Search results for " Population"

The dynamics of soil bacterial community structure in response to yearly repeated agricultural copper treatments

2008

International audience; The annual dynamics of soil bacterial community structure, including early, dose-dependent and transient modifications, was observed consecutively at different levels of copper contamination (high: 48 kg Cu ha−1, low: 16 kg Cu ha−1) repeated yearly over a three-year field experiment. Repeated low-level Cu contamination led to an increase in community stability to metal stress without a long-term shift in the population structure, whereas repeated high-level Cu contamination induced a novel and stable bacterial community structure. Furthermore, field experimentation highlighted that episodic climatic stress can modulate copper impact by enhancing community stability.

Protein and DNA fingerprinting of a soil bacterial community inoculated into three different sterile soils

2007

The functional and genetic structures of a soil bacterial community were characterized after inoculation into three different sterile soils using a protein and DNA fingerprinting method, respectively. Principal component analysis (PCA) of profiles revealed that, depending on soil characteristics, bacterial communities with similar genetic structures harbored different functional structures and thus could potentially be of differing ecological significance for soil functioning. Co-inertia analysis between protein fingerprinting data and the corresponding sets of soil physicochemical characteristics demonstrated the correlation between the functional structure of the bacterial community and s…

Sampling strategy in molecular microbial ecology: influence of soil sample size on DNA fingerprinting analysis of fungal and bacterial communities.

2003

Assessing soil microbial community structure by the use of molecular techniques requires a satisfactory sampling strategy that takes into account the high microbial diversity and the heterogeneous distribution of microorganisms in the soil matrix. The influence of the sample size of three different soil types (sand, silt and clay soils) on the DNA yield and analysis of bacterial and fungal community structure were investigated. Six sample sizes from 0.125 g to 4 g were evaluated. The genetic community structure was assessed by automated ribosomal intergenic spacer analysis (A-RISA fingerprint). Variations between bacterial (B-ARISA) and fungal (F-ARISA) community structure were quantified b…

Contrasting age-specific recruitment and survival at different spatial scales: A case study with the European storm petrel

2009

Evolutionary studies on optimal decisions or conservation guidelines are often derived by generalising patterns from a single population, while inter-population variability in life-history traits is seldom considered. We investigated here how survival and recruitment probabilities changed with age at different geographical scales using the encounter histories of 5523 European storm petrels from three Mediterranean colonies, and also how our estimates of these parameters might be expected to affect population growth rates using population matrix models. We recorded similar patterns among colonies, but also important biological differences. Local survival, recruitment and breeding success inc…

An empirical investigation of the effect of borrowing constraints on Spanish consumption

2003

This work analyses the relevance of borrowing constraints on the intertemporal behaviour of Spanish non-durable consumption. We estimate Euler equations with cohort data extracted from the "Encuesta Continua de Presupuestos Familiares" (ECPF) for the period 1985-1993. The results are robust to the use of different estimators to eliminate fixed individual effects, to different specifications of the model, to the effect of uncertainty and to the presence of habits in consumption. Our results allow us to conclude that non-durable consumption of a considerable fraction of the Spanish population is affected by borrowing constraints. At the same time, and in accordance with similar results for ot…

Adaptation and Initial Validation of the BRCS in an Elderly Spanish Sample

2012

Resilience is understood as a dynamic process encompassing positive adaptation within the context of adversity. This study examined the validity of the Brief Resilient Coping Scale (BRCS), a 4-item measure designed to capture tendencies to cope with stress in a highly adaptive manner, in an elderly Spanish population. A total of 133 elderly people from an association of retired persons in Valencia (Spain) provided the responses for the validation study. The factorial validity of the scale was tested using confirmatory factor analysis, with a single dimension of resilience with adequate fit indexes emerging from this analysis. The BRCS has adequate internal consistency both at the scale and…

The uneven transition towards universal literacy in Spain, 1860–1930

2021

This study provides new evidence on the advance of literacy in Spain during the period 1860–1930. A novel dataset, built with historical information from the Spanish population censuses (over 8000 ...

Identifying sensitive windows of exposure to NO2 and fetal growth trajectories in a Spanish population-based birth cohort

2020

Nondestructive Direct Determination of Heroin in Seized Illicit Street Drugs by Diffuse Reflectance near-Infrared Spectroscopy

2008

A new method has been developed for the fast and nondestructive direct determination of heroin in seized street illicit drugs using partial least-squares regression analysis of diffuse reflectance near-infrared spectra. Data were obtained from untreated samples placed in standard glass chromatography vials. A heterogeneous population of 31 samples, previously analyzed by a reference method, was employed to build the calibration model and to have a separated validation set. Based on the use of zero-order data for a calibration set of 21 samples, after standard normal variate and quadratic linear removed baseline correction (detrending), in the wavelength range from 1111 to 1647 nm, 8 PLS fac…

Overwintering survival in relation to body mass in a field population of the wolf spider ( Hygrolycosa rubrofasciata )

1999

Body size is often considered to be an important trait affecting individual fitness. In arthropods, females commonly benefit from larger size directly through increased fecundity (Roff, 1992), and males through increased mating success (Andersson, 1994). It has also been suggested that larger individuals may in general have a better survival than smaller individuals (Calder, 1983; Peters, 1983). From this suggestion it may be predicted that during stressful environmental conditions larger individuals should do better than smaller individuals.