黑斑侧褶蛙消化道重量及长度的性别和季节差异

消化道是联系脊椎动物能量摄入和能量支出之间关系的纽带,其重量和长度对外界环境具有高度的敏感性和弹性(flexibility)。以黑斑侧褶蛙(Pelophylax nigromaculata)为研究对象,测定了山东聊城地区2012年夏季(16只,8♀/8♂)、秋季(19只,9♀/10♂)及翌年春季(17只,8♀/9♂)其体重、体长、胴体湿重和干重系数、总消化道及各段(食道、胃、小肠和大肠)的湿重、干重和长度系数的性别和季节差异(双因素方差分析),对有性别差异的指标,用单因素方差分析分别比较了雌、雄蛙的季节差异。结果显示,1)雌蛙的体重、体长均高于雄蛙,都在秋季最高,春季或夏季最低;雄蛙的胴体湿重系数高于雌蛙,夏季高于秋季;胴体干重系数既无性别差异,也无季节差异。2)除食道湿重系数无性别差异外,雌蛙总消化道及各段的湿重系数均高于雄蛙;除胃湿重系数无季节差异外,春季或秋季的总消化道及各段的湿重系数都高于夏季;雌蛙的总消化道干重和胃干重系数高于雄蛙,食道、小肠和大肠的干重系数无性别差异,所有的干重系数均无季节性差异。3)除雌蛙的大肠长系数高于雄蛙外,总消化道及各段的长度系数均无性别差异,春季和秋季的总消化道长、食道长及胃长系数均高于夏季,小肠长和大肠长系数均无季节性差异。结果表明,随着季节更替,黑斑侧褶蛙消化道各段的重量和长度表现出一定的弹性特征,这与各器官的功能及其生活环境的多样性是相适应的。     

Formation of extensor digitorum muscle proportions before and after birth

Studies on the formation of the extensor digitorum muscle morphological characteristics were carried out on material of 85 human fetuses (42 males and 43 females), 16 to 36 weeks old, and 45 adults (31 males and 14 females). Intermediary conclusions were drawn on probable changes occurring in the morphological formation of the muscle after birth, as a result of comparing proportions of the muscle at the fetal stage with its form in adults. In this work, the anthropometric method of study and statistical analysis of results have been applied. Analysis of the results in the fetal group has shown that all metrical characteristics of the muscle reach their maximum values at the end of the investigated ontogenetic space. This is, naturally, a consequence of evolution and growth of all fetal body measures, including elongation of forearms. However, the evolution of the individual muscle characteristics is not regular and though the direction of this growth is similar, its extent varies, and also differs slightly in sexual groups. Comparison of the values of muscle indices for 9 month old fetuses with the same indices for adults shows that relative dimensions of all investigated muscular characteristics decrease during the post-natal period except the relative length of the tendon.     

Sexual dimorphism in immune response, fat reserves and muscle mass in a sex role reversed spider

In sex role reversed species, females and males adopt behaviors that are not the traditional ones for that animal group. Furthermore, this reversal can translate into physiological differences between the sexes in characteristics such as energetic demands or immune response. Allocosa brasiliensis shows a reversal in the sex roles and sexual size dimorphism that would be expected for spiders. Males are larger than females and are sedentary, while females are the mobile sex that looks for males and initiates courtship. Our objective was to explore the occurrence of sexual dimorphism in immune response, fat content and muscular mass in A. brasiliensis, and relate the results to the reproductive strategies of the species. An encapsulation response was used as an estimate of the immune response. Abdominal fat content and leg muscular mass were quantified and the results were compared between females (N = 19) and males (N = 21). Males showed higher values of the three characteristics as compared to females. Life history divergences between the sexes regarding size, mobility and foraging opportunities could be factors driving these differences in immune response and energy requirements.     

Mate guarding in a Caribbean village

Behavioral observation, economic, and genealogical data collected in a rural Trinidadian village indicate: (1) males courting the same females have higher rates of agonistic interactions (e.g., arguing, fighting) with each other than they do with other males; (2) females courting the same males do not have higher rates of agonistic interactions with each other than they do with other females; (3) exclusive (monogamous) mating relationships have lower rates of agonistic interactions than nonexclusive (polygamous) mating relationships; (4) coresident mates interact more frequently when the female is fecund; (5) coresident mates have higher rates of agonistic interactions when the female is fecund; (6) males with fecund mates have higher rates of agonistic interactions with other unrelated males than do males with infecund mates; (7) fecund females do not have higher rates of agonistic interactions with other females than do infecund females; and (8) females do not guard prosperous males (those from households with 6 or more acres of land) more intensely than poorer males. These results suggest that mate guarding is an important aspect of reproductive competition, and that there are significant male/female differences in mate guarding strategies in this human population.     

当年生高山姬鼠最大代谢率

用开放式呼吸仪测定了当年生和往年生高山姬鼠的冷诱导和运动诱导最大代谢率。当年生高山姬鼠的冷诱导最大代谢率为:(7.25±0.25)mLO2/(g.h),运动诱导最大代谢率为(9.22±0.27)mLO2/(g.h);当年生鼠冷诱导最大代谢率雌雄间无显著差异,运动诱导最大代谢率雌雄间差异显著。当年生高山姬鼠的冷诱导最大代谢率低于往年个体,运动诱导最大代谢率高于往年生个体。结果表明:当年生高山姬鼠忍受寒冷的能力低于往年个体,可能是对横断山地区年平均气温较低的自然环境的胁迫产生的适应;而雄性运动诱导最大代谢率大于雌性,可能是为了适应避免近亲繁殖和激烈竞争而在性成熟后从出生地向外扩散。     

Viewing time as a measure of sexual interest

Based on the hypothesis that unobtrusively measured viewing time reflects sexual interest, it was predicted that viewing times should correlate with ratings of sexual attractiveness and with phallometrically measured age and gender preferences. Four additional predictions were derived from the Symons (1979) evolutionary theory of human mate preferences: (1) male and female subjects should view slides of young adults of the opposite sex longest and adults of the same sex and prepubescent children of both sexes the shortest, (2) the correlation between viewing time and sexual attractiveness ratings should be higher among males than females (3) males should look at slides of pubescent females longer than females look at slides of pubescent males, and (4) males should look longer at adult females than females look at adult males. Two studies involving 24 heterosexual females and 58 heterosexual males provided statistically significant support for all predictions except the last one.     

Distinct feeding behavior between sexes of shape Frankliniella occidentalis results in higher scar production and lower tospovirus transmission by females

Feeding behavior and scar production of male and female F. occidentalis (Pergande) (Thysanoptera: Thripidae) were studied in relation to transmission of tomato spotted wilt tospovirus (TSWV). Electrical penetration graph (EPG) analysis showed that females feed more frequently and intensively than males. The feeding intensity, reflected by silvery scar production and studied by an image analysis system, demonstrated that females induced more numerous scars than males. At the same time, males transmitted TSWV with a higher efficiency than females, indicating that TSWV transmission and scar production are not positively correlated. Furthermore, males produced significantly more local lesions of TSWV than females. These quantitative differences in scar production and transmission of TSWV can be explained by the lower mobility and higher consumption rate of females. The influence of the sex-ratio on crop damage and virus transmission, and thus to the spread of TSWV, is emphasized.     

Social development of bonnet macaques from six months to three years of age: A longitudinal study

Observations of age-sex class associations of three young female and five young male bonnet macaques born in the spring, 1975, were taken semiannually over three years beginning in the fall, 1975. Analysis reveals several patterns: (1) both males and females show continuous decline in association with age mates; (2) solitary time of females peaks at 1.5 years after which they begin to associate with adult females; (3) solitary time of males peaks at 2.5 years after which they associate predominantly with sub-adult males; (4) both males and females showed higher association with juveniles of the same sex than of opposite sex; and (5) both males and females showed annual cycles of association with some age-sex classes. These results are best understood with reference to the natural breeding cycle of the animals and the different life histories of male and female macaques in the wild.     

ERPs to subclasses of nouns and verbs

The present findings show the existence of significant differences in latency and amplitude of some waves of ERPs to three subclasses of nouns or verbs. Latency LP3 of ERPs to action verbs was shorter than latency of the same wave to abstract verbs. In nouns the relation was a similar (manipulable objects versus abstract ones). The amplitude of early positive components (P1, P2) and BN3 wave also depended on semantic attributes of nouns and verbs. Some waves of ERPs to motion verbs in our experiment had significantly higher amplitude than the same waves of ERPs to nonmanipulable objects. Also revealed was interaction between some ERP features and the subject's gender. It was primarily the amplitude of BP2, the size of which depended on gender in all cases--BP2 amplitude was significantly higher in females then in males. In the other components (BP1, BP4, BN2 and BN4) there were fewer significant differences and if they do occurred, then their amplitude was higher in males than in females. In some cases, gender also affected latency of waves LP2, LN1 and LN4 of ERPs to the same noun or verb subclass--latencies of these waves were shorter in females.     

Growth in the myopathic Syrian hamster (Cricetus auratus)

The objective was to assess the effect of the hereditary myopathic disease (muscular dystrophy) on 4 growth parameters: body-weight, head-body length, skull weight and cranial length in the Syrian hamster over a 4-13 month period. A control colony of 34 males and 32 females was compared to a muscular dystrophy colony consisting of 37 males and 27 females. The monthly means of the 4 growth parameters were computed and full data were used for computations of analysis of variance with regression of each group, sex and growth parameter. Intersex and intergroup comparisons of the same parameters were made using analysis of covariance. In the controls, the male bodies were heavier and longer than the female bodies; males grew over the total period. In dystrophic hamsters, males were heavier than females, but females were longer. In both control and dystrophic hamsters, female skulls were longer and heavier. In all parameters the means of the control colony were greater than those of the dystrophic colony relative to age. The disease factor in the muscular dystrophy colony adversely influenced all 4 growth parameters.     

A projection of benefits due to fecal occult blood test for colorectal cancer

Objectives: A prospective study to estimate benefits due to fecal occult blood tests for colorectal cancer are carried out for both males and females, under different screening frequencies. Methods: We apply the statistical method developed by Wu et al. (2007) [1] using the Minnesota colorectal cancer study group data, to make Bayesian inference for the lead time, the time of diagnosis advanced by screening for both male and female participants in a periodic screening program. The lead time is distributed as a mixture of a point mass at zero and a piecewise continuous distribution. The two parts of the mixture correspond to two aspects of the screening: the probability of no benefit, or the percentage of interval cases; and the probability distribution of the early diagnosis time. We present estimates of these two measures for males and females by simulation studies using the Minnesota study group data. We also provide the mean, mode, variance, and density curve of the program's lead time by gender. This may provide policy makers important information on the effectiveness of the FOBT screening in colorectal cancer early detection. Results: The mean lead time increases as the screening time interval decreases for both males and females. The standard error of the lead time also increases as the screening time interval decreases for both genders. Females seem get more benefit than males, in that females usually have a longer lead time than males if both take the test at the same time interval and the lead time mode for females is greater than that of males in the same screening time interval. Conclusion: According to the predictive estimation of the lead time distribution, to guarantee a 90% chance of early detection, it seems necessary for the males to take the fecal occult blood test every 9 months, while the females can take it annually.     

Lipid and fatty acid content in wild white seabream (Diplodus sargus) broodstock at different stages of the reproductive cycle

The lipid and fatty acid content of the gonads, liver and muscle of wild white seabream males and females was studied at different stages of the reproductive cycle. Samples were taken from mature white seabream at pre-spawning (November), mid-spawning (March) and post-spawning (June) stages. The results showed that lipid accumulates in gonads and muscle from November to March. The gonadosomatic index (GSI) was also increased during this period. Male gonads showed a greater increase in polar lipid (PL) than neutral (NL), while female gonads displayed the reverse. The increase in both neutral and polar lipid was higher in the muscle of males than in females. In the same period, male livers showed no changes either in lipid content or the hepatosomatic index (HSI), while female livers registered an increase in both lipid content and HSI. Between March and June, in both males and females, total, neutral and polar lipid decreased sharply in the gonads and muscle. Muscular lipid content reduction was more pronounced in males than females. On the other hand, the lipid content of the liver in males and females remained relatively constant. In general terms, the amounts of major fatty acids (16:0, 18:1n-9, 20:5n-3 and 22:6n-3) in gonadal and muscular polar and neutral lipid in both males and females increased from November to March and declined thereafter. Variations of the liver fatty acid content were less extreme. In the period from mid-spawning to post-spawning, the presence of 20:4n-6 in polar and neutral lipid increased to a notable extent in all organs studied.     

雌雄福寿螺耐寒能力的差异

为了解福寿螺耐寒性是否存在性别差异,对华南地区的雌雄福寿螺进行了过冷却研究及低温胁迫下存活率调查,并对入冬前后其体内耐寒性生理生化物质进行测定.结果表明: 雌雄螺的过冷却点均值分别为-6.83 ℃和-6.26 ℃,雌螺过冷却点显著低于雄螺;进入冬季后,福寿螺自由水含量明显下降,结合水、甘油、脂肪、糖原含量均出现明显上升,除甘油外,其余各耐寒性生理指标均存在极显著的性别差异;未经过冷驯化的雌雄福寿螺经过10 ℃处理7 d后存活率均在90%以上,继续在5 ℃下培养7 d后存活率出现明显的性别差异和壳高差异.野外调查发现在福寿螺自然种群中雌螺多于雄螺.表明福寿螺雌螺的耐寒能力强于雄螺.这对进一步探索福寿螺的生态适应性、自然性比及其耐寒性机制有一定的参考价值.     

Haematological data for Matsumoto Eosinophilic Shinshu rats as determined by an automated haematology analyser

The Matsumoto Eosinophilic Shinshu (MES) rat originated from an inbred mutant colony of rats with spontaneous eosinophilia. As part of an investigation of the pathogenesis of the MES rat, we examined the haematology data for 106 males and 88 females and age-associated changes using an automated haematology analyser, flow cytometric analysis and morphological examination. The data at 10 weeks of age showed the MES rats had higher counts for eosinophils and neutrophils, slightly higher counts for lymphocytes, monocytes, basophils, and large unstained cells (LUCs), and slightly lower values for the erythrocytic parameters when compared with Sprague-Dawley (SD) rats. In data for MES rats aged 8 to 20 weeks, eosinophil counts increased with age up to 20 weeks together with some increased neutrophil counts. After 11 weeks of age, counts for lymphocytes, monocytes, basophils, and LUCs in the MES rats were also slightly increased. In female MES rats, flow cytometric analysis showed increased counts for pan-T+ cells, but blasts, abnormal granulocytes and lymphocytes were not detected morphologically. The MES rat characterized by the haematological findings could be a useful animal model for studies of hypereosinophilia.     

棕色田鼠探究行为对同种个体气味源反应格局的分析

通过观察非动情期的棕色田鼠对麻醉的同种个体身体气味源的探究行为 ,包括雄鼠对麻醉雄鼠和雌鼠的嗅闻、雌鼠对麻醉雄鼠和雌鼠的嗅闻 ,分析了棕色田鼠在社会探究中对不同气味源的反应格局。结果表明 ,棕色田鼠对同种个体肛殖区和面部的嗅闻频次及嗅闻持续时间最多 (P <0 0 5 ) ;对背部、腹部、肋部嗅闻的频次和持续时间较少。在对同一部位的嗅闻中 ,在嗅闻频次上 ,雄鼠对雄鼠的嗅闻、雌鼠对雌鼠的嗅闻以及雌鼠对雄鼠的嗅闻都显著多于雄鼠对雌鼠的嗅闻 (P <0 0 5 ) ;在嗅闻时间上 ,性别组合对同一部位的探究行为没有显著影响 ,但气味源与性别组合有交互作用 (P <0 0 5 ) ,影响探究行为。这些结果说明棕色田鼠的肛殖区和面部是重要的气味源 ,而且在对同一气味源的探究中存在性别差异。但在非动情期 ,异性间的探究并不总是高于同性间的探究     

Energetic cost of sexual attractiveness: ultrasonic advertisement in wax moths

Pair formation in the lesser wax moth,Achroia grisella(Lepidoptera: Pyralidae), is initiated by male ultrasonic signals that attract receptive females. Individual males vary in attractiveness to females, and the most attractive males are distinguished by exaggeration of three signal characters: pulse rate, peak amplitude and asynchrony interval (temporal separation between pulses generated by movements of the left and right wings during a given wing upstroke or downstroke). Using flow-through respirometry, we measured the resting and signalling metabolic rates of males whose relative attractiveness was known. Acoustic recordings and metabolic measurements were made simultaneously, and we calculated net metabolic rates and factorial metabolic scopes as measures for the energetic cost of signalling. On average, attractive males had higher net metabolic rates and factorial metabolic scopes than unattractive ones, but many unattractive males also had high values. Thus, high expenditure of energy on signalling is necessary but not sufficient for attractiveness. This may result because only one of the three signal characters critical for female preference, pulse rate, is correlated with energy expenditure. Although the results are consistent with the good genes model of sexual selection, they do not conflict with other indirect or direct mechanisms of female choice.     

Male morphology,performance and female mate choice of a swarming insect

1. Females of many species select mates based on important morphological and performance traits. This behaviour likely facilitates reproductive success thus exhibiting sexual selection. Most such studies have evaluated a single morphological variable, and only a minority of them studies the effects of behaviour and performance (functional capacity: Irschick et al., Evolutionary Ecology Research, 10 , 177–196, 2008) at all.
2. This study compares male morphological and performance traits differing in three variables that may correlate with fitness: condition index, flight ascent speed and resistance to torpor in relation to male mating success in the parasitoid wasp species Alabagrus texanus (Braconidae), a species where males swarm about emerging virgin females that display both choosy and non-choosy behavioural phenotypes.
3. Males that successfully mated with choosy females exhibited higher condition indices and somewhat stronger resistance to torpor than other males. Conversely, males that mated with non-choosy females did not differ in any trait from other males we measured. Early-arriving males did not have higher condition indices or greater mating success than other males.
4. Thus, both morphological and performance traits contributed to male success, which acted through female choice, indicating a role for sexual selection. Patterns of choice further differed among females, independent of male traits.

     

Egg load of lab-cultured <Emphasis Type="Italic">Anaphes iole</Emphasis> and effects of mate presence and exposure time on load depletion

Anaphes iole Girault (Hymenoptera: Mymaridae) is a solitary egg parasitoid of Lygus bugs (Heteroptera: Miridae) in North America. This research considered factors that might impact the egg load of lab-cultured A .iole females, reared from Lygus hesperus Knight egg patches. The following hypotheses were tested: (1) egg load was related to body size and not affected by female age, and (2) egg load depletion was not affected by mate presence and time (in days) that females were exposed to host patches. Initial egg load averaged 48 mature eggs and no immature eggs were detected in the ovarioles of dissected females. Egg load was neither related to body size (hind tibia or forewing length) nor affected significantly by age (0, 1 or 2days old honey-fed females). Mate presence (females with or without males) and exposure time (1, 3 or 5days on the same host patch) had no effect on egg load depletion. Females usually depleted most of their egg load within 24h. From 86 to 92% of females contained less than six mature eggs and no immature eggs after 1, 3 or 5days of exposure to host patches. The results of this study suggest that A. iole females are certainly pro-ovigenic and initial egg load does not correlate with body size or age. Since mated and unmated females deplete most of their egg load in 24h, time-efficient production of progeny may result when ovipositing parasitoids are exposed to suitable hosts for just a few days.The United States Government has the right to retain a non-exclusive, royalty-free license in and to any copyright of this article. This article reports the results of research only. Mention of a commercial or proprietary product does not constitute an endorsement of the product by the United States Department of Agriculture.     

Individual and Gender Differences in Subjective and Objective Indices of Pain: Gender,Fear of Pain,Pain Catastrophizing and Cardiovascular Reactivity

According to fear-avoidance models of pain perception, heightened fear of pain may increase disruptive effects of pain; however, the extent to which this affects self-reported pain severity versus physiological indices of pain is not well delineated. The current study examined self-report measures and physiological indices of pain during a cold pressor (CP) task. Individual differences in fear of pain and pain catastrophizing were also assessed via questionnaire. The primary aim of the current study was to examine the extent to which individual differences associated with fear and catastrophizing in response to pain influences subjective and physiological measures of pain. A secondary aim was to examine gender differences associated with response to pain. Average subjective pain ratings were higher for females than males. In contrast, males exhibited higher systolic and diastolic reactivity in response to the CP task relative to females, as well as failure to fully recover to baseline levels. Follow-up correlational analyses revealed that subjective pain ratings were positively associated with fear of pain in both sexes, but were not associated with cardiovascular indices. These results suggest that fear of pain and pain catastrophizing do not influence cardiovascular responses to induced pain. Further research is necessary in order to determine whether these gender differences in blood pressure and heart rate response profiles are due to biological or psychosocial influences. Results support the notion that fear of pain increases subjective pain ratings, but does not influence cardiovascular responses during CP pain-induction.     

Cardiovascular reactivity to mental stress: relationship with menstrual cycle and gender

The purpose of the present study was to determine the fluctuation in cardiovascular reactivity to mental stress during the menstrual cycle by comparing heart rate variability (HRV), and other physiological and psychological data in females with those in males. Cardiovascular reactivity to two mental tasks was measured in 14 females during the follicular and luteal phase of menstruation over two menstrual cycles. The same tasks were subsequently given to a matched pair of males (N=14), at the same intervals as their corresponding females. Heart rate, blood pressure and HRV were used as indices of cardiovascular reactivity. Subjective mental workload was measured at the end of each task. Power spectral analysis of HRV showed that the high frequency (HF) component in HRV decreased more during the luteal phase than the follicular phase. The low frequency (LF) component in HRV and the LF/HF ratio in the luteal phase were significantly higher than that in the follicular phase. The LF component and the LF/HF ratio were significantly lower in females than in males; conversely, the HF component was significantly higher in females than in males. Neither significant effects of menstrual cycle, gender and mental stress nor any significant interactions were found for mental workload. These findings indicate that sympathetic nervous activity in the luteal phase is significantly greater than in the follicular phase whereas parasympathetic nervous activity is predominant in the follicular phase. The results also suggest that predominance of sympathetic nervous activity in males compared with a dominant parasympathetic nervous activity in females.