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Old Population (old + population)
Selected AbstractsPatterns of antidepressants prescriptions in a large Italian old populationINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 8 2008Renzo Rozzini No abstract is available for this article. [source] The Oldest Old in the Last Year of Life: Population-Based Findings from Cambridge City over-75s Cohort Study Participants Aged 85 and Older at DeathJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 1 2010Jun Zhao MSc OBJECTIVES: To characterize people of advanced old age in their last year of life and compare those dying in their late 80s with those dying aged 90 and older to inform policy and planning. DESIGN: Retrospective analysis of prospectively collected population-based data from the Cambridge City over-75s Cohort (CC75C) Study, United Kingdom. PARTICIPANTS: Men and women aged 85 and older at death who died less than 1 year after taking part in any CC75C survey (N=321). MEASUREMENTS: Physical health, functional disability, self-rated health, cognitive status. RESULTS: Functional and cognitive impairments were markedly higher for those who died aged 90 and older, predominantly women,than for those who died aged 85 to 89. At least half (49.4,93.6%) of subjects aged 90 and older needed maximum assistance in virtually every daily activity; those aged 85 to 89 needed this only for shopping and laundry. Disability in basic and instrumental activities rose from 59.1% before to 85.4% after the age of 90 and cognitive impairment (Mini-Mental State Examination score ,21) from 41.7% to 69.4%. Despite this and proximity to death, 60.5% and 67.0%, respectively, rated their health positively. Only one in five reported needing more help. CONCLUSION: This study provides new data identifying high levels of physical and cognitive disability in very old people in the year before death. As the very old population rises, so will support needs for people dying in extreme old age. The mismatch between health perceptions and functional limitations suggests that these vulnerable older adults may not seek help from which they could benefit. These findings have major policy and planning implications for end-of-life care for the oldest old. [source] Formation and evolution of dwarf elliptical galaxies , II.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2009Spatially resolved star formation histories ABSTRACT We present optical Very Large Telescope spectroscopy of 16 dwarf elliptical galaxies (dEs) comparable in mass to NGC 205, and belonging to the Fornax cluster and to nearby groups of galaxies. Using full-spectrum fitting, we derive radial profiles of the SSP-equivalent ages and metallicities. We make a detailed analysis with ulyss and steckmap of the star formation history in the core of the galaxies and in an aperture of one effective radius. We resolved the history into one to four epochs. The statistical significance of these reconstructions was carefully tested; the two programs give remarkably consistent results. The old stellar population of the dEs, which dominates their mass, is likely coeval with that of massive ellipticals or bulges, but the star formation efficiency is lower. Important intermediate age (1,5 Gyr) populations and frequently tails of star formation until recent times are detected. These histories are reminiscent of their lower mass dwarf spheroidal counterparts of the Local Group. Most galaxies (10/16) show significant metallicity gradients, with metallicity declining by 0.5 dex over one half-light radius on average. These gradients are already present in the old population. The flattened (or discy), rotating objects (6/16) have flat metallicity profiles. This may be consistent with a distinct origin for these galaxies or it may be due to their geometry. The central single stellar population equivalent age varies between 1 and 6 Gyr, with the age slowly increasing with radius in the vast majority of objects. The group and cluster galaxies have similar radial gradients and star formation histories. The strong and old metallicity gradients place important constraints on the possible formation scenarios of dEs. Numerical simulations of the formation of spherical low-mass galaxies reproduce these gradients, but they require a longer time for them to build up. A gentle depletion of the gas, by ram pressure stripping or starvation, could drive the gas-rich, star-forming progenitors to the present dEs. [source] Discovery and analysis of three faint dwarf galaxies and a globular cluster in the outer halo of the Andromeda galaxy,MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2006N. F. Martin ABSTRACT We present the discovery of three faint dwarf galaxies and a globular cluster in the halo of the Andromeda galaxy (M31), found in our MegaCam survey that spans the southern quadrant of M31, from a projected distance of ,50 to ,150 kpc. Though the survey covers 57 deg2, the four satellites lie within 2° of one another. From the tip of the red giant branch (RGB), we estimate that the globular cluster lies at a distance of 631 ± 58 kpc from the Milky Way and along with a ,100 kpc projected distance from M31 we derive a total distance of 175 ± 55 kpc from its host, making it the farthest M31 globular cluster known. It also shows the typical characteristics of a bright globular cluster, with a half-light radius of 2.3 ± 0.2 pc and an absolute magnitude in the V band of MV,0=,8.5 ± 0.3. Isochrone fitting reveals that it is dominated by a very old population with a metallicity of [Fe/H],,1.3. The three dwarf galaxies are revealed as overdensities of stars that are aligned along the RGB tracks in their colour,magnitude diagrams. These satellites are all very faint, with absolute magnitudes in the range ,7.3 ,MV,0,,6.4, and show strikingly similar characteristics with metallicities of [Fe/H],,1.4 and half-light radii of ,120 ± 45 pc, making these dwarf galaxies two to three times smaller than the smallest previously known satellites of M31. Given their faintness, their distance is difficult to constrain, but we estimate them to be between 740 and 955 kpc which places them well within the virial radius of the host galaxy. The panoramic view of the MegaCam survey can provide an unbiased view of the satellite distribution of the Andromeda galaxy and, extrapolating from its coverage of the halo, we estimate that up to 45 ± 20 satellites brighter than MV,,6.5 should be orbiting M31. Hence faint dwarf galaxies cannot alone account for the missing satellites that are predicted by , cold dark matter models, unless they reside in dark matter minihaloes that are more massive than the typical masses of 107 M, currently inferred from their central radial velocity dispersion. [source] A deep kinematic survey of planetary nebulae in the Andromeda galaxy using the Planetary Nebula SpectrographMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2006H. R. Merrett ABSTRACT We present a catalogue of positions, magnitudes and velocities for 3300 emission-line objects found by the Planetary Nebula Spectrograph in a survey of the Andromeda galaxy, M31. Of these objects, 2615 are found likely to be planetary nebulae (PNe) associated with M31. The survey area covers the whole of M31's disc out to a radius of . Beyond this radius, observations have been made along the major and minor axes, and the Northern Spur and Southern Stream regions. The calibrated data have been checked for internal consistency and compared with other catalogues. With the exception of the very central, high surface brightness region of M31, this survey is complete to a magnitude limit of m5007, 23.75, 3.5 mag into the PN luminosity function. We have identified emission-line objects associated with M31's satellites and other background galaxies. We have examined the data from the region tentatively identified as a new satellite galaxy, Andromeda VIII, comparing it to data in the other quadrants of the galaxy. We find that the PNe in this region have velocities that appear to be consistent with membership of M31 itself. The luminosity function of the surveyed PNe is well matched to the usual smooth monotonic function. The only significant spatial variation in the luminosity function occurs in the vicinity of M31's molecular ring, where the luminosities of PNe on the near side of the galaxy are systematically ,0.2 mag fainter than those on the far side. This difference can be explained naturally by a modest amount of obscuration by the ring. The absence of any difference in luminosity function between bulge and disc suggests that the sample of PNe is not strongly populated by objects whose progenitors are more massive stars. This conclusion is reinforced by the excellent agreement between the number counts of PNe and the R -band light. The number counts of kinematically selected PNe also allow us to probe the stellar distribution in M31 down to very faint limits. There is no indication of a cut-off in M31's disc out to beyond four scalelengths, and no signs of a spheroidal halo population in excess of the bulge out to 10 effective bulge radii. We have also carried out a preliminary analysis of the kinematics of the surveyed PNe. The mean streaming velocity of the M31 disc PNe is found to show a significant asymmetric drift out to large radii. Their velocity dispersion, although initially declining with radius, flattens out to a constant value in the outer parts of the galaxy. There are no indications that the disc velocity dispersion varies with PN luminosity, once again implying that the progenitors of PNe of all magnitudes form a relatively homogeneous old population. The dispersion profile and asymmetric drift results are shown to be mutually consistent, but require that the disc flares with radius if the shape of its velocity ellipsoid remains invariant. [source] Population changes in Phytophthora infestans in Taiwan associated with the appearance of resistance to metalaxyl,PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 9 2002Kenneth L Deahl Abstract In recent years, late blight, caused by Phytophthora infestans (Mont) De Bary, has increased in severity in many parts of the world, and this has been associated with migrations which have introduced new, arguably more aggressive, populations of the pathogen. In Taiwan, late blight has been endemic on outdoor tomato crops grown in the highlands since the early 1900s, but recent epidemics have been more damaging. To ascertain the present status of the Taiwanese population of P infestans, 139 isolates of the pathogen collected and maintained by the Asian Vegetable Research and Development Center (AVRDC) were characterized using mating type, metalaxyl sensitivity, allozyme genotype, mitochondrial haplotype and RFLP fingerprinting. Up to 1997, all isolates were found to belong to the old clonal lineage of P infestans (US-1 and variants), but in isolates from 1998 a new genotype appeared, and by 2000 this had apparently completely displaced the old population. This new genotype was an A1 mating type and has the dilocus allozyme genotype 100/100/111, 100/100 for the loci coding for glucose-6-phosphate isomerase and peptidase, respectively. These characters, together with RG57 fingerprinting, indicated that these isolates belonged to the US-11 clonal lineage, a minority (11%) being a previously unreported variant of US-11. Whereas metalaxyl-resistant isolates were not detected in the old population, 96% of the new genotypes proved resistant, with the remainder being intermediate in sensitivity. It may be inferred from this sudden, marked change in the characteristics of the Taiwanese P infestans that a new population of the pathogen was introduced around 1997,98 and that this may well have already been metalaxyl-resistant when it arrived, although a role for in situ selection cannot be excluded. © 2002 Society of Chemical Industry [source] Lifetime sexual dimorphism in Juniperus communis var. communisPLANT SPECIES BIOLOGY, Issue 1 2007LENA K. WARD Abstract The sexes of dioecious Juniperus communis were differentially affected over their lifetime in response to ecological and physiological stress in populations of different ages studied over 23 years in southern England. In a young population, the female survival rate was less than the male rate, with more females dying during a severe attack by rabbits and later with fungus disease in the roots. The sex ratio (female : male) in marked individuals was predicted by age, changing from 1:1.13 in 1983 to 1:1.32 in 2005. In an old senescing population, where two-thirds of the individuals died, the sex ratio varied, but overall became more male biased (1:1.51,1:2.10). Males had a greater resistance to terminal disease, and were slightly older than females at death (110 years compared to 106). Young females grew less than males, presumably because of greater trade-offs with reproductive effort: the mean annual shoot growth was 6.7 cm compared to 8.1 cm in males. By approximately 30 years of age, heights of the sexes were significantly different. The annual growth of old females (4.8 cm) was greater than that in males (4.3 cm), possibly because males survived longer in poor health. Sexual differences in height in the old population were progressively lost. Cone abundance in females was less than that in males and cone production had greater periodicity; the young population outperformed the old. There were slightly longer time lags in inverse correlations between growth and reproductive indices in females. [source] Household diversity and migration in mid-life: understanding residential mobility among 45,64 year olds in Melbourne, AustraliaPOPULATION, SPACE AND PLACE (PREVIOUSLY:-INT JOURNAL OF POPULATION GEOGRAPHY), Issue 4 2010Maryann Wulff Abstract This paper focuses on the residential mobility of middle-aged persons, not yet retired, an understudied cohort in mobility research. From the 1950s to the 1980s, mobility studies pointed to mid-life as a settled stage in terms of family, work and housing. Recent demographic and social changes, however, have led to these years being typified by a wide gamut of living arrangements that have complicated decisions about, and patterns of, residential mobility. Using the life-course perspective, this paper suggests that the transition to ,empty nester' status will heighten mobility among this group of middle-aged persons relative to their counterparts in other living arrangements. The analysis uses a customised migration matrix from the Australian 2006 Census and identifies segments of 45,64 year olds most likely to have changed address since the previous census in 2001. CHAID statistical method partitioned the 45,64 year old population in Melbourne, Australia, into eight statistically significant segments based on life-course factors and mobility levels. Younger (45,54 years) mid-life empty-nesters changed residence at 1.4 times the mobility rate of all mid-life persons. For couples in this age group, empty nest status conferred a 13 percentage point ,mobility premium' compared with couples that still had children at home. The results contribute to a better understanding of housing consumption among mid-life households and broader debates on access to affordable housing and processes of urban growth. Copyright © 2009 John Wiley & Sons, Ltd. [source] Transverse motions in CSOs?ASTRONOMISCHE NACHRICHTEN, Issue 2-3 2009C. Stanghellini Abstract The measurement of proper motions in CSOs is a powerful tool to determine the dynamical evolution of the newly born extragalactic radio sources. We observed 3 CSOs with the VLBA in 2004 and in 2006 to monitor changes in their structure and measure the separation velocity of the hot spots. It is important to increase the size of the samples of CSOs with measured expansion velocity to test the existence of frustrated objects, and put stringent constraints on the current models. We found for all the three objects observed a transverse motion of the hot-spots, and we suggest as the more likely explanation a precession in the jet axis. This behaviour likely inhibits or at least slows down the radio source growth because the head of the hot-spot continuously hits new regions of the ISM. Therefore these radio sources may represent an old population of GPS/CSOs (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Long-term changes in the chromosomal inversion polymorphism of Drosophila subobscura.JOURNAL OF ZOOLOGICAL SYSTEMATICS AND EVOLUTIONARY RESEARCH, Issue 3 2004Abstract The chromosomal polymorphism of 13 European populations of Drosophila subobscura has been compared with that of the same populations collected 15,35 years ago. The chromosomal polymorphism of the old populations differs significantly from that of the new populations, mainly for chromosomes U and O. There is a very good agreement between the geographical space and the genetic space as shown by a graphical representation of the 26 statistical populations (13 old and 13 new) obtained by a principal coordinate analysis. This reflects both the existence of significant latitudinal clines for the frequencies of some chromosomal arrangements in the old and new samples and systematic changes that have taken place in these populations during the period that elapsed between the two surveys. An increase in the frequency of those arrangements typical of southern latitudes and a decrease for those common in northern latitudes is observed in all populations , Mediterranean, Atlantic and Central European. Furthermore, the genetic distances of the new populations to a southern population of reference have decreased in comparison with those of the old populations. These changes could be the result of climatic factors that are correlated with latitude. In particular, the assumption that global warming is responsible for all the changes observed appears rather likely. Whether these systematic changes of the chromosomal polymorphism are a consequence of local adaptations or have been produced by migration from the south remains an open question. Zusamennfassung Der gegenwärtige chromosomale Inversionspolymorphismus in 13 europäischen Populationen von Drosophila subobscura wurde mit dem Zustand in denselben Populationen verglichen, die vor 15 bis 35 Jahren untersucht worden waren. Der Chromosomenpolymorphismus der ,,alten'' Populationen unterscheidet sich signifikant von dem der ,,neuen'' Populationen, besonders für die Chromosomen U und O. Eine sehr gute Übereinstimmung zeigt sich zwischen der geographischen Komponente und der genetischen Komponente bei einer graphischen Darstellung der 26 Populationen (13 alte und 13 neue Populationen) durch eine Koordinatenanalyse. Das spiegelt beides wider, die Existenz von signifikanten breitenabhängigen Klinen in der Häufigkeit einiger chromosomaler Strukturtypen in den alten und den neuen Populationen, aber auch die systematischen Änderungen, die sich bei diesen Populationen im Laufe der Zeit zwischen den beiden Untersuchungen ereignet haben. Eine Zunahme in den Häufigkeiten jener Chromosomenstrukturen, die typisch für südliche Breiten sind, und eine Abnahme solcher Strukturen, die häufig in nördliche Breiten sind, konnte beobachtet werden - in den mediterranen, den atlantischen und den mitteleuropäischen Populationen in der gleichen Weise. Außerdem haben die genetischen Distanzen der neuen Populationen zu einer südlichen Referenzpopulation im Vergleich zu denen der alten Populationen abgenommen. Diese Veränderungen wurden vermutlich von klimatischen Faktoren bestimmt, die mit der geographischen Breite korreliert sind. Insbesonders erscheint die Annahme, daß die globale Erwärmung für die Veränderungen des Chromosomenpolymorphismus dafür verantwortlich ist, ziemlich wahrscheinlich. Ob diese systematischen Transformationen des Chromosomenpolymorphismus ein Konsequenz lokaler Anpassungen oder auf Migration aus dem Süden zurückzuführen sind, bleibt eine offene Frage. [source] | ||||||||||||||||