Genetic diversity on the tropical rare wood species of Dalbergia in Vietnam revealed by inter-simple sequence repeat (ISSR) markers

Genetic diversities of three rare hardwood species of Dalbergia (D. assamica, D. nigrescens and D. tonkinensis) were evaluated for conservation based on inter-simple sequence repeat (ISSR) markers. A total of 47 ISSR primers were used for the analysis, but only 31 ISSR primers were successfully amplified for 25 samples from each species. There were 166 fragments across the 75 samples produced, in which 153 were polymorphic with an average of 4.94 polymorphic fragments per primer. The number of amplified fragments ranged from 1 (ISSR13, ISSR54 and ISSR59) to 11 (ISSR14) and their size varied from 200 to 1700 bp. The similarity coefficient ranged from 67.0 to 98.9% in D. assamica; from 71.2 to 98.5% in D. nigrescens and from 68.5 to 95.2% in D. tonkinensis. The estimated value of molecular diversity parameters within species such as the effective number of alleles, Shannon's information index, intralocus gene diversity and Nei’s gene diversity were low among the individuals of the different Dalbergia species (1.227, 0.195, 0.662 and 0.146, respectively in D. assamica; 1.135, 0.111, 0.425 and 0.109, respectively in D. nigrescens; 1.198, 0.166, 0.526 and 0.123, respectively in D. tonkinensis). The analysis of molecular variance (AMOVA) of ISSR data indicated that the greater proportion of total genetic variation existed among species rather than within species. The correlation between genetic and geographic distance was also found in the three Dalbergia species.Key words: Dalbergia, endemic species, genetic similarity, ISSR markers

A Non Mouse-Adapted Dengue Virus Strain as a New Model of Severe Dengue Infection in AG129 Mice

The spread of dengue (DEN) worldwide combined with an increased severity of the DEN-associated clinical outcomes have made this mosquito-borne virus of great global public health importance. Progress in understanding DEN pathogenesis and in developing effective treatments has been hampered by the lack of a suitable small animal model. Most of the DEN clinical isolates and cell culture-passaged DEN virus strains reported so far require either host adaptation, inoculation with a high dose and/or intravenous administration to elicit a virulent phenotype in mice which results, at best, in a productive infection with no, few, or irrelevant disease manifestations, and with mice dying within few days at the peak of viremia. Here we describe a non-mouse-adapted DEN2 virus strain (D2Y98P) that is highly infectious in AG129 mice (lacking interferon-α/β and -γ receptors) upon intraperitoneal administration. Infection with a high dose of D2Y98P induced cytokine storm, massive organ damage, and severe vascular leakage, leading to haemorrhage and rapid death of the animals at the peak of viremia. In contrast, very interestingly and uniquely, infection with a low dose of D2Y98P led to asymptomatic viral dissemination and replication in relevant organs, followed by non-paralytic death of the animals few days after virus clearance, similar to the disease kinetic in humans. Spleen damage, liver dysfunction and increased vascular permeability, but no haemorrhage, were observed in moribund animals, suggesting intact vascular integrity, a cardinal feature in DEN shock syndrome. Infection with D2Y98P thus offers the opportunity to further decipher some of the aspects of dengue pathogenesis and provides a new platform for drug and vaccine testing

AN IMPROVED GENETIC ALGORITHM FOR TEST DATA GENERATION FOR SIMULINK MODELS

Mutation testing is a powerful and effective software testing technique to assess the quality of test suites. Although many research works have been done in the field of search-based testing, automatic test data generation based on the mutation analysis method is not straightforward. In this paper, an Improved Genetic Algorithm (IGA) is proposed to increase the quality of test data based on mutation coverage criterion. This algorithm involves some modifications of genetic operators and the employment of memory mechanism to enhance its effectiveness. The proposed approach is implemented to generate test data for Simulink models. The obtained results indicated that IGA outperformed the conventional genetic algorithm in terms of the quality of test sets, and the execution time

Parallel mutant execution techniques in mutation testing process for simulink models

Mutation testing { a fault-based technique for soft- ware testing { is a computationally expensive approach. One of the powerful methods to improve the performance of mutation without reducing effectiveness is to employ parallel processing, where mutants and tests are executed in parallel. This approach reduces the total time needed to accomplish the mutation analysis. This paper proposes three strategies for parallel execution of mutants on multicore machines using the Parallel Computing Toolbox (PCT) with the Matlab Distributed Computing Server. It aims to demonstrate that the computationally intensive software testing schemes, such as mutation, can be facilitated by using parallel processing. The experiments were carried out on eight different Simulink models. The results represented the efficiency of the pro- posed approaches in terms of execution time during the testing process

A Novel Fitness function of metaheuristic algorithms for test data generation for simulink models based on mutation analysis

Testing is one of the crucial activities to assure the software quality. The main objective of testing is to generate test data uncovering faults in software modules. There are a variety of testing techniques in which mutation testing is a popular approach to generate test sets and evaluate their fault detection ability. Simulink is an environment widely used in industry to design and simulate critical systems. Testing such a system at the design phase could help to detect faults earlier. This study aims to propose a novel fitness function of metaheuristic algorithms to generate test data based on the mutation technique for the Simulink models. The fitness function is designed by analyzing each mutation operator and the features of blocks in the Simulink environment in order to guide the search process to reach the test data killing mutants more easily. Then, this fitness function is used in the multi-parent crossover genetic algorithm to generate test sets. The obtained results indicated that the mutation score has been significantly improved for all models when using the novel fitness function. In addition, each stubborn mutant was killed with a lower number of test data evaluations in comparison with the work of other authors

Exploiting relay nodes for maximizing wireless underground sensor network lifetime

© 2020, Springer Science+Business Media, LLC, part of Springer Nature. A major challenge in wireless underground sensor networks is the signal attenuation originated from multi-environment transmission between underground sensor nodes and the above-ground base station. To overcome this issue, an efficient approach is deploying a set of relay nodes aboveground, thereby reducing transmission loss by shortening transmitting distance. However, this introduces several new challenges, including load balancing and transmission loss minimization. This paper tackles the problem of deploying relay nodes to reduce transmission loss under a load balancing constraint by proposing two approximation algorithms. The first algorithm is inspired by Beam Search, combined with a new selection scheme based on Boltzmann distribution. The second algorithm aims to further improve the solutions obtained by the former by reducing the transmission loss. We observe that we can find an optimal assignment between sensor nodes and a set of the chosen relay in polynomial time by reformulating the part of the problem as a bipartite matching problem with minimum cost. Experimental results indicate that the proposed methods perform better than the other existing ones in most of our test instances while reducing the execution time

Private pharmacy staff in Hanoi dispensing steroids - theory and practice

Objective: To investigate self reported practice and actual practice of private pharmacy staff in relation to drug regulations and provision of prednisolone (a prescription-only corticosteroid) on request to treat lower back pain. Method: Sixty private pharmacies in Hanoi were randomly selected. Self reported practice was assessed through interviews with pharmacy staff using a questionnaire; actual practice was assessed with the Simulated Client Method with 5 encounters in each pharmacy (a total of 295 encounters). Results: Sixty percent of the pharmacy staff interviewed said that they would not dispense corticosteroids without prescription and 60% could mention some adverse effects. In practice all but one pharmacy dispensed corticosteroids without prescription in 76 % of all the encounters. Questions and advice given to the clients were associated with significantly lower dispensing of corticosteroids. Conclusion: The low compliance with prescription regulations and the discrepancy between stated practice and actual practice raises concerns. This study indicates that commercial pressures exceed the deterrent effect of current drug regulations and their implementation and hence enforcement of regulations needs to be improved

Situation Analysis and Needs Assessment Report for Tra Hat Village, Bac Lieu Province, Vietnam

Bac Lieu Province in Vietnam is mainly agricultural. Rice is the dominant staple food and the main crop in the province. Farmers have changed the farming system from paddy monoculture to diversified agricultural products (cash crops and livestock). Livestock production is in small scale. The province has three ecological zones: rice/fruit and vegetable production in the eastern districts, a mixed rice and rice/shrimp/aquaculture environment in the central districts and an area of saline/acid soil for a wide variety of sea-based product in the western districts. Salinization and shifting land use from cultivation to aquaculture have caused soil degradation in Bac Lieu. Meanwhile, Tra Hat village is in Vinh Loi District in Bac Lieu Province. It is about 25 km distance from Bac Lieu City. Nearly 80% of the total area of 400 ha of the village are paddy fields (316 ha). Livelihood in the village include rice production, livestock, fishpond and garden production. The problems in rice production include the degradation of the traditional rice seed, flooding, lack of freshwater, application of more farm chemicals, and difficult access to market information; for fruits and vegetables, the main problem is the poor market demand; for livestock, the main problems are diseases and lack of market; in fisheries, the main problem is the low catch; and for aquaculture, the main problems are the poor quality of water and the lack of market. Households also earn money from off farm activities and thus can buy other food (meat, egg) at the commune market for daily consumption. Many households in the village are food sufficient. The local production systems are well adapted to the natural seasonal fluctuation in rainfall and flooding regime, but occasional extreme flooding events cause crop damage and food shortage situation, the most recent was in 2011. The main concern is the maintenance of food sufficiency and security, and raising household income. The main challenges are increasing climate shocks, salt-water intrusion, and population growth. Households acknowledged their need to receive support from the government and other organizations to develop their production systems for sustainable and stable income and better living conditions with reduced risks of environmental pollution, natural disasters, and climate variability