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181.
Pinus pseudostrobus Lindl. is a widely distributed species in Mexico that also occurs in Guatemala, Honduras and El Salvador and has been tested outside its natural range in Brazil, Chile, Colombia, New Zealand, South Africa and Venezuela. Due to its great potential, it is necessary to select genotypes capable of increasing its production in the shortest possible time through genetic improvement strategies, where individuals are subjected to conditions forcing them to express their growth potential in advance. The objectives of the present study were to evaluate the genetic variation among half-sib progenies and to estimate heritability (h 2 ) of stem height (SH) and diameter (SD) for seedlings grown under different competitive conditions in a common garden trial. A split-plot experimental design with four replications and three competitive environments (treatments) was used: (I) low inter-family competition (0.25 × 0.12 m), (II) high inter-family competition (0.12 × 0.06 m), and (III) high intra-family competition; 13 half-sib families were assessed, carrying out monthly evaluations for 10 months. Estimated h 2 at individual and family-means levels for both SH and SD varied among competitive environments. For conditions I and II, a trend towards increasing h 2 with age of seedlings was shown, but for condition III, a reverse trend was observed (values close to zero). High genetic stability in SH performance was found in both I and II, and II and III, pairs of environments, as measured by the type-B genetic correlation (0.70 ≤ r B  ≤ 1.0), but it tended to decrease after 9 months, when competition increased; genetic stability in SD was lower (0.20 ≤ r B  ≤ 0.80) in both pairs of the environments that were sampled. It was concluded that the competition conditions used in field trials for genotype evaluation may significantly affect the variance components, estimation of genetic parameters and genotype stability.  相似文献   
182.
Currently, periodontitis treatment relies on surgical operations, anti-inflammatory agents, or antibiotics. However, these treatments cause pain and side effects, resulting in a poor prognosis. Therefore, in this study, we evaluated the impact of the compound epiloliolide isolated from Sargassum horneri on the recovery of inflammatory inhibitors and loss of periodontal ligaments, which are essential treatment strategies for periodontitis. Here, human periodontal ligament cells stimulated with PG-LPS were treated with the compound epiloliolide, isolated from S. horneri. In the results of this study, epiloliolide proved the anti-inflammatory effect, cell proliferation capacity, and differentiation potential of periodontal ligament cells into osteoblasts, through the regulation of the PKA/CREB signaling pathway. Epiloliolide effectively increased the proliferation and migration of human periodontal ligament cells without cytotoxicity and suppressed the protein expression of proinflammatory mediators and cytokines, such as iNOS, COX-2, TNF-α, IL-6, and IL-1β, by downregulating NLRP3 activated by PG-LPS. Epiloliolide also upregulated the phosphorylation of PKA/CREB proteins, which play an important role in cell growth and proliferation. It was confirmed that the anti-inflammatory effect in PG-LPS-stimulated large cells was due to the regulation of PKA/CREB signaling. We suggest that epiloliolide could serve as a potential novel therapeutic agent for periodontitis by inhibiting inflammation and restoring the loss of periodontal tissue.  相似文献   
183.
Malaysia is a non‐endemic country for hepatitis E virus (HEV) infection. However, seroprevalence as high as 50% among samples of aboriginal people were reported over two decades ago. A total of 207 samples collected from seven aboriginal villages in rural settlements across two states in Malaysia were analysed for anti‐HEV IgG and IgM by an enzyme‐linked immunoassay. Following the detection of anti‐HEV seroprevalence, we organized health outreach to inform and educate the community. Qualitative interviews were conducted with individuals tested positive for anti‐HEV antibodies. Data derived from interviews and observations were used to investigate possible lifestyle behaviours associated with HEV infection. Anti‐HEV IgG was detected in six samples (5.9%) from the village of Dusun Kubur. Qualitative inquiry and observation study revealed poor dietary and household hygiene, contaminated food and water, contact with animal faeces, unsanitary and domestic waste disposal, and wildlife reservoirs could be the contributing factors for transmission and acquisition of HEV infection. Investigation during health outreach is important to provide insights for future empirical research and implementation for improvement of lifestyle behaviours among the aborigines. Managing the risk of HEV infection in the aborigines may reduce the risk of HEV transmission to the local communities.  相似文献   
184.
185.
Studies were conducted to determine whether interactions occur among dietary lysine, arginine and monovalent minerals in rainbow trout. In one experiment, rainbow trout fingerlings were fed diets containing three levels of lysine (2.4, 3.1 and 3.8 g per 100 g diet), two levels of arginine (1.7 and 2.5 g per 100 g diet) and two mixtures of Na+ K+ and Cl in a 3×2×2 factorial design. The mixtures varied in the proportions of cations to anions such that Cl equalled the sum of Na+ and K+ (cations – anions = 0 mEq/kg diet) in one mixture and exceeded the sum of Na+ and K+ (cations – anions = –200 mEq/kg diet) in the second mixture. Growth and efficiency of feed conversion were not affected by dietary lysine and arginine in fish fed diets containing – 200 mEq/kg balance, but when fish were fed diets containing a 0 mEq/kg balance, 3.8% lysine and a combination of 3.1% lysine and 2.5% arginine depressed both measures of response. Trout receiving the 0 mEq/kg cation-anion balance had significantly higher free histidine concentrations and lower free lysine concentrations in muscle and higher hepatic arginase activity (P0.01) than those receiving –200 mEq/kg. In another experiment, trout were fed diets containing three levels of K+ (21, 191 and 360 mEq/kg), two levels of Na+ (21 and 191 mEq/kg) and two levels of Cl (179 and 347 mEq/kg) in a 3×2×2 factorial design. Growth and efficiency of feed conversion were depressed and hepatosomatic index increased with higher levels of dietary K+ (P0.01), Na+ (P0.05) and Cl (P0.01), with significant K+ x Cl+ (P0.01) and K+ x Na+ x Cl (P0.05) interactions. Increasing dietary K+ resulted in increased levels of muscle free histidine and decreased levels of muscle free lysine and arginine (P0.01), while increasing dietary Cl increased muscle free lysine, the effect of which was dependent on dietary potassium (K+ x Cl, P0.01). It is concluded that dietary levels of K+, Na+ and Cl, irrespective of overall cation-anion balance of these minerals, affects growth rate, efficiency of feed utilization and the metabolism of basic amino acids in tissues of trout. Excess lysine causes depressed growth and efficiency of feed utilization. These effects were due to a lysine toxicity rather than a lysine-arginine antagonism, as they were not prevented by supplemental dietary arginine.  相似文献   
186.
This paper addresses a little‐discussed relationship between wild capture and mariculture, when the latter involves grow‐out of small wild‐caught fish or invertebrates in captivity. Seafood generated in this way is typically considered to be a form of aquaculture because it is assumed that, for animals removed from the wild when natural mortality is still very high, the protection conferred by culture operations will improve survivorship and enhance production. This assumption does not necessarily, however, apply when animals are removed well past the time of early high mortality. As one example of the implications of an early life‐history phase (ELP) fishery supplying culture operations, a preliminary study was conducted on an ELP fishery supplying live reef fish, especially groupers, in Southeast Asia. Grouper culture depends on both hatchery‐produced and wild‐caught fish which are then grown out to market size. Following interest to develop grow‐out operations in Indonesia, a pilot study was conducted to determine the sizes and capture rates of species of interest to the live fish trade, and to determine the likely environmental footprint of an artificial shelter (gango) type of capture method. From the results of the 15‐month study, we drew inferences regarding the sustainability of this fishing method and requirements of space, fish and materials for a viable grow‐out operation. The results showed that gangos were unselective for either species or size. Only 1.4% of the total fish catch (by number) were target species, mainly the grouper Epinephelus coioides, and most were large (mean total length was 13.6 cm) enough to have bypassed the early high mortality phase. Moreover, there were large non‐target catches that included many food fish species too small to be useful in catches. Given the large number and area of gangos needed for a viable operation, and that many groupers captured could probably have survived to reproduce, the ecological footprint of this approach could be substantial. These results, and literature on other ELP fisheries, suggest that these may often need management, have important links to other capture fishery sectors, and require careful evaluation of potential costs and benefits before introduction or development.  相似文献   
187.
Most acquired immunodeficiency syndrome (AIDS) service providers are in countries with little access to scientific developments relevant to their programs. It is critical to transfer advances from the scientific arena to service providers on a global scale. Human immunodeficiency virus (HIV) prevention organizations in 78 countries were randomized to receive either a control condition or a technology transfer condition with an interactive distance learning computer training curriculum and individualized distance consultation. Of 42 nongovernmental organizations in the technology transfer condition, 29 adopted the science-based program in their communities or trained other agencies to also use it. Advanced communication technologies can create a cost-effective infrastructure to disseminate new intervention models to service providers worldwide.  相似文献   
188.
A 4-year-old rabbit was presented with a chronic exfoliative dermatitis and patchy alopecia. General physical examination revealed no abnormalities. Skin scrapings and fungal culture were negative. A blood sample was obtained for a complete blood cell count and biochemical profile, and yielded results that were within normal limits. Radiographic examination of the thorax excluded the presence of a thymoma. Histopathology of the skin showed orthokeratotic hyperkeratosis, absence of sebaceous glands and mural lymphocytic folliculitis, consistent with sebaceous adenitis. Oral treatment was started with ciclosporin dissolved in a medium-chain triglyceride solution (Miglyol 812), combined with essential fatty acids and topical propylene glycol sprays. Within 2 months of treatment, complete regression of skin lesions and regrowth of hair was observed. Serum chemistry values including kidney and liver function tests remained within reference range during the course of treatment. Histopathological examination of control biopsies of the skin showed presence of normal sebaceous glands and active hair follicles. Treatment was changed to a different pharmaceutical formulation of ciclosporin without Miglyol and deterioration of clinical signs was noticed. Using pure Miglyol 812, however, resulted in a gradual improvement of 60%. A nearly complete response was again observed after re-administration of the combination ciclosporin/Miglyol. It is hypothesized that sebaceous adenitis in the rabbit is most likely due to an autoimmune reaction directed at the sebaceous glands and a defect in lipid metabolism. The outcome indicates that a combination of ciclosporin and Miglyol 812 is a promising new treatment for sebaceous adenitis in rabbits.  相似文献   
189.
In contrast to mammals and birds, fish display an amazing diversity of genetic sex determination systems, with frequent changes during evolution possibly associated with the emergence of new sex chromosomes and sex‐determining genes. To better understand the molecular and evolutionary mechanisms driving this diversity, several fish models are studied in parallel. Besides the medaka (Oryzias latipes Temminck and Schlegel, 1846) for which the master sex‐determination gene has been identified, one of the most advanced models for studying sex determination is the Southern platyfish (Xiphophorus maculatus, Günther 1966). Xiphophorus maculatus belongs to the Poeciliids, a family of live‐bearing freshwater fish, including platyfish, swordtails and guppies that perfectly illustrates the diversity of genetic sex‐determination mechanisms observed in teleosts. For X. maculatus, bacterial artificial chromosome contigs covering the sex‐determination region of the X and Y sex chromosomes have been constructed. Initial molecular analysis demonstrated that the sex‐determination region is very unstable and frequently undergoes duplications, deletions, inversions and other rearrangements. Eleven gene candidates linked to the master sex‐determining gene have been identified, some of them corresponding to pseudogenes. All putative genes are present on both the X and the Y chromosomes, suggesting a poor degree of differentiation and a young evolutionary age for platyfish sex chromosomes. When compared with other fish and tetrapod genomes, syntenies were detected only with autosomes. This observation supports an independent origin of sex chromosomes, not only in different vertebrate lineages but also between different fish species.  相似文献   
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