From Disordered Crystal to Glass: Exact Theory

We calculate thermodynamic properties of a disordered model insulator, starting from the ideal simple-cubic lattice ($g = 0$) and increasing the disorder parameter $g$ to $\gg 1/2$. As in earlier Einstein- and Debye- approximations, there is a phase transition at $g_{c} = 1/2$. For $g<g_{c}$ the low-T heat-capacity $C \sim T^{3}$ whereas for $g>g_{c}$, $C \sim T$. The van Hove singularities disappear at {\em any finite $g$}. For $g>1/2$ we discover novel {\em fixed points} in the self-energy and spectral density of this model glass.Comment: Submitted to Phys. Rev. Lett., 8 pages, 4 figure

MECHANISTIC STUDY OF A RUTHENIUM HYDRIDE COMPLEX OF TYPE [RuH(CO)(N-N)(PR3)2]+ AS CATALYST PRECURSOR FOR THE HYDROFORMYLATION REACTION OF 1-HEXENE

Indexación: Web of Science; Scopus; Scielo.The catalytic activity of systems of type [RuH(CO)(N-N)(PR3)(2)](+) was evaluated in the hydroformylation reaction of 1-hexene. The observed activity is explained through a reaction mechanism on the basis of the quantum theory. The mechanism included total energy calculations for each of the intermediaries of the elemental steps considered in the catalytic cycle. The deactivation of the catalyst precursors takes place via dissociation of the polypyridine ligand and the subsequent formation of thermodynamically stable species, such as RuH(CO)(3)(PPh3)(2) and RuH3(CO)(PPh3)(2), which interrupt the catalytic cycle. In addition, the theoretical study allows to explain the observed regioselectivity which is defined in two steps: (a) the hydride migration reaction with an anti-Markovnikov orientation to produce the alkyl-linear-complex (3.1a), which is more stable by 19.4 kJ/mol than the Markovnikov orientation (alkyl-branched-complex) (3.1b); (b) the carbon monoxide insertion step generates the carbonyl alkyl-linear specie (4.1a) which is more stable by 9.5 kJ/mol than the alternative species (4.1b), determining the preferred formation of heptanal in the hydroformylation of 1-hexene. Palabras clavehttp://ref.scielo.org/db4yc

A patient preference study that evaluated fluticasone furoate and mometasone furoate nasal sprays for allergic rhinitis

Background: Corticosteroid nasal sprays are the mainstay of treatment for allergic rhinitis. These sprays have sensory attributes such as scent and/or odor, taste and aftertaste, and run down the throat and/or the nose, which, when unpleasant, can affect patient preference for, and compliance with, treatment. Objective: This study examined patient preference for fluticasone furoate nasal spray (FFNS) or mometasone furoate nasal spray (MFNS) based on their sensory attributes after administration in patients with allergic rhinitis. Methods: This was a multicenter, randomized, double-blind, cross-over study. Patient preferences were determined by using three questionnaires (Overall Preference, Immediate Attributes, and Delayed Attributes). Results: Overall, 56% of patients stated a preference for FFNS versus 32% for MFNS (p _ 0.001); the remaining 12% stated no preference. More patients stated a preference for FFNS versus MFNS for the attributes of “less drip down the throat” (p _ 0.001), “less run out of the nose” (p _ 0.05), “more soothing” (p _ 0.05), and “less irritating” (p _ 0.001). More patients responded in favor of FFNS versus MFNS for the immediate attributes, “run down the throat” (p _ 0.001), and “run out of the nose” (p _ 0.001), and, in the delayed attributes, “run down the throat” (p _ 0.001), “run out of the nose” (p _ 0.01), “presence of aftertaste” (p _ 0.01), and “no nasal irritation” (p _ 0.001). Conclusion: Patients with allergic rhinitis preferred FFNS versus MFNS overall and based on a number of individual attributes, including “less drip down the throat,” “less run out of the nose,” and “less irritating.” Greater preference may improve patient adherence and thereby improve symptom management of the patient’s allergic rhinitis

Constructions of the soluble potentials for the non-relativistic quantum system by means of the Heun functions

The Schr\"{o}dinger equation $\psi"(x)+\kappa^2 \psi(x)=0$ where $\kappa^2=k^2-V(x)$ is rewritten as a more popular form of a second order differential equation through taking a similarity transformation $\psi(z)=\phi(z)u(z)$ with $z=z(x)$. The Schr\"{o}dinger invariant $I_{S}(x)$ can be calculated directly by the Schwarzian derivative $\{z, x\}$ and the invariant $I(z)$ of the differential equation $u_{zz}+f(z)u_{z}+g(z)u=0$. We find an important relation for moving particle as $\nabla^2=-I_{S}(x)$ and thus explain the reason why the Schr\"{o}dinger invariant $I_{S}(x)$ keeps constant. As an illustration, we take the typical Heun differential equation as an object to construct a class of soluble potentials and generalize the previous results through choosing different $\rho=z'(x)$ as before. We get a more general solution $z(x)$ through integrating $(z')^2=\alpha_{1}z^2+\beta_{1}z+\gamma_{1}$ directly and it includes all possibilities for those parameters. Some particular cases are discussed in detail.Comment: 11 page

Special issue on studies in Late Modern English historical phonology using the Eighteenth-Century English Phonology Database (ECEP): introduction

Since Charles Jones referred to the eighteenth and nineteenth centuries as the ‘Cinderellas of English historical linguistic study’ (1989: 279), there has been a great deal of progress in research on this period, but, as Beal (2012: 22) points out, much of this has been in the fields of syntax, morphology, lexis, pragmatics, sociolinguistics and the normative tradition. Beal argues that the availability of corpora of Late Modern English texts has greatly facilitated research in these areas, but, since creating phonological corpora for periods antedating the invention of sound recording is a challenging proposition, the historical phonology of Late Modern English has benefited much less from the corpus revolution. To redress this imbalance, the editors of this issue, with technical support from the Humanities Research Institute, University of Sheffield, created the Eighteenth-Century English Phonology Database (ECEP), which is freely available at www.dhi.ac.uk/projects/ecep

Preschool children’s biophilia and attitudes toward nature: The effect of personal experiences

Regular engagement outside may promote healthy physical and psychological development as well as a respect and appreciation for nature. This exploratory study compared biophilia and attitudes toward nature between young children living in an urban area to those in a rural area. Urban and rural areas may offer different opportunities for exposure and engagement with elements such as water, plants, and animals. A comparison between young children in these settings may determine if experience in these different environments affects their attitudes and biophilia. Thirty-six children (urban n = 27; rural n = 9) participated in one-on-one structured interviews about their attitudes toward and being in nature. Results revealed no significant difference in biophilia between children by geographical area. Common themes in children’s attitudes emerged: 1) young children define nature by identifying specific elements; 2) young children are aware that their actions have consequences for the condition of the natural environment; and 3) children understood that the expectations guiding behavior in the natural environment apply to everyone. Preschool children’s level of cognitive maturity and individual preferences may be better predictors of biophilia and attitude than location alone. Authors suggest implications for teachers and parents

Preschool children’s biophilia and attitudes toward nature: The effect of personal experiences

Regular engagement outside may promote healthy physical and psychological development as well as a respect and appreciation for nature. This exploratory study compared biophilia and attitudes toward nature between young children living in an urban area to those in a rural area. Urban and rural areas may offer different opportunities for exposure and engagement with elements such as water, plants, and animals. A comparison between young children in these settings may determine if experience in these different environments affects their attitudes and biophilia. Thirty-six children (urban n = 27; rural n = 9) participated in one-on-one structured interviews about their attitudes toward and being in nature. Results revealed no significant difference in biophilia between children by geographical area. Common themes in children’s attitudes emerged: 1) young children define nature by identifying specific elements; 2) young children are aware that their actions have consequences for the condition of the natural environment; and 3) children understood that the expectations guiding behavior in the natural environment apply to everyone. Preschool children’s level of cognitive maturity and individual preferences may be better predictors of biophilia and attitude than location alone. Authors suggest implications for teachers and parents

Magnetic Resonance Spectroscopy discriminates the response to microglial stimulation of wild type and Alzheimer's disease models.

Microglia activation has emerged as a potential key factor in the pathogenesis of Alzheimers disease. Metabolite levels assessed by magnetic resonance spectroscopy (MRS) are used as markers of neuroinflammation in neurodegenerative diseases, but how they relate to microglial activation in health and chronic disease is incompletely understood. Using MRS, we monitored the brain metabolic response to lipopolysaccharides (LPS)-induced microglia activation in vivo in a transgenic mouse model of Alzheimers disease (APP/PS1) and healthy controls (wild-type (WT) littermates) over 4 hours. We assessed reactive gliosis by immunohistochemistry and correlated metabolic and histological measures. In WT mice, LPS induced a microglial phenotype consistent with activation, associated with a sustained increase in macromolecule and lipid levels (ML9). This effect was not seen in APP/PS1 mice, where LPS did not lead to a microglial response measured by histology, but induced a late increase in the putative inflammation marker myoinositol (mI) and metabolic changes in total creatine and taurine previously reported to be associated with amyloid load. We argue that ML9 and mI distinguish the response of WT and APP/PS1 mice to immune mediators. Lipid and macromolecule levels may represent a biomarker of activation of healthy microglia, while mI may not be a glial marker