bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recipient country's ‘policies’ and the effect of foreign aid on economic growth in developing countries: additional evidence
Authors: Ram Rati 
Published: February 2004

AbstractThis note adds to the research which questions the recent influential view that recipient country's ‘policies’ play an important role in the effect of foreign aid on economic growth in developing countries. In the first step, the almost universal practice of imposing the constraint of equality on parameters of bilateral and multilateral aid is relaxed and it is shown that ‘policy’ has no role in the effect of aid even in those cases where the usual constrained models do show such an effect. In addition, many cases are noted where there is no indication of recipient country's policies having any role in the effect of aid on growth even in the usual constrained specifications. These cases employ not merely the Burnside–Dollar ‘policy’ index, which almost all scholars have used, but also two other broader measures. It is thus concluded that there is little empirical evidence to support the widely‐disseminated view that redirecting aid toward countries with ‘good’ policies leads to more growth and greater poverty reduction in developing countries. Copyright © 2004 John Wiley & Sons, Ltd.
Japan's official development assistance: recent issues and future directions
Authors: Kawai Masahiro , Takagi Shinji 
Published: February 2004

AbstractThe paper discusses recent issues and possible future directions of Japan's official development assistance (ODA). While Japan remains one of the world's largest donor nations, given its prolonged economic stagnation and mounting public sector debt, the Japanese government is under increasing public pressure to reduce ODA budgets and to use ODA in more explicit pursuit of Japan's own economic and political interests. Internationally, Japan continues to attract criticism for its emphasis on infrastructure‐related projects and for its restrained willingness to participate in multilateral partnerships. This paper argues that Japan can meet these domestic and international challenges by developing a coherent national strategy for ODA, broadly designed to enhance effectiveness, accountability and transparency. Copyright © 2004 John Wiley & Sons, Ltd.
Does saving really matter for growth? Mexico (1970–2000)
Authors: Alguacil Maite , Cuadros Ana , Orts Vicente 
Published: February 2004

AbstractThis paper uses the Granger non‐causality test procedure developed by Toda and Yamamoto (1995) and Dolado and Lütkepohl (1996) to analyse the saving‐growth nexus in Mexico. Contrary to the reverse causation between national saving and domestic income found in recent empirical studies, evidence is presented in favour of Solow's model prediction that higher saving leads to higher economic growth. The confirmation of a saving‐growth nexus in this country seems to be related to the inclusion of foreign direct investment (FDI) in the model, as the most relevant component of foreign saving. As this study will try to show, this last variable enhances economic growth and reinforces the connection between the two focus variables in the analysed country. Copyright © 2004 John Wiley & Sons, Ltd.
T2 and T1ρ MRI in articular cartilage systems
Authors: Menezes Nina M. , Gray Martha L. , Hartke James R. , Burstein Deborah 
Published: February 2004

AbstractT2 and T1ρ have potential to nondestructively detect cartilage degeneration. However, reports in the literature regarding their diagnostic interpretation are conflicting. In this study, T2 and T1ρ were measured at 8.5 T in several systems: 1) Molecular suspensions of collagen and GAG (pure concentration effects): T2 and T1ρ demonstrated an exponential decrease with increasing [collagen] and [GAG], with [collagen] dominating. T2 varied from 90 to 35 ms and T1ρ from 125 to 55 ms in the range of 15–20% [collagen], indicating that hydration may be a more important contributor to these parameters than previously appreciated. 2) Macromolecules in an unoriented matrix (young bovine cartilage): In collagen matrices (trypsinized cartilage) T2 and T1ρ values were consistent with the expected [collagen], suggesting that the matrix per se does not dominate relaxation effects. Collagen/GAG matrices (native cartilage) had 13% lower T2 and 17% lower T1ρ than collagen matrices, consistent with their higher macromolecular concentration. Complex matrix degradation (interleukin‐1 treatment) showed lower T2 and unchanged T1ρ relative to native tissue, consistent with competing effects of concentration and molecular‐level changes. In addition, the heterogeneous GAG profile in these samples was not reflected in T2 or T1ρ. 3) Macromolecules in an oriented matrix (mature human tissue): An oriented collagen matrix (GAG‐depleted human cartilage) showed T2 and T1ρ variation with depth consistent with 16–21% [collagen] and/or fibril orientation (magic angle effects) seen on polarized light microscopy, suggesting that both hydration and structure comprise important factors. In other human cartilage regions, T2 and T1ρ abnormalities were observed unrelated to GAG or collagen orientation differences, demonstrating that hydration and/or molecular‐level changes are important. Overall, these studies illustrate that T2 and T1ρ are sensitive to biologically meaningful changes in cartilage. However, contrary to some previous reports, they are not specific to any one inherent tissue parameter. Magn Reson Med 51:503–509, 2004. © 2004 Wiley‐Liss, Inc.
Quantitation of differential renal blood flow and renal function using dynamic contrast‐enhanced MRI in rats
Authors: Pedersen Michael , Shi Yimin , Anderson Peter , Stødkilde‐Jørgensen Hans , Christian Djurhuus Jens , Gordon Isky , Frøkiær Jørgen 
Published: February 2004

AbstractA first‐pass upslope approach was used to estimate differential renal blood flow (DRBF) and a Patlak‐Rutland approach was used to estimate differential renal function (DRF) using Gd‐DTPA‐BMA‐enhanced MRI. DRBF and DRF were estimated in rat kidneys under three different experimental conditions: 1) transient renal artery occlusion (TRAO); 2) partial unilateral ureteric obstruction (PUO); and 3) sham‐operated control rats (SHAM). A bolus of Gd‐DTPA‐BMA was given intravenously during a dynamic single slice T1‐weighted gradient echo sequence, which allowed calculation of concentration from signal intensity values. Calculations based on the raw signal intensity showed that DRBF was decreased in both PUO (44 ± 1%; P < 0.05) and in TRAO (38 ± 1%; P < 0.05) compared with SHAM (52 ± 1%). Converting the signal intensity into a measure of Gd‐DTPA‐BMA concentration did not substantially alter these findings (PUO: 40 ± 3%, P < 0.05; TRAO: 35 ± 2%, P < 0.05; SHAM 49 ± 1%). Likewise, DRF decreased in both PUO (43 ± 4%; P < 0.05) and TRAO (39 ± 3%; P < 0.05) compared with SHAM (48 ± 2%). Converting the signal intensity into measurements of Gd‐DTPA‐BMA concentration revealed similar findings (PUO: 41 ± 5%, P < 0.05; TRAO: 34 ± 5%, P < 0.05; SHAM: 49 ± 2%). Our results suggest that renal damage in rats may be demonstrated by an observed reduction of DRBF and DRF as estimated from single‐slice Gd‐DTPA‐BMA enhanced signal intensity using time–activity curves with and without quantitation of Gd‐concentration. Magn Reson Med 51:510–517, 2004. © 2004 Wiley‐Liss, Inc.
Parallel imaging reconstruction using automatic regularization
Authors: Lin Fa‐Hsuan , Kwong Kenneth K. , Belliveau John W. , Wald Lawrence L. 
Published: February 2004

AbstractIncreased spatiotemporal resolution in MRI can be achieved by the use of parallel acquisition strategies, which simultaneously sample reduced k‐space data using the information from multiple receivers to reconstruct full‐FOV images. The price for the increased spatiotemporal resolution in parallel MRI is the degradation of the signal‐to‐noise ratio (SNR) in the final reconstructed images. Part of the SNR reduction results when the spatially correlated nature of the information from the multiple receivers destabilizes the matrix inversion used in the reconstruction of the full‐FOV image. In this work, a reconstruction algorithm based on Tikhonov regularization is presented that reduces the SNR loss due to geometric correlations in the spatial information from the array coil elements. Reference scans are utilized as a priori information about the final reconstructed image to provide regularized estimates for the reconstruction using the L‐curve technique. This automatic regularization method reduces the average g‐factors in phantom images from a two‐channel array from 1.47 to 0.80 in twofold sensitivity encoding (SENSE) acceleration. In vivo anatomical images from an eight‐channel system show an averaged g‐factor reduction of 1.22 to 0.84 in 2.67‐fold acceleration. Magn Reson Med 51:559–567, 2004. © 2004 Wiley‐Liss, Inc.
Cortical depth‐dependent gradient‐echo and spin‐echo BOLD fMRI at 9.4T
Authors: Zhao Fuqiang , Wang Ping , Kim Seong‐Gi 
Published: February 2004

AbstractTo examine cortical depth‐related spatial specificity and signal changes in gradient‐echo (GE) and spin‐echo (SE) blood oxygenation level‐dependent (BOLD) fMRI signals, a well‐established cat visual stimulation model was used at 9.4T. The GE BOLD signal percent change is the highest at the surface of the cortex containing pial vessels, and decreases as cortical depth increases. In contrast, the SE BOLD signal is more specific to parenchyma, showing the highest signal change in the middle cortical areas. The stimulation‐induced ΔR to ΔR2 ratio is dependent on the vessel size, which is related to basal susceptibility effects. The averaged ratio of ΔR to ΔR2 in all active regions, including large vessels, is 3.3 ± 0.5 (N = 6). The averaged ratio of ΔR to ΔR2 is 8.8 ± 1.7 (N = 4) on the surface of the cortex with large pial draining vessels, and decreases to 1.9 ± 0.1 on the middle cortical areas with parenchymal microvessels. ΔR/ΔR2 is closely related to basal susceptibility effects and can be used to differentiate tissue from vessel regions. Magn Reson Med 51:518–524, 2004. © 2004 Wiley‐Liss, Inc.
Reference‐scan‐free method for automated correction of nyquist ghost artifacts in echoplanar brain images
Authors: Zhang Yan , Wehrli Felix W. 
Published: February 2004

AbstractOne of the most common artifacts for echo‐planar imaging is the Nyquist ghost, typically overcome with the aid of a reference scan preceding the actual image acquisition. In this work, a nonlinear phase correction obviating the need for a reference scan is proposed. The method is based on computing the second moments of the even and odd subdomains of the phase‐encoding k‐space data to retrieve the phase disparities between even and odd echoes. The method's underlying assumption is that the images are dominated by their low frequency and symmetric part. In vivo data demonstrate the effectiveness of the algorithm showing ghost suppression comparable to that achievable with the reference‐scan method. Magn Reson Med 51:621–624, 2004. © 2004 Wiley‐Liss, Inc.
Noninvasive in vivo determination of intracerebral oxygen concentration in rats by a longitudinally detected ESR (LODESR) technique
Authors: Yokoyama Hidekatsu , Sato Toshiyuki , Fukui Kouichi , Itoh Osamu , Ohya Hiroaki , Akatsuka Takao 
Published: February 2004

AbstractWe have developed a noninvasive method to determine oxygen concentration in the brain tissue of rats in vivo. The method is based upon measuring the fundamental harmonic‐to‐secondary harmonic ratio (FSR) of longitudinal magnetization changes of a blood–brain barrier (BBB)‐permeable nitroxide radical, 3‐hydroxymethyl‐2,2,5,5‐tetramethylpyrrolidine‐1‐oxyl (hydroxymethyl‐PROXYL), by employing a longitudinally detected ESR (LODESR) spectrometer operating at an ESR frequency of 280 MHz. FSRs of phantoms, including a hydroxymethyl‐PROXYL solution and various concentrations of oxygen, were measured. We found that the FSRs of the phantom increased as the oxygen concentration increased. In vivo FSRs in the brains of rats that had received a hydroxymethyl‐PROXYL injection were measured without the use of any surgical procedures. It was found that when the rats breathed 100% oxygen, rather than normal air, the FSR was significantly greater. Magn Reson Med 51:595–601, 2004. © 2004 Wiley‐Liss, Inc.
Novel system for determining contrast agent concentration in mouse blood in vivo
Authors: Pathak Arvind P. , Artemov Dmitri , Bhujwalla Zaver M. 
Published: February 2004

AbstractA method for measuring contrast agent concentration in blood was developed using a switchable RF tail coil to obtain MR signal from the mouse tail vein. The switchable RF coil was used to obtain quantitative high‐resolution T1 maps of the tail in combination with a second coil used to obtain images from regions of interest in a mouse tumor model. The effect of flow rates on the T1 measurements was validated using a flow‐phantom. Reliable estimates of blood T1 were obtained for flow rates up to 0.5 cm/sec in SCID mice. There was no significant difference between the in vivo tail coil measurements and in vitro blood sample relaxation rates of blood. The ability to measure the concentration of contrast agents in mouse blood in vivo is useful for several applications, such as obtaining quantitative values of tumor vascular volume and permeability, determining the effectiveness of drug delivery to tumors, or for detecting lymphatic drain. Magn Reson Med 51:612–615, 2004. © 2004 Wiley‐Liss, Inc.
Detection of amyloid plaques in mouse models of Alzheimer's disease by magnetic resonance imaging
Authors: Zhang Jiangyang , Yarowsky Paul , Gordon Marcia N. , Di Carlo Giovanni , Munireddy Sanjay , van Zijl Peter C.M. , Mori Susumu 
Published: February 2004

AbstractWe performed three‐dimensional, high‐resolution magnetic resonance imaging (MRI) of fixed mouse brains to determine whether MRI can detect amyloid plaques in transgenic mouse models of Alzheimer's disease. Plaque‐like structures in the cortex and hippocampus could be clearly identified in T2‐weighted images with an image resolution of 46 μm × 72 μm × 72 μm. The locations of plaques were confirmed in coregistration studies comparing MR images with Congo red‐stained histological results. This technique is quantitative, less labor‐intensive compared to histology, and is free from artifacts related to sectioning process (deformation and missing tissues). It enabled us to study the distribution of plaques in the entire brain in 3D. The results of this study suggest that this method may be useful for assessing treatment efficacy in mouse models of Alzheimer's disease (AD). Magn Reson Med 51:452–457, 2004. © 2004 Wiley‐Liss, Inc.
Quantification of tumor tissue populations by multispectral analysis
Authors: Carano Richard A.D. , Ross Adrienne L. , Ross Jed , Williams Simon P. , Koeppen Hartmut , Schwall Ralph H. , Van Bruggen Nicholas 
Published: February 2004

AbstractTumor heterogeneity complicates the quantification of a therapeutic response by MRI. To address this issue, a novel approach has been developed that combines MR diffusion imaging with multispectral (MS) analysis to quantify tumor tissue populations. K‐means (KM) clustering of the apparent diffusion coefficient (ADC), T2, and proton density (M0) was employed to estimate the volumes of viable tumor tissue, necrosis, and neighboring subcutaneous adipose tissue in a human colorectal tumor xenograft mouse model. In a second set of experiments, the temporal evolution of the MS tissue classes in response to therapeutic intervention Apo2L/TRAIL and CPT‐11 was observed. The multiple parameters played complementary roles in identifying the various tissues. The ADC was the dominant parameter for identifying regions of necrosis, whereas T2 identified two necrotic subpopulations, and M0 contributed to the differentiation of viable tumor from subcutaneous adipose tissue. MS viable tumor estimates (mean volume = 275 ± 147 mm3) were highly correlated (r = 0.81, P < 0.01) with histological estimates (117 ± 51 mm3). In the treatment study, MS viable tumor volume (at day 10) was 77 ± 67 mm3 for the Apo2L/TRAIL+CPT‐11 group, and was significantly reduced relative to the control group (292 ± 127 mm3, P < 0.01). This method shows promise as a means of detecting an early therapeutic response in vivo. Magn Reson Med 51:542–551, 2004. © 2004 Wiley‐Liss, Inc.
A pneumatic vibrotactile stimulation device for fMRI
Authors: Briggs Richard W. , Dy‐Liacco Iona , Malcolm Matthew P. , Lee Hyunsook , Peck Kyung K. , Gopinath Kaundinya S. , Himes Nathan C. , Soltysik David A. , Browne Paul , Tran‐Son‐Tay Roger 
Published: February 2004

AbstractMapping the functional response of the somatosensory cortex is useful both for characterizing normal brain activity and for determining the functional integrity of damaged cortex compromised by stroke or other neurological insults. A variety of stimulators have been used to produce somatosensory cortex activation in functional brain imaging, including brushes and swabs operated manually, pneumatically and mechanically powered mechanical vibrators, air puffs, and vibrating ceramic piezoelectric wafers and benders. A closed‐system, pneumatically driven rubber diaphragm is reported that overcomes many of the limitations of existing vibrotactile devices and produces robust sensory cortex activation in an fMRI experiment. Magn Reson Med 51:640–643, 2004. © 2004 Wiley‐Liss, Inc.
Fast, pseudo‐continuous arterial spin labeling for functional imaging using a two‐coil system
Authors: Hernandez‐Garcia Luis , Lee Gregory R. , Vazquez Alberto L. , Noll Douglas C. 
Published: February 2004

AbstractA fast, two‐coil, pseudo‐continuous labeling scheme is presented. This new scheme permits the collection of a multislice subtraction pair in <3 s, depending on the subject's arterial transit times. The method consists of acquiring both control and tag images immediately after a labeling period that matches the arterial transit time. The theoretical basis of the technique, and simulations of the signal during changes in both transit time and perfusion are presented. Experimental data from functional imaging experiments were collected to demonstrate the technique and its characteristics. Magn Reson Med 51:577–585, 2004. © 2004 Wiley‐Liss, Inc.
Optimized precision of inversion‐recovery T1 measurements for constrained scan time
Authors: Ogg Robert J. , Kingsley Peter B. 
Published: February 2004

AbstractOptimization of inversion‐recovery (IR) measurements of T1 relaxation times has focused on the efficiency of T1 estimation (precision per unit time), without explicit consideration of the total experimental time. With the modified fast IR method, the repetition time (TR) is constant and each inversion time (TI) must be less than TR. For a fixed total experimental time in the absence of signal averaging, TR and the longest TI time must decrease as more TI times are added. This article investigates the number of TI times and their values to optimize the precision of T1 measurements when time constraints preclude signal averaging and limit the largest TI that can be acquired. If the longest TI is less than approximately three times the longest T1 of interest, then precision is optimum with only four TI times. Suggestions are given for selecting the optimum TI times for 1–16‐fold ranges of T1 times relative to a given maximum T1. Magn Reson Med 51:625–630, 2004. © 2004 Wiley‐Liss, Inc.
Mimicking liver iron overload using liposomal ferritin preparations
Authors: Wood John C. , Fassler Joe D. , Meade Tom 
Published: February 2004

AbstractClose monitoring of liver iron content is necessary to prevent iron overload in transfusion‐dependent anemias. Liver biopsy remains the gold standard; however, MRI potentially offers a noninvasive alternative. Iron metabolism and storage is complicated and tissue/disease‐specific. This report demonstrates that iron distribution may be more important than iron speciation with respect to MRI signal changes. Simple synthetic analogs of hepatic lysosomes were constructed from noncovalent attachment of horse‐spleen ferritin to 0.4 μm diameter phospholipid liposomes suspended in agarose. Graded iron loading was achieved by varying ferritin burden per liposome as well as liposomal volume fraction. T1 and T2 relaxation times were measured on a 60 MHz NMR spectrometer and compared to simple ferritin‐gel combinations. Liposomal‐ferritin had 6‐fold stronger T2 relaxivity than unaggregated ferritin but identical T1 relaxivity. Liposomal‐ferritin T2 relaxivity also more closely matched published results from hemosiderotic marmoset liver, suggesting a potential role as an iron‐calibration phantom. Magn Reson Med 51:607–611, 2004. © 2004 Wiley‐Liss, Inc.
New model for analysis of dynamic contrast‐enhanced MRI data distinguishes metastatic from nonmetastatic transplanted rodent prostate tumors
Authors: Fan Xiaobing , Medved Milica , River Jonathan N. , Zamora Marta , Corot Claire , Robert Philippe , Bourrinet Philippe , Lipton Martin , Culp Rita M. , Karczmar Gregory S. 
Published: February 2004

AbstractDynamic contrast‐enhanced MRI (DCEMRI) data were acquired from metastatic and nonmetastatic tumors in rodents to follow the uptake and washout of a low‐molecular‐weight contrast agent (Gd‐DTPA) and a contrast agent with higher molecular weight (P792). The concentration vs. time curves calculated for the tumor rims and centers were analyzed using the two‐compartment model (TCM) and a newly developed empirical mathematical model (EMM). The EMM provided improved fits to the experimental data compared to the TCM. Parameters derived from the empirical model showed that the contrast agent washout rate was significantly slower in metastatic tumors than in nonmetastatic tumors for both Gd‐DTPA (P < 0.03) and P792 (P < 0.04). The effects of the tumor on blood flow in “normal” tissue immediately adjacent to the tumors were evident: Gd‐DTPA uptake and washout rates were much lower in muscle near the tumor (P < 0.05) than normal muscle farther from the tumor. The results suggest that accurate fits of DCEMRI data provide kinetic parameters that distinguish between metastatic and relatively benign cancers. In addition, a comparison of the dynamics of Gd‐DTPA and P792 provides information regarding the microenvironment of tumors. Magn Reson Med 51:487–494, 2004. © 2004 Wiley‐Liss, Inc.
Single TrAjectory Radial (STAR) imaging
Authors: Sarty Gordon E. 
Published: February 2004

AbstractThe number of MRI applications that use radial k‐space data acquisition have been increasing because of their inherent robustness to motion‐induced reconstruction image artifacts relative to Cartesian acquisition methods. However, images reconstructed from radial data are more prone to image degrading effects due to magnetic field inhomogeneities than images made from Cartesian data. Presented here is a method for acquiring several radial k‐space data lines in one trajectory, the Single TrAjectory Radial, or STAR method, that is a variation of radial EPI. The STAR method allows for angular oversampling without the increase in imaging time that occurs with angularly oversampled single line imaging. It is shown that such oversampling potentially reduces the image degrading effect of magnetic field inhomogeneities so that the motion robust features of radial imaging may be realized in a segmented EPI approach. Magn Reson Med 51:445–451, 2004. © 2004 Wiley‐Liss, Inc.
Spiral readout gradients for the reduction of motion artifacts in chemical shift imaging
Authors: Kim Dong‐Hyun , Adalsteinsson Elfar , Spielman Daniel M. 
Published: February 2004

AbstractA motion artifact reduction method for proton chemical shift imaging (CSI) is presented. The method uses spiral‐based readout gradients for data acquisition. A characteristic of spiral‐based readout gradients is that data are repeatedly sampled at the kxy origin. These data points are used to estimate and correct for motion‐induced phase variations. Both phantom and in vivo spectra reconstructed using the new motion artifact reduction algorithm showed significant signal‐to‐noise ratio (SNR) improvements as compared to uncorrected data. Magn Reson Med 51:458–463, 2004. © 2004 Wiley‐Liss, Inc.