Peat swamp forest conservation withstands pervasive land conversion to oil palm plantation in North Selangor, Malaysia

Tropical deforestation remains one of the major global challenges of the twenty-first century driven to a large extent by the conversion of land for agricultural purposes, such as palm oil production. Malaysia is one of the world’s largest palm oil producers and has seen widespread conversion to oil palm from primary forest, including peat swamp forest (PSF). This study investigates the rate and extent of pervasive oil palm expansion in and around North Selangor Peat Swamp Forest (NSPSF) over the last three decades, exploring how land conversion has affected the region’s tropical forests, and assessing the relative success of PSF conservation measures. Time-series Landsat imagery was used to assess thematic land cover change and improvement in vegetation condition since NSPSF was given protected status in 1990. The results show a near tripling in oil palm cover throughout North Selangor, from 24,930 ha in 1989 to 70,070 ha in 2016; while at the same time tropical forest cover shrank from 145,570 ha to 88,400 ha. Despite concerns over the sustainability and environmental impact of such rapid oil palm conversion at a regional level, at the local scale, NSPSF represents a relative conservation success story. Effective land stewardship by government and non-governmental organization (NGO) management actors has limited illegal encroachment of oil palm around the reserve boundary. PSF rehabilitation measures have also markedly improved vegetation condition in NSPFS’s interior. These findings have broad significance for how oil palm agriculture is managed and especially for PSF stewardship and conservation, and the approaches described here may be usefully adopted elsewhere in Southeast Asia and around the world

The evaluation of k-ε and k-ω turbulence models in modelling flows and performance of S-shaped diffuser

Diffusing S-shaped ducts are critical components in modern vehicle, primarily employed in directing the airflow to the engine. It links the air box and the engine in a very restricted place. The air flow through an S-duct is complex in nature, which perhaps includes boundary layer separation, secondary flow, and total pressure loss effects that influences the engine performance. In this work, the flow and performance of S-shaped duct was predicted and analysed using computational fluid dynamics. The main objective is to evaluate the performance of the realizable k-ε and k-ω SST models qualitatively and quantitatively in modelling flow of a highly bend duct where a high stress distorted flow may have developed in proximity the duct wall leading to stall. CFD computations were performed for the flow entering the diffuser at Reynolds number of 80,000 cases. The results obtained suggested that the k-ω SST model reasonably predicts the flow characteristics qualitatively and quantitatively. The realizable k-ε turbulence model however poorly captures the actual magnitudes of the calculated flow features. The growth of the stream-wise velocity profile was calculated at three stream-wise stations and point out a smooth down the interior profile of the divergent section. An extreme flow distortion and a shift of the region of flow with the highest velocity were developed toward the outer wall of the first bend of the diffuser. A significant pressure recovery potential with no flow separation arise over the diffuser tube range was predicted well by the simulations

Screening of Aloe vera medium with different carbon and nitrogen sources for Lactobacillus acidophilus cultivation using fractional factorial design (FFD)

The aim of this research was to optimize the cultivation medium for economic production of a probiotic bacterium, Lactobacillus acidophilus using Aloe vera medium with different carbon (glucose, fructose and sucrose) and nitrogen (yeast extract, meat peptone, ammonium sulphate and urea) sources. Screening step was performed using 28 1/16 fractional factorial design (FFD) to investigate the significant effect of 8 factors used in this study on the biomass production expressed in log10 cfu/ mL. Biomass production was measured based on total plate count method for enumeration of viable cells. In the process of screening, the concentration range of Aloe vera, carbon and nitrogen used were from 1-2% (w/v), 1-2% (w/v) and 0.5-1% (w/v), respectively. The maximum biomass production was obtained with 11.816 log10 cfu/mL. It was shown that glucose, Aloe vera gel, combination of glucose and fructose and combination of glucose and ammonium sulphate were resulted significant (p <; 0.05) effect towards to the response, biomass production

Experimental Study on the Effects of Methanol and Ethanol on Gasoline Engine Performance and Exhaust Emissions / M. S. M. Zaharin...[et al.]

Increasing demands of energy sources in automotive sector have led to depletion of fossil fuels. In solving the problem of fuel supply, researchers have rapidly raised intentions on alternative fuels since the late 20th century, in which it is highly favourable over gasoline fuel due to its cost-efficiency and environmental friendly. This paper presented the effects of various alcohol-gasoline blends on engine performance and exhaust emissions. Four fuel blends; M5 (methanol 5% + pure gasoline 95%), M15 (methanol 15% + pure gasoline 85%), E5 (ethanol 5% + pure gasoline 95%) and E15 (ethanol 15% + pure gasoline 85%) were tested on a 4-cylinder, 4-strokes, 1.6L natural aspirated spark ignition (SI) engine under condition of wide open throttles and engine speed varied from 1000-4000 rpm. The results showed that methanol and ethanol fuels provide air-fuel charge cooling to increase the density of the charge. Thus, the fuel blends produced higher engine brake power than that of pure gasoline. In relation to brake specific fuel consumption (BSFC), E15 presented the highest result due to the lower energy content compared to that of other blends. Brake thermal efficiency (BTE) produced by M15 was the highest, obtaining 5.17% increment from pure gasoline compared to other fuel blends which were 1.6%, 1.16% and 2.47% for M5, E5 and E15, respectively. The fuel blends emitted lower exhaust emissions of carbon monoxide (CO) and hydrocarbon (HC) gases due to the addition of oxygenated fuel that promoted better combustion process and reduced exhaust emissions of CO and HC. However, the blends have resulted in increase of NOx emissions in comparison to that of pure gasoline which can be attributed to the higher flame temperature of alcohol. Optimized blend ratios for methanol and ethanol with gasoline were found to be better than pure gasoline fuel in terms of fuel properties, combustion behaviour, engine performance and exhaust emissions with E15 producing the highest engine brake power of 60.3 kW and emitting the lowest CO and HC emissions at high engine speed with 0.566% and 114.2 ppm, respectively. Meanwhile, M15 provided the most thermal efficient fuel blend at all operating conditions

Characterization of a diesel-degrading strain isolated from a hydrocarbon-contaminated site,

Abstract: A diesel-degrading bacterium has been isolated from a diesel-polluted site. The isolate was tentatively identified as Staphylococcus aureus strain DRY11 based on partial 16S rDNA molecular phylogeny and Biolog® GP microplate panels and Microlog® database. Isolate 11 showed an almost linear increase in cellular growth with respect to diesel concentrations with optimum growth occurring at 4% (v/v) diesel concentration. Optimization studies using different nitrogen sources showed that the best nitrogen source was potassium nitrite. Sodium nitrite was optimum at 1.2 g l -1 and higher concentrations were strongly inhibitory to cellular growth. The optimal pH that supported growth of the bacterium was between 7.5 to 8.0 and the isolate exhibited optimal broad temperature supporting growth on diesel from 27 to 37 o C. An almost complete removal of diesel components was seen from the reduction in hydrocarbon peaks observed using Solid Phase Microextraction Gas Chromatography analysis after 5 days of incubation. The characteristics of this bacterium suggest that it is suitable for bioremediation of diesel spills and pollutions in the tropics

Using scRNA-seq to identify transcriptional variation in the malaria parasite ookinete stage

The crossing of the mosquito midgut epithelium by the malaria parasite motile ookinete form represents the most extreme population bottleneck in the parasite life cycle and is a prime target for transmission blocking strategies. However, we have little understanding of the clonal variation that exists in a population of ookinetes in the vector, partially because the parasites are difficult to access and are found in low numbers. Within a vector, variation may result as a response to specific environmental cues or may exist independent of those cues as a potential bet-hedging strategy. Here we use single-cell RNA-seq to profile transcriptional variation in Plasmodium berghei ookinetes across different vector species, and between and within individual midguts. We then compare our results to low-input transcriptomes from individual Anopheles coluzzii midguts infected with the human malaria parasite Plasmodium falciparum. Although the vast majority of transcriptional changes in ookinetes are driven by development, we have identified candidate genes that may be responding to environmental cues or are clonally variant within a population. Our results illustrate the value of single-cell and low-input technologies in understanding clonal variation of parasite populations

Characterisation of cholinesterase from kidney tissue of Asian seabass (Lates calcarifer) and its inhibition in presence of metal ion

Aim: The cholinesterase (ChE) based inhibition studies from fish were investigated and presented here emerged to be one of the great potential biomarkers for heavy metals monitoring. Methodology: In this study, the capability of ChE extracted from the kidney of Lates calcarifer was assessed for of metal. ChE was purified through ammonium sulphate precipitation and ion exchange chromatography. Results: The purified enzyme gave 12 fold purification with the recovery of 12.17% with specific activity of 2.889 U mg-1. The Michaelis-Menten constant (Km) and Vmax value obtained was 0.1426 mM and 0.0217 �mol min-1mg-1, respectively. The enzyme has the ability to hydrolyse acetylthiocholine iodide (ATC) at a faster rate compared to other two synthetic substrates, propionylthiocholine iodide (PTC) and butyrylthiocholine iodide (BTC). ChE gave highest activity at 20-30�C in Tris-HCl buffer pH 8.0. The results showed that cholinesterase from L. calcarifer kidney was very sensitive to sensitive to copper and lead after being tested argentum, arsenic, cadmium, chromium, copper, cobalt, mercury, nickel, lead and zinc. Interpretation: The effect of heavy metals studied on the activity of ChE differed from each other. The result of the study can be used as a tool for further developing a biomarker for the detection of heavy metals in aquatic ecosystems. In addition, the information can also be used for designing a kit, that would give a rapid and accurate result

Characterisation of cholinesterase from kidney tissue of Asian seabass (Lates calcarifer) and its inhibition in presence of metal ions

Aim: The chdinesterase (ChE) based inhibition studies from fish were investigated and presented here emerged to be one of thegreat potential biomarkersfor heavy metals monitoring. Methodology: In this study, the capability of ChE extracted from the kidney of Lates calcarifer was assessed for of metal. ChE was purified through ammonium sulphate precipitation and ion exchange chromatography. Results: The piffled enzyme gave 12 fold purification with the recovery of 12.17% with specific activity of 2.889 U mgJ. The Michaelis-Menten constant (K) and V,^ value obtained was 0.1426 mM and 0.0217 pmol irin'mg∗1, respectively. The enzyme has the ability to hydrolyse acetytthiocholine iodde (ATC) at a faster rate compared to other two synthetic su bstra tes , propionylthiocholine iodide (PTC) and butyrylthiocholine iodide (BTC). ChE gave highest activity at 20- 30°C in Tris-HO buffer pH 8.0. The results showed that cholinesterase from L. calcarifer kidney was very sensitive to sensitive to copper and lead after being tested argentum, arsenic, cadmium, chromium, copper, cobalt, mercury, nickel, lead and zinc. Interpretation: The effect of heavy metals studied on the activity of ChE differed from each other. The result of the study can be used as a tool for futher developing a biomarker for the detection of heavy metals in aquatic ecosystems. In addition, the information can also be used for designing a kit, that would give a rapid and accurate result

A single-cell atlas of Plasmodium falciparum transmission through the mosquito

Malaria parasites have a complex life cycle featuring diverse developmental strategies, each uniquely adapted to navigate specific host environments. Here we use single-cell transcriptomics to illuminate gene usage across the transmission cycle of the most virulent agent of human malaria - Plasmodium falciparum. We reveal developmental trajectories associated with the colonization of the mosquito midgut and salivary glands and elucidate the transcriptional signatures of each transmissible stage. Additionally, we identify both conserved and non-conserved gene usage between human and rodent parasites, which point to both essential mechanisms in malaria transmission and species-specific adaptations potentially linked to host tropism. Together, the data presented here, which are made freely available via an interactive website, provide a fine-grained atlas that enables intensive investigation of the P. falciparum transcriptional journey. As well as providing insights into gene function across the transmission cycle, the atlas opens the door for identification of drug and vaccine targets to stop malaria transmission and thereby prevent disease

Parenting and community engagement factors as predictors of religiosity among muslim adolescents from Malaysia.

Despite the plethora of research on correlates of adolescent religiosity, few studies have examined the contribution of social context to religiosity among non-Western Muslim samples using multidimensional religiosity measures. To address this gap, the current study investigated the influence of community engagement and parenting factors on religiosity among 596 Malaysian Muslim secondary school students (M age = 16.10, SD = .29). After controlling for gender, family structure, family income, and social desirability, the results showed that parental monitoring, mosque involvement, and school engagement significantly predicted religious worldview, whereas parental religious socialization, parental monitoring, mosque involvement, school engagement, and youth organization involvement accounted for a significant amount of the variance in religious personality. Implications for further research on socialization influences on religious development among adolescents are discussed