BACKGROUND Focus on the hatching process has so far been in the field of fresh embryos. Cryopreserved-thawed embryos have a lower rate of pregnancy than fresh embryos, which might be due to hardening of the zona pellucida. METHODS During a 2 year period, a prospective randomized study enrolling 253 cryopreserved-thawed cycles was performed on day 2 embryos. Pseudorandomization to assisted hat...

This study was designed to gain insight into the influence of spraying and cooling, during artificial incubation, on the embryo metabolic rate and hatching ability of Muscovy duck eggs. Three times a week 93 incubated eggs were sprayed and cooled for 0.5 h at room temperature. Daily embryo metabolic rate was measured in 30 eggs with a water vapor conductance ranging from 1.15 to 2.07 mg/day-kPa...

Parasite life-history traits reflect past environmental and host selective pressure that act to produce strategies that maximize successful transmission. Pooled human pinworm eggs were pretreated with 0.9% NaCl, acid digestive enzyme, and alkaline solutions (pH 9.0) and then incubated in 0.9% NaCl at room temperature and 37 degrees C both with and without 5% CO2. Eggs pretreated with both acid ...

Laboratory studies were conducted to evaluate effects of selected herbicides on hatching of free eggs of the soybean cyst nematode, Heterodera glycines. The herbicides used were Atrazine (atrazine), Basagran (bentazon), Bladex (cyanazine), Blazer (acifluorfen), Command (clomazone), Lasso (alachlor), Sonalan (ethalfluralin), and Treflan (trifluralin). Treatments comprised two concentrations of c...

—Latitudinal influences on growing season length and winter severity cause variation in prerecruitment life history across species distributions. We evaluated two recruitment hypotheses for a broadly distributed species, largemouth bass Micropterus salmoides, at the southern extent of their natural range. We tested (1) whether early hatching provided a growth and survival advantage relative to ...

Physico-chemical and microbial characteristics of culture water were examined during the induced breeding of Cyprinus carpio in a controlled environmental system. Water temperature, dissolved oxygen, nitrate, phosphate, pH, ammonia nitrogen, total bacterial count, hardness, salinity, carbonate and bicarbonate were estimated before and after spawning and hatching. Average alteration in water pH ...

1. When the eggs of the skin parasitic monogenean Entobdella soleae are subjected in the laboratory to alternating periods of light and darkness (LD 12:12, LD 6:18 or LD 18:6) at constant temperature (selected from the range 12-16 °C), hatching is rhythmical, most of the oncomiracidia emerging during the first 4 h of the period of illumination on each successive day. 2. Rhythmicity in response ...

An experiment was conducted to assess how hatching performance is affected by breeder age and egg holding environment during short-term storage. Response variables analyzed were egg weight loss up to 18 d of incubation, viability (hatchability of fertile eggs), embryonic mortality, hatching time, and weight of male and female chicks, at hatching and at the end of incubation. The trials involved...

background: matrigel (extracellular matrix) can improve the growth of many cell types in vitro. objective: the aim of the present study was to determine the effect of matrigel on the development of 2-4 cells human embryos in culture. material and methods: surplus 2-4 cells human embryos, resulting from icsi, were divided into two groups (control and test). quality of embryos in both groups was ...