bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diagnostic Value of an Automated Breast Volume Scanner for Abdominal Hernias
Authors: Diao Xuehong , Chen Yue , Qiu Zhiying , Pang Yun , Zhan Jia , Chen Lin 
Published: December 2013

ObjectivesThis study explored the diagnostic values of an automated breast volume scanner (ABVS) for abdominal external hernias.MethodsConventional sonograms and ABVS images from 128 abdominal external hernias in 104 patients (98 male and 6 female; age range, 41–79 years; mean age ± SD, 68.0 ± 14.6 years) were analyzed. The results were identified by surgical outcomes. The hernia type, hernial ring position, hernial sac size, hernia content, and hernia structure were evaluated by both sonographic modalities.ResultsThe sensitivity and accuracy differences between the ABVS and conventional sonography for diagnosis of abdominal hernias and hernia size measurements were compared. The hernia types, as confirmed by surgery, included 45 indirect inguinal hernias (30 reducible and 15 irreducible), 12 reducible direct inguinal hernias, 5 femoral hernias, 62 incisional hernias (42 isolated and 20 multiple), and 4 umbilical hernias. The sensitivity of the ABVS was higher than that of conventional sonography for incisional hernias (P < .01), whereas there were no statistical differences in sensitivity for other types of hernias. The ABVS hernial sac number detection rate for both isolated and multiple incisional hernias was significantly higher compared with that of conventional sonography (both P < .01). The ABVS measurements correlated well with surgical results (length, P = .47; width, P = .31).ConclusionsAutomated breast volume scanner images have the outstanding advantage of displaying the entire scope of the internal structure and the relationship with adjacent tissues of abdominal hernias. Therefore, an ABVS has good application prospects for diagnosis of abdominal external hernias and merits further research.
Routine Intraoperative Hepatic Sonography Does Not Affect Staging or Postsurgical Hepatic Recurrence in Pancreatic Adenocarcinoma
Authors: Mui Leonora W. , Pursell Lisa J. , Botwinick Isadora C. , Allendorf John D. , Chabot John A. , Newhouse Jeffrey H. 
Published: December 2013

ObjectivesThe purpose of this study was to evaluate the utility of intraoperative sonography of the liver in the staging of pancreatic adenocarcinoma and its impact on the rate of postoperative tumor recurrence in the liver.MethodsWe performed a retrospective analysis of the rate in which intraoperative sonography of the liver changed surgical management in 470 surgical candidates with pancreatic adenocarcinoma. In postsurgical patients, we performed a χ2 analysis to examine whether the patients who underwent hepatic intraoperative sonography had a lower rate of recurrent disease in the liver within the first 6 months of surgery compared to patients who did not undergo the procedure.ConclusionsHepatic intraoperative sonography affected management in less than 1% of cases, detecting 1 unsuspected liver metastasis in 470 surgical patients with pancreatic adenocarcinoma. Of 3 patients with equivocal liver lesions identified on preoperative computed tomography or magnetic resonance imaging, hepatic intraoperative sonography excluded metastasis and cleared all the patients for surgical resection. There was no significant difference in postoperative liver recurrence between the group of patients who received intraoperative sonography before resection and patients who did not have the procedure done (P > .99).ConclusionsRoutine intraoperative sonography of the liver does not affect staging of pancreatic adenocarcinoma. It may be useful for evaluating equivocal lesions.
Indirect Prediction of Liver Fibrosis by Quantitative Measurement of Spleen Stiffness Using the FibroScan System
Authors: Hu Xiangdong , Xu Xiaoluan , Zhang Qing , Zhang Hong , Liu Jing , Qian Linxue 
Published: December 2013

ObjectivesTo evaluate quantitative measurement of spleen stiffness for indirect assessment of liver fibrosis in patients with chronic hepatitis B and to correlate spleen stiffness with liver stiffness using pathologic examination as a reference standard.MethodsSixty patients with clinically confirmed chronic hepatitis B (n = 54) and liver cirrhosis (n = 6) were enrolled. Quantitative stiffness measurements (kilopascals) were obtained from spleen and liver parenchyma with the FibroScan system (Echosens, Paris, France). Correlation analyses were performed between spleen and liver stiffness and between spleen stiffness and liver fibrosis stages. The diagnostic performance of spleen stiffness for indirect prediction of liver fibrosis was estimated by receiver operating characteristic curves.ResultsBoth spleen and liver stiffness increased as liver fibrosis progressed. Spleen stiffness values had a positive correlation with liver stiffness values in all patients (Pearson r = 0.810; P < .001). The correlation between spleen stiffness and fibrosis stages was statistically significant (Spearman r = 0.833; P < .001). The areas under the receiver operating characteristic curves for spleen stiffness were 0.902 (95% confidence interval [CI], 0.825–0.978) for stage S1 (fibrous portal expansion and limited perisinusoidal or lobular fibrosis) or higher, 0.927 (95% CI, 0.852–1.0) for S2 (periportal fibrosis and few fibrous septa but intact architecture) or higher, 0.962 (95% CI, 0.918–1.0) for S3 (numerous fibrous septa with architectural distortion but no obvious cirrhosis) or higher, and 0.983 (95% CI, 0.957–1.0) for S4 (cirrhosis) (all P < .001). The differences between the areas under the curves for spleen and liver stiffness in liver fibrosis staging were not statistically significant (P = .115–.756).ConclusionsQuantitative measurement of spleen stiffness is a feasible and promising technique for estimating liver fibrosis. The overall diagnostic performance of spleen stiffness for liver fibrosis staging is comparable with that of liver stiffness.
A Computer‐Aided Diagnostic Algorithm Improves the Accuracy of Transesophageal Echocardiography for Left Atrial Thrombi
Authors: Sun Lin , Li Yang , Zhang Ying Tao , Shen Jing Xia , Xue Feng Hua , Cheng Heng Da , Qu Xiu Fen 
Published: December 2013

ObjectivesWe investigated whether transesophageal echocardiography (TEE) assisted with a computer‐aided diagnostic (CAD) algorithm was superior to TEE in diagnosing left atrial (LA)/left atrial appendage (LAA) thrombi in patients with atrial fibrillation (AF) in a single prospective study.MethodsTransesophageal echocardiography was performed in patients with AF, and images were reconstructed. Gray level co‐occurrence matrix–based features were calculated and then classified using an artificial neural network. The original data and processed images by the CAD system were studied by 5 radiologists independently in a blind manner. The diagnostic performance of each radiologist was evaluated.ResultsOne hundred thirty patients with AF were investigated. Thirty‐one patients (23.9%) had a diagnosis of LA/LAA thrombi. The mean sensitivity ± SD of TEE for LA/LAA thrombi was 0.933 ± 0.027, which was noticeably improved by CAD (0.955 ± 0.021; P < .05). The specificity of TEE was 0.811 ± 0.055, which was markedly lower than that by TEE plus CAD (0.970 ± 0.009; P < .05). The positive predictive value of TEE was low (0.613 ± 0.073) compared to that of TEE plus CAD (0.908 ± 0.027; P < .001), whereas the negative predictive values were comparable for TEE, CAD, and TEE plus CAD. Diagnosis of an LA/LAA thrombus by TEE plus CAD had a higher accuracy rate (0.966 ± 0.011) than that by TEE (0.840 ± 0.047; P < .01). The mean area under the receiver operating characteristic curve (Az) for TEE was 0.834 ± 0.009 (95% confidence interval [CI], 0.815–0.852), which was markedly lower than the Az for TEE plus CAD (0.932 ± 0.005; 95% CI, 0.921–0.943). The use of CAD significantly improved the Az values for all 5 radiologists (P < .001).ConclusionsThe CAD algorithm significantly improves the diagnostic accuracy of TEE for LA/LAA thrombi in patients with AF.
How well do general circulation models represent low‐frequency rainfall variability?
Authors: Rocheta Eytan , Sugiyanto Michael , Johnson Fiona , Evans Jason , Sharma Ashish 
Published: December 2013

AbstractGeneral circulation models (GCMs) provide reliable simulations of global‐ and continental‐scale atmospheric variables, yet have limited skill in simulating variables important for water resource management at regional to catchment scales. GCM simulations suffer from a range of uncertainties leading to transient (changing over time) and systemic (consistent over time) biases in the output when compared to observed records. An important GCM bias in managing water resources infrastructure is the underrepresentation of low‐frequency variability a characteristic central to the simulation of floods and droughts. This study presents a performance metric, the aggregated persistence score (APS), which is used to assess the reliability of GCMs in simulating low‐frequency rainfall variability. The APS identifies regions where GCMs poorly represent the amount of variability seen in the observed precipitation. This study calculated the APS at monthly aggregations for GCM precipitation as well as GCM precipitation that was bias‐corrected to better represent low‐frequency variability. It was found that there were (1) large spatial variations in the skill of GCMs to capture observed rainfall persistence, (2) widespread undersimulation of rainfall persistence characteristics in GCMs, and (3) substantial improvement in rainfall persistence after applying bias correction.
First satellite detection of volcanic OClO after the eruption of Puyehue‐Cordón Caulle
Authors: Theys Nicolas , De Smedt Isabelle , Van Roozendael Michel , Froidevaux Lucien , Clarisse Lieven , Hendrick François 
Published: December 2013

AbstractVolcanoes release large amounts of halogen species such as HCl and HBr, which can be converted into reactive halogens by heterogeneous photochemical reactions that are currently not fully characterized. Here we report on the first satellite detection of volcanic chlorine dioxide (OClO). Measurements were performed using the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography instrument for the ash‐laden plume emitted after the 2011 eruption of Puyehue‐Cordón Caulle in Chile. We also identified volcanic BrO using the Ozone Monitoring Instrument, as well as enhanced HCl in data of the Microwave Limb Sounder instrument. These observations suggest that OClO was formed in the plume by the ClO + BrO reaction in presence of a large excess of ClO. The present satellite data set could help better understand reactive halogen chemistry in volcanic plumes and its impact on atmospheric composition.
Weakening of atmospheric information flow in a warming climate in the Community Climate System Model
Authors: Deng Yi , Ebert‐Uphoff Imme 
Published: December 2013

AbstractWe introduce a new perspective of climate change by revealing the changing characteristics of atmospheric information flow in a warming climate. The key idea is to interpret large‐scale atmospheric dynamical processes as information flow around the globe and to identify the pathways of this information flow using a climate network based on causal discovery and graphical models. We construct such networks using the daily geopotential height data from the Community Climate System Model Version 4.0 (CCSM4.0)'s 20th century climate simulation and 21st century climate projection. We show that in the CCSM4.0 model under enhanced greenhouse gases (GHGs) forcing, prominent midlatitude information pathways in the midtroposphere weaken and shift poleward, while major tropical information pathways start diminishing. Averaged over the entire Northern Hemisphere, the atmospheric information flow weakens. The implications of this weakening for the interconnectivity among different geographical locations and for the intrinsic predictability of the atmosphere are discussed.
A statistical analysis of properties of small transients in the solar wind 2007–2009: STEREO and Wind observations
Authors: Yu W. , Farrugia C. J. , Lugaz N. , Galvin A. B. , J. Kilpua E. K. , Kucharek H. , Möstl C. , Leitner M. , Torbert R. B. , C. Simunac K. D. , Luhmann J. G. , Szabo A. , Wilson L. B. , Ogilvie K. W. , Sauvaud J.‐A. 
Published: December 2013

AbstractWe present a comprehensive statistical analysis of small solar wind transients (STs) in 2007–2009. Extending work on STs by Kilpua et al. (2009) to a 3 year period, we arrive at the following identification criteria: (i) a duration < 12 h, (ii) a low proton temperature and/or a low proton beta, and (iii) enhanced field strength relative to the 3 year average. In addition, it must have at least one of the following: (a) decreased magnetic field variability, (b) large, coherent rotation of the field vector, (c) low Alfvén Mach number, and (d) Te/Tp higher than the 3 year average. These criteria include magnetic flux ropes. We searched for STs using Wind and STEREO data. We exclude Alfvénic fluctuations. Case studies illustrate features of these configurations. In total, we find 126 examples, ∼81% of which lie in the slow solar wind (≤ 450 km s−1). Many start or end with sharp field and flow gradients/discontinuities. Year 2009 had the largest number of STs. The average ST duration is ∼4.3 h, 75%<6 h. Comparing with interplanetary coronal mass ejections (ICMEs) in the same solar minimum, we find the major difference to be that Tp in STs is not significantly less than the expected Tp. Thus, whereas a low Tp is generally considered a very reliable signature of ICMEs, it is not a robust signature of STs. Finally, since plasma β∼1, force‐free modeling of STs having a magnetic flux rope geometry may be inappropriate.
Reconstruction of an evolving magnetic flux rope in the solar wind: Decomposing spatial and temporal variations from single‐spacecraft data
Authors: Hasegawa Hiroshi , Sonnerup Bengt U. Ö. , Hu Qiang , Nakamura Takuma 
Published: December 2013

AbstractWe present a novel single‐spacecraft method for decomposing spatial and temporal variations of physical quantities at points along the path of a spacecraft in space‐time. The method is designed for use in the reconstruction of evolving two‐dimensional, approximately magnetohydrostatic structures in a space plasma. It is an extension of the one developed by Sonnerup and Hasegawa (2010) and Hasegawa et al. (2010), in which it was assumed that variations in the time series of data, recorded as the structures move past the spacecraft, are all due to spatial effects. In reality, some of the observed variations are usually caused by temporal evolution of the structure during the time it moves past the observing spacecraft; the information in the data about the spatial structure is aliased by temporal effects. The purpose here is to remove this time aliasing from the reconstructed maps of field and plasma properties. Benchmark tests are performed by use of synthetic data taken by a virtual spacecraft as it traverses, at a constant velocity, a magnetic flux rope growing sufficiently slowly (relative to the Alfvén speed) in a two‐dimensional magnetohydrodynamic simulation of magnetic reconnection. These tests show that the new method can better recover the space‐time behavior of the flux rope than does the original version, in which time‐aliasing effects had not been removed. An application of the new method to a solar wind flux rope, observed by the ACE spacecraft, suggests that the cross‐sectional shape of the core part of the flux rope was varying.
Transmission of large‐amplitude ULF waves through a quasi‐parallel shock at Venus
Authors: Shan Lican , Lu Quanming , Wu Mingyu , Gao Xinliang , Huang Can , Zhang Tielong , Wang Shui 
Published: December 2013

AbstractThere exist large‐amplitude ultralow frequency (ULF) waves in the upstream region of a quasi‐parallel shock, which are excited due to the reflected ions by the shock. These waves are then brought back to the shock by the solar wind, and at last they coalesce and merge with the shock. In this paper, with the magnetic field measurements from Venus Express, for the first time we observe the transmission of large‐amplitude ULF waves from the upstream region to the downstream under quasi‐parallel shock conditions. These waves exist in both the upstream and downstream regions of the Venusian bow shock, which have the similar characteristics: their peak frequencies are 0.04–0.05 Hz in the spacecraft frame, their propagation angles do not change greatly, they have left‐hand polarization with respect to the mean magnetic field in the spacecraft frame, and they also have a large compressibility. We conclude that they are magnetosonic waves. The generation mechanism of such waves at the Venusian bow shock is also discussed in the paper.
Three‐dimensional simulation of the electromagnetic fields induced by the 2011 Tohoku tsunami
Authors: Zhang Luolei , Utada Hisashi , Shimizu Hisayoshi , Baba Kiyoshi , Maeda Takuto 
Published: December 2013

AbstractThe motion of seawater induces electromotive force of significant intensity due to Faraday's law, and the resulting electromagnetic (EM) field can be recorded by instruments installed on land or on the ocean bottom. However, few studies have successfully made a quantitative interpretation to obtain geophysical information from observations of tsunami‐induced EM signals by an exact and accurate application of Maxwell equations. We built a scheme for three‐dimensional numerical simulation to calculate EM fields due to ocean tidal flow and tested the system's accuracy by using the source currents in the ocean as expected from a Tohoku tsunami simulation. Here we show examples of a comparison of data from one land observatory in the Tohoku district, one island observatory in the Izu‐Bonin arc, and one seafloor station in the northwest Pacific Ocean. The water motion that generates source current in the sea consists of both the primary poloidal and toroidal magnetic modes. Our numerical simulation shows that the field of the primary toroidal magnetic mode can be effective for seafloor observations but only when the seafloor is highly conductive. We examined how the conductivity of the shallower part of the seabed, composed of sediments, can be constrained by the tsunami‐induced EM field observations, which is difficult in case of using ordinary seafloor magnetotelluric signals. We also defined the motional impedance just as the case of ordinary magnetotellurics and showed that both modeled and observed impedances approximately indicate the phase velocity of the long wave as predicted by a simple theory.
Physical state of Himalayan crust and uppermost mantle: Constraints from seismic attenuation and velocity tomography
Authors: Sheehan Anne F. , de la Torre Thomas L. , Monsalve Gaspar , Abers Geoffrey A. , Hacker Bradley R. 
Published: December 2013

AbstractWe jointly interpret P and S wave seismic attenuation (1/Q) along with previously published seismic velocity results for the crust and uppermost mantle of eastern Nepal and the southern Tibetan Plateau. Seismic attenuation measurements can provide information complementary to seismic velocity estimates and can help distinguish between compositional and thermal mechanisms for observed anomalies. In addition to a dramatic change in seismic velocity observed between the crust of Nepal and southern Tibet, we find a large increase in seismic attenuation from high Q (low attenuation) in eastern Nepal to low Q (high attenuation) in the crust beneath southern Tibet for both P waves and S waves. We interpret the broad zone of low Q values in the southern Tibetan crust as thermal in origin, requiring an elevated geotherm (warm) relative to Nepal, with low VP/VS corresponding to a dominantly felsic middle and upper crust beneath southern Tibet. We find a sharply bounded region with enhanced low Q and high VP/VS at 45–50 km depth beneath southern Tibet, which we suggest may be due to trapped fluid beneath an impermeable cap associated with the crustal alpha‐beta quartz transition. Using calibrations from mineral physics, the alpha‐beta quartz transition suggests a temperature of 930–960°C at 45 km depth (50 km beneath the surface) beneath the southern Tibetan Plateau. High values of QP and QS throughout the uppermost mantle in the region are consistent with cool temperatures in the underthrusting Indian Plate, contributing to brittle conditions and earthquakes in the uppermost mantle.
A novel adaptive control approach for nonlinearly parameterized systems
Authors: Chen Zhiyong 
Published: December 2013

SUMMARYNonlinearly parameterized systems are commonly encountered in control of practical systems. However, the conventional adaptive estimation and control strategies, based on the essential assumption of linear parameterization, are incapable of dealing with this class of systems. This incapability in turn becomes a bottleneck for prevalent applications of adaptive control. In literature, there have been some attempts to break through this bottleneck by investigating the characteristics of nonlinearities. However, it is still open for an implementable strategy that is powerful for nonlinearly parameterized systems as the certainty equivalence principle for linearly parameterized systems. This paper aims to contribute an attempt to this open problem by proposing a novel adaptive control approach. On the one hand, the controller is conceptually simple, and it does not explicitly rely on the expression of system nonlinearities. On the other hand, the controller is able to achieve system stability and parameter convergence. Copyright © 2013 John Wiley & Sons, Ltd.
Mitochondrial DNA and Y‐chromosome structure at the mediterranean and atlantic façades of the iberian peninsula
Authors: Santos Cristina , Fregel Rosa , Cabrera Vicente M. , Álvarez Luis , Larruga Jose M. , Ramos Amanda , López Miguel A. , Pilar Aluja María , González Ana M. 
Published: December 2013

ABSTRACTObjectivesThe aim of this study is to analyze mitochondrial DNA and Y‐chromosome lineages in a range of Atlantic and Mediterranean populations of the Iberian Peninsula in search of genetic differences between both façades and to uncover the most probable geographic origin and coalescence ages of lineages.MethodsThe control region of mitochondrial DNA and haplogroup diagnostic positions were analyzed in 575 subjects and Y‐chromosome markers were typed in 260 unrelated males. Moreover, previously published data were compiled and used in the analyses.ResultsThe level of genetic structure deduced from uniparental markers for the Iberian Peninsula was weak, with stronger Atlantic versus Mediterranean than North to South differentiation and larger diversities in the South. In general, mitochondrial DNA haplogroups had mainly Paleolithic and Mesolithic coalescences in Europe, although some of them, ruling out drift effects, seem to have younger implantation in Central Europe and the Atlantic areas than in the Mediterranean (I, J, J2a, T1, and W) while others as N1 and X could have reached the Iberian Peninsula at the Neolithic transition. On the other hand, younger coalescence ages are being proposed for the arriving or spread of the bulk of Y‐chromosome lineages in Europe.ConclusionsThe major haplotypic affinities found for all the Iberian Peninsula regions were always with North Africa and the Atlantic Islands. These results draw an Atlantic network that clearly resembles those of the Megalithic Copper and Bronze cultures at this part of Europe. Am. J. Hum. Biol. 26:130–141, 2014. © 2013 Wiley Periodicals, Inc.