bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clinical benefits of diffusion tensor imaging in hydrocephalus
Authors: Ben-Sira Liat , Goder Noam , Bassan Haim , Lifshits Shlomi , Assaf Yaniv , Constantini Shlomi 
Published: May 2015

OBJECT
The object of this study was to use diffusion tensor imaging (DTI) to evaluate and characterize white matter changes in hydrocephalus.

METHODS
The authors performed a retrospective analysis of DTI in a cohort of patients with hydrocephalus (n = 35), 19 of whom had both pre- and postsurgical imaging studies. These patient’s DTI values were compared with values extracted from age-dependent trend lines computed from a healthy subject group (n = 70, age span 14 months-14 years). Several DTI parameters in different regions of interest (ROIs) were evaluated to find the most sensitive parameters for clinical decision making in hydrocephalus.

RESULTS
Compared with healthy controls, patients with active hydrocephalus had a statistically significant change in all DTI parameters. The most sensitive and specific DTI parameter for predicting hydrocephalus was axial diffusivity (λ1) measured at the level of the corona radiata. Diffusion tensor imaging parameters correlated with several conventional radiological parameters in the assessment of hydrocephalus but were not superior to them. There was no convincing correlation between clinical disease severity and DTI parameters. When examining the pre- and postsurgical effect, it was found that DTI may be a sensitive tool for estimating tissue improvement.

CONCLUSIONS
This large-cohort study with a multidisciplinary approach combining clinical, neurological, radiological, and multiple DTI parameters revealed the most sensitive DTI parameters for identifying hydrocephalus and suggested that they may serve as an important tool for the disorder’s quantitative radiological assessment.
Defining the inherent stability of degenerative spondylolisthesis: a systematic review
Authors: Simmonds Andrea M. , Rampersaud Y. Raja , Dvorak Marcel F. , Dea Nicolas , Melnyk Angela D. , Fisher Charles G. 
Published: May 2015

OBJECT
A range of surgical options exists for the treatment of degenerative lumbar spondylolisthesis (DLS). The chosen technique inherently depends on the stability of the DLS. Despite a substantial body of literature dedicated to the outcome analysis of numerous DLS procedures, no consensus has been reached on defining or classifying the disorder with respect to stability or the role that instability should play in a treatment algorithm. The purpose of this study was to define grades of stability and to develop a guide for deciding on the optimal approach in surgically managing patients with DLS.

METHODS
The authors conducted a qualitative systematic review of clinical or biomechanical analyses evaluating the stability of and surgical outcomes for DLS for the period from 1990 to 2013. Research focused on nondegenerative forms of spondylolisthesis or spinal stenosis without associated DLS was excluded. The primary extracted results were clinical and radiographic parameters indicative of DLS instability.

RESULTS
The following preoperative parameters are predictors of stability in DLS: restabilization signs (disc height loss, osteophyte formation, vertebral endplate sclerosis, and ligament ossification), no disc angle change or less than 3 mm of translation on dynamic radiographs, and the absence of low-back pain. The validity and magnitude of each parameter’s contribution can only be determined through appropriately powered prospective evaluation in the future. Identifying these parameters has allowed for the creation of a preliminary DLS instability classification (DSIC) scheme based on the preoperative assessment of DLS stability.

CONCLUSIONS
Spinal stability is an important factor to consider in the evaluation and treatment of patients with DLS. Qualitative assessment of the best available evidence revealed clinical and radiographic parameters for the creation of the DSIC, a decision aid to help surgeons develop a method of preoperative evaluation to better stratify DLS treatment options.
Magnetic Resonance Imaging in Hand Osteoarthritis: Intraobserver Reliability and Criterion Validity for Clinical and Structural Characteristics
Authors: Kortekaas Marion C. , Kwok Wing-Yee , Reijnierse Monique , Wolterbeek Ron , Bøyesen Pernille , van der Heijde Desiree , Bloem Johannes L. , Kloppenburg Margreet 
Published: May 2015

Objective.To investigate criterion validity and intraobserver reliability of magnetic resonance imaging (MRI) in hand osteoarthritis (HOA).Methods.In 16 patients with HOA (median age 57 yrs, 62% women, 13 with erosive OA), 3 Tesla MRI scans with gadolinium-chelate administration of right second to fifth distal interphalangeal/proximal interphalangeal joints were scored according to the Oslo HOA scoring method for synovial thickening, bone marrow lesions (BML), osteophytes, joint space narrowing (JSN), and erosions (grade 0–3). Ultrasound (US) was scored for synovial thickening and osteophytes, radiographs for osteophytes and JSN (Osteoarthritis Research Society International score), and anatomical phases (Verbruggen-Veys score). Pain was assessed during physical examination. Correlations of MRI with US and radiographic features were assessed with generalizability theory. With generalized estimating equations analyses, MRI features were associated with pain, adjusting for confounding.Results.Forty-three percent, 27%, 77%, and 61% of joints had synovial thickening (moderate/severe), BML, osteophytes, and erosions on MRI, respectively. Intraobserver reliability, assessed in 6 patients, was good (ICC 0.77–1.00). Correlations between osteophytes, JSN, and erosions on radiographs and MRI were moderate, substantial, and fair (ICC 0.53, 0.68, and 0.32, respectively); MRI showed more lesions than radiography. Correlation between synovial thickening and osteophytes on MRI and US was moderate (ICC 0.43 and 0.49, respectively). MRI was more sensitive for synovial thickening, US for osteophytes. Pain was associated with moderate/severe synovial thickening (adjusted OR 2.4, 95% CI 1.06–5.5), collateral ligaments (4.2, 2.2–8.3), BML (3.5, 1.6–7.7), erosions (4.5, 1.7–12.2), and osteophytes (2.4, 1.1–5.2).Conclusion.MRI is a reliable and valid method to assess inflammatory and structural features in HOA. It gives additional information over radiographs and US.
Days to Return to Participation After a Hamstrings Strain Among American Collegiate Soccer Players
Authors: Cross Kevin M. , Saliba Susan A. , Conaway Mark , Gurka Kelly K. , Hertel Jay 
Published: May 2015

Context
Among US collegiate soccer players, the incidence rate and the event characteristics of hamstrings strains differ between sexes, but comparisons in the return-to-participation (RTP) time have not been reported.

Objective
To compare the RTP time between male and female collegiate soccer players and analyze the influence of event characteristics on the RTP time for each sex.

Design
Descriptive epidemiology study.

Setting
Data were collected from collegiate teams that voluntarily participated in the National Collegiate Athletic Association Injury Surveillance System.

Patients or Other Participants
Collegiate soccer athletes who sustained 507 hamstrings strains (306 men, 201 women) during the 2004 through 2009 fall seasons.

Main Outcome Measure(s)
Nonparametric statistics were used to evaluate RTP time differences between sexes and among categories of each event characteristic (ie, time of season, practice or competition, player position). Negative binomial regression was used to model the RTP time for each sex. All analyses were performed separately for first-time and recurrent strains.

Results
We found no differences in the RTP time between sexes for first-time (median: men = 7.0 days, women = 6.0 days; P = .07) or recurrent (median: men = 11 days, women = 5.5 days; P = .06) hamstrings strains. For male players with first-time strains, RTP time was increased when the strain occurred during competition or the in-season/postseason and varied depending on the division of play. Among female players with first-time strains, we found no differences in RTP time within characteristics. For male players with recurrent hamstrings strains, the RTP time was longer when the injury occurred during the in-season/postseason. Among female players with recurrent strains, RTP time was longer for forwards than for midfielders or defenders.

Conclusions
Although we found no differences in the RTP time after hamstrings strains in male and female collegiate soccer players, each sex had unique event characteristics that influenced RTP time.
A summary of the BARREL campaigns: Technique for studying electron precipitation
Authors: Woodger L. A. , Halford A. J. , Millan R. M. , McCarthy M. P. , Smith D. M. , Bowers G. S. , Sample J. G. , Anderson B. R. , Liang X. 
Published: May 2015

AbstractThe Balloon Array for Radiation belt Relativistic Electron Losses (BARREL) studies the loss of energetic electrons from Earth's radiation belts. BARREL's array of slowly drifting balloon payloads was designed to capitalize on magnetic conjunctions with NASA's Van Allen Probes. Two campaigns were conducted from Antarctica in 2013 and 2014. During the first campaign in January and February of 2013, there were three moderate geomagnetic storms with SYM‐Hmin < −40 nT. Similarly, two minor geomagnetic storms occurred during the second campaign, starting in December of 2013 and continuing on into February of 2014. Throughout the two campaigns, BARREL observed electron precipitation over a wide range of energies and exhibiting temporal structure from hundreds of milliseconds to hours. Relativistic electron precipitation was observed in the dusk to midnight sector, and microburst precipitation was primarily observed near dawn. In this paper we review the two BARREL science campaigns and discuss the data products and analysis techniques as applied to relativistic electron precipitation observed on 19 January 2013.
Pore connectivity, electrical conductivity, and partial water saturation: Network simulations
Authors: Li M. , Tang Y. B. , Bernabé Y. , Zhao J. Z. , Li X. F. , Bai X. Y. , Zhang L. H. 
Published: May 2015

AbstractThe electrical conductivity of brine‐saturated rock is predominantly dependent on the geometry and topology of the pore space. When a resistive second phase (e.g., air in the vadose zone and oil/gas in hydrocarbon reservoirs) displaces the brine, the geometry and topology of the pore space occupied by the electrically conductive phase are changed. We investigated the effect of these changes on the electrical conductivity of rock partially saturated with brine. We simulated drainage and imbibition as invasion and bond percolation processes, respectively, in pipe networks assumed to be perfectly water‐wet. The simulations included the formation of a water film in the pipes invaded by the nonwetting fluid. During simulated drainage/imbibition, we measured the changes in resistivity index as well as a number of relevant microstructural parameters describing the portion of the pore space saturated with water. Except Euler topological number, all quantities considered here showed a significant level of “universality,” i.e., insensitivity to the type of lattice used (simple cubic, body‐centered cubic, or face‐centered cubic). Hence, the coordination number of the pore network appears to be a more effective measure of connectivity than Euler number. In general, the simulated resistivity index did not obey Archie's simple power law. In log‐log scale, the resistivity index curves displayed a substantial downward or upward curvature depending on the presence or absence of a water film. Our network simulations compared relatively well with experimental data sets, which were obtained using experimental conditions and procedures consistent with the simulations. Finally, we verified that the connectivity/heterogeneity model proposed by Bernabé et al. (2011) could be extended to the partial brine saturation case when water films were not present.
A modified Equivalent Source Dipole method to model partially distributed magnetic field measurements, with application to Mercury
Authors: Oliveira J. S. , Langlais B. , Pais M. A. , Amit H. 
Published: May 2015

AbstractHermean magnetic field measurements acquired over the northern hemisphere by the MErcury Surface Space ENvironment GEochemistry, and Ranging (MESSENGER) spacecraft provide crucial information on the magnetic field of the planet. We develop a new method, the Time Dependent Equivalent Source Dipole, to model a planetary magnetic field and its secular variation over a limited spatial region. Tests with synthetic data distributed on regular grids as well as at spacecraft positions show that our modeled magnetic field can be upward or downward continued in an altitude range of −300 to 1460 km for regular grids and in a narrower range of 10 to 970 km for spacecraft positions. They also show that the method is not sensitive to a very weak secular variation along MESSENGER orbits. We then model the magnetic field of Mercury during the first four individual sidereal days as measured by MESSENGER using the modified Equivalent Source Dipoles scheme and excluding the secular variation terms. We find a dominantly zonal field with small‐scale nonaxisymmetric features corotating with the Sun in the Mercury Body Fixed system and repeating under similar local time, suggestive of external origin. When modeling the field during one complete solar day, these small‐scale features decrease and the field becomes more axisymmetric. The lack of any coherent nonaxisymmetric feature recovered by our method, which was designed to allow for such small‐scale structures, provides strong evidence for the large‐scale and close‐to‐axisymmetry structure of the internal magnetic field of Mercury.
Isotopic and nutritional evidence for species‐ and site‐specific responses to N deposition and elevated CO2 in temperate forests
Authors: Silva Lucas C. R. , Gómez‐Guerrero Armando , Doane Timothy A. , Horwath William R. 
Published: May 2015

AbstractIn this study we show that the effect of rising atmospheric CO2 levels on forest productivity is influenced by changes in nutrient availability caused by nitrogen (N) deposition. We used a dual‐isotope approach (δ15N and δ13C), combined with dendrochronological and nutritional analyses, to evaluate the response of two dominant tree species in natural forest ecosystems near Mexico City (Pinus hartwegii—pine; Abies religiosa—fir). Our analysis focuses on changes that occurred over the past 50 years at two sites, one under high and one under low N deposition rates. Analyses of carbon isotope composition indicate increasing water‐use efficiency in response to rising CO2 levels for both species and sites but this effect did not lead to improved tree growth. The magnitude and direction of shifts in 13C discrimination indicate a process of acclimation that varied with the rate of N deposition and species traits. Since the 1960s, strong negative responses to N deposition have been observed in fir trees, which showed altered foliar nutrition and growth decline, while the negative impacts of N deposition on pine trees remained undetectable until the 1990s. In recent years, both species have shown significant growth decline under high N deposition despite increasing atmospheric CO2. Multivariate analysis of leaf nutrients indicates that growth decline was prompted by depleted soil macronutrient (P, K, and Ca) and micronutrient (Cu, Fe, Zn, and Mn) availability. At both sites, fir trees were a better indicator of N deposition due to differences in canopy rainfall interception.
Determination of low B/Ca ratios in carbonates using ICP‐QQQ
Authors: Diez Fernández Silvia , Ruiz Encinar Jorge , Sanz‐Medel Alfredo , Isensee Kirsten , Stoll Heather M. 
Published: May 2015

AbstractThe very low B/Ca ratios characteristic of some natural biogenic carbonates, are of interest for research in ocean acidification but represent an analytical challenge. We describe a method using a novel instrument configuration (ICP‐QQQ), for which we are not aware of any previously published geological applications, and for coccoliths, a sample type unique in its low B content and organic phases. Detection limits as low as 0.41 µmol/mol were achieved. Isobaric interferences, out of the reach even for SF‐ICP‐MS, can be solved using this instrument, which permits the safe measurement of the lowest abundance Ca isotope (46Ca). This allows maximizing the B concentration measured (matrix concentration up to 800 ppm Ca) while maintaining both B and Ca signals in counting mode. More significantly for low B samples, the ICP‐QQQ is also able to overcome the interference of the ubiquitous 12C tail on the 11B mass, which otherwise leads to significant overestimates at very low B concentrations. This could be a reason for the significantly lower B/Ca ratios observed for the low B content interlaboratory calibration standards (Carrara and OKA), while matching for the high B content standards was good. Finally, results obtained in the analysis of coccoliths grown in laboratory culture seems to corroborate that SIMS analysis of the samples mounted in Indium leads also to B/Ca overestimates due to porosity effects, as previously observed using LA‐ICP‐MS. This approach also permits the interference‐free measurement of P/Ca and S/Ca ratios, which could be used as indicators of the complete removal of the organic matter from the samples.
Isopycnal mixing by mesoscale eddies significantly impacts oceanic anthropogenic carbon uptake
Authors: Gnanadesikan Anand , Pradal Marie‐Aude , Abernathey Ryan 
Published: May 2015

AbstractAnthropogenic carbon dioxide uptake varies across Earth System Models for reasons that have remained obscure. When varied within a single model, the lateral eddy mixing coefficient ARedi produces a range of uptake similar to the modeled range. The highest uptake, resulting from a simulation with a constant ARedi of 2400 m2/s, simulates 15% more historical carbon uptake than a model with ARedi = 400 m2/s. A sudden doubling in carbon dioxide produces a 21% range in carbon uptake across the models. Two spatially dependent representations of ARedi produce uptake that lies in the middle of the range of constant values despite predicting very large values in the subtropical gyres. One‐dimensional diffusive models of the type used for integrated assessments can be fit to the simulations, with ARedi accounting for a substantial fraction of the effective vertical diffusion. Such models, however, mask significant regional changes in stratification and biological carbon storage.
Reconsidering emissions of ammonia from chemical fertilizer usage in Midwest USA
Authors: Balasubramanian Srinidhi , Koloutsou‐Vakakis Sotiria , McFarland D. Michael , Rood Mark J. 
Published: May 2015

AbstractWe present alternative methods for estimating spatial surrogates and temporal factors for ammonia (NH3) emissions from chemical fertilizer usage (CFU), in the USA, at spatial and temporal scales used to simulate regional air quality and deposition of reactive nitrogen to ecosystems. The newly developed Improved Spatial Surrogate (ISS) method incorporates year‐specific fertilizer sales data, high resolution and year‐specific crop maps, and local crop nitrogen demands to allocate NH3 emissions at 4 km × 4 km grid cells. Results are compared with the commonly used gridded emission estimates by the Sparse Matrix Operator Kernel Emissions (SMOKE) preprocessor. NH3 emissions over Central Illinois in the USA, estimated at the 4 km × 4 km grid level in SMOKE and ISS methods, exhibit differences between −10% and 120%, with 58% of the grid cells exhibiting more than ±10% difference. Application of the ISS method for a larger domain over the Midwest USA, at 4 km × 4 km, reflected similar differences. We also employed the Denitrification Decomposition (DNDC) model to develop daily temporal factors of NH3 emissions from CFU using multi‐site and multi‐year analyses. Ratio of temporal factors estimated by SMOKE and DNDC methods is 0.54 ± 2.35, with DNDC identifying daily emission peaks 2.5–8 times greater than SMOKE. Identified emission peaks will be useful for future air quality modeling efforts to understand particulate matter episodes, as well as trends in regional particulate matter formation and nitrogen deposition for Midwest USA, using the proposed NH3 emissions inventory.
Smallpox Eradication
Authors: Henderson Donald A 
Published: May 2015

Abstract

In 1967, the World Health Assembly undertook to eradicate smallpox worldwide. Priority was given to this disease, because, throughout history, it had been the most devastating of all human infections. The key elements of program execution included the World Health Organization's (WHO's) success in recruiting the global cooperation of all nations, an especially effective vaccine, a new instrument that facilitated vaccination and a unique strategy for stopping the spread of smallpox infection. The goal of the program was to eliminate smallpox throughout the world in 10 years. It missed the goal by only a few months. Smallpox Eradication was declared by the WHO in 1980 and smallpox vaccination ceased everywhere. The program, its strategies and organisation provided the impetus for a heightened global program of immunisation that includes poliomyelitis, measles, diphtheria, pertussis and tetanus vaccines.

Key Concepts

The eradication of smallpox was far more than a mass vaccination campaign. It was an exceptionally complex effort requiring global participation of countries, practical and applied research, vision and time.

For a global program necessarily involving many different countries, there is need for a primary force to shape strategy, to goad national authorities into action and to redirect the overall program as necessary. WHO is a basic necessity.

A special effort for disease surveillance and epidemic control was a critical basic requirement.

A heat‐stable vaccine meeting international standards was essential.

Different countries and changing circumstances require continuing adaptation.

The strategies and policies developed during the smallpox program proved to be highly relevant to other vaccination programs.
Dulbecco, Renato
Authors: Grignolio Andrea 
Published: May 2015

Abstract
Dulbecco was an Italian‐born American pioneer in molecular virology who showed how tumour viruses can transform normal cells into cancer‐like cells. Dulbecco (1914–2012) invented the plaque assay technique to quantify the number of viral units in a laboratory culture, as well as an enriched synthetic medium suited for rapidly proliferating cell cultures, contributed to the development of polio vaccines in the early 1960s and discovered that the transformation into cancer cell after the infection of certain types of viruses (oncoviruses) was due to the incorporation of virus‐derived genes into the host‐cell genome. For his work, Dulbecco was awarded a shared Nobel Prize in medicine in 1975.