bluuebunny/crossref_metadata_2025 huggingface dataset:
Mother to child transmission of HIV‐1 in a Thai population: Role of virus characteristics and maternal humoral immune response
Authors: Kittinunvorakoon Chonticha , Morris Mary Kate , Neeyapun Kanchana , Jetsawang Bongkoch , Buehring Gertrude C. , Hanson Carl V.
Published: March 2009

The objective of this study was to investigate factors influencing mother to child transmission of HIV‐1 in Thailand, where HIV‐1 CRF01_AE, the major subtype in Southeast Asia, predominates. Samples from 84 HIV‐1 infected, anti‐retroviral treatment‐naïve, non‐breast feeding mothers, 28 who transmitted HIV‐1 to their babies (transmitters) and 56 who did not (non‐transmitters), were studied for maternal humoral immune response and virus characteristics. Maternal humoral immune response was measured by lymphocyte phenotyping; neutralizing antibodies to laboratory HIV‐1 MN strain and two clinical isolates; peptide binding antibody to gp41 and V3 from strains CRF01_AE, B, and MN; autologous antibodies; and quasispecies diversity. Virus characteristics studied were viral load, co‐receptor usage, and viral replication capacity. No significant difference between transmitters and non‐transmitters was found for any parameter of maternal humoral immune response. However, viral load and viral replication capacity were significantly higher in transmitters versus non‐transmitters and were not correlated with each other. This suggests that viral replication capacity may be a transmission factor independent of viral load, which is already well established as a risk factor for transmission of HIV‐1. All except four viral isolates used the CCR5 co‐receptor. This is one of few studies of vertical transmission in a population where HIV‐1 CRF01_AE predominates. The data suggest that in this population the maternal humoral immune response was not important in preventing transmission at parturition, but that virus characteristics were key factors, and that viral replication capacity may contribute to birth‐associated mother to child transmission of HIV‐1. J. Med. Virol. 81:768–778, 2009. © 2009 Wiley‐Liss, Inc.
Molecular characterization of occult hepatitis B cases in Greek blood donors
Authors: Katsoulidou Antigoni , Paraskevis Dimitrios , Magiorkinis Emmanouil , Moschidis Zissis , Haida Catherine , Hatzitheodorou Eleni , Varaklioti Agoritsa , Karafoulidou Anastasia , Hatzitaki Maria , Kavallierou Lilian , Mouzaki Athanasia , Andrioti Evaggelia , Veneti Chrysanthi , Kaperoni Athanasia , Zervou Eleftheria , Politis Constantina , Hatzakis Angelos
Published: March 2009

The use of sensitive nucleic acid testing for hepatitis B virus in blood donors revealed a number of HBV DNA(+) cases among HBsAg(−) donors, a status known as occult HBV infection. The purpose of this study was the serological and molecular characterization of occult HBV infection in Greek blood donors. A prospective study was undertaken in order to identify occult HBV infection cases in blood donors. As part of the routine screening of blood donations in Greece, blood units were screened individually by a multiplex HIV‐1/HCV/HBV nucleic acid assay. Initially reactive samples were retested with discriminatory assays. HBV DNA(+)/HBsAg(−) samples were tested further for HBV serological markers and HBV DNA was quantified by real‐time PCR. Molecular characterization was performed by sequencing the envelope and polymerase genes of HBV. Preliminary screening revealed 21 occult cases with the following patterns: anti‐HBc only: 7 donors, anti‐HBc/anti‐HBs: 7 donors, anti‐HBc/anti‐HBe: 5 donors, anti‐HBc/anti‐HBs/anti‐HBe: 2 donors. In all cases, the HBV DNA load was <351 IU/ml. Sequencing was successful in 10 donors (classified within genotype D) revealing several amino acid substitutions related to diagnostic escape and antiviral resistance. HBsAg diagnostic failure and low viral replication in occult HBV infection carriers could possibly be attributed to multiple changes in envelope and polymerase regions, respectively. J. Med. Virol. 81:815–825, 2009. © 2009 Wiley‐Liss, Inc.
Preparation of anti‐danofloxacin antibody and development of an indirect competitive enzyme‐linked immunosorbent assay for detection of danofloxacin residue in chicken liver
Authors: Liu Zhongqiu , Lu Shengxin , Zhao Cuihua , Ding Kai , Cao Zhaozhen , Zhan Jinhua , Ma Chen , Liu Jinting , Xi Rimo
Published: March 2009

BACKGROUND: Danofloxacin is used widely as both a clinical medicine for humans and a veterinary drug in animal husbandry. In this study a polyclonal anti‐danofloxacin antibody was prepared for the first time and a simple and rapid indirect competitive enzyme‐linked immunosorbent assay (cELISA) method based on the antibody was developed to monitor danofloxacin residue in chicken liver.

RESULTS: The prepared antibody showed high sensitivity, with an IC50 value of 2.0 ng mL−1 towards danofloxacin, and good specificity, with significant cross‐reactivity only towards pefloxacin (22%) and fleroxacin (21%) among commonly used (fluoro)quinolones evaluated in the study. The developed cELISA test kit had a detection limit of 0.8 ng mL−1, and satisfactory results were obtained when it was applied to chicken liver spiked with various levels of danofloxacin. The cELISA test kit was also used to detect danofloxacin in chicken liver samples purchased from a local food market, and the results were confirmed by liquid chromatography/mass spectrometry.

CONCLUSION: The anti‐danofloxacin antibody prepared in this study exhibits excellent quality, with high sensitivity and good specificity. The cELISA test kit based on the antibody has a very low detection limit and is suitable for use as an efficient screening method to detect danofloxacin residue in foods and food products. Copyright © 2009 Society of Chemical Industry
The latent structure of posttraumatic stress disorder among adolescents
Authors: Broman‐Fulks Joshua J. , Ruggiero Kenneth J. , Green Bradley A. , Smith Daniel W. , Hanson Rochelle F. , Kilpatrick Dean G. , Saunders Benjamin E.
Published: March 2009

Debate has arisen over whether posttraumatic stress disorder (PTSD) is most accurately conceptualized as representing a discrete clinical syndrome or an extreme reaction to traumatic life events. Recent taxometric research using predominately adult samples appears to support a dimensional model of PTSD, raising questions about the utility of current psychiatric nosology which depicts PTSD as a distinct entity. The present study sought to use taxometric procedures to examine the latent structure of posttraumatic stress reactions among a national epidemiologic sample of 2,885 adolescents. Results were consistent with previous taxometric studies in supporting a dimensional model of posttraumatic stress reactions. The implications of these findings for public policy, as well as the etiology and assessment of posttraumatic stress reactions, are discussed.
Spectrally selective B1‐insensitive T2 magnetization preparation sequence
Authors: Nezafat Reza , Ouwerkerk Ronald , Derbyshire Andrew J. , Stuber Matthias , McVeigh Elliot R.
Published: March 2009

A T2 magnetization‐preparation (T2 Prep) sequence is proposed that is insensitive to B1 field variations and simultaneously provides fat suppression without any further increase in specific absorption rate (SAR). Increased B1 inhomogeneity at higher magnetic field strength (B0 ≥ 3T) necessitates a preparation sequence that is less sensitive to B1 variations. For the proposed technique, T2 weighting in the image is achieved using a segmented B1‐insensitive rotation (BIR‐4) adiabatic pulse by inserting two equally long delays, one after the initial reverse adiabatic half passage (AHP), and the other before the final AHP segment of a BIR‐4 pulse. This sequence yields T2 weighting with both B1 and B0 insensitivity. To simultaneously suppress fat signal (at the cost of B0 insensitivity), the second delay is prolonged so that fat accumulates additional phase due to its chemical shift. Numerical simulations as well as phantom and in vivo image acquisitions were performed to show the efficacy of the proposed technique. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
The B‐matrix must be rotated when correcting for subject motion in DTI data
Authors: Leemans Alexander , Jones Derek K.
Published: March 2009

To estimate diffusion tensor MRI (DTI) measures, such as fractional anisotropy and fiber orientation, reliably, a large number of diffusion‐encoded images is needed, preferably cardiac gated to reduce pulsation artifacts. However, the concomitant longer acquisition times increase the chances of subject motion adversely affecting the estimation of these measures. While correcting for motion artifacts improves the accuracy of DTI, an often overlooked step in realigning the images is to reorient the B‐matrix so that orientational information is correctly preserved. To the best of our knowledge, most research groups and software packages currently omit this reorientation step. Given the recent explosion of DTI applications including, for example, neurosurgical planning (in which errors can have drastic consequences), it is important to investigate the impact of neglecting to perform the B‐matrix reorientation. In this work, a systematic study to investigate the effect of neglecting to reorient the B‐matrix on DTI data during motion correction is presented. The consequences for diffusion fiber tractography are also discussed. Magn Reson Med, 61:1336–1349, 2009. © 2009 Wiley‐Liss, Inc.
Transmural myocardial strain in mouse: Quantification of high‐resolution MR tagging using harmonic phase (HARP) analysis
Authors: Zhong Jia , Liu Wei , Yu Xin
Published: March 2009

MR tagging allows noninvasive examination of regional myocardial function with high accuracy and reproducibility. The current tagging method is limited by low tagging resolution for accurate transmural strain quantification. Previously, a spatial modulation of magnetization (SPAMM)‐based method was proposed to increase the tagging resolution by combining two or more tagged images with different tagging grid positions. However, there has been limited application due to the challenge in image processing of multiple data sets. In the current study, we propose a harmonic phase (HARP)‐based method for automated and fast analysis of high tagging resolution images. First‐order harmonic peaks from low tagging resolution images were combined to generate the composite second‐order harmonic peak for strain computation. The combined images reached a tagging resolution of 0.3 mm. The proposed method was applied to the quantification of transmural myocardial wall strain in seven normal C57BL/6 mice. Principal strains, as well as radial and circumferential strains, were quantified using the current method. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Strategies for reducing respiratory motion artifacts in renal perfusion imaging with arterial spin labeling
Authors: Robson Philip M. , Madhuranthakam Ananth J. , Dai Weiying , Pedrosa Ivan , Rofsky Neil M. , Alsop David C.
Published: March 2009

Arterial spin labeling (ASL) perfusion measurements may have many applications outside the brain. In the abdomen, severe image artifacts can arise from motions between acquisitions of multiple signal averages in ASL, even with single‐shot image acquisition. Background suppression and respiratory motion synchronization techniques can be used to ameliorate these artifacts. Two separate in vivo studies of renal perfusion imaging using pulsed continuous ASL (pCASL) were performed. The first study assessed various combinations of background suppression and breathing strategies. The second investigated the retrospective sorting of images acquired during free breathing based on respiratory position. Quantitative assessments of the test‐retest repeatability of perfusion measurements and the image quality scored by two radiologists were made. Image quality was most significantly improved by using background suppression schemes and controlled breathing when compared to other combinations without background suppression or with free breathing, assessed by test‐retests (5% level, F‐test), and by radiologists' scores (5% level, Mann‐Whitney U‐test). Under free breathing, retrospectively sorting images based on respiratory position showed significant improvement. Both radiologists found 100% of the images had preferable image sharpness after sorting. High‐quality renal perfusion measurements with reduced respiratory motion artifacts have been demonstrated using ASL when appropriate background suppression and breathing strategies are applied. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
MR spectroscopy of the human brain with enhanced signal intensity at ultrashort echo times on a clinical platform at 3T and 7T
Authors: Mekle Ralf , Mlynárik Vladimír , Gambarota Giulio , Hergt Martin , Krueger Gunnar , Gruetter Rolf
Published: March 2009

Recently, the spin‐echo full‐intensity acquired localized (SPECIAL) spectroscopy technique was proposed to unite the advantages of short TEs on the order of milliseconds (ms) with full sensitivity and applied to in vivo rat brain. In the present study, SPECIAL was adapted and optimized for use on a clinical platform at 3T and 7T by combining interleaved water suppression (WS) and outer volume saturation (OVS), optimized sequence timing, and improved shimming using FASTMAP. High‐quality single voxel spectra of human brain were acquired at TEs below or equal to 6 ms on a clinical 3T and 7T system for six volunteers. Narrow linewidths (6.6 ± 0.6 Hz at 3T and 12.1 ± 1.0 Hz at 7T for water) and the high signal‐to‐noise ratio (SNR) of the artifact‐free spectra enabled the quantification of a neurochemical profile consisting of 18 metabolites with Cramér‐Rao lower bounds (CRLBs) below 20% at both field strengths. The enhanced sensitivity and increased spectral resolution at 7T compared to 3T allowed a two‐fold reduction in scan time, an increased precision of quantification for 12 metabolites, and the additional quantification of lactate with CRLB below 20%. Improved sensitivity at 7T was also demonstrated by a 1.7‐fold increase in average SNR (= peak height/root mean square [RMS]‐of‐noise) per unit‐time. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Numerical simulation of double‐wave vector experiments investigating diffusion in randomly oriented ellipsoidal pores
Authors: Koch Martin A. , Finsterbusch Jürgen
Published: March 2009

Double‐wave vector diffusion weighting is expected to represent a possibility to acquire information on cell size and shape. In numerical simulations, a theoretical description of the double wave vector‐weighted signal is tested in a situation where the approximating assumptions (infinitely short gradient pulses, infinitely long diffusion time, infinitely long or zero delay between diffusion weightings, small gradient moment) are not strictly met. It is shown how the dependence of the signal on the angle between the diffusion gradient directions changes upon varying the delay between the second and the third gradient pulse, and how the measures of pore geometry derived from signal differences between two angles depend on the duration, temporal separation, and amplitude of the gradient pulses. The results indicate that a violation of the approximation conditions due to finite gradient pulse duration and separation generally leads to an underestimation of pore size and pore eccentricity. It is also concluded from the simulations that for pore sizes on the order of 10 μm the investigated effects are in a range that is observable even with whole‐body gradient systems. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Controlled experimental study depicting moving objects in view‐shared time‐resolved 3D MRA
Authors: Mostardi Petrice M. , Haider Clifton R. , Rossman Phillip J. , Borisch Eric A. , Riederer Stephen J.
Published: March 2009

Various methods have been used for time‐resolved contrast‐enhanced magnetic resonance angiography (CE‐MRA), many involving view sharing. However, the extent to which the resultant image time series represents the actual dynamic behavior of the contrast bolus is not always clear. Although numerical simulations can be used to estimate performance, an experimental study can allow more realistic characterization. The purpose of this work was to use a computer‐controlled motion phantom for study of the temporal fidelity of three‐dimensional (3D) time‐resolved sequences in depicting a contrast bolus. It is hypothesized that the view order of the acquisition and the selection of views in the reconstruction can affect the positional accuracy and sharpness of the leading edge of the bolus and artifactual signal preceding the edge. Phantom studies were performed using dilute gadolinium‐filled vials that were moved along tabletop tracks by a computer‐controlled motor. Several view orders were tested using view‐sharing and Cartesian sampling. Compactness of measuring the k‐space center, consistency of view ordering within each reconstruction frame, and sampling the k‐space center near the end of the temporal footprint were shown to be important in accurate portrayal of the leading edge of the bolus. A number of findings were confirmed in an in vivo CE‐MRA study. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Time‐efficient fast spin echo imaging at 4.7 T with low refocusing angles
Authors: Lebel R. Marc , Wilman Alan H.
Published: March 2009

An implementation of fast spin echo at 4.7 T designed for versatile and time‐efficient T2‐weighted imaging of the human brain is presented. Reduced refocusing angles (α < 180°) were employed to overcome specific absorption rate (SAR) constraints and their effects on image quality assessed. Image intensity and tissue contrast variations from heterogeneous RF transmit fields and incidental magnetization transfer effects were investigated at reduced refocusing angles. We found that intraslice signal variations are minimized with refocusing angles near 180°, but apparent gray/white matter contrast is independent of refocusing angle. Incidental magnetization transfer effects from multislice acquisitions were shown to attenuate white matter intensity by 25% and gray matter intensity by 15% at 180°; less than 5% attenuation was seen in all tissues at flip angles below 60°. We present multislice images acquired without excess delay time for SAR mitigation using a variety of protocols. Subsecond half Fourier acquisition single‐shot turbo spin echo (HASTE) images were obtained with a novel variable refocusing angle echo train (20° < α < 58°) and high‐resolution scans with a voxel volume of 0.18 mm3 were acquired in 6.5 min with refocusing angles of 100°. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Meshfree co‐rotational formulation for two‐dimensional continua
Authors: Yaw L. L. , Sukumar N. , Kunnath S. K.
Published: March 2009

In this paper, a meshfree co‐rotational formulation for two‐dimensional continua is proposed. In a co‐rotational formulation, the motion of a body is separated into rigid motion and strain‐producing deformation. Traditionally, this has been done in the setting of finite elements for beams and shell‐type elements. In the present work every node in a meshfree discretized domain has its own co‐rotating coordinate system. Three key ingredients are established in order to apply the co‐rotational formulation: (i) the relationship between global and local variables, (ii) the angle of rotation of a typical co‐rotating coordinate system, and (iii) a variationally consistent tangent stiffness matrix. An algorithm for the co‐rotational formulation based on load control is provided. Maximum‐entropy basis functions are used to discretize the domain and stabilized nodal integration is implemented to construct the global system of equations. Numerical examples are presented to demonstrate the validity of the meshfree co‐rotational formulation. Copyright © 2009 John Wiley & Sons, Ltd.
It's a choice to move forward: women's perceptions about treatment decision making in recurrent ovarian cancer
Authors: Elit L. , Charles C. , Dimitry S. , Tedford‐Gold S. , Gafni A. , Gold I. , Whelan T.
Published: March 2009

Objective: This research explores the treatment decision‐making (TDM) experiences of women with recurrent ovarian cancer (ROC) with regard to treatment options; their understanding of risks and benefits of various treatment options; the decision‐making role they want for themselves and for their oncologist; and the social context of the consultation as it pertains to the decision.

Methods: We conducted semi‐structured interviews with 26 women at the time of first recurrence. Through inductive data analysis key themes were identified.

Results: Many women describe self‐identifying the cancer recurrence fairly quickly due to new symptoms. Many feel that the goal for treating their recurrence is to control versus cure the cancer. They describe the subsequent process of diagnosis and TDM for ROC as quick and straightforward with all women accepting the oncologists' treatment recommendation. They feel that the type and number of treatment options are limited. They have a strong desire for physician continuity in their care. Participants feel that their doctor's recommendations as well as their previous experience with ovarian cancer are strong factors influencing their current TDM process.

Conclusions: Shared decision making is based on a simultaneous participation of both the physician and patient in TDM. When faced with ROC, women feel that their doctor's recommendation and their past experience with treatment and TDM are prominent factors influencing the current TDM process. Copyright © 2009 John Wiley & Sons, Ltd.
Comprehensive secondary‐structure analysis of disulfide variants of lysozyme by synchrotron‐radiation vacuum‐ultraviolet circular dichroism
Authors: Matsuo Koichi , Watanabe Hidenori , Tate Shin‐ichi , Tachibana Hideki , Gekko Kunihiko
Published: March 2009

To elucidate the effects of specific disulfide bridges (Cys6‐Cys127, Cys30‐Cys115, Cys64‐Cys80, and Cys76‐Cys94) on the secondary structure of hen lysozyme, the vacuum‐ultraviolet circular dichroism (VUVCD) spectra of 13 species of disulfide‐deficient variants in which Cys residues were replaced with Ala or Ser residues were measured down to 170 nm at pH 2.9 and 25°C using a synchrotron‐radiation VUVCD spectrophotometer. Each variant exhibited a VUVCD spectrum characteristic of a considerable amount of residual secondary structures depending on the positions and numbers of deleted disulfide bridges. The contents of α‐helices, β‐strands, turns, and unordered structures were estimated with the SELCON3 program using the VUVCD spectra and PDB data of 31 reference proteins. The numbers of α‐helix and β‐strand segments were also estimated from the VUVCD data. In general, the secondary structures were more effectively stabilized through entropic forces as the number of disulfide bridges increased and as they were formed over larger distances in the primary structure. The structures of three‐disulfide variants were similar to that of the wild type, but other variants exhibited diminished α‐helices with a border between the ordered and disordered structures around the two‐disulfide variants. The sequences of the secondary structures were predicted for all the variants by combining VUVCD data with a neural‐network method. These results revealed the characteristic role of each disulfide bridge in the formation of secondary structures. Proteins 2009. © 2009 Wiley‐Liss, Inc.
Solution structure of the DNA binding domain of AraC protein
Authors: Rodgers Michael E. , Schleif Robert
Published: March 2009

We report the solution structure of the DNA binding domain of the Escherichia coli regulatory protein AraC determined in the absence of DNA. The 20 lowest energy structures, determined on the basis of 1507 unambiguous nuclear Overhauser restraints and 180 angle restraints, are well resolved with a pair wise backbone root mean square deviation of 0.7 Å. The protein, free of DNA, is well folded in solution and contains seven helices arranged in two semi‐independent sub domains, each containing one helix‐turn‐helix DNA binding motif, joined by a 19 residue central helix. This solution structure is discussed in the context of extensive biochemical and physiological data on AraC and with respect to the DNA‐bound structures of the MarA and Rob homologs. Proteins 2009. © 2009 Wiley‐Liss, Inc.
Combining interface core and whole interface descriptors in postscan processing of protein‐protein docking models
Authors: Kowalsman Noga , Eisenstein Miriam
Published: March 2009

Computational protein‐protein docking scans commonly produce correct and nearly correct interaction models, but sometimes these models are ranked low. We present here postscan processing procedures that dramatically enhance the distinction between nearly correct and false predictions. The procedures employ propensity descriptors calculated for the interface core, an interface‐core clusters count, solvation energy, and a geometric‐electrostatic‐hydrophobic complementarity score. The various descriptors rank high different selections of false models (shuffling effect), and therefore, are used as Boolean yes/no classifiers in “soft intersection” filters, which eliminate large proportions of false models. Furthermore, the standardized descriptors are used in new scoring functions that highlight nearly correct models (NCMs). All the tests are performed on unbound docking models produced with MolFit without use of external data. We find that the discrimination between nearly correct and false models by the various descriptors is class dependent; hence, our postscan processing is class specific. The filters reduce the number of putative models from 10,726, 12,517, and 11,054 to 758, 157, and 1218 for enzyme‐inhibitor, antibody‐antigen, and nonclassified systems. When combined with the new scoring functions, they improve the average rank of the highest ranking NCMs from 673 to 122. Application to 23 CAPRI targets demonstrates the effectiveness of the postscan procedures in cases where external information is used in the production of the putative models. Our new per‐molecule residue propensity descriptors show that interacting interfaces are enriched with high propensity residues except for antigenic sites, which resemble more the noninteracting regions of protein surfaces. Proteins 2009. © 2009 Wiley‐Liss, Inc.
Potential for microbial diuron mineralisation in a small wine‐growing watershed: from treated plots to lotic receiver hydrosystem
Authors: Pesce Stéphane , Martin‐Laurent Fabrice , Rouard Nadine , Montuelle Bernard
Published: March 2009

BACKGROUND: Since biological degradation processes are known to be a major driver of the natural attenuation of pesticide residues in the environment, microbial communities adapted to pesticide biodegradation are likely to play a key environmental role in reducing pesticide exposure in contaminated ecosystems. The aim of this study was to assess the diuron‐mineralising potential of microbial communities at a small‐scale watershed level, including a diuron‐treated vineyard (pollution source), its associated grass buffer strip (as a river protection area against pesticide runoff) and the lotic receiver hydrosystem (sediments and epilithon), by using radiorespirometry.

RESULTS: Comparison of results obtained at different sampling sites (in both soil and aquatic systems) revealed the importance of diuron exposure in the adaptation of microbial communities to rapid diuron mineralisation in the vineyard but also in the contaminated grass strip and in downstream epilithic biofilms and sediments.

CONCLUSION: This study provides strong suggestive evidence for high diuron biodegradation potential throughout its course, from the pollution source to the final receiving hydrosystem, and suggests that, after microbial adaptation, grass strips may represent an effective environmental tool for mineralisation and attenuation of intercepted pesticides. Copyright © 2009 Society of Chemical Industry
Anderson localization: 2‐D system in an external magnetic field and the generalized diffusion approach
Authors: Kuzovkov V. N.
Published: March 2009

The analytical approach developed by us for the calculation of the phase diagram for the Anderson localization via disorder [J. Phys.: Condens. Matter 14, 13777 (2002)] is generalized here to the case of a strong magnetic field when q subbands (q = 1, 2, 3) arise. It is shown that in a line with the generally accepted point of view, each subband is characterized by a critical point with a divergent localization length ξ which reveals anomaly in energy and disorder parameters. These critical points belong to the phase coexistence area which cannot be interpreted by means of numerical investigations. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mn and Si influence on the hyperfine properties of the fcc and hcp phases in the Fe–Mn and Fe–Mn–Si systems
Authors: Martínez Javier , Cotes Sonia M. , Desimoni Judith
Published: March 2009

A study of the hyperfine properties of the fcc and hcp phases of the Fe–Mn and Fe–Mn–Si systems, performed on a systematic and accurate set of samples belonging to the 15 at% to 30 at% Mn and 0 at% to 12 at% Si composition ranges, is presented. The samples were characterized using Conversion Electron Mössbauer Spectroscopy. The evolution with the Mn and Si contents of the hyperfine parameters of both phases has been determined. A constancy of the isomer shift parameter of the hcp phase with both constituents of the alloy was observed. While constancy and a linear decrease of the isomer shift values of the fcc phase with Mn and Si, respectively, were determined. The magnetic hyperfine field of the fcc phase presents two different values depending on the Mn content in the binary system and a decrease with the addition of Si when the ternary alloy is considered. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lost in space, the sequel: spatial sampling issues with 1‐D PHABSIM
Authors: Williams John G.
Published: March 2009

The Physical Habitat Simulation System (PHABSIM) is a popular method for evaluating the habitat value of a stream in terms of a statistic, weighted usable area (WUA). Usually, PHABSIM is used with one‐dimensional (1‐D) hydraulic models, and curves of WUA over discharge are calculated at transects and combined to produce a composite curve. Curves of WUA over discharge are often presented as evidence in proceedings to determine instream flow requirements, so the reliability of these curves is important. Representing a reach of stream with transects introduces ordinary statistical questions: is the sample of transects unbiased, and is it large enough to produce usefully precise estimates? Unfortunately, these questions are seldom considered in PHABSIM studies, even though most PHABSIM studies characterize streams with fewer than 15 transects. Moreover, transect locations usually are selected deliberately, so estimates of WUA will usually be biased. This paper extends an earlier analysis of the uncertainty in composite WUA curves with a much larger set of transect curves, with more analysis of uncertainty in the shape of the WUA curves, and with a different method for simulating errors in estimates of WUA at the transects. The results show that even with larger than usual numbers of transect curves, the precision of composite WUA curves is likely to be poor, especially if there are errors in the transect WUA curves. I also offer suggestions regarding sampling, and for estimating the number of transects that might be needed to achieve a given level of precision in WUA estimates. Copyright © 2009 John Wiley & Sons, Ltd.
The climate for undergraduate teaching and learning in STEM fields
Authors: Baldwin Roger G.
Published: March 2009

Many stakeholders must cooperate to improve STEM undergraduate education.
Supportive teaching and learning strategies in STEM education
Authors: Smith Karl A. , Douglas Tameka Clarke , Cox Monica F.
Published: March 2009

This chapter provides faculty with design principles based on the How People Learn framework, as well as current best practices for designing engaged learning environments in STEM classes in the hope of continuing improvement in STEM education.
Facilitating reforms in STEM undergraduate education: An administrative perspective
Authors: Litzinger Thomas A. , Koubek Richard J. , Wormley David N.
Published: March 2009

This chapter describes insights gained in the College of Engineering at Penn State in implementing collegewide, department‐focused, and faculty‐centered educational reforms.
Comparative toxicity of bentazon and molinate on growth, photosynthetic pigments, photosynthesis, and respiration of the Portuguese ricefield cyanobacterium Nostoc muscorum
Authors: Galhano Victor , Peixoto Francisco , Gomes‐Laranjo José , Fernández‐Valiente Eduardo
Published: March 2009

Bentazon and molinate are selective herbicides recommended for integrated weed management in rice. Their toxicity on growth and some biochemical and physiological parameters of Nostoc muscorum, an abundant cyanobacterium in Portuguese rice fields, was evaluated under laboratory conditions during time‐ and concentration‐dependent exposure for 72 h. Results showed that toxic concentrations (0.75–2 mM) of both herbicides have pleiotropic effects on the cyanobacterium. Molinate was more toxic than bentazon to growth, respiration, chlorophyll‐a, carotenoids, and phycobiliproteins contents. Protein content was increased by both herbicides although the effect was particularly evident with higher concentrations of molinate (1.5–2 mM). The herbicides had contrasting effects on carbohydrates content: molinate increased this organic fraction whereas bentazon decreased it. Photosynthesis and respiration were inhibited by both herbicides. © 2009 Wiley Periodicals, Inc. Environ Toxicol, 2010.
On the characteristics of routing paths and the performance of routing protocols in vehicle‐formed mobile ad hoc networks on highways
Authors: Wang S. Y. , Chou C. L. , Lin C. C.
Published: March 2009

Recently, intelligent transportation systems (ITS) is becoming an important research topic. One goal of ITS is to exchange information among vehicles in a timely and efficient manner. In the ITS research community, inter‐vehicle communications (IVC) is considered a way that may be able to achieve this goal. An information network built on the top of vehicles using IVC can be viewed as a type of mobilead hocnetworks (MANETs). In the past, several unicast routing protocols for MANET have been proposed. However, most of them are designed for general MANETs rather than for IVC networks.

In this paper, we first used more realistic vehicle mobility traces generated by a microscopic traffic simulator (VISSIM) to understand the characteristics of routing paths in an IVC network. Based on the insights gained from the derived path characteristics, we designed and implemented an intelligent flooding‐based routing protocol for small‐scale IVC networks.Viaseveral field trials conducted on highways, we compared the performance ofad hocon‐demand distance vector (AODV) and our protocol. Our experimental results show that (1) our protocol outperforms AODV greatly in IVC networks and (2) our protocol can provide text, image, audio, and video services for small‐scale IVC networks (e.g., a platoon) quite well. Copyright © 2009 John Wiley & Sons, Ltd.
Influence of the Solvent on the Formation of New Tin(II) Methoxides Containing Thienyl Substituents: Crystal Structure and NMR Investigations
Authors: Veith Michael , Belot Céline , Huch Volker , Zimmer Michael
Published: March 2009

The synthesis, structural characterization, and NMR studies of new tin(II) alkoxides with thiophene‐based substituents are presented. The reaction of ligand HO–C(C4H3S)3 (1) with bis(hexamethyldisilazyl)tin {Sn[N(SiMe3)2]2} in the ratio 2:1 in toluene yields the dinuclear compound {Sn[OC(C4H3S)3]2}2·2 toluene (2). The same reaction in tetrahydrofuran allows the isolation of two compounds: a dinuclear {Sn[OC(C4H3S)3]2}2·2 thf (3) and a mononuclear Sn[OC(C4H3S)3]2(thf) (4) molecule. The molecular structures of these tin(II) methoxides containing thienyl substituents 2–4 were investigated by single‐crystal X‐ray crystallography. The NMR spectra of solutions of {Sn[OC(C4H3S)3]2}2·2 toluene (2) or {Sn[OC(C4H3S)3]2}2·2 thf (3) and Sn[OC(C4H3S)3]2(thf) (4) are almost identical, showing only variations of the molar ratio of the dimeric and monomeric compounds.
Structure and Properties of Mixed‐valence Compound Eu5Zr3S12
Authors: Jakubcová Petra , Schappacher Falko M. , Pöttgen Rainer , Johrendt Dirk
Published: March 2009

Needle‐shaped crystals of Eu5Zr3S12 and Eu3.67Sr1.33Zr3S12 were synthesized by solid‐state reactions of the elements and ZrS2 at 673–1273 K in alumina crucibles, and their crystal structures were determined by single‐crystal methods. They are isotypic with hexagonal symmetry (space group P2m, Z = 1, Eu5Zr3S12: a = 1170.7(2), c = 394.27(8) pm, wR2 = 0.0636 for 552 F2 and 27 parameters; Eu3.67Sr1.33Zr3S12: a = 1167.0(2), c = 395.71(8) pm, wR2 = 0.0887 for 484 F2 and 29 parameters) and contain one‐dimensional chains of edge‐sharing ZrS2S4/2 octahedra running parallel to [001]. Two europium sites are seven‐ or ninefold‐coordinated by sulfur. Eu5Zr3S12 is a Curie paramagnet with an effective magnetic moment of μeff = 13.37(1) μB per formula unit (fu), in agreement with three Eu2+/fu. 151Eu Mössbauer spectra show two absorption lines suggesting a static mixture of Eu2+ and Eu3+ in accordance with Eu32+Eu23+Zr34+S122–.This assignment is not in line with the observed Eu–S distances. To resolve this, we suggest pure Eu2+ at the 2c site and inhomogeneous mixed valence at the 3f site according to (Eu22+)2c(Eu2+Eu23+)3fZr34+S122–. This is supported by the site preference of Sr2+ in Eu3.67Sr1.33Zr3S12.
Public Health and Policy Issues of Hernia Surgery in Africa
Authors: Kingsnorth Andrew N. , Clarke Michael G. , Shillcutt Samuel D.
Published: March 2009

Inguinal hernia repair has been overlooked as a public health priority in Africa, with its high prevalence largely unrecognized, and traditional public health viewpoints assuming that not enough infrastructure, human resources, or financing capacity are available for effective service provision. Emerging evidence suggests that inguinal hernias in Ghana are approximately ten times as prevalent as in high‐income countries, are much more long‐standing and severe, and can be repaired with low‐cost techniques using mosquito net mesh through international collaboration. Outcomes from surgery are comparable to published literature, and potential exists for scaling up capacity. Special attention must be paid to creating financing systems that encourage eventual local self‐sustainability.
Creatine transporter deficiency in two adult patients with static encephalopathy
Authors: Sempere A. , Fons C. , Arias A. , Rodríguez‐Pombo P. , Colomer R. , Merinero B. , Alcaide P. , Capdevila A. , Ribes A. , Artuch R. , Campistol J.
Published: March 2009

Creatine transporter deficiency is a recently identified X‐linked inborn error of metabolism. The natural course of the disease is not well delineated since clinical data from adult patients have scarcely been reported. A progressive course of the disease has been noted in a few described cases. We report the first two Spanish adult patients with creatine transporter deficiency and compare their clinical phenotype and the evolution of the disease with those of other published cases. The two brothers were identified in a study of a cohort of 610 mentally handicapped male patients. The disease was detected by biochemical studies and confirmed by DNA studies. The most significant clinical features were mental retardation, epilepsy and autistic behaviour, and these symptoms did not worsen, in contrast to other reports. They did not present gastrointestinal problems or movement disorders. Creatine transporter deficiency could be an underdiagnosed metabolic disorder and should be considered in adult patients with mental retardation. Clinical presentation of this disorder showed marked differences among adult patients and the course of the disease was static in our cases. Detection of additional adult patients might allow better understanding of the phenotypic outcome at a later age.
Omental Free-tissue Transfer for Coverage of Complex Upper Extremity and Hand Defects—The Forgotten Flap
Authors: Seitz Iris A. , Williams Craig S. , Wiedrich Thomas A. , Henry Ginard , Seiler John G. , Schechter Loren S.
Published: March 2009

Free omental tissue transfer is a versatile reconstructive option for trunk, head and neck, and extremity reconstruction. Its utility is due to the length and caliber of the vascular pedicle and the malleability and surface area of the flap. We report our experience with omental free flap coverage of complex upper-extremity defects. A retrospective analysis of eight omental free-tissue transfers in seven patients with complex upper-extremity defects between 1999 and 2008 was performed. Indications, operative technique, and outcome were evaluated. Patient age ranged from 12 to 59 years with five male and two female patients. Indications included tissue defects due to crush-degloving injuries, pitbull mauling, or necrotizing soft tissue infection. All patients had prior operations including: revascularization, debridement, tendon repair, skin grafts, and/or fixation of associated fractures. One patient sustained severe bilateral crush-degloving injuries requiring free omental hemiflap coverage of both hands. The mean defect size was 291 cm2 with all patients achieving complete wound coverage. No flap loss or major complications were noted. Laparoscopic-assisted omental free flap harvest was performed in conjunction with the general surgery team in three cases. Mean follow-up was 2 years. The omental free flap is a valuable, often overlooked reconstructive option. The long vascular pedicle and large amount of pliable, well-vascularized tissue allow the flap to be aggressively contoured to meet the needs of complex three-dimensional defects. In addition, laparoscopic-assisted harvest may aid with flap dissection and may result in reduced donor-site morbidity.
High dose Losartan and ACE gene polymorphism in IgA nephritis
Authors: Woo Keng-Thye , Chan Choong-Meng , Choong Hui-Lin , Tan Han-Kim , Foo Marjorie , Lee Evan J. C. , Tan Chorh-Chuan , Lee Grace S. L. , Tan Seng-Hoe , Vathsala A. , Lim Cheng-Hong , Chiang Gilbert S. C. , Fook-Chong Stephanie , Yi Zhao , Tan H. B. , Wong Kok-Seng
Published: March 2009

Background/aimsSeveral studies have reported varying results of the influence of ACE gene on ACEI/ARB therapy. The efficacy of high dose ARB and its influence on ACE gene have not been explored. This is a 6 year randomised trial in IgA nephritis comparing high dose ARB (Losartan 200 mg/day) with normal dose ARB (Losartan 100 mg/day), normal dose ACEI (20 mg/day) and low dose ACEI (10 mg/day).ResultsPatients on high dose ARB had significantly lower proteinuria, 1.0 ± 0.8 gm/day compared to 1.7 ± 1.0 g/day in the other groups (P = 0.0005). The loss in eGFR was 0.7 ml min−1year−1for high dose ARB compared to 3.2–3.5 ml min−1year−1for the other three groups (P = 0.0005). There were more patients on high dose ARB with improvement in eGFR compared to other three groups (P < 0.001). Comparing patients with the three ACE genotypes DD, ID and II, all three groups responded well to therapy with decrease in proteinuria (P < 0.002). Only those on low dose ACEI (10 mg/day) with the I allele had increased in ESRF (P = 0.037).ConclusionHigh dose ARB is more efficacious in reducing proteinuria and preserving renal function when compared with normal dose ARB and ACEI, and also obviates the genomic influence of ACE gene polymorphism on renal survival.
Combination of Polymer Technology and Carbon Nanotube Array for the Development of an Effective Drug Delivery System at Cellular Level
Authors: Riggio Cristina , Ciofani Gianni , Raffa Vittoria , Cuschieri Alfred , Micera Silvestro
Published: March 2009

In this article, a carbon nanotube (CNT) array-based system combined with a polymer thin film is proposed as an effective drug release device directly at cellular level. The polymeric film embedded in the CNT array is described and characterized in terms of release kinetics, while in vitro assays on PC12 cell line have been performed in order to assess the efficiency and functionality of the entrapped agent (neural growth factor, NGF). PC12 cell differentiation, following incubation on the CNT array embedding the alginate delivery film, demonstrated the effectiveness of the proposed solution. The achieved results indicate that polymeric technology could be efficiently embedded in CNT array acting as drug delivery system at cellular level. The implication of this study opens several perspectives in particular in the field of neurointerfaces, combining several functions into a single platform.
Factors associated with deliberate self‐harm behaviour among depressed adolescent outpatients
Authors: Tuisku Virpi , Pelkonen Mirjami , Kiviruusu Olli , Karlsson Linnea , Ruuttu Titta , Marttunen Mauri
Published: March 2009

This study examined whether depressed adolescent outpatients with deliberate self‐harm behaviour (DSH) differed from non‐suicidal depressed adolescent outpatients in depressive and anxiety symptoms, alcohol use, perceived social support and number of negative life‐events. Depressed adolescent outpatients (n = 155) aged 13–19 years were interviewed using K‐SADS‐PL for DSM‐IV Axis I diagnoses and completed self‐report questionnaires. Suicidal behaviour was assessed by K‐SADS‐PL suicidality items. Depressed adolescents with DSH were younger, perceived less support from the family, had more severe depressive symptoms and used more alcohol than non‐suicidal depressed adolescents. Adolescents with DSH and suicidal ideation or suicide attempts had more depressive and anxiety symptoms than adolescents with DSH only. Adolescents with severe internalizing distress symptoms are at risk not only for DSH, but also additional suicidal behaviour. Family interventions may be needed in the treatment of depressed adolescents with DSH.
Developmental changes and gender differences in adolescents' perceptions of friendships
Authors: De Goede Irene H.A. , Branje Susan J.T. , Meeus Wim H.J.
Published: March 2009

This five‐wave study aims to investigate the development of adolescents' perceptions of support, negative interaction, and power in best friendships from ages 12 to 20 years. Furthermore, gender differences and linkages between the three dimensions are explored. A total of 593 early adolescents (53.6% boys) and 337 middle adolescents (43.3% boys) participated. A multigroup multivariate accelerated growth curve showed an increase of support for both boys and girls. Negative interaction was found to temporarily increase and then decrease for boys, while remaining stable for girls. Power temporarily increased for boys and decreased for girls. Results indicated that (1) friendships become more supportive during adolescence, (2) power issues are more prominent in friendships of boys and more powerful peers are perceived as more supportive by boys but not by girls, and (3) friendships of boys show a lagged development towards more equality.
‘Canonici Albi et Moniales’: Perceptions of the Twelfth-Century Double House
Authors: SYKES KATHARINE
Published: March 2009

In contrast with recent assertions that the term ‘double house’ is both anachronistic and dysfunctional when used with reference to mixed communities of the twelfth century, this paper demonstrates that contemporary writers did in fact perceive a difference between religious houses that housed both men and women, and a small group of ‘houses of canons and nuns’. The absence of a more specific term was in itself an indication of the perceived novelty of such houses, which were seen as diverging both from earlier Anglo-Saxon mixed communities, and from other twelfth-century houses for men and women.