625 research outputs found
Atomic beam source of polarized electrons
Polarized electrons produced by atomic beam apparatus - hyperfine structure intervals of alkali atom
CRALBP is a Highly Prevalent Autoantigen for Human Autoimmune Uveitis
Cellular retinaldehyde binding protein (CRALBP) is an autoantigen in spontaneous equine recurrent uveitis. In
order to test whether CRALBP contributes to human autoimmune uveitis, the specificity of antibodies from human
uveitis patient's sera was first evaluated in two-dimensional (2D) Western blot analysis. Subsequent identification of the immunoreactive proteins by mass spectrometry resulted in the identification of CRALBP as a putative autoantigen. Additionally, sera from human uveitis and control patients were by Western blot using purified human recombinant CRALBP. Anti-CRALBP autoantibodies occur more frequently (P<.01) in human uveitis patients than in normal controls. Thirty out of 56 tested uveitis patient's sera contained autoantibodies reactive against CRALBP, compared to only four out of 23 normal control subjects. The presence of CRALBP autoantibodies in 54% of tested uveitis patients supports CRALBP as a possible autoantigen in human autoimmune uveitis
Germline mutations in the oncogene EZH2 cause Weaver syndrome and increased human height.
The biological processes controlling human growth are diverse, complex and poorly understood. Genetic factors are important and human height has been shown to be a highly polygenic trait to which common and rare genetic variation contributes. Weaver syndrome is a human overgrowth condition characterised by tall stature, dysmorphic facial features, learning disability and variable additional features. We performed exome sequencing in four individuals with Weaver syndrome, identifying a mutation in the histone methyltransferase, EZH2, in each case. Sequencing of EZH2 in additional individuals with overgrowth identified a further 15 mutations. The EZH2 mutation spectrum in Weaver syndrome shows considerable overlap with the inactivating somatic EZH2 mutations recently reported in myeloid malignancies. Our data establish EZH2 mutations as the cause of Weaver syndrome and provide further links between histone modifications and regulation of human growth
A Model of Vertical Oligopolistic Competition
This paper develops a model of successive oligopolies with endogenous market entry, allowing for varying degrees of product differentiation and entry costs in both markets. Our analysis shows that the downstream conditions dominate the overall profitability of the two-tier structure while
the upstream conditions mainly affect the distribution of profits. We compare the welfare effects of upstream versus downstream deregulation policies and show that the impact of deregulation may be overvalued when ignoring feedback effects from the other market. Furthermore, we analyze how different forms of vertical restraints influence the endogenous market structure and show when they are welfare enhancing
The possible existence of Hs in nature from a geochemical point of view
A hypothesis of the existence of a long-lived isotope 271Hs in natural
molybdenites and osmirides is considered from a geochemical point of view. It
is shown that the presence of Hs in these minerals can be explained only by
making an additional ad hoc assumption on the existence of an isobaric pair of
271Bh-271Hs. This assumption could be tested by mass-spectrometric measurements
of U, Pb, Kr, Xe, and Zr isotopic shifts.Comment: 5 pages, no figures. Physics of Particles and Nuclei Letters, 2006,
Vol. 3, No. 3, pp. 165-168 in pres
Characterization and Tuning of Ultra High Gradient Permanent Magnet Quadrupoles
The application of quadrupole-devices with high field gradients and small
apertures requires precise control over higher order multipole field
components. We present a new scheme for performance control and tuning, which
allows the illumination of most of the quadrupole-device aperture because of
the reduction of higher order field components. Consequently, the size of the
aperture can be minimized to match the beam size achieving field gradients of
up to 500 T/m at good imaging quality. The characterization method based on a
Hall probe measurement and a Fourier analysis was confirmed using the high
quality electron beam at the Mainz Microtron MAMI
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