bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship of topography to surface water chemistry with particular focus on nitrogen and organic carbon solutes within a forested watershed in Hokkaido, Japan
Authors: Ogawa Akiko , Shibata Hideaki , Suzuki Kei , Mitchell Myron J. , Ikegami Yoshiyuki
Published: February 2006

We studied the relationships between streamwater chemistry and the topography of subcatchments in the Dorokawa watershed in Hokkaido Island, northern Japan, to examine the use of topography as a predictor of streamwater chemistry in a watershed with relatively moderate terrain compared with other regions of Japan. Topographic characteristics of the Dorokawa watershed and its subcatchments were expressed as topographic index (TI) values, which ranged from 4·5 to 20·4 for individual grid cells (50 × 50 m2), but averaged from 6·4 to 7·4 for the 20 subcatchments. Streamwater samples for chemical analyses were collected four times between June and October 2002 from 20 locations in the watershed. The pH of water that passed through the watershed increased from ∼5·0 to 7·0, with major increases in Na+ and Ca2+ and marked decreases in NO3− and SO$_{4}^{2-}$. Distinctive spatial patterns were observed for dissolved organic carbon (DOC), dissolved organic nitrogen (DON), and NO3− concentrations of streamwater across the watershed. Statistical analyses indicated significant linear relationships between the average TI values of subcatchments and DOC, DON, and NO3− concentrations. Furthermore, the proportion of DOC in streamwaters in the wet season increased with TI values relative to other nitrogen species, whereas NO3− concentrations decreased with TI. The gradients of soil wetness and the presence of wetlands explained many of the observed spatial and temporal patterns of DOC, DON, and NO3− concentrations in the surface waters of the Dorokawa watershed. Our results suggest that the TI is especially useful for predicting the spatial distribution of DOC, DON and NO3− in the surface waters of Hokkaido, where topographical relief is moderate and wetlands more common than in other regions of Japan. Copyright © 2006 John Wiley & Sons, Ltd.
Accuracy and precision of different sampling strategies and flux integration methods for runoff water: comparisons based on measurements of the electrical conductivity
Authors: Schleppi Patrick , Waldner Peter A. , Fritschi Bruno
Published: February 2006

Because of their fast response to hydrological events, small catchments show strong quantitative and qualitative variations in their water runoff. Fluxes of solutes or suspended material can be estimated from water samples only if an appropriate sampling scheme is used. We used continuous in‐stream measurements of the electrical conductivity of the runoff in a small subalpine catchment (64 ha) in central Switzerland and in a very small (0·16 ha) subcatchment. Different sampling and flux integration methods were simulated for weekly water analyses. Fluxes calculated directly from grab samples are strongly biased towards high conductivities observed at low discharges. Several regressions and weighted averages have been proposed to correct for this bias. Their accuracy and precision are better, but none of these integration methods gives a consistently low bias and a low residual error. Different methods of peak sampling were also tested. Like regressions, they produce important residual errors and their bias is variable. This variability (both between methods and between catchments) does not allow one to tell a priori which sampling scheme and integration method would be more accurate. Only discharge‐proportional sampling methods were found to give essentially unbiased flux estimates. Programmed samplers with a fraction collector allow for a proportional pooling and are appropriate for short‐term studies. For long‐term monitoring or experiments, sampling at a frequency proportional to the discharge appears to be the best way to obtain accurate and precise flux estimates. Copyright © 2006 John Wiley & Sons, Ltd.
Air pollution and risk of lung cancer in a prospective study in Europe
Authors: Vineis Paolo , Hoek Gerard , Krzyzanowski Michal , Vigna‐Taglianti Federica , Veglia Fabrizio , Airoldi Luisa , Autrup Herman , Dunning Alison , Garte Seymour , Hainaut Pierre , Malaveille Christian , Matullo Giuseppe , Overvad Kim , Raaschou‐Nielsen Ole , Clavel‐Chapelon Francoise , Linseisen Jacob , Boeing Heiner , Trichopoulou Antonia , Palli Domenico , Peluso Marco , Krogh Vittorio , Tumino Rosario , Panico Salvatore , Bueno‐De‐Mesquita H. Bas , Peeters Petra H. , Lund E. Eylin , Gonzalez Carlos A. , Martinez Carmen , Dorronsoro Miren , Barricarte Aurelio , Cirera Lluis , Quiros J. Ramon , Berglund Goran , Forsberg Bertil , Day Nicholas E. , Key Tim J. , Saracci Rodolfo , Kaaks Rudolf , Riboli Elio
Published: February 2006

To estimate the relationship between air pollution and lung cancer, a nested case‐control study was set up within EPIC (European Prospective Investigation on Cancer and Nutrition). Cases had newly diagnosed lung cancer, accrued after a median follow‐up of 7 years among the EPIC exsmokers (since at least 10 years) and never smokers. Three controls per case were matched. Matching criteria were gender, age (±5 years), smoking status, country of recruitment and time elapsed between recruitment and diagnosis. We studied residence in proximity of heavy traffic roads as an indicator of exposure to air pollution. In addition, exposure to air pollutants (NO2, PM10, SO2) was assessed using concentration data from monitoring stations in routine air quality monitoring networks. Cotinine was measured in plasma. We found a nonsignificant association between lung cancer and residence nearby heavy traffic roads (odds ratio = 1.46, 95% confidence interval, CI, 0.89–2.40). Exposure data for single pollutants were available for 197 cases and 556 matched controls. For NO2 we found an odds ratio of 1.14 (95% CI, 0.78–1.67) for each increment of 10 μg/m3, and an odds ratio of 1.30 (1.02–1.66) for concentrations greater than 30 μg/m3. The association with NO2 did not change after adjustment by cotinine and additional potential confounders, including occupational exposures. No clear association was found with other pollutants. © 2006 Wiley‐Liss, Inc.
ErbB4 increases the proliferation potential of human lung cancer cells and its blockage can be used as a target for anti‐cancer therapy
Authors: Starr Alex , Greif Joel , Vexler Akiva , Ashkenazy‐Voghera Maia , Gladesh Valery , Rubin Chanan , Kerber Gabriele , Marmor Sylvia , Lev‐Ari Shahar , Inbar Moshe , Yarden Yosef , Ben‐Yosef Rami
Published: February 2006

Clinical and experimental data suggest that ErbB‐4, a member of the epidermal growth factor receptor family, may have a role in cancer progression and response to treatment. We found recently, using a retrospective clinical analysis, that expression of ErbB‐4 receptor is correlated with metastatic potential and patient survival in non‐small‐cell lung cancer (NSCLC). The purpose of this work was to correlate the expression of the ErbB‐4 and lung cancer cells growth in vitro and in vivo and to determine the therapeutic potential of a monoclonal antibody to ErbB‐4 against lung cancer. For this aim, we ectopically expressed ErbB‐4 in a human NSCLC cell line that did not express the ErbB‐4 protein. Overexpression of ErbB‐4 produced a constitutively activated ErbB‐4 receptor. The transfected ErbB‐4 positive clones showed an increased cell proliferation in vitro and in vivo in comparison with parental ErbB‐4 negative cells and with the cells transfected by neomycin‐resistant gene. A monoclonal antibody to ErbB‐4 showed both an inhibitory effect on growth rate and an increasing apoptotic rate in the cells expressing ErbB‐4. The results of the current study provide evidence that ErbB‐4 plays a significant role in human lung cancer and may serve as a molecular target for anticancer therapy. © 2006 Wiley‐Liss, Inc.
Observed parenting practices of first‐generation Latino families
Authors: Rodríguez Melanie Domenech , Davis Melissa R. , Rodríguez Jesús , Bates Scott C.
Published: February 2006

This study used an established behavioral observation methodology to examine the parenting practices of first‐generation Latino parents of children 4 to 9 years of age. The study had three central aims, to examine: (1) the feasibility of using a behavioral observation methodology with Spanish‐speaking immigrant families, (2) the utility of the Parent Peer Process Code (PPPC; Forgatch, Knutson, & Mayne, 1992) for coding parentñchild interactions, and (3) the relationship between observed parenting practices, as coded with the PPPC, and child outcomes. Families consisted of 48 fathers, 49 mothers, and 50 children. Families participated in cooperative, problem‐solving, and skillsbuilding tasks. The authors coded in five broad categories: problem solving, skills building, positive involvement, effective discipline, and monitoring. Findings show that the behavioral observation methodology is feasible to use with Spanish‐speaking immigrant families, that the PPPC is useful in understanding parentñchild interactions, and that the coded parentñchild interactions predict differential child outcomes. This information can help inform the development or adaptation of culturally sensitive parenting interventions to this underserved population. © 2006 Wiley Periodicals, Inc.
Parent–Child cultural marginalization and depressive symptoms in Asian American family members
Authors: Kim Su Yeong , Gonzales Nancy A. , Stroh Kunise , Wang Jenny Jiun‐Ling
Published: February 2006

The current study findings refute the recent claim that marginality theory lacks construct validity. Cultural marginalization is significantly related to depressive symptoms in Korean American, Chinese American, and Japanese American parents and adolescents living in the United States. Correlational analyses indicate that adolescents' depressive symptoms are significantly related to Asian and Asian American marginality scores, whereas mothers' and fathers' depressive symptoms are significantly related to their levels of Anglo and Asian American marginality. In a structural equation model, adolescents' Asian American marginalization and fathers' Anglo marginalization are significantly related to adolescents' depressive symptoms. It appears that marginality is a significant factor in the depressive symptoms of mothers, fathers, and adolescents. Furthermore, marginality scores of fathers and adolescents are both significant factors in adolescents' depressive symptoms.© 2006 Wiley Periodicals, Inc.
Family, community, and school influences on resilience among American Indian adolescents in the upper midwest
Authors: LaFromboise Teresa D. , Hoyt Dan R. , Oliver Lisa , Whitbeck Les B.
Published: February 2006

This study examines resilience among a sample of American Indian adolescents living on or near reservations in the upper Midwest. Data are from a baseline survey of 212 youth (115 boys and 97 girls) who were enrolled in the fifth through eighth grades. Based upon the definition of resilience, latent class analyses were conducted to identify youth who displayed pro‐social outcomes (60.5%) as opposed to problem behavior outcomes. A measure of family adversity was also developed that indicated only 38.4% of the youth lived in low‐adversity households. Defining resilience in the context of positive outcomes in the face of adversity, logistic regression was used to examine the predictors of pro‐social outcomes among youth who lived in moderate‐ to high‐adversity households. The analyses identified key risk and protective factors. A primary risk factor appeared to be perceived discrimination. Protective factors were from multiple contexts: family, community, and culture. Having a warm and supportive mother, perceiving community support, and exhibiting higher levels of enculturation were each associated with increased likelihood of pro‐social outcomes. © 2006 Wiley Periodicals, Inc.
Developing cultural competence in working with Korean immigrant families
Authors: Kim Irene J. , Kim Luke I. C. , Kelly James G.
Published: February 2006

The authors provide an in‐depth examination of the historical background, cultural values, family roles, and community contexts of Korean Americans as an aid to both researchers and clinicians in developing cultural competence with this particular group. First, the concept of cultural competence is defined. A brief history of Korean immigration patterns to the United States and demographic information about Korean Americans are reviewed. Second, Korean cultural values, family structure, and family roles are examined as they impact relationships in research and clinical contexts. Three indigenous concepts (cf. L. Kim, 1992) that may be useful in developing cultural competence include haan (suppressed anger), jeong (strong feeling of kinship), and noon‐chi (ability to evaluate social situations through implicit cues). Clinical case examples and accounts from a community‐based research perspective illustrate these cultural values. Third, important community resources in the Korean American context are highlighted. Links between cultural competence and “ecological pragmatism” (Kelly, Azelton, Burzette, & Mock, 1994) are discussed. © 2006 Wiley Periodicals, Inc.
Some guiding assumptions and a theoretical model for developing culturally specific preventions with Native American people
Authors: Whitbeck Les B.
Published: February 2006

This author proposes six basic assumptions to guide the development of prevention research partnerships between Native American communities and non‐Native American prevention researchers. He also presents a five‐stage theoretical model for the development of culturally specific prevention research. The theoretical model addresses the need for: (a) the cultural translation of key prevention constructs pertaining to risk and protective factors and (b) the development of measures of culturally specific risk and protective factors that will contribute to explained variance over and above that explained by traditional European models. “Cultural translation” refers to the process of adapting key variables to reflect their expression in specific social contexts. “Culturally specific risk and protective factors” refers to risk and protective factors unique to a specific culture, such as the protective effects of traditional spirituality and traditional activities in Native American cultures. The author concludes with short‐ and long‐term goals for prevention research in Native American communities. © 2006 Wiley Periodicals, Inc.
Culturally centered psychosocial interventions
Authors: Bernal Guillermo , Sáez‐Santiago Emily
Published: February 2006

Over the last few decades, psychologists and other health professionals have called attention to the importance of considering cultural and ethnicminority aspects in any psychosocial interventions. Although, at present, there are published guidelines on the practice of culturally competent psychology, there is still a lack of practical information about how to carry out appropriate interventions with specific populations of different cultural and ethnic backgrounds. In this article, the authors review relevant literature concerning the consideration of cultural issues in psychosocial interventions. They present arguments in favor of culturally centering interventions. In addition, they discuss a culturally sensitive framework that has shown to be effective for working with Latinos and Latinas. This framework may also be applicable to other cultural and ethnic groups. @ 2006 Wiley Periodicals, Inc.
Iterated line graphs are maximally ordered
Authors: Knor Martin , Niepel L'udovít
Published: February 2006

A graph G is k‐ordered if for every ordered sequence of k vertices, there is a cycle in G that encounters the vertices of the sequence in the given order. We prove that if G is a connected graph distinct from a path, then there is a number tG such that for every t ≥ tG the t‐iterated line graph of G, Lt (G), is (δ(Lt (G)) + 1)‐ordered. Since there is no graph H which is (δ(H)+2)‐ordered, the result is best possible. © 2006 Wiley Periodicals, Inc. J Graph Theory 52: 171–180, 2006
Bounding the size of near hexagons with lines of size 3
Authors: De Bruyn Bart
Published: February 2006

We consider finite near hexagons with lines of size 3, and prove that there are only finitely many examples given the nondegeneracy condition that for each point there exists a point at distance 3 to it. © 2006 Wiley Periodicals, Inc. J Graph Theory 52: 108–122, 2006
Quantitative myocardial perfusion analysis with a dual‐bolus contrast‐enhanced first‐pass MRI technique in humans
Authors: Hsu Li‐Yueh , Rhoads Kenneth L. , Holly Jessica E. , Kellman Peter , Aletras Anthony H. , Arai Andrew E.
Published: February 2006

Purpose

To compare fully quantitative and semiquantitative analysis of rest and stress myocardial blood flow (MBF) and myocardial perfusion reserve (MPR) using a dual‐bolus first‐pass perfusion MRI method in humans.

Materials and Methods

Rest and dipyridamole stress perfusion imaging was performed on 10 healthy humans by administering gadolinium contrast using a dual‐bolus protocol. Ventricular and myocardial time‐signal intensity curves were generated from a series of T1‐weighted images and adjusted for surface‐coil intensity variations. Corrected signal intensity curves were then fitted using fully quantitative model constrained deconvolution (MCD) to quantify MBF (mL/min/g) and MPR. The results were compared with semiquantitative contrast enhancement ratio (CER) and upslope index (SLP) measurements.

Results

MBF (mL/min/g) estimated with MCD averaged 1.02 ± 0.22 at rest and 3.39 ± 0.59 for stress with no overlap in measures. MPR was 3.43 ± 0.71, 1.91 ± 0.65, and 1.16 ± 0.19 using MCD, SLP, and CER. Both semiquantitative parameters (SLP and CER) significantly underestimated MPR (P < 0.001) and failed to completely discriminate rest and stress perfusion.

Conclusion

Rest and stress MBF (mL/min/g) and MPR estimated by dual‐bolus perfusion MRI fit within published ranges. Semiquantitative methods (SLP and CER) significantly underestimated MPR. J. Magn. Reson. Imaging 2006. Published by Wiley‐Liss, Inc.
Pulsed arterial spin labeling parameter optimization for an elderly population
Authors: Campbell Alison M. , Beaulieu Christian
Published: February 2006

Purpose

To optimize pulsed arterial spin labeling (PASL) parameters for the elderly to take into account possible perfusion changes that occur in the brain with age.

Materials and Methods

Healthy young (N = 14, age range = 21–27 years) and elderly (N = 12, age range = 61–67 years) subjects were scanned using Q2TIPS (QUIPSS II with thin‐slice TI, periodic saturation) with varying inversion times (TI2) at 1.5T. The difference signal (ΔM), transit time (δt), and cerebral blood flow (CBF) were calculated in segmented gray matter (GM).

Results

The young displayed more perfusion‐weighted signal difference than the elderly at all TI2's. The peak ΔM occurred at TI2 ∼ 1300 msec and 1500 msec in the young and elderly groups, respectively. Qualitatively, intravascular signal was minimal in the younger group by TI2 = 1500 msec, whereas a longer TI2 of 1800 msec was needed to minimize this signal in the elderly. The transit time was ∼100 msec longer in the elderly, and CBF was in the range of literature values.

Conclusion

For acquiring perfusion‐weighted images with minimal intravascular signal and adequate tissue signal for PASL studies of cerebral perfusion in the elderly, a longer inversion time is advantageous. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Magnetic resonance brain perfusion imaging with voxel‐specific arterial input functions
Authors: Grüner Renate , Bjørnarå Bård T. , Moen Gunnar , Taxt Torfinn
Published: February 2006

Purpose

To propose an automatic method for estimating voxel‐specific arterial input functions (AIFs) in dynamic contrast brain perfusion imaging.

Materials and Methods

Voxel‐specific AIFs were estimated blindly using the theory of homomorphic transformations and complex cepstrum analysis. Wiener filtering was used in the subsequent deconvolution. The method was verified using simulated data and evaluated in 10 healthy adults.

Results

Computer simulations accurately estimated differently shaped, normalized AIFs. Simple Wiener filtering resulted in underestimation of flow values. Preliminary in vivo results showed comparable cerebral flow value ratios between gray matter (GM) and white matter (WM) when using blindly estimated voxel‐specific AIFs or a single manually selected AIF. Significant differences (P ≤ 0.0125) in mean transit time (MTT) and time‐to‐peak (TTP) in GM compared to WM was seen with the new method.

Conclusion

Initial results suggest that the proposed method can replace the tedious and difficult task of manually selecting an AIF, while simultaneously providing better differentiation between time‐dependent hemodynamic parameters. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Gastric motor function and emptying in the right decubitus and seated body position as assessed by magnetic resonance imaging
Authors: Treier Reto , Steingoetter Andreas , Weishaupt Dominik , Goetze Oliver , Boesiger Peter , Fried Michael , Schwizer Werner
Published: February 2006

Purpose

To determine the effect of the right decubitus lying body position (RP) on relevant parameters of human gastric motor function in healthy volunteers.

Materials and Methods

Postprandial gastric function after ingestion of a solid/liquid meal (150 g/150 mL) was assessed over 90 minutes in volunteers in the RP and seated position (SP). Ten healthy volunteers were imaged using two MRI systems that differed in architecture and field strength. Stomach and intragastric air volume, intragastric meal distribution, gastric emptying, and gastric peristalsis were compared between the RP and SP.

Results

Body position did not affect gastric relaxation (RP, 372 mL vs. SP, 384 mL) and initial gastric volumes (stomach: RP, 458 mL vs. SP, 462 mL; meal: RP, 377 mL vs. SP, 399 mL; intragastric air: RP, 110 mL vs. SP, 98 mL). Postprandial stomach volume and gastric activity (RP and SP, 3.1 minute–1) were also similar. Meal emptying showed different characteristics, resulting in a significant but small difference in meal volume of –43 mL at t = 90 minutes (P < 0.05).

Conclusion

Gastric MRI in RP is feasible for clinical research assessing gastric motor function. The subtle difference in meal emptying may be induced by posture‐dependent vagal activity. This study confirms that MRI is a highly sensitive imaging technique for assessing gastrointestinal function in humans. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Acute neurobehavioral effects of exposure to static magnetic fields: Analyses of exposure–response relations
Authors: de Vocht Frank , Stevens Tobias , van Wendel‐de‐Joode Berna , Engels Hans , Kromhout Hans
Published: February 2006

Purpose

To assess exposure–response relations between exposure to magnetic fields and neurobehavioral effects.

Materials and Methods

Twenty company volunteers completed a neurobehavioral test battery after they moved their heads with the magnetic field absent, and while they moved their heads in the inhomogenous stray fields of 1.5 and 3.0 T MRI magnets.

Results

The value of the stray fields at the position of the head of the volunteer was estimated to be 0.6 T and 1.0 T on the 1.5 T and 3.0 T systems, respectively. Exposure–response relations were found for visual (–2.1%/100 mT) and auditory (–1.0%/100 mT) working memory, eye–hand coordination speed (–1.0%/100 mT), and visual tracking tasks (–3.1%/100 mT). Eye–hand precision, scanning speed, and visual contrast sensitivity were apparently not influenced by the magnetic field strength.

Conclusion

Additional research should focus on the potential side effects of interventional MR procedures because of the exposure to strong magnetic fields of these systems. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Superficial femoral artery occlusive disease severity correlates with MR cine phase‐contrast flow measurements
Authors: Mohajer Kiyarash , Zhang Honglei , Gurell Daniel , Ersoy Hale , Ho Bernard , Kent K. Craig , Prince Martin R.
Published: February 2006

Purpose

To evaluate how cine phase‐contrast (PC) flow data correlate with the severity of peripheral vascular disease (PVD).

Materials and Methods

Flow waveforms were obtained in 48 patients proximal and distal to superficial femoral artery (SFA) disease using the 2D cine PC technique with velocity encoding (venc) = 100 cm/second. Flow data were correlated with SFA disease severity and compared with data from nine healthy volunteers.

Results

Of 96 arterial segments in 48 patients, 26 were patent or only mildly stenotic, 35 had moderate‐to‐severe stenosis, and 35 were occluded. The flow patterns tended to become low‐resistant below severe stenoses or occlusion. The mean peak flow velocity above/below SFA lesions was significantly higher in patients with severe disease (1.9 ± 1.0, P = 0.01) or occlusion (2.0 ± 1.0, P = 0.003) compared to normal volunteers (1.4 ± 0.6). The delay in peak velocity below the lesions showed a significant positive correlation with lesion severity (r = 0.65, P < 0.001). The mean flow volume ratio above/below SFA lesions was greater in patients with occluded vessels compared to normal volunteers (3.9 and 2.3 respectively; P = 0.04).

Conclusion

Cine PC flow waveform changes across atherosclerotic lesions correlate with disease severity. This may help determine which lesions are hemodynamically significant. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Proton MR spectroscopy in hyperhomocysteinemia with elevated blood methionine levels
Authors: Franco L. Patricia , Anderson Jada , Okoh James , Pomper Martin G. , Braverman Nancy , Barker Peter B.
Published: February 2006

Proton magnetic resonance spectroscopy imaging (MRSI) and serial MRI were performed on a 10‐year‐old girl with B6 unresponsive cystathionine B‐synthase (CBS) deficiency who developed high methionine levels while on betaine therapy. At presentation, T2‐weighted sequences showed diffuse white matter (WM) hyperintensity and sulcal effacement, while MRSI metabolite concentrations were normal. Four months later, after the betaine therapy was discontinued and a methionine‐restricted diet with vitamin B6, B12, and folate supplementation was initiated, blood methionine levels and MRI findings returned to normal. Normal MRSI at presentation was predictive of a positive outcome despite the markedly abnormal initial MRI results. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Investigation of proton density for measuring tissue temperature
Authors: Chen Jing , Daniel Bruce L. , Pauly Kim Butts
Published: February 2006

Purpose

To examine the temperature dependence of the proton density (PD) in both adipose and muscle tissues, and the application of the PD as a thermometry parameter in breast tissues.

Materials and Methods

Porcine fat samples and bovine muscle samples were successively heated to temperatures ranging from 30°C to 76°C and then cooled. They were then imaged with a dual‐echo spin‐echo sequence. T1 and T2 effects were carefully corrected from the images. The apparent PD (APD) in regions of interest (ROIs) and the sum of the APD in all pixels (Sum_APD) were measured and analyzed by linear regression.

Results

APD in adipose tissue is linear and reversible, and changes with a 0.3%/°C to 0.45%/°C temperature variation. The temperature coefficient of Sum_APD in adipose tissue is approximately 0.29%/°C, as predicted from the Boltzmann distribution. However, the results in muscle tissue are more variable. There is an offset in both APD and Sum_APD between heating and cooling phases, as well as different temperature coefficients between these two phases.

Conclusion

The Sum_APD in adipose tissue validates the 1/T dependence on temperature. The APD is a potentially useful parameter for fat thermometry; however, its application in muscle tissue requires further investigation. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Effects of gadopentetate dimeglumine and gadodiamide on serum calcium, magnesium, and creatinine measurements
Authors: Zhang Hong Lei , Ersoy Hale , Prince Martin R.
Published: February 2006

Purpose

To investigate the in vivo effects of gadodiamide (Gd‐DTPA‐BMA) and gadopentetate dimeglumine (Gd‐DTPA) on the laboratory measurements of serum calcium, magnesium, and creatinine.

Materials and Methods

Medical records from 1993 to 2004 were reviewed to identify inpatients for whom laboratory data were available regarding serum calcium, creatinine, and magnesium levels before and within one day after gadodiamide and gadopentetate dimeglumine enhanced MRI. Patients who underwent both gadolinium (Gd)‐enhanced MRI and iodinated contrast‐enhanced examinations on separate days within a six‐month period were also identified to compare changes in serum creatinine.

Results

Serum creatinine did not increase in 2788 cases following gadopentetate dimeglumine and gadodiamide injection. By comparison, serum creatinine increased from 1.21 to 1.28 mg/dL following iodinated contrast, and there were 20 cases (2.6%) of contrast‐induced nephrotoxicity (P < 0.01). Gadopentetate dimeglumine did not affect serum calcium or magnesium measurements. Following 1157 gadodiamide‐enhanced examinations, measured serum calcium spuriously dropped from 8.65 to 8.33 mg/dL (P < 0.0001) and 34 patients had spurious critical hypocalcemia (<6 mg/dL). Of 60 patients with high‐dose gadodiamide injection and renal insufficiency, 36.7% (N = 22) had spurious critical hypocalcemia immediately post MRI. In 216 patients with renal insufficiency, the mean serum magnesium level increased slightly from 1.69 to 1.77 mEq/L following gadodiamide injection (P < 0.0001).

Conclusion

Gd‐based contrast agents are safe for MRI and MR angiography (MRA), and do not induce nephrotoxicity. However, gadodiamide interferes with serum calcium and magnesium measurements—particularly at high doses and/or with renal insufficiency. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Direct quantitative in vivo comparison of calcified atherosclerotic plaque on vascular MRI and CT by multimodality image registration
Authors: Dey Damini , Slomka Piotr , Chien Daisy , Fieno David , Abidov Aiden , Saouaf Rola , Thomson Louise , Friedman John D. , Berman Daniel S.
Published: February 2006

Purpose

To investigate direct volumetric in vivo correspondence of calcified atherosclerotic plaque lesions in MRI and CT images of the thoracic aorta by multimodality image registration and fusion.

Materials and Methods

Twelve CT (11 noncontrast and one contrast) and MRI (TruFISP, contrast T1‐weighted volumetric interpolated breath‐hold examination (VIBE)) data sets were coregistered by approximate segmentation of the aorta and subsequent automatic coregistration by maximization of mutual information (MI). We quantitatively assessed 22 coregistered calcified plaque lesions on CT and MRI.

Results

The three‐dimensional registration consistency and accuracy were 1.74 ± 1.3 mm, and 2.42 ± 1.65 mm, respectively. The ratio of CT/MRI calcified plaque volume decreased asymptotically with MRI volume, and correlated with average CT lesion density (r = 0.72) for small lesions (<25 mm3). The average calcified plaque volume, circumferential extent, and maximal radial width by MRI were significantly smaller compared to CT (35%, 68%, and 53%, respectively; P < 0.05).

Conclusion

Software coregistration allowed precise, direct, and voxel‐based comparison of calcified atherosclerotic plaque lesions imaged by MRI and CT. In comparison with coregistered MRI, overestimation of calcified plaque in aortic CT due to “blooming” correlates with the average lesion density for small plaques, and is greater for small plaques. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Assessing arterial blood flow and vessel area variations using real‐time zonal phase‐contrast MRI
Authors: Oelhafen Markus , Schwitter Juerg , Kozerke Sebastian , Luechinger Roger , Boesiger Peter
Published: February 2006

Purpose

To measure peripheral artery function using a real‐time phase‐contrast (PC)‐MRI sequence with tailored image‐processing algorithms for flow computation.

Materials and Methods

An approach to real‐time flow measurements was developed based on two‐dimensional spatially selective excitation pulses and consecutive tailored processing of the data to derive blood flow and vessel area variations. The data acquisition strategy allows for flow measurements at high spatial and temporal resolutions of 1 mm2 and 50 msec, respectively. In postprocessing the vessel area is automatically extracted using correlation measures in conjunction with morphological image operators. By means of in vitro and in vivo validations, it is shown that the current methods provide accurate and reproducible measurements of flow and vessel area variations.

Results

In vitro the comparison between the lumen area measured with the presented method and the values obtained by calliper gauge measurement showed a difference of 3.4% ± 3.4% (mean ± 2 SD). Similarly, the comparison between the stroke volumes determined with the presented method and by stopwatch and bucket measurements yielded a difference of 6.1% ± 2.1%. In vivo the results from the real‐time measurements for lumen area and stroke volume were compared with those from a gated PC‐MRI technique with differences of 4.8% ± 14% and 3.0% ± 24.7%, respectively.

Conclusion

The presented method constitutes a reliable tool set for quantifying the variations of blood flow and lumen area in the superficial femoral artery during reactive hyperemia and for studying their correlation with cardiovascular risk factors. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Swallowing, arterial pulsation, and breathing induce motion artifacts in carotid artery MRI
Authors: Boussel Loic , Herigault Gwenael , de la Vega Alejandro , Nonent Michel , Douek Philippe Charles , Serfaty Jean Michel
Published: February 2006

Purpose

To identify and quantify the potential sources of motion in carotid artery imaging.

Materials and Methods

Two healthy volunteers and 12 patients (20–75 years old) with atherosclerotic disease were scanned on a Philips Intera 1.5T system. A single‐shot balanced‐fast field echo (bFFE) sequence was used to acquire real‐time axial views of the carotid artery wall (three images per second). A three‐step acquisition protocol was performed to analyze the three types of motion (arterial pulsation, breathing, and swallowing) separately. The isocenter carotid artery motion amplitude in either the x or y direction was measured. Radial variation in the carotid lumen between the systolic and diastolic phases was analyzed. Motion frequency was reported for each patient.

Results

Significant motion related to arterial pulsation (amplitude = 0.27–0.93 mm, mean = 0.6, SD = 0.19), breathing (amplitude = 0.5–3.6 mm, mean = 1.56, SD = 0.99)), and swallowing (amplitude = 1.4–9.2 mm, mean = 4.7, SD = 2.4) were visualized.

Conclusion

Pulsation, breathing, and swallowing are sources of significant motion in the carotid artery wall. Such motion should be considered in the future to improve carotid artery image quality. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Acoustic noise characteristics of a 4 Telsa MRI scanner
Authors: More Shashikant R. , Lim Teik C. , Li Mingfeng , Holland Christy K. , Boyce Suzanne E. , Lee Jing‐Huei
Published: February 2006

Purpose

To quantify the acoustic noise characteristics of a 4 Tesla MRI scanner, and determine the effects of structural acoustics and gradient pulse excitations on the sound field so that feasible noise control measures can be developed.

Materials and Methods

Acoustic noise emissions were measured in the ear and mouth locations of a typical adult. The sound pressure measurements were acquired simultaneously with the electrical current signals of the gradient pulses. Two forms of gradient waveforms (impulsive and operating pulses) were studied.

Results

The sound pressure levels (SPLs) emitted by the MRI scanner operating in echo‐planar imaging (EPI) mode were in the range of 120–130 decibels. Three types of sound pressure responses were observed in the EPI sequences: 1) harmonic, 2) nonharmonic, and 3) broadband. The frequency‐encoding gradient pulses were the most dominant and produced generally odd‐number harmonics and nonharmonics. The phase‐encoding gradient pulses generated mostly even‐number harmonics, and the slice‐selection gradient pulses produced primarily a broadband spectrum.

Conclusion

The operating condition acoustic spectrum can be predicted from the magnet‐structural acoustic transfer functions, which are independent of imaging sequences. This finding is encouraging because it shows that it is possible to treat such noises with an active noise control application. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Phenotypic characterization of food waste degrading Bacillus strains isolated from aerobic bioreactors
Authors: Saraiva Lopes da Silva Maria Teresa , Santo Fátima Espírito , Tavares Pereira Pablo , Pereira Roseiro José Carlos
Published: February 2006

A phenotypic characterization of seventeen Bacillus strains isolated from aerobic thermophilic bioreactors of a food waste processing company was carried out, using fatty acid and enzymatic activity profiles. It was observed that each species possessed a typical fatty acid and enzymatic production profile. Bacillus licheniformis strains exhibited the most significant enzyme production. Numerical analyses (principal component and hierarchical cluster analyses) revealed that Bacillus licheniformis strains were homogeneous regarding their fatty acid profiles whilst B. subtilis and Bacillus pumilus strains showed some phenotypic differences. However, enzymatic activities numerical analyses indicated that these three Bacillus species were more homogeneous regarding this phenotypic characteristic. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The thioredoxin system from Streptomyces coelicolor
Authors: Štefanková Petra , Perečko Dušan , Barák Imrich , Kollárová Marta
Published: February 2006

This paper describes the cloning, purification and characterization of thioredoxin (TrxA) and thioredoxin reductase (TrxR) from bacterial strain Streptomyces coelicolor . The genes of S. coelicolor encoding TrxA and TrxR were amplified by polymerase chain reaction, inserted into pET expression vector and used to overexpress these proteins in Escherichia coli . TrxA and TrxR were produced as the hexahistidine fusion proteins and were recovered from the cytoplasm as the soluble proteins. The activity of the purified recombinant proteins was demonstrated. The activity of TrxA was shown by efficient reduction of insulin and activity of NADPH‐dependent TrxR was revealed by catalyses of 5,5′‐dithiobis (2‐nitrobenzoic acid) (DTNB) reduction reaction. The reduction reaction was fully dependent upon the presence of TrxA as intermediate electron carrier with the pH optimum 7.5 and the temperature optimum 29 °C. Km value of TrxR for TrxA was 0.217 ± 0.02 µM. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Identification of nif genes in N2‐fixing bacterial strains isolated from rice fields along the Yangtze River Plain
Authors: Xie Guang Hui , Cui Zongjun , Yu Jun , Yan Jing , Hai Weili , Steinberger Yosef
Published: February 2006

The aim of this research was to identify nifH and nifHDKYE ′ genes in twenty strains of N2‐fixing heterotrophic bacteria isolated from rice fields in the Yangtze River Plain. Southern hybridization of the total DNA from each strain was performed with the Klebsiella pneumoniae nifHDKYE ′ gene probe (6.2 kb Eco RI fragment from pSA30) and the Azospirillum brasilense nifH gene probe (0.6 kb Eco RI‐Hin dIII fragment from pHU8). We found that Eco RI fragments of total DNA from Aeromonas hydrophila HY2, Bacillus azotoformans FD, Bacillus licheniformis NCH1, NCH5, WH4, Bacillus brevis NC2, Bacillus pumilus NC12, Bacillus cereus NCH2, Citrobacter freundii HY5, HY9, Derxia gummosa HZ5, Pseudomonas mendocina HZ1 and Pseudomonas pseudoalcaligenes WH3 were positively hybridized with both of the probes. Agrobacterium radiobacter HY17, Corynebacterium sp. HY12, YZ and Pseudomonas sp. HY11 had Eco RI fragments hybridized with the K. pneumoniae nifHDKYE ′ gene probe. An Eco RI fragment of total DNA from Bacillus megaterium YY4 was positively hybridized to the A. brasilense nifH gene probe. No hybridization sign was found in the total DNA fragments from Alcaligenes cupidus YY6 and Corynebacterium sp. NC11 hybridized with either of the gene probes. The data provide the number and size of EcoRI fragments of the total DNA hybridized with the nif gene probes for these strains of rarely studied species, suggesting additional evidence for N2 fixing and nif gene diversity of N2‐fixing bacteria in rice fields along the Yangtze River Plain. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Biodegradation of gallotannins and ellagitannins
Authors: Mingshu Li , Kai Yao , Qiang He , Dongying Jia
Published: February 2006

Nowadays, many researches have been made on gallotannin biodegradation and have gained great success in further utilization. Some of industrial applications of these findings are in the production of tannase, the biotransformation of tannic acid to gallic acid or pyrogallol and detannification of food and fodder. Although ellagitannins have the typical C–C bound which is more difficult to be degraded than gallotannins, concerted efforts are still in progress to improve ellagitannin degradation and utilization. Currently, more attention is mainly focused on intestinal microflora biodegradation of tannins especially ellagitannins which can contribute to the definition of their bioavailability for both human beings and ruminants. Also there have been endeavours to utilize the tannin‐degrading activity of different fungi for ellagitannin‐rich biomass, which will facilitate application of tannin‐degrading enzymes in strategies for improving industrial and livestock production. Due to the complicated structures of complex tannins and condensed tannins, the biodegradation of them is much more difficult and there are fewer researches on them. Therefore, the researches on the mechanisms of gallotannin and ellagitannin biodegradation can result in the overall understanding to the biodegradation of complex tannins and condensed tannins. Biodegradation of tannins is in an incipient stage and further studies have to be carried out to exploit the potential of various tannins for largescale applications in food, fodder, medicine and tannery effluent treatment. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Adsorptive removal of textile dyes from aqueous solutions by dead fungal biomass
Authors: Asma Dilek , Kahraman Sibel , Cing Seval , Yesilada Ozfer
Published: February 2006

Dead fungal biomass prepared from Phanerochaete chrysosporium and Funalia trogii was tested for their efficiency in removal of textile dyes. The effects of contact time, initial dye concentration, amount of dead biomass and agitation rate on dye removal have been determined. Removal of all dyes required a very short time (60 min). Experimental results show that, P. chrysosporium was more effective than F. trogii . An increase in the amount of dead biomass positively affected of the dye removal. The removal efficiency of different amount of biomass was in order 1 g > 0.5 g > 0.2 g > 0.1 g. The highest removal was obtained at 150–200 rpm. Slightly lower removing activities were found at lower agitation rates. This study showed that it was possible to remove textile dyes by dead biomass of P. chrysosporium . (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Short‐term microvascular response of striated muscle to cp‐Ti, Ti‐6Al‐4V, and Ti‐6Al‐7Nb
Authors: Pennekamp Peter H. , Gessmann Jan , Diedrich Oliver , Burian Björn , Wimmer Markus A. , Frauchiger Vinzenz M. , Kraft Clayton N.
Published: February 2006

Due to excellent mechanical properties and good corrosion resistance, titanium–aluminium–vanadium (Ti‐6Al‐4V) and titanium–aluminium–niobium (Ti‐6Al‐7Nb) are extensively used for orthopedic surgery. Concern has been voiced concerning the implications of the constituent vanadium in Ti‐6Al‐4V on the surrounding environment. Particularly in osteosynthesis where the alloys stand in direct contact to skeletal muscle, undesirable biologic reactions may have severe consequences. In a comparative study, we assessed in vivo nutritive perfusion and leukocytic response of striated muscle to the metals Ti‐6Al‐4V, Ti‐6Al‐7Nb, and commercially pure titanium (cpTi), thereby drawing conclusions on their short‐term inflammatory potential. In 28 hamsters, utilizing the dorsal skinfold chamber preparation and intravital microscopy, we quantified primary and secondary leukocyte–endothelial cell interaction, leukocyte extravasation, microvascular diameter change, and capillary perfusion in collecting and postcapillary venules of skeletal muscle. A manifest discrepancy between the metals concerning impact on local microvascular parameters was not found. All metals induced an only transient and moderate inflammatory response. Only a slight increase in leukocyte recruitment and a more sluggish recuperation of inflammatory parameters in animals treated with Ti‐6Al‐4V compared to the other two metals suggested a minor, overall not significant discrepancy in biocompatibility. Gross toxicity of bulk Ti‐6Al‐4V on surrounding tissue could not be found. Conclusively, the commonly used biomaterials Ti‐6Al‐4V, Ti‐6Al‐7Nb, and cpTi induce an only transient inflammatory answer of the skeletal muscle microvascular system. Our results indicate that on the microvascular level the tested bulk Ti‐alloys and cpTi do not cause adverse biologic reactions in striated muscle. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:531–540, 2006
Shoulder joint position sense improves with elevation angle in a novel, unconstrained task
Authors: Suprak David N. , Osternig Louis R. , van Donkelaar Paul , Karduna Andrew R.
Published: February 2006

Proprioception, encompassing the submodalities of kinesthesia and joint position sense, is important in the maintenance of joint stability, especially in the shoulder. The purpose of this study was to examine the effects of plane and elevation angle on unconstrained shoulder joint position sense. Twenty‐two subjects (12 male, 10 female) without a history of shoulder pathology were recruited from a university campus. Subjects attempted to replicate, with respect to plane and elevation angles, various target positions. Target positions consisted of five plane angles at 90° of arm elevation and five arm elevation angles in the scapular plane. All target positions were tested twice to assess the reliability of the measurement. Intraclass correlation coefficients were generally low across target positions, possibly owing to the novelty and demanding nature of the task. No differences in repositioning errors were observed between plane angles (p = 0.255). Repositioning errors decreased linearly as the elevation angle increased from 30° to 90° (p = 0.007) and increased again from 90° to 110° of elevation (p = 0.029). Our results suggest that unconstrained joint position sense may be enhanced with increased muscular activation levels. Further, afferent feedback from musculotendinous mechanoreceptors may dominate over that from capsuloligamentous sources in unconstrained movements. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:559–568, 2006
Hermann Staudinger Award 2006
Authors: Mülhaupt Rolf
Published: February 2006

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