光照和氮磷供应比对木荷生长及化学计量特征的影响

光照和养分限制是影响林下植物生长和更新的关键影响因素,以亚热带主要常绿树种木荷（Schima superba）实生幼苗为试验对象,研究了不同光照（全光照、遮阴即45%全光照）和N、P供应比例（5,15,45）对幼苗生长和化学计量特征的影响。结果表明：（1）遮阴不仅严重抑制了木荷各器官和单株生物量积累,更加剧了P限制。尽管N、P添加对木荷生长没有显著促进作用,但N、P供应比例为5时的性状组合更有利于木荷后期生长,但高N、P供应比例可能导致P限制。（2）遮阴下叶N、P含量显著增加,但叶C/N和C/P比显著降低;不同光照处理组中各器官及总N含量均随N、P供应比例增大而显著增加,而C/N比逐渐降低;P的分配格局发生改变,全光照组各器官P含量为茎 > 叶 > 根,遮阴组各器官P含量为根 > 茎 > 叶。（3）随N、P供应比例增加或光照强度降低,木荷均趋向降低根冠比和根质比、增加叶质比或茎质比。（4）木荷生物量与各器官N、P含量、叶质比呈极显著负相关,而与C/N和C/P比及根冠比、茎质比、根质比呈极显著正相关。光强和N、P比例变化均显著影响了木荷幼苗的养分利用特征,因而木荷作为伴生树种优化林分环境对其早期生长具有重要意义。     

Towards a genetic theory for the evolution of the sex ratio II. Haplodiploid and diploid models with sibling and parental control of the brood sex ratio and brood size

Population genetic models involving sister, brother, and father control of the brood sex ratio and brood size in both the haplodiploid and diploid cases are constructed and analyzed. The results are interpreted in light of the verbal theories which predict the evolution of the sex ratio to a value which is proportional to the ratio of relatedness of the controlling members of the family to males and to females produced in the brood. In our models, the sex ratio in a certain class of polymorphic equilibria evolves to equal investment in males and females in those cases where the controlling members of the family are symmetrically related to males and females as predicted by the verbal theory. However, the sex ratio in the case of sister control in haploidiploids does not evolve to 1:3, but rather to a value proportional to the ratio of the regression coefficients of additive genotypes. Even so, the predicted sex ratio, which is proportional to 1:3, is in fact an “ESS” in the sense that fixation of a genotype specifying that sex ratio is resistant to the initial increase of all other genotypes.     

Birth sex ratio and social rank: consistency and variability within and between primate groups

Variations in birth sex ratios in primates are notoriously inconsistentand have been repeatedly suggested to be mainly owing to stochasticprocesses. An examination of temporal consistency within primatepopulations revealed that the effect of dominance rank on birthsex ratio tends to remains stable over time. Furthermore, ameta-analysis of published data on sex ratio variations in primatesshows that although no overall effect was detectable, the relationbetween birth sex ratio and dominance rank was affected by levelof resource availability and degree of sexual dimorphism. Theseresults suggest that purely stochastic processes are unlikelyto explain observed variations in primate birth sex ratios,and may explain why adaptive sex ratio variations in primateshave been so difficult to demonstrate.     

Influence of wastewater composition on nitrogen and phosphorus removal and process control in A2O process

A bench-scale anaerobic–anoxic–oxic (A²O) bioreactor with steady denitrifying phosphorus removal performance was tested to determine the influence of influent C/N ratio (SCOD/TN) and C/P ratio (SCOD/TP) on biological nutrient removal for treating synthetic brewage wastewater; meanwhile, the spatial profiles of DO, pH and ORP sensors in such systems were investigated. The results showed that influent C/N ratio had significant effect on the TN, TP removal efficiencies and the ratio of anoxic to aerobic P uptake amount. The maximal TN and TP removal efficiencies could be achieved when influent C/N ratio was kept at about 7.1 and 5, respectively. Besides, the ratio of anoxic to aerobic P uptake amount was found to be linearly dependent on the influent C/N ratio with coefficient R ² of 0.685 when total recirculation ratio was constant at 3.5. Influent C/P ratio had an important effect on the TP removal efficiency, while it hardly affected TN removal efficiency. In addition, the TP removal efficiency reached the maximum for influent C/P ratio of 42. On the other hand, it was also found that the typical profiles of DO, pH and ORP sensors could be observed, and they have similar trends at the different influent C/N ratio and C/P ratio. It was suggested that the operational state could be well known according to the changes of simple on-line sensors.     

花椰菜主要经济性状的配合力及遗传效应研究

采用Griffing 6×6完全双列杂交设计,对长江流域内秋冬栽培的6个主要花椰菜（Brassica oleraceaLinn.var.botrytis Linn.）资源的自交系育种材料的球高、球径、单球重、成熟期、毛花率和内叶盖球度等6个花球主要经济性状进行一般配合力（GCA）和特殊配合力（SCA）分析,并对花椰菜的各个性状进行了遗传相关性分析。结果表明：花椰菜的6个经济性状同时受加性和非加性效应控制。其中成熟期、毛花率、球高和内叶盖球度性状的一般配合力大于特殊配合力,受加性基因效应影响大;而球径、单球重等性状间一般配合力小于特殊配合力,在相当程度上受非加性基因控制。花椰菜各性状的狭义遗传力由大到小依次为：成熟期、毛花率、内叶盖球度、球高、球径和单球重。花椰菜的球高与单球重、球径与单球重、球高与成熟期、单球重与内叶盖球度、成熟期与内叶盖球度等5个成对性状应该同时选择;而球高与毛花率、球高与内叶盖球度、球径与成熟期、球径与毛花率、单球重与毛花率、成熟期与毛花率、毛花率与内叶盖球度等7个成对性状的选择可以独立进行,彼此间不会相互影响,可实现同一组合或品种具备多种优质性状。在6个自交系中,P2和P5是理想亲本;P4是配制耐寒组合的亲本材料;亲本P6应用价值最低。组合中表现最好的为P2×P4,各性状的特殊配合力均较优。     

Adult sex-ratio in ostracods and its implications for sexual selection

ABSTRACT

The Ostracoda – ubiquitous aquatic micro-crustaceans – show an exceptionally high incidence of female-biased adult sex ratio. Intraspecific sex ratio is known to vary in extant species and yet in the fossil record a species’ adult sex ratio can be highly stable across time. Sex ratio conditions the intensity of sexual selection and influences which sex undergoes stronger selective pressure. However, the impact of variation in spatial and temporal intraspecific sex ratio on the evolution of sexual selection remains an open question, calling for further investigations on the factors controlling adaptive sex ratio. This mini-review aims to introduce the system, and explores some of the key literature addressing factors influencing intraspecific variation in adult sex ratio (ASR) and its implication in the intensity of sexual selection and evolution of mating systems.     

Applicability and limitations of optimal biomass allocation models: a test of two species from fertile and infertile habitats

BACKGROUND AND AIMS: The practical applicability of optimal biomass allocation models is not clear. Plants may have constraints in the plasticity of their root : leaf ratio that prevent them from regulating their root : leaf ratio in the optimal manner predicted by the models. The aim of this study was to examine the applicability and limitations of optimal biomass allocation models and to test the assumption that regulation of the root : leaf ratio enables maximization of the relative growth rate (RGR). METHODS: Polygonum cuspidatum from an infertile habitat and Chenopodium album from a fertile habitat were grown under a range of nitrogen availabilities. The biomass allocation, leaf nitrogen concentration (LNC), RGR, net assimilation rate (NAR), and leaf area ratio (LAR) of each species were compared with optimal values determined using an optimal biomass allocation model. KEY RESULTS: The root : leaf ratio of C. album was smaller than the optimal ratio in the low-nitrogen treatment, while it was almost optimal in the high-nitrogen treatment. In contrast, the root : leaf ratio of P. cuspidatum was close to the optimum under both high- and low-nitrogen conditions. Owing to the optimal regulation of the root : leaf ratio, C. album in the high-nitrogen treatment and P. cuspidatum in both treatments had LNC and RGR (with its two components, NAR and LAR) close to their optima. However, in the low-nitrogen treatment, the suboptimal root : leaf ratio of C. album led to a smaller LNC than the optimum, which in turn resulted in a smaller NAR than the optimum and RGR than the theoretical maximum RGR. CONCLUSIONS: The applicability of optimal biomass allocation models is fairly high, although constraints in the plasticity of biomass allocation could prevent optimal regulation of the root : leaf ratio in some species. The assumption that regulation of the root : leaf ratio enables maximization of RGR was supported.     

Relationship between protein composition and coagulation reactivity, particulate formation, and incorporation of lipids in soymilk

Many studies have suggested that the 11S/7S ratio in soybeans affects the coagulation reaction at the first step. In this study, the 11S/7S ratio in soybeans showed significantly negative correlation with MgCl(2) concentrations for the maximum breaking stress of tofu for six Japanese varieties. To determine the effect of the 11S/7S ratio, soymilk was fractionated by centrifugation after the addition of MgCl(2), and the distribution of lipids and proteins was studied. The amount of precipitate increased as the MgCl(2) concentration or the 11S/7S ratio increased. More triglyceride was incorporated into the precipitate as the MgCl(2) concentration or the 11S/7S ratio increased. The stain intensity of bands after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) indicated that the ratio of oleosin, a membrane protein of the oil body, increased in the precipitate as the MgCl(2) concentration or the 11S/7S ratio increased, while the ratios of glycinin and beta-conglycinin were less variable. These results indicate that the 11S/7S ratio and coagulant concentration may have an effect on the amount of coagulum and the concentration of oil globules in the coagulum at the beginning of coagulation.     

Portein kinases in brown adipose tissue of developing rats. State of activation of protein kinase during development and cold exposure and its relationship to adenosine 3':5'-monophosphate, lipolysis, and heat production.

The addition of norepinephrine to brown fat in vitro produced a dose-dependent increase in the protein kinase activity ratio (the ratio of activity assayed without cAMP to that assayed with cAMP) in extracts subsequently prepared in the presence of 0.5 M NaCl. The ratio was slightly increased by insulin. The effects of norepinephrine were potentiated by theophylline and reduced by propranolol. There was a significant linear regression between protein kinase activity ratio and the rate of glycerol release for ratios between 0.32 and 0.52. Higher activity ratios were associated with a slight but nonsignificant increase in glycerol release. The relationship between the protein kinase activity ratio and the concentration of cAMP in brown fat could be expressed by simple saturation kinetics. There was a significant linear regression between the reciprocal of the concentration of cAMP in the tissue and the reciprocal of the activity ratio over the whole range of observed values. Exposure of 1-month-old rats to cold increased the protein kinase activity ratio in their brown fat. This confirms that activation of protein kinase is involved in the physiological response of a tissue to a specific environmental stimulus. As the rat became fully adapted to the cold, the activity ratio declined. The protein kinase activity ratio in brown fat was low in late fetuses but greatly increased immediately after birth and remained high for the next 2 weeks. During this period the ratio was not further increased by the injection of norepinephrine but was reduced after chemical sympathectomy. The activity ratio in brown fat fell during the 3rd and 4th weeks after birth. At this time injection of norepinephrine increased the ratio whereas chemical sympathectomy had little effect. These observations confirm that the stimulation of the tissue by the sympathetic nerves results in an activation of protein kinase and reflect the reduced requirement for heat production in brown fat as the animals grow.     

Second-to-Fourth Digit Ratio and Impulsivity: A Comparison between Offenders and Nonoffenders

Personality characteristics, particularly impulsive tendencies, have long been conceived as the primary culprit in delinquent behavior. One crucial question to emerge from this line of work is whether impulsivity has a biological basis. To test this possibility, 44 male offenders and 46 nonoffenders completed the Eysenck Impulsivity Questionnaire, and had their 2D∶4D ratio measured. Offenders exhibited smaller right hand digit ratio measurements compared to non-offenders, but higher impulsivity scores. Both impulsivity and 2D∶4D ratio measurements significantly predicted criminality (offenders vs. nonoffenders). Controlling for education level, the 2D∶4D ratio measurements had remained a significant predictor of criminality, while impulsivity scores no longer predicted criminality significantly. Our data, thus, indicates that impulsivity but not 2D∶4D ratio measurements relate to educational attainment. As offenders varied in their number of previous convictions and the nature of their individual crimes, we also tested for differences in 2D∶4D ratio and impulsivity among offenders. Number of previous convictions did not correlate significantly with the 2D∶4D ratio measurements or impulsivity scores. Our study established a link between a biological marker and impulsivity among offenders (and lack thereof among non-offenders), which emphasise the importance of studying the relationship between biological markers, impulsivity and criminal behavior.     

Rare male advantage and sex ratio

Relative success of mutant white and wild-type CS Drosophila melanogaster males is frequency-dependent, if sex ratio is 1:1. If the number of females is constant, this success depends on the ratio between the mutant and wild-type males. The sex ratio changes strongly affect the male mating activity of both genotypes.Emphasis is placed on the general interest of the Ayala equation and the Wattiaux-Lichtenberger equation in frequency-dependence and sex ratio dependence analysis.     

关节置换前后髌骨高度对膝关节功能的影响

目的:研究全膝关节置换术前、术后Insall-Salvati指数和改良Insall-Salvati指数与术后膝关节活动度的关系。方法:采用HSS评分系统对患者全膝关节置换术后半年至一年的关节功能、活动度、肌力、屈曲畸形、稳定性等进行评价。测量81例(106膝)患者术前、术后X线片Insall-salvati指数及改良Insall-salvati指数。结果:术后HSS评分为(89±10)分,术前Insall-salvati指数及改良Insall-salvati指数分别为(1.00±0.13)、(1.61±0.21),术后Insall-salvati指数及改良Insall-salvati指数分别为(0.94±0.19)、(1.67±0.34)。关节置换术后Insall-salvati指数较置换前显著降低(P0.05),改良Insall-salvati指数显著提高(P0.05)。术后低位髌骨组(Insall-salvati指数0.8)HSS评分、活动度和屈曲畸形分值均较正常髌骨组(0.8Insall-salvati指数1.5)显著降低(P0.05)(P0.05)。高位髌骨组(Insall-salvati指数1.5)和正常髌骨组各项评分均无显著差异(P0.05)。术前改良Insall-salvati指数小于1.8的患者术后膝关节HSS评分、功能、活动度、肌力、屈曲畸形、稳定性显著高于大于1.8的患者(P0.05)。结论:术前改良Insall-salvati指数和术后Insall-salvati指数可作为评价术后膝关节功能的参考指标。术前、术后的膝关节高度均会影响术后关节功能,全膝关节置换术中精确截骨对术后关节功能十分重要。     

Fibonacci,quasicrystals and the beauty of flowers

The appearance of Fibonacci sequences and the golden ratio in plant structures is one of the great outstanding puzzles of biology. Here I suggest that quasicrystals, which naturally pack in the golden ratio, may be ubiquitous in biological systems and introduce the golden ratio into plant phyllotaxy. The appearance of golden ratio-based structures as beautiful indicates that the golden ratio may play a role in the development of consciousness and lead to the aesthetic natural selection of flowering plants.     

Parental care and adaptive brood sex ratio manipulation in birds

Under many circumstances, it might be adaptive for parents to bias the investment in offspring in relation to sex. Recently developed molecular techniques that allow sex determination of newly hatched offspring have caused a surge in studies of avian sex allocation. Whether females bias the primary brood sex ratio in relation to factors such as environmental and parental quality is debated. Progress is hampered because the mechanisms for primary sex ratio manipulation are unknown. Moreover, publication bias against non-significant results may distort our view of adaptive sex ratio manipulation. Despite this, there is recent experimental evidence for adaptive brood sex ratio manipulation in birds. Parental care is a particularly likely candidate to affect the brood sex ratio because it can have strong direct effects on the fitness of both parents and their offspring. We investigate and make predictions of factors that can be important for adaptive brood sex ratio manipulation under different patterns of parental care. We encourage correlational studies based on sufficiently large datasets to ensure high statistical power, studies identifying and experimentally altering factors with sex-differential fitness effects that may cause brood sex ratio skew, and studies that experimentally manipulate brood sex ratio and investigate fitness effects.     

Sex-specific sibling interactions and offspring fitness in vertebrates: patterns and implications for maternal sex ratios

Vertebrate sex ratios are notorious for their lack of fit to theoretical models, both with respect to the direction and the magnitude of the sex ratio adjustment. The reasons for this are likely to be linked to simplifying assumptions regarding vertebrate life histories. More specifically, if the sex ratio adjustment itself influences offspring fitness, due to sex-specific interactions among offspring, this could affect optimal sex ratios. A review of the literature suggests that sex-specific sibling interactions in vertebrates result from three major causes: (i) sex asymmetries in competitive ability, for example due to sexual dimorphism, (ii) sex-specific cooperation or helping, and (iii) sex asymmetries in non-competitive interactions, for example steroid leakage between fetuses. Incorporating sex-specific sibling interactions into a sex ratio model shows that they will affect maternal sex ratio strategies and, under some conditions, can repress other selection pressures for sex ratio adjustment. Furthermore, sex-specific interactions could also explain patterns of within-brood sex ratio (e.g. in relation to laying order). Failure to take sex-specific sibling interactions into account could partly explain the lack of sex ratio adjustment in accordance with theoretical expectations in vertebrates, and differences among taxa in sex-specific sibling interactions generate predictions for comparative and experimental studies.     

Relationship between Protein Composition and Coagulation Reactivity,Particulate Formation,and Incorporation of Lipids in Soymilk

Many studies have suggested that the 11S/7S ratio in soybeans affects the coagulation reaction at the first step. In this study, the 11S/7S ratio in soybeans showed significantly negative correlation with MgCl₂ concentrations for the maximum breaking stress of tofu for six Japanese varieties. To determine the effect of the 11S/7S ratio, soymilk was fractionated by centrifugation after the addition of MgCl₂, and the distribution of lipids and proteins was studied. The amount of precipitate increased as the MgCl₂ concentration or the 11S/7S ratio increased. More triglyceride was incorporated into the precipitate as the MgCl₂ concentration or the 11S/7S ratio increased. The stain intensity of bands after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS–PAGE) indicated that the ratio of oleosin, a membrane protein of the oil body, increased in the precipitate as the MgCl₂ concentration or the 11S/7S ratio increased, while the ratios of glycinin and β-conglycinin were less variable. These results indicate that the 11S/7S ratio and coagulant concentration may have an effect on the amount of coagulum and the concentration of oil globules in the coagulum at the beginning of coagulation.     

Microstructure and nanomechanical properties in osteons relate to tissue and animal age

Material property changes in bone tissue with ageing are a crucial missing component in our ability to understand and predict age-related fracture. Cortical bone osteons contain a natural gradient in tissue age, providing an ideal location to examine these effects. This study utilized osteons from baboons aged 0-32 years (n=12 females), representing the baboon lifespan, to examine effects of tissue and animal age on mechanical properties and composition of the material. Tissue mechanical properties (indentation modulus and hardness), composition (mineral-to-matrix ratio, carbonate substitution, and crystallinity), and aligned collagen content (aligned collagen peak height ratio) were sampled along three radial lines in three osteons per sample by nanoindentation, Raman spectroscopy, and second harmonic generation microscopy, respectively. Indentation modulus, hardness, mineral-to-matrix ratio, carbonate substitution, and aligned collagen peak height ratio followed biphasic relationships with animal age, increasing sharply during rapid growth before leveling off at sexual maturity. Mineral-to-matrix ratio and carbonate substitution increased 12% and 6.7%, respectively, per year across young animals during growth, corresponding with a nearly 7% increase in stiffness and hardness. Carbonate substitution and aligned collagen peak height ratio both increased with tissue age, increasing 6-12% across the osteon radii. Indentation modulus most strongly correlated with mineral-to-matrix ratio, which explained 78% of the variation in indentation modulus. Overall, the measured compositional and mechanical parameters were the lowest in tissue of the youngest animals. These results demonstrate that composition and mechanical function are closely related and influenced by tissue and animal age.     

Matching and ideal free distributions

Ideal free distributions characterise how a group of animals should be distributed between sources of food. In a simple case, the ratio of the number of animals matches the ratio of input rates, a result known as input matching. The matching law characterises how an animal should allocate responses to sources of food. If matching holds then the ratio of behaviour allocated to the sources matches the ratio of rewards obtained. Several authors have drawn attention to the analogy between input matching and the matching law. I present a critical review of this topic, and go on to investigate the claim that the distribution of animals should be analyzed in the same way that the generalized matching law is analyzed. This involves assuming that the relationship between the ratio of animals and the ratio of resources obeys a power law with two parameters, one corresponding to bias and the other to sensitivity. On this view, a plot of the log of the ratio of animals against the log of the ratio of input rates will be a straight line and its intercept and slope will provide estimates of bias and sensitivity. I show that this approach can give a good fit even when the underlying model does not result in a power law. A consequence is that the parameters estimated cannot be interpreted as bias and sensitivity. I conclude that there are no compelling reasons for analyzing the distribution of animals using log-log plots, and the method has the disadvantage of encouraging the mistaken view that deviations from input matching follow a power law.     

A theory of gene-culture coevolution of parental preference and sex ratio in humans

A theory on the evolution of human primary sex ratio is proposed. Effects of parental preference for sons, reflected in birth control based on offspring sex ratio and female biased infanticide, on the evolution of primary sex ratio are analyzed. Both are shown to select for female bias in primary sex ratio. The gene-culture coevolution of female infanticide and primary sex ratio is also studied and it is shown that female infanticide develops more in societies in which the father plays a more important role in the transmission of culture than the mother does.     

Causes and consequences of adaptive seasonal sex ratio variation in house sparrows

1. Here we examine how sex ratio variation in house sparrow broods interacts with other demographic traits and parental characteristics to improve the understanding of adaptive significance and demographic effects on variation in sex ratio. 2. The sex ratio in complete broods did not deviate significantly from parity (54.9% males). 3. There was sex-specific seasonal variation in the probability of recruitment. Male nestlings that hatched late in the breeding season had larger probability of surviving than early hatched males. 4. An adaptive adjustment of sex ratio should favour production of an excess of males late in the breeding season. Accordingly, the proportion of male offspring increased throughout the breeding season. 5. A significant nonlinear relationship was present between sex ratio and age of the female. However, there was no relationship between parental phenotype and standardized hatch day that could explain the observed seasonal change in sex ratio. 6. The sex-specific number of offspring recruited by a pair to subsequent generations was closely related to the brood sex ratio. 7. These results indicate an adaptive adjustment of sex ratio to seasonal variation in environmental conditions that affects the offspring fitness of the two sexes differently. Our results also suggest that such a sex ratio variation can strongly influence the demography and structural composition of small passerine populations.