bluuebunny/crossref_metadata_2025_split huggingface dataset:
Examining publication bias—a simulation-based evaluation of statistical tests on publication bias
Authors: Schneck Andreas 
Published: November 2017

Background
Publication bias is a form of scientific misconduct. It threatens the validity of research results and the credibility of science. Although several tests on publication bias exist, no in-depth evaluations are available that examine which test performs best for different research settings.

Methods
Four tests on publication bias, Egger’s test (FAT), p-uniform, the test of excess significance (TES), as well as the caliper test, were evaluated in a Monte Carlo simulation. Two different types of publication bias and its degree (0%, 50%, 100%) were simulated. The type of publication bias was defined either as file-drawer, meaning the repeated analysis of new datasets, or p-hacking, meaning the inclusion of covariates in order to obtain a significant result. In addition, the underlying effect (β = 0, 0.5, 1, 1.5), effect heterogeneity, the number of observations in the simulated primary studies (N = 100, 500), and the number of observations for the publication bias tests (K = 100, 1,000) were varied.

Results
All tests evaluated were able to identify publication bias both in the file-drawer and p-hacking condition. The false positive rates were, with the exception of the 15%- and 20%-caliper test, unbiased. The FAT had the largest statistical power in the file-drawer conditions, whereas under p-hacking the TES was, except under effect heterogeneity, slightly better. The CTs were, however, inferior to the other tests under effect homogeneity and had a decent statistical power only in conditions with 1,000 primary studies.

Discussion
The FAT is recommended as a test for publication bias in standard meta-analyses with no or only small effect heterogeneity. If two-sided publication bias is suspected as well as under p-hacking the TES is the first alternative to the FAT. The 5%-caliper test is recommended under conditions of effect heterogeneity and a large number of primary studies, which may be found if publication bias is examined in a discipline-wide setting when primary studies cover different research problems.
Acute ischemic preconditioning does not influence high-intensity intermittent exercise performance
Authors: Marocolo Isabela Coelho , da Mota Gustavo Ribeiro , Londe André Monteiro , Patterson Stephen D. , Barbosa Neto Octávio , Marocolo Moacir 
Published: November 2017

This study evaluated the acute effect of ischemic preconditioning (IPC) on a high-intensity intermittent exercise performance and physiological indicators in amateur soccer players. Thirteen players (21.5 ± 2 yrs) attended three trials separated by 3–5 days in a counterbalanced randomized cross-over design: IPC (4 × 5-min occlusion 220 mmHg/reperfusion 0 mmHg) in each thigh; SHAM (similar to the IPC protocol but “occlusion” at 20 mmHg) and control (seated during the same time of IPC). After 6-min of each trial (IPC, SHAM or control), the players performed the YoYo Intermittent Endurance Test level 2 (YoYoIE2). The distance covered in the YoYoIE2 (IPC 867 ± 205 m; SHAM 873 ± 212 m; control 921 ± 206 m) was not different among trials (p = 0.10), furthermore, lactate concentration and rate of perceived exertion did not differ (P > 0.05) among protocols. There were also no significant differences in either mean heart rate (HR) or peak HR (p > 0.05) for both IPC and SHAM compared to control. Therefore, we conclude that acute IPC does not influence high-intensity intermittent exercise performance in amateur soccer players and that rate of perceived exertion, heart rate and lactate do not differ between the intervention IPC, SHAM and control.
Observational Inferences of Lateral Eddy Diffusivity in the Halocline of the Beaufort Gyre
Authors: Meneghello Gianluca , Marshall John , Cole Sylvia T. , Timmermans Mary‐Louise 
Published: November 2017

AbstractUsing Ekman pumping rates mediated by sea ice in the Arctic Ocean's Beaufort Gyre (BG), the magnitude of lateral eddy diffusivities required to balance downward pumping is inferred. In this limit—that of vanishing residual‐mean circulation—eddy‐induced upwelling exactly balances downward pumping. The implied eddy diffusivity varies spatially and decays with depth, with values of 50–400 m2/s. Eddy diffusivity estimated using mixing length theory applied to BG mooring data exhibits a similar decay with depth and range of values from 100 m2/s to more than 600 m2/s. We conclude that eddy diffusivities in the BG are likely large enough to balance downward Ekman pumping, arresting the deepening of the gyre and suggesting that eddies play a zero‐order role in buoyancy and freshwater budgets of the BG.
The Active Role of the Ocean in the Temporal Evolution of Climate Sensitivity
Authors: Garuba Oluwayemi A. , Lu Jian , Liu Fukai , Singh Hansi A. 
Published: November 2017

AbstractThe temporal evolution of the effective climate sensitivity is shown to be influenced by the changing pattern of sea surface temperature (SST) and ocean heat uptake (OHU), which in turn have been attributed to ocean circulation changes. A set of novel experiments are performed to isolate the active role of the ocean by comparing a fully coupled CO2 quadrupling community Earth System Model (CESM) simulation against a partially coupled one, where the effect of the ocean circulation change and its impact on surface fluxes are disabled. The active OHU is responsible for the reduced effective climate sensitivity and weaker surface warming response in the fully coupled simulation. The passive OHU excites qualitatively similar feedbacks to CO2 quadrupling in a slab ocean model configuration due to the similar SST spatial pattern response in both experiments. Additionally, the nonunitary forcing efficacy of the active OHU (1.7) explains the very different net feedback parameters in the fully and partially coupled responses.
Very Oblique Whistler Mode Propagation in the Radiation Belts: Effects of Hot Plasma and Landau Damping
Authors: Ma Q. , Artemyev A. V. , Mourenas D. , Li W. , Thorne R. M. , Kletzing C. A. , Kurth W. S. , Hospodarsky G. B. , Reeves G. D. , Spence H. E. , Wygant J. 
Published: November 2017

AbstractSatellite observations of a significant population of very oblique chorus waves in the outer radiation belt have fueled considerable interest in the effects of these waves on energetic electron scattering and acceleration. However, corresponding diffusion rates are extremely sensitive to the refractive index N, controlled by hot plasma effects including Landau damping and wave dispersion modifications by suprathermal (15–100 eV) electrons. A combined investigation of wave and electron distribution characteristics obtained from the Van Allen Probes shows that peculiarities of the measured electron distribution significantly reduce Landau damping, allowing wave propagation with high N ∼ 100–200. Further comparing measured refractive indexes with theoretical estimates incorporating hot plasma corrections to the wave dispersion, we provide the first experimental demonstration that suprathermal electrons indeed control the upper limit of the refractive index of highly oblique whistler mode waves. Such results further support the importance of incorporating very oblique waves into radiation belt models.
Mapping Mantle Transition Zone Discontinuities Beneath the Central Pacific With Array Processing of SS Precursors
Authors: Yu Chunquan , Day Elizabeth A. , de Hoop Maarten V. , Campillo Michel , van der Hilst Robert D. 
Published: November 2017

AbstractWe image mantle transition zone (MTZ) discontinuities beneath the Central Pacific using ~120,000 broadband SS waveforms. With a wave packet‐based array processing technique (curvelet transform), we improve the signal‐to‐noise ratio of SS precursors and remove interfering phases, so that precursors can be identified and measured over a larger distance range. Removal of interfering phases reveals possible phase shifts in the underside reflection at the 660, that is, S660S, which if ignored could lead to biased discontinuity depth estimates. The combination of data quantity and improved quality allows improved imaging and uncertainty estimation. Time to depth conversions after corrections for bathymetry, crustal thickness, and tomographically inferred mantle heterogeneity show that the mean depths of 410 and 660 beneath the Central Pacific are 420 ± 3 km and 659 ± 4 km, respectively. The mean MTZ thickness (239 ± 2 km) is close to global estimates and suggests an adiabatic mantle temperature of ~1,400°C for the Central Pacific. Depth variations of the 410 and 660 appear to be relatively small, with peak‐to‐peak amplitudes of the order of 10–15 km. The 410 and 660 are weakly anticorrelated, and MTZ is thinner beneath Hawaii and to the north and east of the hotspot and thicker southwest of it. The relatively small discontinuity topography argues against the presence of large‐scale (more than 5° wide) thermal anomalies with excess temperatures over 200 K across the transition zone. The data used cannot exclude stronger thermal anomalies that are of more limited lateral extent or that are not continuous across the MTZ.
Reduced‐Rank Array Modes of the California Current Observing System
Authors: Moore Andrew M. , Arango Hernan G. , Edwards Christopher A. 
Published: November 2017

AbstractThe information content of the ocean observing array spanning the U.S. west coast is explored using the reduced‐rank array modes (RAMs) derived from a four‐dimensional variational (4D‐Var) data assimilation system covering a period of three decades. RAMs are an extension of the original formulation of array modes introduced by Bennett (1985) but in the reduced model state‐space explored by the 4D‐Var system, and reveal the extent to which this space is activated by the observations. The projection of the RAMs onto the empirical orthogonal functions (EOFs) of the 4D‐Var background error correlation matrix provides a quantitative measure of the effectiveness of the measurements in observing the circulation. It is found that much of the space spanned by the background error covariance is unconstrained by the present ocean observing system. The RAM spectrum is also used to introduce a new criterion to prevent 4D‐Var from overfitting the model to the observations.
Mixing and Formation of Layers by Internal Wave Forcing
Authors: Dossmann Yvan , Pollet Florence , Odier Philippe , Dauxois Thierry 
Published: November 2017

AbstractThe energy pathways from propagating internal waves to the scales of irreversible mixing in the ocean are not fully described. In the ocean interior, the triadic resonant instability is an intrinsic destabilization process that may enhance the energy cascade away from topographies. The present study focuses on the integrated impact of mixing processes induced by a propagative normal mode‐1 over long‐term experiments in an idealized setup. The internal wave dynamics and the evolution of the density profile are followed using the light attenuation technique. Diagnostics of the turbulent diffusivity KT and background potential energy BPE are provided. Mixing effects result in a partially mixed layer colocated with the region of maximum shear induced by the forcing normal mode. The maximum measured turbulent diffusivity is 250 times larger than the molecular value, showing that diapycnal mixing is largely enhanced by small‐scale turbulent processes. Intermittency and reversible energy transfers are discussed to bridge the gap between the present diagnostic and the larger values measured in Dossmann et al. (). The mixing efficiency η is assessed by relating the BPE growth to the linearized KE input. One finds a value of
, larger than the mixing efficiency in the case of breaking interfacial wave. After several hours of forcing, the development of staircases in the density profile is observed. This mechanism has been previously observed in experiments with weak homogeneous turbulence and explained by Phillips (1972) argument. The present experiments suggest that internal wave forcing could also induce the formation of density interfaces in the ocean.
Electronic and Ionic Materials for Neurointerfaces
Authors: Ferro Marc D. , Melosh Nicholas A. 
Published: November 2017

AbstractCommunication between living brain tissue and engineered devices is the key link to understand brain function and restore neurological deficits from disease, injury, and old age. Enabled by new materials and device designs, a new generation of brain interface technologies is replacing bulkier systems, offering lower tissue damage, reduced immunogenicity, and long‐term stability. New electrode materials with improved chronic performance and increasing emphasis on multimodal capabilities are being integrated onto ultraflexible and mechanically compliant architectures. As these scale to smaller dimensions and higher channel counts, the goal of bidirectional, single‐cell interfaces is nearly within reach. However, promising, long‐term reliability, toxicity, and performance of these systems are still largely unknown. Here, the basics of electrode materials and in vivo technologies are reviewed, and recent advances in electronic and ionic materials are highlighted.
Mesoporous Silica and Organosilica Nanoparticles: Physical Chemistry, Biosafety, Delivery Strategies, and Biomedical Applications
Authors: Croissant Jonas G. , Fatieiev Yevhen , Almalik Abdulaziz , Khashab Niveen M. 
Published: November 2017

AbstractPredetermining the physico‐chemical properties, biosafety, and stimuli‐responsiveness of nanomaterials in biological environments is essential for safe and effective biomedical applications. At the forefront of biomedical research, mesoporous silica nanoparticles and mesoporous organosilica nanoparticles are increasingly investigated to predict their biological outcome by materials design. In this review, it is first chronicled that how the nanomaterial design of pure silica, partially hybridized organosilica, and fully hybridized organosilica (periodic mesoporous organosilicas) governs not only the physico‐chemical properties but also the biosafety of the nanoparticles. The impact of the hybridization on the biocompatibility, protein corona, biodistribution, biodegradability, and clearance of the silica‐based particles is described. Then, the influence of the surface engineering, the framework hybridization, as well as the morphology of the particles, on the ability to load and controllably deliver drugs under internal biological stimuli (e.g., pH, redox, enzymes) and external noninvasive stimuli (e.g., light, magnetic, ultrasound) are presented. To conclude, trends in the biomedical applications of silica and organosilica nanovectors are delineated, such as unconventional bioimaging techniques, large cargo delivery, combination therapy, gaseous molecule delivery, antimicrobial protection, and Alzheimer's disease therapy.
Dynamic and Responsive Growth Factor Delivery from Electrospun and Hydrogel Tissue Engineering Materials
Authors: Bruggeman Kiara F. , Williams Richard J. , Nisbet David R. 
Published: November 2017

AbstractTissue engineering scaffolds are designed to mimic physical, chemical, and biological features of the extracellular matrix, thereby providing a constant support that is crucial to improved regenerative medicine outcomes. Beyond mechanical and structural support, the next generation of these materials must also consider the more dynamic presentation and delivery of drugs or growth factors to guide new and regenerating tissue development. These two aspects are explored expansively separately, but they must interact synergistically to achieve optimal regeneration. This review explores common tissue engineering materials types, electrospun polymers and hydrogels, and strategies used for incorporating drug delivery systems into these scaffolds.
Ligand‐Assisted Pd‐Catalyzed N‐Dealkylative Carbonylation of Tertiary Amines with (Hetero)Aryl Halides to Tertiary Amides
Authors: Mane Rajendra S. , Bhanage Bhalchandra M. 
Published: November 2017

AbstractThis work reports an efficient synthesis of tertiary amides using a ligand‐assisted Pd‐catalyzed carbonylation of (hetero)aryl halides with tertiary amines. A key step in this reaction is C(sp3)−N bond cleavage using CuO as an oxidant. The reaction proceeds with high efficiency employing a bidentate phosphine ligand (dppp), which is a key for the carbonylation of unreactive (hetero)aryl halides and series of tertiary amines at atmospheric pressure of carbon monoxide.
Diverged Plant Terpene Synthases Reroute the Carbocation Cyclization Path towards the Formation of Unprecedented 6/11/5 and 6/6/7/5 Sesterterpene Scaffolds
Authors: Huang Ancheng C. , Hong Young J. , Bond Andrew D. , Tantillo Dean J. , Osbourn Anne 
Published: November 2017

AbstractSesterterpenoids are a relatively rare class of plant terpenes. Sesterterpene synthase (STS)‐mediated cyclization of the linear C25 isoprenoid precursor geranylfarnesyl diphosphate (GFPP) defines sesterterpene scaffolds. So far only a very limited number of STSs have been characterized. The discovery of three new plant STSs is reported that produce a suite of sesterterpenes with unprecedented 6/11/5 and 6/6/7/5 fused ring systems when transiently co‐expressed with a GFPP synthase in Nicotiana benthamiana. Structural elucidation, feeding experiments, and quantum chemical calculations suggest that these STSs catalyze an unusual cyclization path involving reprotonation, intramolecular 1,6 proton transfer, and concerted but asynchronous bicyclization events. The cyclization is diverted from those catalyzed by the characterized plant STSs by forming unified 15/5 bicyclic sesterterpene intermediates. Mutagenesis further revealed a conserved amino acid residue implicated in reprotonation.
PET/CT imaging in management of concomitant Hodgkin lymphoma and tuberculosis – a problem solver tool
Authors: Jehanno Nina , Cassou‐Mounat Thibaut , Vincent‐Salomon Anne , Luporsi Marie , Bedoui Manel , Kuhnowski Frédérique 
Published: November 2017

Key Clinical MessageInfectious lymph nodes mimicking lymphoma is challenging for accurate staging. Although 18F‐FDG is a nonspecific tracer accumulating not only in tumor cells but also in inflammatory tissues, the metabolic features and uptake kinetics give valuable information: 18F‐FDG PET/CT appears as a useful problem solver tool in ambiguous situation.
Harnessing the Maltodextrin Transport Mechanism for Targeted Bacterial Imaging: Structural Requirements for Improved in vivo Stability in Tracer Design
Authors: Axer Alexander , Hermann Sven , Kehr Gerald , Clases David , Karst Uwe , Fischer‐Riepe Lena , Roth Johannes , Fobker Manfred , Schäfers Michael , Gilmour Ryan , Faust Andreas 
Published: November 2017

AbstractDiagnosis and localization of bacterial infections remains a significant clinical challenge. Harnessing bacteria‐specific metabolic pathways, such as the maltodextrin transport mechanism, may allow specific localization and imaging of small or hidden colonies. This requires that the intrabacterial tracer accumulation provided by the transporter is matched by high serum stability of the tracer molecule. Herein, radiolabeled maltodextrins of varying chain lengths and with free nonreducing/reducing ends are reported and their behavior against starch‐degrading enzymes in the blood, which compromise their serum stability, is evaluated. Successful single‐photon emission computed tomography (SPECT) imaging is shown in a footpad infection model in vivo by using the newly developed model tracer, [99mTc]MB1143, and the signal is compared with that of 18F‐fluorodeoxyglucose positron emission tomography ([18F]FDG‐PET) as a nonbacterial specific marker for inflammation. Although the [99mTc]MB1143 imaging signal is highly specific, it is low, most probably due to insufficient serum stability of the tracer. A series of stability tests with different 18F‐labeled maltodextrins finally yielded clear structural guidelines regarding substitution patterns and chain lengths of maltodextrin‐based tracers for nuclear imaging of bacterial infections.
Computational Screening of Doped α‐MnO2 Catalysts for the Oxygen Evolution Reaction
Authors: Tripkovic Vladimir , Hansen Heine Anton , Vegge Tejs 
Published: November 2017

AbstractMinimizing energy and materials costs for driving the oxygen evolution reaction (OER) is paramount for the commercialization of water electrolysis cells and rechargeable metal–air batteries. Structural stability, catalytic activity, and electronic conductivity of pure and doped α‐MnO2 for the OER are studied using density functional theory calculations. As model surfaces, we investigate the (110) and (100) facets, on which three possible active sites are identified: a coordination unsaturated, a bridge, and a bulk site. For pure and Cr‐, Fe‐, Co‐, Ni‐, Cu‐, Zn‐, Cd‐, Mg‐, Al‐, Ga‐, In‐, Sc‐, Ru‐, Rh‐, Ir‐, Pd‐, Pt‐, Ti‐, Zr‐, Nb‐, and Sn‐doped α‐MnO2, the preferred valence at each site is imposed by adding/subtracting electron donors (hydrogen atoms) and electron acceptors (hydroxy groups). From a subset of stable dopants, Pd‐doped α‐MnO2 is identified as the best catalyst and the only material that can outperform pristine α‐MnO2. Different approaches to increase the bulk electron conductivity of semiconducting α‐MnO2 are discussed.
Contribution of cardiac and extra‐cardiac disease burden to risk of cardiovascular outcomes varies by ejection fraction in heart failure
Authors: Wolsk Emil , Claggett Brian , Køber Lars , Pocock Stuart , Yusuf Salim , Swedberg Karl , McMurray John J.V. , Granger Christopher B. , Pfeffer Marc A. , Solomon Scott D. 
Published: November 2017

AimsPatients with heart failure (HF) often have multiple co‐morbidities that contribute to the risk of adverse cardiovascular (CV) and non‐CV outcomes. We assessed the relative contribution of cardiac and extra‐cardiac disease burden and demographic factors to CV outcomes in HF patients with reduced (HFrEF) or preserved (HFpEF) left ventricular ejection fraction (LVEF).Methods and resultsWe utilized data from the CHARM trial, which enrolled HF patients across the ejection fraction spectrum. We decomposed the previously validated MAGGIC risk score into cardiac (LVEF, New York Heart Association class, systolic blood pressure, time since HF diagnosis, HF medication use), extra‐cardiac (body mass index, creatinine, diabetes mellitus, chronic obstructive pulmonary disease, smoker), and demographic (age, gender) categories, and calculated subscores for each patient representing the burden of each component. Cox proportional hazards models were used to estimate the population attributable risk (PAR) associated with each component to the outcomes of death, CV death, HF, myocardial infarction, and stroke relative to patients with the lowest risk score. PARs for each component were depicted across the spectrum of LVEF. in 2675 chronic HF patients from North America [HFrEF (LVEF ≤40%): n = 1589, HFpEF (LVEF >40%): n = 1086] with data available for calculation of the MAGGIC score, the highest risk of death and CV death was attributed to cardiac burden. This was especially evident in HFrEF patients (PAR: 76% cardiac disease vs. 58% extra‐cardiac disease, P < 0.05). Conversely, in HFpEF patients, extra‐cardiac burden accounted for a greater proportion of risk for death than cardiac burden (PAR: 15% cardiac disease vs. 49% extra‐cardiac disease, P < 0.05). For HF hospitalization, the contribution of both cardiac and extra‐cardiac burden was comparable in HFpEF patients (PAR: 42% cardiac disease vs. 53% extra‐cardiac disease, P = NS). In addition, demographic burden was especially high in HFpEF patients, with 62% of deaths attributable to demographic characteristics.ConclusionIn North American HF patients enrolled in the CHARM trials, the relative contribution of cardiac and extra‐cardiac disease burden to CV outcomes and death differed depending on LVEF. The high risk of events attributable to non‐cardiac disease burden may help explain why cardiac disease‐modifying medication proven to be efficacious in HFrEF patients has not proven beneficial in HFpEF.