Length at birth

An individual in the population is characterized by its length /. It is assumed that all individuals have the same length (/ ) at birth and that they do not shrink, so that < /. If nutrient is available at concentration S in the chemostat, then the rate of nutrient uptake by an individual of length / is given by... 

The equations describing the competition between two size-structured populations for a single nutrient can easily be inferred from (2.1). A subscript i is used for variables and parameters associated with the /th population, i = 1,2. In particular, let /, denote the length at birth of an individual of the /th population. We consider only two populations for simplicity a similar analysis can be carried out for any number of competitors [Cu2]. The equations are... 

Figure 2 The unadjusted relationship between maternal blood lead concentration during pregnancy and infant length at birth n = 202 r = — 0.13 p <0.05.

OECD TG 421 and TG 422 Reproduction/ Developmental Toxicity Screening Test (with or without the Combined Repeat Dose Toxicity Study) From 2 weeks prior to mating until at least day 4 postnatally 3 dose levels plus control n = 8-10 pregnant females Fertility Pregnancy length and birth Fetal and pup growth and survival until day 3 + short-term test - limited exposure period - limited number of end-points - limited sensitivity due to number of animals... 

Women appear to be at an increased risk of torsades de pointes because the baseline heart rate-corrected QT interval in women is, on average, longer than it is in men (103). The length of the QT interval is similar in males and females at birth, but shortens in males at puberty. The risk of this arrhythmia shows no sex difference before adolescence, and women have an increased incidence of torsades de pointes only after puberty. These observations are consistent with the fact that sex hormones affect potassium channel activity. Thus, estrogens have a down-regulating effect on potassium channel activity and androgens may be responsible for the QT interval shortening that is seen in postpubertal males (95, 96, 104). 

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