Search results for "cura"
showing 10 items of 624 documents
Structural analysis of Drosophila subobscura gypsy elements (gypsyDs)
1997
The study of gypsy elements in Drosophila subobscura (gypsyDs) indicated that they are transcriptionally active and mobile. From the comparative analysis of a complete gypsyDs element with the canonical gypsy sequence from D. melanogaster (gypsyDm) it can be deduced that while the whole structure is maintained, the gypsyDs ORF3 encodes a non-functional Env protein. The PCR amplification and sequencing of the ORF3 from different laboratory strains and H271 clones show that all gypsyDs sequences studied have frame-shifting mutations in this region. These results support that gypsyDs elements lack functional Env proteins and consequently they lack infective ability. In this way, it can be prop…
Molecular variation in the Odh gene in Chilean natural populations of Drosophila subobscura
2008
A 793-nucleotide fragment from the D. subobscura Odh gene was sequenced in 46 lethal chromosomal lines from two South American colonizing populations (18 from Santiago de Chile and 28 from Puerto Montt). Only eight different haplotypes were found and, with just one exception, all had previously been detected in North American samples. The exception probably corresponds to a genetic exchange between two American haplotypes. Our results confirm the loss in genetic variability due to the recent founder event, and the high resemblance between the two colonized hemispheres. One haplotype is entirely associated with the O5 inversion, the same association found in North America. Two different hapl…
Temporal changes of chromosomal polymorphism in natural populations of Drosophila subobscura
1984
The behaviour of the chromosomal polymorphism of D. subobscura was analyzed in relation to temporal changes, daily, seasonal and annual. Firstly, chromosome analyses were carried out over a year in a natural population. Samples were taken at monthly intervals in Tibidabo, a locality close to Barcelona. In all the months except January, the number of individuals captured was enough to carry out a chromosome analysis of that population. The A, E and O chromosomes showed a great uniformity in the frequencies of gene arrangement over the year. However, significant changes occur in the frequencies of J and U chromosomes. The J1 and U1+2+8 arrangements showed a similar tendency, with two maxima, …
Colonization of America by Drosophila subobscura: association between Odh gene haplotypes, lethal genes and chromosomal arrangements.
2004
The colonization of America by Drosophila subobscura has been a unique exper iment in nature that has allowed us to explore the effects of evolution on a continental scale. To analyze this evolutionary event, nucleotide sequences of the Odh (Octanol dehydrogenase) gene were obtained for 43 lethal chromosomal lines from colonizing populations of North America and 5 from South America, in addition to 5 chromosomal lines from Europe with different viabilities and 2 from laboratory marker stocks. Since 10 different Odh haplotypes were found in America, the minimum number of colonizers would be 5 (or 3 mated females). Only one Odh haplotype was found in American O(5) inversions confirming that o…
PATTERNS OF PUFFING ACTIVITY AND CHROMOSOMAL POLYMORPHISM IN DROSOPHILA SUBOBSCURA . IV. EFFECT OF INVERSIONS ON GENE EXPRESSION
1988
We have observed that, contrary to a common assumption, the puffing patterns manifest in the salivary chromosomes of Drosophila subobscura are modified by chromosomal inversions as well as by genic content. An inversion effect is apparent in the E and A chromosomes of five strains coming from four different natural populations. An effect due to the geographical location of the populations is also detected in the J and O chromosomes. The chromosomal and geographic effects are distinguishable but not contradictory. Indeed, a statistical test using the DK2 coefficient of distance shows that, for a given chromosomal arrangement, strains of different geographic origin exhibit puffing patterns si…
Gene activity of polytene chromosomes in Drosophila species of the obscura group.
1988
The polytene chromosome puffing patterns of Drosophila guanche were established and compared with those of Drosophila subobscura. A total of 150 loci, active in some of the 17 developmental stages studied, were described and 23 of them were found to form the characteristic puffing pattern of D. guanche. Taking into account the number of puffs as well as the gene activity of each chromosome and the total gene activity, D. guanche seems to be less active than D. subobscura. Although both species show a degree of homology in their puffing patterns lower than that found for sibling species, the degree of homology is stronger than that between species belonging to the same group but to different…
Patterns of puffing activity and chromosomal polymorphism in Drosophila subobscura II. Puffing patterns at the prepupa stage
1985
Puffing activity patterns of the five large polytene chromosomes of Drosophila subobscura were studied during the late third-larval instar and through the prepupal period. A total of 166 loci active in some of the eleven stages studied were described. The distribution of these active loci per chromosome is the following: 25 on chromosome A, 33 on chromosome J, 31 on chromosome U, 34 on chromosome E and 43 on chromosome O. Seven principal patterns of puffing activity were defined taking into account the different curves of the puffing histograms. Gene activities per chromosome as well as total were analysed. Three peaks of gene activity at the beginning, middle and ending of prepupation can …
Differences in gene activity in a Drosophila species cluster belonging to the Obscura group
1993
The polytene chromosome puffing pattern of Drosophila madeirensis was established and compared with those of the related species D. subobscura and D. guanche. A total of 145 loci, active in some of the 12 developmental stages analysed, were described, 38 of which were found to form the puffing pattern characteristic to this species. Taking into account the number of puffs as well as the mean puff expression, D. madeirensis shows a similar activity level to D. guanche, both species being less active than D. subobscura. The low gene activity of D. madeirensis and D. guanche was explained as a consequence of their ecological characteristics.
Predicting risk and outcomes for frail older adults: an umbrella review of frailty screening tools
2017
EXECUTIVE SUMMARY Background A scoping search identified systematic reviews on diagnostic accuracy and predictive ability of frailty measures in older adults. In most cases, research was confined to specific assessment measures related to a specific clinical model. Objectives To summarize the best available evidence from systematic reviews in relation to reliability, validity, diagnostic accuracy and predictive ability of frailty measures in older adults. Inclusion criteria Population Older adults aged 60 years or older recruited from community, primary care, long-term residential care and hospitals. Index test Available frailty measures in older adults. Reference test Cardiovascular Health…
Profiles of Frailty among Older People Users of a Home-Based Primary Care Service in an Urban Area of Barcelona (Spain): An Observational Study and C…
2021
Background: The multidimensional assessment of frailty allows stratifying it into degrees