2,868 research outputs found

    Nonclassical rotational inertia for a supersolid under rotation

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    As proposed by Leggett [4], the supersolidity of a crystal is characterized by the Non Classical Rotational Inertia (NCRI) property. Using a model of quantum crystal introduced by Josserand, Pomeau and Rica [5], we prove that NCRI occurs. This is done by analyzing the ground state of the aforementioned model, which is related to a sphere packing problem, and then deriving a theoretical formula for the inertia momentum. We infer a lower estimate for the NCRI fraction, which is a landmark of supersolidity

    A History of the Chilean Vicariate of the Precious Blood Fathers, 1947-1972

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    Methylmalonic acidemia (MMA) in pregnancy: a case series and literature review

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    IntroductionWomen with inherited metabolic disorders, including those with previously life‐limiting conditions such as MMA, are reaching child‐bearing age more often due to advances in early diagnosis and improved pediatric care. Information surrounding maternal and fetal complications associated with the underlying disorders remains largely unexplored.MethodsPregnancies affected by maternal MMA were ascertained through study 04‐HG‐0127 “Clinical and Basic Investigations of Methylmalonic Acidemia and Related Disorders” (clinicaltrials.gov identifier: NCT00078078) and via literature review. Prenatal and delivery records in study participants were reviewed.ResultsSeventeen pregnancies were identified in women with isolated MMA, including three abortions, one termination, and 13 completed pregnancies [three cases with cblA (four pregnancies), four cases of mut‐ (one cobalamin responsive, three non‐responsive), five cases with unknown type of MMA]. Seventeen percent (3/17) of the pregnancies resulted in a first trimester abortion, while 38.5 % (5/13) of the completed pregnancies resulted in preterm deliveries. A cesarean delivery rate of 53.8 % (7/13) was noted among the cohort. Fetal distress or nonreassuring fetal status was the indication for 57 % (4/7) cesarean deliveries. One patient was reported to have metabolic crisis as well as episodes of mild hyperammonemia. Malformations or adverse outcomes in the progeny were not observed.ConclusionAlthough there have been a small number of pregnancies identified in women with MMA, the cumulative results suggest that the majority of pregnancies can be complicated by cesarean delivery and increased risk of prematurity. A pregnancy registry could clarify perinatal complications and define management approaches needed to ensure optimal maternal and fetal outcomes in this growing patient population.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147009/1/jimd0839.pd

    Radio Observations of the Hubble Deep Field South region: I. Survey Description and Initial Results

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    This paper is the first of a series describing the results of the Australia Telescope Hubble Deep Field South (ATHDFS) radio survey. The survey was conducted at four wavelengths - 20, 11, 6, and 3 cm, over a 4-year period, and achieves an rms sensitivity of about 10 microJy at each wavelength. We describe the observations and data reduction processes, and present data on radio sources close to the centre of the HDF-S. We discuss in detail the properties of a subset of these sources. The sources include both starburst galaxies and galaxies powered by an active galactic nucleus, and range in redshift from 0.1 to 2.2. Some of them are characterised by unusually high radio-to-optical luminosities, presumably caused by dust extinction.Comment: Accepted by AJ. 32 pages, 4 tables, 3 figures. PDF with full-resolution figures is on http://www.atnf.csiro.au/people/rnorris/N197.pd

    A cautionary tale of pyridoxine toxicity in cystathionine beta‐synthase deficiency detected by two‐tier newborn screening highlights the need for clear pyridoxine dosing guidelines

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    Classic homocystinuria is due to deficiency of cystathionine beta‐synthase (CBS), a pyridoxine‐dependent enzyme that, depending on the molecular variants, may be co‐factor responsive. Elevated methionine is often used as the primary analyte to detect CBS deficiency (CBSD) on newborn screening (NBS), but is limited by increased detection of other biochemical disorders with less clear clinical significance such as methionine aminotransferase (MAT) I/III heterozygotes. Our state has implemented a two‐tier NBS algorithm for CBSD that successfully reduced the number of MATI/III heterozygotes, yet effectively detected a mild, co‐factor responsive form of CBSD. After initial diagnosis, newborns with CBSD often undergo a pyridoxine challenge with high‐dose pyridoxine to determine responsiveness. Here we describe our NBS‐identified patient with a mild form of pyridoxine responsive CBSD who developed respiratory failure and rhabdomyolysis consistent with pyridoxine toxicity during a pyridoxine challenge. This case highlights the need for weight‐based dosing and duration recommendations for pyridoxine challenge in neonates.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163455/2/ajmga61815.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163455/1/ajmga61815_am.pd

    Atmospheric O2/N2 changes, 1993-2002: Implications for the partitioning of fossil fuel CO2 sequestration

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    Improvements made to an established mass spectrometric method for measuring changes in atmospheric O2/N2 are described. With the improvements in sample handling and analysis, sample throughput and analytical precision have both increased. Aliquots from duplicate flasks are repeatedly measured over a period of 2 weeks, with an overall standard error in each flask of 3-4 per meg, corresponding to 0.6-0.8 ppm O2 in air. Records of changes in O2/N2 from six global sampling stations (Barrow, American Samoa, Cape Grim, Amsterdam Island, Macquarie Island, and Syowa Station) are presented. Combined with measurements Of CO2 from the same sample flasks, land and ocean carbon uptake were calculated from the three sampling stations with the longest records (Barrow, Samoa, and Cape Grim). From 1994-2002, We find the average CO2 uptake by the ocean and the land biosphere was 1.7 ± 0.5 and 1.0 ± 0.6 GtC yr -1 respectively; these numbers include a correction of 0.3 Gt C yr-l due to secular outgassing of ocean O2. Interannual variability calculated from these data shows a strong land carbon source associated with the 1997-1998 El Niño event, supporting many previous studies indicating that high atmospheric growth rates observed during most El Niño events reflect diminished land uptake. Calculations of interannual variability in land and ocean uptake are probably confounded by non-zero annual air sea fluxes of O2. The origin of these fluxes is not yet understood. Copyright 2005 by the American Geophysical Union

    Atmospheric potential oxygen: New observations and their implications for some atmospheric and oceanic models

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    Measurements of atmospheric O2/N2 ratios and CO2 concentrations can be combined into a tracer known as atmospheric potential oxygen (APO ≈ O2/N2 + CO2) that is conservative with respect to terrestrial biological activity. Consequently, APO reflects primarily ocean biogeochemistry and atmospheric circulation. Building on the work of Stephens et al. (1998), we present a set of APO observations for the years 1996-2003 with unprecedented spatial coverage. Combining data from the Princeton and Scripps air sampling programs, the data set includes new observations collected from ships in the low-latitude Pacific. The data show a smaller interhemispheric APO gradient than was observed in past studies, and different structure within the hemispheres. These differences appear to be due primarily to real changes in the APO field over time. The data also show a significant maximum in APO near the equator. Following the approach of Gruber et al. (2001), we compare these observations with predictions of APO generated from ocean O2 and CO2 flux fields and forward models of atmospheric transport. Our model predictions differ from those of earlier modeling studies, reflecting primarily the choice of atmospheric transport model (TM3 in this study). The model predictions show generally good agreement with the observations, matching the size of the interhemispheric gradient, the approximate amplitude and extent of the equatorial maximum, and the amplitude and phasing of the seasonal APO cycle at most stations. Room for improvement remains. The agreement in the interhemispheric gradient appears to be coincidental; over the last decade, the true APO gradient has evolved to a value that is consistent with our time-independent model. In addition, the equatorial maximum is somewhat more pronounced in the data than the model. This may be due to overly vigorous model transport, or insufficient spatial resolution in the air-sea fluxes used in our modeling effort. Finally, the seasonal cycles predicted by the model of atmospheric transport show evidence of an excessive seasonal rectifier in the Aleutian Islands and smaller problems elsewhere. Copyright 2006 by the American Geophysical Union

    Classification of hyperbolic Dynkin diagrams, root lengths and Weyl group orbits

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    We give a criterion for a Dynkin diagram, equivalently a generalized Cartan matrix, to be symmetrizable. This criterion is easily checked on the Dynkin diagram. We obtain a simple proof that the maximal rank of a Dynkin diagram of compact hyperbolic type is 5, while the maximal rank of a symmetrizable Dynkin diagram of compact hyperbolic type is 4. Building on earlier classification results of Kac, Kobayashi-Morita, Li and Sa\c{c}lio\~{g}lu, we present the 238 hyperbolic Dynkin diagrams in ranks 3-10, 142 of which are symmetrizable. For each symmetrizable hyperbolic generalized Cartan matrix, we give a symmetrization and hence the distinct lengths of real roots in the corresponding root system. For each such hyperbolic root system we determine the disjoint orbits of the action of the Weyl group on real roots. It follows that the maximal number of disjoint Weyl group orbits on real roots in a hyperbolic root system is 4.Comment: J. Phys. A: Math. Theor (to appear

    Social effects of diazepam use: A longitudinal field study

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    A longitudinal panel study examined the effects of actual use of diazepam (ValiumR) on subjective reports of life quality, affect, performance, stress, social support, control, coping and other variables related to mental health. Standardized interviews were conducted with 675 persons from the Detroit Metropolitan Area. Based on prescription records, diazepam users and nonusers were selected to represent a variety of sociodemographic characteristics rather than to be a completely random sample. Significant others in work and in personal life were also interviewed. Four interviews took place, one approximately every 6 weeks. Testing for social effects was conducted by within- and accross-person analyses of 367 respondents who reported taking the medication at some time during the study and by comparisons with 308 respondents who did not report taking Valium. Users of Valium tended to take less Valium than prescribed. They also reported consuming less alcohol when using Valium than at other times and less than non-Valium users. Although there was a modest, positive cross-sectional relation between Valium use and distress, numerous multivariate analyses controlling for levels of stress and health indicated no notable effects of Valium use on any of the social or psychological indicators, including anxiety. Several interpretations of the results are examined including the possibility that the effects of Valium use were short-lived rather than long-term and that Valium may have been taken in anticipation of anxiety rather than after its occurrence.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25927/1/0000490.pd
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