271 research outputs found

    Evaluation of Luffa (Luffa acutangula (L.) Roxb) varieties under low country intermediate zone of Sri Lanka

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    Luffa (Luffa acutangulu) is a popular low country vegetable in Sri Lanka and it is one of the mosthighly utilized vegetable species in the fanning systems of dry and intermediate zones. The existingLuffa varieties in Sri Lanka, recommended by the Department of Agriculture, and the introducedhybrids are vulnerable to pests and diseases and the cost for pest control mainly accounts for thehigher production cost of Luffa. Makandura Selection (MK) is a Luffa variety selected from farmerfields and it shows tolerance to fruit fly (Bactrocera cucurbitae (Coquillettj), which is the mostserious pest causing high level of economic losses. Therefore, an experiment was conducted at theRegional Agricultural Research and Development Centre, Makandura, to evaluate the performanceof Makandura Selection along with the two Department of Agricu Iture recommended Luffa varieties,Asiri and LA 33. The experiment was laid out in a randomized complete block design with fourreplicates. Evaluation was done based on reproductive, yield and fruit quality parameters. Though thevariety LA 33 recorded the significantly highest yield (9.08 t/ha), the higher fruit length (35.02 ern),higher fruit weight (280.5 g) and high fruit firmness (4.38 kg) were not desirable in the context ofconsumer preference. The variety Asiri recorded a significantly lower yield (7.05 t ha') and thelowest fruit firmness (3.89 kg) wh ich are not preferred by the farmers. The variety MakanduraSelection showed moderate yields (8.98 t ha') and better performance in fruit quality attributes suchas lower fru it length (21.7 ern), lower fru it weight (207.2 g) and moderate firmness (4.25 kg). Therefore,the fruit fly tolerant ability, along with these positive fruit characteristics makes Makandura Selectiona suitable variety to introduce to the Luffa growers in Sri Lanka after further testing

    Development of new cultivation technology for straw mushroom (Volvariella volvacea) using locally available raw materials

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    Paddy straw mushroom (Volvariel1a volvacea) is an edible mushroom variety which can be cultivatedunder tropical and sub tropical conditions. In Sri Lanka, though the majority of farmers grow oystermushroom they are willing to undertake other mushroom types, including straw mushroom and milkymushroom. Straw mushroom cultivation is highly rewarding because of the favourable climaticconditions in Sri Lanka and the abundant availability of raw materials. The existing outdoor methodfor straw mushroom cultivation introduced by the Department of Agriculture (DOA) gives low orlandirregular yield. As the optimum environmental conditions are crucial in straw mushroom production,an indoor cultivation method using a polythcne house was tested with the existing outdoor method.Cotton waste and paddy straw were used as the growing media in both outdoor and indoor conditionsunder four treatments viz. paddy straw compost in polythene house (T 1), cotton waste compost inpolythene house (T2), paddy straw in outdoor environment (T3) and cotton waste in outdoor environment(T4), arranged in a Completely Randomized Design with three replicates. The results revealed that the indoor cultivation method with cotton waste compost substrate (TI) gave significantly highervalues for average yield (6901.\8 kg/ha) and average marketable yield (6489 kg/ha) compared toother treatments. Outdoor culture in straw substrate (T3) resulted lowest values for the same yieldparameters (567.\3 kg/ha, 516.3\ kg/ha, respectively). Indoor cultivation method with paddy strawcompost and cotton waste compost both resulted higher yields when compared to the outdoor cu Iture.As paddy straw is freely available in Sri Lanka, combining of paddy straw compost and cotton wastecompost as the substrate for straw mushroom culture under indoor conditions would be more profitabl

    Formulation of a fertilizer package for hybrid varieties of pumpkin (Cucurbita maxima)

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    Pumpkin (Cucurbita maxima) is a popular low country vegetable in Sri Lanka and it has become afundamental crop species in the farming systems of dry and intermediate zones. Introduced hybridpumpkin varieties are becoming popular in Sri Lanka because ofthe higher yield. However, there isno fertilizer recommendation for hybrid pumpkin. Local farmers apply high dosages ofNitrogen(N),Phosphorus(P) and Potassium(K) levels which causes increased cost of production and reducedprofit. Therefore, a field experiment was conducted to identify the effects of higher N, P and K levelson yield of hybrid pumpkin. The hybrid variety Arjuna was tested under eight different fertilizer levelswhere the Department of Agriculture (DOA) recommendation was taken as the control and one andhalf times of that was used as the higher levels of N, P and K. The experiment was arranged in aconfounding design with three replicates with two blocks per each. Reproductive parameters andyield parameters viz. yield, number of fruits per vine, fruit width and diameter were recorded. Thetested fertilizer levels did not show any significant effect on reproductive parameters and yieldparameters of hybrid pumpkin, thus, indicating that the application of higher dosages ofN, P and K isnot economical. Hence, the DOA fertilizer recommendation is adequate for hybrid pumpkins thoughthe yield is higher when compared to local pumpkin varieties

    Impact of culture towards disaster risk reduction

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    Number of natural disasters has risen sharply worldwide making the risk of disasters a global concern. These disasters have created significant losses and damages to humans, economy and society. Despite the losses and damages created by disasters, some individuals and communities do not attached much significance to natural disasters. Risk perception towards a disaster not only depends on the danger it could create but also the behaviour of the communities and individuals that is governed by their culture. Within this context, this study examines the relationship between culture and disaster risk reduction (DRR). A comprehensive literature review is used for the study to evaluate culture, its components and to analyse a series of case studies related to disaster risk. It was evident from the study that in some situations, culture has become a factor for the survival of the communities from disasters where as in some situations culture has acted as a barrier for effective DRR activities. The study suggests community based DRR activities as a mechanism to integrate with culture to effectively manage disaster risk

    Pulsed Feedback Defers Cellular Differentiation

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    Environmental signals induce diverse cellular differentiation programs. In certain systems, cells defer differentiation for extended time periods after the signal appears, proliferating through multiple rounds of cell division before committing to a new fate. How can cells set a deferral time much longer than the cell cycle? Here we study Bacillus subtilis cells that respond to sudden nutrient limitation with multiple rounds of growth and division before differentiating into spores. A well-characterized genetic circuit controls the concentration and phosphorylation of the master regulator Spo0A, which rises to a critical concentration to initiate sporulation. However, it remains unclear how this circuit enables cells to defer sporulation for multiple cell cycles. Using quantitative time-lapse fluorescence microscopy of Spo0A dynamics in individual cells, we observed pulses of Spo0A phosphorylation at a characteristic cell cycle phase. Pulse amplitudes grew systematically and cell-autonomously over multiple cell cycles leading up to sporulation. This pulse growth required a key positive feedback loop involving the sporulation kinases, without which the deferral of sporulation became ultrasensitive to kinase expression. Thus, deferral is controlled by a pulsed positive feedback loop in which kinase expression is activated by pulses of Spo0A phosphorylation. This pulsed positive feedback architecture provides a more robust mechanism for setting deferral times than constitutive kinase expression. Finally, using mathematical modeling, we show how pulsing and time delays together enable “polyphasic” positive feedback, in which different parts of a feedback loop are active at different times. Polyphasic feedback can enable more accurate tuning of long deferral times. Together, these results suggest that Bacillus subtilis uses a pulsed positive feedback loop to implement a “timer” that operates over timescales much longer than a cell cycle

    Polyacetylenes from Sardinian Oenanthe fistulosa: A Molecular Clue to risus sardonicus

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    An investigation of Oenanthe fistulosa from Sardinia afforded oenanthotoxin (1a) and dihydrooenanthotoxin (1b) from the roots and the diacetylenic epoxydiol 2 from the seeds. The absolute configuration of 1a and 1b was established as R by the modified Mosher's method, and the structure of 2 by chemical correlation with (+)-(3R,8S)-falcarindiol. Oenanthotoxin (1a) and dihydrooenanthotoxin (1b) were found to potently block GABAergic responses, providing a molecular rationale for the symptoms of poisoning from water-dropwort (Oenanthe crocata) and related plants. These observations bear relevance for a series of historical and ethnopharmacological observations on the identification of the Sardonic herb and the molecular details of the facial muscular contraction caused by its ingestion (risus sardonicus)

    Allelic expression analysis of the osteoarthritis susceptibility locus that maps to MICAL3

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    <p>Abstract</p> <p>Background</p> <p>A genome-wide association scan with subsequent replication study that involved over 67,000 individuals of European ancestry has produced evidence of association of single nucleotide polymorphism rs2277831 to primary osteoarthritis (OA) with a P-value of 2.9 × 10<sup>-5</sup>. rs2277831, an A/G transition, is located in an intron of <it>MICAL3</it>. This gene is located on chromosome 22q11.21 and the association signal encompasses two additional genes, <it>BCL2L13 </it>and <it>BID</it>. It is becoming increasingly apparent that many common complex traits are mediated by <it>cis</it>-acting regulatory polymorphisms that influence, in a tissue-specific manner, gene expression or transcript stability.</p> <p>Methods</p> <p>We used total and allelic expression analysis to assess whether the OA association to rs2277831 is mediated by an influence on MICAL3, BCL2L13 or BID expression. Using RNA extracted from joint tissues of 60 patients who had undergone elective joint replacement surgery, we assessed whether rs2277831 correlated with allelic expression of either of the three genes by: 1) measuring the expression of each gene by quantitative PCR and then stratifying the data by genotype at rs2277831 and 2) accurately discriminating and quantifying the mRNA synthesised from the alleles of OA patients using allelic-quantitative PCR.</p> <p>Results</p> <p>We found no evidence for a correlation between gene expression and genotype at rs2277831, with P-values of 0.09 for <it>BCL2L13</it>, 0.07 for <it>BID </it>and 0.33 for <it>MICAL3</it>. In the allelic expression analysis we observed several examples of significant (p < 0.05) allelic imbalances, with an allelic expression ratio of 2.82 observed in <it>BCL2L13 </it>(P = 0.004), 2.09 at <it>BID </it>(P = 0.001) and the most extreme case being at <it>MICAL3</it>, with an allelic expression ratio of 5.47 (P = 0.001). However, there was no correlation observed between the pattern of allelic expression and the genotype at rs2277831.</p> <p>Conclusions</p> <p>In the tissues that we have studied, our data do not support our hypothesis that the association between rs2277831 and OA is due to the effect this SNP has on <it>MICAL3, BCL2L13 </it>or <it>BID </it>gene expression. Instead, our data point towards other functional effects accounting for the OA associated signal.</p

    Cellular Radiosensitivity: How much better do we understand it?

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    Purpose: Ionizing radiation exposure gives rise to a variety of lesions in DNA that result in genetic instability and potentially tumorigenesis or cell death. Radiation extends its effects on DNA by direct interaction or by radiolysis of H2O that generates free radicals or aqueous electrons capable of interacting with and causing indirect damage to DNA. While the various lesions arising in DNA after radiation exposure can contribute to the mutagenising effects of this agent, the potentially most damaging lesion is the DNA double strand break (DSB) that contributes to genome instability and/or cell death. Thus in many cases failure to recognise and/or repair this lesion determines the radiosensitivity status of the cell. DNA repair mechanisms including homologous recombination (HR) and non-homologous end-joining (NHEJ) have evolved to protect cells against DNA DSB. Mutations in proteins that constitute these repair pathways are characterised by radiosensitivity and genome instability. Defects in a number of these proteins also give rise to genetic disorders that feature not only genetic instability but also immunodeficiency, cancer predisposition, neurodegeneration and other pathologies. Conclusions: In the past fifty years our understanding of the cellular response to radiation damage has advanced enormously with insight being gained from a wide range of approaches extending from more basic early studies to the sophisticated approaches used today. In this review we discuss our current understanding of the impact of radiation on the cell and the organism gained from the array of past and present studies and attempt to provide an explanation for what it is that determines the response to radiation

    pSESYNTH project: Community mobilization for a multi-disciplinary paleo database of the Global South

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    How to enhance paleoscientific research, collaboration and application in the Global South? The INQUA-funded multi-year pSESYNTH project envisions the first multi-disciplinary Holocene paleo database through a collaborative vision for past human-environmental systems in the Global South, and their future sustainability

    Cholesterol-raising diterpenes in types of coffee commonly consumed in Singapore, Indonesia and India and associations with blood lipids: A survey and cross sectional study

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    <p>Abstract</p> <p>Background</p> <p>To measure the content of cholesterol-raising diterpenes in coffee sold at the retailer level in Singapore, Indonesia and India and to determine the relationship of coffee consumption with lipid levels in a population-based study in Singapore.</p> <p>Methods</p> <p>Survey and cross-sectional study in local coffee shops in Singapore, Indonesia and India to measure the diterpene content in coffee, and a population-based study in Singapore to examine the relationship of coffee consumption and blood lipid levels. Interviews and coffee samples (n = 27) were collected from coffee shops in Singapore, Indonesia and India. In addition, 3000 men and women who were Chinese, Malay, and Indian residents of Singapore participated in a cross-sectional study.</p> <p>Results and Discussion</p> <p>The traditional 'sock' method of coffee preparation used in Singapore resulted in cafestol concentrations comparable to European paper drip filtered coffee (mean 0.09 ± SD 0.064 mg/cup). This amount would result in negligible predicted increases in serum cholesterol and triglyceride concentrations. Similarly low amounts of cafestol were found in Indian 'filter' coffee that used a metal mesh filter (0.05 ± 0.05 mg/cup). Coffee samples from Indonesia using the 'sock' method (0.85 ± 0.41 mg/cup) or a metal mesh filter (0.98 mg/cup) contained higher amounts of cafestol comparable to espresso coffee. Unfiltered coffee from Indonesia contained an amount of cafestol (4.43 mg/cup) similar to Scandinavian boiled, Turkish and French press coffee with substantial predicted increases in serum cholesterol (0.33 mmol/l) and triglycerides (0.20 mmol/l) concentrations for consumption of 5 cups per day. In the Singaporean population, higher coffee consumption was not substantially associated with serum lipid concentrations after adjustment for potential confounders [LDL-cholesterol: 3.07 (95% confidence interval 2.97-3.18) for <1 cup/week versus 3.12 (2.99-3.26) for ≥ 3 cups/day; p trend 0.12].</p> <p>Conclusions</p> <p>Based on the low levels of diterpenes found in traditionally prepared coffee consumed in Singapore and India, coffee consumption in these countries does not appear to be a risk factor for elevation of serum cholesterol, whereas samples tested from Indonesia showed mixed results depending on the type of preparation method used.</p
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