A new class of Caulobacter crescentus flagellar genes

Eight Caulobacter crescentus flagellar genes, flmA, flmB, flmC, flmD, flmE, flmF, flmG, and flmH, have been cloned and characterized. These eight genes are clustered in pairs (flmAB, flmCD, flmEF, and flmGH) that appear to be structurally organized as operons. Homology comparisons suggest that the proteins encoded by the flm genes may be involved in posttranslational modification of flagellins or proteins that interact with flagellin monomers prior to their assembly into a flagellar filament. Expression of the flmAB, flmEF, and flmGH operons was shown to occur primarily in predivisional cells. In contrast, the flmCD operon was expressed throughout the cell cycle, with only a twofold increase in predivisional cells. The expression of the three temporally regulated operons was subject to positive regulation by the CtrA response regulator protein. Mutations in class II and III flagellar genes had no significant effect on the expression of the flm genes. Furthermore, the flm genes did not affect the expression of class II or class III flagellar genes. However, mutations in the flm genes did result in reduced synthesis of the class IV flagellin proteins. Taken together, these data indicate that the flm operons belong to a new class of flagellar genes.     

Comprehensive computerized assessment of cognitive sequelae of a complete 12-16 hour fast.

Food deprivation has been shown to deleteriously affect human cognition, but findings are equivocal, and few studies have examined several cognitive domains. In this study, the authors used computerized testing to describe the profile of shifts in cognition attributable to short-term religious fasting. Multiple cognitive domains were evaluated at midday and late afternoon following complete abstention from eating and drinking beginning at midnight. Cross-domain, fasting-related deficits were found for tasks requiring perception of spatial relations. Fasting-related information processing deficits were found for response time but not accuracy for test levels of intermediate difficulty. Time-of-day effects often reflected poorer afternoon performance. These findings provide a detailed profile of cognitive consequences of food deprivation, affected by time of day, task demands, and type of outcome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of region, herd size, and milk production on reasons cows leave the herd

Dairy Herd Improvement Holstein herd summary records (n = 11,259) were obtained for the year ending 1998. Reasons cows reportedly left the herd based on termination codes were analyzed for the effect of region, herd size, and herd milk production level. Regions were: North, Midsouth, and South. Herd sizes were: small (25 to 99), low medium (100 to 149), high medium (150 to 299), and large (greater than or equal to 300 cows). Milk production levels were: low (less than 7258 kg), medium (7258 to 9072 kg), and high (greater than 9072 kg). The overall percentage of cows leaving the herd was higher in the Midsouth than the South and increased with herd size. Low producing herds reported a lower percentage of cows left than high producing herds. Herds in the South reported more cows leaving for reproduction, death, and low production and fewer leaving for mastitis. Herds in the North and Midsouth reported more cows leaving for injury/other and disease, respectively. Cows left herds for disease less frequently in the North. Large herds in the South had a higher percentage leaving for low production than any herd size group in the North. Small herds reported more cows leaving for reproduction and mastitis than high medium and low medium size herds. The percentage of cows leaving for feet and leg problems was lowest for small size herds. High producing herds reported more cows leaving for reproduction, mastitis, feet and legs and disease.     

Comments on "On estimating the orders of an autoregressive process"

This correspondence makes some critical remarks on the method suggested in the above paper for estimating the order of an autoregressive process. An alternative method is then suggested.     

Extension of an improved one-fluid conformal solution theory to real fluid mixtures with large size differences

Conformal solution theories have been shown to be inadequate as the size ratio of the molecules in a mixture increases. We present an improved van der Waals-1 fluid conformal solution theory which incorporates a correction term developed using statistical mechanical perturbation theory. The correction addresses the effect of different size molecules on the Helmholtz free energy of the mixture. Results of the new model are compared with other conformal solution theories for model Lennard-Jones systems. We also show how to extend the model to perform computations on real fluid mixtures. Results for selected hydrocarbon mixtures are given.Paper presented at the Tenth Symposium on Thermophysical Properties, June 20–23, 1988, Gaithersburg, Maryland, U.S.A.FormerlyNational Bureau of Standards     

Progress and Prospects of Anti-HBV Gene Therapy Development

Despite the availability of an effective vaccine against hepatitis B virus (HBV), chronic infection with the virus remains a major global health concern. Current drugs against HBV infection are limited by emergence of resistance and rarely achieve complete viral clearance. This has prompted vigorous research on developing better drugs against chronic HBV infection. Advances in understanding the life cycle of HBV and improvements in gene-disabling technologies have been impressive. This has led to development of better HBV infection models and discovery of new drug candidates. Ideally, a regimen against chronic HBV infection should completely eliminate all viral replicative intermediates, especially covalently closed circular DNA (cccDNA). For the past few decades, nucleic acid-based therapy has emerged as an attractive alternative that may result in complete clearance of HBV in infected patients. Several genetic anti-HBV strategies have been developed. The most studied approaches include the use of antisense oligonucleotides, ribozymes, RNA interference effectors and gene editing tools. This review will summarize recent developments and progress made in the use of gene therapy against HBV.     

Effect of region and herd size on dairy herd performance parameters

Differences in selected Dairy Herd Improvement (DHI) performance parameters among regions and herds of different size categories were evaluated. DHI records from herds in 37 states were grouped into North, Midsouth, and South regions, and six herd size categories (20 to 49, 50 to 99, 100 to 149, 150 to 249, 250 to 449, and > or = 450 cows). The North region had higher income over feed costs (IOFC); milk, fat, and protein rolling herd averages; summit milk; standardized 150-d milk; and percentage of cows in milk, than the other regions. These variables were lowest for the South region. Cost/45.4 kg of milk, days open, days dry, and somatic cell counts were lowest in the North region and were highest in the South. Percentage of cows entering and leaving the herd were highest in the Midsouth and were lowest in the South. Larger herds had higher total feed cost, IOFC, milk, fat, and protein rolling herd averages, summit milk, standardized 150-d milk, percentage of cows entering and percentage leaving the herd than smaller herds. Larger herds had lower somatic cell counts than smaller herds. Cost/45.4 kg of milk, days dry, days open, days in milk, and percentage of cows in milk did not show clear trends among different herd sizes. There were significant interactions between region and herd size for some of the variables.     

纱线在线检测装置

本文介绍了一种新的纱线在线检测装置。该装置设计速度可超过 60 0 m/min,检测的适应性较传统检测装置有了很大的提高。结合试验装置简要介绍该装置的 6大功能 ,并以各种功能为例 ,给出试验结果。1　引　言　　根据纱线的加工工序及成品的特性 ,常需对纱线进行各种测试 ,如纱线的强度、线密度、弹性、毛羽等。传统的方法一般是从纱管或筒子纱中截取一定长度或连续截断纱线 ,测试其断裂强度。虽然也有自动装置测试强度、张力等 ,也能在瞬间内测试到大量数据 ,但这些测试是离线检测 ,且对纱线具有破坏性 ,而且测试速度偏低。本文将介绍一种新…