Premature bovine parturition induced by ponderosa pine: effects of pine needles, bark and branch tips.

Three components of Ponderosa pine trees were administered via gavage to pregnant cows to determine their ability to induce premature parturition. When tips of branches, bark or needles were administered (2.7 kg/day) starting at 250 d of pregnancy, early parturition was induced in an average of 3.

Mammary glands in male marsupials: I. Primordia in neonatal opossums Didelphis virginiana and Monodelphis domestica.

Neonates of the American didelphid marsupials Didelphis virginiana and Monodelphis domestica were sexed by karyotype and histologically examined on the day of birth. Mammary anlagen were found in both sexes of both species, but the neonatal males had less than one-third of the full female complement of mammary glands. Male neonates of both species also had paired scrotal bulges anterior to the genital tubercle but these were never present in females, once again raising the question of whether the pouch and scrotum are homologous structures.

13-week inhalation toxicity study and fertility assessment in rats exposed to atmospheres containing adiponitrile.

Adiponitrile is an aliphatic dinitrile that is used as an intermediate in the synthesis of hexamethylenediamine. In order to asses potential health effects associated with industrial exposure, rats were exposed 6 h/d, 5 d/wk for 4 or 13 wk to atmospheres containing a range of adiponitrile concentrations and observed for signs of toxicity. A fertility assessment was also included as a component of the 13-wk study.

XPS and SSIMS analysis of the surface chemical structure of poly(caprolactone) and poly(beta-hydroxybutyrate-beta-hydroxyvalerate) copolymers.

The surface chemical structures of poly(beta-hydroxybutyrate), poly(caprolactone) and poly(beta-hydroxybutyrate-co-beta-hydroxyvalerate) have been analysed using static secondary ion mass spectrometry and X-ray photoelectron spectroscopy. The X-ray photoelectron spectroscopy data confirm the purity of the polyester surfaces and there is close agreement between the stoichiometric and experimentally determined ratios of the peaks and different carbon environments within the C1s envelopes. The static secondary ion mass spectrometry analysis reveals general fragmentation pathways which permit the ready distinction between the different polyesters examined.

Postpartum interval to estrus and patterns of LH and progesterone in first-calf suckled beef cows exposed to mature bulls.

Two trials were conducted in which Angus x Hereford first-calf cows were assigned randomly at calving to one of two treatments: exposure to mature penile-blocked bulls (BE) or isolation from bulls (NE). In Trial 1 (BE, n = 38; NE, n = 37), cow to bull ratio increased from 12:1 to 19:1 over a 14-d period; in Trial 2 (BE, n = 25; NE, n = 24), this ratio was maintained at 13:1. In both trials, blood samples were collected weekly for progesterone and ovaries and uteri of cows were examined rectally.

Constructing an instrument to measure the rate of aging in female pigtailed macaques (Macaca nemestrina).

To develop a battery of innocuous tests measuring individual differences in the rate of biological aging, longitudinal data were gathered on 28 biochemical, physiological, and morphological characteristics of 40 adult female pigtailed macaques. The change in each variable over time, i.e.

Physiological mechanisms controlling anestrus and infertility in postpartum beef cattle.

Postpartum infertility is caused by four factors: general infertility, lack of uterine involution, short estrous cycles and anestrus. The general infertility component is common to any estrous cycle and reduces potential fertility by 20 to 30%. Incomplete uterine involution prevents fertilization during the first 20 d after calving but is not related to anestrus.

Fingernail growth rate as a biomarker of aging in the pigtailed macaque (Macaca nemestrina).

Rate of fingernail growth (FNG) of the middle digit of the right hand was assessed in 46 healthy pigtailed macaques at approximately 6-month intervals for 4 to 6 years. Mean FNG for 24 females, ranging in mean age at measurement from 7 to 24 years, was 104 mu/day; the mean for 22 males, ranging from 7 to 20 years, was 111 mu/day. Longitudinal analysis showed that FNG declined in animals of both sexes and that the rate of decline (-4.

Conventional Giemsa-stained and C-banded chromosomes of seven strains of Schistosoma mansoni.

Karyotypes stained with conventional Giemsa and with a C-banding method were compared among 7 strains of Schistosoma mansoni: 2 from Puerto Rico and 1 each from St. Lucia, Brazil, Venezuela, Egypt, and Kenya. A few differences were noted in relative lengths and centromeric indexes, but overall karyotypes of all strains were similar, with 2n = 16.

Ovarian cyclicity, hormones, and behavior as markers of aging in female pigtailed macaques (Macaca nemestrina).

Age-related differences in reproductive function were studied to identify variables suitable for a battery of noninvasive tests used to measure aging rate. Twenty-seven adult female pigtailed macaques, ranging in age from 8 to 31 years, were studied in a cross-sectional design. Perineal tumescence, menses, and activity in the home environment were recorded daily.