养禽业中沙门氏菌的控制与HACCP管理

1控制沙门氏菌的重要性 人们对食品安全的担心早已不仅仅局限在美国或欧洲,已成为一个全球性的问题.随着贸易的全球化,随着消费者要求对他们所吃的食品是如何生产出来的、含有什么成分的知情权的呼声在一个国家又一个国家日益高涨,政府的法规制定部门越来越限制抗生素生长促进剂的使用.     

鸡场饮用水的氯化处理

鸡场饮用水采用氯化处理是一个相对实用的办法,它能降低微生物尤其是细菌的水平,因而为鸡群提供清洁卫生的饮水。当水源不卫生时,这种处理方法显得尤为重要。饮用水的氯化处理也阻止水中生物膜的形成(生物膜是由大量     

Growth and performance of Penaeus semisulcatus (de Haan) fed with two commercial shrimp feeds

Two feeding trials were conducted in two stages to compare growth and performance, grow‐out (1–9 g b.w.) and fattening (13–19 g b.w.), of Penaeus semisulcatus. Shrimps were fed with two commercial feeds: P. monodon feed and P. japonicus feed. Both experiments were conducted using an indoor flow‐through tank culture system. The results reveal that the growth performance of shrimp fed with P. japonicus feeds (0.91 g shrimp^?1 week^?1) for the grow‐out stage was significantly better than shrimp fed with P. monodon feeds (0.63 g shrimp^?1 week^?1). The growth performance of shrimp fed with P. monodon feed (0.56 g shrimp^?1 week^?1) for the fattening stage was significantly better than shrimp fed with P. japonicus feed (0.42 g shrimp^?1 week^?1). The feed conversion ratios of both diets for the two sizes did not differ significantly. Thus, it is recommended that P. japonicus feeds be fed to P. semisulcatus during the grow‐out stage. During the fattening stage, the better growth performance of the shrimp fed with P. monodon feed makes it a better feed. However, colour and overall acceptability of shrimp fed with P. japonicus feed were generally higher than those fed with P. monodon feed.     

A heat-sensitive TRP channel expressed in keratinocytes

Mechanical and thermal cues stimulate a specialized group of sensory neurons that terminate in the skin. Three members of the transient receptor potential (TRP) family of channels are expressed in subsets of these neurons and are activated at distinct physiological temperatures. Here, we describe the cloning and characterization of a novel thermosensitive TRP channel. TRPV3 has a unique threshold: It is activated at innocuous (warm) temperatures and shows an increased response at noxious temperatures. TRPV3 is specifically expressed in keratinocytes; hence, skin cells are capable of detecting heat via molecules similar to those in heat-sensing neurons.     

Homo erectus calvarium from the Pleistocene of Java

A Homo erectus calvarium [Sambungmacan 4 (Sm 4)] was recovered from Pleistocene sediments at Sambungmacan in central Java. Micro-computed tomography analysis shows a modern human-like cranial base flexion associated with a low platycephalic vault, implying that the evolution of human cranial globularity was independent of cranial base flexion. The overall morphology of Sm 4 is intermediate between that of earlier and later Javanese Homo erectus; apparent morphological specializations are more strongly expressed in the latter. This supports the hypothesis that later Pleistocene Javanese populations were substantially isolated and made minimal contributions to the ancestry of modern humans.     

Antimicrobial Activity of Untenospongin B,a Metabolite from the Marine Sponge Hippospongia communis collected from the Atlantic Coast of Morocco

(−)-Untenospongin B isolated from the marine sponge Hippospongia communis has been tested for its antimicrobial activity against bacteria and human pathogenic fungi using agar disk method and was found to possess a broad and strong activity toward the test organisms. Its antifungal activity was further characterized by determination of the minimum inhibitory concentration (MIC) against five fungal species using broth microdilution method.     

Induction of systemic resistance to Agrobacterium tumefaciens by endophytic bacteria in grapevine

Crown gall disease of grapevine, caused by Agrobacterium tumefaciens, often results in severe economic loss to grape production worldwide. This study demonstrated the ability of the endophytic bacteria Pseudomonas sp. Sn48 and Pantoea sp. Sa14 isolated from domesticated and wild grapevines to induce resistance in both above- and belowground tissues of grapevines infected with A. tumefaciens. Our results provide evidence that both strains can colonize roots and/or shoots. We showed that the strains Pseudomonas sp. Sn48 and Pantoea sp. Sa14 are capable of inducing stilbenic phytoalexin production in grapevine tissues and to further prime plantlets for enhanced phytoalexin production after A. tumefaciens inoculation. We also showed that in the majority of treatments, polyamine accumulation remained unchanged or slightly increased in plantlets treated with Pseudomonas sp. Sn48 and Pantoea sp. Sa14 compared with the control. Our findings indicated that the levels of polyamines remain unchanged or significantly decrease in plantlets treated with endophytic bacteria after A. tumefaciens challenge compared to the control and plantlets treated with individual endophytic bacterial strains. PR1, PR2, and PR4 gene expression levels of plantlets treated with Pseudomonas sp. Sn48 and Pantoea sp. Sa14 significantly increased after A. tumefaciens inoculation. The findings revealed the efficacy of the selected endophytic bacteria in triggering grapevine resistance against A. tumefaciens and the possible use of these strains as an alternative to chemical control methods in grapevine crown gall disease management.