Modelling the effects of salt solutions on the hydration of calcium ions

Classical molecular dynamics simulations of several aqueous alkali halide salt solutions have been used to determine the effect of electrolytes on the structure of water and the hydration properties of calcium ions. Compared with the simulations of Ca2+ ions in pure liquid water, the frequency of water exchange in the first hydration shell of calcium, which is a fundamental process in controlling the reactivity of calcium(II) aqua-ions, is drastically reduced in the presence of other electrolytes in solution. The strong stabilization of the hydration shell of Ca2+ occurs not only when the halide anions are directly coordinated to calcium, but also when the alkali and halide ions are placed at or outside the second coordination shell of Ca2+, suggesting that the reactivity of the first solvation shell of the calcium ion can be influenced by the specific affinity of other ions in solution for the water molecules coordinated to Ca2+. Analysis of the hydrogen-bonded structure of water in the vicinity of the calcium ion shows that the average number of hydrogen bonds per water molecules, which is 1.8 in pure liquid water, decreases as the concentration of alkali–halide salts in solution increases, and that the temporal fluctuations of hydrogen bonds are significantly larger than those obtained for Ca2+ in pure liquid water. This effect has been explained in terms of the dynamics of reorganization of the O–H X (X = F, Cl and Br) hydrogen bond. This work shows the importance of solution composition in determining the hydrogen-bonding network and ligand-exchange dynamics around metal ions, both in solution and at the mineral–water interfaces, which in turn has implications for interactions occurring at the mineral–water interface, ultimately controlling the mobilization of ions in the environment as well as in industrial processes

Asymptotic Bethe equations for open boundaries in planar AdS/CFT

We solve, by means of a nested coordinate Bethe ansatz, the open-boundaries scattering theory describing the excitations of a free open string propagating in $AdS_5\times S^5$, carrying large angular momentum $J=J_{56}$, and ending on a maximal giant graviton whose angular momentum is in the same plane. We thus obtain the all-loop Bethe equations describing the spectrum, for $J$ finite but large, of the energies of such strings, or equivalently, on the gauge side of the AdS/CFT correspondence, the anomalous dimensions of certain operators built using the epsilon tensor of SU(N). We also give the Bethe equations for strings ending on a probe D7-brane, corresponding to meson-like operators in an $\mathcal N=2$ gauge theory with fundamental matter.Comment: 30 pages. v2: minor changes and discussion section added, J.Phys.A version

Novel actions of next-generation taxanes benefit advanced stages of prostate cancer.

PURPOSE: To improve the outcomes of patients with castration-resistant prostate cancer (CRPC), there is an urgent need for more effective therapies and approaches that individualize specific treatments for patients with CRPC. These studies compared the novel taxane cabazitaxel with the previous generation docetaxel, and aimed to determine which tumors are most likely to respond. EXPERIMENTAL DESIGN: Cabazitaxel and docetaxel were compared via in vitro modeling to determine the molecular mechanism, biochemical and cell biologic impact, and cell proliferation, which was further assessed ex vivo in human tumor explants. Isogenic pairs of RB knockdown and control cells were interrogated in vitro and in xenograft tumors for cabazitaxel response. RESULTS: The data herein show that (i) cabazitaxel exerts stronger cytostatic and cytotoxic response compared with docetaxel, especially in CRPC; (ii) cabazitaxel induces aberrant mitosis, leading to pyknotic and multinucleated cells; (iii) taxanes do not act through the androgen receptor (AR); (iv) gene-expression profiling reveals distinct molecular actions for cabazitaxel; and (v) tumors that have progressed to castration resistance via loss of RB show enhanced sensitivity to cabazitaxel. CONCLUSIONS: Cabazitaxel not only induces improved cytostatic and cytotoxic effects, but also affects distinct molecular pathways, compared with docetaxel, which could underlie its efficacy after docetaxel treatment has failed in patients with CRPC. Finally, RB is identified as the first potential biomarker that could define the therapeutic response to taxanes in metastatic CRPC. This would suggest that loss of RB function induces sensitization to taxanes, which could benefit up to 50% of CRPC cases

The Impact of Mixing Modes on Reliability in Longitudinal Studies

Mixed-mode designs are increasingly important in surveys, and large longitudinal studies are progressively moving to or considering such a design. In this context, our knowledge regarding the impact of mixing modes on data quality indicators in longitudinal studies is sparse. This study tries to ameliorate this situation by taking advantage of a quasi-experimental design in a longitudinal survey. Using models that estimate reliability for repeated measures, quasi-simplex models, 33 variables are analyzed by comparing a single-mode CAPI design to a sequential CATI-CAPI design. Results show no differences in reliabilities and stabilities across mixed modes either in the wave when the switch was made or in the subsequent waves. Implications and limitations are discussed. </jats:p

Wintertime Arctic Ocean sea water properties and primary marine aerosol concentrations

Sea spray aerosols are an important part of the climate system through their direct and indirect effects. Due to the diminishing sea ice, the Arctic Ocean is one of the most rapidly changing sea spray aerosol source areas. However, the influence of these changes on primary particle production is not known. &lt;br&gt;&lt;br&gt; In laboratory experiments we examined the influence of Arctic Ocean water temperature, salinity, and oxygen saturation on primary particle concentration characteristics. Sea water temperature was identified as the most important of these parameters. A strong decrease in sea spray aerosol production with increasing water temperature was observed for water temperatures between &amp;minus;1&amp;deg;C and 9&amp;deg;C. Aerosol number concentrations decreased from at least 1400 cm&lt;sup&gt;&amp;minus;3&lt;/sup&gt; to 350 cm&lt;sup&gt;&amp;minus;3&lt;/sup&gt;. In general, the aerosol number size distribution exhibited a robust shape with one mode close to dry diameter &lt;i&gt;D&lt;/i&gt;&lt;sub&gt;p&lt;/sub&gt; 0.2 &amp;mu;m with approximately 45% of particles at smaller sizes. Changes in sea water temperature did not result in pronounced change of the shape of the aerosol size distribution, only in the magnitude of the concentrations. Our experiments indicate that changes in aerosol emissions are most likely linked to changes of the physical properties of sea water at low temperatures. The observed strong dependence of sea spray aerosol concentrations on sea water temperature, with a large fraction of the emitted particles in the typical cloud condensation nuclei size range, provide strong arguments for a more careful consideration of this effect in climate models

Terrace Standard, January, 06, 1999

Transfer of graphene and other two-dimensional materials is still a technical challenge. The 2D-materials are typically patterned after transfer, which leads to a major loss of material. Here, we present laser induced forward transfer of chemical vapor deposition grown graphene layers with well-defined shapes and geometries. The transfer is based on photo-decomposition of a triazene-based transfer layer that produces N2 gas, which propels a graphene layer from the donor to the acceptor substrate. The functionality of the graphene-metal junction was verified by realizing functional bottom contact bottom gate field-effect transistors

Developing a model to estimate the potential impact of municipal investment on city health

This article summarizes a process which exemplifies the potential impact of municipal investment on the burden of cardiovascular disease (CVD) in city populations. We report on Developing an evidence-based approach to city public health planning and investment in Europe (DECiPHEr), a project part funded by the European Union. It had twin objectives: first, to develop and validate a vocational educational training package for policy makers and political decision takers; second, to use this opportunity to iterate a robust and user-friendly investment tool for maximizing the public health impact of 'mainstream' municipal policies, programs and investments. There were seven stages in the development process shared by an academic team from Sheffield Hallam University and partners from four cities drawn from the WHO European Healthy Cities Network. There were five iterations of the model resulting from this process. The initial focus was CVD as the biggest cause of death and disability in Europe. Our original prototype 'cost offset' model was confined to proximal determinants of CVD, utilizing modified 'Framingham' equations to estimate the impact of population level cardiovascular risk factor reduction on future demand for acute hospital admissions. The DECiPHEr iterations first extended the scope of the model to distal determinants and then focused progressively on practical interventions. Six key domains of local influence on population health were introduced into the model by the development process: education, housing, environment, public health, economy and security. Deploying a realist synthesis methodology, the model then connected distal with proximal determinants of CVD. Existing scientific evidence and cities' experiential knowledge were 'plugged-in' or 'triangulated' to elaborate the causal pathways from domain interventions to public health impacts. A key product is an enhanced version of the cost offset model, named Sheffield Health Effectiveness Framework Tool, incorporating both proximal and distal determinants in estimating the cost benefits of domain interventions. A key message is that the insights of the policy community are essential in developing and then utilising such a predictive tool

Exposure to Movie Reckless Driving in Early Adolescence Predicts Reckless, but Not Inattentive Driving

Objective: We examine the association between exposure to depictions of reckless driving in movies and unsafe driving, modeling inattentive and reckless driving as separate outcomes. Methods: Data were obtained by telephone from 1,630 US adolescents aged 10 to 14 years at baseline who were drivers at a survey 6 years later. Exposure to movie reckless driving was measured based on movies seen from a randomly selected list of 50 movie titles that had been content coded for reckless driving among characters. Associations were tested with inattentive and reckless driving behaviors in the subsequent survey–controlling for baseline age, sex, socioeconomic status, parental education, school performance, extracurricular activities, daily television and video/computer game exposure, number of movies watched per week, self- regulation and sensation seeking. Results: Exposure to movie reckless driving was common, with approximately 10% of movie characters having driven recklessly. Confirmatory factor analysis revealed a significant distinction between items tapping reckless and inattentive driving at the 6 th wave. Age and exposure to movie reckless driving at baseline were directly associated with wave-6 reckless (but not inattentive) driving. Additionally, growth in sensation seeking mediated a prospective relation between the total number of movies watched per week at baseline and reckless driving, independent of exposure to movie reckless driving. Males and high sensation seekers reported lower seatbelt usage and more reckless driving, whereas lower self-regulation predicted inattentive driving. Discussion: In this study, exposure to movie reckless driving during early adolescence predicted adolescents’ reckless driving, suggesting a direct modeling effect. Other aspects of movies were also associated with reckless driving, with that association mediated through growth in sensation seeking. Predictors of reckless driving were different from predictors of inattentive driving, with lower self-regulation associated with the latter outcome. Making a clear distinction between interventions for reckless or inattentive driving seems crucial for accident prevention

The existence problem for dynamics of dissipative systems in quantum probability

Motivated by existence problems for dissipative systems arising naturally in lattice models from quantum statistical mechanics, we consider the following $C^{\ast}$-algebraic setting: A given hermitian dissipative mapping $\delta$ is densely defined in a unital $C^{\ast}$-algebra $\mathfrak{A}$. The identity element in ${\frak A}$ is also in the domain of $\delta$. Completely dissipative maps $\delta$ are defined by the requirement that the induced maps, $(a_{ij})\to (\delta (a_{ij}))$, are dissipative on the $n$ by $n$ complex matrices over ${\frak A}$ for all $n$. We establish the existence of different types of maximal extensions of completely dissipative maps. If the enveloping von Neumann algebra of ${\frak A}$ is injective, we show the existence of an extension of $\delta$ which is the infinitesimal generator of a quantum dynamical semigroup of completely positive maps in the von Neumann algebra. If $\delta$ is a given well-behaved *-derivation, then we show that each of the maps $\delta$ and $-\delta$ is completely dissipative.Comment: 24 pages, LaTeX/REVTeX v. 4.0, submitted to J. Math. Phys.; PACS 02., 02.10.Hh, 02.30.Tb, 03.65.-w, 05.30.-