混杂试验的多元分析

本文首次提出混杂试验的多元统计分析方法,并以香茅肥料试验为实例,论述平方和与乘积和矩阵的分解及总自由度的裂分方法,各种WilksA统计量的构造及其显著性测验法．最后给出了笔者编制的SAS统计分析程序．     

Effects of training for two ball games on the saliva response of adrenocortical hormones to exercise in elite sportswomen

In a group of 20 elite female handball or volleyball players, an evaluation was made of the response to a 4-month training period of cortisol, androstenedione and dehydroepiandrosterone in the saliva. At the beginning of the training programme (W₁) and at the 7th (W₇) and 16th weeks (W₁₆), hormone concentrations were measured on awakening (8 a.m.; resting samples), and also before (t ₀) and at the end (t ₁₂₀) of a 2-h exercise session (simulated match) which took place at 6 p.m. The training programme increased the concentrations of adrenal androgens in the saliva at rest (P<0.05) for both groups of subjects, with no change being noted in cortisol concentrations. In contrast, amongst the volleyball players, stressful stimuli produced by an increase in the amount of training did not affect adrenocortical metabolism during exercise. Indeed, a simulated volleyball match resulted in a decrease in salivary cortisol (P<0.05) and androgen concentrations (P<0.05) without regard for the week chosen for the test investigations. In contrast, a simulated handball match caused an increase in cortisol concentrations at W₁ only (P<0.05), with no change in the adrenal androgens concentration in any week of the training programme. The regulators of these hormones during a period of exercise and during the course of a training programme would seem to be different. Accepted: 30 October 1997     

Natural selection of Varroa jacobsoni explains the different reproductive strategies in colonies of Apis cerana and Apis mellifera

In colonies of European Apis mellifera, Varroa jacobsoni reproduces both in drone and in worker cells. In colonies of its original Asian host, Apis cerana, the mites invade both drone and worker brood cells, but reproduce only in drone cells. Absence of reproduction in worker cells is probably crucial for the tolerance of A. cerana towards V. jacobsoni because it implies that the mite population can only grow during periods in which drones are reared. To test if non-reproduction of V. jacobsoni in worker brood cells of A. cerana is due to a trait of the mites or of the honey-bee species, mites from bees in A. mellifera colonies were artificially introduced into A. cerana worker brood cells and vice versa. Approximately 80% of the mites from A. mellifera colonies reproduced in naturally infested worker cells as well as when introduced into worker cells of A. mellifera and A. cerana. Conversely, only 10% of the mites from A. cerana colonies reproduced, both in naturally infested worker cells of A. cerana and when introduced into worker cells of A. mellifera. Hence, absence of reproduction in worker cells is due to a trait of the mites. Additional experiments showed that A. cerana bees removed 84% of the worker brood that was artificially infested with mites from A. mellifera colonies. Brood removal started 2 days after artificial infestation, which suggests that the bees responded to behaviour of the mites. Since removal behaviour of the bees will have a large impact on fitness of the mites, it probably plays an important role in selection for differential reproductive strategies. Our findings have large implications for selection programmes to breed less-susceptible bee strains. If differences in non-reproduction are mite specific, we should not only look for non-reproduction as such, but for colonies in which non-reproduction in worker cells is selected. Hence, in selection programmes fitness of mites that reproduce in both drone and worker cells should be compared to fitness of mites that reproduce only in drone cells. © Rapid Science Ltd. 1998     

High genetic diversity and no inbreeding in the endangered copper redhorse, Moxostoma hubbsi (Catostomidae, Pisces): the positive sides of a long generation time

The evolutionary potential of a species is determined by its genetic diversity. Thus, management plans should integrate genetic concerns into active conservation efforts. The copper redhorse (Moxostoma hubbsi) is an endangered species, with an endemic distribution limited to the Richelieu River and a short section of the St Lawrence River in Quebec, Canada. The population, gradually fragmented since 1849, is characterized by a decline in population size and a lack of recruitment. A total of 269 samples were collected between 1984 and 2004 and genotyped using 22 microsatellite loci, which indicated that these fish comprise a single population, with a global F(ST) value of only 0.0038. Despite a small census size ( approximately 500), a high degree of genetic diversity was observed compared to common values for freshwater fishes (average number of 12.5 alleles/locus and average HO of 0.77 +/- 0.08). No difference was observed between expected and observed pairwise values of relatedness (r(xy): -0.00013 +/- 0.11737), suggesting an outbred population. Long-term Ne was estimated at 4476 whereas contemporary Ne values ranged from 107 to 568, suggesting a pronounced yet gradual demographic decline of the population, as no bottleneck could be detected for the recent past. By means of simulations, we estimated Ne would need to remain at more than approximately 400 to retain 90% of the genetic diversity over 100 years. Overall, these observations corroborate other recent empirical studies confirming that long generation times may act as a buffering effect contributing to a reduction in the pace of genetic diversity erosion in threatened species.     

Isolation of the abdomen releases oviposition behaviour in females of the cricket, Acheta domesticus

Upon isolation, abdomens of adult female house crickets (Acheta domesticus) produced abdominal and ovipositor movements characteristic of normal oviposition. Oviposition behaviour was thus released even in reproductively mature or immature virgins where under normal conditions it was never observed. Decapitation was not sufficient to release oviposition behaviour but transection of the ventral nerve cord between the thorax and the abdomen of immobilized females evoked the response. These observations indicate that the motor programmes for certain components of the oviposition sequence reside in the abdominal ganglia. Moreover, the prerequisite circuitry for ovipositional posturing of the abdomen and ovipositor appears to be functional prior to sexual maturity and insemination, primed by mating, and subject to inhibition by the thoracic ganglia.     

The Death Programme in Cultured Sympathetic Neurones Can Be Suppressed at the Posttranslational Level by Nerve Growth Factor, Cyclic AMP, and Depolarization

We have examined whether sympathetic neurones that have lost the potential to be rescued by protein and RNA synthesis inhibitors after a period of nerve growth factor (NGF) deprivation are irreversibly committed to die. We found that 15 h after withdrawal of NGF from 7-day cultures of neonatal rat superior cervical ganglion neurones, 50% of the neurones lost the potential to be rescued by cycloheximide but that NGF rescued most of the neurones. By 22 h after NGF withdrawal, only 10% of the neurones were rescued by inhibition of macromolecular synthesis with cycloheximide, puromycin, or actinomycin D, but as many as 60-80% of the neurones were rescued by NGF. This is after the time at which a DNA "ladder," consistent with cell death by apoptosis, was first detected (18 h). As long as 27 h of NGF withdrawal was required before 50% of the neurones lost the potential to be rescued by NGF. The survival-promoting agent 8-(4-chlorophenylthio)cyclic AMP (CPTcAMP) or depolarization with 50 mM KCl (HK) rescued neurones with kinetics similar to those of NGF, and rescue by all three agents did not require protein synthesis. Thus, NGF, CPTcAMP, and HK can rescue neurones deprived of NGF at much later times than either protein or RNA synthesis inhibitors by acting at the posttranslational level, a finding suggesting that initiation of the cell death programme in sympathetic neurones is not an irreversible step.     

乙型肝炎疫苗与卡介苗、百白破、脊髓灰质炎疫苗联合免疫的免疫应答观察

本文报道在对婴幼儿实施基础免疹(BCC、DPT和TOPV)的同时,接种国产血源乙肝疫苗的免疫应答。对八月龄的婴儿血清学检测结果表明:乙肝疫苗接种组1(10μg)、2(20μg)抗-HBs达到临界保护(P/N≥10.0)的分别为80.65％,78.49％,未检出HBV感染标志物;未接种乙肝疫苗组的HBV感染率边10.5％。血清学检测还表明乙肝疫苗与BCG、DPT和TOPV等生物制品联合免疫应答是好的,各抗原间无干扰作用,提示乙肝疫苗可列入扩大免疫规划,并将有效地控制乙肝病毒感染。     

How normal is abnormal? Discrimination between deformations and natural variation in gonad morphology of European whitefish Coregonus lavaretus

The gonad morphology of whitefish Coregonus lavaretus collected in Lake Thun, Switzerland, and two neighbouring lakes was assessed in order to differentiate between 'normal' and 'abnormal' character states of gonad morphology, which had been previously described in C. lavaretus from Lake Thun (constrictions, asymmetries, aplasia, compartmentations, fusions and hermaphroditism). In total, 4668 fish were collected and analysed using two complementary sampling schemes: (1) monthly samples of catches by the commercial fishermen and (2) samples of ripe spawners of all known 33 spawning sites of the three lakes. Considerable variation in gonad morphology in C. lavaretus populations of all lakes was found. Notably, all deviation types were observed in fish of all three lakes. Asymmetries and constrictions were frequent in all three lakes and showed systematic differences in frequency between the two sampling strategies. This indicates that asymmetries and constrictions represent to a large extent natural variation in gonad morphology of C. lavaretus and are also prone to considerable measurement error. In contrast, aplasia, fusions, compartmentations and hermaphroditism occurred predominantly in one C. lavaretus form of Lake Thun and in particular in populations spawning at great depths. This suggests that these deviation types are probably reliable indicators for gonad deformations and supports the interpretation that Lake Thun harbours a unique case of deformed gonads in C. lavaretus of yet unknown origin.