The Drosophila nannoptera species group, a taxon of Mexican cactophilic flies, is an excellent model system to study the influence of abiotic and biotic factors on speciation, the genetic causes of ecological specialization and the evolution of unusual reproductive characters. However, the phylogenetic relationships in the nannoptera species group and its position within the virilis-repleta phy...

This study describes a case of a patient with traumatic rupture of a maxillary sinus retention cyst, which had an interesting clinical presentation of unilateral rhinorrhea, mimicking a CSF leak. The diagnosis was made fortuitously by comparison of a posttraumatic CT brain examination with a CT sinus study performed 1 day earlier.

Long-term records of nitrogen in deposition and streamwater were analysed at 30 sites covering major acid sensitive regions in Europe. Large regions of Europe have received high inputs of inorganic nitrogen for the past 20-30 years, with an approximate 20% decline in central and northern Europe during the late 1990s. Nitrate concentrations in streamwaters are related to the amount of N depositi...

Two experiments were conducted to determine the lysine:DE ratio that would maximize nitrogen retention and lean growth in growing pigs. Diets were formulated to contain 2.5, 3.0, 3.5, or 4.0 g of lysine/Mcal of DE at 3.5 and 3.75 Mcal of DE/kg of diet arranged in a 4 x 2 factorial. Experiment 1 used 48, 20-kg crossbred barrows in a nitrogen balance study. Feeding diets containing 3.75 Mcal of D...

Customer activity has received more attention due to the increase of social network applications. Moreover, customer activity could be an answer to the research debate about the significant relationship between retention rate and lifetime profitability of customers. Several researchers believe that an increase in the retention rate of customers may enhance their customer lifetime value (CLV), o...

Females of many animal species store sperm for taxon-specific periods of time, ranging from a few hours to years. Female sperm storage has important reproductive and evolutionary consequences, yet relatively little is known of its molecular basis. Here, we report the isolation of a loss-of-function mutation of the Drosophila melanogaster Acp29AB gene, which encodes a seminal fluid protein that ...

The evolution of obligate parthenogenesis may induce the degeneration of female mating ability and subsequently affect the morphology of the female reproductive organs related to mating and ⁄or sperm storage. Here, we investigated the size and structure of the sperm storage organ, the spermatheca, in three thelytokous parthenogenetic myrmicine ant species, Pristomyrmex punctatus, Pyramica membr...

Reproductive behaviors have evolved through severe inter-sexual competition. We have recently described a behavior in post-mated female Drosophila melanogaster that controls ejaculate retention and sperm storage, and is a possible mechanism by which females who have mated with several partners can choose which sperm that is stored and used for fertilization. This behavior can also regulate expo...

We secured data from 243 men in committed, sexual, heterosexual relationships to test the sperm retention hypothesis of oral sex. We predicted that, among men who perform cunnilingus on their partner, those at greater risk of sperm competition are more likely to perform cunnilingus until their partner achieves orgasm (Prediction 1), and that, among men who ejaculate during penile-vaginal interc...