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951.
Dave Speijer 《BioEssays : news and reviews in molecular, cellular and developmental biology》2017,39(9)
952.
Alternating terminal electron‐acceptors at the basis of symbiogenesis: How oxygen ignited eukaryotic evolution 下载免费PDF全文
Dave Speijer 《BioEssays : news and reviews in molecular, cellular and developmental biology》2017,39(2)
953.
目的:探讨红细胞分布宽度血小板比率(RDW)和中性粒细胞淋巴细胞比率(NLR)预测急诊经皮冠状动脉介入(PCI)术后冠脉无复流的应用价值。方法:选取2016年1月~2016年12月于我院行急诊PCI手术治疗的患者66例为研究对象,检测其治疗前的RDW和NLR,统计其急诊PCI术后冠脉无复流现象的发生情况,比较冠脉无复流和正常血流患者的RDW和NLR,分析患者RDW和NLR与其冠脉无复流的关系及其对冠脉无复流的预测价值。结果:66例患者急诊PCI术后冠脉无复流发生率为30.30%(20/66)。与正常血流患者比较,冠脉无复流患者RDW和NLR均升高(P0.05)。Spearman相关分析结果显示患者RDW和NLR与其冠脉无复流均呈正相关(r=0.826,0.878,P0.05)。进一步ROC曲线分析结果显示急诊PCI术前RDW和NLR联合预测其术后冠脉无复流的的ROC曲线下面积高于二者单独预测。结论:急诊PCI患者RDW和NLR与其术后冠脉无复流密切相关且两者联合预测患者术后冠脉无复流的价值良好,可能作为急诊PCI术后冠脉无复流评估的参考指标。 相似文献
954.
Jalal Jalilian Azin Najafabadi Mohammad Reza Zardashti 《Journal of Plant Interactions》2017,12(1):92-99
This factorial field experiment was done based on a randomized complete block design in Urmia University, Iran, in 2013 and was repeated in 2014. Treatments included two farming systems (high input and organic) and different intercropping patterns that alternated bitter vetch (Vicia ervilia L.) and safflower (Carthamus tinctorius L.) with row ratios of 2:2, 3:2, 4:2 and 5:2. Sole cropping of bitter vetch and safflower was used as the control. In both years, the 2:2 intercropping pattern had biomass yield advantages compared to sole cropping and the other intercropping ratios, based on greater land equivalent ratio values. Safflower had higher relative crowding coef?cients, competitive ratio (CR) and aggressivity (A) values than bitter vetch. High-input farming was more effective than the organic system in both years. Safflower was the superior competitor when grown with bitter vetch, and its productivity dominated the total biomass yields. Thus, intercropping of safflower with bitter vetch has the potential to improve performance with high land-use efficiency. 相似文献
955.
Patterns of seasonality and group membership characterize the gut microbiota in a longitudinal study of wild Verreaux's sifakas (Propithecus verreauxi) 下载免费PDF全文
Andrea Springer Claudia Fichtel Gabriel A. Al‐Ghalith Flávia Koch Katherine R. Amato Jonathan B. Clayton Dan Knights Peter M. Kappeler 《Ecology and evolution》2017,7(15):5732-5745
The intestinal microbiota plays a major role in host development, metabolism, and health. To date, few longitudinal studies have investigated the causes and consequences of microbiota variation in wildlife, although such studies provide a comparative context for interpreting the adaptive significance of findings from studies on humans or captive animals. Here, we investigate the impact of seasonality, diet, group membership, sex, age, and reproductive state on gut microbiota composition in a wild population of group‐living, frugi‐folivorous primates, Verreaux's sifakas (Propithecus verreauxi). We repeatedly sampled 32 individually recognizable animals from eight adjacent groups over the course of two different climatic seasons. We used high‐throughput sequencing of the 16S rRNA gene to determine the microbiota composition of 187 fecal samples. We demonstrate a clear pattern of seasonal variation in the intestinal microbiota, especially affecting the Firmicutes‐Bacteroidetes ratio, which may be driven by seasonal differences in diet. The relative abundances of certain polysaccharide‐fermenting taxa, for example, Lachnospiraceae, were correlated with fruit and fiber consumption. Additionally, group membership influenced microbiota composition independent of season, but further studies are needed to determine whether this pattern is driven by group divergences in diet, social contacts, or genetic factors. In accordance with findings in other wild mammals and primates with seasonally fluctuating food availability, we demonstrate seasonal variation in the microbiota of wild Verreaux's sifakas, which may be driven by food availability. This study adds to mounting evidence that variation in the intestinal microbiota may play an important role in the ability of primates to cope with seasonal variation in food availability. 相似文献
956.
Hui Wang Michinari Matsushita Nobuhiro Tomaru Michiko Nakagawa 《Ecology and evolution》2017,7(7):2340-2345
Sex change affects the sex ratios of plant populations and may play an essential role in the evolutionary shift of sexual systems. Sex change can be a strategy for increasing fitness over the lifetime of a plant, and plant size, environmental factors, and growth rate may affect sex change. We described frequent, repeated sex changes following various patterns in a subdioecious Eurya japonica population over five successive years. Of the individuals, 27.5% changed their sex at least once, and these changes were unidirectional or bidirectional. The sex ratio (females/males/all hermaphrodite types) did not fluctuate over the 5 years. In our study plots, although the current sex ratio among the sexes appears to be stable, the change in sex ratio may be slowly progressing toward increasing females and decreasing males. Sex was more likely to change with higher growth rates and more exposure to light throughout the year. Among individuals that changed sex, those that were less exposed to light in the leafy season and had less diameter growth tended to shift from hermaphrodite to a single sex. Therefore, sex change in E. japonica seemed to be explained by a response to the internal physiological condition of an individual mediated by intrinsic and abiotic environmental factors. 相似文献
957.
Flvio D. Fuchs Miguel Gus Leila B. Moreira Renan S. Moraes Mrio Wiehe Grson M. Pereira Sandra C. Fuchs 《Obesity (Silver Spring, Md.)》2005,13(9):1515-1517
Objective: To investigate the association between several anthropometric measurements of obesity with the incidence of hypertension. Research Methods and Procedures: Participants were 592 individuals free of hypertension, selected at random from the community. In the baseline evaluation, they were submitted to completed measures of demographics, anthropometrics, blood pressure, and other risk factors for hypertension. Incident hypertension was defined by blood pressure equal or higher than 140/90 mm Hg or use of blood pressure‐lowering drugs. Results: During a mean follow‐up time of 5.6 ± 1.1 years, 127 developed hypertension. The hazard ratios for the development of hypertension, adjusted for age, baseline blood pressure, gender, and alcohol consumption, were 1.042 (p = 0.091) for BMI, 1.023 (p = 0.028) for waist circumference, 1.042 (p = 0.013) for waist‐to‐height ratio, 1.061 (p = 0.014) for waist‐to‐height2 index, 1.079 (p = 0.022) for waist‐to‐height3 index, and 1.033 (p = 0.006) for the waist‐to‐hip ratio. Discussion: The correction of the circumference of waist for stature or hip circumference improves its performance in the prediction of the incidence of hypertension. 相似文献
958.
Gian Battista Bischetti Enrico A. Chiaradia Tommaso Simonato Barbara Speziali Barbara Vitali Paolo Vullo Antonio Zocco 《Plant and Soil》2005,278(1-2):11-22
Forest vegetation is known to increase hillslope stability by reinforcing soil shear resistance and by influencing hydrologic
conditions of soil. Although the importance of plant root systems for hillslope stability has received considerable attention
in recent years, the quantification of such an effect needs more investigation. In this paper, we present a synthesis of the
data gathered in the last 5 years for some species in different locations of the Alps and Prealps of Lombardy (Northern Italy)
with the aim to increase our knowledge on root tensile strength and on Root Area Ratio distribution within the soil. Concerning
root tensile strength we developed tensile strength–diameter relationships for eight species: green alder (Alnus viridis(Chaix) D.C.), beech (Fagus sylvatica L.), red willow (Salix purpurea L.), goat willow (Salix caprea L.), hazel (Corylus avellana L.), European ash (Fraxinus excelsior L.), Norway spruce (Picea abies (L.) Karst.) and European larch (Larix decidua Mill.). Results show a great variability among the different species and also for the same species. In general, however,
root strength (in terms of tension) tends to decrease with diameter according to a power law, as observed by other Authors.
Comparing the power law fitting curves for the considered species, it can be observed that they fall in a relatively narrow
band, with the exception of hazel, which appears the most resistant. Concerning the evaluation of root distribution within
the soil we estimated the Root Area Ratio (the ratio between the area occupied by roots in a unit area of soil) according
to its depth for five species (beech, Norway spruce, European larch, mixed hazel and ash) in three locations of Lombardy.
Results show that there is a great variability of root density for the same species well as for different points at the same
locality. The general behaviour of root density, in any case, is to decrease with depth according to a gamma function for
all the studied species. The results presented in this paper contribute to expanding the knowledge on root resistance behaviour
and on root density distribution within the soil. The studied location have allowed the implementation of soil–root reinforcement
models and the evaluation of the vegetation contribution to soil stability. 相似文献
959.
M. Zavodna S. G. Compton S. Raja P. M. Gilmartin J. M. M. van Damme 《Journal of Insect Behavior》2005,18(3):351-362
Pollinating fig wasps (Hymenoptera, Agaonidae) have been the focus of numerous studies examining sex ratio evolution. Recently, molecular genetic techniques have been introduced that assume single matings in fig wasps, yet their mating biology has not been investigated genetically. We used recently developed microsatellite markers to investigate whether a pollinating fig wasp (Liporrhopalum tentacularis Grandi) produces single or mixed paternity clutches. The clutches of 12 females which had had the opportunity to mate with males of different genotypes were investigated. The results suggest that, at least in this species of fig wasp, single paternity clutches are the norm. Based on our behavioural observations, this appears to be due to mating with a single male rather than sperm competition. 相似文献
960.
Effects of Nitrogen fertilisation and regrowth period on fatty acid concentrations in perennial ryegrass (Lolium perenne L.) 总被引:1,自引:1,他引:0
A. Elgersma P. Maudet I.M. Witkowska & A.C. Wever 《The Annals of applied biology》2005,147(2):145-152
Information on lipids in forages is scarce, and effects of nitrogen (N) application level and regrowth period on the fatty acid (FA) concentration and composition of perennial ryegrass (Lolium perenne L.) were studied. N was applied at 0, 45 and 100 kg ha?1, and swards were cut after various regrowth periods, resulting in six treatments designed as randomised blocks with three replicates. The stages of development ranged from vegetative to elongating swards, with herbage yield levels from 1.9 to 4.2 t dry matter (DM) ha?1. Concentrations of individual FA were determined by gas chromatography, and canopy characteristics and herbage quality were assessed. The treatments resulted in canopies with contrasting DM yields and protein concentrations. Five FAs, representing 98% of total FAs, were studied in detail. On an average, the concentration of these major FAs in fresh grass was 15.1 g kg?1 DM, and 69% of the major FAs consisted of C18:3. Regrowth period affected (P < 0.05) the total FA concentration, and significantly (P < 0.01) lower concentrations of C18:3 and C16:1 were found after a longer period of regrowth. N application resulted in higher (P < 0.001) concentrations of all FAs. The FA composition was not affected by N application, but a longer regrowth period significantly (P < 0.001) decreased the proportion of C18:3 and increased those of C18:2 and C16:0. A strong, positive overall linear relation was found between the concentrations of total FAs and C18:3 with the crude protein concentration in the herbage. These studies demonstrate opportunities to affect the FA concentration and composition of FA in herbage through management strategies, which could affect milk FA composition. 相似文献