bluuebunny/crossref_metadata_2025_split huggingface dataset:
Physicochemical properties of bottom ice from Dome Fuji, inland East Antarctica
Authors: Ohno Hiroshi , Iizuka Yoshinori , Hori Akira , Miyamoto Atsushi , Hirabayashi Motohiro , Miyake Takayuki , Kuramoto Takayuki , Fujita Shuji , Segawa Takahiro , Uemura Ryu , Sakurai Toshimitsu , Suzuki Toshitaka , Motoyama Hideaki 
Published: June 2016

AbstractThe deepest ice in inland Antarctica is expected to preserve the oldest ice records and to potentially contain microorganisms. However, little is known about the physicochemical conditions in the deepest part of ice sheets. This study investigates the physicochemical properties of the bottom section (3000–3035 m) of the Dome Fuji inland ice core, which is located immediately above unfrozen bedrock. The ubiquitous presence of air hydrates and the water isotope composition of ice comparable to the upper main ice core show that the bottom ice is meteoric. However, ion concentrations exhibit abnormal drops at the greatest depths (approximately below 3033 m). In the same depth range, microscopic investigations reveal that considerable relocation of air hydrates and microinclusions (water‐soluble impurities) occurs, suggesting that the observed reduction in ion concentration results from the segregation of inclusions to ice grain boundaries and the subsequent discharge of chemicals through liquid‐water veins. Principal component analysis of ion data supports the meteoric‐ice hypothesis, suggesting that the bottom ice had similar original chemistry through all depths. Statistical analyses of chemical data suggest that the water‐soluble impurities attached to hydrates or dust (water‐insoluble), the ice‐soluble chemical species (such as chlorine), and solid particles are less affected by this chemical displacement phenomenon. It is also noteworthy that in the bottom ice, impurity chemicals, which are limiting nutrients for ice‐dwelling microorganisms, are concentrated largely to ice‐hydrate interfaces, where oxygen, another vital matter for aerobic microorganisms, is also enriched.
Sea ice leads in the Arctic Ocean: Model assessment, interannual variability and trends
Authors: Wang Q. , Danilov S. , Jung T. , Kaleschke L. , Wernecke A. 
Published: June 2016

AbstractSea ice leads in the Arctic are important features that give rise to strong localized atmospheric heating; they provide the opportunity for vigorous biological primary production, and predicting leads may be of relevance for Arctic shipping. It is commonly believed that traditional sea ice models that employ elastic‐viscous‐plastic (EVP) rheologies are not capable of properly simulating sea ice deformation, including lead formation, and thus, new formulations for sea ice rheologies have been suggested. Here we show that classical sea ice models have skill in simulating the spatial and temporal variation of lead area fraction in the Arctic when horizontal resolution is increased (here 4.5 km in the Arctic) and when numerical convergence in sea ice solvers is considered, which is frequently neglected. The model results are consistent with satellite remote sensing data and discussed in terms of variability and trends of Arctic sea ice leads. It is found, for example, that wintertime lead area fraction during the last three decades has not undergone significant trends.
Resilience of coastal wetlands to extreme hydrologic events in Apalachicola Bay
Authors: Tahsin Subrina , Medeiros Stephen C. , Singh Arvind 
Published: June 2016

AbstractExtreme hydrologic events such as hurricanes and droughts continuously threaten wetlands which provide key ecosystem services in coastal areas. The recovery time for vegetation after impact from these extreme events can be highly variable depending on the hazard type and intensity. Apalachicola Bay in Florida is home to a rich variety of saltwater and freshwater wetlands and is subject to a wide range of hydrologic hazards. Using spatiotemporal changes in Landsat‐based empirical vegetation indices, we investigate the impact of hurricane and drought on both freshwater and saltwater wetlands from year 2000 to 2015 in Apalachicola Bay. Our results indicate that saltwater wetlands are more resilient than freshwater wetlands and suggest that in response to hurricanes, the coastal wetlands took almost a year to recover, while recovery following a drought period was observed after only a month.
Waveform inversion of acoustic waves for explosion yield estimation
Authors: Kim K. , Rodgers A. 
Published: June 2016

AbstractWe present a new waveform inversion technique to estimate the energy of near‐surface explosions using atmospheric acoustic waves. Conventional methods often employ air blast models based on a homogeneous atmosphere, where the acoustic wave propagation effects (e.g., refraction and diffraction) are not taken into account, and therefore, their accuracy decreases with increasing source‐receiver distance. In this study, three‐dimensional acoustic simulations are performed with a finite difference method in realistic atmospheres and topography, and the modeled acoustic Green's functions are incorporated into the waveform inversion for the acoustic source time functions. The strength of the acoustic source is related to explosion yield based on a standard air blast model. The technique was applied to local explosions (<10 km) and provided reasonable yield estimates (<∼30% error) in the presence of realistic topography and atmospheric structure. The presented method can be extended to explosions recorded at far distance provided proper meteorological specifications.
Next‐generation solid‐state detectors for charged particle spectroscopy
Authors: Ogasawara K. , Livi S. A. , Allegrini F. , Broiles T. W. , Dayeh M. A. , Desai M. I. , Ebert R. W. , Llera K. , Vines S. K. , McComas D. J. 
Published: June 2016

AbstractThe performance of silicon avalanche photodiodes (APDs) and single crystal chemical vapor deposit diamond detectors (DDs) is reviewed in comparison with conventional silicon‐based solid‐state detectors (SSDs) from the perspective of space plasma applications. Although the low‐energy threshold and the energy resolution are equivalent to SSDs, DDs offer a high radiation tolerance and very low leakage currents due to a wider band gap than silicon. In addition, DDs can operate at higher temperatures, are insensitive to light (>226 nm), and are capable of timing analysis due to the higher intrinsic carrier mobility. APDs also offer several advantageous features. Specifically, APDs have a lower energy threshold (<0.9 keV) and a higher energy resolution (<0.7 keV full width at half maximum at room temperature), along with a linear response due to a strong electric field causing signal amplifications within the detector. Therefore, APDs can be used to detect lower energy particles, covering a larger portion of the energy spectrum than conventional SSDs. Further, the strong internal electric field gives them a subnanosecond response time by the charge mobility saturation, allowing them to make precise timing measurements of ions. These novel detector techniques can be potentially applied to improve the measurements of suprathermal particles, whose energies lie between typical ranges of conventional sensors for low‐energy plasmas and energetic particles. Although the origin and evolution of the suprathermal particles are the key to understanding the acceleration and heating processes in space plasma, they are not well understood due to the technical difficulties of making the measurement.
Horizontal variability of high‐frequency nonlinear internal waves in Massachusetts Bay detected by an array of seafloor pressure sensors
Authors: Thomas J. A. , Lerczak J. A. , Moum J. N. 
Published: June 2016

AbstractA two‐dimensional array of 14 seafloor pressure sensors was deployed to measure properties of tidally generated, nonlinear, high‐frequency internal waves over a 14 km by 12 km area west of Stellwagen Bank in Massachusetts Bay during summer 2009. Thirteen high‐frequency internal wave packets propagated through the region over 6.5 days (one packet every semidiurnal cycle). Propagation speed and direction of wave packets were determined by triangulation, using arrival times and distances between triads of sensor locations. Wavefront curvature ranged from straight to radially spreading, with wave speeds generally faster to the south. Waves propagated to the southwest, rotating to more westward with shoreward propagation. Linear theory predicts a relationship between kinetic energy and bottom pressure variance of internal waves that is sensitive to sheared background currents, water depth, and stratification. By comparison to seafloor acoustic Doppler current profiler measurements, observations nonetheless show a strong relationship between kinetic energy and bottom pressure variance. This is presumably due to phase‐locking of the wave packets to the internal tide that dominates background currents and to horizontally uniform and relatively constant stratification throughout the study. This relationship was used to qualitatively describe variations in kinetic energy of the high‐frequency wave packets. In general, high‐frequency internal wave kinetic energy was greater near the southern extent of wavefronts and greatly decreased upon propagating shoreward of the 40 m isobath.
Confronting the “Indian summer monsoon response to black carbon aerosol” with the uncertainty in its radiative forcing and beyond
Authors: Kovilakam Mahesh , Mahajan Salil 
Published: June 2016

AbstractWhile black carbon aerosols (BC) are believed to modulate the Indian monsoons, the radiative forcing estimate of BC suffers from large uncertainties globally. We analyze a suite of idealized experiments forced with a range of BC concentrations that span a large swath of the latest estimates of its global radiative forcing. Within those bounds of uncertainty, summer precipitation over the Indian region increases nearly linearly with the increase in BC burden. The linearity holds even as the BC concentration is increased to levels resembling those hypothesized in nuclear winter scenarios, despite large surface cooling over India and adjoining regions. The enhanced monsoonal circulation is associated with a linear increase in the large‐scale meridional tropospheric temperature gradient. The precipitable water over the region also increases linearly with an increase in BC burden, due to increased moisture transport from the Arabian sea to the land areas. The wide range of Indian monsoon response elicited in these experiments emphasizes the need to reduce the uncertainty in BC estimates to accurately quantify their role in modulating the Indian monsoons. The increase in monsoonal circulation in response to large BC concentrations contrasts earlier findings that the Indian summer monsoon may break down following a nuclear war.
Electrical stratigraphy of the WAIS Divide ice core: Identification of centimeter‐scale irregular layering
Authors: Fudge T. J. , Taylor Kendrick C. , Waddington Edwin D. , Fitzpatrick Joan J. , Conway Howard 
Published: June 2016

AbstractMultitrack electrical conductivity measurements imaged a continuous record of the two‐dimensional electrical stratigraphy for the deepest 40% of the WAIS Divide ice core (1956 m to 3405 m, 11.5 to 68 ka). The electrical stratigraphy showed clear banding driven primarily by annual variations. Centimeter‐scale pinched layers and other irregularities were concentrated between 2700 m and 2900 m (27 ka to 33 ka); below 2900 m, decreasing amplitude of conductance variations likely due to diffusion prevented confident interpretation of both annual and irregular layering. The effective diffusivity at −30°C is 2.2 × 10−8 m2 yr−1, approximately 5 times greater than for self‐diffusion of water molecules, implying diffusion at grain boundaries. The irregular layering indicates that the centimeter‐scale layering was disturbed in sections even though other records, such as atmospheric methane, indicate meter and larger layering is not compromised. Preservation of irregular layering at deposition is unlikely to be the cause of the identified irregular layering; instead, the irregular layering likely arises from variations in the deformation of ice.
Intravenous iron therapy in non‐anemic iron‐deficient menstruating adolescent females with fatigue
Authors: Sharma Ruchika , Stanek Joseph R. , Koch Terah L. , Grooms Linda , O'Brien Sarah H. 
Published: June 2016

Menstruating women, with or without underlying bleeding disorders, are at increased risk for developing iron deficiency‐related fatigue, even in the absence of anemia. Oral iron therapy has limitations which include poor absorption and non‐adherence due to gastrointestinal side effects. We performed a prospective clinical trial of post‐menarchal adolescent females with iron‐deficiency with or without mild anemia and fatigue who received a standardized regimen of intravenous iron sucrose. The baseline mean (SD) hemoglobin was 11.96 g dl−1 (1.05) in 20 girls (ages 14–21 years); with a range of 10.3–14.1 g dl−1. In this cohort, intravenous iron was well tolerated and patients demonstrated a sustained increase in ferritin levels with means (SD) of 13.4 ng ml−1 (13.1) at baseline to 141.5 ng ml−1 (104.5) at 6 weeks and 85.2 ng ml−1 (128.4) at 6 months after the infusions. We used a standardized (Peds QLTM Multidimensional) fatigue scale to objectively measure fatigue and proxy scores by parents with mean screening scores (SD) of 35.2 (16.8) and 31.9 (19.6), respectively. We demonstrated a clinically significant improvement both in patient as well as parent fatigue scores (in 19 out of 20 subjects) at 6 weeks (Mean (SD) 58.3 (21.3) [P < 0.0001] and 57 (24.4) [P < 0.0001], respectively); as well as 3 and 6 months after the iron infusions. In nonanemic patients, iron administration did not significantly influence hemoglobin concentration. Therefore, the fatigue‐reducing effects of iron therapy reflect the nonhematological functions of iron. Am. J. Hematol. 91:973–977, 2016. © 2016 Wiley Periodicals, Inc.
Health‐related quality of life and burden of fatigue in patients with primary immune thrombocytopenia by phase of disease
Authors: Efficace Fabio , Mandelli Franco , Fazi Paola , Santoro Cristina , Gaidano Gianluca , Cottone Francesco , Borchiellini Alessandra , Carpenedo Monica , Simula Maria Pina , Di Giacomo Valeria , Bergamaschi Micaela , Vincelli Iolanda Donatella , Rodeghiero Francesco , Ruggeri Marco , Scaramucci Laura , Rambaldi Alessandro , Cascavilla Nicola , Forghieri Fabio , Petrungaro Annamaria , Ditonno Paolo , Caocci Giovanni , Cirrincione Sonia , Mazzucconi Maria Gabriella 
Published: June 2016

The main objective of this study was to compare health‐related quality of life (HRQOL) of primary immune thrombocytopenia (pITP) patients with that of general population, overall, and by patient group (i.e., newly diagnosed, persistent, and chronic patients). Fatigue was also investigated as a secondary objective. Overall, 424 adult patients were enrolled in a multicenter observational study and the control group consisted of a representative sample from the general population. Propensity score matching plus further multivariate linear regression adjustment was used to compare HRQOL outcomes between pITP patients and general population. Mean age of patients was 54 years. Of those with HRQOL assessment, 99 patients (23.6%) were newly diagnosed, 53 (12.6%) were persistent, and 268 (63.8%) were chronic pITP patients. Comparison by patient group versus their respective peers in the general population revealed greater impairments in persistent pITP patients. Persistent pITP patients reported clinically meaningful impairments in physical functioning (−15; 95% CI −24.1 to −5.8; P = 0.002), social functioning (−15.3; 95% CI −25.5 to −5.1; P = 0.004), role physical (−28.4; 95% CI −43.1 to −13.7; P < 0.001), role emotional (−23.9; 95% CI −40.1 to −7.7; P = 0.004), and mental health scales (−11.3; 95% CI −21.2 to −1.4; P = 0.026) of the SF‐36 questionnaire. Higher fatigue severity was associated with lower physical and mental HRQOL outcomes. Our findings suggest that the burden of the disease and treatment might depend on the disease phase and that persistent pITP patients are the most vulnerable subgroup. Am. J. Hematol. 91:995–1001, 2016. © 2016 Wiley Periodicals, Inc.
The pressure difference between eye and brain changes with posture
Authors: Eklund Anders , Jóhannesson Gauti , Johansson Elias , Holmlund Petter , Qvarlander Sara , Ambarki Khalid , Wåhlin Anders , Koskinen Lars‐Owe D. , Malm Jan 
Published: June 2016

ObjectiveThe discovery of a posture‐dependent effect on the difference between intraocular pressure (IOP) and intracranial pressure (ICP) at the level of lamina cribrosa could have important implications for understanding glaucoma and idiopathic intracranial hypertension and could help explain visual impairments in astronauts exposed to microgravity. The aim of this study was to determine the postural influence on the difference between simultaneously measured ICP and IOP.MethodsEleven healthy adult volunteers (age = 46 ± 10 years) were investigated with simultaneous ICP, assessed through lumbar puncture, and IOP measurements when supine, sitting, and in 9° head‐down tilt (HDT). The trans–lamina cribrosa pressure difference (TLCPD) was calculated as the difference between the IOP and ICP. To estimate the pressures at the lamina cribrosa, geometrical distances were estimated from magnetic resonance imaging and used to adjust for hydrostatic effects.ResultsThe TLCPD (in millimeters of mercury) between IOP and ICP was 12.3 ± 2.2 for supine, 19.8 ± 4.6 for sitting, and 6.6 ± 2.5 for HDT. The expected 24‐hour average TLCPD on earth—assuming 8 hours supine and 16 hours upright—was estimated to be 17.3mmHg. By removing the hydrostatic effects on pressure, a corresponding 24‐hour average TLCPD in microgravity environment was simulated to be 6.7mmHg.InterpretationWe provide a possible physiological explanation for how microgravity can cause symptoms similar to those seen in patients with elevated ICP. The observed posture dependency of TLCPD also implies that assessment of the difference between IOP and ICP in upright position may offer new understanding of the pathophysiology of idiopathic intracranial hypertension and glaucoma. Ann Neurol 2016;80:269–276
Too good to treat? ischemic stroke patients with small computed tomography perfusion lesions may not benefit from thrombolysis
Authors: Bivard Andrew , Lou Min , Levi Christopher R. , Krishnamurthy Venkatesh , Cheng Xin , Aviv Richard I. , McElduff Patrick , Lin Longting , Kleinig Tim , O'Brien Billy , Butcher Kenneth , Jingfen Zhang , Jannes Jim , Dong Qiang , Parsons Mark W. 
Published: June 2016

ObjectiveAlthough commonly used in clinical practice, there remains much uncertainty about whether perfusion computed tomography (CTP) should be used to select stroke patients for acute reperfusion therapy. In this study, we tested the hypothesis that a small acute perfusion lesion predicts good clinical outcome regardless of thrombolysis administration.MethodsWe used a prospectively collected cohort of acute ischemic stroke patients being assessed for treatment with IV‐alteplase, who had CTP before a treatment decision. Volumetric CTP was retrospectively analyded to identify patients with a small perfusion lesion (<15ml in volume). The primary analysis was excellent 3‐month outcome in patients with a small perfusion lesion who were treated with alteplase compared to those who were not treated.ResultsOf 1526 patients, 366 had a perfusion lesion <15ml and were clinically eligible for alteplase (212 being treated and 154 not treated). Median acute National Institutes of Health Stroke Scale score was 8 in each group. Of the 366 patients with a small perfusion lesion, 227 (62%) were modified Rankin Scale (mRS) 0 to 1 at day 90. Alteplase‐treated patients were less likely to achieve 90‐day mRS 0 to 1 (57%) than untreated patients (69%; relative risk [RR] = 0.83; 95% confidence interval [CI], 0.71–0.97; p = 0.022) and did not have different rates of mRS 0 to 2 (72% treated patients vs 77% untreated; RR, 0.93; 95% CI, 0.82–1.95; p = 0.23).InterpretationThis large observational cohort suggests that a portion of ischemic stroke patients clinically eligible for alteplase therapy with a small perfusion lesion have a good natural history and may not benefit from treatment. Ann Neurol 2016;80:286–293
Seed‐competent high‐molecular‐weight tau species accumulates in the cerebrospinal fluid of Alzheimer's disease mouse model and human patients
Authors: Takeda Shuko , Commins Caitlin , DeVos Sarah L. , Nobuhara Chloe K. , Wegmann Susanne , Roe Allyson D. , Costantino Isabel , Fan Zhanyun , Nicholls Samantha B. , Sherman Alexis E. , Trisini Lipsanopoulos Ana T. , Scherzer Clemens R. , Carlson George A. , Pitstick Rose , Peskind Elaine R. , Raskind Murray A. , Li Ge , Montine Thomas J. , Frosch Matthew P. , Hyman Bradley T. 
Published: June 2016

ObjectiveCerebrospinal fluid (CSF) tau is an excellent surrogate marker for assessing neuropathological changes that occur in Alzheimer's disease (AD) patients. However, whether the elevated tau in AD CSF is just a marker of neurodegeneration or, in fact, a part of the disease process is uncertain. Moreover, it is unknown how CSF tau relates to the recently described soluble high‐molecular‐weight (HMW) species that is found in the postmortem AD brain and can be taken up by neurons and seed aggregates.MethodsWe have examined seeding and uptake properties of brain extracellular tau from various sources, including interstitial fluid (ISF) and CSF from an AD transgenic mouse model and postmortem ventricular and antemortem lumbar CSF from AD patients.ResultsWe found that brain ISF and CSF tau from the AD mouse model can be taken up by cells and induce intracellular aggregates. Ventricular CSF from AD patients contained a rare HMW tau species that exerted a higher seeding activity. Notably, the HMW tau species was also detected in lumbar CSF from AD patients, and its levels were significantly elevated compared to control subjects. HMW tau derived from CSF of AD patients was seed competent in vitro.InterpretationThese findings suggest that CSF from an AD brain contains potentially bioactive HMW tau species, giving new insights into the role of CSF tau and biomarker development for AD. Ann Neurol 2016;80:355–367
Highly Efficient, Selective, and Stable CO2 Electroreduction on a Hexagonal Zn Catalyst
Authors: Won Da Hye , Shin Hyeyoung , Koh Jaekang , Chung Jaehoon , Lee Hee Sang , Kim Hyungjun , Woo Seong Ihl 
Published: June 2016

AbstractElectrocatalytic CO2 conversion into fuel is a prospective strategy for the sustainable energy production. However, still many parts of the catalyst such as low catalytic activity, selectivity, and stability are challenging. Herein, a hierarchical hexagonal Zn catalyst showed highly efficient and, more importantly, stable performance as an electrocatalyst for selectively producing CO. Moreover, we found that its high selectivity for CO is attributed to morphology. In electrochemical analysis, Zn (101) facet is favorable to CO formation whereas Zn (002) facet favors the H2 evolution during CO2 electrolysis. Indeed, DFT calculations showed that (101) facet lowers a reduction potential for CO2 to CO by more effectively stabilizing a .COOH intermediate than (002) facet. This further suggests that tuning the crystal structure to control (101)/(002) facet ratio of Zn can be considered as a key design principle to achieve a desirable product from Zn catalyst.