太白红杉种群的生殖对策研究Ⅱ．生殖力和生殖值

研究了太白红杉种群的年龄结构、生殖年龄结构、生殖力和生殖值,分析了太白红杉种群的生殖适合度和生殖对策.结果如下(1)北坡和南坡两个种群的低龄级个体数都非常少,种群间的生育力差异不显著(P>0.05),但北坡太白红杉的生殖年龄比南坡大,平均生殖时间比南坡长,平均寿命也比南坡长.(2)北坡各龄级的生殖值比南坡高,剩余生殖值随年龄下降的速度比南坡小,北坡的生殖适合度比南坡高.(3)北坡第Ⅰ～Ⅶ龄级的剩余生殖值比南坡高,第Ⅶ龄级后由于下降速度较快,其值要比南坡小.     

Sires influence fetal death in pigtailed macaques (Macaca nemestrina)

Computerized colony records were used to identify dams and sires whose reproductive histories while breeding in harem groups indicated high or low risk for producing fetal deaths. The monkeys were then singly caged and bred within and between risk conditions during 24- to 72-hour matings. Although the low- and high-risk sires did not differ in ability to achieve conceptions, the results revealed that reproductive history predicted subsequent fetal death rates, and sires made a substantial contribution. Overall, high-risk sires had a 4.86 times higher relative risk of producing fetal death than low-risk sires. Compared with this figure, high-risk dams had only a 2.64 times higher risk for fetal death than low-risk dams. The male effect was most evident in comparisons of between- and within-risk matings. Females with excellent reproductive histories experienced a threefold increase in fetal deaths when mated with high-risk males, whereas females with poor reproductive histories experienced almost a 50% reduction in fetal deaths when mated with low-risk males. The results show that male factors beyond fertility need to be considered when examining the causes of reproductive failure in captive primates.     

Sociality and sex allocation in an Australian allodapine bee Braunsapis protuberans

Abstract  Herein the first detailed study of sociality and life history in an Australian species of the allodapine bee genus Braunsapis is provided. Colonies of B. protuberans were sampled from the Great Sandy National Park in Queensland from late winter until later summer. Single-female colonies appear to have suffered substantially higher rates of total brood loss, or failure to produce brood, than multifemale colonies, but rearing efficiency in colonies with at least some brood did not differ between these two colony types. There was marked reproductive skew in multifemale colonies and ovary size was strongly linked to relative body size. However, females with smaller body size and smaller ovaries also had lower levels of wing wear, suggesting that they do not specialise in foraging. These patterns are similar to an African species, Braunsapis vitrea , and suggest that colonies may principally comprise a dominant reproductive female who provides food for her juvenile offspring, along with a variable number of subordinate females who may be waiting to inherit their natal nest in the event of their mother's death. However, it is likely that in such events, the remaining female(s) will care for orphaned brood as some single-female colonies contained substantial older brood, even though the sole female had little or no wing wear. Such alloparental care in the case of orphaning may help explain the high level of female bias in sex ratios.     

Reproductive tolerance in male primates: Old paradigms and new evidence

Within social groups of primates, males commonly compete over reproduction, but they may also rely on cooperation with other males. Theory suggests that it may be adaptive for male primates to tolerate some reproduction by other males if reproductive tolerance fosters cooperation, particularly that dominant males yield so‐called reproductive concessions to subordinates to entice their cooperation. We review four recent studies that claimed to have found evidence for reproductive concessions or similar forms of reproductive tolerance. However, upon critical reevaluation of their results, no study provides conclusive support for reproductive concessions as predicted by theoretical models. Yet two studies demonstrated a form of reproductive tolerance that cannot be explained by any of the existing models, and that seems to have evolved only in multi‐male, multi‐female societies with diverse strategic options for males. Our article provides guidance how to study this form of reproductive tolerance in the absence of a unifying model.     

Regulatory Mechanisms of Reproductive Effort in Plants 1. Plasticity in Reproductive Energy Allocation and Propagule Output of Helianthus annuus L. (Compositae) Cultivated at Varying Densities and Nitrogen Levels

Abstract Plasticity in growth, reproductive energy allocation (RA), and reproductive output were investigated in Helianthus annuus L. cultivar. Russia (Compositae) grown under varying densities and soil nitrogen levels. The role and behaviour of pollinators in seed production was also examined.
Exceedingly marked plastic responses were detected in individual biomass, the patterns of resource allocation to total reproductive structures (RA) and also to propagules, fecundity, reproductive outputs, and propagule size and weight under changing densities and soil nitrogen levels. Plants cultivated at higher densities exhibited proportionately lower individual biomass, lower RA, lower fecundity, lower seed output, and smaller seed size in response to increasing density and decreasing soil nitrogen levels. However, differences due to different N-levels were not as great as those to changing density.
One of the most significant findings was that seed production under limited resource availability, i.e., lack of ample solar radiation and soil nutrients, due to strong interference at higher density plots, is exceedingly costlty , This was most clearly demonstrated by a very sharp increase in relative energy partitioning to a single propagule in response to the increased density and decreasing nitrogen levels, the relative energy cost to a single achcne (R_A) increasing from one to twenty-fourfold. Reproduction was also affected by pollinator-limitations, and seed size showed a marked position effect.     

Whose autonomy,whose interests? A donor-focused analysis of surrogacy and egg donation from the global South

This article provides a donor-focused analysis of how transnational reproductive donation intersects with issues central to bodily autonomy of surrogates and egg donors from the global South. Little is known about the autonomy of surrogates and egg donors, especially among those from the global South. This article addresses this gap by examining two key issues on surrogacy and egg donation—conflict of interest and recruitment market. With these issues, this paper presents contexts of the reproductive body as a space of contestation for autonomy. Analysis reveals that bodily autonomy is not an absolute entitlement available for surrogates and egg donors from the global South. Having bodily autonomy is a privileged disposition rather than a universal liberty for reproductive donors. The discussions in this work encourage further examination to understand the multi-layered experiences of reproductive donors from the global South, towards deeper interrogation of the processes of reproductive industry.     

Effects of early rearing experience on subsequent adult sexual behavior using domestic cats (Felis catus) as a model for exotic small felids

Zoo professionals generally believe that maternal rearing of zoo animals is preferable to human/nursery raising. The lack of consistent reproductive success in small captive exotic felids has been partially attributed to an excess of human-raised individuals. To investigate experimentally the effects of human/nursery rearing on adult sexual behavior, domestic cats were used as a model for small captive exotic felids. Three groups of female domestic cats were reared under three different conditions (intended to mimic typical zoo rearing situations) and then paired at sexual maturity with sexually experienced males. Cats in Condition 1 were Human-Raised Alone, i.e., had no physical or visual contact with con-specifics until sexual maturity; cats in Condition II were Human-Raised with a Sibling, i.e., had no physical or visual contact with any conspecifics except their respective sibling until sexual maturity; cats in Condition 3 were Maternally Raised with a female sibling, but had no other physical or visual contact with other conspecifics until sexual maturity. Individuals in Condition 3 copulated significantly more often than did the individuals in Condition 1. The individuals in Condition 1 were distinguished by the extreme aggression they displayed toward both the males with which they were paired and their human-caretakers. Data suggest that human-reared female cats are less likely to reproduce than are their maternally-reared counterparts. These results suggest that, whenever possible, nursery-raising of small exotic felids should be avoided.     

Comparison of reproductive development in triploid and diploid female rainbow trout Oncorhynchus mykiss

The diploid rainbow trout Oncorhynchus mykiss reached sexual maturity 3 years after hatching and its oogenesis underwent four stages, which were oogonia, primary oocyte, secondary oocyte and egg. Reproductive development and hormone changes of 4 to 35 month‐old female O. mykiss were investigated using histological and radioimmunoassay methods in order to provide a theoretical and practical basis for the use of triploid female O. mykiss. The oogonium of the triploid female could develop into the oocytes of the prophase with abortion occurring later; the oogonium was surrounded by stroma cells to form the oogonium cluster and the gonads showed a virilescent tendency when the oogonium clusters were gradually replaced by spermatogenic‐like cytocysts. After 13 months, amounts of gonadotropic hormone (GtH‐I, GtH‐II) and oestradiol (17β‐E₂) in triploid females were lower than in diploid fish at corresponding time periods, but the amounts of testosterone (T) increased consistently after 21 months and were more than in diploid fish in the corresponding time periods (P > 0·05). The infertility of triploid females resulted from meiosis failure, which caused developmental abortion of oocytes and oogonium formed cytocysts before the prophase oocytes. The cytocyst formation was due to the lack of the normal interaction of ovum and follicular cells, the development of follicular cells producing steroids were inhibited, the arylate path from T to 17β‐E₂ was interrupted, concentration of 17β‐E₂ decreased and concentration of T increased in the blood, the content of vitellogenin (Vg) decreased in the liver with a low 17β‐E₂ and high T caused to ovaries to show a tendency to be virilescent.     

Regulatory Mechanisms of Reproductive Effort in Plants II. Plasticity in Reproductive Energy Allocation and Propagule Output of Glycine max Merr. (Leguminosae) Cultivated at Varying Densities and Nitrogen Levels

Abstract Plasticity in growth, reproductive energy allocation (RA), and reproductive output were studied in Glycine max Merr. Cv. Enrei (Leguminosae) grown under varying densities and soil nitrogen levels.
Marked plastic responses were detected in individual biomass, the patterns of resource allocation to total reproductive structures (RA) and also to propagules, reproductive outputs, and propagule weight under changing densities and soil nitrogen levels. Plants cultivated at higher densities exhibited proportionately lower individual biomass, lower RA, lower seed output, and smaller seed size in response to increasing density and decreasing soil nitrogen levels, although some deviations were observed, especially in the highest density plot with no fertilization. Differences due to different N-levels were not as great as those to changing density, which may in part be due to the fact that soybean has nitrogen-fixing bacteria in root tubercles, just as in any other Leguminosae. Fecundity was also maintained at the similar high rates of 80–97% in all plots examined, although slight but steady decreases were noted with increasing density. This resemblance in fecundity may be due to its strong inbreeding system.
Another important finding was that seed production under limited resource availability, notably lack of ample solar radiation due to strong interference at higher density plots, is exceedingly costly. This was most clearly exhibited by a sharp increase in relative energy partitioning to a single propagule in response to the increased density, the relative energy cost to a single propagule (RA) increasing from one to seven-fold. The results obtained in this study coincide well with the findings made in other plants, e.g., Helianthus annuus, Oryza sativa , and Coix ma-yuen , with the same experimental designs.     

CARE ETHICS AND THE GLOBAL PRACTICE OF COMMERCIAL SURROGACY

This essay will focus on the moral issues relating to surrogacy in the global context, and will critique the liberal arguments that have been offered in support of it. Liberal arguments hold sway concerning reproductive arrangements made between commissioning couples from wealthy nations and the surrogates from socioeconomically weak backgrounds that they hire to do their reproductive labor. My argument in this paper is motivated by a concern for controlling harms by putting the practice of globalized commercial surrogacy into the context of care ethics. As I will argue, the unstable situations into which children of global surrogacy arrangements are born is symbolic of the crisis of care that the practice raises. Using the Baby Manji case as my touch point, I will suggest that liberalism cannot address the harms experienced by Manji and children like her who are created through the global practice of assisted reproductive technology. I will argue that, if commissioning couples consider their proposed surrogacy contracts from a care ethics point of view, they will begin to think relationally about their actions, considering the practice from an ethical lens, not just an economic or contractual one.     

植物种群的繁殖对策

植物种群的繁殖对策钟章成（西南师范大学,重庆６３０７１５）ＲｅｐｒｏｄｕｃｔｉｖｅＳｔｒａｔｅｇｉｅｓｏｆＰｌａｎｔＰｏｐｕｌａｔｉｏｎｓ．￥ＺｈｏｎｇＺｈａｎｇｃｈｅｎｇ（ＳｏｕｔｈｗｅｓｔＣｈｉｎａＴｅａｃｈｅｒｓＵ－ｎｉｖｅｒｓｉｔｙ,Ｃｈｏｎ...     

Post-parturial reproduction in terrestrial isopods: a partial review

This review deals with some aspects of terrestrial isopod reproduction including breeding season, breeding periods, patterns and strategies, parturition, number and size of broods and mancae. Reproductive period is described by the exact dates (i.e. season) marsupial females were collected in the field, and the duration of the breeding period. The information for both aspects was generally obtained through field work by observing marsupial females. Two reproductive patterns are used by terrestrial isopods, either a discrete (i.e. seasonal) or a continuous (i.e. non-seasonal) pattern. The discrete pattern can be either annual when females breed once a year, or they can breed biannually or multi-annually (two or more times during the year). This conclusion is based generally on observing marsupial females in the field. Therefore, this information does not apply to the reproductive pattern of the individual female since a female may use either or both patterns, i.e. seasonal and continuous. Only by raising individual females singly (with a male) can this point be clarified. This way, the breeding strategy of the same individual female can be studied. The subject is discussed and reviewed based on my research data.     

生殖道微生物与生殖健康

人类生殖道有多种微生物定殖,它们构成生殖道正常微生物菌群.乳酸杆菌是健康人群生殖道中最主要的微生物,具有维持生殖道生态平衡和防止病原体入侵的功能.微生态环境遭到破坏会导致各种感染,如细菌性阴道病、性传播感染、不良妊娠结局、不孕不育和肿瘤等.对生殖道炎症的治疗除常规的抗菌治疗外,益生菌在恢复菌群结构和维系生殖健康方面发挥...     

The evolved psychological mechanisms of fertility motivation: hunting for causation in a sea of correlation

Cultural, ecological, familial and physiological factors consistently influence fertility behaviours, however, the proximate psychological mechanisms underlying fertility decisions in humans are poorly understood. Understanding the psychological mechanisms underlying human fertility may illuminate the final processes by which some of these known predictors have their influence. To date, research into the psychological mechanisms underlying fertility has been fragmented. Aspects of reproductive psychology have been examined by researchers in a range of fields, but the findings have not been systematically integrated in one review. We provide such a review, examining current theories and research on psychological mechanisms of fertility. We examine the methods and populations used in the research, as well as the disciplines and theoretical perspectives from which the work has come. Much of the work that has been done to date is methodologically limited to examining correlations between ecological, social and economic factors and fertility. We propose, and support with examples, the use of experimental methods to differentiate causal factors from correlates. We also discuss weaknesses in the experimental research, including limited work with non-WEIRD (western, educated, industrialized, rich and democratic) populations.     

Behavioral, ecological, and molecular genetic analyses of reproductive strategies in the Amazonian dart-poison frog, Dendrobates ventrimaculatus

We report the first field and genetic studies of the reproductivestrategies of the Amazonian dart-poison frog Dendrobates ventrimaculatus,a species with biparental care. Neither males nor females arestrictly monogamous. Males are aggressively territorial, butsome females interact without aggression. Monitoring of breedingpools revealed high rates of multiple clutch deposition andhigh levels of larval cannibalism. Laboratory experiments confirmedlarval cannibalism and suggested a benefit to cannibals in increasedgrowth rate. Genetic analyses indicate that offspring from differentclutches in or above the same pool vary in relatedness and areon average intermediate in relatedness between individuals fromthe same clutch and unrelated individuals (from different pools).These data suggest that reproductive parasitism may be commonin this species     

松嫩平原碱化草甸朝鲜碱茅(Puccinellia chinampoensis)种群生殖分蘖株的生长规律

朝鲜碱茅(Puccinellia chinampoensis)是一种耐盐碱丛生型禾草,广泛分布于松嫩平原碱化草甸.采用每隔3d对朝鲜碱茅种群中处于抽穗初期的生殖分蘖株随机挂一次标签,于籽实蜡熟期同时进行大样本取样与测定的方法,定量分析了5次所标记的生殖分蘖株的数量性状的变化规律及生殖分蘖株的生长规律.结果表明,在朝鲜碱茅种群中,虽然抽穗时间只相隔3d,但生殖分蘖株的各数量性状均具有较大的表型可塑性,总的变化趋势是抽穗时间相隔越长,差异越大.其中,5次样本中的相邻平均花序生物量之间的差异均达到了显著水平.延长生殖生长16d,平均分蘖株高增加了23.16%,花序长增加了25.70%,分蘖株生物量增加了74.99%,花序生物量增加到2.63倍,生殖分配增加了93.25%.随着生殖生长时间的延长,朝鲜碱茅种群生殖分蘖株高、分蘖株生物量和花序生物量均呈指数增加,花序长和生殖分配呈直线增加,生殖生长比率呈先增加后降低的抛物线变化.不同时间进入生殖生长阶段的生殖分蘖株均具有相同的生长规律.其中,花序长均随分蘖株高的增加呈指数异速增长,花序生物量均随分蘖株生物量的增加呈直线同速增长.分蘖株的生殖生长越延长,对现实种群的贡献就越大,对未来种群的贡献更大.     

Senescence and costs of reproduction in the life history of a small precocial species

Species following a fast life history are expected to express fitness costs mainly as increased mortality, while slow‐lived species should suffer fertility costs. Because observational studies have limited power to disentangle intrinsic and extrinsic factors influencing senescence, we manipulated reproductive effort experimentally in the cavy (Cavia aperea) which produces extremely precocial young. We created two experimental groups: One was allowed continuous reproduction (CR) and the other intermittent reproduction (IR) by removing males at regular intervals. We predicted that the CR females should senesce (and die) earlier and produce either fewer and/or smaller, slower growing offspring per litter than those of the IR group. CR females had 16% more litters during three years than IR females. CR females increased mass and body condition more steeply and both remained higher until the experiment ended. Female survival showed no group difference. Reproductive senescence in litter size, litter mass, and reproductive effort (litter mass/maternal mass) began after about 600 days and was slightly stronger in CR than IR females. Litter size, litter mass, and offspring survival declined with maternal age and were influenced by seasonality. IR females decreased reproductive effort less during cold seasons and only at higher age than CR females. Nevertheless, offspring winter mortality was higher in IR females. Our results show small costs of reproduction despite high reproductive effort, suggesting that under ad libitum food conditions costs depend largely on internal regulation of allocation decisions.     

火柴头的繁殖对策和繁殖代价

火柴头具有地上茎和地下生殖枝同时开花结实的特性,产生地上大、小种子和地下大、小种子4种不同类型的种子。对4种类型种子的研究表明,地下大种子、小种子,地上大种子、小种子的平均百粒重有极显著差异,分别是1．0547g、0．4400g、0．5980g和0．3145g。火柴头种子的萌发很不整齐,特别是小种子。萌发持续时间很长。地上大种子和地下大种子的最终萌发率没有显著差异,均在97％左右,但地下大种子的种子活力要明显高于地上大种子。地下小种子的萌发率要高于地上小种子,达80％左右,而且其种子活力也明显高于地上小种子。4种种子形成的幼苗第1片真叶的生物量有极显著差异,其大小顺序依次是地下大种〉地上大种〉地下小种〉地上小种。在正常情况下,火柴头的繁殖投资以地上种子特别是地上小种子为主,在面临损伤逆境条件时,依靠高繁殖代价的地下种子特别是地下大种子。来降低其物种生存的风险,保持其种群的繁衍。     

桂林唇柱苣苔传粉生物学及生殖配置研究

对桂林唇柱苣苔在不同生境下（YZ居群,半野生,林下裸露岩石上;DB居群,洞穴岩石上）的生殖生态学进行了比较研究。结果表明：（1）桂林唇柱苣苔的花期为2月下旬至4月中旬,受环境因素的影响,单花期在DB居群（16~24 d）明显长于YZ居群（10~17 d）;（2）两个居群的P/O比差异显著,花粉量比胚珠量有更明显的变化,这可能与其生境有关;（3）桂林唇柱苣苔属于兼性异交系统,不存在无融合生殖现象;(4)传粉和种子后熟阶段均存在限制,致使各种处理的结实率均处在较低的水平（<45％）;（5）白颊尤垫蜂与小蜂类(DB居群)或蜜蜂(YZ居群)为桂林唇柱苣苔较为稳定的传粉者;（6）桂林唇柱苣苔植株个体越大,花期繁殖投入就越高,繁殖分配越低;（7）与DB居群相比,YZ居群可利用资源较为丰富、植株生物量较大,因此其花期投入繁殖也较高,而DB居群将更多的资源分配给营养器官,从而提高了对资源获取能力。     

A RIGHT TO REPRODUCE?

How should we conceive of a right to reproduce? And, morally speaking, what might be said to justify such a right? These are just two questions of interest that are raised by the technologies of assisted reproduction. This paper analyses the possible legitimate grounds for a right to reproduce within the two main theories of rights; interest theory and choice theory.