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Based on the data from the Next Generation Virgo cluster Survey (NGVS), we statistically study the photometric properties of globular clusters (GCs), ultra-compact dwarfs (UCDs) and dwarf nuclei in the Virgo core (M87) region. We found an obvious negative color (g - z) gradient in GC system associate with M87, i.e. GCs in the outer regions are bluer. However, such color gradient does not exist in UCD system, neither in dwarf nuclei system around M87. In addition, we found that many UCDs are surrounded by extended, low surface brightness envelopes. The dwarf nuclei and UCDs show different spatial distributions from GCs, with dwarf nuclei and UCDs (especially for the UCDs with visible envelopes) lying at larger distances to the Virgo center. These results support the view that UCDs (at least for a fraction of UCDs) are more tied to dwarf nuclei than to GCs.
The new generation of energy-dispersive X-ray (EDX) detectors with higher count rates than ever before, paves the way for a new approach to quantitative elemental analysis in the scanning transmission electron microscope. Here we demonstrate a method of calculating partial cross sections for use in quantifying EDX data, beneficial especially because of the simplicity of its implementation. Applying this approach to acid-leached PtCo catalyst nanoparticles leads to quantitative determination of the Pt surface enrichment.
Questions about the development of multiple birth infants have accompanied an increase in their rate. Multiple birth has been associated with preterm birth and a higher incidence of disability than for singletons. The possible influence of birth order (first vs. second born), gender, and birthweight were considered at 4 years in 56 twins (28 pairs) who weighed less than 1500 grams at birth. Gender and birth order differences did not produce significont results in the cognitive, language, behaviour, and motor areas assessed. However, some significant findings in these areas were revealed when children < 1000 and ≥ 1000 grams were compared. The lighter weight group performed less well than the heavier group on the Stanford-Binet Intelligence Scale, in Abstract/Visual Reasoning, Quantitative Reasoning, and Test Composite. Furthermore, results were significantly lower for Fine Motor and Motor Standard Score (Motor Skills Domain of the Vineland Behavior Scales) and for Quality of Language and Intelligibility of Speech. Twins < 1000 grams birthweight need close educational surveillance prior to school entry.
Postnatal depression affects about 10–15% of women in the year after giving birth. Many women and healthcare professionals would like an effective and accessible non-pharmacological treatment for postnatal depression.
Women who fulfilled the International Classification of Diseases (ICD)-10 criteria for major depression in the first 6 months postnatally were randomized to receive usual care plus a facilitated exercise intervention or usual care only. The intervention involved two face-to-face consultations and two telephone support calls with a physical activity facilitator over 6 months to support participants to engage in regular exercise. The primary outcome was symptoms of depression using the Edinburgh Postnatal Depression Scale (EPDS) at 6 months post-randomization. Secondary outcomes included EPDS score as a binary variable (recovered and improved) at 6 and 12 months post-randomization.
A total of 146 women were potentially eligible and 94 were randomized. Of these, 34% reported thoughts of self-harming at baseline. After adjusting for baseline EPDS, analyses revealed a −2.04 mean difference in EPDS score, favouring the exercise group [95% confidence interval (CI) −4.11 to 0.03, p = 0.05]. When also adjusting for pre-specified demographic variables the effect was larger and statistically significant (mean difference = −2.26, 95% CI −4.36 to −0.16, p = 0.03). Based on EPDS score a larger proportion of the intervention group was recovered (46.5% v. 23.8%, p = 0.03) compared with usual care at 6 months follow-up.
This trial shows that an exercise intervention that involved encouragement to exercise and to seek out social support to exercise may be an effective treatment for women with postnatal depression, including those with thoughts of self-harming.
The Next Generation Virgo Cluster Survey (NGVS) is a CFHT Large Program that is using the wide field of view capabilities of the MegaCam camera to map the entire Virgo Cluster from its core to virial radius. The observing strategy has been optimized to detect very low surface brightness structures in the cluster, including intracluster stellar streams and faint dwarf spheroidal galaxies. We present here the current status of this ongoing survey, with an emphasis on the detection and analysis of the very low-mass galaxies in the cluster that have been revealed by the NGVS.
The mass assembly of galaxies leaves various imprints on their surroundings, such as shells, streams and tidal tails. The frequency and properties of these fine structures depend on the mechanism driving the mass assembly: e.g. a monolithic collapse, rapid cold-gas accretion followed by violent disk instabilities, minor mergers or major dry/wet mergers. Therefore, by studying the outskirts of galaxies, one can learn about their main formation mechanism. I present here our on-going work to characterize the outskirts of Early-Type Galaxies (ETGs), which are powerful probes at low redshift of the hierarchical mass assembly of galaxies. This work relies on ultra–deep optical images obtained at CFHT with the wide-field of view MegaCam camera of field and cluster ETGs obtained as part of the ATLAS3D and NGVS projects. State of the art numerical simulations are used to interpret the data. The images reveal a wealth of unknown faint structures at levels as faint as 29 mag arcsec−2 in the g-band. Initial results for two galaxies are presented here.
We present a detailed study of the stellar populations (SPs) and kinematics of the bulge and inner disk regions of nearby spiral galaxies (Sa-Sd) based on deep long-slit Gemini/GMOS data. We find that the SPs of spiral galaxies are not well matched by single episodes of star formation; representative SPs must involve average SP values integrated over the star formation history (SFH) of the galaxy, such as those derived from the “full population synthesis” method used here. Our spiral bulges follow the same correlations of increasing light-weighted age and metallicity with central velocity dispersion as those of elliptical galaxies and early-type bulges found in other studies, but when SFHs more complex and realistic than a single burst are invoked, the trend with age is shallower and its scatter much reduced. In a mass-weighted context, all bulges are predominantly composed of old and metal-rich SPs. Bulge formation appears to be dominated by early processes that are common to all spheroids, whether they currently reside in disks or not. While monolithic collapse cannot be ruled out in some cases, merging must be invoked to explain the SP gradients in most bulges. Further bulge growth via secular processes, or “rejuvenated” star formation, generally contributes minimally to the stellar mass budget. We also demonstrate how the combination of our full population synthesis modeling of high-quality optical spectra of integrated SPs along with optical-NIR broad-band imaging can single out potential model weaknesses and help determine the reliability of the inferred SFHs.
This study describes aspects of measles in non-human primates. Monkeys infected before importation are shown to produce non-immune offspring in captivity in England. The high antibody titres found in most recently imported monkeys decline slowly during captivity in England. While measles is often fatal to monkeys, we have described an outbreak in which a number of symptomless infections occurred. Histological examination of fatal cases produced evidence of infection in the wall of the urinary bladder in one monkey. The close similarity between measles in humans and monkeys has been confirmed. It is considered that the study of infection among the latter may have significance for the former.
We report preliminary results of the characterization of bulge and inner disk stellar populations for 8 nearby spiral galaxies using Gemini/GMOS. The long-slit spectra extend out to 1–2 disk scale lengths with S/N/Å>50. Two different model fitting techniques, absorption-line indices and full spectral synthesis, are found to weigh age, metallicity, and abundance ratios differently, but with careful attention to the data/model matching (resolution & flux calibration), we are able constrain real signatures of age and metallicity gradients in star-forming galaxies.
This study of 123 children who weighed under 1500 grams at birth examined cognitive ability and behaviour at 4 years of age, in conjunction with two categories of birthweight and parental socioeconomic status, respectively. Analysis revealed a number of significant differences between the two birthweight groups, with children under 1000 grams performing less well on some WPPSI Scales. These effects of preterm birth, in turn, appeared to be further influenced by socioeconomic status.
Five potato varieties were grown at four sites over 2 years, and assessed for yield, specific gravity and for sloughing, texture and discoloration following steaming. Variation in discoloration was attributed to differences between sites. Genetic differences were established for specific gravity, sloughing and texture, all of which were positively correlated. Genotype × environment interactions and years × sites interactions contributed to the variation for these and the remaining variables.
The Church and science have often enough been or at least appeared to be in conflict with each other, though it might be truer to say that it is Churchmen and scientists who have found themselves in opposition. Who has been to blame? In such strife it is rare that the fault can be attributed to only one side, and it may be that a more accurate delineation of the nature and purpose of the Church on the one hand and of the scope and function of science on the other might resolve the causes of the conflict.
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