bluuebunny/crossref_metadata_2025_split huggingface dataset:
A diversity of localized timescales in network activity
Authors: Chaudhuri Rishidev , Bernacchia Alberto , Wang Xiao-Jing 
Published: January 2014

Neurons show diverse timescales, so that different parts of a network respond with disparate temporal dynamics. Such diversity is observed both when comparing timescales across brain areas and among cells within local populations; the underlying circuit mechanism remains unknown. We examine conditions under which spatially local connectivity can produce such diverse temporal behavior.In a linear network, timescales are segregated if the eigenvectors of the connectivity matrix are localized to different parts of the network. We develop a framework to predict the shapes of localized eigenvectors. Notably, local connectivity alone is insufficient for separate timescales. However, localization of timescales can be realized by heterogeneity in the connectivity profile, and we demonstrate two classes of network architecture that allow such localization. Our results suggest a framework to relate structural heterogeneity to functional diversity and, beyond neural dynamics, are generally applicable to the relationship between structure and dynamics in biological networks.
Contribution of Contrast–Enhanced Sonography in the Detection of Intrahepatic Cholangiocarcinoma
Authors: Kong Wen-Tao , Wang Wen-Ping , Zhang Wei-Wei , Qiu Yu-Dong , Ding Hong , Huang Bei-Jian 
Published: January 2014

ObjectivesThe purpose of this study was to evaluate the contribution of contrast‐enhanced sonography in the diagnosis of intrahepatic cholangiocarcinoma up to 3 cm and analyze its dynamic enhancement patterns.MethodsForty‐five patients (29 male and 16 female; mean age ± SD, 61.3 ± 10.7 years; range, 38–79 years) with a preliminary diagnosis of intrahepatic cholangiocarcinoma by contrast‐enhanced sonography were retrospectively analyzed. For each nodule, the enhancement pattern, level, and dynamic change during the arterial, portal, and late phases after the injection of a sulfur hexafluoride microbubble contrast agent were evaluated.ResultsAmong the 35 patients with a histopathologic diagnosis of intrahepatic cholangiocarcinoma, 18 nodules showed hyperenhancement during the arterial phase, and 17 showed hypoenhancement. Heterogeneous, peripheral, and partial enhancement were found in 24, 8, and 2 nodules, respectively. However, only 1 nodule showed homogeneous enhancement. During the portal phase, 34 nodules showed hypoenhancement, and 1 showed isoenhancement. Hypoenhancement during the late phase was observed in all cases. Ten patients had a misdiagnosis of intrahepatic cholangiocarcinoma.ConclusionsIntrahepatic cholangiocarcinoma up to 3 cm may display a variety of arterial enhancement patterns on contrast‐enhanced sonography. However, some other nodules may manifest findings similar to those of intrahepatic cholangiocarcinoma.
Sonographic Features of Thyroid Follicular Carcinoma in Comparison With Thyroid Follicular Adenoma
Authors: Zhang Ji-Zhen , Hu Bing 
Published: January 2014

ObjectivesThe purpose of this study was to determine the sonographic features of thyroid follicular carcinoma in comparison with thyroid follicular adenoma.MethodsThis retrospective study included 36 pathologically proven follicular carcinomas (5 widely invasive and 31 minimally invasive) and 52 follicular adenomas in 88 patients who underwent thyroid surgery. We analyzed the sonographic features of each tumor, including maximum diameter, peripheral halo, echogenicity, echo texture, calcifications, and nodularity. The frequencies of the sonographic features were compared by χ2 and Fisher exact tests between follicular adenomas and carcinomas. The relative risk of malignancy was evaluated by logistic regression analysis.ResultsPredominantly solid contents, hypoechoic echogenicity, a heterogeneous echo texture, the presence of calcifications, and an absent or irregular thick halo were associated with follicular carcinoma (P < .05). Logistic regression analysis demonstrated that predominantly solid contents, a heterogeneous echo texture, and the presence of calcifications were associated with significant increases in the relative risk of follicular carcinoma (odds ratios, 9.4, 24.9, and 25.6, respectively; P < .01).ConclusionsSonography could provide useful information for differentiating follicular carcinoma from follicular adenoma.
Predictive Factors for Extrathyroidal Extension of Papillary Thyroid Carcinoma Based on Preoperative Sonography
Authors: Lee Chang Yoon , Kim Soo Jin , Ko Kyung Ran , Chung Ki-Wook , Lee Joo-Hyuk 
Published: January 2014

ObjectivesThe purpose of this study was to evaluate the diagnostic performance and predictive factors of extrathyroidal extension of papillary thyroid carcinoma based on preoperative sonography.MethodsPreoperative sonography was performed for 568 patients who underwent surgery for papillary thyroid cancer between May 2009 and December 2010. Patients' T stages based on preoperative sonography were compared with their T stages based on pathologic examination, and we statistically analyzed the discriminatory performance of sonography. Among the 568 patients enrolled in this study, we selected 320 patients in whom extrathyroidal extension was suspected on sonography. We analyzed several predictive factors for extrathyroidal extension.ResultsTwo hundred seventy‐five of the 568 patients were proven to have pathologic extrathyroidal extension of papillary thyroid cancer after surgery (75.9% diagnostic accuracy, 83.3% sensitivity, 68.9% specificity, 71.6% positive predictive value, and 81.5% negative predictive value). Of 320 patients with sonographically suspected extrathyroidal extension, a larger lesion size (P < .001) and a higher lymph node stage on sonography (P = .004) were the best predictors of extrathyroidal extension among the features that we measured. There were no significant differences in terms of the lesion site or thyroid parenchymal background echogenicity. Thyroid capsular protrusion had a higher predictive value than the abutting ratio (P = .001). However, increasing the abutting ratio enabled the prediction of extrathyroidal extension on sonography (P = .009).ConclusionsPreoperative sonography is a helpful tool for predicting pathologic extrathyroidal extension of papillary thyroid cancer. In particular, clinicians should focus on the lesion size, nodal stage, and abutment or capsular protrusion of the lesion while performing sonography because these are the most useful predictive factors for extrathyroidal extension.
Sonographic Detection of Thyroid Pyramidal Lobes Before Thyroid Surgery
Authors: Kim Dong Wook , Ha Tae Kwun , Park Ha Kyoung , Kang Taewoo 
Published: January 2014

ObjectivesThis study aimed to assess the rate of preoperative sonographic detection of thyroid pyramidal lobes with subsequent surgical findings as the reference standard.MethodsFrom January 2013 to March 2013, a single radiologist prospectively performed thyroid sonography to detect thyroid pyramidal lobes in consecutive patients who were scheduled for thyroid surgery on the same day. The location, anteroposterior and transverse diameters, length, and location of the upper end of each thyroid pyramidal lobe and its separation or contiguity with the main thyroid gland were investigated by thyroid sonography and surgery.ResultsThe types of thyroid surgery included total thyroidectomy (n = 85), subtotal thyroidectomy (n = 4), and hemithyroidectomy (n = 43). The surgical incidence of thyroid pyramidal lobes was 59.8% (79 of 132), and the sensitivity, specificity, positive and negative predictive values, and accuracy of sonography for detection of thyroid pyramidal lobes were 81.0%, 79.2%, 85.3%, 73.7%, and 80.3%, respectively. The mean values for the anteroposterior diameter, transverse diameter, and length of the 79 thyroid pyramidal lobes at surgery were 2.2, 6.2, and 26.5 mm, respectively, but these measurements did not show statistically significant correlations with the sonographic detection rate of thyroid pyramidal lobes.ConclusionsOur study indicates that thyroid sonography may be helpful for identifying the presence and location of thyroid pyramidal lobes.
Orientation of the Uterine Fundus in Reference to the Longitudinal Axis of the Body
Authors: Sakhel Khaled , Sinkovskaya Elena , Horton Sharon , Beydoun Hind , Chauhan Suneet P. , Abuhamad Alfred Z. 
Published: January 2014

ObjectivesThe aim of this pilot study was to measure the angle of rotation of the uterus at the fundus from horizontal using 3‐dimensional sonography in women presenting for annual gynecologic examinations.MethodsA total of 51 patients participated in the study. All patients underwent transvaginal sonography, and 3‐dimensional volumes were acquired. The cervicouterine angle and the angle of rotation at the fundus were measured.ResultsThe uteri were noted to be anteverted in 64.7%, retroverted in 25.5%, and euverted in 9.8%. They were noted to be pointing toward the right side of the pelvis in 49.0%, to the left side in 39.2%, and at the midline in 11.8%. The median cervicouterine angle was 122° (interquartile range [IQR], 105°–137°). The median angle of rotation at the fundus away from horizontal in either a clockwise or counterclockwise direction on the transverse B‐plane was 10.4° (IQR, 7.1°–19.0°), with a maximal angle of 43°, and on the coronal C‐plane, it was 10.0° (IQR, 3.0°–20.0°), with a maximal angle of 43°. Noneuverted uteri were more likely to be rotated at the fundus.ConclusionsOur study reveals that, contrary to traditional thinking, the uterus can be rotated at the fundus in relation to the body (z‐axis) along the longitudinal axis of the cervical canal.
Use of Cerclage in Triplet Pregnancies With an Asymptomatic Short Cervix
Authors: Young Christopher M. , Stanisic Tatiana , Wynn Lisa Blair , Shrivastava Vineet L. , Haydon Michael L. , Wing Deborah A. 
Published: January 2014

ObjectivesThe purpose of this study was to compare the outcomes of triplet pregnancies in women with asymptomatic cervical shortening with and without a cervical cerclage.MethodsA retrospective review of all triplet pregnancies with biweekly serial cervical length surveillance was performed. Cervical shortening was defined as a cervical length of 2.5 cm or less before 24 weeks' gestation. Patients with cervical shortening managed with cerclage were compared to those managed expectantly. The primary outcome was the gestational age at delivery, with secondary outcomes including birth weight, neonatal intensive care unit length of stay, and composite neonatal outcome. Statistical significance was defined as P < .05.ResultsSixteen patients underwent cerclage placement versus 8 managed expectantly (control group). The median gestational ages at delivery were similar between the groups (cerclage, 31.3 weeks; interquartile range [IQR], 29.3–32.3 weeks; control, 29.8 weeks; IQR, 27.5–32.4 weeks; P = .71). The median birth weights were also similar between the groups (cerclage, 1283 g; IQR, 800–1626 g; control, 1109 g; IQR, 776–1500 g; P = .54). There was no significant difference in composite neonatal outcomes between the cerclage and control groups (P = .67).ConclusionsIn this limited case‐control study, we found no benefit in terms of pregnancy prolongation or neonatal outcomes with cerclage placement for triplet gestations complicated by an asymptomatic short cervix.
Nonrandom X Chromosome Inactivation Detection
Authors: Jones Julie R. 
Published: January 2014

AbstractX chromosome inactivation patterns may be clinically useful in assessing tumor clonality, determining carrier status for certain X‐linked disorders and evaluating the pathogenicity of a genetic variant identified in an X‐linked gene. The protocols in this unit utilize the highly polymorphic trinucleotide repeat within the first exon of the human androgen receptor gene (AR) and the methylation‐sensitive restriction enzyme HpaII to distinguish between the maternal and paternal alleles and simultaneously determine their methylation status. The data obtained from these protocols can be used to calculate the ratio of inactivation between the two alleles that ultimately reflects whether a female has a random or nonrandom pattern of X chromosome inactivation. Curr. Protoc. Hum. Genet. 80:9.7.1‐9.7.7. © 2014 by John Wiley & Sons, Inc.
Anisotropy beneath a highly extended continental rift
Authors: Eilon Zachary , Abers Geoffrey A. , Jin Ge , Gaherty James B. 
Published: January 2014

AbstractWe have employed shear wave splitting techniques to image anisotropy beneath the D'Entrecasteaux Islands, in southeastern Papua New Guinea. Our results provide a detailed picture of the extending continent that lies immediately ahead of a propagating mid‐ocean ridge tip; we image the transition from continental to oceanic extension. A dense shear wave splitting data set from a 2010 to 2011 passive‐source seismic deployment is analyzed using single and multichannel methods. Splitting delay times of 1–1.5 s are observed and fast axes of anisotropy trending N‐S, parallel to rifting direction, predominate the results. This trend is linked to lattice‐preferred orientation of olivine, primarily in the shallow convecting mantle, driven by up to 200 km of N‐S continental extension ahead of the westward‐propagating Woodlark Rift. This pattern differs from several other continental rifts that evince rift‐strike‐parallel fast axes and is evident despite the complex recent tectonic history. We contend that across most of this rift, the unusually high rate and magnitude of extension has been sufficient to produce a regime change to a mid‐ocean‐ridge‐like mantle fabric. Stations in the south of our array show more complex splitting that might be related to melt or to complex inherited structure at the edge of the extended region.
The response to MJO‐like forcing in a nonlinear shallow‐water model
Authors: Bao Ming , Hartmann Dennis L. 
Published: January 2014

AbstractThis study examines the response to Madden‐Julian Oscillation (MJO)‐like heat forcing in a nonlinear shallow‐water model, including monopolar heating source traveling eastward with an around the world period of 48 days and dipolar heating with zonal wave period of 48 days, with zonal wave number 2 confined in longitude to the MJO active regions. A jet localized in the Pacific is compared to a zonally uniform boreal basic flow. The results show that the Rossby wave response downstream exhibits intensified quasi‐stationary anomalies in the Pacific jet exit region when the MJO‐like heat forcing passes the Maritime Continent, in accord with the observational analysis by Adames and Wallace (2014). The dynamical mechanism suggested in this study can be used to interpret the intraseasonal MJO‐Pacific North American pattern coherence and other extratropical intraseasonal events.
Pressure‐induced enhancement of proton conduction in brucite
Authors: Guo Xinzhuan , Yoshino Takashi 
Published: January 2014

AbstractThe electrical conductivity of single‐crystal brucite was measured as a function of pressure and temperature (P‐T) using impedance spectroscopy (IS). IS measurements demonstrated that electrical conductivity perpendicular to the c axis is nearly half order of magnitude higher than that parallel to the c axis under the same P‐T conditions. Electrical conductivity increased by 2 orders of magnitude during compression from 3.7 to 11 GPa, irrespective of crystallographic direction. However, the conductivity increase with pressure became less significant upon further compression from 11 to 13 GPa. The pressure effect is closely related to the interactions between neighboring hydroxyls. The ratio of free protons to total hydrogen increases from 2% to 33% when pressure increases from 3.7 to 13 GPa at 950 K. This indicates that most of the protons are bound within the crystal structure at low pressures, whereas more protons become free and mobile at higher pressures.
Mobilization of optically invisible dissolved organic matter in response to rainstorm events in a tropical forest headwater river
Authors: Pereira Ryan , Isabella Bovolo C. , Spencer Robert G. M. , Hernes Peter J. , Tipping Edward , Vieth‐Hillebrand Andrea , Pedentchouk Nikolai , Chappell Nick A. , Parkin Geoff , Wagner Thomas 
Published: January 2014

AbstractThis study emphasizes the importance of rainstorm events in mobilizing carbon at the soil‐stream interface from tropical rainforests. Half‐hourly geochemical/isotopic records over a 13.5 h period from a 20 km2 tropical rainforest headwater in Guyana show an order of magnitude increase in dissolved organic carbon (DOC) concentration in less than 30 mins (10.6–114 mg/L). The composition of DOC varies significantly and includes optically invisible dissolved organic matter (iDOM) that accounts for a large proportion (4–89%) of the total DOC, quantified using size exclusion chromatography (SEC). SEC suggests that iDOM is comprised of low molecular weight organic moieties, which are likely sourced from fresh leaf litter and/or topsoil, as shown in soils from the surrounding environment. Although poorly constrained at present, the presence of iDOM further downstream during the wet season suggests that this organic matter fraction may represent an unquantified source of riverine CO2 outgassing in tropical headwaters, requiring further consideration.
Energy coupling during the August 2011 magnetic storm
Authors: Huang C. Y. , Su Y.‐J. , Sutton E. K. , Weimer D. R. , Davidson R. L. 
Published: January 2014

AbstractWe present results from an analysis of high‐latitude ionosphere‐thermosphere (IT) coupling to the solar wind during a moderate magnetic storm which occurred on 5–6 August 2011. During the storm, a multipoint set of observations of the ionosphere and thermosphere was available. We make use of ionospheric measurements of electromagnetic and particle energy made by the Defense Meteorological Satellite Program and neutral densities measured by the Gravity Recovery and Climate Experiment satellite to infer (1) the energy budget and (2) timing of the energy transfer process during the storm. We conclude that the primary location for energy input to the IT system may be the extremely high latitude region. We suggest that the total energy available to the IT system is not completely captured either by observation or empirical models.
Chorus wave scattering responsible for the Earth's dayside diffuse auroral precipitation: A detailed case study
Authors: Ni Binbin , Bortnik Jacob , Nishimura Yukitoshi , Thorne Richard M. , Li Wen , Angelopoulos Vassilis , Ebihara Yusuke , Weatherwax Allan T. 
Published: January 2014

AbstractThe diffuse aurora is an almost permanent feature in the Earth's upper polar atmosphere, providing the major source of ionizing energy input into the high‐latitude region. Previous theoretical and observational studies have demonstrated that whistler mode chorus scattering primarily accounts for intense nightside diffuse auroral precipitation within ~ 8 RE, but what causes the dayside diffuse aurora remains poorly understood. Using conjugate satellite wave and particle observations on 13 August 2009 from the Time History of Events and Macroscale Interactions during Substorms spacecraft and ground‐based all‐sky imager measurements at the South Pole on the dayside, we perform a quantitative analysis of wave‐driven diffusion and electron precipitation. Our results demonstrate that the dayside chorus scattering was the dominant contributor to the observed dayside diffuse auroral precipitation and that the chorus wave intensity primarily controlled its brightness, indicating that dayside chorus can be the major driver of the Earth's dayside diffuse aurora. While further investigations are required to bring closure to the origin of the dayside diffuse aurora under differing solar wind conditions and geomagnetic situations, our finding is an important complement to recent work on the formation mechanism of the diffuse aurora and provides improved understanding of the roles of resonant wave‐particle interactions in diffuse auroral precipitation pattern on a global scale.
Northern hemispheric winter warming pattern after tropical volcanic eruptions: Sensitivity to the ozone climatology
Authors: Muthers S. , Anet J. G. , Raible C. C. , Brönnimann S. , Rozanov E. , Arfeuille F. , Peter T. , Shapiro A. I. , Beer J. , Steinhilber F. , Brugnara Y. , Schmutz W. 
Published: January 2014

AbstractAn important key for the understanding of the dynamic response to large tropical volcanic eruptions is the warming of the tropical lower stratosphere and the concomitant intensification of the polar vortices. Although this mechanism is reproduced by most general circulation models today, most models still fail in producing an appropriate winter warming pattern in the Northern Hemisphere. In this study ensemble sensitivity experiments were carried out with a coupled atmosphere‐ocean model to assess the influence of different ozone climatologies on the atmospheric dynamics and in particular on the northern hemispheric winter warming. The ensemble experiments were perturbed by a single Tambora‐like eruption. Larger meridional gradients in the lower stratospheric ozone favor the coupling of zonal wind anomalies between the stratosphere and the troposphere after the eruption. The associated sea level pressure, temperature, and precipitation patterns are more pronounced and the northern hemispheric winter warming is highly significant. Conversely, weaker meridional ozone gradients lead to a weaker response of the winter warming and the associated patterns. The differences in the number of stratosphere‐troposphere coupling events between the ensembles experiments indicate a nonlinear response behavior of the dynamics with respect to the ozone and the volcanic forcing.
The effects of temperature and nitrogen and sulfur additions on carbon accumulation in a nutrient‐poor boreal mire: Decadal effects assessed using 210Pb peat chronologies
Authors: Olid Carolina , Nilsson Mats B. , Eriksson Tobias , Klaminder Jonatan 
Published: January 2014

AbstractBoreal peatlands are a major long‐term reservoir of atmospheric carbon (C) and play an important role in the global C cycle. It is unclear how C accumulation in peatlands responds to changing temperatures and nutrients (specifically, nitrogen and sulfur). In this study, we assessed how the C input rate and C accumulation rate in decadal old peat layers respond to increased air temperatures (+3.6°C) during the growing season and the annual additions of nitrogen (N) and sulfur (S) (30 and 20 kg ha−1 yr−1, respectively) over 12 years of field treatments in a boreal mire. An empirical mass balance model was applied to 210Pb‐dated peat cores to evaluate changes in C inputs, C mass loss, and net C accumulation rates in response to the treatments. We found that (i) none of the treatments generated a significant effect on peat mass loss decay rates, (ii) C input rates were positively affected by N additions and negatively affected by S additions, (iii) the C accumulation rate in the uppermost (10 to 12 cm) peat was increased by N additions and decreased by S additions, and (iv) only air temperature significantly affected the main effects induced by N and S additions. Based on our findings, we argue that C accumulation rates in surface peat layers of nutrient‐poor boreal mires can increase despite the predicted rise in air temperatures as long as N loads increase and acid atmospheric S remains low.