2,427 research outputs found

    Discovery of a Very Young Field L Dwarf, 2MASS J01415823-4633574

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    While following up L dwarf candidates selected photometrically from the Two Micron All Sky Survey, we uncovered an unusual object designated 2MASS J01415823-4633574. Its optical spectrum exhibits very strong bands of vanadium oxide but abnormally weak absorptions by titanium oxide, potassium, and sodium. Morphologically such spectroscopic characteristics fall intermediate between old, field early-L dwarfs (log(g)~5) and very late M giants (log(g)~0), leading us to favor low gravity as the explanation for the unique spectral signatures of this L dwarf. Such a low gravity can be explained only if this L dwarf is much lower in mass than a typical old field L dwarf of similar temperature and is still contracting to its final radius. These conditions imply a very young age. Further evidence of youth is found in the near-infrared spectrum, including a triangular-shaped H-band continuum reminiscent of young brown dwarf candidates discovered in the Orion Nebula Cluster. Using the above information along with comparisons to brown dwarf atmospheric and interior models, our current best estimate is that this L dwarf has an age of 1-50 Myr and a mass of 6-25 M_Jupiter. The location of 2MASS 0141-4633 on the sky coupled with a distance estimate of ~35 pc and the above age estimate suggests that this object may be a brown dwarf member of either the 30-Myr-old Tucana/Horologium Association or the ~12-Myr-old beta Pic Moving Group.Comment: Accepted for publication in the 10 March 2006 issue (volume 639) of the Astrophysical Journa

    The Impact of Depression on Patient Outcomes in Hip Arthroscopic Surgery.

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    Background: Mental health impairments have been shown to negatively affect preoperative self-reported function in patients with various musculoskeletal disorders, including those with femoroacetabular impingement. Hypothesis: Those with symptoms of depression will have lower self-reported function, more pain, and less satisfaction on initial assessment and at 2-year follow-up than those without symptoms of depression. Study Design: Cohort study; Level of evidence, 3. Methods: Patients who were enrolled in a multicenter hip arthroscopic surgery registry and had 2-year outcome data available were included in the study. Patients completed the 12-item International Hip Outcome Tool (iHOT-12), visual analog scale (VAS) for pain, and 12-item Short-Form Health Survey (SF-12) when consenting for surgery. At 2-year follow-up, patients were emailed the iHOT, the VAS, and a rating scale of surgical satisfaction. Initial SF-12 mental component summary (MCS) scores Results: A total of 781 patients achieved the approximate 2-year milestone (mean follow-up, 735 ± 68 days), with 651 (83%) having 2-year outcome data available. There were 434 (67%) female and 217 (33%) male patients, with a mean age of 35.8 ± 13.0 years and a mean body mass index of 25.4 ± 8.8 kg/m Conclusion: A large number of patients who underwent hip arthroscopic surgery presented with symptoms of depression, which negatively affected self-reported function, pain levels, and satisfaction on initial assessment and at 2-year follow-up. Surgeons who perform hip arthroscopic surgery may need to identify the symptoms of depression and be aware of the impact that depression can have on surgical outcomes

    Gásir in Eyjafjörđur: International Exchange and Local Economy in Medieval Iceland

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    The site of Gásir in Eyjafjörður in northeast Iceland was excavated from 2001–2006, revealing details of one of the larger seasonal trading centers of medieval Iceland. Interdisciplinary investigations of the site have shed light upon the organization of the site and provided confirmation of documentary accounts of both prestige items (gyrfalcons, walrus ivory) and bulk goods (sulphur) concentrated for export. Gásir was a major point of cultural contact as well as economic exchange between Icelanders and the world of medieval Europe, and the zooarchaeological analyses indicated a mix of foodways and the presence of exotic animals and a well-developed provisioning system, which supplied high-quality meat and fresh fish to the traders. The excavations demonstrated an unexpected regional-level economic impact of the seasonally occupied site on the surrounding rural countryside, and contribute to ongoing investigations of the extent and impact of overseas trade in medieval Iceland

    Effect of single embryo transfer on the risk of preterm birth associated with in vitro fertilization

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    To determine whether elective single embryo transfer (eSET) reduces the risk of preterm delivery associated with in vitro fertilization (IVF). This is an observational study of 3125 eSET cycles performed from 2008 to 2009 and reported to the Society for Assisted Reproductive Technology (SART) database. Preterm delivery rates were compared to the overall preterm delivery rate among all patients undergoing IVF over the same time period. The 3125 eSET cycles resulted in 1507 live births (live birth rate 48.2 %) Among these deliveries were 27 twins (1.8 %) and one set of triplets (0.07 %). The overall preterm delivery rate (20-37 weeks gestation) following eSET was 17.6 % (269/1527). This is significantly greater than the preterm birth rate for all patients undergoing IVF over the same time period (12 %, P \u3c 0.001). Elective single embryo transfer does not reduce the risk of preterm delivery associated with in vitro fertilization (IVF)

    Relative Attraction of the Mediterranean Fruit Fly (Diptera: Tephritidae) to the Eight Isomers of Trimedlure

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    ABSTRACT Relative attractiveness tests with the eight individual racemic isomers of trimedlure, teTt-butyl 4(and 5)-chloro-c1s-and tTans-2-methylcyclohexane-l-carboxylate (TML), showed that one of the four cis isomers, TML-Y (teTt-butyl c1s-5-chloro-cis-2-methylcyclohexane-I-carboxylate), was attractive to CeTatitis capitata (Wiedemann) and long lasting. The isomer is present in cis-TML in a concentration of about 5%. The three other cis isomers, which are present in about equal amounts, were unattractive. The relative attractiveness of the four tTans isomers was the same as reported previously. Possible structure-activity relationships are discussed. KEY WORDS Insecta, CeTatitis capitata, attractant, lure MALE MEDITERRANEAN FRUIT FLIES, CeTatitis capitata (Wiedemann) are strongly attracted to trimedlure, tert-butyl 4(and 5)-chloro-cis-and trans-2-methy Icyclohexane-l-carboxylate (TML), which consists of a blend of eight racemic isomers (Beroza et a!. 1961). Commercially synthesized TML contains 90-95% of the four possible trans isomers, which are designated TML-A

    Beginning of Viniculture in France

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    Chemical analyses of ancient organic compounds absorbed into the pottery fabrics of imported Etruscan amphoras (ca. 500-475 B.C.) and into a limestone pressing platform (ca. 425-400 B.C.) at the ancient coastal port site of Lattara in southern France provide the earliest biomolecular archaeological evidence for grape wine and viniculture from this country, which is crucial to the later history of wine in Europe and the rest of the world. The data support the hypothesis that export of wine by ship from Etruria in central Italy to southern Mediterranean France fueled an ever-growing market and interest in wine there, which, in turn, as evidenced by the winepress, led to transplantation of the Eurasian grapevine and the beginning of a Celtic industry in France. Herbal and pine resin additives to the Etruscan wine point to the medicinal role of wine in antiquity, as well as a means of preserving it during marine transport

    Neutron Beta Decay Studies with Nab

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    Precision measurements in neutron beta decay serve to determine the coupling constants of beta decay and allow for several stringent tests of the standard model. This paper discusses the design and the expected performance of the Nab spectrometer.Comment: Submitted to Proceedings of the Conference CIPANP12, St.Petersburg, Florida, May 201
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