bluuebunny/crossref_metadata_2025_split huggingface dataset:
Important global and regional differences in aerosol cloud‐albedo effect estimates between simulations with and without prognostic aerosol microphysics
Authors: Kodros J. K. , Pierce J. R. 
Published: April 2017

AbstractAerosol‐cloud interactions are among the most uncertain climate forcings, in part due to the strong sensitivity of cloud droplet number concentration (CDNC) to changes in the size distribution of potential cloud condensation nuclei. Despite this sensitivity of simulated aerosol‐cloud interactions to variations in size‐resolved aerosol concentrations being well established, many chemistry‐climate and chemical‐transport models do not include explicit treatment of the aerosol size distribution. We use a global chemical‐transport model to estimate the aerosol cloud‐albedo effect (CAE) due to anthropogenic emissions with prognostic sectional aerosol microphysics and compare this to the CAE calculated when the simulated aerosol mass of each species is remapped onto a prescribed size distribution. We find that although both the prescribed and prognostic methods compare similarly well with present‐day size‐distribution observations, there are substantial differences in the relative CDNC and CAE due to anthropogenic emissions. When using the prognostic size‐distribution method, anthropogenic emissions yield a 25–75% larger increase in CDNC over most land masses but a 50–75% smaller increase in some remote‐marine regions than in the prescribed size‐distribution methods. Simulations using the prognostic scheme yield a global mean anthropogenic CAE of −0.87 W m−2, while the simulations with the prescribed scheme predict −0.66 W m−2. In South America and South Asia, differences in the CAE exceed 3.0 W m−2. These differences suggest that simulations with prescribed size‐distribution mapping are unable to capture regional and temporal variability in size‐resolved aerosol number and thus may lead to biases in estimates of the CAE.
Quantifying the effect of riming on snowfall using ground‐based observations
Authors: Moisseev Dmitri , von Lerber Annakaisa , Tiira Jussi 
Published: April 2017

AbstractGround‐based observations of ice particle size distribution and ensemble mean density are used to quantify the effect of riming on snowfall. The rime mass fraction is derived from these measurements by following the approach that is used in a single ice‐phase category microphysical scheme proposed for the use in numerical weather prediction models. One of the characteristics of the proposed scheme is that the prefactor of a power law relation that links mass and size of ice particles is determined by the rime mass fraction, while the exponent does not change. To derive the rime mass fraction, a mass‐dimensional relation representative of unrimed snow is also determined. To check the validity of the proposed retrieval method, the derived rime mass fraction is converted to the effective liquid water path that is compared to microwave radiometer observations. Since dual‐polarization radar observations are often used to detect riming, the impact of riming on dual‐polarization radar variables is studied for differential reflectivity measurements. It is shown that the relation between rime mass fraction and differential reflectivity is ambiguous, other factors such as change in median volume diameter need also be considered. Given the current interest on sensitivity of precipitation to aerosol pollution, which could inhibit riming, the importance of riming for surface snow accumulation is investigated. It is found that riming is responsible for 5% to 40% of snowfall mass. The study is based on data collected at the University of Helsinki field station in Hyytiälä during U.S. Department of Energy Biogenic Aerosols Effects on Clouds and Climate (BAECC) field campaign and the winter 2014/2015. In total 22 winter storms were analyzed, and detailed analysis of two events is presented to illustrate the study.
Effects of environment forcing on marine boundary layer cloud‐drizzle processes
Authors: Wu Peng , Dong Xiquan , Xi Baike , Liu Yangang , Thieman Mandana , Minnis Patrick 
Published: April 2017

AbstractDetermining the factors affecting drizzle formation in marine boundary layer (MBL) clouds remains a challenge for both observation and modeling communities. To investigate the roles of vertical wind shear and buoyancy (static instability) in drizzle formation, ground‐based observations from the Atmospheric Radiation Measurement Program at the Azores are analyzed for two types of conditions. The type I clouds should last for at least 5 h and more than 90% time must be nondrizzling and then followed by at least 2 h of drizzling periods, while the type II clouds are characterized by mesoscale convection cellular structures with drizzle occur every 2 to 4 h. By analyzing the boundary layer wind profiles (direction and speed), it was found that either directional or speed shear is required to promote drizzle production in the type I clouds. Observations and a recent model study both suggest that vertical wind shear helps the production of turbulent kinetic energy (TKE), stimulates turbulence within cloud layer, and enhances drizzle formation near the cloud top. The type II clouds do not require strong wind shear to produce drizzle. The small values of lower tropospheric stability (LTS) and negative Richardson number (Ri) in the type II cases suggest that boundary layer instability plays an important role in TKE production and cloud‐drizzle processes. By analyzing the relationships between LTS and wind shear for all cases and all time periods, a stronger connection was found between LTS and wind directional shear than that between LTS and wind speed shear.
Sunshine duration and global radiation trends in Italy (1959–2013): To what extent do they agree?
Authors: Manara V. , Brunetti M. , Maugeri M. , Sanchez‐Lorenzo A. , Wild M. 
Published: April 2017

AbstractTwo Italian homogenized data sets of sunshine duration (SD) and global radiation (Eg↓) relative anomalies are used to investigate to what extent these two variables agree with respect to their temporal evolution. They are compared for northern and southern Italy over the period 1959–2013. Both under all‐sky and clear‐sky conditions, the SD records tend to show a shorter and less intense decrease until the 1980s (“global dimming”) with respect to the Eg↓ ones, while there is a better agreement in the subsequent period when both variables increase (“brightening period”). To investigate whether such behavior can be explained by a different sensitivity of SD and Eg↓ to atmospheric turbidity variations, the observed clear‐sky trends are compared to those estimated by a model based both on Lambert‐Beer's law and on a simple estimation of diffuse radiation. Results show that most of the differences observed in the trends of the clear‐sky SD and Eg↓ records can be explained considering a realistic pattern of atmospheric turbidity in the 1959–2013 period. The only exception concerns winter and autumn in northern Italy where clear‐sky SD does not decrease in the dimming period as much as it would be expected on the basis of the corresponding increase in atmospheric turbidity. One reason for this discrepancy could be the influence of other variables like relative humidity. This case study highlights that changes in atmospheric turbidity have to be kept in mind when SD is used to investigate the multidecadal evolution of Eg↓.
Ion trapping by dust grains: Simulation applications to the Enceladus plume
Authors: Farrell W. M. , Wahlund J.‐E. , Morooka M. , Kurth W. S. , Gurnett D. A. , MacDowall R. J. 
Published: April 2017

AbstractUsing a particle‐in‐cell electrostatic simulation, we examine the conditions that allow low‐energy ions, like those produced in the Enceladus plume, to be attracted and trapped within the sheaths of negatively charged dust grains. The conventional wisdom is that all new ions produced in the Enceladus plume are free to get picked up (i.e., accelerated by the local E field to then undergo vB acceleration). However, we suggest herein that the presence of submicron‐charged dust in the plume impedes this pickup process since the local grain electric field greatly exceeds the corotation E fields. The simulations demonstrate that cold ions will tend to accelerate toward the negatively charged grains and become part of the ion plasma sheath. These trapped ions will move with the grains, exiting the plume region at the dust speed. We suggest that Cassini's Langmuir probe is measuring the entire ion population (free and trapped ions), while the Cassini magnetometer detects the magnetic perturbations associated with pickup currents from the smaller population of free ions, with this distinction possibly reconciling the ongoing debate in the literature on the ion density in the plume.
Major pathways to electron distribution function formation in regions of diffuse aurora
Authors: Khazanov George V. , Sibeck David G. , Zesta Eftyhia 
Published: April 2017

AbstractThis paper discusses the major pathways of electron distribution function formation in the region of diffuse aurora. The diffuse aurora accounts for about of 75% of the auroral energy precipitating into the upper atmosphere, and its origin has been the subject of much discussion. We show that an earthward stream of precipitating electrons initially injected from the Earth's plasma sheet via wave‐particle interactions degrades in the atmosphere toward lower energies and produces secondary electrons via impact ionization of the neutral atmosphere. These electrons of magnetospheric origin are then reflected back into the magnetosphere along closed dipolar magnetic field lines, leading to a series of reflections and consequent magnetospheric interactions that greatly augment the initially precipitating flux at the upper ionospheric boundary (700–800 km). To date this, systematic magnetosphere‐ionosphere coupling element has not been included in auroral research models, and, as we demonstrate in this article, has a dramatic effect (200–300%) on the formation of the precipitating fluxes that result in the diffuse aurora. It is shown that wave‐particle interaction processes that drive precipitating fluxes in the region of diffuse aurora from the magnetospheric altitudes are only the first step in the formation of electron precipitation at ionospheric altitudes, and they cannot be separated from the atmospheric “collisional machine” that redistributes and transfers their energy inside the magnetosphere‐ionosphere‐atmosphere coupling system.
Multivariate Methods for Binary Longitudinal Data
Authors: Glynn Robert J. , Rosner Bernard , Ilk Ozlem 
Published: April 2017

AbstractLongitudinal data in which the repeatedly measured response variable is binary often occur in many fields including medical investigations, particularly clinical trials, and social sciences. This article describes a number of suitable approaches to exploring and modeling such data including marginal models, mixed‐effects models, transition models, and multilevel models. Approaches to inferences, including generalized estimating equations, maximum likelihood method, and Gibbs sampling, are discussed.
Synthesis, characterization, and performance evaluation of N,N‐Dimethylacrylamide–alkyl acrylate copolymers as novel multifunctional additives for lube oil
Authors: Singh Raj K. , Kukrety Aruna , Kumar Arvind , Chouhan Ajay , Saxena Rakesh C. , Ray Siddharth S. , Jain Suman L. 
Published: April 2017

AbstractThree copolymeric and two homopolymeric additives were synthesized utilizing the C18 alkyl acrylate (C18Ac) and N,N‐dimethylacrylamide (DMAA) monomers. Three additives named as additive 1, additive 2, and additive 3 were synthesized by varying the ratio between C18Ac: DMAA as 1:1, 1:2 and 2:1 respectively by free radical polymerization using AIBN (azobis(isobutyronitrile)) as initiator, whereas additive 4 and additive 5 were the homopolymers of C18Ac and DMAA, respectively. All the synthesized polymers were characterized by FT‐IR (fourier transform infrared spectroscopy), NMR (nuclear magnetic resonance), and GPC (gel permeation chromatography) analysis. Performance evaluation of the copolymers as viscosity index improver (VII), pour point depressant (PPD), antiwear, antifriction, and anticorrosion additives in polyol base oil was done by standard methods. As far as the VII, anti‐wear, antifriction, and anticorrosive properties are concerned, additive 2 revealed best performance; however, none of the above synthesized additives was found to be suitable for PPD activity.
The association of histologic grade with acute graft‐versus‐host disease response and outcomes
Authors: Narkhede Mayur , Rybicki Lisa , Abounader Donna , Bolwell Brian , Dean Robert , Gerds Aaron T. , Hanna Rabi , Hill Brian , Jagadeesh Deepa , Kalaycio Matt , Liu Hien D. , Pohlman Brad , Sobecks Ronald , Majhail Navneet S. , Ky Hamilton Betty 
Published: April 2017

AbstractConsensus criteria are routinely used to clinically grade acute graft‐versus‐host disease (GVHD). A histologic grading system for acute GVHD is available, but there are limited data on its correlation with clinical grade and hematopoietic cell transplantation (HCT) outcomes. Among 503 patients who underwent allogeneic HCT from 2005 to 2013, we identified 300 biopsy episodes of the skin and gastrointestinal (GI) tract in 231 patients. Histologic grade was correlated with clinical grade of GVHD, day 28 treatment response, and outcome. Both skin (R = 0.32) and GI (R = 0.61) histologic grade correlated with clinical grade (P < 0.001). On multivariable analysis, histologic grade (HR 0.87, P = 0.011) and clinical grade (HR 0.86, P = 0.008) were significantly associated with day 28‐treatment response. A histologic grade lower than its associated clinical grade predicted for better response (HR 1.26, P = 0.027), while a histologic grade higher than associated clinical grade had no correlation with response (P = 0.89). Both clinical and histologic GVHD grade were significant predictors of non‐relapse mortality (HR 1.47, P = 0.04 and HR 1.67, P = 0.002, respectively) and all‐cause mortality (HR 1.57, P = 0.001 and HR 1.29, P = 0.046, respectively). Histologic GVHD grade thus is correlated with clinical grading and treatment response, and may play a role in further predicting severity and treatment response of acute GVHD.
The role of carbon monoxide and heme oxygenase in the prevention of sickle cell disease vaso‐occlusive crises
Authors: Gomperts Edward , Belcher John D. , Otterbein Leo E. , Coates Thomas D. , Wood John , Skolnick Brett E. , Levy Howard , Vercellotti Gregory M. 
Published: April 2017

AbstractSickle Cell Disease (SCD) is a painful, lifelong hemoglobinopathy inherited as a missense point mutation in the hemoglobin (Hb) beta‐globin gene. This disease has significant impact on quality of life and mortality, thus a substantial medical need exists to reduce the vaso‐occlusive crises which underlie the pathophysiology of the disease. The concept that a gaseous molecule may exert biological function has been well known for over one hundred years. Carbon monoxide (CO), although studied in SCD for over 50 years, has recently emerged as a powerful cytoprotective biological response modifier capable of regulating a host of physiologic and therapeutic processes that, at low concentrations, exerts key physiological functions in various models of tissue inflammation and injury. CO is physiologically generated by the metabolism of heme by the heme oxygenase enzymes and is measurable in blood. A substantial amount of preclinical and clinical data with CO have been generated, which provide compelling support for CO as a potential therapeutic in a number of pathological conditions. Data underlying the therapeutic mechanisms of CO, including in SCD, have been generated by a plethora of in vitro and preclinical studies including multiple SCD mouse models. These data show CO to have key signaling impacts on a host of metallo‐enzymes as well as key modulating genes that in sum, result in significant anti‐inflammatory, anti‐oxidant and anti‐apoptotic effects as well as vasodilation and anti‐adhesion of cells to the endothelium resulting in preservation of vascular flow. CO may also have a role as an anti‐polymerization HbS agent. In addition, considerable scientific data in the non‐SCD literature provide evidence for a beneficial impact of CO on cerebrovascular complications, suggesting that in SCD, CO could potentially limit these highly problematic neurologic outcomes. Research is needed and hopefully forthcoming, to carefully elucidate the safety and benefits of this potential therapy across the age spectrum of patients impacted by the host of pathophysiological complications of this devastating disease.
What is significant about a single nursing session? An exploratory study
Authors: Miller Elizabeth M. 
Published: April 2017

AbstractObjectivesResearchers and clinicians specializing in breastfeeding often rely on measuring one nursing session to characterize the breastfeeding relationship. However, less is known about the descriptive or statistically predictive characteristics of one nursing session. The purposes of this study are twofold: (1) to explore the relationships between variables in a single nursing session; and (2) to study the association between variables in a single nursing session and infant length‐for‐age (LAZ) and weight‐for‐age (WAZ).MethodsIn 63 nursing mother‐infant pairs in the United States, anthropometric measurement and observation of a single nursing session revealed six nursing session variables: fore milk fat percent, hind milk fat percent, infant milk intake, duration of session, time since last session, and time of day of session.ResultsA principle factor analysis, undertaken to explore latent variables underlying the six session variables, revealed two factors: (1) loaded highly on fore and hind milk fat percentage, reflecting the overall fat percent in a feed; and (2) loaded highly on milk intake and hind milk fat percentage, indicating the process of breast emptying. In multivariate analyses of all session variables on infant LAZ and WAZ, only hind milk fat percentage was significantly negatively associated with LAZ (β = −0.14, P = .01 (two‐tailed), R2 = 0.070), confirmed by a significant negative association between LAZ and factor one (β = −0.32, P = .05 (two‐tailed), R2 = 0.090).ConclusionsThis research describes the dynamics of a single nursing session, and has the potential to help explain variation in infant growth and nutrition.
Uncatalyzed C−H Amination of Aromatic Compounds under Unusually Mild Conditions with Negative Enthalpies of Activation
Authors: Langhals Heinz , Eberspächer Moritz , Mayer Peter 
Published: April 2017

AbstractAromatic amines have been synthesized by the simple treatment of carboximides with concentrated azetidine in a fast reaction at room temperature. Strongly negative energies of activation and high reaction order for azetidine were found, which violated Arrhenius′ theory for a simple activated complex. The application of this reaction to perylenes allowed the synthesis of bathochromically absorbing functional dyes.
Structural and Aromaticity Control of [34]Octaphyrin(1.1.1.0.1.1.1.0) by Protonation and Deprotonation
Authors: Naoda Koji , Osuka Atsuhiro 
Published: April 2017

AbstractThe structural and aromaticity control of hexakis(pentafluorophenyl) [34]octaphyrin(1.1.1.0.1.1.1.0) 1 was examined by protonation and deprotonation. Protonation of 1 with methanesulfonic acid (MSA) induced a structural change from a figure‐eight to a rectangular shape, accompanied by an aromaticity change from nonaromatic to strong Hückel aromatic. Deprotonation of 1 with tetrabutylammonium difluorotriphenylsilicate (TBAT) or fluoride (TBAF) produced a mono‐deprotonated species with a similar figure‐eight conformation and nonaromaticity.
Ratiometric Fluorescence Detection of Anthrax Biomarker with EuIII‐EDTA Functionalized Mixed Poly(diacetylene) Liposomes
Authors: Seo Hyewon , Singha Subhankar , Ahn Kyo Han 
Published: April 2017

AbstractAnthrax, a bacteriogenic fatal infectious disease that is harmful to humans, requires the early and ready detection of its bacterial endospores. We report herein the use of poly(diacetylene acid) derived liposomes functionalized with EuIII‐EDTA complexes as a ratiometric fluorescence detection system for dipicolinate, an anthrax biomarker and major component of the endospores. The red fluorescence of the polymerized liposomes provides a built‐in reference signal to monitor the relative change of the europium luminescence sensitized by the bound dipicolinate relative to the reference liposome emission. The liposome‐based integrated sensing system shows reasonable sensitivity as well as remarkable selectivity toward dipicolinate over other structurally related analytes. Paper strip sensors based on the polymerized liposomes are also prepared for the visible detection of dipicolinate.
Transition‐Metal‐Free Oxidative Cross‐Coupling of Methylhetarenes with Imidazoheterocycles towards Efficient C(sp2)−H Carbonylation
Authors: Sultana Faria , Shaik Siddiq Pasha , Alarifi Abdullah , Srivastava Ajay Kumar , Kamal Ahmed 
Published: April 2017

AbstractAn efficient method for the oxidative cross‐coupling of methylhetarenes with imidazoheterocycles by employing an eco‐friendly iodine/DMSO reagent system has been developed. This C(sp2)−H carbonylation reaction proceeds through an in situ oxidation of a methylhetarene into a formylhetarene followed by an oxidative cross‐coupling reaction with an imidazoheterocycle. This method has a wide substrate scope and good functional group tolerance and enables the construction of a large number of carbonylated imidazoheterocycles in very good yields.
Lewis Acid‐Catalyzed Stereoselective [7+7] Intermolecular Cyclization of Aniline‐Tethered Alkylidenecyclopropanes: A One‐Step Synthetic Protocol of 14‐Membered Macrocyclic Dimers
Authors: Hu Xu‐Bo , Chen Kai , Yang Xue‐Yan , Wei Yin , Shi Min 
Published: April 2017

AbstractA one‐step stereoselective synthetic method of 14‐membered aza‐macrocyclic dimers has been developed by a Lewis acid‐catalyzed ring‐opening and intermolecular cyclization reaction of aniline‐tethered alkylidenecyclopropanes, affording 14‐membered aza‐macrocyclic dimers (mainly as E‐configuration) in moderate to good yields under mild conditions.