X-Ray Wind Tomography of the highly absorbed HMXB IGR J17252-3616

Our goal is to understand the specificities of highly absorbed sgHMXB and in particular of the companion stellar wind, thought to be responsible for the strong absorption. We have monitored IGR J17252-3616, a highly absorbed system featuring eclipses, with XMM-Newton to study the vari- ability of the column density and of the Fe K{\alpha} emission line along the orbit and during the eclipses. We also built a 3D model of the structure of the stellar wind to reproduce the observed variability. We first derived a refined orbital solution built from INTEGRAL, RXTE and XMM data. The XMM monitoring campaign revealed significant variation of intrinsic absorbing column density along the orbit and of the Fe K{\alpha} line equivalent width around the eclipses. The origin of the soft X-ray absorption is modeled with an dense and extended hydrodynamical tail, trailing the neutron star. This structure extends along most of the orbit, indicating that the stellar wind is strongly disrupted by the neutron star. The variability of the absorbing column density suggests that the terminal velocity of the wind is smaller (~400 km/s) than observed in classical systems. This can also explain the much stronger density perturbation inferred from the observations. Most of the Fe K{\alpha} emission is generated in the most inner region of the hydrodynamical tail. This region, that extends over a few accretion radii, is ionized and does not contribute to the soft X-ray absorption. We have built a qualitative model of the stellar wind of IGR J17252-3616 that can represent the observations and suggest that highly absorbed systems have a lower wind velocity than classical sgHMXB. This proposal could be tested with de- tailed numerical simulations and high-resolution infrared/optical observations. If confirmed, it may turn out that half of the persistent sgHMXB have low stellar wind speeds.Comment: 9 pages, 8 figure

Fissure Sealant Knowledge and Characteristics of Parents as a Function of Their Child's Sealant Status

A survey was conducted to identify and compare sealant knowledge and sources of sealant information of parents whose children had and had not received fissure sealants. The socioeconomic characteristics of these individuals were also compared. The sealant group was composed of the parents of children found to have a sealant on at least one permanent tooth during dental examinations of 2,036 elementary schoolchildren in southwestern Michigan. Another group of children was selected from the same population and matched to the children with sealants by child's age, sex, school location, and community. Surveys were returned by 210 of 260 sets of parents (81% response rate). Significant differences were found between the two groups with regard to parents' ages and levels of income. Parents of children with sealants had more correct information about the procedure and 74 percent of these individuals reported that the dental office was their primary source of information. For the group without sealants, 48 percent of respondents reported no source of sealant information. Findings suggest that dental personnel may strongly influence dissemination of information about sealants and utilization of this preventive procedure.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65637/1/j.1752-7325.1988.tb03182.x.pd

Microarray analysis of replicative senescence

AbstractBackground: Limited replicative capacity is a defining characteristic of most normal human cells and culminates in senescence, an arrested state in which cells remain viable but display an altered pattern of gene and protein expression. To survey widely the alterations in gene expression, we have developed a DNA microarray analysis system that contains genes previously reported to be involved in aging, as well as those involved in many of the major biochemical signaling pathways.Results: Senescence-associated gene expression was assessed in three cell types: dermal fibroblasts, retinal pigment epithelial cells, and vascular endothelial cells. Fibroblasts demonstrated a strong inflammatory-type response, but shared limited overlap in senescent gene expression patterns with the other two cell types. The characteristics of the senescence response were highly cell-type specific. A comparison of early- and late-passage cells stimulated with serum showed specific deficits in the early and mid G1 response of senescent cells. Several genes that are constitutively overexpressed in senescent fibroblasts are regulated during the cell cycle in early-passage cells, suggesting that senescent cells are locked in an activated state that mimics the early remodeling phase of wound repair.Conclusions: Replicative senescence triggers mRNA expression patterns that vary widely and cell lineage strongly influences these patterns. In fibroblasts, the senescent state mimics inflammatory wound repair processes and, as such, senescent cells may contribute to chronic wound pathologies

Thomas-Fermi Statistical Models of Finite Quark Matter

I introduce and discuss models of finite quark matter using the formalism of the Thomas-Fermi statistical model. Similar to bag models, a vacuum energy term is introduced to model long distance confinement, but the model produces bound states from the residual color Coulomb attraction even in the absence of such a term. I discuss three baryonic applications: an equal mass nonrelativistic model with and without volume pressure, the ultra-relativistic limit confined by volume pressure, and a color-flavor locking massless model. These model may be extended to multi-meson and other mixed hadronic states. Hopefully, it can help lead to a better understanding of the phenomenology of high multi-quark states in preparation for more detailed lattice QCD calculations.Comment: 29 pages, 14 figures; final journal version (Nucl. Phys. A

Effective Field Theory and Unification in AdS Backgrounds

This work is an extension of our previous work, hep-th/0204160, which showed how to systematically calculate the high energy evolution of gauge couplings in compact AdS_5 backgrounds. We first directly compute the one-loop effects of massive charged scalar fields on the low energy couplings of a gauge theory propagating in the AdS background. It is found that scalar bulk mass scales (which generically are of order the Planck scale) enter only logarithmically in the corrections to the tree-level gauge couplings. As we pointed out previously, we show that the large logarithms that appear in the AdS one-loop calculation can be obtained within the confines of an effective field theory, by running the Planck brane correlator from a high UV matching scale down to the TeV scale. This result exactly reproduces our previous calculation, which was based on AdS/CFT duality. We also calculate the effects of scalar fields satisfying non-trivial boundary conditions (relevant for orbifold breaking of bulk symmetries) on the running of gauge couplings.Comment: LaTeX, 27 pages; minor typos fixed, comments adde