Objective:To determine the genetic diversity of Plasmodium(P.)knowlesi isolates from Sabah,Malaysian Borneo and Peninsular Malaysia,targeting the S-type SSU rRNA gene and including aspects of natural selection and hap...Objective:To determine the genetic diversity of Plasmodium(P.)knowlesi isolates from Sabah,Malaysian Borneo and Peninsular Malaysia,targeting the S-type SSU rRNA gene and including aspects of natural selection and haplotype.Methods:Thirty-nine blood samples infected with P.knowlesi were collected in Sabah,Malaysian Borneo and Peninsular Malaysia.The S-type SSU rRNA gene was amplified using polymerase chain reaction,cloned into a vector,and sequenced.The natural selection and haplotype of the S-type SSU rRNA gene sequences were determined using DnaSP v6 and illustrated using NETWORK v10.This study's 39 S-type SSU rRNA sequences and eight sequences from the Genbank database were subjected to phylogenetic analysis using MEGA 11.Results:Overall,the phylogenetic analysis showed no evidence of a geographical cluster of P.knowlesi isolates from different areas in Malaysia based on the S-type SSU rRNA gene sequences.The S-type SSU rRNA gene sequences were relatively conserved and with a purifying effect.Haplotype sharing of the S-type SSU rRNA gene was observed between the P.knowlesi isolates in Sabah,Malaysian Borneo,but not between Sabah,Malaysian Borneo and Peninsular Malaysia.Conclusions:This study suggests that the S-type SSU rRNA gene of P.knowlesi isolates in Sabah,Malaysian Borneo,and Peninsular Malaysia has fewer polymorphic sites,representing the conservation of the gene.These features make the S-type SSU rRNA gene suitable for comparative studies,such as determining the evolutionary relationships and common ancestry among P.knowlesi species.展开更多
The inverse relationship between the warm phase of the El Nino Southern Oscillation(ENSO)and the Indian Summer Monsoon Rainfall(ISMR)is well established.Yet,some El Nino events that occur in the early months of the ye...The inverse relationship between the warm phase of the El Nino Southern Oscillation(ENSO)and the Indian Summer Monsoon Rainfall(ISMR)is well established.Yet,some El Nino events that occur in the early months of the year(boreal spring)transform into a neutral phase before the start of summer,whereas others begin in the boreal summer and persist in a positive phase throughout the summer monsoon season.This study investigates the distinct influences of an exhausted spring El Nino(springtime)and emerging summer El Nino(summertime)on the regional variability of ISMR.The two ENSO categories were formulated based on the time of occurrence of positive SST anomalies over the Nino-3.4 region in the Pacific.The ISMR’s dynamical and thermodynamical responses to such events were investigated using standard metrics such as the Walker and Hadley circulations,vertically integrated moisture flux convergence(VIMFC),wind shear,and upper atmospheric circulation.The monsoon circulation features are remarkably different in response to the exhausted spring El Nino and emerging summer El Nino phases,which distinctly dictate regional rainfall variability.The dynamic and thermodynamic responses reveal that exhausted spring El Nino events favor excess monsoon rainfall over eastern peninsular India and deficit rainfall over the core monsoon regions of central India.In contrast,emerging summer El Nino events negatively impact the seasonal rainfall over the country,except for a few regions along the west coast and northeast India.展开更多
Lignin extraction from bark can maximize the utilization of biomass waste,offer cost-effectiveness,and promote environmental friendliness when employed as an adhesive material in bark particleboard production.Particle...Lignin extraction from bark can maximize the utilization of biomass waste,offer cost-effectiveness,and promote environmental friendliness when employed as an adhesive material in bark particleboard production.Particles of fine(0.2 to 1.0 mm),medium(1.0 to 2.5 mm),and coarse(2.5 to 12.0 mm)sizes,derived from the bark of Leucaena leucocephala,were hot-pressed using a heating plate at 175℃for 7 min to create single-layer particleboards measuring 320 mm×320 mm×10 mm,targeting a density of 700 kg/m^(3).Subsequently,the samples were trimmed and conditioned at 20℃and 65%relative humidity.In this study,we compared bark particleboard bonded with urea formaldehyde(UF)adhesive to fine-sized particleboard bonded with demethylated lignin adhesive.The results indicated that bark particleboards utilizing demethylated lignin and UF adhesives exhibited similar qualities.Coarse particleboard showed differences in modulus of elasticity(MOE)and modulus of rupture(MOR),while medium-sized particles exhibited significant variations in moisture content(MC)and water absorption(WA).Furthermore,the thickness swelling of coarse and medium-sized particles under wet and oven-dried conditions exhibited notable distinctions.Overall,the demethylated lignin adhesive extracted from L.leucocephala bark demonstrated similar quality to UF adhesive,with particle size correlating inversely to the strength of the bark particleboard.展开更多
Heavy metal contents along the Northwest coast of Sabah were determined to interpret the pollution level in the marine sediment. The metal abundance is regulated by the physico-chemical properties such as the average ...Heavy metal contents along the Northwest coast of Sabah were determined to interpret the pollution level in the marine sediment. The metal abundance is regulated by the physico-chemical properties such as the average sediment pH(7.82, 9.00 and 8.99), organic matter(0.62%, 1.60%, and 2.27%), moisture content(25.00%, 29.70%, and 15.00%) and sandy texture in Kota Belud, Kudat and Mantanani Island,respectively. The major elements show Ca>Fe>Mg>Al>Mn for all study sites, while the heavy metals show Ni>Cr>Zn>Cu>Co>Pb, Cr>Ni>Zn>Cu>Pb>Co and Zn>Pb>Cr>Ni, for Kota Belud, Kudat and Mantanani Island, respectively. The pollution degree of heavy metals was evaluated by using the Sediment Quality Assessment(SQA). The SQA parameters indicated none to moderate pollution in Kota Belud that shows Class 0, Class 1 and Class 2 pollution. The parameters also indicated none to low pollution in Kudat and Mantanani Island that show only Class 0 pollution. The enrichment factor(EF) suggested minor to moderately severe metal enrichment by anthropogenic sources in Kota Belud, whereas only minor enrichment in Kudat and Mantanani Island. The modified pollution degree(MCD<1.5) and pollution load index(0 PLI<1) indicating only low pollution level in the marine sediments for all study sites. The objectives of this study are:(1) to determine the physico-chemical parameters of sediments,(2) interpret the heavy metal contents and(3) evaluate the sediment quality.展开更多
Malaria is one of the most devastating infectious diseases that caused millions of clinical cases annually despite decades of prevention efforts. Recent cases of Plasmodium falciparum resistance against the only remai...Malaria is one of the most devastating infectious diseases that caused millions of clinical cases annually despite decades of prevention efforts. Recent cases of Plasmodium falciparum resistance against the only remaining class of effective antimalarial(artemisinin) in South East Asia may soon pose a significant threat. Hence, the identification of new antimalarial compounds with a novel mode of action is necessary to curb this problem. Protein kinase has been implicated as a valid target for drug development in diseases such as cancer and diabetes in humans. A similar approach is now recognized for the treatment of protozoan-related disease including malaria. Few Plasmodium protein kinases that are not only crucial for their survival but also have unique structural features have been identified as a potential target for drug development. In this review, studies on antimalarial drug development exploiting the size of Plasmodium protein kinase ATP gatekeeper over the past 15 years are mainly discussed. The ATP-binding site of Plasmodium protein kinases such as Pf CDPK1, Pf CDPK4, Pf PKG, Pf PK7, and Pf PI4K showed great potential for selective and multi-target inhibitions owing to their smaller or unique ATP-gatekeeper amino acid subunits compared to that of human protein kinase. Hence it is a feasible solution to identify a new class of active antimalarial agents with a novel mode of action and longer clinical life-span.展开更多
The South China,Indochina,and Borneo margins surrounding the South China Sea contain long-lived arcs that became inactive at approximately 85 Ma,even though an embayment of oceanic crust(the‘Proto-South China Sea’)r...The South China,Indochina,and Borneo margins surrounding the South China Sea contain long-lived arcs that became inactive at approximately 85 Ma,even though an embayment of oceanic crust(the‘Proto-South China Sea’)remained in the intervening region.This oceanic crust eventually subducted in the Cenozoic below Borneo and the Cagayan arc,while the modern South China Sea opened in its wake.To investigate the enigmatic cessation of Mesozoic subduction below South China and Borneo,we studied a fragment of oceanic crust and overlying trench-fill sediments that accreted to NW Borneo during the final stages of Paleo-Pacific subduction.Based on radiolarian biostratigraphy of cherts overlying the pillow basalts and detrital zircon geochronology of the trench-fill,we constrained the minimum age of the oceanic crust during accretion to 40 Ma.This shows that subduction cessation was not related to ridge subduction.Geochemical analysis of pillow basalts revealed an enriched mid-ocean ridge basalt signature comparable to oceanic plateaus.Using paleomagnetism,we show that this fragment of oceanic crust was not part of the Izanagi Plate but was part of a plate(the‘Pontus’Plate)separated from the Izanagi Plate by a subduction zone.Based on the minimum 40 Ma age of the oceanic crust and its geochemistry,we suggest that Mesozoic subduction below South China and Borneo stopped when an oceanic plateau entered the trench,while the eastern plate margin with the Izanagi Plate remained active.We show how our findings offer opportunities to restore plate configurations of the Panthalassa-Tethys junction region.展开更多
A well-known adsorbent, poly(amidoxime)ligand, was prepared from polyacrylonitrile(PAN) grafted kenaf cellulose, and subsequent characterization was performed by Fourier transform infrared spectroscopy(FTIR),field emi...A well-known adsorbent, poly(amidoxime)ligand, was prepared from polyacrylonitrile(PAN) grafted kenaf cellulose, and subsequent characterization was performed by Fourier transform infrared spectroscopy(FTIR),field emission scanning electron microscope(FESEM) and inductively coupled plasma mass spectrometry(ICP-MS).The adsorption capacities of the prepared ligand for rare earth metals are found to be excellent, with adsorptions of La^(3+), Ce^(3+), Pr^(3+), Gd^(3+) and Nd^(3+) experimentally determined to be 262, 255, 244, 241 and 233 mg·g^(-1), respectively, at pH 6. The experimental values of the adsorption of rare earth metals are well matched with the pseudosecond-order rate equation. The reusability of the adsorbent is examined for seven cycles of sorption/desorption,demonstrating that the proposed adsorbent could be reused for over seven cycles without any significant loss in the original removal capability of the ligand.展开更多
Lanthanide-ion imprinted polymers（L-IIPs） were synthesized by stoichiometric amounts of rare earth ions and the cavities in the polymers were created for the corresponding lanthanide ions. The maximum sorption capac...Lanthanide-ion imprinted polymers（L-IIPs） were synthesized by stoichiometric amounts of rare earth ions and the cavities in the polymers were created for the corresponding lanthanide ions. The maximum sorption capacities were estimated to be 125.3, 126.5, 127.6, 128.2 and 129.1 mg/g for Pr, Nd, Sm, Eu and Gd, respectively at p H 6. In the selectivity study, the L-IIPs exhibited good selectivity to the specific rare earth ions in the presence of coexisting cations. The imprinting results were found to be excellent with some rare earth ions over other competitor rare earth ions with the same charges and close ionic radius.展开更多
Sea-level rise is a long-term,intractable problem during which costly,large-scale inundation could occur in many countries;hence,tourismdevelopment should take this matter into account because ecology and biodiversity...Sea-level rise is a long-term,intractable problem during which costly,large-scale inundation could occur in many countries;hence,tourismdevelopment should take this matter into account because ecology and biodiversity are the fundamentals underpinning tourism performance.This study conceptualizes an economic mechanism of the potential effects of sea-level rise on tourism development based on projected impactsfor the 2001e2100 period.Data for 48 developing countries across Africa,Asia,and South America are analyzed.The theoretical frameworkproposes two hypotheses to determine the extent of contradiction between awareness and destruction in relation to environmental protection fortourism development.From the panel data regression results,although destructive effects are bound to dominate the entire 21st century,awareness is latent and has the potential to reverse the destructive outcomes.With evidence from essential economic elements,this study givesnew insights into how severe the impacts of sea-level rise on tourism could be if shared values and adaptation measures to mitigate rising sealevel are not substantively promoted around the globe.The new findings show a 0.95 standard-deviation decrease in tourism performancefollowing a 1 standard-deviation increase in the economic loss related sea-level rise.Hence,in the main conclusions,we highlight that theprojected effect of inundation-related deterioration on a country's tourism sector appears to be approximately on par with the costs of inundationsto its economic growth.展开更多
This study investigates the recent extreme temperature trends across 19 stations in the Klang Valley, Malaysia, over the period 2006^-16. Fourteen extreme index trends were analyzed using the Mann-Kendall non-parametr...This study investigates the recent extreme temperature trends across 19 stations in the Klang Valley, Malaysia, over the period 2006^-16. Fourteen extreme index trends were analyzed using the Mann-Kendall non-parametric test, with Sen’s slope as a magnitude estimator. Generally, the annual daily mean temperature, daily mean maximum temperature, and daily mean minimum temperature in the Klang Valley increased significantly, by 0.07°C yr^-1, 0.07°C yr^-1 and 0.08°C yr^-1, respectively. For the warm temperature indices, the results indicated a significant upward trend for the annual maximum of maximum temperature, by 0.09°C yr^-1, and the annual maximum of minimum temperature, by 0.11°C yr^-1. The results for the total number of warm days and warm nights showed significant increasing trends of 5.02 d yr^-1 and 6.92 d yr^-1, respectively. For the cold temperature indices, there were upward trends for the annual minimum of maximum temperature, by 0.09°C yr^-1, and the annual minimum of minimum temperature, by 0.03°C yr^-1, concurrent with the decreases in the total number cold days (TX10P), with -3.80 d yr^-1, and cold nights (TN10P), with -4.33 d yr^-1. The 34°C and 37°C summer days results showed significant upward trends of 4.10 d yr^-1 and 0.25 d yr^-1, respectively. Overall, these findings showed upward warming trends in the Klang Valley, with the minimum temperature rate increasing more than that of the maximum temperature, especially in urban areas.展开更多
Surface ozone(O3)is a secondary pollutant harmful to human health and a greenhouse gas which is one of the prime climate forcers.Due to the clean atmospheric environment of the Antarctic region and given the complexit...Surface ozone(O3)is a secondary pollutant harmful to human health and a greenhouse gas which is one of the prime climate forcers.Due to the clean atmospheric environment of the Antarctic region and given the complexity of O3 chemistry,the observation of surface O3 variability in this region is necessary in the quest to better understand the potential sources and sink of polar surface O3.In this paper,we highlighted our observations on O3 variability at the Great Wall Station(GWS)during austral summer in December 2018 and January 2019.The continuous surface O3 measurement at the GWS,Antarctica was carried out using the Ecotech Ozone analyzer.To understand the roles of the meteorological conditions on the temporal variations of O3,meteorological data was obtained from the conventional auto-observational station at the GWS.The Hybrid Single-Particle Lagrangian Integrated Trajectory(HYSPLIT)model was employed to investigate the air mass transport over the region.The observed austral summer surface O3 concentrations at the GWS exhibited variability and were significantly lower than those previously observed at other permanent coastal stations in Antarctica.The surface ozone variability at the GWS was strongly influenced by the synoptic change of air mass origin although the roles of photochemistry production and destruction were still uncertain.Marine characteristics and stable surface O3 characterized the air masses that reached the GWS.The unique characteristic of surface O3 at the coastal site of GWS was emphasized by its synoptic air mass characteristics,which displayed a significant influence on surface O3 variability.Air mass that traveled over the ocean with relatively shorter distance was linked to the lower O3 level,whereby the marine transport of reactive bromine(Br)species was thought to play a significant role in the tropospheric chemistry that leads to O3 destruction.Meanwhile,the diurnal variation indicated that the O3 background concentration levels were not strongly associated with the local atmospheric conditions.展开更多
This experiment aimed to determine how Cd exposure impacts CD4 cell activation,macrophage cells,pinocytosis activity,metallothionine expression,and Cd levels in juvenile Gambusia affinis gills.Four treatment groups we...This experiment aimed to determine how Cd exposure impacts CD4 cell activation,macrophage cells,pinocytosis activity,metallothionine expression,and Cd levels in juvenile Gambusia affinis gills.Four treatment groups were used,with one control and treatments A,B,C,and D at dosages of 0.03 mg/L,0.023 mg/L,0.015 mg/L,and 0.008 mg/L,respectively.The results showed that the number of CD4 with CD8 cell markers differed significantly from each treatment compared to the control(0.33%).The value in A,namely 0.54%,was the highest,followed by B,C,and D of 0.46%,0.44%,and 0.42%,respectively.The number of macrophages increased as the Cd level of the medium increased,as did the activity of pinocytosis.Furthermore,the immunofluorescence test on the gills with the Anti-MT Mouse and goat IgG fluoresce in Rhodamine on the gills showed that luminescence increased with increasing Cd levels in the gills.Similarly,the MT intensity increased at Cd-exposed gills as compared to the control.As the Cd level in the gills increased,the MT levels ascended significantly.展开更多
Background Urban heat island(UHI)is an urban climate phenomenon that primarily responds to urban conditions and land use change.The extent of hard surfaces significantly influences the thermal properties of the land.T...Background Urban heat island(UHI)is an urban climate phenomenon that primarily responds to urban conditions and land use change.The extent of hard surfaces significantly influences the thermal properties of the land.To address this issue,a novel approach quantifying the association between land use and UHI is developed.This study offers a new technique for effectively estimating the effect of land use on the UHI intensity using the combination of urban heat intensity index(UHII)and land contribution index(LCI)derived from Landsat 8 OLI images.The time-series thermal effect of land use on the UHI intensity can be determined according to the ratio in mean temperature between specific land use and the whole study site.The study was conducted in the Hulu Langat district,Malaysia during 2014-2021.Results The UHI intensity rose from 0.19 in 2014 to 0.70 in 2021.The negative value of LCI for vegetation areas and water bodies obtained its negative contribution to the urban heat island,while the positive value of LCI for bare areas and built-up areas showed its positive effect on the urban heat island.The LCI value for urban areas showed a significant increase in the 7 years such as 0.51,0.66,0.69,and 0.75 for periods 2014,2016,2018,and 2021,respectively.The change in LCI from 2014 to 2021 for the transformation of bare area and forest was recorded to be 0.23 and−0.02,respectively.Thus,the conversion of forests into urban areas had a negative effect on the increment of UHI intensity.Conclusions Overall,these findings are useful for policy-making agency in developing an effective policy for reducing high UHI intensity and planning long-term land use management.展开更多
Among the various techniques of power scavenging,piezoelectric energy harvesting usually has more power density.Although piezoceramics are usually more efficient than other piezoelectric materials,since they are very ...Among the various techniques of power scavenging,piezoelectric energy harvesting usually has more power density.Although piezoceramics are usually more efficient than other piezoelectric materials,since they are very brittle and fragile,researchers are looking for alternative materials.Recently Cellulose Electro-active paper(EAPap)has been recognized as a smart material with piezoelectric behavior that can be used in energy scavenging systems.The majority of researches in energy harvesting area,use unimorph piezoelectric cantilever beams.This paper presents an analytical solution based on distributed parameter model for partially covered pieoelectric cantilever energy harvester.The purpose of the paper is to describe the changes in generated power with damping and the load resistance using analytical calculations.The analytical data are verified using experiment on a vibrating cantilever substrate that is partially covered by EAPap films.The results are very close to each other.Also asymptotic trends of the voltage,current and power outputs are investigated and expressions are obtained for the extreme conditions of the load resistance.These new findings provide guidelines for identification and manipulation of effective parameters in order to achieve the efficient performance in different ambient source conditions.展开更多
Introduction:COVID-19 has affected almost every country in the world,which causing many negative implications in terms of education,economy and mental health.Worryingly,the trend of second or third wave of the pandemi...Introduction:COVID-19 has affected almost every country in the world,which causing many negative implications in terms of education,economy and mental health.Worryingly,the trend of second or third wave of the pandemic has been noted in multiple regions despite early success of flattening the curve,such as in the case of Malaysia,post Sabah state election in September 2020.Hence,it is imperative to predict ongoing trend of COVID-19 to assist crucial policymaking in curbing the transmission.Method:Generalized logistic growth modelling(GLM)approach was adopted to make prediction of growth of cases according to each state in Malaysia.The data was obtained from official Ministry of Health Malaysia daily report,starting from 26 September 2020 until 1 January 2021.Result:Sabah,Johor,Selangor and Kuala Lumpur are predicted to exceed 10,000 cumulative cases by 2 February 2021.Nationally,the growth factor has been shown to range between 0.25 to a peak of 3.1 throughout the current Movement Control Order(MCO).The growth factor range for Sabah ranged from 1.00 to 1.25,while Selangor,the state which has the highest case,has a mean growth factor ranging from 1.22 to 1.52.The highest growth rates reported were inWP Labuan for the time periods of 22 Nov-5 Dec 2020 with growth rates of 4.77.States with higher population densities were predicted to have higher cases of COVID-19.Conclusion:GLM is helpful to provide governments and policymakers with accurate and helpful forecasts on magnitude of epidemic and peak time.This forecast could assist government in devising short-and long-term plan to tackle the ongoing pandemic.展开更多
This book review provides a multi-dimensional discussion on how the text(two editions)delivers not only factual information regarding European economic history,but focuses on the relevance and constructive uses of eco...This book review provides a multi-dimensional discussion on how the text(two editions)delivers not only factual information regarding European economic history,but focuses on the relevance and constructive uses of economic concepts,theories,and statistical analyses on issues regarding industrial economics.One major concern within industrial economics is the failure to recognize past experiences(the importance of history).Accordingly,the book contains a considerable amount of discussion about the problems and changes in the history of economic distribution associated with specific locations of economic activities,income,resources,production,international economic integration,and spatial economic activities in Europe.Furthermore,economic issues related to the international relationship between Europe and some developing countries are also elaborated.This book review serves as more than a summary:it highlights several intellectual and research-oriented aspects of the book that may benefit studies of economic industrialization and the humanities and social sciences more broadly.In particular,several aspects are evaluated,suggesting the extent of its comprehensiveness and the important data provided in the book.Finally,certain differences observed between the first and second editions of the book are also acknowledged and explained.展开更多
基金This study was supported by the Ministry of Higher Education,Malaysia(FRGS0322-SG-1/2013)Universiti Malaysia Sabah(GUG0521-2/2020).
文摘Objective:To determine the genetic diversity of Plasmodium(P.)knowlesi isolates from Sabah,Malaysian Borneo and Peninsular Malaysia,targeting the S-type SSU rRNA gene and including aspects of natural selection and haplotype.Methods:Thirty-nine blood samples infected with P.knowlesi were collected in Sabah,Malaysian Borneo and Peninsular Malaysia.The S-type SSU rRNA gene was amplified using polymerase chain reaction,cloned into a vector,and sequenced.The natural selection and haplotype of the S-type SSU rRNA gene sequences were determined using DnaSP v6 and illustrated using NETWORK v10.This study's 39 S-type SSU rRNA sequences and eight sequences from the Genbank database were subjected to phylogenetic analysis using MEGA 11.Results:Overall,the phylogenetic analysis showed no evidence of a geographical cluster of P.knowlesi isolates from different areas in Malaysia based on the S-type SSU rRNA gene sequences.The S-type SSU rRNA gene sequences were relatively conserved and with a purifying effect.Haplotype sharing of the S-type SSU rRNA gene was observed between the P.knowlesi isolates in Sabah,Malaysian Borneo,but not between Sabah,Malaysian Borneo and Peninsular Malaysia.Conclusions:This study suggests that the S-type SSU rRNA gene of P.knowlesi isolates in Sabah,Malaysian Borneo,and Peninsular Malaysia has fewer polymorphic sites,representing the conservation of the gene.These features make the S-type SSU rRNA gene suitable for comparative studies,such as determining the evolutionary relationships and common ancestry among P.knowlesi species.
基金funding support from the National Monsoon Mission program of the Ministry of Earth Sciences(MoES),New Delhi。
文摘The inverse relationship between the warm phase of the El Nino Southern Oscillation(ENSO)and the Indian Summer Monsoon Rainfall(ISMR)is well established.Yet,some El Nino events that occur in the early months of the year(boreal spring)transform into a neutral phase before the start of summer,whereas others begin in the boreal summer and persist in a positive phase throughout the summer monsoon season.This study investigates the distinct influences of an exhausted spring El Nino(springtime)and emerging summer El Nino(summertime)on the regional variability of ISMR.The two ENSO categories were formulated based on the time of occurrence of positive SST anomalies over the Nino-3.4 region in the Pacific.The ISMR’s dynamical and thermodynamical responses to such events were investigated using standard metrics such as the Walker and Hadley circulations,vertically integrated moisture flux convergence(VIMFC),wind shear,and upper atmospheric circulation.The monsoon circulation features are remarkably different in response to the exhausted spring El Nino and emerging summer El Nino phases,which distinctly dictate regional rainfall variability.The dynamic and thermodynamic responses reveal that exhausted spring El Nino events favor excess monsoon rainfall over eastern peninsular India and deficit rainfall over the core monsoon regions of central India.In contrast,emerging summer El Nino events negatively impact the seasonal rainfall over the country,except for a few regions along the west coast and northeast India.
基金the financial support provided by UMS Great(GUG0217-1/2018),which played a crucial role in the completion of this study.
文摘Lignin extraction from bark can maximize the utilization of biomass waste,offer cost-effectiveness,and promote environmental friendliness when employed as an adhesive material in bark particleboard production.Particles of fine(0.2 to 1.0 mm),medium(1.0 to 2.5 mm),and coarse(2.5 to 12.0 mm)sizes,derived from the bark of Leucaena leucocephala,were hot-pressed using a heating plate at 175℃for 7 min to create single-layer particleboards measuring 320 mm×320 mm×10 mm,targeting a density of 700 kg/m^(3).Subsequently,the samples were trimmed and conditioned at 20℃and 65%relative humidity.In this study,we compared bark particleboard bonded with urea formaldehyde(UF)adhesive to fine-sized particleboard bonded with demethylated lignin adhesive.The results indicated that bark particleboards utilizing demethylated lignin and UF adhesives exhibited similar qualities.Coarse particleboard showed differences in modulus of elasticity(MOE)and modulus of rupture(MOR),while medium-sized particles exhibited significant variations in moisture content(MC)and water absorption(WA).Furthermore,the thickness swelling of coarse and medium-sized particles under wet and oven-dried conditions exhibited notable distinctions.Overall,the demethylated lignin adhesive extracted from L.leucocephala bark demonstrated similar quality to UF adhesive,with particle size correlating inversely to the strength of the bark particleboard.
基金supported by the Ministry of Higher Education of Malaysia for University Malaysia Sabah under the research grant TR@M001-2019。
文摘Heavy metal contents along the Northwest coast of Sabah were determined to interpret the pollution level in the marine sediment. The metal abundance is regulated by the physico-chemical properties such as the average sediment pH(7.82, 9.00 and 8.99), organic matter(0.62%, 1.60%, and 2.27%), moisture content(25.00%, 29.70%, and 15.00%) and sandy texture in Kota Belud, Kudat and Mantanani Island,respectively. The major elements show Ca>Fe>Mg>Al>Mn for all study sites, while the heavy metals show Ni>Cr>Zn>Cu>Co>Pb, Cr>Ni>Zn>Cu>Pb>Co and Zn>Pb>Cr>Ni, for Kota Belud, Kudat and Mantanani Island, respectively. The pollution degree of heavy metals was evaluated by using the Sediment Quality Assessment(SQA). The SQA parameters indicated none to moderate pollution in Kota Belud that shows Class 0, Class 1 and Class 2 pollution. The parameters also indicated none to low pollution in Kudat and Mantanani Island that show only Class 0 pollution. The enrichment factor(EF) suggested minor to moderately severe metal enrichment by anthropogenic sources in Kota Belud, whereas only minor enrichment in Kudat and Mantanani Island. The modified pollution degree(MCD<1.5) and pollution load index(0 PLI<1) indicating only low pollution level in the marine sediments for all study sites. The objectives of this study are:(1) to determine the physico-chemical parameters of sediments,(2) interpret the heavy metal contents and(3) evaluate the sediment quality.
文摘Malaria is one of the most devastating infectious diseases that caused millions of clinical cases annually despite decades of prevention efforts. Recent cases of Plasmodium falciparum resistance against the only remaining class of effective antimalarial(artemisinin) in South East Asia may soon pose a significant threat. Hence, the identification of new antimalarial compounds with a novel mode of action is necessary to curb this problem. Protein kinase has been implicated as a valid target for drug development in diseases such as cancer and diabetes in humans. A similar approach is now recognized for the treatment of protozoan-related disease including malaria. Few Plasmodium protein kinases that are not only crucial for their survival but also have unique structural features have been identified as a potential target for drug development. In this review, studies on antimalarial drug development exploiting the size of Plasmodium protein kinase ATP gatekeeper over the past 15 years are mainly discussed. The ATP-binding site of Plasmodium protein kinases such as Pf CDPK1, Pf CDPK4, Pf PKG, Pf PK7, and Pf PI4K showed great potential for selective and multi-target inhibitions owing to their smaller or unique ATP-gatekeeper amino acid subunits compared to that of human protein kinase. Hence it is a feasible solution to identify a new class of active antimalarial agents with a novel mode of action and longer clinical life-span.
基金SHAvdL and DJJvH were funded by NWO Vici grant 865.17.001 to DJJvH.LC acknowledges funding from the National Natural Science Foundation of China(grant 42106073)Open Fund of the State Key Laboratory of Marine Geology(Tongji University)(grant MGK202107).
文摘The South China,Indochina,and Borneo margins surrounding the South China Sea contain long-lived arcs that became inactive at approximately 85 Ma,even though an embayment of oceanic crust(the‘Proto-South China Sea’)remained in the intervening region.This oceanic crust eventually subducted in the Cenozoic below Borneo and the Cagayan arc,while the modern South China Sea opened in its wake.To investigate the enigmatic cessation of Mesozoic subduction below South China and Borneo,we studied a fragment of oceanic crust and overlying trench-fill sediments that accreted to NW Borneo during the final stages of Paleo-Pacific subduction.Based on radiolarian biostratigraphy of cherts overlying the pillow basalts and detrital zircon geochronology of the trench-fill,we constrained the minimum age of the oceanic crust during accretion to 40 Ma.This shows that subduction cessation was not related to ridge subduction.Geochemical analysis of pillow basalts revealed an enriched mid-ocean ridge basalt signature comparable to oceanic plateaus.Using paleomagnetism,we show that this fragment of oceanic crust was not part of the Izanagi Plate but was part of a plate(the‘Pontus’Plate)separated from the Izanagi Plate by a subduction zone.Based on the minimum 40 Ma age of the oceanic crust and its geochemistry,we suggest that Mesozoic subduction below South China and Borneo stopped when an oceanic plateau entered the trench,while the eastern plate margin with the Izanagi Plate remained active.We show how our findings offer opportunities to restore plate configurations of the Panthalassa-Tethys junction region.
基金financially supported by the Universiti Malaysia Sabah (No. SBK0260-ST-2016)
文摘A well-known adsorbent, poly(amidoxime)ligand, was prepared from polyacrylonitrile(PAN) grafted kenaf cellulose, and subsequent characterization was performed by Fourier transform infrared spectroscopy(FTIR),field emission scanning electron microscope(FESEM) and inductively coupled plasma mass spectrometry(ICP-MS).The adsorption capacities of the prepared ligand for rare earth metals are found to be excellent, with adsorptions of La^(3+), Ce^(3+), Pr^(3+), Gd^(3+) and Nd^(3+) experimentally determined to be 262, 255, 244, 241 and 233 mg·g^(-1), respectively, at pH 6. The experimental values of the adsorption of rare earth metals are well matched with the pseudosecond-order rate equation. The reusability of the adsorbent is examined for seven cycles of sorption/desorption,demonstrating that the proposed adsorbent could be reused for over seven cycles without any significant loss in the original removal capability of the ligand.
基金Project supported by the Ministry of Science,Technology and Innovation,Malaysia(RDU130505,SBK0260-ST-2016)
文摘Lanthanide-ion imprinted polymers（L-IIPs） were synthesized by stoichiometric amounts of rare earth ions and the cavities in the polymers were created for the corresponding lanthanide ions. The maximum sorption capacities were estimated to be 125.3, 126.5, 127.6, 128.2 and 129.1 mg/g for Pr, Nd, Sm, Eu and Gd, respectively at p H 6. In the selectivity study, the L-IIPs exhibited good selectivity to the specific rare earth ions in the presence of coexisting cations. The imprinting results were found to be excellent with some rare earth ions over other competitor rare earth ions with the same charges and close ionic radius.
文摘Sea-level rise is a long-term,intractable problem during which costly,large-scale inundation could occur in many countries;hence,tourismdevelopment should take this matter into account because ecology and biodiversity are the fundamentals underpinning tourism performance.This study conceptualizes an economic mechanism of the potential effects of sea-level rise on tourism development based on projected impactsfor the 2001e2100 period.Data for 48 developing countries across Africa,Asia,and South America are analyzed.The theoretical frameworkproposes two hypotheses to determine the extent of contradiction between awareness and destruction in relation to environmental protection fortourism development.From the panel data regression results,although destructive effects are bound to dominate the entire 21st century,awareness is latent and has the potential to reverse the destructive outcomes.With evidence from essential economic elements,this study givesnew insights into how severe the impacts of sea-level rise on tourism could be if shared values and adaptation measures to mitigate rising sealevel are not substantively promoted around the globe.The new findings show a 0.95 standard-deviation decrease in tourism performancefollowing a 1 standard-deviation increase in the economic loss related sea-level rise.Hence,in the main conclusions,we highlight that theprojected effect of inundation-related deterioration on a country's tourism sector appears to be approximately on par with the costs of inundationsto its economic growth.
基金supported by Newton-Ungku Omar Grant (XX-2017-002)
文摘This study investigates the recent extreme temperature trends across 19 stations in the Klang Valley, Malaysia, over the period 2006^-16. Fourteen extreme index trends were analyzed using the Mann-Kendall non-parametric test, with Sen’s slope as a magnitude estimator. Generally, the annual daily mean temperature, daily mean maximum temperature, and daily mean minimum temperature in the Klang Valley increased significantly, by 0.07°C yr^-1, 0.07°C yr^-1 and 0.08°C yr^-1, respectively. For the warm temperature indices, the results indicated a significant upward trend for the annual maximum of maximum temperature, by 0.09°C yr^-1, and the annual maximum of minimum temperature, by 0.11°C yr^-1. The results for the total number of warm days and warm nights showed significant increasing trends of 5.02 d yr^-1 and 6.92 d yr^-1, respectively. For the cold temperature indices, there were upward trends for the annual minimum of maximum temperature, by 0.09°C yr^-1, and the annual minimum of minimum temperature, by 0.03°C yr^-1, concurrent with the decreases in the total number cold days (TX10P), with -3.80 d yr^-1, and cold nights (TN10P), with -4.33 d yr^-1. The 34°C and 37°C summer days results showed significant upward trends of 4.10 d yr^-1 and 0.25 d yr^-1, respectively. Overall, these findings showed upward warming trends in the Klang Valley, with the minimum temperature rate increasing more than that of the maximum temperature, especially in urban areas.
基金funded by the Sultan Mizan Antarctic Research Foundation(YPASM,2017)Malaysiasupported by the Chinese Arctic and Antarctic Administration(CAA)support by Universiti Malaysia Sabah(UMS)。
文摘Surface ozone(O3)is a secondary pollutant harmful to human health and a greenhouse gas which is one of the prime climate forcers.Due to the clean atmospheric environment of the Antarctic region and given the complexity of O3 chemistry,the observation of surface O3 variability in this region is necessary in the quest to better understand the potential sources and sink of polar surface O3.In this paper,we highlighted our observations on O3 variability at the Great Wall Station(GWS)during austral summer in December 2018 and January 2019.The continuous surface O3 measurement at the GWS,Antarctica was carried out using the Ecotech Ozone analyzer.To understand the roles of the meteorological conditions on the temporal variations of O3,meteorological data was obtained from the conventional auto-observational station at the GWS.The Hybrid Single-Particle Lagrangian Integrated Trajectory(HYSPLIT)model was employed to investigate the air mass transport over the region.The observed austral summer surface O3 concentrations at the GWS exhibited variability and were significantly lower than those previously observed at other permanent coastal stations in Antarctica.The surface ozone variability at the GWS was strongly influenced by the synoptic change of air mass origin although the roles of photochemistry production and destruction were still uncertain.Marine characteristics and stable surface O3 characterized the air masses that reached the GWS.The unique characteristic of surface O3 at the coastal site of GWS was emphasized by its synoptic air mass characteristics,which displayed a significant influence on surface O3 variability.Air mass that traveled over the ocean with relatively shorter distance was linked to the lower O3 level,whereby the marine transport of reactive bromine(Br)species was thought to play a significant role in the tropospheric chemistry that leads to O3 destruction.Meanwhile,the diurnal variation indicated that the O3 background concentration levels were not strongly associated with the local atmospheric conditions.
基金Ministry Education and Culture,Directorate of Research and Technology for Research and Innovation,grant number 028/AMD-SP2H/LT-MULTI-PDPK/LL7/2021.
文摘This experiment aimed to determine how Cd exposure impacts CD4 cell activation,macrophage cells,pinocytosis activity,metallothionine expression,and Cd levels in juvenile Gambusia affinis gills.Four treatment groups were used,with one control and treatments A,B,C,and D at dosages of 0.03 mg/L,0.023 mg/L,0.015 mg/L,and 0.008 mg/L,respectively.The results showed that the number of CD4 with CD8 cell markers differed significantly from each treatment compared to the control(0.33%).The value in A,namely 0.54%,was the highest,followed by B,C,and D of 0.46%,0.44%,and 0.42%,respectively.The number of macrophages increased as the Cd level of the medium increased,as did the activity of pinocytosis.Furthermore,the immunofluorescence test on the gills with the Anti-MT Mouse and goat IgG fluoresce in Rhodamine on the gills showed that luminescence increased with increasing Cd levels in the gills.Similarly,the MT intensity increased at Cd-exposed gills as compared to the control.As the Cd level in the gills increased,the MT levels ascended significantly.
基金funded by Princess Nourah bint Abdulrahman University Research Supporting Project Number PNURSP2022R241,Princess Nourah bint Abdulrahman University,Riyadh,Saudi Arabia.
文摘Background Urban heat island(UHI)is an urban climate phenomenon that primarily responds to urban conditions and land use change.The extent of hard surfaces significantly influences the thermal properties of the land.To address this issue,a novel approach quantifying the association between land use and UHI is developed.This study offers a new technique for effectively estimating the effect of land use on the UHI intensity using the combination of urban heat intensity index(UHII)and land contribution index(LCI)derived from Landsat 8 OLI images.The time-series thermal effect of land use on the UHI intensity can be determined according to the ratio in mean temperature between specific land use and the whole study site.The study was conducted in the Hulu Langat district,Malaysia during 2014-2021.Results The UHI intensity rose from 0.19 in 2014 to 0.70 in 2021.The negative value of LCI for vegetation areas and water bodies obtained its negative contribution to the urban heat island,while the positive value of LCI for bare areas and built-up areas showed its positive effect on the urban heat island.The LCI value for urban areas showed a significant increase in the 7 years such as 0.51,0.66,0.69,and 0.75 for periods 2014,2016,2018,and 2021,respectively.The change in LCI from 2014 to 2021 for the transformation of bare area and forest was recorded to be 0.23 and−0.02,respectively.Thus,the conversion of forests into urban areas had a negative effect on the increment of UHI intensity.Conclusions Overall,these findings are useful for policy-making agency in developing an effective policy for reducing high UHI intensity and planning long-term land use management.
文摘Among the various techniques of power scavenging,piezoelectric energy harvesting usually has more power density.Although piezoceramics are usually more efficient than other piezoelectric materials,since they are very brittle and fragile,researchers are looking for alternative materials.Recently Cellulose Electro-active paper(EAPap)has been recognized as a smart material with piezoelectric behavior that can be used in energy scavenging systems.The majority of researches in energy harvesting area,use unimorph piezoelectric cantilever beams.This paper presents an analytical solution based on distributed parameter model for partially covered pieoelectric cantilever energy harvester.The purpose of the paper is to describe the changes in generated power with damping and the load resistance using analytical calculations.The analytical data are verified using experiment on a vibrating cantilever substrate that is partially covered by EAPap films.The results are very close to each other.Also asymptotic trends of the voltage,current and power outputs are investigated and expressions are obtained for the extreme conditions of the load resistance.These new findings provide guidelines for identification and manipulation of effective parameters in order to achieve the efficient performance in different ambient source conditions.
文摘Introduction:COVID-19 has affected almost every country in the world,which causing many negative implications in terms of education,economy and mental health.Worryingly,the trend of second or third wave of the pandemic has been noted in multiple regions despite early success of flattening the curve,such as in the case of Malaysia,post Sabah state election in September 2020.Hence,it is imperative to predict ongoing trend of COVID-19 to assist crucial policymaking in curbing the transmission.Method:Generalized logistic growth modelling(GLM)approach was adopted to make prediction of growth of cases according to each state in Malaysia.The data was obtained from official Ministry of Health Malaysia daily report,starting from 26 September 2020 until 1 January 2021.Result:Sabah,Johor,Selangor and Kuala Lumpur are predicted to exceed 10,000 cumulative cases by 2 February 2021.Nationally,the growth factor has been shown to range between 0.25 to a peak of 3.1 throughout the current Movement Control Order(MCO).The growth factor range for Sabah ranged from 1.00 to 1.25,while Selangor,the state which has the highest case,has a mean growth factor ranging from 1.22 to 1.52.The highest growth rates reported were inWP Labuan for the time periods of 22 Nov-5 Dec 2020 with growth rates of 4.77.States with higher population densities were predicted to have higher cases of COVID-19.Conclusion:GLM is helpful to provide governments and policymakers with accurate and helpful forecasts on magnitude of epidemic and peak time.This forecast could assist government in devising short-and long-term plan to tackle the ongoing pandemic.
文摘This book review provides a multi-dimensional discussion on how the text(two editions)delivers not only factual information regarding European economic history,but focuses on the relevance and constructive uses of economic concepts,theories,and statistical analyses on issues regarding industrial economics.One major concern within industrial economics is the failure to recognize past experiences(the importance of history).Accordingly,the book contains a considerable amount of discussion about the problems and changes in the history of economic distribution associated with specific locations of economic activities,income,resources,production,international economic integration,and spatial economic activities in Europe.Furthermore,economic issues related to the international relationship between Europe and some developing countries are also elaborated.This book review serves as more than a summary:it highlights several intellectual and research-oriented aspects of the book that may benefit studies of economic industrialization and the humanities and social sciences more broadly.In particular,several aspects are evaluated,suggesting the extent of its comprehensiveness and the important data provided in the book.Finally,certain differences observed between the first and second editions of the book are also acknowledged and explained.
