Allometric scaling of echocardiographic measurements in healthy Spanish foals with different body weight

Scaling in biology is usually allometric, and therefore, the size of the heart may be expressed as a power function of body weight (BW). The present research analyses the echocardiographic measurements in 68 healthy Spanish foals weighed between 70 and 347 kg in order to determine the correct scaling exponent for the allometric equation. The echocardiographic parameters measured were: left ventricular internal dimensions (LVID), free wall thickness (LVFWT), interventricular septum thickness (IVST) at systole (s) and diastole (d), EPSS (distance between the point E of the mitral valve and the interventricular septum), and aorta diameters at the level of the aortic valve (AOD), base of valve leaflets (ABS), sinus of Valsalva (ASV) and sino-tubular junction (AJT). Indices of left ventricular performance were calculated. It was found that LVIDd, IVSTs, AOD, and ASV have a relationship to BW raised to 0.300-0.368 power, whereas left ventricular end-diastolic volume and stroke volume scaled to BW raised to 0.731-0.712 power. With these data, appropriate values can be calculated for normal Spanish foals.     

黄河中游粗山羊草三种y-型高分子量谷蛋白亚基的鉴定、克隆及系统进化分析

粗山羊草(Aegilops tauschii, 2n = 2x = 14, DD)是六倍体普通小麦的祖先之一,其高分子量谷蛋白亚基(HMW-GS)变异类型丰富,是小麦品质改良的重要基因资源。利用十二烷基硫酸钠聚丙烯酰胺凝胶电泳(SDS-PAGE)分析了黄河中游地区161份粗山羊草的HMW-GS,发现3种编码序列未知的y-型亚基,即Dy10.5^t、Dy10.4^t和Dy10.5^*t亚基。通过AS-PCR扩增、克隆、测序和氨基酸序列推导,发现3种未知序列均具有典型HMW-GS的序列结构特征且较为相似,仅Dy10.4^t与Dy10.5^t亚基存在一个氨基酸重复单元的缺失,Dy10.5^t与Dy10.5^*t亚基在信号肽部位有一个氨基酸的替换(L-F)。通过对这3种HMW-GS与32个已知氨基酸序列的HMW-GS多序列比对和系统进化关系分析,证实Dy10.5^t、Dy10.4^t和Dy10.5^*t 3个亚基是D基因组编码的高分子量谷蛋白y-型亚基家族的新成员。     

Small-Scale Shrimp Grower–Collector Relationships: The Case of Thua Thien Hue Province,Central Vietnam

Small-scale shrimp-culture is an important livelihood for rural residents in Thua Thien Hue (TTH) province, central Vietnam. However, they are facing the risk of exclusion from the food system due to globalization and trade liberalization. To keep these farmers in modern supply chains, their relationships with other chain actors, foremost the collectors, need to be improved. Thus, this study explores the characteristics and constructs of the relationships between the small-scale shrimp growers and their collectors. Data was based on a survey on 83 small-scale shrimp growers, together with 16 unstructured interviews with growers (10) and collectors (6). It was revealed that the relationships between small-scale shrimp growers and collectors in TTH province are short-term and price-driven and are influenced by the power of collectors. The relationship strength was measured by five intercorrelated constructs including reliability, willingness-to-maintain, desire-fulfilment, negotiation capacity, and discussion capacity. Although some constructs were positively correlated, the strength of the relationships was weak. Both business linkages and social connections affected the grower-collector relationships. Female traders had stronger relationships with collectors than males. Therefore, interventions should be focused on business and social linkages as well as females’ involvement in shrimp trade.     

周口地区大叶黄杨白粉病菌的鉴定和进化分析

对周口地区的大叶黄杨白粉病菌进行了显微形态、核糖体DNA转录间隔区(ITS)及进化树分析。结果表明:在扫描电子显微镜下病菌分生孢子呈圆柱形或椭圆形,无支链;ITS序列与来自日本和阿根廷的Erysipheeuonymi-japonici的ITS序列聚在一个进化枝上。表明来自河南周口地区的白粉病属于E.euonymi-japonici,与日本和阿根廷的E.euonymi-japonici亲缘关系最近。     

Suitability of weed species prevailing in Spanish vineyards as hosts for root-knot nematodes

Commercial vineyards in southern Spain were surveyed and sampled during October to December 2004 to determine the extent to which common weeds present were suitable hosts of root-knot nematodes infesting soils of those vineyards. Seven weed species commonly growing in grapevine soils in southern Spain were found infected by either Meloidogyne incognita or M. javanica: Amaranthus retroflexus (redroot pigweed), Anchusa azurea (ox-tongue), Chenopodium album (goosefoot), Erodium moschatum (musk stork’s bill), Malva rotundifolia (low mallow), Sinapis alba (white mustard), and Solanum nigrum (black nightshade). The host suitability of the weeds to root-knot nematodes was evaluated on the basis of root galling severity and nematode population densities in soil and roots. Also, the host–parasite relationship in these naturally Meloidogyne-infected weeds was examined. All the weed species in the study were considered suitable hosts for M. incognita and M. javanica because: (a) high Meloidogyne spp. populations occurred in roots and surrounding soil of the weed species; (b) the severity of root galling was high, and (c) well-established permanent feeding sites were observed in the histopathological studies of infected root tissues. In addition, this study presents the first reports of S. alba and A. azurea as hosts for M. incognita, and of E. moschatum as a new host for M. javanica, thus increasing the list of reported weed hosts for Meloidogyne spp. These results indicate that noticeable population densities of M. incognita and M. javanica can be maintained or increased in these weeds, at population levels higher than those previously reported for the same nematodes infecting grapevine roots. The weeds infesting vineyards thus represent an important source of inoculum of Meloidogyne spp., and furthermore may act as reservoirs of these nematodes which can be disseminated within or among vineyards by agricultural operations.     

Actions of quinolizidine alkaloids on Periplaneta americana nicotinic acetylcholine receptors

BACKGROUND: Botanical insecticides do not play a major role as crop protectants, but they are beneficial in some applications. The authors investigated the actions of naturally occurring alkaloids on insect nicotinic acetylcholine (ACh) receptors (nAChRs) by evaluating their abilities to inhibit specific binding of [³H]imidacloprid (IMI) to nerve‐cord membranes from Periplaneta americana L. Two alkaloids were also tested for their actions on nAChRs expressed by cockroach neurons using patch‐clamp electrophysiology. RESULTS: Four natural quinolizidine alkaloids (matrine, sophocarpine, cytisine and aloperine) exhibited more than 50% inhibition of [³H]IMI binding at 10 µM , although other compounds were found to have no or low inhibitory activity. The rank order of potency based on concentration–inhibition curves was cytisine > sophocarpine ≥ aloperine ≥ matrine. Patch‐clamp analysis indicated that sophocarpine and aloperine were not agonists of nAChRs expressed in P. americana neurons, yet, at 10 µM , aloperine, but not sophocarpine, suppressed ACh‐induced inward currents significantly. CONCLUSION: Three of the four natural alkaloids tested possess structural moieties that are necessary for interaction with P. americana nAChRs. Aloperine, which possesses a unique structure and showed a distinctive dose–response curve, was found to act as an antagonist. Appropriate modifications of these alkaloids might result in novel insecticidal nAChR ligands. Copyright © 2008 Society of Chemical Industry     

Ameliorative effects of nurse shrubs on soil chemical characteristics are driven by plant size in the Monte desert

In deserts, shrubs determine landscape structure and influence plant productivity by creating nutrient-enriched environments. Attributes vary among shrub species, thus their contribution to soil characteristics is expected to vary as well, and nutrient input under shrub cover will depend on species attributes. We propose that plant size determines the contribution to soil chemical characteristics. Therefore, the contribution of larger species will be higher than smaller ones. Also, each species will contribute differentially for each chemical parameter. To corroborate these premises, we measured six soil chemical characteristics in areas covered by shrubs and in bare soil, as well as among five nurse species, in four sites of the Monte desert (La Rioja, Argentina). A multivariate analysis of variance (MANOVA) indicated significant variation between cover conditions and locations. Supporting previous studies, the presence of shrubs improved soil properties. Chemical concentration between soils under shrubs and bare soils, respectively, showed as mean and (SD) were: carbon(%): 0.82 (0,47), 0.52 (0.22); nitrates (ppm): 33,33 (67,36), 2.63 (0.56); phosphorous(ppm): 16.76 (25.02), 6.56 (1.92); electrical conductivity (dS m^?1): 0.24 (0,43), 0.03 (0,02); pH: 6.93 (0.56), 7.62 (0.53); and water content (%): 3,17 (8.94), 2.47 (9.15). Chemical characteristics also varied according to the nurse species. Larger nurse species affected the ensemble of chemical characteristics, after controlling for cover condition and site. Larger plant species (Bulnesia retama, Prosopis torquata, and Zuccagnia punctata) were significantly associated with higher carbon and higher nitrates concentration. These results suggest that soil properties are enhanced by the size of nurse plant species.     

Conservation priorities for the different lines of Dutch Red and White Friesian cattle change when relationships with other breeds are taken into account

From a genetic point of view, the selection of breeds and animals within breeds for conservation in a national gene pool can be based on a maximum diversity strategy. This implies that priority is given to conservation of breeds and animals that diverge most and overlap of conserved diversity is minimized. This study investigated the genetic diversity in the Dutch Red and White Friesian (DFR) cattle breed and its contribution to the total genetic diversity in the pool of the Dutch dairy breeds. All Dutch cattle breeds are clearly distinct, except for Dutch Friesian breed (DF) and DFR and have their own specific genetic identity. DFR has a small but unique contribution to the total genetic diversity of Dutch cattle breeds and is closely related to the Dutch Friesian breed. Seven different lines are distinguished within the DFR breed and all contribute to the diversity of the DFR breed. Two lines show the largest contributions to the genetic diversity in DFR. One of these lines comprises unique diversity both within the breed and across all cattle breeds. The other line comprises unique diversity for the DFR but overlaps with the Holstein Friesian breed. There seems to be no necessity to conserve the other five lines separately, because their level of differentiation is very low. This study illustrates that, when taking conservation decisions for a breed, it is worthwhile to take into account the population structure of the breed itself and the relationships with other breeds.     

福建省地级市代谢系统差异性研究

以福建省9个地级市的代谢系统为研究对象,根据城市代谢的基本原理,运用能值理论和城市代谢系统互动关系分析方法,从代谢系统生态流和代谢系统中自然子系统与社会经济子系统之间的互动关系这两个方面对9个地级市代谢系统差异性研究,并结合GIS技术对其结果进行等级划分和空间差异性比较。结果表明代谢系统的可更新资源能值投入和进出口能值存在明显的海陆差异性;代谢系统的不可更新资源能值投入存在明显的南北差异性;福州市、厦门市、泉州市和漳州市这4个地级市代谢系统中自然生态子系统对社会经济子系统存在着限制关系,三明市、南平市、龙岩市、宁德市和莆田市这5个地级市代谢系统的社会经济子系统对自然生态子系统存在掠夺关系。     

Etude de la nutrition potassique du sorgho III‐relations entee les teneurs en cations et la composition en acides organiques des feuilles

Abstract

Extracts that are coloured, owing to dissolved organic matter, give rise to an interference when boron is determined by the colorimetric Azomethine‐H method. A scheme is presented in which boron is removed from coloured extracts by dialysis. In this way the interference can be removed automatically. The suggested scheme allows hydroponic solutions and extracts of soils, peat‐based composts and plant materials to be analysed without further treatment at a rate of 20 hr^‐1. The limit of detection is 0.05ppm B in solution. Recoveries of boron added to extracts from all types of sample were excellent. The effects of some interferences were investigated and found not to be significant under normal working.