Adaptation and Recovery of a Styrene‐Acrylic Acid Copolymer Surface to Water

Drops sliding down an adaptive surface lead to changes of the dynamic contact angles. Two adaptation processes play a role: 1) the adaptation of the surface upon bringing it into contact to the drop (wetting) and 2) the adaptation of the surface after the drop passed (dewetting). In order to study both processes, the authors investigate samples made from random styrene (PS)/acrylic acid (PAA) copolymers, which are exposed to water. Sum-frequency generation spectroscopy and tilted-plate measurements indicate that during wetting, the PS segments displace from the interface, while PAA segments are enriched. This structural adaptation of the PS/PAA random copolymer to water remains after dewetting. Annealing the adapted polymer induces reorientation of the PS segments to the surface

Understanding Treatment Burden and Quality of Life Impact of Participating in an Early-Phase Pediatric Oncology Clinical Trial: A Pilot Study

PURPOSE: Early-phase clinical trials (EPTs) have led to new, more effective treatment options for children with cancer. Despite the extensive use of EPTs in pediatric oncology, little is known about parent and child experiences during EPT participation. The purposes of this pilot study were to assess the feasibility and preliminary results of having children with cancer and their parents complete measures of treatment burden and quality of life (QOL) concurrent with EPT participation. METHODS: In this descriptive, longitudinal, pilot study, parents and children were followed for the first 60 days of an EPT. Feasibility was assessed by participant enrollment and retention and completion of measures. Measures completed included the following: demographic form (completed at baseline); Diary of Trial Experiences to capture treatment burden (completed ongoing); and PedsQL™ Quality of Life Inventories, Cancer Modules, and Family Impact Module (completed at baseline, post-first disease evaluation, and off-study). Data were analyzed using descriptive statistics. RESULTS: Feasibility goals of enrollment, retention, and measure completion were partially met. Preliminary treatment burden and QOL results are provided. CONCLUSIONS: While QOL assessments may provide insight into EPT experiences, future studies need to be conducted at multiple sites and enrollment goals must account for participant attrition

New Interstellar Dust Models Consistent with Extinction, Emission, and Abundance Constraints

We present new interstellar dust models which have been derived by simultaneously fitting the far-ultraviolet to near-infrared extinction, the diffuse infrared (IR) emission and, unlike previous models, the elemental abundance constraints on the dust for different interstellar medium abundances, including solar, F and G star, and B star abundances. The fitting problem is a typical ill-posed inversion problem, in which the grain size distribution is the unknown, which we solve by using the method of regularization. The dust model contains various components: PAHs, bare silicate, graphite, and amorphous carbon particles, as well as composite particles containing silicate, organic refractory material, water ice, and voids. The optical properties of these components were calculated using physical optical constants. As a special case, we reproduce the Li & Draine (2001) results, however their model requires an excessive amount of silicon, magnesium, and iron to be locked up in dust: about 50 ppm (atoms per million of H atoms), significantly more than the upper limit imposed by solar abundances of these elements, about 34, 35, and 28 ppm, respectively. A major conclusion of this paper is that there is no unique interstellar dust model that simultaneously fits the observed extinction, diffuse IR emission, and abundances constraints.Comment: 70 pages, 23 figures, accepted for publication in the Astrophysical Journal Supplemen

Variational data assimilation for the initial-value dynamo problem

The secular variation of the geomagnetic field as observed at the Earth's surface results from the complex magnetohydrodynamics taking place in the fluid core of the Earth. One way to analyze this system is to use the data in concert with an underlying dynamical model of the system through the technique of variational data assimilation, in much the same way as is employed in meteorology and oceanography. The aim is to discover an optimal initial condition that leads to a trajectory of the system in agreement with observations. Taking the Earth's core to be an electrically conducting fluid sphere in which convection takes place, we develop the continuous adjoint forms of the magnetohydrodynamic equations that govern the dynamical system together with the corresponding numerical algorithms appropriate for a fully spectral method. These adjoint equations enable a computationally fast iterative improvement of the initial condition that determines the system evolution. The initial condition depends on the three dimensional form of quantities such as the magnetic field in the entire sphere. For the magnetic field, conservation of the divergence-free condition for the adjoint magnetic field requires the introduction of an adjoint pressure term satisfying a zero boundary condition. We thus find that solving the forward and adjoint dynamo system requires different numerical algorithms. In this paper, an efficient algorithm for numerically solving this problem is developed and tested for two illustrative problems in a whole sphere: one is a kinematic problem with prescribed velocity field, and the second is associated with the Hall-effect dynamo, exhibiting considerable nonlinearity. The algorithm exhibits reliable numerical accuracy and stability. Using both the analytical and the numerical techniques of this paper, the adjoint dynamo system can be solved directly with the same order of computational complexity as that required to solve the forward problem. These numerical techniques form a foundation for ultimate application to observations of the geomagnetic field over the time scale of centuries

Streptomyces sparsus, sp. nov., a novel member of the genus Streptomyces from saline and alkaline soil in China

Salt and alkaline-tolerant actinomycete strain, YIM 90018T, was isolated from a saline and alkaline soil sample collected from Qinghai, China, and was then subjected to polyphasic taxonomy. Aerial hyphae of strain YIM 90018T were not produced on almost tested media except YIM 82# agar. Vegetative hyphae were abundant, developed well, and not fragmented. Straight or flexuous (Rectiflexibiles) spore chains. The strain grew well at 25% of MgCl2.6H2O and pH 10. All of these characters consistently assign the strain YIM 90018T to known species of the genus Streptomyces. Based on phylogenetic analysis of 16S rDNA, DNA-DNA hybridization, phenotypic characters and comparison with known species of the genus, strain YIM 90018T can be differentiated from all the validly described Streptomyces species. A novel species, Streptomyces sparsus sp. nov. is proposed. The type strain of the new species is YIM 90018T (CCTCC AA204019= DSM 41858T)

Earthquakes: from chemical alteration to mechanical rupture

In the standard rebound theory of earthquakes, elastic deformation energy is progressively stored in the crust until a threshold is reached at which it is suddenly released in an earthquake. We review three important paradoxes, the strain paradox, the stress paradox and the heat flow paradox, that are difficult to account for in this picture, either individually or when taken together. Resolutions of these paradoxes usually call for additional assumptions on the nature of the rupture process (such as novel modes of deformations and ruptures) prior to and/or during an earthquake, on the nature of the fault and on the effect of trapped fluids within the crust at seismogenic depths. We review the evidence for the essential importance of water and its interaction with the modes of deformations. Water is usually seen to have mainly the mechanical effect of decreasing the normal lithostatic stress in the fault core on one hand and to weaken rock materials via hydrolytic weakening and stress corrosion on the other hand. We also review the evidences that water plays a major role in the alteration of minerals subjected to finite strains into other structures in out-of-equilibrium conditions. This suggests novel exciting routes to understand what is an earthquake, that requires to develop a truly multidisciplinary approach involving mineral chemistry, geology, rupture mechanics and statistical physics.Comment: 44 pages, 1 figures, submitted to Physics Report

Cause-Specific Excess Mortality in Siblings of Patients Co-Infected with HIV and Hepatitis C Virus

BACKGROUND: Co-infection with hepatitis C in HIV-infected individuals is associated with 3- to 4-fold higher mortality among these patients' siblings, compared with siblings of mono-infected HIV-patients or population controls. This indicates that risk factors shared by family members partially account for the excess mortality of HIV/HCV-co-infected patients. We aimed to explore the causes of death contributing to the excess sibling mortality. METHODOLOGY AND PRINCIPAL FINDINGS: We retrieved causes of death from the Danish National Registry of Deaths and estimated cause-specific excess mortality rates (EMR) for siblings of HIV/HCV-co-infected individuals (n = 436) and siblings of HIV mono-infected individuals (n = 1837) compared with siblings of population controls (n = 281,221). Siblings of HIV/HCV-co-infected individuals had an all-cause EMR of 3.03 (95% CI, 1.56-4.50) per 1,000 person-years, compared with siblings of matched population controls. Substance abuse-related deaths contributed most to the elevated mortality among siblings [EMR = 2.25 (1.09-3.40)] followed by unnatural deaths [EMR = 0.67 (-0.05-1.39)]. No siblings of HIV/HCV co-infected patients had a liver-related diagnosis as underlying cause of death. Siblings of HIV-mono-infected individuals had an all-cause EMR of 0.60 (0.16-1.05) compared with siblings of controls. This modest excess mortality was due to deaths from an unknown cause [EMR = 0.28 (0.07-0.48)], deaths from substance abuse [EMR = 0.19 (-0.04-0.43)], and unnatural deaths [EMR = 0.18 (-0.06-0.42)]. CONCLUSIONS: HCV co-infection among HIV-infected patients was a strong marker for family-related mortality due to substance abuse and other unnatural causes. To reduce morbidity and mortality in HIV/HCV-co-infected patients, the advances in antiviral treatment of HCV should be accompanied by continued focus on interventions targeted at substance abuse-related risk factors

Asymmetric shallow mantle structure beneath the Hawaiian Swell—evidence from Rayleigh waves recorded by the PLUME network

Author Posting. © The Author(s), 2011. This article is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Geophysical Journal International 187 (2011): 1725–1742, doi:10.1111/j.1365-246X.2011.05238.x.We present models of the 3-D shear velocity structure of the lithosphere and asthenosphere beneath the Hawaiian hotspot and surrounding region. The models are derived from long-period Rayleigh-wave phase velocities that were obtained from the analysis of seismic recordings collected during two year-long deployments for the Hawaiian Plume-Lithosphere Undersea Mantle Experiment. For this experiment, broad-band seismic sensors were deployed at nearly 70 seafloor sites as well as 10 sites on the Hawaiian Islands. Our seismic images result from a two-step inversion of path-averaged dispersion curves using the two-station method. The images reveal an asymmetry in shear velocity structure with respect to the island chain, most notably in the lower lithosphere at depths of 60 km and greater, and in the asthenosphere. An elongated, 100-km-wide and 300-km-long low-velocity anomaly reaches to depths of at least 140 km. At depths of 60 km and shallower, the lowest velocities are found near the northern end of the island of Hawaii. No major velocity anomalies are found to the south or southeast of Hawaii, at any depth. The low-velocity anomaly in the asthenosphere is consistent with an excess temperature of 200–250 °C and partial melt at the level of a few percent by volume, if we assume that compositional variations as a result of melt extraction play a minor role. We also image small-scale low-velocity anomalies within the lithosphere that may be associated with the volcanic fields surrounding the Hawaiian Islands.This research was financed by the National Science Foundation under grants OCE-00-02470 and OCE-00-02819. Markee was partly sponsored by a SIO graduate student fellowship

Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS

Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations