Strong inbreeding depression in male mating behaviour in a poeciliid fish

The magnitude of inbreeding depression is often larger in traits closely related to fitness, such as survival and fecundity, compared to morphological traits. Reproductive behaviour is also closely associated with fitness, and therefore expected to show strong inbreeding depression. Despite this, little is known about how reproductive behaviour is affected by inbreeding. Here we show that one generation of full‐sib mating results in a decrease in male reproductive performance in the least killifish (Heterandria formosa). Inbred males performed less gonopodial thrusts and thrust attempts than outbred males (δ = 0.38). We show that this behaviour is closely linked with fitness as gonopodial performance correlates with paternity success. Other traits that show inbreeding depression are offspring viability (δ = 0.06) and maturation time of males (δ = 0.19) and females (δ = 0.14). Outbred matings produced a female biased sex ratio whereas inbred matings produced an even sex ratio.     

Imported Amoebic Liver Abscess in France

Background

Worldwide, amoebic liver abscess (ALA) can be found in individuals in non-endemic areas, especially in foreign-born travelers.

Methods

We performed a retrospective analysis of ALA in patients admitted to French hospitals between 2002 and 2006. We compared imported ALA cases in European and foreign-born patients and assessed the factors associated with abscess size using a logistic regression model.

Results

We investigated 90 ALA cases. Patient median age was 41. The male:female ratio was 3.5∶1. We were able to determine the origin for 75 patients: 38 were European-born and 37 foreign-born. With respect to clinical characteristics, no significant difference was observed between European and foreign-born patients except a longer lag time between the return to France after traveling abroad and the onset of symptoms for foreign-born. Factors associated with an abscess size of more than 69 mm were being male (OR = 11.25, p<0.01), aged more than 41 years old (OR = 3.63, p = 0.02) and being an immigrant (OR = 11.56, p = 0.03). Percutaneous aspiration was not based on initial abscess size but was carried out significantly more often on patients who were admitted to surgical units (OR = 10, p<0.01). The median time to abscess disappearance for 24 ALA was 7.5 months.

Conclusions/Significance

In this study on imported ALA was one of the largest worldwide in terms of the number of cases included males, older patients and foreign-born patients presented with larger abscesses, suggesting that hormonal and immunological factors may be involved in ALA physiopathology. The long lag time before developing ALA after returning to a non-endemic area must be highlighted to clinicians so that they will consider Entamoeba histolytica as a possible pathogen of liver abscesses more often.     

长期运动训练对机体血清中AMPK 水平的影响

目的:探讨长期运动训练对机体血清中磷酸化腺苷活化蛋白激酶(AMPK)水平的影响.方法:采用双抗体两步夹心酶联免疫吸附法( ELISA)测定29名专业运动员(运动组)和26名健康志愿者(对照组)血清中AMPK水平.结果:运动组和对照组血清中AMPK浓度值分别为211.00±13.68U/L和9.70± 2.45 U/L,组间比较具有显著性差异(P＜0.01).结论:长期运动训练能显著提高机体血清中AMPK水平,有效增加组织的能量代谢.