Market turtle mystery solved in Vietnam

Asian turtles are overharvested for food, medicinal purposes and pets, and most species are now at risk of extinction (‘Asian turtle crisis’). As a result of high levels of trade, some species of Asian turtles are known to science mostly or only from animals found in trade. The Vietnamese box turtle (Cuora picturata) was described in 1998 and is known only from markets. This species is likely to be highly threatened, and identifying the origin of this “market species” is imperative if it is to be conserved. We used evidence from phylogeny, biogeography and trade patterns to focus field searches for this species, and in July 2010–January 2011 found it in the wild at three localities on the Langbian Plateau of southern Vietnam. This discovery provides the first opportunity to conserve the Vietnamese box turtle, and provides hope for determining the wild origin of other rare Asian turtles that remain known only from commercial trade.     

GOVERNING THE ENVIRONMENTAL AND SOCIAL DIMENSIONS OF PANGASIUS PRODUCTION IN VIETNAM: A REVIEW∗

The Vietnamese government's policies for an export-led economy have supported the rapid growth of Pangasius production but have had limited success in mitigating the environmental and social impacts stemming from unplanned and ad hoc expansion. Recognising the poor performance of state regulation the industry and government have turned to private or market-based environmental and social standards for Pangasius production. The success of these private governance arrangements is dependent on the capacity of producers to comply with standards within their wider environmental, social, cultural and economic context. This paper reviews current concerns over the sustainability of Pangasius production and draws attention to the challenges private governance initiatives face in steering towards sustainable production.     

A study of genetic diversity of sesame (<Emphasis Type="Italic">Sesamum indicum</Emphasis> L.) in Vietnam and Cambodia estimated by RAPD markers

Sesame (Sesamum indicum L.) is a traditional oil crop cultivated throughout South East Asia. To estimate the genetic diversity of this crop in parts at the region, 22 sesame accessions collected in Vietnam and Cambodia were analyzed using 10 RAPD markers. The 10 primers generated 107 amplification products of which 88 were polymorphic fragments (83%). Genetic diversity of all populations was H_t = 0.34 when estimated by Nei’s genetic diversity and species diversity was H′_sp = 0.513 when estimated by Shannon diversity index. Genetic distance ranged from 0.03 to 0.43, with a mean genetic distance of 0.23. The unweighted pair group method with arithmetic averages (UPGMA) cluster analysis for the 22 accessions divided the material in four groups. The dendrogram revealed a clear division among the sesame accessions based on their geographical region. Interestingly, some geographically distant accessions clustered in the same group, which might indicate the human factor involved in the spreading of sesame varieties. The high level of polymorphism shown suggests that RAPD techniques can also be useful for the selection of parents in sesame (Sesamum indicum L.) breeding program and for cultivar differentiation.     

Low levels of nitrogen addition stimulate decomposition by boreal forest fungi

Climate warming and associated increases in nutrient mineralization may increase the availability of soil nitrogen (N) in high latitude ecosystems, such as boreal forests. These changes in N availability could feed back to affect the decomposition of litter and organic matter by soil microbes. Since fungi are important decomposers in boreal forest ecosystems, we conducted a 69-day incubation study to examine N constraints on fungal decomposition of organic substrates common in boreal ecosystems, including cellulose, lignin, spruce wood, spruce needle litter, and moss litter. We added 0, 20, or 200 μg N to vials containing 200 mg substrate in factorial combination with five fungal species isolated from boreal soil, including an Ascomycete, a Zygomycete, and three Basidiomycetes. We hypothesized that N addition would increase CO₂ mineralization from the substrates, particularly those with low N concentrations. In addition we predicted that Basidiomycetes would be more effective decomposers than the other fungi, but would respond weakly or negatively to N additions. In support of the first hypothesis, cumulative CO₂ mineralization increased from 635 ± 117 to 806 + 108 μg C across all fungal species and substrates in response to 20 μg added N; however, there was no significant increase at the highest level of N addition. The positive effect of N addition was only significant on cellulose and wood substrates which contained very little N. We also observed clear differences in the substrate preferences of the fungal species. The Zygomycete mineralized little CO₂ from any of the substrates, while the Basidiomycetes mineralized all of the substrates except spruce needles. However, the Ascomycete (Penicillium) was surprisingly efficient at mineralizing spruce wood and was the only species that substantially mineralized spruce litter. The activities of β-glucosidase and N-acetyl-glucosaminidase were strongly correlated with cumulative respiration (r = 0.78 and 0.74, respectively), and Penicillium was particularly effective at producing these enzymes. On moss litter, the different fungal species produced enzymes that targeted different chemical components. Overall, our results suggest that fungal species specialize on different organic substrates, and only respond to N addition on low N substrates, such as wood. Furthermore, the response to N addition is non-linear, with the greatest substrate mineralization at intermediate N levels.     

Fine-Scale Movements and Spatial Behaviors of Bear Hunters: Combining GPS With Survey Methods

Traditionally, information on hunter behavior has been obtained from questionnaires, which are useful, but provide limited information on spatial movements and behaviors. We used a global positioning system (GPS) to track movements of black bear hunters and determine if harvest success was influenced by effort (e.g., time spent afield) and spatial behaviors (e.g., distance traveled from roads). Furthermore, we used mail questionnaires to determine whether hunter perceptions of space use and effort differed from reality (GPS data). Most spatial variables did not differ between hunters and study area averages, indicating that hunters did not select for landscape characteristics differently than expected based on availability. The questionnaires were generally unreliable in describing space use, as hunters overestimated distance traveled from roads and underestimated distances traveled while afield. Studies should consider GPS to obtain more accurate assessments of behaviors while afield. When combined with questionnaire information, GPS data can reveal correction factors to improve spatial behavior estimates.     

Supplementation of Chelated Magnesium to Diets of the Pacific White Shrimp,Litopenaeus vannamei,Reared in Low‐salinity Waters of West Alabama

Shrimp farmers using inland low‐salinity waters in west Alabama have traditionally used agricultural fertilizers (K‐Mag®, muriate of potash) to raise pond water levels of potassium (K) and magnesium (Mg) to improve the rearing medium for Litopenaeus vannamei. Laboratory and farm trials were performed to investigate the potential of using dietary supplementation of Mg instead of costly agricultural fertilizers. A 5‐wk laboratory trial was devised to test four diets with varying levels of Mg supplementation (0, 0.15, 0.30, and 0.60% Mg chelate) using a magnesium chelate (MgC)–amino acid complex. Juvenile shrimp were stocked into artificial low‐salinity water (5 ppt) designed to contain low levels of Mg. A farm trial was also conducted to test the same diets under field conditions. Although both laboratory and on‐farm trials revealed a trend for increased growth using the diet with the highest Mg supplement, results were not significantly different. The use of magnesium chelates as dietary supplements at levels higher than the requirement level to enhance survival, growth, and osmoregulatory capacity of shrimp reared in inland low‐salinity well waters appeared to have limited potential. Until effective specialized diet formulations are produced, farmers should continue to supplement pond waters with fertilizers containing K and Mg.     

Proteomic analysis of wheat flour allergens

Wheat can cause severe IgE-mediated systematic reactions, but knowledge on relevant wheat allergens at the molecular level is scanty. The aim of the present study was to achieve a more detailed and comprehensive characterization of the wheat allergens involved in food allergy to wheat using proteomic strategies, referred to as "allergenomics". Whole flour proteins were separated by two-dimensional gel electrophoresis with isoelectric focusing and lithium dodecyl sulfate-polyacrylamide gel electrophoresis. Then, IgE-binding proteins were detected by immunoblotting with sera of patients with a food allergy to wheat. After tryptic digestion, the peptides of IgE-binding proteins were analyzed by matrix-assisted laser desorption ionization tandem time-of-flight mass spectrometry. In this study, we identified four previously reported wheat allergens or their sequentially homologous proteins [serpin, alpha-amylase inhibitor, gamma-gliadin, and low molecular weight (LMW) glutenin] by a database search. As a result of the high resolution of two-dimensional gel electrophoresis, nine subunits of LMW glutenins were identified as the most predominant IgE-binding antigens. The two-dimensional allergen map can be beneficial in many ways. It could be used, for example, for precise diagnosis of wheat-allergic patients and assessment of wheat allergens in food. Additionally, we compared allergenomics to conventional biochemical methods and evaluated the usefulness of a proteomic strategy for identifying putative allergens to wheat allergy.