bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fine structure of the male genital system of the predatory mite Rhagidia halophila (Rhagidiidae, Prostigmata, Actinotrichida)
Authors: Alberti Gerd , Ehrnsberger Rainer 
Published: April 2015

ABSTRACTThe male genital system of the actinotrichid mite Rhagidia halophila is described and compared with other mites and arachnids. The large testes are composed of germinal and glandular parts and produce numerous small sperm cells. The glandular parts are connected via a testicular bridge. Spermiogenesis occurs in cysts containing spermatids in equal stages of development. Cysts of spermatids are embedded in huge somatic cells. The nuclei of the spermatids loose their envelope. Mature sperm cells are simple exhibiting a ring‐shaped chromatin body and lacking an acrosomal complex. They are most similar to the sperm cells of the related mite Linopodes motatorius. The spermatopositor contains the ejaculatory duct divided into a dorsal channel and a ventral channel that are connected via a narrow passage. At its distal end, the spermatopositor is divided into three eugenital lips. The function of the spermatopositor during deposition of the peculiar thread‐like spermatophores is discussed. Details of the sensilla of the spermatopositor and the progenital lips are reported. The genital papillae located on the inner side of the progenital lips exhibit characteristics of cells performing transport of ions and/or water. The results confirm the overall similarity of actinotrichid genital systems, which is profoundly different from that of anactinotrichid mites. With reference to other Arachnida it is corroborated that testes and sperm structure of Actinotrichida are most similar to that of Solifugae. However, synapomorphies between sperm cells of Rhagidia and Solifugae that could suggest a closer relationship between these two taxa as was suggested in earlier studies were not recognizable. On the contrary, the sperm cells of Rh. halophila being devoid of an acrosomal complex appeared to be more apomorphic than those of many other actinotrichid mites as well as Solifugae. J. Morphol. 276:832–859, 2015. © 2015 Wiley Periodicals, Inc.
Breast cancer subtype intertumor heterogeneity: MRI‐based features predict results of a genomic assay
Authors: Sutton Elizabeth J. , Oh Jung Hun , Dashevsky Brittany Z. , Veeraraghavan Harini , Apte Aditya P. , Thakur Sunitha B. , Deasy Joseph O. , Morris Elizabeth A. 
Published: April 2015

PurposeTo investigate the association between a validated, gene‐expression‐based, aggressiveness assay, Oncotype Dx RS, and morphological and texture‐based image features extracted from magnetic resonance imaging (MRI).Materials and MethodsThis retrospective study received Internal Review Board approval and need for informed consent was waived. Between 2006–2012, we identified breast cancer patients with: 1) ER+, PR+, and HER2– invasive ductal carcinoma (IDC); 2) preoperative breast MRI; and 3) Oncotype Dx RS test results. Extracted features included morphological, histogram, and gray‐scale correlation matrix (GLCM)‐based texture features computed from tumors contoured on pre‐ and three postcontrast MR images. Linear regression analysis was performed to investigate the association between Oncotype Dx RS and different clinical, pathologic, and imaging features. P < 0.05 was considered statistically significant.ResultsNinety‐five patients with IDC were included with a median Oncotype Dx RS of 16 (range: 0–45). Using stepwise multiple linear regression modeling, two MR‐derived image features, kurtosis in the first and third postcontrast images and histologic nuclear grade, were found to be significantly correlated with the Oncotype Dx RS with P = 0.0056, 0.0005, and 0.0105, respectively. The overall model resulted in statistically significant correlation with Oncotype Dx RS with an R‐squared value of 0.23 (adjusted R‐squared = 0.20; P = 0.0002) and a Spearman's rank correlation coefficient of 0.49 (P < 0.0001).ConclusionA model for IDC using imaging and pathology information correlates with Oncotype Dx RS scores, suggesting that image‐based features could also predict the likelihood of recurrence and magnitude of chemotherapy benefit. J. Magn. Reson. Imaging 2015;42:1398–1406.
High‐temporal velocity‐encoded MRI for the assessment of left ventricular inflow propagation velocity: Comparison with color M‐mode echocardiography
Authors: Calkoen Emmeline E. , Marsan Nina Ajmone , Bax Jeroen J. , van den Boogaard Pieter J. , Roest Arno A.W. , de Roos Albert , Westenberg Jos J.M. 
Published: April 2015

PurposeTo develop an alternative method for Vp‐assessment using high‐temporal velocity‐encoded magnetic resonance imaging (VE‐MRI). Left ventricular (LV) inflow propagation velocity (Vp) is considered a useful parameter in the complex assessment of LV diastolic function and is measured by Color M‐mode echocardiography.Materials and MethodsA total of 43 patients diagnosed with ischemic heart failure (61 ± 11 years) and 22 healthy volunteers (29 ± 13 years) underwent Color M‐mode echocardiography and VE‐MRI to assess the inflow velocity through the mitral valve (mean interexamination time 14 days). Temporal resolution of VE‐MRI was 10.8–11.8 msec. Local LV inflow velocity was sampled along a 4‐cm line starting from the tip of the mitral leaflets and for consecutive sample points the point‐in‐time was assessed when local velocity exceeded 30 cm/s. From the position–time relation, Vp was calculated by both the difference quotient (Vp‐MRI‐DQ) as well as from linear regression (Vp‐MRI‐LR).ResultsGood correlation was found between Vp‐echo and both Vp‐MRI‐DQ (r = 0.83, P < 0.001) and Vp‐MRI‐LR (r = 0.84, P < 0.001). Vp‐MRI showed a significant but small underestimation as compared to Vp measured by echocardiography (Vp‐MRI‐DQ: 5.5 ± 16.2 cm/s, P = 0.008; Vp‐MRI‐LR: 9.9 ± 15.2 cm/s, P < 0.001). Applying age‐related cutoff values for Vp to identify LV impaired relaxation, kappa‐agreement with echocardiography was 0.72 (P < 0.001) for Vp‐MRI‐DQ and 0.69 (P < 0.001) for Vp‐MRI‐LR.ConclusionHigh temporal VE‐MRI represents a novel approach to assess Vp, showing good correlation with Color M‐mode echocardiography. In healthy subjects and patients with ischemic heart failure, this new method demonstrated good agreement with echocardiography to identify LV impaired relaxation. J. Magn. Reson. Imaging 2015;42:1297–1304.
Cetacean diversity of the continental shelf and slope off southern australia
Authors: Gill Peter C. , Pirzl Rebecca , Morrice Margie G. , Lawton Kieran 
Published: April 2015

ABSTRACTWe recorded a diverse cetacean assemblage from systematic aerial surveys in productive upwelling waters off southern Australia in 2002–2013. Surveys recorded 133 sightings of 15 identified cetacean species consisting of 7 mysticete (baleen) whale species, 8 odontocete (toothed) species, and 384 sightings of unidentified dolphins. This is the first assessment of cetacean diversity for the region and we found diversity to be comparable with other productive regions elsewhere. Differential spatial and temporal distributions of mysticete and odontocete species were apparent, and were associated with habitat variables and seasonal migration cycles. The study contributes new information to assist the environmental planning and management of activities in the region, including oil, and gas exploration and production, fishing, shipping, and renewable energy development. © 2015 The Wildlife Society.
Soil Amendment Improves Tree Growth and Soil Carbon and Nitrogen Pools in Mongolian Pine Plantations on Post‐Mining Land in Northeast China
Authors: Hu Ya‐Lin , Niu Zhi‐Xin , Zeng De‐Hui , Wang Cheng‐Yi 
Published: April 2015

AbstractMining activities leave large areas of post‐mining lands to be reclaimed. Increases in soil C and N pools and N availability are important to successfully reestablish trees on post‐mining land. In this study, we determined C and N concentrations and natural stable isotope of 13C and 15N in soil and plant in Mongolian pine (Pinus sylvestris L. var. mongolica Litv.) plantations 8 years after establishment on non‐mined land (NM), post‐mining land without soil amendment (NAM), and post‐mining land with soil amendment (AM) in a placer gold mining region of Northeast China. We found that the growth of Mongolian pine was significantly slower on NAM as compared with NM (decreasing by 73% in tree height and 63% in basal diameter), but tree growth improved on AM. Soil C and N concentrations, plant N concentration, and soil δ15N value decreased in the order of NM > AM > NAM, implying that soil N availability decreased in post‐mining land, but soil amendment could increase soil N availability. However, the values of δ15N in plant tissues of Mongolian pine were higher on NAM than on NM and AM, suggesting that soil inorganic N form absorbed by trees might be changed when trees were directly planted on post‐mining land with lower soil N availability. In addition, the values of δ13C in 1‐ and 2‐year‐old leaves of Mongolian pine were lowest when planted on NAM, indicating a decrease in intrinsic water‐use efficiency of Mongolian pine. Our results suggest that soil amendment helps us establish forests successfully on post‐mining lands. Copyright © 2015 John Wiley & Sons, Ltd.
Relative Contribution of Rill/Interrill and Gully/Channel Erosion to Small Reservoir Siltation in Mediterranean Environments
Authors: Ben Slimane Abir , Raclot Damien , Evrard Olivier , Sanaa Mustapha , Lefevre Irène , Le Bissonnais Yves 
Published: April 2015

AbstractReservoir siltation because of water erosion is an important environmental issue in Mediterranean countries where storage of clear surface water is crucial for their economic and agricultural development. The high density of gully systems observed in Mediterranean regions raises the question of their contribution to reservoir siltation. In this context, this study quantified the absolute and relative contributions of rill/interrill and gully/channel erosion in sediment accumulation at the outlet of small Tunisian catchments (0·1–10 km2) during the last 15 years (1995–2010). To this end, a fingerprinting method based on measurements of caesium‐137 and total organic carbon combined with long‐term field monitoring of catchment sediment yield was applied to five catchments in order to cover the diversity of environmental conditions found along the Tunisian Ridge and in the Cape Bon region. Results showed the very large variability of erosion processes among the selected catchments, with rill/interrill erosion contributions to sediment accumulated in outlet reservoirs ranging from 20 to 80%. Overall, rill/interrill erosion was the dominant process controlling reservoir siltation in three catchments whereas gully/channel erosion dominated in the other two catchments. We identified the presence of marly gypsum substrates and the proportion of catchment surface covered by soil management/conservation measures as the main drivers of erosion process variability at the catchment scale. These results provided a sound basis to propose guidelines for erosion mitigation in these Mediterranean environments and suggested to apply models simulating both rill/interrill and gully/channel erosion in catchments of the region. Copyright © 2015 John Wiley & Sons, Ltd.
Diet rich in high glucoraphanin broccoli reduces plasma LDL cholesterol: Evidence from randomised controlled trials
Authors: Armah Charlotte N. , Derdemezis Christos , Traka Maria H. , Dainty Jack R. , Doleman Joanne F. , Saha Shikha , Leung Wing , Potter John F. , Lovegrove Julie A. , Mithen Richard F. 
Published: April 2015

ScopeCruciferous‐rich diets have been associated with reduction in plasma LDL‐cholesterol (LDL‐C), which may be due to the action of isothiocyanates derived from glucosinolates that accumulate in these vegetables. This study tests the hypothesis that a diet rich in high glucoraphanin (HG) broccoli will reduce plasma LDL‐C.Methods and resultsOne hundred and thirty volunteers were recruited to two independent double‐blind, randomly allocated parallel dietary intervention studies, and were assigned to consume either 400 g standard broccoli or 400 g HG broccoli per week for 12 weeks. Plasma lipids were quantified before and after the intervention. In study 1 (37 volunteers), the HG broccoli diet reduced plasma LDL‐C by 7.1% (95% CI: –1.8%, –12.3%, p = 0.011), whereas standard broccoli reduced LDL‐C by 1.8% (95% CI +3.9%, –7.5%, ns). In study 2 (93 volunteers), the HG broccoli diet resulted in a reduction of 5.1% (95% CI: –2.1%, –8.1%, p = 0.001), whereas standard broccoli reduced LDL‐C by 2.5% (95% CI: +0.8%, –5.7%, ns). When data from the two studies were combined the reduction in LDL‐C by the HG broccoli was significantly greater than standard broccoli (p = 0.031).ConclusionEvidence from two independent human studies indicates that consumption of high glucoraphanin broccoli significantly reduces plasma LDL‐C.
Multisite evaluations of a T2‐relaxation‐under‐spin‐tagging (TRUST) MRI technique to measure brain oxygenation
Authors: Liu Peiying , Dimitrov Ivan , Andrews Trevor , Crane David E. , Dariotis Jacinda K. , Desmond John , Dumas Julie , Gilbert Guillaume , Kumar Anand , Maclntosh Bradley J. , Tucholka Alan , Yang Shaolin , Xiao Guanghua , Lu Hanzhang 
Published: April 2015

PurposeVenous oxygenation (Yv) is an important index of brain physiology and may be indicative of brain diseases. A T2‐relaxation‐under‐spin‐tagging (TRUST) MRI technique was recently developed to measure Yv. A multisite evaluation of this technique would be an important step toward broader availability and potential clinical utilizations of Yv measures.MethodsTRUST MRI was performed on a total of 250 healthy subjects, 125 from the developer's site and 25 each from five other sites. All sites were equipped with a 3 Tesla (T) MRI of the same vendor. The estimated Yv and the standard error (SE) of the estimation εYv were compared across sites.ResultsThe averaged Yv and εYv across six sites were 61.1% ± 1.4% and 1.3% ± 0.2%, respectively. Multivariate regression analysis showed that the estimated Yv was dependent on age (P = 0.009) but not on performance site. In contrast, the SE of the Yv estimation was site‐dependent (P = 0.024) but was less than 1.5%. Further analysis revealed that εYv was positively associated with the amount of subject motion (P < 0.001) but negatively associated with blood signal intensity (P < 0.001).ConclusionThis work suggests that TRUST MRI can yield equivalent results of Yv estimation across different sites. Magn Reson Med 75:680–687, 2016. © 2015 Wiley Periodicals, Inc.
Sensitive imaging of magnetic nanoparticles for cancer detection by active feedback MR
Authors: Li Zhao , Hsu Chao‐Hsiung , Dimitrov Nikolay , Hwang Dennis W. , Chang Hsin‐Wei , Hwang Lian‐Pin , Lin Yung‐Ya 
Published: April 2015

PurposeSensitive imaging of superparamagnetic nanoparticles or aggregates is of great importance in MR molecular imaging and medical diagnosis. For this purpose, a conceptually new approach, termedactive feedback magnetic resonance, was developed.MethodsIn the presence of the Zeeman field, a dipolar field is induced by the superparamagnetic nanoparticles or aggregates. Such dipolar field creates spatial and temporal (due to water diffusion) variations to the precession frequency of the nearby water1H magnetization. Sensitive imaging of magnetic nanoparticles or aggregates can be achieved by manipulating the intrinsic spin dynamics by selective self‐excitation and fixed‐point dynamics under active feedback fields.ResultsPhantom experiments of superparamagnetic nanoparticles; in vitro experiments of brain tissue with blood clots; and in vivo mouse images of colon cancers, with and without labeling by magnetic nanoparticles, suggest that this new approach provides enhanced, robust, and positive contrast in imaging magnetic nanoparticles or aggregates for cancer detection.ConclusionThe spin dynamics originated from selective self‐excitation and fixed‐point dynamics under active feedback fields have been shown to be sensitive to dipolar fields generated by magnetic nanoparticles. Magn Reson Med 74:33–41, 2015. © 2014 Wiley Periodicals, Inc.
Sensitivity of chemical shift‐encoded fat quantification to calibration of fat MR spectrum
Authors: Wang Xiaoke , Hernando Diego , Reeder Scott B. 
Published: April 2015

PurposeTo evaluate the impact of different fat spectral models on proton density fat fraction quantification using chemical shift‐encoded MRI (CSE‐MRI).MethodsIn a simulation study, spectral models of fat were compared pairwise. Comparison of magnitude fitting and mixed fitting was performed over a range of echo times and fat fractions. In vivo acquisitions from 41 patients were reconstructed using seven published spectral models of fat. T2‐corrected stimulated echo acquisition mode MR spectroscopy was used as a reference.ResultsThe simulations demonstrated that imperfectly calibrated spectral models of fat result in biases that depend on echo times and fat fraction. Mixed fitting was more robust against this bias than magnitude fitting. Multipeak spectral models showed much smaller differences among themselves than from the single‐peak spectral model. In vivo studies showed that all multipeak models agreed better (for mixed fitting, the slope ranged from 0.967 to 1.045 using linear regression) with the reference standard than the single‐peak model (for mixed fitting, slope = 0.76).ConclusionIt is essential to use a multipeak fat model for accurate quantification of fat with CSE‐MRI. Furthermore, fat quantification techniques using multipeak fat models are comparable, and no specific choice of spectral model has been shown to be superior to the rest. Magn Reson Med 75:845–851, 2016. © 2015 Wiley Periodicals, Inc.
Quantification of cell size using temporal diffusion spectroscopy
Authors: Jiang Xiaoyu , Li Hua , Xie Jingping , Zhao Ping , Gore John C. , Xu Junzhong 
Published: April 2015

PurposeA new approach has been developed to quantify cell sizes and intracellular volume fractions using temporal diffusion spectroscopy with diffusion‐weighted acquisitions.MethodsTemporal diffusion spectra may be used to characterize tissue microstructure by measuring the effects of restrictions over a range of diffusion times. Oscillating gradients have been used previously to probe variations on cellular and subcellular scales, but their ability to accurately measure cell sizes larger than 10 μm is limited. By combining measurements made using oscillating gradient spin echo (OGSE) and a conventional pulsed gradient spin echo (PGSE) acquisition with a single, relatively long diffusion time, we can accurately quantify cell sizes and intracellular volume fractions.ResultsBased on a two compartment model (incorporating intra‐ and extracellular spaces), accurate estimates of cell sizes and intracellular volume fractions were obtained in vitro for (i) different cell types with sizes ranging from 10 to 20 μm, (ii) different cell densities, and (iii) before and after anticancer treatment.ConclusionHybrid OGSE‐PGSE acquisitions sample a larger region of temporal diffusion spectra and can accurately quantify cell sizes over a wide range. Moreover, the maximum gradient strength used was lower than 15 G/cm, suggesting that this approach is translatable to practical MR imaging. Magn Reson Med 75:1076–1085, 2016. © 2015 Wiley Periodicals, Inc.
Comparison of phase‐constrained parallel MRI approaches: Analogies and differences
Authors: Blaimer Martin , Heim Marius , Neumann Daniel , Jakob Peter M. , Kannengiesser Stephan , Breuer Felix A. 
Published: April 2015

PurposePhase‐constrained parallel MRI approaches have the potential for significantly improving the image quality of accelerated MRI scans. The purpose of this study was to investigate the properties of two different phase‐constrained parallel MRI formulations, namely the standard phase‐constrained approach and the virtual conjugate coil (VCC) concept utilizing conjugate k‐space symmetry.MethodsBoth formulations were combined with image‐domain algorithms (SENSE) and a mathematical analysis was performed. Furthermore, the VCC concept was combined with k‐space algorithms (GRAPPA and ESPIRiT) for image reconstruction. In vivo experiments were conducted to illustrate analogies and differences between the individual methods. Furthermore, a simple method of improving the signal‐to‐noise ratio by modifying the sampling scheme was implemented.ResultsFor SENSE, the VCC concept was mathematically equivalent to the standard phase‐constrained formulation and therefore yielded identical results. In conjunction with k‐space algorithms, the VCC concept provided more robust results when only a limited amount of calibration data were available. Additionally, VCC‐GRAPPA reconstructed images provided spatial phase information with full resolution.ConclusionsAlthough both phase‐constrained parallel MRI formulations are very similar conceptually, there exist important differences between image‐domain and k‐space domain reconstructions regarding the calibration robustness and the availability of high‐resolution phase information. Magn Reson Med 75:1086–1099, 2016. © 2015 Wiley Periodicals, Inc.
Correction and optimization of a T2‐based approach to map blood oxygenation in small cerebral veins
Authors: Krishnamurthy Lisa C. , Mao Deng , King Kevin S. , Lu Hanzhang 
Published: April 2015

PurposeCerebral venous blood oxygenation (Yv) is an important biomarker in brain physiology and function. The present study proposes a procedure to provide a quantitative map of the brain's intravascular Yv.Theory and MethodsThe method is based on a pulse sequence, T2‐Relaxation‐Under‐Phase‐Contrast (TRU‐PC) MRI, with postprocessing approaches to correct eddy‐current effects. A complete scan protocol consists of four TRU‐PC scans sensitized to large and small vessels with anterior–posterior and foot–head flow‐encoding directions, and the data are analyzed conjunctively. Eddy‐current correction was performed by fitting the tissue phase to a hyperplane, and then subtracting the eddy‐current phase from the measured vessel phase. The reproducibility of the Yv‐maps was examined in five participants. Sensitivity of the Yv map to a caffeine challenge was studied in another five participants.ResultsRemoval of eddy‐current induced artifact allowed for the correction of T2 measurements, as demonstrated in vivo and with simulation. A Yv‐map depicting all vessels in the slice can be obtained with the proposed protocol. Test–retest variability of the Yv‐map was 3.7 ± 1.2%. Yv reduction can be reliably detected (P < 0.001) following the caffeine ingestion.ConclusionWith the proposed TRU‐PC protocol and eddy‐current correction procedure, an accurate, vessel‐specific Yv map of the human brain can be obtained. Magn Reson Med 75:1100–1109, 2016. © 2015 Wiley Periodicals, Inc.
Triple‐quantum‐filtered sodium imaging at 9.4 Tesla
Authors: Mirkes Christian , Shajan G. , Bause Jonas , Buckenmaier Kai , Hoffmann Jens , Scheffler Klaus 
Published: April 2015

PurposeEfficient acquisition of triple‐quantum‐filtered (TQF) sodium images at ultra‐high field (UHF) strength.MethodsA three‐pulse preparation and a stack of double‐spirals were used for the acquisition of TQF images at 9.4 Tesla. The flip angles of the TQ preparation were smoothly reduced toward the edge of k‐space along the partition‐encoding direction. In doing so, the specific absorption rate could be reduced while preserving the maximal signal intensity for the partitions most relevant for image contrast in the center of k‐space. Simulations, phantom and in vivo measurements were used to demonstrate the usefulness of the proposed method.ResultsA higher sensitivity (∼20%) was achieved compared to the standard acquisition without flip angle apodization. Signals from free sodium ions were successfully suppressed irrespective of the amount of apodization used. B0 corrected TQF images with a nominal resolution of 5 × 5 × 5 mm3 and an acceptable signal‐to‐noise ratio could be acquired in vivo within 21 min.ConclusionConventional TQF in combination with flip angle apodization permits to exploit more efficiently the increased sensitivity available at 9.4T. Magn Reson Med 75:1278–1289, 2016. © 2015 Wiley Periodicals, Inc.