bluuebunny/crossref_metadata_2025_split huggingface dataset:
Key drivers of patient satisfaction in lumbar spine surgery
Authors: Levin Jay M. , Winkelman Robert D. , Tanenbaum Joseph E. , Benzel Edward C. , Mroz Thomas E. , Steinmetz Michael P. 
Published: March 2018

OBJECTIVEThe Patient Experience of Care, composed of 9 dimensions derived from the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey, is being used by the Centers for Medicare & Medicaid Services to adjust hospital reimbursement. Currently, there are minimal data on how scores on the constituent HCAHPS items impact the global dimension of satisfaction, the Overall Hospital Rating (OHR). The purpose of this study was to determine the key drivers of overall patient satisfaction in the setting of inpatient lumbar spine surgery.METHODSDemographic and preoperative patient characteristics were obtained. Patients selecting a top-box score for OHR (a 9 or 10 of 10) were considered to be satisfied with their hospital experience. A baseline multivariable logistic regression model was then developed to analyze the association between patient characteristics and top-box OHR. Then, multivariable logistic regression models adjusting for patient-level covariates were used to determine the association between individual components of the HCAHPS survey and a top-box OHR.RESULTSA total of 453 patients undergoing lumbar spine surgery were included, 80.1% of whom selected a top-box OHR. Diminishing overall health status (OR 0.63, 95% CI 0.43–0.91) was negatively associated with top-box OHR. After adjusting for potential confounders, the survey items that were associated with the greatest increased odds of selecting a top-box OHR were: staff always did everything they could to help with pain (OR 12.5, 95% CI 6.6–23.7), and nurses were always respectful (OR 11.0, 95% CI 5.3–22.6).CONCLUSIONSPatient experience of care is increasingly being used to determine hospital and physician reimbursement. The present study analyzed the key drivers of patient experience among patients undergoing lumbar spine surgery and found several important associations. Patient overall health status was associated with top-box OHR. After adjusting for potential confounders, staff always doing everything they could to help with pain and nurses always being respectful were the strongest predictors of overall satisfaction in this population. These findings highlight opportunities for quality improvement efforts in the spine care setting.
Intraoperative use of transcranial motor/sensory evoked potential monitoring in the clipping of intracranial aneurysms: evaluation of false-positive and false-negative cases
Authors: Chung Jaewoo , Park Wonhyoung , Hong Seok Ho , Park Jung Cheol , Ahn Jae Sung , Kwun Byung Duk , Lee Sang-Ahm , Kim Sung-Hoon , Jeon Ji-Ye 
Published: March 2018

OBJECTIVESomatosensory and motor evoked potentials (SEPs and MEPs) are often used to prevent ischemic complications during aneurysm surgeries. However, surgeons often encounter cases with suspicious false-positive and false-negative results from intraoperative evoked potential (EP) monitoring, but the incidence and possible causes for these results are not well established. The aim of this study was to investigate the efficacy and reliability of EP monitoring in the microsurgical treatment of intracranial aneurysms by evaluating false-positive and false-negative cases.METHODSFrom January 2012 to April 2016, 1514 patients underwent surgery for unruptured intracranial aneurysms (UIAs) with EP monitoring at the authors’ institution. An EP amplitude decrease of 50% or greater compared with the baseline amplitude was defined as a significant EP change. Correlations between immediate postoperative motor weakness and EP monitoring results were retrospectively reviewed. The authors calculated the sensitivity, specificity, and positive and negative predictive values of intraoperative MEP monitoring, as well as the incidence of false-positive and false-negative results.RESULTSEighteen (1.19%) of the 1514 patients had a symptomatic infarction, and 4 (0.26%) had a symptomatic hemorrhage. A total of 15 patients showed motor weakness, with the weakness detected on the immediate postoperative motor function test in 10 of these cases. Fifteen false-positive cases (0.99%) and 8 false-negative cases (0.53%) were reported. Therefore, MEP during UIA surgery resulted in a sensitivity of 0.10, specificity of 0.94, positive predictive value of 0.01, and negative predictive value of 0.99.CONCLUSIONSIntraoperative EP monitoring has high specificity and negative predictive value. Both false-positive and false-negative findings were present. However, it is likely that a more meticulously designed protocol will make EP monitoring a better surrogate indicator of possible ischemic neurological deficits.
Validation of diffusion tensor imaging tractography to visualize the dentatorubrothalamic tract for surgical planning
Authors: Nowacki Andreas , Schlaier Jürgen , Debove Ines , Pollo Claudio 
Published: March 2018

OBJECTIVEThe dentatorubrothalamic tract (DRTT) has been suggested as the anatomical substrate for deep brain stimulation (DBS)–induced tremor alleviation. So far, little is known about how accurately and reliably tracking results correspond to the anatomical DRTT. The objective of this study was to systematically investigate and validate the results of different tractography approaches for surgical planning.METHODSThe authors retrospectively analyzed 4 methodological approaches for diffusion tensor imaging (DTI)–based fiber tracking using different regions of interest in 6 patients with essential tremor. Tracking results were analyzed and validated with reference to MRI-based anatomical landmarks, were projected onto the stereotactic atlas of Morel at 3 predetermined levels (vertical levels −3.6, −1.8, and 0 mm below the anterior commissure–posterior commissure line), and were correlated to clinical outcome.RESULTSThe 4 different methodologies for tracking the DRTT led to divergent results with respect to the MRI-based anatomical landmarks and when projected onto the stereotactic atlas of Morel. There was a statistically significant difference in the lateral and anteroposterior coordinates at the 3 vertical levels (p < 0.001, 2-way ANOVA). Different fractional anisotropy values ranging from 0.1 to 0.46 were required for anatomically plausible tracking results and led to varying degrees of success. Tracking results were not correlated to postoperative tremor reduction.CONCLUSIONSDifferent tracking methods can yield results with good anatomical approximation. The authors recommend using 3 regions of interest including the dentate nucleus of the cerebellum, the posterior subthalamic area, and the precentral gyrus to visualize the DRTT. Tracking results must be cautiously evaluated for anatomical plausibility and accuracy in each patient.
Value of pituitary gland MRI at 7 T in Cushing’s disease and relationship to inferior petrosal sinus sampling: case report
Authors: Law Meng , Wang Regina , Liu Chia-Shang J. , Shiroishi Mark S. , Carmichael John D. , Mack William J. , Weiss Martin , Wang Danny J. J. , Toga Arthur W. , Zada Gabriel 
Published: March 2018

Cushing’s disease is caused by adrenocorticotrophic hormone (ACTH)–secreting pituitary adenomas, which are often difficult to identify on standard 1.5-T or 3-T MRI, including dynamic contrast imaging. Inferior petrosal and cavernous sinus sampling remains the gold standard for MRI-negative Cushing’s disease.The authors report on a 27-year-old woman with Cushing’s disease in whom the results of standard 1.5-T and 3-T MRI, including 1.5-T dynamic contrast imaging, were negative. Inferior petrosal sinus sampling showed a high central-to-peripheral ACTH ratio (148:1) as well as a right-to-left ACTH gradient (19:1), suggesting a right-sided pituitary microadenoma. The patient underwent 7-T MRI, which showed evidence of a right-sided pituitary lesion with focal hypoenhancement not visualized on 1.5-T or 3-T MRI. The patient underwent an endoscopic endonasal transsphenoidal operation, with resection of a right-sided pituitary mass. Postoperatively, she developed clinical symptoms suggestive of adrenal insufficiency and a nadir cortisol level of 1.6 μg/dl on postoperative day 3, and hydrocortisone therapy was initiated. Permanent histopathology specimens showed Crooke’s hyaline change and ACTH-positive cells suggestive of an adenoma.MRI at 7 T may be beneficial in identifying pituitary microadenoma location in cases of standard 1.5-T and 3-T MRI-negative Cushing’s disease. In the future, 7-T MRI may preempt inferior petrosal sinus sampling and help in cases of standard and dynamic contrast 1.5-T and 3-T MRI-negative Cushing’s disease.
Laser interstitial thermal therapy of the spine: technical aspects
Authors: Moussazadeh Nelson , Evans Linton T. , Grasu Roxana , Rhines Laurence D. , Tatsui Claudio E. 
Published: March 2018

Spinal laser interstitial thermal therapy has been developed as a minimally invasive modality to treat epidural spinal tumors percutaneously. The safe and effective use of this technology requires meticulous preoperative trajectory planning and an intraoperative workflow incorporating navigation and MR thermography. Instrumented stabilization can be performed during the same operation if needed. Operative considerations and technical aspects are reviewed.The video can be found here: https://youtu.be/P--frsag6gU.
Laser interstitial thermal therapy for an eloquent region supratentorial brain lesion
Authors: Sharma Mayur , Krivosheya Daria , Borghei-Razavi Hamid , Barnett Gene H. , Mohammadi Alireza M. 
Published: March 2018

Laser interstitial thermal therapy (LITT) is a minimally invasive stereotactic technique that causes tumor ablation using thermal energy. LITT has shown to be efficacious for the treatment of deep-seated brain lesions, including those near eloquent areas. In this video, the authors present the case of a 62-year-old man with a history of metastatic melanoma who presented with worsening right-sided hemiparesis. MRI revealed a contrast-enhancing lesion in left centrum semiovale in close proximity to corticospinal tracts, consistent with radiation necrosis. The authors review their stepwise technique of LITT with special attention to details for a lesion located near eloquent area.The video can be found here: https://youtu.be/ndrTgi6MXqE.
Contemporaneous biopsy and laser interstitial thermal therapy for two treatment-refractory brain metastases
Authors: Shah Ashish H. , Richardson Angela M. , Burks Joshua D. , Komotar Ricardo J. 
Published: March 2018

Recurrent treatment-refractory brain metastases can be treated with modern adjuvant therapies such as laser interstitial thermal therapy (LITT). Since previously radiated lesions may be indolent (treatment effect) or recurrent tumor, histological confirmation may be helpful. The authors present the utility of contemporaneous biopsy and LITT using intraoperative O-arm navigation in a patient who presented with multiple refractory metastases. The authors demonstrate the utility of O-arm navigation to confirm intraoperative biopsy and LITT placement. Concurrent stereotactic biopsy and LITT may be a safe and efficacious method for both the diagnosis and treatment of deep lesions that are unamenable to standard adjuvant treatment modalities.The video can be found here: https://youtu.be/SUY-qiahMyo.
Young Surface of Pluto’s Sputnik Planitia Caused by Viscous Relaxation
Authors: Wei Qiang , Hu Yongyun , Liu Yonggang , Lin Douglas N. C. , Yang Jun , Showman Adam P. 
Published: March 2018

Abstract
One of the most prominent features of Pluto observed by the New Horizon mission is the absence of craters on Sputnik Planitia (SP). Vigorous thermal convection could renew the SP surface with sufficient depth at a timescale of ∼500,000 years. Here we present numerical simulations demonstrating that craters can be removed much more quickly across all of SP by viscous relaxation of nitrogen (N2) ice. The timescale of relaxation is in years if the N2 layer is 4 km thick and the viscosity is as determined in the lab, and will increase to 104 years if the viscosity is 104 times larger than the measured value. For such high viscosity, the thermal convection will have a timescale of greater than 106 years if it happens at all, so that the relaxation timescale is still more than 2 orders of magnitude shorter. The relaxation timescale decreases with increasing thickness and temperature of the ice layer. The existence of pits on SP can be explained by the surface enhancement of viscosity. Such enhancement does not have significant influence on the relaxation timescale of craters with diameters greater than a few kilometers. Therefore, although convection is required to explain the polygon shapes, it may have a lesser role in the absence of craters on SP. The viscous relaxation mechanism can readily explain the nondetection of both craters and polygon shapes on the southeast SP.
Energy Dissipation in the Upper Atmospheres of TRAPPIST-1 Planets
Authors: Cohen Ofer , Glocer Alex , Garraffo Cecilia , Drake Jeremy J. , Bell Jared M. 
Published: March 2018

Abstract
We present a method to quantify the upper limit of the energy transmitted from the intense stellar wind to the upper atmospheres of three of the TRAPPIST-1 planets (e, f, and g). We use a formalism that treats the system as two electromagnetic regions, where the efficiency of the energy transmission between one region (the stellar wind at the planetary orbits) to the other (the planetary ionospheres) depends on the relation between the conductances and impedances of the two regions. Since the energy flux of the stellar wind is very high at these planetary orbits, we find that for the case of high transmission efficiency (when the conductances and impedances are close in magnitude), the energy dissipation in the upper planetary atmospheres is also very large. On average, the Ohmic energy can reach 0.5–1 W m−2, about 1% of the stellar irradiance and 5–15 times the EUV irradiance. Here, using constant values for the ionospheric conductance, we demonstrate that the stellar wind energy could potentially drive large atmospheric heating in terrestrial planets, as well as in hot Jupiters. More detailed calculations are needed to assess the ionospheric conductance and to determine more accurately the amount of heating the stellar wind can drive in close-orbit planets.
Heliosphere Responds to a Large Solar Wind Intensification: Decisive Observations from IBEX
Authors: McComas D. J. , Dayeh M. A. , Funsten H. O. , Heerikhuisen J. , Janzen P. H. , Reisenfeld D. B. , Schwadron N. A. , Szalay J. R. , Zirnstein E. J. 
Published: March 2018

Abstract
Our heliosphere—the bubble in the local interstellar medium produced by the Sun’s outflowing solar wind—has finally responded to a large increase in solar wind output and pressure in the second half of 2014. NASA’s Interstellar Boundary Explorer (IBEX) mission remotely monitors the outer heliosphere by observing energetic neutral atoms (ENAs) returning from the heliosheath, the region between the termination shock and heliopause. IBEX observed a significant enhancement in higher energy ENAs starting in late 2016. While IBEX observations over the previous decade reflected a general reduction of ENA intensities, indicative of a deflating heliosphere, new observations show that the large (∼50%), persistent increase in the solar wind dynamic pressure has modified the heliosheath, producing enhanced ENA emissions. The combination of these new observations with simulation results indicate that this pressure is re-expanding our heliosphere, with the termination shock and heliopause already driven outward in the locations closest to the Sun. The timing between the IBEX observations, a large transient pressure enhancement seen by Voyager 2, and the simulations indicates that the pressure increase propagated through the heliosheath, reflected off the heliopause, and the enhanced density of the solar wind filled the heliosheath behind it before generating significantly enhanced ENA emissions. The coming years should see significant changes in anomalous cosmic rays, galactic cosmic radiation, and the filtration of interstellar neutral atoms into the inner heliosphere.
A hydrological emulator for global applications – HE v1.0.0
Authors: Liu Yaling , Hejazi Mohamad , Li Hongyi , Zhang Xuesong , Leng Guoyong 
Published: March 2018

Abstract. While global hydrological models (GHMs) are very useful in exploring water resources and interactions between the Earth and human systems, their use often requires numerous model inputs, complex model calibration, and high computation costs. To overcome these challenges, we construct an efficient open-source and ready-to-use hydrological emulator (HE) that can mimic complex GHMs at a range of spatial scales (e.g., basin, region, globe). More specifically, we construct both a lumped and a distributed scheme of the HE based on the monthly abcd model to explore the tradeoff between computational cost and model fidelity. Model predictability and computational efficiency are evaluated in simulating global runoff from 1971 to 2010 with both the lumped and distributed schemes. The results are compared against the runoff product from the widely used Variable Infiltration Capacity (VIC) model. Our evaluation indicates that the lumped and distributed schemes present comparable results regarding annual total quantity, spatial pattern, and temporal variation of the major water fluxes (e.g., total runoff, evapotranspiration) across the global 235 basins (e.g., correlation coefficient r between the annual total runoff from either of these two schemes and the VIC is  > 0.96), except for several cold (e.g., Arctic, interior Tibet), dry (e.g., North Africa) and mountainous (e.g., Argentina) regions. Compared against the monthly total runoff product from the VIC (aggregated from daily runoff), the global mean Kling–Gupta efficiencies are 0.75 and 0.79 for the lumped and distributed schemes, respectively, with the distributed scheme better capturing spatial heterogeneity. Notably, the computation efficiency of the lumped scheme is 2 orders of magnitude higher than the distributed one and 7 orders more efficient than the VIC model. A case study of uncertainty analysis for the world's 16 basins with top annual streamflow is conducted using 100 000 model simulations, and it demonstrates the lumped scheme's extraordinary advantage in computational efficiency. Our results suggest that the revised lumped abcd model can serve as an efficient and reasonable HE for complex GHMs and is suitable for broad practical use, and the distributed scheme is also an efficient alternative if spatial heterogeneity is of more interest.
Damage during the 6–24 February 2017 Ayvacık (Çanakkale) earthquake swarm
Authors: Livaoğlu Ramazan , Timurağaoğlu Mehmet Ömer , Serhatoğlu Cavit , Döven Mahmud Sami 
Published: March 2018

Abstract. On 6 February 2017 an earthquake swarm began at the western end of Turkey.
This was the first recorded swarm in the Çanakkale region since
continuous seismic monitoring began in 1970. The number of earthquakes
located increased during the following 10 days. This paper describes the
output of a survey carried out in the earthquake-prone towns in the area of
Ayvacık, Çanakkale, Turkey, in February 2017 after the earthquakes.
Observations of traditional buildings were made on site at the rural area of
Ayvacık. A description of the main structural features and their effects on
the most frequently viewed damage modes were made according to in-plane,
out-of-plane behavior of the wall regarding construction practice, connection
type, etc. It was found that there were no convenient connections like cavity ties or sufficient mortar strength resulting in
decreased and/or lack of lateral load bearing capacity of the wall.
Furthermore, distribution maps of damaged/undamaged buildings according to
villages, damage ratios, structures and damage levels are generated.
Distribution maps showed that damage ratio of structures is higher in
villages close to epicenter and decrease away from epicenter except
Gülpınar, where past experiences and
development level affect the construction quality.
Time-variable gravity fields and ocean mass change from 37 months of kinematic Swarm orbits
Authors: Lück Christina , Kusche Jürgen , Rietbroek Roelof , Löcher Anno 
Published: March 2018

Abstract. Measuring the spatiotemporal variation of ocean mass allows for partitioning of volumetric sea level change, sampled by radar altimeters, into mass-driven and steric parts. The latter is related to ocean heat change and the current Earth's energy imbalance. Since 2002, the Gravity Recovery and Climate Experiment (GRACE) mission has provided monthly snapshots of the Earth's time-variable gravity field, from which one can derive ocean mass variability. However, GRACE has reached the end of its lifetime with data degradation and several gaps occurred during the last years, and there will be a prolonged gap until the launch of the follow-on mission GRACE-FO. Therefore, efforts focus on generating a long and consistent ocean mass time series by analyzing kinematic orbits from other low-flying satellites, i.e. extending the GRACE time series. Here we utilize data from the European Space Agency's (ESA) Swarm Earth Explorer satellites to derive and investigate ocean mass variations. For this aim, we use the integral equation approach with short arcs (Mayer-Gürr, 2006) to compute more than 500 time-variable gravity fields with different parameterizations from kinematic orbits. We investigate the potential to bridge the gap between the GRACE and the GRACE-FO mission and to substitute missing monthly solutions with Swarm results of significantly lower resolution. Our monthly Swarm solutions have a root mean square error (RMSE) of 4.0 mm with respect to GRACE, whereas directly estimating constant, trend, annual, and semiannual (CTAS) signal terms leads to an RMSE of only 1.7 mm. Concerning monthly gaps, our CTAS Swarm solution appears better than interpolating existing GRACE data in 13.5 % of all cases, when artificially removing one solution. In the case of an 18-month artificial gap, 80.0 % of all CTAS Swarm solutions were found closer to the observed GRACE data compared to interpolated GRACE data. Furthermore, we show that precise modeling of non-gravitational forces acting on the Swarm satellites is the key for reaching these accuracies. Our results have implications for sea level budget studies, but they may also guide further research in gravity field analysis schemes, including satellites not dedicated to gravity field studies.
Guess Who's Coming to Dinner—Stockbridge—August 5, 1850
Authors: Olson Les E. 
Published: March 2018

ABSTRACT
Despite all of the analysis of the initial meeting between Nathaniel Hawthorne and Herman Melville and the friendship that followed, the purpose of that first meeting is often dismissed with the excuse that “the origins of the party are wrapped in obscurity.” Analysis of friends' letters and memoirs of family members, however, reveal that the day was organized by Sophia Hawthorne and Harriet Field, a close friend of Hawthorne's old publisher John Louis O'Sullivan. While the intent of the organizers is not stated, the list of those invited implies that it was simply a celebration of Hawthorne's arrival in the Berkshires. The extension of a last-minute invitation to Melville, however, led to the friendship of the two great writers, the refinement of Melville's novel into something new and different, and its dedication to the genius of Nathaniel Hawthorne.