Flood loss models and risk analysis for private households in can Tho City, Vietnam

Vietnam has a long history and experience with floods. Flood risk is expected to increase further due to climatic, land use and other global changes. Can Tho City, the cultural and economic center of the Mekong delta in Vietnam, is at high risk of flooding. To improve flood risk analyses for Vietnam, this study presents novel multi-variable flood loss models for residential buildings and contents and demonstrates their application in a flood risk assessment for the inner city of Can Tho. Cross-validation reveals that decision tree based loss models using the three input variables water depth, flood duration and floor space of building are more appropriate for estimating building and contents loss in comparison with depth-damage functions. The flood risk assessment reveals a median expected annual flood damage to private households of US$3340 thousand for the inner city of Can Tho. This is approximately 2.5%of the total annual income of households in the study area. For damage reduction improved flood risk management is required for the Mekong Delta, based on reliable damage and risk analyses

Multi-variate analyses of flood loss in Can Tho city, Mekong delta

Floods in the Mekong delta are recurring events and cause substantial losses to the economy. Sea level rise and increasing precipitation during the wet season result in more frequent floods. For effective flood risk management, reliable losses and risk analyses are necessary. However, knowledge about damaging processes and robust assessments of flood losses in the Mekong delta are scarce. In order to fill this gap, we identify and quantify the effects of the most important variables determining flood losses in Can Tho city through multi-variate statistical analyses. Our analysis is limited to the losses of residential buildings and contents. Results reveal that under the specific flooding characteristics in the Mekong delta with relatively well-adapted households, long inundation durations and shallow water depths, inundation duration is more important than water depth for the resulting loss. However, also building and content values, floor space of buildings and building quality are important loss-determining variables. Human activities like undertaking precautionary measures also influence flood losses. The results are important for improving flood loss modelling and, consequently, flood risk assessments in the Mekong delta

Knowledge-based extraction of adverse drug events from biomedical text

Background: Many biomedical relation extraction systems are machine-learning based and have to be trained on large annotated corpora that are expensive and cumbersome to construct. We developed a knowledge-based relation extraction system that requires minimal training data, and applied the system for the extraction of adverse drug events from biomedical text. The system consists of a concept recognition module that identifies drugs and adverse effects in sentences, and a knowledg

Volatile constituents of Atalantia roxburghiana Hook. f., Tetradium trichotorum Lour. and Macclurodendron oligophlebia (Merr.) Hartl. (Rutaceae) from Vietnam

The chemical constituents of essential oils obtained by hydrodistillation of the leaves of Atalantia roxburghiana Hook. f. and Tetradium trichotomum Lour., as well as the leaves and fruits of Macclurodendron oligophlebia (Merr.) Hartl. (Rutaceae) are being reported. The essential oils were analysed by using gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS). Sabinene (36.9%) was the most singly abundant compound in the leaf of A. roxburghiana. The major constituents present in the leaf oil of T. trichotorum were (E)-β-ocimene (24.8%), α-pinene (10.4%), (Z)-β-ocimene (9.4%) and β-caryophyllene (8.0%). On the other hand, while α-pinene (17.5%), β-caryophyllene (15.5%) and caryophyllene oxide (10.6%) occurred in higher proportion in the leaf of M. oligophlebia, the fruit oil was dominated by benzyl benzoate (16.8%), (E, E)-farnesol (8.3%) and β-caryophyllene (6.0%)

Efficient Management of Natural Resources: A Way to Sustain Food Security in the Rainfed Sloping Lands of Northern Vietnam

Rainfed sloping lands occupy one-third area of northern Vietnam and are threatened with destruction of natural resource base due to improper land use practices. Current production practices are exacerbating soil loss and destruction of the natural habitat as the soils are deeply weathered, poor in nutrients, and highly vulnerable to erosion. These ecosystems have much lower carrying capacity and respond to crop intensification by rapid decline in productivity, even total collapse if not managed properly. Remoteness and inaccessibility, low biological productivity, environmental degradation, disease and health problems, population increase, and lack of a development paradigm tailored to the special conditions are the key constraints for development. Sustainable farming on these lands in the perspective of a seriously deteriorated ecology and environment is not an easy task. Proper understanding of constraints and development of appropriate technologies with focus on soil, water, and nutrient management help optimize food production and combat resource degradation. Research and application of watershed based integrated natural resource management technologies offered excellent opportunities for crop diversification to meet market orientation, sustaining food production at higher levels, improving soil health, recharge of aquifers, and enhancing household incomes for better rural livelihoods in the sloping land ecoregions of northern Vietna

Корреляционные свойства шумовых сигналов на выходах приемных каналов с одиночным резонансным контуром

When suppressing active noise interference, an important task is to determine the mutual correlation function and the power of noise signals at the outputs of receiving channels. The solution of this problem makes it possible to analyze the influence of non-identical frequency characteristics of receiving channels on the quality of compensation of active noise interference. The analysis was carried out for a model of the frequency characteristics of the receiving channels in the form of the frequency response of a single resonant circuit in a narrow-band approximation. It was assumed that the frequency response of one of the channels differs from the second channel by the central frequency and bandwidth. In the analysis, an approximate approximation of the frequency response of the detuned channel was used, assuming a slight detuning of the parameters of the resonant circuit. The input noise of the receiving channels was assumed to be white. The use of the obtained results is demonstrated in obtaining an expression for the potential effectiveness of a single-channel autocompensator. При подавлении активных шумовых помех важной задачей является определение взаимной корреляционной функции и мощности шумовых сигналов на выходах приемных каналов. Решение этой задачи позволяет анализировать влияние неидентичностей частотных характеристик приемных каналов на качество компенсации активных шумовых помех. Анализ проводился для модели частотных характеристик приемных каналов в виде частотной характеристики одиночного резонансного контура в узкополосном приближении. Предполагалось, что частотная характеристика одного из каналов отличается от второго канала центральной частотой и полосой пропускания. При анализе использовалась приближенная аппроксимация частотной характеристики расстроенного канала в предположении незначительной расстройки параметров резонансного контура. Входной шум приемных каналов предполагался белым. Использование полученных результатов продемонстрировано при получении выражения для потенциальной эффективности одноканального автокомпенсатора

Rapid evolution of virulence and drug resistance in the emerging zoonotic pathogen Streptococcus suis

Background: Streptococcus suis is a zoonotic pathogen that infects pigs and can occasionally cause serious infections in humans. S. suis infections occur sporadically in human Europe and North America, but a recent major outbreak has been described in China with high levels of mortality. The mechanisms of S. suis pathogenesis in humans and pigs are poorly understood. Methodology/Principal Findings: The sequencing of whole genomes of S. suis isolates provides opportunities to investigate the genetic basis of infection. Here we describe whole genome sequences of three S. suis strains from the same lineage: one from European pigs, and two from human cases from China and Vietnam. Comparative genomic analysis was used to investigate the variability of these strains. S. suis is phylogenetically distinct from other Streptococcus species for which genome sequences are currently available. Accordingly, ,40% of the ,2 Mb genome is unique in comparison to other Streptococcus species. Finer genomic comparisons within the species showed a high level of sequence conservation; virtually all of the genome is common to the S. suis strains. The only exceptions are three ,90 kb regions, present in the two isolates from humans, composed of integrative conjugative elements and transposons. Carried in these regions are coding sequences associated with drug resistance. In addition, small-scale sequence variation has generated pseudogenes in putative virulence and colonization factors. Conclusions/Significance: The genomic inventories of genetically related S. suis strains, isolated from distinct hosts and diseases, exhibit high levels of conservation. However, the genomes provide evidence that horizontal gene transfer has contributed to the evolution of drug resistance

Yield Gap Analysis of Major Rainfed Crops of Northern Vietnam Using Simulation Modeling. Global Theme on Agroecosystems Report No. 26

Total population of Vietnam is 82 million as of today. It is expected to increase to 95 million by 2010 and 126 million by 2020. With increasing demand for food in future, the pressure on uplands and midlands of northern Vietnam would increase to produce more food for millions of poor residing in Vietnam. Major crops of northern Vietnam are rice, sweet potato, maize, tea, peanut and soybean, in addition to other annual and perennial crops. The current study investigated the potential yields; yield gaps and water balance of maize, peanut and soybean crops, which have high potential in the region. We used crop simulation models of the three crops and the field data to evaluate the scope for increasing productivity and water harvesting in the six selected provinces of northern Vietnam. Analysis of the production data revealed that since 1994–95 the area, production and productivity of these crops have increased substantially. Improvements in productivity have been obtained with the introduction of improved crop varieties and management practices. However, large yield gaps still exist which are variable among districts and provinces. Overall, the yield gap is 1010 kg ha-1 for summer season and 680 kg ha-1 for spring season for soybean; 2650 kg ha-1 for spring season and 2010 kg ha-1 for autumn season for peanut; and for maize it is 1990 kg ha-1 for summer season and 1650 kg ha-1 for spring season, indicating the potential for future yield improvements. Because of high rainfall in northern Vietnam, significant amount of surface runoff and deep drainage occurs leading to land degradation. The vast potential of the rainfed areas of northern Vietnam could be harnessed through large- scale adoption of integrated genetic and natural resource management technologies in watershed context for increasing productivity and reducing land degradation