bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical simulation of the falling snow deposition over complex terrain
Authors: Wang Zhengshi , Huang Ning
Published: December 2016

Snow is one of the most dynamic natural elements on the Earth's surface, and the variations in its distribution in time and space profoundly affect the hydrological cycle, climate system, and ecological evolution as well as other natural processes. Most previous studies have paid less attention to the process determining the distribution of snow on the ground as a result of the effect of nonuniform mountain wind on the trajectories of snow particles. In this paper, we present a numerical study on the falling snow deposition process involving snow particles of mixed grain sizes over complex terrain. A three‐dimensional large‐eddy simulation code was used to predict the wind field by considering the fluid‐solid coupling effect, and the Lagrangian particle tracking method was employed to track the movement of each tracking snow particle. The grid resolution and model parameters were determined by the best fit with the field experiment, and the coupling effect between snow particles and wind field was found to be nonnegligible when the drifting snow occurred. In general, the preferential deposition on a single ridge showed a tendency from windward slope toward leeward slope with the increasing advection, while it was hard to describe the snow distribution over complex terrains with a unified deposition model due to the interaction of surrounding topographies and different atmospheric stabilities, and the particle tracking approach was substantially suitable for this issue. Our study significantly improved the understanding of the evolution of snow distributions at high levels of resolution.
Parameterizing surface wind speed over complex topography
Authors: Helbig N. , Mott R. , van Herwijnen A. , Winstral A. , Jonas T.
Published: December 2016

Subgrid parameterizations are used in coarse‐scale meteorological and land surface models to account for the impact of unresolved topography on wind speed. While various parameterizations have been suggested, these were generally validated on a limited number of measurements in specific geographical areas. We used high‐resolution wind fields to investigate which terrain parameters most affect near‐surface wind speed over complex topography under neutral conditions. Wind fields were simulated using the Advanced Regional Prediction System (ARPS) on Gaussian random fields as model topographies to cover a wide range of terrain characteristics. We computed coarse‐scale wind speed, i.e., a spatial average over the large grid cell accounting for influence of unresolved topography, using a previously suggested subgrid parameterization for the sky view factor. We only require correlation length of subgrid topographic features and mean square slope in the coarse grid cell. Computed coarse‐scale wind speed compared well with domain‐averaged ARPS wind speed. To further statistically downscale coarse‐scale wind speed, we use local, fine‐scale topographic parameters, namely, the Laplacian of terrain elevations and mean square slope. Both parameters showed large correlations with fine‐scale ARPS wind speed. Comparing downscaled numerical weather prediction wind speed with measurements from a large number of stations throughout Switzerland resulted in overall improved correlations and distribution statistics. Since we used a large number of model topographies to derive the subgrid parameterization and the downscaling framework, both are not scale dependent nor bound to a specific geographic region. Both can readily be implemented since they are based on easy to derive terrain parameters.
Shipborne observations of the radiative effect of Southern Ocean clouds
Authors: Protat Alain , Schulz Eric , Rikus Lawrence , Sun Zhian , Xiao Yi , Keywood Melita
Published: December 2016

This study uses shipborne cloud radar and surface radiation measurements collected over the Southern Ocean to characterize the cloud frequency, cloud fraction, and cloud radiative effects on the ocean surface. These cloud and radiative properties are also used to evaluate a regional forecast model. Low‐level clouds, either alone or cooccurring with cloud layers aloft, are present ~ 77% of the time in this data set. These clouds either had a very low or a very high cloud fraction at 12 km horizontal resolution, with about half of the clouds characterized by a cloud fraction higher than 80%. Overall, shortwave surface cooling effect dominates longwave heating, with an estimate net radiative cooling of −22 W m−2, resulting from a −71 W m−2 shortwave cooling and a +49 W m−2 longwave heating. A strong relationship between daily surface cloud radiative effect and daily low‐level cloud fraction is found, which, if confirmed with a larger data set, could be exploited in satellite retrievals or model parameterizations for the Southern Ocean. The regional model underestimates the frequency of low‐level clouds but largely overestimates the frequency of multilayer situations. The associated radiative errors are large and complex, including reduced surface radiative cooling due to low‐level clouds compensated by enhanced surface cooling in multilayer situations.
Incisional cyclic steps of permanent form in mixed bedrock‐alluvial rivers
Authors: Izumi Norihiro , Yokokawa Miwa , Parker Gary
Published: December 2016

Most bedrock river channels have a relatively thin, discontinuous cover of alluvium and are thus termed mixed bedrock‐alluvial channels. Such channels often show a series of steps formed at relatively regular intervals. This bed form is the bedrock equivalent of cyclic steps formed on beds composed of cohesive soil in gullies. In this paper, we perform a full nonlinear analysis for the case of cyclic steps in mixed bedrock‐alluvial channels to explain the formation of these steps. We employ the shallow water equations in conjunction with equations describing the process of bedrock incision. As a model of bedrock incision, we employ the recently introduced Macro‐Roughness Saltation Abrasion Alluviation model, which allows direct interaction between alluvial and bedrock morphodynamics. The analysis is greatly simplified by making the quasi‐steady assumption that alluvial processes occur much faster than bedrock erosional processes. From our analysis, we obtain the conditions for the formation of cyclic steps in bedrock, as well as the longitudinal profiles of bed elevation, water surface elevation, and areal fraction of alluvial cover. It is found from the analysis that when the sediment supply is small relative to the transport capacity, cyclic steps form only on slopes with very high gradients. The analysis indicates that the shape of a step formed on bedrock is characterized by a relatively short upstream portion with an adverse slope and a long, almost planar downstream portion with a constant slope.
Controls on Last Glacial Maximum ice extent in the Weddell Sea embayment, Antarctica
Authors: Whitehouse Pippa L. , Bentley Michael J. , Vieli Andreas , Jamieson Stewart S. R. , Hein Andrew S. , Sugden David E.
Published: December 2016

The Weddell Sea sector of the Antarctic Ice Sheet is hypothesized to have made a significant contribution to sea‐level rise since the Last Glacial Maximum. Using a numerical flowline model we investigate the controls on grounding line motion across the eastern Weddell Sea and compare our results with field data relating to past ice extent. Specifically, we investigate the influence of changes in ice temperature, accumulation, sea level, ice shelf basal melt, and ice shelf buttressing on the dynamics of the Foundation Ice Stream. We find that ice shelf basal melt plays an important role in controlling grounding line advance, while a reduction in ice shelf buttressing is found to be necessary for grounding line retreat. There are two stable positions for the grounding line under glacial conditions: at the northern margin of Berkner Island and at the continental shelf break. Global mean sea‐level contributions associated with these two scenarios are ~50 mm and ~130 mm, respectively. Comparing model results with field evidence from the Pensacola Mountains and the Shackleton Range, we find it unlikely that ice was grounded at the continental shelf break for a prolonged period during the last glacial cycle. However, we cannot rule out a brief advance to this position or a scenario in which the grounding line retreated behind present during deglaciation and has since re‐advanced. Better constraints on past ice sheet and ice shelf geometry, ocean temperature, and ocean circulation are needed to reconstruct more robustly past behavior of the Foundation Ice Stream.
Extreme geomagnetic storms: Probabilistic forecasts and their uncertainties
Authors: Riley Pete , Love Jeffrey J.
Published: December 2016

Extreme space weather events are low‐frequency, high‐risk phenomena. Estimating their rates of occurrence, as well as their associated uncertainties, is difficult. In this study, we derive statistical estimates and uncertainties for the occurrence rate of an extreme geomagnetic storm on the scale of the Carrington event (or worse) occurring within the next decade. We model the distribution of events as either a power law or lognormal distribution and use (1) Kolmogorov‐Smirnov statistic to estimate goodness of fit, (2) bootstrapping to quantify the uncertainty in the estimates, and (3) likelihood ratio tests to assess whether one distribution is preferred over another. Our best estimate for the probability of another extreme geomagnetic event comparable to the Carrington event occurring within the next 10 years is 10.3% 95%  confidence interval (CI) [0.9,18.7] for a power law distribution but only 3.0% 95% CI [0.6,9.0] for a lognormal distribution. However, our results depend crucially on (1) how we define an extreme event, (2) the statistical model used to describe how the events are distributed in intensity, (3) the techniques used to infer the model parameters, and (4) the data and duration used for the analysis. We test a major assumption that the data represent time stationary processes and discuss the implications. If the current trends persist, suggesting that we are entering a period of lower activity, our forecasts may represent upper limits rather than best estimates.
A 277 year cool season dam inflow reconstruction forTasmania, southeasternAustralia
Authors: Allen K. J. , Nichols S. C. , Evans R. , Allie S. , Carson G. , Ling F. , Cook E.R. , Lee G. , Baker P. J.
Published: December 2016

Seasonal variability is a significant source of uncertainty in projected changes to precipitation across southeastern Australia (SEA). While existing instrumental records provide seasonal data for recent decades, most proxy records (e.g., tree rings, corals, speleothems) offer only annual reconstructions of hydroclimate. We present the first cool‐season (July–August) reconstruction of dam inflow (Lake Burbury) for western Tasmania in SEA based on tree‐ring width (Athrotaxis selaginoides) and mean latewood cell wall thickness (Phyllocladus aspleniifolius) chronologies. The reconstruction, produced using principal component regression, verifies back to 1731 and is moderately skillful, explaining around 23% of the variance. According to the reconstruction, relatively low inflow periods occurred around 1860, the early 1900s and 1970, while relatively high inflows occurred in the 1770s and 1810s. Highest reconstructed inflows occurred in 1816, and lowest in 1909. Comparison with available documentary and instrumental records indicates that the reconstruction better captures high rather than low flow events. There is virtually no correlation between our reconstruction and another for December–January inflow for the same catchment, a result consistent with the relationship between seasonal instrumental data. This suggests that conditions in one season have not generally reflected conditions in the other season over the instrumental record, or for the past 277 years. This illustrates the value of obtaining reconstructions of regional hydroclimatic variability for multiple individual seasons in regions where dry and wet seasons are not strongly defined. The results also indicate that the hydroclimate of the southeastern Australian region cannot be adequately represented by a single regional reconstruction.
Benthic biofilm controls on fine particle dynamics in streams
Authors: Roche K. R. , Drummond J. D. , Boano F. , Packman A. I. , Battin T. J. , Hunter W. R.
Published: December 2016

Benthic (streambed) biofilms metabolize a substantial fraction of particulate organic matter and nutrient inputs to streams. These microbial communities comprise a significant proportion of overall biomass in headwater streams, and they present a primary control on the transformation and export of labile organic carbon. Biofilm growth has been linked to enhanced fine particle deposition and retention, a feedback that confers a distinct advantage for the acquisition and utilization of energy sources. We quantified the influence of biofilm structure on fine particle deposition and resuspension in experimental stream mesocosms. Biofilms were grown in identical 3 m recirculating flumes over periods of 18–47 days to obtain a range of biofilm characteristics. Fluorescent, 8 µm particles were introduced to each flume, and their concentrations in the water column were monitored over a 30 min period. We measured particle concentrations using a flow cytometer and mesoscale (10 µm to 1 cm) biofilm structure using optical coherence tomography. Particle deposition‐resuspension dynamics were determined by fitting results to a stochastic mobile‐immobile model, which showed that retention timescales for particles within the biofilm‐covered streambeds followed a power‐law residence time distribution. Particle retention times increased with biofilm areal coverage, biofilm roughness, and mean biofilm height. Our findings suggest that biofilm structural parameters are key predictors of particle retention in streams and rivers.
Variational assimilation of streamflow data in distributed flood forecasting
Authors: Ercolani Giulia , Castelli Fabio
Published: December 2016

Data assimilation has the potential to improve flood forecasting. However, research efforts are still needed for an effective development of assimilation schemes suitable for operational usage, especially in case of distributed hydrologic models. This work presents a new assimilation system of streamflow data from multiple locations in a distributed hydrologic model. The system adopts a mixed variational‐Monte Carlo approach, and is here tested with the hydrologic model MOBIDIC, that is part of the operational flood forecasting chain for Arno river in central Italy. The main objective of the work is to evaluate the actual gain that the system can lead to flood predictions in a real‐time operational usage. Accordingly, a specifically designed assessment strategy is employed. It is based on several hindcast experiments that include both high flow and false alarm events in the period 2009–2014 in Arno river basin. Results show that the assimilation system can significantly increase the accuracy of flow predictions in respect to open loop simulations in both cases. Specific performances depend on location and event, but in the majority of cases the error on predicted peak flow is reduced of more than 50% with a lead time of around 10 h. The analysis reveals also that the structure of the hydrologic model, the coherence between observations at various sites, and the initial watershed saturation level, considerably affect the obtainable performances. Conditions that may lead to a worsening of open loop predictions are identified and discussed.
Evaporation fractionation in a peatland drainage network affects stream water isotope composition
Authors: Sprenger Matthias , Tetzlaff Doerthe , Tunaley Claire , Dick Jonathan , Soulsby Chris
Published: December 2016

There is increasing interest in improving understanding of evaporation within a catchment for an enhanced representation of dominant processes in hydrological models. We used a dual‐isotope approach within a nested experimental design in a boreal catchment in the Scottish Highlands (Bruntland Burn) to quantify the spatiotemporal dynamics of evaporation fractionation in a peatland drainage network and its effect on stream water isotopes. We conducted spatially distributed water sampling within the saturated peatland under different wetness conditions. We used the lc‐excess—which describes the offset of a water sample from the local meteoric water line in the dual‐isotope space—to understand the development of kinetic fractionation during runoff in a peatland network. The evaporation fractionation signal correlated positively with the potential evapotranspiration and negatively with the discharge. The variability of the isotopic enrichment within the peatland drainage network was higher with higher potential evapotranspiration and lower with higher discharge. We found an increased evaporation fractionation toward the center of the peatland, while groundwater seepage from minerogenic soils influenced the isotopic signal at the edge of the peatland. The evaporation signal was imprinted on the stream water, as the discharge from a peatland dominated subcatchment showed a more intense deviation from the local meteoric water line than the discharge from the Bruntland Burn. The findings underline that evaporation fractionation within peatland drainage networks affects the isotopic signal of headwater catchments, which questions the common assumption in hydrological modeling that the isotopic composition of stream waters did not undergo fractionation processes.
Direct and indirect urban water footprints of the United States
Authors: Chini Christopher M. , Konar Megan , Stillwell Ashlynn S.
Published: December 2016

The water footprint of the urban environment is not limited to direct water consumption (i.e., municipal supplies); embedded water in imported resources, or virtual water transfers, provides an additional component of the urban water footprint. Using empirical data, our analysis extends traditional urban water footprinting analysis to quantify both direct and indirect urban resources for the United States. We determine direct water volumes and their embedded energy through open records requests of water utilities. The indirect component of the urban water footprint includes water indirectly consumed through energy and food, relating to the food‐energy‐water nexus. We comprehensively quantify the indirect water footprint for 74 metropolitan statistical areas through the combination of various databases, including the Commodity Flow Survey of the U.S. Census Bureau, the U.S. Department of Agriculture, the Water Footprint Network, and the Energy Information Administration. We then analyze spatial heterogeneity in both direct and indirect water footprints, determining the average urban water footprint in the United States to be 1.64 million gallons of water per person per year [6200 m3/person/yr or 17,000 L/person/d], dominated by indirect water. Additionally, our study of the urban water cycle extends beyond considering only water resources to include embedded energy and equivalent carbon dioxide emissions. The inclusion of multiple sectors of the urban water cycle and their underlying processes provides important insights to the overall urban environment, the interdependencies of the food‐energy‐water nexus, and water resource sustainability. Our results provide opportunities for benchmarking the urban energy‐water nexus, water footprints, and climate change potential.
Adaptive implicit finite element methods for multicomponent compressible flow in heterogeneous and fractured porous media
Authors: Moortgat Joachim
Published: December 2016

This work presents adaptive implicit first‐order and second‐order discontinuous Galerkin (DG) methods for the transport of multicomponent compressible fluids in heterogeneous and fractured porous media, discretized by triangular, quadrilateral, and hexahedral grids. The adaptive implicit method (AIM) combines the advantages of purely explicit or implicit methods (in time). In grid cells with high fluxes or low pore volumes, the transport update is done implicitly to alleviate the Courant‐Friedrichs‐Lewy (CFL) time step constraints of the conditionally stable explicit approach. Grid cells with a large CFL condition are updated explicitly. Combined, this allows higher efficiency than explicit methods, but it reduces the “penalty” of implicit methods, which exhibit high numerical dispersion and are more computationally and storage expensive per time step. The advantages of AIM are modest for uniform grids and rock properties. However, in heterogeneous or fractured reservoirs explicit methods may become impractical, while a fully implicit approach introduces unnecessary numerical dispersion and is overkill for low‐permeability layers and matrix blocks. In such applications, AIM is shown to be significantly more efficient and accurate. The division between explicit and implicit grid cells is made adaptively in space and time. This allows for a high level of explicitness and can also adapt to high fluxes caused by, e.g., viscous and gravitational flow instabilities. Numerical examples demonstrate the powerful features of AIM to model, e.g., solute transport, carbon sequestration in saline aquifers, and miscible gas injection in fractured oil and gas reservoirs.
The integral suspension pressure method (ISP) for precise particle‐size analysis by gravitational sedimentation
Authors: Durner Wolfgang , Iden Sascha C. , von Unold Georg
Published: December 2016

The particle‐size distribution (PSD) of a soil expresses the mass fractions of various sizes of mineral particles which constitute the soil material. It is a fundamental soil property, closely related to most physical and chemical soil properties and it affects almost any soil function. The experimental determination of soil texture, i.e., the relative amounts of sand, silt, and clay‐sized particles, is done in the laboratory by a combination of sieving (sand) and gravitational sedimentation (silt and clay). In the latter, Stokes' law is applied to derive the particle size from the settling velocity in an aqueous suspension. Traditionally, there are two methodologies for particle‐size analysis from sedimentation experiments: the pipette method and the hydrometer method. Both techniques rely on measuring the temporal change of the particle concentration or density of the suspension at a certain depth within the suspension. In this paper, we propose a new method which is based on the pressure in the suspension at a selected depth, which is an integral measure of all particles in suspension above the measuring depth. We derive a mathematical model which predicts the pressure decrease due to settling of particles as function of the PSD. The PSD of the analyzed sample is identified by fitting the simulated time series of pressure to the observed one by inverse modeling using global optimization. The new method yields the PSD in very high resolution and its experimental realization completely avoids any disturbance by the measuring process. A sensitivity analysis of different soil textures demonstrates that the method yields unbiased estimates of the PSD with very small estimation variance and an absolute error in the clay and silt fraction of less than 0.5%.
Dicer, a new regulator of pluripotency exit and LINE‐1 elements in mouse embryonic stem cells
Authors: Bodak Maxime , Cirera‐Salinas Daniel , Yu Jian , Ngondo Richard P. , Ciaudo Constance
Published: December 2016

A gene regulation network orchestrates processes ensuring the maintenance of cellular identity and genome integrity. Small RNAs generated by the RNAse III DICER have emerged as central players in this network. Moreover, deletion of Dicer in mice leads to early embryonic lethality. To better understand the underlying mechanisms leading to this phenotype, we generated Dicer‐deficient mouse embryonic stem cells (mESCs). Their detailed characterization revealed an impaired differentiation potential, and incapacity to exit from the pluripotency state. We also observed a strong accumulation of LINE‐1 (L1s) transcripts, which was translated at protein level and led to an increased L1s retrotransposition. Our findings reveal Dicer as a new essential player that sustains mESCs self‐renewal and genome integrity by controlling L1s regulation.
Engineered Hydrogels for Local and Sustained Delivery of RNA‐Interference Therapies
Authors: Wang Leo L. , Burdick Jason A.
Published: December 2016

It has been nearly two decades since RNA‐interference (RNAi) was first reported. While there are no approved clinical uses, several phase II and III clinical trials suggest the great promise of RNAi therapeutics. One challenge for RNAi therapies is the controlled localization and sustained presentation to target tissues, to both overcome systemic toxicity concerns and to enhance in vivo efficacy. One approach that is emerging to address these limitations is the entrapment of RNAi molecules within hydrogels for local and sustained release. In these systems, nucleic acids are either delivered as siRNA conjugates or within nanoparticles. A plethora of hydrogels has been implemented using these approaches, including both traditional hydrogels that have already been developed for other applications and new hydrogels developed specifically for RNAi delivery. These hydrogels have been applied to various applications in vivo, including cancer, bone regeneration, inflammation and cardiac repair. This review will examine the design and implementation of such hydrogel RNAi systems and will cover the most recent applications of these systems.
Protein‐Modified CuS Nanotriangles: A Potential Multimodal Nanoplatform for In Vivo Tumor Photoacoustic/Magnetic Resonance Dual‐Modal Imaging
Authors: Gao Duyang , Sheng Zonghai , Liu Yubin , Hu Dehong , Zhang Jian , Zhang Xuanjun , Zheng Hairong , Yuan Zhen
Published: December 2016

Controllable preparation of water‐soluble multifunctional nanoprobes is of great significance for cancer early diagnosis. In this study, protein‐modified hydrophilic copper sufide (CuS) nanotriangles with tunable absorption in the second near‐infrared region are developed in the presence of halide ions. Further, gadolinium ions chelated diethylenetriaminepentaacetic acid is conjugated on it by using the unique characteristics of the protein‐protected nanotriangles. Specifically, the as‐obtained nanostructures are investigated as contrast agents for enhanced in vivo photoacoustic/magnetic resonance dual‐modal tumor imaging. More importantly, in vitro and in vivo toxicity analysis are also performed, which show that the dual‐modal nanoprobes are biocompatible for most of the cases. It is demonstrated that the novel as‐prepared protein‐modified nanotriangles are able to work as a nanoplatform to construct dual‐modal nanoprobes, which paves a new avenue for improving the photoacoustic/magnetic resonance imaging contrast in cancer detection. It should be pointed out that other functional blocks may also be linked on it, which makes it a general method to design multifunctional nanoprobes.
Progress in 3D Printing of Carbon Materials for Energy‐Related Applications
Authors: Fu Kun , Yao Yonggang , Dai Jiaqi , Hu Liangbing
Published: December 2016

The additive‐manufacturing (AM) technique, known as three‐dimensional (3D) printing, has attracted much attention in industry and academia in recent years. 3D printing has been developed for a variety of applications. Printable inks are the most important component for 3D printing, and are related to the materials, the printing method, and the structures of the final 3D‐printed products. Carbon materials, due to their good chemical stability and versatile nanostructure, have been widely used in 3D printing for different applications. Good inks are mainly based on volatile solutions having carbon materials as fillers such as graphene oxide (GO), carbon nanotubes (CNT), carbon blacks, and solvent, as well as polymers and other additives. Studies of carbon materials in 3D printing, especially GO‐based materials, have been extensively reported for energy‐related applications. In these circumstances, understanding the very recent developments of 3D‐printed carbon materials and their extended applications to address energy‐related challenges and bring new concepts for material designs are becoming urgent and important. Here, recent developments in 3D printing of emerging devices for energy‐related applications are reviewed, including energy‐storage applications, electronic circuits, and thermal‐energy applications at high temperature. To close, a conclusion and outlook are provided, pointing out future designs and developments of 3D‐printing technology based on carbon materials for energy‐related applications and beyond.
Automatic detection of contact lines in slot coating flows
Authors: Hong Hyeyoung , Nam Jaewook
Published: December 2016

Slot coating is a versatile method used to manufacture thin films at high speed. The success of the method lies in controlling a coating flow surrounded by upstream and downstream menisci. The meniscus edges that are in contact with either the die lips or the substrate surfaces are called contact lines. Visualizations of such lines are important in coating flow research because their shapes and locations are sensitive to operating conditions. In this study, we propose a robust image analysis algorithm for images acquired from flow visualizations. The images are dissected into three regions with different characteristics that need to be treated using different pre‐processing techniques. A standard optimal edge detector is then sufficient to capture the contact lines, and post‐processing steps can be simplified. We also highlight two applications of the proposed algorithm: coating windows, and transient behaviors under external disturbances. © 2017 American Institute of Chemical Engineers AIChE J, 63: 2440–2450, 2017
Quantification of metal‐acid balance in hydroisomerization catalysts: A step further toward catalyst design
Authors: Mendes Pedro S. F. , Silva João M. , Ribeiro M. Filipa , Duchêne Pascal , Daudin Antoine , Bouchy Christophe
Published: December 2016

A methodology was developed to interpret the results of n‐paraffins hydroisomerization over bifunctional catalysts based on two simple kinetic models used consecutively. First, a macrokinetic model was used to obtain the corresponding turnover frequency over the acid sites and the maximum of C16 isomer yield. Second, a dual‐function model was used to correlate these catalytic descriptors to the ratio of metal to acid sites of the catalyst. To illustrate the methodology, Pt/HBEA and Pt/HUSY catalysts with different Pt loadings were evaluated. The impact of metal‐acid balance on the catalytic turnover frequency and the maximal C16 isomer yield were adequately captured for the bifunctional HUSY and HBEA catalysts. Moreover, the parameters of the dual‐function model revealed to be intrinsic to the catalytic properties of the zeolite under the scope. This methodology is believed to be of interest for information‐driven catalyst design for the hydroisomerization of n‐paraffins. © 2017 American Institute of Chemical Engineers AIChE J, 63: 2864–2875, 2017
Mass and heat transfer behavior of oscillating helical coils in relation to heterogeneous reactor design
Authors: Abdel‐Aziz Mohamed Helmy , Nirdosh Inderjit , Sedahmed Gomaa H.
Published: December 2016

Rates of mass and heat transfer at vibrating helical coils were studied by the electrochemical technique with the object of using helical coils as heat exchanger/reactor for conducting liquid–solid diffusion controlled reactions. Variables studied were frequency and amplitude of vibration, tube diameter, and superimposed axial flow velocity. The data for vibrating coil (batch reactor) were correlated for 59 < 
 < 4965; Sc = 2314 by the equation:

urn:x-wiley:00011541:media:aic15614:aic15614-math-0002
The data were found to be consistent with the analogy model. For vibrated helical coils with superimposed axial flow, the data were correlated by the equation:

urn:x-wiley:00011541:media:aic15614:aic15614-math-0003
Importance of the present results in the design and operation of heterogeneous reactors used to conduct diffusion controlled exothermic reactions involving heat sensitive materials was pointed out. Also the importance of the present results in the design and operation of shell and helical tube heat exchangers of improved performance was highlighted. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3141–3149, 2017
Action Civics for Promoting Civic Development: Main Effects of Program Participation and Differences by Project Characteristics
Authors: Ballard Parissa J. , Cohen Alison K. , Littenberg‐Tobias Joshua
Published: December 2016

Using both quantitative and qualitative data, this study examined the effect of participating in an action civics intervention, Generation Citizen (GC), on civic commitment, civic self‐efficacy, and two forms of civic knowledge. The sample consisted of 617 middle and high schools students in 55 classrooms who participated, or were soon to participate, in Generation Citizen. Hierarchical linear models revealed that participating in Generation Citizen was associated with positive gains in action civics knowledge and civic self‐efficacy. Qualitative coding identified three types of project characteristics that captured variability in the action projects student chose to complete: context, content, and contact with decision makers. Interactions between project characteristics and participation in GC revealed differences in civic outcomes depending on project characteristics.
Reflections on the Future of Community Psychology from the Generations after Swampscott: A Commentary and Introduction to the Special Issue
Authors: Tebes Jacob Kraemer
Published: December 2016

This special issue commemorates the 50th anniversary of the founding of U.S. community psychology in Swampscott, Massachusetts in 1965. The issue includes commentaries from a cross‐section of community psychologists educated in community psychology training programs established after Swampscott, in the 1970s or later. The contributors, who vary in their involvement in community‐engaged research, training, and practice, offer a diverse set of perspectives on the field. Each was asked to reflect on the future of community psychology based on their own training and experiences. After providing some background to the Swampscott Conference and the era in which it took place, I offer a few of my own reflections on community psychology's future growth and development. I then introduce the 15 commentaries that follow.
Developmental changes in neuromagnetic rhythms and network synchrony in autism
Authors: Vakorin Vasily A. , Doesburg Sam M. , Leung Rachel C. , Vogan Vanessa M. , Anagnostou Evdokia , Taylor Margot J.
Published: December 2016

Objective

There is gathering consensus that altered connectivity is a hallmark of the autistic brain. This includes atypical neural oscillations and their coordination across brain regions, which are understood to mediate information processing and integration. It remains unclear whether and how connectivity in various neurophysiological frequency ranges develops atypically in autism spectrum disorder (ASD).

Methods

To address this in a cross‐sectional sample, we recorded resting‐state magnetoencephalography from 134 children and adolescents with and without ASD, and calculated resting spectral power and inter‐regional synchrony (functional connectivity).

Results

Although no overall group differences were observed, significant alterations in linear and nonlinear age‐related changes in resting oscillatory power and network synchrony were found. These differences were frequency‐ and region‐specific and implicated brain systems thought to play a prominent role in ASD, such as the frontal cortex and cerebellum. We also found correlations between Autism Diagnostic Observation Schedule scores and the degree to which connectivity in cerebellar networks is “idiosyncratic” in an individual with autism.

Interpretation

We provide the first evidence that it is the curvatures of maturational changes in neurophysiological oscillations and synchrony, rather than disturbances in a particular direction, that characterize the brain function in individuals with ASD. Moreover, the patterns of idiosyncratic distortions of network synchrony relative to the group curve are associated with behavioral symptoms of ASD. Ann Neurol 2017;81:199–211
α‐Arylation and Ring Expansion of Annulated Cyclobutanones: Stereoselective Synthesis of Functionalized Tetralones
Authors: Chang Stanley , Holmes Michael , Mowat Jeffrey , Meanwell Michael , Britton Robert
Published: December 2016

α‐Arylcyclobutanones display unique reactivity that makes them valuable synthetic intermediates and target molecules. We describe the preparation of α‐aryl‐ and α‐heteroarylcyclobutanones through a direct α‐arylation reaction. Problematic fragmentations are avoided by the use of LiOtBu, which promotes a rapid but reversible self‐aldol reaction that slowly releases the enolate required for α‐arylation. We also demonstrate the ring expansion of α‐arylcyclobutanones, a process that is highlighted in the stereoselective synthesis of 1‐methoxy coniothyrinone D.
Graphene Oxide Restricts Growth and Recrystallization of Ice Crystals
Authors: Geng Hongya , Liu Xing , Shi Guosheng , Bai Guoying , Ma Ji , Chen Jingbo , Wu Zhuangyuan , Song Yanlin , Fang Haiping , Wang Jianjun
Published: December 2016

We show graphene oxide (GO) greatly suppresses the growth and recrystallization of ice crystals, and ice crystals display a hexagonal shape in the GO dispersion. Preferred adsorption of GO on the ice crystal surface in liquid water leads to curved ice crystal surface. Therefore, the growth of ice crystal is suppressed owing to the Gibbs–Thompson effect, that is, the curved surface lowers the freezing temperature. Molecular dynamics simulation analysis reveals that oxidized groups on the basal plane of GO form more hydrogen bonds with ice in comparison with liquid water because of the honeycomb hexagonal scaffold of graphene, giving a molecular‐level mechanism for controlling ice formation. Application of GO for cryopreservation shows that addition of only 0.01 wt % of GO to a culture medium greatly increases the motility (from 24.3 % to 71.3 %) of horse sperms. This work reports the control of growth of ice with GO, and opens a new avenue for the application of 2D materials.
A Redox‐Activatable Fluorescent Sensor for the High‐Throughput Quantification of Cytosolic Delivery of Macromolecules
Authors: Wang Zhaohui , Luo Min , Mao Chengqiong , Wei Qi , Zhao Tian , Li Yang , Huang Gang , Gao Jinming
Published: December 2016

Efficient delivery of biomacromolecules (e.g., proteins, nucleic acids) into cell cytosol remains a critical challenge for the development of macromolecular therapeutics or diagnostics. To date, most common approaches to assess cytosolic delivery rely on fluorescent labeling of macromolecules with an “always on” reporter and subcellular imaging of endolysosomal escape by confocal microscopy. This strategy is limited by poor signal‐to‐noise ratio and only offers low throughput, qualitative information. Herein we describe a quantitative redox‐activatable sensor (qRAS) for the real‐time monitoring of cytosolic delivery of macromolecules. qRAS‐labeled macromolecules are silent (off) inside the intact endocytic organelles, but can be turned on by redox activation after endolysosomal disruption and delivery into the cytosol, thereby greatly improving the detection accuracy. In addition to confocal microscopy, this quantitative sensing technology allowed for a high‐throughput screening of a panel of polymer carriers toward efficient cytosolic delivery of model proteins on a plate reader. The simple and versatile qRAS design offers a useful tool for the investigation of new strategies for endolysosomal escape of biomacromolecules to facilitate the development of macromolecular therapeutics for a variety of disease indications.
High‐Performance Electrolytic Oxygen Evolution in Neutral Media Catalyzed by a Cobalt Phosphate Nanoarray
Authors: Xie Lisi , Zhang Rong , Cui Liang , Liu Danni , Hao Shuai , Ma Yongjun , Du Gu , Asiri Abdullah M. , Sun Xuping
Published: December 2016

The topotactic conversion of cobalt phosphide nanoarray on Ti mesh into a cobalt phosphate nanoarray (Co‐Pi NA) via oxidative polarization in phosphate‐buffered water is presented. As a 3D oxygen evolution reaction (OER) catalyst electrode at neutral pH, the resulting Co‐Pi NA/Ti shows exceptionally high catalytic activity and demands an overpotential of only 450 mV to drive a geometrical catalytic current density of 10 mA cm−2. Notably, this catalyst also shows superior long‐term electrochemical stability. The excellent catalytic activity can be attributed to that such 3D nanoarray configuration allows for the exposure of more active sites and the easier diffusion of electrolytes and oxygen.
A Whole Proteome Inventory of Background Photocrosslinker Binding
Authors: Kleiner Philipp , Heydenreuter Wolfgang , Stahl Matthias , Korotkov Vadim S. , Sieber Stephan A.
Published: December 2016

Affinity‐based protein profiling (AfBPP) is a widely applied method for the target identification of bioactive molecules. Probes containing photocrosslinkers, such as benzophenones, diazirines, and aryl azides, irreversibly link the molecule of interest to its target protein upon irradiation with UV light. Despite their prevalent application, little is known about photocrosslinker‐specific off‐targets, affecting the reliability of results. Herein, we investigated background protein labeling by gel‐free quantitative proteomics. Characteristic off‐targets were identified for each photoreactive group and compiled in a comprehensive inventory. In a proof‐of‐principle study, H8, a protein kinase A inhibitor, was equipped with a diazirine moiety. Application of this photoprobe revealed, by alignment with the diazirine background, unprecedented insight into its in situ proteome targets. Taken together, our findings guide the identification of biologically relevant binders in photoprobe experiments.
A Stable Neutral Radical in the Coordination Sphere of Aluminum
Authors: Li Bin , Kundu Subrata , Stückl A. Claudia , Zhu Hongping , Keil Helena , Herbst‐Irmer Regine , Stalke Dietmar , Schwederski Brigitte , Kaim Wolfgang , Andrada Diego M. , Frenking Gernot , Roesky Herbert W.
Published: December 2016

The neutral radical (Me2‐cAAC)2AlCl2 (2) is stabilized by cyclic (alkyl)(amino)carbenes (cAACs). Complex 2 was synthesized by reduction of the Me2‐cAAC:→AlCl3 (1) adduct with KC8 in the presence of another equivalent of Me2‐cAAC. The crystal structure of 2 shows that the Al−C bond lengths of the two carbenes bound to the Al center are considerably different, which is likely the result of intermolecular interactions. Quantum‐chemical calculations from the gas phase give an equilibrium structure with identical Al−C bond lengths. Compound 2 exhibits monoradical character, which was confirmed by EPR measurements. A bonding analysis indicates that the unpaired electron resides mainly at the carbene carbon atoms. Compound 2 is an example for an unusual neutral Al radical.
Hybrid Palladium Nanoparticles for Direct Hydrogen Peroxide Synthesis: The Key Role of the Ligand
Authors: Lari Giacomo M. , Puértolas Begoña , Shahrokhi Masoud , López Núria , Pérez‐Ramírez Javier
Published: December 2016

Ligand‐modified palladium nanoparticles deposited on a carbon carrier efficiently catalyze the direct synthesis of H2O2 and the unique performance is due to their hybrid nanostructure. Catalytic testing demonstrated that the selectivity increases with the HHDMA ligand content from 10 % for naked nanoparticles up to 80 %, rivalling that obtained with state‐of‐the‐art bimetallic catalysts (HHDMA=C20H46NO5P). Furthermore, it remains stable over five consecutive reaction runs owing to the high resistance towards leaching of the organic moiety, arising from its bond with the metal surface. As rationalized by density functional theory, this behavior is attributed to the adsorption mode of the reaction intermediates on the metal surface. Whereas they lie flat in the absence of the organic shell, their electrostatic interaction with the ligand result in a unique vertical configuration which prevents further dissociation and over‐hydrogenation. These findings demonstrate the importance of understanding substrate–ligand interactions in capped nanoparticles to develop smart catalysts for the sustainable manufacture of hydrogen peroxide.
A Novel Method for Constructing Histological Section Datasets of the Basal Ganglia in Digitized Human Brain
Authors: Xie Luoyingzi , Rong Jingjing , Li Qiyu
Published: December 2016

To investigate the construction of the histological section datasets in the basal ganglia of digitized human brain to provide a reference for the meso‐level histological data acquisition. A fresh adult brain from a cadaver with no neurological disease was selected, and tissue blocks of the basal ganglia in the right hemisphere was extracted using the visualization method, followed by pretreatments including gradient dehydrating, gelatin‐embedding and setting of calibration points. And then the tissue blocks was cryosectioned into 60‐μm‐thick coronal sections and the sectional images were captured simultaneously by a digital camera at a fixed position. Two series of sections (one section out of ten) were Nissl‐stained with Toluidine blue and immunostained with the calbindin D‐28K, respectively. Stained sections were digitized by a high resolution scanner. After alignment and registration, contours of nuclei and different nucleic function divisions in the digital images of stained sections were identified, and then were segmented and labeled using software exploited by ourselves. Datasets of one set of registrated serial sectional images and two sets of registrated histochemically stained images in basal ganglia area were obtained, which provide a histological reference for the neurosurgery and diagnostic imaging. a systematic method of cutting, slicing, staining, data acquisition and image registration of large tissue blocks was established, providing a reference for histological data acquisition on the digital human. Anat Rec, 300:1011–1021, 2017. © 2016 Wiley Periodicals, Inc.
Thalamic dopaminergic neurons projects to the paraventricular nucleus‐rostral ventrolateral medulla/C1 neural circuit
Authors: Ogundele Olalekan M. , Lee Charles C. , Francis Joseph
Published: December 2016

Paraventricular nuclei (PVN) projections to the rostral ventrolateral medulla (RVLM)/C1 catecholaminergic neuron group constitute the pre‐autonomic sympathetic center involved in the neural control of systemic cardiovascular function. However, the role of extra‐hypothalamic and thalamic dopaminergic (DA) inputs in this circuit remains underexplored. Using retrograde neuroanatomical tracing and high contrast confocal imaging methods, we investigated the projections and morphology of the discrete thalamic DA neuron groups in the dorsal hypothalamic area and their contribution to the PVN‐RVLM neural circuit. We found that DA neuron subgroups in the Zona Incerta (Zi; 60%) and Reuniens thalamic nuclei (Re; 40%) were labeled comparably to the PVN (85%) after a retrograde tracer was injected into the RVLM/C1 (P < 0.01 mean ± SEM). The Re/Zi DA neuron subgroups were characterized by angulated cell bodies, superiomedial and inferiomedial projections reaching the contralateral Re/Zi and ipsilateral PVN DA neurons respectively. Ultimately, we deduced that the DA projections of the Re/Zi to the PVN contribute to the PVN‐RVLM/C1 neural circuit. As a result of these connections, the Re/Zi DA neuron groups may regulate preautonomic sympathetic events associated with the PVN‐RVLM pathway. Anat Rec, 300:1307–1314, 2017. © 2016 Wiley Periodicals, Inc.