Period Of Cohabitation Research Articles

Cambios en las estructuras de los hogares Rurales. Formas de adaptación y resiliencia

This paper examines the capacity of household structures to respond to environmental conditions. First, it looks at the relationship between demographic sustainability and the resilience of rural households. Afterwards, it examines basic mechanisms of adaptation between household structures and the socioeconomic environment based on the theories of Chayanov and Le Play. The empirical research, carried out in rural Spain, found that household structures first underwent a process of modernization, followed more recently by certain diversification. Within this process, what stands out is the number of adult children that extend the period of cohabitation with their parents, constituting similar strategies to those traditionally employed by stem families. In the current context of rural areas, household structures have shown resilience in the face of socioeconomic changes.

Is ethnicity a risk factor for developing preeclampsia? An analysis of the prevalence of preeclampsia in China

Preeclampsia is a major complication of pregnancy. Risk factors for preeclampsia include population and regional ethnicity. Chinese women living outside the Chinese mainland have a lower prevalence of preeclampsia than resident Caucasians. We performed a retrospective study to identify potential factors that may be associated with developing preeclampsia in China. A total of 67,746 pregnant women were included in this study from 2002 to 2011. Data included maternal age, maternal body mass index (BMI), age at marriage, parity, gestation and blood pressure at diagnosis, proteinuria, and birth weight. In the study period, 1301 (1.92%) nulliparous women developed preeclampsia. The prevalence of mild or severe preeclampsia was 1.42% or 0.49%, respectively. The average BMI was 21.61 kg m(-2). On the basis of the WHO BMI classification, 78.8% of women were of normal BMI, 18.3% were overweight and 2.9% were obese. A total of 37.8% of preeclamptic women had lived with the same partner for less than 1 year, which was significantly higher than those healthy pregnant women who did not develop preeclampsia (24.2%). The prevalence of preeclampsia in China is low compared with Caucasians, and the contribution to this lower prevalence may be dependent on BMI or lifestyle including period of cohabitation with the partner. Our data suggest that Chinese ethnicity may be a factor responsible for the low risk of developing preeclampsia in the populations studied.

"Stay Tuned": The Role of ICTs in Elderly Life.

Ageing in western society has become a key issue in political and academic debate: politicians, sociologists, doctors, demographers, psychologists, economists are trying to understand how ageing will impact our future society. In this frame, media and communication technologies seem to be more and more relevant for the elderly, thanks to those services and devices helping people to grow old actively. Technologies, the Internet and ICTs could help the elderly to improve their quality of life, to be healthy and independent and to get better assistance. Our ongoing research investigates the relationship between the elderly and use of technologies, and explores the role played by media and ICTs in building a friendly and positive environment for the elderly, and in constructing and maintaining social relations and promoting healthy ageing. Specifically, the research will investigate the use of ICTs by the elderly by taking into account two different perspectives: a) Exchanges between generations: lengthening of life corresponds to a longer period of cohabitation between at least three generations (grandparents, children, grandchildren), and also of co-use of digital media. The research wants to investigate relations between two age groups (grandparents and grandchildren; young people and older people) to understand the dynamics of intergenerational mutuality in the use of technologies and ICTs. b) Media, ICTs, Health: the Western world is increasingly populated by elderly population. Technologies and ICTs can help elderly people to improve their quality of life, to be healthy and independent and to get better assistance. ICTs should encourage active ageing and, in the case of health technologies, new models of care. The project, lasting 1 year, is based on (1) a survey on young elderly (65-74 yrs) population in Italy, and (2) a field-work which consists of family interviews and ethnographical sections in natural contexts.

μ-Opioid Receptors within Subregions of the Striatum Mediate Pair Bond Formation through Parallel Yet Distinct Reward Mechanisms

The prairie vole is a socially monogamous rodent that is an excellent animal model for studies of the neurobiology of social attachment. Such studies have demonstrated that activation of reward circuitry during social interactions facilitates pair bond formation. Within this circuitry, μ-opioid receptors (MORs) modulate naturally rewarding behavior in an anatomically segregated manner; MORs located throughout the striatum (dorsal striatum, NAc core, and the entire NAc shell) are implicated in general motivational processes, whereas those located specifically within the dorsomedial NAc shell mediate positive hedonics (and are referred to as a "hedonic hotspot"). The purpose of the present study was to determine whether MORs within these distinct subregions differentially mediate pair bond formation. We first used receptor autoradiography to compare MOR binding densities between these regions. MOR binding was significantly higher in the NAc core and dorsomedial NAc shell compared with the ventral NAc shell. We next used partner preference testing to determine whether MORs within these subregions differentially mediate pair bonding. Blockade of MORs using 1 or 3 μg of H-d-Phe-Cys-Tyr-d-Trp-Arg-Thr-Pen-Thr-NH2 within the dorsal striatum decreased mating during the cohabitation period and inhibited partner preference formation. In contrast, blockade of MORs within dorsomedial NAc shell inhibited partner preference formation without effecting mating behavior, whereas other regions were not involved. Thus, MORs within the dorsal striatum mediate partner preference formation via impairment of mating, whereas those in the dorsomedial NAc shell appear to mediate pair bond formation through the positive hedonics associated with mating.

Subchronic and reproductive toxicity of whole dried Hoodia parviflora aerial parts in the rat

Hoodia parviflora is being developed commercially for use in weight loss food and dietary supplement products. As part of the safety assessment process for H. parviflora, a freeze dried powder preparation was tested in a 90-day oral toxicity study with reproductive/recovery component in rats. Groups of 10 male and female Sprague-Dawley rats were administered H. parviflora dried powder at doses of 0, 100, 250, and 350 mg/kg body weight/day by gavage for an 11-week pre-mating period and a 14-day co-habitation period, and for females, through lactation day 4. An additional 5 rats/sex/group received 0 or 350 mg/kg bw/day for 90 days and were sacrificed 28 days after cessation of treatment. Statistically significant, non-adverse reductions in body weight, body weight gain, food consumption and food efficiency were observed at 250 and 350 mg/kg/day in females. Food consumption was reduced in high-dose males. There were no adverse effects on hematological, blood biochemical, coagulation or urinalysis parameters or on the results of the functional observational battery and histopathological examinations. No evidence of any effect was noted on reproductive or developmental parameters. The NOAEL for dried H. parviflora powder was 350 mg/kg bw/day, the highest permissible dose tested, for both male and female rats.

Períodos de interferência de plantas daninhas na cultura do girassol

Objetivou-se neste trabalho determinar os períodos de interferência de plantas daninhas na cultura do girassol. Foram realizados dois experimentos com o girassol híbrido Helio 250, sendo um conduzido no verão e o outro, no inverno. Para ambos, o delineamento experimental utilizado foi em blocos casualizados, com quatro repetições, e cada unidade experimental foi constituída de cinco linhas de plantas com 6,0 m de comprimento, espaçadas por 0,7 m. No experimento de verão foram avaliados oito períodos de convivência e controle de plantas daninhas: 10, 20, 30, 40, 50, 60, 70 e 88 dias após a emergência (dae). No experimento de inverno, os períodos foram: 7, 14, 21, 28, 38, 48, 58 e 82 dae. Avaliaram-se a massa da matéria seca e a área foliar das plantas de girassol, produtividade, massa de mil aquênios e massa da matéria seca de plantas daninhas. Estimaram-se os períodos anteriores à interferência (PAI), períodos críticos de prevenção à interferência (PCPI) e períodos totais de prevenção à interferência (PTPI). Considerando-se a produtividade de aquênios no verão, o PAI foi de 16 dae da cultura, o PTPI, de 39 dae e o PCPI abrangeu 23 dias do ciclo da cultura. No inverno, o PAI foi de 12 dae, o PTPI estendeu-se até os 34 dae, resultando em um PCPI de 22 dias.

CD4+ regulatory T lymphocytes in preeclamptic women and in their newborns: preliminary results.

Event Abstract Back to Event CD4+ regulatory T lymphocytes in preeclamptic women and in their newborns: preliminary results. David F. Navarro Barquín1, 2, Leonel Daza Benítez2*, Sergio Lopez Briones3, Ana Laura Macías Rocha4 and Alma Patricia González5 1 University Of Guanajuato, Department of Medicine and Nutrition, Mexico 2 High Specialty Medicine Unit Number 48, Mexican Institut of Social Security, Research Division, Mexico 3 University of Guanjuato, Deparment of Medical Sciences, Mexico 4 High Specialty Medicine Unit Number 48, Mexican Institut of Social Security, Gynecology Division, Mexico 5 High Specialty Medicine Unit Number 48, Mexican Institut of Social Security, Neonatal Division, Mexico Introduction: Preeclampsia is one of the most important cause of mortality and morbility in pregnancy worldwide right below obstetric hemorrhage and in Mexico it takes the first place in maternal dead, also is consider the first cause of preterm birth associated to maternal cause. 1-2 One of the bigger challenges in these pathology is that the pathogenic mechanism is still unknown, at the moment there are only hypothesis about it and one of the most important is that a immunological mechanism is involve in their genesis. This hypothesis is supported primarily by epidemiological studies where it was associated with the first pregnancy, short sexual cohabitation period, diminished exposition to sperm (assisted reproduction technics) and change of paternity in secondary pregnancies. 3-6 The pathogenesis of the immunological mechanism is study by different angles one is the diminish of the population of the Tregs cells (CD4+CD25+FOXP3+) that are documented that they increase during healthy pregnancy 7, and first studied their decrease in the decidua and in peripheral blood at the third trimester and documented the decrease of these population 8. Nevertheless there are also some authors that haven’t found these alterations, that is why the role of this population is still uncertain. 9 The immune profile of the newborn is still in study, and is basically affected by the gestational age of the newborn, but certain parameters are already established and their proportion in the umbilical cord blood 10. However we search in the pubmed database information about references of if there is alteration in the newborns of mothers with this pathology. Objective: Our aim was to study the proportion of regulatory T cells in preeclamptic women and in their newborns. Methods: The CD4+CD25+high FOXP3+, CD3+, CD4+, CD8+, CD20+, TCR gamma-delta, CD69+ surface markers and hormone profile were measured in 23 women with preeclampsia (PE) and in 14 of their newborns the T-reg, CD3+, CD4+, CD8+, CD20+, TCR gamma-delta, CD69+ surface markers were measured also the Fenton prescriptive growth charts for classifying into intrauterine growth-restricted and small for gestational age infants were applied. Fourteen healthy women paired by age and pregnancy number (HC) and 5 newborns paired by gestational age were included as controls. To measure the cell surface markers was use a FAC scan canto II ®, software: BD FACSDiva 6.1.3 Beckton Dickinson. The statistical analysis used was t student for the parametric variables and logistic regression in SPSS 15. Results: The T-regs cells proportion was 2.93% in PE and vs. 5.54% in HC (p = 0.031). The CD4+CD25+high cells were in PE 3.71% vs. HC 7.41% in HC, (p= 0.020); Total IgG level was 847mg/dl in PE vs. 955 mg/dl in HC (p= 0.117). In the umbilical cord blood samples we found 4.56% in T regs cells in PE vs.8.54% in HC (p = 0.201). While gamma-delta T-cells were 3.61 in PE vs. 20.87% in HC, (p= 0.063). Interestingly, CD4+CD69+ cells were 10.03% in PE and 28.22% in HC (p=0.190). Conclusions: We found decreased proportion of T-regs cells in preeclamptic women as previously have been reported by other authors. Also we observed a tendency of decreasing levels of IgG in women with PE, in relation to the hypothesis of the increased of immunologic response mediated by T cells. Regarding, hormone profiles we found no statistical significance. In the newborns we found a tendency of decreased T-regs cells, gamma-delta T cells, and a low expression of CD69 on CD4 cells, an important early activation marker expressed by lymphocytes. Nevertheless, the number of patients included in this study is still small, but we can suggest that PE has a repercussion in the immunological cell profile of their newborns, and it could be an explanation for the increased morbility and mortality in the newborns.

Do wild fish species contribute to the transmission of koi herpesvirus to carp in hatchery ponds?

The koi herpesvirus (KHV) has spread worldwide since its discovery in 1998 and causes disease and mortality in koi and common carp populations with a high impact on the carp production industry. Many investigations have been conducted to examine ways of distribution and to identify possible transmission vectors. The answers, however, raise many new questions. In the present study, different wild fish species taken from carp ponds with a history of KHV infection were examined for their susceptibility to the virus. In the tissue of these fish, the virus load was determined and it was tested whether a release of the virus could be induced by stress and the virus then could be transferred to naive carp. Wild fish were gathered from carp ponds during acute outbreaks of virus-induced mortality in summer and from ponds stocked with carp carrying a latent KHV infection. From these ponds, wild fish were collected during the harvesting process in autumn or spring when the ponds were drained. We found that regardless of season, temperature variation, age and infection status of the carp stock, wild fish from carp ponds and its outlets could be tested positive for the KHV genome using real-time PCR with a low prevalence and virus load. Furthermore, virus transfer to naive carp was observed after a period of cohabitation. Cyprinid and non-cyprinid wild fish can therefore be considered as an epidemiological risk for pond carp farms.

Prenatal di‐n‐butyl phthalate exposure alters reproductive functions at adulthood in male rats

This study was aimed to investigate the reproductive health in adult male rats exposed to di-n-butyl phthalate (DBP) during embryonic development. Pregnant rats were injected with DBP and F1 male rats were weaned and on postnatal day 100, used for mating with normal cycling females to assess reproductive performance. After completion of cohabitation period, rats were analyzed for other reproductive end points. Transplacental exposure to DBP significantly decreased fertility in adult male rats. Prenatal exposure to DBP significantly decreased sperm density, number of motile sperms, viable sperms, and hypoosmotic swelling tail coiled sperms with an increase in morphological abnormalities in sperms. Testicular steroidogenic enzyme activity levels and serum testosterone levels were significantly decreased in rats exposed to DBP during embryonic development. In conclusion, transplacental exposure to DBP impairs male reproductive performance by decreasing steroidogenesis and spermatogenesis.

To mate or not to mate? Mate preference and fidelity in monogamous Ansell's mole-rats,Fukomys anselli, Bathyergidae

According to a hypothesis addressing the evolution of eusociality in mole-rats, the female (queen) is not able to raise her (first) offspring without a mate and thus to found a family. Therefore, we predict that the reproductive male (king) has to be socially faithful. In this study we tested this prediction and addressed the related question whether or not the presentation of a new female provokes enhanced sexual interest in male Ansell's mole-rats (Fukomys anselli).We performed behavioral partner preference tests in Ansell's mole-rats where two animals of choice were presented to a subject without allowing direct access. The kings spent significantly more time sniffing an unfamiliar queen or female than their own mate. If given the choice between an unfamiliar queen and her respective non-reproductive daughter, however, the tested kings significantly preferred the queen. In contrast, queens did not show a preference for either their own mate, an unrelated unfamiliar king, or a non-reproductive male.In a second experiment, we allowed the males to access the compartment of an unfamiliar female while their respective family stayed in an adjacent compartment. Only the non-reproductive adult males seized their chances to copulate with the unfamiliar female whereas the kings remained faithful. When reversing the test condition (i.e. females were given access to an unfamiliar male), aggressiveness of the males impeded sexual encounters in most cases. We recorded only three copulations, all of them between queens and non-reproductive males.We conclude that the reproductive status is crucial for reproductive decisions. Furthermore, the presence of family members influences the kings' behavior. Since in Ansell's mole-rats, repeated copulations over a longer period of cohabitation are necessary for ovulation and fertilization, the kings' sexual fidelity could have been expected. We postulate that the maintenance of Ansell's mole-rats' families depends on the kings' faithfulness.

The Accidental Transfer of Gyrodactylus (Monogenea) during Short Duration Fish Transportation

The potential of parasite transfer to an alternative host during short periods of cohabitation was explored. The work described in this paper suggests that either the field sampling process itself or the subsequent transportation of multiple fish species in the same container, may affect the correct allocation of parasites to hosts, and the diagnosis, management and control of gyrodactylosis in a variety of fish. Gyrodactylus infected specimens of three-spine sticklebacks Gasterosteus aculeatus, minnows Phoxinus phoxinus and stone loach Barbatula barbatula from one Scottish river were cohabited with one another in small volumes of water for 3 h. The study found that a small number of Gyrodactylus spp. transfer to atypical hosts. This study indicates that personnel involved in fish disease surveillance programmes should be aware of the possible consequences, in terms of inter-host transfer, of transporting multiple species in the same transport vessel. Diagnosticians should be aware of the facts that fish may act as temporary/paratenic hosts and that the apparent gyrodactylid fauna present following transport may not reflect that encountered under normal circumstances.

Four rounds in a row: The impact of presidential election outcomes on legislative elections in France

This article focuses on the consequences of presidential election outcomes on legislative election results in the context of the French semi-presidential regime. Through an analysis based on aggregated national- and constituency-level data, it shows that presidential elections do have an impact on legislative elections. Furthermore, this impact is proven to affect the balance between presidential majority and opposition coalitions and between core and fringe parties. The 2000 and 2002 reforms aligning presidential and National Assembly mandates and instituting a situation of repeated honeymoon elections significantly decrease the likelihood of any future period of cohabitation between a president and an Assembly from opposing partisan coalitions. They also foster presidentialization and explain the relative decrease in fragmentation within the party system.

Changes in Paternal Responsiveness of Prairie Voles (Microtus ochrogaster) in Response to Olfactory Cues and Continuous Physical Contact with a Female

AbstractIn mammals, paternal care is rarely displayed, and we know little about the mechanisms regulating this behavior. Prairie voles (Microtus ochrogaster) are ideal mammals for the study of paternal behavior because they are a monogamous, bi‐parental species that is easily raised in the laboratory. Paternal responsiveness occurs at moderate levels in sexually‐naive voles and is heightened following a short cohabitation period of 72 h with a female. To determine how increased levels of paternal care are maintained after the initial cohabitation period, we tested the paternal behavior of males that were housed in isolation, were in physical contact with a female, or were exposed to various olfactory cues. The results indicate that the absence of odor cues from a female did not diminish the male’s motivation to care for infants following the initial cohabitation period. In contrast, odor cues from a male appeared to negatively influence the male’s paternal tendencies. The data also show that males that had continuous physical contact with a female spent more time responding paternally and more time hovering over the young compared to males that were housed alone. Together, these results suggest that although paternal behavior is maximized in response to continuous physical contact with females, olfactory cues may not be necessary for the maintenance of heightened paternal behavior.

Trop pauvre pour se marier ? Crise de l'emploi urbain et entrée en première union des hommes au Burkina Faso.

En s’appuyant sur une enquete biographique detaillee realisee en 2000 au Burkina Faso (EMIUB), cet article etudie l’effet de la deterioration des conditions d’emploi en milieu urbain au cours des annees 1990 sur l’entree en premiere union des hommes. Les resultats montrent que la premiere mise en couple des jeunes citadins est aujourd’hui clairement retardee et que le mode d’entree en union s’est egalement transforme. Les periodes d’union libre sont plus frequentes parmi les hommes de la jeune generation (1965-1974), certaines celebrations matrimoniales sont aujourd’hui reportees ou annulees et l’ensemble du processus matrimonial a tendance a s’etirer dans le temps. Si, pour la generation la plus ancienne (1945-1954), le premier mariage n’etait pas une affaire d’argent, pour les hommes de la plus jeune generation, en revanche, l’obtention d’un emploi remunere est cruciale pour la formation d’une premiere union. Les resultats montrent egalement que, dans un contexte ou les emplois urbains sont de plus en plus informels, on assiste a l’emergence d’inegalites face au mariage entre les hommes de la jeune generation selon le type d’emploi qu’ils occupent.

CLINAL VARIATION IN MHC DIVERSITY WITH TEMPERATURE: EVIDENCE FOR THE ROLE OF HOST?PATHOGEN INTERACTION ON LOCAL ADAPTATION IN ATLANTIC SALMON

In vertebrates, variability at genes of the Major Histocompatibility Complex (MHC) represents an important adaptation for pathogen resistance, whereby high allelic diversity confers resistance to a greater number of pathogens. Pathogens can maintain diversifying selection pressure on their host's immune system that can vary in intensity based on pathogen richness, pathogen virulence, and length of the cohabitation period, which tend to increase with temperature. In this study, we tested the hypothesis that genetic diversity of MHC increases with temperature along a latitudinal gradient in response to pathogen selective pressure in the wild. A total of 1549 Atlantic salmon from 34 rivers were sampled between 46 degrees N and 58 degrees N in Eastern Canada. The results supported our working hypothesis. In contrast to the overall pattern observed at microsatellites, MHC class II allelic diversity increased with temperature, thus creating a latitudinal gradient. The observed temperature gradient was more pronounced for MHC amino acids of the peptide-binding region (PBR), a region that specifically binds to pathogens, than for the non-PBR. For the subset of rivers analyzed for bacterial diversity, MHC amino acid diversity of the PBR also increased significantly with bacterial diversity in each river. A comparison of the relative influence of temperature and bacterial diversity revealed that the latter could have a predominant role on MHC PBR variability. However, temperature was also identified as an important selective agent maintaining MHC diversity in the wild. Based on the bacteria results and given the putative role of temperature in shaping large-scale patterns of pathogen diversity and virulence, bacterial diversity is a plausible selection mechanism explaining the observed association between temperature and MHC variability. Therefore, we propose that genetic diversity at MHC class II represents local adaptation to cope with pathogen diversity in rivers associated with different thermal regimes. This study illuminates the link between selection pressure from the environment, host immune adaptation, and the large-scale genetic population structure for a nonmodel vertebrate in the wild.

대학생의 노인과 노화에 대한 태도가 조모와의 친밀감에 미치는 영향

This study examines undergraduate students' intimacy toward the grandmother and their attitudes toward the elderly and aging. The study also identifies the variances that influence undergraduate students' intimacy toward the grandmother. The subjects were 397 undergraduates. Statistical analysis was conducted to examine frequency, percentage, mean, standard deviation, Cronbach's , t-test, Duncan test, ANOVA, and stepwise multiple regression. The results of this study were as follows; 1) The undergraduates' attitudes were mid-range, but their intimacy level toward their grandmother was high. 2) The undergraduates' intimacy level toward the grandmother differed significantly according to gender, experience of cohabitation, the presence of her, and religion, and it showed a significant correlation with attitudes toward the elderly and aging traits, period of cohabitation, and frequent contact with the grandmother. The undergraduates' intimacy level toward grandmother-in-low, however, was significantly different according to the religion. There was also had a significant correlation with the undergraduate students' attitudes toward the elderly and aging traits. 3) The variables that affect the undergraduates' intimacy level toward the grandmother were attitude, frequency of contact with the grandmother, gender, period of cohabitation, experience of cohabitation, and the presence of the grandmother, which explained about 35% of total variance. Attitudes toward the elderly and aging traits were very important variables for undergraduates' intimacy with their grandmother. The undergraduates' intimacy toward grandmother-in-low was affected by the variables of attitude, religion, experience of volunteer, frequency of contact with the grandmother, gender, and the presence of grandmother, which explained about 24% of the total variance. Attitude toward the elderly and aging traits were the most important variables for undergraduates' intimacy with their grandmother-in-low.

Fertility and early embryonic development toxicity of penequine hydrochloride in mice

Penequine hydrochloride, a novel anticholinergic agent, was developed as an effective treatment for organophosphorus intoxication. The potential for penequine hydrochloride to induce fertility and early embryonic developmental toxicity was evaluated in AMMS-1 mice. Totally 320 healthy, sexual mature and nulliparous AMMS-1 mice were orally treated with the chemical in drinking water at dose levels of 0, 2.5, 12.5 and 62.5 mg/L from 60 days before cohabitation to successful copulation in 160 males and from two weeks before cohabitation to GD 6 in 160 females, respectively. All the parental mice were observed for body weights, water consumption and any abnormal change during treatment period. Caesarean sections were carried out on day 14 of pregnancy in half assumed-pregnant females, and all the intrauterine data were recorded. Pups naturally delivered by the other half females were weighed, and examined for viability, sex ratio and gross malformations. About 7 days after cohabitation period, all the paternal males were examined for epididymal and testicular weights, sperm number and sperm motility. The decreases in fertility/fecundity indices and maternal weight gain were found at high-dose level in both caesarean sections and natural delivery observations. The primary developmental toxicity of the chemical included decreases in relative organ (epididymis, liver and lung) weights at mid- and high-dose levels in pups on postnatal day (PND) 35. The cause of both the decreased fertility/fecundity indices in F0 males and the decreased relative organ weights in F1 pups are not well known but are presently under investigation. Under the experimental conditions, penequine hydrochloride did not produce any adverse effects (expect the decreases in certain relative organ weights) up to and including 12.5 mg/L (2.53 mg/kg/day in males and 2.19 mg/kg/day in females) corresponding to approximately 72 times above anticipated dosage in human.

The Why and What of Intimate Conflict: Effect of the Partners’ Divergent Perceptions on Verbal Aggression

The aim of this study is to explore the effect on expressions of verbal aggression of intimate partners’ divergent perceptions of what the conflict is about (its subject) and why fight over it (its motive), together with the effect of the period of cohabitation. The study focused on the couple as the unit of analysis. A structured self-report questionnaire was administered to a stratified probability sample drawn from the general population in Israel, including 452 couples (904 men and women). Findings show that there is an association between the couples’ divergent perceptions of the conflict motive and of its subject, and that these disagreements amplify the partners’ aggression toward each other. However, the perception of conflict motive has a stronger effect on the expressions of aggression than that of conflict subject, while duration of cohabitation has a moderating effect on the divergent perceptions of conflict subject and on aggression between the partners. The discussion embraces both the theoretical and practical implications of the findings, as well as the limitations of the study.

Rythmes d'activité locomotrice chez deux insectes parasitoïdes sympatriques : Eupelmus orientalis et Eupelmus vuilleti (Hyménoptère, Eupelmidae)

With an automatic image analysis device, we studied the temporal distribution of the locomotor activity of E. orientalis and E. vuilleti during 24 h, and over several days to know whether the activity rhythms of these two Eupelmidae play a role in their competitive interactions. The analysis of locomotor activity rhythms of E. orientalis and E. vuilleti shows that the locomotor activity of both species presents daily cyclic variations. These two Eupelmidae have similar activity rhythms. Displacements of these parasitoids essentially take place during the photophase. But the activity of E. vuilleti is earlier, because the individuals of this species start their activity on average 4 to 5 h earlier than those of E. orientalis. E. vuilleti begins its displacements several hours before the onset of lighting, whereas E. orientalis is active only in the presence of the light. This shift of starting activity is thus a factor allowing these concurrent species to minimize their interactions during the cohabitation period in traditional granaries after the harvests of cowpea. To cite this article: A. Ndoutoume-Ndong et al., C. R. Biologies 329 (2006).

The disappearing link between premarital cohabitation and subsequent marital stability, 1970–2001

Previous research has demonstrated that marriages preceded by premarital cohabitation have higher rates of dissolution than those in which the couple marry without first living together. Most of this research relies on data generated by couples who cohabited in the 1970s and early 1980s when premarital cohabitation was relatively uncommon and usually of brief duration. Since then, premarital cohabitation in Australia has become normative and thus less prone to selection effects. The period of premarital cohabitation has also lengthened and is thus more likely to provide opportunities to screen out unviable matches. This paper uses national survey data from Australia to explore whether, in the light of these changes, the previously observed higher level of marital dissolution among those who live together before marrying has persisted. It demonstrates that the higher risk of marital dissolution among those who cohabited before marriage has declined substantially in the 1990s marriage cohort and, after controlling for selection factors, has disappeared altogether.