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Slope erosion and shallow failures occur in developed areas in Malaysia as a result of the natural vegetation removal, resulting in soil disturbance and greater exposure of bare ground. The use of bioengineering techniques through vegetation is a preferred solution to these problems by providing cover from rainfall and reinforcing the soil through root systems. Considering the potential of bioengineering in slope management, the current study aims to (i) review slope bioengineering techniques that uses vegetation to stabilise slope in Malaysia and (ii) highlight research gaps. Findings were discussed from 17 original studies published between 2000 and 2020, which were selected from the output of four databases (Scopus, Web of Science, Science Direct, and Google Scholar), several grey literature works, and local scientific publications. The studies on bioengineering using vegetation recorded that several slope species with superior performance in terms of beneficial traits, such as root length density and transpiration rate, were more prominent in Melastoma malabathricum and Leucaena leucocephala. Moreover, previous studies identified biomaterials that protected slopes, including empty fruit bunch and geotextiles, despite the currently critical limitations in the applicability of these techniques. This study highlighted the research gaps that may lead to the progress of the bioengineering techniques, such as beneficial traits and techniques, the exploration of mix-culture systems, and the utilisation of modelling techniques. This review serves as a structured and current overview of bioengineering knowledge for shallow slope instability and erosion management in Malaysia. [ABSTRACT FROM AUTHOR]

Saving energy and cutting costs without compromising indoor comfort conditions are challenging, especially in hot and humid regions such as Malaysia. This study explores a new approach to reducing energy consumption without compromising staff comfort in office buildings. This study aims to develop a method for lowering Building Energy Index (BEI) and maintaining acceptable indoor conditions while increasing productivity in office buildings. A developed triangulation method using Building Use Studies (BUS) for evaluating occupant satisfaction, physical measurements, and simulation modelling was implemented to measure indoor performance in an office building. The results indicated that enhancing six variables of building conditions managed to improve occupant satisfaction by 44%. Hence, the productivity of staff in the building increased by 16%. The findings demonstrated that a reduction of 3 h in the operating times of chillers while an increase in chillers' temperature by 1.5 °C maintained an acceptable indoor environment and reduced the building's BEI to 89.48 kWh/m2/year, with an energy saving of 21.51%, turning the case study into a low energy building. [ABSTRACT FROM AUTHOR]

Due to the essential nature and increased appreciation to the issue of sustainability in recent decades, the evaluation and assessment of environmental impacts of concrete structures have been considered extensively by the scientific and construction fraternity. To enhance the resilience in the design of concrete structures in the tropics, it is essential to understand and acknowledge the impact of the geographical context, taking into account the widespread socio-economic circumstances in the tropics. Moreover, since all environmental impacts of a concrete structures through its life-cycle use are predictable through its Life-Cycle Sustainability Assessment (LCSA), it is therefore necessary to investigate this framework comprehensively. This research was undertaken to study and assess the existing methods in LCSA, as well as to assess the steps and materials that can significantly affect the environment during the whole life-span of concrete structures, and also to qualitatively understand the interaction among the geographic sense and sustainability in the tropics, considering the case of Malaysia. This study proposes a more comprehensive framework for LCSA in the design of concrete structures. The findings suggest that according to LCSA analysis, the environmental effects of concrete structures with almost the same functional quality can be different from each other. [ABSTRACT FROM AUTHOR]

The Peregrine Falcon (Falco peregrinus) is the most widely distributed bird species in the world, but very little is known about its tropical populations, where even very basic information (e.g. about population density) is mostly lacking. In January 2017, 2018 and 2019, we conducted three intensive surveys amounting to 27 days and 5,400 km driven by car in West Malaysia at latitudes between 3 and 7 °N, where the ernesti subspecies was confirmed to be a resident breeder only as recently as 1996. Here, we summarize our findings and combine them in a synthesis that includes all published and unpublished records of nesting peregrines that we could obtain in that area. In particular, we draw on the foundational work conducted by our late colleague Laurent Molard in 2003–2005. We give information about breeding habitats, local density, behavior and breeding phenology. We also describe and discuss our use of call playback during the surveys. Much more extensive reports for each survey, with plenty of photographs of all sites visited, are available upon request from the authors. According to current knowledge, Peregrines in West Malaysia nest mainly in cliffs, with some nesters on buildings exceptionally found (in Kuala Lumpur and suspected also elsewhere in cities) and possibly on large towers. Virtually all natural nesting places are limestone mountains with vertical cliffs. Owing to the mostly flat terrain in West Malaysia, with limestone cliffs only occurring very locally, the peregrine breeding distribution is extremely patchy. We found local aggregations in the regions of Ipoh (Perak), Gua Musang (Kelantan) and in the state of Perlis. However, local density is fairly low even in these hotspots, with nearest-neighbor distances in the densest cluster ranging from 3.7–5.6 km (mean 4.7). Overall, by the end of 2019, 36 occupied sites had been found in West Malaysia, of which 10 were known before 2003, 9 were found during the surveys by Mo-lard and his colleagues in 2003–2005, and 17 were new discoveries during our surveys in 2017–2019. In West Malaysia, the start of egg-laying appears to be late January and early February. We found playback of the 'eeechup' courtship calls to be extremely helpful when locating pairs. Playing a 26-sec sequence twice enticed the majority of birds to become airborne and/or to call, which greatly increased their detection probability and therefore survey success. In spite of the great increase in the number of known peregrine sites owing to our surveys, the currently known number of pairs is still considerably lower than the estimate by Molard et al. (2007) of 70–80 pairs. Although this latter may perhaps be a slight overestimate, we are convinced that many more pairs remain to be discovered in cliffs, where most of the future survey effort should be concentrated. This will then also provide the basic knowledge required to protect limestone outcrop sites, e.g. from quarrying activities, which may destroy entire limestone hills. However, we believe that the major uncertainty about the size of the population of nesting F. p. ernesti in Malaysia arguably comes from the population segment of nesters on buildings, which is likely underestimated and hard to survey and even discover in the first place. Moreover, given the rate of increase of nesters on buildings in other parts of the world, it is likely that the proportion of pairs nesting on buildings will increase also in Malaysia. Hence, we believe that new pairs will be discovered in the future also where there were none in earlier years. [ABSTRACT FROM AUTHOR]

The present study presents the bin weather data for four cities in the tropical region and its significance in the building energy analysis. The bin weather data for four cities in Malaysia, which are Bayan Lepas, Kuala Terengganu, Senai and Kuching, were generated. The bin weather data are in the range from 18 to 38 °C with 2 °C intervals and tabulated based on six 4-h shifts. Since there is a lack of updated bin weather data in Malaysia, the present paper provides valuable data for engineers and designers to conduct an energy analysis using the bin method in this region. This data may also serve as an important reference for all tropical regions with similar weather characteristics. Energy analysis is an important tool for estimating the energy usage of a building in order to minimize energy wastage and maximize energy efficiency. The significance of applying bin weather data in energy analysis is also investigated using a case simulation. When the mean outdoor temperature of occupied period is used in simulation, the results deviate less than 1.6% from the results with the bin weather data, but the deviation rises up to 16.68% with the use of the annual mean outdoor dry bulb temperature. [ABSTRACT FROM AUTHOR]

The freshwater mussel fauna of Borneo is highly endemic, with at least 11 species being unique to that island. Most of these species have not been recorded for at least 50 years owing to a lack of sampling effort and large-scale habitat destruction and degradation. Surveys conducted in 2016 across much of Malaysian Borneo failed to locate four out of five native species historically recorded in the study area. The present study aimed to determine the diversity and distribution of freshwater mussels of Brunei and adjacent Limbang Division, Malaysia. In 2018, we conducted interviews with locals, recorded environmental data and surveyed mussels at 43 sites, and conducted interviews at a further 38 sites. Only one population of native mussels, i.e. Ctenodesma borneensis, was found in a small tributary of the Limbang River situated in a patch of intact rainforest, representing the first record of this Bornean endemic genus since 1962. In addition, Sinanodonta lauta was found in a pond in Lawas district, representing the first record of this species outside its native East Asian distribution. Our data suggest that C. borneensis can sustain populations in relatively undisturbed habitats and is likely to have suffered population losses across northern Borneo. The first molecular phylogenetic analysis (COI + 28S) including an endemic Bornean freshwater mussel genus revealed that Ctenodesma is phylogenetically divergent from all other previously sampled lineages, rendering it a particularly valuable conservation target. [ABSTRACT FROM AUTHOR]

This paper explores the interesting diversity within the group of "smooth chanterelles" and introduces several new taxa from the tropics: C. sublaevis Buyck & Eyssart. and C. cibarioides (Heinem.) Buyck comb. nov. from Africa, C. eccentricus Buyck & V. Hofstetter and C. neocaledonicus Buyck, V. Hofstetter, Eyssart. & Ducousso from New Caledonia and C. incrassatus Buyck & V. Hofstetter from Malaysia. [ABSTRACT FROM AUTHOR]

Abstract: Remote sensing for geology in tropical environments is very challenging, because of the dense vegetation cover and the problem of persistent cloud cover. In this research paper, we have investigated and demonstrated the detection of hydrothermal alteration zones and structural elements associated with intrusion-related gold mineralization using various types of remote sensing data in the Bau gold mining district in the State of Sarawak, East Malaysia, on the island of Borneo. The climate of Bau is tropical with persistent cloud cover and very dense vegetation ground. Geological analyses coupled with remote sensing data were used to detect hydrothermally altered rocks and structural elements associated with gold mineralization in the Bau area. Landsat Enhanced Thematic Mapper+ (ETM+), Hyperion and Phased Array type L-band Synthetic Aperture Radar (PALSAR) data were used to carry out lithological–structural mapping of the mineralized zones in the study area and surrounding terrain. Hydrothermal alteration zones were detected along the SSW to NNE structural trend of the Tai Parit fault that corresponds with the occurrence of other gold mineralization in the Bau Limestone. The results show that the known gold prospects and potential areas of mineralization are recognizable by the methods used, despite limited bedrock exposure. The approach used in this study is broadly applicable to the detection of gold mineralization using ETM+, Hyperion and PALSAR data in tropical/sub-tropical regions. [Copyright &y& Elsevier]

A field study was conducted to investigate the thermal environment and occupants’ comfort in the National Museum of Malaysia. The occupants’ thermal perceptions in the museum were measured and characterised. The response of the occupants has indicated that the thermal conditions inside the museum did not satisfactorily fulfil the ASHRAE Standard 55, because only 78% of the occupants were satisfied with their environment. Besides, actual mean vote (AMV) and predicted mean vote (PMV) were compared. The Fanger’s model gave a neutral operative temperature of 22.2°C from the PMV, whereas the questionnaire data used in the mean thermal sensation vote (MTSV) of the present study gave a higher value (22.5°C) for the neutral operative temperature. The preferred operative temperature was found to be 22.3°C. The minimum air temperature in three galleries was below the lower limit of the temperature range of 18–22°C as recommended by Museums Australia Victoria. The mean indoor humidity was too high compared to the optimal range of 55 ± 5% relative humidity (RH). The mean air velocity, ≤0.15 m·s−1, in each gallery was satisfactory. Findings of this study are very useful for designing heating, ventilating and air-conditioning (HVAC) systems with energy-saving methodology for museum buildings in tropical regions. [ABSTRACT FROM AUTHOR]

Abstract: Tidal variation in tropical coastal water plays an important role on physicochemical characteristics and nutrients concentration. Baseline measurements were made for nutrients concentration and physicochemical properties of coastal water, Port Dickson, Malaysia. pH, temperature, oxidation reduction potential, salinity and electrical conductivity have high values at high tides. Principal Components Analysis (PCA) was used to understand spatial variation of nutrients and physicochemical pattern of Port Dickson coastal water at high and low tide. Four principal components of PCA were extracted at low and high tides. Positively loaded nutrients with negative loadings of DO, pH and ORP in PCA outputs indicated nutrients contribution related with pollution sources. This study output will be a baseline frame for future studies in Port Dickson involving water and sediment samples. Water and sediment samples of future monitoring studies in Port Dickson coastal water will help in understanding of coastal water chemistry and pollution sources. [Copyright &y& Elsevier]

Abstract: Energy efficiency in office buildings for the tropical climate has been a subject of much discussion in the building industry. The Malaysia Energy Commission Sustainable Building, also known as the Diamond Building was built as the third Government Energy Efficient building after the Low Energy Office (LEO) and the Green Energy Office (GEO). It is located in Putrajaya, Malaysia which has a hot and humid tropical climate. The cutting-edge design has incorporated the most advanced features available in Malaysia for sustainability and energy efficiency. The aim of this paper is to investigate the design of active energy conserving features for a sustainable office building in the tropical climate and assess the effectiveness of these strategies. In carrying out this study, the methodologies used are non-participant observation conducted through visits to the building and interviews with the designers and users of the building. An analysis is then made on the effectiveness of the various energy conserving strategies implemented. It was found that the implementation of active energy-conserving design strategies are still under experimental investigations in Malaysia and that designers have yet to make compromises in deciding on the energy conserving strategies to be used. Finally, this paper provides a useful reference in the field of sustainable design in the humid tropical climate. [Copyright &y& Elsevier]

Oil palm plantations cover ≈14.6 million ha worldwide and the total area under cultivation is expected to increase during the 21st century . Indonesia and Malaysia together account for 87% of global palm oil production and the combined harvested area in these countries has expanded by 6.5 million ha since 1990. Despite this, soil C cycling in oil palm systems is not well quantified but such information is needed for C budget inventories. We quantified soil C storage (root biomass, soil organic matter ( SOM) and microbial biomass) and losses [potential soil respiration ( Rs) and soil surface CO2 flux ( Fs)] in mineral soils from an oil palm plantation chronosequence (11-34 years since planting) in Selangor, Malaysia. There were no significant effects of plantation age on SOM, microbial biomass, Rs or Fs, implying soil C was in dynamic equilibrium over the chronosequence. However, there was a significant increase in root biomass with plantation age, indicating a short-term C sink. Across the chronosequence, Rs was driven by soil moisture, soil particle size, root biomass and soil microbial biomass N but not microbial biomass C. This suggests that the nutrient status of the microbial community may be of equal or greater importance for soil CO2 losses than substrate availability and also raises particular concerns regarding the addition of nitrogenous fertilizer, i.e. increased yields will be associated with increased soil CO2 emissions. To fully assess the impact of oil palm plantations on soil C storage, initial soil C losses following land conversion (e.g. from native forest or other previous plantations) must be accounted for. If initial soil C losses are large, our data show that there is no accumulation of stable C in the soil as the plantation matures and hence the conversion to oil palm would probably represent a net loss of soil C. [ABSTRACT FROM AUTHOR]

The dominant factors controlling soil bacterial community variation within the tropics are poorly known. We sampled soils across a range of land use types-primary (unlogged) and logged forests and crop and pasture lands in Malaysia. PCR-amplified soil DNA for the bacterial 16S rRNA gene targeting the V1-V3 region was pyrosequenced using the 454 Roche machine. We found that land use in itself has a weak but significant effect on the bacterial community composition. However, bacterial community composition and diversity was strongly correlated with soil properties, especially soil pH, total carbon, and C/N ratio. Soil pH was the best predictor of bacterial community composition and diversity across the various land use types, with the highest diversity close to neutral pH values. In addition, variation in phylogenetic structure of dominant lineages ( Alphaproteobacteria, Beta/Gammaproteobacteria, Acidobacteria, and Actinobacteria) is also significantly correlated with soil pH. Together, these results confirm the importance of soil pH in structuring soil bacterial communities in Southeast Asia. Our results also suggest that unlike the general diversity pattern found for larger organisms, primary tropical forest is no richer in operational taxonomic units of soil bacteria than logged forest, and agricultural land (crop and pasture) is actually richer than primary forest, partly due to selection of more fertile soils that have higher pH for agriculture and the effects of soil liming raising pH. [ABSTRACT FROM AUTHOR]

ABSTRACT The elimination of the largest herbivores (elephants and rhinoceroses) from many forests in tropical East Asia may have severe consequences for plant species that depend on them for seed dispersal. We assessed the capacity of Malayan tapirs Tapirus indicus-the next largest nonruminant herbivore in the region-as a substitute for the lost megafauna in this role by studying their ability to disperse the seeds of nine fleshy-fruited plants with seeds 5-97 mm in length. We combined information from feeding trials, germination tests, and field telemetry to assess the effect of tapir consumption on seed viability and to estimate how far the seeds would be dispersed. The tapirs ( N=8) ingested few seeds. Seed survival through gut passage was moderately high for small-seeded plants ( e.g., 36.9% for Dillenia indica) but very low for medium- ( e.g., 7.6% for Tamarindus indica) and large-seeded ( e.g., 2.8% for Artocarpus integer) plants. Mean seed gut passage times were long (63-236 h) and only the smallest seeds germinated afterwards. Using movement data from four wild tapirs in Peninsular Malaysia we estimated mean dispersal distances of 917-1287 m (range=22-3289 m) for small-seeded plants. Malayan tapirs effectively dispersed small-seeded plants but acted as seed predators for the large-seeded plants included in our study, suggesting that they cannot replace larger herbivores in seed dispersal. With the absence of elephants and rhinos many megafaunal-syndrome plants in tropical East Asia are expected to face severe dispersal limitation problems. [ABSTRACT FROM AUTHOR]

Malaysia located in a tropical region which is interested with a heavy rainfall through the whole seasons of the year. Construction stages usually associated with soil disturbing due to land clearing and grading activities, this combined with the tropical climate in Malaysia, will generate an enormous amount of soil to be eroded and then deposited into the adjacent water bodies. There are many kinds of mitigation measures used so as to reduce the impact of erosion and sedimentation that are generated due to the stormwater in construction sites. This paper aims to develop and apply Multi Criteria Analysis (MCA) software called Multi Criteria Erosion and Sediment Control (MCESC) software in which it can be applied in selecting the best stormwater control measure by depending on specified criteria and criterion weight. Visual Basic 6 was adopted as a development tool. This software can help the engineers, contractors on site and decision makers to find the best stormwater control measure in any construction site in Malaysia. Users of the MCESC software are given the opportunity to select the best stormwater control measure via expert's judgments that are built in the system or via their own expertise. MCESC software has many benefits since the experts are not always available and the consultancy is a costly issue which add further financial allocations to the project [ABSTRACT FROM AUTHOR]

Abstract: This paper presents the studies conducted on the effect of climate change on the air conditioner in terms of performance and reliability in the tropics. Basically, three aspects of impact were focused, which were cooling and heating load, electricity consumption and outdoor design conditions for the air conditioning system. The related papers were categorized into three groups and analysis of theoretical and experimental studies was made. A lot of researches had been carried out on the climate change impacts towards the air conditioner in the tropics since last few decades, but most of the researches were focused on existing cooling or heating demands, region overall electricity consumption and existing outdoor design conditions for the air conditioning system instead of the possible impacts on the heating, ventilation and air conditioning system in the future. Based on literature review, further substantial researches are needed in order to have a clearer picture on the climate variation effect towards the air conditioning system so that a complete guideline can be prepared for the future air conditioning system design in the tropics by taking consideration of possible climate change. [Copyright &y& Elsevier]

The enclosed lift lobby distinguishes itself as a unique form of region categorised under building transitional spaces. This paper reports on an evaluation of thermal comfort conditions in a prominent transitional space in buildings which is the enclosed lift lobby of an educational institution in Malaysia, using field survey which included objective measurement and subjective assessment. The temperature set-point of air conditioner was increased and maintained at 26°C to investigate the human thermal perceptions in the enclosed region. Comparison was made on the percentage of thermal sensation, preference, acceptability and general comfort votes obtained from field survey. The outcomes clearly indicated that the human thermal perception in the enclosed lift lobby would be directly proportional to the level of human occupancy, and any sudden temperature change could lead to thermal discomfort of occupants. The respondents generally preferred to have cooler environment, rather than warmer one. Also, comfortable temperature can be obtained even with higher air conditioner thermostat settings. These findings may serve as a guide for building operators in the tropics to control the energy consumption of cooling equipment attached to the enclosed transitional spaces. [ABSTRACT FROM PUBLISHER]

The article discusses a study that assessed the tree planting program of Kuala Lumpur, Malaysia along the major roads of the city. Systematic survey on tree structure, species composition, species diversity and tree defects and disorders were collected from 2,191 street trees. Results of the survey suggest that the trees are moderately hazardous and that City Hall should increase the species diversity to maintain the level of stability of street tree population.

The extent to which environmental heterogeneity can account for tree species coexistence in diverse ecosystems, such as tropical rainforests, is hotly debated, although the importance of spatial variability in contributing to species co-existence is well recognized. Termites contribute to the micro-topographical and nutrient spatial heterogeneity of tropical forests. We therefore investigated whether epigeal termite mounds could contribute to the coexistence of plant species within a 50 ha plot at Pasoh Forest Reserve, Malaysia. Overall, stem density was significantly higher on mounds than in their immediate surroundings, but tree species diversity was significantly lower. Canonical correspondence analysis showed that location on or off mounds significantly influenced species distribution when stems were characterized by basal area. Like studies of termite mounds in other ecosystems, our results suggest that epigeal termite mounds provide a specific microhabitat for the enhanced growth and survival of certain species in these species-rich tropical forests. However, the extent to which epigeal termite mounds facilitate species coexistence warrants further investigation. [ABSTRACT FROM AUTHOR]

In this study we assessed the species density and relative abundance of termites in peat land in Sarawak, Malaysia. Termites were sampled in near-natural peat swamp forest, logged-over peat swamp forest, young oil palm plantation and a cleared and burned site. Species density and relative abundance were calculated for each site. Both species density and relative abundance differed significantly between sites. Near-natural peat swamp forest had the highest termite density, followed by logged-over peat swamp forest, young oil palm plantation and the cleared site. In contrast, the relative abundance of termites was highest in the young oil palm plantation due to the omnipresent genus Schedorhinotermes. Most of the species found in the cleared site and young oil palm plantation did not occur at the other sites. We conclude that ongoing forest degradation and conversion in tropical peat land result in shifting termite assemblages and declining species density. Species that originally occur at low densities in peat swamp forests are typically lost as a result of peat swamp forest conversion. [ABSTRACT FROM AUTHOR]

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Abstract: We studied the effects of forest composition and structure, and related biotic and abiotic factors on soil respiration rates in a tropical logged forest in Malaysian Borneo. Forest stands were classified into gap, pioneer, non-pioneer and mixed (pioneer, non-pioneer and unclassified trees) based on the species composition of trees >10cm diameter breast height. Soil respiration rates did not differ significantly between non-gap sites (1290±210mgCO2 m−2 h−1) but were double those in gap sites (640±130mgCO2 m−2 h−1). Post hoc analyses found that an increase in soil temperature and a decrease in litterfall and fine root biomass explained 72% of the difference between gap and non-gap sites. The significant decrease of soil respiration rates in gaps, irrespective of day or night time, suggests that autotrophic respiration may be an important contributor to total soil respiration in logged forests. We conclude that biosphere-atmosphere carbon exchange models in tropical systems should incorporate gap frequency and that future research in tropical forest should emphasize the contribution of autotrophic respiration to total soil respiration. [Copyright &y& Elsevier]

Abstract: This study investigates the effectiveness of night ventilation technique for residential buildings in hot-humid climate of Malaysia. This paper firstly presents the results of a survey on usage patterns of windows and air-conditioners in typical Malaysian residential areas. Secondly, the effects of different natural ventilation strategies on indoor thermal environment for Malaysian terraced houses are evaluated based on the results of a full-scale field experiment. The results show that the majority of occupants tend to apply not night ventilation but daytime ventilation in Malaysian residential areas. It can be seen from the field experiment that night ventilation would provide better thermal comfort for occupants in Malaysian terraced houses compared with the other ventilation strategies in terms of operative temperature. However, when the evaporative heat loss of occupants is taken into account by using SET*, the night ventilation would not be the superior technique to the others in providing daytime thermal comfort mainly due to the high humidity conditions. Therefore, the indoor humidity control during the daytime such as by dehumidification would be needed when the night ventilation technique is applied to Malaysian terraced houses. Otherwise, full-day ventilation would be a better option compared with night ventilation. [Copyright &y& Elsevier]

Abstract  Natives of the tropics are able to tolerate high ambient temperatures. This results from their long-term residence in hot and often humid tropical climates. This study was designed to compare the peripheral mechanisms of thermal sweating in tropical natives with that of their temperate counterparts. Fifty-five healthy male subjects including 20 native Koreans who live in the temperate Korean climate (Temperate-N) and 35 native tropical Malaysian men that have lived all of their lives in Malaysia (Tropical-N) were enrolled in this study after providing written informed consent to participate. Quantitative sudomotor axon reflex testing after iontophoresis (2 mA for 5 min) with 10% acetylcholine (ACh) was used to determine directly activated (DIR) and axon reflex-mediated (AXR) sweating during ACh iontophoresis. The sweat rate, activated sweat gland density, sweat gland output per single gland activated, and oral and skin temperature changes were measured. The sweat onset time of AXR (nicotinic-receptor-mediated) was 56 s shorter in the Temperate-N than in the Tropical-N subjects (P P P P  [ABSTRACT FROM AUTHOR]

There is good potential for the application of ectomycorrhizas in improving dipterocarp seedling establishment, survival and growth through enhanced mineral nutrition and improved drought tolerance. However, these mycorrhizas must be easily propagated and applied as well as competitive with the native mycoflora, and indigenous ectomycorrhizal fungi are preferred. In this paper we report on the ability of a fungus isolated locally from ectomycorrhizas of Shorea parvifolia (Dipterocarpaceae) to form characteristic ectomycorrhizas with two different dipterocarp hosts, namely, Hopea odorata and Shorea leprosula. The fungus, designated FP160, has been provisionally identified as a member of the Thelephoraceae and efforts are on-going to identify it using molecular methods. FP160-inoculated H. odorata cuttings showed a positive growth response in the nursery but this effect was not significant when such cuttings were outplanted to a sandy tin tailing site. The smaller inoculated cuttings of S. leprosula, however, showed a significant growth response for up to three months in the field after outplanting but this effect disappeared thereafter. The synthesized FP160 ectomycorhizas on the dipterocarps were able to persist and remain dominant on inoculated plants for up to 23 months after outplanting in the sandy tin tailing site. FP160 appears to be a good candidate for enhancing the growth and development of plants in the nursery and in assisting the establishment of more fragile dipterocarps in the field. [ABSTRACT FROM AUTHOR]

Understanding the intensity and duration of tropical rain events is critical to modelling the rate and timing of wet- canopy evaporation, the suppression of transpiration, the generation of infiltration-excess overland flow and hence to erosion, and to river responsiveness. Despite this central role, few studies have addressed the characteristics of equatorial rainstorms. This study analyses rainfall data for a 5 km2 region largely comprising of the 4 km2 Sapat Kalisun Experimental Catchment in the interior of northeastern Borneo at sampling frequencies from 1 min-1 to 1 day-1. The work clearly shows that most rainfall within this inland, forested area is received during regular short-duration events (<15 mm) that have a relatively low intensity (i.e. less than two 0.2 mm rain-gauge tips in almost all 5 mm periods). The rainfall appears localized, with significant losses in intergauge correlations being observable in minutes in the case of the typical mid-afternoon, convective events. This suggests that a dense rain-gauge network, sampled at a high temporal frequency, is required for accurate distributed rainfall-runoff modelling of such small catchments. Observed rain-event intensity is much less than the measured infiltration capacities, and thus supports the tenet of the dominance of quick subsurface responses in controlling river behaviour in this small equatorial catchment. [ABSTRACT FROM AUTHOR]

Quantifying patterns of fine root dynamics is crucial to the understanding of ecosystem structure and function, and in predicting how ecosystems respond to disturbance. Part of this understanding involves consideration of the carbon lost through root turnover. In the context of the rainfall pattern in the tropics, it was hypothesised that rainfall would strongly influence fine root biomass and longevity. A field study was conducted to determine root biomass, elemental composition and the influence of rainfall on longevity of fine roots in a tropical lowland evergreen rainforest at Danum Valley, Sabah, Malaysia. A combination of root coring, elemental analysis and rhizotron observation methods were used. Fine (less than 2 mm diameter) root biomass was relatively low (1700 kg ha −1) compared with previously described rainforest data. Standing root biomass was positively correlated with preceding rainfall, and the low fine root biomass in the dry season contained higher concentrations of N and lower concentrations of P and K than at other times. Observations on rhizotrons demonstrated that the decrease in fine root biomass in the dry season was a product of both a decrease in fine root length appearance and an increase in fine root length disappearance. Fitting an overall model to root survival time showed significant effects of rainfall preceding root disappearance, with the hazard of root disappearance decreasing by 8 for each 1 mm increase in the average daily (30 day) rainfall preceding root disappearance. While it is acknowledged that other factors have a part to play, this work demonstrates the importance of rainfall and soil moisture in influencing root biomass and root disappearance in this tropical rainforest. [ABSTRACT FROM AUTHOR]

Antioxidants play an important role in inhibiting and scavenging radicals, thus providing protection to humans against infections and degenerative diseases. Literature shows that the antioxidant activity is high on herbal and vegetable plants. Realizing the fact, this research was carried out to determine total antioxidant activity and the potential anticancer properties in three types of selected local vegetable shoots such as Diplazium esculentum (paku shoot), Manihot utillissima (tapioca shoot) and Sauropous androgynus (cekur manis). The research was also done to determine the effect of boiling, on total antioxidant activity whereby samples of fresh shoots are compared with samples of boiled shoots. In every case, antioxidant activity is compared to alpha-tocopherol and two methods of extraction used are the organic and the aqueous methods. Besides that, two research methods used were the ferric thiocyanate (FTC) and thiobarbituric acid (TBA) with absorbance of 500nm and 532nm respectively. Oneway ANOVA test at P < 0.05 determines significant differences between various samples. In the cytotoxic study, the ethanolic extract and several cell lines i.e. breast cancer (MDA-MB-231 and MCF-7), colon cancer (Caco-2), liver cancer (HepG2) and normal liver (Chang liver) were used. The IC50-value was determined by using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. The antioxidant study found that all the samples in both aqueous and organic extraction were significantly different. The total antioxidant activity values of aqueous extract in descending order are as follows M. utilissima (fresh) > D. esculentum (fresh) > S.androgynus (fresh) > M.utilissima (boiled) > D. esculentum (boiled) > S.androgynus (boiled). It also was found that S.androgynus shoots ethanolic extract was able to inhibit the viability of the breast cancer cell lines, MDA-MB-231 with the IC50 value of 53.33 μg/ml. [ABSTRACT FROM AUTHOR]

• First microbiome asthma association analysis in tropics. • First microbiome asthma association analysis in school environment. • Five bacterial and two fungal genera were protective for asthma severity. • Visible dampness/mold was negatively associated with protective bacteria of asthma. • Complex interactions between microbes, environmental characteristics and asthma. Indoor microbial diversity and composition are suggested to affect the prevalence and severity of asthma by previous home microbiome studies, but no microbiome-health association study has been conducted in a school environment, especially in tropical countries. In this study, we collected floor dust and environmental characteristics from 21 classrooms, and health data related to asthma symptoms from 309 students, in junior high schools in Johor Bahru, Malaysia. The bacterial and fungal composition was characterized by sequencing 16s rRNA gene and internal transcribed spacer (ITS) region, and the absolute microbial concentration was quantified by qPCR. In total, 326 bacterial and 255 fungal genera were characterized. Five bacterial (Sphingobium , Rhodomicrobium , Shimwellia , Solirubrobacter , Pleurocapsa) and two fungal (Torulaspora and Leptosphaeriaceae) taxa were protective for asthma severity. Two bacterial taxa, Izhakiella and Robinsoniella , were positively associated with asthma severity. Several protective bacterial taxa including Rhodomicrobium , Shimwellia and Sphingobium have been reported as protective microbes in previous studies, whereas other taxa were first time reported. Environmental characteristics, such as age of building, size of textile curtain per room volume, occurrence of cockroaches, concentration of house dust mite allergens transferred from homes by the occupants, were involved in shaping the overall microbial community but not asthma-associated taxa; whereas visible dampness and mold, which did not change the overall microbial community for floor dust, was negatively associated with the concentration of protective bacteria Rhodomicrobium (β = −2.86, p = 0.021) of asthma. The result indicates complex interactions between microbes, environmental characteristics and asthma symptoms. Overall, this is the first indoor microbiome study to characterize the asthma-associated microbes and their environmental determinant in the tropical area, promoting the understanding of microbial exposure and respiratory health in this region. [ABSTRACT FROM AUTHOR]

Tropical ectotherms are generally believed to be more vulnerable to global heating than temperate species. Currently, however, we have insufficient knowledge of the thermoregulatory physiology of equatorial tropical mammals, particularly of small diurnal mammals, to enable similar predictions. In this study, we measured the resting metabolic rates (via oxygen consumption) of wild-caught lesser treeshrews ( Tupaia minor , order Scandentia) over a range of ambient temperatures. We predicted that, similar to other treeshrews, T. minor would exhibit more flexibility in body temperature regulation and a wider thermoneutral zone compared with other small mammals because these thermoregulatory traits provide both energy and water savings at high ambient temperatures. Basal metabolic rate was on average 1.03 ± 0.10 mL O 2 h -1 g -1 , which is within the range predicted for a 65-g mammal. We calculated the lower critical temperature of the thermoneutral zone at 31.0°C (95% confidence interval: 29.3°-32.7°C), but using metabolic rates alone, we could not determine the upper critical temperature at ambient temperatures as high as 36°C. The thermoregulatory characteristics of lesser treeshrews provide a means of saving energy and water at temperatures well in excess of their current environmental temperatures. Our research highlights the knowledge gaps in our understanding of the energetics of mammals living in high-temperature environments, specifically in the equatorial tropics, and questions the purported lack of variance in the upper critical temperatures of the thermoneutral zone in mammals, emphasizing the importance of further research in the tropics.

Introduction. Co-infection of leptospirosis-malaria is not uncommon due to their overlapping geographical distribution in the tropics. Aim. This study aimed to describe and compare the demographic, clinical and laboratory features of leptospirosis-malaria co-infection (LMCI) against leptospirosis mono-infection (LMI) in Peninsular Malaysia. Methodology. Data of patients admitted to various hospitals in Peninsular Malaysia from 2011 to 2014 diagnosed with leptospirosis in our laboratory were obtained from their admission records. Co-infections with malaria were identified via blood film for malaria parasites (BFMP). Description with inferential statistics analysis and multiple logistic regressions were used to distinguish features between dual and mono-infections. Results. Of 111 leptospirosis-positive patients, 26 (23.4 %) tested positive for malaria. Co-infections were predominant among male patients with a mean age of 33 years and were prevalent among immigrant populations who had settled in high-density suburban areas. Chills and rigor with splenomegaly were the only significant distinguishing clinical features of LMCI while leukocytosis and raised transaminases were significant laboratory parameters. Only chills and rigor demonstrated a predictive value for LMCI from analysis of multiple logistic regressions. No death was attributed to co-infection in this study, in contrast to LMI (11.8 %, n =10). Conclusion. The significant prevalence of LMCI found in this study with overlapping demographic, clinical and laboratory parameters makes diagnosis of co-infection challenging. It is essential to evaluate co-infection in endemic areas. Strengthened awareness of LMCI, comprehensive diagnostic services and further prospective studies are warranted.

The rapid urban expansion in East-Asian cities has increased the need for comfortable public spaces. This study presents field measurements and parametric simulations to evaluate the microclimatic characteristics in a university campus in the tropical climate of Kuala Lumpur, Malaysia. The study attempts to identify the thermally uncomfortable areas and their physical and design characteristics while debating on the circumstances of enhancing the outdoor comfort conditions for the campus users. Simulations in Envi-met and IES-VE are used to investigate the current outdoor thermal conditions, using classic thermal metric indices. Findings show high levels of thermal discomfort in most of the studied spaces. As a result, suggestions to improve the design quality of outdoor areas optimizing their thermal comfort conditions are proposed. The study concludes that effective re-design of outdoor spaces in the tropics, through adequate attention to the significant impacts of shading and vegetation, can result in achieving outdoor spaces with high frequency of use and improved comfort level., (Copyright © 2019. Published by Elsevier B.V.)

Comparing the functional gene composition of soils at opposite extremes of environmental gradients may allow testing of hypotheses about community and ecosystem function. Here, we were interested in comparing how tropical microbial ecosystems differ from those of polar climates. We sampled several sites in the equatorial rainforest of Malaysia and Brunei, and the high Arctic of Svalbard, Canada, and Greenland, comparing the composition and the functional attributes of soil biota between the two extremes of latitude, using shotgun metagenomic Illumina HiSeq2000 sequencing. Based upon "classical" views of how tropical and higher latitude ecosystems differ, we made a series of predictions as to how various gene function categories would differ in relative abundance between tropical and polar environments. Results showed that in some respects our predictions were correct: the polar samples had higher relative abundance of dormancy related genes, and lower relative abundance of genes associated with respiration, and with metabolism of aromatic compounds. The network complexity of the Arctic was also lower than the tropics. However, in various other respects, the pattern was not as predicted; there were no differences in relative abundance of stress response genes or in genes associated with secondary metabolism. Conversely, CRISPR genes, phage-related genes, and virulence disease and defense genes, were unexpectedly more abundant in the Arctic, suggesting more intense biotic interaction. Also, eukaryote diversity and bacterial diversity were higher in the Arctic of Svalbard compared to tropical Brunei, which is consistent with what may expected from amplicon studies in terms of the higher pH of the Svalbard soil. Our results in some respects confirm expectations of how tropical versus polar nature may differ, and in other respects challenge them.

Much of our knowledge of the thermoregulation of endotherms has been obtained from species inhabiting cold and temperate climates, our knowledge of the thermoregulatory physiology of tropical endotherms is scarce. We studied the thermoregulatory physiology of a small, tropical mammal, the large treeshrew (Tupaia tana, Order Scandentia) by recording the body temperatures of free-ranging individuals, and by measuring the resting metabolic rates of wild individuals held temporarily in captivity. The amplitude of daily body temperature (~ 4 °C) was higher in treeshrews than in many homeothermic eutherian mammals; a consequence of high active-phase body temperatures (~ 40 °C), and relatively low rest-phase body temperatures (~ 36 °C). We hypothesized that high body temperatures enable T. tana to maintain a suitable gradient between ambient and body temperature to allow for passive heat dissipation, important in high-humidity environments where opportunities for evaporative cooling are rare. Whether this thermoregulatory phenotype is unique to Scandentians, or whether other warm-climate diurnal small mammals share similar thermoregulatory characteristics, is currently unknown.

Premise of the Study: Underutilized crops and their wild relatives are important resources for crop improvement and food security. Cempedak [Artocarpus integer (Thunb). Merr.] is a significant crop in Malaysia but underutilized elsewhere. Here we performed molecular characterization of cempedak and its putative wild relative bangkong (Artocarpus integer (Thunb). Merr. var. silvestris Corner) to address questions regarding the origin and diversity of cempedak., Methods: Using data from 12 microsatellite loci, we assessed the genetic diversity and genetic/geographic structure for 353 cempedak and 175 bangkong accessions from Malaysia and neighboring countries and employed clonal analysis to characterize cempedak cultivars. We conducted haplotype network analyses on the trnH-psbA region in a subset of these samples. We also analyzed key vegetative characters that reportedly differentiate cempedak and bangkong., Key Results: We show that cempedak and bangkong are sister taxa and distinct genetically and morphologically, but the directionality of domestication origin is unclear. Genetic diversity was generally higher in bangkong than in cempedak. We found a distinct genetic cluster for cempedak from Borneo as compared to cempedak from Peninsular Malaysia. Finally, cempedak cultivars with the same names did not always share the same genetic fingerprint., Conclusions: Cempedak origins are complex, with likely admixture and hybridization with bangkong, warranting further investigation. We provide a baseline of genetic diversity of cempedak and bangkong in Malaysia and found that germplasm collections in Malaysia represent diverse coverage of the four cempedak genetic clusters detected., (© 2018 Botanical Society of America.)

Reports on the bioprospecting meeting scheduled in February 2004 in Kuala Lumpur, Malaysia. Plans to update the Convention on Biological Diversity; Issues on bioprospecting; Potential of bioprospecting in tropical regions.