WIYN Open Cluster Study. LXIII. Abundance in the Super-Metal-Rich Open Cluster NGC 6253 from Hydra Sprectroscopy of the 7774 Å Oxygen Triplet Region

We present a spectroscopic abundance analysis of the old, super-metal-rich open cluster NGC 6253, with emphasis on its O abundance. High-dispersion, 7774 Å O i triplet region spectra of 47 stars were obtained using Hydra II on the CTIO Blanco 4 m. Radial velocity analysis confirms 39 stars consistent with single star membership, primarily at the turnoff. Thirty-six of these are included in our abundance analysis. Our differential analysis relative to the Sun yields primarily scaled-solar values, with weighted cluster averages of [O/H] = +0.440 ± 0.020, [Fe/H] = +0.445 ± 0.014, [Al/H] = +0.487 ± 0.020, [Si/H] = +0.504 ± 0.018, and [Ni/H] = +0.702 ± 0.018 (where the errors are ${{\sigma }_{\mu }}$). We discuss possible origins for the three known super-metal-rich clusters based upon their abundance patterns, Galactic locations, and space motions. The abundance patterns of NGC 6253 are very similar to those of NGC 6791 and NGC 6583. With the possible exception of oxygen, the abundances of these clusters are all close to scaled-solar, and they are similar to patterns seen in metal-rich disk dwarfs and giants. However, they also seem to differ from those of metal-rich bulge stars. We demonstrate that NGC 6253 is unusually oxygen rich (in [O/H]) for its 3.3 Gyr age. While we find [O/Fe] to be scaled-solar for NGC 6253, the more recently reported values for NGC 6791 show a large variation, from values close to scaled-solar down to values at least a factor of two below scaled-solar. We discuss the possibility that the scaled-solar [O/Fe] abundances of NGC 6253 and NGC 6791 might reflect a flattening of the Galactic [O/Fe] versus [Fe/H] relationship. This possibility may be consistent with disk star abundance data, which show an apparent "floor" at [O/Fe] $\sim -0.1$ for [Fe/H] $\gt \;0$, and with chemical evolution model results, which may predict such a flattening due to a decrease in supernova Fe yields at super-solar-metallicities. Orbit solutions for NGC 6791 allow that it may have formed in the inner disk and was then kicked out, but the origins of the other two much younger clusters remain mysterious. We re-evaluate the age of NGC 6583 in view of the evidence that the cluster is super-metal-rich, and confirm a probable age less than 1 Gyr (best range: 500–900 Myr). We also argue that it is unlikely the cluster is more than 3 kpc away (best range: 2–3 kpc) if the apparent turnoff, main sequence, and giants are all cluster members

Life on Jackson Creek, Smith County, Texas: Archeological Investigations of a 14th Century Caddo Domicile at the Leaning Rock Site (41SM325)

The 14th century Caddo Leaning Rock site was initially discovered in the Fall of 2004. It was located during reconnaissance to search out a location for the survey portion of the Texas Archeologica! Society\u27s Academy IO I held in Tyler in February 2005. This was not a formal survey with transect lines. nor one using regularly spaced shovel tests. but was rather more of a windshield \u27 type survey, consisting of driving across pasture lands looking at gopher mounds and checking fore, evidence of archeological deposits on likely looking landforms. !n this area. landform and soil type seem to be the major determining factors in locating Caddo sites. The sandy soils in the scattered gopher mounds appeared almost white. especially in droughty conditions that prevailed at the time. causing an area with darker mounds of soil to catch my attention. Pocket gophers (G. breviceps) can play havoc with buried archeological deposits but can also be useful in bringing buried soils along with archeological materials to the surface from their underground tunnel system. While this dark area could have been the result of past historic land clearing and burning activities. a closer inspection revealed burned bone. mussel she!L and Caddo sherds mixed in the dark brown soils in the scattered gopher mounds. The next step was to record the site with the State of Texas, obtaining the trinomial 41SM325. It is common practice to also gin: sites informal names and after recording several hundred sites, selecting a name becomes a challenge. One large sandstone slab, pan of the R-horizon that is exposed around the margins of Leaning Rock. was unearthed during prior landclearing activities and pushed up against a lonely pine tree on the northern margins of the site: consequently the nom de plume Leaning Rock

Metastable liquid-liquid phase transition in a single-component system with only one crystal phase and no density anomaly

We investigate the phase behavior of a single-component system in 3 dimensions with spherically-symmetric, pairwise-additive, soft-core interactions with an attractive well at a long distance, a repulsive soft-core shoulder at an intermediate distance, and a hard-core repulsion at a short distance, similar to potentials used to describe liquid systems such as colloids, protein solutions, or liquid metals. We showed [Nature {\bf 409}, 692 (2001)] that, even with no evidences of the density anomaly, the phase diagram has two first-order fluid-fluid phase transitions, one ending in a gas--low-density liquid (LDL) critical point, and the other in a gas--high-density liquid (HDL) critical point, with a LDL-HDL phase transition at low temperatures. Here we use integral equation calculations to explore the 3-parameter space of the soft-core potential and we perform molecular dynamics simulations in the interesting region of parameters. For the equilibrium phase diagram we analyze the structure of the crystal phase and find that, within the considered range of densities, the structure is independent of the density. Then, we analyze in detail the fluid metastable phases and, by explicit thermodynamic calculation in the supercooled phase, we show the absence of the density anomaly. We suggest that this absence is related to the presence of only one stable crystal structure.Comment: 15 pages, 21 figure

Falls in young, middle-aged and older community dwelling adults: perceived cause, environmental factors and injury

BACKGROUND: Falls in older people have been characterized extensively in the literature, however little has been reported regarding falls in middle-aged and younger adults. The objective of this paper is to describe the perceived cause, environmental influences and resultant injuries of falls in 1497 young (20–45 years), middle-aged (46–65 years) and older (> 65 years) men and women from the Baltimore Longitudinal Study on Aging. METHODS: A descriptive study where participants completed a fall history questionnaire describing the circumstances surrounding falls in the previous two years. RESULTS: The reporting of falls increased with age from 18% in young, to 21% in middle-aged and 35% in older adults, with higher rates in women than men. Ambulation was cited as the cause of the fall most frequently in all gender and age groups. Our population reported a higher percentage of injuries (70.5%) than previous studies. The young group reported injuries most frequently to wrist/hand, knees and ankles; the middle-aged to their knees and the older group to their head and knees. Women reported a higher percentage of injuries in all age groups. CONCLUSION: This is the first study to compare falls in young, middle and older aged men and women. Significant differences were found between the three age groups with respect to number of falls, activities engaged in prior to falling, perceived causes of the fall and where they fell

Polymorphisms of genes coding for ghrelin and its receptor in relation to colorectal cancer risk: a two-step gene-wide case-control study

<p>Abstract</p> <p>Background</p> <p>Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor (GHSR), has two major functions: the stimulation of the growth hormone production and the stimulation of food intake. Accumulating evidence also indicates a role of ghrelin in cancer development.</p> <p>Methods</p> <p>We conducted a case-control study to examine the association of common genetic variants in the genes coding for ghrelin (GHRL) and its receptor (GHSR) with colorectal cancer risk. Pairwise tagging was used to select the 11 polymorphisms included in the study. The selected polymorphisms were genotyped in 680 cases and 593 controls from the Czech Republic.</p> <p>Results</p> <p>We found two SNPs associated with lower risk of colorectal cancer, namely SNPs rs27647 and rs35683. We replicated the two hits, in additional 569 cases and 726 controls from Germany.</p> <p>Conclusion</p> <p>A joint analysis of the two populations indicated that the T allele of rs27647 SNP exerted a protective borderline effect (P_trend= 0.004).</p

Eye Size at Birth in Prosimian Primates: Life History Correlates and Growth Patterns

BACKGROUND: Primates have large eyes relative to head size, which profoundly influence the ontogenetic emergence of facial form. However, growth of the primate eye is only understood in a narrow taxonomic perspective, with information biased toward anthropoids.\ud \ud METHODOLOGY/PRINCIPAL FINDINGS: We measured eye and bony orbit size in perinatal prosimian primates (17 strepsirrhine taxa and Tarsius syrichta) to infer the extent of prenatal as compared to postnatal eye growth. In addition, multiple linear regression was used to detect relationships of relative eye and orbit diameter to life history variables. ANOVA was used to determine if eye size differed according to activity pattern. In most of the species, eye diameter at birth measures more than half of that for adults. Two exceptions include Nycticebus and Tarsius, in which more than half of eye diameter growth occurs postnatally. Ratios of neonate/adult eye and orbit diameters indicate prenatal growth of the eye is actually more rapid than that of the orbit. For example, mean neonatal transverse eye diameter is 57.5% of the adult value (excluding Nycticebus and Tarsius), compared to 50.8% for orbital diameter. If Nycticebus is excluded, relative gestation age has a significant positive correlation with relative eye diameter in strepsirrhines, explaining 59% of the variance in relative transverse eye diameter. No significant differences were found among species with different activity patterns.\ud \ud CONCLUSIONS/SIGNIFICANCE: The primate developmental strategy of relatively long gestations is probably tied to an extended period of neural development, and this principle appears to apply to eye growth as well. Our findings indicate that growth rates of the eye and bony orbit are disassociated, with eyes growing faster prenatally, and the growth rate of the bony orbit exceeding that of the eyes after birth. Some well-documented patterns of orbital morphology in adult primates, such as the enlarged orbits of nocturnal species, mainly emerge during postnatal development.\ud \u

Trading water to improve environmental flow outcomes

As consumptive extractions and water scarcity pressures brought about by climate change increase in many world river basins, so do the risks to water-dependent ecological assets. In response, public or not for profit environmental water holders (EWHs) have been established in many areas and bestowed with endowments of water and mandates to manage water for ecological outcomes. Water scarcity has also increasingly spawned water trade arrangements in many river basins, and in many instances, EWHs are now operating in water markets. A number of EWHs, especially in Australia, begin with an endowment of permanent water entitlements purchased from irrigators. Such water entitlements typically have relatively constant interannual supply profiles that often do not match ecological water demand involving flood pulses and periods of drying. This article develops a hydrologic-economic simulation model of the Murrumbidgee catchment within the Murray-Darling Basin to assess the scope of possibilities to improve environmental outcomes through EWH trading on an annual water lease market. We find that there are some modest opportunities for EWHs to improve environmental outcomes through water trade. The best opportunities occur in periods of drought and for ecological outcomes that benefit from moderately large floods. We also assess the extent to which EWH trading in annual water leases may create pecuniary externalities via bidding up or down the water lease prices faced by irrigators. Environmental water trading is found to have relatively small impacts on water market price outcomes. Overall our results suggest that the benefits of developing EWH trading may well justify the costs. © 2013. American Geophysical Union. All Rights Reserved.Jeffery D. Connor, Brad Franklin, Adam Loch, Mac Kirby, Sarah Ann Wheele

Estimating Dengue Transmission Intensity from Sero-Prevalence Surveys in Multiple Countries

BACKGROUND:Estimates of dengue transmission intensity remain ambiguous. Since the majority of infections are asymptomatic, surveillance systems substantially underestimate true rates of infection. With advances in the development of novel control measures, obtaining robust estimates of average dengue transmission intensity is key for assessing both the burden of disease from dengue and the likely impact of interventions. METHODOLOGY/PRINCIPAL FINDINGS:The force of infection (λ) and corresponding basic reproduction numbers (R0) for dengue were estimated from non-serotype (IgG) and serotype-specific (PRNT) age-stratified seroprevalence surveys identified from the literature. The majority of R0 estimates ranged from 1-4. Assuming that two heterologous infections result in complete immunity produced up to two-fold higher estimates of R0 than when tertiary and quaternary infections were included. λ estimated from IgG data were comparable to the sum of serotype-specific forces of infection derived from PRNT data, particularly when inter-serotype interactions were allowed for. CONCLUSIONS/SIGNIFICANCE:Our analysis highlights the highly heterogeneous nature of dengue transmission. How underlying assumptions about serotype interactions and immunity affect the relationship between the force of infection and R0 will have implications for control planning. While PRNT data provides the maximum information, our study shows that even the much cheaper ELISA-based assays would provide comparable baseline estimates of overall transmission intensity which will be an important consideration in resource-constrained settings

Genetic effects on gene expression across human tissues

Characterization of the molecular function of the human genome and its variation across individuals is essential for identifying the cellular mechanisms that underlie human genetic traits and diseases. The Genotype-Tissue Expression (GTEx) project aims to characterize variation in gene expression levels across individuals and diverse tissues of the human body, many of which are not easily accessible. Here we describe genetic effects on gene expression levels across 44 human tissues. We find that local genetic variation affects gene expression levels for the majority of genes, and we further identify inter-chromosomal genetic effects for 93 genes and 112 loci. On the basis of the identified genetic effects, we characterize patterns of tissue specificity, compare local and distal effects, and evaluate the functional properties of the genetic effects. We also demonstrate that multi-tissue, multi-individual data can be used to identify genes and pathways affected by human disease-associated variation, enabling a mechanistic interpretation of gene regulation and the genetic basis of diseas