4,617 research outputs found

    Limnological aspects of three man-made lakes in Sri Lanka

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    An investigation was undertaken to study the physicochemical characteristics, phytoplankton and fish fauna of three major deep lakes on the River Mahaweli: Kotmale, Victoria and Randenigala. These lakes were created mainly for hydroelectric purposes during the period 1984 to 1986. In all three lakes, thermoclines were present during most months of the year, but did not appear to be very stable. They tended to disappear during January - February but were well established in August - November. Fifteen species of blue-green algae were identified as well as 27 desmid species and 25 non-desmid green algae. Melosira granulata and M. undulata were the dominant diatom species. The family Cyprinidae dominated the fish fauna by number of species, but by biomass the exotic cichlids (tilapias) were dominant

    Limnological aspects of three man-made lakes in Sri Lanka

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    Sri Lanka, a tropical island with an area of 65,525 km2 (Fig. 1), is situated tothe south of the Indian sub-continent and separated from it by the narrow PalkStrait. Based on the amount of annual rainfall, two major climatic zones areusually recognised in the island: a wet zone covering the south-eastern quarterand a dry zone extending over the rest of the country (Fig. 1); the 2000 mmisohyet is usually the boundary between the two zones. The island contains nonatural lakes, except for a few small floodplain lakes, but this absence isamply compensated by the creation of a large number of reservoirs forirrigating rice fields, most of which date back 800 to 2500 years. These are inthe lowlands at altitudes below 200 m in the drier part of the country (Fig. 1),and they number more than 10,000 ranging in size from less than 2 ha to morethan 2000 ha. Most of these reservoirs are small, shallow and seasonal, dryingup completely or almost completely during the dry season by the end of therice-growing period. Of the perennial reservoirs, only a few are large andexceed 300 ha at the full supply level (FSL), and others are medium-sized (10to 300 ha) to small in area (<10 ha) (Table 1). In addition to these, a few large,deep reservoirs have been created recently in the uplands (200 to 1000 mabove sea level) and highlands (>1000 m) primarily for hydroelectricpurposes. Several of these reservoirs have been created by damming anddiverting the River Mahaweli

    Utilization of sawdust and coconut coir fiber for producing noise reducing wall tile

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    Today noise control has become a major requirement to provide a calm and pleasing living environment. With the technological development, industrial noises, which are mainly induced by machines, affects negatively on the day-today life of surrounding people. They have faced with many problems mentally and healthily. Noise control and its principles play an important role in creating a pleasing environment. This can be achieved when the intensity of sound is brought down to a level that is not harmful to human ears. Noise barriers, noise absorbers, reflectors are used for noise controlling purpose. This research was conducted to investigate the potential of using saw dust and coconut coir fiber as sound reducers for giving a solution for the existing industrial noise problem. Wall tiles were made by using saw dust. The effects of the thickness of the tiles, their surface condition and the sawdust particle sizes on noise controlling properties were investigated. In addition, panels were casted mixing coconut coir fiber with latex of rubber. Noise Reduction Co-efficient (NRC) of these tiles was investigated by using an experimental setup including signal generator, speakers and noise level meter. The results for the saw dust tiles have showed that there was a significant effect of the tile thickness, surface condition, mix proportion and sawdust particle sizes on NRC. The NRC values obtained for sawdust tiles ranged from 0.1 to 0.5 while that for the coir fiber panels was 0.01-0.6

    A G-quadruplex structure within the 5′-UTR of TRF2 mRNA represses translation in human cells

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    Telomeres protect chromosome ends from being recognized as double-stranded breaks. Telomeric function is ensured by the shelterin complex in which TRF2 protein is an essential player. The G-rich strand of telomere DNA can fold into G-quadruplex (G4) structure. Small molecules stabilizing G4 structures, named G4 ligands, have been shown to alter telomeric functions in human cells. In this study, we show that a guanine-rich RNA sequence located in the 5′-UTR region of the TRF2 mRNA (hereafter 91TRF2G) is capable of forming a stable quadruplex that causes a 2.8-fold decrease in the translation of a reporter gene in human cells, as compared to a mutant 5′-UTR unable to fold into G4. We also demonstrate that several highly selective G4 ligands, the pyridine dicarboxamide derivative 360A and bisquinolinium compounds Phen-DC(3) and Phen-DC(6), are able to bind the 91TRF2G:RNA sequence and to modulate TRF2 protein translation in vitro. Since the naturally occurring 5′-UTR TRF2:RNA G4 element was used here, which is conserved in several vertebrate orthologs, the present data substantiate a potential translational mechanism mediated by a G4 RNA motif for the downregulation of TRF2 expression

    Burkholderia pseudomallei in soil and natural water bodies in rural Sri Lanka: A hidden threat to public health

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    Burkholderia pseudomallei is the causative agent of the potentially fatal infection, melioidosis. This study provides the first evidence for the presence of B. pseudomallei in soil and water in Sri Lanka. Targeted sampling of soil and natural water sources was done between November 2019 and October 2020 over eight field visits encompassing the neighborhood of 28 culture and/or antibody-positive melioidosis patients in northwestern, western and southern Sri Lanka. A total of eight environmental isolates of B. pseudomallei (BPs-env1 to BPs-env8) were cultured from 116 soil and 117 natural water samples collected from 72 locations. The presence of B. pseudomallei in soil and natural water in these areas poses a risk of melioidosis for populations cultivating crops in such soils and using untreated water from these sources for drinking, bathing, and other domestic purposes. Identifying sites positive for B. pseudomallei may help to mitigate risk by raising public awareness of contaminated environmental sources and allowing soil and water remediation

    Effect of high parity on occurrence of anemia in pregnancy: a cohort study

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    <p>Abstract</p> <p>Background</p> <p>Studies that explore the controversial association between parity and anaemia-in-pregnancy (AIP) were often hampered by not distinguishing incident cases caused by pregnancy from prevalent cases complicated by pregnancy. The authors' aim in conducting this study was to overcome this methodological concern.</p> <p>Methods</p> <p>A retrospective cohort study was conducted in Oman on 1939 pregnancies among 479 parous female participants with available pregnancy records in a community trial. We collected information from participants, the community trial, and health records of each pregnancy. Throughout the follow-up period, we enumerated 684 AIP cases of which 289 (42.2%) were incident cases. High parity (HP, ≥ 5 pregnancies) accounted for 48.7% of total pregnancies. Two sets of regression analyses were conducted: the first restricted to incident cases only, and the second inclusive of all cases. The relation with parity as a dichotomy and as multiple categories was examined for each set; multi-level logistic regression (MLLR) was employed to produce adjusted models.</p> <p>Results</p> <p>In the fully adjusted MLLR models that were restricted to incident cases, women with HP pregnancies had a higher risk of AIP compared to those who had had fewer pregnancies (Risk Ratio, RR = 2.92; 95% CI 2.02, 4.59); the AIP risk increased in a dose-response fashion over multiple categories of parity. In the fully adjusted MLLR models that included all cases, the association disappeared (RR = 1.11; 95% CI 0.91, 1.18) and the dose-response pattern flattened.</p> <p>Conclusions</p> <p>This study shows the importance of specifying which cases of AIP are incident and provides supportive evidence for a causal relation between parity and occurrence of incidental AIP.</p

    Replication and Characterization of Association between ABO SNPs and Red Blood Cell Traits by Meta-Analysis in Europeans.

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    Red blood cell (RBC) traits are routinely measured in clinical practice as important markers of health. Deviations from the physiological ranges are usually a sign of disease, although variation between healthy individuals also occurs, at least partly due to genetic factors. Recent large scale genetic studies identified loci associated with one or more of these traits; further characterization of known loci and identification of new loci is necessary to better understand their role in health and disease and to identify potential molecular mechanisms. We performed meta-analysis of Metabochip association results for six RBC traits-hemoglobin concentration (Hb), hematocrit (Hct), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), mean corpuscular volume (MCV) and red blood cell count (RCC)-in 11 093 Europeans from seven studies of the UCL-LSHTM-Edinburgh-Bristol (UCLEB) Consortium. We identified 394 non-overlapping SNPs in five loci at genome-wide significance: 6p22.1-6p21.33 (with HFE among others), 6q23.2 (with HBS1L among others), 6q23.3 (contains no genes), 9q34.3 (only ABO gene) and 22q13.1 (with TMPRSS6 among others), replicating previous findings of association with RBC traits at these loci and extending them by imputation to 1000 Genomes. We further characterized associations between ABO SNPs and three traits: hemoglobin, hematocrit and red blood cell count, replicating them in an independent cohort. Conditional analyses indicated the independent association of each of these traits with ABO SNPs and a role for blood group O in mediating the association. The 15 most significant RBC-associated ABO SNPs were also associated with five cardiometabolic traits, with discordance in the direction of effect between groups of traits, suggesting that ABO may act through more than one mechanism to influence cardiometabolic risk.British Heart Foundation (Grant ID: RG/10/12/28456, RG/08/013/25942, RG/13/16/30528, RG/98002, RG/07/008/23674); Medical Research Council (Grant ID: G0000934, G0500877, MC_UU_12019/1, K013351); Wellcome Trust (Grant ID: 068545/Z/02, 097451/Z/11/Z); European Commission Framework Programme 6 (Grant ID: 018996); French Ministry of Research; Department of Health Policy Research Programme (England); Chief Scientist Office of Scotland (Grant ID: CZB/4/672, CZQ/1/38); National Institute on Ageing (NIA) (Grant ID: AG1764406S1, 5RO1AG13196); Pfizer plc (Unrestricted Investigator Led Grant); Diabetes UK (Clinical Research Fellowship 10/0003985); Stroke Association; National Heart Lung and Blood Institute (5RO1HL036310); Agency for Health Care Policy Research (HS06516); John D. and Catherine T. MacArthur Foundation Research Networks on Successful Midlife Development and Socio-economic Status and Health; Swiss National Science Foundation (33CSCO-122661); GlaxoSmithKline. Faculty of Biology and Medicine of Lausanne,Switzerland.This is the final version of the article. It first appeared from Public Library of Science (PLOS) via http://dx.doi.org/10.1371/journal.pone.015691
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