Displaying publications 1 - 20 of 547 in total

Abstract:
Sort:
  1. Rimmelzwaan GF, de Jong JC, Donker GA, Meijer A, Fouchier RA, Osterhaus AD
    Ned Tijdschr Geneeskd, 2006 Oct 7;150(40):2209-14.
    PMID: 17061434
    The first sign of influenza activity in the Netherlands during the 2005-2006 influenza season was the isolation of influenza viruses in the last week of 2005. From Week 1 of 2006 onwards, an increase in clinical influenza activity was also observed that did not return to baseline levels until Week 15. Two waves of influenza activity were observed with peak incidences of 13.8 and 9.8 influenza-like illnesses per 10,000 inhabitants on Weeks 7 and 12, respectively. The first wave of influenza was caused primarily by influenza B viruses, whereas the second wave was caused predominantly by influenza A/H3N2 viruses. The influenza B viruses appeared to belong to two different phylogenetic lineages and were antigenically distinguishable from the vaccine strain. The isolated influenza A/H3N2 viruses were closely related to the vaccine strain for this subtype and only minor antigenic differences with the vaccine strain were observed for a limited number of isolates. Only a small number of influenza A/H1N1 viruses were isolated, which all closely resembled the H1N1 vaccine strain. For the 2006-2007 influenza season, the World Health Organization has recommended the following vaccine composition: A/Wisconsin/67/05 (H3N2), A/New Caledonia/20/99 (H1N1) and B/Malaysia/2506/05.
    Matched MeSH terms: Seasons
  2. Kaku Y
    Uirusu, 2004 Dec;54(2):237-42.
    PMID: 15745162
    Nipah virus (NiV), emerged in Peninsular Malaysia, caused an outbreak of severe febrile encephalitis in humans and respiratory diseases in pigs between 1998 and 1999. By May of 1999, the death of 105 humans and the culling of about 1.1 million pigs were reported. Fruitbats of Pteropid species were identified as the natural reservoir hosts. The epidemiological studies suggested that NiV was introduced into pig farms by fruitbats, and was than transmitted to humans (mainly pig farmers) and other animals such as dogs, cats and horses. In 2004, NiV reappeared in Bangladesh with greater lethality. In contrast to the Malaysia case, epidemiologic characteristics of this outbreak suggested the possibility of fruitbats-to-person, or person-to-person transmission. In this article, the epidemiological comparison between two outbreaks in Malaysia and Bangladesh, and the new-trends of virological studies of NiV will be discussed.
    Matched MeSH terms: Seasons
  3. Takasaka M, Morota S, Kasono T, Abe M, Honjo S
    Jikken Dobutsu, 1973 Jul;22(3):227-36.
    PMID: 4204642
    Matched MeSH terms: Seasons
  4. Gothe R, Wegerdt S
    Tierarztl Prax, 1991 Apr;19(2):170-3.
    PMID: 2068714
    Between January 1987 and February 1990 Babesia infections were detected in 320 dogs in Germany by means of microscopical and/or serological methods. It was found, that 316 dogs were infected with Babesia canis and 4 animals with Babesia gibsoni. Of the Babesia-canis-positive dogs 184 were abroad up to 4 months before diagnosis, mainly in France, Spain and Italy, but also in Hungary, Greece, Jugoslavia, Portugal, Morocco, Togo, Pakistan, Sri Lanka, Malaysia, Turkey, Romania, Austria and the Netherlands. For further 36 dogs the possible place of infection for Babesia canis could not be clarified geographically. 5 dogs each were simultaneously infested with Rhipicephalus sanguineus and Dermacentor reticulatus, respectively. The four dogs infected with Babesia gibsoni were previously in Sri Lanka (2), Brazil (1) or Algeria/Kenya (1). In 88 dogs from the Offenburg/Lahr/Freiburg area, which were not abroad, infections with Babesia canis were diagnosed from January to June as well as from September to December, however, most cases occurring in April and May. Of these dogs approximately 20% were found to be infested with Dermacentor reticulatus. These ticks were also collected on the vegetation in the Offenburg area. Therefore, an endemic focus of Babesia canis can be deduced in the area of Offenburg/Lahr/Freiburg and Dermacentor reticulatus as vector also in Germany.
    Matched MeSH terms: Seasons
  5. Karupaiah T, Chinna K, Mee LH, Mei LS, Noor MI
    Asia Pac J Clin Nutr, 2008;17(3):483-91.
    PMID: 18818170
    The Malaysian government recently introduced a ban on fast food advertisements targeting children on television. This study reports on data covering 6 months of television food advertising targeting children. Six out of seven of the Nation's commercial television networks participated (response rate = 85.7%). Based on reported timings of children's programmes, prime time significantly differed ( p <0.05) between weekdays (mean = 1.89 +/- 0.18 hr) and weekends (mean = 4.61 +/- 0.33 hr). The increased trend during weekends, school vacation and Ramadhan was evident. Over the six-month period, the mean number of food advertisements appearing per month varied greatly between television stations (C = 1104; D = 643; F = 407; B = 327; A = 59; E = 47). Food advertising also increased the most in September (n = 3158), followed by July (n = 2770), August (n = 2431), October (n = 2291), November (n = 2245) and June (n = 2211). Content analysis of advertisements indicated snacks were the highest (34.5%), followed by dairy products (20.3%), sugars and candies (13.4%), biscuits (11.2%), fast food (6.7%), breakfast cereal (6.4%), beverages (4.1%), supplements (0.9%), rice (0.6%), noodles (0.5%), bread (0.3%), miscellaneous and processed foods (0.2%). Paradoxically, we found that the frequency of snack food advertised during children's prime time was 5 times more than fast foods. The sodium content (mean = 620 mg per 100g) of these snack foods was found to be highest.
    Matched MeSH terms: Seasons
  6. Jani J, Lusk MG, Yang YY, Toor GS
    PLoS One, 2020;15(4):e0230908.
    PMID: 32236119 DOI: 10.1371/journal.pone.0230908
    Stormwater runoff is recognized as a cause of water quality degradation because it may carry nitrogen (N) and other pollutants to aquatic ecosystems. Stormwater ponds are a stormwater control measure often used to manage stormwater runoff by holding a permanent pool of water, which reduces the peak flow, magnitude of runoff volume, and concentrations of nutrients and pollutants. We instrumented the outlet of a stormwater pond in an urban residential neighbourhood in Florida, United States to (1) investigate the concentration and composition of N forms during the summer rainy season (May to September 2016), and (2) determine the bioavailability of organic N in the stormwater pond with a bioassay experiment. A total of 144 outflow water samples over 13 storm events were collected at the outlet of the stormwater pond that collects runoff from the residential catchment. Samples were analysed for various inorganic N [ammonium (NH4-N), nitrate (NO3-N)], and organic N forms [dissolved organic nitrogen (DON), and particulate organic nitrogen (PON)]. Flow-weighted mean concentration of total N (TN) in pond outflow for all collected storm events was 1.3±1.42 mg L-1, with DON as the dominant form (78%), followed by PON and NO3-N (each at 8%), and NH4-N (6%). In the bioassay experiment, organic N (DON+PON) was significantly decreased by 25-28% after 5 days of incubation, suggesting that a portion of the DON carried from the pond outflow to receiving water bodies may be bioavailable. These results suggest that efforts to mitigate stormwater N outflows from urban ponds should incorporate both inorganic and organic N in management plans.
    Matched MeSH terms: Seasons
  7. Sharif Nia H, Chan YH, Froelicher ES, Pahlevan Sharif S, Yaghoobzadeh A, Jafari A, et al.
    Health Promot Perspect, 2019;9(2):123-130.
    PMID: 31249799 DOI: 10.15171/hpp.2019.17
    Background: Meteorological parameters and seasonal changes can play an important role in the occurrence of acute coronary syndrome (ACS). However, there is almost no evidence on a national level to suggest the associations between these variables and ACS in Iran. We aim to identify the meteorological parameters and seasonal changes in relationship to ACS. Methods: This retrospective cross-sectional study was conducted between 03/19/2015 to 03/18/2016 and used documents and records of patients with ACS in Mazandaran ProvinceHeart Center, Iran. The following definitive diagnostic criteria for ACS were used: (1) existence of cardiac enzymes (CK or CK-MB) above the normal range; (2) Greater than 1 mm ST-segment elevation or depression; (3) abnormal Q waves; and (4) manifestation of troponin enzyme in the blood. Data were collected daily, such as temperature (Celsius) changes, wind speed and its direction, rainfall, daily evaporation rate; number of sunny days, and relative humidity were provided by the Meteorological Organization of Iran. Results: A sample of 2,054 patients with ACS were recruited. The results indicated the highest ACS events from March to May. Generally, wind speed (18 PM) [IRR = 1.051 (95% CI: 1.019 to1.083), P=0.001], daily evaporation [IRR = 1.039 (95% CI: 1.003 to 1.077), P=0.032], daily maximum (P<0.001) and minimum (P=0.003) relative humidity was positively correlated withACS events. Also, negatively correlated variables were daily relative humidity (18 PM) [IRR =0.985 (95% CI: 0.978 to 0.992), P<0.001], and daily minimum temperature [IRR = 0.942 (95%CI: 0.927 to 0.958), P<0.001]. Conclusion: Climate changes were found to be significantly associated with ACS; especially from cold weather to hot weather in March, April and May. Further research is needed to fully understand the specific conditions and cold exposures.
    Matched MeSH terms: Seasons
  8. Zulkafli Abdul Rashid, Mohammad Noor Azmai Amal
    Sains Malaysiana, 2018;47:1941-1951.
    This study assesses the influence of water quality on fish occurrences in Sungai Pahang, Maran District, Pahang, Malaysia. Water quality and fish samplings were conducted at seven sampling sites in the district for 13 consecutive months. We used canonical correspondence analyses (CCA) to determine the influence of water quality on monthly fish species occurrences. The ranges of water quality parameters were quite high considering the measurements were made during rainy and dry seasons throughout the year. A total of 2,075 individual fish was captured which comprised of 22 different families and 65 species. Family Cyprinidae recorded the highest number of fish species of the area (27 species; 41.5%), followed by Bagridae (five species; 7.69%) and Pangasiidae (five species; 7.69%). Three fish species categorized as endangered, including Balantiocheilos melanopterus, Probarbus jullieni and Pangasianodon hypophthalmus were also collected. The collected fish species were divided into three groups (A to C), which was clearly separated in the CCA ordination diagram. The most important water quality variables for the fish occurrences in this river were pH, followed by temperature, conductivity, alkalinity and phosphate. Data analysis indicates that the occurrence of fishes were influenced by a combination of water quality parameters, but not associated with sampling month. The results present a new data from a study of fish assemblage and their habitat condition which may be important in fisheries activity and fish conservation of the river in the future.
    Matched MeSH terms: Seasons
  9. Shuhaimi-Othman M, Lim EC, Mushrifah I
    Environ Monit Assess, 2007 Aug;131(1-3):279-92.
    PMID: 17171269
    A study of the water quality changes of Chini Lake was conducted for 12 months, which began in May 2004 and ended in April 2005. Fifteen sampling stations were selected representing the open water body in the lake. A total of 14 water quality parameters were measured and Malaysian Department of Environment Water Quality Index (DOE-WQI) was calculated and classified according to the Interim National Water Quality Standard, Malaysia (INWQS). The physical and chemical variables were temperature, dissolved oxygen (DO), conductivity, pH, total dissolved solid (TDS), turbidity, chlorophyll-a, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solid (TSS), ammonia-N, nitrate, phosphate and sulphate. Results show that base on Malaysian WQI, the water in Chini Lake is classified as class II, which is suitable for recreational activities and allows body contact. With respect to the Interim National Water Quality Standard (INWQS), temperature was within the normal range, conductivity, TSS, nitrate, sulphate and TDS are categorized under class I. Parameters for DO, pH, turbidity, BOD, COD and ammonia-N are categorized under class II. Comparison with eutrophic status indicates that chlorophyll-a concentration in the lake was in mesotrophic condition. In general water quality in Chini Lake varied temporally and spatially, and the most affected water quality parameters were TSS, turbidity, chlorophyll-a, sulphate, DO, ammonia-N, pH and conductivity.
    Matched MeSH terms: Seasons*
  10. Dalu T, Wasserman RJ, Tonkin JD, Mwedzi T, Magoro ML, Weyl OLF
    Sci Total Environ, 2017 Dec 31;607-608:317-325.
    PMID: 28692901 DOI: 10.1016/j.scitotenv.2017.06.267
    Water pollution is a critical management issue, with many rivers and streams draining urban areas being polluted by the disposal of untreated solid waste and wastewater discharge, storm water and agricultural runoff. This has implications for biodiversity, and many rivers in the developing world are now considered compromised. We investigated benthic macroinvertebrate community structure and composition in relation to physico-chemical conditions of the water column and sediments. The study was conducted in an Austral catchment subject to both urban and agricultural pollutants in two different seasons. We assessed whether sediment characteristics were more important drivers of macroinvertebrate community composition than water column characteristics. We expected clear differences in macroinvertebrate community composition and in the associated community metrics due to distinct flow conditions between the two seasons. A combination of multivariate analyses (canonical correspondence analysis (CCA)) and biological indicator analysis were used to examine these patterns. Chironomidae was the most abundant family (>60%) in the upper mainstem river and stream sites. Stream sites were positively associated with CCA axis 2, being characterised by high turbidity and lower pH, salinity, phosphate concentration, channel width and canopy cover. Canopy cover, channel width, substrate embeddedness, phosphate concentration, pH, salinity and turbidity all had a significant effect on macroinvertebrate community composition. Using CCA variation partitioning, water quality was, however, a better predictor of benthic macroinvertebrate composition than sediment chemical conditions. Furthermore, our results suggest that seasonality had little effect on structuring benthic macroinvertebrate communities in this south-eastern zone of South Africa, despite clear changes in sediment chemistry. This likely reflects the relative lack of major variability in water chemistry compared to sediment chemistry between seasons and the relatively muted variability in precipitation between seasons than the more classic Austral temperate climates.
    Matched MeSH terms: Seasons
  11. Islam MA, Khandker SS, Alam SS, Kotyla P, Hassan R
    Autoimmun Rev, 2019 Sep 11.
    PMID: 31520805 DOI: 10.1016/j.autrev.2019.102392
    BACKGROUND: Systemic lupus erythematosus (SLE) is a systemic autoimmune disease where chronic inflammation and tissue or organ damage is observed. Due to various suspected causes, inadequate levels of vitamin D (a steroid hormone with immunomodulatory effects) has been reported in patients with SLE, however, contradictory.

    AIMS: The aim of this systematic review and meta-analysis was to evaluate the serum levels of vitamin D in patients with SLE in compared to healthy controls.

    METHODS: PubMed, SCOPUS, ScienceDirect and Google Scholar electronic databases were searched systematically without restricting the languages and year (up to March 2, 2019) and studies were selected based on the inclusion criteria. Mean difference (MD) along with 95% confidence intervals (CI) were used and the analyses were carried out by using a random-effects model. Different subgroup and sensitivity analyses were conducted. Study quality was assessed by the modified Newcastle-Ottawa Scale (NOS) and publication bias was evaluated by a contour-enhanced funnel plot, Begg's and Egger's tests.

    RESULTS: We included 34 case-control studies (2265 SLE patients and 1846 healthy controls) based on the inclusion criteria. Serum levels of vitamin D was detected significantly lower in the SLE patients than that in the healthy controls (MD: -10.44, 95% CI: -13.85 to -7.03; p 

    Matched MeSH terms: Seasons
  12. Vinjamuri KS, Mhawish A, Banerjee T, Sorek-Hamer M, Broday DM, Mall RK, et al.
    Environ Pollut, 2020 Feb;257:113377.
    PMID: 31672363 DOI: 10.1016/j.envpol.2019.113377
    Attenuated backscatter profiles retrieved by the space borne active lidar CALIOP on-board CALIPSO satellite were used to measure the vertical distribution of smoke aerosols and to compare it against the ECMWF planetary boundary layer height (PBLH) over the smoke dominated region of Indo-Gangetic Plain (IGP), South Asia. Initially, the relative abundance of smoke aerosols was investigated considering multiple satellite retrieved aerosol optical properties. Only the upper IGP was selectively considered for CALIPSO retrieval based on prevalence of smoke aerosols. Smoke extinction was found to contribute 2-50% of the total aerosol extinction, with strong seasonal and altitudinal attributes. During winter (DJF), smoke aerosols contribute almost 50% of total aerosol extinction only near to the surface while in post-monsoon (ON) and monsoon (JJAS), relative contribution of smoke aerosols to total extinction was highest at about 8 km height. There was strong diurnal variation in smoke extinction, evident throughout the year, with frequent abundance of smoke particles at lower height (<4 km) during daytime compared to higher height during night (>4 km). Smoke injection height also varied considerably during rice (ON: 0.71 ± 0.65 km) and wheat (AM: 2.34 ± 1.34 km) residue burning period having a significant positive correlation with prevailing PBLH. Partitioning smoke AOD against PBLH into the free troposphere (FT) and boundary layer (BL) yield interesting results. BL contribute 36% (16%) of smoke AOD during daytime (nighttime) and the BL-FT distinction increased particularly at night. There was evidence that despite travelling efficiently to FT, major proportion of smoke AOD (50-80%) continue to remain close to the surface (<3 km) thereby, may have greater implications on regional climate, air quality, smoke transport and AOD-particulate modelling.
    Matched MeSH terms: Seasons
  13. Saravi HN, Din ZB, Makhlough A
    Pak J Biol Sci, 2008 May 01;11(9):1179-93.
    PMID: 18819525
    Temporal variations and regional distributions of dissolved nutrients and their elemental ratios in the Iranian coastal waters of the Southern Caspian Sea were investigated. The data were collected in 1996-97 (Phase I, as a background data and undisturbed ecosystem) and in 2005 (Phase II, as a disturbed ecosystem) at sampling points (from 10 to 100 m depths). In addition to the two main sampling exercises, additional sample collections were carried out during the period of 1994 to 2004 as a long-term study. This study showed that the dissolved inorganic nitrogen/dissolved inorganic phosphorus (DIN/DIP) ratios in the southern Caspian Sea vary within a very narrow range (4.47 to 5.78) within the euphotic and aphotic layers and is by one order of magnitude lower than what have been reported for several other marine ecosystems. Phytoplankton growth seems to be nitrogen limited while the levels of P and Si always remain high. Factor Analysis/Principal Component Analysis (FA/PCA) of the correlation matrix showed that the nitrogen compounds are associated with the main factor accounting for 25.7-26.2% of the total variance for both the sampling periods. During Phase I, the Chrysophyta were the major group, whereas during Phase II the proportion of Chrysophyta in the total community progressively decreased, while the other groups increased.
    Matched MeSH terms: Seasons
  14. Bienaymé A, Servant M
    DOI: 10.1007/BF01884062
    During two years the authors have assembled monthly analytical data of oilpalms, from 15 different stations. The determinations spread as far as the French, Portuguese and Spanish territory in Africa and British Malaya also. The following analyses were carried out: iodine number, titer point, melting point and the carotenoids of these oils, according to origine, race and time of gathering. As to iodine number and amount of carotenoid, the race is decisive for these data; the oils from the natural stock of the Ivory Coast have a higher iodine number (57-60). The oils from the natural stock of Togo, Dahomey, Portuguese and French Guinea are richer in carotene (up to 0.16, even 0.19%) with medium iodine number (54-56). The oils from the industrial plantations, with selected trees of the race Dura-Deli, from the Far East as well as from the Ivory Coast, have lower iodine numbers (52-53) and are poor in carotene (0.05). South of the equator in Africa, all analysed races of oil palms had a lower iodine number (53-55) and were poor in carotene (0.05). During one year the amount of carotene fluctuates about one third of its maximum; this maximum is rather striking in Togo and Dahomey; it is to be found from January to May; period of high production of the oil in the Palm groves, e.g. in the dry season with warm climate and good insolation. Heavy rain-showers effect a rapid decrease of the contents of carotene after six weeks (duration of the formation of the fruit). Furthermore, the residual oils (extracted by solvents) were analysed; they are 2 to 3 times richer in carotenoids than the common palm oil; but the contents of β-carotene seems somewhat lower. The authors think it possible to find exactly defined uses for the different oils. © 1958 Uitgeverij Dr. W. Junk.
    Matched MeSH terms: Seasons
  15. Dalu T, Wasserman RJ, Magoro ML, Mwedzi T, Froneman PW, Weyl OLF
    Sci Total Environ, 2017 Dec 01;601-602:73-82.
    PMID: 28551541 DOI: 10.1016/j.scitotenv.2017.05.162
    This study explores diatom community dynamics in a highly modified semi-arid temperate region river system characterised by inconsistent river flow. Various water and sediment environmental variables were assessed using a multi-faceted analysis approach to determine the spatio-temporal drivers of benthic diatom communities in the river system. Overall, the diatom community was generally dominated by pollution tolerant species, reflecting the anthropogenic intensity and activities on the river system. Diatom community composition was found to be largely determined by water column chemistry variables particularly nutrient concentrations in comparison to sediment chemistry and physical variables. Strong seasonal diatom species composition was also observed and this was driven by strong seasonal variations in nutrient loads and metal concentrations, a result of the variable water flow across the two seasons. However, the greater temporal variation in communities was observed in the smaller systems with the mainstream river system being more homogenous over time. In addition, diatom community composition and environmental variables were found to be different and more pronounced between streams and mainstream sites, than between canals and streams. The study highlights the complex interaction between water column, sediment and physical variables in determining the diatom species composition in small river systems. It also highlights the importance of river flow inconsistency as an indirect variable that alters primary drivers such as nutrient concentrations in the water column and heavy metal levels in the sediment.
    Matched MeSH terms: Seasons
  16. Chiang GL
    PMID: 7973951
    The genus Mansonia is divided into two subgenera, Mansonia and Mansonioides. The subgenus Mansonioides includes the important vectors of lymphatic filariasis caused by Brugia malayi in South and Southeast Asia. Six species of this subgenus are vectors of two types of brugian filariasis, periodic and subperiodic. All six species, viz Mansonia bonneae, Ma. dives, Ma. uniformis, Ma. annulifera, Ma. annulata and Ma. indiana are present in this country. The ecological factors governing the larval and adult biology and their control measures are discussed.
    Matched MeSH terms: Seasons
  17. Saifur RG, Hassan AA, Dieng H, Ahmad H, Salmah MR, Satho T, et al.
    J Am Mosq Control Assoc, 2012 Jun;28(2):84-92.
    PMID: 22894118
    It is important to obtain frequent measurements of the abundance, distribution, and seasonality of mosquito vectors to determine the risk of disease transmission. The number of cases of dengue infection has increased in recent years on Penang Island, Malaysia, with recurring epidemics. However, ongoing control attempts are being critically hampered by the lack of up-to-date information regarding the vectors. To overcome this problem, we examined the current situation and distribution of dengue vectors on the island. Residences throughout the urban, suburban, and rural areas were inspected through wet and dry seasons between February 2009 and February 2010. Two vectors were encountered in the survey, with Aedes aegypti present in especially high numbers mostly in urban areas. Similar observations were noted for Ae. albopictus in rural areas. The former species was more abundant in outdoor containers, while the latter showed almost equivalent abundance both outdoors and indoors. The dengue virus was active in both urban and rural areas, and the number of cases of infection was higher in areas where Ae. aegypti was predominant. The abundance of immature Ae. albopictus was positively correlated with rainfall (r2 = 0.461; P < 0.05), but this was not the case for Ae. aegypti. For both species, the size of immature populations tended to increase with increasing intensity of rain, but heavy rains resulted in population loss. In addition to updating data regarding the larval habitats and locations (outdoors and indoors), this study highlighted the importance of spatial vector control stratification, which has the potential to reduce costs in control programs.
    Matched MeSH terms: Seasons
  18. Li Q, Zhang K, Li R, Yang L, Yi Y, Liu Z, et al.
    Sci Total Environ, 2023 May 10;872:162071.
    PMID: 36775179 DOI: 10.1016/j.scitotenv.2023.162071
    Biomass burning (BB) has significant impacts on air quality and climate change, especially during harvest seasons. In previous studies, levoglucosan was frequently used for the calculation of BB contribution to PM2.5, however, the degradation of levoglucosan (Lev) could lead to large uncertainties. To quantify the influence of the degradation of Lev on the contribution of BB to PM2.5, PM2.5-bound biomass burning-derived markers were measured in Changzhou from November 2020 to March 2021 using the thermal desorption aerosol gas chromatography-mass spectrometry (TAG-GC/MS) system. Temporal variations of three anhydro-sugar BB tracers (e.g., levoglucosan, mannosan (Man), and galactosan (Gal)) were obtained. During the sampling period, the degradation level of air mass (x) was 0.13, indicating that ~87 % of levoglucosan had degraded before sampling in Changzhou. Without considering the degradation of levoglucosan in the atmosphere, the contribution of BB to OC were 7.8 %, 10.2 %, and 9.3 % in the clean period, BB period, and whole period, respectively, which were 2.4-2.6 times lower than those (20.8 %-25.9 %) considered levoglucosan degradation. This illustrated that the relative contribution of BB to OC could be underestimated (~14.9 %) without considering degradation of levoglucosan. Compared to the traditional method (i.e., only using K+ as BB tracer), organic tracers (Lev, Man, Gal) were put into the Positive Matrix Factorization (PMF) model in this study. With the addition of BB organic tracers and replaced K+ with K+BB (the water-soluble potassium produced by biomass burning), the overall contribution of BB to PM2.5 was enhanced by 3.2 % after accounting for levoglucosan degradation based on the PMF analysis. This study provides useful information to better understand the effect of biomass burning on the air quality in the Yangtze River Delta region.
    Matched MeSH terms: Seasons
  19. 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
Filters
Contact Us

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

External Links