1,604 research outputs found
An Investigation of the Nature, Sources and Properties of Pyrogenic Substances
1 . The test for the detection of pyrogen by the thermometer method was examined and found to be unreliable although the results obtained were within the limits of the test as described in the United States Pharmacopoeia, thirteenth revision, and the British Pharmacopoeia, 1948. 2. A thermocouple circuit was constructed which could accommodate ten rabbits and a test for detection using this apparatus devised. The sensitivity of the test was such that an average maximum rise in rectal temperature of 0.3
The Three-Dimensional Spatial Structure of Cirrus Clouds Determined from Lidar Satellite Observations
Simultaneous imagery from the University of Wisconsin Volume Imaging Lidar (VIL) and meteorological satellites were used to quantify the spatial structure of cirrus clouds with 60 m resolution. This data was used to determine the spatial distributions of cloud base altitude, cloud top altitude, and mid-cloud altitude. Two dimensional auto-correlation functions describing the mean shape of cirrus clouds were computed. Because cirrus clouds seldom have distinct edges, these correlation functions are derived as a function of a threshold value which defines the cloud edge
Casimir Force between a Dielectric Sphere and a Wall: A Model for Amplification of Vacuum Fluctuations
The interaction between a polarizable particle and a reflecting wall is
examined. A macroscopic approach is adopted in which the averaged force is
computed from the Maxwell stress tensor. The particular case of a perfectly
reflecting wall and a sphere with a dielectric function given by the Drude
model is examined in detail. It is found that the force can be expressed as the
sum of a monotonically decaying function of position and of an oscillatory
piece. At large separations, the oscillatory piece is the dominant
contribution, and is much larger than the Casimir-Polder interaction that
arises in the limit that the sphere is a perfect conductor. It is argued that
this enhancement of the force can be interpreted in terms of the frequency
spectrum of vacuum fluctuations. In the limit of a perfectly conducting sphere,
there are cancellations between different parts of the spectrum which no longer
occur as completely in the case of a sphere with frequency dependent
polarizability. Estimates of the magnitude of the oscillatory component of the
force suggest that it may be large enough to be observable.Comment: 18pp, LaTex, 7 figures, uses epsf. Several minor errors corrected,
additional comments added in the final two sections, and references update
The Asymptotic Giant Branches of GCs: Selective Entry Only
The handful of available observations of AGB stars in Galactic Globular
Clusters suggest that the GC AGB populations are dominated by cyanogen-weak
stars. This contrasts strongly with the distributions in the RGB (and other)
populations, which generally show a 50:50 bimodality in CN band strength. If it
is true that the AGB populations show very different distributions then it
presents a serious problem for low mass stellar evolution theory, since such a
surface abundance change going from the RGB to AGB is not predicted by stellar
models. However this is only a tentative conclusion, since it is based on very
small AGB sample sizes. To test whether this problem really exists we have
carried out an observational campaign specifically targeting AGB stars in GCs.
We have obtained medium resolution spectra for about 250 AGB stars across 9
Galactic GCs using the multi-object spectrograph on the AAT (2df/AAOmega). We
present some of the preliminary findings of the study for the second parameter
trio of GCs: NGC 288, NGC 362 and NGC 1851. The results indeed show that there
is a deficiency of stars with strong CN bands on the AGB. To confirm that this
phenomenon is robust and not just confined to CN band strengths and their
vagaries, we have made observations using FLAMES/VLT to measure elemental
abundances for NGC 6752.We present some initial results from this study also.
Our sodium abundance results show conclusively that only a subset of stars in
GCs experience the AGB phase of evolution. This is the first direct, concrete
confirmation of the phenomenon.Comment: 4 pages, to appear in conference proceedings of "Reading the book of
globular clusters with the lens of stellar evolution", Rome, 26-28 November
201
Who I Am: The Meaning of Early Adolescents’ Most Valued Activities and Relationships, and Implications for Self-Concept Research
Self-concept research in early adolescence typically measures young people’s self-perceptions of competence in specific, adult-defined domains. However, studies have rarely explored young people’s own views of valued self-concept factors and their meanings. For two major self domains, the active and the social self, this mixed-methods study identified factors valued most by 526 young people from socioeconomically diverse backgrounds in Ireland (10-12 years), and explored the meanings associated with these in a stratified subsample (n = 99). Findings indicate that self-concept scales for early adolescence omit active and social self factors and meanings valued by young people, raising questions about content validity of scales in these domains. Findings also suggest scales may under-represent girls’ active and social selves; focus too much on some school-based competencies; and, in omitting intrinsically salient self domains and meanings, may focus more on contingent (extrinsic) rather than true (intrinsic) self-esteem
Myers' type theorems and some related oscillation results
In this paper we study the behavior of solutions of a second order
differential equation. The existence of a zero and its localization allow us to
get some compactness results. In particular we obtain a Myers' type theorem
even in the presence of an amount of negative curvature. The technique we use
also applies to the study of spectral properties of Schroedinger operators on
complete manifolds.Comment: 16 page
Monoclonal antibodies specific for mercuric ions
Monoclonal antibodies (mAbs) that react with soluble mercuric ions have been produced by i \u27ection of BALB/c mice with a hapten-carrier complex designed to maximize exposure of the metal to the immune system. Three hybridomas producing antibodies that reacted with bovine serum albumin (BSA)-glutathione-HgCI, but not with BSAglutathione, were isolated from the spleen of a mouse given multiple iqjections with glutathione-HgCl conjugated to keyhole limpet hemocyanin. Stable subclones were established from two of these antibodies, designated mAb 4A10 and mAb IF10. The binding of both antibodies to immobilized BSAglutathione- HgCl was inhibited by soluble HgCl2, and dissociation constants for mercuric chloride binding were 2.3 and 3.7 nM for mAbs 4A10 and l10, respectively. Both antibodies bound mercuric acetate with similar affinities, demonstrating that the antibodies were capable of binding to mercuric ions in the presence of a different counterion than the one used in the immunogen. Reactions were not observed with other metal cations by either antibody. These data demonstrate the successful induction of antibodies that react very specifically with mercuric ions in solution regardless of the presence of a carrier
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