Search results for "VARIATION"
showing 10 items of 2124 documents
El uso de tú y usted en el área metropolitana de Valencia. Un enfoque variacionista
2017
espanolEn este trabajo se realiza un estudio estadistico sobre el uso de las formas de tratamiento en Valencia y su area metropolitana. Tras una breve introduccion teorica sobre el tema y la explicacion de la metodologia utilizada, ofrecemos los resultados en terminos porcentuales. Pero, al tratarse de un fenomeno en el que intervienen multiples factores al mismo tiempo, hemos realizado tambien un analisis de regresion, que permite ver los resultados cuando todos los factores actuan de manera simultanea. Todas las variables que hemos analizado, salvo la lengua habitual (castellano o valenciano), resultan estadisticamente significativas, si bien las probabilidades de aparicion del tuteo son …
Association of ADHD with genetic variants in the 5'-region of the dopamine transporter gene: evidence for allelic heterogeneity.
2008
Contains fulltext : 69953.pdf (Publisher’s version ) (Closed access) Multiple studies have reported an association between attention deficit hyperactivity disorder (ADHD) and the 10-repeat allele of a variable number tandem repeat (VNTR) polymorphism in the 3'-untranslated region (3'UTR) of the dopamine transporter gene (DAT1). Yet, recent meta-analyses of available data find little or no evidence for this association; although there is strong evidence for heterogeneity between datasets. This pattern of findings could arise for several reasons including the presence of relatively rare risk alleles on common haplotype backgrounds or the functional interaction of two or more loci within the g…
Genetic signature consistent with selection against the CYP3A4*1B allele in non-African populations.
2005
Cytochrome P450 3A enzymes (CYP3A) play a major role in the metabolism of steroid hormones, drugs and other chemicals, including many carcinogens. The individually variable CYP3A expression, which remains mostly unexplained, has been suggested to affect clinical phenotypes. We investigated the CYP3A locus in five ethnic groups. The degree of linkage disequilibrium (LD) differed among ethnic groups, but the most common alleles of the conserved LD regions were remarkably similar. Non-African haplotypes are few; for example, only four haplotypes account for 80% of common European Caucasian alleles. Large LD blocks of high frequencies were suggestive of selection. Accordingly, European Caucasia…
Phylogeography of lions (Panthera leossp.) reveals three distinct taxa and a late Pleistocene reduction in genetic diversity
2009
Lions were the most widespread carnivores in the late Pleistocene, ranging from southern Africa to the southern USA, but little is known about the evolutionary relationships among these Pleistocene populations or the dynamics that led to their extinction. Using ancient DNA techniques, we obtained mitochondrial sequences from 52 individuals sampled across the present and former range of lions. Phylogenetic analysis revealed three distinct clusters: (i) modern lions, Panthera leo; (ii) extinct Pleistocene cave lions, which formed a homogeneous population extending from Europe across Beringia (Siberia, Alaska and western Canada); and (iii) extinct American lions, which formed a separate popula…
La incorporación de la regla variable en la enseñanza de E/LE
2017
Resumen: Desde hace algunos anos se viene insitiendo en la conveniencia de incorporar la informacion sociolinguistica en la didactica de una lengua. En el ambito anglosajon ya se habla en ocasiones de la «gramatica sociolinguistica», y existen algunos intentos de enriquecer la informacion gramatical con datos variacionistas. Sin embargo, en el caso del espanol pocas veces se atiende a esa informacion, mas alla de la necesidad de atender a las diferencias de registro a la hora de ensenar espanol a los alumnos extranjeros. Presentamos una propuesta de incorporacion de la variable sociolinguistica a la ensenanza de ELE, retomando la diferencia de Bernstein entre codigo restringido y codigo ela…
Association between MICA Gene Variants and the Risk of Hepatitis C Virus-Induced Hepatocellular Cancer in a Sicilian Population Sample
2018
There are currently no biomarkers that predict hepatocellular carcinoma (HCC) risk in patients with hepatitis C virus (HCV)-related cirrhosis. We investigated the relationships among major histocompatibility complex (MHC) class I chain-related gene A (MICA) polymorphisms, plasma levels of soluble MICA (sMICA), and HCC risk in patients with HCV-related HCC. One hundred fifty-four HCV-related HCC patients, 93 HCV-related liver cirrhosis (LC) cases, and 244 healthy controls, all sampled from the native Sicilian population, were genotyped using the KASP™ single-nucleotide polymorphism genotyping method. The MICA rs2596542 polymorphism showed that the G/G genotype was significantly more frequent…
Genetic variation in the TLL1 gene is not associated with fibrosis in patients with metabolic associated fatty liver disease.
2020
Metabolic associated fatty liver disease (MAFLD) is the most prevalent liver disease in Western nations, with high heritability. A recent study of Japanese patients with the disease suggested that TLL1 rs17047200 is associated with fibrosis; whether a similar association is observed in Caucasian patients with MAFLD is unknown. We investigated the association of the TLL1 rs17047200 polymorphism with liver fibrosis in a cohort of Caucasian patients with MAFLD (n = 728). We also investigated whether TLL1 expression is altered during liver injury in humans, in murine models of fibrosis, and in in-vitro. While TLL1 expression is upregulated in the liver of humans with MAFLD and in mice, the rs17…
Variational measures related to local systems and the Ward propery of P-adic path bases
2006
Some properties of absolutely continuous variational measures associated with local systems of sets are established. The classes of functions generating such measures are described. It is shown by constructing an example that there exists a P-adic path system that defines a differentiation basis which does not possess Ward property.
Incomplete sequence homogenization in 45S rDNA multigene families: intermixed IGS heterogeneity within the single NOR locus of the polyploid species …
2014
† Background and Aims Ribosomal sequences have become the classical example of the genomic homogenization of nuclear multigene families. Despite theoretical advantages and modelling predictions that support concerted evolution of the 45S rDNA, several reports have found intragenomic polymorphisms. However, the origins and causes of these rDNA polymorphisms are difficult to assess because seed plants show a wide range of 45S rDNA loci number variation, especially in polyploids. Medicago arborea is a tetraploid species that has a single 45S rDNA locus. This feature makes this species a suitable case study to assess the fate of ribosomal IGS homogenization in polyploid species showing nucleolu…
Contextual and strategic knowledge in the acquisition of design expertise
2000
Abstract This study examines the acquisition of expertise in designing and developing information systems. The aim was to investigate how practical experience is related to contextual and strategic knowledge in problem-solving. Using a combination of expert–novice comparisons and longitudinal methods, professional systems analysts were compared with novices at the beginning and end of a seven month project-based course. The results show that during the course, the novices acquired a good deal of strategic competence in using domain-specific methods. Compared to the novices, the experts showed a more comprehensive and higher level of awareness of clients' contextual constraints. The study de…