bluuebunny/crossref_metadata_2025 huggingface dataset:
MR Lymphography with a Lymphotropic T1‐Type MR Contrast Agent: Gd‐DTPA‐PGM
Authors: Harika Liliane , Weissleder Ralph , Poss Kirtland , Zimmer Claus , Papisov Mikhail I. , Brady Thomas J.
Published: March 2007

A model system of a paramagnetic lymphotropic MR contrast agent (Gd‐DTPA labeled polyglucose associated macrocomplex, PGM) for T1‐weighted MR imaging of lymph nodes in rats and rabbits was evaluated. Pharmacokinetic (tissue accumulation) and MR imaging data (optimal dose and timing parameters) were obtained in normal rats (n = 88) after subcutaneous (SC) injection of paramagnetic, radiolabeled [111In]Gd‐DTPA‐PGM. A rabbit model of lymph node metastases (n = 8) was ultimately used to demonstrate the potential of MR imaging with Gd‐DTPA‐PGM for nodal tumor detection. Maximum concentrations of Gd‐DTPA‐PGM were found in popliteal and paraaortic lymph nodes within 24 h after SC administration, and highest lymph node SNR values were obtained by MR imaging at this time point. The optimum imaging dose was 6–12 μmol Gd/kg. Tumor‐lymph node contrast increased from 0.0 ± 1.2 precontrast to 19.2 ± 6.5 (spoiled gradient echo sequence, TR 50/TE 7/flip angle 60°) postcontrast and conspicuity of nodal metastases was improved. Gd‐DTPA‐PGM accumulates in lymph nodes after SC administration and significantly enhances lymph node signal intensity of normal animals but not metastatic lymph nodes.
On the Relationship Between Feature‐Recognizing MRI and MRI Encoded by Singular Value Decomposition
Authors: Cao Yue , Levin David N.
Published: March 2007

This paper describes the similarity between two methods of non‐Fourier MRI: feature‐recognizing MRI (FR MRI) and MRI with encoding by singular value decomposition (SVD MRI). Both methods represented images as truncated expansions of non‐Fourier basis functions; these basis images were derived from prior image data by using closely‐related mathematical techniques: the Karhunen‐Loeve decomposition (or principal components analysis) and singular value decomposition, respectively. We demonstrate that FR and SVD MRI are equivalent in the following sense: given the same prior image data, they lead to exactly the same basis functions. FR MRI utilized prior images of the same body part in many “training” subjects, thought to be similar to the “unknown” subject to be imaged. SVD MRI utilized a single prior image of one subject in order to perform dynamic imaging of that subject. We demonstrate that the basis function expansion derived from a single prior image may not be capable of representing new features (features not found in the prior image). Therefore, the SVD basis functions may be inappropriate for dynamic imaging.
In Vivo Selective Measurement of {1−13C}‐Glucose Metabolism in Tumors by Heteronuclear Cross Polarization
Authors: Artemov Dmitri , Bhujwalla Zaver M. , Glickson Jerry D.
Published: March 2007

Selective detection of {1−13C}‐glucose and its glycolytic product, {3−13C}‐lactate, was achieved by selective 13C NMR spectroscopy with 1H cross polarization. The total sensitivity of conventional broadband experiments was retained, and peak intensities were at least equivalent to those obtained with the inverse detection technique (i.e., 1H{13C}) for single proton resonances. A key advantage of the method is that it maintains the specific absorption rate (SAR) within FDA limits of 5 W/kg by reducing power deposition during decoupling. In this study we have monitored the kinetics of metabolism of 13C‐labeled glucose to lactate following intravenous infusion of 0.55 ml of 0.18 M labeled glucose. Physiological effects were minimized by a) maintaining total plasma glucose concentrations below 20 mM throughout the course of NMR experiment and b) by avoiding significant heating of the tumor.
Incorporation of A Phosphonium Analogue of Choline Into The Rat Brain as Measured by Magnetic Resonance Spectroscopy
Authors: Jiménez Jilma V. , Richards Todd L. , Heide Aaron C. , Grierson John R. , Shankland Eric G.
Published: March 2007

A clear understanding of choline metabolism is important in our goal to modify demyelination and remyelination in multiple sclerosis. To develop a technique capable of measuring metabolic changes in the brain, we have studied the incorporation of a phosphonium analogue of choline (P‐choline) in tissue extracts of rats. After feeding adult rats a choline‐deficient diet supplemented with P‐choline, the analogue was not detectable by in vivo volume‐localized 1H spectroscopy. However, in vitro 31P measurements of brain extracts revealed an 11 % incorporation of P‐choline into phosphatidylcholine. We report that P‐choline incorporates preferentially into the lipid pool over the lipid precursor pool and we provide evidence that the choline peak resolved by in vivo 1H spectroscopy is only composed of small molecular weight choline‐containing compounds.
Susceptibility Insensitive Single Shot MRI Combining BURST and Multiple Spin Echoes
Authors: Gelderen Peter Van , Moonen Chrit T.W. , Duyn Jeff H.
Published: March 2007

A single shot MR imaging technique insensitive to magnetic susceptibility effects is introduced. The method allows multislice imaging in areas with poor magnetic field homogeneity, and can be implemented on standard clinical scanners. The design is based on the combination of a BURST excitation with multiple RF refocusing pulses. Images were obtained at 1.5 T on phantoms and human brain with a matrix size of 64 x 54 and a resolution of 4 x 4 mm in 230 ms.
Multi‐Shot EPI for Improvement of Myocardial Tag Contrast: Comparison with Segmented SPGR
Authors: Tang Chao , Mcveigh Elliot R. , Zerhouni Elias A.
Published: March 2007

To assess the potential value of multi‐shot EPI relative to segmented k‐space SPGR for myocardial tagging, we measured tag contrast for both sequences in a phantom and human study and compared it with theoretical predictions. In the human heart, EPI tag contrast was three times that of SPGR at the end of systole. Tag duration was lengthened with EPI to at least 600 ms. In addition, the entire heart was examined in a total of 32 heartbeats with EPI versus 152 heartbeats with SPGR.
Susceptibility Magnetic Resonance Imaging Using Spectral Decomposition
Authors: Ro Yong M. , Cho Zang‐Hee
Published: March 2007

Susceptibility differences of materials in magnetic resonance imaging (MRI) usually lead to the intravoxel spin phase variations. Subsequently, the phase variation in the voxel results in a reduction of the signal intensity. This signal intensity reduction is known as the susceptibility effect in MRI and has been studied extensively. In this paper, a new spectral decomposition technique is proposed with which the signal change due to the susceptibility effect can be analyzed. Further, an NMR pulse sequence for the spectral decomposition of the susceptibility was developed and applied to susceptibility imaging of venous blood possessing paramagnetic properties. The computer simulations of the spectral decomposition method and their corresponding experimental results obtained using both a phantom and human volunteers are reported.
GRASE Improves Spatial Resolution in Single Shot Imaging
Authors: Feinberg David A. , Kiefer Berthold , Johnson Glyn
Published: March 2007

In single shot echo train imaging all the data required for a two dimensional image is acquired from a series of echoes generated following a single RF excitation pulse. Spatial resolution is limited because all samples must be acquired before the signal decays. In this paper we show theoretically that more echoes and hence better spatial resolution can be obtained with single shot GRASE imaging than with either echo planar imaging or single shot RARE imaging. This conclusion holds for both conventional imaging hardware and specialized gradient hardware designed for EPI. High quality single shot GRASE images support the theoretical conclusions.
Quantitative Analysis of Dynamic Gd‐DTPA Enhancement in Breast Tumors Using a Permeability Model
Authors: Tofts Paul S. , Berkowitz Bruce , Schnall Mitchell D.
Published: March 2007

The MRI signal enhancement in a breast tumor, measured as a function of time after a bolus injection of Gd‐DTPA, may contain enough information to differentiate malignant from benign tissue. We find a physiological model for measuring capillary permeability and leakage space (P. S. Tofts, A. G. Kermode, measurement of the blood‐brain barrier permeability and leakage space using dynamic MR imaging. 1. Fundamental concepts. Magn. Reson. Med. 17, 357–367 (1991)) fits the data well. The enhancement curve is particularly sensitive to the preinjection T1, of the tumor, the dose, and the time of injection. This model may provide a means of characterizing the pathophysiology of breast tumors from the Gd‐DTPA enhancement curve.
Segmentation and Feature Extraction Techniques, with Applications to MRI Head Studies
Authors: Ashton Edward A. , Berg Michel J. , Parker Kevin J. , Weisberg Jeffrey , Chen Chang Wen , Ketonen Leena
Published: March 2007

To obtain a three‐dimensional reconstruction of the hippocampus from a volumetric MRI head study, it is necessary to separate that structure not only from the surrounding white matter, but also from contiguous areas of gray matter–the amygdala and cerebral cortex. At present it is necessary for a physician to manually segment the hippocampus on each slice of the volume to obtain such a reconstruction. This process is time consuming, and is subject to inter‐ and intra‐operator variation as well as large discontinuities between slices. We propose a novel technique, making use of a combination of gray scale and edge‐detection algorithms and somea prioriknowledge, by which a computer may make an unsupervised identification of a given structure through a series of contiguous images. This technique is applicable even if the structure includes so‐called false contours or missing contours. Applications include three‐dimensional reconstruction of difficult‐to‐segment regions of the brain, and volumetric measurements of structures from series of two‐dimensional images.
Multi‐Slice, Breathhold Imaging of the Lung with Submillisecond Echo Times
Authors: Alsop David C. , Hatabu Hiroto , Bonnet Mathieu , Listerud John , Gefter Warren
Published: March 2007

The signal from the lungs is heavily attenuated by T2 and T2* decay in standard MR images of the thorax. The authors utilized the capabilities of a prototype fast gradient system to develop a multi‐slice gradient echo sequence that can obtain images with an echo time of 0.7 ms. Images acquired in a single breath‐hold are free from respiratory motion artifacts and clearly display signal from lung parenchyma. The use of fast gradients makes short echo times possible without the use of nonstandard RF pulses and spatial encoding techniques and their associated limitations.
Resolving Anatomical Details in Lung Parenchyma: Theory and Experiment for a Structurally and Magnetically Inhomogeneous Lung Imaging Model
Authors: Su Sunyu , Saunders John K. , Smith Ian C. P.
Published: March 2007

Lung parenchyma is, structurally and magnetically, a very inhomogeneous system. The strong local field gradients due to magnetic susceptibility variation across the air‐tissue interfaces impose a spatially dependent phase on spins that are inhomogeneously distributed. As a result, the slice selection process can cause destructive interference and corresponding partial cancellation of the NMR signals from different parts of the slice. The mechanism of this effect was studied by expanding the internal magnetic field gradient as a Fourier series and determining the Fourier components with a foam model, which consists of air bubbles preferentially at the alveolar diameter. The effect of signal cancellation as a function of slice thickness is characterized by a sinc‐like function with destructive interference of higher orders shown as lobes and the zeroth order as the main peak. Computer simulation of the slice selection process was conducted to illustrate the combined effects of signal cancellation and spatial average, and their dependence on slice thickness. Finally, images of rat lungs are presented to demonstrate the significant improvement in image quality by avoiding the high order destructive interference of NMR signals in the slice selection process.
Vascular transit times in calcarine cortex: Kinetic analysis of R2* changes observed using localized 1H spectroscopy
Authors: Detre John A. , Wang Zhiyue , Stecker Mark M. , Zimmerman Robert A.
Published: March 2007

A kinetic analysis of water signal intensity changes measured in human visual cortex by PRESS localized 1H spectroscopy at 500 ms resolution with light‐emitting diode (LED) goggle stimulation was used to determine vascular transit times for transitions between rest and activation. Monoexponential curve fitting was used to determine both R2* values for each free induction decay and the time constants for R2* changes with activation and deactivation. Measured transit time values were in general agreement with the literature, and were significantly shorter for “Off→On” than for “On→Off” transitions, consistent with known alterations in blood flow with activation and deactivation. The differences in transit times between “Off→On” and “On→Off” also varied with stimulus frequency in accordance with known physiology. This type of analysis may provide a useful means of analyzing functional activation data and for quantitatively comparing functional activation results from differing subjects and imaging sessions.
Interleaved asymmetric echo‐planar imaging
Authors: Hennel Franciszek , Nédélec Jean‐François
Published: March 2007

A version of interleaved echo‐planar imaging (EPI) is presented in which only one polarity of the readout gradient is used for signal acquisition to avoid ghosting artifacts. Two possible forms of the phase encoding gradient, blipped and constant, are discussed. With the constant phase encoding, interleaving of partial trajectories in the Fourier domain (k‐space) is controlled automatically by the echo train delay. The constant phase encoding gradient introduces a shear distortion of the k‐space grid. A modification of the reconstruction procedure is given which corrects for this effect. The method provides a 128 × 128 image in 1 s on a clinical system with standard gradients.
Magnetization transfer in hemopoietic bone marrow examined by localized proton spectroscopy
Authors: Schick Fritz , Forster JÜRgen , Einsele Hermann , Weiß Burkhard , Lutz Otto , Claussen Claus D.
Published: March 2007

The sensitivity of hemopoietic bone marrow to magnetization transfer is analyzed in 15 healthy volunteers and seven patients with different hematological disorders (inflammation, plasmacytoma, hemopoietic reconstitution after bone marrow transplantation). To obtain sufficient signal‐to‐noise ratio, a 90° −180° −180° double spin echo (PRESS) single voxel spectroscopic method was combined with pulsed magnetization transfer. Several spectra were recorded from each volume element inside the vertebral marrow, alternately with and without prepulses for magnetization transfer. Water signals from marrow with increased content of extracellular water due to inflammation or edema revealed less magnetization transfer effects than marrow with increased intracellular water content due to high cellularity. The preliminary results show magnetization transfer to be a promising tool for the clinically important characterization of the water composition in red bone marrow.
Mr perfusion studies with t1‐weighted echo planar imaging
Authors: Kwong Kenneth K. , Chesler David A. , Weisskoff Robert M. , Donahue Kathleen M. , Davis Timothy L. , Ostergaard Leif , Campbell Terrence A. , Rosen Bruce R.
Published: March 2007

The T1 perfusion model has worked well in brain functional studies where flow changes are measured. Using selective and nonselective inversion pulses, a new method has been developed to study steady‐state brain blood flow. The authors obtained flow‐sensitive images using selective inversion and flow‐insensitive images using nonselective inversion. Subtraction of flow‐insensitive images from flow‐sensitive images gave us flow‐weighted images with good gray‐white flow contrast in cortical gray matter as well as in the thalamus and basal ganglia. Fitting T1S of flow‐insensitive and flow‐sensitive images allowed us to obtain preliminary results of brain blood flow maps. Two specific problems can seriously affect the accuracy of the brain blood flow values and the gray‐white flow contrast of brain blood flow maps. These are the problems of the partial volume effect of CSF and gray matter, and the difference between blood T1 and white matter T1. The authors discuss in detail the character of these problems and present a number of approaches to manage such problems.
Evaluation of consumer satisfaction and quality of life in patients changing to Novopen II
Authors: Henderson M J , Tindall H
Published: March 2007

We evaluated patient satisfaction and acceptability of the new Novopen II, which takes pre‐mixed insulin cartridges (Actraphane). In addition an attempt was made to measure changes in ‘quality of life’. A quality of life questionnaire was devised which proved to have satisfactory test re‐test reliability. Subjects showed no significant differences following a three months trial of Novopen II compared to a control group. Although 67% of patients found the device easy to use, only half found it more convenient than conventional syringes. The results suggest although more convenient for half the subjects, Novopen II did not markedly alter the quality of their life.
Why are impotent diabetic men not being treated?
Authors: Price D E , O'Malley B P , James M A , Roshan M , Hearnshaw J R
Published: March 2007

The prevalence of impotence among a group of 158 consecutive men attending a diabetic clinic was studied by questionnaire. The frequency of reporting of impotence and the advice and treatment patients had received were determined.

The prevalence of impotence was 36.7%. Forty‐nine of the impotent men (84%) wanted treatment; 21 had never asked for medical advice because of embarrassment, ignorance of availability of treatments or a belief that impotence was normal at their age. Twenty‐eight had consulted a doctor, nine presented at the diabetic clinic and were treated successfully; 19 consulted their general practitioner alone and were advised incorrectly.

Most impotent diabetic men want treatment but do not ask for help or are advised incorrectly. Both patients and doctors need to be better informed about the management of impotence in diabetes.
Photography combined with ophthalmoscopy in retinal screening
Authors: Ryder R E J , Griffiths H , Moriarty K T , Kennedy R L , Blumsohn A , Hardisty C A
Published: March 2007

To assess a 4mm pupil camera (Canon CR3 45NM “non‐mydriatic” retinal camera) Polaroid photography combined with diabetic clinic ophthalmoscopy, 137 annual‐review patients not already under an ophthalmologist were randomly assigned to: ophthalmoscopy with mydriatic (Group 1); retinal photography with mydriatic only if required (Group 2); retinal photography with mydriatic (Group 3). Ophthalmoscopy was undertaken in all Group 3 patients but in only Group 2 patients with retinopathy on the Polaroid. They were graded for quality. Groups 2 and 3 achieved similar diabetic retinopathy detection and good‐quality photograph rates. Clinic doctors reported diabetic retinopathy in 9/41 (22%) Group 1 and 26/96 (27%) in Groups 2 and 3. Review of the Polaroids by an experienced observer revealed a further seven patients with probable retinopathy. This review also identified four patients warranting an ophthalmologist's opinion (three required laser therapy). More diabetic retinopathy was detected with ophthalmoscopy and photography than with ophthalmoscopy alone. It is only necessary to dilate about 17% of eyes to obtain >90% good quality Polaroids and may not be necessary to use ophthalmoscopy if there is definitely no retinopathy on good quality photographs. The photograph allows senior members of the team to review the fundi of patients seen by juniors and discussion with an ophthalmologist without the patient being present, the ophthalmologist choosing whom to see further.
Insulin‐dependent diabetes of over 50 years' duration — clinical and biochemical features
Authors: Gill G , Hardy K
Published: March 2007

We have investigated the clinical and biochemical features (including C‐peptide responsiveness) in 10 patients with insulin‐dependent diabetes (IDDM) of over 50 years' duration (Nabarro Medal Winners). Age (mean ± SD) was 67 ± 7 years and diabetes duration 54 ± 2 years. Serum C‐peptide was undetectable both fasting and 2 hours after 1 mg intramuscular (I/M) glucagon. Glycosylated haemoglobin (HbA1) was 10.0 ± 1.5% and cholesterol 6.2 ± 0.7 mmol/1. Only one had hypertension and only one was obese (BMI > 30.0). Four (40%) had microvascular complications (4 retinopathy, 1 nephropathy and 1 neuropathy). None were blind, had amputations, or required renal support therapy. Large vessel disease was present in only 1 (mild, stable angina). This group thus represented patients with “true” IDDM, who for their long diabetes duration were remarkably fit and relatively free of complications (particularly macrovascular). Further detailed investigation of larger numbers of Nabarro Medal Winners may provide valuable clues as to “protective” factors operating in the evolution of complications in IDDM.
The Alan Nabarro Medal: The what and the whence
Authors: Alexander William , Redmond Suzanne
Published: March 2007

The Alan Nabarro Medal is awarded by the British Diabetic Association to people who have had diabetes for more than 50 years. We have analysed the national distribution of medal winners by Regional Health Authorities/Boards of the UK and the English Health Districts. Up to December 31st 1990, 446 medals had been awarded but sufficient details were available only for the 303 requested between mid‐1987 and the end of 1990. Number of mean annual awards was 82. All Regions/Boards were represented. The Regional mean was 18 (range 8–41) for total medals and 5.7 (2.3–17) for medals per million total population. The estimated mean “expected medal number” per Region should be 134 (64–208) with a total of 2,272 medals awarded. There is therefore a potential shortfall of 1,826; Regional shortfalls varying from 64 to 191 (67%–94%). English District Health Authorities were also analysed −88 (46%) were not represented at all. Clinical details of medal winners from one English District are reported. We present this survey hoping to increase awareness of the Alan Nabarro Medal.
The diabetic emergency line: A prospective survey
Authors: Flynn M D , Beer S F , Watkins P J
Published: March 2007

The telephone is an important tool in diabetic management and is a recommended component of an overall diabetic service. The aim of this prospective survey was to audit out‐of‐hours emergency telephone calls initiated by patients. relatives or carers. Altogether, 114 calls were received on an emergency line in a two year period; 79 calls related to specific diabetic emergency problems. A total of 23 patients (29.1% of diabetic emergency calls) were advised to seek immediate medical assessment, including 10 patients (12.7%) admitted with uncontrolled diabetes/diabetic ketoacidosis. In all, 26 patients (32.9%) were given specific advice on changes of treatment and a further 10 (12.7%) offered a next day clinic assessment. Of all the calls 31.6% related to hypoglycaemia, of which 11/25 were initiated by relatives seeking help with an unconscious or disabled patient. Overall 46% of calls were initiated by a patient's relative or companion unfamiliar with diabetes and needing immediate help. The information derived from this study demonstrates that a safe and effective structured emergency telephone service can be operated by ward‐based medical and nursing staff to give help and advice and facilitate admission.
Prevalence of diabetic patients in hospital: Changing trends over a 10‐year period
Authors: Harrower A D B
Published: March 2007

The prevalence of diabetic patients was assessed in a new District General Hospital (DGH) a year after opening, and again after 10 years. The initial prevalence was 5.4%, increasing to 8.6%. Vascular disease was the most common diagnostic category for both medical and surgical patients. There were no differences in prevalence between men and women, although there was a preponderance of women especially in the medical category. Initially the patients were fairly evenly spread between the three treatment groups — diet, oral hypoglycaemic agent, insulin — but, after 10 years, the percentage of patients taking insulin had fallen to 13%. The prevalence of diabetic patients over 50 years of age was high in both studies (92.6% in the first study and 89.3% in the second study. This high prevalence of older diabetic patients in hospital is in keeping with the increased morbidity associated with the disorder, particularly vascular disease, and has significant cost implications.
Water‐resistant conducting hybrids from electrostatic interactions
Authors: Luo Jing , Wang Qiguan , Wang Xianhong , Li Ji , Zhao Xiaojiang , Wang Fosong
Published: March 2007

Conductive hybrids were prepared in a water/ethanol solution via the sol–gel process from an inorganic sol containing carboxyl groups and water‐borne conductive polyaniline (cPANI). The inorganic sol was prepared by the hydrolysis and condensation of methyltriethoxysilane with the condensed product of maleic anhydride and aminopropyltriethoxysilane as a catalyst, for which the carboxyl counterion along the cPANI backbone acted as an electrostatic‐interaction moiety. The existence of this electrostatic interaction could improve the compatibility of the two components and contribute to the homogeneous dispersion of cPANI in the silica phase. The electrostatic‐interaction hybrids displayed a conductivity percolation threshold as low as 1.1 wt % polyaniline in an emeraldine base, showing 2 orders of magnitude higher electrical conductivity than that without electrostatic interactions. The electrostatic‐interaction hybrids also showed good water resistance; the electrical conductivity with a cPANI loading of 16 wt % underwent a slight change after 14 days of soaking in water. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1424–1431, 2007
Crystal structure of human myo‐inositol monophosphatase 2, the product of the putative susceptibility gene for bipolar disorder, schizophrenia, and febrile seizures
Authors: Arai Ryoichi , Ito Kaori , Ohnishi Tetsuo , Ohba Hisako , Akasaka Ryogo , Bessho Yoshitaka , Hanawa‐Suetsugu Kyoko , Yoshikawa Takeo , Shirouzu Mikako , Yokoyama Shigeyuki
Published: March 2007

The human IMPA2 gene, which encodes myo‐inositol monophosphatase 2 (IMPA2), is mapped onto 18p11.2, a susceptibility region for bipolar disorder. This chromosomal region has also been proposed to include a susceptibility locus for schizophrenia and febrile seizures. Here we report the crystal structures of human IMPA2 and its complex with calcium and phosphate ions. Human IMPA2 comprises an α–β protein with a five‐layered sandwich of α‐helices and β‐sheets (α–β–α–β–α). The crystal structure and analytical ultracentrifugation results indicated that IMPA2 exists as a dimer in solution. The overall structure of IMPA2 is similar to that of IMPA1, except for the loop regions. In IMPA1, the loop region (31–43) is located at the entrance of the active site cavity. In the corresponding region (42–54) of IMPA2, the residues are disordered and partially form an α‐helix. The structural difference in the opening of the active site cavity suggests that the substrate specificity differs between IMPA1 and IMPA2. The widely opened cavity of IMPA2 implies that the physiological substrate may be a larger compound than inositol monophosphate. The structure of IMPA2 complexed with Ca2+ revealed two metals and one phosphate binding sites, which were the same sites as in IMPA1 complexed with Mn2+ and phosphate, suggesting that the mechanism of the enzymatic reaction is similar to that of IMPA1. The crystal structures of human IMPA2 are useful for understanding the effect of nonsynonymous polymorphism reported in IMPA2, and will contribute to further functional analyses of IMPA2 that potentially predisposes to the vulnerabilities of bipolar disorder, schizophrenia, and febrile seizures. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Structural determination of monoacylglycerols extracted from marine sponge by fast atom bombardment tandem mass spectrometry
Authors: Gil Ji‐Hye , Hong Joo‐Yeon , Jung Jee H. , Kim Kang‐Jin , Hong Jongki
Published: March 2007

Five new monoacylglycerols (MAGs) were isolated from the marine sponge Stelletta sp. by reversed‐phase high‐performance liquid chromatography and analyzed by positive ion fast atom bombardment mass spectrometry (FAB‐MS). FAB mass spectra of these compounds produced abundant sodium‐adducted molecules [M+Na]+ from a mixture of 3‐nitrobenzyl alcohol and sodium iodide. The structural elucidation of these sponge MAGs was carried out by FAB tandem mass spectrometry (MS/MS). To find diagnostic ions for the characterization of the MAGs, authentic MAGs were initially analyzed by collision‐induced dissociation (CID) MS/MS. The CID MS/MS of [M+Na]+ precursor ions resulted in the formation of numerous characteristic product ions via a series of dissociative processes. The product ions formed by charge‐remote fragmentation (CRF) provided important information for the characterization of acyl chains substituted at the glycerol backbone, and product ions at m/z 84, 97, 113 and 139 were diagnostic for the sodiated glycerol backbone. On the basis of these fragmentation patterns, the structures of five MAGs extracted from marine sponge were elucidated. In addition, high‐resolution mass measurement was performed to obtain the elemental compositions of the MAGs. Copyright © 2007 John Wiley & Sons, Ltd.
Analysis of the energy‐based swing‐up control of the Acrobot
Authors: Xin X. , Kaneda M.
Published: March 2007

This paper addresses the energy‐based swing‐up control problem for the Acrobot, a two‐link underactuated robot with a single actuator at the joint of the two links. In line with the energy‐based control approach, this paper presents a necessary and sufficient condition for non‐existence of any singular point in the derived control law, and provides a complete analysis of the convergence of the energy and the motion of the Acrobot. Specifically, forany initial stateof the Acrobot, this paper shows clearly how to choose control parameters such that the Acrobot will eventually either be swung up to any arbitrarily small neighbourhood of the upright equilibrium point, or remain in a set containing a finite number of equilibrium points. Moreover, this paper shows that these equilibrium points are unstable. Furthermore, imposing a stronger condition on a control parameter yields that the equilibrium set contains only the downward equilibrium point, which is shown to behyperbolicand unstable. This proves that the Acrobot will eventually enter the basin of attraction of any stabilizing controller for all initial conditions with the exception of a set of Lebesgue measure zero. Copyright © 2007 John Wiley & Sons, Ltd.
The application of multilevel modelling to dental caries data
Authors: Burnside G. , Pine C. M. , Williamson P. R.
Published: March 2007

Clinical studies of dental caries experience generate multiple outcome data for each participant, with information collected for each individual tooth surface. This paper investigates multilevel modelling as a method of analysis for dental caries data, allowing for full use of the data collected at surface level. Data from a clinical trial of a caries preventive agent in adolescents are modelled. The effect of tooth position within the mouth on the development of dental caries is investigated, with the results showing the importance of differentiating between the upper and lower arches, when modelling the probabilities of caries developing on teeth. Calculation of the intracluster correlation using the threshold model is suggested for use in multilevel logistic regression modelling of caries data. This model, which assumes that a dichotomous outcome is based on an underlying continuous variable with a threshold point where the outcome changes from zero to one, is identified to be appropriate for the analysis of caries which is a continuous process, but is only identified as present in a clinical trial when it has reached a certain level of severity. Copyright © 2007 John Wiley & Sons, Ltd.
HIV/AIDS and immigrant Cape Verdean women: Contextualized perspectives of Cape Verdean community advocates
Authors: De Jesus Maria
Published: March 2007

This research explored Cape Verdean community advocates' understandings of the structural and social realities that contribute to the increased HIV/AIDS risk of Northeastern U.S.‐based immigrant Cape Verdean women. A community perspective informed the analysis of the multi‐layered contextual barriers that these advocates identified as limiting the effectiveness of individual‐level HIV/AIDS prevention and intervention models. Qualitative content analysis of interviews with nine community advocates revealed several thematic clusters including challenges to (1) perceived institutional and community realities; (2) traditional gender relations; and, (3) traditional ways of thinking. These findings challenge universalist cognitive‐behavioral change models of HIV/AIDS prevention and intervention and are critically discussed to better understand the complex realities faced by Cape Verdean immigrant women. A liberatory community psychology perspective framed the research process and contributed to reconceptualizing HIV/AIDS risk as a community problem that requires interventions not simply at the individual and relational levels, but also at the structural level.
Spin dynamics of an ultra-small nanoscale molecular magnet
Authors: Ciftja Orion
Published: March 2007

We present mathematical transformations which allow us to calculate the spin dynamics of an ultra-small nanoscale molecular magnet consisting of a dimer system of classical (high) Heisenberg spins. We derive exact analytic expressions (in integral form) for the time-dependent spin autocorrelation function and several other quantities. The properties of the time-dependent spin autocorrelation function in terms of various coupling parameters and temperature are discussed in detail.
Plasma B‐type natriuretic peptide concentration in β‐thalassaemia patients
Authors: Aessopos Athanasios , Farmakis Dimitrios , Polonifi Aikaterini , Tsironi Maria , Fragodimitri Christina , Hatziliami Antonia , Karagiorga Markisia , Diamanti‐Kandarakis Evanthia
Published: March 2007

Background

Plasma B‐type natriuretic peptide (BNP) concentration has significant diagnostic accuracy and prognostic value in various forms of heart disease. Whether BNP is also useful in the evaluation and management of thalassaemia heart disease remains to be determined.

Methods and results

Eighty three thalassaemia major patients; 8 with acutely decompensated heart failure (New York Heart Association [NYHA] class III or IV, group A), 25 with NYHA class II symptoms and impaired systolic left ventricular function (ejection fraction<55% or fractional shortening<30%, group B) and 50 with normal systolic function (group C), as well as 50 healthy controls, were studied. Assessment included history, physical examination, Doppler echocardiography and plasma BNP determination. Mean BNP levels were 431±219 pg/mL (range, 283–890 pg/mL) in group A, 158±31 pg/mL in group B, 176±54 pg/mL in group C and 43±24 pg/mL in controls. BNP levels were significantly higher in group A (p<0.001), but did not differ between groups B and C. Moreover, BNP was not correlated with left ventricular end‐diastolic diameter, left ventricular mass, right ventricular diameter index, Doppler diastolic indexes (except in group C), the mean 2‐year serum ferritin concentration or the peak serum ferritin concentration in any of the three patient groups.

Conclusion

A potential deficiency of BNP‐related neurohormonal mechanisms may impair its clinical usefulness in thalassaemia major.
Offshore outsourcing of professional services: A transaction cost economics perspective
Authors: Ellram Lisa M. , Tate Wendy L. , Billington Corey
Published: March 2007

This research utilizes the framework of transaction cost economics (TCE) to develop an understanding of how firms manage the costs and risks of offshore outsourcing of professional services. This research examines the perspectives of eight organizations through interviews with 10 high‐ranking supply management executives. The paper first explores the rationale for offshore outsourcing among the organizations studied. Using the tenants of TCE, this paper postulates that fixed costs of establishing the relationship dominate the variable costs of day‐to‐day transactions, and that organizations will not offshore outsource areas where there is high perceived degree of unmanageable risk. The paper expands on themes provided by TCE and offers some lessons learned, and guidelines for managing and controlling offshore outsourced services relationships.
Inheritance of high oleic acid content in the seed oil of mutant Ethiopian mustard lines and its relationship with erucic acid content
Authors: RÍO-CELESTINO M. DEL , FONT R. , DE HARO-BAILÓN A.
Published: March 2007

Ethiopian mustard (Brassica carinata) genotypes with different contents of oleic acid (C18:1) in the seed oil could be useful for food and industrial applications. The objectives of the present research were to study the inheritance of high C18:1 in the seed oil of different lines of Ethiopian mustard and its relationship with erucic acid content (C22:1). The low C18:1/high C22:1 mutant line L-1806, the high C18:1/high C22:1 mutant line L-482, the high C18:1/low C22:1 mutant line L-2890 and the low C18:1/very high C22:1 mutant line L-1630 were isolated after a chemical mutagen treatment of C-101 seeds (about 94 g C18:1/kg and 450 g C22:1/kg). The high C18:1/zero C22:1 line L-25X-1 was obtained by interspecific crosses of Ethiopian mustard with rapeseed and Indian mustard. Plants of lines L-2890×C-101, L-482×L-2890, L-1630×L-25X-1, L-1630×L-2890 and L-482×L-1806 were reciprocally crossed and F2 and the BC1F1 generations were obtained. Cytoplasmic effects were not observed in any of the crosses. The segregation pattern in F2 and BC1F1 populations differed in the crosses studied. The inheritance of C18:1 content in crosses segregating for this fatty acid was that expected for one (crosses between L-482×L-1806), two (L-2890×C-101) or three (L-1630×L-2890, L-1630×L-25X-1 and L-482×2890) loci. Oleic acid segregation indicated control of accumulation by two segregating genetic systems, one acting on chain elongation from C18:1 to C22:1 and the other involving desaturation from C18:1 to linoleic acid (C18:2). Accumulations of C18:1 and C22:1 were influenced by the same loci (M1, M2, E1 and E2), which control the chain elongation steps leading from C18:1 to C22:1. In addition, C18:1 was influenced by one additional locus (tentatively named OL) involved in control of desaturation of C18:1 to form C18:2. The genetic constitution of the parent lines would be OlOlE1E1E2E2m1m1m2m2 for L-2890, OlOlE1E1E2E2M1M1M2M2 for C-101, ololE1E1E2E2M1M1M2M2 for L-1630, OlOle1e1e2e2M1M1M2M2 for L-25X-1, ol1ol1E1E1E2E2M1M1M2M2 for L-482 and Ol1Ol1E1E1E2E2M1M1M2M2 for L-1806. Transgressive recombinants were obtained from the cross L-1630×L-25X-1, with about three-fold increase of the C18:1 content of the parents (>643 g/kg) and free of C22:1 content, which represent a high potential for commercial exploitation.
Industrial Relations as a Source of Solidarity in Times of Welfare State Retrenchment
Authors: TRAMPUSCH CHRISTINE
Published: March 2007

Within the literature on retrenchment policies, the ‘solidarity-decline thesis’ is discussed. It is argued that current welfare state restructuring leads to a decrease in the actual social cohesion of society because redistributive public benefits are cut. The article addresses this thesis by presenting empirical evidence on social security based on collective bargaining. In Denmark, France, Germany and the Netherlands, collective agreements are increasingly used to regulate and finance social benefits. These collectively negotiated benefits may compensate to a certain degree for solidarity losses caused by retrenchment policies. The article reviews concepts of solidarity used in the literature and develops a two-dimensional scheme of four different concepts. The conclusion for comparative welfare state research is twofold. First, when viewing policies of welfare state retrenchment, the research should systematically include industrial relations in its frame of reference. Second, further studies should analyse the politics as well as the outcomes of collectively negotiated benefits more systematically. Under certain conditions, which are worth specifying, collective bargaining may lead to complex public–private mixes that shift welfare states in other directions than outright market liberalisation, not only in factual but also in normative terms.
Social Policy Digest Online
Authors: Bennett Fran , Jones Ken
Published: March 2007

The Social Policy Digest went online in the summer of 2003. This means that the Digest, which used to be printed as part of the Journal of Social Policy, is now only available via the web.
Seasonal variation of arthropod abundance in gaps and the understorey of a lowland moist forest in Panama
Authors: Richards Lora A. , Windsor Donald M.
Published: March 2007

Treefalls gaps contribute to the habitat heterogeneity of tropical forest floors. Previous studies have shown that these gaps play an important role in plant and bird communities, however less is known about their role in arthropod communities. Using eight Malaise traps we investigated the difference in arthropod abundance of 19 taxonomic groups between gaps and understorey for 21 wk during the rainy season and 8 wk in the dry season on Barro Colorado Island, Panama. More (33.8%) arthropods were collected in gaps during the rainy season and 32.2% more in the understorey during the dry season. To assess the possible factors contributing to these differences we measured light, plant densities and young leaf densities, as indicators of abiotic factors and food resources for insect herbivores. Arthropod abundance was negatively correlated with light in the dry season. Thus, abiotic stress may explain the pattern of abundance in the dry season. While there was no correlation with light in the rainy season, predator abundance was positively correlated with herbivore abundance. The plant and young leaf density data suggest that there is significantly higher food availability for herbivores in gaps. Thus, less stressful abiotic conditions and more food resources may contribute to more herbivores followed by more predators in gaps during the rainy season.
The development of self-efficacy and outcome expectation measures regarding glycaemic load and the nutritional management of type 2 diabetes
Authors: Miller Carla K , Gutschall Melissa Davis , Lawrence Frank
Published: March 2007

Objective

Traditionally, carbohydrate has been the largest contributor to energy intake among people with diabetes, yet different carbohydrate foods produce different glycaemic responses. Glycaemic load represents the total glycaemic effect of the diet and influences glycaemic control. Adequate self-efficacy and outcome expectations are needed to change carbohydrate intake and to evaluate relevant interventions. The purpose of this research was to develop and test instruments regarding self-efficacy and outcome expectations for the adoption of a lower glycaemic load diet.

Design

Participants completed each instrument at their convenience and mailed the instruments to the investigators.

Setting/subjects

A community sample of individuals 21–75 years of age with type 2 diabetes for ≥ 1 year (n = 108) was recruited.

Results

Principal components analysis revealed three factors on the self-efficacy questionnaire: glycaemic index, negative food selection and self-regulation efficacy which accounted for 62% of the variance in these items. The outcome expectations instrument yielded three factors: barriers to dietary change and glycaemic control, and family support expectations which accounted for 48% of the variance. Coefficient α for each construct was >0.70 and coefficientHfor each construct was ≥ 0.80.

Conclusions

The two instruments developed for this study can provide important insights about the self-efficacy and outcome expectations regarding the quantity and quality of carbohydrate consumed and self-monitoring performed for diabetes management. Future research is needed to evaluate the relationship among these constructs, dietary intake and glycaemic control.
Television food advertising to children: the extent and nature of exposure
Authors: Kelly Bridget , Smith Ben , King Lesley , Flood Victoria , Bauman Adrian
Published: March 2007

Objective

To describe the pattern and prevalence of food and drink advertisements to children on commercial television in Sydney, Australia, and compare these with advertising regulations set out in the Children's Television Standards and results from a similar study in 2002.

Design

Data were collected by recording television from 06.00 hours until 23.00 hours on all three commercial channels from Sunday 14 May 2006 to Saturday 20 May 2006 (357 h). The study analysed advertisements in two children's viewing periods, one as defined in the 2002 study and the other according to current standards. Food advertisements were coded using 18 food categories and were analysed by time period and popular children's programmes.

Results

Food advertisements occurred in similar proportions during children's viewing hours and adult's viewing hours (25.5 vs. 26.9% of all advertisements, respectively), although there was a higher rate of high-fat/high-sugar food advertisements during children's viewing hours (49 vs. 39% of all food advertisements,P < 0.001). There were even more advertisements for high-fat/high-sugar foods during popular children's programmes, contributing to 65.9% of all food advertisements. Estimates of exposure indicate that children aged 5–12 years were exposed to 96 food advertisements, including 63 high-fat/high-sugar advertisements per week. Since 2002, there has been a reduction in overall food and high-fat/high-sugar food advertisements.

Conclusion

Despite reductions in overall levels of food advertising, children continue to experience high levels of exposure to food advertisements, which remain skewed towards unhealthy foods. Further food advertising regulation should be required to curtail the current levels of advertising of high-fat/high-sugar foods to children, to make them commensurate with recommended levels of consumption.
Farm woodlots in northern New England, USA: Characteristics, management, and contributions to the whole farm system
Authors: Egan A.F.
Published: March 2007

Farms and forests dominate the rural landscape of the northern New England states of Maine, New Hampshire and Vermont, among the most heavily forested states in the US. However, we know little about the stewardship of farm woodlots and their contributions to the whole farm system, despite region-wide increases in farm forest acreage. Using a mail survey, this study found that almost half of respondents had a written management plan for their forestland, most of which had been written by a forester, and approximately three-quarters took an active role in the management of their woodlots. Farm woodlot harvesting and management contributed over 7% of total farm income. Variables such as respondent's state of residence, age, education and type of farm were investigated in order to better understand farmers’ forest stewardship behavior. Implications for effective outreach to farm forest owners are offered.