5,974 research outputs found
Totally umbilical disks and applications to surfaces in three-dimensional homogeneous spaces
Following [Ch] and [dCF], we give sufficient conditions for a disk type surface, with
piecewise smooth boundary, to be totally umbilical for a given Coddazi pair. As a consequence,
we obtain rigidity results for surfaces in space forms and in homogeneous product
spaces that generalizes some known results.Ministerio de Educación y Ciencia MTM2007-65249Ministerio de Educación y Ciencia MTM2007-64504Junta de Andalucía P06-FQM-01642Junta de Andalucía FQM32
Multivariate Orthogonal Polynomials and Modified Moment Functionals
Multivariate orthogonal polynomials can be introduced by using a moment
functional defined on the linear space of polynomials in several variables with
real coefficients. We study the so-called Uvarov and Christoffel modifications
obtained by adding to the moment functional a finite set of mass points, or by
multiplying it times a polynomial of total degree 2, respectively. Orthogonal
polynomials associated with modified moment functionals will be studied, as
well as the impact of the modification in useful properties of the orthogonal
polynomials. Finally, some illustrative examples will be given
Short-term memory binding in mild cognitive impairment
We showed that short-term memory (STM) binding is sensitive to sporadic and familial Alzheimer's disease (AD) but is not affected by healthy ageing, chronic depression in the elderly or other forms of dementia. STM binding deficits were also observed in individuals with a genetic susceptibility for AD in the preclinical stages. Hence, we aim to investigate longitudinally individuals with Mild Cognitive Impairment (MCI) using STM binding tasks. Here we report on preliminary cross-sectional results. A comprehensive neuropsychological test battery and a visual STM task were given to 21 MCI patients and 20 controls. The STM task required participants to recognise changes across two consecutive arrays presenting either single features (colour or shape) or feature bindings. The MCI group performed significantly poorer than controls on standard tests of memory, attention and on the binding condition of the STM task, but not on single feature conditions. Performance on the binding task and on standard memory tests did not correlate. Eight MCI patients clearly performed outwith the range of normality in the binding task. However, they did not significantly differ from the other 13 MCI patients in disease severity or demographic and neuropsychological variables. Six patients with binding impairments showed a multiple domain profile whereas ten patients with a preserved binding function showed an amnesic profile [Chi-square = 5.45, p = 0.020]. These results suggest that (1) the binding task is assessing a function different from other memory tests and that (2) STM binding may be differentially impaired in MCI subgroups
Liberación experimental de bases en suelos de origen granítico del Maresme (Barcelona):posibles componentes periódicos en las series cronológicas de valores
Peer Reviewe
Liberación experimental de bases en suelos de origen granitico del maresme (Barcelona): posibles componentes periodicos en las series cronologicas de valores
Peer Reviewe
TÉCNICA DE FOTOTRAMPEO PARA REGISTRAR INSECTOS Y REPTILES
A new photo trapping technique is proposed to count and identify insects and reptiles, taking into consideration that with the conventional techniques and equipment they are usually not recorded because of the limited capacity that the lenses have to focus on small and nearby animals or to detect their subtle movements. The technique allows recording diurnal and nocturnal pollinators of species of interest, insects with the potential to be pests, and recording the activity of reptiles and their capacity for seed dispersion,among others.Se propone una técnica nueva de fototrampeo para contabilizar e identificar insectos y reptiles, considerando que con las técnicas y equipo convencionales no suelen ser registrados por la limitada capacidad que tienen las lentes para enfocar animales pequeños y cercanos o detectar sus sutiles movimientos. La técnica permite registrar a los polinizadores diurnos y nocturnos de especies de interés, a los insectos con potencial de plaga, registrar la actividad de reptiles y su capacidad de dispersión de semillas, entre otros
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