10,872 research outputs found
A study of the leisure time activities, television viewing habits, and the expressed interests of a selected population of fifth grade children in connection with their studying of natural science by television
Thesis (Ed.M.)--Boston Universit
Between anaphora and deixis...the resolution of the demonstrative noun-phrase ‘that N’
Three experiments examined the hypothesis that the demonstrative noun phrase (NP) that N, as an anadeictic expression, preferentially refers to the less salient referent in a discourse representation when used anaphorically, whereas the anaphoric pronoun he or she preferentially refers to the highly-focused referent. The findings, from a sentence completion task and two reading time experiments that used gender to create ambiguous and unambiguous coreference, reveal that the demonstrative NP specifically orients processing toward a less salient referent when there is no gender cue discriminating between different possible referents. These findings show the importance of taking into account the discourse function of the anaphor itself and its influence on the process of searching for the referent
Physics of SNeIa and Cosmology
We give an overview of the current understanding of Type Ia supernovae
relevant for their use as cosmological distance indicators. We present the
physical basis to understand their homogeneity of the observed light curves and
spectra and the observed correlations. This provides a robust method to
determine the Hubble constant, 67 +- 8 (2 sigma) km/Mpc/sec, independently from
primary distance indicators.
We discuss the uncertainties and tests which include SNe Ia based distance
determinations prior to delta-Ceph. measurements for the host galaxies. Based
on detailed models, we study the small variations from homogeneities and their
observable consequences. In combination with future data, this underlines the
suitability and promises the refinements needed to determine accurate relative
distances within 2 to 3 % and to use SNe Ia for high precision cosmology.Comment: to be published in "Stellar Candles", eds. Gieren et al. Lecture
Notes in Physics (http://link.springer.de/series/lnpp
Evidence Against an Association Between Gamma-Ray Bursts and Type I Supernovae
We present a rigorous method, based on Bayesian inference, for calculating
the odds favoring the hypothesis that any particular class of astronomical
transients produce gamma-ray bursts over the hypothesis that they do not. We
then apply this method to a sample of 83 Type Ia supernovae and a sample of 20
Type Ib-Ic supernovae. We find overwhelming odds against the hypothesis that
all Type Ia supernovae produce gamma-ray bursts, whether at low redshift
() or high-redshift (), and very large odds ()
against the hypothesis that all Type Ib, Ib/c, and Ic supernovae produce
observable gamma-ray bursts. We find large odds () against the hypothesis
that a fraction of Type Ia supernovae produce observable gamma-ray bursts, and
moderate odds () against the hypothesis that a fraction of Type Ib-Ic
supernovae produce observable bursts. We have also re-analyzed both a corrected
version of the Wang & Wheeler sample of Type Ib-Ic SNe and our larger sample of
20 Type Ib-Ic SNe, using a generalization of their frequentist method. We find
no significant evidence in either case of a correlation between Type Ib-Ic SNe
and GRBs, consistent with the very strong evidence against such a correlation
that we find from our Bayesian analysis.Comment: 45 pages, 2 PostScript figures. Uses AASTEX macros. Submitted to The
Astrophysical Journa
Cortisol awakening response in infants during the first six postnatal months and its relation to birth outcome
Context: The rise of cortisol concentrations after awakening is well documented in adults and children and commonly used as easily accessible marker of hypothalamic-pituitary-adrenal (HPA) reactivity.
Objective: The purpose of this study was to demonstrate the existence of a salivary cortisol awakening response (CAR) in infants, and to estimate its association with birth outcome.
Setting: The study was conducted in the general community.
Participants: Healthy infants up to six months age (N=64).
Main outcome measures: Mothers were instructed to collect their infant’s saliva immediately and 30 min after awakening on two days within 45 days, irrespective of awakening time. Information on birth outcome was collected from medical records and questionnaires.
Results: Linear mixed models analysis revealed a significant rise of infant salivary cortisol concentrations within 30 minutes after awakening (b=0.128, SE=0.024, t61=5.31, p<0.001), which was quite stable across the two sampling days (r=0.40, p=0.002). The infant CAR was predicted by length of gestation (t61=2.43, p=0.018).
Conclusions: The current data demonstrate the existence of a CAR in infants as early as during the first six postnatal months; its relationship with length of gestation supports its usefulness for questions related to developmental neuroscience. Therefore, the infant CAR emerges as non-invasive biomarker of HPA axis dynamics at this early stage of life, with relevance for future research and potential clinical applications
Marion H. Smoak to Senator & Mrs. James O. Eastland, 16 July 1973
Telegram dated 16 July 1973 from Marion H. Smoak, Chief of Protocol at State Department, to James O. Eastland, re: Agnew invitation to Eastland & wife to a luncheon honoring the Shah of Iran; 2 pages.https://egrove.olemiss.edu/joecorr_f/1017/thumbnail.jp
MULTIPLE ISOTOPE EFFECTS ON ENZYME-CATALYZED REACTIONS
Isotope effects have long been popular as a method for studying mechanisms of chemical reactions (1, 2). Application of this method to enzymatic reactions has come slowly, in part because of the difficulty of making measurements of the necessary precision, and in part because of the difficulty of interpreting the variations in rate that occur in multistep reactions. The theory and practice of isotope effects has now reached the stage where a variety of interesting mechanistic studies are possible (3-9), including use of heavy atom isotope effects (5), application to multireactant enzymes (9a, 10), pH dependence of isotope effects (11, 12), proton inventory studies (9), relative deuterium and tritium isotope effects (13), the remote label method (14), and the use of deuterium and tritium isotope effects for the study of tunneling (J. Klinman, personal communication)
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