1,928 research outputs found
Differences in trajectories and predictive factors of cognition over time in a sample of cognitively healthy adults, in zaragoza, spain
Great inter-individual variability has been reported in the maintenance of cognitive function in aging. We examined this heterogeneity by modeling cognitive trajectories in a population-based longitudinal study of adults aged 55+ years. We hypothesized that (1) distinct classes of cognitive trajectories would be found, and (2) between-class differences in associated factors would be ob-served. The sample comprised 2403 cognitively healthy individuals from the Zaragoza Dementia and Depression (ZARADEMP) project, who had at least three measurements of the Mini-Mental State Examination (MMSE) in a 12-year follow-up. Longitudinal changes in cognitive functioning were modeled using growth mixture models (GMM) in the data. The best-fitting age-adjusted model showed 3 distinct trajectories, with 1-high-to-moderate (21.2% of participants), 2-moderate-stable (67.5%) and, 3-low-and-declining (9.9%) cognitive function over time, respectively. Compared with the reference 2-trajectory, the association of education and depression was significantly different in trajectories 1 and 3. Instrumental activities of daily living (iADLs) were only associated with the declining trajectory. This suggests that intervention strategies should be tailored specifically to individuals with different trajectories of cognitive aging, and intervention strategies designed to maintain cognitive function might be different from those to prevent decline. A stable cognitive performance (âsuccessful cognitive agingâ) rather than a mild decline, might be more ânormalâ than generally expected
Toxoplasma gondii in Spanish commercial dry-cured meat products
Toxoplasmosis is an infection caused by Toxoplasma gondii, the transmission of which has usually been attributed to ingestion of undercooked or raw meat. Epidemiological studies also mention cured meat products as a potential risk factor for acquiring toxoplasmosis. With the aim of contributing to the risk assessment process, 552 samples of commercial dry-cured hams/shoulders and dry-cured sausages of different trademarks from different localities in Spain were randomly purchased for analysis. These were, specifically, 311 dry-cured hams/shoulders and 241 dry-cured sausages (76 samples of chorizo, 75 samples of fuet/longaniza, and 90 samples of salchichĂłn). Additionally, data featured on labels of each meat product were gathered with the purpose of studying the influence of curing time and salt content, among other parameters, on the viability of Toxoplasma. Real-time polymerase chain reaction technique (qPCR) was performed to detect T. gondii DNA in the samples, and infectivity was determined by mouse bioassay of positive qPCR samples. The presence of T. gondii was detected in 57 samples (10.3%), with a parasite load between 28.05 and 35.66 Ct. Bioassay test showed that 47 out of the 57 meat products in which the parasite has been detected produced mice seropositive response (IFA), which represents 8.5 of the total number of samples analyzed. Of those samples, DNA of Toxoplasma gondii in mice brain was detected in 6 meat products, indicating its viability (1.1%). Ct values obtained by qPCR in the brains of seropositive mice ranged from 33.10 to 36.04. According to product type, the parasite was viable in 3 dry-cured ham/shoulder samples and in 3 salchichĂłn samples. Statistical analysis showed that none of the variables under consideration detailed on the meat product labels had a significant influence on the viability of the parasite. In conclusion, we found a low prevalence of the infective forms of Toxoplasma gondii in cured meat products, although the risk for consumers cannot be completely excluded. However, scientific monitoring of commercial meat products continues to be necessary in order to provide data for risk assessment of Toxoplasma gondii through the meat industry's Hazard Analysis and Critical Control Point (HACCP-based self-control system). In order to ensure that consumers can make a safe choice among these ready-to-eat products, it is important for food labels to include information on those parameters which are relevant for the survival of the parasite, such as curing times, or freezing treatment of meat used as an ingredient
The effect of a stellar magnetic variation on the jet velocity
Stellar jets are normally constituted by chains of knots with some
periodicity in their spatial distribution, corresponding to a variability of
order of several years in the ejection from the protostar/disk system. A widely
accepted theory for the presence of knots is related to the generation of
internal working surfaces due to variations in the jet ejection velocity. In
this paper we study the effect of variations in the inner disk-wind radius on
the jet ejection velocity. We show that a small variation in the inner
disk-wind radius produce a variation in the jet velocity large enough to
generate the observed knots. We also show that the variation in the inner
radius may be related to a variation of the stellar magnetic field.Comment: 5 pages, 3 figures, accepted for publication in Ap
Gas injection laboratory experiments on Opalinus clay.
Understanding gas transport processes is one of the key issues in the assessment of radioactive waste repository performance and is the focus of this research. To this aim, this research programme was started with the
following specific objectives. 1) To develop and calibrate an experimental set-up to perform controlled flow-rate gas injection experiments using a high-pressure triaxial cell to apply isotropic/anisotropic stress states. 2) To carry out a series of tests on Opalinus clay OPA samples to study the conditions under which gas breakthrough processes occur, to analyse the influence of the gas injection rate, the stress state, the orientation of rock discontinuities and other relevant hydro-mechanical variables (porosity, degree of saturation, âŠ), as well as the observation of the induced desaturation (pore water displacement by gas), ingoing and outgoing gas fluxes,
aperture and preferential paths created, and so on.Peer ReviewedPostprint (authorâs final draft
Fluctuating Dimension in a Discrete Model for Quantum Gravity Based on the Spectral Principle
The spectral principle of Connes and Chamseddine is used as a starting point
to define a discrete model for Euclidean quantum gravity. Instead of summing
over ordinary geometries, we consider the sum over generalized geometries where
topology, metric and dimension can fluctuate. The model describes the geometry
of spaces with a countable number of points, and is related to the Gaussian
unitary ensemble of Hermitian matrices. We show that this simple model has two
phases. The expectation value . Moreover, the
space-time dimension is a dynamical observable in our model, and plays
the role of an order parameter. The computation of is discussed and
an upper bound is found, .Comment: 10 pages, no figures. Third version: This new version emphasizes the
spectral principle rather than the spectral action. Title has been changed
accordingly. We also reformulated the computation of the dimension, and added
a new reference. To appear in Physical Review Letter
Anxiety and risk of vascular dementia in an elderly community sample: The role of sex
Background: To assess the association between anxiety and risk of vascular dementia (VaD), as well as potential sex differences, in a community-based cohort.
Methods: A random sample of 4057 dementia-free community participants aged 55 or older, from the longitudinal, community-based Zaragoza Dementia and Depression Project (ZARADEMP) study were followed for 4.5 years. Geriatric Mental State B (GMS)-Automated Geriatric Examination for Computer Assisted Taxonomy (AGECAT) was used for the assessment and diagnosis of anxiety, and a panel of research psychiatrists diagnosed the incident cases of VaD according to DSM-IV (Diagnostic and Statistical Manual of mental disordes). Multivariate survival analysis with competing risk regression model was performed.
Results: In men, the incidence rate of VaD was significantly higher among anxiety subjects compared with non-anxiety subjects (incidence rate ratio (IRR) (95% confidence interval (CI)): 3.24 (1.13â9.35); p = 0.029), and no difference was observed in women (IRR (95%CI): 0.68 (0.19â 2.23); p = 0.168). In the multivariate model, for men, cases of anxiety had 2.6-fold higher risk of VaD (subdistribution hazard ratio (SHR): 2.61; 95%CI: 0.88â7.74) when all potential confounding factors were controlled, with no statistical significance (p = 0.084), but a clinically relevant effect (Cohenâs d: 0.74). No association was found in women.
Conclusions: In men, but not in women, risk of VaD was higher among individuals with anxiety, with a clinically relevant effect. Potential anxiety-related preventive interventions for VaD might be tailored to men and women separately
OBSERVACIONES BIOLĂGICAS Y CONDUCTUALES DE ALGUNOS SALTAMONTES (ORTHOPTERA: ACRIDOIDEA) DE PANAMĂ.
The present work collects observations made both in the field and in the laboratory of some grasshoppers (Orthoptera: Acridoidea), where aspects of their biology and behavior are described. Rowell (2013) points out that, in Panama, the Acridoidea is composed of 66 genera and 108 species; being the Acrididae the family that has more than 65% of the total grasshoppers; which have a great structural, ecological and behavioral diversity. We observed that Abracris flavolineata (DeGeer), 1773, Orphulella punctata (DeGeer), 1773 and Stenopola puncticeps (StĂ„l), 1860, they are species that are more frequently found in different collection points; furthermore, the grasshoppers studied were generally located in Poaceace and there are nematodes that parasitize.El presente trabajo recoge observaciones hechas tanto en campo como en el laboratorio de algunos saltamontes (Orthoptera: Acridoidea), en donde se describen aspectos sobre su biologĂa y comportamiento. Rowell (2013), señala que, en PanamĂĄ, la Acridoidea estĂĄ compuesta por 66 gĂ©neros y 108 especies; siendo la Acrididae la familia que tiene a su haber mĂĄs del 65% del total de saltamontes; los cuales tienen una gran diversidad estructural, ecolĂłgica y de comportamiento. Observamos que Abracris flavolineata (DeGeer), 1773, Orphulella punctata (DeGeer), 1773 y Stenopola puncticeps (StĂ„l), 1860, son especies que se encuentran distribuĂdos en casi todo el territorio nacional; ademĂĄs, los saltamontes estudiados se encontraron generalmente en plantas de la familia Poaceae, del cual se alimentaban. Se reportan nemĂĄtodos que los parasitan
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