Displaying publications 61 - 80 of 267 in total

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  1. Hai T, Ali MA, Alizadeh A, Almojil SF, Almohana AI, Alali AF
    Chemosphere, 2023 Apr;319:137847.
    PMID: 36657576 DOI: 10.1016/j.chemosphere.2023.137847
    Renewable energy sources are undoubtedly necessary, considering global electricity demand is expected to rise dramatically in the coming years. This research looks at a unique multi-generation plant from the perspectives of exergy, energy, and economics; also, an environmental evaluation is performed to estimate the systems' CO2 emissions. The unit is made up of a biomass digester and gasifier, a Multi effect Desalination unit, and a supercritical CO2 (SCO2) cycle. In this study, two methods for using biomass are considered: the first is using synthesis gas generated by the gasifier, and the second is utilizing a digester to generate biogas. A comprehensive parametric study is performed on the designed energy unit to assess the influence of compressor pressure ratio, Gas turbine inlet temperature, supercritical CO2 cycle pressure ratio, and the number of effects of multi-effect distillation on the system performance. Furthermore, the exergy study revealed that the exergy destruction in the digestion unit was 11,337 kW, which was greater than the exergy destruction in the gasification unit, which was 9629. Finally, when compared to the gasifier, the amount of exergy efficiency, net output power, and freshwater production in the digester was greater.
    Matched MeSH terms: Fresh Water*
  2. Shuhaimi-Othman M, Pascoe D, Borgmann U, Norwood WP
    Environ Monit Assess, 2006 Jun;117(1-3):27-44.
    PMID: 16917696
    Hyalella azteca (Crustacea: Amphipoda), water and sediments from 12 circum-neutral lakes between Sudbury and North Bay in Ontario, Canada were sampled in August 1998 and analyzed for 10 metals including Cu, Zn, Cd, Ni, Pb, Co, Mo, V, Ba and Ti. Statistical analyses showed that concentrations of the metals in H. azteca, water and sediment differed significantly (ANOVA, P<0.05) among lakes (except for Zn and Pb in H. azteca and Mo in water). There was a trend of declining metal concentration, especially for Cu, Ni and Co (in water, Hyalella and sediment), with distance from the smelters indicating the reduced impact of atmospheric pollution. Metal concentrations of lakes (water) in the Sudbury area were found to be lower compared to data from the 1970s and 1980s indicating an improvement in water quality. Metal concentrations in field-collected amphipods compared favorably with those measured in the laboratory in animals exposed to deep-water sediments, provided metal concentrations were not extremely low (e.g., Pb) and that water chemistry differences (e.g., pH) were taken into account for some metals (especially Cd). In general bioaccumulation of metals in H. azteca was predicted better from surface water than from sediment total metal.
    Matched MeSH terms: Fresh Water
  3. Yule CM, Lim YY, Lim TY
    Carbon Balance Manag, 2018 Feb 07;13(1):3.
    PMID: 29417248 DOI: 10.1186/s13021-018-0092-6
    BACKGROUND: Tropical peat swamp forests (TPSF) are globally significant carbon stores, sequestering carbon mainly as phenolic polymers and phenolic compounds (particularly as lignin and its derivatives) in peat layers, in plants, and in the acidic blackwaters. Previous studies show that TPSF plants have particularly high levels of phenolic compounds which inhibit the decomposition of organic matter and thus promote peat accumulation. The studies of phenolic compounds are thus crucial to further understand how TPSF function with respect to carbon sequestration. Here we present a study of cycling of phenolic compounds in five forests in Borneo differing in flooding and acidity, leaching of phenolic compounds from senescent Macaranga pruinosa leaves, and absorption of phenolics by M. pruinosa seedlings.

    RESULTS: The results of the study show that total phenolic content (TPC) in soil and leaves of three species of Macaranga were highest in TPSF followed by freshwater swamp forest and flooded limestone forest, then dry land sites. Highest TPC values were associated with acidity (in TPSF) and waterlogging (in flooded forests). Moreover, phenolic compounds are rapidly leached from fallen senescent leaves, and could be reabsorbed by tree roots and converted into more complex phenolics within the leaves.

    CONCLUSIONS: Extreme conditions-waterlogging and acidity-may facilitate uptake and synthesis of protective phenolic compounds which are essential for impeded decomposition of organic matter in TPSF. Conversely, the ongoing drainage and degradation of TPSF, particularly for conversion to oil palm plantations, reverses the conditions necessary for peat accretion and carbon sequestration.

    Matched MeSH terms: Fresh Water
  4. Ruppert N, Mansor A, Sah SA
    Trop Life Sci Res, 2017 Jan;28(1):33-44.
    PMID: 28228915 MyJurnal DOI: 10.21315/tlsr2017.28.1.3
    Rattans (subfamily Calamoideae) are an important component of the forests of the Old World. However, few studies have been conducted on the distribution of these abundant palms within different habitats, specifically in Peninsular Malaysia. This study was aimed at assessing rattan diversity, abundance and biomass change across two different habitat types, namely, dipterocarp forests and fresh-water swamps within the Segari Melintang Forest Reserve, Perak, within two years. All rattan stems within five 100 m × 100 m sized study plots (A-E) of the two habitat types were counted in 2011 and 2013, and Shannon-Wiener diversity indices (H') and Bray-Curtis dissimilarity indices were calculated. A total of 11 species from 5 genera (161 stems ha(-1)) were sampled. Rattan abundance was higher in all swamp plots; however, rattan diversity (H') was highest in the dipterocarp plot (D: H' (2011)1.79; H' (2013)1.84). Bray-Curtis indices of rattan abundance (highest similarity in swamp: plot BC(2011) 0.484, BC(2013) 0.262) and biomass were highest for study plots with the same vegetation types in both years. For rattan biomass, the most similar plot pairs changed during the years: dipterocarp plots A and D were most similar in 2011 (0.509), and swamp plots B and C were most similar in 2013 (0.282). This study helped contribute information regarding the distribution and dynamics of rattans in a primary rainforest of Peninsular Malaysia.
    Matched MeSH terms: Fresh Water
  5. Vythalingam LM, Hossain MAM, Bhassu S
    Mol Cell Probes, 2021 02;55:101683.
    PMID: 33259896 DOI: 10.1016/j.mcp.2020.101683
    Invasive alien fish species have become a silent treat towards the ecosystem especially the native fish population in Malaysia. There has been a need to develop rapid identification methods that can aid management teams in identifying fish species that are not native to our ecosystem. Current visual identification methods are highly tedious and require time, delaying action towards curbing the invasion. The LAMP assay successfully identified six popular invasive fish species in Malaysia. None of the LAMP assays showed false positives and the Limit of Detection of the LAMP primers were highly sensitive and could detect DNA samples up to 1 × 10-15 ng/μl. The LAMP primers designed were highly specific to the target species and did not amplify non target species. DNA sequencing was done to ensure the accuracy of LAMP assay results. This study demonstrates that LAMP is a suitable tool in species identification efforts of invasive fish species in Malaysia.
    Matched MeSH terms: Fresh Water*
  6. Rao R, Bing Zhu Y, Alinejad T, Tiruvayipati S, Lin Thong K, Wang J, et al.
    Gut Pathog, 2015;7:6.
    PMID: 25922623 DOI: 10.1186/s13099-015-0052-6
    The Malaysian giant freshwater prawn, Macrobrachium rosenbergii, is an economically important crustacean worldwide. However, production of this prawn is facing a serious threat from Vibriosis disease caused by Vibrio species such as Vibrio parahaemolyticus. Unfortunately, the mechanisms involved in the immune response of this species to bacterial infection are not fully understood. We therefore used a high-throughput deep sequencing technology to investigate the transcriptome and comparative expression profiles of the hepatopancreas from this freshwater prawn infected with V. parahaemolyticus to gain an increased understanding of the molecular mechanisms underlying the species' immune response to this pathogenic bacteria.
    Matched MeSH terms: Fresh Water
  7. Cook S, Peacock M, Evans CD, Page SE, Whelan MJ, Gauci V, et al.
    Water Res, 2017 05 15;115:229-235.
    PMID: 28284089 DOI: 10.1016/j.watres.2017.02.059
    UV-visible spectroscopy has been shown to be a useful technique for determining dissolved organic carbon (DOC) concentrations. However, at present we are unaware of any studies in the literature that have investigated the suitability of this approach for tropical DOC water samples from any tropical peatlands, although some work has been performed in other tropical environments. We used water samples from two oil palm estates in Sarawak, Malaysia to: i) investigate the suitability of both single and two-wavelength proxies for tropical DOC determination; ii) develop a calibration dataset and set of parameters to calculate DOC concentrations indirectly; iii) provide tropical researchers with guidance on the best spectrophotometric approaches to use in future analyses of DOC. Both single and two-wavelength model approaches performed well with no one model significantly outperforming the other. The predictive ability of the models suggests that UV-visible spectroscopy is both a viable and low cost method for rapidly analyzing DOC in water samples immediately post-collection, which can be important when working at remote field sites with access to only basic laboratory facilities.
    Matched MeSH terms: Fresh Water/chemistry
  8. Pavlova A, Gan HM, Lee YP, Austin CM, Gilligan DM, Lintermans M, et al.
    Heredity (Edinb), 2017 05;118(5):466-476.
    PMID: 28051058 DOI: 10.1038/hdy.2016.120
    Genetic variation in mitochondrial genes could underlie metabolic adaptations because mitochondrially encoded proteins are directly involved in a pathway supplying energy to metabolism. Macquarie perch from river basins exposed to different climates differ in size and growth rate, suggesting potential presence of adaptive metabolic differences. We used complete mitochondrial genome sequences to build a phylogeny, estimate lineage divergence times and identify signatures of purifying and positive selection acting on mitochondrial genes for 25 Macquarie perch from three basins: Murray-Darling Basin (MDB), Hawkesbury-Nepean Basin (HNB) and Shoalhaven Basin (SB). Phylogenetic analysis resolved basin-level clades, supporting incipient speciation previously inferred from differentiation in allozymes, microsatellites and mitochondrial control region. The estimated time of lineage divergence suggested an early- to mid-Pleistocene split between SB and the common ancestor of HNB+MDB, followed by mid-to-late Pleistocene splitting between HNB and MDB. These divergence estimates are more recent than previous ones. Our analyses suggested that evolutionary drivers differed between inland MDB and coastal HNB. In the cooler and more climatically variable MDB, mitogenomes evolved under strong purifying selection, whereas in the warmer and more climatically stable HNB, purifying selection was relaxed. Evidence for relaxed selection in the HNB includes elevated transfer RNA and 16S ribosomal RNA polymorphism, presence of potentially mildly deleterious mutations and a codon (ATP6113) displaying signatures of positive selection (ratio of nonsynonymous to synonymous substitution rates (dN/dS) >1, radical change of an amino-acid property and phylogenetic conservation across the Percichthyidae). In addition, the difference could be because of stronger genetic drift in the smaller and historically more subdivided HNB with low per-population effective population sizes.
    Matched MeSH terms: Fresh Water
  9. Ng CKC, Lim TY, Ahmad AB, Khaironizam MZ
    Zootaxa, 2019 Mar 18;4567(3):zootaxa.4567.3.5.
    PMID: 31715885 DOI: 10.11646/zootaxa.4567.3.5
    This study investigates the published literature and incorporates our field data from 1997 to September 2018 to generate an inventory report of primary freshwater fishes for Perak State in Malaysia. We critically examined and enumerated 186 species from 2 classes, 16 orders, 43 families and 114 genera in 57 localities. A total of 173 fish species (91.4%) are native to Perak and 17 species (8.6%) are non-native. The provisional checklist presented herein is conservative and excludes doubtful inventory records that lack synthesis and traceability. We encountered seven taxonomic discrepancies and we also could not confidently identify eight species. These are explicitly discussed to inform future workers.
    Matched MeSH terms: Fresh Water*
  10. Noorlis, A., Ghazali, F.M., Cheah, Y.K., Tuan Zainazor, T.C., Ponniah, J., Tunung, R., et al.
    MyJurnal
    Little is known on the biosafety level of Vibrio spp. in freshwater fish in Malaysia. The purpose of this study was to investigate the prevalence and concentration of Vibrio spp. and V. parahaemolyticus in
    freshwater fish using the Most Probable Number-Polymerase Chain Reaction (MPN-PCR) method. The study was conducted on 150 samples from two types of freshwater fish commonly sold at hypermarkets, i.e. Pangasius hypophthalmus (catfish) and Oreochromis sp. (red tilapia). Sampling was done on the flesh, intestinal tract and gills of each fish. The prevalence of Vibrio spp. and V. parahaemolyticus was found to be 98.67% and 24% respectively with higher percentages detected in samples from the gills followed by the intestinal tract and flesh. Vibrio spp. was detected in almost all red tilapia and catfish samples. V. parahaemolyticus was detected in 25% of the catfish samples compared to 22.6% of red tilapia fish. The density of Vibrio spp. and V. parahaemolyticus in the samples ranged from 0 to 1.1x107 MPN/g. Although the maximum value was 1.1x107 MPN/g, most samples had microbial loads ranging from 0 to >104 MPN/g. The outcome on the biosafety assessment of Vibrio spp. and V. parahaemolyticus in freshwater fish indicates another potential source of food safety issues to consumers.
    Matched MeSH terms: Fresh Water
  11. Zzaman, W., Yusoff, M.M., Yang, T.A.
    MyJurnal
    Fish crackers made from freshwater fishes is a new dimension in fish cracker industry. In this study, three species were chosen based on their general preference and acceptability by Malaysian. Together with other ingredients, these crackers were prepared using standard formulation and tested in laboratory for their proximate analysis and physical characteristic analysis includes linear expansion, oil absorption, color measurement and texture. Sensory analysis for overall acceptability was carried out among trained panelist in the school. The results for proximate composition and physical analysis showed that there were significant differences (p
    Matched MeSH terms: Fresh Water
  12. Noorain Mohd Isa, Ahmad Zaharin Aris
    Sains Malaysiana, 2012;41:23-32.
    Classified as a small island, Kapas Island experiences major problems especially in supplying freshwater where groundwater abstraction is the only way to meet the demand of drinking water and domestic use. Groundwater samples were collected from seven constructed boreholes to examine the hydrochemistry properties of major ions and in-situ parameters as these could provide a basis for future reference. The chemical composition showed strong and significant correlation for each studied parameter; an indication of the effect of environmental variables to the groundwater composition. The composition changed from Ca-rich to Na-rich are explained mostly by mixing and cation exchange processes. This study provided an input for water management at Kapas Island where groundwater is a crucial resource to maintain the hydrogeological balance of the island.
    Matched MeSH terms: Fresh Water
  13. Nor Aziella Mohd Rosli, Khaironizam Md Zain
    Trop Life Sci Res, 2016;27(11):63-69.
    MyJurnal
    Like many other countries, reservoirs in Malaysia are primarily built for various
    functions such as hydroelectric power generation, drinking water supply, flood mitigation
    and irrigation for agricultural purposes. Artisanal fisheries activities were also performed in
    these reservoirs. The freshwater fish are a requisite source of protein for the rural
    population. Consequently, the fish resources in reservoirs should be carefully maintained
    at sustainable level. Present study elucidates the preliminary assessment on autecological
    studies of beardless barb, Cyclocheilichthys apogon as a model of fish biota in Muda
    Reservoir. This research investigates the growth pattern of C. apogon using length-weight
    relationship and their condition factor. A total of 307 specimens were captured using cast
    net for six consecutive months from March 2014 until August 2014. The growth coefficient
    (b) from the length-weight equation (W = aLb
    ) for male and female of C. apogon were
    3.150 and 3.185, respectively, indicating positive allometric growth. The condition factor
    values of male and female of C. apogon were 1.023 ± 0.111 and 1.026 ± 0.100,
    respectively, suggesting that C. apogon is in good condition in Muda Reservoir. The
    paucity of research on the autecological study in the Muda Reservoir contributes to the
    main reason of performing this research. The findings will serve as baseline information of
    this species in Muda Reservoir, as well as for comparative study in the future.
    Matched MeSH terms: Fresh Water
  14. Ahmad AK, Nur-Hazwani MNR, Aisyah Syed Omar S, Aweng ER, Taweel A
    Pak J Biol Sci, 2020 Jan;23(11):1374-1379.
    PMID: 33274864 DOI: 10.3923/pjbs.2020.1374.1379
    BACKGROUND AND OBJECTIVE: Malaysia reported experiencing serious invasive species intrusion in various rivers and threatening some local species to distinct. A study was undertaken to estimate and compare their composition and species richness in two pristine and two disturbed freshwater ecosystems.

    MATERIALS AND METHODS: Invasive and local species growth pattern was also estimated using length-weight analysis. Sampling was conducted using cast net and electric shock in each river twice in 12 months. Fish collected were identified, photo captured and measured for their weight and length. The growth pattern was also estimated using length-weight analysis.

    RESULTS: A total of 188 fishes were caught, comprises of 8 families and 15 species (ten local species with 119 individuals and five alien species with 69 individuals). Sistomus binotatus was the most dominant local species, whereas Tilapia nilotica was the most dominant alien species. There is no significant difference in composition between local and invasive species occur indicates the raise of alien species in those ecosystems even local species still dominated. The growth pattern for Sistomus binotatus and Clarias batrachus is isometric in the pristine ecosystem but negative isometric in disturbed rivers. Contrary, Tilapia nilotica has isometric for both ecosystems.

    CONCLUSION: This study concluded the capability and potential of colonization of alien species in stress ecosystem especially Tilapia nilotica. Thus, there is potential colonization of alien in Malaysia freshwater systems and a threat to local species due to food competition, site preferences and survival ability.

    Matched MeSH terms: Fresh Water*
  15. Sinang SC, Poh KB, Shamsudin S, Sinden A
    Bull Environ Contam Toxicol, 2015 Oct;95(4):542-7.
    PMID: 26248788 DOI: 10.1007/s00128-015-1620-7
    Toxic cyanobacteria blooms are increasing in magnitude and frequency worldwide. However, this issue has not been adequately addressed in Malaysia. Therefore, this study aims to better understand eutrophication levels, cyanobacteria diversity, and microcystin concentrations in ten Malaysian freshwater lakes. The results revealed that most lakes were eutrophic, with total phosphorus and total chlorophyll-a concentrations ranging from 15 to 4270 µg L(-1) and 1.1 to 903.1 µg L(-1), respectively. Cyanobacteria were detected in all lakes, and identified as Microcystis spp., Planktothrix spp., Phormidium spp., Oscillatoria spp., and Lyngbya spp. Microcystis spp. was the most commonly observed and most abundant cyanobacteria recorded. Semi-quantitative microcystin analysis indicated the presence of microcystin in all lakes. These findings illustrate the potential health risk of cyanobacteria in Malaysia freshwater lakes, thus magnifying the importance of cyanobacteria monitoring and management in Malaysian waterways.
    Matched MeSH terms: Fresh Water/microbiology; Fresh Water/chemistry
  16. Page LM, Nor SA
    Zootaxa, 2015;3962(1):5-9.
    PMID: 26249377 DOI: 10.11646/zootaxa.3962.1.3
    The U.S. National Science Foundation-funded (DEB 1022720) 'All Cypriniformes Species Inventory' was initiated in 2010 and will be completed in 2015.  It has accelerated the rate of discovery and description of cypriniform fishes, expanded our knowledge of the phylogenetic relationships of cypriniforms, increased the capacity for systematic research in other countries through student training and establishing long-term collaborations, including conferences in Thailand in 2012, Brunei in 2013, Burundi in 2013, and Malaysia in 2014, led to the formation of the Asian Society of Ichthyologists, and made available large numbers of specimens and tissues of freshwater fishes, including many species never before collected, in permanent collections in foreign and U.S. institutions.
    Matched MeSH terms: Fresh Water
  17. Muthukumaravel K, Kanagavalli V, Pradhoshini KP, Vasanthi N, Santhanabharathi B, Alam L, et al.
    PMID: 36283648 DOI: 10.1016/j.cbpc.2022.109492
    In this modern industrialized era of large-scale production of agrochemicals, various emerging contaminants form the main components of waste water and sludge in most of the developing countries of the world. In this concern, phenol- an inevitable and alarming chemical pollutant in aquatic ecosystem, gains a speedy access into the water bodies as an industrial by-product. Though the detrimental effects of phenol have been studied in various aspects of aquatic life, current study is an initiative to unravel the toxic effects of phenol at molecular level in Cirrhinus mrigala. Plasma cortisol level and acetylcholine esterase activity in fish was estimated by Chemiluminescent immunoassay technique and Ellman assay respectively. Scanning electron microscopic studies were carried out to unravel the gill histopathological alterations in exposed fish. It was observed that phenol (22.32 mg/l) inhibits 50 % of acetylcholine esterase activity in brain thereby affecting the locomotion of the targeted carp. Cortisol elevated during the 7th day in exposed fish, but declined progressively on the forthcoming 21st and 28th days. Manifestations in gill encompass curling, fusion, aberrations, sloughing of gill epithelium, wider inter filamentary space and mucus coating in the primary gill filament. It concludes that the discernable deviations produced in both biochemical parameters and key organ gill can be used as a biomarker and bio-indicator respectively for assessing the existence of emerging toxicants in aquatic ecosystem.
    Matched MeSH terms: Fresh Water
  18. Akazawa, Noriaki, Eguchi, Mitsuru
    MyJurnal
    Microcosm experiments simulating the occurrence of early mortality syndrome/acute hepatopancreatic necrosis disease (EMS/AHPND) in white shrimp production ponds were performed in 30-L aquariums. Healthy white shrimp, Litopenaeus vannamei, were reared in aquariums containing EMS/AHPND-free hatchery or pond water. Raw pond sludge, collected from shrimp ponds where EMS/AHPND had occurred, was added to some test aquariums, while others were treated with sterilized pond sludge. In some aquariums, water pH was increased from 7.5 to 8.8. Microcosms with stable pH (around 7.5) and/or autoclaved sludge served as controls. The combination of raw sludge and increased pH induced EMS/AHPND and killed white shrimp, whereas raw sludge/stable pH and autoclaved sludge/increased pH combinations did not affect healthy shrimp. Thus, EMS/AHPND outbreaks are due not only to the causative agent but also to environmental stresses such as pH fluctuation. These findings contribute to improved management in shrimp production farms.
    Matched MeSH terms: Fresh Water
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