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1.
树皮pH值的变化及其对大气酸性气体污染的指示作用   总被引:5,自引:0,他引:5  
1991~1993年在河北省承德市5个大气监测点测定8种常见绿化树种树皮pH值的变化,结果表明8种树皮pH值为3.5~7.0,平均值为5.7±0.6。不同功能区树皮pH从大到小依次为:公园区>工业区>生活居住区(P<0.05),与大气SO2等酸性气体的污染有关。同种植物的树皮浸提液SO2-4含量相对清洁区为2.516mg/g,污染区为5.342mg/g(P<0.001),两者之间的相关公式为Y=2.576+6.4736X(r=0.7730,P<0.001)。树皮pH与SO2-4呈极显著负相关,相关公式为Y=7.1-0.3865X(r=-0.8941,P<0.001)。榆树等4种落叶阔叶树树皮对大气SO2的变化较敏感,可作为SO2等酸性气体的适宜指示与监测植物。  相似文献   

2.
最大摄氧量(Vo2max)是评价人体体力的重要指标,其测定方法分直接法和间接法两种。目前所推导的间接计算公式都是在平原、或是在进入高原初期推导的,不适用于高原习服人群。本研究采用逐步回归的方法,推导出移居高原7-27个月、不同高度的青年男性Vo2max间接计算公式。在海拔3680m地区,Vo2max(L/min)=1.1531+0.007327身高(cm)+0.01613体重(kg)-0.005883晨脉(b/min)-0.004534运动心率(60W,6/min),R=0.745,P<0.01,SS=3.7799;或Vo2max(L/min)=1.2186+0.01984体重(kg)+0.07259肺活量(L)-0.006659晨脉(b/min),R=0.713,p<0.01,ss=3.9636。在4350m地区,Vo2.max(L/min)=0.4917+0.01687体重(kg)+0.1109肺活量(L)+0.001983屏气时间(S),R=0.781,P<0.01,SS=2.1356。计算值与实测值比较,变异系数在13%以内,结果准确可靠,适用于青年男性高原习服移居者。  相似文献   

3.
寄主植物对瓜蚜酯酶活性及其耐药性的影响   总被引:8,自引:2,他引:6  
王健  吴振廷 《昆虫知识》1996,33(1):20-22
寄主植物对瓜蚜无翅胎生雌蚜体重、体色、体内酯酶活性均有明显影响。取食笋瓜、南瓜、瓠子、黄瓜和冬瓜的瓜蚜,体重依次增加,体色渐深,而体内羧酸酯酶活性依次渐低。取食不同奇主植物的瓜蚜对杀虫剂的耐药性与其体内酯酶活性呈正相关。瓜蚜体内羧酸酯酶活性(X)与乐果对瓜蚜的LC50(Y)附会Y=8.3827X-67.8530(r=0.952),与功夫菊酯对瓜蚜的LC50(Y)附合Y=1.040X-28.89(r=0.985)的线性关系。  相似文献   

4.
封闭群FMMU白化豚鼠繁殖性能与生长发育的初步观察   总被引:1,自引:0,他引:1  
对本室培育的封闭群FMMU白化豚鼠的繁殖性能和生长发育情况进行初步观察,结果表明:FMMU白化豚鼠系三色豚鼠的变异株(种),由于严格采用循环交配的封闭群繁育方法,其产仔数、泌乳力、哺乳期增重等繁殖性能和生长发育指标仍维持较高水平,和三色豚鼠相接近。有关繁殖性能指标为:胎间隔8.67±17.4/d、窝产仔数2.89±0.66/只、初生个体重86.39±10.17/g,泌乳力402.1±48.32/g、离乳数为2.68±0.41,离乳率为90.71±12.71%,离乳个体重为178.65±26.68/g。3、9、15、20日龄豚鼠个体重分别为88.76±10.81/g、123.18±12.55/g、163.41±21.13/g、175.36±22.17/g;雌性豚鼠个体重分别为90.37±13.72/g、130.74±22.18/g、169.79±27.82/g、179.98±28.12/g。  相似文献   

5.
为评估γ干扰素释放试验(T-SPOT .TB)和结核菌素皮肤试验(TST )在我国活动性肺结核病患者的家庭接触者中预测活动性结核病的能力,选取157例家庭接触者行T-SPOT .TB和TST筛查,并前瞻性随访6年。将121例参与随访的家庭接触者纳入分析,T-SPOT .TB阳性率为49.6%,与年龄﹝ OR=1.03(95%CI 1.00~1.05),P=0.032﹞和接触菌阳患者﹝ OR=2.13(95% CI为1.01~4.51),P=0.048﹞呈正相关。TST≥5 mm和TST≥10 mm的接触者分别占57.5%和37.2%,其中TST≥10 mm与接触菌阳患者呈正相关﹝ OR=2.30(95% CI为1.05~5.06),P=0.038﹞。共随访626人年,7例发展为活动性结核病,发病率为11.0/1000人年。T-SPOT .TB的阳性预测值(PPV)为8.3%,阴性预测值(NPV)为96.7%。TST≥5 mm和TST≥10 mm的PPV分别为7.7%和9.5%,NPV均为95.8%。总之,活动性肺结核病患者的家庭接触者发展为活动性结核病的风险高于一般人群,而T-SPOT .TB与TST对活动性结核病的预测能力相当。  相似文献   

6.
李仲来 《兽类学报》1998,18(3):196-201
介绍了高原鼠兔室外体重生长的分段Logistic-指数饱和模型W(t)=K/{1 {[K—W(t0)]/W(t0)exp{-[r1(t-t0)]}t≤tc;W(t)=W.-exp{-r2(t-tc)}[Wa-W(tc)]t≥tc,其中W(t)是在时刻t鼠兔的体重,K是体重饱和量,r1和r2是体重的瞬时增长率,tc是转变点,W(t)在t=tc连续。利用非线性模型的正割法(DUD,Doesn'tusederivatives),可同时确定模型的所有参数(包括转变点tc在内)。并分别得到描述高原鼠兔室外体重生长动态的模型为高原鼠兔(室内)体重生长的分段直线-直线-对数-指数饱和模型为  相似文献   

7.
母兔配种后10小时血清中若干生理指标与子代性比的相关   总被引:1,自引:0,他引:1  
测定日本大耳白兔母兔配种后10小时血清中的10项生理指标,并与母兔所产每窝仔兔的性比(雄性个体所占比率)进行对应分析(窝仔数<6的数据未参与此项分析)。结果表明:母兔血清中FSH、T(睾酮)、 Na+和M2+的浓度在高、低两个性比组间有显著差异, T3(三碘甲状腺原氨酸)的差异接近显著水平(P<0.1);并且,FSH和T3与子代性比里显著负相关(r分别为-0.50和-0.46),Mg2+与子代性比里显著正相关(r=0.39);同时,Mg2+/Ca2+、Mg2+×Na+、Mg2+×K+和T3×FSH与子代性比的相关分别为0.40、0.43、0.39和-0.53(P<0.05)。  相似文献   

8.
DBA/2小鼠生长和繁殖的研究   总被引:2,自引:2,他引:0  
DBA/2小鼠最长妊娠期为24d,最短妊娠期为19d,平均妊娠期为20.9d。平均窝产仔数为4.3只,与昆明小鼠平均窝产仔数6.4只比较,差异高度显著(P<0.001)。24~36日龄段为生长最迅速时期,成熟日龄为60d,90日龄为适配期。1~108日龄与平均体重的相关系数为0.977,呈强正相关,相关系数t测验的结果为(P<0.001),显示日龄增长与体重变化之间相关高度显著。  相似文献   

9.
目的:探讨高脂饮食致肥胖小鼠脂肪组织RIP140mRNA表达水平的变化及其与胰岛素抵抗的关系。方法:将C57BL/6J雄性小鼠随机分为正常饮食(NFD)组、高脂饮食(HFD)纽分别喂养14周后,测量两组小鼠体重,以NFD组小鼠体重作为对照,选取HFD组中体重大于对照组小鼠平均体重20%的小鼠作为肥胖组小鼠。对照组和肥胖组小鼠取血测甘油三酯(TG)、总胆固醇(TC)、空腹血糖(FBG)、空腹胰岛素水平(FIns),计算稳态模型胰岛素抵抗指数(HOMA-IR);采用RT—PCR技术检测两组小鼠附睾脂肪组织RIP140 mRNA的表达水平,并进行统计学分析。结果:HDF组小鼠中有12只符合标准计入肥胖组。肥胖组小鼠TG、TC、FBG、Fins(P〈0.05),HOMA-1R(P〈0.01)均明显高于对照组;肥胖组小鼠脂肪组织RIP140mRNA的表达高于对照组,差异具有统计学意义(P〈0.05);相关分析显示小鼠脂肪组织R1P140 mRNA表达水平与TG水平呈正相关(r=0.536,P〈0.05),与胰岛素抵抗指数呈正相关(r=0.465,P〈0.05),而与TC、FBG、Fins水平相关分析无统计学意义(P〉0.05)。结论:高脂饮食诱导的肥胖小鼠脂肪组织RIP140 mRNA表达增加,并与胰岛素抵抗程度呈正相关。  相似文献   

10.
周碧燕  李友邕  李洁  钟德斌  郑文 《生物磁学》2011,(16):3111-3113
目的:探讨前列腺增生患者年龄,前列腺体积以及BMI与血清前列腺特异性抗原(PSA)之间的关系。方法:对224例前列腺增生患者的年龄,前列腺体积以BMI与PSA的相关性进行Spearman相关性分析。结果:224例前列腺增生患者有25%的患者PSA水平高于正常,并且年龄,前列腺体积与血清PSA存在明显的正相关:(r=0.672.P〈0.01,r=0.785.P〈0.01),而血清PSA与BMI指数存在明显的负相关:(r=-0.873,P〈0.01)。结论:前列腺增生患者的血清PSA值随患者年龄增长和体积增大而增加,对于PSA轻度升高的前列腺增生患者,要考率到体重因素对结果的影响。  相似文献   

11.
In order to investigate the effect of different levels of oral glucose supplementation and/or reproductive method on productive and reproductive performance of New Zealand White (NZW) doe rabbits in the tropic, 36 bucks and 120 doe NZW rabbits were equally divided among four treatment groups (n = 9 bucks + 30 does). The treatments consisted of supplementing drinking water with 0 (control), 2.5, 5 and 10 g glucose/l, respectively. To study the effect of reproduction method (natural v. artificial), each group was divided into two sub-groups (naturally mated and artificially inseminated) with the same bucks of the same treatment group. Glucose supplementation at 5 or 10 g/l of water increased (P < 0.01) litter weight at birth and at weaning, and litter weight gain during the 4 weeks. However, glucose supplementation at 2.5 or 5.0 g/l water decreased (P < 0.01) feed consumption from 7 to 14 days after delivery. Glucose supplementation at 2.5 g/l water did not affect productive and reproductive performance of rabbits. Artificially inseminated does had higher daily litter weight gain between 21 and 28 days post partum. Artificially inseminated group had better milk conversion during the 1st and 4th week as compared to naturally mated groups. Compared with the control group, the economic efficiency and performance index of NZW rabbits was significantly improved by 5 g glucose supplementation under tropic condition.  相似文献   

12.
Juha Tuomi 《Oecologia》1980,45(1):39-44
Summary A generalized relationship of litter size to mammalian body size was predicted by a graph model. The model was used to generate hypotheses explaining specific features of variation in gestation time, relative litter weight, birth weight, and reproductive capacity. The predictions were tested by means of data from the literature.Mammals were assumed to maximize neonatal survival of offspring to the limits allowed by litter weight per female body weight. Gestation time correlated negatively with the foetal growth rate of relative litter weight. Gestation time did not correlate with the foetal growth rate of individual offspring.Relative litter weight correlated negatively with adult body weight. This relationship was explained by the higher assimilation rate per unit weight relative to metabolic rate in small mammals.Birth weight correlated positively with body weight. However, small mammals produce larger offspring than predicted by the linear relationship of birth weight to body weight in large mammals. There is obviously a minimum birth weight which cannot be decreased without special arrangements for parental care.The prediction of the relationship of litter size to body size was derived from the relations of relative litter weight and birth weight to body weight. In small mammals (less than 1 kg) litter the correlation was negative. When litter size was compared with body length, the correlation was positive in small mammals (less than 30 cm) and negative in large mammals. In both sets of data there was a negative overall correlation between litter size and body size.Reproductive capacity, defined as the number of offspring per season, correlated negatively with life-span.  相似文献   

13.
Summary A short-term selection experiment for increasing the first-day litter size (LS1) and 28-day litter weight (LW28) was conducted with three populations of mice over 8 generations. Different methods of litter size manipulation were used for the populations — in S the litter size was standardized to 8 (4 , 4 ) on the first day, in LA it was adjusted to the average size of all litters born on the same day and NL had the natural litter size. To eliminate temporary environmental effects, a control population was kept in each case. The selection results per generation were, for LS 1 b=0.30 (S, NL) and 0.20 (LA), and for LW28 b=5.62 g (S), 5.26 g (NL), and 4.32 g (LA). The heritability obtained was between 0.18 and 0.13 for LS 1 and from 0.42 to 0.12 for LW28. The populations differed in the correlated responses for body weight parameters (litter weight gain). The implantation rate increased in populations S and NL (b=0.19, 0.37), but not in population LA. Postnatal mortality went down (b=-0.07) and the dam's milk production rose (b=1.11 g) only in population LA. The estimated partial regression coefficient linking body weight at mating (BWM) for the dam and the daughter's litter size showed an effect on the litter size.  相似文献   

14.
撒坝猪血清酯酶多态性与繁殖性能关系的研究   总被引:5,自引:2,他引:3  
采用垂直板聚丙烯酰胺凝胶电泳法(PAGE), 对115头撒坝猪的血清酯酶(ES)多态性进行了检测,计算了该位点的基因型频率、基因频率和位点多态杂合度(h),并用二因素有互作的最小二乘模型对血清酯酶多态性与繁殖性能的关系进行了分析。结果表明,撒坝猪血清酯酶3种基因型AA、AB和BB的频率分别为0.2696、0.5826和0.1478。两个等位基因A和B的基因频率分别为0.5609和0.4391。该位点的杂合度为0.4926。在3种基因型中,不同基因型母猪的繁殖性能在产仔数、仔猪初生窝重、20日龄窝重、断奶仔猪数和断奶窝重等性状上存在着显著差异(P<0.05);公、母猪不同基因型交配组合在产仔数、断奶仔猪数、仔猪断奶体重和断奶窝重等性状上亦有显著差异(P<0.05)。显示出猪的血清酯酶多态性可望作为繁殖性能选种的遗传标记。 Abstract: Serum esterase polymorphisms of 115 Saba pigs were investigated by using the method of vertical polyacrylamide gel electrophoresis. The genotype frequency, gene frequency and heterozygosity of this locus were calculated. The relationship between the serum esterase polymorphism and reproductive performance was analyzed by the least square analysis of two factors (ES genotype of boar and sow) with interaction. The results demonstrated that the genotype frequency of AA, ABandBBwas 0.2696, 0.5826 and 0.1478 respectively, the gene frequency of the alleleAandBwas 0.5609 and 0.4391 respectively. The heterozygosity of this locus was 0.4926. There are significant differences (P<0.05) on litter size, litter weight at birth, litter weight at 20 days, litter size at weaning and litter weight at weaning of different genotypic sows. The significant differences (P<0.05) were showed on litter size, litter size at weaning, weaning weight and litter weight at weaning of different genotypic mating combinations. It indicated that the serum esterase polymorphism was expected to be the genetic marker of pig reproductive performance.  相似文献   

15.
蝘蜓头、体大小的两性异形和雌体繁殖   总被引:30,自引:4,他引:26  
计翔  杜卫国 《动物学研究》2000,21(5):349-354
报道了蜓 (Sphenomorphusindicus)头、体大小的两性异形和雌性繁殖。性成熟雌体大于雄体。雄性成体头长大于雌性成体 ,但头宽与雌性成体无显著差异。初生幼仔的头长和头宽无两性差异。雄性幼体头长和头宽大于雌性幼体。设置SVL恒定时 ,雄性幼体和雄性成体的头长和头宽无显著差异 ,雌性幼体的头长和头宽大于雌性成体。初生幼仔具有相对较大的头部。产仔雌体的最小SVL为 6 7 7mm ,大于此SVL的雌体均年产单窝仔。平均窝仔数、窝仔重和幼仔重分别为 7 2 ( 3~ 11)、 3 34( 1 30~ 5 19)和 0 48( 0 36~ 0 5 8)g。用卵黄沉积卵巢卵和输卵管计数的窝仔数比用幼仔计数的窝仔数多约 1 0个后代。幼仔体重与雌体SVL无关。相对窝仔重与雌体SVL边缘性地呈正相关。窝仔数、窝仔重与雌体SVL呈正相关 ,幼仔体重与窝仔数呈负相关。窝仔数与雌体状态无关。  相似文献   

16.
Summary The influence of purebred selection on the combining abilities of five lines of mice was examined. Two replicated testcross diallels were made after 10 and 20 generations of purebred selection for litter size, weaning weight, weight gain, and feed efficiency. Average direct genetic effects were of major importance, followed by average maternal genetic effects. In all of the replications, between two and four out of ten crosses showed significant heterosis. Heterosis ranged from 0 to 38% in litter size, from 0 to 20% in weaning weight, from -11 to 11% in weight gain, and from -8 to 17% in feed efficiency. For litter size and weaning weight, heterosis estimates increased between 80 and 100% from generation 10 to 20. Weight gain and feed efficiency showed decreasing heterosis with partly negative estimates in the second diallel. Combinations exhibiting significant heterosis varied between replicates and between the two diallels.  相似文献   

17.
Within-litter variation of piglet birth weight (BW0) is associated with an increased piglet mortality and a high variability in pig weight at weaning and weight or age at slaughter. Data collected in two experimental herds were used to quantify within-litter variability in BW0 and to assess the influence of factors mainly related to the sow. Within 24 h after birth, piglets born alive were individually weighed and stillborn piglets were collectively (first data set) or individually (second data set) weighed. The first data set was restricted to litters with no or only one stillborn piglet (3338 litters). It was used to assess the influence of genetic selection on BW0 variation by comparing litter characteristics before (1994 to 1996) and after (2001 to 2004) the development of hyperprolific sows in this herd. The second data set included all litters (n = 1596) from sows born between 2000 and 2004. For each litter, mean BW0 (mBW0) and its coefficient of variation (CVBW0) were calculated. Then, variance analyses were performed to test the influence of litter size, parity, year of sow birth and season at conception. Prolificacy improvement was associated with an increased CVBW0 in litters from pure Large White (LW) and Landrace × Large White (LR × LW) crossbred sows. The CVBW0 averaged 21% and was significantly influenced by litter size and parity. It increased from 15% to 24% when litter size varied from less than 10 piglets to more than 15 piglets. The proportion of small piglets (i.e. weighing less than 1 kg) increased concomitantly. The CVBW0 was not repeatable from a parity to the following. It was lowest for first and second parities (20%) and thereafter increased progressively. The CVBW0 was positively related to sow's backfat thickness gain during gestation. Taking into account litter size, parity, year of sow birth and season at conception explained 20% of BW0 variation. Thus, major part of heterogeneity is due to other factors, presumably including embryo genotype, on the one hand, and factors that influence embryo and foetus development, such as epigenetic factors, on the other hand.  相似文献   

18.
The relationship between various semen evaluation tests and fertility in fertile and subfertile artificial insemination (AI) boars was examined. In total, 36 boars, 19 Finnish Landrace and 17 Yorkshire, were included. The average value of three ejaculates extended in an X-cell extender from each boar was used in the analysis. Based on nonreturn results (NR60d, later referred to nonreturn rate, NR%), the boars were divided into two groups: those with poor fertility (NR% < 80, n = 19) and those with normal or above average nonreturn rates (NR% = 83, n = 17). Semen quality was determined after 1 and 7 days of storage at 17 degrees C. Sperm motility before and after each methanol stress was assessed both subjectively and using a computer-assisted semen analyzer (CASA). The sperm cells were stained with calcein AM and propidium iodide and evaluated for plasma membrane integrity under an epifluorescence microscope. Propidium iodide and Hoechst 33258 dyes were used in parallel to stain sperm cells for fluorometric analysis with an automatic fluorometer. Sperm morphology was evaluated in stained smears. The percentage of sows reported as not having returned to estrus within 60 days after AI (nonreturn rate, NR%) and litter size of primiparous and multiparous farrowings were used as measures of fertility. Of the parameters analyzed, only CASA-assessed total sperm motility and methanol-stressed total sperm motility correlated significantly (P < 0.05) with nonreturn rate. Those tests presenting the highest correlation with nonreturn rate were CASA-assessed total motility (r = 0.54, P < 0.01) and subjective sperm motility (r = 0.52, P < 0.01) after 7 days of storage. The highest correlation with fertility at 1 day of storage was shown by methanol-stressed total sperm motility assessed with the CASA (r = 0.46, P < 0.01). The only semen parameter that correlated significantly (r = 0.37, P < 0.05) with litter size of multiparous farrowings was viability of seven-day stored semen stained with Hoechst 33258 and analyzed with a fluorometer. The methanol stress test described here could serve as a rapid test whose results could be used to predict NR% better than motility.  相似文献   

19.
The relationships between placental characteristics and litter weight, factors affecting these characteristics, and the relationship between these characteristics and neonatal behaviour of goat kids were investigated in this study. The study was carried out over three consecutive years and animal material consisted of total 152 Turkish Saanen goats and their 230 kids. The results of the study demonstrated that there were positive correlations between litter weight (LW), cotyledon number (CN), placental weight (PW) (r=0.64 and 0.76, P<0.01), but there was negative correlation between LW and cotyledon density (CD) (r=-0.42, P<0.01). CD was negatively correlated with PW (r=-0.61, P<0.01). CN and PW were influenced by the parity of doe, birth type-sex combination, buck within years and year of the study. On the other hand, parity and birth type-sex combination had no effect on PE (P>0.05), but buck within year affected placental efficiency (P<0.01). CD was only influenced by the parity of doe (P<0.01). Duration of birth (D) was not significantly related with CD, but if CD declined, it prolonged (r=-0.23, P>0.05). There were strong relationships between CD and birth-to-standing (B-St), and CD and birth-to-suckling (B-Su) (r=-0.42 and -0.51, P=0.01 and P<0.01).The results of the present study have shown similarities to the findings of the studies in sheep. Further studies are required to investigate the basis of the relationship between CD and neonatal behaviour.  相似文献   

20.
Correlated responses to selection for postweaning gain in mice were studied to determine the influence of population size and selection intensity. Correlated traits measured were three-, six- and eight-week body weights, litter size, twelve-day litter weight, proportion infertile matings and two indexes of reproductive performance. In general, the results agreed with observations made on direct response: correlated responses in the body weight traits and litter size increased as (1) selection intensity increased and (2) effective population size increased. Correlated responses in the body weight traits and litter size were positive in the large population size lines (16 pairs), as expected from the positive genetic correlation between these traits and postweaning gain. However, several negative correlated responses were observed at small population sizes (one and two pairs). Within each level of selection intensity, traits generally associated with fitness tended to decline most in the very small populations (one and two pairs) and in the large populations (16 pairs) for apparently different reasons. The fitness decline at the small effective population sizes was attributable to inbreeding depression. In contrast, it was postulated that the fitness decline at the large effective population size was due to selection moving the population mean for body weight and a trait positively correlated genetically with body weight (i.e., percent body fat) away from an optimum.  相似文献   

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