bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantifying peat carbon accumulation in Alaska using a process‐based biogeochemistry model
Authors: Wang Sirui , Zhuang Qianlai , Yu Zicheng , Bridgham Scott , Keller Jason K. 
Published: August 2016

AbstractThis study uses an integrated modeling framework that couples the dynamics of hydrology, soil thermal regime, and ecosystem carbon and nitrogen to quantify the long‐term peat carbon accumulation in Alaska during the Holocene. Modeled hydrology, soil thermal regime, carbon pools and fluxes, and methane emissions are evaluated using observation data at several peatland sites in Minnesota, Alaska, and Canada. The model is then applied for a 10,000 year (15 ka to 5 ka; 1 ka = 1000 cal years before present) simulation at four peatland sites. We find that model simulations match the observed carbon accumulation rates at fen sites during the Holocene (R2 = 0.88, 0.87, 0.38, and −0.05 using comparisons in 500 year bins). The simulated (2.04 m) and observed peat depths (on average 1.98 m) were also compared well (R2 = 0.91). The early Holocene carbon accumulation rates, especially during the Holocene thermal maximum (HTM) (35.9 g C m− 2 yr− 1), are estimated up to 6 times higher than the rest of the Holocene (6.5 g C m− 2 yr− 1). Our analysis suggests that high summer temperature and the lengthened growing season resulted from the elevated insolation seasonality, along with wetter‐than‐before conditions might be major factors causing the rapid carbon accumulation in Alaska during the HTM. Our sensitivity tests indicate that, apart from climate, initial water table depth and vegetation canopy are major drivers to the estimated peat carbon accumulation. When the modeling framework is evaluated for various peatland types in the Arctic, it can quantify peatland carbon accumulation at regional scales.
Epidemics
Authors: Kretzschmar Mirjam 
Published: August 2016

AbstractStatistical and mathematical models are important tools for analyzing the spread of infectious diseases. This article begins with some historical remarks on the application of mathematical methods in infectious disease epidemiology. Subsequently, types of data occurring in infectious disease epidemiology are discussed, methodological concepts like the basic reproduction number are introduced, and important applications of mathematical modeling for assessing the effectiveness of interventions are presented. An important example for the latter is vaccination, where statistical analysis of serological and surveillance data are used to evaluate the impact of vaccination on immune status of a population and transmission dynamic models are used for estimating long‐term effects on prevalence. Particular attention is then paid to analysis of HIV/AIDS, as the changing epidemiology of this infectious disease and the increasing availability of treatment options have inspired the development of many new methods in the field of statistics and modeling since the onset of the epidemic.
Linear Stochastic Control with Transfer Functions
Authors: Harris Thomas J. 
Published: August 2016

AbstractControl charts, cusums, exponentially weighted‐moving averages and Shewhart schemes are traditional methods used for industrial quality control. These methods may be used to ascertain when a process is in statistical control and to visualize patterns and abnormal events. These methods do not provide a comprehensive strategy for controlling a process to a target value. Stochastic control theory provides a unified framework for the design of controllers for industrial processes. By employing a model for the process dynamics and disturbances, very flexible control algorithms can be designed. The presence of serially correlated observations, inherent in many industrial processes, and delays associated with analytical measurements are incorporated in the control strategy. These algorithms are specifically designed to control the process variable at its target value. In this article, the basic elements of stochastic control are reviewed, an example is used to illustrate the methodology, and references provided to applications in quality control and process monitoring and assessment.
Reference Priors
Authors: Datta Gauri S. , Liseo Brunero 
Published: August 2016

AbstractMany different methods for producing prior distributions that do not depend on extra‐experimental information have been proposed in Bayesian literature. The reference prior algorithm is one of the most successful, both in terms of general applicability and in terms of frequentist and conditional properties. In this article, we briefly sketch the main features of the method and illustrate it with several examples.
The
B
ahadur Model
Authors: Heumann Christian 
Published: August 2016

Abstract

In 1961, Raghu Raj Bahadur (1924–1997) published the paper “A representation of the joint distribution of
n
dichotomous items.”

In general, the joint distribution of binary random variables, , , can be fully described by a multinomial distribution with parameters that are the profile probabilities , where can be 0 or 1. In the regression context, a direct link of the covariates on these profile probabilities is not attractive, especially when it comes to interpretation. The Bahadur model and parametrization allows a relative straightforward implementation of the so‐called marginal regression models, that is, models where the covariates are linked to marginal probabilities of lower order (usually only first order, sometimes also second order).
The literature has picked up the Bahadur model in several articles. The final conclusion is that the model has severe deficiencies because the estimated parameters have to fulfill difficult constraints to define a proper joint distribution.
Rhodium‐Catalyzed Asymmetric Allenylation of Sulfonylimines and Application to the Stereospecific Allylic Allenylation
Authors: Sieber Joshua D. , Angeles‐Dunham Veronica V. , Chennamadhavuni Divya , Fandrick Daniel R. , Haddad Nizar , Grinberg Nelu , Kurouski Dimitry , Lee Heewon , Song Jinhua J. , Yee Nathan K. , Mattson Anita E. , Senanayake Chris H. 
Published: August 2016

AbstractThe rhodium‐catalyzed asymmetric allenylation of sulfonylimines is disclosed providing silyl homoallenylamide products in up to 99:1 er. Through subsequent activation of the C−N bond of the silyl homoallenyl sulfonamide, palladium‐catalyzed stereospecific allylic allenylation could be achieved giving C−C bond formation with high chirality transfer. The synthetic utility of both the silyl homoallenyl sulfonamides and the silyl homoallenyl malonates as bis(nucleophiles) is demonstrated.magnified image
Solid–Vapor Reaction Growth of Transition‐Metal Dichalcogenide Monolayers
Authors: Li Bo , Gong Yongji , Hu Zhili , Brunetto Gustavo , Yang Yingchao , Ye Gonglan , Zhang Zhuhua , Lei Sidong , Jin Zehua , Bianco Elisabeth , Zhang Xiang , Wang Weipeng , Lou Jun , Galvão Douglas S. , Tang Ming , Yakobson Boris I. , Vajtai Robert , Ajayan Pulickel M. 
Published: August 2016

AbstractTwo‐dimensional (2D) layered semiconducting transition‐metal dichalcogenides (TMDCs) are promising candidates for next‐generation ultrathin, flexible, and transparent electronics. Chemical vapor deposition (CVD) is a promising method for their controllable, scalable synthesis but the growth mechanism is poorly understood. Herein, we present systematic studies to understand the CVD growth mechanism of monolayer MoSe2, showing reaction pathways for growth from solid and vapor precursors. Examination of metastable nanoparticles deposited on the substrate during growth shows intermediate growth stages and conversion of non‐stoichiometric nanoparticles into stoichiometric 2D MoSe2 monolayers. The growth steps involve the evaporation and reduction of MoO3 solid precursors to sub‐oxides and stepwise reactions with Se vapor to finally form MoSe2. The experimental results and proposed model were corroborated by ab initio Car–Parrinello molecular dynamics studies.
Nucleation of Amyloid Oligomers by RepA‐WH1‐Prionoid‐Functionalized Gold Nanorods
Authors: Fernández Cristina , González‐Rubio Guillermo , Langer Judith , Tardajos Gloria , Liz‐Marzán Luis M. , Giraldo Rafael , Guerrero‐Martínez Andrés 
Published: August 2016

AbstractUnderstanding protein amyloidogenesis is an important topic in protein science, fueled by the role of amyloid aggregates, especially oligomers, in the etiology of a number of devastating human degenerative diseases. However, the mechanisms that determine the formation of amyloid oligomers remain elusive due to the high complexity of the amyloidogenesis process. For instance, gold nanoparticles promote or inhibit amyloid fibrillation. We have functionalized gold nanorods with a metal‐chelating group to selectively immobilize soluble RepA‐WH1, a model synthetic bacterial prionoid, using a hexa‐histidine tag (H6). H6‐RepA‐WH1 undergoes stable amyloid oligomerization in the presence of catalytic concentrations of anisotropic nanoparticles. Then, in a physically separated event, such oligomers promote the growth of amyloid fibers of untagged RepA‐WH1. SERS spectral changes of H6‐RepA‐WH1 on spherical citrate‐AuNP substrates provide evidence for structural modifications in the protein, which are compatible with a gradual increase in β‐sheet structure, as expected in amyloid oligomerization.
Smart Organic Two‐Dimensional Materials Based on a Rational Combination of Non‐covalent Interactions
Authors: Bai Wei , Jiang Ziwen , Ribbe Alexander E. , Thayumanavan S. 
Published: August 2016

AbstractRational design of organic 2D (O2D) materials has made some progress, but it is still in its infancy. A class of self‐assembling small molecules is presented that form nano/microscale supramolecular 2D materials in aqueous media. A judicial combination of four different intermolecular interactions forms the basis for the robust formation of these ultrathin assemblies. These assemblies can be programmed to disassemble in response to a specific protein and release its non‐covalently bound guest molecules.
Metal‐Free Cross‐Coupling of Arylboronic Acids and Derivatives with DAST‐Type Reagents for Direct Access to Diverse Aromatic Sulfinamides and Sulfonamides
Authors: Wang Qiang , Tang Xiang‐Ying , Shi Min 
Published: August 2016

AbstractWe have developed a simple and convenient method for the cross‐coupling of arylboronic acids and their derivatives with DAST‐type reagents under mild and metal‐free conditions to directly afford sulfinamides in moderate to good yields. Moreover, sulfonamides were obtained after a simple oxidation reaction. The reaction mechanism was investigated by 18O‐labeling experiments, and the synthetic utility was demonstrated by the sulfoxidation of natural products.
Development of biobased microwave absorbing composites with various magnetic metals and carbons
Authors: Kanehashi Shinji , Oyagi Hiroki , Iwamaru Toraki , Ando Shota , Nagai Kazukiyo , Uekusa Shinichiro , Miyakoshi Tetsuo 
Published: August 2016

ABSTRACTThe preparation and characterization of a biobased electromagnetic absorbing composites derived from natural lacquer as a renewable resource with microwave‐absorption fillers, including Ni–Zn ferrite and carbonyl iron (CI) as magnetic metals and soot and carbon nanotube (CNT) as carbon materials, were investigated in terms of the gel content, hardness, drying properties, and electromagnetic absorption properties. Interestingly, composites with ferrite and CI contained up to 320 and 550 wt %, respectively, of these compounds. This quite high loading capacity of the metal fillers in a natural‐lacquer base could have been due to the high compatibility between the filler and the natural lacquer; this indicated that the natural lacquer worked as a binder for these metals. The morphology of the biobased composite was characterized by scanning electron microscopy. The electromagnetic absorption properties of composites were characterized in the frequency range from 0.05 and 20 GHz by the reflection loss (RL) measurement method in terms of the kind of fillers and filler loading. The natural lacquer did not affect the absorption properties of the fillers. Biobased composites showed over 99% electromagnetic absorption in the frequency range 3.0–4.0 GHz for 280 wt % ferrite and 8.9–9.7 GHz for 200 wt % CI. Conversely, 10 and 20 wt % soot exhibited good performance (RL < −20 dB) between 16.5 and 17.3 and between 8.8 and 9.2 GHz, respectively. The areas with RL values of less than −20 dB of the CNT composites were 10.4–11.0 GHz for 5 wt % and 14.6–15.2 GHz for 10 wt %. Hence, natural lacquer can be used as a binder material for electromagnetic absorption composites. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44131.
A Comparative Study of Intratesticular Ductules in the Spermatogenically Active Testes of Shortfin Mako and Thresher Sharks
Authors: McClusky Leon Mendel , Sulikowski James 
Published: August 2016

ABSTRACTThis comparative study of the radial testes of sexually mature thresher sharks (Alopias vulpinus) and shortfin mako sharks (Isurus oxyrinchus) describes the histology of the three‐tiered network of sperm‐carrying ductules in the testis and the lymphomyeloid tissue associated with it, namely the epigonal organ. In both species, a testis → epigonal gradient was evident regarding the thickness of the ductule epithelial lining and subepithelial investment of connective tissue. Ductules straddling the testis–epigonal border often displayed luminal leukocytes and various signs of regression, including the progressive thickening of the ductule epithelial lining, dissolution of the cytoplasm, and loss of normal histoarchitecture. In Isurus, large amorphous areas formed due to the fusion of neighboring regressing ductules. The epigonal organ of Alopias additionally revealed circular degenerative sperm‐containing, Hassall‐like bodies with either a degenerate or cellular appearance, the latter the result of cell proliferative activity (as shown by proliferating cell nuclear antigen (PCNA) immunohistochemistry) in an expanding outer border comprising cells with intensely PCNA immunoreactive slender and oblong nuclei. The latter cells exhibited a periphery‐to‐center transformation of their nuclei, at which stage they were PCNA‐negative and most likely in a terminally differentiated state as they phagocytized the cell debris in the degenerate core. Intermediate stages of these circular bodies were a rarity. The relationship between these degenerate bodies, and the common occurrence of blind pockets in the epithelial linings and non‐apoptosis‐related degenerate patches in the apical cytoplasmic regions of the irregular shaped ductules in Alopias is unclear, and needs further elucidation. Anat Rec, 299:1435–1448, 2016. © 2016 Wiley Periodicals, Inc.
Concept of an upright wearable positron emission tomography imager in humans
Authors: Bauer Christopher E. , Brefczynski‐Lewis Julie , Marano Gary , Mandich Mary‐Beth , Stolin Alexander , Martone Peter , Lewis James W. , Jaliparthi Gangadhar , Raylman Raymond R. , Majewski Stan 
Published: August 2016

AbstractBackgroundPositron Emission Tomography (PET) is traditionally used to image patients in restrictive positions, with few devices allowing for upright, brain‐dedicated imaging. Our team has explored the concept of wearable PET imagers which could provide functional brain imaging of freely moving subjects. To test feasibility and determine future considerations for development, we built a rudimentary proof‐of‐concept prototype (Helmet_PET) and conducted tests in phantoms and four human volunteers.MethodsTwelve Silicon Photomultiplier‐based detectors were assembled in a ring with exterior weight support and an interior mechanism that could be adjustably fitted to the head. We conducted brain phantom tests as well as scanned four patients scheduled for diagnostic F18‐FDG PET/CT imaging. For human subjects the imager was angled such that field of view included basal ganglia and visual cortex to test for typical resting‐state pattern. Imaging in two subjects was performed ~4 hr after PET/CT imaging to simulate lower injected F18‐FDG dose by taking advantage of the natural radioactive decay of the tracer (F18 half‐life of 110 min), with an estimated imaging dosage of 25% of the standard.ResultsWe found that imaging with a simple lightweight ring of detectors was feasible using a fraction of the standard radioligand dose. Activity levels in the human participants were quantitatively similar to standard PET in a set of anatomical ROIs. Typical resting‐state brain pattern activation was demonstrated even in a 1 min scan of active head rotation.ConclusionTo our knowledge, this is the first demonstration of imaging a human subject with a novel wearable PET imager that moves with robust head movements. We discuss potential research and clinical applications that will drive the design of a fully functional device. Designs will need to consider trade‐offs between a low weight device with high mobility and a heavier device with greater sensitivity and larger field of view.
Numerical elucidation of three‐dimensional problems in the chemical engineering graduate curriculum
Authors: Binous Housam , Kaddeche Slim , Abdennadher Ali , Bellagi Ahmed 
Published: August 2016

ABSTRACTWe illustrate in the present paper how steady‐state and unsteady‐steady three‐dimensional transport phenomena problems can be solved using the Chebyshev orthogonal collocation technique. All problems are elucidated using the ubiquitous software: MATLAB®. The treated case studies include: (1) unsteady‐state heat conduction in a parallelepiped body, (2) quenching of a brick, (3) transient diffusion of a colorant in a liquid, and (4) steady‐state natural convection in an enclosure. Whenever possible, the results obtained with the spectral method are bench‐marked against the analytical solution in order to validate the proposed numerical technique. © 2016 Wiley Periodicals, Inc. Comput Appl Eng Educ 24:866–875, 2016; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21756
Spherical Core–Shell Titanium (Oxy)nitride@Nitrided Carbon Composites as Catalysts for the Oxygen Reduction Reaction: Synthesis and Electrocatalytic Performance
Authors: Wassner Maximilian , Eckardt Markus , Gebauer Christian , Hüsing Nicola , Behm R. Jürgen 
Published: August 2016

AbstractAiming at the development of highly active and stable platinum‐free catalysts for the oxygen reduction reaction (ORR) in polymer electrolyte fuel cells (PEFCs), we explored the potential of a new composite material, where the core–shell structure should result in a combination of high ORR activity and improved electric conductivity. TiOxNy@CnNm composite nanoparticles were prepared by covering uniform carbon spheres of about 300 nm in size, synthesized through the hydrothermal reaction of glucose, with a homogeneous titania shell made by sol‐gel processing. The core–shell particles were then subjected to nitridation in ammonia vapor at different temperatures (550 °C–150 °C). The influence of the nitridation temperature on the structure and phase composition of the resulting composite particles was evaluated by a variety of techniques, including electron microscopy (SEM, TEM), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), elemental analysis, thermogravimetric (TG) analysis, and N2 sorption measurements, the electrochemical properties and the ORR performance of the materials were determined by rotating ring disk electrode (RRDE) measurements. Trends in the evolution of the structural/chemical properties and electrochemical/electrocatalytic properties as well as correlations between them are discussed; an optimized mesoporosity of the titanium (oxy)nitride shell was identified as the key criterion for the catalyst's ORR performance.
Constrained Cyclopeptides: Biaryl Formation through Pd‐Catalyzed C−H Activation in Peptides—Structural Control of the Cyclization vs. Cyclodimerization Outcome
Authors: Mendive‐Tapia Lorena , Bertran Alexandra , García Jesús , Acosta Gerardo , Albericio Fernando , Lavilla Rodolfo 
Published: August 2016

AbstractA series of short tryptophan‐phenylalanine peptides containing an iodo substituent on the phenyl ring was subjected to Pd‐catalyzed CH activation reactions to give the corresponding aryl‐indole coupled products. Two types of adducts were generated: cyclomonomer and cyclodimeric peptides; no evidence of oligo‐ or polymerization products was detected. Contrary to standard peptide macrocyclizations, the factors controlling the fate of the reaction are the number of amino acids between the aromatic residues and the regiochemistry of the parent iodo derivative, independent of both the concentration and the cyclization mode. The method is general and allows access to novel biaryl peptidic topologies, which have been fully characterized.
Motion Control of Micro‐/Nanomotors
Authors: Teo Wei Zhe , Pumera Martin 
Published: August 2016

AbstractAs we progress towards employing self‐propelled micro‐/nanomotors in envisioned applications such as cargo delivery, environmental remediation, and therapeutic treatments, precise control of the micro‐/nanomotors direction and their speed is essential. In this Review, major emerging approaches utilized for the motion control of micro‐/nanomotors have been discussed, together with the lastest publications describing these approaches. Future studies could incorporate investigations on micro‐/nanomotors motion control in a real‐world environment in which matrix complexity might disrupt successful manipulation of these small‐scale devices.
pH‐Responsive Relaxometric Behaviour of Coordination Polymer Nanoparticles Made of a Stable Macrocyclic Gadolinium Chelate
Authors: Aríñez‐Soriano Javier , Albalad Jorge , Carné‐Sánchez Arnau , Bonnet Célia S. , Busqué Félix , Lorenzo Julia , Juanhuix Jordi , Terban Maxwell W. , Imaz Inhar , Tóth Éva , Maspoch Daniel 
Published: August 2016

AbstractLanthanide‐containing nanoscale particles have been widely explored for various biomedical purposes, however, they are often prone to metal leaching. Here we have created a new coordination polymer (CP) by applying, for the first time, a stable GdIII chelate as building block in order to prevent any fortuitous release of free lanthanide(III) ion. The use of the Gd‐DOTA‐4AmP complex as a design element in the CP allows not only for enhanced relaxometric properties (maximum r1=16.4 mm−1 s−1 at 10 MHz), but also for a pH responsiveness (Δr1=108 % between pH 4 and 6.5), beyond the values obtained for the low molecular weight Gd‐DOTA‐4AmP itself. The CP can be miniaturised to the nanoscale to form colloids that are stable in physiological saline solution and in cell culture media and does not show cytotoxicity.