Sex determination in the order Hymenoptera is based on arrhenotoky, hymenopteran males are usually haploid and females diploid. Males of the Ichneumonidae Diadromus pulchellus , solitary endoparasitoid of A. assectella pupae are normally haploid, but diploid males are present in a natural population and can be obtained in a experimental population. The future of an ovocyte laid by mated females...

The effects of five rates of nitrogen fertiliser applications on the performance of the cereal aphid Metopolophium dirhodum on winter wheat, within the range of rates recommended for UK crops, were investigated over two seasons in field-grown crops and also on plants grown in the glasshouse. Longevity was unaffected by the level of fertilisation, but aphid intrinsic rate of increase and fecundi...

Since the first successful birth in 1978 following in vitro fertilisation (IVF), this has become established treatment for infertility and is available at more than thirty centres in the United Kingdom. Oocyte donation has extended the use of IVF technology for conditions where a genetic abnormality exists or where repeated attempts at IVF have failed to achieve fertilisation. In cases where th...

The Report of the Committee of Inquiry into Human Fertilisation and Embryology, commonly called the Warnock Report after the chair of the committee Mary Warnock, is the 1984 publication of a UK governmental inquiry into the social impacts of infertility [4] treatment and embryological research. The birth of Louise Brown in 1978 in Oldham, UK, sparked debate about reproductive and embryological ...

We wish to thank Dr Davies for raising an issue we were not able to address in our original letter due to space limitations. The issue with emergency contraception intrauterine devices (EC IUDs) is slightly different. An EC IUD has to be fitted prior to implantation. This is a process that starts no sooner than 6 days after fertilisation, and fertilisation cannot happen prior to sexual intercou...

The striking amount of variation in the mating systems of higher plants has stimulated fruitful research by both ecologists and population geneticists. Historically, these two schools of thought have developed independent theoretical treatments and empirical approaches to account for the evolution of such diversity. We highlight the approach adopted by each field. Population geneticists have de...

ACKNOWLEDGEMENTS The authors would like to thank Rochford Medical for the kind donation of P-1 throughout the duration of this study. 1. Waterstone, JJ. and Parsons, JH. (1992) A prospective study to Investigate the value of flushing follicles during transvaginal ultrasound-directed follicle aspiration, Fertil. Steril. 57,221-223. 2. Staessen, C., Janssenwillen, C. et al. (1998) Controlled comp...

To evaluate whether the sperm DNA fragmentation affects male pronucleus epigenetic factors, semen analysis was performed and DNA fragmentation was assessed by the method of sperm chromatin structure assay (SCSA). Human-mouse interspecies fertilisation was used to create human male pronucleus. Male pronucleus DNA methylation and H4K12 acetylation were evaluated by immunostaining. Results showed ...

Under dryland systems of the Mediterranean basin, water management is widely recognised critical for improving grain yield. It has been proposed that nitrogen (N) fertilisation may be a tool to increase yield by increasing use efficiency. We tested in multilocation-multiyear study four different areas Basin if durum wheat and barley respond positively N under rainfed cultivation. The involved 1...