5,905 research outputs found
ProMC: Input-output data format for HEP applications using varint encoding
A new data format for Monte Carlo (MC) events, or any structural data,
including experimental data, is discussed. The format is designed to store data
in a compact binary form using variable-size integer encoding as implemented in
the Google's Protocol Buffers package. This approach is implemented in the
ProMC library which produces smaller file sizes for MC records compared to the
existing input-output libraries used in high-energy physics (HEP). Other
important features of the proposed format are a separation of abstract data
layouts from concrete programming implementations, self-description and random
access. Data stored in ProMC files can be written, read and manipulated in a
number of programming languages, such C++, JAVA, FORTRAN and PYTHON.Comment: 17 pages, 2 figure
A Field Guide for Grasses and Grass-like Plants of Idaho
The purpose of this project is to develop a user-friendly field guide to grasses and grass-like plants in Idaho, specifically geared to those with limited background in botany. The guide will feature 60 Idaho grasses and grass-like plants, intended for K-16 educators and students, ranchers, land owners, recreationists, and nature enthusiasts, with accompanying K-12 lesson plans. In the form of both a printed book and an offline app for iPhones and Androids, the guide will include colorful images showing detailed characteristics and vegetative features of each grass, an easy-to-use dichotomous key, and information on each plant’s history, forage value, and fire resistance. This dual resource will meet the needs of land managers making economic decisions regarding livestock production and field treatments; university students in wildlife and range sciences conducting class exercises and field research; K-12 educators during field botany excursions, teaching the use of dichotomous keys, and ecosystem studies; and recreationists engaged in nature study. Both book and app will be distributed via the University of Idaho Rangeland Center and the Idaho Range Resource Commission
Spin injection from the Heusler alloy Co_2MnGe into Al_0.1Ga_0.9As/GaAs heterostructures
Electrical spin injection from the Heusler alloy Co_2MnGe into a p-i-n
Al_0.1Ga_0.9As/GaAs light emitting diode is demonstrated. A maximum
steady-state spin polarization of approximately 13% at 2 K is measured in two
types of heterostructures. The injected spin polarization at 2 K is calculated
to be 27% based on a calibration of the spin detector using Hanle effect
measurements. Although the dependence on electrical bias conditions is
qualitatively similar to Fe-based spin injection devices of the same design,
the spin polarization injected from Co_2MnGe decays more rapidly with
increasing temperature.Comment: 8 pages, 4 figure
The limits of social class in explaining ethnic gaps in educational attainment
This paper reports an analysis of the educational attainment and progress between age 11 and age 14 of over 14,500 students from the nationally representative Longitudinal Study of Young People in England (LSYPE). The mean attainment gap in national tests at age 14 between White British and several ethnic minority groups were large, more than three times the size of the gender gap, but at the same time only about one-third of the size of the social class gap. Socio-economic variables could account for the attainment gaps for Black African, Pakistani and Bangladeshi students, but not for Black Caribbean students. Further controls for parental and student attitudes, expectations and behaviours indicated minority ethnic groups were on average more advantaged on these measures than White British students, but this was not reflected proportionately in their levels of attainment. Black Caribbean students were distinctive as the only group making less progress than White British students between age 11 and 14 and this could not be accounted for by any of the measured contextual variables. Possible explanations for the White British-Black Caribbean gap are considered
Photometric and Spectroscopic Analysis of Cool White Dwarfs with Trigonometric Parallax Measurements
A photometric and spectroscopic analysis of 152 cool white dwarf stars is
presented. The discovery of 7 new DA white dwarfs, 2 new DQ white dwarfs, 1 new
magnetic white dwarf, and 3 weak magnetic white dwarf candidates, is reported,
as well as 19 known or suspected double degenerates. The photometric energy
distributions, the Halpha line profiles, and the trigonometric parallax
measurements are combined and compared to model atmosphere calculations to
determine the effective temperature and the radius of each object, and also to
constrain the atmospheric composition. New evolutionary sequences with C/O
cores with thin and thick hydrogen layers are used to derive masses and ages.
We confirm the existence of a range in Teff between 5000 and 6000K where almost
all white dwarfs have H-rich atmospheres. There is little evidence for mixed
H/He dwarfs, with the exception of 2 He-rich DA stars, and 5 C2H white dwarfs
which possibly have mixed H/He/C atmospheres. The DQ sequence terminates near
6500K, below which they are believed to turn into C2H stars. True DC stars
slightly above this temperature are found to exhibit H-like energy
distributions despite the lack of Halpha absorption. Attempts to interpret the
chemical evolution show the problem to be complex. Convective mixing is
necessary to account for the non-DA to DA ratio as a function of temperature.
The presence of helium in cool DA stars, the existence of the non-DA gap, and
the peculiar DC stars are also explained in terms of convective mixing,
although our understanding of how this mechanism works needs to be revised. The
oldest object in our sample is about 7.9 Gyr or 9.7 Gyr old depending on
whether thin or thick hydrogen layer models are used. The mean mass of our
sample is 0.65 +/- 0.20 Msun.Comment: Accepted by ApJ Suppl (~April 2001); 79 pages incl. 25 figure
Regression models for linking patterns of growth to a later outcome:Infant growth and childhood overweight
Abstract Background Regression models are widely used to link serial measures of anthropometric size or changes in size to a later outcome. Different parameterisations of these models enable one to target different questions about the effect of growth, however, their interpretation can be challenging. Our objective was to formulate and classify several sets of parameterisations by their underlying growth pattern contrast, and to discuss their utility using an expository example. Methods We describe and classify five sets of model parameterisations in accordance with their underlying growth pattern contrast (conditional growth; being bigger v being smaller; becoming bigger and staying bigger; growing faster v being bigger; becoming and staying bigger versus being bigger). The contrasts are estimated by including different sets of repeated measures of size and changes in size in a regression model. We illustrate these models in the setting of linking infant growth (measured on 6 occasions: birth, 6 weeks, 3, 6, 12 and 24 months) in weight-for-height-for-age z-scores to later childhood overweight at 8y using complete cases from the Norwegian Childhood Growth study (n = 900). Results In our expository example, conditional growth during all periods, becoming bigger in any interval and staying bigger through infancy, and being bigger from birth were all associated with higher odds of later overweight. The highest odds of later overweight occurred for individuals who experienced high conditional growth or became bigger in the 3 to 6 month period and stayed bigger, and those who were bigger from birth to 24 months. Comparisons between periods and between growth patterns require large sample sizes and need to consider how to scale associations to make comparisons fair; with respect to the latter, we show one approach. Conclusion Studies interested in detrimental growth patterns may gain extra insight from reporting several sets of growth pattern contrasts, and hence an approach that incorporates several sets of model parameterisations. Co-efficients from these models require careful interpretation, taking account of the other variables that are conditioned on
Changing of flight phenology and ecotype expansion of the European corn borer (Ostrinia nubilalis Hbn.) in Hungary Part
The studies aimed to acquire the widest possible information on the annual flight in Hungary of the European corn borer (ECB), Ostrinia nubilalis Hübner (Lepidoptera: Pyralidae). The investigations used biomathematical (Part 1) and graphical (Part 2) evaluation to document changes in the individual population number.The study was conducted in Hungary using ECB moth capture records from the Plant Protection Information System black light trap system (1991–2004). We have drawn conclusions on the appearance of annual flights and the tendency of alterations in flight direction by means of light trap results in four different areas in Hungary. We calculated the flight peak quotients, the individual population numbers of the second flight peak, the distinctions of individual numbers of two flight peaks in this part.As previously published, alterations in flight direction of ECB flights began at different times in Hungary. In the current study, a gradual disappearance of the univoltine ecotype and gradual appearance of the bivoltine ecotype ECB in Hungary is confirmed by the data obtained between 1991–2004. Flight peak quotients and data concerning the second flight peak have confirmed change this process, too: the appearance of a second flight peak in Northwestern Hungary from 1995–1996 (FP = 1.27), the more significant appearance of flights in August in Western Hungary (FP = 1.05) and Northeastern Hungary (FP = 1.45), and a three and four times more individual number of the second flight peak in Southeastern Hungary (FP = 3.44). Flight peak quotients, individual population numbers of the second flight peak, the tendency towards a difference in population number of the two peaks, and size of increase of these values demonstrates the southeastern-northwestern presence of the bivoltine ecotype in Hungary
Spin-Rotation Symmetry Breaking in the Superconducting State of CuxBi2Se3
Spontaneous symmetry breaking is an important concept for understanding
physics ranging from the elementary particles to states of matter. For example,
the superconducting state breaks global gauge symmetry, and unconventional
superconductors can break additional symmetries. In particular, spin rotational
symmetry is expected to be broken in spin-triplet superconductors. However,
experimental evidence for such symmetry breaking has not been conclusively
obtained so far in any candidate compounds. Here, by 77Se nuclear magnetic
resonance measurements, we show that spin rotation symmetry is spontaneously
broken in the hexagonal plane of the electron-doped topological insulator
Cu0.3Bi2Se3 below the superconducting transition temperature Tc=3.4 K. Our
results not only establish spin-triplet superconductivity in this compound, but
may also serve to lay a foundation for the research of topological
superconductivity
Cobalamin and folate status in 6 to 35 months old children presenting with acute diarrhea in Bhaktapur, Nepal
Background: Cobalamin and folate are essential micronutrients and are important in DNA and RNA synthesis, cell proliferation, growth, hematopoiesis, and cognitive function. However, data on cobalamin and folate status are lacking particularly from young children residing in low and middle income countries.
Objective: To measure cobalamin and folate status and identifies their predictors among 6 to 35 months old children presenting with acute diarrhea.
Design: This was a cross-sectional study in 823 children presenting with acute diarrhea. We measured plasma cobalamin, folate, methylmalonic acid and total homocysteine who sought treatment for acute diarrhea between June 1998 and August 2000.
Results: The mean (SD) plasma concentrations of cobalamin, folate, total homocysteine and methylmalonic acid were 206 (124) pmol/L, 55 (32) nmol/L, 11.4 (5.6) mmol/L and 0.79 (1.2) mmol/L, respectively. The prevalence of low plasma cobalamin (,150 pmol/L) was 41% but less than 2% (15) children had low folate concentration (,10 nmol/L). Plasma homocysteine and methylmalonic acid concentrations were negatively associated with cobalamin concentration but not associated with folate status. The prevalence of cobalamin deficiency was higher in breastfed than non-breastfed children (44% vs 24%; p =,0.001). The prevalence of hyperhomocysteinemia (.10 mmol/L) and elevated methylmalonic acid (.0.28 mmol/L) were 73% and 52%, respectively. In the regression analyses, the plasma cobalamin concentration was positively associated with age, and introduction of animal or formula milk.
Conclusions: Our study indicated that poor cobalamin status was common particularly among breastfed children. Folate deficiency was virtually none existent. Possible consequences of cobalamin deficiency in young children need to be explored
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