Showing papers in "Ceylon Journal of Science in 2012"
TL;DR: It can be concluded that predictive models, successfully validated in agreement with defined performance criteria, will continue to be an essential element of exposure assessment within formal quantitative risk assessment.
Abstract: Predictive microbiology is the integration of traditional microbiology knowledge with those found in the disciplines of mathematics, statistics and information systems and technology to describe microbial behaviour in order to prevent food spoilage as well as food-borne illnesses. The behaviour of microbial populations in foods (growth, survival, or death) is determined by the properties of food (e.g., water activity and pH) and the storage conditions (e.g., temperature, relative humidity, and atmosphere). The effect of these properties can be predicted by mathematical models derived from quantitative studies on microbial populations. Using predictive models changes in microbial populations in foods from production/ harvest to consumption can be estimated from changes in product parameters (temperature, storage atmosphere, pH, salt /water activity, etc.). Predictive microbiology models have immediate practical applications to improve microbial food safety, quality, and are leading to the development of a quantitative understanding of the microbial ecology of foods. While models are very useful decision-support tools it must be remembered that models are, at best, only a simplified representation of reality. Because of the complexity of microbial behaviour and food systems, predictive microbiology presents some limitations. Predictive microbiology provides a powerful tool to aid the exposure assessment phase of 'quantitative microbial risk assessment‘ and it can be concluded that predictive models, successfully validated in agreement with defined performance criteria, will continue to be an essential element of exposure assessment within formal quantitative risk assessment. Keywords: validation; applications; limitations DOI: http://dx.doi.org/10.4038/cjsbs.v40i2.3928 CJSBS 2011; 40(2): 121-131
72 citations
TL;DR: Having reviewed most of these aspects of cyanobacteria, it is concluded that knowledge on these little known organisms would be invaluable not only for students, scientists and environmentalists but also for industrialists and policy makers.
Abstract: Cyanobacteria are among the earliest of inhabitants of Planet Earth and their existence can be traced back to 3.8 billion years. Their oxygenic photosynthesis led to the gradual conversion of the Earth‟s atmosphere from an anaerobic to an aerobic one. This change enabled the advent of aerobic organisms that eventually underwent rapid evolution and became the dominant, highly diverse members of the current global biodiversity. Cyanobacteria are ubiquitous in their distribution and are found in all the latitudes from Arctic and Anatarctic regions to the Tropical deserts perhaps reflecting their pioneering habitation of the primitive earth. They are also unique in their ability to simultaneously perform oxygenic photosynthesis and oxygen labile nitrogen fixation. Through these processes they make significant contributions to the Carbon and Nitrogen bio-geochemical cycles, particularly in the deep oceans. The ability of these organisms to fix N 2 either independently or in symbiosis with other organisms not only contributes to natural ecosystems but is applied in certain countries particularly for rice cultivation. Their ability to grow in highly polluted environments is also used in the treatment of sewage and industrial effluents. Cyanobacteria are the most efficient among all living organisms in the harvesting of solar energy and are currently looked at as highly attractive candidates for biofuel production. A few species are being used for the production of highly nutritive food supplements. On the negative side, some cyanobacteria form massive growths called „blooms‟ in water bodies and many of them produce toxins harmful to fish, digastric animals and are suspected to be responsible for certain human ailments. Having reviewed most of these aspects of cyanobacteria, it is concluded that knowledge on these little known organisms would be invaluable not only for students, scientists and environmentalists but also for industrialists and policy makers. Key words: cyanobacteria; blue-green algae; algal toxins; biofertilizers; biofuels DOI: http://dx.doi.org/10.4038/cjsbs.v40i2.3925 CJSBS 2011; 40(2): 71-88
62 citations
TL;DR: A survey of thrips and their host plants was conducted in several parts of Sri Lanka during 2005-2008 with a view to record the species present, their distribution, host plant relationships and damage caused.
Abstract: Thrips of Sri Lanka have been poorly studied despite their significance to agriculture and horticulture of the country. A survey of thrips and their host plants was conducted in several parts of Sri Lanka during 2005-2008, with a view to record the species present, their distribution, host plant relationships and damage caused. Over 1,000 plant species comprising crops, ornamental plants, weeds, shrubs , and trees were examined for thrips in 22 study sites, representing a range of habitats in nine districts covering 12 agrochemical regions of the country. Damage in plants due to thrips infestations was documented. This paper presents a list of 72 thrips species in 45 genera recorded during the survey from 324 host plant species in 83 plant families. Megalurothrips usitatus, Thrips palmi , and Haplothrips gowdeyi were the most widely distributed species. The grass infesting Haplothrips spp., several species of Thrips, Microcephalothrips abdominalis , M. usitatus and Scirtothrips dorsalis are some of the species with a large number of host records. Thrips simplex in particular was confined to the Upcountry Wet zone, while Thrips flavus was most widespread in this region and was present on almost all the vegetation. The survey identified 24 species of thrips represented in 20 genera that were not recorded previously from Sri Lanka. Majority of the thrips recorded are pest species, cosmopolitan in distribution. The most common damage due to thrips infestations was discolouration, scarring and browning of leaves and flowers, most pronounced in cut flowers. The survey updates the information on the Thysanoptera of Sri Lanka and highlights their importance in agriculture and floriculture. Key words : agriculture; floriculture; damage; pest species; new records DOI: http://dx.doi.org/10.4038/cjsbs.v40i2.3926 CJSBS 2011; 40(2): 89-108
25 citations
TL;DR: In this article, the authors show that Sri Lanka's old-growth forests have been reduced to less than 20% of their pre-colonial extent, increasing areas of land, formerly heavily influenced by humans, are being allowed to return to secondary forests.
Abstract: With Sri Lanka's old-growth forests having been reduced to less than 20% of their pre-colonial extent, increasing areas of land, formerly heavily influenced by humans, are being allowed to return to secondary forests. These range from land recovering from swidden cultivation in the dry zone, through abandoned tea plantations in the lower-montane zone, to partly-logged forests throughout the country. Although the secondary vegetation of these ‘emerging ecosystems’ is often dominated by alien plant species and includes only a depauperate native flora, many threatened animals, ranging from amphibians to elephants, are able to utilize them for part or all of their life cycles. These novel ecosystems offer valuable conservation opportunities in two ways: (1) by increasing the area of occupancy of threatened species they contribute directly to a reduction in the level of threat; and (2) they provide a filter for triage, whereby threatened species that are intolerant of modified habitats could be awarded higher priority in the design of recovery plans. Available data suggest that among the Sri Lankan terrestrial vertebrates presently assessed as Endangered or Critically Endangered in the IUCN Red List , 12 of 14 mammal species, three of four reptile species and 40 of 48 amphibian species occur also in emerging ecosystems. Despite their impoverished plant diversity, therefore, such ecosystems should be viewed as a conservation opportunity rather than a threat; they should be incorporated into the national protected areas network and their biodiversity monitored, especially in relation to threatened species. Those that establish stable populations over multiple generations could be down-listed so that greater conservation attention could be allocated to threatened species obligatorily dependent on old-growth forests. DOI: http://dx.doi.org/10.4038/cjsbs.v41i1.4532 Ceylon Journal of Science ( Bio. Sci. ) 41 (1): 1-10, 2012
24 citations
TL;DR: Anti HIV and anticancer properties of active fraction of stem ethanol extracts of E. agallocha showed significant anti-reverse transcriptase activity in the enzyme-based direct binding assay which was as good as that of the standard synthetic inhibitor.
Abstract: Excoecaria agallocha L. (Euphorbiaceae) is a mangrove plant widely used in folklore medicine for the treatment of several diseases. In the present study anti HIV and anticancer properties of active fraction of stem ethanol extracts of the plant were investigated. The fraction showed significant anti-reverse transcriptase activity in the enzyme-based direct binding assay which was as good as that of the standard synthetic inhibitor. Anticancer activity of the same fraction was determined using MTS in vitro assay. It showed potent cytotoxicity against pancreatic cancer cell lines Capan-1 and Miapaca-2 with IC 50 values of 4 μg/ml and 7 μg/ml respectively. These results clearly indicate strong anti HIV and anticancer properties in stem extracts of E. agallocha. Key words : mangrove; pancreatic cancer; activity guided fractionation; anti HIV properties DOI: http://dx.doi.org/10.4038/cjsbs.v40i2.3931 CJSBS 2011; 40(2): 147-155
19 citations
TL;DR: The tadpoles of Ramanella obscura are tree-hole or small-ground-pool dwellers that feed on particulate matter and infusoria both in the substratum and the water column, for which they have morphological adaptations.
Abstract: External, buccal and chondrocranial morphology, bone development and ecology of the tadpoles of Ramanella obscura , a narrow-mouthed frog species endemic to Sri Lanka is described. The tadpoles have a dorsoventrally flattend body, keratinous ridge on lower lip, a postnarial ridge that extends anteriorly between narial papillae and an expanded fenestrated sheet of cartilage associated with the larval otic process and processus lateralis posterior. But they do not possess a medial preglottal papilla in ventral buccal floor as in Microhyla . At Gosner stage 25, there is no bone development; but by stage 35, exoccipitals, parasphenoid, frontoparietals and prootics are developed. By stage 40, in addition to the bones at stage 35, nasals are formed. The tadpoles are tree-hole or small-ground-pool dwellers that feed on particulate matter and infusoria both in the substratum and the water column, for which they have morphological adaptations. No other anuran tadpoles were observed in syntopy with R. obscura tadpoles. Key words : Chondrocranium; buccal morphology; tadpole ecology; endemic; Sri Lanka DOI: http://dx.doi.org/10.4038/cjsbs.v40i2.3927 CJSBS 2011; 40(2): 109-120
14 citations
TL;DR: In this paper, the authors studied the succession of tropical montane cloud forests in the Sri Lanka highlands and found that the invasive Neotropical shrub Austroeupatorium inulifolium and Australian tree Acacia decurrens dominated the vegetation.
Abstract: An understanding of floral succession is vital in planning the restoration of native vegetation in abandoned agricultural landscapes. Although such restoration is essential for the establishment of habitat corridors between the fragments of tropical montane cloud forest in the Sri Lankan highlands, in which > 90% of the land has been converted to tea plantations, no studies of succession have hitherto been possible because of the near-total absence of secondary forest in this region. In a pioneering restoration initiative in 1998, however, tea cultivation was abandoned on a 25 ha site (elevation 1540–1780 m) at Agrapatana, ~500 m from a natural forest. Succession was allowed to proceed without intervention, except that tea was removed from 10 ha. By 2009, the invasive Neotropical shrub Austroeupatorium inulifolium and Australian tree Acacia decurrens dominated the vegetation (0.43±0.14 and 0.03±0.04 stems m -2 , respectively), to the total exclusion of native woody species. There was no significant difference in the density of Austroeupatorium (82±12%) and Acacia (14±9%) between quadrats with and without tea. Methods to suppress these two aggressive invasive species are urgently needed, especially given that Austroeupatorium has recently become established within pristine montane forests such as Horton Plains National Park (2,100 m elevation). Key words: Acacia decurrens; Eupatorium; montane cloud forest; invasive species DOI: http://dx.doi.org/10.4038/cjsbs.v40i2.3934 CJSBS 2011; 40(2): 175-181
13 citations
TL;DR: The study investigated the occurrence of trypanosomosis in water buffaloes using parasitological and molecular methods and found two animals were positive for T. evansi in both, blood parasite examination and PCR.
Abstract: The study investigated the occurrence of trypanosomosis in water buffaloes using parasitological and molecular methods. Buffaloes of different ages and both sexes comprising Bulgarian Murrah and some crosses were used in the study. Two of the 145 samples (0.13%) were positive for Trypanosoma evansi in both, blood parasite examination and PCR. One female buffalo (1/54 samples; 1.86%) from a lactating herd in the city of Munoz, Nueva Ecija (Region 3) and another (1/51 samples; 1.96%) non-pregnant female belonging to caraheifer population from Los Banos, Laguna (Region 4) were found infected by T. evansi. The positive animals were in the age group of 3-4 years. Blood samples obtained from 40 buffaloes from Cagayan (Region 2) were found negative for trypanosome infection. Key words: Bulgarian Murrah buffaloes; Surra ; Laguna; Nueva Ecija DOI: http://dx.doi.org/10.4038/cjsbs.v40i2.3930 CJSBS 2011; 40(2): 141-146
13 citations
TL;DR: It is confirmed that P. malabarica existed during the time the gastropod layer was being laid down, thus confirming a Burdigalian age for the latter, and helping to date a substantial portion of the Sri Lankan fossil fauna with confidence.
Abstract: Aruwakkalu fossil bed is a part of Sri Lanka’s Jaffna limestone, which underlies the whole of Jaffna Peninsula and extends southwards mostly along the west coast. Previous authors have suggested that Aruwakkalu contains a rich assemblage of vertebrate and invertebrate fossils. We sought to confirm the Burdigalian age of this northwestern Miocene deposit at Aruwakkalu on the basis of the foraminifer Pseudotaberina malabarica , an index fossil of the Burdigalian stage. General and timeline collections were made at seven selected sites and the fossils collected were identified. The study sites contained six sedimentary layers of which, third and sixth from top were fossiliferous. The sixth (deepest) layer was dominated by gastropod fossils while the third was dominated by fossils of giant oysters. Fossils of P. malabarica were recovered both from timeline and general collections. In the timeline collection, samples of this index fossil were recovered only from the gastropod layer, suggesting that P. malabarica existed during the time the gastropod layer was being laid down, thus confirming a Burdigalian age for the latter, and helping to date a substantial portion of the Sri Lankan fossil fauna with confidence. Key words: Pseudotaberina malabarica; foraminifera; index fossil; Miocene; gastropod layer; oyster layer DOI: http://dx.doi.org/10.4038/cjsbs.v40i2.3933 CJSBS 2011; 40(2): 163-174
12 citations
TL;DR: In this paper, the authors used single-catch rat traps from July 2006 to February 2007 to detect ecto and endoparasites of urban rodents in two selected urban areas in Sri Lanka.
Abstract: Urban rodents play an important role in public health being reservoirs of many zoonotic diseases. Screening of rodents for ecto and endoparasites from two selected urban areas, Peradeniya and Pilimathalawe in Kandy district was carried out to assess their potential as reservoirs of zoonoses. Rodents were caught live using single-catch rat traps from July 2006 to February 2007. Six traps were set twice a week and three rodent species, the common house rat, Rattus rattus (n = 17), the Indian house mouse, Mus musculus (n = 2), and bandicoot, Bandicota indica (n = 2) were examined. Of the eleven species of parasites found, five were zoonotic namely, Hymenolepis diminuta, Moniliformis moniliformis, Cysticercus fasciolaris, Raillietina sp. and Xenopsylla cheopis. Tapeworms were the predominant parasitic group (52.4%) of which C. fasciolaris (42.7%) was the most common type followed by strongyle type eggs (19.0%). Among the infected rodents, 23.8% had mixed infections of H. diminuta, X. cheopis and M. moniliformis as well as that of H. diminuta, Raillietina sp. and C. fasciolaris . Although Raillietina madagascariensis was recorded in R. rattus in 1954, none of the rats examined in subsequent studies or in the present study were infected with Raillietina. However, one bandicoot was infected with Raillietina sp. in the present study w hich presents a new host record. Urban rodents carry many zoonotic infections and urbanization is in favour of the spread of these infections to humans specifically in developing countries where the communities are socio-economically challenged. DOI: http://dx.doi.org/10.4038/cjsbs.v41i1.4539 Ceylon Journal of Science ( Bio. Sci. ) 41 (1): 71-77, 2012
11 citations
TL;DR: In vivo investigation of fruits of both papaya cultivars harvested from fruit plantations in Sri Lanka indicated that papaya washed in 1% alum and subsequently sprayed with an emulsion solution of 0.16% basil oil and enclosed in styrofoam sleeves could be stored for 14 days at 12–14 °C.
Abstract: Anthracnose ( Colletotrichum gloeosporioides ) , stem-end rot ( Lasiodiplodia theobromae ) and Phomopsis rot ( Phomopsis caricae-papayae ) are major post-harvest diseases in papaya resulting in relatively high postharvest losses, up to 45%, in Sri Lanka. The current consumer preference is for tropical fruits free of synthetic pesticides. The objectives of the present investigation were to identify major post-harvest pathogens in papaya fruits, test in vitro fungitoxic effect of basil oil ( Ocimum basillicum ) and alum (sodium aluminium sulphate) on major fungal pathogens of papaya fruit and develop a relatively safe, disease control strategy. Alum (1% w/v) and basil oil (0.12– 0.16% v/v) in a liquid bioassay, indicated fungistatic and fungicidal efficacy on C. gloeosporioides, L. theobromae and P. caricae-papayae isolated from ‘Red Lady’ and ‘Rathna’ cultivars of papaya. In vivo investigation of fruits of both papaya cultivars harvested from fruit plantations in Sri Lanka (‘Red Lady’–Yatawarawatta plantation, Kurunegala, ‘Rathna’ – CIC plantation, Kekirawa and the Agricultural farm, Polonnaruwa) at 25% maturity level indicated that papaya washed in 1% (w/v) alum and subsequently sprayed with an emulsion solution of 0.16% (v/v) basil oil and enclosed in styrofoam sleeves could be stored for 14 days at 12–14 °C. The visual quality rating (VQR) was high (11–13), shriveling and ‘green islands’ were low on fruits with zero disease severity where results were statistically similar to 500 mg/L Bavistin treatment. Physicochemical properties assessed were unaffected by the treatments and were comparable to the controls washed only in water. The organoleptic properties were slightly low in fruits subjected to cold temperature compared to fruits subjected to ambient temperature. No residues of basil oil could be detected on fruit peel by gas chromatography at the end of the experimental period of 14 days. The treatment strategy developed could be adopted for sea shipment or temperature-regulated supermarket storage of papaya fruits where storage life could be lengthened up to 14 days. DOI: http://dx.doi.org/10.4038/cjsbs.v41i1.4535 Ceylon Journal of Science ( Bio. Sci. ) 41 (1): 27-34, 2012
TL;DR: In this article, three locally grown pulses; mung beans, black gram and soya bean were investigated to determine the effects of popular processing methods on their Zn, Fe and Ca bioavailability as affected mainly by phytic acid (PA).
Abstract: Pulses, an essential component of the Sri Lankan diet, have high levels of phytic acid (PA) which chelate essential mineral nutrients limiting their bioavailability. Three locally grown pulses; mung beans, black gram and soya bean were investigated to determine the effects of popular processing methods on their Zn, Fe and Ca bioavailability as affected mainly by phytic acid (PA). Processed mung beans ( Vigna radiata var . MI 6) and black gram ( Vigna mungo var. MI 1) had very high levels of PA. In mung beans, with increasing germination time, a significant decrease (P=0.05) in PA from 2517 to 1998 mg per 100g (dry weight basis) was observed but PA:Zn molar ratio did not improve. Natural fermentation of black gram, did not affect PA level effectively, but levels decreased when inoculated with a lactic acid bacterium or with Pantoea agglomerans . In soya bean ( Glycine max var. Pb ), significant (P=0.05) reduction in PA was observed in tempeh (487 mg/100 g dry weight). Overall, in soya products, the Zn bioavailability has increased from low to moderate levels in both tofu and tempeh. The molar ratio of PA:Fe was lower in all soya products. Although, PA:Zn molar ratio has decreased in germinated mung beans, the Ca x PA:Zn ratio exceeded 0.5 indicating that Ca influences Zn bioavailability DOI: http://dx.doi.org/10.4038/cjsbs.v41i1.4534 Ceylon Journal of Science ( Bio. Sci. ) 41 (1): 19-26, 2012
TL;DR: In this paper, the authors examined cross-sections, cuticular scale patterns, medulla patterns and made measurements (length and maximal diameter) of dorsal guard hairs (GH1 and GH2).
Abstract: We report here characteristic features of hair anatomy of all twelve shrew species and subspecies occurring in Sri Lanka. They can be reliably identified using hair anatomy, in most cases by a single characteristic feature. We examined cross-sections, cuticular scale patterns, medulla patterns and made measurements (length and maximal diameter) of dorsal guard hairs (GH1 and GH2). We also provide a dichotomous key for identification of shrew species and subspecies based on hair anatomy supported by reference illustrations of cross-sections, photomicrographs of cuticular scales and medullae. Cross-sections of GH2 hairs are characteristic to most species and seven species ( Solisorex pearsoni, Feroculus feroculus , Crocidura miya, C. hikmiya, C. horsfieldii, Suncus zeylanicus and S. fellowesgordoni ) can be distinguished using cross-sections of GH2 hairs alone. Cuticular scale patterns are also characteristic to species and subspecies of S. murinus , even with variation within species and among hairs of individuals. Medulla pattern is of least importance in shrew species identification, since all have unicellular ladder pattern, but can be used in combination with other characters to distinguish certain species based on whether the ladder pattern is regular or irregular. Hair measurements alone cannot be used in species identification except for S. etruscus , which has the shortest guard hairs among the shrews studied. DOI: http://dx.doi.org/10.4038/cjsbs.v41i1.4537 Ceylon Journal of Science ( Bio. Sci. ) 41 (1): 45-66, 2012
TL;DR: Effect of different cations on the enhancement of stability of α-amylase from Bacillus licheniformis ATCC 6346 was examined and α-Amylase activity was strongly inhibited by Cu 2+ , Hg 2+ and Mn 2+ but less affected by Mg 2- and Ba 2+ .
Abstract: α-Amylases (1,4-α-D-glucan glucanohydrolase; E.C.3.2.1.1) catalyze the cleavage of α-1,4-glucosidic linkages in starch, glycogen, and various oligosaccharides. Thermostable α-amylases from Bacillus species are of great industrial importance in the production of corn syrup or dextrose. In this study effect of different cations on the enhancement of stability of α-amylase from Bacillus licheniformis ATCC 6346 was examined. Optimal activity of the enzyme was at pH 7.0 and 85 °C. α-Amylase activity was strongly inhibited by Cu 2+ , Hg 2+ and Mn 2+ but less affected by Mg 2+ and Ba 2+ . Ca 2+ and Na + stimulated the enzyme activity at 85 °C and at pH 7.0. Addition of 0.01 M Na + enhanced the enzyme stability from 1-33% for 60 min at 85 °C and pH 7.0. With 0.1M Na + , 100 % of initial enzyme activity was retained for 150 min and 70 min at 60 °C and 70 °C, respectively and 88% activity was retained at 80 °C, at pH 7.0 for 60 min. In the presence of 1 mM Ca 2+ , no loss of activity was observed in 60 min, at 85 °C and pH 7.0. Combined addition of 1mM Ca 2+ and 0.1 M Na + , retained 17.3 % of the enzyme activity for180 min. But the enzyme in the presence of 1 mM Ca 2+ and 0.1 M Na + separately, lost its total activity in 120 min and 90 min, respectively at 95 °C and pH 7.0. DOI: http://dx.doi.org/10.4038/cjsbs.v41i1.4536 Ceylon Journal of Science ( Bio. Sci. ) 41 (1): 35-44, 2012
TL;DR: Results suggest that the application of 25 μM BAP as a pulse treatment for 24 h can be recommended to prolong the postharvest life through delayed leaf senescence and thus enhance the marketability of cut leaves of Dracaena marginata ‘bi colour’,Dracaena sanderiana ‘white’ and DracaENA deremensis.
Abstract: Leaf yellowing associated with early senescence is a major problem associated with cut decorative leaves and flowers of many tropical plant species. Effect of postharvest application of benzylaminopurine (BAP), gibberellic acid (GA 3 ), silver-thiosulphate (STS) and silver nitrate (AgNO 3 ) on vase life of cut leaves of three Dracaena species Dracaena marginata ‘bi colour’, Dracaena sanderiana ‘white’ and Dracaena deremensis were investigated. Deionized water (DIW) was used as the control. All the BAP treatments (25, 50 and 100 μM) applied either as 10 minutes immersion or as 24 h pulse improved the vase life of all three species examined. Application of STS (2 mM) and AgNO 3 ( 10 mM Ag ions) did not increase the vase life of D. marginata ‘bi colour’ and D. sanderiana ‘white’ significantly while GA 3 (50, 100 and 250 μM) either as a pulse or immersion, significantly reduced the postharvest life of D. deremensis compared to untreated leaves. Results suggest that the application of 25 μM BAP as a pulse treatment for 24 h can be recommended to prolong the postharvest life through delayed leaf senescence and thus enhance the marketability of cut leaves of Dracaena marginata ‘bi colour’, Dracaena sanderiana ‘white’ and Dracaena deremensis . Key words : postharvest life; Dracaena marginata ‘bi colour’; Dracaena sanderiana ‘white’; Dracaena deremensis ; marketability DOI: http://dx.doi.org/10.4038/cjsbs.v40i2.3932 CJSBS 2011; 40(2): 157-162
TL;DR: It is confirmed that S. fellowesgordoni is a distinct species, which constitutes the sister species to S. malayanus from Southeast Asia and Suncus etruscus from South Asia to Madagascar and their low genetic distance confirm that the two populations constitute a single species.
Abstract: A corrected PDF for this article was loaded on 07/08/2012. Please use this version. This study evaluates the taxonomic and phylogenetic position of S. fellowesgordoni with S. malayanus , S. etruscus and S. ' madagascariensis ' . We reconfirm that S. fellowesgordoni is a distinct species, which constitutes the sister species to S. malayanus from Southeast Asia. The pairwise uncorrected genetic distance of 9.1–9.7% between the two species suggests a prolonged independent evolution of each and they may constitute relict species of formally widely distributed group of shrews from South Asia to Southeast Asia. Suncus etruscus from Sri Lanka and India fall as the sister taxon to S. ' madagascariensis' , suggesting a recent introduction of S. etruscus from South Asia to Madagascar and their low genetic distance of 1.2–1.4%, confirm that the two populations constitute a single species. Suncus etruscus being a widely distributed species shows a substantial genetic divergence among populations. Individuals from Italy show a 7.3–7.5% genetic distance to those from South Asia and Madagascar, which can be explained by geographic distance. However, additional data from many other populations of S. etruscus is needed to evaluate the status of this species in extreme locations of its geographic range. DOI: http://dx.doi.org/10.4038/cjsbs.v41i1.4541 Ceylon Journal of Science ( Bio. Sci. ) 41 (1): 83-87, 2012
TL;DR: In this article, the authors developed microsatellite genetic markers using skipjack tuna (SJT) found around Sri Lanka in the Indian Ocean, and characterized one tri-and seven tetra-nucleotide micro-satellite loci isolated from enriched genomic libraries from SJT, to provide tools for addressing both conservation and fisheries management strategies.
Abstract: Skipjack tuna (SJT), Katsuwonus pelamis is the largest tuna fishery in all the major oceans around the world, and the largest marine fishery in Sri Lanka. Knowledge of genetic population structure and effective population size of SJT in the Indian Ocean and other major oceans, however, is still lacking for improved management practices and conservation strategies. We developed microsatellite genetic markers using SJT found around Sri Lanka in the Indian Ocean, and characterized one tri- and seven tetra-nucleotide microsatellite loci isolated from enriched genomic libraries from SJT, to provide tools for addressing both conservation and fisheries management strategies. Analysis of these eight microsatellite markers in two populations of SJT from eastern Sri Lanka (n = 44) and the Maldives Islands (n = 53) showed that all eight microsatellites were polymorphic with an average number of alleles per locus of 11.80 (range 5–27). Expected heterozygosities at marker loci ranged from 0.450 to 0.961. No significant linkage disequilibrium was detected among any loci pairs. These markers are currently being used to characterize population structure and extent of natural gene flow in SJT populations from the eastern and western Indian Ocean. DOI: http://dx.doi.org/10.4038/cjsbs.v41i1.4533 Ceylon Journal of Science ( Bio. Sci. ) 41 (1): 11-17, 2012
TL;DR: In this article, a field survey was carried out to find out information on aspects of post-harvest handling and postharvest losses in Up-country produced cut flowers supplied to the local market.
Abstract: Cut flowers produced for the local market come mainly from the Up-country region of Sri Lanka. Using a questionnaire, a field survey was carried out to find out information on aspects of postharvest handling and postharvest losses in Up-country produced cut flowers supplied to the local market. Forty-seven personnel involved in the cut flower handling chain in and around Nuwara Eliya town, Ragala, Bandarawela and Kandy were interviewed. A variety of postharvest problems related to Up-country cut flower production were identified. Inadequate knowledge on proper pre-and postharvest handling methods among the majority of farmers and sellers contributed largely to considerable postharvest losses in cut flowers. DOI: http://dx.doi.org/10.4038/cjsbs.v41i1.4538 Ceylon Journal of Science ( Bio. Sci. ) 41 (1): 67-70, 2012
TL;DR: The study shows that Abate is lethal to the early stages of the Asian common toad but the toxicity decreased as the tadpoles grow older.
Abstract: Exposure to chemical contaminants has been identified as a key factor causing widespread mortalities and malformations in amphibians world over. We examined the effect of exposure to commonly used mosquito larvicide, Abate ® which has temephos as the active ingredient, on the Asian common toad, Bufo melanostictus, under laboratory conditions . The LC 50 values of 16.56 ppm and 17.03 ppm were obtained when one-day old tadpoles (Gosner stage 21-24) and one-week old tadpoles (Gosner stage 25) were exposed to Abate for two weeks, respectively. Chronic exposure to Abate at effective field concentrations used in mosquito control programmes (WHO recommended doses) had a significant effect on the survival of egg stage (Gosner stages 12-14), and one day old tadpoles but not on one week old tadpoles. Tadpoles exposed to Abate grew larger and had a longer larval period and the difference in the duration of larval period was statistically significant. Exposed tadpoles also developed malformations such as rotation of bones, micromelia of the limb bones, hemimelia of femur, skin webbing in the hind limbs and ectrodactyly. Edemas were also observed in the exposed tadpoles. Exposure to all concentrations of Abate had a significant effect on the survival, growth and development of malformations in the early tadpole stages compared to the control group. The reduction in survival was not significant when older tadpoles of one week post-hatch were exposed, although they developed malformations and their larval period was prolonged significantly compared to the control group. Thus, the study shows that Abate is lethal to the early stages of the Asian common toad but the toxicity decreased as the tadpoles grow older. Key words : temephos; amphibians; survival; growth; malformations DOI: http://dx.doi.org/10.4038/cjsbs.v40i2.3929 CJSBS 2011; 40(2): 133-140
TL;DR: The recent record of an unusually long inflorescence of Cassia fistula ('Ehela') from Sri Lanka, reaching up to 238 cm can be considered as the longest recorded legume inflorescence.
Abstract: The recent record of an unusually long inflorescence of Cassia fistula ('Ehela') from Sri Lanka, reaching up to 238 cm can be considered as the longest recorded legume inflorescence. In the world of legumes, records surpassing such lengths are very rare and are not well authenticated. Therefore, the present record can be considered as a strong contender for the longest inflorescence in the legume family. DOI: http://dx.doi.org/10.4038/cjsbs.v41i1.4540 Ceylon Journal of Science ( Bio. Sci. ) 41 (1): 79-82, 2012
TL;DR: This is the very first attempt at field collecting and monitoring for precipitating antibodies for H. capsulatum in Philippine wildlife, particularly in Philippine bats.
Abstract: Histoplasmosis is a disease of medical and veterinary concern. Bats are considered as reservoir hosts of the etiologic agent Histoplasma capsulatum, and are therefore used as animal subjects in experimental studies. Thirty six bats, consisiting of nine bats (Microchiroptera: Vespertilionidae) from Aklan, 22 bats (Megachiroptera: Pterodidae) from Quezon City and another five bats (Microchiroptera: Vespertilionidae) from Quezon City, Philippines were tested for the presence of precipitating antibodies to H. capsulatum using immunodiffusion assay. Results revealed that none of the bats tested were positive for H. capsulatum in agar gel precipitation assay. This may be due to no previous exposure of the bats to the pathogen, exposure to the pathogen with insufficient time for seroconversion (infection time H. capsulatum in the tested bats. This is the very first attempt at field collecting and monitoring for precipitating antibodies for H. capsulatum in Philippine wildlife, particularly in Philippine bats. Key words: Immunodiffusion assay; wildlife; antibodies; Aklan; Quezon City DOI: http://dx.doi.org/10.4038/cjsbs.v40i2.3935 CJSBS 2011; 40(2): 183-186