Tropical life sciences research最新文献

It becomes imperative to understand the eco-climatic predictors and know the suitable habitat for Porphyrio porphyrio indicus and Amaurornis phoenicurus in the urban wetlands to prevent their local extinction. The study explored the habitat suitability for Porphyrio porphyrio indicus and Amaurornis phoenicurus in Paya Indah wetlands and Putrajaya wetlands of Peninsular Malaysia. Porphyrio porphyrio indicus and Amaurornis phoenicurus surveyed using the point count technique, and a stratified random design. The maximum entropy modelling (MEM) approach and geographic information systems employed to determine the influence of 17 eco-climatic factors on the suitable habitats for the species. Water at a minimum depth (44.30%) and rainfall (74.20%) contributed to the availability of suitable habitats for Porphyrio porphyrio indicus in Paya Indah and Putrajaya wetlands. Also, dissolved oxygen (56.60%) and salinity (43.50%) contributed to habitat suitability for Amaurornis phoenicurus in Paya Indah and Putrajaya wetlands. Large portions of the two urban wetlands were unsuitable for the Porphyrio porphyrio indicus and Amaurornis phoenicurus populations because of several eco-climatic factors. Thus, the models as management tools with a robust population monitoring database and framework would enhance the management effectiveness of the two species and urban wetlands.

The Pangasianodon hypophthalmus (striped or tra catfish) is a Pangasiidae family member famous for its high unsaturated fatty acid content flesh. This riverine catfish can breathe in the air unlike the channel catfish. One of the most well-known ecotoxicological protein superfamily, the ATP-binding cassette (ABC) transporters, has been characterised in channel catfish through a genome-wide approach. Therefore, it is interesting to unearth these proteins within the striped catfish genome for a comprehensive comparison across all catfishes available. A total of 52 ABC transporters were discovered from the striped catfish genome. The motif analysis has unconcealed various unshared characteristics of some catfishes. The phylogenetic analysis has evidenced its effectiveness in the successful annotations of these transporter proteins. Duplicated genes such as ABCA1, ABCB3, ABCB6, ABCC5, ABCD3, ABCE1, ABCF2 as well as ABCG2 were uncovered within the striped and channel catfish genomes. This entire set of ABC transporters yields precious genomic data for future ecotoxicological, biochemical and physiological research in striped catfish.

Blue swimming crab (Portunus pelagicus) fishery has emerged to become an important export-oriented fishery in Sri Lanka over a decade and recently resulted in a rapid increase in the exploitation. The present study attempts to understand the reproductive biology and feeding ecology of blue swimming crab which will be vital in the management of capture fishery. Five major landing sites in the Jaffna district in Northern Sri Lanka, where blue swimming crab is frequently landed throughout the year were selected for the study. Biological parameters relating to sex, carapace width, body weight, maturity, and egg sac colour with egg sac weight were recorded at the field from November 2014 to October 2015. Randomly selected crab samples were brought to the laboratory and analysed for their maturity stages, length at first maturity, Gonadosomatic Index, fecundity, and gut contents. The study revealed that male crabs mature at a smaller size than females. The sex ratio varied greatly with time and males were always dominant in the catch. The blue swimming crabs in the Northern waters of Sri Lanka spawn throughout the year, with two spawning peaks in February and May. The total fecundity of ovigerous blue swimming crab increased with increased carapace width and body weight and it ranged from 123,482 to 3,179,928 eggs, with an average of 884,982 ± 676,420. A remarkably higher percentage of empty stomachs were observed under the present study in both mature and immature crabs and this could be due to lack of food availability in the environment and different digestibility rates of food items. The diet of blue swimming crab is highly variable reflecting the ability to adopt to different modes of feeding.

Probiotic Lactobacillus reuteri has positive effects on health through inhibiting pathogenic bacteria and the ability to reduce inflammation. This study investigates the ability of reuterin isolated from L. reuteri Indonesian strain for increasing mRNA expression of interleukin (IL)-8 and human beta-defensin (hBD)-2 gene by epithelial cells, after exposure to oral bacteria. L. reuteri isolated from Indonesian's saliva, and species was confirmed by PCR, using 16S rRNA specific gene. To produce reuterin, the isolate was mixed in glycerol-containing MRS broth. Reuterin molecule's weight was counted by SDS-PAGE. Streptococcus mutans ATCC-25175 and Porphyromonas gingivalis ATCC-33277 were put in water (80°C) for 30 min, and each killed bacterial (10⁷ CFU/mL) was inoculated into HaCat cell line (10⁵ cell/mL). Reuterin was added in different concentrations (100%, 50%, 25%, 12,5%) and different incubation time at 37°C, 5% CO₂. RNA was extracted, and a reverse transcription procedure was performed to obtain cDNA. Subsequently, a quantitative PCR method was performed to analyse the transcription level of IL-8 and HBD-2 mRNA expressed by inflamed HaCat cells. All results were statistically analysed by ANOVA test. PCR assays showed that clinical isolates were L. reuteri. Quantitative PCR results showed reuterin decreased the expression of IL-8 and increased the expression of hBD-2 in all concentrations and time periods set in this study (p < 0.05). Reuterin isolated from L. reuteri Indonesian strain increased expression of human beta defensin-2 as antimicrobial peptide and may be useful in combating inflammation.

An inventory of herpetofauna species from western part of Nusa Kambangan Island, Central Java, Indonesia, is presented. There are 43 herpetofauna species reported (16 amphibians and 27 reptiles). This study confirmed new distribution record and list some of threatened species. In light of the imminent human disturbances on Nusa Kambangan Island, a conservation plan is urgently needed.

This paper discusses the identification of mollusc (bivalve and gastropod) remains from three archaeological sites in Semporna, Sabah, namely Bukit Tengkorak, Melanta Tutup and Bukit Kamiri, dated to the prehistoric period, from 3,000 to 800 years ago. Samples of mollusc remains used in this study were obtained from a series of archaeological excavations conducted at these three sites by the Centre for Global Archaeological Research, Universiti Sains Malaysia (CGAR, USM), Penang in collaboration with the Sabah Museum Department (SMD) from 1994 to 2007. In total, 90 taxa of molluscan species, of which 30 are bivalves and 60 are gastropods, had been identified. Out of 90, there were 55 taxa identified to the species level, of which 18 are bivalves and 37 are gastropods. They consisted mainly of marine species with small numbers of freshwater, brackish and terrestrial species. This study had provided new data and insights into the distribution and exploitation of molluscs by ancient human societies in different environments in Semporna, which will be useful not only for malacological research in the tropics but also for future biological and environmental studies in Sabah, Malaysia as well as for the Southeast Asian and Pacific regions.

Salam leaf has a β-ocimene as a key volatile compound that gives a fresh aroma to the food when the salam leaves are involved in the cooking process. As a secondary metabolic product, enzymatic biosynthesis as the early stage of β-ocimene is a factor that needs to be known. Thus, this study was done to identify the mechanism of the two well-known terpenoid biosynthetic pathways, namely Mevalonate Acid (MVA) and 1-Deoxy-D-Xylulose 5-Phosphate (DXP) pathways, in the biosynthesis of β-ocimene in salam leaves. The activity of the 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR)-MVA pathway-determining enzyme and 1-deoxy-D-xylulose-5-phosphate synthase (DXS)-DXP pathway-determining enzyme in the crude enzyme and their derivative products of salam leaves were analysed for their changes by differences of substrate ratios and enzyme inhibitors. The results showed that the activity of the HMGR enzyme was lower significantly than the DXS enzyme based on the addition of variations to the substrate ratio. These results were also supported by the enzyme and substrate reaction products, MVA and Isopentenyl diphosphate (IPP) intermediates from the MVA pathway, which were significantly lower when compared to DXP and IPP intermediates from the DXP pathway. As the end product of the reaction, β-ocimene gave a significantly higher value of the DXP pathway than the MVA pathway. Therefore, it can conclude that the mechanism of the biosynthetic pathway of β-ocimene in salam leaves was synthesised via the DXP pathway. The production of β-ocimene could have crosstalk-pathway through the MVA pathway, especially when the DXP pathway was blocked.

Excoecaria agallocha is a dioecious mangrove species, reported to have various medicinal properties. This study compares the gender-related biological activities between the sexes of E. agallocha in accordance with morpho-biochemical parameters which indicate their fitness over various environmental stresses as well as some information about the investment of their resources over defence and growth. For this investigation, mature sun leaves of E. agallocha were collected from each sex from three different ecological regions like Bokkhali, Jharkhali, and Kolkata, West Bengal. The comparative study found that leaf of female plants yielded more compounds than males and also resulted in higher anti-bacterial, reducing power, total antioxidant, and lipid peroxidation activities. Female leaves also showed higher concentrations of biochemical constituents like chlorophyll a, chlorophyll b, total carotenoids, total phenolic compounds and total protein content than male leaves. However, leaf area of all-male leaves in all sites was found to be greater than female leaves. The differences in growth rate and secondary metabolite content-based defences between sexes suggest that females invest resources in defences or resistance (Relative electrolytic leakages and TBARS content), whereas male invests their resources in growth (Leaf area) or tolerance. The present study strongly suggests that the female plant's yields are more beneficial in terms of medicinal properties as compared to the male plant.

Drought stress significantly reduces grain yield (GY) due to poor spikelet fertility and anthesis quality. Aim of this study was to understand the changes of flowering capacity, anthesis quality traits and seed set in the re-watered drought stressed modern high yielding drought susceptible rice cultivar, IR64 at heading (DSH) and booting (DSB) stages. The well-watered plants served as control of the experiment. Results obtained suggest that spikelet moisture content at above 80% was required to maintain optimum anthesis process in rice. Anthesis process in DSH plant was suspended when leaf relative water content (LRWC) dropped to below than 70%. Effects of drought stress on the spikelet moisture were irreversible as compared to the leaf rolling and LRWC. Hence, seed set was failed to occur at the upper rachis branches of the DSH plant. Anthesis process in the re-watered drought stress plants was resumed on the third day after re-watering with about 50% and 80% of anthers managed to dehisce in the DSH and DSB plants. Consequently, percentage of spikelet fertility and seed set in the DSH and DSB plants were increased towards the lower parts of the panicle. The GY, number of seeds, spikelet fertility, and harvest index however were significantly lower in the DSH plant (0.30 g, 13, 16.40% and 14.81) as compared to DSB plant (1.34 g, 57, 59.14% and 48.30), respectively. In addition, all interrelated traits involved in the flowering process of rice could be collectively termed as the anthesis quality traits due to their significant correlation with the grain yield and other yield components.

This study aims to determine the level of nine trace elements - As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn in liver, gill and muscle of Oreochromis niloticus in Bukit Merah Lake (BML). The concentration of trace elements was measured using Inductively Coupled Plasma-Optical Emission Spectrometers (ICP-OES). Cd and Ni were found below the detection level, while Cr was only detected in gill and muscle tissues. The Metal Pollution Index (MPI) established were liver > gill > muscle. The ranking order of trace elements in the gills was Fe > Zn > Mn > Pb > As > Cu > Cr. For the liver, the ranking order was Fe > Cu > Zn > As > Mn > Pb, while in the muscle, the ranking order was Fe > Zn > Pb > As > Cu > Mn > Cr. The estimated daily intake (EDI) for all the trace elements in this study was calculated based on 168 g.day^-1 of Malaysians' fish consumption, indicating no potential risk. From the human health point of view, there was no significant non-carcinogenic risk of individual trace elements as evaluated by Target Hazard Quotient (THQ). As indicated by the Hazardous Index (HI), the cumulative effect of all trace elements also suggested no potential of non-carcinogenic risk. The carcinogenic risks assessed from Pb and As were also neglectable and there was no likelihood of getting cancer during one's life span.