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71.
Although there are a number of Vietnamese native pig (VnP) populations, some are on the verge of extinction, and therefore adequate management and conservation are necessary. In this study, we conducted a field survey of VnP populations and analyzed interrelationships among their characteristics. We also established a relational database for management of field data on these populations. For data collection, we conducted interviews with farmers and visual inspection of 32 VnP populations in 22 provinces of Vietnam, as well as taking photographs of individual animals. Data on the characteristics of VnP populations were subjected to multiple correspondence analysis (MCA). For establishment of the database, normalization and table partitioning were performed to eliminate redundancy and ensure consistency of the collected data items. Passport data, characteristics data, and image data were collected from a total of 1,918 VnPs and entered as a normalized table. Upon MCA, most of the populations were not separated from each other, but the Mong Cai, O Lam, and Chu Prong populations were separated from the other populations. Thus, we have constructed a relational database from comprehensive information on the characteristics of VnP populations.  相似文献   
72.
Porcine circovirus type 2 (PCV2) plays a crucial role in the pathogenesis of post-weaning multisystemic wasting syndrome (PMWS) in swine. As PCV2 displays significant homology with PCV1 (a non-pathogenic virus) at the nucleotide and amino-acid level, a discriminative antigen is needed for specific serological diagnosis. The ORF2-encoded capsid protein from PCV2 was used to develop an indirect enzyme-linked immunosorbent assay (ELISA). GST-fused capsid protein from PCV2 and GST alone (both expressed in recombinant baculovirus-infected cells) were used as antigens for serodiagnosis. The specificity of the ELISA for detection of PCV2 antibodies was demonstrated in sera from pigs experimentally infected with PCV1, PCV2 and other swine viruses. The semi-quantitative nature of the test was evaluated versus an immunoperoxidase monolayer assay (IPMA). The ELISA was performed on 322 sera from pigs in eight Brittany herds and compared with IPMA. The sensitivity (98.2%) and specificity (94.5%) of this test were considered suitable for individual serological detection. High PCV2 seroprevalence was found in sows and pigs at the end of the growth phase (18-19 weeks) in all eight herds. The seroprevalence in piglets (11-17 weeks) was statistically correlated with clinical symptoms of PMWS (93% in affected versus 54%, in non-affected farms). A cohort study performed in PMWS-free farms showed that 57% of piglets exhibited active seroconversion after 13 weeks, indicating that PCV2 infection occurred earlier in PMWS-affected piglets.  相似文献   
73.
An unique procedure for the mass shoot propagation of Gerbera using receptacle transverse thin cell layer (tTCL) culture procedure was developed. Genotype, flower bud age, explant size, position of receptacle tTCLs and culture media were found to affect the success of culture. Ten interspecific crosses of Gerbera showed different shoot regeneration rates and callus induction via receptacle tTCL culture, all of which had shoot regeneration rates higher than 57%. Flower buds collected on the 10th day resulted in 91% shoot regeneration after 6 weeks of culture on basal MS medium [Murashige, T., Skoog, F., 1962. A revised medium for rapid growth and bioassay with tobacco tissue cultures. Physiol. Plant. 15, 475–497] supplemented with 0.02 mg l−1 thidiazuron (TDZ), 0.8 mg l−1 adenine and 10% (v/v) coconut water (CW). This was significantly higher than those from flower buds on the 7th and 14th days (22% and 54%), respectively. Shoot regeneration rate was the highest (94–100%) in the middle layers of the receptacle. For mass shoot propagation, shoot clusters were subcultured on half-strength MS medium supplemented with 0.5 mg l−1 indole-3-butyric acid (IBA), 0.5 mg l−1 6-benzyladenine (BA) and 2.0 mg l−1 kinetin after every 4 weeks. Plantlets formed when single shoots were cultured on half-strength MS medium containing 1 mg l−1 IBA. All plantlets acclimatized well in the greenhouse.  相似文献   
74.

Purpose  

Even though sediments may represent a reservoir for antimicrobial agents, little is known about the persistence of these molecules over time or their accumulation. In this study, six antimicrobial agents, oxolinic acid, flumequine, nalidixic acid, norfloxacin, sulphamethoxazole and trimethoprim, were investigated in a sediment core from the Seine River. This work aimed to (1) measure antimicrobial agent contamination levels in the sediment and identify their origins, (2) obtain information on the persistence of these compounds in sediment over long periods (>4 years) and (3) show the existence of a historical record in sediment of river contamination by antimicrobial agents.  相似文献   
75.
We examined utilitarian and hedonic values as motivations for rhino horn use in Vietnam. We also evaluated consumers’ response to consequences of the illegal trade in behavior modification campaigns and the likely outcome of a legalized trade. The most prevalent use was for treatment of hangovers indicating utilitarian values, although difficult to separate from the hedonic value in projecting success in business. A ritualized way of honoring terminally ill relatives represented a hedonic value replacing belief in effective treatment. Demand reduction campaigns need to appropriately reflect all relevant values determining specific uses. The plight of rhino populations, Vietnam’s penal code, and the possible contribution to international crime mattered little to consumers. Horn from wild rhino was preferred over farmed, and respondents would demand more if available in a legalized trade. This suggested that a legalized trade could maintain or even increase demand for poached rhino horn.  相似文献   
76.
Taxus chinensis and T. wallichiana in have been threatened in their distribution areas in recent decades because of their over-exploitation and reduction and destruction of native habitats. Determining the genetic diversity in populations of the two species will provide guidelines for their protection and preservation. Two hundred and fifteen trees from six populations of T. chinensis and 150 sampled trees of T. wallichiana were sampled. Six microsatellite primer pairs selected from 16 primer pairs were used to investigate genetic variation at the population and species levels. Five yielded polymorphic alleles, and among the 13 putative alleles amplified, 11 were polymorphic (accounting for 76.33 %).Shannon’s information index (I) and percentage of polymorphic bands (PPB) (I = 0.202 and PPB = 67.22 % for T. chinensis; I = 0.217 and PPB = 65.03 % for T. wallichiana). Both species had low levels of genetic diversity (mean H o = 0.107, H e = 0.121 for T. chinensis; H o = 0.095, H e = 0.109 for T. wallichiana). Genetic differentiation among populations was higher (F ST = 0.189) for T. chinensis and lower (0.156) for T. wallichiana, indicating limited gene flow (Nm) among populations for T. chinensis (0.68) and T. wallichiana (0.65). Variation among individuals of T. chinensis was 63.59 and 73.12 % for T. wallichiana. Thus, the threatened status of the two conifers is related to a lack of genetic diversity. All populations are isolated in small forest remnants. An ex situ conservation site should be established with a new population for these species that comprises all the genetic groups for the best chance to improve their fitness under environmental stresses.  相似文献   
77.
78.
根据考察和学术交流收集到的资料,综述了越南柑桔生产概况、不同生态区柑橙生产情况、越南柑桔种质资源和商业化栽培的主栽柑桔品种特性,对促进中越柑桔学术交流具有重要的意义。  相似文献   
79.
Artificial polyacrylamide gel (PAG) and urea-formaldehyde resin foam (UFRF) amendments are used for putative enhancement of soil physical properties, including increasing their water holding capacity (WHC). Effects were investigated of these two amendments alone and combined on growth and development of Orthosiphon aristatus (Cats’ Whiskers) grown in either composted pine bark or washed river sand, including under transient water deficit stress. UFRF and PAG were incorporated into these potting media substrates at recommended rates of 30% (v/v) and 0.1% (w/w), respectively. UFRF incorporation reduced bulk density and increased air-filled porosity of composted pine bark from 0.24 g cm−3 and 43.3% to 0.18 g cm−3 and 50.2%, respectively. UFRF also reduced bulk density of sand from 1.43 g cm−3 to 1.17 g cm−3 and increased its air-filled porosity from 18.5% to 25.3%. PAG slightly decreased bulk density of composted pine bark to 0.23 g cm−3 and also reduced sand bulk density to 1.32 g cm−3. Water content of composted pine bark and sand was increased by PAG addition from 47.6% and 27.7% to 51.0% and 34.2%, respectively. However, UFRF and/or PAG did not increase plant available water (PAW) in either composted pine bark or sand. PAW was 23.8% and 14.4%, 23.6% and 15.8%, 22.8% and 14.8%, and 25.2% and 17.8% for composted pine bark and sand controls, these two substrates amended with UFRF, these substrates amended with PAG, and these substrates with UFRF plus PAG, respectively. Neither shoot length nor number was increased by adding UFRF and/or PAG. Similarly, neither shoot fresh nor dry weight was increased by UFRF and/or PAG amendments. UFRF and, moreso, UFRF plus PAG slightly delayed the onset of wilting by 4–15 h in water deficit stressed O. aristatus compared to control and PAG alone in composted pine bark (experiment 1), but PAG did not. However, in experiment 2, UFRF and/or PAG did not delay wilting in either composted pine bark or sand. Thus, when incorporated at suppliers recommended rates, neither UFRF nor PAG conferred appreciable benefits for O. aristatus plant growth in either composted pine bark or sand potting media.  相似文献   
80.
Chemical investigation of a coculture of the marine-derived fungi Beauveria felina KMM 4639 and Aspergillus carneus KMM 4638 led to the identification of three new drimane-type sesquiterpenes, asperflavinoids B, D and E (2, 4, 5), and nine previously reported related compounds. The structures of these compounds were established using spectroscopic methods and by comparison with known analogues. We also investigated the cytotoxic activity of the isolated compounds against several cancer and normal cell lines. Asperflavinoid C (3) and ustusolate E (9) exerted a significant effect on human breast cancer MCF-7 cell viability, with IC50 values of 10 µM, and induced in caspase-dependent apoptosis and arrest of the MCF-7 cell cycle in the G2/M phase in these cells.  相似文献   
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