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11.
Summary Fruit of the blackberry, Rubus pennsylvanicus Poir. (Rosaceae), were examined to determine variation in maturation characteristics. Maturation timing and rate varied greatly among individual fruits, resulting in a bi-colored fruiting display comprised largely of two maturation stages, pre-ripe (salmon and scarlet) and ripe (dark brown and black). While ripe fruit were generally larger and heavier than pre-ripe fruit, exhibiting greater fresh and dry fruit weight, diameter, water content, and total seed weight, no significant differences were found in energy content, i.e. numbers of calories per gram pulp, or in pulp:seed ratio. The differences between ripe and pre-ripe fruit appear to be due largely to an increase in water content and seed weight with maturity. The fact that little energetic benefit accrues to the preferential selection of ripe fruit suggests that bi-colored Rubus displays may be considered to be unicolored. 相似文献
12.
R. Haven Wiley Joe Poston 《Evolution; international journal of organic evolution》1996,50(4):1371-1381
When Darwin first proposed the possibility of sexual selection, he identified two mechanisms, male competition for mates and female choice of mates. Extending this classification, we distinguish two forms of mate choice, direct and indirect. This distinction clarifies the relationship between Darwin's two mechanisms and, furthermore, indicates that the potential scope for sexual selection is much wider than thus far realized. Direct mate choice, the focus of most research on sexual selection in recent decades, requires discrimination between attributes of individuals of the opposite sex. Indirect mate choice includes all other behavior or morphology that restricts an individual's set of potential mates. Possibilities for indirect mate choice include advertisement of fertility or copulation, evasive behavior, aggregation or synchronization with other individuals of the same sex, and preferences for mating in particular locations. In each of these cases, indirect mate choice sets the conditions for competition among individuals of the opposite sex and increases the chances of mating with a successful competitor. Like direct mate choice, indirect mate choice produces assortative mating. As a consequence, the genetic correlation between alleles affecting indirect choice and those affecting success in competition for mates can produce self-accelerating evolution of these complementary features of the sexes. The broad possibilities for indirect mate choice indicate that sexual selection has more pervasive influences on the coevolution of male and female characteristics than previously realized. 相似文献
13.
Shona L. Kirk Anne-Maj Samuelsson Marco Argenton Hannah Dhonye Theodosis Kalamatianos Lucilla Poston Paul D. Taylor Clive W. Coen 《PloS one》2009,4(6)
Hypothalamic systems which regulate appetite may be permanently modified during early development. We have previously reported hyperphagia and increased adiposity in the adult offspring of rodents fed an obesogenic diet prior to and throughout pregnancy and lactation. We now report that offspring of obese (OffOb) rats display an amplified and prolonged neonatal leptin surge, which is accompanied by elevated leptin mRNA expression in their abdominal white adipose tissue. At postnatal Day 30, before the onset of hyperphagia in these animals, serum leptin is normal, but leptin-induced appetite suppression and phosphorylation of STAT3 in the arcuate nucleus (ARC) are attenuated; the level of AgRP-immunoreactivity in the hypothalamic paraventricular nucleus (PVH), which derives from neurones in the ARC and is developmentally dependent on leptin, is also diminished. We hypothesise that prolonged release of abnormally high levels of leptin by neonatal OffOb rats leads to leptin resistance and permanently affects hypothalamic functions involving the ARC and PVH. Such effects may underlie the developmental programming of hyperphagia and obesity in these rats. 相似文献
14.
McCowan LM North RA Kho EM Black MA Chan EH Dekker GA Poston L Taylor RS Roberts CT 《Obesity (Silver Spring, Md.)》2011,19(5):1035-1039
Our aims were to investigate whether men who fathered small for gestational age (SGA) infants themselves had lower birthweight, were more likely to be obese, have central adiposity and elevated blood pressure in adult life compared with men who fathered non-SGA infants. A total of 2,002 couples participating in the Screening for Pregnancy Endpoints (SCOPE) study were enrolled in early pregnancy and pregnancy outcome data collected prospectively. SGA was defined as birthweight <10th customized centile, obesity as BMI ≥30 kg/m(2), central adiposity as waist circumference >102 cm. Logistic regression was used to compare rates of obesity, and central adiposity between men who fathered SGA infants compared with those with non-SGA infants and the final model was adjusted for maternal and paternal confounders. The men who fathered an SGA infant (209 (10.4%)) themselves had lower mean birthweight (3,291 (530) g vs. 3,472 (584) g, P < 0.0001), were more likely to be obese (50 (24.8%) vs. 321 (18.3%), adjusted odds ratio (OR) 1.50, 95% confidence interval 1.05-2.16, adjusted for maternal and paternal factors) and to have central adiposity (52 (25.1%) vs. 341 (19.2%), adjusted OR 1.53, 95% confidence interval 1.06-2.20) compared with men who fathered a non-SGA infant. Elevated paternal blood pressure was not associated with SGA. In conclusion, we report a novel relationship between paternal obesity/central adiposity and birth of an SGA infant, which appears to be independent of maternal factors associated with fetal growth restriction. 相似文献
15.
Serge Evrard Graeme Poston Peter Kissmeyer-Nielsen Abou Diallo Grégoire Desolneux Véronique Brouste Caroline Lalet Frank Mortensen Stefan St?ttner Stephen Fenwick Hassan Malik Ioannis Konstantinidis Ronald DeMatteo Michael D'Angelica Peter Allen William Jarnagin Simone Mathoulin-Pelissier Yuman Fong 《PloS one》2014,9(12)
Background
Combined intra-operative ablation and resection (CARe) is proposed to treat extensive colorectal liver metastases (CLM). This multicenter study was conducted to evaluate overall survival (OS), local recurrence-free survival (LRFS), hepatic recurrence-free survival (HRFS) and progression-free survival (PFS), to identify factors associated with survival, and to report complications.Materials and Methods
Four centers combined retropectively their clinical experiences regarding CLM treated by CARe. CLM characteristics, pre- and post-operative chemotherapy regimens, surgical procedures, complications and survivals were analyzed.Results
Of the 288 patients who received CARe, 210 (73%) had synchronous and 255 (88%) had bilateral CLM. Twenty-two patients (8%) had extrahepatic disease. Median follow-up was 3.17 years (95%CI 2.83–4.08). Median OS was 3.33 years (95%CI 3.08–4.17) and 5-year OS was 37% (95%CI 29–45). One- and 5-year LRFS from ablated lesions were 87.9% (95%CI 83.3–91.2) and 78.0% (95%CI 71–83), respectively. Median HRFS and PFS were 14 months (95%CI 11–18) and 9 months (95%CI 8–11), respectively. One hundred patients experienced complications: 29 grade I, 68 grade II–III–IV, and three deaths. In the multivariate models adjusted for center, the occurrence of complications was confirmed as a major independent factor associated with 3-year OS (HR 1.80; P = 0.008). Five-year OS was 25.6% (95%CI 14.9–37.6) for patients with complications and 45% (95%CI 33.3–53.4) for patients without.Conclusions
Recent strategies facing advanced CLM include non-anatomic resections, portal-induced hypertrophy of the future remnant liver and aggressive medical preoperative treatments. CARe has the qualities of an approach that allows effective tumor clearance while maintaining good tolerance for the patient. 相似文献16.
17.
18.
Cleo Robinson Marinella Callow Sandra Stevenson Bruce WS Robinson Richard A Lake 《Respiratory research》2001,2(2):119-6
Background
The pathogenetic mechanisms that underlie the interstitial lung disease cryptogenic fibrosing alveolitis (CFA) may involve an immunological reaction to unidentified antigens in the lung, resulting in tissue damage. 相似文献19.
D L Poston 《Social biology》1974,21(3):296-307
20.