bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of Sonography in Clinically Occult Femoral Hernias
Authors: Brandel David W. , Girish Gandikota , Brandon Catherine J. , Dong Qian , Yablon Corrie , Jamadar David A. 
Published: December 2015

ObjectivesThe purpose of this article is to evaluate the diagnostic accuracy of sonography in clinically occult femoral hernias and to describe our sonographic technique.MethodsThe clinical and imaging data for 93 outpatients referred by general surgeons, all of whom underwent sonographic evaluation and surgery, were reviewed retrospectively. Of these, 55 patients who underwent surgical exploration for groin hernias within 3 months of sonography and met all inclusion criteria were included in the study. The sonographic technique involves using the pubic tubercle as an osseous landmark to identify and appropriately visualize the femoral canal. The Valsalva maneuver is then used to differentiate the movement of normal fat (a potential pitfall) from true herniation in the femoral canal. Surgical findings were used as the reference standard by which sonographic results were judged. Two‐by‐two contingency tables were used to calculate the sensitivity, specificity, positive predictive value, and negative predictive value.ResultsIn these 55 patients, surgery revealed 15 femoral hernias. Eight femoral hernias occurred in women, and 7 occurred in men. For diagnosing femoral hernias, sonography demonstrated sensitivity of 80%, specificity of 88%, a positive predictive value of 71%, and a negative predictive value of 92%. True‐positive cases of femoral hernias have a sonographic appearance of a hypoechoic sac with speckled internal echoes. When examining during the Valsalva maneuver, a femoral hernia passes deep to the inguinal ligament, expands the femoral canal, displacing the normal canal fat, and effaces the femoral vein.ConclusionsSonography can exclude femoral hernias with high confidence in light of its exceptional negative predictive value. With attention to technique and imaging criteria, the diagnostic accuracy of sonography can be enhanced.
Effect of Anticoagulation Medication on the Thyroid Fine‐Needle Aspiration Pathologic Diagnostic Sufficiency Rate
Authors: Denham S. LeeAnn Wilson , Ismail Aimen , Bolus David N. , Lockhart Mark E. 
Published: December 2015

ObjectivesThis study examined whether ultrasound‐guided thyroid fine‐needle aspiration (FNA) biopsy performed on patients taking anticoagulation medication results in a greater number of nondiagnostic pathologic samples due to a higher propensity to bleed, and thus fill the needle with blood rather than cellular material, compared to patients not taking anticoagulation medication.MethodsIn this retrospective review, data were collected on 1100 patients who underwent ultrasound‐guided thyroid FNA over a 4‐year period. Of these patients, 438 were included. Each thyroid FNA was performed by a board‐certified radiologist using a 6‐pass capillary fill technique. Data including patient age, sex, nodule size, nodule consistency, and whether the patient was or was not taking anticoagulation medication (and, if they were, which medication) were recorded from the electronic medical record, and the nodule characteristics were confirmed on imaging by a senior radiology resident (postgraduate year 5).ResultsOf the 438 patients included, 12 (2.7%) had an FNA aspirate that was deemed insufficient for diagnostic evaluation. Nondiagnostic pathologic yields were seen in 7 of the 309 patients (2.3%) who were not taking anticoagulation medication and 5 of 129 patients (3.9%) who were taking aspirin, warfarin, or clopidogrel, resulting in no statistically significant difference in the rates of nondiagnostic pathologic yields between the two groups (P = .35).ConclusionsBased on these data, cessation of anticoagulation medication before thyroid FNA is not necessary to obtain sufficient cellular material for diagnosis, thus eliminating the need for procedural delays, patient inconvenience, and risks associated with anticoagulation medication cessation.
A flow law for ilmenite in dislocation creep: Implications for lunar cumulate mantle overturn
Authors: Dygert Nick , Hirth Greg , Liang Yan 
Published: December 2015

AbstractWe present results from new deformation experiments and a dislocation creep flow law for synthetic ilmenite. The flow law predicts an effective viscosity more than 3 orders of magnitude lower than dry olivine at mantle stresses and temperatures. Using the flow law, we predict that lunar ilmenite‐bearing cumulates (IBC) will be weakened by the presence of low‐viscosity ilmenite. Dense, low‐viscosity IBC are expected to flow into the lunar interior by a process known as cumulate mantle overturn. Low‐viscosity IBC that sink to the core‐mantle boundary may be dynamically stable with respect to upwelling. A hot, stable layer of IBC surrounding the lunar core would suppress the development of a core dynamo. A layer of partially molten IBC can also explain the inferred zone of seismic attenuation around the lunar core, as well as a low‐viscosity layer suggested by tidal dissipation.
Outer radiation belt dropout dynamics following the arrival of two interplanetary coronal mass ejections
Authors: Alves L. R. , Da Silva L. A. , Souza V. M. , Sibeck D. G. , Jauer P. R. , Vieira L. E. A. , Walsh B. M. , Silveira M. V. D. , Marchezi J. P. , Rockenbach M. , Lago A. Dal , Mendes O. , Tsurutani B. T. , Koga D. , Kanekal S. G. , Baker D. N. , Wygant J. R. , Kletzing C. A. 
Published: December 2015

AbstractMagnetopause shadowing and wave‐particle interactions are recognized as the two primary mechanisms for losses of electrons from the outer radiation belt. We investigate these mechanisms, using satellite observations both in interplanetary space and within the magnetosphere and particle drift modeling. Two interplanetary shocks/sheaths impinged upon the magnetopause causing a relativistic electron flux dropout. The magnetic cloud (MC) and interplanetary structure sunward of the MC had primarily northward magnetic field, perhaps leading to a concomitant lack of substorm activity and a 10 daylong quiescent period. The arrival of two shocks caused an unusual electron flux dropout. Test‐particle simulations have shown ∼ 2 to 5 MeV energy, equatorially mirroring electrons with initial values of L≥5.5 can be lost to the magnetosheath via magnetopause shadowing alone. For electron losses at lower L‐shells, coherent chorus wave‐driven pitch angle scattering and ULF wave‐driven radial transport have been shown to be viable mechanisms.
Energy‐dependent dynamics of keV to MeV electrons in the inner zone, outer zone, and slot regions
Authors: Reeves Geoffrey D. , Friedel Reiner H. W. , Larsen Brian A. , Skoug Ruth M. , Funsten Herbert O. , Claudepierre Seth G. , Fennell Joseph F. , Turner Drew L. , Denton Mick H. , Spence Harlan E. , Blake J. Bernard , Baker Daniel N. 
Published: December 2015

AbstractWe present observations of the radiation belts from the Helium Oxygen Proton Electron and Magnetic Electron Ion Spectrometer particle detectors on the Van Allen Probes satellites that illustrate the energy dependence and L shell dependence of radiation belt enhancements and decays. We survey events in 2013 and analyze an event on 1 March in more detail. The observations show the following: (a) at all L shells, lower energy electrons are enhanced more often than higher energies; (b) events that fill the slot region are more common at lower energies; (c) enhancements of electrons in the inner zone are more common at lower energies; and (d) even when events do not fully fill the slot region, enhancements at lower energies tend to extend to lower L shells than higher energies. During enhancement events the outer zone extends to lower L shells at lower energies while being confined to higher L shells at higher energies. The inner zone shows the opposite with an outer boundary at higher L shells for lower energies. Both boundaries are nearly straight in log(energy) versus L shell space. At energies below a few 100 keV, radiation belt electron penetration through the slot region into the inner zone is commonplace, but the number and frequency of “slot filling” events decreases with increasing energy. The inner zone is enhanced only at energies that penetrate through the slot. Energy‐ and L shell‐dependent losses (that are consistent with whistler hiss interactions) return the belts to more quiescent conditions.
A modeling study of global ionospheric and thermospheric responses to extreme solar flare
Authors: Le Huijun , Liu Libo , Ren Zhipeng , Chen Yiding , Zhang Hui , Wan Weixing 
Published: December 2015

AbstractIn this study, we employed a thermosphere and ionosphere coupling model to investigate ionospheric and thermospheric responses to an extreme solar flare of X40. The simulated results show that the peak enhancement of total electron content reaches about 35 TECU (total electron content unit, 1 TECU = 1016 el m−2), and there are as long as more than 4 h ionospheric disturbances induced by the extreme solar flare. At the same time, the extreme solar flare causes significant disturbances in the thermosphere. The peak enhancement of neutral density at 400 km reaches more than 100%, and the peak enhancement in neutral temperature at 400 km is about 250 K. Several numerical experiments for different class solar flares were further carried out to study the ionosphere and thermosphere variations with solar flare level. The results show that the increasing amplitude of electron density at low altitude decreases with increasing flare level; however, the increasing amplitude of electron density at topside ionosphere increases with increasing flare level. The thermosphere density has the same variation trends with flare level. These results suggest that the extreme solar flare would cause the strong disturbances at high height.
Properties of Hermean plasma belt: Numerical simulations and comparison with MESSENGER data
Authors: Herčík David , Trávníček Pavel M. , Štverák Štěpán , Hellinger Petr 
Published: December 2015

AbstractUsing a global hybrid model and test particle simulations we present a detailed analysis of the Hermean plasma belt structure. We investigate characteristic properties of quasi‐trapped particle population characteristics and its behavior under different orientations of the interplanetary magnetic field. The plasma belt region is constantly supplied with solar wind protons via magnetospheric flanks and tail current sheet region. Protons inside the plasma belt region are quasi‐trapped in the magnetic field of Mercury and perform westward drift along the planet. This region is well separated by a magnetic shell and has higher average temperatures and lower bulk proton current densities than the surrounding area. On the dayside the population exhibits loss cone distribution function matching the theoretical loss cone angle. The simulation results are in good agreement with in situ observations of MESSENGER's (MErcury Surface Space ENvironment GEochemistry, and Ranging) MAG and FIPS instruments.
Seasonal variations in North Atlantic atmospheric river activity and associations with anomalous precipitation over the Iberian Atlantic Margin
Authors: Eiras‐Barca Jorge , Brands Swen , Miguez‐Macho Gonzalo 
Published: December 2015

AbstractIn the present study, a novel atmospheric river (AR) detection scheme based on column‐integrated water vapor and column‐integrated water vapor flux is presented and applied for the Iberian Atlantic Margin (IAM) and a wider area covering the North Atlantic Ocean for the period 1979–2013. The seasonal cycle in AR frequency over the North Atlantic exhibits a relatively small amplitude, being more pronounced toward the east and south of the oceanic basin, as it is increasingly related to the seasonal cycle in storm activity and the meridional displacement of the subtropical high. In the eastern North Atlantic, downwind of the North American continent, it shows a more complex behavior. The interannual variability of AR frequency is weak across the entire North Atlantic, and it does not present consistent long‐term spatiotemporal patterns. For the southern IAM, AR occurrence is slightly enhanced by the negative phase of the North Atlantic Oscillation during the previous days. Up to 80% of the anomalous precipitation events (above the 95th percentile) in the IAM are associated with ARs; these values exceed 90% in winter and decrease to 75% in spring when convection not related to ARs becomes a significant precipitation mechanism. Moisture advection within ARs is thus a very important contributor to anomalous precipitation. Likewise, the strength of the associated storm systems and the characteristics of the ARs themselves are also very relevant factors. The percentage of total ARs linked to anomalous precipitation is relatively low, only reaching 20% where topographic features are favorable.
Atmospheric conditions in the central Arctic Ocean through the melt seasons of 2012 and 2013: Impact on surface conditions and solar energy deposition into the ice‐ocean system
Authors: Wang Caixin , Granskog Mats A. , Hudson Stephen R. , Gerland Sebastian , Pavlov Alexey K. , Perovich Donald K. , Nicolaus Marcel 
Published: December 2015

AbstractSpectral Radiation Buoys and ice mass balance buoys were deployed on first‐year ice near the North Pole in April 2012 and 2013, collecting in‐band (350–800 nm) solar radiation and ice and snow mass balance data over the complete summer melt seasons. With complementary European ERA‐Interim reanalysis, National Centers for Environmental Prediction (NCEP) Climate forecast system version 2 (CFSv2) analysis and satellite passive microwave data, we examine the evolution of atmospheric and surface melt conditions in the two differing melt seasons. Prevailing atmospheric conditions contributed to a longer and more continuous melt season in summer 2012 than in 2013, which was corroborated by in situ observations. ERA‐Interim reanalysis data showed that longwave radiation likely played a key role in delaying the snowmelt onset in 2013. The earlier melt onset in 2012 reduced the albedo, providing a positive ice‐albedo feedback at a time when solar insolation was high. Due to earlier melt onset and later freeze‐up in 2012, more solar heat was deposited into the ice‐ocean system than in 2013. Summer 2013 was characterized by later melt onset, intermittent freezing events and an earlier fall freeze‐up, resulting in considerably fewer effective days of surface melt and a higher average albedo. Calculations for idealized seasonal albedo evolution show that moving the melt onset just 1 week earlier in mid‐June increases the total absorbed solar radiation by nearly 14% for the summer season. Therefore, the earlier melt onset may have been one of the most important factors driving the more dramatic melt season in 2012 than 2013, though atmospheric circulation patterns, e.g., cyclone in early August 2012, likely contributed as well.
Year‐round records of sea salt, gaseous, and particulate inorganic bromine in the atmospheric boundary layer at coastal (Dumont d'Urville) and central (Concordia) East Antarctic sites
Authors: Legrand Michel , Yang Xin , Preunkert Susanne , Theys Nicolas 
Published: December 2015

AbstractMultiple year‐round records of bulk and size‐segregated compositions of aerosol were obtained at the coastal Dumont d'Urville (DDU) and inland Concordia sites located in East Antarctica. They document the sea‐salt aerosol load and composition including, for the first time in Antarctica, the bromide depletion of sea‐salt aerosol relative to sodium with respect to seawater. In parallel, measurements of bromide trapped in mist chambers and denuder tubes were done to investigate the concentrations of gaseous inorganic bromine species. These data are compared to simulations done with an off‐line chemistry transport model, coupled with a full tropospheric bromine chemistry scheme and a process‐based sea‐salt production module that includes both sea‐ice‐sourced and open‐ocean‐sourced aerosol emissions. Observed and simulated sea‐salt concentrations sometime differ by up to a factor of 2 to 3, particularly at DDU possibly due to local wind pattern. In spite of these discrepancies, both at coastal and inland Antarctica, the dominance of sea‐ice‐related processes with respect to open ocean emissions for the sea‐salt aerosol load in winter is confirmed. For summer, observations and simulations point out sea salt as the main source of gaseous inorganic bromine species. Investigations of bromide in snow pit samples do not support the importance of snowpack bromine emissions over the Antarctic Plateau. To evaluate the overall importance of the bromine chemistry over East Antarctica, BrO simulations were also discussed with respect data derived from GOME‐2 satellite observations over Antarctica.
The variability of the rainfall rate as a function of area
Authors: Jameson A. R. , Larsen M. L. 
Published: December 2015

AbstractDistributions of drop sizes can be expressed as DSD = Nt × PSD, where Nt is the total number of drops in a sample and PSD is the frequency distribution of drop diameters (D). Their discovery permitted remote sensing techniques for rainfall estimation using radars and satellites measuring over large domains of several kilometers. Because these techniques depend heavily on higher moments of the PSD, there has been a bias toward attributing the variability of the intrinsic rainfall rates R over areas (σR) to the variability of the PSDs. While this variability does increase up to a point with increasing domain dimension L, the variability of the rainfall rate R also depends upon the variability in the total number of drops Nt. We show that while the importance of PSDs looms large for small domains used in past studies, it is the variability of Nt that dominates the variability of R as L increases to 1 km and beyond. The PSDs contribute to the variability of R through the relative dispersion of χ = D3Vt, where Vt is the terminal fall speed of drops of diameter D. However, the variability of χ is inherently limited because drop sizes and fall speeds are physically limited. In contrast, it is shown that the variance of Nt continuously increases as the domain expands for physical reasons explained below. Over domains larger than around 1 km, it is shown that Nt dominates the variance of the rainfall rate with increasing L regardless of the PSD.
Magnesium sulfate as a key mineral for the detection of organic molecules on Mars using pyrolysis
Authors: François P. , Szopa C. , Buch A. , Coll P. , McAdam A. C. , Mahaffy P. R. , Freissinet C. , Glavin D. P. , Navarro‐Gonzalez R. , Cabane M. 
Published: December 2015

AbstractPyrolysis of soil or rock samples is the preferred preparation technique used on Mars to search for organic molecules up today. During pyrolysis, oxichlorines present in the soil of Mars release oxidant species that alter the organic molecules potentially contained in the samples collected by the space probes. This process can explain the difficulty experienced by in situ exploration probes to detect organic materials in Mars soil samples until recently. Within a few months, the Curiosity rover should reach and analyze for the first time soils rich in sulfates which could induce a different behavior of the organics during the pyrolysis compared with the types of soils analyzed up today. For this reason, we systematically studied the pyrolysis of organic molecules trapped in magnesium sulfate, in the presence or absence of calcium perchlorate. Our results show that organics trapped in magnesium sulfate can undergo some oxidation and sulfuration during the pyrolysis. But these sulfates are also shown to protect organics trapped inside the crystal lattice and/or present in fluid inclusions from the oxidation induced by the decomposition of calcium perchlorate and probably other oxychlorine phases currently detected on Mars. Trapped organics may also be protected from degradation processes induced by other minerals present in the sample, at least until these organics are released from the pyrolyzed sulfate mineral (~700°C in our experiment). Hence, we suggest magnesium sulfate as one of the minerals to target in priority for the search of organic molecules by the Curiosity and ExoMars 2018 rovers.
Spatial and temporal Antarctic Ice Sheet mass trends, glacio‐isostatic adjustment, and surface processes from a joint inversion of satellite altimeter, gravity, and GPS data
Authors: Martín‐Español Alba , Zammit‐Mangion Andrew , Clarke Peter J. , Flament Thomas , Helm Veit , King Matt A. , Luthcke Scott B. , Petrie Elizabeth , Rémy Frederique , Schön Nana , Wouters Bert , Bamber Jonathan L. 
Published: December 2015

We present spatiotemporal mass balance trends for the Antarctic Ice Sheet from a statistical inversion of satellite altimetry, gravimetry, and elastic‐corrected GPS data for the period 2003–2013. Our method simultaneously determines annual trends in ice dynamics, surface mass balance anomalies, and a time‐invariant solution for glacio‐isostatic adjustment while remaining largely independent of forward models. We establish that over the period 2003–2013, Antarctica has been losing mass at a rate of −84 ± 22 Gt yr−1, with a sustained negative mean trend of dynamic imbalance of −111 ± 13 Gt yr−1. West Antarctica is the largest contributor with −112 ± 10 Gt yr−1, mainly triggered by high thinning rates of glaciers draining into the Amundsen Sea Embayment. The Antarctic Peninsula has experienced a dramatic increase in mass loss in the last decade, with a mean rate of −28 ± 7 Gt yr−1 and significantly higher values for the most recent years following the destabilization of the Southern Antarctic Peninsula around 2010. The total mass loss is partly compensated by a significant mass gain of 56 ± 18 Gt yr−1 in East Antarctica due to a positive trend of surface mass balance anomalies.
Ring Index: A new strategy to evaluate the integrity of TEX86 paleothermometry
Authors: Zhang Yi Ge , Pagani Mark , Wang Zhengrong 
Published: December 2015

AbstractThe TEX86 (tetraether index of 86 carbon atoms) sea surface temperature proxy has been increasingly applied in the reconstruction of Mesozoic and Cenozoic ocean temperatures. However, the archaeal lipids that compose TEX86 indices, glycerol dialkyl glycerol tetraethers (GDGTs), can derive from water column production, terrestrial sources, and/or within sediments. TEX86‐sea surface temperature estimates can also be influenced by non‐temperature factors, such as growth phase and nutrient levels. Here we show that the weighted average of cyclopentane moieties, known as the Ring Index (RI), can be used to determine if TEX86 temperature estimates are influenced by non‐thermal factors and/or deviate from modern analogues. We demonstrate that RI and TEX86 indices from the published global core top data set and mesocosm cultures are significantly correlated, as predicted through the influence of temperature on lipid biochemistry. We further show that when RI and TEX86 indices in modern or ancient records deviate from the modern global TEX86‐RI relationship, GDGT distributions are not solely controlled by environmental temperature and/or TEX86‐based temperature reconstructions are questionable.