Adrenal involvement in the biostimulatory effect of bulls

<p>Abstract</p> <p>Background</p> <p>The objective was to evaluate if cortisol concentrations are associated with the resumption of luteal activity in postpartum, primiparous cows exposed to bulls. The hypotheses were that 1) interval from start of exposure to resumption of luteal activity; 2) proportions of cows that resumed luteal function during the exposure period; and 3) cortisol concentrations do not differ among cows exposed or not exposed to bulls (Exp. 1), and cows continuously exposed to bull or steer urine (Exp. 2).</p> <p>Methods</p> <p>In Exp. 1, 28 anovular cows were exposed (BE; n = 13) or not exposed (NE; n = 15) to bulls for 30 d at 58 d after calving. In Exp. 2, 38 anovular cows were fitted with a controlled urine delivery device at 45 d after calving and exposed continuously (24 h/d) to bull (BUE; n = 19) or steer (SUE; n = 19) urine. Length of exposure was ~64 d. Blood samples were collected from each cow on D 0 and every 3 d throughout exposure periods in both experiments and assayed for progesterone. Cortisol was assayed in samples collected on D 0, 8, 16, and 24 in Exp. 1; and, D 0, 19, 38, and 57 in Exp. 2.</p> <p>Results</p> <p>In Exp. 1, interval from the start of exposure to resumption of luteal activity was shorter (P < 0.05) for BE cows than NE cows, similarly, more (P < 0.05) BE cows than NE cows resumed luteal function during the exposure period. In Exp. 2, there was no difference in intervals from the start of exposure to resumption of luteal activity and proportions of cows that resumed luteal function during the exposure period between BUE and SUE cows. In Exp. 1, there was no difference in cortisol concentrations between BE and NE cows at the start of the experiment (D 0), however, cortisol concentrations were greater (P < 0.05) in BE cows than NE cows on D 9, 18, and 27. In Exp. 2, cortisol concentrations were higher for BUE than SUE cows on D 0 (P < 0.05), thereafter cortisol decreased (P < 0.05) but did not differ between BUE and SUE cows.</p> <p>Conclusion</p> <p>We conclude that the physical presence of bulls stimulates resumption of luteal activity and is coincident with increased cortisol concentrations, and hypothesize a possible association between adrenal activation and the biostimulatory effect of bulls.</p

Pre-zygotic isolation in the macroalgal genus Fucus from four contact zones spanning 100-10 000 years : a tale of reinforcement?

Hybrid zones provide an ideal natural experiment to study the selective forces driving evolution of reproductive barriers and speciation. If hybrid offspring are less fit than the parental species, pre-zygotic isolating barriers can evolve and strengthen in response to selection against the hybrids (reinforcement). Four contact zones between the intertidal macroalgae Fucus serratus (Fs) and Fucus distichus (Fd), characterized by varying times of sympatry and order of species introduction provide an opportunity to investigate reinforcement. We examined patterns of hybridization and reproductive isolation between Fs and Fd in: (i) northern Norway (consisting of two natural sites, 10 000 years old), (ii) the Kattegat near Denmark (Fd introduced, nineteenth century) and (iii) Iceland (Fs introduced, nineteenth century). Using 10 microsatellites and chloroplast DNA, we showed that hybridization and introgression decreased with increasing duration of sympatry. The two younger contact zones revealed 13 and 24% hybrids and several F(1) individuals, in contrast to the older contact zone with 2–3% hybrids and an absence of F(1)s. Cross-fertilization experiments revealed that the reduction in hybridization in the oldest zone is consistent with increased gametic incompatibility

Empirically Constrained Color-Temperature Relations. II. uvby

(Abriged) A new grid of theoretical color indices for the Stromgren uvby photometric system has been derived from MARCS model atmospheres and SSG synthetic spectra for cool dwarf and giant stars. At warmer temperatures this grid has been supplemented with the synthetic uvby colors from recent Kurucz atmospheric models without overshooting. Our transformations appear to reproduce the observed colors of extremely metal-poor turnoff and giant stars (i.e., [Fe/H]<-2). Due to a number of assumptions made in the synthetic color calculations, however, our color-temperature relations for cool stars fail to provide a suitable match to the uvby photometry of both cluster and field stars having [Fe/H]>-2. To overcome this problem, the theoretical indices at intermediate and high metallicities have been corrected using a set of color calibrations based on field stars having accurate IRFM temperature estimates and spectroscopic [Fe/H] values. Encouragingly, isochrones that employ the transformations derived in this study are able to reproduce the observed CMDs (involving u-v, v-b, and b-y colors) for a number of open and globular clusters (including M92, M67, the Hyades, and 47Tuc) rather well. Moreover, our interpretations of such data are very similar, if not identical, with those given by VandenBerg & Clem (2003, AJ, 126, 778) from a consideration of BV(RI)c observations for the same clusters. In the present investigation, we have also analyzed the observed Stromgren photometry for the classic Population II subdwarfs, compared our "final" (b-y)-Teff relationship with those derived empirically in a number of recent studies, and examined in some detail the dependence of the m1 index on [Fe/H].Comment: 70 pages, 26 figures. Accepted for publication in AJ (Feb 2004). Postscript version with high resolution figures and complete Table 3 available at http://astrowww.phys.uvic.ca/~jclem/uvb

Impact of age and race on outcomes of a program to prevent excess weight gain and disordered eating in adolescent girls

Interpersonal psychotherapy (IPT) prevents weight gain and reduces loss-of-control (LOC)-eating in adults. However, IPT was not superior to health-education (HE) for preventing excess weight gain and reducing LOC-eating over 1-year in adolescent girls at risk for excess weight gain and eating disorders. Limited data suggest that older and non-White youth may be especially responsive to IPT. In secondary analyses, we examined if age or race moderated weight and LOC-eating outcomes. The 113 participants (12–17 years; 56.6% White) from the original trial were re-contacted 3 years later for assessment. At baseline and follow-up visits through 3 years, we assessed BMI, adiposity by dual energy X-ray absorptiometry, and LOC-eating presence. In linear mixed models, baseline age moderated 3-year BMI outcome; older girls in IPT had the lowest 3-year BMI gain compared to younger girls in IPT and all girls in HE, p = 0.04. A similar pattern was observed for adiposity. Race moderated 3-year LOC-eating; non-White girls in IPT were most likely to abstain from LOC-eating at 3 years compared to all other girls, p = 0.04. This hypothesis-generating analysis suggests future studies should determine if IPT is especially efficacious at reducing LOC-eating in older, non-White adolescents

All-Versus-Nothing Proof of Einstein-Podolsky-Rosen Steering

Einstein-Podolsky-Rosen steering is a form of quantum nonlocality intermediate between entanglement and Bell nonlocality. Although Schr\"odinger already mooted the idea in 1935, steering still defies a complete understanding. In analogy to "all-versus-nothing" proofs of Bell nonlocality, here we present a proof of steering without inequalities rendering the detection of correlations leading to a violation of steering inequalities unnecessary. We show that, given any two-qubit entangled state, the existence of certain projective measurement by Alice so that Bob's normalized conditional states can be regarded as two different pure states provides a criterion for Alice-to-Bob steerability. A steering inequality equivalent to the all-versus-nothing proof is also obtained. Our result clearly demonstrates that there exist many quantum states which do not violate any previously known steering inequality but are indeed steerable. Our method offers advantages over the existing methods for experimentally testing steerability, and sheds new light on the asymmetric steering problem.Comment: 7 pages, 2 figures. Accepted in Sci. Re

Characteristics of temporal patterns of cortisol and luteinizing hormone in primiparous, postpartum, anovular, suckled, beef cows exposed acutely to bulls

BACKGROUND: The physiological mechanism by which bulls stimulate resumption of ovarian cycling activity in postpartum, anovular, suckled cows after calving may involve the concurrent activation of the hypothalamic-hypophyseal-ovarian (HPO) axis and hypothalamic-hypophyseal-adrenal (HPA) axis. Thus, the objectives of this experiment were to determine if characteristics of temporal patterns of cortisol and luteinizing hormone (LH) in postpartum, anovular, beef cows are influenced by acute exposure to bulls. The null hypotheses were that daily, temporal characteristics of cortisol and LH concentration patterns do not differ between cows exposed acutely to bulls or steers. METHODS: Sixteen cows were assigned randomly 67 +/- 4 (+/- SE) after calving to be exposed to bulls (EB, n = 8) or steers (ES, n = 8) 5 h daily for 9 d (D 0 to 8). Blood samples were collected daily from each cow via jugular catheters at 15-min intervals for 6 h from 1000 to 1600 h each day. The 5-h exposure period began 1 h after the start of the intensive bleeding period. Characteristics of cortisol and LH concentration patterns (mean, baseline, pulse frequency, pulse amplitude, and pulse duration) were identified by PULSAR analyses. RESULTS: Mean cortisol concentrations decreased (P < 0.05) in cows in both treatments from D 0 to D 2. Thereafter, mean cortisol concentrations stabilized and did not differ (P > 0.10) between EB and ES cows. The decrease in mean cortisol concentrations in EB and ES cows from D 0 to D 2 was attributed to cows acclimatizing to intensive blood sampling and handling procedures. Consequently, analyses for characteristics of cortisol and LH concentration patterns included D 2 through 8 only. Cortisol mean and baseline concentrations, and pulse amplitude did not differ (P > 0.10) between EB and ES cows. However, cortisol pulse duration tended to be longer (P = 0.09) and pulse frequency was lower (P = 0.05) in EB than ES cows. LH pulse frequency was greater (P = 0.06) in EB than ES cows. All other characteristics of LH concentration patterns did not differ (P > 0.10) between EB and ES cows. Characteristics of cortisol concentration patterns were not related to characteristics of LH concentration patterns for ES cows (P > 0.10). However, as cortisol pulse amplitude increased, LH pulse amplitude decreased (b1 = -0.04; P < 0.05) for EB cows. CONCLUSIONS: In conclusion, exposing primiparous, postpartum, anovular, suckled cows to bulls for 5-h daily over a 9-d period did not alter mean concentrations of cortisol or LH compared to mean concentrations of cortisol and LH in cows exposed to steers. However, exposing cows to bull in this manner altered characteristics of temporal patterns of both LH and cortisol by increasing LH pulse frequency and decreasing cortisol pulse frequency. Interestingly, in cows exposed to bulls, as amplitude and frequency of cortisol pulses decreased, amplitudes of LH pulses increased and frequency of LH pulses tended to increase. Thus, the physiological mechanism of the biostimulatory effect of bulls may initially involve modification of the HPA axis and these changes may facilitate activation of the HPO axis and resumption of ovulatory cycles in postpartum, anovular, suckled cows

Pleistocene divergence of two disjunct conifers in the eastern Australian temperate zone

The eastern Australian temperate biota harbours many plants with fragmented geographic ranges distributed over 1000s of kilometres, yet the spatial genetic structure of their populations remains largely unstudied. In this study, we investigated genetic variation of the nuclear internal transcribed spacer (ITS) and chloroplast DNA sequences to disentangle the phylogeography of two widely distributed but highly fragmented eastern Australian fire-sensitive temperate conifers: Callitris oblonga (12 populations and 121 individuals) and C. rhomboidea (22 populations and 263 individuals). The three highly disjunct populations of C. oblonga all had unique chloroplast and ITS haplotypes consistent with the classification of these three populations as distinct subspecies. Molecular dating indicates that divergences of these populations occurred pre- to mid- Pleistocene (2.66 to 1.08 mya). Callitris rhomboidea showed greater diversity of chloroplast haplotypes which was strongly phylogeographically structured (Gst = 0.972), with haplotypes unique to specific geographic regions. ITS haplotype diversity was far higher than in C. oblonga with 38 haplotypes displaying high geographic structuring (Gst = 0.387) with many population-specific haplotypes. A phylogeographic break was identified between populations north and south of eastern Victoria dated at 0.43–0.47 mya. In both species, the strong genetic structuring of both chloroplast and ITS haplotypes provides evidence that their widespread ranges have resulted from long term persistence in low fire frequency refugia combined with poor dispersal. Any loss of populations due to increasing fire frequency or habitat loss is likely to result in a reduction of genetic diversity

Developing a risk stratification model for surgical site infection after abdominal hysterectomy

OBJECTIVE: The incidence of surgical site infection (SSI) ranges widely from 2-21% after hysterectomy. There is insufficient understanding of risk factors to build a specific risk stratification index. METHODS: Retrospective case-control study of 545 abdominal and 275 vaginal hysterectomies from 7/1/03 - 6/30/05 at four institutions. SSIs were defined using CDC/NNIS criteria. Independent risk factors for abdominal hysterectomy were identified by logistic regression. RESULTS: There were 13 deep incisional, 53 superficial incisional, and 18 organ-space SSI after abdominal and 14 organ-space SSI after vaginal hysterectomy. Because risk factors for organ-space SSI were different in univariate analysis, further analyses focused on incisional SSI after abdominal hysterectomy. The maximum serum glucose within 5 days after operation was highest in patients with deep incisional SSI, lower in patients with superficial incisional SSI and lowest in uninfected patients (median 189, 156, and 141mg/dL, p = .005). Independent risk factors for incisional SSI included blood transfusion (odds ratio (OR) 2.4) and morbid obesity (body mass index (BMI) > 35, OR 5.7). Duration of operation > 75th percentile (OR 1.7), obesity (BMI 30-35, OR 3.0), and lack of private health insurance (OR 1.7) were marginally associated with increased odds of SSI. CONCLUSIONS: Incisional SSI after abdominal hysterectomy was associated with increased BMI and blood transfusion. Longer operative time and lack of private health insurance were marginally associated with SSI. A specific risk stratification index could help to more accurately predict the risk of incisional SSI following abdominal hysterectomy

Pre-pregnancy habitual intake of vitamin D from diet and supplements in relation to risk of gestational diabetes mellitus: a prospective cohort study

Background Vitamin D may play a pivotal role in regulating insulin secretion and insulin sensitivity. However, the impact of vitamin D intake either from diet or from supplements on the development of gestational diabetes mellitus (GDM) remains unknown. We prospectively examined the association of pre-pregnancy habitual intake of vitamin D from diet and supplements with risk of incident GDM in a well-established cohort. Methods We included 21,356 singleton pregnancies from 15,225 women in the Nurses' Health Study II cohort. Diet information, including vitamin D intakes from food sources and supplements, was assessed in 1991 and every four years thereafter by validated food frequency questionnaires. We used log-binomial models with generalized estimating equations to estimate the relative risks (RRs) and 95% confidence intervals (CIs). Results We documented 865 incident GDM cases during 10 years of follow-up. After adjustment for age, parity, race/ethnicity, family history of diabetes, dietary and lifestyle factors, and body mass index, the RRs (95% CIs) of GDM risk associated with supplemental vitamin D intake of 0, 1–399, ≥ 400 IU/d were 1.00 (reference), 0.80 (0.67-0.96), and 0.71 (0.56-0.90), respectively (P for trend = 0.002). Dietary and total vitamin D intakes were also inversely associated with GDM risk, but the associations were not statistically significant. Conclusions Pre-pregnancy supplemental vitamin D intake was significantly and inversely associated with risk of GDM. Our study indicates potential benefits of increasing vitamin D intake from supplements in the prevention of GDM in women of reproductive age