Kasetsart University

International audience

BACKGROUND: Global maps, in particular those based on vector distributions, have long been used to help visualise the global extent of malaria. Few, however, have been created with the support of a comprehensive and extensive evidence-based approach. METHODS: Here we describe the generation of a global map of the dominant vector species (DVS) of malaria that makes use of predicted distribution maps for individual species or species complexes. RESULTS: Our global map highlights the spatial variability in the complexity of the vector situation. In Africa, An. gambiae, An. arabiensis and An. funestus are co-dominant across much of the continent, whereas in the Asian-Pacific region there is a highly complex situation with multi-species coexistence and variable species dominance. CONCLUSIONS: The competence of the mapping methodology to accurately portray DVS distributions is discussed. The comprehensive and contemporary database of species-specific spatial occurrence (currently available on request) will be made directly available via the Malaria Atlas Project (MAP) website from early 2012.

Abstract Systematic assessments of species extinction risk at regular intervals are necessary for informing conservation action 1,2 . Ongoing developments in taxonomy, threatening processes and research further underscore the need for reassessment 3,4 . Here we report the findings of the second Global Amphibian Assessment, evaluating 8,011 species for the International Union for Conservation of Nature Red List of Threatened Species. We find that amphibians are the most threatened vertebrate class (40.7% of species are globally threatened). The updated Red List Index shows that the status of amphibians is deteriorating globally, particularly for salamanders and in the Neotropics. Disease and habitat loss drove 91% of status deteriorations between 1980 and 2004. Ongoing and projected climate change effects are now of increasing concern, driving 39% of status deteriorations since 2004, followed by habitat loss (37%). Although signs of species recoveries incentivize immediate conservation action, scaled-up investment is urgently needed to reverse the current trends.

Purpose The importance of packaging design and the role of packaging as a vehicle for consumer communication and branding are necessarily growing. To achieve communication goals effectively, knowledge about consumer psychology is important so that manufacturers understand consumer response to their packages. this paper aims to investigate this issue. Design/methodology/approach The paper examines these issues using a conjoint study among consumers for packaged food products in Thailand, which is a very competitive packaged food products market. Findings The conjoint results indicate that perceptions about packaging technology (portraying convenience) play the most important role overall in consumer likelihood to buy. Research limitations/implications There is strong segmentation in which packaging elements consumers consider most important. Some consumers are mostly oriented toward the visual aesthetics, while a small segment focuses on product detail on the label. Originality/value Segmentation variables based on packaging response can provide very useful information to help marketers maximize the package's impact.

Characterizing nanoparticle dispersions and understanding the effect of parameters that alter dispersion properties are important for both environmental applications and toxicity investigations. The role of particle surface area, primary particle size, and crystal phase on TiO2 nanoparticle dispersion properties is reported. Hydrodynamic size, zeta potential, and isoelectric point (IEP) of ten laboratory synthesized TiO2 samples, and one commercial Degussa TiO2 sample (P25) dispersed in different solutions were characterized. Solution ionic strength and pH affect titania dispersion properties. The effect of monovalent (NaCl) and divalent (MgCl2) inert electrolytes on dispersion properties was quantified through their contribution to ionic strength. Increasing titania particle surface area resulted in a decrease in solution pH. At fixed pH, increasing the particle surface area enhanced the collision frequency between particles and led to a higher degree of agglomeration. In addition to the synthesis method, TiO2 isoelectric point was found to be dependent on particle size. As anatase TiO2 primary particle size increased from 6 nm to 104 nm, its IEP decreased from 6.0 to 3.8 that also results in changes in dispersion zeta potential and hydrodynamic size. In contrast to particle size, TiO2 nanoparticle IEP was found to be insensitive to particle crystal structure.

BACKGROUND: The final article in a series of three publications examining the global distribution of 41 dominant vector species (DVS) of malaria is presented here. The first publication examined the DVS from the Americas, with the second covering those species present in Africa, Europe and the Middle East. Here we discuss the 19 DVS of the Asian-Pacific region. This region experiences a high diversity of vector species, many occurring sympatrically, which, combined with the occurrence of a high number of species complexes and suspected species complexes, and behavioural plasticity of many of these major vectors, adds a level of entomological complexity not comparable elsewhere globally. To try and untangle the intricacy of the vectors of this region and to increase the effectiveness of vector control interventions, an understanding of the contemporary distribution of each species, combined with a synthesis of the current knowledge of their behaviour and ecology is needed. RESULTS: Expert opinion (EO) range maps, created with the most up-to-date expert knowledge of each DVS distribution, were combined with a contemporary database of occurrence data and a suite of open access, environmental and climatic variables. Using the Boosted Regression Tree (BRT) modelling method, distribution maps of each DVS were produced. The occurrence data were abstracted from the formal, published literature, plus other relevant sources, resulting in the collation of DVS occurrence at 10116 locations across 31 countries, of which 8853 were successfully geo-referenced and 7430 were resolved to spatial areas that could be included in the BRT model. A detailed summary of the information on the bionomics of each species and species complex is also presented. CONCLUSIONS: This article concludes a project aimed to establish the contemporary global distribution of the DVS of malaria. The three articles produced are intended as a detailed reference for scientists continuing research into the aspects of taxonomy, biology and ecology relevant to species-specific vector control. This research is particularly relevant to help unravel the complicated taxonomic status, ecology and epidemiology of the vectors of the Asia-Pacific region. All the occurrence data, predictive maps and EO-shape files generated during the production of these publications will be made available in the public domain. We hope that this will encourage data sharing to improve future iterations of the distribution maps.

Abstract Aim To examine the contribution of large‐diameter trees to biomass, stand structure, and species richness across forest biomes. Location Global. Time period Early 21st century. Major taxa studied Woody plants. Methods We examined the contribution of large trees to forest density, richness and biomass using a global network of 48 large (from 2 to 60 ha) forest plots representing 5,601,473 stems across 9,298 species and 210 plant families. This contribution was assessed using three metrics: the largest 1% of trees ≥ 1 cm diameter at breast height (DBH), all trees ≥ 60 cm DBH, and those rank‐ordered largest trees that cumulatively comprise 50% of forest biomass. Results Averaged across these 48 forest plots, the largest 1% of trees ≥ 1 cm DBH comprised 50% of aboveground live biomass, with hectare‐scale standard deviation of 26%. Trees ≥ 60 cm DBH comprised 41% of aboveground live tree biomass. The size of the largest trees correlated with total forest biomass ( r 2 = .62, p < .001). Large‐diameter trees in high biomass forests represented far fewer species relative to overall forest richness ( r 2 = .45, p < .001). Forests with more diverse large‐diameter tree communities were comprised of smaller trees ( r 2 = .33, p < .001). Lower large‐diameter richness was associated with large‐diameter trees being individuals of more common species ( r 2 = .17, p = .002). The concentration of biomass in the largest 1% of trees declined with increasing absolute latitude ( r 2 = .46, p < .001), as did forest density ( r 2 = .31, p < .001). Forest structural complexity increased with increasing absolute latitude ( r 2 = .26, p < .001). Main conclusions Because large‐diameter trees constitute roughly half of the mature forest biomass worldwide, their dynamics and sensitivities to environmental change represent potentially large controls on global forest carbon cycling. We recommend managing forests for conservation of existing large‐diameter trees or those that can soon reach large diameters as a simple way to conserve and potentially enhance ecosystem services.

The importance of packaging design as a vehicle for communication and branding is growing in competitive markets for packaged food products. This research utilized a focus group methodology to understand consumer behavior toward such products and how packaging elements can affect buying decisions. Visual package elements play a major role, representing the product for many consumers, especially in low involvement, and when they are rushed. Most focus group participants say they use label information, but they would like it if simplified. The challenge for researchers is to integrate packaging into an effective purchasing decision model, by understanding packaging elements as important marketing communications tools. Propositions for future research are proposed which will help in developing better understanding of consumer response to packaging elements.

Aflatoxins and ochratoxins are among the most important mycotoxins of all and producers of both types of mycotoxins are present in Aspergillus section Flavi , albeit never in the same species. Some of the most efficient producers of aflatoxins and ochratoxins have not been described yet. Using a polyphasic approach combining phenotype, physiology, sequence and extrolite data, we describe here eight new species in section Flavi . Phylogenetically, section Flavi is split in eight clades and the section currently contains 33 species. Two species only produce aflatoxin B<inf>1</inf> and B<inf>2</inf> ( A. pseudotamarii and A. togoensis ), and 14 species are able to produce aflatoxin B<inf>1</inf>, B<inf>2</inf>, G<inf>1</inf> and G<inf>2</inf>: three newly described species A. aflatoxiformans, A. austwickii and A. cerealis in addition to A. arachidicola , A. minisclerotigenes , A. mottae, A. luteovirescens (formerly A. bombycis ) , A. nomius, A. novoparasiticus, A. parasiticus, A. pseudocaelatus, A. pseudonomius, A. sergii and A. transmontanensis . It is generally accepted that A. flavus is unable to produce type G aflatoxins, but here we report on Korean strains that also produce aflatoxin G<inf>1</inf> and G<inf>2</inf>. One strain of A. bertholletius can produce the immediate aflatoxin precursor 3-O-methylsterigmatocystin, and one strain of Aspergillus sojae and two strains of Aspergillus alliaceus produced versicolorins. Strains of the domesticated forms of A. flavus and A. parasiticus , A. oryzae and A. sojae , respectively, lost their ability to produce aflatoxins, and from the remaining phylogenetically closely related species (belonging to the A. flavus -, A. tamarii -, A. bertholletius - and A. nomius -clades), only A. caelatus , A. subflavus and A. tamarii are unable to produce aflatoxins. With exception of A. togoensis in the A. coremiiformis -clade, all species in the phylogenetically more distant clades ( A. alliaceus -, A. coremiiformis -, A. leporis - and A. avenaceus -clade) are unable to produce aflatoxins. Three out of the four species in the A. alliaceus -clade can produce the mycotoxin ochratoxin A: A. alliaceus s . str . and two new species described here as A. neoalliaceus and A. vandermerwei . Eight species produced the mycotoxin tenuazonic acid: A. bertholletius , A. caelatus, A. luteovirescens , A. nomius, A. pseudocaelatus , A. pseudonomius, A. pseudotamarii and A. tamarii while the related mycotoxin cyclopiazonic acid was produced by 13 species: A. aflatoxiformans, A. austwickii, A. bertholletius, A. cerealis, A. flavus, A. minisclerotigenes, A. mottae, A. oryzae, A. pipericola, A. pseudocaelatus , A. pseudotamarii, A. sergii and A. tamarii . Furthermore, A. hancockii produced speradine A, a compound related to cyclopiazonic acid. Selected A. aflatoxiformans, A. austwickii, A. cerealis, A. flavus, A. minisclerotigenes, A. pipericola and A. sergii strains produced small sclerotia containing the mycotoxin aflatrem. Kojic acid has been found in all species in section Flavi , except A. avenaceus and A. coremiiformis . Only six species in the section did not produce any known mycotoxins: A. aspearensis , A. coremiiformis, A. lanosus, A. leporis, A. sojae and A. subflavus . An overview of other small molecule extrolites produced in Aspergillus section Flavi is given.

In this article we analyzed and designed air flow controllers that protect the fuel cell (FC) stack from oxygen starvation during step changes of current demand. The steady-state regulation of the oxygen excess ratio in the FCS cathode achieved by assigning an integrator to the compressor flow. Linear observability techniques were employed to demonstrate improvements in transient oxygen regulation when the FCS voltage is included as a measurement for the feedback controller. The FCS voltage signal contains high frequency information about the FC oxygen utilization, and thus, is a natural and valuable output for feedback. We used linear optimal control design to identify the frequencies at which there is a severe tradeoff between the transient system net power performance and the stack starvation control. The limitation arises when the FCS system architecture dictates that all auxiliary equipment is powered directly from the FC with no secondary power sources. This plant configuration is preferred due to its simplicity, compactness, and low cost. The FCS impedance given the closed-loop air flow and perfect humidification and temperature regulation captures the FC current-voltage dynamic relationship. It is expected that the closed-loop FCS impedance will provide the basis for the systematic design of FC stack electronic components.

Semiconductor photocatalysis is a promising approach to combat both environmental pollution and the global energy shortage. Advanced TiO2-based photocatalysts with novel photoelectronic properties are benchmark materials that have been pursued for their high solar-energy conversion efficiency. In general, the photocatalytic efficiency is affected by the degree of light absorption, charge separation, and surface reactivity. Consequently, in this review we first discuss a series of interesting studies that aim to extend the light absorption of TiO2 from UV wavelengths into the visible or even the near-infrared region. We next focus on attempts to overcome the drawback that dopants usually act as charge recombination centres. We discuss the use of either selective local doping or the introduction of disorder together with doping, which aims to facilitate charge separation while preserving the visible-light response. We also show that crystal facet engineering can endow TiO2 with superior physicochemical properties, thus yielding high surface reactivity in photocatalytic reactions. Finally, we examine the recent theoretical advances of TiO2-based photocatalysis.

In this paper, two robust decentralized control design methodologies for load frequency control (LFC) are proposed. The first one is based on H/sub /spl infin// control design using linear matrix inequalities (LMI) technique in order to obtain robustness against uncertainties. The second controller has a simpler structure, which is more appealing from an implementation point of view, and it is tuned by a proposed novel robust control design algorithm to achieve the same robust performance as the first one. More specifically, genetic algorithms (GAs) optimization is used to tune the control parameters of the proportional-integral (PI) controller subject to the H/sub /spl infin// constraints in terms of LMI. Hence, the second control design is called GALMI. Both proposed controllers are tested on a three-area power system with three scenarios of load disturbances to demonstrate their robust performances.

This article outlines the use of the so-called beneficial image as a framework for the analysis of destination image for decision to visit a country for a vacation. The beneficial image is conceptualized as the image characteristics of a destination that subsequently influence tourists’ decision to visit particular vacation destinations. The beneficial image characteristics are conceptualized under five value dimensions—functional, social, emotional, epistemic, and conditional—which are a part of consumption value theory. In addition, the development of measurement in destination image via a category-based approach is outlined. The proposed framework and method are used to assess the destination images of both Thailand and the United States. The findings of the study have demonstrated the effectiveness of the proposed conceptual and methodological frameworks, both at theoretical and practical levels.

The tobacco cutworm, Spodoptera litura, is among the most widespread and destructive agricultural pests, feeding on over 100 crops throughout tropical and subtropical Asia. By genome sequencing, physical mapping and transcriptome analysis, we found that the gene families encoding receptors for bitter or toxic substances and detoxification enzymes, such as cytochrome P450, carboxylesterase and glutathione-S-transferase, were massively expanded in this polyphagous species, enabling its extraordinary ability to detect and detoxify many plant secondary compounds. Larval exposure to insecticidal toxins induced expression of detoxification genes, and knockdown of representative genes using short interfering RNA (siRNA) reduced larval survival, consistent with their contribution to the insect's natural pesticide tolerance. A population genetics study indicated that this species expanded throughout southeast Asia by migrating along a South India-South China-Japan axis, adapting to wide-ranging ecological conditions with diverse host plants and insecticides, surviving and adapting with the aid of its expanded detoxification systems. The findings of this study will enable the development of new pest management strategies for the control of major agricultural pests such as S. litura.

Methane emission from peatlands contributes substantially to global warming but is significantly reduced by sulfate reduction, which is fuelled by globally increasing aerial sulfur pollution. However, the biology behind sulfate reduction in terrestrial ecosystems is not well understood and the key players for this process as well as their abundance remained unidentified. Comparative 16S rRNA gene stable isotope probing (SIP) in the presence and absence of sulfate indicated that a Desulfosporosinus species, which constitutes only 0.006% of the total microbial community 16S rRNA genes, is an important sulfate reducer in a long-term experimental peatland field site. Parallel SIP using dsrAB (encoding subunit A and B of the dissimilatory (bi)sulfite reductase) identified no additional sulfate reducers under the conditions tested. For the identified Desulfosporosinus species a high cell-specific sulfate reduction rate of up to 341 fmol SO₄²⁻ cell⁻¹ day⁻¹ was estimated. Thus, the small Desulfosporosinus population has the potential to reduce sulfate in situ at a rate of 4.0-36.8 nmol (g soil w. wt.)⁻¹ day⁻¹, sufficient to account for a considerable part of sulfate reduction in the peat soil. Modeling of sulfate diffusion to such highly active cells identified no limitation in sulfate supply even at bulk concentrations as low as 10 μM. Collectively, these data show that the identified Desulfosporosinus species, despite being a member of the 'rare biosphere', contributes to an important biogeochemical process that diverts the carbon flow in peatlands from methane to CO₂ and, thus, alters their contribution to global warming.

Among the many questions unanswered for the COVID-19 pandemic are the origin of SARS-CoV-2 and the potential role of intermediate animal host(s) in the early animal-to-human transmission. The discovery of RaTG13 bat coronavirus in China suggested a high probability of a bat origin. Here we report molecular and serological evidence of SARS-CoV-2 related coronaviruses (SC2r-CoVs) actively circulating in bats in Southeast Asia. Whole genome sequences were obtained from five independent bats (Rhinolophus acuminatus) in a Thai cave yielding a single isolate (named RacCS203) which is most related to the RmYN02 isolate found in Rhinolophus malayanus in Yunnan, China. SARS-CoV-2 neutralizing antibodies were also detected in bats of the same colony and in a pangolin at a wildlife checkpoint in Southern Thailand. Antisera raised against the receptor binding domain (RBD) of RmYN02 was able to cross-neutralize SARS-CoV-2 despite the fact that the RBD of RacCS203 or RmYN02 failed to bind ACE2. Although the origin of the virus remains unresolved, our study extended the geographic distribution of genetically diverse SC2r-CoVs from Japan and China to Thailand over a 4800-km range. Cross-border surveillance is urgently needed to find the immediate progenitor virus of SARS-CoV-2.

Information fusion by utilizing multiple distributed sensors is studied in this work. Extending the classical parallel fusion structure by incorporating the fading channel layer that is omnipresent in wireless sensor networks, we derive the likelihood ratio based fusion rule given fixed local decision devices. This optimum fusion rule, however, requires perfect knowledge of the local decision performance indices as well as the fading channel. To address this issue, two alternative fusion schemes, namely, the maximum ratio combining statistic and a two-stage approach using the Chair-Varshney fusion rule, are proposed that alleviate these requirements and are shown to be the low and high signal-to-noise ratio (SNR) equivalents of the likelihood-based fusion rule. To further robustify the fusion rule and motivated by the maximum ratio combining statistics, we also propose a statistic analogous to an equal gain combiner that requires minimum a priori information. Performance evaluation is performed both analytically and through simulation.

Trypanosoma evansi, the agent of "surra," is a salivarian trypanosome, originating from Africa. It is thought to derive from Trypanosoma brucei by deletion of the maxicircle kinetoplastic DNA (genetic material required for cyclical development in tsetse flies). It is mostly mechanically transmitted by tabanids and stomoxes, initially to camels, in sub-Saharan area. The disease spread from North Africa towards the Middle East, Turkey, India, up to 53° North in Russia, across all South-East Asia, down to Indonesia and the Philippines, and it was also introduced by the conquistadores into Latin America. It can affect a very large range of domestic and wild hosts including camelids, equines, cattle, buffaloes, sheep, goats, pigs, dogs and other carnivores, deer, gazelles, and elephants. It found a new large range of wild and domestic hosts in Latin America, including reservoirs (capybaras) and biological vectors (vampire bats). Surra is a major disease in camels, equines, and dogs, in which it can often be fatal in the absence of treatment, and exhibits nonspecific clinical signs (anaemia, loss of weight, abortion, and death), which are variable from one host and one place to another; however, its immunosuppressive effects interfering with intercurrent diseases or vaccination campaigns might be its most significant and questionable aspect.

This review offers a vision of the chemical behaviour of natural ingredients, synthetic drugs and other related compounds complexed using cyclodextrins. The review takes care of different sections related to i) the inclusion complexes formation with cyclodextrins, ii) the determination of the inclusion formation constant, iii) the most used methods to prepare host inclusion in the non-polar cavity of cyclodextrins and iv) the analytical techniques to evidence host inclusion. The review provides different literature that shows the application of cyclodextrins to improve physical, chemical, and biological characteristics of food compounds including solubility, stability and their elimination/masking. Moreover, the review also offers examples of commercial food/supplement products of cyclodextrins to indicate that cyclodextrins can be used to generate biotechnological substances with innovative properties and improve the development of food products.

Translational regulation contributes to plasticity in metabolism and growth that enables plants to survive in a dynamic environment. Here, we used the precise mapping of ribosome footprints (RFs) on mRNAs to investigate translational regulation under control and sublethal hypoxia stress conditions in seedlings of Arabidopsis thaliana. Ribosomes were obtained by differential centrifugation or immunopurification and were digested with RNase I to generate footprint fragments that were deep-sequenced. Comparison of RF number and position on genic regions with fragmented total and polysomal mRNA illuminated numerous aspects of posttranscriptional and translational control under both growth conditions. When seedlings were oxygen-deprived, the frequency of ribosomes at the start codon was reduced, consistent with a global decline in initiation of translation. Hypoxia-up-regulated gene transcripts increased in polysome complexes during the stress, but the number of ribosomes per transcript relative to normoxic conditions was not enhanced. On the other hand, many mRNAs with limited change in steady-state abundance had significantly fewer ribosomes but with an overall similar distribution under hypoxia, consistent with restriction of initiation rather than elongation of translation. RF profiling also exposed the inhibitory effect of upstream ORFs on the translation of downstream protein-coding regions under normoxia, which was further modulated by hypoxia. The data document translation of alternatively spliced mRNAs and expose ribosome association with some noncoding RNAs. Altogether, we present an experimental approach that illuminates prevalent and nuanced regulation of protein synthesis under optimal and energy-limiting conditions.