MyMedR

Displaying publications 161 - 180 of 558 in total

Abstract:

Sort:

First discovery of Pleistocene orangutan (Pongo sp.) fossils in Peninsular Malaysia: biogeographic and paleoenvironmental implications

Ibrahim YKh, Tshen LT, Westaway KE, Cranbrook EO, Humphrey L, Muhammad RF, et al.

J Hum Evol, 2013 Dec;65(6):770-97.
PMID: 24210657 DOI: 10.1016/j.jhevol.2013.09.005

Nine isolated fossil Pongo teeth from two cave sites in Peninsular Malaysia are reported. These are the first fossil Pongo specimens recorded in Peninsular Malaysia and represent significant southward extensions of the ancient Southeast Asian continental range of fossil Pongo during two key periods of the Quaternary. These new records from Peninsular Malaysia show that ancestral Pongo successfully passed the major biogeographical divide between mainland continental Southeast Asia and the Sunda subregion before 500 ka (thousand years ago). If the presence of Pongo remains in fossil assemblages indicates prevailing forest habitat, then the persistence of Pongo at Batu Caves until 60 ka implies that during the Last Glacial Phase sufficient forest cover persisted in the west coast plain of what is now Peninsular Malaysia at least ten millennia after a presumed corridor of desiccation had extended to central and east Java. Ultimately, environmental conditions of the peninsula during the Last Glacial Maximum evidently became inhospitable for Pongo, causing local extinction. Following post-glacial climatic amelioration and reforestation, a renewed sea barrier prevented re-colonization from the rainforest refugium in Sumatra, accounting for the present day absence of Pongo in apparently hospitable lowland evergreen rainforest of Peninsular Malaysia. The new teeth provide further evidence that Pongo did not undergo a consistent trend toward dental size reduction over time.

Matched MeSH terms: Environment*
Analysis of developed transition road safety barrier systems

Soltani M, Moghaddam TB, Karim MR, Sulong NH

Accid Anal Prev, 2013 Oct;59:240-52.
PMID: 23820073 DOI: 10.1016/j.aap.2013.05.029

Road safety barriers protect vehicles from roadside hazards by redirecting errant vehicles in a safe manner as well as providing high levels of safety during and after impact. This paper focused on transition safety barrier systems which were located at the point of attachment between a bridge and roadside barriers. The aim of this study was to provide an overview of the behavior of transition systems located at upstream bridge rail with different designs and performance levels. Design factors such as occupant risk and vehicle trajectory for different systems were collected and compared. To achieve this aim a comprehensive database was developed using previous studies. The comparison showed that Test 3-21, which is conducted by impacting a pickup truck with speed of 100 km/h and angle of 25° to transition system, was the most severe test. Occupant impact velocity and ridedown acceleration for heavy vehicles were lower than the amounts for passenger cars and pickup trucks, and in most cases higher occupant lateral impact ridedown acceleration was observed on vehicles subjected to higher levels of damage. The best transition system was selected to give optimum performance which reduced occupant risk factors using the similar crashes in accordance with Test 3-21.

Matched MeSH terms: Environment Design/standards*
Fulltext Range Measurement and a Habitat Suitability Map for the Norway Rat in a Highly Developed Urban Environment

Oyedele DT, Sah SA, Kairuddinand L, Wan Ibrahim WM

Trop Life Sci Res, 2015 Dec;26(2):27-44.
PMID: 26868708 MyJurnal

Studies of habitat suitability (HS) are essential when animals' habitats have been altered or when animals migrate to a habitat different from their natural habitat. This study assessed HS and used an integrated geographic information system in the assessment of Rattus norvegicus in a highly developed urban environment. Using data from the Campbell market and the police quarters of George Town, Malaysia, home range (through the use of 100% Minimum Convex Polygon [MCP], 95% MCP and 95% Harmonic Mean [HM]) was estimated. Home range for male rats at Campbell market reached an asymptote, with a slight increase, at 96 radio fixes (home range = 133.52 m(2); core area = 29.39 m(2)). Female rats reached an asymptote at 62 radio fixes (home range = 13.38 m(2); core area = 9.17 m(2)). At Campbell market, male rats emerged at 1900 hours every day, whereas females emerged at 2000 hours; at police quarters, the most common time of emergence for males was 2000 hours and for females was 2200. Raster charts of R. norvegicus showed that rat hot spots can be grouped into 4 zones (market, shop houses, settlement and general places). The standardised raster chart isolated the market as the major rallying points of the rats (hot spots) by producing the highest rats frequencies of 255. All of the habitat suitability thresholds, including the built-up points, skip bins, water source and nature of the site explored in this study, produced a structural pattern (monotonic increase or decrease) of habitat suitability.

Matched MeSH terms: Environment; Social Environment
The interplay of socio-psychological factors on school engagement among early adolescents

Awang-Hashim R, Kaur A, Noman M

J Adolesc, 2015 Dec;45:214-24.
PMID: 26513126 DOI: 10.1016/j.adolescence.2015.10.001

The study examined a conceptual model integrating existing knowledge on the linkages between life satisfaction, affect, purpose in life, and resilience with school engagement. This model posits direct relationships between all the social psychological variables and school engagement, and also indirect relationships between life satisfaction and school engagement as mediated by all the other variables in the study. The participants were 2381 students (1119 boys and 1262 girls) with average age of 15 years, from 40 national secondary schools in Malaysia. The findings supported the theoretical conceptualization. All variables were positively associated with school engagement. The strongest relationship was observed between overall life satisfaction and school engagement. The mediating model was partially supported. The study reiterates the adage that "it takes a village to raise a child". Implications for practice and future research are discussed in the context of engagement in school learning.

Matched MeSH terms: Social Environment*
Fulltext Applications of Environmental Epidemiology in Addressing Public Health Challenges in East Asia

Su SB, Hashim JH, Yan CH

Biomed Res Int, 2015;2015:462426.
PMID: 26295038 DOI: 10.1155/2015/462426
Matched MeSH terms: Environment*
Fulltext Ambient factors influencing Photovoltaic module temperature in Klang valley

Hedzlin Zainuddin, Maisarah Ismail, Nurul Hidayah Bostamam, Muhamad Mukhzani Muhamad Hanifah, Mohamad Fariz Mohamad Taib, Mohamad Zhafran Hussin

Science Letter, 2016;10(2):23-25.
MyJurnal

The study is conducted to evaluate the significance of solar irradiance, ambient temperature and relative humidity as predictors and to quantify the relative contribution of these ambient parameters as predictors for photovoltaic module temperature model. The module temperature model was developed from experimental data of mono-crystalline and poly-crystalline PV modules retrofitted on metal roof in Klang Valley. The model was developed and analyzed using Multiple Linear Regressions (MLR) and Principle Component Analysis (PCA) Techniques. Solar irradiance, ambient temperature and relative humidity have been proven to be the significant predictors for module temperature. For poly-crystalline PV module, the relative contribution of solar irradiance, ambient temperature and relative humidity are 64.28 %, 17.45 % and 12.64 % respectively. For mono-crystalline PV module, the relative contribution of solar irradiance, ambient temperature and relative humidity are 66.12 %, 17.46 % and 12.48 % respectively. Thus, there is no significant difference in terms of relative contribution of these ambient parameters towards photovoltaic module temperature between poly-crystalline and mono-crystalline PV module technologies.

Matched MeSH terms: Environment
Fulltext Forecasting ozone concentration levels using Box-Jenkins ARIMA modelling and artificial neural networks: a comparative study

Norhashidah Awang, Ng, Kar Yong, Soo, Yin Hoeng

MATEMATIKA, 2017;33(2):119-130.
MyJurnal

An accurate forecasting of tropospheric ozone (O3) concentration is benefi-
cial for strategic planning of air quality. In this study, various forecasting techniques are
used to forecast the daily maximum O3 concentration levels at a monitoring station
in the Klang Valley, Malaysia. The Box-Jenkins autoregressive integrated movingaverage
(ARIMA) approach and three types of neural network models, namely, backpropagation
neural network, Elman recurrent neural network and radial basis function
neural network are considered. The daily maximum data, spanning from 1 January
2011 to 7 August 2011, was obtained from the Department of Environment, Malaysia.
The performance of the four methods in forecasting future values of ozone concentrations
is evaluated based on three criteria, which are root mean square error (RMSE),
mean absolute error (MAE) and mean absolute percentage error (MAPE). The findings
show that the Box-Jenkins approach outperformed the artificial neural network
methods.

Matched MeSH terms: Environment
Fulltext Evaluation of the spatial growth of Bauchi metropolis using remote sensing and geographic information systems (GIS) techniques

Mohammed Aliyu Modibbo, Mohammed Arif Shahidah, Isah Funtua Abdulkadir, Umar Wali

Journal of Advanced Research in Applied Sciences and Engineering Technology, 2017;6(1):28-36.
MyJurnal

This paper has evaluated the spatial growth of Bauchi Metropolis from 1976 to 2015
through the application of Remote Sensing and GIS techniques. Various satellite
imageries of the metropolis (Landsat MSS of 1976, TM of 1986, 1996 and ETM+ of 2006
and 2015) were integrated; processed and classified using ERDAS imagine 9.1. The
results showed an increase in area from 11.68km2
in 1976 to 12.51km2
in 1986 to
32.44km2 in 1996, to 49.66km2
in 2006 and finally to 89.23km2 in 2015. It is
recommended that government should provide the required capacities for the use of
Remote Sensing and GIS in planning for the growth of the town.

Matched MeSH terms: Environment
Fulltext Ornamental potted plant as air bio-filters for indoor environments

Mohd Mahathir Suhaimi Shamsuri, Leman, A.M., Azian Hariri, Azizi Afandi

Journal of Occupational Safety and Health, 2016;13(2):1-8.
MyJurnal

The cultivation of indoor plants in indoor environment has become a topic of interest among researchers worldwide for its
potential to improve indoor air quality (IAQ). However, the adaptations of environmental factor of each plant need to be investigated
to correspond with the native environment. The study investigate the capability of plants selected to live indoor. Before experiment was
conducted, all plants selected were assimilated with indoor environment for two months. Photosynthesis proses in this experiment will
be a guidance to determine the comparative for every plant. The portable photosynthesis system equipment (LI-COR 6400) was used to
determine the level of photosynthesis rate for each of plants. Accordingly, among of all plants tested, Spider Plant showed less effective
to be grown with indoor environment by the rate of photosynthesis value up to -0.15. Moreover, light compensation point (LCP) of
Spider Plant also indicated the light intensity consumption was 2960 lux which is extremely higher than 300 lux. As a conclusion, only
six plants in this study which are Anthurium, Dumb Cane, Golden Pothos, Kadaka Fern, Prayer Plant, and Syngonium are able to
survive with indoor environment. In the next stage of study, this six plants may give good results to enhance the IAQ.

Matched MeSH terms: Environment
Fulltext Fuzzy-controlled humidity variation by Silica gel and Nitrogen gas in an atmospheric chamber

Ali Ghahraei, Nurul Amziah Md Yunus, Izhal Abdul Halin, Nasri Sulaiman

Pertanika Journal of Science & Technology, 2017;25(102):133-142.
MyJurnal

Controlled humidity environment is of significance in many scientific researches and experiments. In most laboratory-scale atmospheric chambers, an electrical temperature-based control system is used to adjust humidity. Since these chambers are not affordable in every laboratory, other low cost chambers using nitrogen gas or silica gel are used to adjust humidity. In this paper, a mechanism was developed to control the relative humidity in closed lab-scale chambers. Humidification is done by spraying water through a blower fan while de-humidification is by pumping air through silica gel as well as nitrogen gas injection. A Mamdani type fuzzy controller was designed to control the components and relative humidity. The results show the proposed system and controller can adjust and maintain relative humidity from 41% to 100% with maximum overshoot of 1% and the maximum range of error of steady state of 1.2 %.

Matched MeSH terms: Environment, Controlled
Fulltext Land snail fauna in Gunung Kuang Limestone Hill, Perak, Malaysia and its conservation implications (Mollusca, Gastropoda)

Phung CC, Yong YZ, Said MAM, Liew TS

Zookeys, 2018.
PMID: 29988791 DOI: 10.3897/zookeys.769.25571

This paper presents the first land snail species checklist for Gunung Kuang (Kuang Hill), a limestone hill located next to Gunung Kanthan that is recognised as one of the most important limestone hills for its diverse land snail fauna in Kinta Valley. Samplings were carried out at five plots in Gunung Kuang. This survey documented 47 land snail species, in which six species were identified as unique to Gunung Kuang. Approximately half of the land snails from Gunung Kanthan were found in Gunung Kuang. In addition, one of six unique species from Gunung Kanthan was also found in Gunung Kuang. These rich land snail species in Gunung Kuang are similar to other hills in Kinta Valley, but it is relatively lesser than the adjacent Gunung Kanthan. In view of Gunung Kuang's unique land snail species, and its location closest to disturbed Gunung Kanthan, Gunung Kuang should be considered in the conservation management plan for Gunung Kanthan.

Matched MeSH terms: Environment
Fulltext Challenges faced and lessons learned A multi-component prospective memory training program for Malaysian older adults

Farzin A, Ibrahim R, Madon Z, Basri H

Dement Neuropsychol, 2018 7 11;12(2):189-195.
PMID: 29988335 DOI: 10.1590/1980-57642018dn12-020012

The surrounding circumstances and environments of Malaysian older adults could make conducting interventions (mainly in terms of clinical or randomized controlled trials) a challenge. Working with older adults and facing cultural issues could be challenging.
Objective: This paper illustrates a significant perspective of some of the challenges faced while conducting a randomized controlled trial exploring the impact of a multi-component intervention that included strategy- and process-based prospective memory (PM) training among Malaysian older adults.
Methods: The current study was a randomized controlled trial (RCT) and therefore the challenges were presented in accordance with the CONSORT statement style.
Results: A discussion on how these issues were addressed is provided.
Conclusion: Some suggestions were presented to help researchers plan and create interventions for similar studies and to support a practical method of addressing all related challenges.

Matched MeSH terms: Environment
Fulltext The freshwater crabs of Danum Valley Conservation Area in Sabah, East Malaysia, with a description of a new species of Thelphusula Bott, 1969 (Crustacea, Brachyura, Gecarcinucidae, Potamidae, Sesarmidae)

Ng PKL, Ng PYC

Zookeys, 2018.
PMID: 29872365 DOI: 10.3897/zookeys.760.24787

Seven species of freshwater crabs from three families are recorded from and around the Danum Valley Conservation Area in Sabah, Malaysian Borneo: Thelphusula capillodigitussp. n., Thelphusula dicerophilus Ng & Stuebing, 1990, Arachnothelphusa terrapes Ng, 1991, Terrathelphusa secula Ng & Tan, 2015, Parathelphusa valida Ng & Goh, 1987 (new record) (Gecarcinucidae); Isolapotamon ingeri Ng & Tan, 1998 (Potamidae); and Geosesarma danumense Ng, 2002 (Sesarmidae). The new species of Thelphusula Bott, 1979, can be distinguished from all congeners by a unique combination of morphological features, most notably the presence of dense patches of short setae on the fingers of the adult male chelipeds, as well as the structure of the male first gonopod. Arachnothelphusa terrapes is confirmed to be a phytotelm species. A key to all species in the conservation area is provided.

Matched MeSH terms: Environment
Fulltext Global energy security and North America: a review

Muhammad Adil Khattak, Nurul Syahrizzat Mohd Yasin, Hannah Natasha Andjani, Puteri Nurailah Husna Mohd Tajuddin, Sakeshraj Narajah, See, Zhi Fei, et al.

Journal of Advanced Research in Applied Sciences and Engineering Technology, 2018;11(1):82-98.
MyJurnal

Geopolitical risks will less affect the oil supply in the United States due to its stability
and widespread oil sectors since 1970s. Nevertheless, energy prosperity in the United
States appears differently in relation to a fuller period for conventional energy export
states where geopolitical challenges have been intensified by monetary pressure and
escalating energy demand in residential areas. The relationship between the United
States and other energy export states will continue to change as the United States
becomes more independent and non-OPEC resources become worthwhile especially
in Western Hemisphere. With expansion of global economic growth, maintained
multilateral relationship among countries and technological development are two
prominent concerns to secure long-term energy supplies and to enable further
exploration of new energy sources.

Matched MeSH terms: Environment
Fulltext Pesticides contamination and analytical methods of determination in environmental matrices in Malaysia and their potential human health effects – a review

Siti Zulfa Zaidon, Ho, Yu Bin, Zailina Hashim, Praveena, Sarva Mangala, Nazamid Saari

Malaysian Journal of Medicine and Health Sciences, 2018;14(101):81-88.
MyJurnal

Pesticides application is essential in protecting crops and increases their productivity. However, this causes the pesticide residues to contaminate the crops and their surrounding environment that will eventually lead to exposure to human being. There is very little understanding on the human health effects of pesticides, thus many studies are being carried out for this purpose. In conjunction to this, there are various analytical methods on multi-residue pesticides analysis that have been developed over the years in various samples. This review provides an overview of the reported concentration of pesticides, the extraction and determination techniques of pesticides in environmental samples and the potential health effects they imposed on human in Malaysia from 2007 to 2017.

Matched MeSH terms: Environment
Anaerobic digestion of lignocellulosic waste: Environmental impact and economic assessment

Fan YV, Klemeš JJ, Perry S, Lee CT

J Environ Manage, 2019 Feb 01;231:352-363.
PMID: 30366314 DOI: 10.1016/j.jenvman.2018.10.020

Lignocellulosic waste (LW) is abundant in availability and is one of the suitable substrates for anaerobic digestion (AD). However, it is a complex solid substrate matrix that hinders the hydrolysis stage of anaerobic digestion. This study assessed various pre-treatment and post-treatments of lignocellulosic waste for anaerobic digestion benefiting from advanced P-graph and GaBi software (Thinkstep, Germany) from the perspective of cost and environmental performances (global warming potential, human toxicity, ozone depletion potential, particulate matter, photochemical oxidant creation, acidification and eutrophication potential). CaO pre-treatment (P4), H2S removal with membrane separation post-treatment (HSR MS) and without the composting of digestate is identified as the cost-optimal pathway. The biological (P7- Enzyme, P8- Microbial Consortium) and physical (P1- Grinding, P2- Steam Explosion, P3- Water Vapour) pre-treatments alternatives have lower environmental impacts than chemical pre-treatments (P4- CaO, P5- NaOH, P6- H2SO4) however they are not part of the near cost optimal solutions. For post-treatment, the near cost optimal alternatives are H2S removal with organic physical scrubbing (HSR OPS) and H2S removal with amine scrubbing (HSR AS). HSR AS has a better performance in the overall environmental impacts followed by HSR MS and HSR OPS. In general, the suggested cost-optimal solution is still having relatively lower environmental impacts and feasible for implementation (cost effective). There is very complicated to find a universal AD solution. Different scenarios (the type of substrate, the scale, product demand, policies) have different constraints and consequently solutions. The trade-offs between cost and environment performances should be a future extension of this work.

Matched MeSH terms: Environment
Fulltext Development of community-based early warning system (CBEWS) in enhancing community preparedness for dam-related disasters in Malaysia

Azrul Ghazali, Sivadass Thiruchelvam, Kamal Nasharuddin Mustapha, Ahmad Kamal Kadir, Fatin Faiqa Norkhairi, Nora Yahya, et al.

ASM Science Journal, 2018;11(2):117-123.
MyJurnal

Series of catastrophic floods that we have witnessed over the last decade in Malaysia have necessitated the adoption of reliable early warning system. Ultimate concern during any event of natural or manmade disaster would be information dissemination to lessen the disaster impact on lives and property. The Bertam Valley incident in the wee hours of 23rd October 2013 has been considered as the game changer of how we view the role of vulnerable communities in facing dam-related disasters. Empowerment of local communities has been considered as vital in disaster management, as they are often the first responders to disaster. Local Community-Based Early Warning System (CBEWS) is a smart mechanism operated by the communities. This study revolves around the actual implementation of such system in Cameron Highlands in the effort of increasing human resilience towards damrelated disasters. While establishing the system, the Bertam Valley community has received support from different individuals and organisations. It is paramount that the community develops and maintains close coordination and strong links with these stakeholders. The performance of early warning systems can be evaluated via key parameters such as timeliness, accuracy, reliability, user friendliness, flexibility, and costs & benefits.

Matched MeSH terms: Environment
Urban blue: A global analysis of the factors shaping people's perceptions of the marine environment and ecological engineering in harbours

Strain EMA, Alexander KA, Kienker S, Morris R, Jarvis R, Coleman R, et al.

Sci Total Environ, 2019 Mar 25;658:1293-1305.
PMID: 30677991 DOI: 10.1016/j.scitotenv.2018.12.285

Marine harbours are the focus of a diverse range of activities and subject to multiple anthropogenically induced pressures. Support for environmental management options aimed at improving degraded harbours depends on understanding the factors which influence people's perceptions of harbour environments. We used an online survey, across 12 harbours, to assess sources of variation people's perceptions of harbour health and ecological engineering. We tested the hypotheses: 1) people living near impacted harbours would consider their environment to be more unhealthy and degraded, be more concerned about the environment and supportive of and willing to pay for ecological engineering relative to those living by less impacted harbours, and 2) people with greater connectedness to the harbour would be more concerned about and have greater perceived knowledge of the environment, and be more supportive of, knowledgeable about and willing to pay for ecological engineering, than those with less connectedness. Across twelve locations, the levels of degradation and modification by artificial structures were lower and the concern and knowledge about the environment and ecological engineering were greater in the six Australasian and American than the six European and Asian harbours surveyed. We found that people's perception of harbours as healthy or degraded, but not their concern for the environment, reflected the degree to which harbours were impacted. There was a positive relationship between the percentage of shoreline modified and the extent of support for and people's willingness to pay indirect costs for ecological engineering. At the individual level, measures of connectedness to the harbour environment were good predictors of concern for and perceived knowledge about the environment but not support for and perceived knowledge about ecological engineering. To make informed decisions, it is important that people are empowered with sufficient knowledge of the environmental issues facing their harbour and ecological engineering options.

Matched MeSH terms: Environment
Colour and size influences plastic microbead underestimation, regardless of sediment grain size

Nel HA, Dalu T, Wasserman RJ, Hean JW

Sci Total Environ, 2019 Mar 10;655:567-570.
PMID: 30476836 DOI: 10.1016/j.scitotenv.2018.11.261

The quantification of microplastics in environmental samples often requires an observer to determine whether a particle is plastic or non-plastic, prior to further verification procedures. This implies that inconspicuous microplastics with a low natural detection may be underestimated. The present study aimed at assessing this underestimation, looking at how colour (white, green and blue), size (large; ~1000 μm and small; <400 μm) and grain size fraction may affect detection. Sediment treatments varying in grain size were inoculated with known quantities of low-density polyethylene microbeads extracted from commercially bought facial scrubs. These microbeads varied in colour and size. Once extracted using a density separation method microbeads were counted. An overall underestimation of 78.59% may be a result of observer error and/or technical error. More specifically, the results suggested that microbeads varying in colour and size have a different detection probability and that these microbead features are more important in underestimation likelihoods than grain sizes.

Matched MeSH terms: Environment
Effects of season on the yield and quality of extracts from Gracilaria changii (Gracilariaceae, Rhodophyta)

Sasidharan S, Darah I, Jain K

Sains Malaysiana, 2009;38.

The effect of season on yield and quality of organic solvent extracts from Gracilaria changii was determined. The sustainability of the bioactive compound of G. changii from Malaysia was investigated by using the TLC and FTIR standards methods. Studies was carried out to examine the sustainability of the bioactive compound in the various extract obtained from G. changii collected from Pantai Morib, Beach Selangor Malaysia on bimonthly for a period of one year in 2003. This study revealed that the bioactive compounds was present all over the year but with different quantities. In general the variation in yield or quantities of bioactive compound was related to environment. G. changii can be considered a candidate for drug development since it retained the number of bioactive compound.

Matched MeSH terms: Environment

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links