Factors influencing developmental

McLachlan, J.A., R.R. Newbold, K.S. Korach, J.C. Lamb, IV, and Y. Suzuki. 1981. Transplacental toxicology prenatal factors influencing postnatal fertility. Pp. 213-232 in Developmental Toxicology, C.A. Kimmel, and J. Buelke-Sam, eds. New York Raven Press. 

As reviewed before," differences in results obtained in IVEP systems are caused by various factors such as time taken to transport ovaries to lab after collection, temperature changes during ovary collection and transport to the laboratory, cow breed, oocyte quality and follicular, maturation, fertilization and embryo culture environments. In particular, cattle breed has been shown to influence developmental competence of oocytes and blastocyst rates. The effect of breed on oocyte quality is amplified by environmental conditions. For example, although Holstein cows Bos taurus) have bigger ovaries, they produce oocytes of lower quality compared to Brahman cows Bos indicus) However, for both cases, the in-vitro-fertilized embryos at the 4- and 8-celI stage when subjected to heat stress results in decreased blastocyst rate but the effect is more severe in Holstein embryos compared to zebu embyros. ... 

This volume, number 10 of the Encyclopedia of Plant Physiology, New Series, deals with our most current understanding of plant hormones and how they regulate or influence developmental events at the level of the cell up to and including the whole plant. Volume 10 is the second in a subset of three in a series. It commences where Volume 9, Molecular and Subcellular Aspects of Hormonal Regulation in Plants ended. In turn, this volume leads naturally to the consideration of the relationship between environmental factors and their effects on hormone-regulated processes in plants — this being the domain of consideration to be found in Volume 11. 

As with any nervous system, the way in which the AOS functions is regulated by developmental and heritable factors (Chaps. 4 and 6), whose interplay determines its operation under any given conditions. Some of its processes can vary with the prior experience of the individual others are almost invariant and appear as stereotypical responses with little experiential influence. They range from the transient guidance role in GnRH-cell migration, to the alteration in the timing of puberty and the diminution of fertility in adults. Differences in the... 

Hg concentrations in forest soils, mosses and fungal fruiting bodies are variable, and are influenced by many factors, such as the extent of forest-based capture of atmospheric Hg deposition, transmission of Hg from the forest canopy to the litter layer whether covered with mosses or not, and type of moss and soil layer conditions and configurations. Within the fungal fruiting bodies, further alternation of the Hg cycle occurs on account of mycelia substrate preferences and Hg allocation to stalk and caps, according to developmental stage. 

An important complication that is specific to human developmental toxicity studies is the necessity to control for confounding factors that influence human development, such as parental intelligence, quality of home environment, nutritional factors and socioeconomic status (Bellinger et al., 1992 Bellinger, 1995). These may influence the outcomes from the newborn period to adulthood. In addition, assessment methods must take into consideration the time (days, months or years) that may intervene between exposure/insult and the expression of toxicity at a much later age. 

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