Fertilizer efficiency directly affects the production of continuous cropping greenhouse cucumber. So analyzing the fertilizer efficiency is of great significance in providing decision-making support for fertilization of greenhouse cucumber. By establishing the DEA models of continuous cropping greenhouse cucumber and taking existing data samples as study objects, the problems of fertilizer effi...

This study investigates the effects of dietary lipid sources on the growth and reproductive performance of Nile tilapia over three consecutive spawnings. Fish were reared using three experimental diets, with the goal of replacing dietary fish oil with palm oil. Three experimental diets and a commercial   trout diet was used as the control. The effect of dietary lipid on the growth performance, ...

Birth of babies through in vitro fertilization procedures has Tenewed interest by clinicians as well as laymen in the phenomenon of fertilizatien. In most medical text books, fertilization is treated very lightly giving students the impressien that fertilization is a simple mechanical penetration of a spermatozoon into an egg. This is far frorn the truth. Fertilization comprises ・a series of co...

It is widely accepted that sex steroid hormones play an important and a specific role during the process of sex differentiation in fish. In order to describe the role of the three main sex steroid hormones (testosterone--T, 17beta-estradiol--E2 and 11keto-testosterone--11KT) during embryogenesis and sex differentiation in Eurasian perch, Perca fluviatilis, eggs, larvae and juveniles originating...

Parasites can impose strong selection on hosts. In response, some host populations have adapted via the evolution of defenses that prevent or impede infection by parasites. However, host populations have also evolved life history shifts that maximize host fitness despite infection. Outcrossing and self-fertilization can have contrasting effects on evolutionary trajectories of host populations. ...

The purpose of this study was to examine: 1) whether caffeine in the fertilization medium under mineral oil is essential for bovine in vitro fertilization by fully capacitated spermatozoa, 2) the minimum concentration of caffeine that shows an adverse effect on the motility of preincubated spermatozoa. Cumulus-oocyte complexes with heterogeneous-appearing ooplasm were matured in in vitro cultur...

Theoretical studies show that, although inbreeding depression (ID) will counterbalance the transmission advantage of selfing, it can only maintain a mixed mating system in plants when at least one of the following two conditions is met: (1) there is a positive association between selfing rates and the level of ID; and (2) ID is greater than 0.5 for the female component of fitness, while the ave...

ECENT studies on experimental populations of barley and lima beans (JAIN and ALLARD 1960; ALLARD and WORKMAN 1963; HARDING, ALLARD and SMELTZER, in preparation) have provided estimates of the intensity of the selection maintaining genetic variation in these predominantly self-fertilized species. In each experiment, selective values were estimated from census data on genotypic frequencies in suc...