190 research outputs found
How Multivalency controls Ionic Criticality
To understand how multivalency influences the reduced critical temperatures,
Tce (z), and densities, roce (z), of z : 1 ionic fluids, we study equisized
hard-sphere models with z = 1-3. Following Debye, Hueckel and Bjerrum,
association into ion clusters is treated with, also, ionic solvation and
excluded volume. In good accord with simulations but contradicting
integral-equation and field theories, Tce falls when z increases while roce
rises steeply: that 80-90% of the ions are bound in clusters near T_c serves to
explain these trends. For z \neq 1 interphase Galvani potentials arise and are
evaluated.Comment: 4 pages, 4 figure
Expression of aldehyde dehydrogenase family 1, member A3 in glycogen trophoblast cells of the murine placenta
Introduction: Retinoic acid (RA) signaling is a well known regulator of trophoblast differentiation and placental development, and maternal decidual cells are recognized as the source of much of this RA. We explored possible trophoblast-derived sources of RA by examining the expression of RA synthesis enzymes in the developing mouse placenta, as well as addressed potential sites of RA action by examining the ontogeny of gene expression for other RA metabolizing and receptor genes. Furthermore, we investigated the effects of endogenous RA production on trophoblast differentiation
Alcohol exposure impairs trophoblast survival and alters subtype-specific gene expression in vitro
Maternal alcohol consumption is common prior to pregnancy recognition and in the rat results in altered placental development and fetal growth restriction. To assess the effect of ethanol (EtOH) exposure on the differentiation of trophoblast stem (TS) cells, mouse TS lines were differentiated in vitro for 6 days in 0%, 0.2% or 1% EtOH. This reduced both trophoblast survival and expression of labyrinth and junctional zone trophoblast subtype-specific genes. This suggests that fetal growth restriction and altered placental development associated with maternal alcohol consumption in the periconceptional period could be mediated in part by direct effects on trophoblast development. (C) 2016 Elsevier Ltd. All rights reserved
Charge Oscillations in Debye-Hueckel Theory
The recent generalized Debye-Hueckel (GDH) theory is applied to the
calculation of the charge-charge correlation function G_{ZZ}(r). The resulting
expression satisfies both (i) the charge neutrality condition and (ii) the
Stillinger-Lovett second-moment condition for all T and rho_N, the overall ion
density, and (iii) exhibits charge oscillations for densities above a "Kirkwood
line" in the (rho_N,T) plane. This corrects the normally assumed DH
correlations, and, when combined with the GDH analysis of the density
correlations, leaves the GDH theory as the only complete description of ionic
correlation functions, as judged by (i)-(iii), (iv) exact low-density (rho_N,T)
variation, and (v) reasonable behavior near criticality.Comment: 6 pages, EuroPhys.sty (now available on archive), 1 eps figur
Field-theoretic description of ionic crystallization in the restricted primitive model
Effects of charge-density fluctuations on a phase behavior of the restricted
primitive model (RPM) are studied within a field-theoretic formalism. We focus
on a -line of continuous transitions between charge-ordered and
charge-disordered phases that is observed in several mean-field (MF) theories,
but is absent in simulation results. In our study the RPM is reduced to a
theory, and a fluctuation contribution to a grand thermodynamic
potential is obtained by generalizing the Brazovskii approach. We find that in
a presence of fluctuations the -line disappears. Instead, a
fluctuation-induced first-order transition to a charge-ordered phase appears in
the same region of a phase diagram, where the liquid -- ionic-crystal
transition is obtained in simulations. Our results indicate that the
charge-ordered phase should be identified with an ionic crystal.Comment: 31 pages, 10 figure
The making of European society: contesting methodological nationalism
The paper is concerned with the problem of ‘society’ and in particular with the notion of ‘European society.’ Rather than reject the possibility of society, it draws on theories of the social as networks. The thesis proposed is that the concept of society should rather be understood as a relational field of interconnections. It is argued that this is highly relevant to the analysis of Europe conceived of in terms of a society. This approach can be seen as an alternative to methodological nationalism. The paper applies a network conception of society to Europe with the emphasis on the on the nineteenth century. In this account, European society is not something that was produced by European integration. Rather than see European society as a recent development, it is argued that the field of tensions between capitalism and democracy constituted the major elements that shaped a European model of society
Mesoscopic theory for size- and charge- asymmetric ionic systems. I. Case of extreme asymmetry
A mesoscopic theory for the primitive model of ionic systems is developed for
arbitrary size, , and charge, ,
asymmetry. Our theory is an extension of the theory we developed earlier for
the restricted primitive model. The case of extreme asymmetries
and is studied in some detail in a mean-field
approximation. The phase diagram and correlation functions are obtained in the
asymptotic regime and , and for infinite
dilution of the larger ions (volume fraction or less). We find a
coexistence between a very dilute 'gas' phase and a crystalline phase in which
the macroions form a bcc structure with the lattice constant . Such coexistence was observed experimentally in deionized aqueous
solutions of highly charged colloidal particles
Hydration interactions: aqueous solvent effects in electric double layers
A model for ionic solutions with an attractive short-range pair interaction
between the ions is presented. The short-range interaction is accounted for by
adding a quadratic non-local term to the Poisson-Boltzmann free energy. The
model is used to study solvent effects in a planar electric double layer. The
counter-ion density is found to increase near the charged surface, as compared
with the Poisson-Boltzmann theory, and to decrease at larger distances. The ion
density profile is studied analytically in the case where the ion distribution
near the plate is dominated only by counter-ions. Further away from the plate
the density distribution can be described using a Poisson-Boltzmann theory with
an effective surface charge that is smaller than the actual one.Comment: 11 Figures in 13 files + LaTex file. 20 pages. Accepted to Phys. Rev.
E. Corrected typos and reference
European Permanent Grasslands: A Systematic Review of Economic Drivers of Change, Including a Detailed Analysis of the Czech Republic, Spain, Sweden, and UK
\ua9 2024 by the authors. Permanent grasslands (PG) feature in the European rural landscape and represent a major agricultural production resource. They support multiple non-provisioning ecosystem services (ES), including climate regulation, flood control, biodiversity, and pollination. PG are at risk of loss or degradation due to agricultural land use and land management changes. The objective of this systematic review is to identify the main economic influences shaping management and maintenance of PG, and the risks and opportunities for delivery of a range of ES. A total of 51 papers were included. Relevant policy interventions and economic drivers are identified in relation to how they shape the management of EU grasslands over time and across farming systems, countries, or biogeographic zones. A high reliance on public payments from the EU Common Agricultural Policy (CAP), with uneven impact on mitigating PG losses and associated ES provisions, was identified, which needs to be considered in relation to ongoing CAP reform. There is a gap in the literature regarding economic tipping points for change. Future research needs to identify and map ES provisions by PG along with trade-offs and synergies, and link this to policy. There are substantive challenges to maintaining Europe’s PG area and management, which must be addressed through EU-wide instruments
Changing Fortunes: Criminology and the Sociological Condition
Criminology and its relationships with sociology are today at a crossroads, and this article explores the changing fortunes of each as they have evolved over the last 50 years. The separation has occurred as criminology has successfully established itself as an independent subject with an impressive ability to attract students, scholars and research grants. Some see the striking expansion of criminology and move away from the basic disciplines as an indication of success and impressive achievement, while others are more sceptical and highlight the costs such isolation brings. The article examines the consequences of these changes, then it focuses on the fates of some of the key concepts in sociological criminology, before concluding that social theory can be a unifying force, capable of reinvigorating the ties between the two disciplines
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