bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonmasslike Lesions on Breast Sonography
Authors: Kim Suk Jung , Park Young Mi , Jung Hyun Kyung 
Published: February 2014

ObjectivesTo compare the imaging and clinical features of benign and malignant nonmasslike lesions in the breast.MethodsDuring a 2‐year period at a single institution, 186 nonmasslike lesions in 158 women were pathologically confirmed through surgery or sonographically guided biopsy. The sonographic patterns (mottled, geographic, and indistinct) and distributions (focal and regional) were compared between benign and malignant lesions. The presence of sonographically visible calcifications, amount of color Doppler signals, presence of positive findings on mammography, and presence of symptoms were also compared between the two groups.ResultsA total of 156 lesions (84%) were confirmed as benign and 30 (16%) as malignant. On sonography, malignant nonmasslike lesions more frequently had mottled and geographic patterns and regional distribution than benign lesions (P < .0001). Malignant lesions also more frequently had sonographically visible calcifications (40% versus 0%; P < 0.0001) and a greater amount of color Doppler signals than benign lesions (P< .0001). On mammography, malignant lesions more frequently had densities and calcifications than benign lesions (30.4% versus 7.1%; P= 0.0052; 73.9% versus 6.1%; P < .0001, respectively). Clinically, malignant lesions were more frequently palpable and accompanied by localized pain than benign lesions (50% versus 2.6%; P< .0001; 13.3% versus 0.6%; P = .0025).ConclusionsThe imaging and clinical features of malignant nonmasslike lesions differed significantly from those of benign nonmasslike lesions.
Differentiation of Branch Duct Intraductal Papillary Mucinous Neoplasms From Serous Cystadenomas of the Pancreas Using Contrast‐Enhanced Sonography
Authors: Chen Fen , Liang Jun-ying , Zhao Qi-yu , Wang Li-yin , Li Ju , Deng Zhuang , Jiang Tian-an 
Published: February 2014

ObjectivesThe purpose of this study was to determine whether contrast‐enhanced sonography can improve the ability to differentiate branch duct intraductal mucinous neoplasms from serous cystadenomas of the pancreas compared to conventional (unenhanced) sonography alone.MethodsBetween March 2008 and May 2012, there were 20 patients with branch duct intraductal mucinous neoplasms and 25 with serous cystadenomas in our institute, for whom preoperative conventional and contrast‐enhanced sonographic results were available. The final diagnosis was obtained by histopathology. Various conventional and contrast‐enhanced sonographic characteristics were retrospectively evaluated by 2 radiologists in consensus. A receiver operating characteristic curve analysis was used to evaluate the diagnostic value of conventional and contrast‐enhanced sonography for discriminating between the two entities.ResultsThree conventional sonographic characteristics (microcysts, cysts with internal echoes, and main pancreatic duct dilatation) and 2 contrast‐enhanced sonographic characteristics (communication between the lesion and main pancreatic duct and enhancement of mural nodules) significantly improved the ability to differentiate branch duct intraductal mucinous neoplasms from serous cystadenomas. The area under the receiver operating characteristic curve increased from 0.691 with conventional sonography to 0.859 with combined contrast‐enhanced and conventional ultrasonography (P = .043).ConclusionsIn this series of patients, the addition of contrast‐enhanced sonography to conventional sonography improved the ability to differentiate branch duct intraductal mucinous neoplasms from serous cystadenomas.
Time to Revisit the Human Chorionic Gonadotropin Discriminatory Level in the Management of Pregnancy of Unknown Location
Authors: Ko Jennifer K. Y. , Cheung Vincent Y. T. 
Published: February 2014

ObjectivesThe purpose of this study was to review the management and outcomes of all patients with pregnancy of unknown location who had serum human chorionic gonadotropin (hCG) levels greater than 1000 mIU/mL in our institution and to determine the likelihood of a subsequent normal intrauterine pregnancy at different hCG discriminatory levels.MethodsA retrospective review was performed on all women admitted with the diagnosis of pregnancy of unknown location and an hCG level greater than 1000 mIU/mL over a 5‐year period (July 2007 to June 2012). Patients were identified from a computerized hCG result database. The medical records, including sonographic findings, hCG levels, and outcomes, were reviewed.ResultsA total of 113 patients were identified. There were 23 viable intrauterine pregnancies (20.4%) and 22 visualized ectopic pregnancies (19.5%). The highest hCG level associated with a subsequent normal intrauterine pregnancy was 9083 mIU/mL in a patient with triplet pregnancy. Possible factors associated with nonvisualization of a normal intrauterine pregnancy included uterine fibroids, adenomyosis, endometrial polyps, and obesity. The negative laparoscopy rate was 48.8%.ConclusionsViable intrauterine pregnancy is possible in patients with pregnancy of unknown location and hCG levels above the generally accepted discriminatory zone, strict adherence to which can potentially disrupt a normal pregnancy. We support the need for judicious use of the hCG discriminatory level in hemodynamically stable patients with pregnancy of unknown location, and the decision to intervene should not be based solely on a single hCG level.
Biometric Sonographic Findings of Abnormally Adherent Trophoblastic Implantations on Cesarean Delivery Scars
Authors: Moschos Elysia , Wells C. Edward , Twickler Diane M. 
Published: February 2014

ObjectivesThe purpose of this study was to review first‐trimester transvaginal sonograms of patients with cervicoisthmic implantations and prior cesarean deliveries to determine whether sonographic biometric measurements can distinguish between abnormally adherent trophoblastic implantations and normally implanted pregnancies.MethodsOur database was reviewed from October 2006 through December 2011 for patients with first‐trimester sonographic diagnoses of cervicoisthmic implantations and previous cesarean deliveries. Biometric measurements of the smallest distance from the anterior trophoblastic border to the uterine serosa were performed on transvaginal sagittal images of the uterus. Outcomes were classified into 5 categories: cesarean scar pregnancy, placental invasion (accreta/increta/percreta), previa without invasion, spontaneous abortion, and delivered intrauterine pregnancy. Statistical methods included analysis of variance with the Tukey range test and Student t test.ResultsOf 77 studies, outcome data were available for 56 patients. The mean gestational age was 8.8 weeks (minimum, 2.0 weeks; maximum, 14.9 weeks). The anterior trophoblastic border distances from the uterine serosa were significantly smaller in cesarean scar pregnancies (mean, 1.6 mm; SD, 0.6 mm) and placental invasion pregnancies (mean, 2.2 mm; SD, 1.0 mm) than the normally implanted groups (mean, 7.9 mm, SD, 3.3 mm; P < .0001).ConclusionsSmaller trophoblastic border distances to the anterior uterine serosa are seen in abnormally adherent trophoblastic implantations, and these distances distinguish them from other pregnancy outcomes.
Relative Proportions of Stromal to Cellular Components of Pleomorphic Adenomas
Authors: Olgun Deniz Cebi , Kantarci Fatih , Taskin Umit , Kilic Fahrettin , Oktay Mehmet Faruk , Altinay Serdar , Kepil Nuray , Adaletli Ibrahim , Ada Mehmet , Mihmanli Ismail 
Published: February 2014

ObjectivesThe purpose of this study was to evaluate whether the relative proportions of stromal to cellular components of pleomorphic adenomas have an effect on the shear elastic modulus determined by shear wave elastography (SWE).MethodsThis study was approved by the Ethics Committee of our institution and performed between September 2011 and December 2012. Thirty‐five patients who underwent surgery for a parotid mass were included in the study. The maximum shear elastic modulus of the mass was measured by SWE. Pleomorphic adenomas were histopathologically subdivided into stroma‐poor, intermediate‐stroma, and stroma‐rich tumors based on the relative proportion of stromal to cellular components.ResultsThe maximum shear elastic modulus values of the pleomorphic adenomas ranged from 12.6 to 291.9 kPa (mean ± SD, 120.9 ± 92.8 kPa). The Friedman test revealed a statistically significant relationship between the stromal amount and maximum shear elastic modulus (P < .001). Stroma‐poor adenomas (mean, 32.3 ± 27.7 kPa; range, 12.6–81.1 kPa) were softer on SWE than stroma‐rich adenomas (mean, 174.1 ± 48.4 kPa; range, 92.7–217.2 kPa; P = .009). No such significant difference was detected between stroma‐poor and intermediate‐stroma tumors (mean, 146.3 ± 106.1 kPa; range, 19.1–291.9 kPa; P = .062) or between intermediate‐stroma and stroma‐rich tumors (P = .465).ConclusionsShear wave elastography depicts pleomorphic adenomas with a variable appearance, which is due to the relative proportions of stromal to cellular contents in the tumors.
Modeling U.S. water resources under climate change
Authors: Blanc Elodie , Strzepek Kenneth , Schlosser Adam , Jacoby Henry , Gueneau Arthur , Fant Charles , Rausch Sebastian , Reilly John 
Published: February 2014

AbstractWater is at the center of a complex and dynamic system involving climatic, biological, hydrological, physical, and human interactions. We demonstrate a new modeling system that integrates climatic and hydrological determinants of water supply with economic and biological drivers of sectoral and regional water requirement while taking into account constraints of engineered water storage and transport systems. This modeling system is an extension of the Massachusetts Institute of Technology (MIT) Integrated Global System Model framework and is unique in its consistent treatment of factors affecting water resources and water requirements. Irrigation demand, for example, is driven by the same climatic conditions that drive evapotranspiration in natural systems and runoff, and future scenarios of water demand for power plant cooling are consistent with energy scenarios driving climate change. To illustrate the modeling system we select “wet” and “dry” patterns of precipitation for the United States from general circulation models used in the Climate Model Intercomparison Project (CMIP3). Results suggest that population and economic growth alone would increase water stress in the United States through mid‐century. Climate change generally increases water stress with the largest increases in the Southwest. By identifying areas of potential stress in the absence of specific adaptation responses, the modeling system can help direct attention to water planning that might then limit use or add storage in potentially stressed regions, while illustrating how avoiding climate change through mitigation could change likely outcomes.
Incoherent scatter radar‐FAST satellite common volume observations of upflow‐to‐outflow conversion
Authors: Sánchez Ennio R. , StrØmme Anja 
Published: February 2014

AbstractIncoherent scatter radar measurements from the Sondrestrom Research Facility and the European Incoherent Scatter Svalbard radar have been combined with all‐sky images, polar convection measurements, and FAST particle and field measurements to quantify the contribution of different magnetosphere‐ionosphere coupling processes to the extraction efficiency of ions from the ionosphere. Upflowing ions are traced from their source vertically and horizontally to determine where and when they are likely to intersect the acceleration region observed by FAST. The duration and location of auroral emissions are used to estimate the size and duration of the acceleration region. The upflow‐to‐outflow efficiency is estimated for three periods of polar cap boundary intensifications and streamers during substorm recovery and steady magnetospheric convection. The extraction efficiency of conics ranges between 0.1%, for the lowest amplitude of broadband extremely low frequency waves, and 5%, for the highest‐amplitude waves sampled. Simultaneous measurements of all‐sky images and magnetic field‐aligned radar measurements show that the most intense ion upflux occurs adjacent to the boundary of intense electron precipitation characteristic of polar cap boundary intensifications and streamers, suggesting that the most efficient acceleration mechanisms couple ionospheric heating at F region altitude with dispersive Alfvén waves that grow from horizontal gradients in electric field and conductivity.
Azimuthal extent and properties of midtail plasmoids from two‐point ARTEMIS observations at the Earth‐Moon Lagrange points
Authors: Li S.‐S. , Angelopoulos V. , Runov A. , Kiehas S. A. 
Published: February 2014

AbstractAlthough distant‐tail plasmoids are perceived to extend across most of the magnetotail (~40 RE), recent studies in the near‐Earth region (X > −30 RE) have revealed that near‐Earth reconnection (where plasmoids originate) is likely localized and takes place preferentially on the duskside. This discrepancy in plasmoid azimuthal extent suggests that a plasmoid may grow as it moves from near‐Earth to the distant tail. Comprehensive multipoint, midtail plasmoid observations can be used to test this hypothesis. Between October 2010 and July 2011 the ARTEMIS spacecraft (P1 and P2) at the Earth‐Moon Lagrange points (midtail, X ~ −45 to −65 RE) provided simultaneous two‐point observations across the magnetotail for 4 days every lunar month, with a large range of spacecraft separations (0.1 to 25 RE). We find that plasmoids near lunar orbit, like other near‐Earth reconnection‐related phenomena, occur preferentially on the duskside of the magnetotail. Two‐point ARTEMIS observations reveal that the typical plasmoid azimuthal size in our data set is about 5 to 10 RE, much smaller than expected from previous distant‐tail observations. Plasmoids with an azimuthal size greater than 9 RE also exist but only at geomagnetic activity levels higher (AEpeak > 400 nT) than typically found in our data set (median AEpeak ~ 230 nT for our plasmoid data set and median AE ~ 100 nT during the entire period of ARTEMIS magnetotail observations). We conclude that plasmoids during small to moderate substorms (AEpeak < 400 nT) do not grow beyond ~10 RE until they have moved tailward of ~ −45 to −65 RE. Plasmoids during large substorms (AEpeak > 400 nT), however, either grow beyond ~10 RE before they reach lunar distance or initially extend across a large portion of the magnetotail.
Statistically measuring the amount of pitch angle scattering that energetic electrons undergo as they drift across the plasmaspheric drainage plume at geosynchronous orbit
Authors: Borovsky Joseph E. , Friedel Reiner H. W. , Denton Michael H. 
Published: February 2014

AbstractUsing five spacecraft in geosynchronous orbit, plasmaspheric drainage plumes are located in the dayside magnetosphere and the measured pitch angle anisotropies of radiation belt electrons are compared duskward and dawnward of the plumes. Two hundred twenty‐six plume crossings are analyzed. It is found that the radiation belt anisotropy is systematically greater dawnward of plumes (before the electrons cross the plumes) than it is duskward of plumes (after the electrons have crossed the plumes). This change in anisotropy is attributed to pitch angle scattering of the radiation belt electrons during their passage through the plumes. A test database in the absence of plumes finds no equivalent change in the radiation belt anisotropy. The amount of pitch angle scattering by the plume is quantified, scattering times are estimated, and effective pitch angle diffusion coefficients within the plume are estimated. The pitch angle diffusion coefficients obtained from the scattering measurements are of the same magnitude as expected values for electromagnetic ion cyclotron (EMIC) waves at high electron energies (1.5 MeV); however, expected EMIC diffusion coefficients do not extend to pitch angles of 90° and would have difficulties explaining the observed isotropization of electrons. The pitch angle diffusion coefficients obtained from the scattering measurements are of the same magnitude as expected values for whistler mode hiss at lower electron energies (150 keV). Outward radial transport of the radiation belt caused by the pitch angle scattering in the plume is discussed.
The quiet evening auroral arc and the structure of the growth phase near‐Earth plasma sheet
Authors: Coroniti F. V. , Pritchett P. L. 
Published: February 2014

AbstractThe plasma pressure and current configuration of the near‐Earth plasma sheet that creates and sustains the quiet evening auroral arc during the growth phase of magnetospheric substorms is investigated. We propose that the quiet evening arc (QEA) connects to the thin near‐Earth current sheet, which forms during the development of the growth phase enhancement of convection. The current sheet's large polarization electric fields are shielded from the ionosphere by an Inverted‐V parallel potential drop, thereby producing the electron precipitation responsible for the arc's luminosity. The QEA is located in the plasma sheet region of maximal radial pressure gradient and, in the east‐west direction, follows the vanishing of the approximately dawn‐dusk‐directed gradient or fold in the plasma pressure. In the evening sector, the boundary between the Region1 and Region 2 current systems occurs where the pressure maximizes (approximately radial gradient of the pressure vanishes) and where the approximately radial gradient of the magnetic flux tube volume also vanishes in an inflection region. The proposed intricate balance of plasma sheet pressure and currents may well be very sensitive to disruption by the arrival of equatorward traveling auroral streamers and their associated earthward traveling dipolarization fronts.
Assessing variability of evapotranspiration over the Ganga river basin using water balance computations
Authors: Syed Tajdarul H. , Webster Peter J. , Famiglietti James S. 
Published: February 2014

AbstractA thorough assessment of evapotranspiration (ET) pervades several important issues of the 21st century including climate change, food‐security, land‐management, flood and drought prediction, and water resources assessment and management. Such a proper assessment is of particular importance in the Ganga river basin (GRB) with its backdrop of a rapidly increasing population pressure and unregulated use of water resources. Spatially averaged ET over the GRB is computed as the residual of atmospheric and terrestrial water budget computations using a combination of model simulations and satellite and ground‐based observations. The best estimate of monthly ET is obtained as the monthly mean of atmospheric and terrestrial water balance computations for the period 1980–2007. The mean monthly average of ET from these various estimates is 72.3 ± 18.8 mm month−1. Monthly variations of ET peak between July and August and reach a minimum in February. For the entire study period, the rate of change of ET across the GRB is −11 mm yr−2 (i.e., mm/yr/yr). Alongside a notable influence of the 1997–1998 El Niño, results allude to the existence of interim periods during which ET trends varied significantly. More specifically, during the period of 1998–2002, the rate of decline increased to −55.8 mm yr−2, which is almost 5 times the overall trend. Based on the correlation between ET and independent estimates of near‐surface temperature and soil moisture, we can infer that the ET over the GRB is primarily limited by moisture availability. The analysis has important potential for use in large‐scale water budget assessments and intercomparison studies. The analysis also emphasizes the importance of synergistic use of mutliplatform hydrologic information.
Laboratory study of gravel‐bed cluster formation and disintegration
Authors: Heays K. G. , Friedrich H. , Melville B. W. 
Published: February 2014

AbstractIncreased knowledge of clusters is essential for the understanding of sediment transport behavior and the monitoring and protection of aquatic life. A physical study using graded river gravels is conducted in a laboratory environment. Using photogrammetry and painted gravels, a cluster identification tool (CIT) is developed based on image subtraction between subsequent frames, allowing identification of any stable areas and groups of particles on the bed. This is combined with digital particle tracking (DPT) to present a novel approach for monitoring the formation and disintegration of clusters. Clusters from graded gravels are formed successfully during the experimental stage, allowing investigation into the complex dynamic behavior of cluster formation and disintegration in a simulated natural environment. Various anchor stone arrangements are used in the experiments. However, only about one fifth of the potential anchor stones on the bed surface enable cluster formation. In general, clusters classified as “typical” and “heap” are most common. Inspection of temporal cluster coverage of the test‐bed surface shows that the proportion of clusters present on the surface tends to grow with time. Maximum cluster surface coverage of between 5% and 34% is observed. In addition, particles entering and departing from clusters are monitored. Most commonly, particles enter from directly upstream of the cluster, however >20% of particles approach from a direction >20 deg from the streamwise direction. Approximately 35% of all particles directly upstream of a cluster bypass the cluster.
Modeling dependence between extreme rainfall and storm surge to estimate coastal flooding risk
Authors: Zheng Feifei , Westra Seth , Leonard Michael , Sisson Scott A. 
Published: February 2014

AbstractAccounting for dependence between extreme rainfall and storm surge can be critical for correctly estimating coastal flood risk. Several statistical methods are available for modeling such extremal dependence, but the comparative performance of these methods for quantifying the exceedance probability of rare coastal floods is unknown. This paper compares three classes of statistical methods—threshold‐excess, point process, and conditional—in terms of their ability to quantify flood risk. The threshold‐excess method offers approximately unbiased estimates for dependence parameters, but its application for quantifying flood risk is limited because it is unable to handle situations where only one of the two variables is extreme. In contrast, the point process method (with the logistic and negative logistic models) and the conditional method describe the full distribution of extremes, but they overestimate and underestimate the dependence strength, respectively. We conclude that the point process method is the most suitable approach for modeling dependence between extreme rainfall and storm surge when the dependence is relatively strong, while none of the three methods produces satisfactory results for bivariate extremes with very weak dependence. It is therefore important to take the bias of each method into account when applying them to flood estimation problems. A case study is used to demonstrate the three statistical methods and illustrate the implication of dependence to flood risk.