounds with adamantane moieties have recently been identified, which have high potency at target receptors and are undetectable on conventional toxicology testing. However, little is known about any harmful effects, and their potential to cause serious ill health. We describe a case of myocardial infarction following the use of this class of drug. CASE PRESENTATION: We report the case of a 39-year-old man admitted after an out-of-hospital cardiac arrest, in whom ECG and elevated cardiac enzymes confirmed ST-elevation myocardial infarction. Normal coronary perfusion was restored after thrombectomy and coronary artery stenting. In the hours preceding his admission, the patient is known to have consumed the legal high product “Black Mamba”. Subsequent urine testing confirmed the presence of an adamantyl-group synthetic cannabinoid, whilst cannabis, cocaine, amphetamines and other drugs of abuse were not detected. CONCLUSION: The use of legal highs is being increasingly recognised, but the chemical compositions and physiological effects of these drugs are poorly characterised and are continually changing. Synthetic cannabinoids, rarely identified on toxicological testing, can be linked to serious adverse cardiovascular events. This case highlights the importance of testing for novel psychoactive compounds, and recognising their potential to cause life-threatening conditions
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