491 research outputs found
Estimating logged-over lowland rainforest aboveground biomass in Sabah, Malaysia using airborne LiDAR data
Unprecedented deforestation and forest degradation in recent decades have severely depleted the carbon storage in Borneo. Estimating aboveground biomass (AGB) with high accuracy is crucial to quantifying carbon stocks for Reducing Emissions from Deforestation and Forest Degradation-plus implementation (REDD+). Airborne Light Detection and Ranging (LiDAR) is a promising remote sensing technology that provides fine-scale forest structure variability data. This paper highlights the use of airborne LiDAR data for estimating the AGB of a logged-over tropical forest in Sabah, Malaysia. The LiDAR data was acquired using an Optech Orion C200 sensor onboard a fixed wing aircraft. The canopy height of each LiDAR point was calculated from the height difference between the first returns and the Digital Terrain Model (DTM) constructed from the ground points. Among the obtained LiDAR height metrics, the mean canopy height produced the strongest relationship with the observed AGB. This single-variable model had a root mean squared error (RMSE) of 80.02 t ha-1 or 22.31% of the mean AGB, which performed exceptionally when compared with recent tropical rainforest studies. Overall, airborne LiDAR did provide fine-scale canopy height measurements for accurately and reliably estimating the AGB in a logged-over forest in Sabah, thus supporting the state's effort in realizing the REDD+ mechanism
The use of a blood conservation device to reduce red blood cell transfusion requirements: a before and after study
10.1186/cc8859Critical Care141R
Epidemiological analysis of typhoid fever in Kelantan from a retrieved registry
Aim: Despite the endemicity of typhoid in Kelantan, epidemiological data showing typhoid association to age, sex,ethnicity and district of patients is limited. This retrospective study investigated the statistical association of thesevariables from a retrieved registry.Methodology and results: Cross-tabulation using SPSS was used to analyze 1394 cases of confirmed typhoid patientsadmitted to various hospitals in Kelantan state over a six-year period. Fourteen age groups with a five-year rangeinterval were generated. There was a significant association between typhoid infection and sex of subjects, wherebyfemales were generally more susceptible than males. Ethnicity and district of typhoid patients did not show significantassociation.Conclusion, significance and impact of study: The observation of an increased number of typhoid cases with a malepredominance in the age group 5-14 and female predominance in the 20-60 age group calls for improved hygiene,continued public health education, together with better laboratory diagnostics to identify carriers, are some measures tocontrol this disease
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Assessment parameters for coal-fired generation plant site selection
In order to meet future demand for electricity, Tenaga Nasional Berhad (TNB) is committedto the long-term strategic planning in locating suitable sites for future development of power stations.Site selection is an important process in the early planning stage of any power plant development asit will have significant implications on the capital investment, operational as well as the environmentand socio-economic costs of the power plant.The aim of this presentation is to briefly describe the ten (10) main assessment parametershaving the most profound effects on the selection of potential coal-fired generation plant sites.These assessment parameters were derived based on a survey of approximately 40 experts, comprisingfrom various specialists such as engineers from TNB, senior officers from Department Of EnvironmentMalaysia (DOE), scientist from University Malaya (UM) and a number of other independentconsultants
Quantum Physics and Human Language
Human languages employ constructions that tacitly assume specific properties
of the limited range of phenomena they evolved to describe. These assumed
properties are true features of that limited context, but may not be general or
precise properties of all the physical situations allowed by fundamental
physics. In brief, human languages contain `excess baggage' that must be
qualified, discarded, or otherwise reformed to give a clear account in the
context of fundamental physics of even the everyday phenomena that the
languages evolved to describe. The surest route to clarity is to express the
constructions of human languages in the language of fundamental physical
theory, not the other way around. These ideas are illustrated by an analysis of
the verb `to happen' and the word `reality' in special relativity and the
modern quantum mechanics of closed systems.Comment: Contribution to the festschrift for G.C. Ghirardi on his 70th
Birthday, minor correction
First detection of a Vssc allele V1016G conferring a high level of insecticide resistance in Aedes albopictus collected from Europe (Italy) and Asia (Vietnam), 2016. A new emerging threat to controlling arboviral diseases
Introduction
Aedes albopictus (Skuse) is an important vector of arboviral diseases, including dengue, chikungunya and Zika virus disease. Monitoring insecticide resistance and mechanisms by which the mosquito develops resistance is crucial to minimise disease transmission.
Aim
To determine insecticide resistance status and mechanisms in Ae. albopictus from different geographical regions.
Methods
We sampled 33 populations of Ae. albopictus from Asia, Europe and South America, and tested these for susceptibility to permethrin, a pyrethroid insecticide. In resistant populations, the target site for pyrethroids, a voltage-sensitive sodium channel (Vssc) was genotyped. Three resistant sub-strains, each harbouring a resistance allele homozygously, were established and susceptibilities to three different pyrethroids (with and without a cytochrome P450 inhibitor) were assayed.
Results
Most populations of Ae. albopictus tested were highly susceptible to permethrin but a few from Italy and Vietnam (4/33), exhibited high-level resistance. Genotyping studies detected a knockdown resistance (kdr) allele V1016G in Vssc for the first time in Ae. albopictus. Two previously reported kdr alleles, F1534C and F1534S, were also detected. The bioassays indicated that the strain homozygous for the V1016G allele showed much greater levels of pyrethroid resistance than other strains harbouring F1534C or F1534S.
Conclusion
The V1016G allele was detected in bothAsian and Italian Ae. albopictus populations, thus a spread of this allele beyond Italy in Europe cannot be ruled out. This study emphasises the necessity to frequently and regularly monitor the V1016G allele in Ae. albopictus, particularly where this mosquito species is the main vector of arboviruses
Household catastrophic healthcare expenditure and impoverishment due to rotavirus gastroenteritis requiring hospitalization in Malaysia.
BACKGROUND: While healthcare costs for rotavirus gastroenteritis requiring hospitalization may be burdensome on households in Malaysia, exploration on the distribution and catastrophic impact of these expenses on households are lacking. OBJECTIVES: We assessed the economic burden, levels and distribution of catastrophic healthcare expenditure, the poverty impact on households and inequities related to healthcare payments for acute gastroenteritis requiring hospitalization in Malaysia. METHODS: A two-year prospective, hospital-based study was conducted from 2008 to 2010 in an urban (Kuala Lumpur) and rural (Kuala Terengganu) setting in Malaysia. All children under the age of 5 years admitted for acute gastroenteritis were included. Patients were screened for rotavirus and information on healthcare expenditure was obtained. RESULTS: Of the 658 stool samples collected at both centers, 248 (38%) were positive for rotavirus. Direct and indirect costs incurred were significantly higher in Kuala Lumpur compared with Kuala Terengganu (US45; p<0.001). The mean direct and indirect costs for rotavirus gastroenteritis consisted 20% of monthly household income in Kuala Lumpur, as compared with only 5% in Kuala Terengganu. Direct medical costs paid out-of-pocket caused 141 (33%) households in Kuala Lumpur to experience catastrophic expenditure and 11 (3%) households to incur poverty. However in Kuala Terengganu, only one household (0.5%) experienced catastrophic healthcare expenditure and none were impoverished. The lowest income quintile in Kuala Lumpur was more likely to experience catastrophic payments compared to the highest quintile (87% vs 8%). The concentration index for out-of-pocket healthcare payments was closer to zero at Kuala Lumpur (0.03) than at Kuala Terengganu (0.24). CONCLUSIONS: While urban households were wealthier, healthcare expenditure due to gastroenteritis had more catastrophic and poverty impact on the urban poor. Universal rotavirus vaccination would reduce both disease burden and health inequities in Malaysia
Larvicidal effects of Chinaberry (Melia azederach) powder on Anopheles arabiensis in Ethiopia
<p>Abstract</p> <p>Background</p> <p>Synthetic insecticides are employed in the widely-used currently favored malaria control techniques involving indoor residual spraying and treated bednets. These methods have repeatedly proven to be highly effective at reducing malaria incidence and prevalence. However, rapidly emerging mosquito resistance to the chemicals and logistical problems in transporting supplies to remote locations threaten the long-term sustainability of these techniques. Chinaberry (<it>Melia azederach</it>) extracts have been shown to be effective growth-inhibiting larvicides against several insects. Because several active chemicals in the trees' seeds have insecticidal properties, the emergence of resistance is unlikely. Here, we investigate the feasibility of Chinaberry as a locally available, low-cost sustainable insecticide that can aid in controlling malaria. Chinaberry fruits were collected from Asendabo, Ethiopia. The seeds were removed from the fruits, dried and crushed into a powder. From developmental habitats in the same village, <it>Anopheles arabiensis </it>larvae were collected and placed into laboratory containers. Chinaberry seed powder was added to the larval containers at three treatment levels: 5 g m<sup>-2</sup>, 10 g m<sup>-2 </sup>and 20 g m<sup>-2</sup>, with 100 individual larvae in each treatment level and a control. The containers were monitored daily and larvae, pupae and adult mosquitoes were counted. This experimental procedure was replicated three times.</p> <p>Results</p> <p>Chinaberry seed powder caused an inhibition of emergence of 93% at the 5 g m<sup>-2 </sup>treatment level, and 100% inhibition of emergence at the two higher treatment levels. The Chinaberry had a highly statistically significant larvicidal effect at all treatment levels (χ<sup>2 </sup>= 184, 184, and 155 for 5 g m<sup>-2</sup>, 10 g m<sup>-2 </sup>and 20 g m<sup>-2</sup>, respectively; p < 0.0001 in all cases). In addition, estimates suggest that sufficient Chinaberry seed exists in Asendabo to treat developmental habitat for the duration of the rainy season and support a field trial.</p> <p>Conclusions</p> <p>Chinaberry seed is a very potent growth-inhibiting larvicide against the major African malaria vector <it>An. arabiensis</it>. The seed could provide a sustainable additional malaria vector control tool that can be used where the tree is abundant and where <it>An. arabiensis </it>is a dominant vector. Based on these results, a future village-scale field trial using the technique is warranted.</p
Social sciences research in neglected tropical diseases 2: A bibliographic analysis
The official published version of the article can be found at the link below.Background
There are strong arguments for social science and interdisciplinary research in the neglected tropical diseases. These diseases represent a rich and dynamic interplay between vector, host, and pathogen which occurs within social, physical and biological contexts. The overwhelming sense, however, is that neglected tropical diseases research is a biomedical endeavour largely excluding the social sciences. The purpose of this review is to provide a baseline for discussing the quantum and nature of the science that is being conducted, and the extent to which the social sciences are a part of that.
Methods
A bibliographic analysis was conducted of neglected tropical diseases related research papers published over the past 10 years in biomedical and social sciences. The analysis had textual and bibliometric facets, and focussed on chikungunya, dengue, visceral leishmaniasis, and onchocerciasis.
Results
There is substantial variation in the number of publications associated with each disease. The proportion of the research that is social science based appears remarkably consistent (<4%). A textual analysis, however, reveals a degree of misclassification by the abstracting service where a surprising proportion of the "social sciences" research was pure clinical research. Much of the social sciences research also tends to be "hand maiden" research focused on the implementation of biomedical solutions.
Conclusion
There is little evidence that scientists pay any attention to the complex social, cultural, biological, and environmental dynamic involved in human pathogenesis. There is little investigator driven social science and a poor presence of interdisciplinary science. The research needs more sophisticated funders and priority setters who are not beguiled by uncritical biomedical promises
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