210 research outputs found

    Expression analysis of rubber biosynthetic pathway genes in Hevea brasiliensis

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    Hevea brasiliensisis, the primary commercial source of natural rubber (cis-1, 4-polyisoprene), is a fundamental raw material used for manufacturing a wide range of industrial and domestic rubber products in automobile, medical and defense industries. In Hevea, biosynthesis of rubber takes place through mevalonate pathway. Clonal variations in the productivity of rubber may be the result of variations in the activities of the enzymes involved in rubber biosynthesis in different Hevea clones. In this study, expression of 14 genes corresponding to enzymes/regulatory proteins involved in rubber biosynthesis was analyzed in high and low latex yielding clones of Hevea brasiliensis. The level of expression of HbSUT3, a sucrose transporter and enzymes related to the synthesis of rubber such as hydroxymethyl glutaryl-CoA synthase (hmgs), HMG-CoA reductase (hmgr) and mevalonate diphosphate decarboxylase (MVD) were found to be significantly higher in high rubber yielding clones compared to the low rubber yielding clones. The higher expression of these genes might result in an increased supply of IPP, the isoprenoid monomer, required for rubber biosynthesis. Expression of genes in the downstream rubber biosynthetic pathway such as FPPS, RuT and REF2 were also found to be significantly higher in high rubber yielding clones than low yielders. The results suggest that high rubber yield is associated with high expression of these genes and these genes can be used as markers for high yield potential in Hevea

    ATP concentration in latex as an indicator for early evaluation of yield in Hevea brasiliensis

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    Adenosine 5’ triphosphate (ATP) in the laticiferous tissues of Hevea brasiliensis plays a major role in rubber biosynthesis through its direct involvement in metabolic pathways and indirectly through H+ ATPase activity. A strong positive correlation was observed between dry rubber yield and latex ATP, when ATP was measured in the latex of ten Hevea clones with different yield potentials such as low, medium and high. The latex ATP was significantly high in clones with higher yield than medium and low yielding clones. The correlation between same day latex yield and ATP during the peak yielding season (September-November) also showed a direct relationship. This study was extended to immature plants of the same clones to confirm the practical application of this finding in crop improvement programme. Latex ATP was analysed in two year old young plants and continued for five years to correlate with rubber yield of the mature trees in field trial. A positive correlation was noticed between ATP in young plants and mature tree rubber yield. Young plants of high yielding clones always showed higher latex ATP concentration. In view of the direct relationship with yield, significant differences between clones and its seasonal insensitivity, latex ATP could be used as an indicator for early prediction of high yield in Hevea

    In vitro shoot multiplication and conservation of Caralluma bhupenderiana Sarkaria - an endangered medicinal plant from South India

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    An efficient protocol was described for the rapid in vitro multiplication of an endangered medicinal plant, Caralluma bhupenderiana Sarkaria, via enhanced axillary bud proliferation from nodal explants collected from young shoots of six-months-old plant. The physiological effects of growth regulators [6- Benzyladenine (BA), kinetin (Kn), 2-Isopentyl adenine (2iP), zeatin (Zn), indole-3-acetic acid (IAA), indole-3-butyric acid (IBA)], different strengths of Murashige and Skoog (MS) medium and various pH levels on in vitro morphogenesis were investigated. The highest number (8.40 + 0.50) of shoots and the maximum average shoot length (3.2 ± 0.31 cm) were recorded on MS medium supplemented with BA (8.87 μM) at pH 5.8. Rooting was best achieved on half-strength MS medium augmented with NAA (2.69 μM). The plantlets regenerated in vitro with well-developed shoot and roots were successfully established in pots containing peat mass and garden manure in 1:1 ratio and grown in a greenhouse with 80% survival rate. The regenerated plants did not show any immediate detectable phenotypic variation.Key words: Apocynaceae, asclepiadoideae, conservation, micro-propagation, endangered, Caralluma bhupenderiana

    Drought tolerance in MnSOD transgenic Hevea brasiliensis in a dry sub-humid environment

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    One year old bud-grafted plants of MnSOD transgenic Hevea lines (L1 and L2) and an untransformed line of clone RRII 105 were used in the present study to evaluate their physiological performance in a dry sub-humid environment by withholding irrigation and to assess the recovery by re-watering. The dry matter partitioning was more towards the root in transgenic lines (55% and 60% in Ll and L2, respectively) but, was less in the untransformed RRII 105 (43%). After six days of moisture stress in polybags, pre-dawn leaf water potential and relative water content declined in all the lines, however, transgenic line L1 showed higher tissue water content throughout the drought as well as recovery period. Chlorophyll content did not show any significant reduction. Net photosynthetic rate (PN) declined rapidly and it reached near zero on the third day of drought imposition except for line L1, which showed lesser decline in PN. The decline in stomatal conductance (gs) was more rapid than PN in all the lines. On re-watering, recovery of PN and gs was better in the transgenic lines than untransformed RRII 105, which did not recover fully from the drought impact. Antioxidant enzymes, superoxide dismutase and peroxidase did not show a definite trend in their activities in these lines. However, it was found that the transgenic line L1 had better drought tolerant capacity in terms of lesser inhibition of photosynthetic rate under drought and faster recovery on re-watering

    Managing The Tomato Leaf Disease Detection Accuracy Using Computer Vision Based Deep Neural Network

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    Development of leaf disease in the agricultural sector would decrease crop yield output. Thus, leaf disease identification can be achieved in an automatic way to increase the yield in the agriculture sector. However, most of the disease recognition system works with poor disease recognition due to varying patterns of leaf disease which impair detection accuracy. In this article, we are managing this issue by designing a computer vision model that assists in building a system that involves real-time image detection, feature extraction and image classification. The findings are given by the classifier, whether the leaf is diseased or not. In this paper we use Deep Neural Network (DNN) for real-time image classification. The experimental findings on tomato plant indicate that classification rates have increased with the proposed system relative to other current methods

    MENCA experiment aboard India’s Mars Orbiter Mission

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    The Mars Exospheric Neutral Composition Analyser (MENCA) aboard the Indian Mars Orbiter Mission (MOM) is a quadrupole mass spectrometer-based experiment. Making use of the highly elliptical and low inclination (~150°) orbit of MOM, MENCA will conduct in situ measurements of the composition and radial distribution of the Martian neutral exosphere in the 1–300 amu mass range in the equatorial and low latitudes of Mars. The functionality of MENCA has been tested during the Earth-bound and heliocentric phases of MOM before its operation in the Martian orbit. This article describes the scientific objectives, instrument details, design and development, test and evaluation, and calibration of the MENCA instrument

    Impact of exposure to cooking fuels on stillbirths, perinatal, very early and late neonatal mortality - a multicenter prospective cohort study in rural communities in India, Pakistan, Kenya, Zambia and Guatemala

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    BACKGROUND: Consequences of exposure to household air pollution (HAP) from biomass fuels used for cooking on neonatal deaths and stillbirths is poorly understood. In a large multi-country observational study, we examined whether exposure to HAP was associated with perinatal mortality (stillbirths from gestation week 20 and deaths through day 7 of life) as well as when the deaths occurred (macerated, non-macerated stillbirths, very early neonatal mortality (day 0-2) and later neonatal mortality (day 3-28). Questions addressing household fuel use were asked at pregnancy, delivery, and neonatal follow-up visits in a prospective cohort study of pregnant women in rural communities in five low and lower middle income countries participating in the Global Network for Women and Children's Health's Maternal and Newborn Health Registry. The study was conducted between May 2011 and October 2012. Polluting fuels included kerosene, charcoal, coal, wood, straw, crop waste and dung. Clean fuels included electricity, liquefied petroleum gas (LPG), natural gas and biogas. RESULTS: We studied the outcomes of 65,912 singleton pregnancies, 18 % from households using clean fuels (59 % LPG) and 82 % from households using polluting fuels (86 % wood). Compared to households cooking with clean fuels, there was an increased risk of perinatal mortality among households using polluting fuels (adjusted relative risk (aRR) 1.44, 95 % confidence interval (CI) 1.30-1.61). Exposure to HAP increased the risk of having a macerated stillbirth (adjusted odds ratio (aOR) 1.66, 95%CI 1.23-2.25), non-macerated stillbirth (aOR 1.43, 95 % CI 1.15-1.85) and very early neonatal mortality (aOR 1.82, 95 % CI 1.47-2.22). CONCLUSIONS: Perinatal mortality was associated with exposure to HAP from week 20 of pregnancy through at least day 2 of life. Since pregnancy losses before labor and delivery are difficult to track, the effect of exposure to polluting fuels on global perinatal mortality may have previously been underestimated. TRIAL REGISTRATION: ClinicalTrials.gov NCT01073475

    Downregulation of uPAR and Cathepsin B Induces Apoptosis via Regulation of Bcl-2 and Bax and Inhibition of the PI3K/Akt Pathway in Gliomas

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    Glioma is the most commonly diagnosed primary brain tumor and is characterized by invasive and infiltrative behavior. uPAR and cathepsin B are known to be overexpressed in high-grade gliomas and are strongly correlated with invasive cancer phenotypes.In the present study, we observed that simultaneous downregulation of uPAR and cathepsin B induces upregulation of some pro-apoptotic genes and suppression of anti-apoptotic genes in human glioma cells. uPAR and cathepsin B (pCU)-downregulated cells exhibited decreases in the Bcl-2/Bax ratio and initiated the collapse of mitochondrial membrane potential. We also observed that the broad caspase inhibitor, Z-Asp-2, 6-dichlorobenzoylmethylketone rescued pCU-induced apoptosis in U251 cells but not in 5310 cells. Immunoblot analysis of caspase-9 immunoprecipitates for Apaf-1 showed that uPAR and cathepsin B knockdown activated apoptosome complex formation in U251 cells. Downregulation of uPAR and cathepsin B also retarded nuclear translocation and interfered with DNA binding activity of CREB in both U251 and 5310 cells. Further western blotting analysis demonstrated that downregulation of uPAR and cathepsin B significantly decreased expression of the signaling molecules p-PDGFR-β, p-PI3K and p-Akt. An increase in the number of TUNEL-positive cells, increased Bax expression, and decreased Bcl-2 expression in nude mice brain tumor sections and brain tissue lysates confirm our in vitro results.In conclusion, RNAi-mediated downregulation of uPAR and cathepsin B initiates caspase-dependent mitochondrial apoptosis in U251 cells and caspase-independent mitochondrial apoptosis in 5310 cells. Thus, targeting uPAR and cathepsin B-mediated signaling using siRNA may serve as a novel therapeutic strategy for the treatment of gliomas

    Dietary iron intake in the first 4 months of infancy and the development of type 1 diabetes: a pilot study

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    <p>Abstract</p> <p>Aims</p> <p>To investigate the impact of iron intake on the development of type 1 diabetes (T1DM).</p> <p>Methods</p> <p>Case-control study with self-administered questionnaire among families of children with T1DM who were less than 10 years old at the time of the survey and developed diabetes between age 1 and 6 years. Data on the types of infant feeding in the first 4 months of life was collected from parents of children with T1DM (n = 128) and controls (n = 67) <10 years old. Because some cases had sibling controls, we used conditional logistic regression models to analyze the data in two ways. First we performed a case-control analysis of all 128 cases and 67 controls. Next, we performed a case-control analysis restricted to cases (n = 59) that had a sibling without diabetes (n = 59). Total iron intake was modeled as one standard deviation (SD) increase in iron intake. The SD for iron intake was 540 mg in the total sample and 539 mg in the restricted sample as defined above.</p> <p>Results</p> <p>The median (min, max) total iron intake in the first 4 months of life was 1159 (50, 2399) mg in T1DM cases and 466 (50, 1224) mg among controls (<it>P </it>< 0.001). For each one standard deviation increase in iron intake, the odds ratio (95% confidence interval) for type 1 diabetes was 2.01 (1.183, 3.41) among all participants (128 cases and 67 controls) while it was 2.26 (1.27, 4.03) in a restricted sample of T1 D cases with a control sibling (59 cases and 59 controls) in models adjusted for birth weight, age at the time of the survey, and birth order.</p> <p>Conclusion</p> <p>In this pilot study, high iron intake in the first 4 months of infancy is associated with T1DM. Whether iron intake is causal or a marker of another risk factor warrants further investigation.</p

    Genome-wide association and Meta-analysis of age at onset in Parkinson Disease

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    Background and Objectives Considerable heterogeneity exists in the literature concerning genetic determinants of the age at onset (AAO) of Parkinson disease (PD), which could be attributed to a lack of well-powered replication cohorts. The previous largest genome-wide association studies (GWAS) identified SNCA and TMEM175 loci on chromosome (Chr) 4 with a significant influence on the AAO of PD; these have not been independently replicated. This study aims to conduct a meta-analysis of GWAS of PD AAO and validate previously observed findings in worldwide populations. Methods A meta-analysis was performed on PD AAO GWAS of 30 populations of predominantly European ancestry from the Comprehensive Unbiased Risk Factor Assessment for Genetics and Environment in Parkinson's Disease (COURAGE-PD) Consortium. This was followed by combining our study with the largest publicly available European ancestry dataset compiled by the International Parkinson Disease Genomics Consortium (IPDGC). Results The COURAGE-PD Consortium included a cohort of 8,535 patients with PD (91.9%: Europeans and 9.1%: East Asians). The average AAO in the COURAGE-PD dataset was 58.9 years (SD = 11.6), with an underrepresentation of females (40.2%). The heritability estimate for AAO in COURAGE-PD was 0.083 (SE = 0.057). None of the loci reached genome-wide significance (p < 5 × 10−8). Nevertheless, the COURAGE-PD dataset confirmed the role of the previously published TMEM175 variant as a genetic determinant of the AAO of PD with Bonferroni-corrected nominal levels of significance (p < 0.025): (rs34311866: β(SE)COURAGE = 0.477(0.203), pCOURAGE = 0.0185). The subsequent meta-analysis of COURAGE-PD and IPDGC datasets (Ntotal = 25,950) led to the identification of 2 genome-wide significant association signals on Chr 4, including the previously reported SNCA locus (rs983361: β(SE)COURAGE+IPDGC = 0.720(0.122), pCOURAGE+IPDGC = 3.13 × 10−9) and a novel BST1 locus (rs4698412: β(SE)COURAGE+IPDGC = −0.526(0.096), pCOURAGE+IPDGC = 4.41 × 10−8). Discussion Our study further refines the genetic architecture of Chr 4 underlying the AAO of the PD phenotype through the identification of BST1 as a novel AAO PD locus. These findings open a new direction for the development of treatments to delay the onset of PD
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