Underlying mechanisms of ANAMMOX bacteria adaptation to salinity stress

Journal of Industrial Microbiology & Biotechnology - Dealing with nitrogen-rich saline wastewater produced by industries remains challenging because of the inhibition of functional...     

西藏野生油菜种群间角果趋同生长格局研究

西藏地处我国西南边陲,素有"世界屋脊"和"地球第三极"之称。由于地质史独特,地形地貌复杂,气候带全,土壤类型繁多,野生植被多样,凡此种种,西藏油菜生境具有全球最典型的立体生境特色,其生态环境千差万别,堪称全球之最,独特而复杂的油菜生境,产生了丰富多样的野生白菜型油菜(Brassica Campestris)和野生芥菜型油菜(Brassica juncea)遗传资源。本文根据植物种群的构件理论,采用大样本取样方法,对西藏野生白菜型油菜和野生芥菜型油菜分枝进行了角果种群统计的生长分析。结果表明,西藏野生白菜型油菜和野生芥菜型油菜一级分枝的角果数、角果生物量、角果生物量比例均呈现Peel-Reed模型变化规律,角果宽度与角果长度之间的生长关系均呈现Yield Density模型变化规律,显示出角果种群形成与生长过程的趋同生长格局与物质分配策略。     

El lavado de la aguja aumenta la rentabilidad diagnóstica de la punción-aspiración con aguja fina de tiroides

Background and objectiveNodular thyroid disease is a common condition in our clinical practice, and fine needle aspiration biopsy (FNAB) is the diagnostic procedure of choice. Its main limitation is the number of non-diagnostic samples. Since the Bethesda criteria were implemented in 2007 (a consensus document on the morphologic criteria and diagnostic terminology for interpretation of thyroid cytological samples), a higher prevalence of non-diagnostic FNAB was shown. In addition to the standard technique, we decided to collect and centrifuge the material remaining in puncture needles by washing them in a ThinPrep^® solution, and to assess the increase in the diagnostic yield of FNAB after this change.Patients and methodsSystematic sampling of 168 patients who underwent FNAB at the Nutrition and Endocrinology Department of the Xeral-Cies Hospital (Vigo, Spain) from January 2010 to November 2011. Patients were classified into 2 groups: 75 patients in whom the residual material in the needle was not collected (non-washing group) and 93 patients in whom the material was collected (washing-group). All FNABs were performed by the same endocrinologist. Data are shown as percentage (± standard error) for ordinal variables or as mean (± standard deviation) for quantitative variables. A Chi-square test was used for statistical analysis of comparisons between percentages, and a Student's t test for comparisons between quantitative variables. A value of p < 0.05 was considered statistically significant.ResultsNo significant differences were found between the groups in age, sex, plasma TSH levels or nodule size. The rate of non-diagnostic FNABs was 44% (± 0.06) in the non-washing group and 17.2% (± 0.04%) in the washing group, with a significant difference (p < 0.01).DiscussionCollection and subsequent processing of the residual material in the needle after FNAB significantly decreased the prevalence of non-diagnostic punctures in our patients. Collection of the residual material in the needle in this way is strongly recommended.     

Atomistic behavior analysis of Cu nanowire under uniaxial tension with maximum local stress method

This study analyzes the atomistic behaviors of a Cu nanowire (NW) during uniaxial tensile deformation by molecular dynamics simulation. In this work, the maximum local stress calculated method (MLS) is proposed to validly elucidate the plastic behaviors of the Cu NW. Analysis results demonstrate that the pre-tension stress is caused by the intense surface tension, which is an important factor for dislocation emission from surface. The motion of Shockley partials that interact to produce a stair-rod dislocation is determined. Following the dislocation mechanism, deformation twinning is the primary mechanism that dominates the plastic deformation at such a high strain rate. Immediately before fracture, the stress increases markedly since the primary failure mode is atomic bond breakage.     

烟草叶组织培养中光与激素对形态发生的调节作用

我们在烟草叶的组织培养中,研究了光与激素对形态发生所起调节作用的相互关系。在培养基中细胞分裂素与生长素的浓度比例都取得最佳值,而浓度绝对值则取两组不同数值。在这两组实验条件下,分别考察了不同波段,不同强度的光照射对于不定芽的发生和愈伤组织增重的影响。用不同波段的光照射,改变光强,光促进生长的效应都有一极大值。用蓝光照射,极大值的数值最高。激素浓度低时光的效应较大;浓度高时,除蓝光外,其他波段的光效应都很微弱。     

THE EVOLUTION OF INDIVIDUAL VARIATION IN COMMUNICATION STRATEGIES

Communication is a process in which senders provide information via signals and receivers respond accordingly. This process relies on two coevolving conventions: a “sender code” that determines what kind of signal is to be sent given the sender's state; and a “receiver code” that determines the appropriate responses to different signal types. By means of a simple but generic model, we show that polymorphic sender and receiver strategies emerge naturally during the evolution of communication, and that the number of alternative strategies observed at equilibrium depends on the potential for error in signal production. Our model suggests that alternative communication strategies will evolve whenever senders possess imperfect information about their own quality or state, signals are costly, and genetic mechanisms allow for a correlation between sender and receiver behavior. These findings provide an explanation for recent reports of individual differences in communication strategies, and suggest that the amount of individual variation that can be expected in communication systems depends on the type of information being conveyed. Our model also suggests a link between communication and the evolution of animal personalities, which is that individual differences in the production and interpretation of signals can result in consistent differences in behavior.     

Has inbreeding depression led to avoidance of sib mating in the Glanville fritillary butterfly (Melitaea cinxia)?

Previous work on the Glanville fritillary butterfly (Melitaea cinxia) shows substantial inbreeding depression in both of our two study regions, Finland and southern France. The influence of inbreeding depression on population dynamics should depend on the strength of inbreeding avoidance. We conducted mate choice experiments to ascertain whether and to what extent butterflies avoid mating with their sibs. Experiments with similar design were done in the laboratory with Finnish butterflies and in the field with French butterflies. Each female was given a choice of mates with equal opportunity to mate with a sib or with a non-sib. In neither experiment was there a trend towards avoidance of sib mating. 95% confidence intervals for the proportion of non-sib matings were 12–62% in the laboratory experiment and 28–69% in the field experiment. Any preference for non-sibs must be slight, and can provisionally be ignored in modelling the dynamics of M. cinxia populations. This revised version was published online in August 2006 with corrections to the Cover Date.     

Habituation of bean (Phaseolus vulgaris) cell cultures to Quinclorac and analysis of the subsequent cell wall modifications

Background and Aims

The herbicide quinclorac has been reported to inhibit incorporation of glucose both into cellulose and other cell wall polysaccharides. However, further work has failed to detect any apparent effect of this herbicide on the synthesis of the wall. In order to elucidate whether quinclorac elicits the inhibition of cellulose biosynthesis directly, in this study bean cell calli were habituated to grow on lethal concentrations of the herbicide and the modifications in cell wall composition due to the habituation process were analysed.

Methods

Fourier transform infrared spectroscopy associated with multivariate analysis, cell wall fractionation techniques, biochemical analyses and the immunolocation of different cell wall components with specific monoclonal antibodies were used to characterize the cell walls of quinclorac-habituated cells.

Key Results

Quinclorac-habituated cells were more irregularly shaped than non-habituated cells and they accumulated an extracellular material, which was more abundant as the level of habituation rose. Habituated cells did not show any decrease in cellulose content, but cell wall fractionation revealed that changes occurred in the distribution and post-depositional modifications of homogalacturonan and rhamnogalacturonan I during the habituation process. Therefore, since the action of quinclorac on the cell wall does not seem to be due to a direct inhibition of any cell wall component, it is suggested that the effect of quinclorac on the cell wall could be due to a side-effect of the herbicide.

Conclusions

Long-term modifications of the cell wall caused by the habituation of bean cell cultures to quinclorac did not resemble those of bean cells habituated to the well-known cellulose biosynthesis inhibitors dichlobenil or isoxaben. Quinclorac does not seem to act primarily as an inhibitor of cellulose biosynthesis.Key words: Quinclorac, herbicide, Phaseolus vulgaris, cell culture habituation, primary cell wall, cellulose, FTIR spectroscopy