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991.
Joan Llusià Josep Peñuelas Giorgio A. Alessio Marc Estiarte 《Physiologia plantarum》2006,127(4):632-649
To test the effect of forecasted drought and warming conditions for the next decades by GCM and ecophysiological models on foliar concentrations of volatile organic compounds (VOCs) and especially of volatile terpenes, we studied four typical Mediterranean woody plants (Pinus halepensis L., Pistacia lentiscus L., Rosmarinus officinalis L. and Globularia alypum L.) under a field experimental drought and warming generated using automatically sliding curtains. Terpenes were detected in the four studied species (R. officinalis L., P halepensis L., Pistacia lentiscus L. and G. alypum L.). In general, maximum concentrations of terpenes were found in the coldest periods and minimum concentrations in the summer. Their concentrations ranged between 0.003 mg g?1 DM (eugenol) in G. alypum under drought conditions and 37 mg g?1 DM in R. officinalis under control conditions. Main volatile terpenes found in all studied species except in G. alypum were α‐pinene, camphene, β‐pinene, β‐phellandrene and caryophyllene. In general, VOC leaf concentrations increased when soil moisture increased and decreased when air temperature increased. However, contrasting not consistent responses to the drought and warming treatments were found among species, seasons and years. For example, in P. halepensis, the concentrations decreased in response to drought in winter and instead increased in summer. Contrarily, drought decreased concentrations in summer and increased them in winter in Pistacia lentiscus. In any case, the data on seasonal VOC concentration in Mediterranean woody species provided here will add new knowledge of seasonal variation in essential oil contents of these species. These data might help in the study of flammability of Mediterranean ecosystems and in improving prediction algorithms, inventories and modelling of monoterpene emissions in response to climate change, which mostly do not consider the changes in concentration under drought stress. However, the lack of general and consistent response patterns to increasing drought and warming among species, seasons and years found here makes this task difficult. 相似文献
992.
993.
Michele E. R. Pierotti Josep A. Martín-Fernández Ole Seehausen 《Evolution; international journal of organic evolution》2009,63(9):2372-2388
Sexual selection theory largely rests on the assumption that populations contain individual variation in mating preferences and that individuals are consistent in their preferences. However, there are few empirical studies of within-population variation and even fewer have examined individual male mating preferences. Here, we studied a color polymorphic population of the Lake Victoria cichlid fish Neochromis omnicaeruleus , a species in which color morphs are associated with different sex-determining factors. Wild-caught males were tested in three-way choice trials with multiple combinations of different females belonging to the three color morphs. Compositional log-ratio techniques were applied to analyze individual male mating preferences. Large individual variation in consistency, strength, and direction of male mating preferences for female color morphs was found and hierarchical clustering of the compositional data revealed the presence of four distinct preference groups corresponding to the three color morphs in addition to a no-preference class. Consistency of individual male mating preferences was higher in males with strongest preferences. We discuss the implications of these findings for our understanding of the mechanisms underlying polymorphism in mating preferences. 相似文献
994.
Ernestina Aguilar‐Fenollosa Tatiana Pina María A. Gómez‐Martínez Mónica A. Hurtado Josep A. Jacas 《Entomologia Experimentalis et Applicata》2012,144(2):181-190
Tetranychus urticae Koch (Acari: Tetranychidae) is a key pest of clementine mandarins, Citrus clementina Tanaka (Rutaceae), in Spain. This mite is highly polyphagous and can be easily found in clementine orchards, both in the trees and in the associated flora. In a previous study we found that the use of a cover of Festuca arundinacea Schreber (Poaceae) offered a better regulation of T. urticae populations than either bare soil or the traditional wild cover, which included a mix of weed species. We hypothesized that the selection of two host races of T. urticae, specialized in F. arundinacea and C. clementina, could partly explain the results obtained (bottom‐up regulation). Reciprocal transplant experiments show that sympatric deme × host combinations had higher mean fitness values than the allopatric combinations in clementine, but not in F. arundinacea, for most of the fitness parameters evaluated in our study. Because local adaptation implies mean deme fitness to be systematically higher for the sympatric deme × habitat combinations than for the allopatric ones, these results can be taken as indicative of occurrence of local adaptation in T. urticae. Molecular genetic analyses with microsatellite markers support this conclusion and indicate that local adaptation of T. urticae found in our system may indeed contribute to a better natural regulation of this mite. 相似文献
995.
In vitro cell-based reporter assays are a useful tool for the discovery and characterization of nuclear receptor modulators. However, the properties of a given molecule can differ when tested in vitro and in vivo as a result of the molecule's bioavailability. In this work, we describe a methodology that allows the detection of the PPARγ (peroxisome proliferator-activated receptor gamma) agonist bezafibrate in rat serum by an in vitro cell-based reporter assay. This methodology could be adapted to the detection and characterization of bioavailable PPARγ or other nuclear receptor modulators in serum, extending the possibilities of the classical in vitro assays. 相似文献
996.
This study presents an analysis of temperature and precipitation trends and their impact on grape harvests in the Penedès region (NE Spain). It includes analyses of maximum, minimum and mean daily temperatures (for both the growing and ripening seasons) and daily rainfall (for the hydrological year, the growing season and each phenological stage) for three observatories in the immediate area. We analysed a series of factors: beginning and end harvest dates; the day on which a given potential alcoholic degree was reached; and yield for several varieties of grape grown in the area in relation to climatic variables. Maximum temperatures increased at all the observatories, with greater values being recorded in recent years (1996–2009) than in previous decades (1960s–2000s): we observed increases in average growing season temperatures of 0.11°C per year for the period 1996–2009 vs 0.04°C per year for the period 1960–2009 at Vilafranca del Penedès. These temperature changes were due mainly to increases in maximum temperatures and an increase in the incidence of extreme heat (number of days with T > 30°C). Crop evapotranspiration also increased significantly during the same period. The Winkler index also increased, so the study area would correspond to region IV according to that climatic classification. There were no significant trends in annual rainfall but rainfall recorded between bloom and veraison decreased significantly at the three observatories, with the greatest decrease corresponding to the period 1996–2009. The dates on which harvests started and ended showed a continuous advance (of between −0.7 and −1.1 days per year, depending on the variety), which was significantly correlated with the average mean and maximum daily growing season temperatures (up to −7.68 days for 1°C increase). Winegrape yield was influenced by the estimated water deficit (crop evapotranspiration minus precipitation) in the bloom-veraison period; this value increased due to a reduction in precipitation and an increase in evapotranspiration. Yield may have been reduced by up to 30 kg/ha for each millimetre increase in the estimated water deficit. Under these conditions, new strategies need to be followed in this area in order to maintain grape quality and yield. 相似文献
997.
998.
Ramon Clèries José Miguel Martínez Josep Maria Escribà Laura Esteban Laura Pareja Josep Maria Borràs Josepa Ribes 《Cancer epidemiology》2010,34(3):244-256
Purpose: To assess time trends of testicular cancer (TC) mortality in Spain for period 1985–2019 for age groups 15–74 years old through a Bayesian age–period–cohort (APC) analysis. Methods: A Bayesian age–drift model has been fitted to describe trends. Projections for 2005–2019 have been calculated by means of an autoregressive APC model. Prior precision for these parameters has been selected through evaluation of an adaptive precision parameter and 95% credible intervals (95% CRI) have been obtained for each model parameter. Results: A decrease of ?2.41% (95% CRI: ?3.65%; ?1.13%) per year has been found for TC mortality rates in age groups 15–74 during 1985–2004, whereas mortality showed a lower annual decrease when data was restricted to age groups 15–54 (?1.18%; 95% CRI: ?2.60%; ?0.31%). During 2005–2019 is expected a decrease of TC mortality of 2.30% per year for men younger than 35, whereas a leveling off for TC mortality rates is expected for men older than 35. Conclusions: A Bayesian approach should be recommended to describe and project time trends for those diseases with low number of cases. Through this model it has been assessed that management of TC and advances in therapy led to decreasing trend of TC mortality during the period 1985–2004, whereas a leveling off for these trends can be considered during 2005–2019 among men older than 35. 相似文献
999.
Assessing the contribution of promoters and coding sequences to gene evolution is an important step toward discovering the major genetic determinants of human evolution. Many specific examples have revealed the evolutionary importance of cis-regulatory regions. However, the relative contribution of regulatory and coding regions to the evolutionary process and whether systemic factors differentially influence their evolution remains unclear. To address these questions, we carried out an analysis at the genome scale to identify signatures of positive selection in human proximal promoters. Next, we examined whether genes with positively selected promoters (Prom+ genes) show systemic differences with respect to a set of genes with positively selected protein-coding regions (Cod+ genes). We found that the number of genes in each set was not significantly different (8.1% and 8.5%, respectively). Furthermore, a functional analysis showed that, in both cases, positive selection affects almost all biological processes and only a few genes of each group are located in enriched categories, indicating that promoters and coding regions are not evolutionarily specialized with respect to gene function. On the other hand, we show that the topology of the human protein network has a different influence on the molecular evolution of proximal promoters and coding regions. Notably, Prom+ genes have an unexpectedly high centrality when compared with a reference distribution (P = 0.008, for Eigenvalue centrality). Moreover, the frequency of Prom+ genes increases from the periphery to the center of the protein network (P = 0.02, for the logistic regression coefficient). This means that gene centrality does not constrain the evolution of proximal promoters, unlike the case with coding regions, and further indicates that the evolution of proximal promoters is more efficient in the center of the protein network than in the periphery. These results show that proximal promoters have had a systemic contribution to human evolution by increasing the participation of central genes in the evolutionary process. 相似文献
1000.
Matthew D. Dyer Chris Neff Max Dufford Corban G. Rivera Donna Shattuck Josep Bassaganya-Riera T. M. Murali Bruno W. Sobral 《PloS one》2010,5(8)