1,071 research outputs found

    A three-dimensional turbulent boundary layer undergoing transverse strain and streamwise pressure gradient

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    Results from an experimental investigation designed to provide data on both mean and turbulence quantities in the axisymmetric, swirling boundary layer (with and without pressure gradient) flowing over a stationary cylinder downstreams of a spinning cylindrical section are presented. The pressure gradient was introduced into the flow field by a 25.4 mm-high, forward-facing, circular step mounted on the stationary cylinder, the step height being nearly equal to the thickness of the approaching boundary layer. All the measurements were made at a nominal upstream reference Reynolds number of 2.4 x 10 to the 6th power/m (corresponding to an upstream reference velocity of 36 to 37 m/sec) with the rotation of the spinner set to make its peripheral speed equal the reference velocity. The data reported included measurements of surface pressure and the mean surface shear-stress vector taken with a miniature, directional, surface-fence gage. These measurements were supplemented by oil-flow visualization studies of the stationary cylinder. The data indicates that the streamwise pressure gradient controls the development of the streamwise component of wall shear, but leaves the peripheral component of wall shear practically unaffected

    Quantification of yield gaps in rain-fed rice, wheat, cotton and mustard in India

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    Rainfed farming / Crop yield / Simulation / Rice / Wheat / Cotton / Mustard / India

    Control of Cocoa Pod Borer and Phytophthora Pod Rot Using Degradable Plastic Pod Sleeves and a Nematode, Steinernema Carpocapsae

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    Cocoa pod borer (CPB; Conopomorpha cramerella) and Phytophthora pod rot (PPR; Phytophthora palmivora) are serious pest and disease on cocoa plantations in Indonesia. Both pest and disease have been controlled with limited success using cultural practices such as pruning, frequent harvesting, sanitation, plastic sleeving, and chemical pesticides. An experiment was conducted on cocoa plantings in Pinrang Regency, South Sulawesi during the wet season of 2008/09 to test the effect of pod sleeving (with transparent degradable and non-degradable plastic bags) and nematode application on CPB and PPR infestation. The nematode, Steinernema carpocapsae (10,000 active juveniles per pod) was sprayed three times at intervals of 10 and 20 days. Pod damage by CPB was observed at harvest time, while PPR disease incidence was evaluated every week until harvest time. Results showed that all pods in the field were infested by CPB as indicated in control samples. Pod sleeving using both non-degradable and degradable plastics significantly reduced pod damage by CPB, from 62.3% in the control treatment compared to 8.4% in the CPB treatment. A combination of pod sleeving and nematode application had a synergistic reduction of pod damage by CPB resulting in totally healthy pods. Pod sleeving with degradable and non-degradable plastics also reduced pod damage by PPR significantly. Pod sleeving with non-degradable plastic suppressed the disease incidence almost zero until 6 weeks after sleeving and the rate of disease incidence was 3.6% per week. However, with degradable plastic, the disease suppression was even longer (7 weeks after sleeving), indicating that the degradable plastic is more effective. Combination of sleeving and nematode application slightly increased PPR infection. Sleeved pods in general had lower rates of PPR infection compared to pods treated with nematode or untreated pods (control). In these two applications, the rate of disease incidence was 7.8% and 8.3% per week respectively. The study implies that biological control using entomopathogenic S. carpocapsae and degradable plastic sleeves are effective and environmentally-friendly to control C. cramerella and P. palmivor

    Probing the morphology and anti-organic fouling behaviour of a polyetherimide membrane modified with hydrophilic organic acids as additives

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    A facile approach for the preparation of an organic antifouling polymer membrane has been developed using low molecular weight organic acids as additives. The presence of these additives in the membrane was analysed by FTIR spectroscopy. The properties of the modified membranes were investigated in terms of contact angle, water uptake capacity, SEM and AFM analysis. These additives exerted a strong impact on the rheological properties of the casting solution, thereby altering the membrane morphology, surface roughness, water flux and the hydrophilicity of the membranes, as compared to those of the pristine polyetherimide (PEI) membrane. The organic antifouling properties of the modified membrane were analysed by filtering both bovine serum albumin (BSA) and humic acid solutions. The results showed that the additives exhibited a remarkable improvement in the antifouling properties (FRR of 72%) and a humic acid rejection of up to 86%. These outcomes offer new insights into the use of cheaper and readily available organic acids as additives, compared to the traditional, synthetic polymer materials as additives in membrane preparation

    Human Female Genital Tract Infection by the Obligate Intracellular Bacterium Chlamydia trachomatis Elicits Robust Type 2 Immunity

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    While Chlamydia trachomatis infections are frequently asymptomatic, mechanisms that regulate host response to this intracellular Gram-negative bacterium remain undefined. This investigation thus used peripheral blood mononuclear cells and endometrial tissue from women with or without Chlamydia genital tract infection to better define this response. Initial genome-wide microarray analysis revealed highly elevated expression of matrix metalloproteinase 10 and other molecules characteristic of Type 2 immunity (e.g., fibrosis and wound repair) in Chlamydia-infected tissue. This result was corroborated in flow cytometry and immunohistochemistry studies that showed extant upper genital tract Chlamydia infection was associated with increased co-expression of CD200 receptor and CD206 (markers of alternative macrophage activation) by endometrial macrophages as well as increased expression of GATA-3 (the transcription factor regulating TH2 differentiation) by endometrial CD4+ T cells. Also among women with genital tract Chlamydia infection, peripheral CD3+ CD4+ and CD3+ CD4- cells that proliferated in response to ex vivo stimulation with inactivated chlamydial antigen secreted significantly more interleukin (IL)-4 than tumor necrosis factor, interferon-γ, or IL-17; findings that repeated in T cells isolated from these same women 1 and 4 months after infection had been eradicated. Our results thus newly reveal that genital infection by an obligate intracellular bacterium induces polarization towards Type 2 immunity, including Chlamydia-specific TH2 development. Based on these findings, we now speculate that Type 2 immunity was selected by evolution as the host response to C. trachomatis in the human female genital tract to control infection and minimize immunopathological damage to vital reproductive structures. © 2013 Vicetti Miguel et al

    Lipid metabolic perturbation is an early-onset phenotype in adult spinster mutants: a Drosophila model for lysosomal storage disorders

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    Intracellular accumulation of lipids and swollen dysfunctional lysosomes are linked to several neurodegenerative diseases, including lysosomal storage disorders (LSD). Detailed characterization of lipid metabolic changes in relation to the onset and progression of neurodegeneration is currently missing. We systematically analyzed lipid perturbations in spinster (spin) mutants, a Drosophila model of LSD-like neurodegeneration. Our results highlight an imbalance in brain ceramide and sphingosine in the early stages of neurodegeneration, preceding the accumulation of endomembranous structures, manifestation of altered behavior, and buildup of lipofuscin. Manipulating levels of ceramidase and altering these lipids in spin mutants allowed us to conclude that ceramide homeostasis is the driving force in disease progression and is integral to spin function in the adult nervous system. We identified 29 novel physical interaction partners of Spin and focused on the lipid carrier protein, Lipophorin (Lpp). A subset of Lpp and Spin colocalize in the brain and within organs specialized for lipid metabolism (fat bodies and oenocytes). Reduced Lpp protein was observed in spin mutant tissues. Finally, increased levels of lipid metabolites produced by oenocytes in spin mutants allude to a functional interaction between Spin and Lpp, underscoring the systemic nature of lipid perturbation in LSD

    Mutual dependence of the expression of the cell differentiation regulatory protein HetR and the global nitrogen regulator NtcA during heterocyst development

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    Heterocyst differentiation in the cyanobacterium Anabaena sp. strain PCC 7120 depends on both the global nitrogen regulator NtcA and the cell differentiation regulatory protein HetR, and induction of hetR upon nitrogen step-down depends on NtcA. The use of two out of the four transcription start points (tsps) described for the hetR gene (those located at positions -728 and -271) was found to be dependent on NtcA, and the use of the tsp located at position -271 was also dependent on HetR. Thus, autoregulation of hetR could take place via the activation of transcription from this tsp. Expression of ntcA in nitrogen-fixing cultures was higher than in cells growing in the presence of ammonium or nitrate, and high expression of ntcA under nitrogen deficiency resulted from an increased use of tsps located at positions -180 and -49. The induction of the use of these tsps did not take place in ntcA or hetR mutant strains. These results indicate a mutual dependency in the induction of the regulatory genes hetR and ntcA that takes place in response to nitrogen step-down in Anabaena cells. Expression of the hetC gene, which is also involved in the early steps of heterocyst differentiation, from its NtcA-dependent tsp was, however, not dependent on HetR.Dirección General de Enseñanza Superior e Investigación Científica (PB97-1137)Dirección General de Investigación BMC2001–050

    Autoimmune diseases in pregnancy: maternal and fetal outcomes

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    Background: The aim of this study was to assess the impact of autoimmune connective tissue disorders on the outcomes of pregnancy and the influence of treatment on pregnancy.  Methods: Thirty-seven antenatal patients with autoimmune connective tissue diseases, comprising of Systemic Lupus Erythematosus (SLE), primary antiphospholipid antibody syndrome (APS), Mixed Connective Tissue Diseases (MCTD), ankylosing spondylitis and Takayasu arteritis were analysed.Results: Multigravidas constituted 89.4% and were associated with bad obstetric history. Before diagnosis and treatment, serious maternal complications of eclampsia and thromboembolism were observed in patients with SLE and APS. The live birth rates were 9% and 2.4% respectively in patients with SLE and APS. With appropriate treatment- aspirin, heparin and immunosuppressant, the live birth rates were raised to 70% in SLE and 100% in APS patients. Investigation for autoimmune disease in recurrent pregnancy loss is important. A rare association between MCTD and congenital anomaly - Rhizomelic chondrodysplasia punctata was observed. Preeclampsia, gestational diabetes, fetal growth restriction and preterm labour were the common complications noted.  Conclusions: Active disease at onset of pregnancy, presence of Anti-ds DNA antibodies and secondary APS were strong predictors of poor pregnancy outcomes among patients with SLE. Vigilant monitoring during pregnancy is required for favourable outcomes

    Plasma Metabolomics in Human Pulmonary Tuberculosis Disease: A Pilot Study

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    We aimed to characterize metabolites during tuberculosis (TB) disease and identify new pathophysiologic pathways involved in infection as well as biomarkers of TB onset, progression and resolution. Such data may inform development of new anti-tuberculosis drugs. Plasma samples from adults with newly diagnosed pulmonary TB disease and their matched, asymptomatic, sputum culture-negative household contacts were analyzed using liquid chromatography high-resolution mass spectrometry (LC-MS) to identify metabolites. Statistical and bioinformatics methods were used to select accurate mass/charge (m/z) ions that were significantly different between the two groups at a false discovery rate (FDR) of q<0.05. Two-way hierarchical cluster analysis (HCA) was used to identify clusters of ions contributing to separation of cases and controls, and metabolomics databases were used to match these ions to known metabolites. Identity of specific D-series resolvins, glutamate and Mycobacterium tuberculosis (Mtb)-derived trehalose-6-mycolate was confirmed using LC-MS/MS analysis. Over 23,000 metabolites were detected in untargeted metabolomic analysis and 61 metabolites were significantly different between the two groups. HCA revealed 8 metabolite clusters containing metabolites largely upregulated in patients with TB disease, including anti-TB drugs, glutamate, choline derivatives, Mycobacterium tuberculosis-derived cell wall glycolipids (trehalose-6-mycolate and phosphatidylinositol) and pro-resolving lipid mediators of inflammation, known to stimulate resolution, efferocytosis and microbial killing. The resolvins were confirmed to be RvD1, aspirin-triggered RvD1, and RvD2. This study shows that high-resolution metabolomic analysis can differentiate patients with active TB disease from their asymptomatic household contacts. Specific metabolites upregulated in the plasma of patients with active TB disease, including Mtb-derived glycolipids and resolvins, have potential as biomarkers and may reveal pathways involved in TB disease pathogenesis and resolution

    Effect of fertigation on growth and yield on Chilli hybrid Arka Meghana

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    A field experiment was conducted to study the effect of fertigation on chilli F1 Hybrid Arka Meghana during kharif of 2017 and 2018, with ten treatments, including different doses, sources of fertilizers and its frequency of application, in randomized block design with three replications. The pooled analysis revealed that application of fertilizer dose (125:100:125 kg N: P2O5: K2O ha-1) through fertigation on bi-weekly basis resulted in higher plant height (76.3 cm) at 80 days after transplanting, which was on par with the same dose and source applied at weekly interval (74.0 cm). These two treatments recorded higher fruit length (12.63 and 12.27 cm), number of fruits per plant (153.33 and 169.67) and dry weight of 10 fruits (9.00 and 8.63 g), respectively. All the fertigation treatments recorded higher yields over the conventional soil application of fertilizers to the tune of 14.84 to 61.55%. Among the fertigation treatments, application of 100% of fertilizer dose using water soluble fertilizers at bi-weekly interval resulted in significantly higher yield (32.44 t ha-1) compared to all treatments except the treatment where the weekly application of same dose of fertilizer through the same sources (31.81 t ha-1) and 75% of 125:100:125 kg N: P2O5: K2O ha-1 was applied weekly or bi-weekly intervals (29.23 and 30.01 t ha-1). Biweekly and weekly application of 100% fertilizer dose of 125:100:125 kg N: P2O5: K2O ha-1 through fertigation could yield maximum net income (Rs. 400151 and Rs. 387551 ha-1) with B: C (1.61 and 1.56). However, fertilizer applied to soil resulted in minimum net income of Rs.183054 ha-1 and B: C (0.84)
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