Heterogeneity in the Relationship between Disinfection By-Products in Drinking Water and Cancer: A Systematic Review.

The epidemiological evidence demonstrating the effect of disinfection by-products (DBPs) from drinking water on colon and rectal cancers is well documented. However, no systematic assessment has been conducted to assess the potential effect measure modification (EMM) in the relationship between DBPs and cancer. The objective of this paper is to conduct a systematic literature review to determine the extent to which EMM has been assessed in the relationship between DBPs in drinking water in past epidemiological studies. Selected articles (n = 19) were reviewed, and effect estimates and covariates that could have been used in an EMM assessment were gathered. Approximately half of the studies assess EMM (n = 10), but the majority of studies only estimate it relative to sex subgroups (n = 6 for bladder cancer and n = 2 both for rectal and colon cancers). Although EMM is rarely assessed, several variables that could have a potential modification effect are routinely collected in these studies, such as socioeconomic status or age. The role of environmental exposures through drinking water can play an important role and contribute to cancer disparities. We encourage a systematic use of subgroup analysis to understand which populations or territories are more vulnerable to the health impacts of DBPs

Fast Mapping of Terahertz Bursting Thresholds and Characteristics at Synchrotron Light Sources

Dedicated optics with extremely short electron bunches enable synchrotron light sources to generate intense coherent THz radiation. The high degree of spatial compression in this so-called low-alpha optics entails a complex longitudinal dynamics of the electron bunches, which can be probed studying the fluctuations in the emitted terahertz radiation caused by the micro-bunching instability ("bursting"). This article presents a "quasi-instantaneous" method for measuring the bursting characteristics by simultaneously collecting and evaluating the information from all bunches in a multi-bunch fill, reducing the measurement time from hours to seconds. This speed-up allows systematic studies of the bursting characteristics for various accelerator settings within a single fill of the machine, enabling a comprehensive comparison of the measured bursting thresholds with theoretical predictions by the bunched-beam theory. This paper introduces the method and presents first results obtained at the ANKA synchrotron radiation facility.Comment: 7 pages, 7 figures, to be published in Physical Review Accelerators and Beam

String Equations for the Unitary Matrix Model and the Periodic Flag Manifold

The periodic flag manifold (in the Sato Grassmannian context) description of the modified Korteweg--de Vries hierarchy is used to analyse the translational and scaling self--similar solutions of this hierarchy. These solutions are characterized by the string equations appearing in the double scaling limit of the symmetric unitary matrix model with boundary terms. The moduli space is a double covering of the moduli space in the Sato Grassmannian for the corresponding self--similar solutions of the Korteweg--de Vries hierarchy, i.e. of stable 2D quantum gravity. The potential modified Korteweg--de Vries hierarchy, which can be described in terms of a line bundle over the periodic flag manifold, and its self--similar solutions corresponds to the symmetric unitary matrix model. Now, the moduli space is in one--to--one correspondence with a subset of codimension one of the moduli space in the Sato Grassmannian corresponding to self--similar solutions of the Korteweg--de Vries hierarchy.Comment: 21 pages in LaTeX-AMSTe

Meson Exchange Effect on Color Superconductivity

We investigate the effects of pion and gluon exchanges on the formation of two-flavor color superconductivity at moderate density, $\mu <1 GeV$. The chiral quark model proposed by Manohar and Georgi containing pions as well as gluons is employed to show that the pion exchange reduces substantially the value of the superconducting gap gotten with the gluon exchange only. It turns out that the pion exchanges produce a repulsion between quark-quark pair in a spin and isospin singlet state. We suggest that the phase consisiting of pions, gluons and quarks is one of the candidates of in-medium QCD phase at moderate density.Comment: 8 pages, 1 figure, minor correction

Analysis of the osseointegrative force of a hyperhydrophilic and nanostructured surface refinement for TPS surfaces in a gap healing model with the Göttingen minipig

Background: A lot of advantages can result in a high wettability as well as a nanostructure at a titanium surface on bone implants. Thus, the aim of this study was to evaluate the osseointegrative potential of a titan plasma-sprayed (TPS) surface refinement by acid-etching with chromosulfuric acid. This results in a hyperhydrophilic surface with a nanostructure and an extreme high wetting rate. Methods: In total, 72 dumbbell shape titan implants were inserted in the spongy bone of the femora of 18 Göttingen minipigs in a conservative gap model. Thirty-six titan implants were coated with a standard TPS surface and 36 with the hyperhydrophilic chromosulfuric acid (CSA) surface. After a healing period of 4, 8, and 12 weeks, the animals were killed. The chronological healing process was histomorphometrically analyzed. Results: The de novo bone formation, represented by the bone area (BA), is increased by approximately 1.5 times after 12 weeks with little additional benefit by use of the CSA surface. The bone-to-implant contact (BIC), which represents osseoconductive forces, shows results with a highly increased osteoid production in the CSA implants beginning at 8 and 12 weeks compared to TPS. This culminates in a 17-fold increase in BIC after a healing period of 12 weeks. After 4 weeks, significantly more osteoid was seen in the gap as de novo formation in the CSA group (p = 0.0062). Osteoid was also found more frequently after 12 weeks at the CSA-treated surface (p = 0.0355). The site of implantation, intertrochanteric or intercondylar, may influence on the de novo bone formation in the gap. Conclusions: There is a benefit by the CSA surface treatment of the TPS layer for osseointegration over an observation time up to 12 weeks. Significant differences were able to be shown in two direct comparisons between the CSA and the TPS surface for osteoid formation in the gap model. Further trials may reveal the benefit of the CSA treatment of the TPS layer involving mechanical tests if possible

Fast mapping of terahertz bursting thresholds and characteristics at synchrotron light sources

Dedicated optics with extremely short electron bunches enable synchrotron light sources to generate intense coherent THz radiation. The high degree of spatial compression in this so-called low-α$_{c}$ optics entails a complex longitudinal dynamics of the electron bunches, which can be probed studying the fluctuations in the emitted terahertz radiation caused by the microbunching instability (“bursting”). This article presents a “quasi-instantaneous” method for measuring the bursting characteristics by simultaneously collecting and evaluating the information from all bunches in a multibunch fill, reducing the measurement time from hours to seconds. This speed-up allows systematic studies of the bursting characteristics for various accelerator settings within a single fill of the machine, enabling a comprehensive comparison of the measured bursting thresholds with theoretical predictions by the bunched-beam theory. This paper introduces the method and presents first results obtained at the ANKA synchrotron radiation facility

Two lectures on color superconductivity

The first lecture provides an introduction to the physics of color superconductivity in cold dense quark matter. The main color superconducting phases are briefly described and their properties are listed. The second lecture covers recent developments in studies of color superconducting phases in neutral and beta-equilibrated matter. The properties of gapless color superconducting phases are discussed.Comment: 56 pages, 9 figures. Minor corrections and references added. Lectures delivered at the IARD 2004 conference, Saas Fee, Switzerland, June 12 - 19, 2004, and at the Helmholtz International Summer School and Workshop on Hot points in Astrophysics and Cosmology, JINR, Dubna, Russia, August 2 - 13, 200

Active wetting of epithelial tissues

Development, regeneration and cancer involve drastic transitions in tissue morphology. In analogy with the behavior of inert fluids, some of these transitions have been interpreted as wetting transitions. The validity and scope of this analogy are unclear, however, because the active cellular forces that drive tissue wetting have been neither measured nor theoretically accounted for. Here we show that the transition between 2D epithelial monolayers and 3D spheroidal aggregates can be understood as an active wetting transition whose physics differs fundamentally from that of passive wetting phenomena. By combining an active polar fluid model with measurements of physical forces as a function of tissue size, contractility, cell-cell and cell-substrate adhesion, and substrate stiffness, we show that the wetting transition results from the competition between traction forces and contractile intercellular stresses. This competition defines a new intrinsic lengthscale that gives rise to a critical size for the wetting transition in tissues, a striking feature that has no counterpart in classical wetting. Finally, we show that active shape fluctuations are dynamically amplified during tissue dewetting. Overall, we conclude that tissue spreading constitutes a prominent example of active wetting --- a novel physical scenario that may explain morphological transitions during tissue morphogenesis and tumor progression