Receptive Behavior Research Articles

The Association Between Fraternal Birth Order and Anal-Erotic Roles of Men Who Have Sex with Men.

The fraternal birth order effect (FBOE) describes the phenomenon that homosexual men tend to have a greater number of older brothers than do heterosexual men. The FBOE is a marker for an innate, biological predisposition for androphilia in genotypic males. The FBOE has been studied since the 1930s and is the most consistent biodemographic correlate of sexual orientation in men. This study sought to determine whether the FBOE applies equally to all men who have sex with men (MSM), or disproportionately to MSM whose anal intercourse behavior is predominantly receptive (Bottoms). Participants included 243 North American adult MSM who responded to advertisements posted on a Web site and other electronic media associated with the GALA festival, a quadrennial gathering of gay and lesbian choruses. Each was asked whether his anal intercourse behavior during the preceding year was predominantly receptive, predominantly penetrative, or about equally receptive and penetrative. Those who indicated their behavior was predominantly receptive were coded "Bottoms"; all others were coded "Not-Bottoms." Participants were also surveyed as to their sibship composition. Bottoms had a significantly greater mean number of older brothers than did Not-Bottoms. There was no significant difference with respect to older or younger sisters or younger brothers. Further, the older sibling sex ratio (OSSR) for the Bottom cohort, but not for the Not-Bottom cohort, was significantly higher than the expected OSSR for the general male population (OSSR = No. older brothers/No. older sisters × 100; expected OSSR for general population = 106). Thus, late fraternal birth order was correlated with receptive anal-erotic behavior among MSM.

Female control of reproductive behaviour in the platypus (Ornithorhynchus anatinus), with notes on female competition for mating

AbstractOpportunities for studying platypus courtship and mating behaviours in the wild are limited due to the nocturnal and cryptic nature of this species. We report on platypus courtship and mating behaviour from a successful breeding program at Healesville Sanctuary, Victoria, in which platypuses were held as either breeding pairs or trios over seven years. Behaviour was recorded daily on infrared cameras resulting in over 80,000 h of footage that was analysed for activity periods, and courtship and mating behaviours including non-contact and contact courtship, mating and avoidance. Our aims were to describe and quantify courtship and mating interactions between males and females, and to determine if either sex controlled the initiation and continuation of the behaviours. From our observations, we describe a new courtship behaviour, non-contact courtship, which constituted the majority of all mating season interactions between males and females. The time between first and last appearance of a courtship and mating behaviour was 41.0 ± 6.6 days, with the females showing behavioural receptivity for 29.6 ± 5.1 days. Female platypuses used three evasive strategies in relation to approaches by males: avoidance, flight and resistance. Females controlled the duration of 79% of encounters using resistance. For the first time, two females were seen competing with each other over access to the male platypus in their enclosure and for nesting material. Time investment in courtship and mating behaviours was a poor indicator of receptivity and breeding success, and we suggest that breeding failure is more likely to be associated with failure of fertilisation, nest building, embryonic development or incubation. We describe how female platypuses demonstrate evasiveness and control of courtship and mating behaviours, and the importance of providing these opportunities in captivity to promote successful breeding.

Biochemical constituents, protein profile and effect of male accessory gland extract on egg production in mother moth of Antheraea mylitta Drury

Male accessory gland factors greatly influence the ovulation and oviposition and male receptivity behaviour of female insects. Some important biochemical constituents available in the male accessory gland extract of Antheraea mylitta during first and second crop grainage were analyzed and injected to just decouple mother tasar moth to observe the impact of extract injection on egg laying parameters. During first crop grainage, in just emerged male moth accessory gland extract the concentration of amino acid was recorded to be 0.049 ± 0.095 to 0.033 ± 0.012 mg/ml, glycerol - 0.007 ± 0.001 to 0.019 ± 0.004 milimole/ml, glycogen 0.827± 0.164 to 1.219 ± 0.060 mg/ml, protein - 9.405 ± 0.417 to 19.305 ± 0.946 to mg/ml, trehalose - 0.080 ± 0.059 to 0.295 ± 0.028 mg/ml and lipid 0.151 ± 0.008 to 0.263±Q.001g/ml. During second crop concentration of amino acid was recorded to be 0.009 ± 0.001 to 0.057±0.002 mg/ml, glycerol - 0.005 ± 0.001 to 0.016±0.0001 milimole/ml, glycogen 0.997± 0.700 to 1.482±1.217 mg/ml, protein- 3.389 ± 1.841 to 9.141 ± 3.023 to mg/ml, trehalose - 0.085 ± 0.029 to 0.132 ± 0.036 mg/ml and lipid 0.050 ± 0.012 to 0.510 ± 0.071g/ ml. The concentration of total proteins and lipid was also recorded to be in higher proportion than other biochemical constituents, extract of lOpI of single male accessory gland in first crop and 20pl in second crop grainage enhanced fecundity at 26' C. No difference in the qualitative protein profile of male accessory gland extract of0to6h old males was observed. There were altogether 17 detectable protein bands ranging in between molecular weight of 8.403 to 155.595 kD. When male moths were 28 hr old a higher molecular weight protein band of 184.746kD appeared. Very low molecular protein band of8.403kD disappeared. When male moths became older i.e of 24 to 36 hours old total 18 bands were seen in the molecular weight range of 155.95 to 8.779kD

Effect of Ovarian Hormones and Mating Experience on the Preference of Female Mice to Investigate Male Urinary Pheromones.

In female mice, the expression of receptive lordosis behavior requires estradiol and progesterone actions in the nervous system; however, the contribution of these hormones to females' motivation to seek out male pheromones is less clear. In an initial experiment, sexually naïve ovary-intact female mice preferred to investigate (make nasal contact with) testes-intact male as opposed to estrous female urine, provided they were in vaginal estrus. In a second experiment, groups of sexually naïve and mating-experienced, ovariectomized females were tested for urinary pheromone preference first without and then with ovarian hormone replacement. Without hormone replacement, sexually naïve ovariectomized females showed no preference for male over female urinary pheromones whereas mating-experienced females preferred to investigate male pheromones. Ovariectomized females in both groups preferred male over female urine after sequential s.c. injections with estradiol benzoate followed 2 days later with progesterone and after prolonged (7 days) exposure to estradiol alone. Our results indicate that in sexually naïve female mice estradiol, perhaps aided by progesterone, is required to motivate a preference to seek out male pheromones whereas after mating experience females' preference to investigate male pheromones persists even in the absence of ovarian hormone action.

Behaviors associated with mating success in the “purring” wolf spider Gladicosa gulosa

AbstractStudies of sexual selection in animal systems frequently use courtship and receptivity behaviors as metrics for mating success, and this is generally built upon data associating such behaviors with mating. Spider systems are becoming increasingly popular in sexual selection research, and the wolf spider Gladicosa gulosa has the potential to help answer unique questions in animal communication. However, this species is understudied, and no quantitative data exist that demonstrate which male and female behaviors may be indicators of mating success. We paired male and female G. gulosa and recorded the behaviors involved in their courtship and mating. We found a number of significant behaviors from both males and females, and we suggest which behaviors/variables are perhaps most predictive of mating success. Beyond building a data‐based foundation for future work, we also suggest that the relationship of certain male and female variables may shed light on some of the more unique features of this species.

DREADD-induced silencing of the medial amygdala reduces the preference for male pheromones and the expression of lordosis in estrous female mice.

Sexually naïve estrous female mice seek out male urinary pheromones; however, they initially display little receptive (lordosis) behavior in response to male mounts. Vomeronasal-accessory olfactory bulb inputs to the medial amygdala (Me) regulate courtship in female rodents. We used a reversible inhibitory chemogenetic technique (Designer Receptors Exclusively Activated by Designer Drugs; DREADDs) to assess the contribution of Me signaling to females' preference for male pheromones and improvement in receptivity normally seen with repeated testing. Sexually naïve females received bilateral Me injections of an adeno-associated virus carrying an inhibitory DREADD. Females were later ovariectomized, treated with ovarian hormones, and given behavioral tests following intraperitoneal injections of saline or clozapine-N-oxide (CNO; which hyperpolarizes infected Me neurons). CNO attenuated females' preference to investigate male vs. female urinary odors. Repeated CNO treatment also slowed the increase in lordosis otherwise seen in females given saline. However, when saline was given to females previously treated with CNO, their lordosis quotients were as high as other females repeatedly given saline. No disruptive behavioral effects of CNO were seen in estrous females lacking DREADD infections of the Me. Finally, CNO attenuated the ability of male pheromones to stimulate Fos expression in the Me of DREADD-infected mice but not in non-infected females. Our results affirm the importance of Me signaling in females' chemosensory preferences and in the acute expression of lordosis. However, they provide no indication that Me signaling is required for the increase in receptivity normally seen after repeated hormone priming and testing with a male.

Apterous Brain Neurons Control Receptivity to Male Courtship in Drosophila Melanogaster Females

Courtship behaviours allow animals to interact and display their qualities before committing to reproduction. In fly courtship, the female decides whether or not to mate and is thought to display receptivity by slowing down to accept the male. Very little is known on the neuronal brain circuitry controlling female receptivity. Here we use genetic manipulation and behavioural studies to identify a novel set of neurons in the brain that controls sexual receptivity in the female without triggering the postmating response. We show that these neurons, defined by the expression of the transcription factor apterous, affect the modulation of female walking speed during courtship. Interestingly, we found that the apterous neurons required for female receptivity are neither doublesex nor fruitless positive suggesting that apterous neurons are not specified by the sex-determination cascade. Overall, these findings identify a neuronal substrate underlying female response to courtship and highlight the central role of walking speed in the receptivity behaviour.

Implementing foreign language curriculum innovation in a Chinese secondary school: An ethnographic study on teacher cognition and classroom practices

This article reports on a four-year-long ethnographic study on a curriculum innovation project introducing a weak form of communicative language teaching (CLT) at a Chinese secondary school. A total of ten teachers, who taught twelve project classes were observed across five stages of the project: the pre-project stage, the top-down stage, the bottom-up stage; the exam preparation stage, and the post-project stage, in an attempt to explore the changes that took place in the teacher's receptivity and classroom behaviors. Focusing on a focal informant (Marian, pseudonym), this paper illustrates how teacher cognition changed in accordance with the project goal and highlights how the trajectory of change was much more tangled and complicated than what was initially expected. Changes in the project teacher's teaching practices reflect the consistency between teacher cognition and classroom practices at the pre-project, the bottom-up and the post-project stages. In contrast, at the top-down and the exam stages of the innovation project, changes in teachers' cognition did not conform to changes in her classroom practices. These findings suggest the external pressure caused by top-down imperatives and high-stake exams might have caused the cognition-practices incongruence, which deserves language teacher educators' and administrators' further attention when promoting curriculum innovation.

Roles of estrogen receptor-alpha in mediating life span: the hypothalamic deregulation hypothesis.

In several species caloric restriction (CR) extends life span. In this paper we integrate data from studies on CR and other sources to articulate the hypothalamic deregulation hypothesis by which estrogen receptor-alpha (ER-α) signaling in the hypothalamus and limbic system affects life span under the stress of CR in mammals. ER-α is one of two principal estrogen-binding receptors differentially expressed in the amygdala, hippocampus, and several key hypothalamic nuclei: the arcuate nucleus (ARN), preoptic area (POA), ventromedial nucleus (VMN), antero ventral periventricular nucleus (AVPV), paraventricular nucleus (PVN), supraoptic nucleus (SON), and suprachiasmatic nucleus (SCN). Estradiol signaling via ER-α is essential in basal level functioning of reproductive cycle, sexually receptive behaviors, physiological stress responses, as well as sleep cycle, and other nonsexual behaviors. When an organism is placed under long-term CR, which introduces an external stress to this ER-α signaling, the reduction of ER-α expression is attenuated over time in the hypothalamus. This review paper seeks to characterize the downstream effects of ER-α in the hypothalamus and limbic system that affect normal endocrine functioning.

Factors associated with commercial sexual behavior among men who have sex with men in Shenzhen, China, in 2011-2015

Objective: To investigate the status and factors associated with commercial sexual behavior among men who have sex with men (MSM) in Shenzhen. Methods: A convenience sampling method was used to recruit MSM in Shenzhen from 2011 to 2015. Questionnaire-based interviews were conducted on a one-on-one basis. Data were collected, including socio-demographic information, HIV testing history, history of blood donation and drug abuse in the last 2 years, self-reported sexual orientation, role in homosexual behavior, and experience serving as a male sex worker and/or as a client of male sex workers. Blood samples (5 ml) were taken and tested for treponema pallidum and HIV antibodies. The rate of MSM serving as male sex workers among different age groups was analyzed using the Cochran-Armitage trend test. Factors associated with commercial sexual behavior were analyzed by univariate logistic regression and multivariate unconditional logistic regression. Results: Among the 3 040 MSM recruited, 341 (11.2%) reported having served as male sex worker. The prevalence rates of syphilis, HIV, and syphilis-HIV co-infection among all recruited MSM were 18.3% (556/3 040), 9.8% (297/3 040), and 5.1% (154/3 040), respectively. The prevalence rates of syphilis, HIV, and syphilis-HIV co-infection among those who served as male sex worker were 27.0% (92/341), 16.4% (56/341), and 8.8% (30/341), respectively, and the prevalence rates among MSM with no experience as male sex worker were 17.2% (464/2 699), 8.9% (241/2 699), and 4.6% (124/2 699), respectively. Compared with non-male sex worker MSM, male sex worker had a significantly higher prevalence rates of syphilis, HIV, and syphilis-HIV co-infection (with χ2 values of 19.41, 19.28, and 11.12, and P-values of <0.001,<0.001, 0.001, respectively). The results of the multivariate logistic regression analysis indicate that>30-year-old MSM or education level of college or above, reside in Shenzhen for 0.5-3.0 years or the living years above 3.0 years are less likely to serve as male sex worker compared with<30-year-old MSM, education level of high school or below, who reside in Shenzhen for less than 0.5 years; the OR (95%CI) values were 0.55 (0.42-0.71), 0.10 (0.06-0.14), 0.46 (0.31-0.68), and 0.23 (0.16-0.33), respectively. MSM having a monthly income of >5 000 yuan, drug abuse history, experience as male sex worker clients, and self-reported insertive and receptive anal sex behaviors were more likely to have experience serving as male sex worker compared with those having a monthly income of <3 000 yuan (OR=2.57, 95%CI: 1.85-3.57), no drug abuse history (OR=3.23, 95% CI: 2.14-4.87), no experience as male sex worker clients (OR =1.50, 95% CI: 1.04-2.15) and who engage in predominantly insertive anal sex behaviors (OR=1.77, 95% CI: 1.34-2.35). Conclusion: Age, education level, duration of residence in Shenzhen, monthly income, history of drug abuse, role in homosexual activity, and had experience commercial sex activity were associated with serving as a male sex worker among MSM. These factors need to be considered when designing syphilis/HIV prevention programs for MSM.

De plaats van cultuur in de opvoeding: een studie naar het belang dat ouders hechten aan culturele competenties en participatie bij hun adolescente kinderen

Research reveals that participation in social and cultural activities at a young age has positive effects on the participation in later life and the development of (cultural) competencies. Furthermore, research points at the prominent role parents fulfill in guiding their children towards cultural participation. Based on ethnographic fieldwork, Lareau identifies that this guidance is bound to social class. Mainly middle-class parents make use of the parenting-style Lareau calls ‘concerted cultivation’. In this research, Lareau’s thesis is tested in a Belgian (Flemish) context, by means of large-scale survey research. In this article, we investigate to what extent the importance parents attach to culture and the guidance of their children to participation is class-bound, and differs according to their cultural participation and gender. In the analyses, a dataset of 1.980 parents of adolescents is used. Multilevel analyses reveal that the receptive cultural participation behaviour of the parents is the strongest determinant for their parenting-style. Besides, especially the cultural components of social class (educational level, subject of study and job content characteristics) have an effect on the importance parents attach to cultural competencies in the education of children and actually guide their children towards more participation. Economic and material aspects of social class (e.g. occupational status and salary) on the contrary, only have an effect on the parents’ actual guiding behaviour (not on the importance they attach to culture). Although mothers and fathers value cultural characteristics to the same extent, we could speak of gendered cultivation, since mothers stimulate cultural participation of their children more.

Activation of Latent Courtship Circuitry in the Brain of Drosophila Females Induces Male-like Behaviors

SummaryCourtship in Drosophila melanogaster offers a powerful experimental paradigm for the study of innate sexually dimorphic behaviors [1, 2]. Fruit fly males exhibit an elaborate courtship display toward a potential mate [1, 2]. Females never actively court males, but their response to the male’s display determines whether mating will actually occur. Sex-specific behaviors are hardwired into the nervous system via the actions of the sex determination genes doublesex (dsx) and fruitless (fru) [1]. Activation of male-specific dsx/fru+ P1 neurons in the brain initiates the male’s courtship display [3, 4], suggesting that neurons unique to males trigger this sex-specific behavior. In females, dsx+ neurons play a pivotal role in sexual receptivity and post-mating behaviors [1, 2, 5, 6, 7, 8, 9]. Yet it is still unclear how dsx+ neurons and dimorphisms in these circuits give rise to the different behaviors displayed by males and females. Here, we manipulated the function of dsx+ neurons in the female brain to investigate higher-order neurons that drive female behaviors. Surprisingly, we found that activation of female dsx+ neurons in the brain induces females to behave like males by promoting male-typical courtship behaviors. Activated females display courtship toward conspecific males or females, as well other Drosophila species. We uncovered specific dsx+ neurons critical for driving male courtship and identified pheromones that trigger such behaviors in activated females. While male courtship behavior was thought to arise from male-specific central neurons, our study shows that the female brain is equipped with latent courtship circuitry capable of inducing this male-specific behavioral program.

Female feeding history impacts gonad development and reproductive timing in the wolf spiderSchizocosa ocreata(Hentz, 1844)

In mating systems that include semelparous reproduction and/or scramble competition, synchronous maturation of the sexes is vital for success. However, food limitation may alter the onset of maturation or the overall quality of the mature individuals and affect reproductive success. We examined the role of feeding history (well-fed vs. long-term deprivation) on female reproductive timing and its correlation with temporal patterns of receptivity behavior in the wolf spider Schizocosa ocreata (Hentz, 1844). We found that feeding history influenced developmental time and delayed maturation in long-term food-limited females. There was no significant difference in relative condition between treatments, yet well-fed females showed higher rates of receptivity. Peak receptivity behavior was correlated with the estimated overall mass of female ovaries/eggs, with females that possess larger ovaries and eggs showing more receptive behavior. This supports the hypothesis that while a food-limited female may attain maturity, the limiting factor underlying reproductive success is gonad maturation.

아버지의 양육참여도 및 양육행동이 아동의 행복감에 미치는 영향

The study examined the effects of fathers' parenting involvement and parenting behaviors on child happiness. A total of 270 elementary school students in 4th, 5th, and 6th grades (139 boys and 131 girls) participated in the study and completed the questionnaires. The collected data were analyzed using descriptive statistics, analyses of variances, correlation coefficients, and multiple regression. Fathers' parenting involvement and parenting behaviors did not differ by gender and grades, but child happiness partially differed in response to those factors. Additionally, child happiness was significantly positively correlated with fathers' parenting involvement and parenting behaviors. Moreover, fathers involvement in leisure activities, daily-life guidance, and study guidance, as well as their being warm receptive and rejective restrictive parenting behaviors were found to be significant variables influencing child happiness. Overall, the results of this study suggest fathers' play important roles in child happiness and that development of an education program for fathers is warranted.

Synergistic Effects of Reserve and Adaptive Personality in Multiple Sclerosis.

Cognitive reserve moderates the effects of gray matter (GM) atrophy on cognitive function in neurological disease. Broadly speaking, Reserve explains how persons maintain function in the face of cerebral injury in cognitive and other functional domains (e.g., physical, social). Personality, as operationalized by the Five Factor Model (FFM), is also implicated as a moderator of this relationship. It is conceivable that these protective mechanisms are related. Prior studies suggest links between Reserve and personality, but the degree to which these constructs overlap and buffer the clinical effects of neuropathology is unclear. We evaluated Reserve and FFM traits-Neuroticism, Extraversion, Openness, Agreeableness, and Conscientiousness-in a cohort of 67 multiple sclerosis (MS) patients. We also examined the extent to which FFM traits and aspects of Reserve interact in predicting cognitive processing speed. Retrospectively reported educational/occupational achievement was associated with higher Openness, and childhood social engagement was associated with higher Extraversion, Agreeableness, and Conscientiousness. Current involvement in exercise activities and social activities was associated with Extraversion, current involvement in hobbies was associated with Neuroticism, and current receptive behaviors were associated with Agreeableness and Conscientiousness. When tested as predictors, Conscientiousness and childhood enrichment activities interacted in predicting cognitive processing speed after accounting for age, disease duration, disability, and GM volume. Childhood enrichment activities and Conscientiousness have a synergistic effect on cognitive processing speed. Current findings have implications for using psychological interventions to foster both Reserve and adaptive personality characteristics to stave off clinical symptoms in MS. (JINS, 2016, 22, 920-927).

Effects of Long-Term Flutamide Treatment During Development on Sexual Behaviour and Hormone Responsiveness in Rams.

Testosterone exposure during midgestation differentiates neural circuits controlling sex-specific behaviours and patterns of gonadotrophin secretion in male sheep. Testosterone acts through androgen receptors (AR) and/or after aromatisation to oestradiol and binding to oestrogen receptors. The present study assessed the role of AR activation in male sexual differentiation. We compared rams that were exposed to the AR antagonist flutamide (Flu) throughout the critical period (i.e. days 30-90 of gestation) to control rams and ewes that received no prenatal treatments. The external genitalia of all Flu rams were phenotypically female. Testes were positioned s.c. in the inguinal region of the abdomen, exhibited seasonally impaired androgen secretion and were azospermic. Flu rams displayed male-typical precopulatory and mounting behaviours but could not intromit or ejaculate because they lacked a penis. Flu rams exhibited greater mounting behaviour than control rams and, similar to controls, showed sexual partner preferences for oestrous ewes. Neither control, nor Flu rams responded to oestradiol treatments with displays of female-typical receptive behaviour or LH surge responses, whereas all control ewes responded as expected. The ovine sexually dimorphic nucleus in Flu rams was intermediate in volume between control rams and ewes and significantly different from both. These results indicate that prenatal anti-androgen exposure is not able to block male sexual differentiation in sheep and suggest that compensatory mechanisms intervene to maintain sufficient androgen stimulation during development.

Self-Exposure to the Male Pheromone ESP1 Enhances Male Aggressiveness in Mice

Exocrine gland-secreting peptide 1 (ESP1) released into male tear fluids is a male pheromone that stimulates sexually receptive behavior in female mice via the vomeronasal sensory system. ESP1 also induces c-Fos expression in male brain regions distinct fromthose in females. However, behavior in males following ESP1 exposure has not been examined. In the present study, we show that ESP1, in conjunction with unfamiliar male urine, enhances male aggression via the specific vomeronasal receptor V2Rp5. In addition, male mice that secrete ESP1 but lack V2Rp5 exhibit a lower level of aggressiveness than do mice that express V2Rp5. These results suggest that ESP1 not only acts as a male pheromone in both sexes but also serves as an auto-stimulatory factor that enhances male aggressiveness by self-exposure. Finally, re-activation of ESP1-induced c-Fos-positive neurons by using the designer receptor exclusively activated by designer drug (DREADD) approach resulted in enhancement of sexual and aggressive behaviors in female and male mice, respectively, indicating that sexually dimorphic activation in the brain is a neural basis for the sex-specific behavioral responses to ESP1.

Signalling behaviour is influenced by transient social context in a spontaneously ovulating mammal

Behavioural flexibility may be a mechanism that confers resilience in the face of rapid environmental changes. However, behavioural flexibility is constrained by a number of factors, including physiology. Giant pandas, Ailuropoda melanoleuca, are an endangered ursid found in fragmented habitats at social densities far below their historical carrying capacity. Giant pandas use chemical, visual and acoustic signals to communicate during reproduction. Females are seasonally mono-oestrous, ovulate spontaneously and, thus, fertility and sexual receptivity are temporally constrained. However, because signalling behaviour is energetically costly, the ability to adjust signalling effort according to the presence of an appropriate receiver would be beneficial. Using female giant pandas at the Wolong Breeding Centre in Sichuan, China, we explored the interaction between social context and reproductive status on signalling and maintenance behaviours. To do so, we used linear mixed models and an information-theoretic approach to assess the temporal relationship between signalling behaviours and the timing of first mating. Our results show that signalling behaviour is correlated with time relative to first mating and that multimodal signalling was the best predictor of this timing. Furthermore, we found that social context also influenced signalling behaviours. Specifically, vocal and visual signalling effort were lower in the exclusive presence of other females, reducing the degree of wasted effort. Thus, in spite of the temporal constraints that spontaneous ovulation might impose on sexually proceptive and receptive behaviour, females can modify their behavioural efforts during the preovulatory period according to the prevailing social context. As an iconic endangered species, the giant panda may benefit from research that informs management. Our study provides information that can be applied to increase the success of conservation breeding efforts and their associated reintroduction programmes.

Sexual Receptivity and Mating Behavior ofDiaeretiella rapae(Hymenoptera: Aphidiidae)

Sexual receptivity and mating behavior of the cabbage aphid parasitoid Diaeretiella rapae McIntosh were studied under laboratory conditions. When male and female D. rapae were paired females, males actively courted females, while females kept themselves away from males and displayed grooming behavior. Males became sexually active immediately after emergence and made mating attempts, whereas females took longer to become receptive to mating. Virgin males quickly detected female presence, resulting in a significant increase in the frequency of male courtship. Males encountered females within 5 min of pairing, and 90% of the males displayed courtship behavior by fanning their wings and chasing the female for mating. Before successful mating, males tended to approach females more often than females approached males. The time between pairing and mating in newly emerged females was longer than in 1-d-old females. The overall mating success in D. rapae was about 70%, and successful mating was largely dependent on females’ decision to mate. Unlike females, males remained sexually receptive after mating.

Assimilation in American Life: An Empirical Assessment of Milton Gordon’s Multi-dimensional Theory

This study empirically assesses Milton Gordon's theory of interrelated stages of assimilation. I focus on one small but salient religious minority—American Jews—to show how structural assimilation is associated with other dimensions of assimilation: marital, identification, and behavior reception. Findings from multivariate analyses suggest that structural assimilation encourages Jews to marry non-Jews. Such a marriage composition has become a major determinant of identificational assimilation, with non-Jewish social relationships having important if somewhat weaker association with group identification. Social and economic attainments are moderate factors of identificational behavior that may sometimes strengthen, rather than weaken, religio-ethnic identification. The various components of structural assimilation are not significant for reception assimilation. The findings are discussed in relation to the functionalism concept, in connection with the more recent literature on immigration and assimilation and in view of the changing social context of America in the second half of the twentieth century from the dominance of the melting pot ethos to cultural pluralism.