bluuebunny/crossref_metadata_2025 huggingface dataset:
μ3‐ vs. μ‐Hydroxido Bridges – Peripheral Function Controls the Nuclearity of Hydroxido‐Bridged Copper(II) Complexes
Authors: Chiboub Fellah Fatima Zohra , Costes Jean‐Pierre , Vendier Laure , Duhayon Carine , Ladeira Sonia , Tuchagues Jean‐Pierre
Published: October 2012

The synthesis and characterization of three monohydroxido‐bridged dinuclear CuII complexes, [{Cu2(L1)2(μ‐OH)}(ClO4){Cu2(L1)2(μ‐OH)}](ClO4)·5.5H2O (1), Cu2(L2)2(OH)(ClO4)(H2O)2 (2), [{Cu2(L3)2(μ‐OH)(ClO4)}2]·5H2O (3) and three monohydroxido‐bridged trinuclear CuII complexes, [Cu3(L4)3(μ3‐OMe)(ClO4)2] (4), [Cu3(L5)3(μ3‐OH) (ClO4)2]·0.5{(CH3)2CO}·0.5(H2O) (5), [Cu3(L6)3(μ3‐OH)(ClO4)2] (6), is reported (HL1–HL6 = tridentate N2O ligands resulting from the Schiff base condensation of salicylaldehyde or 3‐methoxysalicylaldehyde with ethylenediamine, 1,2‐diaminopropane, 2‐methylpropane‐1,2‐diamine or 1,2‐diaminocyclohexane). The six new complexes are obtained through aggregation of the corresponding mononuclear precursor Cu(Li)(py)(ClO4) in the presence of HO– (MeO–) anions in methanol. The nuclearity of the resulting complex depends on the steric requirement of Li: in the presence of an OMe substituent α to the Ophenoxido atom (L1–L3), μ‐HO– single‐bridged dinuclear compounds are obtained (1–3); in the absence of an α‐substituent (L4–L6), the aggregation proceeds to the μ3‐OH– (μ3‐OMe–) bridged trinuclear compounds 4–6. The molecular structures of 1, 3 and 4–6 have been established through single‐crystal X‐ray studies. Antiferromagnetic interactions operate in 1 (J = –57 cm–1, –2JS1S2 formalism), 2 is paramagnetic, and 3 is the first example of a ferromagnetic monohydroxido‐bridged dinuclear CuII complex (J = 16 cm–1). The structural and magnetic parameters for the 22 μ‐HO– single‐bridged dinuclear CuII compounds reported to date are compared. Antiferromagnetic interactions operate in all three monohydroxido‐bridged trinuclear CuII complexes 4, 5, and 6 (J = –16.9, –6.3, and –6.7 cm–1, respectively). The structural and magnetic parameters for the seven μ3‐hydroxido (methoxido) bridged trinuclear CuII compounds presently known in the series based on tridentate Schiff bases that result from condensation of diamines with salicylaldehydes are compared.
Large floods, alluvial overprint, and bedrock erosion
Authors: Turowski Jens M. , Badoux Alexandre , Leuzinger James , Hegglin Ramon
Published: October 2012

Depending on their behaviour during extreme floods, streams can be divided into two distinct classes, which derive from a simple threshold model of transport dynamics. ‘Flood‐cleaning’ streams erode during high flows and deposit during small and medium flows. ‘Flood‐depositing’ streams deposit during high flows and erode during small and medium flows. Using published descriptions of the geomorphic effects of large floods, rivers with a wide range of drainage areas and other characteristics are classified as either ‘flood‐cleaning’ or ‘flood‐depositing’. In bedrock channels, this behaviour can lead to a feedback effect, the ‘overprint effect’, between sediment transport processes and bedrock erosion, which can modulate long‐term bedrock erosion rates. The ‘overprint effect’ arises when alluvium covers the bedrock and typical alluvial channel forms (e.g. meandering or braiding patterns, armour layers or bedforms) develop, which influence sediment transport rates. This effect may accelerate or decelerate sediment export from a reach, causing increased or decreased long‐term bedrock erosion rates. The ‘overprint effect’ is illustrated using field data from the Erlenbach, Switzerland, and its implications for channel dynamics and bedrock erosion are discussed. Copyright © 2012 John Wiley & Sons, Ltd.
Distribution and properties of soft weathered bedrock at ≤ 1 m depth in the contiguous United States
Authors: Wald Jonathan A. , Graham Robert C. , Schoeneberger Phillip J.
Published: October 2012

The weathered bedrock zone is increasingly recognized as an important part of ecological and hydrologic systems, but its distribution is poorly known in the contiguous United States. We used spatial and laboratory characterization data from the US Department of Agriculture (USDA)‐Natural Resources Conservation Service to assess the distribution and soil‐like properties of soft weathered bedrock (saprock and saprolite) within the 48 contiguous United States. Because USDA soil inventories generally do not extend below 2 m, and because the upper 1 m is clearly involved in ecosystem function and vadose zone hydrology, we restricted our inquiry to soft weathered bedrock within 1 m of the land surface. Soft weathered bedrock within 1 m of the land surface is widespread throughout the contiguous United States, underlying at least 6% of the land area. In‐depth analysis of three states showed that soft weathered bedrock at the ≤ 1‐m depth underlies 22% of the total land area in California, 33% in Wyoming, and 18% in North Carolina. Soft weathered bedrock hosts pedogenic activity, as indicated by morphological features such as roots, clay films, and iron (Fe)‐/manganese (Mn)‐oxide concretions recorded in pedon descriptions in the database. The physical and chemical properties of soft weathered bedrock are often similar to those of the overlying soil, suggesting that in many respects soft weathered bedrock behaves like soil. It supplies water and nutrients to plants whose roots penetrate into it and it modulates throughflow runoff to streams. For a more complete understanding of soft weathered bedrock, systematic data are needed on its thickness across landscapes and a consistent terminology for its various forms needs to be adopted and widely used. Copyright © 2012 John Wiley & Sons, Ltd.
Diversity and conservation of Philodendron Schott (Araceae) in Atlantic Forest of Rio de Janeiro State, Brazil
Authors: Sakuragui Cassia Mônica , Luana Silva Braucks Calazans  , Barroso de Morais Érica , Nadruz Coelho Marcus Alberto , Octávio de Oliveira Pellegrini Marco
Published: October 2012

The study presents a new and expanded treatment of the taxonomy, diversity and conservation status of all species of the genus Philodendron Schott (Araceae) so far discovered in Rio de Janeiro State, Southeastern Brazil. It contributes to taxonomic and biological knowledge of the humid flora of the Brazilian Atlantic Forest, a globally recognized hotspot of biodiversity. The taxonomic treatment is based on 60 field collecting expeditions carried out since 2006, mainly in Southeastern Brazil, and the study of over 2200 herbarium specimens. Twenty eight species are recognized and their morphological descriptions, nomenclature and typification of relevant names are given. Lectotypes are designated for fourteen names, neotypes are designated for two names and epitypes for twelve names. Illustrations of all species are provided, together with a key and information on habitat and phenology for each species. The evaluations of the conservation status of the species were based on field observations, specialist literature, information from herbarium specimens and lists of endangered species. Evaluations of 16 of the 28 species found in Rio de Janeiro State are presented for the first time here and revised evaluations are presented for another six (P. altomacaense, P. cordatum, P. inops, P. hastatum, P. hatschbachii, P. roseopetiolatum) (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
One‐dimensional shock‐capturing for high‐order discontinuous Galerkin methods
Authors: Casoni E. , Peraire J. , Huerta A.
Published: October 2012

Discontinuous Galerkin methods have emerged in recent years as an alternative for nonlinear conservation equations. In particular, their inherent structure (a numerical flux based on a suitable approximate Riemann solver introduces some stabilization) suggests that they are specially adapted to capture shocks. However, numerical fluxes are not sufficient to stabilize the solution in the presence of shocks. Thus, slope limiter methods, which are extensions of finite volume methods, have been proposed. These techniques require, in practice, mesh adaption to localize the shock structure. This is is more obvious for large elements typical of high‐order approximations. Here, a new approach based on the introduction of artificial diffusion into the original equations is presented. The order is not systematically decreased to one in the presence of the shock, large high‐order elements can be used, and several linear and nonlinear tests demonstrate the efficiency of the proposed methodology. Copyright © 2012 John Wiley & Sons, Ltd.
Mechanical and suboptimal pharmacologic prophylaxis and delayed mobilization but not morbid obesity are associated with venous thromboembolism after total knee arthroplasty: A case‐control study
Authors: Sadeghi Banafsheh , Romano Patrick S. , Maynard Gregory , Strater Amy L. , Hensley Laurie , Cerese Julie , White Richard H.
Published: October 2012

BACKGROUND:

The FDA‐approved dose of low‐molecular‐weight heparin (LMWH) may not provide adequate thromboprophylaxis in morbidly obese patients after total knee arthroplasty (TKA). Suboptimal dosing, delayed initiation, and overreliance on mechanical methods may also limit the effectiveness of thromboprophylaxis.

OBJECTIVE:

We explored the associations between the type of thromboprophylaxis, obesity, time of mobilization, and undergoing bilateral TKA on development of symptomatic venous thromboembolism (VTE) after TKA.

DESIGN/SETTING/PATIENTS:

This was a case‐control study of patients undergoing TKA in 15 teaching hospitals between October 2008 and March 2010. Cases were screened using the Agency for Healthcare Research and Quality's Patient Safety Indicator 12 and had objectively documented acute VTE within 9 days of surgery; controls were randomly selected from the same hospital. Multivariable logistic regression was used to analyze risk factors for postoperative VTE, adjusted for age and gender.

RESULTS:

Among 130 cases with and 463 controls without acute VTE, body mass index (BMI) ranged from 17 to 61 (median = 34). Thromboprophylaxis was LMWH in 284 (48%), warfarin in 189 (32%), both in 55 (10%), and mechanical prophylaxis alone in 120 (20%). Overall, 77% ambulated on day 1 or 2 after surgery. Factors significantly associated with VTE were bilateral simultaneous TKA (odds ratio [OR] = 4.2; 95% confidence interval [CI]: 1.9–9.1), receipt of FDA‐approved pharmacological prophylaxis (OR = 0.5; 95% CI: 0.3–0.8), and ambulation by postoperative day 2 (OR = 0.3; 95% CI: 0.1–0.9). Obesity was neither a significant confounder nor a modifier of these effects.

CONCLUSIONS:

Severe obesity was not a significant independent predictor for VTE and did not modify the beneficial effect of FDA‐approved pharmacological thromboprophylaxis. Bilateral TKA and failure to ambulate by the second day after surgery were significant risk factors. Journal of Hospital Medicine 2012. © 2012 Society of Hospital Medicine
Resource‐Light Approaches to Computational Morphology Part 1: Monolingual Approaches
Authors: Hana Jirka , Feldman Anna
Published: October 2012

This article surveys resource‐light monolingual approaches to morphological analysis and tagging. While supervised analyzers and taggers are very accurate, they are extremely expensive to create. Therefore, most of the world languages and dialects have no realistic prospect for morphological tools created in this way. The weakly‐supervised approaches aim to minimize time, expertise and/or financial cost needed for their development. We discuss the algorithms and their performance considering issues such as accuracy, portability, development time and granularity of the output.
Glycopolymers and Glyco‐nanoparticles in Biomolecular Recognition Processes and Vaccine Development
Authors: Sunasee Rajesh , Narain Ravin
Published: October 2012

With advances in polymerization techniques as well as selective chemical modification of carbohydrates, glycopolymers and glyco‐nanoparticles are emerging as an important class of materials with tailored properties or novel nanotechnology‐based platforms for a number of applications. The field of the so‐called glyco‐nanotechnology is starting to show some promises for future clinical applications. Glyco‐nanoparticles, due to their versatile nature, could offer a platform for the design of carbohydrate‐based vaccines and possibly allow the development of new single‐dose vaccines in disease areas of unmet need. This paper surveys the emerging roles of carbohydrate‐based polymeric and nanomaterials for biomolecular recognition processes and vaccine development.

magnified image
Functionalized Polystyrene Nanoparticles Trigger Human Dendritic Cell Maturation Resulting in Enhanced CD4+ T Cell Activation
Authors: Frick Stefanie U. , Bacher Nicole , Baier Grit , Mailänder Volker , Landfester Katharina , Steinbrink Kerstin
Published: October 2012

Nanoparticles (NP) represent a promising tool for biomedical applications. Here, sulfonate‐ and phosphonate‐functionalized polystyrene NP are analyzed for their interaction with human monocyte‐derived dendritic cells (DC). Immature dendritic cells (iDC) display a higher time‐ and dose‐dependent uptake of functionalized polystyrene NP compared to mature dendritic cells (mDC). Notably, NP induce an enhanced maturation of iDC but not of mDC (upregulation of stimulatory molecules and cytokines). NP‐triggered maturation results in a significantly enhanced T cell stimulatory capacity (increased CD4+ T cell proliferation and IFN‐γ production), indicating a shift to a pronounced Th1 response. Immunomodulatory properties of NP may be a useful strategy for strengthening the efficacy of NP‐based approaches in immunotherapy.

magnified image
Cognitive training for children: Effects on inductive reasoning, deductive reasoning, and mathematics achievement in an Australian school setting
Authors: BARKL SOPHIE , PORTER AMY , GINNS PAUL
Published: October 2012

Inductive reasoning is a core cognitive process of fluid intelligence, predicting a variety of educational outcomes. The Cognitive Training for Children (CTC) program is an educational intervention designed to develop children's inductive reasoning skills, with previous investigations finding substantial effects of the program on both inductive reasoning ability and classroom learning. The present study assessed both individual and small‐group CTC training against a no‐treatment control condition to investigate the effects on inductive and deductive reasoning and mathematics achievement in a primary school‐aged Australian cohort. Students who received individual training outperformed those in the control condition on measures of inductive and deductive reasoning, and those in the small‐group condition also outperformed the control condition on a measure of inductive reasoning 3 months following training. However, hypotheses regarding transfer effects to mathematics achievement were not supported. Directions for future research, focusing on extended longitudinal studies and motivational variables, are discussed.
MiTexCube: MicroTextCluster Cube for online analysis of text cells and its applications
Authors: Zhang Duo , Zhai ChengXiang , Han Jiawei
Published: October 2012

A fundamental problem of multidimensional text database analysis is efficient and effective support of various kinds of online applications, such as summarizing the content of a text cell or comparing the contents across multiple text cells. In this paper, we propose a new infrastructure called MicroTextCluster Cube (or MiTexCube) to support efficient online text analysis on multidimensional text databases by introducing micro‐clusters of text documents as a compact representation of text content. Experimental results on real multidimensional text databases show that (i) MiTexCube can be materialized efficiently with reasonable overhead in space, and (ii) applications based on the proposed materialized MiTexCube are more efficient than the baseline method of direct analysis based on document units in each cell, without sacrificing much quality of analysis, and MiTexCube naturally accommodates flexible trade‐off between efficiency and quality of analysis. © 2012 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 6: 243–259, 2013
A goodness‐of‐fit test for the proportional odds regression model
Authors: Fagerland Morten W. , Hosmer David W.
Published: October 2012

We examine goodness‐of‐fit tests for the proportional odds logistic regression model—the most commonly used regression model for an ordinal response variable. We derive a test statistic based on the Hosmer–Lemeshow test for binary logistic regression. Using a simulation study, we investigate the distribution and power properties of this test and compare these with those of three other goodness‐of‐fit tests. The new test has lower power than the existing tests; however, it was able to detect a greater number of the different types of lack of fit considered in this study. Moreover, the test allows for the results to be summarized in a contingency table of observed and estimated frequencies, which is a useful supplementary tool to assess model fit. We illustrate the ability of the tests to detect lack of fit using a study of aftercare decisions for psychiatrically hospitalized adolescents. The test proposed in this paper is similar to a recently developed goodness‐of‐fit test for multinomial logistic regression. A unified approach for testing goodness of fit is now available for binary, multinomial, and ordinal logistic regression models. Copyright © 2012 John Wiley & Sons, Ltd.
Steel Thermo‐Fluid‐Dynamics at Tundish Drainage and Quality Features
Authors: Battaglia Valerio , De Santis Michele , Volponi Vincenzo , Zanforlin Maurizio
Published: October 2012

In steelmaking and casting, transient operations are very critical for product quality and process regularity. This holds especially for the tundish. Typical drawbacks can occur at ladle change, where, for example, refilling high flow rates induce flow short‐circuits risky for dispersed oxides (“inclusions”) dragging towards the strands. At drainage, vortices formation can affect steel cleanliness via slag entrapment. Such topics were investigated for an industrial tundish with computational fluid dynamics validated tools. The focus was given on a multi‐strand layout more prone to unevenness features. As a matter of fact, the different steel path to reach different strands causes often too high temperature differences and different strand cleanliness levels. Strands closer to the tundish center, are generally hotter and less clean; the others, slightly colder but cleaner. Multiphase models, together with advanced meshing techniques and validated boundary conditions, were used to describe tundish refilling and drainage. Within the operating conditions of concern, a bath height of 300 mm was found as a best compromise between the need of avoiding slag entrapment through vortices and to have maximum yield. Once applied into operating practice, no rejection for cleanliness or customer claims were achieved. As refers to temperature loss from ladle to tundish, a drop at strands of about 2 and of 4°C from tundish inlet to strand, in agreement with plant data over about 700 heats and literature experiments under the same operating conditions, were found.
Effect of Thermo‐Mechanical Process on Phase Transformation Behaviors of V–Ti–N Microalloyed Steel
Authors: Baochun Zhao , Tan Zhao , Guiyan Li , Qiang Lu
Published: October 2012

Thermo‐mechanical simulation tests were performed on V–Ti–N microalloyed steel under three hot working conditions by using Gleeble‐3800 thermo‐mechanical simulator to study the effects of hot deformation and post‐deformation holding process on the continuous cooling transformation behaviors of overcooled austenite. The continuous cooling transformation diagrams (CCT diagrams) were determined by thermal dilation method and metallographic method. The effects of the hot deformation, post‐deformation holding, and cooling rate on the microstructure evolution were analyzed. The results show that deformation promotes ferrite and pearlite transformation. In addition, deformation leads to an increase in bainite start temperature, which becomes more markedly with the increase in cooling rate. The post‐deformation holding process is much favorable to promote carbonitride precipitation of the microalloying elements, which contributes to ferrite nucleation and smaller austenite grains. As a result, an increase in ferrite quantity and a decrease in ferrite grain size can be observed. And further more, the post‐deformation holding process reduces the effect of hot deformation on the bainite start temperature.
A History of the Electron
Authors: Navarro Jaume
Published: October 2012

Two landmarks in the history of physics are the discovery of the particulate nature of cathode rays (the electron) by J. J. Thomson in 1897 and the experimental demonstration by his son G. P. Thomson in 1927 that the electron exhibits the properties of a wave. Together, the Thomsons are two of the most significant figures in modern physics, both winning Nobel prizes for their work. This book presents the intellectual biographies of the father-and-son physicists, shedding new light on their combined understanding of the nature of electrons and, by extension, of the continuous nature of matter. It is the first text to explore J. J. Thomson's early and later work, as well as the role he played in G. P. Thomson's education as a physicist and how he reacted to his son's discovery of electron diffraction. This fresh perspective will interest academics and graduate students working in the history of early twentieth-century physics.
Roger Bacon and the Defence of Christendom
Authors: Power Amanda
Published: October 2012

The English Franciscan Roger Bacon (c.1214–92) holds a controversial but important position in the development of modern science. He has been portrayed as an isolated figure, at odds with his influential order and ultimately condemned by it. This major study, the first in English for nearly sixty years, offers a provocative new interpretation of both Bacon and his environment. Amanda Power argues that his famous writings for the papal curia were the product of his critical engagement with the objectives of the Franciscan order and the reform agenda of the thirteenth-century church. Fearing that the apocalypse was at hand and Christians unprepared, Bacon explored radical methods for defending, renewing and promulgating the faith within Christendom and beyond. Read in this light, his work indicates the breadth of imagination possible in a time of expanding geographical and intellectual horizons.
Spatial and glacial‐interglacial variations in provenance of the Chinese Loess Plateau
Authors: Xiao Guoqiao , Zong Keqing , Li Gaojun , Hu Zhaochu , Dupont‐Nivet Guillaume , Peng Shuzhen , Zhang Kexin
Published: October 2012

The Chinese Loess Plateau (CLP) covers an extensive area over 440,000 km2and provides an unprecedented terrestrial record of Neogene climate. However, it is still unclear whether the provenance of these loess deposits is uniform or contains spatial and temporal differences. Here this is addressed by comparing detrital‐zircon age spectra of typical loess and paleosol samples from three distant sites located at the western, middle, and southeastern parts of the CLP. Our results reveal that the zircon age spectra not only change between loess and paleosol layers but also vary from the western to the eastern CLP, at least during the last glacial cycle. The discrepancies of the zircon age spectra among different sites suggest that the loess provenance of CLP is heterogeneous and spatially variable, although it has been suggested that the mineralogical, elemental and isotopic compositions of loess deposits on CLP are highly homogenous spatially and in glacial‐interglacial cycles.
Relating the strength of the tropospheric biennial oscillation (TBO) to the phase of the Interdecadal Pacific Oscillation (IPO)
Authors: Meehl Gerald A. , Arblaster Julie M.
Published: October 2012

The phase of the Interdecadal Pacific Oscillation (IPO) can influence the Tropospheric Biennial Oscillation (TBO) such that a shift from a negative to positive phase of the IPO was associated with a weakening of the TBO after the mid‐1970s. Here it is shown that the most recent transition in the late 1990s of the IPO from positive to negative was associated with a larger‐amplitude TBO in the Indo‐Pacific region, thus confirming and strengthening the previous results by extending them to the opposite phase of the IPO. A major contributor to this change in the TBO has been an ongoing increase of sea surface temperatures (SSTs) in the Indian Ocean that contributes to stronger trade winds in the Pacific, one of the processes previously identified with strengthening the TBO. Such modulation of interannual variability by decadal timescale processes has implications for understanding possible skill of decadal climate predictions.
Electrical conductivity of magnetite‐bearing serpentinite during shear deformation
Authors: Kawano Seiya , Yoshino Takashi , Katayama Ikuo
Published: October 2012

Electrical conductivity of serpentinite with various amounts of magnetite was measured during shear deformation at high pressure and temperatures (P = 1.0 GPa, T = 750 K) corresponding to mantle wedge conditions to evaluate the contribution of aligned magnetite to the bulk conductivity of serpentinite. Under hydrostatic conditions, the sample conductivity considerably increases when the magnetite volume fraction exceeds 25% in volume, suggesting the presence of the percolation threshold for magnetite interconnection. During shear deformation, the conductivity for the samples with less than 25 vol.% magnetite increased by an order of magnitude or higher with increasing shear strain up to 9, which is likely a result of the clustering or realignment of magnetite grains in the serpentinites. However, activation enthalpy was nearly constant before and after deformation experiments, suggesting that shear deformation is unlikely to enhance establishment of interconnection of magnetite. Consequently, more than 25 vol.% magnetite is needed to establish connectivity of magnetite in serpentinite. On the other hand, the conductivity of serpentinite with low volume fraction of magnetite (5%), which is typical concentration of natural serpentinites, is almost similar to that of magnetite‐free serpentinites. The present results show that the interconnection of magnetite in serpentinites by shear deformation is not expected as an origin of the high conductivity anomaly occasionally observed at the slab interface in the mantle wedge. The origin of high conductivity, therefore, indicates the presence of aqueous fluid with high salinity rather than the magnetite interconnection.
A conceptual model for self‐sustained active‐break Indian summer monsoon
Authors: Liu Fei , Wang Bin
Published: October 2012

The Indian summer monsoon (ISM) exhibits a salient intraseasonal oscillation (ISO), and there have two ISO variability centers that are located at the equatorial Indian Ocean (EIO) and ISM regions, respectively. The prevalence of these two centers indicates that this active‐break monsoon cycle has a prominent stationary oscillation. To understand this aspect of the ISM ISO, a two‐box model is advanced to represent the ISO in these two variability centers. Linking by the local Hadley circulation, these two boxes can enhance each other's variability, but air‐sea interaction is shown to be necessary for producing a sustainable model ISO. Associated with a positive (negative) precipitation dipole anomaly, the reduced (enhanced) short wave radiation cools (warms) the sea surface and leads to an anomalous sea surface temperature dipole, which in turn stimulate development of a reversed precipitation dipole. This leads to a transition from one to the other phase of the monsoon cycle. This model demonstrates that even without the northward propagation, the air‐sea interaction, in cooperation with the instability caused by the local Hadley circulation and frictional boundary layer moisture convergence, can produce a self‐sustained ISM ISO.
Detection of ionospheric Alfvén resonator signatures in the equatorial ionosphere
Authors: Simões Fernando , Klenzing Jeffrey , Ivanov Stoyan , Pfaff Robert , Freudenreich Henry , Bilitza Dieter , Rowland Douglas , Bromund Kenneth , Liebrecht Maria Carmen , Martin Steven , Schuck Peter , Uribe Paulo , Yokoyama Tatsuhiro
Published: October 2012

The ionosphere response resulting from minimum solar activity during cycle 23/24 was unusual and offered unique opportunities for investigating space weather in the near‐Earth environment. We report ultra low frequency electric field signatures related to the ionospheric Alfvén resonator detected by the Communications/Navigation Outage Forecasting System (C/NOFS) satellite in the equatorial region. These signatures are used to constrain ionospheric empirical models and offer a new approach for monitoring ionosphere dynamics and space weather phenomena, namely aeronomy processes, Alfvén wave propagation, and troposphere‐ionosphere‐magnetosphere coupling mechanisms.
Experiments with the assimilation of fine aerosols using an ensemble Kalman filter
Authors: Pagowski Mariusz , Grell Georg A.
Published: October 2012

In a series of experiments we issue forecasts of fine aerosol concentration over the coterminous USA and southern Canada using the Weather Research and Forecasting – Chemistry model initialized with 3D‐VAR or ensemble Kalman filter (EnKF) assimilation methods. Assimilated observations include surface measurements of fine aerosols from the United States Environmental Protection Agency AIRNow Data Exchange program. Evaluation statistics calculated over a month‐and‐half‐long summer period demonstrate the advantage of EnKF over 3D‐VAR and point to the limitations of applying a simple aerosol parameterization for predicting air quality over the forecast area. Strategies for further improvement of forecasting aerosol concentrations are discussed.
Promoter-associated small double-stranded RNA interacts with heterogeneous nuclear ribonucleoprotein A2/B1 to induce transcriptional activation
Authors: Hu Jia , Chen Zhong , Xia Ding , Wu Jia , Xu Hua , Ye Zhang-Qun
Published: October 2012

Several recent reports have demonstrated that small activating dsRNA [double-stranded RNA; saRNA (small activating dsRNA)] complementary to promoter regions can up-regulate gene expression in mammalian cells, a phenomenon termed RNAa (RNA activation). However, the mechanism of RNAa remains obscure with regard to what is the target molecule for promoter-targeted saRNA and what are the proteins involved in this process. p21Waf1/Cip1 (p21) [CDKN1A (cyclin-dependent kinase inhibitor 1A)], an important tumour suppressor gene, is among the genes that can be activated by RNAa in tumour cells. In the present study, we provide direct evidence that p21 promoter-targeted saRNA interact with its intended target on the p21 promoter to activate p21 expression. This process is associated with recruitment of RNA polymerase II and AGO2 (argonaute 2) protein to the saRNA-target site. Additionally, we found that several hnRNPs (heterogeneous nuclear ribonucleoproteins) (A1, A2/B1 and C1/C2) are associated with saRNA. Further studies show that hnRNPA2/B1 interacts with the saRNA in vivo and in vitro and is required for RNAa activity. These findings indicate that RNAa results from specific targeting of promoters and reveals additional mechanistic details of RNAa.
Improved coarse-graining of Markov state models via explicit consideration of statistical uncertainty
Authors: Bowman Gregory R.
Published: October 2012

Markov state models (MSMs)–or discrete-time master equation models–are a powerful way of modeling the structure and function of molecular systems like proteins. Unfortunately, MSMs with sufficiently many states to make a quantitative connection with experiments (often tens of thousands of states even for small systems) are generally too complicated to understand. Here, I present a Bayesian agglomerative clustering engine (BACE) for coarse-graining such Markov models, thereby reducing their complexity and making them more comprehensible. An important feature of this algorithm is its ability to explicitly account for statistical uncertainty in model parameters that arises from finite sampling. This advance builds on a number of recent works highlighting the importance of accounting for uncertainty in the analysis of MSMs and provides significant advantages over existing methods for coarse-graining Markov state models. The closed-form expression I derive here for determining which states to merge is equivalent to the generalized Jensen-Shannon divergence, an important measure from information theory that is related to the relative entropy. Therefore, the method has an appealing information theoretic interpretation in terms of minimizing information loss. The bottom-up nature of the algorithm likely makes it particularly well suited for constructing mesoscale models. I also present an extremely efficient expression for Bayesian model comparison that can be used to identify the most meaningful levels of the hierarchy of models from BACE.
Comparative evaluation of ultrasound scanner accuracy in distance measurement
Authors: Branca F. P. , Sciuto S. A. , Scorza A.
Published: October 2012

The aim of the present study is to develop and compare two different automatic methods for accuracy evaluation in ultrasound phantom measurements on B-mode images: both of them give as a result the relative error e between measured distances, performed by 14 brand new ultrasound medical scanners, and nominal distances, among nylon wires embedded in a reference test object. The first method is based on a least squares estimation, while the second one applies the mean value of the same distance evaluated at different locations in ultrasound image (same distance method). Results for both of them are proposed and explained.
Impact of oxygen bonding on the atomic structure and photoluminescence properties of Si-rich silicon nitride thin films
Authors: Nguyen P. D. , Kepaptsoglou D. M. , Ramasse Q. M. , Sunding M. F. , Vestland L. O. , Finstad T. G. , Olsen A.
Published: October 2012

The atomic structure and optical properties of Si-rich silicon nitride thin films have been for decades the subject of intense research, both theoretically and experimentally. It has been established in particular that modifying the chemical composition of this material (e.g., the Si excess concentration) can lead to dramatic differences in its physical, optical, and electrical properties. The present paper reports on how the incorporation of oxygen into silicon nitride networks influences their chemical bonding and photoluminescence properties. Here, by using a combination of analytical scanning transmission electron microscopy and x-ray photoelectron spectroscopy it is demonstrated that the structure of Si-rich silicon nitride with low O content can be described by the co-existence of Si nanocrystals in a Si3N4 matrix, with occasional localized nano-regions of a Si2ON2 phase, depending on the amount of excess Si. Furthermore, it is shown that the structure of silicon nitride with high O content can be adequately described by a so-called random bonding model, according to which the material consists in bonded networks of randomly distributed tetrahedral SiOxN4−x (where x = 0, 1, 2, 3, and 4). Photoluminescence measurements indicate that the effect of O is to introduce a gap state in the band gap of Si3N4 matrix. When a large amount of O is introduced, on the other hand, the photoluminescence measurements are in agreement with a shifted conduction band minimum in the dielectric. For both cases (high and low O content), Si dangling bonds were found to give rise to the deep level in the band gap of the nitride matrix, causing the dominant emission band in the photoluminescence of the films.
The phase diagram of ice Ih, II, and III: A quasi-harmonic study
Authors: Ramírez R. , Neuerburg N. , Herrero C. P.
Published: October 2012

The phase diagram of ice Ih, II, and III is studied by a quasi-harmonic approximation. The results of this approach are compared to phase diagrams previously derived by thermodynamic integration using path integral and classical simulations, as well as to experimental data. The studied models are based on both flexible (q-TIP4P/F) and rigid (TIP4P/2005, TIP4PQ/2005) descriptions of the water molecule. Many aspects of the simulated phase diagrams are reasonably reproduced by the quasi-harmonic approximation. Advantages of this simple approach are that it is free from the statistical errors inherent to computer simulations, both classical and quantum limits are easily accessible, and the error of the approximation is expected to decrease in the zero temperature limit. We find that the calculated phase diagram of ice Ih, II, and III depends strongly on the hydrogen disorder of ice III, at least for cell sizes typically used in phase coexistence simulations. Either ice II (in the classical limit) or ice III (in the quantum one) may become unstable depending upon the proton disorder in ice III. The comparison of quantum and classical limits shows that the stabilization of ice II is the most important quantum effect in the phase diagram. The lower vibrational zero-point energy of ice II, compared to either ice Ih or III, is the microscopic origin of this stabilization. The necessity of performing an average of the lattice energy over the proton disorder of ice III is discussed.
The effect of hydrogen on the surface segregation of phosphorus in epitaxially grown relaxed Si0.7Ge0.3 films by rapid thermal chemical vapor deposition
Authors: Li Jiun-Yun , Huang Chiao-Ti , Sturm James C.
Published: October 2012

The surface segregation of phosphorus in relaxed Si0.7Ge0.3 epitaxial films grown on Si (100) substrates by rapid thermal chemical vapor deposition was investigated in this letter. The effect of the growth temperature on phosphorus segregation was studied experimentally and examined using a two-state model. As the growth temperature is reduced, phosphorus segregation is greatly suppressed, and we report an extremely sharp phosphorus turn-off slope of 6 nm/dec at 500 °C. The sharper slopes at low temperatures are explained by a modified two-state model which includes the effect of increased surface coverage of hydrogen at low temperatures.
The Effects of Competition on the Quality of Primary Schools in the Netherlands
Authors: Noailly Joëlle , Vujić Sunčica , Aouragh Ali
Published: October 2012

We investigate the impact of competition between primary schools on the quality of education in the Netherlands. Do schools facing more competition in their neighbourhood perform better than schools facing less competition? As a measure of school quality, we look at the performance of pupils at the nationwide standard test (the so-called ‘Cito test’) in the final year of primary education. Since competition is likely to be endogenous to the quality of schools, we use the distance between the school and the city centre as an instrument for the level of competition faced by a school. Using a large range of data on pupil, school, and market characteristics, we find that school competition has a positive significant effect on pupil achievement, although the effect is very small. An increase in competition by one standard deviation (comparable to five additional schools in the market) increases pupil achievement as measured by the Cito test by 5% to 10% of the mean standard deviation, which is less than one point (on the Cito test scale from 500 to 550 points).
Pretreatment of Asian elephant (Elephas maximus) spermatozoa with cholesterol-loaded cyclodextrins and glycerol addition at 4°C improves cryosurvival
Authors: Kiso Wendy K. , Asano Atsushi , Travis Alexander J. , Schmitt Dennis L. , Brown Janine L. , Pukazhenthi Budhan S.
Published: October 2012

Asian elephant spermatozoa are sensitive to chilling and do not respond well to cryopreservation. The objectives of the present study were to: (1) determine whether cholesterol content can be modified by preincubation of Asian elephant spermatozoa with cholesterol-loaded cyclodextrin (CLC); and (2) assess the effects of CLC concentration(s), temperature at time of glycerol addition (22°C vs 4°C) and dilution medium on post-thaw sperm survival. Spermatozoa incubated with ≥1.5 mg CLC exhibited increased (P < 0.05) cholesterol concentrations. Pretreatment of spermatozoa with 1.5 mg CLC resulted in improvements (P < 0.05) in all post-thaw parameters. Glycerol addition at 4°C also improved all post-thaw parameters compared with 22°C. Dilution of thawed spermatozoa in an egg yolk-based medium improved (P < 0.05) motility compared with Ham’s F-10 culture medium. In summary, our findings indicate that modifying cholesterol content within the plasma membrane improves the cryosurvival of Asian elephant spermatozoa. The development of an improved cryopreservation method that includes modification of membrane cholesterol and the addition of glycerol at 4°C, as reported in the present study, is an important step towards utilisation of cryopreserved spermatozoa in captive management of this species.
Contribution of a Winged Phlebotomy Device Design to Blood Splatter
Authors: Haiduven Donna J. , McGuire-Wolfe Christine , Applegarth Shawn P.
Published: October 2012

Background.

Despite a proliferation of phlebotomy devices with engineered sharps injury protection (ESIP), the impact of various winged device designs on blood splatter occurring during venipuncture procedures has not been explored.

Objectives.

To evaluate the potential for blood splatter of 6 designs of winged phlebotomy devices.

Design.

A laboratory-based device evaluation without human subjects, using a simulated patient venous system.

Methods.

We evaluated 18 winged phlebotomy devices of 6 device designs by Terumo, BD Vacutainer (2 designs), Greiner, Smith Medical, and Kendall (designated A-F, respectively). Scientific filters were positioned around the devices and weighed before and after venipuncture was performed. Visible blood on filters, exam gloves, and devices and measurable blood splatter were the primary units of analysis.

Results.

The percentages of devices and gloves with visible blood on them and filters with measurable blood splatter ranged from 0% to 20%. There was a statistically significant association between device design and visible blood on devices (P< .0001) and between device design and filters with measurable blood splatter (P< .0001), but not between device design and visible blood on gloves. A wide range of associations were demonstrated between device design and visible blood on gloves or devices and incidence of blood splatter.

Conclusions.

The results of this evaluation suggest that winged phlebotomy devices with ESIP may produce blood splatter during venipuncture. Reinforcing the importance of eye protection and developing a methodology to assess ocular exposure to blood splatter are major implications for healthcare personnel who use these devices. Future studies should focus on evaluating different designs of intravascular devices (intravenous catheters, other phlebotomy devices) for blood splatter.
Sexual quality of life in women who have undergone female genital mutilation: a case–control study
Authors: Andersson SHA , Rymer J , Joyce DW , Momoh C , Gayle CM
Published: October 2012

Please cite this paper as: Andersson S, Rymer J, Joyce D, Momoh C, Gayle C. Sexual quality of life in women who have undergone female genital mutilation: a case–control study. BJOG 2012;119:1606–1611.

Objective  To investigate the sexual quality of life of women who have undergone female genital mutilation (FGM) and compare them with a similar group who has not undergone FGM.

Design  Case–control study.

Setting  A large central London teaching hospital.

Population  A total of 73 women who had undergone FGM and 37 control women, who had not undergone FGM but were from a similar cultural background where FGM is practiced.

Methods  The women completed a questionnaire containing the Sexual Quality of Life‐Female (SQOL‐F) questionnaire.

Main outcome measures  SQOL‐F score.

Results  Women who have undergone FGM of any type have a significantly lower (P < 0.001) overall SQOL‐F score than control women (mean = 62.44, SD = 27.93 versus mean = 88.84, SD = 13.73). Women who were sexually active and had undergone FGM type III differed the most from sexually active controls (P < 0.05) in their SQOL‐F score. Women who were sexually inactive but who had undergone FGM reported significantly lower overall SQOL‐F scores (P = 0.015) than sexually inactive controls, but were not differentiated by type of FGM.

Conclusion  FGM significantly reduces women’s sexual quality of life, based on the results of the SQOL‐F questionnaire.
Transcatheter arterial embolization followed by octreotide and celecoxib synergistically prolongs survival of rabbits with hepatic VX2 allografts
Authors: Tong Huan , Li Xiao , Zhang Chun Le , Gao Jin Hang , Wen Shi Lei , Huang Zhi Yin , Wen Fu Qiang , Fu Ping , Tang Cheng Wei
Published: October 2012

Objective

To validate the efficacy of an innovative multimodality therapy with transcatheter arterial embolization (TAE) plus octreotide and celecoxib in reducing neoangiogenesis and prolonging the survival of rabbits with hepatocellular carcinoma.

Methods

Rabbits with hepatic VX2 allografts were divided into four groups: control group, TAE group, octreotide + celecoxib (O + C) group and the multimodality therapy (TAE + O + C) group. Survival of the rabbits was analyzed using the Kaplan–Meier method and the expression of CD31 in tumor tissues was detected by immunohistochemistry.

Results

Rabbits in the TAE + O + C group lived nearly 20 days longer than those in the control group. The survival rate of the TAE + O + C group was 50% at day 80 and was the highest among the four groups (P < 0.05). No VX2 allograft‐bearing rabbits in the control group lived longer than 60 days. Compared with the control group, the survival time of the other two intervention groups were not prolonged significantly (P > 0.05). The CD31 expression induced by TAE was reduced significantly in TAE + O + C group (P < 0.05). Less metastasis was detected in TAE + O + C group.

Conclusion

TAE followed by the long‐term administration of octreotide and celecoxib can synergistically prolong the survival of rabbits with hepatic VX2 allografts by inhibiting potential neoangiogenesis, tumor growth and metastasis.
The ‘real world’ utility of a web‐based bipolar disorder screening measure
Authors: Parker G. , Fletcher K. , Blanch B. , Greenfield L.
Published: October 2012

Objective

To determine whether those completing a self‐report bipolar self‐test measure and identified as having a likely bipolar disorder judged the self‐test as useful and had a subsequent superior illness course.

Method

We invited those completing the web‐based Mood Swings Questionnaire (or MSQ) to provide contact details and contribute to a 3‐month study evaluating their responses to being identified as having a likely bipolar disorder, any subsequent action taken and the impact of such actions on their illness trajectory.

Results

We analysed data received from 665 participants screening ‘positive’ on the MSQ and completing baseline and 3‐month follow‐up data. High rates of satisfaction with the MSQ were quantified, with respondents viewing the measure as informative, validating and/or motivating. Of those receiving a confirmed bipolar diagnosis, such clarification occurred on average 12 years after their first depressive episode. Most implemented self‐management strategies irrespective of whether seeking formal diagnostic clarification or not. Participants improved on depressive, quality of life and overall functioning measures over the study period, but with results indicating (via analysis of three sample subsets differing by the degree of ‘actions taken’) that those who took assertive action and had the diagnosis confirmed had the most superior outcome.

Conclusion

This is the first study to formally evaluate the clinical impact of a self‐report bipolar disorder screening measure. High acceptance and superior outcomes quantified for those acting assertively in response to such a new diagnosis argue for its ‘real world’ utility.