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The comparison of basal physiological values in racial groups. Part 1. Metabolism, pulse rate and blood pressure

Macgregor RGS, Loh GL

Journal of the Malaya Branch of the British Medical Association, 1940;4:217-60.

Matched MeSH terms: Tropical Climate
Genotypic character relationship and phenotypic path coefficient analysis in chili pepper genotypes grown under tropical condition

Usman MG, Rafii MY, Martini MY, Oladosu Y, Kashiani P

J Sci Food Agric, 2017 Mar;97(4):1164-1171.
PMID: 27290898 DOI: 10.1002/jsfa.7843

BACKGROUND: Studies on genotypic and phenotypic correlations among characters of crop plants are useful in planning, evaluating and setting selection criteria for the desired characters in a breeding program. The present study aimed to estimate the phenotypic correlation coefficients among yield and yield attributed characters and to work out the direct and indirect effects of yield-related characters on yield per plant using path coefficient analysis. Twenty-six genotypes of chili pepper were laid out in a randomized complete block design with three replications.
RESULTS: Yield per plant showed positive and highly significant (P ≤ 0.01) correlations with most of the characters studied at both the phenotypic and genotypic levels. By contrast, disease incidence and days to flowering showed a significant negative association with yield. Fruit weight and number of fruits exerted positive direct effect on yield and also had a positive and significant (P ≤ 0.01) correlation with yield per plant. However, fruit length showed a low negative direct effect with a strong and positive indirect effect through fruit weight on yield and had a positive and significant association with yield.
CONCLUSION: Longer fruits, heavy fruits and a high number of fruits are variables that are related to higher yields of chili pepper under tropical conditions and hence could be used as a reliable indicator in indirect selection for yield. © 2016 Society of Chemical Industry.

Matched MeSH terms: Tropical Climate*
Gross mismatch between thermal tolerances and environmental temperatures in a tropical freshwater snail: climate warming and evolutionary implications

Polgar G, Khang TF, Chua T, Marshall DJ

J Therm Biol, 2015 Jan;47:99-108.
PMID: 25526660 DOI: 10.1016/j.jtherbio.2014.11.009

The relationship between acute thermal tolerance and habitat temperature in ectotherm animals informs about their thermal adaptation and is used to assess thermal safety margins and sensitivity to climate warming. We studied this relationship in an equatorial freshwater snail (Clea nigricans), belonging to a predominantly marine gastropod lineage (Neogastropoda, Buccinidae). We found that tolerance of heating and cooling exceeded average daily maximum and minimum temperatures, by roughly 20°C in each case. Because habitat temperature is generally assumed to be the main selective factor acting on the fundamental thermal niche, the discordance between thermal tolerance and environmental temperature implies trait conservation following 'in situ' environmental change, or following novel colonisation of a thermally less-variable habitat. Whereas heat tolerance could relate to an historical association with the thermally variable and extreme marine intertidal fringe zone, cold tolerance could associate with either an ancestral life at higher latitudes, or represent adaptation to cooler, higher-altitudinal, tropical lotic systems. The broad upper thermal safety margin (difference between heat tolerance and maximum environmental temperature) observed in this snail is grossly incompatible with the very narrow safety margins typically found in most terrestrial tropical ectotherms (insects and lizards), and hence with the emerging prediction that tropical ectotherms, are especially vulnerable to environmental warming. A more comprehensive understanding of climatic vulnerability of animal ectotherms thus requires greater consideration of taxonomic diversity, ecological transition and evolutionary history.

Matched MeSH terms: Tropical Climate
Thermal comfort of various building layouts with a proposed discomfort index range for tropical climate

Md Din MF, Lee YY, Ponraj M, Ossen DR, Iwao K, Chelliapan S

J Therm Biol, 2014 Apr;41:6-15.
PMID: 24679966 DOI: 10.1016/j.jtherbio.2014.01.004

Recent years have seen issues related to thermal comfort gaining more momentum in tropical countries. The thermal adaptation and thermal comfort index play a significant role in evaluating the outdoor thermal comfort. In this study, the aim is to capture the thermal sensation of respondents at outdoor environment through questionnaire survey and to determine the discomfort index (DI) to measure the thermal discomfort level. The results indicated that most respondents had thermally accepted the existing environment conditions although they felt slightly warm and hot. A strong correlation between thermal sensation and measured DI was also identified. As a result, a new discomfort index range had been proposed in association with local climate and thermal sensation of occupants to evaluate thermal comfort. The results had proved that the respondents can adapt to a wider range of thermal conditions.Validation of the questionnaire data at Putrajaya was done to prove that the thermal sensation in both Putrajaya and UTM was almost similar since they are located in the same tropical climate region. Hence, a quantitative field study on building layouts was done to facilitate the outdoor human discomfort level based on newly proposed discomfort index range. The results showed that slightly shaded building layouts of type- A and B exhibited higher temperature and discomfort index. The resultant adaptive thermal comfort theory was incorporated into the field studies as well. Finally, the study also showed that the DI values were highly dependent on ambient temperature and relative humidity but had fewer effects for solar radiation intensity.

Matched MeSH terms: Tropical Climate*
Thermal tolerance and preference of exploited turbinid snails near their range limit in a global warming hotspot

Lah RA, Benkendorff K, Bucher D

J Therm Biol, 2017 Feb;64:100-108.
PMID: 28166939 DOI: 10.1016/j.jtherbio.2017.01.008

Predicted global climate change has prompted numerous studies of thermal tolerances of marine species. The upper thermal tolerance is unknown for most marine species, but will determine their vulnerability to ocean warming. Gastropods in the family Turbinidae are widely harvested for human consumption. To investigate the responses of turbinid snails to future conditions we determined critical thermal maxima (CTMax) and preferred temperatures of Turbo militaris and Lunella undulata from the tropical-temperate overlap region of northern New South Wales, on the Australian east coast. CTMax were determined at two warming rates: 1°C/30min and 1°C/12h. The number of snails that lost attachment to the tank wall was recorded at each temperature increment. At the faster rate, T. militaris had a significantly higher CTMax (34.0°C) than L. undulata (32.2°C). At the slower rate the mean of both species was lower and there was no significant difference between them (29.4°C for T. militaris and 29.6°C for L. undulata). This is consistent with differences in thermal inertia possibly allowing animals to tolerate short periods at higher temperatures than is possible during longer exposure times, but other mechanisms are not discounted. The thermoregulatory behaviour of the turban snails was determined in a horizontal thermal gradient. Both species actively sought out particular temperatures along the gradient, suggesting that behavioural responses may be important in ameliorating short-term temperature changes. The preferred temperatures of both species were higher at night (24.0°C and 26.0°C) than during the day (22.0°C and 23.9°C). As the snails approached their preferred temperature, net hourly displacement decreased. Preferred temperatures were within the average seasonal seawater temperature range in this region. However, with future predicted water temperature trends, the species could experience increased periods of thermal stress, possibly exceeding CTMax and potentially leading to range contractions.

Matched MeSH terms: Tropical Climate
Heat shock response and metabolic stress in the tropical estuarine copepod Pseudodiaptomus annandalei converge at its upper thermal optimum

Low JSY, Chew LL, Ng CC, Goh HC, Lehette P, Chong VC

J Therm Biol, 2018 May;74:14-22.
PMID: 29801619 DOI: 10.1016/j.jtherbio.2018.02.012

Heat shock response (HSR), in terms of transcription regulation of two heat shock proteins genes hsp70 and hsp90), was analysed in a widespread tropical copepod Pseudodiaptomus annandalei. The mRNA transcripts of both genes were quantified after copepods at a salinity of 20 underwent an acclimation process involving an initial acclimation temperature of 29 °C, followed by gradual thermal ramping to the target exposure temperature range of 24-36 °C. The respective cellular HSR and organismal metabolism, measured by respiratory activity at exposure temperatures, were compared. The fold change in mRNA expression for both hsp70 and hsp90 (8-9 fold) peaks at 32 °C, which is very close to 32.4 °C, the upper thermal optimum for respiration in the species. Unexpectedly, the modelled HSR curves peak at only 3 °C (hsp90) and 3.5 °C (hsp70) above the mean water temperature (29.32 °C) of the copepod in the field. We propose that copepods in tropical waters adopt a preparative HSR strategy, early at the upper limit of its thermal optimum, due to the narrow thermal range of its habitat thus precluding substantial energy demand at higher temperatures. However, the model suggests that the species could survive to at least 36 °C with short acclimation time. Nevertheless, the significant overlap between its thermal range of hsp synthesis and the narrow temperature range of its habitat also suggests that any unprecedented rise in sea temperature would have a detrimental effect on the species.

Matched MeSH terms: Tropical Climate
Fulltext Wolbachia endosymbionts, Rickettsia felis and Bartonella species, in Ctenocephalides felis fleas in a tropical region

Tay ST

J Vector Ecol, 2013 Jun;38(1):200-2.
PMID: 23701629 DOI: 10.1111/j.1948-7134.2013.12030.x
Matched MeSH terms: Tropical Climate
Fulltext Occurrence of oriental flies associated with indoor and outdoor human remains in the tropical climate of north Malaysia

Kumara TK, Disney RH, Abu Hassan A, Flores M, Hwa TS, Mohamed Z, et al.

J Vector Ecol, 2012 Jun;37(1):62-8.
PMID: 22548537 DOI: 10.1111/j.1948-7134.2012.00200.x

Flies attracted to human remains during death investigations were surveyed in north Peninsular Malaysia. Six families, eight genera, and 16 species were identified from human remains, with the greatest fly diversity occurring on remains recovered indoors. The total relative frequency of species was led by Chrysomya megacephala (Fabricius, 1794) (46%), followed by Chrysomya rufifacies (Macquart, 1842) (22%), Sarcophaga (Liopygia) ruficornis (Fabricius, 1974) (5%), Sarcophaga spp. (4%), Synthesiomyia nudiseta Wulp, 1883 (6%), Megaselia spp. (3%), Megaselia scalaris (Loew, 1866), (2%), Megaselia spiracularis Schmitz, 1938 (2%), and Chrysomya villeneuvi Patton, 1922 (2%). Hemipyrellia tagaliana (Bigot, 1877), Desmometopa sp., Megaselia curtineura (Brues, 1909), Hemipyrellia ligurriens Wiedemann 1830, Ophyra sp., Sarcophaga princeps Wiedemann 1830, Piophila casei (Linnaeus, 1758), and unidentified pupae each represented 1%, respectively.

Matched MeSH terms: Tropical Climate*
Childhood pneumonia: a neglected, climate-sensitive disease?

Paynter S, Ware RS, Weinstein P, Williams G, Sly PD

Lancet, 2010 Nov 27;376(9755):1804-5.
PMID: 21111894 DOI: 10.1016/S0140-6736(10)62141-1
Matched MeSH terms: Tropical Climate*
On mental hygiene in the tropics

Scott GW

Malayan Medical Journal, 1931;6:88-92.

Matched MeSH terms: Tropical Climate
Health in the tropics

Malayan Medical Journal, 1932;7:132.

Matched MeSH terms: Tropical Climate
Fulltext Dampness and mold exposure in buildings as a risk factor for health effects

Pei Zam H, Emilia Z, Karmegam K, Mohd Sapuan S

Malaysian Journal of Public Health Medicine, 2017;17 Special(1):28-40.

This study aims to review existing studies on the relations between indoor dampness and mould in different public occupied buildings with the risk of adverse health effects among both children and adults. This study specifically focused on the dampness-related problems from countries with tropical climate. A systematic literature search of ScienceDirect, PubMed, Google Scholar and Wiley Online Library from 2000 through December 2015 was conducted. Furthermore, the reference lists of recent reviews and of relevant articles were identified in our search. Crosssectional, case-control, and cohort studies in children or adults were selected according to a priori criteria. The search yielded a total of 18 studies on damp buildings, dampness and mould in buildings and indoor mould. Dampness and mould exposure in buildings is a risk factors for respiratory symptoms, wheeze, cough, bronchitis, rhinitis, eczema and upper respiratory tract infection as well as general symptoms such as headache and tiredness. Evident strongly suggested increased asthma development and exacerbation of current or ever diagnosis of asthma in children. Based on the results of the review, indoor dampness and mould problems in buildings are associated with substantial and increases in prevalence of a variety of respiratory and asthma-related health outcomes.

Matched MeSH terms: Tropical Climate
Polyethylene degradation and heavy metals leaching under realistic tropical marine climate

Tan E, Ong MC, Mohd Zanuri NB

Mar Environ Res, 2023 Oct;191:106113.
PMID: 37619477 DOI: 10.1016/j.marenvres.2023.106113

The study examines the influence of temperature and pH on the leaching of six heavy metals (HMs) species: aluminum (Al), zinc (Zn), chromium (Cr), copper (Cu), lead (Pb) and arsenic (As) from transparent polyethylene pellets into seawater. The idea is to understand the potential influence of intensifying global warming and ocean acidification towards microplastic toxicity in the ocean. HMs leaching was obvious by 24th hours, with most HMs concentration decreased in water by 120th and 240th hours except Al. Nevertheless, we report that temperature and pH do not influence the overall HMs leaching from PE pellets with statistical analysis showing no significance (p

Matched MeSH terms: Tropical Climate
Occurrence of Enterococcus species with virulence markers in an urban flow-influenced tropical recreational beach

Ahmad A, Dada AC, Usup G, Heng LY

Mar Pollut Bull, 2014 May 15;82(1-2):26-38.
PMID: 24725825 DOI: 10.1016/j.marpolbul.2014.03.028

Median enterococci counts of beach water samples gradually increased at statistically significant levels (χ2: 26.53, df: 4; p<0.0001) with increasing proximity to river influx. The difference in proportion of antibiotic resistant enterococci in beach water and river water samples was statistically significant (p<0.05) for the tested antibiotics with river isolates generally presenting higher resistance frequencies. Virulence genes cyl, esp, gelE and asa were detected at varying frequencies (7.32%, 21.95%, 100% and 63.41% respectively) among river isolates. On the other hand, the prevalence of these genes was lower (0%, 20%, 67.27% and 41.82% respectively) among beach water isolates. Multi-Locus-Sequence-Typing analysis of Enterococcus faecalis presented four sequence types (ST) one of which shared six out of seven tested loci with ST6, a member of the clonal complex of multi-drug resistant strains associated with hospital outbreaks.

Matched MeSH terms: Tropical Climate
Effect of mercury and cadmium on early life stages of Java medaka (Oryzias javanicus): a potential tropical test fish

Ismail A, Yusof S

Mar Pollut Bull, 2011;63(5-12):347-9.
PMID: 21377175 DOI: 10.1016/j.marpolbul.2011.02.014

Several organisms have been used as indicators, bio-monitoring agents or test organisms in ecotoxicological studies. A close relative of the well established Japanese medaka, the Java medaka (Oryzias javanicus), has the potential to be a test organism. The fish is native to the estuaries of the Malaysian Peninsula, Thailand, Indonesia and Singapore. In this study, newly fertilised eggs were exposed to different concentrations of Cd and Hg. Observations were done on the development of the embryos. Exposure to low levels of Cd and Hg (0.01-0.05 ppm) resulted in several developmental disorders that led to death. Exposure to ≥1.0 ppm Cd resulted in immediate developmental arrest. The embryos of Java medaka showed tolerance to a certain extent when exposed to ≥1.0 ppm Hg compared to Cd. Based on the sensitivity of the embryos, Java medaka is a suitable test organism for ecotoxicology in the tropical region.

Matched MeSH terms: Tropical Climate
Sources of sedimentary PAHs in tropical Asian waters: differentiation between pyrogenic and petrogenic sources by alkyl homolog abundance

Saha M, Togo A, Mizukawa K, Murakami M, Takada H, Zakaria MP, et al.

Mar Pollut Bull, 2009 Feb;58(2):189-200.
PMID: 19117577 DOI: 10.1016/j.marpolbul.2008.04.049

We collected surface sediment samples from 174 locations in India, Indonesia, Malaysia, Thailand, Vietnam, Cambodia, Laos, and the Philippines and analyzed them for polycyclic aromatic hydrocarbons (PAHs) and hopanes. PAHs were widely distributed in the sediments, with comparatively higher concentrations in urban areas (Sigma PAHs: approximately 1000 to approximately 100,000 ng/g-dry) than in rural areas ( approximately 10 to approximately 100g-dry), indicating large sources of PAHs in urban areas. To distinguish petrogenic and pyrogenic sources of PAHs, we calculated the ratios of alkyl PAHs to parent PAHs: methylphenanthrenes to phenanthrene (MP/P), methylpyrenes+methylfluoranthenes to pyrene+fluoranthene (MPy/Py), and methylchrysenes+methylbenz[a]anthracenes to chrysene+benz[a]anthracene (MC/C). Analysis of source materials (crude oil, automobile exhaust, and coal and wood combustion products) gave thresholds of MP/P=0.4, MPy/Py=0.5, and MC/C=1.0 for exclusive combustion origin. All the combustion product samples had the ratios of alkyl PAHs to parent PAHs below these threshold values. Contributions of petrogenic and pyrogenic sources to the sedimentary PAHs were uneven among the homologs: the phenanthrene series had a greater petrogenic contribution, whereas the chrysene series had a greater pyrogenic contribution. All the Indian sediments showed a strong pyrogenic signature with MP/P approximately 0.5, MPy/Py approximately 0.1, and MC/C approximately 0.2, together with depletion of hopanes indicating intensive inputs of combustion products of coal and/or wood, probably due to the heavy dependence on these fuels as sources of energy. In contrast, sedimentary PAHs from all other tropical Asian cities were abundant in alkylated PAHs with MP/P approximately 1-4, MPy/Py approximately 0.3-1, and MC/C approximately 0.2-1.0, suggesting a ubiquitous input of petrogenic PAHs. Petrogenic contributions to PAH homologs varied among the countries: largest in Malaysia whereas inferior in Laos. The higher abundance of alkylated PAHs together with constant hopane profiles suggests widespread inputs of automobile-derived petrogenic PAHs to Asian waters.

Matched MeSH terms: Tropical Climate*
Characterization of spatial and temporal variability in hydrochemistry of Johor Straits, Malaysia

Abdullah P, Abdullah SMS, Jaafar O, Mahmud M, Khalik WMAWM

Mar Pollut Bull, 2015 Dec 15;101(1):378-385.
PMID: 26476861 DOI: 10.1016/j.marpolbul.2015.10.014

Characterization of hydrochemistry changes in Johor Straits within 5 years of monitoring works was successfully carried out. Water quality data sets (27 stations and 19 parameters) collected in this area were interpreted subject to multivariate statistical analysis. Cluster analysis grouped all the stations into four clusters ((Dlink/Dmax) × 100<90) and two clusters ((Dlink/Dmax) × 100<80) for site and period similarities. Principal component analysis rendered six significant components (eigenvalue>1) that explained 82.6% of the total variance of the data set. Classification matrix of discriminant analysis assigned 88.9-92.6% and 83.3-100% correctness in spatial and temporal variability, respectively. Times series analysis then confirmed that only four parameters were not significant over time change. Therefore, it is imperative that the environmental impact of reclamation and dredging works, municipal or industrial discharge, marine aquaculture and shipping activities in this area be effectively controlled and managed.

Matched MeSH terms: Tropical Climate
Occurrence, distribution, and sources of emerging organic contaminants in tropical coastal sediments of anthropogenically impacted Klang River estuary, Malaysia

Omar TFT, Aris AZ, Yusoff FM, Mustafa S

Mar Pollut Bull, 2018 Jun;131(Pt A):284-293.
PMID: 29886949 DOI: 10.1016/j.marpolbul.2018.04.019

This baseline assessment reports on the occurrence, distribution, and sources of emerging organic contaminants (EOCs) in tropical coastal sediments of anthropogenically impacted Klang River estuary, Malaysia. Bisphenol A was the highest concentration detected at 16.84 ng g-1 dry weight, followed by diclofenac (13.88 ng g-1 dry weight) and E1 (12.47 ng g-1 dry weight). Five compounds, namely, amoxicillin, progesterone, diazinon, bisphenol A, and E1, were found in all sampling stations assessed, and other compounds such as primidone, diclofenac, testosterone, E2, and EE2 were ubiquitously present in sediment samples, with percentage of detection range from 89.04% to 98.38%. Organic carbon content and pH were the important factors controlling the fate of targeted compounds in the tropical estuarine sediment. On the basis of the literature from other studies, the sources of EOCs are thought to be from wastewater treatment plants, domestic/medical waste discharge, livestock activities, industrial waste discharge, and agricultural activities.

Matched MeSH terms: Tropical Climate
[Emergence of new viruses in Asia: is climate change involved?]

Chastel C

Med Mal Infect, 2004 Nov;34(11):499-505.
PMID: 15620053

Tropical Africa is not the only area where deadly viruses have recently emerged. In South-East Asia severe epidemics of dengue hemorrhagic fever started in 1954 and flu pandemics have originated from China such as the Asian flu (H2N2) in 1957, the Hong-Kong flu (H3N2) in 1968, and the Russian flu (H1N1) in 1977. However, it is especially during the last ten years that very dangerous viruses for mankind have repeatedly developed in Asia, with the occurrence of Alkhurma hemorrhagic fever in Saudi Arabia (1995), avian flu (H5N1) in Hong-Kong (1997), Nipah virus encephalitis in Malaysia (1998,) and, above all, the SARS pandemic fever from Southern China (2002). The evolution of these viral diseases was probably not directly affected by climate change. In fact, their emergential success may be better explained by the development of large industry poultry flocks increasing the risks of epizootics, dietary habits, economic and demographic constraints, and negligence in the surveillance and reporting of the first cases.

Matched MeSH terms: Tropical Climate
Fecundity, nymphal development and longevity of field-collected tropical bedbugs, Cimex hemipterus

How YF, Lee CY

Med Vet Entomol, 2010 Jun;24(2):108-16.
PMID: 20202109 DOI: 10.1111/j.1365-2915.2010.00852.x

This study examined the fecundity, oviposition, nymphal development and longevity of field-collected samples of the tropical bedbug, Cimex hemipterus (Fabricius) (Hemiptera: Cimicidae). Under environmental conditions of 26+/-2 degrees C, 70 +/- 5% relative humidity and a 12-h photoperiod, with bloodmeals provided by a human host, six strains of tropical bedbug had a fecundity of up to 50 eggs per lifetime, over 11-14 oviposition cycles. Increased feeding frequency improved fecundity. After feeding and mating, adult females normally took 2-3 days to produce a first batch of eggs. The oviposition period lasted 2-7 days before cessation of the oviposition cycle. The egg incubation period usually lasted 5-7 days before the emergence of first instars. The nymphs underwent five stadia (the first four of which each took 3-4 days, whereas the last took 4-5 days) before becoming adults at a sex ratio of 1 : 1. More than five bloodmeals were required by the nymphs to ensure a successful moult. Unmated adults lived significantly longer than mated adults (P < 0.05). Unmated females lived up to almost 7 months, but the longevity of mated males and females did not differ significantly (P > 0.05).

Matched MeSH terms: Tropical Climate*

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