bluuebunny/crossref_metadata_2025_split huggingface dataset:
Community voices: barriers and opportunities for programmes to successfully prevent vertical transmission of HIV identified through consultations among people living with HIV
Authors: Anderson Ginna , Caswell Georgina , Edwards Olive , Hsieh Amy , Hull Beri , Mallouris Christoforos , Mason Naisiadet , Nöstlinger Christiana 
Published: July 2012

IntroductionIn 2010, two global networks of people living with HIV, the International Community of Women Living with HIV (ICW Global) and the Global Network of People living with HIV (GNP +) were invited to review a draft strategic framework for the global scale up of prevention of vertical transmission (PVT) through the primary prevention of HIV and the prevention of unintended pregnancies among women living with HIV. In order to ensure recommendations were based on expressed needs of people living with HIV, GNP+ and ICW Global undertook a consultation amongst people living with HIV which highlighted both facilitators and barriers to prevention services. This commentary summarizes the results of that consultation.DiscussionThe consultation was comprised of an online consultation (moderated chat‐forum with 36 participants from 16 countries), an anonymous online e‐survey (601 respondents from 58 countries), and focus‐group discussions with people living with HIV in Jamaica (27 participants). The consultation highlighted the discrepancies across regions with respect to access to essential packages of PVT services. However, the consultation participants also identified common barriers to access, including a lack of trustworthy sources of information, service providers' attitudes, and gender‐based violence. In addition, participant responses revealed common facilitators of access, including quality counselling on reproductive choices, male involvement, and decentralized services.ConclusionsThe consultation provided some understanding and insight into the participants' experiences with and recommendations for PVT strategies. Participants agreed that successful, comprehensive PVT programming require greater efforts to both prevent primary HIV infection among young women and girls and, in particular, targeted efforts to ensure that women living with HIV and their partners are supported to avoid unintended pregnancies and to have safe, healthy pregnancies instead. In addition to providing the insights into prevention services discussed above, the consultation served as a valuable example of the meaningful involvement of people living with HIV in programming and implementation to ensure that programs are tailored to individuals' needs and to circumvent rights abuses within those settings.
Axial velocity gradient effects in tubular loop polymerization reactors
Authors: Zheng Tao , Jiang Chong‐wen , Luo Zheng‐hong 
Published: July 2012

ABSTRACTGenerally, a comprehensively distributed reactor model must incorporate a momentum balance equation to calculate velocity gradient. However, the momentum balance equation also leads to the increasing complexity of the reactor model, which was neglected in previous works. In this work, issues whether the velocity gradient can be neglected or not are addressed. On the basis of mass, energy and momentum balances, polymerization kinetics as well as the thermodynamic state equations, two dynamically distributed reactor models either considering or neglecting axial velocity gradient are presented to examine its effect in tubular loop polymerization reactors. The results indicate that the axial velocity gradient has an important effect on the reactor flow‐field parameters (i.e. propylene concentration, catalyst concentration, hydrogen concentration, polypropylene concentration, temperature and pressure) at low recycle ratios (Rec < 50) and its effect on these aforementioned parameters can be neglected yet at high recycle ratios (Rec ≥ 50). Namely, herein, we suggest that the momentum balance equation must be incorporated into the reactor model at Rec < 50 and it can be neglected for the reactor model at Rec ≥ 50, which is helpful to the distributed modeling of the tubular loop polymerization reactor. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.
Correlated set coordination in fault tolerant message logging protocols for many‐core clusters
Authors: Bouteiller Aurelien , Herault Thomas , Bosilca George , Dongarra Jack J. 
Published: July 2012

SUMMARYWith our current expectation for the exascale systems, composed of hundred of thousands of many‐core nodes, the mean time between failures will become small, even under the most optimistic assumptions. One of the most scalable checkpoint restart techniques, the message logging approach, is the most challenged when the number of cores per node increases because of the high overhead of saving the message payload. Fortunately, for two processes on the same node, the failure probability is correlated, meaning that coordinated recovery is free. In this paper, we propose an intermediate approach that uses coordination between correlated processes but retains the scalability advantage of message logging between independent ones. The algorithm still belongs to the family of event logging protocols but eliminates the need for costly payload logging between coordinated processes. Copyright © 2012 John Wiley & Sons, Ltd.
Strength of density feedback in census data increases from slow to fast life histories
Authors: Herrando‐Pérez Salvador , Delean Steven , Brook Barry W. , Bradshaw Corey J. A. 
Published: July 2012

AbstractLife‐history theory predicts an increasing rate of population growth among species arranged along a continuum from slow to fast life histories. We examine the effects of this continuum on density‐feedback strength estimated using long‐term census data from >700 vertebrates, invertebrates, and plants. Four life‐history traits (Age at first reproduction, Body size, Fertility, Longevity) were related statistically to Gompertz strength of density feedback using generalized linear mixed‐effects models and multi‐model inference. Life‐history traits alone explained 10 to 30% of the variation in strength across species (after controlling for time‐series length and phylogenetic nonindependence). Effect sizes were largest for body size in mammals and longevity in birds, and density feedback was consistently stronger for smaller‐bodied and shorter‐lived species. Overcompensatory density feedback (strength <−1) occurred in 20% of species, predominantly at the fast end of the life‐history continuum, implying relatively high population variability. These results support the idea that life history leaves an evolutionary signal in long‐term population trends as inferred from census data. Where there is a lack of detailed demographic data, broad life‐history information can inform management and conservation decisions about rebound capacity from low numbers, and propensity to fluctuate, of arrays of species in areas planned for development, harvesting, protection, and population recovery.
Intermolecular hydrogen bond energies in crystals evaluated using electron density properties: DFT computations with periodic boundary conditions
Authors: Vener M. V. , Egorova A. N. , Churakov A. V. , Tsirelson V. G. 
Published: July 2012

AbstractThe hydrogen bond (H‐bond) energies are evaluated for 18 molecular crystals with 28 moderate and strong OH···O bonds using the approaches based on the electron density properties, which are derived from the B3LYP/6‐311G** calculations with periodic boundary conditions. The approaches considered explore linear relationships between the local electronic kineticGband potentialVbdensities at the H···O bond critical point and the H‐bond energyEHB. Comparison of the computedEHBvalues with the experimental data and enthalpies evaluated using the empirical correlation of spectral and thermodynamic parameters (Iogansen, Spectrochim. Acta Part A1999,55, 1585) enables to estimate the accuracy and applicability limits of the approaches used. TheVb−EHBapproach overestimates the energy of moderate H‐bonds (EHB< 60 kJ/mol) by ∼20% and gives unreliably high energies for crystals with strong H‐bonds. On the other hand, theGb−EHBapproach affords reliable results for the crystals under consideration. The linear relationship betweenGbandEHBis basis set superposition error (BSSE) free and allows to estimate the H‐bond energy without computing it by means of the supramolecular approach. Therefore, for the evaluation of H‐bond energies in molecular crystals, theGbvalue can be recommended to be obtained from both density functional theory (DFT) computations with periodic boundary conditions and precise X‐ray diffraction experiments. © 2012 Wiley Periodicals, Inc.
Transparent Hydrophilic Materials Containing Covalently Attached Phthalimide Azo Dyes
Authors: Maatz Gero , Ritter Helmut 
Published: July 2012

AbstractThe synthesis of the new yellow and red polymerizable azo dyes 1‐[4‐(N,N‐dimethylaminophenyl)azo]‐4‐phthalimidopropylmethacrylate (9) and 2‐(4‐methylphenol)azo‐4‐phthalimidopropylmethacrylate (10) that are based on phthalimide derivates is described. The polymerization and crosslinking of the (meth)acrylated dyes are carried out. The covalent attachment and crosslinking properties of the dyes are proven by swelling and extraction with H2O/EtOH. A potential application of those polymerizable dyes for development of optical clear materials, for example, in the area of ophthalmology, is discussed.
Maximum carbonyl‐coordination number of scandium Computational study of Sc(CO)n (n = 1–7), Sc(CO)7− and Sc(CO)63−
Authors: Gao Si‐Meng , Guo Wen‐Ping , Jin Lin , Ding Yi‐Hong 
Published: July 2012

AbstractUnderstanding the maximum bonding ability is very important with the potential both to design new compounds and to broaden chemists' imagination. While the coordination ability of the late transition metals has been richly understood, that of scandium is very poor. In this work, a detailed computational study on the equilibrium geometries, stability and vibrational frequencies of a series of Sc(CO)n (n = 1–7), Sc(CO) and Sc(CO) is reported using density functional theory functionals and the coupled cluster (single‐point) method with 6‐311+G(3df) basis set. It was shown that the obtained sequential and average CO binding energies of Sc(CO)n (n = 4–7), Sc(CO) and Sc(CO) are comparable to those of the experimentally known species, i.e., smaller Sc‐carbonyls (n ≤3) and the analog Ti(CO)7+. Thus, the studied high scandium carbonyls could all be experimentally accessible. In addition, the studied Sc(CO)n generally favor the low‐spin ground state (doublet) structures except ScCO and Sc(CO)3 that are in the quartet states. The previously uncertain spectrum bands were assigned to Sc(CO)4 and Sc(CO)5 in this work. In all, the appreciable stability suggested that the last 18‐electron first‐row transition metal carbonyls, that is, Sc(CO) and Sc(CO), could be accessible in experiment. © 2013 Wiley Periodicals, Inc.
Exchange, correlation, and the effective mass m* of electrons in two‐dimensional layers calculated via a DFT‐based classical map
Authors: Dharma‐wardana M. W. C. 
Published: July 2012

AbstractDensity functional theory uses the electron density n(r), instead of the electronic wavefunction. We side‐step the kinetic energy functional by constructing a thermodynamically equivalent classical map (CM). A classical Coulomb fluid whose zeroth‐order pair‐distribution function (PDF) g0(r) that agrees with the quantum g0, and interacting via a “Pauli exclusion potential” reproduces the thermodynamics of the electron fluid, when the classical‐fluid temperature Tcf is chosen optimally. This Tcf is chosen so that the correlation energy of the classical fluid is the Kohn–Sham correlation energy. Then, the PDFs of the classical fluid closely agree with the PDFs of the two‐dimensional (2D) and 3D uniform electron systems. Can we calculate sensitive Fermi‐liquid properties (e.g., quasiparticle mass m*, Landé g‐factor) of interacting electrons via this CM? Given the wide interest in the effective mass m* of electrons in 2D layers, we chose the 2D system for this study. Analytical and numerical results are used to define a partially regularized m* valid to logarithmic accuracy in the sense of Landau for the Hartree–Fock (H–F) approximation. The resulting H–F m* decreases linearly with the electron‐disk radius rs. The m* including correlation is calculated via a physically transparent formula. This uses the CM of the 2D PDF and its finite‐T exchange‐correlation free energy Fxc(T). Our results for m* fall well within the results from recent quantum Monte‐Carlo simulations at T = 0, and other theoretical and experimental results. © 2012 Wiley Periodicals, Inc.
Molecular modeling of bioactive neuropeptides: Substrates of angiotensin I‐converting enzyme
Authors: dos Santos Luísa Silva Nangi , Sonoda Milton Taidi , Gomes Roseli Aparecida da Silva , Abrahão Odonírio 
Published: July 2012

AbstractAngiotensin I (Ang‐I)‐converting enzyme (ACE) is a chloride‐dependent zinc metallopeptidase that is important in the regulation of cardiovascular functions. In addition to Ang‐I and bradykinin, ACE is able to cleave several other peptides, such as neurotensin (NT), substance P, and Angiotensin‐(1‐7) (Ang‐1‐7). We have investigated by computational methods the structural and dynamical similarities among these peptides that could be responsible to their molecular recognition by ACE. Conformational and clustering analyses, semiempirical, and density functional theory calculations were performed; in addition, molecular dynamics (MD) simulations of Ang‐1‐7 both in pure water and in saline conditions were undertaken. Backbones folding pattern between the conformers of each peptide was very similar, mainly sustained by noncovalent interactions, denoting high conservation of the cleavage site. Also, cleavage site showed high folding similarity between the three different substrates and could mean a structural pattern. Highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital showed no pattern between the substrates; however, NT‐(8‐13) HOMO is located at the cleavage site. MD studies showed that Ang‐(1‐7) has faster relaxation in saline system and less content of intramolecular hydrogen bonds, which could explain the higher cleavage activity of this peptide by ACE in such conditions. © 2012 Wiley Periodicals, Inc.
Introduction to manifold learning
Authors: Izenman Alan Julian 
Published: July 2012

AbstractA popular research area today in statistics and machine learning is that of manifold learning, which is related to the algorithmic techniques of dimensionality reduction. Manifold learning can be divided into linear and nonlinear methods. Linear methods, which have long been part of the statistician's toolbox for analyzing multivariate data, include principal component analysis (PCA) and multidimensional scaling (MDS). Recently, there has been a flurry of research activity on nonlinear manifold learning, which includes Isomap, local linear embedding, Laplacian eigenmaps, Hessian eigenmaps, and diffusion maps. Some of these techniques are nonlinear generalizations of the linear methods. The algorithmic process of most of these techniques consists of three steps: a nearest‐neighbor search, a definition of distances or affinities between points (a key ingredient for the success of these methods), and an eigenproblem for embedding high‐dimensional points into a lower dimensional space. This article gives us a brief survey of these new methods and indicates their strengths and weaknesses. WIREs Comput Stat 2012 doi: 10.1002/wics.1222This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Dimension Reduction
Statistical Learning and Exploratory Methods of the Data Sciences > Manifold Learning
Statistical and Graphical Methods of Data Analysis > Multivariate Analysis
Computational biology perspective: kernel methods and deep learning
Authors: Lodhi Huma 
Published: July 2012

AbstractThe field of machine learning provides useful means and tools for finding accurate solutions to complex and challenging biological problems. In recent years a class of learning algorithms namely kernel methods has been successfully applied to various tasks in computational biology. In this article we present an overview of kernel methods and support vector machines and focus on their applications to biological sequences. We also describe a new class of approaches that is termed as deep learning. These techniques have desirable characteristics and their use can be highly effective within the field of computational biology. WIREs Comput Stat 2012 doi: 10.1002/wics.1223This article is categorized under:

Applications of Computational Statistics > Computational and Molecular Biology
Statistical Learning and Exploratory Methods of the Data Sciences > Neural Networks
Statistical Learning and Exploratory Methods of the Data Sciences > Support Vector Machines
Fetal and maternal hemodynamics in acute malaria during pregnancy
Authors: Rulisa Stephen , Kaligirwa Nadine , Agaba Steven , Karangayire Placide , Mens Petra F. , de Vries Peter J. 
Published: July 2012

AbstractObjectiveTo measure maternal and fetal hemodynamics during acute malaria in pregnancy.MethodsTime courses of maternal heart rate (MHR), maternal blood pressure (BP), and fetal heart rate (FHR) were performed until 56 days after initiation of anti‐malarial treatment with artemether–lumefantrine. Women with malaria were hospitalized for at least 3 days until recovery.ResultsMean baseline characteristics of pregnant women with malaria (n = 38) versus pregnant women without malaria (n = 39) were as follows: gestational age (28.8 vs 24.6 weeks; P = 0.006); maximum FHR (165.3 vs 158.3 beats per minute [bpm]; P = 0.054); minimum FHR (137.6 vs 128.7 bpm; P = 0.016); mean BP (74.7 vs 80.9 mm Hg; P = 0.001); pulse pressure (40.3 vs 42.1 mm Hg; P = 0.300); and MHR (107.4 vs 81.3 bpm; P < 0.001). The geometric mean parasite count was 13 795 per μL. Complete time courses were collected from a subgroup of participants. For women with malaria, maternal body temperature and BP normalized within 24 hours and after 72 hours, respectively. The MHR among pregnant women without malaria showed a physiologic increase during pregnancy of approximately 7 bpm between days 0 and 56. The mean FHR among women with malaria normalized after 72 hours.ConclusionAcute malaria induces maternal and fetal hemodynamic changes.
The association between phthalate exposure and asthma
Authors: Tsai Ming‐Ju , Kuo Po‐Lin , Ko Ying‐Chin 
Published: July 2012

AbstractAsthma is a chronic inflammatory disorder of the airway, characterized by airway hyperresponsiveness. It is a disabling disease with an increasing prevalence, resulting in heavy social and economic burdens worldwide. Humans are extensively exposed to phthalates, and many epidemiological studies have shown a relationship between phthalate exposure and asthma in recent decades. Earlier experimental studies focused on inflammatory cells, demonstrating the adjuvant effects, immunomodulatory effects, or immunosuppressive effects related to phthalate exposure. Recent studies have shown that phthalates may have a direct effect on airway epithelial cells and contribute to airway remodeling, which is the cardinal pathologic characteristic of chronic asthma, with a high correlation with disease severity. Through these efforts, phthalates have been recognized as important environmental factors in the pathogenesis of asthma, but further studies are still required to elucidate the detailed mechanism. This review discusses the current status of human exposure to phthalates in Taiwan and summarizes the epidemiological and experimental evidence related to the roles of phthalate exposure in the development of asthma and associated diseases.
Stability of biomimetic membranes in DC electric fields
Authors: Seiwert Jacopo , Miksis Michael J. , Vlahovska Petia M. 
Published: July 2012

AbstractThe interface defining a biological cell is a thin membrane, which acts as a leaky capacitor. We investigate the influence of capacitance and conductivity on the stability of a planar membrane subjected to a DC electric field. We develop a zero-thickness model of the membrane, in which the bilayer finite thickness is effectively accounted for by membrane electro-mechanical properties such as bending modulus, capacitance and conductance. The linear stability analysis shows that membrane conductance and asymmetry in the embedding electrolyte solutions destabilize the interface. However, the capacitive charging acts to stabilize the system under conditions where an ordinary fluid–fluid interface is unstable.
Tropical cyclogenesis and vertical shear in a moist Boussinesq model
Authors: Deng Qiang , Smith Leslie , Majda Andrew 
Published: July 2012

AbstractTropical cyclogenesis is studied in the context of idealized three-dimensional Boussinesq dynamics with perhaps the simplest possible model for bulk cloud physics. With low-altitude input of water vapour on realistic length and time scales, numerical simulations capture the formation of vortical hot towers. From measurements of water vapour, vertical velocity, vertical vorticity and rain, it is demonstrated that the structure, strength and lifetime of the hot towers are similar to results from models including more detailed cloud microphysics. The effects of low-altitude vertical shear are investigated by varying the initial zonal velocity profile. In the presence of weak low-level vertical shear, the hot towers retain the low-altitude monopole cyclonic structure characteristic of the zero-shear case (starting from zero velocity). Some initial velocity profiles with small vertical shear can have the effect of increasing cyclonic predominance of individual hot towers in a statistical sense, as measured by the skewness of vertical vorticity. Convergence of horizontal winds in the atmospheric boundary layer is mimicked by increasing the frequency of the moisture forcing in a horizontal subdomain. When the moisture forcing is turned off, and again for zero shear or weak low-level shear, merger of cyclonic activity results in the formation of a larger-scale cyclonic vortex. An effect of the shear is to limit the vertical extent of the resulting emergent moist vortex. For stronger low-altitude vertical shear, the individual hot towers have a low-altitude vorticity dipole rather than a cyclonic monopole. The dipoles are not conducive to the formation of larger-scale vortices, and thus sufficiently strong low-level shear prevents the vortical-hot-tower route to cyclogenesis. The results indicate that the simplest condensation and evaporation schemes are useful for exploratory numerical simulations aimed at better understanding of competing effects such as low-level moisture and vertical shear.