DETERMINATION OF TIME OF ONSET AND LOCATION OF EARLY SKELETAL LESIONS IN YOUNG DOGS EXPERIMENTALLY INFECTED WITH HEPATOZOON AMERICANUM USING BONE SCINTIGRAPHY

Canine hepatozoonosis caused by Hepatozoon americanum has periosteal proliferation on long bones, pelvis, vertebrae, and skull. The pathogenesis of the periosteal proliferation is unknown but may be similar to hypertrophic osteopathy. Objectives were to determine the time frame for onset of bone lesions, to characterize spatial distribution of early bone lesions, and to describe the scintigraphic appearance of bone lesions in six immature dogs infected with 400 H. americanum oocysts on day 0. 99mTc-MDP bone scintigraphy was performed before and after infection. The onset bone lesions noted using scintigraphy was before day 35/36 in three dogs, day 46 in one dog, day 53 in one dog, and between days 46 and 67 in one dog. Early bone lesions primarily occur proximal to the carpus/tarsus and on the axial skeleton. Bone lesions were diffuse, bilaterally symmetric, homogenous, high intensity regions of radiopharmaceutical uptake.     

黄土地表生物结皮对土壤贮水性能及水分入渗特征的影响

采用双环法对山西省偏关县3种结皮覆盖下(苔藓藻结皮、藻结皮和薄层藻结皮)土壤的贮水性能和渗透特征进行了对比研究.结果表明:不同结皮覆盖下土壤的贮水能力受结皮厚度和孔隙度状况的影响较大,0～10 cm土层饱和贮水量为502.69～525.80 t/hm2 ,滞留贮水量为169.71～198.29 t/hm2;初渗速率的变化范围为5. 19～11.10 mm/min,无结皮最高,苔藓藻结皮最低;稳渗速率变化范围为1.6 7～2.67 mm/min.采用的3种入渗模型(Kostiakov模型、Horton模型和Ph ilip模型)中Horton模型的拟合值更接近于实测值, 决定系数R2在0.98～0.99,更适用于描述本研究区具有生物结皮土壤的入渗特征.     

作物定位轮作体系长期试验研究(Ⅱ)--不同轮作方式对大豆田土壤微生物数量的影响

1994～2002年在东北农业大学校内农学试验田进行作物定位轮作的长期试验研究,分别对不同作物轮作体系的土壤微生物、土壤优质真菌及土壤肥力的演变做了研究和分析。现将不同轮作方式对大豆田土壤微生物数量的影响加以总结。结果表明,不同轮作大豆田土壤细菌和放线菌数量均前期较低,生育盛期和成熟期较高,土壤真菌数量以苗期、结荚期较高,生育中后期有所减少;不同轮作方式相比,连作种植促使大豆田土壤微生物区系由细菌型向真菌型转化。     

Incorporation of yolk fatty acids into body lipids of goldfish (Carassius auratus L.) larvae raised at two different temperatures

In five separate experiments, eggs from a single female goldfish were fertilized at 20°C. They were incubated at 22°C for 6 hours, after which some of the eggs were transferred to 13°C. When a defined post-hatch developmental stage was reached, lipid extracts were prepared from larvae, both with yolk sacs intact and after removal of the yolk sac by dissection. Other larvae were sampled at yolk exhaustion. Gas chromatographic analysis of fatty acid profiles revealed that larvae incorporated 16:0, 18:0, 20:4 (n–6) and 22:6 (n–3) into their tissues in proportions higher than those present in the eggs from which they were derived. At 22°C, these trends were particularly apparent at yolk exhaustion. At 13°C, proportions of polyunsaturated fatty acids in the bodies of newly hatched larvae were higher than those in the 22°C larval bodies. Monounsaturated fatty acids were preferentially depleted during development, especially in larvae from high quality eggs. No dependence of egg quality, as assessed by larval viability at 22°C, on total egg lipid mass or fatty acid composition was found. Larvae from the lowest quality eggs showed a reduced preference for incorporation of (n–3) polyunsaturated fatty acids into their tissues.     

温室甜瓜膜下滴灌初花期适宜蒸发皿系数研究

在日光温室膜下滴灌条件下,采用E20蒸发皿的水面蒸发量控制灌溉,研究了不同蒸发皿系数(Kcp=0.45,0.6,0.75,0.9)对初花期甜瓜生长、生理特性的影响. 结果表明:(1)水分处理对温室膜下滴灌甜瓜15 cm处地温产生了显著影响,其中T2(0.6) 与T3(0.75)处理的地温对甜瓜生长较为有利;(2)水分处理对甜瓜叶片扩展和叶面积大小影响较大,以2 d为灌溉周期,蒸发皿系数(Kcp)采用0.6有利于甜瓜叶片扩展,而且植株叶面积最大;(3)从甜瓜株高、茎粗/株高、总生物量与根冠比、叶片水分状况、叶片光合生理指标等综合分析,蒸发皿系数Kcp采用0.6(T2)都要优于其它水分处理.     

湖南省柿树叶片中黄酮类化合物含量的分析

通过建立稳定的柿树叶片黄酮类化合物HPLC分析方法,初步探讨柿树叶片黄酮类化合物的代谢累积规律,确定适宜的柿树叶片采收时期;同时检测分析了湖南省不同柿树品种的柿树叶片黄酮类化合物含量。结果表明,试验建立的HPLC分析方法稳定、可靠、重现性好,柿树叶片黄酮类化合物各物质峰之间分离度好;根据试验得出的柿树叶片黄酮类化合物代谢累积规律,确定适宜的柿树叶片采收时期为3月份的新叶萌发期和9~10月的果实成熟期;湖南省内7个地区17个不同柿树品种之间柿树叶片黄酮类化合物含量都有差异,其中含量最高的品种为次郎甜柿,含量最低的为野生腰带柿。     

三峡库区蓄水172m水位线前后江面江岸鸳鸯越冬种群的分布调查

2006-2009年,对三峡库区长江干流及12条主要支流的冬季水禽分布状况进行了较为系统的调查,其中鸳鸯的总体数量大约为100~120只.水位变动对鸳鸯的分布格局造成一定程度的影响,随着三峡大坝不同工程阶段的分期蓄水,三峡库区长江主河道的越冬鸳鸯种群数量呈明显减少趋势.2009年1月和2010年1月的调查结果表明,蓄水达172 m和168 m水位线后越冬鸳鸯集中分布于3条支流河道中,长江主河道中未见有越冬鸳鸯分布.     

尼罗罗非鱼β2m基因的克隆、多态性分析及组织表达特征

β2-微球蛋白(β2-microglobulin,β2m)是主要组织相容性复合体(major histocompatibility complex,MHC)Ⅰ分子的亚基之一,与MHC-Ioα链非共价结合构成MHC Ⅰ分子.本实验通过反转录PCR(RT-PCR)和cDNA末端快速扩增技术(rapid-amplification of cDNA ends,RACE)克隆了尼罗罗非鱼(Oreochromis niloticus) β2m基因的全长cDNA序列及基因组序列,并对cDNA多态性、mRNA组织分布及感染链球菌后表达的变化进行了分析.结果共获得尼罗罗非鱼2条β2m基因cDNA,全长分别为900和906 bp.两cDNA均包括351 bp的ORF,共编码116个氨基酸残基,还包含68 bp的5'非编码区(5'-UTR)和486(492) bp的3'-UTR.两条cDNA对应各自不同的基因组序列.基因组序列分析发现,β2m基因含3个外显子和2个内含子.尼罗罗非鱼β2m基因推测氨基酸序列与其他物种的β2m基因相似性在39.20％～89.80％之间.β2m基因cDNA多态性分析表明,尼罗罗非鱼中共有2种不同类型的β2m cDNA,每种类型cDNA又有3种不同的亚型.定量PCR分析表明,β2m基因在尼罗罗非鱼脾脏、心脏和肾脏中表达量最高,鳃与肠中的表达量较高,在皮肤和肌肉中的表达量最低.腹腔注射无乳链球菌(Streptococcus agalactiae)后,尼罗罗非鱼β2mmRNA表达量在4个所检测组织(鳃,肾脏,心脏和脾脏)中均出现了先上升后下降的变化趋势.本实验结果表明,β2m基因可能参与尼罗罗非鱼的免疫应答,在免疫反应中发挥重要功能.本研究有助于进一步了解尼罗罗非鱼的免疫调节机制和更好地理解鱼β2类m的生理功能.     

广东省高水平百米跑运动员体能结构特征模型的构建与应用*

以广东省优秀男子百米跑运动员14人为研究对象，采用文献资料法、问卷调查法、专家访谈法、测试法与数理统计法等，运用因子分析法筛选出了有效反映广东省优秀男子百米跑运动员体能水平的9项指标，入选的9项指标可以分别从身体形态、生理机能和运动素质三个层面有效反映运动员的体能水平；并构建了广东省高水平男子百米跑运动员体能水平定量评价模型。