Behavioral effects of bidirectional selection for behavior towards human in virgin and lactate Norway rats

Although numerous studies have demonstrated strong differences in behavioral, hormonal and neurobiological characteristics between male rats selected for elimination (tame) and enhancement (aggressive) of aggressiveness towards humans, few studies have examined changes in female behavior under this selection. The objective of the current work was to evaluate the effects of bidirectional selection for aggressiveness towards humans on behavioral profiles of virgin and lactating rats compared with the behavior in tame, aggressive and unselected (wild-type) females. The behavior of virgin females was studied using the light-dark box, the startle response test and the modified glove test. Tame females were less anxious and more tolerant towards humans than unselected and aggressive rats. Principal component analysis of all behavioral parameters produced three independent factors, explaining 66.37% of the total variability. The measures of behavior towards humans and the measures of anxiety mainly loaded on PC1 (first principal component) which separated the tame females from the unselected and aggressive ones. These data suggest the genetic correlation between the selected behavior towards humans and anxiety-related behavior in virgin rats. No significant effect of line was found for PC2 scores, associated with risk assessment behavior. Measurements of freezing behavior mainly loaded on PC3, and this component separated rats of different genetic groups from each other. The behavior of lactating rats was studied in maternal defense and pup retrieval tests. Females of selected lines did not significantly differ in behavioral measurements of these tests and were characterized by higher maternal motivation than unselected rats. It is suggested that long-term breeding of tame and aggressive rats in captivity has reduced the threshold for maternal behavior.     

Genetic diversity and admixture patterns in Indian populations

India is a diverse land whose population holds the history of waves of human dispersal. Recent studies suggest two major ancestral contributions to most of the Indian sub-populations. However, present day Indians are thought to contain huge genetic diversity derived consequent to multiple cultural, linguistic and geographical variations. Genome-wide survey of individuals from current North (N-In) and South (S-In) India along with populations from HapMap Phase III and Indian sub-populations from HUGO Pan-Asian SNP Consortium is performed. Multivariate analysis (MDS and PCA) was carried out after merging data from the current study and other consortia. Indian sub-populations clustered separately from populations of major global geographical regions in MDS and PCA in a loose agglomeration except for two Indian subpopulations clustering near far eastern populations. F_st values indicated diversity among Indian sub-populations which was substantiated by STRUCTURE analysis suggesting the possibility of additional admixture events.     

美拉德反应在烟草薄片减害中的应用

根据美拉德反应的原理及条件,调节烟草薄片精制液的pH值,并加入果糖和不同种类的氨基酸经高温浓缩处理,制成样品后检测烟气中NNK、巴豆醛、CO和NH3的含量。结果表明:精制液浓缩过程中发生的美拉德反应,可有效降低薄片烟气中多种有害成分的含量。因此,在烟草薄片中应用美拉德反应是一条有效的减害途径。     

曲靖烤烟主要化学成分及其协调性空间分布

利用GIS和地统计学方法,对曲靖烟区烤烟8个主要化学指标空间分布特征进行了分析;然后采用模糊综合评价法对烤烟化学成分协调性进行综合评价;最后基于地统计学原理,借助ArcGIS9.3软件中的反距离权重插值法(IDW)绘制曲靖烤烟化学成分协调性综合评价图。结果表明,曲靖烟区烤烟8项化学指标具有中等的空间自相关性,表现为明显的各向异性分布;烤烟化学成分协调性为优的区域占研究区域总面积的1.82%,为良的区域占54.30%,为一般的区域占41.39%,为中等的区域占2.49%,为差的区域空缺。     

Seasonal dynamics of sperm morphometric subpopulations and its association with sperm quality parameters in ram ejaculates

Sperm morphologic assessment is considered an irreplaceable part of standard laboratory routine analyses in the diagnosis of male fertility. Thus, in an attempt to quantify the effects of season on sperm morphology and its functional significance in relation to sperm quality parameters, sperm head morphometric traits were analyzed by using an objective computerized analysis combined with principal components analysis (PCA) cluster analysis to establish the relationship between the distribution of the subpopulations found and sperm quality in each season. There were slight variations on sperm motility and sperm membrane integrity indexes (P > 0.05). However, the mean values for sperm concentration substantially changed among seasons in all individuals studied (P < 0.01). There were significant differences in sperm morphometric parameters (P < 0.01) as well as in the distribution of morphometric subpopulations between seasons (P < 0.001). In conclusion, this study confirmed that there was an important seasonal effect on sperm morphometric traits. In addition, the distribution of these subpopulations seems to be related to the season studied and the ejaculate quality which would be a very important indicator of sperm function. The substantial information derived from these morphometric subpopulations has provided new knowledge which can be used in future studies using sperm morphometry as a seasonal indicator in ram ejaculates.     

Sperm head morphometry in ejaculates of adult marmosets (Callithrix jacchus): A model for studying sperm subpopulations and among-donor variations

In humans and other mammals, sperm morphology has been considered one of the most important predictive parameters of fertility. The objective was to determine the presence and distribution of sperm head morphometric subpopulations in a nonhuman primate model (Callithrix jacchus), using an objective computer analysis system and principal component analysis (PCA) methods to establish the relationship between the subpopulation distribution observed and among-donor variation. The PCA method revealed a stable number of principal components in all donors studied, that represented more than 85% of the cumulative variance in all cases. After cluster analysis, a variable number (from three to seven) sperm morphometric subpopulations were identified with defined sperm dimensions and shapes. There were differences in the distribution of the sperm morphometric subpopulations (P < 0.001) in all ejaculates among the four donors analyzed. In conclusion, in this study, computerized sperm analysis methods combined with PCA cluster analyses were useful to identify, classify, and characterize various head sperm morphometric subpopulations in nonhuman primates, yielding considerable biological information. In addition, because all individuals were kept in the same conditions, differences in the distribution of these subpopulations were not attributed to external or management factors. Finally, the substantial information derived from subpopulation analyses provided new and relevant biological knowledge which may have a practical use for future studies in human and nonhuman primate ejaculates, including identifying individuals more suitable for assisted reproductive technologies.     

Identification and structural analysis of a glycophospholipid component from the venom of ant Paraponera clavata

The venom of South American ant Paraponera clavata and its low-molecular-mass fraction were shown to possess insectotoxic and pore-forming activities. A number of glycophospholipid components were isolated from this ant venom by means of gel filtration and reversed-phase chromatography. Some of the compounds cause conductivity fluctuations in lipid bilayer membranes within the ranges 3–25 pS and 200–400 pS at concentrations of 10^?6 to 10^?7 M. N-Acetylglucosamine, a fatty acid, and phosphoric acid residues were found in their structures. A full structure, 3-myristoyl-2-acetamido-2-deoxy-α-D-glucopyranosyl phosphate, was elucidated for one of the compounds by the use of ¹H-, ¹³C-, and ³¹P NMR spectroscopy and mass spectrometry.     

Uptake by wheat plants and turnover within soil fractions of residual N from leguminous plant material and inorganic fertilizer

Summary The availability and turnover in different soil fractions of residual N from leguminous plant material and inorganic fertilizer was studied in a pot culture experiment using wheat as a test crop. Plants utilized 64% of the residual fertilizer N and 20% of the residual legume N. 50–60% of the N taken up by plants was recovered in grain and 4–8% in roots. After harvesting wheat up to 35% and 38% of the residual legume N and fertilizer N, respectively was found in humic compounds. A loss of humus N derived from legume and fertilizer was found during wheat growth but the unlabelled N increased in this fraction. Biomass contained 6% and 8% of the residual legume and fertilizer N, respectively when both were available. The mineralizable component contained upto 28% of both the residual legume and residual fertilizer N. Only a small percentage of the soil N (3–4%) was observed in biomass whereas the mineralizable component accounted for 7–14% of the soil N. In this fraction legume derived N increased during wheat growth whereas unlabelled N increased in both the mineralizable component and microbial biomass. Some loss of N occurred from residual legume and fertilizer N. Nevertheless, a positive total N balance was observed and was attributed to the addition of unlabelled N in the soil-plant system by N₂ fixation. The gain in N was equivalent to about 38% of the plant available N in the soil amended with leguminous material. The additional N was concentrated mainly in the mineralizable fraction and microbial biomass, although some addition was also noted in humus fractions.     

Effects of a short-term p-hydroxybenzoic acid application on grain yield and yield components in different tiller categories of spring barley

The aim of these experiments was to evaluate how thresholds for phytotoxic substances obtained in seedling bioassays relate to yield losses or changes in yield components of mature barley crops after a short-term exposure to p-hydroxybenzoic acid. Under laboratory conditions a treatment with 1.81 mM p-hydroxybenzoic acid significantly reduced the radicle length of barley, whereas coleoptile elongation was less sensitive. The inhibition of the radicle length and coleoptile elongation was greater if the pH of the test solution was not buffered at pH 5.5. In a glasshouse trial the effect of p-hydroxybenzoic acid on the radicle and coleoptile elongation of spring barley was compared with the yield response after a three day exposure either during germination or at the double ridge stage of apex development. Applications of 0.72 mM, 1.44 mM and 3.62 mM p-hydroxybenzoic acid averaged over the treatments during germination or at the double ridge stage of development caused a yield reduction in the single ear weight of 5%, 13% and 19% in comparison with the control, respectively. The higher tiller categories in general showed a greater sensitivity towards an application of p-hydroxybenzoic acid and, therefore, could not compensate for the yield decrease of the main stem tiller. A single application of p-hydroxybenzoic acid either at germination or at the double ridge stage may cause yield losses, as reported from no-till systems or cereal monocultures. The data have implications for the interpretation of seedlings bioassays in allelopathic research and their applicability in estimating yield losses caused by phytotoxic substances. ei]Section editor: R Merckx