235 research outputs found

    Flowering event of Johannesteijsmannia lanceolata: An understorey palm in the Angsi Forest Reserve, Malaysia

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    The flowering event of an understorey palm; Johannesteijsmannia lanceolata J. Dransfield was investigated in the Angsi Forest Reserve, Malaysia for a total period of 18 months. The study commenced from the appearance of the inflorescence until the fall of mature ripe fruits. Results showed that the flowering phase lasted between 8.7 to 9.4 months and of the 1086 - 2150 fruit sets produced per inflorescence, only 5 - 8 fruits (of 3.5 - 5.0 cm diameter) reached maturity. 71% of the 24 adult trees produced new inflorescences within the study period, with 1.4 inflorescences per plant per year which gives 7 - 11 fruits per plant per year

    Detection of somaclonal variation by random amplified polymorphic DNA analysis during micropropagation of Phalaenopsis bellina (Rchb.f.) Christenson

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    Phalaenopsis bellina (Rchb.f.) Christenson orchid species are known for their beautiful flower shape, graceful inflorescence and fragrance. Protocorm-like bodies (PLBs) of P. bellina were induced from leaf segments. The PLBs were then subjected to proliferation using ½ strength Murashige and Skoog (MS) media with two subcultures at three months intervals. Twelve decamer random amplified polymorphic DNA (RAPD) primers were used to study somaclonal variation among the mother plant, the initially induced PLBs and proliferated PLBs after 3 and 6 months in culture. Eight out of twelve primers produced 172 bands with 18 polymorphic bands in all the treatments. The amplified products varied between 125 to 8000 bp. Among the primers used, P 16 produced the highest number of bands (29), while primer OPU 10 produced the lowest number (15). The range of similarity coefficient was from 0.83 to 1.0 among the different sub-cultures and mother plant (MP). It was found that minimal or no changes occurred between the MP and the PLBs produced after 3 months of induction. The induced PLBs were then subcultured for six months for proliferation and this resulted in about 17% dissimilarity with MP. It is reported that micropropagation of P. bellina can be carried out successfully using ½ strength MS media for 6 months but further proliferation may result in somaclonal variation which might change the prolific characteristic of this orchids.Key word: Moth orchid, somaclonal variation, random amplified polymorphic DNA, protocorm-like bodies

    Preliminary analysis of cryopreservation of Dendrobium Bobby Messina orchid using an encapsulation-dehydration technique with Evans blue assay

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    In vitro grown protocorm-like bodies (PLBs) of Dendrobium Bobby Messina hybrid were cryopreserved in liquid nitrogen (LN) at -196°C by an encapsulation-dehydration technique. PLBs (1 to 2 and 3 to 4 mm) were precultured in half strength semi-solid MS media supplemented with six different concentrations of sucrose (0.0, 0.2, 0.4, 0.6, 0.8 and 1.0 M). The PLBs were then encapsulated to form the beads in halfstrength liquid MS media supplemented with different concentrations of sodium alginate (2.5, 3.0 and 3.5%). The beads were placed in 2 ml cryovials and plunged into LN for 24 h. The beads were then thawed in a 40°C water bath for 90 s and were placed in recovery media composed of half strength semisolid MS media supplemented with 2% sucrose for four days under dark condition. After 12 days, the Evans blue dye assay was carried out to determine the viability of the PLBs. The highest viability was found in 1 to 2mm PLBs precultured in half strength semi-solid MS media supplemented with 1.0 M sucrose and encapsulated in 2.5% sodium alginate. Biochemical content analyses (chlorophyll, total soluble protein and peroxidase activities) were done to investigate the physiological responses of the PLBs after cryopreservation.Key words: Orchid, protocorm-like bodies, Dendrobium Bobby Messina, encapsulation-dehydration

    Bridging the data gaps in the epidemiology of hepatitis C virus infection in Malaysia using multi-parameter evidence synthesis

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    BACKGROUND: Collecting adequate information on key epidemiological indicators is a prerequisite to informing a public health response to reduce the impact of hepatitis C virus (HCV) infection in Malaysia. Our goal was to overcome the acute data shortage typical of low/middle income countries using statistical modelling to estimate the national HCV prevalence and the distribution over transmission pathways as of the end of 2009. METHODS: Multi-parameter evidence synthesis methods were applied to combine all available relevant data sources - both direct and indirect - that inform the epidemiological parameters of interest. RESULTS: An estimated 454,000 (95% credible interval [CrI]: 392,000 to 535,000) HCV antibody-positive individuals were living in Malaysia in 2009; this represents 2.5% (95% CrI: 2.2-3.0%) of the population aged 15-64 years. Among males of Malay ethnicity, for 77% (95% CrI: 69-85%) the route of probable transmission was active or a previous history of injecting drugs. The corresponding proportions were smaller for male Chinese and Indian/other ethnic groups (40% and 71%, respectively). The estimated prevalence in females of all ethnicities was 1% (95% CrI: 0.6 to 1.4%); 92% (95% CrI: 88 to 95%) of infections were attributable to non-drug injecting routes of transmission. CONCLUSIONS: The prevalent number of persons living with HCV infection in Malaysia is estimated to be very high. Low/middle income countries often lack a comprehensive evidence base; however, evidence synthesis methods can assist in filling the data gaps required for the development of effective policy to address the future public health and economic burden due to HCV. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12879-014-0564-6) contains supplementary material, which is available to authorized users

    Effect of solar heater boxes on seed quality of adzuki bean (Vigna angularis)

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    The effect of solar heater boxes on germination, moisture content and seedling characteristics of adzuki bean beans seeds V. angularis was determined using cardboard and plywood solar heater boxes. Results showed that, exposure to cardboard and plywood solar heater boxes did not show enormous effect on germination characters for adzuki bean seeds. In addition, experiment in oven was done for more verification. Exposure to temperatures of 40, 50, 60, and 70°C did not affect germination of adzuki bean seeds

    The role of the Annexin-A1/FPR2 system in the regulation of mast cell degranulation provoked by compound 48/80 and in the inhibitory action of nedocromil

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    Abstract1.We investigated the role of Annexin (ANX)-A1 and its receptor, ALX/FPR2, in the regulation of mast cell degranulation produced by compound 48/80.2.Both human cord-blood derived mast cells (CBDMCs) and murine bone marrow derived mast cells (BMDMCs) release phosphorylated ANX-A1 during treatment with glucocorticoids or the mast cell ‘stabilising’ drugs ketotifen and nedocromil.3.Compound 48/80 also stimulated ANX-A1 phosphorylation and release and this was also potentiated by nedocromil. Anti-ANX-A1 neutralising monoclonal antibodies (Mabs) enhanced the release of pro-inflammatory mediators in response to compound 48/80.4.Nedocromil and ketotifen potently inhibited the release of histamine, PGD2, tryptase and β-hexosaminidase from mast cells challenged with compound 48/80. Anti-ANX-A1 neutralising Mabs prevented the inhibitory effect of these drugs.5.BMDMCs derived from Anx-A1−/− mice were insensitive to the inhibitory effects of nedocromil or ketotifen but cells retained their sensitivity to the inhibitory action of hu-r-ANX-A1.6.The fpr2/3 antagonist WRW4 blocked the action of nedocromil on PGD2, but not histamine, release. BMDMCs derived from fpr2/3−/− mice were insensitive to the inhibitory effects of nedocromil on PGD2, but not histamine release.7.Compound 48/80 stimulated both p38 and JNK phosphorylation in CBDMCs and this was inhibited by nedocromil. Inhibition of p38 phosphorylation was ANX-A1 dependent.8.We conclude that ANX-A1 is an important regulator of mast cell reactivity to compound 48/80 exerting a negative feedback effect through a mechanism that depends at least partly on the FPR receptor

    In vitro induction and proliferation of protocorm-like bodies (PLBs) from leaf segments of Phalaenopsis bellina (Rchb.f.) Christenson

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    An in vitro culture procedure was established to induce protocorm-like bodies (PLBs) from leaf segments of the Phalaenopsis bellina (Rchb.f.) Christenson directly from epidermal cells without intervening callus on ½ strength modified Murashige and Skoog (MS) (in Physiol Plant 15:473–497, 1962) medium supplemented with 1-Naphthaleneacetic acid (NAA; 0, 0.1, 1 mg/l) and Thidiazuron (TDZ; 0, 0.1, 1, 3 mg/l). The best response was established at 3 mg/l TDZ which induced 78% of leaf segments to form a mean number of 14 PLBs per explant after 16 weeks of culture. No PLBs were found when leaf segments were cultured on ½ strength modified MS media supplemented with 0.1 and 1 mg/l NAA. The best induction percentage for auxin: cytokinin combination was at the combination of NAA and TDZ at 1.0 and 3.0 mg/l which gave 72% induction with 9 PLBs per explant. Semi-solid ½ strength MS and liquid Vacin and Went (VW) (in Bot Gaz 110:605–613, 1949) medium were used in order to find the highest survival and number of PLBs proliferation after 3 months in culture. Half strength MS showed an average of 9 PLBs in comparison with VW with an average of 5.3 PLBs per explants. Histological observations revealed that the regenerated PLBs were generally formed from the epidermal layers of the posterior regions of the leaf segments. Scanning electron micrograph of PLBs showed the origin of newly formed PLB from the peripheral region of leaf segments
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