秦岭细鳞鲑耗氧率和窒息点的初步研究

对两种不同体重规格的秦岭细鳞鲑(Brachymystax lenok tsinlingensis)的耗氧率、耗氧量及窒息点进行了测定,结果表明,秦岭细鳞鲑的耗氧率随温度的升高而增加,随体重的增加而减小;耗氧量和窒息点随温度的升高和体重的增加而增加。温度在10~18℃范围内,平均体重25.15 g的秦岭细鳞鲑的平均耗氧率为1.113 mg/g.h,平均耗氧量为9.244 mg/尾.h;平均体重45.93 g的秦岭细鳞鲑平均耗氧率为0.856mg/g.h,平均耗氧量为13.104 mg/尾.h。在10~20℃温度范围内,体重15.30 g的秦岭细鳞鲑,窒息点为(1.487±0.04)mg/L,平均体重48.36 g的秦岭细鳞鲑窒息点为(1.830±0.03)mg/L。在同一适温(14℃)条件下,秦岭细鳞鲑耗氧率呈明显的昼夜变化规律,夜间耗氧率明显大于白天。     

信阳桃花水母对几种生态因子胁迫的耐受反应

在不同温度、盐度、pH等因子胁迫条件下,研究观察了信阳桃花水母(Craspedacusta sowerbyi xinyangensis)的生活状态、形态变化及存活等耐受反应,并测定了信阳桃花水母在不同温度下的耗氧率和最低耐氧能力.结果表明,信阳桃花水母的最适生活温度范围为15 ℃～25 ℃,pH为6.0～8.2.信阳桃花水母对盐度耐受力差,盐度为2时,仅能存活96 h;但具有较强的耐低氧能力,20 ℃时窒息点为026 mg·L^-1,平均耗氧量和平均耗氧率随温度的升高而升高.     

厚颌鲂和圆口铜鱼耗氧率与窒息点的测定

用封闭静水式装置测定了体重2.3-4.7g厚颌鲂幼鱼的耗氧率和窒息点,用封闭静水式和封闭流水式装置测定了体重9.9-55.1g圆口铜鱼的耗氧率和窒息点。结果表明:在15-27℃条件下,厚颌鲂的耗氧率随着温度的升高而升高,耗氧率与水温呈线性关系;在水温24.8℃时厚颌鲂的窒息点为(0.91±0.08)mg/L。在水温23-27℃、封闭静水实验条件下,圆口铜鱼的耗氧率随体重增加而降低,两者呈指数关系;圆口铜鱼耗氧率昼夜变化明显,夜间耗氧率大于白天,推测圆口铜鱼夜间活动较多。在水温24.5-26.0℃条件下,体重21.8-46.3g圆口铜鱼的窒息点变幅较小,平均(1.14±0.23)mg/L。研究表明两种鱼都为耗氧率和窒息点较高的鱼类。       

温度、盐度对强壮箭虫耗氧率和窒息点的影响

研究了不同温度、盐度下强壮箭虫的耗氧率和窒息点.结果表明:温度和盐度均对强壮箭虫的耗氧率和比耗氧率有显著影响.试验温度在5℃-25℃,强壮箭虫个体耗氧率(IO)和比耗氧率(SO)开始随温度的升高而升高,之后呈明显下降趋势.其回归方程分别为y=0.0058x3 -0.2956x2+4.415x-8.7816(R2=0.99,P＜0.05)和y=0.0011x3 -0.0546x2+0.8161x-1.6232(R2=0.99,P＜0.05),数值分别为6.30～11.71μg·ind-1·h-1和1.22 ～2.16μg· mg-1·h-1,窒息点为4.18～6.87 mg·L-1.盐度10 ～40条件下,IO和SO随盐度的升高逐渐下降,回归方程分别为y=-0.0068x2 -0.1412x+21.702(R2=0.89,P＜0.05)和y=-0.0013x2-0.0261x+4.0114( R2 =0.89,P＜0.05),数值分别为4.98～17.73μg ·ind-1·h-1和0.92～3.56 μg·mg-1 ·h-1,窒息点为4.02～6.24 mg·L-1.对强壮箭虫与其他水生动物的耗氧率和窒息点进行比较得出,强壮箭虫是一种狭氧性浮游动物.     

不同高温水平对虾夷扇贝存活率、耗氧率和体腔液免疫酶活力的影响

实验室内营造不同升温模式,研究了2种规格(10和46月龄)虾夷扇贝(Mizuhopecten yessoensis)的存活率、耗氧率及体腔液免疫酶活力对不同高温水平(20、22、24、26、28℃)的响应,分析了2种规格虾夷扇贝在不同升温模式下的耐高温能力。实验设计了缓慢升温和快速升温2种升温模式。缓慢升温模式,将在15℃暂养的2种规格扇贝分别驯化到20、22、24、26和28℃温度水平(升温幅度为1℃·d-1),暂养14 d后进行实验。快速升温模式,将在15℃暂养的2种规格扇贝分别快速升温到20、24及28℃温度水平(升温幅度为4℃·d-1),暂养1 d后进行实验。结果表明:缓慢升温模式时,随温度升高,扇贝存活率逐渐降低,28℃时,46和10月龄贝存活率最低分别为96.7%和77.3%,此外,26~28℃时,各实验处理组,46月龄贝存活率显著高于10月龄贝(P0.05);2种规格扇贝耗氧率随温度升高均呈先上升后下降趋势;15~24℃时,10月龄贝的耗氧率显著高于46月龄贝(P0.05);28℃时,10和46月龄贝的耗氧率降至最低,分别为0.527和0.482 mg·g-1·h-1;另外,扇贝的体腔液免疫酶活力随温度升高也均呈现先上升后下降的变化趋势,且在相同升温模式下,46月龄贝的免疫酶活力显著高于10月龄贝(P0.05)。综上,规格较大的虾夷扇贝在不同高温水平时均表现出较强的耐高温能力。     

体重和时间节律对俄罗斯鲟(Acipenser gueldenstaedti Brandt)幼鱼耗氧率和窒息点的影响

采用流水法研究了在温度(20.7±0.55)℃下体重和时间节律对俄罗斯鲟(Acipenser gueldenstaedti Brandt)幼鱼耗氧率和窒息点的影响。结果表明,俄罗斯鲟的耗氧率、窒息点与体重负相关,耗氧量与体重正相关。俄罗斯鲟体重(1.39±0.24)g时平均耗氧率为(0.51±0.06)mg/h.g,平均耗氧量为(0.68±0.03)mg/h.ind;体重(3.16±0.22)g时,平均耗氧率为(0.35±0.04)mg/h.g,平均耗氧量为(0.97±0.10)mg/h.ind;体重(6.20±0.36)g时平均耗氧率为(0.28±0.04)mg/h.g,平均耗氧量为(1.46±0.33)mg/h.ind。3种规格俄罗斯鲟的窒息点分别为2.38、2.35和1.98 mg/L。     

瓦氏黄颡鱼与黄颡鱼的耗氧率及窒息点

在平均水温25℃条件下,测得平均体重10.0 g的瓦氏黄颡鱼(Pelteobagrus vachelli)及平均体重12.6g的黄颡鱼(P.fulvidraco)耗氧率分别为0.21和0.23 mg/g.h,窒息点分别为0.91和0.75 mg/L;平均体重75.8 g的瓦氏黄颡鱼及平均体重85.4 g的黄颡鱼耗氧率分别为0.16和0.12 mg/g.h,窒息点分别为0.77和0.54 mg/L。分析表明,瓦氏黄颡鱼的耗氧率和窒息点都高于黄颡鱼。     

鲻幼鱼耗氧率、排氨率和窒息点的研究

为探讨鲻幼鱼的耗氧率、排氨率和窒息点,采用封闭流水式实验方法,在不同体质量、光照、放养密度、水流速度以及昼夜更替的条件下,测定鲻幼鱼的耗氧率和排氨率,并且观测体质量对幼鱼窒息点和窒息时间的影响。实验期间水温为19℃±1℃,盐度30,pH7.7。研究结果显示:鲻幼鱼的耗氧率随体质量增加而上升,其变化趋势可用幂函数方程表达:Y=0.4759X0.1878(R2=0.9454);光照对耗氧率的影响较大,对排氨率无明显影响;放养密度对耗氧率的影响差异显著(P0.05),对排氨率的影响差异极显著(P0.01);幼鱼的呼吸代谢旺盛时段在中午11∶00至夜间23∶00;流速对耗氧率和排氨率的影响差异均极显著(P0.01);不同体质量幼鱼窒息点和窒息时间的差异极显著(P0.01)。     

温度对黑鱾幼鱼耗氧率和排氨率的影响

本文研究了温度对饱食和饥饿状态下黑纪(Girella melanichthys)幼鱼耗氧率和排氨率的影响.结果表明:在温度为15～30℃范围内,黑纪幼鱼在饱食状态下的耗氧率、饥饿状态下的耗氧率、饱食状态下的排氨率和摄食率均随温度的升高而增加(P＜0.01),30℃时达到最大,温度为32℃时,均下降;在温度为15～32℃范围内,黑鱾幼鱼在饥饿状态下的排氨率随温度升高而增加(P＜0.01),32℃时达到最大.多项指标表明黑纪幼鱼生长适温在30℃左右.     

红尾副鳅耗氧率和窒息点的初步研究

用封闭流水式装置测定了红尾副鳅的耗氧率变化及窒息点。结果表明,红尾副鳅耗氧率随着体重的增加而减小,红尾副鳅其耗氧率昼夜变化差异显著(P<0.05)。在水温14.0℃时,平均体重4.0 g的红尾副鳅的平均耗氧率为0.1659 mg/(g·h),日平均耗氧率为0.1389 mg/(g·h),夜间其平均耗氧率为0.1930 mg/(g·h);平均体重为7.9 g的红尾副鳅的平均耗氧率为0.1175 mg/(g·h),日平均耗氧率为0.1099 mg/(g·h),夜间其平均耗氧率为0.1251 mg/(g·h);平均体重9.5 g的红尾副鳅平均耗氧率为0.0534 mg/(g·h),日平均耗氧率为0.0509 mg/(g·h),夜间平均耗氧率为0.0559mg/(g·h),窒息点为1.137 mg/L。本研究表明红尾副鳅为耗氧率和窒息点较高的鱼类。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.