ppGpp and RNA-polymerase backtracking guide antibiotic-induced mutable gambler cells

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Early Detection of Bacterium-induced Basal Resistance in Tobacco Leaves with Diaminobenzidine and Dichlorofluorescein Diacetate

The present study demonstrate that in tobacco leaves the diaminobenzidine (DAB) and 2′,7′‐dichlorofluorescein diacetate (DCFH‐DA) staining is a useful indicator of the basal (also known as general or innate) defence‐associated reactions, especially of the early developing form of basal resistance (EBR). DAB and DCFH‐DA, in the presence of H₂O₂ and peroxidase converts to a brown polymer and fluorescent DCF respectively. In the present study, the hypersensitive response (HR)‐inducing avirulent Pseudomonas syringae pv. syringae 61, its HR‐negative hrp/hrc mutants and even non‐pathogenic bacteria such as P. fluorescens and Escherichia coli caused DAB and DCFH‐DA staining, if the dyes were injected 3–4 h after bacterial inoculation into tobacco leaves. The conditions that enable the staining of plant leaves infiltrated with HR‐negative bacteria were persisted for 1 to several days depending on the physiological state of the plant, and plant activity was required to the development of the staining. The live virulent P. syringae pv. tabaci was able to suppress the development of the staining reaction. Bacteria that induced more intensive staining reaction triggered stronger local resistance response, which was verified by its ability to inhibit the HR by challenging avirulent bacteria and by expression analysis of genes that are activated during the basal defence response. The peroxidase enzyme activity increased in bacterially treated tobacco tissue, and inhibition of peroxidase activity blocked the development of the staining. The results showed that in tobacco leaves the staining reactions were associated with the general recognition and basal defence reaction of tobacco plant and can be used as markers in tobacco leaves for testing the occurrence of this type of defence.     

A study of the effects of truncation in bivariate normal distribution

The moments of bivariate normal distribution, which is truncated with respect to both the random variables, are obtained by using the orthogonal expansion of the distribution and the properties of HERMITE polynomials. In particular the correlation coefficient of the truncated distribution is derived in terms of the actual correlation coefficient. In order to study the effect of truncation tables have been prepared of this correlation coefficient for certain given values of the actual correlation coefficient and for a few selected values of the points of truncation. A listing of the computer program for this purpose is also given.     

A three-dimensional general circulation model of the surface layers of Lake Baikal

A three-dimensional general circulation model has been developed to investigate mixing processes in Lake Baikal, Siberia. Emphasis is placed on the 4–5-month period when the lake is completely ice-covered, a time of particular importance to the re-population of the lake by diatoms. The model represents the top 250 m and includes a new mixing scheme developed specifically for the investigation of under-ice flows. The effects of spatial patterns of snow and ice transparency on circulation and temperature are investigated. In general, temperature profiles provide an indication of the extent and depth of mixing and are highly sensitive to the presence of snow and to the transparency of ice. Generated profiles agree well with in situ measurements, which are difficult to obtain during this period. The model is shown to be particularly successful in simulating mixing processes in Lake Baikal. The surface heat fluxes that are required for a model of this type were estimated using satellite data, which provide complete coverage of the lake within one image. An increase in albedo values of 20% has no significant impact on the development of the temperature profile. Finally, density driven currents generated in the model were investigated. The magnitudes of the model currents compared to observations suggest that the background flow under ice in the lake may be density driven.     

Defining tolerance as a norm of reaction

Tolerance of an environmental factor is the ability to maintain fitness in the face of stress imposed by that factor. A tolerant genotype minimizes the decline in fitness from that achieved in a relatively benign environment to that produced in environments with more stressful levels of the factor. Hence, tolerance is a phenotypically plastic characteristic of a genotype that can be assessed only by measuring the genotype's fitness in more than one environment. The genotype's tolerance is characterized by the shape of the fitness reaction norm along the environmental gradient whereas the overall height of the function represents its general vigor. This revised version was published online in July 2006 with corrections to the Cover Date.     

Changes in Size and Demographic Composition of Transgender and Gender Non-Binary Population Receiving Care at Integrated Health Systems

ObjectiveTo examine temporal changes in the number and demographic composition of transgender/gender non-binary (TGNB) population using data from integrated health care systems.MethodsElectronic health records from Kaiser Permanente health plans in Georgia and Northern and Southern California were used to identify TGNB individuals, who sought care from January 2006 to December 2014, and the data were analyzed by year, site, age, and sex assigned at birth.ResultsIn 2006, the number of TGNB people (and corresponding 95% CI) per 100 000 population were 3.5 (1.9, 6.3) in Georgia, 5.5 (4.8, 6.4) in Southern California, and 17 (16, 19) in Northern California. In 2014, these frequencies increased to 38 (32, 45), 44 (42, 46), and 75 (72, 78) per 100 000 population, respectively. When analyzed by age, the most rapid increase was observed among persons 18 to 25 years old, and this increase accelerated after 2010. The ratio of transmasculine to transfeminine persons also changed from 1:1.7 in 2006 to 1:1 in 2014 overall and from 1:1 in 2006 to 1.8:1 in 2014 among persons <18 years of age.ConclusionThis analysis confirms previous observations that the proportion of TGNB people is growing, especially among young adults. The composition of the TGNB population is also changing from predominantly transfeminine to roughly 1:1 overall and to predominantly transmasculine in children and adolescents.     

七氟烷全身麻醉对失血性休克复苏小鼠血流动力学及记忆功能的影响机制

摘要 目的：探讨七氟烷全身麻醉对失血性休克复苏小鼠血流动力学及记忆功能的影响机制。方法：将建立成功的42只失血性休克复苏小鼠按照随机数字表法平分为3组-模型组、氧气组、七氟烷组，对照组吸入空气4 h，氧气组吸入100.0 %氧气4 h，七氟烷组吸入100.0 %氧气和2.5 %七氟烷4 h，监测与记录小鼠血流动力学及记忆功能变化情况。结果：氧气组、七氟烷组麻醉后第3 d与第7 d的Morris水迷宫逃避潜伏期少于模型组，穿越原平台次数多于模型组(P<0.05)，氧气组与七氟烷组对比差异有统计学意义(P<0.05)。氧气组、七氟烷组麻醉后第3 d与第7 d的去甲肾上腺素(Norepinephrine，NE)pD₂与Emax值高于模型组(P<0.05)，七氟烷组高于氧气组(P<0.05)。氧气组、七氟烷组麻醉后第3 d与第7 d的脑组织凋亡指数低于模型组(P<0.05)，七氟烷组低于氧气组(P<0.05)。氧气组、七氟烷组麻醉后第3 d与第7 d的海马组织Akt、Caspase-3蛋白相对表达水平低于模型组(P<0.05)，七氟烷组低于氧气组(P<0.05)。结论：七氟烷全身麻醉在失血性休克复苏小鼠的应用能抑制Akt、Caspase-3蛋白的表达，可抑制脑组织神经细胞凋亡，可改善血流动力学状况，促进小鼠记忆能力的恢复。