Displaying publications 21 - 40 of 547 in total

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  1. FAIQAH MOHAMAD FUDZI, ZAHAYU MD YUSOF, MASNITA MISIRAN
    MyJurnal
    The prediction of rainfall on monthly and seasonal time scales is not only scientifically challenging but is also important for planning and devising agricultural strategies. In this paper, the study is conducted to examine the pattern of monthly rainfall in Alor Setar, Kedah within ten years which is from 2008 to 2018. This paper considered a model based on real data that obtained from Department of Meteorology Malaysia. This study indicates that the monthly rainfall in Alor Setar has a seasonal and trend pattern based on yt vs t plotting, autocorrelation function and Kruskal Wallis Test for seasonality. The examined rainfall time-series modelling approaches include Naïve Model, Decomposition Method, Holt-Winter’s and Box-Jenkins ARIMA. Multiplicative Decomposition Method was identified as the best model to forecast rainfall for the year of 2019 by analysing the previous ten-year’s data (2008-2018).As a result from the forecast of 2019, October is the wettest month with highest forecasted rainfall of 276.15mm while the driest month is in February with lowest forecasted rainfall of 50.55mm. The model is therefore adequate and appropriate to forecast future monthly rainfall values in the catchment which can help farmers to plan their farming activities ahead of time.
    Matched MeSH terms: Seasons
  2. Knox SH, Bansal S, McNicol G, Schafer K, Sturtevant C, Ueyama M, et al.
    Glob Chang Biol, 2021 08;27(15):3582-3604.
    PMID: 33914985 DOI: 10.1111/gcb.15661
    While wetlands are the largest natural source of methane (CH4 ) to the atmosphere, they represent a large source of uncertainty in the global CH4 budget due to the complex biogeochemical controls on CH4 dynamics. Here we present, to our knowledge, the first multi-site synthesis of how predictors of CH4 fluxes (FCH4) in freshwater wetlands vary across wetland types at diel, multiday (synoptic), and seasonal time scales. We used several statistical approaches (correlation analysis, generalized additive modeling, mutual information, and random forests) in a wavelet-based multi-resolution framework to assess the importance of environmental predictors, nonlinearities and lags on FCH4 across 23 eddy covariance sites. Seasonally, soil and air temperature were dominant predictors of FCH4 at sites with smaller seasonal variation in water table depth (WTD). In contrast, WTD was the dominant predictor for wetlands with smaller variations in temperature (e.g., seasonal tropical/subtropical wetlands). Changes in seasonal FCH4 lagged fluctuations in WTD by ~17 ± 11 days, and lagged air and soil temperature by median values of 8 ± 16 and 5 ± 15 days, respectively. Temperature and WTD were also dominant predictors at the multiday scale. Atmospheric pressure (PA) was another important multiday scale predictor for peat-dominated sites, with drops in PA coinciding with synchronous releases of CH4 . At the diel scale, synchronous relationships with latent heat flux and vapor pressure deficit suggest that physical processes controlling evaporation and boundary layer mixing exert similar controls on CH4 volatilization, and suggest the influence of pressurized ventilation in aerenchymatous vegetation. In addition, 1- to 4-h lagged relationships with ecosystem photosynthesis indicate recent carbon substrates, such as root exudates, may also control FCH4. By addressing issues of scale, asynchrony, and nonlinearity, this work improves understanding of the predictors and timing of wetland FCH4 that can inform future studies and models, and help constrain wetland CH4 emissions.
    Matched MeSH terms: Seasons
  3. Wiyono ES, Ihsan
    Trop Life Sci Res, 2018 Mar;29(1):1-15.
    PMID: 29644012 DOI: 10.21315/tlsr2018.29.1.1
    In order to manage blue swimming crabs in Pangkajene Kepulauan, management measures are required. Since the environment which affects the abundance of the blue swimming crab varies seasonally, it is necessary to take into account the seasonal nature with the aim of developing a management strategy. The objectives of this study are to define the abundance of and fishing season of blue swimming crabs in the Pangkajene Kepulauan waters, South Sulawesi, Indonesia. The fishing season was analysed using seasonal index analysis, while fish abundance was analysed by means of Equilibrium-Schaefer. The result of this study demonstrated that fishermen allocate their fishing gear all year, although the fish catch is seasonal. Based on analysis of the result, the fishing season for the blue swimming crabs is short. The peak fishing season starts in May and finishes in June. However, in order to enable their families to earn a living, fishermen operated their fishing gear throughout the year. As a result, both catch landing and effort were close to maximum sustainable yield (MSY). In order to reduce fishing pressure, it is necessary to reduce fishing gear and have a seasonal arrangement regarding fishing gear allocation.
    Matched MeSH terms: Seasons
  4. Wongyai N, Jutagate A, Grudpan C, Jutagate T
    Trop Life Sci Res, 2020 Jul;31(2):159-173.
    PMID: 32922673 DOI: 10.21315/tlsr2020.31.2.8
    Condition index, reproduction and feeding of three non-obligatory riverine Mekong cyprinids namely Hampala dispar, Hampala macrolepidota and Osteochilus vittatus were examined. The samples were from the Nam Ngiep (NN) River and Bueng Khong Long (BKL) Swamp, which are the representative of the lotic- and lentic-environments, respectively. These two habitats lay in the same geographical area but on the opposite banks of the Mekong mainstream. The samplings were conducted between May 2017 and April 2018. There were 365 H. dispar, 259 H. macrolepidota and 298 O. vittatus samples in this study. The condition index of all three species were beyond 90% implying they can live well in both lotic and lentic environments. Reproductions of all three species were taken place in both environments with two peaks at the onset and end of rainy season. The samples from BKL showed early maturation than NN samples in all three (3) species. Feeding plasticity, though dominant by insects, was observed in Hampala spp., while O. vittatus can utilise any available detritus in both environments. Results clearly show that all the three selected non-obligatory riverine fish species can live very well in either lotic or lentic environments and imply that they can adjust themselves to reservoir environment.
    Matched MeSH terms: Seasons
  5. Asnor Azrin Sabuti, Che Abd Rahim Mohamed, Zaharudin Ahmad
    MyJurnal
    Various environmental samples (seawater, TSS, sediment, rainwater and fly ash) from eight different stations near Kapar coastal area were analyzed. The 210 Po activity concentrations in liquid samples (seawater and rainwater) varied between 0.34 ± 0.03 mBq L-1 to 22.44 ± 0.53 mBq L-1 . Whereas the concentrations in particulate samples (TSS, sediment and fly ash) varied between 43.79 ± 2.31 Bqkg-1 to 364.48 ± 5.43 Bqkg-1 . Results also showed the radioactivity in Kapar coastal is higher than most of Malaysian coast, reaching a factor of seven. This condition is mainly due to the operation of a coal-fired power plant nearby. This study also clarify the variability of 210 Po in environment was strongly influenced from rainfall events especially during wet seasons.
    Matched MeSH terms: Seasons
  6. Chen, Chee Dhang, Teoh Pei Sze, Wan-Norafikah Othman, Mohd Sofian-Azirun, Lee Han Lim
    MyJurnal
    This study was conducted to evaluate the effectiveness of a floor gully come with grating to prevent the oviposition of Aedes aegypti in the floor trap. In order to conduct the test, two containers were placed into a mosquito cage (30 cm × 30 cm × 30 cm). Both containers were filled with declorinated seasoned tap water and covered with floor gully c/w grating and normal floor gully, respectively. A total of 50 gravid Ae. aegypti females were then released into the cage and left for a week. All the eggs obtained from the test were allowed to remain inside the containers for the eggs to hatch. The number of hatched larvae was counted and recorded. Five replicates were conducted concurrently. There was a significant difference of Ae. aegypti larvae obtained between container with floor gully c/w grating and normal floor gully (p < 0.05). A total of 96.41% reduction of Ae. aegypti larvae was obtained in the container with floor gully c/w grating compared with the normal floor gully, indicating that the floor gully c/w grating used in this study was able to prevent oviposition of Ae. aegypti in holding water.
    Matched MeSH terms: Seasons
  7. M. Jayaprakash, R. Nagarajan, P. M. Velmurugan, L. Giridharan, girilogu@yahoo.com, B. Urban
    MyJurnal
    The composite nature of Ennore Creek, receiving polluted waters from Buckingham canal, River Kortalaiyar, and the presence of numerous industries rapidly degrade the coastal environment. In this study, multivariate statistical technique was used to assess the nature of pollution and to identify the factors responsible for the enrichment of trace metals in the creek sediments. Forty samples were collected during pre- and post-monsoon periods to evaluate the seasonal variations on the concentration of trace metals in the sediments. The results indicate that not much seasonal variation exists in the concentration of trace metals in the sediments of Ennore creek. Results of the cluster analysis illustrate that the enrichment of trace metals was mainly from anthropogenic sources. Meanwhile, correlation coefficient among the metals reveals that some of the metals (Fe and Al) derived were of natural origin. The complex data matrix of the sediment were interpreted after reduction to three factors and the results illustrate the extent of the influence of anthropogenic activities. The spatial distribution diagrams demonstrate and demarcate the region of enrichment of metals in the sediments of Ennore creek.
    Matched MeSH terms: Seasons
  8. Rajakumar MK
    DOI: 10.1007/978-94-011-6731-4_13 ISBN: 978-94-011-6731-4
    Citation: Rajakumar MK. Practising Primary Care in Developing Nations. In: Fabb W, Fry J (ed). Principles of Practice Management. Springer; 1984:230-238
    Matched MeSH terms: Seasons
  9. Adipriyana, Raditianto, Rosmahaida Jamaludin, Hayati Habibah Abdul Talib
    MyJurnal
    Management is consistently facing fast-flowing and lots of changes in business, including in the inventory management. Especially for fast-moving inventories, the correct stocking, controlling, checking and safety stock calculation is highly needed to have an exquisite inventory management and to reduce the possibility of running out of inventory which leads to unavailability to meet the demand. One of the ways to overcome this is by doing an excellent and appropriate forecasting. Therefore, the objective of this concept paper is to analyse and recommend tools to improve inventory management using the appropriate time-series forecasting method. The firm studied in this study is serving its employees as customers that demand the routine items including stationeries and other routine products to support their job as auditors and consultants for its client. However, there are occasions when there is out-of-stock situation for fast-moving items, especially in the peak season period. Furthermore, the firm is only applying replenishment based on the used inventories from the previous month. Therefore, this study suggests to eliminate out-of-stock items situation by applying precaution initiatives such as time-series forecasting. This study is planned to employ 10 time-series forecasting methods such as moving average, exponential smoothing, regression analysis, Holt-Winters analysis, Seasonal analysis and Autoregressive Integrated Moving Average (ARIMA) using Risk Simulator Software. By simulating those methods, the most appropriate method is selected based on the forecasting accuracy measurement.
    Matched MeSH terms: Seasons
  10. Pavitra SP, Low VL, Tan TK, Lim YAL, Ya'cob Z
    Acta Trop, 2020 Feb;202:105275.
    PMID: 31747545 DOI: 10.1016/j.actatropica.2019.105275
    Blackflies (Diptera: Simuliidae) are ecologically and medically important insects but they have been understudied in Malaysia. Accordingly, a study on the temporal variation in diversity and community structure of preimaginal blackflies was conducted for the first time in Malaysia. A total of 865 preimaginal blackflies were collected in 120 samplings from five streams across three monsoon seasons from February 2018 until January 2019. Ten species were recorded and most frequently collected species were Simulium cheongi, Simulium vanluni and Simulium jeffreyi. Relatively common species were Simulium roslihashimi, Simulium tani complex and Simulium trangense. No significant changes of rainfall was observed between three monsoon seasons as well as the seasons with species and physiochemical parameters except acidity (pH) (P 20%) indicated that S. vanluni and S. jeffreyi were commonly associated with wider, deeper and fast-flowing streams with low conductivity and larger streambed particle. In contrast, S. cheongi was associated with smaller, slower and small streambed particle. This first extensive bimonthly study has uncovered the species community structure as well as the changes of stream physicochemical parameters over time although they were not greatly and significantly influenced by the monsoon seasons. Species distribution, richness and abundance, however, were highly determined by the stream width, depth and velocity, therefore, were vital in shaping diversity and community structure of preimaginal blackflies.
    Matched MeSH terms: Seasons
  11. Sayang Mohd Deni, Suhaila Jamaluddin, Wan Zawiah Wan Zin, Abdul Aziz Jemain
    This study attempts to trace changes in the wet spells over Peninsular Malaysia based on the daily rainfall data from 32 selected rainfall stations which include four sub-regions; northwest, west, south and east, for the period of 1975 to 2004. Six wet spells indices comprising of the main characteristics (maximum, mean, standard deviation), the persistency of two consecutive wet days and the frequency of the short and long duration of wet spells will be used to identify whether or not these indices increase or decrease over Peninsular Malaysia during the monsoon seasons. The study indicates that the eastern areas of the peninsula could be considered as the wettest areas since almost all the indices of wet spells over these areas are higher than over the other regions during the northeast monsoon (NE). The Mann-Kendall (MK) trend test revealed that almost all of the stations located in the eastern areas of the peninsula exhibited a positive trend in the mean, variability and persistency of wet spells indices during the NE monsoon, while a negative trend was observed during the southwest monsoon (SW) in these areas. Moreover, these indices showed a positive trend, and at the same time a decreasing trend was observed in the frequency of the long wet spells in most stations located over the west coast of Peninsular Malaysia during the SW monsoon for the period of 1975 to 2004.
    Matched MeSH terms: Seasons
  12. Suhailah A, Che Salmah M
    Sains Malaysiana, 2014;43:667-674.
    Seasonal changes in Ephemeroptera, Plecoptera and Trichoptera (EPT) community was studied at rivers in Gunung Jerai Forest Reserve, Kedah, Malaysia. The rivers were visited monthly from September 2007 to August 2008 to sample aquatic insects using D-pond nets. More EPT were found in the wet season (10664 individuals) compared with the dry season (6599 individuals). In all rivers, ephemeropteran populations was highest during the wet season (z=-2.465, p=0.014). Meanwhile, the plecopteran population was low and almost constant throughout seasons in all rivers (z=-2.280, p=0.023). Trichopterans exhibited the highest peak of abundance in the dry season (z=-6.096, p=0.00). Concomitantly, higher diversity was recorded in the dry season (29 taxa) compared with 25 taxa recorded in wet season from all rivers. Tupah River had the most diverse EPT assemblage during the dry season. In wet season, the abundance of ephemeropterans genera such as Baetis, Platybaetis, Campsoneuria and Thalerosphyrus increased tremendously especially in Teroi River.
    Matched MeSH terms: Seasons
  13. Norela Sulaiman, Toh LF, Hazzila Abdul Samat, Ismail Sahid, Maimon Abdullah, Mohd. Rozali Othman
    Sains Malaysiana, 2007;36(2):91-95.
    This study was carried out to determine the concentrations of cypermethrin in total suspended particulate in air in several farming areas of Cameron Highlands. Samples of total suspended particulate were collected using a high volume air sampler (Model Graseby) from six different sampling sites around Cameron Highlands. Laboratory analysis of total suspended particulate was conducted by the standard method. High dosages of cypermethrin were used by farmers in the dry season. Results of the study showed that the concentrations of cypermethrin in total suspended particulate in the air samples were higher during the dry season (May-July 2004) compared to the rainy season (September-October 2004). There was a significant positive correlation between the concentrations of cypermethrin and total suspended particulate (p<0.05).
    Matched MeSH terms: Seasons
  14. Suhaila J, Sayang Mohd Deni, Wan Zawiah Wan Zin, Abdul Aziz Jemain
    This study investigated the spatial pattern and trends of the daily rainfall data in Peninsular Malaysia based on seasonal rainfall indices. Five rainfall indices which describe the main characteristics of rainfall, the total amount of rainfall, frequency of wet days, rainfall intensity, extreme frequency, and extreme intensity, were employed in this study. The statistics of rainfall indices were calculated in terms of their means for four regions in Peninsular Malaysia for the period 1975 to 2004. The findings indicate that the southwest monsoon had the greatest impact on the western part of the Peninsula, particularly in characterizing the rainfall pattern of the northwest region. During this season, the northwest region could be considered as the wettest region since all rainfall indices tested are higher than in other regions of the Peninsula. Otherwise, the northwest region is denoted as the driest part of the Peninsula during the northeast monsoon period. The northwest region is less influenced by the northeast monsoon because of the existence of the Titiwangsa Range, which blocks the region from receiving heavy rainfall. On the other hand, it is found that the lowlands areas such as the eastern part of the Peninsula are strongly characterized by the northeast monsoonal flow. Based on the results of the Mann-Kendall test, as the trend of the total amount of rainfall and the frequency of wet days during the southwest monsoon decrease at most of the stations, the rainfall intensity increases. In contrast, increasing trends in both the total amount of rainfall and the frequency of wet days were observed at several stations during the northeast monsoon, which give rise to the increasing trend of rainfall intensity. The results for both seasons indicate that there are significantly decreasing trends in the frequency of wet days during the extreme events for most of the stations on the peninsula. However, a smaller number of significant trends was found for extreme intensity.
    Matched MeSH terms: Seasons
  15. Salmiati, Nor Zaiha A., Mohd Ismid M.S.
    Sains Malaysiana, 2015;44:1223-1228.
    Temporal changes of Ephemeroptera, Plecoptera and Trichoptera (EPT) communities were investigated at the study area of Gunung Pulai Recreational Forest, Johor, Malaysia. Taxa diversity were also studied to determine the seasonality impact on certain benthic communities. Sampling of aquatic insects were carried out from November 2012 to July 2013 using rectangular dip net. As a result, more EPT were found during the dry season (1533 individuals) compared to wet season (321 individuals). Concomitantly, higher diversity was also recorded in the dry season. Among these three investigated orders, Trichoptera represented the most diverse community with three families recorded, followed by Plecoptera (2 families) and Ephemeroptera (1 family). Caddisfly family Hydropsychidae were found to be abundant in the study area. Therefore, seasonality impact on EPT assemblage at Gunung Pulai Recreational Forest is extremely evident.
    Matched MeSH terms: Seasons
  16. Mohd Fauzie Jusoh, Mohamed Azwan Mohamed Zawawi, Hasfalina Che Man, Suzilawati Kamaruddin
    Sains Malaysiana, 2013;42:1101-1108.
    Groundwater irrigation is one of the alternative methods to irrigate the paddy crops beside surface water. The use of shallow tube well for paddy irrigation is able to overcome water scarcity especially during dry season and off planting season in Malaysia. The performance of a shallow tube well was evaluated based on well efficiency and pump efficiency. The study was conducted at Seberang Perak Integrated Agricultural Development Area (Seberang Perak IADA). In this study, on-off automatic water controller was installed in the field and connected to the pump system which gave the command to the pump to irrigate the field during pre-saturation and normal growth plantation period. Water level inside the pumping well and cultivation plot was observed and recorded by the water level transducers. The result of the study showed that the pumping well is moderately productive with the well efficiency between 91 and 94%. The submersible pump efficiency was 87.5%. The potential yield of the pumping well was 450 m3day-1 and it was enough and sufficient to irrigate 1 ha of paddy field.
    Matched MeSH terms: Seasons
  17. Pang Swee Yun, Juriffah Ariffin, Norhayati Mohd Tahir, Hii Yii Siang
    Sains Malaysiana, 2015;44:941-945.
    Three short sediment cores (12-32 cm) from South China Sea off Southern Terengganu were collected during May (postNortheast monsoon) and September (pre-Northeast monsoon) 2007. The concentration of total organic carbon (TOC) obtained ranged from 0.41-2.23 and 0.38-2.31% during post and pre-monsoon, respectively. TOC concentration was found to decrease with depth and distance from the coast and river mouth. In particular, station with close proximity to the coast exhibits most pronounced variation of TOC with depth. Besides spatial variation, it is noted that the seasonal variations also considerably affect the distribution and concentrations of TOC, where both near and offshore sampling stations showed significant variations in TOC content during May and September sampling. These findings suggest the importance of terrestrial organic carbon flux, physical mixing and seasonal variations in regulating the concentration and distribution of the organic carbon in the study area.
    Matched MeSH terms: Seasons
  18. Dzulhelmi M, Norma-Rashid Y
    Sains Malaysiana, 2014;43:497-502.
    The seasonal variation of spider assemblages in botanical garden was investigated. The spiders were manually collected by diurnal and nocturnal session between two seasons. A total of 19 families from 65 genera and 96 species were recorded. Richness-estimator indicates the inventory were 67% complete within the botanical garden. The capture rate for web-weavers were higher compared with non-web weavers. The comparison value showed the species composition and abundance were similar between seasons. Spider abundance was not affected between wet and dry season in tropical countries.
    Matched MeSH terms: Seasons
  19. Idris MS, Lee Siang H, Amin RM
    Data Brief, 2020 Feb;28:104982.
    PMID: 31890817 DOI: 10.1016/j.dib.2019.104982
    The biophysical data presented in this article were collected in the east coast of Peninsular Malaysia from May to November 2009. These monthly surface data were obtained from 32 stations along the coastal-offshore transect and were analyzed to understand the spatial and temporal distributions of biophysical parameters during different monsoon seasons. The data presented here include sea surface temperature (SST), sea surface salinity (SSS), Secchi disk depth (SDD), Chlorophyll-a (Chl-a), suspended particulate matter (SPM), mineral suspended solid (MSS) and chromophoric dissolved organic matter (CDOM).
    Matched MeSH terms: Seasons
  20. Nelson BR, David G, Mokhtar AF, Mamat MA, Rahman AJA
    Data Brief, 2018 Dec;21:2633-2637.
    PMID: 30761345 DOI: 10.1016/j.dib.2018.11.119
    This data article is constructed using avian (bird) counts from a recently identified trail in Kenyir rainforest, East Peninsular Malaysia. Avian chirps and naked eye visual were simultaneously used to locate the birds. After visual binocular and digital image inspection, identification of avian species were carried out using reference books. Data tabulation are divided by monsoon seasons and months before interpret using Shannon and Evenness indices. The highlights like feeding guilds, nativity, iconic species and statuses in the wild are presented with the data to increase its value. Within these, a total of 457 avian individuals from 36 avian family groups were recorded from which, 25 of these avian species occur as near threatened, vulnerable, endangered and critically endangered in the wild. Having these, the tabulated data becomes a calendar for seasonal availability of avian species which considers the 1.0 km trail suitable for bird watching, scientific study and ecotourism purposes.
    Matched MeSH terms: Seasons
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