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81.
R de la Cuesta M L Maestro J Solana J A Vidart M Escudero E Iglesias R Valor 《The International journal of biological markers》1999,14(2):106-114
The objectives of this study were the determination of CA 125 in the cytosol of healthy and carcinomatous ovarian tissue by immunoanalysis, analysis of its correlation with the biological characteristics of ovarian carcinoma, determination of serum CA 125 levels, and study of the prognostic value of the marker in cytosol. The levels of the marker depend not only on the tumor's production rate, so its determination in tissue can indicate more accurately if the tumor is a producer of the marker and establish its value for the prognosis of the disease. Determination of CA 125 in tissue was performed by immunoanalysis in 50 ovarian epithelial cancer samples, 13 benign pathology samples and 32 healthy ovary samples. The presurgical serum level of the marker was also obtained. The correlation between the CA 125 level in the cytosol and the different biological characteristics of the ovarian carcinoma, the serum levels of the marker and survival were analyzed. The CA 125 level proved to be higher in malignant tissue (p < 0.0001). There was a significant association between the tissue marker and histological type (high CA 125 was associated with serous and endometrioid tumors) and between the marker and survival. No relation with stage was found. There was a correlation between the CA 125 level in the cytosol and serum both variables being dependent, with a correlation coefficient of 0.44. This good correlation speaks in favor of the usefulness of CA 125 determination in serum in the follow-up of ovarian cancer. Tumors having high tissue expression of CA 125 were found to have a double relative risk of death, independently of tumor stage. 相似文献
82.
Ana Lázaro-Nogal Silvia Matesanz Teresa E. Gimeno Adrián Escudero Fernando Valladares 《Plant and Soil》2012,358(1-2):213-223
Background and aims
Plant-soil interactions are a crucial component of ecosystem functioning. However, most global change studies focus on plant communities, with information on soil properties and performance being scarce. Our goal was to assess the individual and joint effect of habitat heterogeneity and three global change drivers (fragmentation, loss of habitat quality and climate change) on nutrient availability and soil microbial activity in Mediterranean gypsum soils.Methods
We collected soil samples from an experimental field site from large/small fragments, with high/low habitat quality, subjected to two levels of water availability (dry/mesic) and from two microhabitats (under the canopy of shrubs and in the open). We analyzed nutrient concentrations (C, N and P) and enzymatic activities (?-glucosidase, urease and acid phosphatase).Results
C, N, P content, ?-glucosidase, urease and acid phosphatase activities were higher under the canopy than in the open and in high- than in poor- habitat quality sites. These differences were exacerbated in small fragments.Conclusions
The strong interdependence between plant and soil was modulated by fragmentation in the Mediterranean gypsum soils studied. Drought did not exert a direct negative effect on soil properties, although the effect might arise under more intense drought or under drought taking place at times of the year different from those explored here. Results highlight the importance of considering several drivers simultaneously to forecast realistic ecosystem responses to global change. 相似文献83.
Esmeralda Martinez-Duro Arantzazu L. Luzuriaga Pablo Ferrandis Adrián Escudero José M. Herranz 《Ecological Research》2012,27(1):43-51
This paper evaluates the aboveground vegetation in relation to the soil seed bank throughout a 60-year succession process
following agricultural abandonment in a semi-arid Mediterranean gypsum habitat. There is little information regarding the
relationship between these two community components in the context of succession on semi-arid gypsum soils. Aboveground vegetation
and the corresponding seed bank of gypsum plant communities were sampled through a chronosequence of 24 abandoned fields.
Generalized linear models were used to model seed species richness and density, redundancy analyses to model the effect of
time since abandonment and the effect of soil physicochemical parameters on seed bank species composition, and Mantel tests
to analyze resemblance between above- and belowground species composition. In this last case, the effect of time since abandonment
was controlled using a partial Mantel test. Mantel correlograms using time intervals instead of distances were used to describe
the resemblance of above- to belowground species occurrence in different aged fields. No significant variability in seed species
richness, seed density, or species composition due to time since abandonment was found. Differences in seed species composition
were mainly due to small spatial scale predictors such as slope and soil calcium content. High correlations between species
composition in the soil seed bank and the aboveground vegetation were detected during succession. The lack of a significant
trend in aboveground species replacement over time was also reflected in seed bank composition. We concluded that the rapid
establishment of strict gypsophyte species relied mainly on the long-term persistence of these species in the seed bank. 相似文献
84.
Rubén Milla Diana M. Forero Adrián Escudero Jose M. Iriondo 《Proceedings. Biological sciences / The Royal Society》2009,276(1667):2531-2540
Recent work has shown that certain plants can identify their kin in competitive settings through root recognition, and react by decreasing root growth when competing with relatives. Although this may be a necessary step in kin selection, no clear associated improvement in individual or group fitness has been reported to qualify as such. We designed an experiment to address whether genetic relatedness between neighbouring plants affects individual or group fitness in artificial populations. Seeds of Lupinus angustifolius were sown in groups of siblings, groups of different genotypes from the same population and groups of genotypes from different populations. Both plants surrounded by siblings and by genotypes from the same population had lower individual fitness and produced fewer flowers and less vegetative biomass as a group. We conclude that genetic relatedness entails decreased individual and group fitness in L. angustifolius. This, together with earlier work, precludes the generalization that kin recognition may act as a widespread, major microevolutionary mechanism in plants. 相似文献
85.
El-Hachemi Z Escudero C Arteaga O Canillas A Crusats J Mancini G Purrello R Sorrenti A D'Urso A Ribo JM 《Chirality》2009,21(4):408-412
Traces of biological contaminants that cannot be detected, but are expected to be present, in ultra-pure water suffice to select the emerging chiral sign in the spontaneous mirror symmetry breaking that takes place during the formation of the J-aggregates of the amphiphilic diprotonated tetrakis-(4-sulfonatophenyl)porphyrin (H(4)TPPS(4)(2-)). This is demonstrated by competition experiments with a chiral cationic surfactant. The sensitivity of the detection depends on the hierarchical control of the H(4)TPPS(4)(2-) self-aggregation. 相似文献
86.
Plant disjunctions have provided one of the most intriguing distribution patterns historically addressed by biogeographers. Carex sect. Spirostachyae (Cyperaceae) displays an interesting pattern of disjunction to evaluate these scenarios, with species occurring in the main continental landmasses and in oceanic islands of the two hemispheres. Internal transcribed spacer and 5'-trnK intron plastid gene sequences were analyzed to determine (1) the times of diversification using penalized likelihood, and (2) reconstructions of the regions using maximum likelihood and Bayesian approaches of origin of sect. Spirostachyae and internal main lineages. The times for the diversification of sect. Spirostachyae are dated to between the end of the Eocene and the Oligocene, whereas the two main lineages are dated to between the end of the Oligocene and the beginning of Miocene. The phylogenetic analyses reveal a Mediterranean-Eurasian center of differentiation for sect. Spirostachyae and subsection Spirostachyae, whereas no clear, single ancestral area could be inferred for subsection Elatae. Both long-distance dispersal and ecological vicariance appear to have been involved in the evolutionary history of the disjunct distribution of the main lineages of sect. Spirostachyae. These organisms appear to have a special ability to colonize remote areas (through transoceanic and interhemispherical colonizations), but special long-distance dispersal mechanisms are not evident. 相似文献
87.
Raquel Sobrino Pelayo Acevedo Marco A. Escudero Javier Marco Christian Gortázar 《European Journal of Wildlife Research》2009,55(2):161-165
We conducted spotlight counts from 1992 to 2006 in 59 localities to describe carnivore presence, distribution and relative
abundance in open agriculture lands in Aragon, northeastern Spain. During the study period, urban waste and carcases of domestic
livestock became less available to wild animals, and rabbit (Oryctolagus cuniculus) abundance was low after rabbit haemorragic disease. We calculated a kilometric abundance index (KAI, individuals seen per
100 km surveyed) and the ratio between the number of positive localities in which a species was detected and the total of
localities surveyed in a year. Indices to abundance and presence included: red fox (Vulpes vulpes), KAI per 100 km 10.70 and 100.0% localities per year; stray dog (Canis familiaris), KAI 0.48 and 22.6% localities; wildcat (Felis silvestris), KAI 0.10 and 19.1% localities; domestic cat (Felis catus), KAI 0.21 and 20.6% localities; polecat (Mustela putorius), KAI 0.02 and 2.0% localities; badger (Meles meles), KAI 0.16 and 23.6% localities; stone marten (Martes foina), KAI 0.11 and 19.6% localities; weasel (Mustela nivalis), KAI 0.002 and 0.6% localities; and genet (Genetta genetta), KAI 0.06 and 10.0% localities. Indices of badger abundance increased significantly, whereas indices of stray dogs decreased
significantly over the study period. Abundance indices of red fox, the most important predator of small game, were stable
throughout the study period. No significant trend was observed to other studied species. This study concludes that Aragon
region maintains a diverse and rather stable carnivore community and shows that large scale data may help to identify trends
of the more abundant wild and feral carnivores. 相似文献
88.
Pedro Francisco Quintana-Ascencio Idoia Caballero José Miguel Olano Adrián Escudero Maria José Albert 《Population Ecology》2009,51(2):317-328
Habitat heterogeneity may influence plant demography because conditions for survival, growth, and reproduction vary within
a species’ range. We assessed the role of microhabitat spatial structure on the demography of Helianthemum squamatum, a shrubby gypsum specialist endemic to the Iberian Peninsula. We evaluated the demographic effect of microhabitat spatial
variation using an approach that combined cellular automata with matrix population models, and included environmental and
demographic stochasticty. We collected data on seed bank (2003–2005), seedling emergence (2003–2006), and adult survivorship
(2004–2007) for H. squamatum in two independent blocks with different grazing intensity in Belinchón (Cuenca, Spain). We built spatial scenarios for each
block based on field data of cover and spatial pattern of four microhabitats: lichenic crust, litter, H. squamatum, and shrub. Seedling survivorship was affected by year, block, and microhabitat, with individuals emerging under conspecifics
having the highest survival rate and on litter the lowest in both blocks, whereas the effect of crust and other shrubs differed
across blocks. Our models indicated population increase in the block with low grazing, but population decline in the block
with intense grazing. We hypothesize that higher pressure of livestock grazing and trampling leads to a shift in relative
microhabitat suitability for crust and shrub. This potential effect of grazing on spatial demographic variation opens interesting
questions for future research. We emphasize the importance of considering microhabitat spatial structure when evaluating management
and conservation strategies.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
89.
? Premise of the study: Limited availability of seeds and microsites are important constraints for seedling emergence and survival. However, little is known about population-level feedbacks between seed and microsite limitation and how these relationships vary in contrasting conditions. Focusing on Armeria caespitosa, a high-mountain endemic, we asked whether seedling establishment was simultaneously limited by seed and microsite availability, whether the balance between seed and microsite limitations varied with contrasting environments, and whether seed and microsite limitations interacted with each other. ? Methods: We studied seedling emergence and survival at the edges of the elevation range of A. caespitosa in central Spain over 4 years. We used mixed linear models and structural equation modeling. ? Key results: Our results showed that A. caespitosa recruits similar numbers of new seedlings per plot in contrasting environments. Seedling emergence and survival in A. caespitosa were both limited by seed and microsite availability. Habitat suitability (the surrogate of microsite limitation) varied between populations and indirectly affected fertility (the surrogate of seed limitation). ? Conclusions: Seedling emergence and survival are both seed and microsite limited, there are interactions between seed and microsite limitations, and both factors, which control seedling establishment, and their interconnections, vary among local populations. 相似文献
90.
J. R. Arévalo R. Otto C. Escudero S. Fernández-Lugo M. Arteaga J. D. Delgado J. M. Fernández-Palacios 《Plant Ecology》2010,209(1):23-35
Biological homogenization is defined as a process that occurs when native species are replaced by common and dominant exotic
species or due to depletion and expansion of native species, reducing the beta diversity between areas or habitats. Islands
are particularly vulnerable to plant invasion, and as a consequence, homogenization is a process that can become faster and
more intense in islands than in continental areas. We recorded vascular plant species composition in roadside communities
along a strong altitudinal gradient using plots beside the road and at two distances from the road (0–50 and 50–100 m). We
analyzed the results separately for each group of plots with a Detrended Correspondence Analysis (DCA) including and excluding
exotic species. The results revealed that where exotic species were most abundant, i.e., at the road edge, they can create
an effect of floristic homogenization where three similar roads are compared. At a distance of >50 m from the road, where
exotic species are less frequent, this effect has already disappeared, indicating that it is a local phenomenon, closely related
to the highly disturbed roadside environment. Furthermore, floristic homogenization seems to be more important at higher altitudes
(>1000 m), probably related to higher diversity in native plant communities and lower levels of human disturbances. Roads
allow humans to reach relatively remote and sometimes well-conserved areas, and, at the same time, facilitate the spread of
exotic plants and the most common native species which can locally create floristic homogenization in roadside communities
on this oceanic island. A deeper understanding of the effects of these anthropogenic corridors at the local and regional scales
is therefore required to integrate road planning and management with the aim of conserving the value of the natural areas. 相似文献