A smaller length ratio for the second relative to the fourth finger (2D∶4D) is repeatedly associated with fetal male-typical testosterone (T) and is implicated as a biomarker for a variety of traits and susceptibility to a number of diseases, but no experimental human studies have been performed. The present study utilizes the rhesus monkey, a close relative of humans, and employs discrete gestational exposure of female monkeys to fetal male-typical T levels for 15–35 days during early-to-mid (40–76 days; n = 7) or late (94–139 days; n = 7) gestation (term: 165 days) by daily subcutaneous injection of their dams with 10 mg T propionate. Such gestational exposures are known to enhance male-typical behavior. In this study, compared to control females (n = 19), only early-to-mid gestation T exposure virilizes female external genitalia while increasing 2D∶4D ratio in the right hand (RH) by male-like elongation of RH2D. RH2D length and 2D∶4D positively correlate with androgen-dependent anogenital distance (AG), and RH2D and AG positively correlate with duration of early-to-mid gestation T exposure. Male monkeys (n = 9) exhibit a sexually dimorphic 2D∶4D in the right foot, but this trait is not emulated by early-to-mid or late gestation T exposed females. X-ray determined phalanx measurements indicate elongated finger and toe phalanx length in males, but no other phalanx-related differences. Discrete T exposure during early-to-mid gestation in female rhesus monkeys thus appears to increase RH2D∶4D through right-side biased, non-skeletal tissue growth. As variation in timing and duration of gestational T exposure alter male-like dimensions of RH2D independently of RH4D, postnatal RH2D∶4D provides a complex biomarker for fetal T exposure.
Summary:A study was made of important factors in analyzing the base content, i.e., acid neutralization capacity, of additive concentrates used to compound highly basic lubricants and of the lubricants themselves.It was found that the standard analytical method now in general use for determining base content of petroleum products, ASTM D664-58 (corresponding methods, (British) IP-177/64 and (Japanese) JIS K 2502), is not entirely satisfactory.The principal disadvantages of the ASTM D664 method are as follows:(1) With some complex additives, the results give a significantly false measure of the base that neutralizes strong acids, such as sulfuric acid, which are produced during normal diesel engine operation; (2) lengthy titration times are required to get reproducible results; and (3) the end point is often difficult to determine.The use of a back titration as a modification of the ASTM D664 method overcomes some of these difficulties, but unreliable results can still be obtained. The use of mechanical titrimeters likewise can lead to erroneous "ASTM D664" results.The use of sulfuric acid in place of the hydrochloric acid specified in the ASTM D664 method cangive reliable results but has the disadvantages of long titration times and unclear end points.The method found to be most satisfactory in this study is based on a perchloric acid titration in glacial acetic acid solvent.This method is rapid, provides sharp end points, and gives measured base numbers that are essentially identical with the theoretical values.The base content as measured by the perchloric acid method was shown to give better correlation with measured wear in laboratory diesel engine tests than did the base content as measured by the ASTM D664 method. The perchloric acid method is recommended.
In thas paper a n approach t o provade Web-based framework for dastrabuted executaon of collaboratave app-
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The mean diffusion coefficient at 25°has been determined for dodecanesulfonic acid in perchloric acid solutions. The micellar radii have been estimated. After substantially complete "swamping" the radii gradually increase in size with increase in perchloric acid concentration up to the point where a second phase appears.
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