Surveillance of swine influenza viruses in sentinel familial farms in Hung Yen province in Northern Vietnam in 2013–2014

From May 2013 to April 2014, 15 swine family‐run farms (17 pig litters) in two districts in Hung Yen province, near Hanoi, were virologically and epizootiologically monitored for swine influenza viruses (SIV) monthly. No SIV was isolated from nasal swabs. Maternal antibodies were detected in 10 litters, and seroconversion against SIV was detected in six litters. There was a marked difference in patterns of SIV transmission in the two districts. Van Lam district which has low density of swine with mainly smallholder farms had low intensity of SIV, with much of the infection caused by H1N1 2009 pandemic‐like viruses A(H1N1)pdm09, likely originated from humans. In contrast, Van Giang district, which has high swine density and larger farms, had high levels of typical SIV (triple reassortants H3N2 and H3N2 Binh Duong lineage viruses) circulating within swine. With one exception, the SIV lineages detected were those we concurrently isolated from studies in a large central abattoir in Hanoi. Influenza‐like illness symptoms reported by farmers were poorly correlated with serological evidence of SIV infection.     

Evaluation of non-linear growth curve models in the Vietnamese indigenous Mia chicken

Understanding of animal growth is important for the improvement of management and feeding practices; however, little is known about the growth curve in Vietnamese indigenous chicken. This study was performed to determine the most appropriate models for describing the growth curve of Vietnamese Mia chicken. The study evaluated the performances of the Logistic, Gompertz, Richards, and Bridges models of body weights in 224 Mia chickens. Models were fitted using minpack.lm package in R software and Akaike’s information criterion and Bayesian information criterion were used for model comparison. Based on these criteria, the Gompertz and Bridges were the best models for males and females, respectively. Estimated asymmetric weights (α) were ranged from 2,241.91 ± 14.74 (g) (Logistic) to 2,623.86 ± 30.23 (g) (Gompertz) for males and from 1,537.36 ± 10.97 (g) (Logistic) and 1,958.36 ± 72.92 (g) (Bridges) for females, respectively. The age at the inflection point was estimated from 9.32 to 10.5 weeks and from 8.51 to 9.86 weeks for males and females, respectively. In conclusion, the Gompertz model is the most suitable model for describing the growth curve of Mia chicken. The parameters obtained from growth models could help define feeding programs to meet nutritional needs from hatching to the age of maximum growth, reproduction programs, and marketing strategies.     

Accumulation patterns and health risk assessment of potentially toxic elements in the topsoil of two sloping vineyards (Tokaj-Hegyalja,Hungary)

Journal of Soils and Sediments - In agricultural soils, accumulation and bioavailability patterns of potentially toxic elements (PTEs) are key ecological and health risk issues, especially in...     

Hunters'structured questionnaires enhance ecological knowledge and provide circumstantial survival evidence for the world's rarest turtle

1. Rafetus swinhoei, a giant softshell turtle from southern China and northern Vietnam, is the rarest turtle species on Earth, and only two individuals are known worldwide (one in the wild). There is very little ecological information for this species, and the remnant distribution remains completely unknown.
2. This article reports for the first time in the international literature the results of a structured questionnaire survey concerning the ecology and distribution of R. swinhoei in Vietnam. The standardized questionnaire consisted of 15 questions and was administered to 10 former Rafetus hunters with several years of experience in catching this species.
3. There was considerable consensus among the hunters regarding several aspects of the biology of R. swinhoei, with special reference to its reproductive and feeding habits. The mean weight of 58 captured individuals was 53 kg, with the majority of individuals weighing 15–40 kg (median = 40 kg) and only 17.2% of individuals weighing more than 100 kg.
4. Based on the hunters'answers, it was established that the population collapse of R. swinhoei in Vietnam occurred in two phases: first during the 1980s, when the population size dramatically decreased, and second, at the beginning of the 1990s, when many hunters simultaneously collected multiple individuals from populations already experiencing severe impacts. There was also a general agreement that these turtles became very rare after 1991–92.
5. In total, 90% of the hunters agreed that there should still be wild R. swinhoei individuals at their respective sites, and some of the hunters also reported a few recent sightings that they attributed to the target species.
6. As several sites of likely presence were identified, we suggest that extensive trapping should be planned at these sites in future.

     

Fishers,dams, and the potential survival of the world's rarest turtle,Rafetus swinhoei,in two river basins in northern Vietnam

1. Next to cetaceans and megafishes, freshwater turtles are the most iconic endangered freshwater species.
2. A detailed questionnaire survey conducted with more than 100 individuals from fishing communities in northern Vietnam was used to investigate the current status of Southeast Asian turtles and provides new hope concerning the survival of Rafetus swinhoei, for which recent official records in the wild are limited to a single individual in Vietnam.
3. The survey included the entire Vietnamese portion of the Da River in Hoa Binh and Son La provinces, as well as the Chu and Ma river system in Thanh Hoa Province, as they are the last sites where the world's rarest and largest Asian softshell turtle has been seen. The questionnaire, conducted in Vietnamese, focused on demographic details, fishing intensity and gear, the status of fishing grounds, and the frequency of interaction with turtles.
4. The great majority of fishers could recognize different turtle species from photographs and describe their preferential breeding habitats; not all knew that they are protected. A few confirmed that more than once each year they still encounter freshwater turtles during their fishing activities.
5. This survey provides detailed information on sites where freshwater turtles are still seen in northern Vietnam and broadens our hope that wild individuals of the extremely rare R. swinhoei may still be present in the remaining riparian wetlands of these biodiverse, dammed, and controlled river basins in North Vietnam.

     

Genetic variation for bacterial wilt resistance in a population of tetraploid potato

Summary Genetic variance components and heritability were estimated for resistance to bacterial wilt in a population of tetraploid potato with resistance derived from several specific sources. Both additive and non-additive variance components were significant. Their relative magnitudes indicated the importance of non-additive gene action in the genetic control of the resistance. Narrow-sense heritability was relatively low for both disease index and % survival indicating that progress in population development would be slow. Broad-sense heritability was, however, relatively high which promises success of clonal selection in developing clonal resistant cultivars.     

Effects of resistance genes,heat tolerance genes and cytoplasms on expression of resistance to Pseudomonas solanacearum (E.F. Smith) in potato

Summary Effects of resistance genes and heat tolerance genes on expression of resistance to bacterial wilt caused by Pseudomonas solanacearum were investigated in 30 F₁ progenies from parents with different levels of bacterial wilt resistance and heat tolerance. A race 1 and a race 3 isolate of the bacterium were used for inoculation under screenhouse conditions at two locations. Results obtained indicated that with reduction in levels of parental resistance, resistance in the F₁ progenies was also reduced. Under hot conditions, a reduced heat tolerance in the genetic background also resulted in lower levels of resistance expression. The effect of heat tolerance tended to diminish at lower temperatures leaving the effect of resistance genes more consistent. There existed a strong interaction between resistance genes and genes for heat tolerance. The nature of resistance to bacterial wilt in potato and implications for breeding for resistance are discussed.Effects of reciprocal crosses on expression of resistance to a race 1 isolate under hot screenhouse conditions, were studied in 5 sets of reciprocal F₁ progenies involving different resistant and susceptible parents. The reciprocal differences observed were not significant suggesting absence of cytoplasmic effects on expression of resistance.     

Contribution of human alpha-defensin 1, 2, and 3 to the anti-HIV-1 activity of CD8 antiviral factor

It has been known since 1986 that CD8 T lymphocytes from certain HIV-1-infected individuals who are immunologically stable secrete a soluble factor, termed CAF, that suppresses HIV-1 replication. However, the identity of CAF remained elusive despite an extensive search. By means of a protein-chip technology, we identified a cluster of proteins that were secreted when CD8 T cells from long-term nonprogressors with HIV-1 infection were stimulated. These proteins were identified as alpha-defensin 1, 2, and 3 on the basis of specific antibody recognition and amino acid sequencing. CAF activity was eliminated or neutralized by an antibody specific for human alpha-defensins. Synthetic and purified preparations of alpha-defensins also inhibited the replication of HIV-1 isolates in vitro. Taken together, our results indicate that alpha-defensin 1, 2, and 3 collectively account for much of the anti-HIV-1 activity of CAF that is not attributable to beta-chemokines.     

Coordination of early protective immunity to viral infection by regulatory T cells

Suppression of immune responses by regulatory T cells (Tregs) is thought to limit late stages of pathogen-specific immunity as a means of minimizing associated tissue damage. We examined a role for Tregs during mucosal herpes simplex virus infection in mice, and observed an accelerated fatal infection with increased viral loads in the mucosa and central nervous system after ablation of Tregs. Although augmented interferon production was detected in the draining lymph nodes (dLNs) in Treg-deprived mice, it was profoundly reduced at the infection site. This was associated with a delay in the arrival of natural killer cells, dendritic cells, and T cells to the site of infection and a sharp increase in proinflammatory chemokine levels in the dLNs. Our results suggest that Tregs facilitate early protective responses to local viral infection by allowing a timely entry of immune cells into infected tissue.