The Balkan chamois,an archipelago or a peninsula? Insights from nuclear and mitochondrial DNA

The Balkan chamois (Rupicapra rupicapra balcanica) is widespread on the Balkan Peninsula, along mountain massifs from Croatia in the north to Greece in the south and Bulgaria in the east. Knowledge on the genetic structure of Balkan chamois populations is limited and restricted to local studies. Therefore, the main objective of this study was to use nuclear (16 microsatellites) and mitochondrial (partial 376 base pairs control region) markers to investigate the genetic structure of this chamois subspecies throughout its distribution range and to obtain information on the degree of connectivity of the different (sub)populations. We extracted DNA from bone, dried skin and muscle tissue and successfully genotyped 92 individuals of Balkan chamois and sequenced the partial control region in 44 individuals. The Bayesian analysis suggested 3 genetic clusters and assigned individuals from Serbia and Bulgaria to two separate clusters, while individuals from the other countries belonged to the same cluster. Thirty new haplotypes were obtained from partial mitochondrial DNA sequences, with private haplotypes in all analyzed populations and only two haplotypes shared among populations, indicating the possibility of past translocations. The subspecies genetic composition presented here provides the necessary starting point to assess the conservation status of the Balkan chamois and allows the development of conservation strategies necessary for its sustainable management and conservation.

     

水杉凋落物水浸提液对其种子萌发和生长的化感作用

为探究水杉凋落物的化感作用是否是影响其天然更新的障碍因素,该文设置了8种水杉新鲜凋落物和自然凋落物水浸提液浓度200、100、50、20、10、5、2、1 g·L^-1和CK,分析不同类型不同浓度凋落物水浸提液对水杉种子萌发和生长的化感作用的影响。结果表明：(1)水杉新鲜凋落物水浸提液对水杉种子发芽率和发芽势影响不显著(P>0.05),对发芽指数有显著影响(P<0.05),1、100、200 g·L^-1显著抑制种子发芽;水杉自然凋落物水浸提液对水杉种子萌发3个指标影响均不显著(P>0.05),而浓度为5、10、50、200 g·L^-1时则有抑制效应。(2)水杉种子芽长、胚轴和主根长度均在不同浓度的新鲜和自然水杉凋落物水浸提液间差异显著(P<0.05),并随着水浸提液浓度的增加(≥10 g·L^-1)而逐渐降低,尤其是50～200 g·L^-1范围内抑制作用显著增强。(3)新鲜和自然水杉凋落物水浸提液对自身种子萌发后生长的抑制作用相较于对种子萌发强,并且新鲜凋落...     

Solid state and solution studies of a vanadium(III)-L-cysteine compound and demonstration of its antimetastatic, antioxidant and inhibition of neutral endopeptidase activities

Reaction of one equivalent of vanadium(III) chloride with three equivalents of l-cysteine(H2Cys) in methyl alcohol affords a VIII-Cys compound that is formulated as [VIII(Hcys)3].2HCl.2.5H2O 1. The solid state characterization of 1 was performed by microanalysis, circular dichroism (CD) and infrared studies as well as room temperature magnetic susceptibility. These studies have shown coordination of each HCys- ligand to the VIII atom through an amine nitrogen and a carboxylate oxygen atoms. Solution studies of 1 were carried out in water and methanol by UV-visible, CD and electron paramagnetic resonance (EPR) spectroscopies. According to these studies, it was evident that despite the progressive oxidation of 1 to oxovanadium(IV) species, some V(III) species were also present in solution after several hours. Compound 1, VIVOSO4.5H2O and l-cysteine were examined for their total antioxidant capacity (TAC) and lag time. Compound 1 exhibited significantly greater total antioxidant capacity and lag time values than l-cysteine. VIVOSO4.5H2O did not show any total antioxidant capacity or lag time. The inhibition of neutral endopeptidase (NEP) activity caused by 1, VIVOSO4.5H2O and thiorphan was also measured. Compound 1, at a concentration of 10(-3) M, showed inhibition of NEP activity as potent as thiorphan at 10(-6) M, while VIVOSO4.5H2O in the same concentration exhibited less than 50% inhibitory activity than that of thiorphan at 10(-6) M. Moreover, the antimetastatic effects of compound 1, l-cysteine and VIVOSO4.5H2O were examined on Wistar rats, treated with 3,4-benzopyrene. The results revealed that 1 prevents significantly lung metastases (only 9.5% of animals treated with 1 showed metastases), whereas 47-52% of the rats of the control group and those treated with l-cysteine and VIVOSO4.5H2O exhibited metastases.     

Rapid alterations of serum oxidant and antioxidant status with the intravenous administration of n-6 polyunsaturated fatty acids

In an attempt to achieve the safe intravenous administration of two n-6 polyunsaturated fatty acids (PUFAs), gamma-linolenic acid (GLA) and arachidonic acid (AA), and to study the subsequent changes on the total oxidant and antioxidant status, various steadily increasing doses of each acid were injected intravenously at different infusion times in 28 male rabbits. Blood samples were collected at 15-min time intervals by the hepatic veins and from the carotid artery; oxidant status was determined by the thiobarbiturate assay and total antioxidant status (TAS) was assessed by a colorimetric assay. Both n-6 PUFAs were administered with safety at a dose of 25 mg/kg within 10 min accompanied by an increase of malonodialdehyde concentrations in the hepatic veins and in the carotid artery 30-45 min, respectively, after the end of the infusion of GLA and/or AA. Similar changes did not occur in red cell membranes after the infusion of AA. TAS presented reciprocal changes to malonodialdehyde production; the main consumption of TAS was observed in all samples 30-60 min after the end of the infusion of n-6 PUFAs. The above-mentioned rapid alterations occurring in both serum oxidant and antioxidant status after GLA might have a future clinical therapeutic significance in conditions like cancer and disseminated infectious diseases.     

An EMG-based, muscle driven forward simulation of single support phase of gait

This paper describes the process used to generate lower limb kinematics during single limb stance phase of gait, using musculoskeletal modelling, muscle driven forward simulation and gradient based optimisation techniques (including design of experiment techniques).Initial inputs to the forward simulation process were the normalised quantified muscle activation patterns of 22 muscles, and the initial segmental configuration (both angles and angular velocity) derived from Winter (The biomechanics and motor control of human gait, 1987, University of Waterloo Press, pp. 1-72). Two distinct musculoskeletal models (one including 6 DOF, the other 7 DOF) were defined and a muscle driven forward simulation was implemented.A series of optimisation sequences then were executed to modify the muscle activation patterns and initial segmental configuration, until the system output of the forward simulation approximated the angle data reported by. The accuracy and effectiveness of the analysis sequence proposed and the model response obtained using two distinct musculoskeletal models were verified and analysed with respect to the kinesiology of normal walking.     

Technicolour transgenics: imaging tools for functional genomics in the mouse

Over the past decade, a battery of powerful tools that encompass forward and reverse genetic approaches have been developed to dissect the molecular and cellular processes that regulate development and disease. The advent of genetically-encoded fluorescent proteins that are expressed in wild type and mutant mice, together with advances in imaging technology, make it possible to study these biological processes in many dimensions. Importantly, these technologies allow direct visual access to complex events as they happen in their native environment, which provides greater insights into mammalian biology than ever before.     

Effects of cadmium chloride administration on the macroscopic and microscopic characteristics of ejaculates from Chios ram-lambs

The effects of cadmium chloride on the volume of the ejaculate, semen density, total number of spermatozoa per ejaculate, viability, grade of motility, and morphological abnormalities were studied in 3-month-old ram-lambs of the Chios breed. Two groups of seven animals each were used. For a period of 7 months, one group was treated with a daily oral dose (3 mg/kg b.w.) of cadmium chloride and the other group received the corresponding volume of doubly distilled water. Blood samples were collected for cadmium determinations, whereas semen was collected weekly. In the cadmium-treated animals, cadmium concentration in the whole blood was increased and the testes weight was lower. The volume of the ejaculate, the semen density and the total number of spermatozoa were significantly reduced by the administration of cadmium chloride. No differences were observed in the viability, the grade motility of spermatozoa, or the percentage of dead and morphologically abnormal spermatozoa between the control and the cadmium-treated animals. Histopathological examination in the cadmium-treated animals revealed the presence of lesions in the Sertoli cells, the seminiferous tubules, the primary and the secondary spermatocytes and the spermatides, whereas in the Leydig cells no significant lesions were evident.     

Topology and transport of membrane lipids in bacteria

The last two decades have witnessed a break-through in identifying and understanding the functions of both the proteins and lipids of bacterial membranes. This development was parallelled by increasing insights into the biogenesis, topology, transport and sorting of membrane proteins. However, progress in research on the membrane distribution and transport of lipids in bacteria has been slow in that period. The development of novel biochemical in vitro approaches and recent genetic studies have increased our understanding of these subjects. The aim of this review is to present an overview of the current knowledge of the distribution and transport of lipids in both Gram-positive and Gram-negative bacteria. Special attention is paid to recently obtained results, which are expected to inspire further research to finally unravel these poorly understood phenomena.     

根黄酮在植物生长和营养中的作用

 本文简要综述了80年代以来国际上对根黄酮在调节植物根生长、完善根功能、影响氮素循环及在施加他感作用方面的研究进展,并对有关方面作了一些展望,以期引起植物营养工作者对植物次生物质的注意。     

鄂西南五种野生荚蒾属植物种群结构与动态特征研究

为探明鄂西南地区野生荚蒾属(Viburnum)植物的种群数量特征及区域分布状况，并揭示宜昌荚蒾(V.erosum)、桦叶荚蒾(V.betulifolium)、合轴荚蒾(V.sympodiale)、茶荚蒾(V.setigerum)、荚蒾(V.dilatatum)5种荚蒾属植物种群的生存现状及发展趋势，在鄂西南金子山国有林场、木林子国家级自然保护区及七姊妹山国家级自然保护区，共布设27 hm²固定动态监测样地对荚蒾属植物进行调查，通过对5种荚蒾属植物种群进行年龄结构、动态量化分析和静态生命表以及相关曲线等研究，探讨荚蒾属植物种群结构与动态特征及未来发展潜力。结果表明：(1)鄂西南荚蒾属植物在分布区域及种群数量大小上均存在明显差异。(2)种群结构与动态分析显示，5种荚蒾属植物种群年龄结构呈现为金字塔型，幼龄阶段种群个体数量较多，具有较强的增长潜力，但对外界干扰均具有较强的敏感性。(3)静态生命表显示，5种荚蒾属植物存活量均随着龄级的增加而单调递减；消失率与死亡率曲线变化趋势相似，但不同植物消失率与死亡率曲线波动具有差异性；种群存活曲线均趋近于Deevey-Ⅱ型。(4)4...