Directions pour la conscience d'un roi , composées pour l'instruction de Louis de France, duc de Bourgogne ; par François de Salignac de La Motte Fénelon,..

Collection : Bibliothèque d'une maison de campagne ; t. 52

Sex-mediated herbivory by galling insects on Baccharis concinna (Asteraceae)

The interaction patterns between the dioecious shrub Baccharis concinna Barroso (Asteraceae) and its speciose galling insect community were studied in southeastern Brazil. Two hypotheses were tested in this study: "the differential reproduction and growth hypothesis" that predicts that male plants present fewer reproductive structures and are larger than female plants; and the 'sex-biased herbivory hypothesis' that predicts that male plants support a larger abundance of insect galls than female plants. Plants did not show sexual dimorphism in growth (= mean leaf number). However, male plants had longer shoots and a lower average number of inflorescences than female plants. These results corroborate the hypothesis that male plants grow more and reproduce less than female plants. No statistically significant difference was found in the number of galls between male and female plants, but a sex by environmental effect on gall number was detected. When each species of galling insect was individually analyzed per population of the host plant, the rates of attack varied between sex and population of the host plant, and they were highly variable among the species of galling insects. These results highlight the importance of the interaction between sex and environment in the community structure of galling insects and indicate that other variables besides host sex may influence the patterns of attack by galling herbivores.

Divers écrits ou mémoires sur le livre intitulé "Explication des maximes des saints" ; Préface sur l'instruction pastorale donnée à Cambray le quinzième de Septembre 1697 ; Premier écrit, ou Mémoire de M. l'archevesque de Meaux à M. l'archevesque de Cambray ; Second écrit, ou Mémoire de M. l'evesque de Meaux : pour répondre à quelques lettres, où l'état de la question est détourné ([Reprod.]) / par messire Jacques-Bénigne Bossuet,...

Collection : French books 1601-1700 ; 53.4

Resurgence of HIV infection among men who have sex with men in Switzerland: mathematical modelling study.

BACKGROUND: New HIV infections in men who have sex with men (MSM) have increased in Switzerland since 2000 despite combination antiretroviral therapy (cART). The objectives of this mathematical modelling study were: to describe the dynamics of the HIV epidemic in MSM in Switzerland using national data; to explore the effects of hypothetical prevention scenarios; and to conduct a multivariate sensitivity analysis. METHODOLOGY/PRINCIPAL FINDINGS: The model describes HIV transmission, progression and the effects of cART using differential equations. The model was fitted to Swiss HIV and AIDS surveillance data and twelve unknown parameters were estimated. Predicted numbers of diagnosed HIV infections and AIDS cases fitted the observed data well. By the end of 2010, an estimated 13.5% (95% CI 12.5, 14.6%) of all HIV-infected MSM were undiagnosed and accounted for 81.8% (95% CI 81.1, 82.4%) of new HIV infections. The transmission rate was at its lowest from 1995-1999, with a nadir of 46 incident HIV infections in 1999, but increased from 2000. The estimated number of new infections continued to increase to more than 250 in 2010, although the reproduction number was still below the epidemic threshold. Prevention scenarios included temporary reductions in risk behaviour, annual test and treat, and reduction in risk behaviour to levels observed earlier in the epidemic. These led to predicted reductions in new infections from 2 to 26% by 2020. Parameters related to disease progression and relative infectiousness at different HIV stages had the greatest influence on estimates of the net transmission rate. CONCLUSIONS/SIGNIFICANCE: The model outputs suggest that the increase in HIV transmission amongst MSM in Switzerland is the result of continuing risky sexual behaviour, particularly by those unaware of their infection status. Long term reductions in the incidence of HIV infection in MSM in Switzerland will require increased and sustained uptake of effective interventions.

Adult sex ratio effects on male survivorship of Drosophila melanogaster Meigen (Diptera, Drosophilidae)

The behavioral biology has a central role in evolutionary biology mainly because the antagonistic relations that occur in the sexual reproduction. One involves the effect of reproduction on the future life expectation. In this scenario, changes in male operational sex ratio could lead to an increase in mortality due to costs associated with excessive courtship and mating displays. Thus, this work experimentally altered the male sex ratio of Drosophila melanogaster Meigen, 1830, to determine its impact on mortality. The results indicated that mortality increases as the sex ratio changes, including modifications in the survivorship curve type and in the curve concavity, measured by entropy.

Effects of sex, host-plant deprivation and presence of conspecific immatures on the cannibalistic behavior of wild Ascia monuste orseis (Godart) (Lepidoptera, Pieridae)

Effects of sex, host-plant deprivation and presence of conspecific immatures on the cannibalistic behavior of wild Ascia monuste orseis (Godart) (Lepidoptera, Pieridae). The specialist cabbage caterpillar Ascia monuste orseis (Lepidoptera, Pieridae) feeds on plants of the Brassicaceae family, but may eventually ingest conspecific eggs and larvae during the larval stage. The present study examines feeding behavior of 4th and 5th instar cabbage caterpillars in relation to sex, host-plant deprivation and presence of conspecifics. We recorded number of egg ingested per larvae, developmental indices and duration of feeding, exploratory and resting behavior. Kale deprived caterpillars presented high rates of cannibalism, development delay and decreased fecundity. Cannibalism rates were not influenced by the sex of the larvae. In general, the presence of conspecific eggs did not interfere with the frequency and duration of the categorical behavioral events. We conclude that food availability is a strong factor influencing the extent to which A. monuste orseis caterpillars cannibalize.

Instruction pastorale sur l'Angelus

[Acte. 1872-12-08]

Effects of female diet and age on offspring sex ratio of the solitary parasitoid Pachycrepoideus vindemmiae (Rondani) (Hymenoptera, Pteromalidae)

Effects of female diet and age on offspring sex ratio of the solitary parasitoid Pachycrepoideus vindemmiae (Rondani) (Hymenoptera, Pteromalidae). Theories predict that females of parasitoid wasps would adjust the offspring sex ratio to environmental conditions in the oviposition patch, but the diet and age of females would also affect the sex ratio adjustment. Our focus was to test the effects of female diet and age on offspring sex ratio of the solitary parasitoid wasp, Pachycrepoideus vindemmiae (Rondani, 1875). Our results showed that females fed with honey had significantly less female biased offspring sex ratio than those fed only with water. Offspring sex ratio (male percentage) decreased with female age or female longevity at the beginning of oviposition but increased at the end. There should be a sperm limitation in P. vindemmiae females at the end of oviposition, and a higher frequency of unfertilized eggs were laid then. Females also laid more unfertilized eggs at the beginning of oviposition, which would be necessary to insure the mating among offspring. Male offspring developed faster and emerged earlier, which would also reduce the risk of virginity in offspring with female-biased sex ratio.