bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of a reference region model with direct measurement of an AIF in the analysis of DCE‐MRI data
Authors: Yankeelov Thomas E. , Cron Greg O. , Addison Christina L. , Wallace Julia C. , Wilkins Ruth C. , Pappas Bruce A. , Santyr Giles E. , Gore John C.
Published: January 2007

Models have been developed for analyzing dynamic contrast‐enhanced (DCE)‐MRI data that do not require measurements of the arterial input function (AIF). In this study, experimental results obtained from a reference region (RR) analysis are compared with results of an AIF analysis in the same set of five animals (four imaged twice, yielding nine data sets), returning estimates of the volume transfer constant (Ktrans) and the extravascular extracellular volume fraction (ve). Student's t‐test values for comparisons of Ktrans and ve between the two models were 0.14 (P = 0.88) and 0.85 (P > 0.4), respectively (where the high P‐values indicate no significant difference between values derived from the two models). Linear regression analysis indicated there was a correlation between Ktrans extracted by the two methods: r2 = 0.80, P = 0.001 (where the low P‐value indicates a significant linear correlation). For ve there was no such correlation (r2 = 0.02). The mean (absolute) percent difference between the models was 22.0% for Ktrans and 28.1% for ve. However, the RR parameter values were much less precise than the AIF method. The mean SDs for Ktrans and ve for the RR analysis were 0.024 min–1 and 0.06, respectively, vs. 0.002 min–1 and 0.03 for AIF analysis. Magn Reson Med 57:353–361, 2007. © 2007 Wiley‐Liss, Inc.
Single‐shot ADC imaging for fMRI
Authors: Song Allen W. , Guo Hua , Truong Trong‐Kha
Published: January 2007

It has been suggested that apparent diffusion coefficient (ADC) contrast can be sensitive to cerebral blood flow (CBF) changes during brain activation. However, current ADC imaging techniques have an inherently low temporal resolution due to the requirement of multiple acquisitions with different b‐factors, as well as potential confounds from cross talk between the deoxyhemoglobin‐induced background gradients and the externally applied diffusion‐weighting gradients. In this report a new method is proposed and implemented that addresses these two limitations. Specifically, a single‐shot pulse sequence that sequentially acquires one gradient‐echo (GRE) and two diffusion‐weighted spin‐echo (SE) images was developed. In addition, the diffusion‐weighting gradient waveform was numerically optimized to null the cross terms with the deoxyhemoglobin‐induced background gradients to fully isolate the effect of diffusion weighting from that of oxygenation‐level changes. The experimental results show that this new single‐shot method can acquire ADC maps with sufficient signal‐to‐noise ratio (SNR), and establish its practical utility in functional MRI (fMRI) to complement the blood oxygenation level‐dependent (BOLD) technique and provide differential sensitivity for different vasculatures to better localize neural activity originating from the small vessels. Magn Reson Med 57:417–422, 2007. © 2007 Wiley‐Liss, Inc.
Real‐time shimming to compensate for respiration‐induced B0 fluctuations
Authors: van Gelderen P. , de Zwart J.A. , Starewicz P. , Hinks R.S. , Duyn J.H.
Published: January 2007

In MRI of human brain, the respiratory cycle can induce B0‐field fluctuations through motion of the chest and fluctuations in local oxygen concentration. The associated NMR frequency changes can affect the MRI data in various ways and lead to temporal signal fluctuations, and image artifacts such as ghosting and blurring. Since the size of the effect scales with magnetic field strength, artifacts become particularly problematic at fields above 3.0T. Furthermore, the spatial dependence of the B0‐field fluctuations complicates their correction. In this work, a new method is presented that allows compensation of field fluctuations by modulating the B0 shims in real time. In this method, a reference scan is acquired to measure the spatial distribution of the B0 effect related to chest motion. During the actual scan, this information is then used, together with chest motion data, to apply compensating B0 shims in real time. The method can be combined with any type of scan without modifications to the pulse sequence. Real‐time B0 shimming is demonstrated to substantially improve the phase stability of EPI data and the image quality of multishot gradient‐echo (GRE) MRI at 7T. Magn Reson Med 57:362–368, 2007. © 2007 Wiley‐Liss, Inc.
Proposed radiofrequency phased‐array excitation scheme for homogenous and localized 7‐Tesla whole‐body imaging based on full‐wave numerical simulations
Authors: Abraham Roney , Ibrahim Tamer S.
Published: January 2007

In this article, a radiofrequency (RF) excitation scheme for 7‐Tesla (T) whole‐body applications is derived and analyzed using the finite difference time domain (FDTD) method. Important features of the proposed excitation scheme and coil (a potential 7T whole‐body transverse electromagnetic [TEM] resonator design), from both operational and electromagnetic perspectives, are discussed. The choice of the coil's operational mode is unconventional; instead of the typical “homogenous mode,” we use a mode that provides a null field in the center of the coil at low‐field applications. Using a 3D FDTD implementation of Maxwell's equations, we demonstrate that the whole‐body 7T TEM coil (tuned to the aforementioned unconventional mode and excited in an optimized near‐field, phased‐array fashion) can potentially provide 1) homogenous whole‐slice (demonstrated in three axial, sagittal, and coronal slices) and 2) 3D localized (demonstrated in the heart) excitations. As RF power was not considered as a part of the optimization in several cases, the significant improvements achieved by whole‐slice RF excitation came at the cost of considerable increases in RF power requirements. Magn Reson Med 57:235–242, 2007. © 2007 Wiley‐Liss, Inc.
Quantitative magnetization transfer imaging via selective inversion recovery with short repetition times
Authors: Gochberg Daniel F. , Gore John C.
Published: January 2007

Quantitative magnetization transfer imaging (qMTI) methods are able to estimate fundamental sample parameters, such as the relative size of the solid‐like macromolecular proton pool and the spin exchange rate between this pool and the directly measured free water protons. One such method is selective inversion recovery (SIR), in which the free water protons are selectively inverted and the signal is fit to a biexponential function of the inversion time (TI). SIR uses only low‐power pulses and requires no separate RF (B1) or static field (B0) field maps, and the analysis is largely independent of the macromolecular pool lineshape. These are all advantages over steady‐state off‐resonance saturation qMTI methods. However, up to now, SIR has been implemented only with repetition times TR ≫ T1. This paper describes a modification of SIR with smaller TR values and a greater signal‐to‐noise ratio (SNR) efficiency. Magn Reson Med 57:437–441, 2007. © 2007 Wiley‐Liss, Inc.
Impact of coil design on the contrast‐to‐noise ratio, precision, and consistency of quantitative cartilage morphometry at 3 Tesla: A pilot study for the osteoarthritis initiative
Authors: Eckstein Felix , Kunz Manuela , Hudelmaier Martin , Jackson Rebecca , Yu Joseph , Eaton Charles B. , Schneider Erika
Published: January 2007

Phased‐array (PA) coils generally provide higher signal‐to‐noise ratios (SNRs) than quadrature knee coils. In this pilot study for the Osteoarthritis Initiative (OAI) we compared these two types of coils in terms of contrast‐to‐noise ratio (CNR), precision, and consistency of quantitative femorotibial cartilage measurements. Test‐retest measurements were acquired using coronal fast low‐angle shot with water excitation (FLASHwe) and coronal multiplanar reconstruction (MPR) of sagittal double‐echo steady state with water excitation (DESSwe) at 3T. The precision errors for cartilage volume and thickness were ≤2.6% for the quadrature coil and ≤2.3% for the PA coil with FLASHwe, and ≤2.3%/≤2.5% with DESSwe. The precision for aggregate medial and lateral cartilage measures was significantly higher than that for single plates, independently of coil and sequence. The PA coil measurements did not always fully agree with the quadrature coil measurements, and some differences were significant. The higher CNR of the PA coil did not translate directly into improved precision of cartilage measurement; however, summing up cartilage plates within the medial and lateral compartment reduced precision errors. Magn Reson Med 57:448–454, 2007. © 2007 Wiley‐Liss, Inc.
Novel strategy for cerebral 13C MRS using very low RF power for proton decoupling
Authors: Li Shizhe , Yang Jehoon , Shen Jun
Published: January 2007

One of the major difficulties of in vivo 13C MRS is the need to decouple the large, one‐bond, 1H‐13C scalar couplings in order to obtain useful signal‐to‐noise ratios (SNRs) and spectral resolution at magnetic field strengths that are accessible to clinical studies. In this report a new strategy for in vivo cerebral 13C MRS is proposed. We realized that the turnover kinetics of glutamate (Glu) C5 from exogenous [2‐13C]glucose (Glc) is identical to that of Glu C4 from exogenous [1‐13C]Glc. The carboxylic/amide carbons are only coupled to protons via very weak long‐range 1H‐13C scalar couplings. As such, they can be effectively decoupled at very low RF power. Therefore, decoupling of the large 1H‐13C scalar couplings can be avoided by the use of [2‐13C]Glc. An additional advantage of this strategy is the lack of contamination from subcutaneous lipids because there are no overlapping fat signals in the vicinity of the Glu C5 and glutamine (Gln) C5 peaks. The feasibility of this strategy was demonstrated using 13C MRS on rhesus monkey brains at 4.7T. Magn Reson Med 57:265–271, 2007. © 2007 Wiley‐Liss, Inc.
Reducing susceptibility artifacts in fMRI using volume‐selective z‐shim compensation
Authors: Du Yiping P. , Dalwani Manish , Wylie Korey , Claus Eric , Tregellas Jason R.
Published: January 2007

Susceptibility‐induced magnetic field gradients (SFGs) can result in severe signal loss in the orbitofrontal cortex (OFC) in gradient‐echo‐based functional MRI (fMRI) studies. Although conventional z‐shim techniques can effectively recover the MRI signal in this region, the substantial penalty in imaging time hampers their use in routine fMRI studies. A modified z‐shim technique with high imaging efficiency is presented in this study. In this technique, z‐shim compensations are applied only to a selective volume where the susceptibility artifact is severe. The results of an fMRI study (N = 6) demonstrate the feasibility of detecting the OFC activation with z‐shim in whole‐brain fMRI studies at a temporal resolution of 2 s. Magn Reson Med 57:396–404, 2007. © 2007 Wiley‐Liss, Inc.
Simplified quantitative description of amide proton transfer (APT) imaging during acute ischemia
Authors: Sun Phillip Zhe , Zhou Jinyuan , Huang Judy , van Zijl Peter
Published: January 2007

Amide proton transfer (APT) imaging employs the chemical exchange saturation transfer (CEST) mechanism to detect mobile endogenous proteins and peptides. It can be used to detect pH reduction during acute ischemia and thus provide complementary information to perfusion‐weighted (PWI) and diffusion‐weighted (DWI) imaging. However, the APT contrast depends strongly on the choice of imaging parameters, especially the radiofrequency (RF) saturation time and strength, which need to be optimized. In this work it is shown that even though at least three proton pools are present, the description of the APT process during acute ischemia can be greatly simplified by means of a dual two‐pool model analysis. With this approach, the experimentally measured RF irradiation power dependence of the effect in the rat brain was well predicted. The results showed an optimal RF strength of 0.75 μT for our particular coil setup, and a maximally obtainable APT ratio difference of 2.9% ± 0.3% between ischemic and normal brain regions. Magn Reson Med 57:405–410, 2007. © 2007 Wiley‐Liss, Inc.
Transceive surface coil array for MRI of the human prostate at 4T
Authors: Pinkerton Robert G. , Near James P. , Barberi Enzo A. , Menon Ravi S. , Bartha Robert
Published: January 2007

A novel torso transceive surface coil array for prostate magnetic resonance imaging (MRI) and spectroscopy (MRS) at 4T is presented. It is shown that with the use of a conformal transceive surface coil array with 50 Ω transmitter amplifiers and receiver preamplifiers, one can perform whole‐volume torso imaging while maintaining the high signal‐to‐noise ratio (SNR) inherent to surface coil designs. Recent theoretical considerations have shown that by focusing the infringing radiofrequency (RF) electromagnetic field, one can achieve increased penetration and signal homogeneity compared to a conventional circularly polarized driving scheme. A variation of this driving scheme particular to the proposed coil design resulted in a twofold increase in SNR in the prostate compared to that achieved with a conventional circularly polarized driving scheme. The novel transceive surface coil array presented is capable of full‐volume imaging of the human torso at 4T while maintaining signal penetration in the deep region of the prostate gland. Magn Reson Med 57:455–458, 2007. © 2007 Wiley‐Liss, Inc.
Minimizing macrovessel signal in cerebral perfusion imaging using independent component analysis
Authors: Reishofer G. , Fazekas F. , Keeling S. , Enzinger C. , Payer F. , Simbrunner J. , Stollberger R.
Published: January 2007

The pronounced susceptibility effect of macrovessels in MR bolus‐tracking studies induces spots of artificially high blood flow and volume in perfusion parameter images. These high‐intensity regions impede the detection of perfusion changes and lead to elevated perfusion parameters in adjacent tissues. The purpose of this work was to explore postprocessing methods to reduce the influence of macrovessel signal in dynamic MRI. After data reduction was performed with the use of a principal component analysis (PCA), an independent component analysis (ICA) was applied to separate signal components of different compartments. Based on this decomposition, the dynamic time series were reconstructed with minimized contributions of macrovessel signal and noise. The influence of the temporal resolution and signal‐to‐noise ratio (SNR) of the source data were investigated by means of a simulation study. A region‐of‐interest (ROI)‐based analysis of corrected and uncorrected in vivo data demonstrated that the influence of arteries and veins was reduced at least by 50%, while gray matter (GM) and white matter (WM) tissues were nearly unaffected by the correction process. Hemodynamic parameter images of the cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) were calculated from corrected and uncorrected scans. The corrected parameter images showed a clearly reduced macrovessel signal and an improved perceptibility of microvascular perfusion changes compared to the uncorrected ones. Magn Reson Med 57:278–288, 2007. © 2007 Wiley‐Liss, Inc.
Tunneling time of electronic wave packet through a parabolic quantum well with double barrier
Authors: Gong J. , Liang X. X. , Ban S. L.
Published: January 2007

The tunneling time of electrons through a parabolic quantum well structure has been investigated. A time‐dependent Schrödinger equation has been numerically solved using the transfer‐matrix method and wave packet dynamic theory. The results show that the probability density of the electron inside the parabolic well first builds up to a maximum and then decays exponentially with time. Furthermore, the dependence of the build‐up time on the structure parameters of the system is weak, but the resonant tunneling lifetime decreases rapidly with the increase of the well width and barrier thickness. It can also be seen from our results that the build‐up time may be longer than the resonant tunneling lifetime for a narrow well. By comparing the parabolic well with a rectangular well, it is also found that the resonant tunneling lifetime through the parabolic quantum well is longer than that through the rectangular one in the case of a wide well with thin barriers. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of cubic nonlinearity on laser radiation transmission in a photonic crystal with spatially modified media properties
Authors: Vetrov S. Ya. , Timofeev I. V. , Shabanov A. V.
Published: January 2007

The transfer matrix method was modified to explore the Kerr nonlinearity influence on laser radiation propagation in a one‐dimensional photonic crystal. The suggested spatial distribution of the refractive index allows to remove minibands and to make the transmission curve much steeper. Plain and steep photonic band gap edges are effective in creation of transmission anisotropy of powerful laser radiation. The investigated photonic crystal has a strong anisotropic optical transmission and acts as an optical analog of the electronic diode. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Desegregated learning: An innovative framework for programs of study
Authors: Fuentes Arturo A. , Freeman Robert , Crown Stephen , Kypuros Javier , Mahdi Hashim
Published: January 2007

This chapter presents an innovative framework for a mechanical engineering program of study termed desegregated learning. The goal is not desegregation but rather to promote a higher level of learning and to look for opportunities where desegregating the learning environment yields optimal results with reasonable costs and complexity.
The development of adaptive expertise in biotransport
Authors: Martin Taylor , Petrosino Anthony J. , Rivale Stephanie , Diller Kenneth R.
Published: January 2007

This chapter describes a model for continuous development of adaptive expertise, including growth along the dimensions of innovation and knowledge, examined in the context of a biotransport course in biomedical engineering. Students improved on both knowledge and innovation, moving along a continuum toward adaptive expertise.
Teaching writing in a laboratory‐based engineering course with a “How People Learn” framework
Authors: Yalvac Bugrahan , Smith H. David , Hirsch Penny L. , Birol Gülnor
Published: January 2007

This chapter discusses the effectiveness of an HPL framework used in a laboratory‐based, tissue‐engineering module designed in part to improve students' written communication skills. It illustrates a successful implementation of written communication instruction that does not compromise content knowledge instruction.
Framing youth issues for public support
Authors: Lochner Ann , Bales Susan Nall
Published: January 2007

Communicating effectively about the community's role in promoting positive youth development is critical to generating public support for quality youth programs.
Toward a new paradigm for youth development
Authors: Blyth Dale A.
Published: January 2007

A diet‐and‐exercise analogy is proposed to provide a new way of understanding the complexity of youth development and the increased role of youth in shaping that development during the middle years.
Dilemmas of youth work: Balancing the professional and personal
Authors: Walker Kathrin C. , Larson Reed W.
Published: January 2007

Youth workers encounter numerous dilemmas in their daily practice, including tension created by relating to youth in a professional versus a personal way.
A Prospective, Longitudinal Outcome Study of Patients with Carpal Tunnel Surgery and the Relationship of Body Mass Index
Authors: Bodavula Venkata Krishna Rao , Dubin Norman H. , Wilgis E. F. Shaw , Burke Frank D. , Bradley Mary J.
Published: January 2007

This study investigated whether body mass index (BMI) was associated with effectiveness of carpal tunnel release as measured by physical and self-assessment tests. This prospective, longitudinal study was conducted from March 2001 to March 2003 using 598 cases (hands) diagnosed with carpal tunnel syndrome and scheduled for surgery at The Curtis National Hand Center, Baltimore, Maryland, and at the Pulvertaft Hand Centre, Derby, England. Body mass index was calculated, and demographic, clinical, and functional data were collected preoperatively and at 6-month follow-up. Grip, pinch, and Semmes–Weinstein scores were measured preoperatively and at 6-month follow-up. Levine–Katz self-assessment scores for symptom severity and functional status were measured preoperatively and at 6-month follow-up. Grip and pinch increased, whereas Semmes–Weinstein, symptom severity, and functional scores decreased by 6-month follow-up. Cases with BMI >35 had lower grip strength and higher symptom severity in males and higher functional status in both sexes pre- and postoperatively compared to normal-weight BMI cases. BMI had no relationship to patient satisfaction. Although morbidly obese cases did worse on some physical and self-assessment tests compared to normal BMI cases preoperatively, all improved to the same extent postoperatively regardless of BMI.
Comparison of the Structures of Triacylglycerols from Native and Transgenic Medium‐Chain Fatty Acid‐Enriched Rape Seed Oil by Liquid Chromatography–Atmospheric Pressure Chemical Ionization Ion‐Trap Mass Spectrometry (LC–APCI‐ITMS)
Authors: Beermann Christopher , Winterling Nadine , Green Angelika , Möbius Michael , Schmitt Joachim J. , Boehm Günther
Published: January 2007

The sn position of fatty acids in seed oil lipids affects physiological function in pharmaceutical and dietary applications. In this study the composition of acyl‐chain substituents in the sn positions of glycerol backbones in triacylglycerols (TAG) have been compared. TAG from native and transgenic medium‐chain fatty acid‐enriched rape seed oil were analyzed by reversed‐phase high performance liquid chromatography coupled with online atmospheric‐pressure chemical ionization ion‐trap mass spectrometry. The transformation of summer rape with thioesterase and 3‐ketoacyl‐[ACP]‐synthase genes of Cuphea lanceolata led to increased expression of 1.5% (w/w) caprylic acid (8:0), 6.7% (w/w) capric acid (10:0), 0.9% (w/w) lauric acid (12:0), and 0.2% (w/w) myristic acid (14:0). In contrast, linoleic (18:2n6) and alpha‐linolenic acid (18:3n3) levels decreased compared with the original seed oil. The TAG sn position distribution of fatty acids was also modified. The original oil included eleven unique TAG species whereas the transgenic oil contained sixty. Twenty species were common to both oils. The transgenic oil included trioctadecenoyl‐glycerol (18:1/18:1/18:1) and trioctadecatrienoyl‐glycerol (18:3/18:3/18:3) whereas the native oil included only the latter. The transgenic TAG were dominated by combinations of caprylic, capric, lauric, myrisitic, palmitic (16:0), stearic (18:0), oleic (18:1n9), linoleic, arachidic (20:0), behenic (22:0), and lignoceric acids (24:0), which accounted for 52% of the total fat. In the original TAG palmitic, stearic, oleic, and linoleic acids accounted for 50% of the total fat. Medium‐chain triacylglycerols with capric and lauric acids combined with stearic, oleic, linoleic, alpha‐linolenic, arachidic, and gondoic acids (20:1n9) accounted for 25% of the transgenic oil. The medium‐chain fatty acids were mainly integrated into the sn‐1/3 position combined with the essential linoleic and alpha‐linolenic acids at the sn‐2 position. Eight species contained caprylic, capric, and lauric acids in the sn‐2 position. The appearance of new TAG in the transgenic oil illustrates the extensive effect of genetic modification on fat metabolism by transformed plants and offers interesting possibilities for improved enteral applications.
Substance P enhances soluble ICAM‐1 release from adult rat cardiac fibroblasts by a p42/44 MAPK‐ and PKC‐mediated mechanism
Authors: Sapna S. , Shivakumar K.
Published: January 2007

Substance P, a pro‐inflammatory neuropeptide, is released from cardiac peptidergic nerves under conditions like ischemia but whether it modulates inflammatory processes in the heart remains unexplored. This study demonstrates for the first time that substance P augments the production of the soluble form of intercellular adhesion molecule‐1, sICAM‐1, by adult rat cardiac fibroblasts. However, RT‐PCR showed no concomitant increase in ICAM‐1 transcript levels, suggesting that the increase in sICAM‐1 may involve post‐transcriptional/translational mechanisms. Use of pharmacological inhibitors revealed that the stimulatory effect of substance P on sICAM‐1 production is mediated by p42/44 MAPK and protein kinase C. Preliminary experiments also showed that the neuropeptide stimulates the production of prostaglandin E2 by cardiac fibroblasts. The findings support the postulation that substance P may modulate multiple inflammatory responses within the myocardium through release of pro‐inflammatory mediators from resident fibroblasts.
Anti‐apoptotic activity of Bcl‐2 is enhanced by its interaction with RTN3
Authors: Zhu Lei , Xiang Rong , Dong Wei , Liu Yingle , Qi Yipeng
Published: January 2007

Bcl‐2 is known as a critical inhibitor of apoptosis triggered by a broad range of stimuli, mainly acting on the mitochondria. It can interact with many members of the Bcl‐2 family, influence mitochondrial membrane permeability and modulate cell apoptosis. RTN3, a member of the reticulon (RTN) family, was predominantly localized on the endoplasmic reticulum (ER). Its N‐ and C‐termini, both facing the cytoplasm, can recruit some proteins to the ER to modulate some physiological functions. We found that RTN3, which does not belong to the Bcl‐2 family, can interact with Bcl‐2 on the ER. In normal HeLa cells, ectopic overexpressed Bcl‐2 could reduce the cell apoptosis induced by overexpressed RTN3. When the HeLa cells stably expressing Bcl‐2 were treated with tunicamycin, endogenous RTN3 increased in the cell microsomal fraction. This change increased the Bcl‐2 in microsomal fractions and also in the mitochondrial fractions where the anti‐apoptotic activity of Bcl‐2 mainly acts. These results suggest that RTN3 could bind with Bcl‐2 and mediate its accumulation in mitochondria, which modulate the anti‐apoptotic activity of Bcl‐2.
α1‐adrenergic stress induces downregulation of Na+/Ca2+ exchanger in myocardial preparations from rabbits at physiological preload
Authors: Schillinger Wolfgang , Christians Claus , Sossalla Samuel , Teucher Nils , Nguyen Van Phuc , Kögler Harald , Zeitz Oliver , Hasenfuss Gerd
Published: January 2007

α1‐adrenergic stimulation and mechanical load are considered crucial for the expression of sarcolemmal Na+/Ca2+ exchanger (NCX1). However, the interaction between these processes is unknown.

We investigated electrically stimulated (1 Hz, 1.75 mmol/L Ca2+) rabbit ventricular trabeculae at physiological preload under stimulation by the selective α1‐agonist phenylephrine (PE, 10 μmol/L). Using quantitative real‐time PCR, downregulation of mRNA to 76.5% (p<0.05) was found, while B‐type natriuretic peptide (BNP) was increased to 569.5% (p<0.05) compared to control. These changes were abolished in the presence of both the β1‐blocker prazosin (13 μmol/L) and the PKC inhibitor GF109203X (1 μmol/L). Furthermore, no changes in NCX mRNA levels under the influence of PE were found in unstretched trabeculae or in unstretched isolated rabbit myocytes (24 h), while BNP was increased in both preparations. In addition, since the α1‐adrenergic effect could be Ca2+‐dependent we tested increased extracellular Ca2+ (3.0 mmol/L) in stretched trabeculae and found downregulation of NCX1 to 75.2% (p<0.05).

α1‐stimulation decreases NCX1 mRNA in rabbit myocardium via PKC. This is critically load‐dependent and may be mediated by changes in [Ca2+]. In hypertrophy and heart failure, distinct phenotypes with respect to NCX1 expression may result from the interaction between mechanical load and α1‐adrenergic stimulation.
The feasibility of left ventricular mechanical support as a bridge to cardiac recovery
Authors: Liden Hans , Karason Kristjan , Bergh Claes‐Håkan , Nilsson Folke , Koul Bansi , Wiklund Lars
Published: January 2007

Objective

To study the achievability of device weaning in patients receiving left ventricular assist devices (LVADs) as a bridge to transplantation.

Methods

Eighteen consecutive patients receiving a LVAD between September 1997 and June 2002 were included in the study. During a four‐month follow‐up, patients were repeatedly evaluated with right heart catheterization and echocardiography and, if functional improvement was observed, studied with the device turned off. Cardiac recovery was defined as off‐pump LVEF≥40% together with a significant improvement in invasive haemodynamic measurements (CI≥2.5 and PCWP≤10–12 mm Hg). Patients fulfilling these criteria were considered for weaning.

Results

Three patients fulfilled the predefined criteria for cardiac recovery and were subjected to device explantation. In one patient, a young female with acute myocarditis, the following course was uneventful. In the second patient, a male with dilated cardiomyopathy, heart failure reoccurred only a few days later. The third patient had a relapse of giant cell myocarditis and was transplanted. One patient underwent transplantation before follow‐up evaluation could be performed.

Conclusion

In our experience, patients with severe advanced heart failure are unlikely to show significant cardiac recovery following treatment with LVAD, in contrast to previous suggestions.
ALK activation induces Shc and FRS2 recruitment: Signaling and phenotypic outcomes in PC12 cells differentiation
Authors: Degoutin Joffrey , Vigny Marc , Gouzi Jean Y.
Published: January 2007

Activation of the neuronal receptor tyrosine kinase ALK (anaplastic lymphoma kinase) promoted the neuron‐like differentiation of PC12 cells through specific activation of the ERK MAP‐kinase pathway. However, the nature of primary signaling events initiated is still poorly documented. Here, we established that Shc and FRS2 adaptors were recruited and phosphorylated following antibody‐based ALK activation. We further demonstrated that Shc was recruited to the consensus phosphotyrosine site NPTpY1507 and FRS2 was likely recruited to a novel non‐orthodox phosphotyrosine site within ALK. Finally, we characterized a functional role for Shc and likely FRS2 in ALK‐dependant MAP‐kinase activation and neuronal differentiation of PC12 cells. These findings hence open attractive perspectives concerning specific characteristics of ALK in the control of the mechanisms driving neuronal differentiation.
Three‐dimensional cell organization leads to almost immediate HRE activity as demonstrated by molecular imaging of MG‐63 spheroids using two‐photon excitation microscopy
Authors: Indovina Paola , Collini Maddalena , Chirico Giuseppe , Santini Maria Teresa
Published: January 2007

Hypoxia through HRE (hypoxia‐responsive element) activity in MG‐63 human osteosarcoma cells grown in monolayer and as very small, three‐dimensional tumor spheroids was investigated using molecular imaging techniques. MG‐63 cells were stably transfected with a vector constructed with multiple copies of the HRE sequence of the human vascular endothelial growth factor (VEGF) gene and with the enhanced green fluorescent protein (EGFP) coding sequence. During hypoxia when HIF‐1α (hypoxia‐inducible factor‐1α) is stabilized, the binding of HIF‐1 to the HRE sequences of the vector allows the transcription of EGFP and the appearance of fluorescence. Transfected monolayer cells were characterized by flow cytometric analysis in response to various hypoxic conditions and HIF‐1α expression in these cells was assessed by Western blotting. Two‐photon excitation (TPE) microscopy was then used to examine both MG‐63‐transfected monolayer cells and spheroids at 2 and 5 days of growth in normoxic conditions. Monolayer cells reveal almost no fluorescence, whereas even very small spheroids (<100 μm) after 2 days of growth contain regions of high fluorescence. For the first time in the literature, at least to our knowledge, it is demonstrated, using highly sensitive and non‐perturbing molecular imaging techniques, that three‐dimensional cell organization leads to almost immediate HRE activation. This activation of the HRE sequences, which control a wide variety of genes, suggests that monolayer cells and spheroids of the MG‐63 cell line have different genes activated and thus diverse functional activities.
DNA polymerase β catalytic efficiency mirrors the Asn279–dCTP H‐bonding strength
Authors: Martínek Václav , Bren Urban , Goodman Myron F. , Warshel Arieh , Florián Jan
Published: January 2007

Ternary complexes of wild type or mutant form of human DNA polymerase β (pol β) bound to DNA and dCTP substrates were studied by molecular dynamics (MD) simulations. The occurrences of contact configurations (CC) of structurally important atom pairs were sampled along the MD trajectories, and converted into free‐energy differences, ΔG
CC. ΔG
CC values were correlated with the experimental binding and catalytic free energies for the wild type pol β and its Arg183Ala, Tyr271Ala, Asp276Val, Lys280Gly, Arg283Ala, and Glu295Ala mutants. The correlation coefficients show that the strength of the H‐bond between dCTP and Asn279 is a strong predictor of the mutation‐induced changes in the catalytic efficiency of pol β. This finding is consistent with the view that enzyme preorganization plays a major role in controlling DNA polymerase specific activity.
Eugenol inhibit 7,12‐dimethylbenz[a]anthracene‐induced genotoxicity in MCF‐7 cells: Bifunctional effects on CYP1 and NAD(P)H:quinone oxidoreductase
Authors: Han Eun Hee , Hwang Yong Pil , Jeong Tae Cheon , Lee Sang Seop , Shin Jae-Gook , Jeong Hye Gwang
Published: January 2007

Typically, chemopreventive agents either inhibit the cytochrome P450s (CYPs) that are essential for the metabolism of carcinogens or induce phase II detoxifying enzymes. This study examined the chemopreventive effect of eugenol on 7,12‐dimethylbenz[a]anthracene (DMBA)‐induced DNA damage in MCF‐7 cells. Eugenol inhibited the formation of the DMBA–DNA adduct in a dose dependent manner. CYP1A1 and CYP1B1 activity, which catalyze the biotransformation of DMBA, were strongly inhibited by eugenol. Eugenol also suppressed the CYP1A induction by DMBA through decreased aryl hydrocarbon receptor activation and subsequent DNA binding. Furthermore, eugenol increased the expression and activity of NAD(P)H:quinone oxidoreductase (QR), a major detoxifying enzyme for DMBA, through NF‐E2 related factor2 binding to antioxidant response element in QR gene. Therefore, eugenol has a potent protective effect against DMBA‐induced genotoxicity, presumably through the suppression of the DMBA activation and the induction of its detoxification. These results suggest that eugenol has potential as a chemopreventive.
Women, Islam and rights in Europe: beyond a universalist/culturalist dichotomy
Authors: FREEDMAN JANE
Published: January 2007

In 2004 the French National Assembly and Senate passed legislation which makes it illegal for Muslim women to wear headscarves (the hijab) within French public schools. To be precise the legislation refers to the banning of ostentatious religious symbols within the secular domain of the public school system, but is clearly aimed primarily at Muslim women, following a long-running dispute over this issue. Similar debates are taking place in other European countries such as Germany, Italy, Belgium, the Netherlands and Spain. A bill modelled on the recent French legislation has been tabled in the Belgian senate, whilst various court cases have been brought in other European countries by Muslim women who have been banned from wearing headscarves by employers or schools. Following a ruling of the German Supreme Court that a Muslim teacher should be allowed to wear a headscarf, as this did not contravene current legislation, the state of Baden-Wuerttenberg acted to introduce legislation to ban headscarves, and this legislation is likely to be copied by six other German states.
Women workers and labour standards: the problem of ‘human rights’
Authors: ELIAS JUANITA
Published: January 2007

The International Labour Organisation’s Declaration of Fundamental Principles and Rights at Work of 1998 formalised an approach to global labour issues known as the Core Labour Standards (CLS). The CLS have privileged a specific set of labour standards as possessing the kinds of universalistic qualities associated with ideas of ‘human rights’; the abolition of forced and child labour, equality of opportunity, and trade union rights. But what does this ‘human rights’ approach mean from the point of view of those women workers who dominate employment in some of the most globalised, and insecure, industries in the world? In this article, I make the case for critical feminist engagement with the gender-blind, and neoliberal-compatible, approach to economic rights as set out in the CLS. Not least, this article raises wider concerns about the insufficiency of approaches to economic rights that are designed to work within the (gendered) structures of a neoliberal economic development paradigm. It is suggested that the CLS have endorsed a voluntarist approach to labour standards that views the promotion and regulation of human rights by global corporations as unproblematic. The article challenges this perspective, drawing upon the work of number of feminist scholars working in the area of women’s employment and corporate codes of conduct. These feminist writings have specifically avoided the language of human rights; thus questions need to be asked concerning the possibilities and the limitations that the CLS opens up for women’s human rights activism.
Universal human rights and non-Western normative systems: a comparative analysis of violence against women in Mexico and Pakistan
Authors: BOVARNICK SILVIE
Published: January 2007

How universally useful are human rights in addressing violence against women? This article addresses this question by looking at the link between gender, ethnicity and human rights to uncover the complexities that underpin current debates about universal justice and multiculturalism. While my discussion of rape in Mexico and Pakistan illustrates significant particularities with respect to how violence against women is constituted in these different cultural contexts, it also shows that culturally specific manifestations of violence against women often share striking similarities in the way that they are allowed to persist, justified and made invisible. As such, they are part of a global mechanism that reproduces gender subordination in a predominantly patriachal world.
(Women’s) human rights: paradoxes and possibilities
Authors: LLOYD MOYA
Published: January 2007

Such is its pervasiveness that human rights discourse is used to legitimise humanitarian and military intervention in the affairs of other states, provide a rationale for ‘ethical’ foreign policy, justify the punishment of war crimes, and validate the formation of international coalitions mandated to eradicate terrorism wherever its is found. At grass-roots level, human rights talk is deployed to lobby governments and to press for socioeconomic and legal change, to combat the dehumanising treatment of specific populations, to ground educational initiatives and spawn local, national, international, and sometimes global networks oriented to its advancement, and to induce the patient and meticulous documentation of its violations. In terms of women, human rights activism has been instrumental in problematising violence against women, prompting the recognition by the UN Human Rights Commission in 1992 of rape during war as a form of torture, and as a war crime or crime against humanity in the Rome Statute of the International Criminal Court (which came into force in 2001). It also led to the appointment in 1994 by the UN Human Rights Commission of Radhika Coomaraswamy as the first Special Rapporteur on Violence against Women and its Causes and Consequences. Activities centring on human rights produced the Convention on the Elimination of All Forms of Discrimination against Women (CEDAW), which was adopted by the UN General Assembly on 18 December 1979 and became operational as an international treaty on 3 September 1981 when it was ratified by its twentieth signatory.
The Queen Boat case in Egypt: sexuality, national security and state sovereignty
Authors: PRATT NICOLA
Published: January 2007

The government’s targeting of homosexuality in May 2001, following years of ‘turning a blind eye’ to Cairo’s gay scene, is studied here in terms of the links between the sphere of interpersonal relations and notions of national security within international relations. The persecution of men for alleged same-sex relations not only filled newspaper columns and created a spectacle to divert people’s attention away from the government’s failings. More importantly, the event represented an opportunity for government officials, the media and other civil society activists – both within Egypt and abroad – to ‘perform’ a discourse of national security through which national sovereignty was (re)produced and political order was maintained. However, this national security threat was not only posed by the external threat of Western governments, international NGOs and other transnational actors concerned with respect for human rights within Egypt. More importantly, this threat was constructed as originating with those people failing to conform to the ‘norm’ of heterosexual relationships.
Financial incentives and psychiatric services in Australia: an empirical analysis of three policy changes
Authors: Doessel D. P. , Scheurer Roman W. , Chant David C. , Whiteford Harvey
Published: January 2007

Australia has a national, compulsory and universal health insurance scheme, called Medicare. In 1996 the Government changed the Medicare Benefit Schedule Book in such a way as to create different financial incentives for consumers or producers of out-of-hospital private psychiatric services, once an individual consumer had received 50 such services in a 12-month period. The Australian Government introduced a new Item (319) to cover some special cases that were affected by the policy change. At the same time, the Commonwealth introduced a ‘fee-freeze’ for all medical services. The purpose of this study is two-fold. First, it is necessary to describe the three policy interventions (the constraints on utilization, the operation of the new Item and the general ‘fee-freeze’.) The new Item policy was essentially a mechanism to ‘dampen’ the effect of the ‘constraint’ policy, and these two policy changes will be consequently analysed as a single intervention. The second objective is to evaluate the policy intervention in terms of the (stated) Australian purpose of reducing utilization of psychiatric services, and thus reducing financial outlays. Thus, it is important to separate out the different effects of the three policies that were introduced at much the same time in November 1996 and January 1997. The econometric results indicate that the composite policy change (constraining services and the new 319 Item) had a statistically significant effect. The analysis of the Medicare Benefit (in constant prices) indicates that the ‘fee-freeze’ policy also had a statistically significant effect. This enables separate determination of the several policy changes. In fact, the empirical results indicate that the Commonwealth Government underestimated the ‘savings’ that would arise from the ‘constraint’ policy.
Medicaid policy changes in mental health care and their effect on mental health outcomes
Authors: Cuellar Alison Evans , Markowitz Sara
Published: January 2007

In recent years, Medicaid has experienced a dramatic increase in spending on prescription drugs in general and psychotropic medications in particular. The purpose of this study is to examine the effects of increased Medicaid spending on psychotropic drugs on improving the mental health and well-being of participants at the population level. Specifically, we study the effect on outcomes that are strongly correlated with mood disorders, including depression and Attention Deficit/Hyperactivity disorder, controlling for concomitant increases in Medicaid eligibility thresholds and expansion into managed care for mental health services. Knowledge of the effects of changes in the Medicaid program is crucial to policymakers as they consider implementing and expanding mental health services. Our results show that increased spending on antidepressants and stimulants are associated with improvements in some outcomes, but not in others.
A climatology of sea ice embayments in the Cosmonaut Sea, Antarctica
Authors: Geddes Jeffrey A. , Moore G. W. K.
Published: January 2007

The Cosmonaut Sea off the coast of Antarctica is characterized by highly variable sea ice conditions. As the sea ice expands during the austral fall and winter, embayments, open bodies of water surrounded on three sides by sea ice, as well as polynyas often form. Using sea ice concentration data provided by satellite‐based passive microwave instruments from 1979 to 2004, we characterize these embayment events by their size and temporal evolution. The data suggests a striking periodicity in the occurrence of these embayments, with the exception of a “quiet” period between 1984 and 1987. The large embayment events seem to appear approximately every three years in the same location and persist for anywhere between mid‐June to mid‐August. These results indicate there is predictability in the occurrence of embayment events, adding important insight into the characterization of sea ice variability in this region.
Triggered non‐similar slip events on repeating earthquake asperities: Results from 3D numerical simulations based on a friction law
Authors: Ariyoshi Keisuke , Matsuzawa Toru , Hino Ryota , Hasegawa Akira
Published: January 2007

We investigated the changes in slip rate and recurrence interval of repeating earthquakes using 3‐D numerical simulations of a subduction zone involving large and small asperities and based on a rate‐ and state‐dependent friction law. Our results reveal that the postseismic slip of a large earthquake can trigger an event at a nearby small asperity, although the event may differ to other repeating earthquakes at the asperity because the slip velocity of the event tends to be slower than that of other repeaters; the slip distribution also differs. These results probably explain the observation that the slip amount estimated from repeating earthquake analyses tends to be smaller than that estimated from GPS analyses for large amounts of postseismic slip, as observed for postseismic activity following the 2003 Tokachi‐oki earthquake.
On Martian nitrogen dayglow emission observed by SPICAM UV spectrograph/Mars Express
Authors: Leblanc F. , Chaufray J. Y. , Bertaux J. L.
Published: January 2007

SPICAM UV spectrograph on board Mars Express has reported, for the first time, the identification of the N2 VK (0,5) and (0,6) band emissions in the Martian dayglow. The derived exospheric temperature of the N2 species in the upper Martian atmosphere is equal to 190 ± 51 K for areocentric longitudes between 100° and 171° and equal to 257 ± 71 K for areocentric longitudes between 287° and 321°. These temperatures are in agreement with the ones deduced from the analysis of the 289 nm emission associated with the CO2 major Martian atmospheric species. The intensity of the N2 VK (0,6) band is found to be ∼3 times smaller than the calculated intensity of Fox and Dalgarno (1979) which is reasonable when considering the uncertainties in the parameters used by Fox and Dalgarno (1979) and the uncertainties on SPICAM UVS observations.