bluuebunny/crossref_metadata_2025 huggingface dataset:
The Weber equation as a normal form with applications to top of the barrier scattering
Authors: Costin Rodica D. , Park Hyejin , Schlag Wilhelm
Published: February 2018

In the paper we revisit the basic problem of tunneling near a nondegenerate global maximum of a potential on the line. We reduce the semiclassical Schrödinger equation to a Weber normal form by means of the Liouville–Green transform. We show that the diffeomorphism which effects this stretching of the independent variable lies in the same regularity class as the potential (analytic or infinitely differentiable) with respect to both variables, i.e., space and energy. We then apply the Weber normal form to the scattering problem for energies near the potential maximum. In particular we obtain a representation of the scattering matrix which is accurate up to multiplicative factors of the form

1 + o(1)

.
Quality assurance in the creative enterprise: an appraisal of select plays of Emeka Nwabueze
Authors: Nwosu Canice Chukwuma , Nwosu Emeka
Published: February 2018

Live performances on live stage, the mother medium are no longer common sights in Nigeria. Thus, the waning influence of the live stage in the nation’s contemporary theatre practice is becoming a newly found but embarrassing tradition among young and even some old theatre practitioners. Hence, the problem of this study is the lull in different stages and sectors of the creative industry that led to the decline in live performance. Poor creativity is one of the cancerous worms that is eating deep into the fabrics of the vibrancy of contemporary African theatre practice. Commercial interest, sexploitation and peripheral creativity are now the order of the day. Thus, the aim of this study is how to assure quality in the creative process through adherence to theoretical provisions, professionalism and finesse in the creative process; reinforced with indebt knowledge of the practitioner’s worldview. Objectives include drawing the practitioners’ attention to existing theories and aspiration towards a robust, vibrant and entertaining live theatre. To achieve this creative process based on a marriage of theory and practice; two of Emeka Nwabueze’s plays, Guardian of the Cosmos and A Parliament of Vultures are examined in this article using case study and content analysis research approaches of the qualitative research method. The researchers concluded that adherence to theory can build and sustain quality assurance mechanism and vibrancy into the postmodern African theatre practice.
Formation and characteristics of secondary aerosols in an
industrialized environment during cold seasons
Authors: Wu Yangzhou , Ge Xinlei , Wang Junfeng , Shen Yafei , Ye Zhaolian , Ge Shun , Wu Yun , Yu Huan , Chen Mindong
Published: February 2018

Abstract. Secondary aerosols including inorganic and organic components often dominate the fine aerosol mass, it is thus important to elucidate the formation and characteristics of these species. In this work, we measured the submicron aerosols (PM1) by using an Aerodyne high resolution soot-particle aerosol mass spectrometer in suburban Nanjing, China. The site was surrounded by industry plants, and the measurement was conducted during cold seasons (February–March 2015). We found that under such environment, the PM1 was predominantly comprised of secondary species (on average 63.2 % from ammonium sulfate and nitrate). Results show that moisture plays a key role to enhance both nitrate and sulfate formations. The moisture promotes the gas-particle partitioning and nocturnal heterogeneous production of nitrate, while transformation of SO2 into sulfate directly in aqueous phase is more significant. The organic aerosol (OA) occupied ~1/4 of total PM1 mass, and the primary OA (POA) and secondary OA (SOA) contributions were almost equal. A specific industry-related OA was separated and a modified graphical method was introduced to describe the evolution of OA. Results further show that the most abundant OA factor, which is the one with highest oxidation degree, is also mainly driven by aqueous-phase processing, while the other two less oxygenated SOA factors are mainly governed by photochemical processing. Peak sizes of sulfate, nitrate and OA all shifted towards larger sizes with the increases of relative humidity, reflecting the effects of aqueousphase processing too. Aqueous-phase driven secondary aerosols were found to be very important in enhancing the PM1 pollution, while photochemical processed SOA was important to OA pollution, leading to a fresher OA at higher OA concentrations. We further demonstrated influences of the aqueous-phase processing and photochemical processing on formation of secondary aerosols by using two typical cases, respectively. This paper highlights the importance of aqueous-phase chemistry on sulfate and nitrate formations, and that different portions of SOA can be dominated by different mechanisms in an industrialized environment.
Alaskan Stream flow in the eastern subarctic Pacific and the eastern
Bering Sea and its impact on biological productivity
Authors: Prants Sergey , Andreev Andrey , Uleysky Michael , Budyansky Maxim
Published: February 2018

Abstract. We demonstrate the transport pathways of Alaskan Stream water in the eastern subarctic Pacific and the eastern Bering Sea from October 1, 1994 to September 12, 2016 with the help of altimetry-based Lagrangian maps. A mesoscale eddy activity along the shelf-deep basin boundaries in the Alaskan Stream region and the eastern Bering Sea is shown to be related with the wind stress curl in the northern North Pacific in winter. A significant correlation is found between the concentration of chlorophyll-a in the Alaskan Stream area and eastern Bering Sea in August–September and the wind stress curl in the northern North Pacific in November–March. The mesoscale dynamics, forced by the wind stress curl in winter, may determine not only lower-trophic-level organism biomass but also salmon abundance/catch in the study area.
Ostracods (Crustacea) as shelf to basin indicators: evidence from Late Devonian Yangdi and Nandong sections in Guangxi, South China
Authors: Song Junjun , Crasquin Sylvie , Gong Yiming
Published: February 2018

Abstract. Forty-eight ostracod species belonging to 28 genera from the Late Devonian of Guangxi in South China are described and figured. The ostracod assemblage from the Nandong section can be attributed to the rhenana–linguiformis conodont zones. The ecological assemblages of ostracods from the Yangdi section correspond to a smooth-podocopid association accompanied by some pelagic entomozoids. This mixed assemblage is indicative of an environment of carbonate platform to slope during an ongoing regression. The ostracod faunas from the Nandong section are on the contrary composed of both pelagic and benthic ostracods and pelagic forms dominate in number of specimens suggesting a basin environment.
Physical laws for precursory phenomena of impending large earthquakes and their applications to predictions
Authors: Takeda Fumihide
Published: February 2018

Abstract. Changes in crustal stresses create an earthquake fault motion which radiates seismic waves. Their analyses quantify the properties of the earthquake with its rupture time, location, fault motion and size that are called earthquake source parameters. We may then regard the event as the emergence of a virtual particle of unit mass at a position in the property space whose coordinate axes are source parameters. At the next event, the particle takes a new position in the space. The consecutive events draw a pathway of the moving particle, which is a trace of the stress changes causing the particle motion. The pathway is zigzagged and non–derivative with respect to time. A mathematical tool named physical wavelets is applied to extracting the equations of particle motion. The extracted equations detect periodic anomalous accelerations precursory to large impending earthquakes weeks and months ahead of time. The periodic particle motions enable us to predict the fault size and motion, rupture time, and epicenter of impending large earthquakes. The mathematical tool with which to extract deterministic precursors embedded in the highly irregular time series of natural and earth systems is also concisely described for mitigating their hazards.
Collective memories and present-day intergroup relations: Introduction to the Special Thematic Section
Authors: Figueiredo Ana , Martinovic Borja , Rees Jonas , Licata Laurent
Published: February 2018

This special thematic section aims to bring together current research on the connections between collective memories – or representations of history – and present-day intergroup relations. Drawing from a multitude of geographical and historical contexts as well as different methodologies, we bring forth ten articles focusing on distinct aspects of the relations between representations of the past and present day intergroup dynamics. The topics covered in these articles focus on one or more of the four research lines identified within this field: 1) the antecedents of collective memories; 2) the contents and structure of collective memories; 3) the official or institutional transmission of collective memories; and 4) distinct socio-psychological correlates of collective memories in present-day societies. Together, the contributions in this special thematic section showcase current directions of research within the field and highlight the need to consider the role of representations of the past for understanding present day instances of intergroup conflict or harmony. We discuss the need for more interdisciplinary work in this field, as well as more applied research in the future.
Permafrost Stores a Globally Significant Amount of Mercury
Authors: Schuster Paul F. , Schaefer Kevin M. , Aiken George R. , Antweiler Ronald C. , Dewild John F. , Gryziec Joshua D. , Gusmeroli Alessio , Hugelius Gustaf , Jafarov Elchin , Krabbenhoft David P. , Liu Lin , Herman‐Mercer Nicole , Mu Cuicui , Roth David A. , Schaefer Tim , Striegl Robert G. , Wickland Kimberly P. , Zhang Tingjun
Published: February 2018

Changing climate in northern regions is causing permafrost to thaw with major implications for the global mercury (Hg) cycle. We estimated Hg in permafrost regions based on in situ measurements of sediment total mercury (STHg), soil organic carbon (SOC), and the Hg to carbon ratio (RHgC) combined with maps of soil carbon. We measured a median STHg of 43 ± 30 ng Hg g soil−1 and a median RHgC of 1.6 ± 0.9 μg Hg g C−1, consistent with published results of STHg for tundra soils and 11,000 measurements from 4,926 temperate, nonpermafrost sites in North America and Eurasia. We estimate that the Northern Hemisphere permafrost regions contain 1,656 ± 962 Gg Hg, of which 793 ± 461 Gg Hg is frozen in permafrost. Permafrost soils store nearly twice as much Hg as all other soils, the ocean, and the atmosphere combined, and this Hg is vulnerable to release as permafrost thaws over the next century. Existing estimates greatly underestimate Hg in permafrost soils, indicating a need to reevaluate the role of the Arctic regions in the global Hg cycle.
Turbulent Kinematic Dynamos in Ellipsoids Driven by Mechanical Forcing
Authors: Reddy K. Sandeep , Favier Benjamin , Le Bars Michael
Published: February 2018

Dynamo action in planetary cores has been extensively studied in the context of convectively driven flows. We show in this letter that mechanical forcings, namely, tides, libration, and precession, are also able to kinematically sustain a magnetic field against ohmic diffusion. Previous attempts published in the literature focused on the laminar response or considered idealized spherical configurations. In contrast, we focus here on the developed turbulent regime and we self‐consistently solve the magnetohydrodynamic equations in an ellipsoidal container. Our results open new avenues of research in dynamo theory where both convection and mechanical forcing can play a role, independently or simultaneously.
On the Nocturnal Downward and Westward Equatorial Ionospheric Plasma Drifts During the 17 March 2015 Geomagnetic Storm
Authors: Bagiya Mala S. , Vichare Geeta , Sinha A. K. , Sripathi S.
Published: February 2018

During quiet period, the nocturnal equatorial ionospheric plasma drifts eastward in the zonal direction and downward in the vertical direction. This quiet time drift pattern could be understood through dynamo processes in the nighttime equatorial ionosphere. The present case study reports the nocturnal simultaneous occurrence of the vertically downward and zonally westward plasma drifts over the Indian latitudes during the geomagnetic storm of 17 March 2015. After ~17:00 UT (~22:10 local time), the vertical plasma drift became downward and coincided with the westward zonal drift, a rarely observed feature of low latitude plasma drifts. The vertical drift turned upward after ~18:00 UT, while the zonal drift became eastward. We mainly emphasize here the distinct bipolar type variations of vertical and zonal plasma drifts observed around 18:00 UT. We explain the vertical plasma drift in terms of the competing effects between the storm time prompt penetration and disturbance dynamo electric fields. Whereas, the westward drift is attributed to the storm time local electrodynamical changes mainly through the disturbance dynamo field in addition to the vertical Pedersen current arising from the spatial (longitudinal) gradient of the field aligned Pedersen conductivity.
Variations of the Electron Fluxes in the Terrestrial Radiation Belts Due To the Impact of Corotating Interaction Regions and Interplanetary Coronal Mass Ejections
Authors: Benacquista R. , Boscher D. , Rochel S. , Maget V.
Published: February 2018

In this paper, we study the variations of the radiation belts electron fluxes induced by the interaction of two types of solar wind structures with the Earth magnetosphere: the corotating interaction regions and the interplanetary coronal mass ejections. We use a statistical method based on the comparison of the preevent and postevent fluxes. Applied to the National Oceanic and Atmospheric Administration‐Polar Operational Environmental Satellites data, this gives us the opportunity to extend previous studies focused on relativistic electrons at geosynchronous orbit. We enlighten how corotating interaction regions and Interplanetary Coronal Mass Ejections can impact differently the electron belts depending on the energy and the L shell. In addition, we provide a new insight concerning these variations by considering their amplitude. Finally, we show strong relations between the intensity of the magnetic storms related to the events and the variation of the flux. These relations concern both the capacity of the events to increase the flux and the deepness of these increases.
First Results From the Ionospheric Extension of WACCM‐X During the Deep Solar Minimum Year of 2008
Authors: Liu Jing , Liu Hanli , Wang Wenbin , Burns Alan G. , Wu Qian , Gan Quan , Solomon Stanley C. , Marsh Daniel R. , Qian Liying , Lu Gang , Pedatella Nicholas M. , McInerney Joe M. , Russell James M. , Schreiner William S.
Published: February 2018

New ionosphere and electrodynamics modules have been incorporated in the thermosphere and ionosphere eXtension of the Whole Atmosphere Community Climate Model (WACCM‐X), in order to self‐consistently simulate the coupled atmosphere‐ionosphere system. The first specified dynamics WACCM‐X v.2.0 results are compared with several data sets, and with the Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model (TIE‐GCM), during the deep solar minimum year. Comparisons with Thermosphere Ionosphere Mesosphere Energetics and Dynamics satellite of temperature and zonal wind in the lower thermosphere show that WACCM‐X reproduces the seasonal variability of tides remarkably well, including the migrating diurnal and semidiurnal components and the nonmigrating diurnal eastward propagating zonal wavenumber 3 component. There is overall agreement between WACCM‐X, TIE‐GCM, and vertical drifts observed by the Communication/Navigation Outage Forecast System (C/NOFS) satellite over the magnetic equator, but apparent discrepancies also exist. Both model results are dominated by diurnal variations, while C/NOFS observed vertical plasma drifts exhibit strong temporal variations. The climatological features of ionospheric peak densities and heights (NmF2 and hmF2) from WACCM‐X are in general agreement with the results derived from Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) data, although the WACCM‐X predicted NmF2 values are smaller, and the equatorial ionization anomaly crests are closer to the magnetic equator compared to COSMIC and ionosonde observations. This may result from the excessive mixing in the lower thermosphere due to the gravity wave parameterization. These data‐model comparisons demonstrate that WACCM‐X can capture the dynamic behavior of the coupled atmosphere and ionosphere in a climatological sense.
Breakpoint Forcing Revisited: Phase Between Forcing and Response
Authors: Contardo S. , Symonds G. , Dufois F.
Published: February 2018

Using the breakpoint forcing model, for long wave generation in the surf zone, expressions for the phase difference between the breakpoint‐forced long waves and the incident short wave groups are obtained. Contrary to assumptions made in previous studies, the breakpoint‐forced long waves and incident wave groups are not in phase and outgoing breakpoint‐forced long waves and incident wave groups are not π out of phase. The phase between the breakpoint‐forced long wave and the incident wave group is shown to depend on beach geometry and wave group parameters. The breakpoint‐forced incoming long wave lags behind the wave group, by a phase smaller than π/2. The phase lag decreases as the beach slope decreases and the group frequency increases, approaching approximately π/16 within reasonable limits of the parameter space. The phase between the breakpoint‐forced outgoing long wave and the wave group is between π/2 and π and it increases as the beach slope decreases and the group frequency increases, approaching 15π/16 within reasonable limits of the parameter space. The phase between the standing long wave (composed of the incoming long wave and its reflection) and the incident wave group tends to zero when the wave group is long compared to the surf zone width. These results clarify the phase relationships in the breakpoint forcing model and provide a new base for the identification of breakpoint forcing signal from observations, laboratory experiments and numerical modeling.
On the Decrease of the Oceanic Drag Coefficient in High Winds
Authors: Donelan Mark A.
Published: February 2018

The sheltering coefficient – prefixing Jeffreys' concept of the exponential wave growth rate at a gas‐liquid interface – is shown to be Reynolds number dependent from laboratory measurements of waves and Reynolds stresses. There are two turbulent flow regimes: wind speed range of 2.5 to 30 m/s where the drag coefficients increase with wind speed, and wind speed range of 30 to 50 m/s where sheltering/drag coefficients decrease/saturate with wind speed. By comparing model calculations of drag coefficients – using a fixed sheltering coefficient – with ocean observations over a wind speed range of 1 to 50 m/s a similar Reynolds number dependence of the oceanic sheltering coefficient is revealed. In consequence the drag coefficient is a function of Reynolds number and wave age, and not just wind speed as frequently assumed. The resulting decreasing drag coefficient above 30 m/s is shown to be critical in explaining the rapid intensification so prominent in the climatology of Atlantic hurricanes. The Reynolds number dependence of the sheltering coefficient, when employed in coupled models, should lead to significant improvements in the prediction of intensification and decay of tropical cyclones. A calculation of curvature at the wave crest suggests that at wind speeds above 56.15 m/s all waves––breaking or not––induce steady flow separation leading to a minimum in the drag coefficient. This is further evidence of the veracity of the observations of the oceanic drag coefficient at high winds.
Reconstruction of the 3‐D Dynamics From Surface Variables in a High‐Resolution Simulation of North Atlantic
Authors: Fresnay S. , Ponte A. L. , Le Gentil S. , Le Sommer J.
Published: February 2018

Several methods that reconstruct the three‐dimensional ocean dynamics from sea level are presented and evaluated in the Gulf Stream region with a 1/60° realistic numerical simulation. The use of sea level is motivated by its better correlation with interior pressure or quasi‐geostrophic potential vorticity (PV) compared to sea surface temperature and sea surface salinity, and, by its observability via satellite altimetry. The simplest method of reconstruction relies on a linear estimation of pressure at depth from sea level. Another method consists in linearly estimating PV from sea level first and then performing a PV inversion. The last method considered, labeled SQG for surface quasi‐geostrophy, relies on a PV inversion but assumes no PV anomalies. The first two methods show comparable skill at levels above −800 m. They moderately outperform SQG which emphasizes the difficulty of estimating interior PV from surface variables. Over the 250–1,000 m depth range, the three methods skillfully reconstruct pressure at wavelengths between 500 and 200 km whereas they exhibit a rapid loss of skill between 200 and 100 km wavelengths. Applicability to a real case scenario and leads for improvements are discussed.
Sodium‐Ion Batteries: Building Effective Layered Cathode Materials with Long‐Term Cycling by Modifying the Surface via Sodium Phosphate
Authors: Jo Jae Hyeon , Choi Ji Ung , Konarov Aishuak , Yashiro Hitoshi , Yuan Shuai , Shi Liyi , Sun Yang‐Kook , Myung Seung‐Taek
Published: February 2018

Surface stabilization of cathode materials is urgent for guaranteeing long‐term cyclability, and is important in Na cells where a corrosive Na‐based electrolyte is used. The surface of P2‐type layered Na2/3[Ni1/3Mn2/3]O2 is modified with ionic, conducting sodium phosphate (NaPO3) nanolayers, ≈10 nm in thickness, via melt‐impregnation at 300 °C; the nanolayers are autogenously formed from the reaction of NH4H2PO4 with surface sodium residues. Although the material suffers from a large anisotropic change in the c‐axis due to transformation from the P2 to O2 phase above 4 V versus Na+/Na, the NaPO3‐coated Na2/3[Ni1/3Mn2/3]O2/hard carbon full cell exhibits excellent capacity retention for 300 cycles, with 73% retention. The surface NaPO3 nanolayers positively impact the cell performance by scavenging HF and H2O in the electrolyte, leading to less formation of byproducts on the surface of the cathodes, which lowers the cell resistance, as evidenced by X‐ray photoelectron spectroscopy and time‐of‐flight secondary‐ion mass spectroscopy. Time‐resolved in situ high‐temperature X‐ray diffraction study reveals that the NaPO3 coating layer is delayed for decomposition to Mn3O4, thereby suppressing oxygen release in the highly desodiated state, enabling delay of exothermic decomposition. The findings presented herein are applicable to the development of high‐voltage cathode materials for sodium batteries.
A Novel, Well‐Resolved Direct Laser Bioprinting System for Rapid Cell Encapsulation and Microwell Fabrication
Authors: Wang Zongjie , Jin Xian , Tian Zhenlin , Menard Frederic , Holzman Jonathan F. , Kim Keekyoung
Published: February 2018

A direct laser bioprinting (DLBP) system is introduced in this work. The DLBP system applies visible‐laser‐induced photo‐crosslinking at a wavelength of 405 nm using the photoinitiator VA‐086. It is shown that such a system can fabricate vertical structures with fine features (less than 50 µm) and high cell viability (greater than 95%). Experimental characterizations and theoretical simulations are presented, and good agreement is seen between the experiments and theory. The DLBP system is applied to the fabrication of (1) cell‐laden hydrogel microgrids, (2) hydrogel microwells, as well as a test of (3) cell encapsulation, and (4) cell seeding. The DLBP system is found to be a promising tool for bioprinting.
Progress of Multicompartmental Particles for Medical Applications
Authors: Misra Asish C. , Lahann Joerg
Published: February 2018

Particulate materials are becoming increasingly used in the literature for medical applications, but translation to the clinical setting has remained challenging as many particle systems face challenges from in vivo barriers. Multicompartmental particles that can incorporate several materials in an individual particle may allow for more intricate control and addressing of issues that otherwise standard particles are unable to. Here, some of the advances made in the use of multicompartmental particles for medical applications are briefly described.
Manipulation of Phonon Transport in Thermoelectrics
Authors: Chen Zhiwei , Zhang Xinyue , Pei Yanzhong
Published: February 2018

For several decades, thermoelectric advancements have largely relied on the reduction of lattice thermal conductivity (κL). According to the Boltzmann transport theory of phonons, κL mainly depends on the specific heat, the velocity, and the scattering of phonons. Intensifying the scattering rate of phonons is the focus for reducing the lattice thermal conductivity. Effective scattering sources include 0D point defects, 1D dislocations, and 2D interfaces, each of which has a particular range of frequencies where phonon scattering is most effective. Because acoustic phonons are generally the main contributors to κL due to their much higher velocities compared to optical phonons, many low‐κL thermoelectrics rely on crystal structure complexity leading to a small fraction of acoustic phonons and/or weak chemical bonds enabling an overall low phonon propagation velocity. While these thermal strategies are successful for advancing thermoelectrics, the principles used can be integrated with approaches such as band engineering to improve the electronic properties, which can promote this energy technology from niche applications into the mainstream.
Mimicking Synaptic Plasticity and Neural Network Using Memtranstors
Authors: Shen Jian‐Xin , Shang Da‐Shan , Chai Yi‐Sheng , Wang Shou‐Guo , Shen Bao‐Gen , Sun Young
Published: February 2018

Artificial synaptic devices that mimic the functions of biological synapses have drawn enormous interest because of their potential in developing brain‐inspired computing. Current studies are focusing on memristive devices in which the change of the conductance state is used to emulate synaptic behaviors. Here, a new type of artificial synaptic devices based on the memtranstor is demonstrated, which is a fundamental circuit memelement in addition to the memristor, memcapacitor, and meminductor. The state of transtance (presented by the magnetoelectric voltage) in memtranstors acting as the synaptic weight can be tuned continuously with a large number of nonvolatile levels by engineering the applied voltage pulses. Synaptic behaviors including the long‐term potentiation, long‐term depression, and spiking‐time‐dependent plasticity are implemented in memtranstors made of Ni/0.7Pb(Mg1/3Nb2/3)O3‐0.3PbTiO3/Ni multiferroic heterostructures. Simulations reveal the capability of pattern learning in a memtranstor network. The work elucidates the promise of memtranstors as artificial synaptic devices with low energy consumption.
Lubricin Antiadhesive Coatings Exhibit Size‐Selective Transport Properties that Inhibit Biofouling of Electrode Surfaces with Minimal Loss in Electrochemical Activity
Authors: Greene George W. , Ortiz Vanessa , Pozo‐Gonzalo Cristina , Moulton Simon E. , Wang Xiaoen , Martin Lisandra L. , Michalczky Agnes , Howlett Patrick C.
Published: February 2018

Electrochemical sensing is a highly effective technique for rapidly detecting and quantifying the presence of electroactive compounds in solution. However, effective sensing requires the electrode surface to be free of contamination, which makes this technique particularly susceptible to the effects of surface fouling due to the unwanted adhesion of biomolecules. Unfortunately, coating electrodes with antiadhesive molecules typically causes electrical passivation with detrimental effects upon electrochemical processes. Lubricin is a large glycoprotein found in articular joints, which self‐assembles on most substrates and exhibits excellent antiadhesive properties. This report finds that lubricin antiadhesive coatings function as a size‐selective transport barrier that physically blocks large, fouling molecules (e.g., proteins) while still allowing small molecules to diffuse into, out‐of, and within this layer more‐or‐less unimpeded. The diffuse nature of the lubricin coatings ensures the electrode retains a large, “free” surface area that facilitates efficient charge transfer. Using cyclic voltammetry to measure the oxidation/reduction of a K3[Fe(CN)6] redox couple at a gold electrode (a system particularly susceptible to fouling), this report shows that antiadhesive lubricin brush coatings can be used for highly sensitive amperometric/voltametric detection of small electroactive compounds in highly fouling solutions of proteins and blood plasma with minimal, immediate impact upon the electrochemistry.
The Importance of Parents' Community Connections for Adolescent Well‐being: An Examination of Military Families
Authors: O'Neal Catherine Walker , Mallette Jacquelyn K. , Mancini Jay A.
Published: February 2018

Drawing from the Social Organization Theory of Action and Change (SOAC), this analysis of 223 military families, including active duty (AD) military and civilian partners, examines how parents' sense of community and community engagement (two elements of community connections) are associated with their own resilient coping, and ultimately with important outcomes capturing their adolescent offspring's individual well‐being (depression, anxiety, and self‐efficacy) and family well‐being (family functioning and parenting quality). The roles of child gender and military context were also examined. Parents with stronger community connections, including greater sense of community and community engagement, reported more resilient coping when faced with adversity. The resilient coping of mothers, in turn, was particularly significant for more positive youth outcomes, when compared to that of fathers. While gender and military context were associated with individual and family well‐being, analyses of model invariance indicated that the model fit similarly for male and female adolescents and those experiencing high and low levels of military transitions. Indirect effects were also examined. These findings illuminate malleable dimensions of both community life and family life, primarily showing that community contexts matter for multiple family members.
Interaction Effects of Neighborhood Disadvantage and Individual Social Support on Frequency of Alcohol Use in Youth Living with HIV
Authors: Brick Leslie Ann D. , Nugent Nicole R. , Kahana Shoshana Y. , Bruce Douglas , Tanney Mary R. , Fernández M. Isabel , Bauermeister Jose A.
Published: February 2018

Youth living with HIV (YLH) experience multiple disease‐related stresses along with the same structural and developmental challenges faced by their uninfected peers; alcohol use among YLH represents a risk behavior by virtue of potential effects on youth health and increased likelihood of engaging in unprotected sex while drinking alcohol. Research aimed at better understanding the interplay of individual‐ and neighborhood‐level influences on alcohol use for YLH is needed to inform interventions. This study examined whether socioeconomic disadvantage (SED) and social support influence, independently and through interaction, alcohol use in YLH. Data from the Adolescent Medicine Trials Network for HIV/AIDS Interventions (ATN) consisted of YLH across 538 neighborhoods in the United States who acquired HIV behaviorally. Neighborhood‐specific data were compiled from the 2010 U.S. Census Bureau and matched with individual‐level data from the ATN (N = 1,357) to examine effects that contribute to variation in frequency of alcohol use. Other drug use, being male, being non‐Black, and older age were associated with greater alcohol use. Higher social support was negatively associated with alcohol use frequency. A cross‐level interaction indicated that the association found between decreasing social support and increasing alcohol use frequency was weakened in areas with lower SED. Implications are discussed.
Discussion group networks in occupational medicine: A tool for continuing education to promote the integration of workers with disabilities
Authors: Rinsky‐Halivni Lilah , Lerman Yehuda
Published: February 2018

Background

Despite their legal rights, individuals with disabilities face numerous obstacles to integration in the workplace which can result in their discharge from the labor force. Currently occupational physicians have few resources to help decide whether to integrate disabled workers in pre‐placement, or in cases of return‐to‐work.

Methods

A network of 13 discussion groups comprised of the occupational physicians of each regional clinic of a large Health Maintenance Organization (HMO) in Israel was created to deal with disability management dilemmas. A moderator compiles and shares the physicians’ opinions and experiences with all network members thus assisting the consulting physician in decision‐making.

Results

Successful management of three representative cases is described to illustrate real‐life implementations of this network.

Conclusion

The network enables both the consulting and other physicians to tap a large knowledge base and decision‐making experience concerning cases of occupational disability management, contributing to professional development and improved service delivery.
A parent‐of‐origin analysis of paternal genetic variants and increased risk of conotruncal heart defects
Authors: Nembhard Wendy N. , Tang Xinyu , Li Jingyun , MacLeod Stewart L. , Levy Joseph , Schaefer Gerald B. , Hobbs Charlotte A. ,   the National Birth Defects Prevention Study
Published: February 2018

The association between conotruncal heart defects (CTHDs) and maternal genetic and environmental exposures is well studied. However, little is known about paternal genetic or environmental exposures and risk of CTHDs. We assessed the effect of paternal genetic variants in the folate, homocysteine, and transsulfuration pathways on risk of CTHDs in offspring. We utilized National Birth Defects Prevention Study data to conduct a family‐based case only study using 616 live‐born infants with CTHDs, born October 1997—August 2008. Maternal, paternal and infant DNA was genotyped using an Illumina® Golden Gate custom single nucleotide polymorphism (SNP) panel. Relative risks (RR) and 95% confidence intervals (CI) from log‐linear models determined parent of origin effects for 921 SNPs in 60 candidate genes involved in the folate, homocysteine, and transsulfuration pathways on risk of CTHDs. The risk of CTHD among children who inherited a paternally derived copy of the A allele on GLRX (rs17085159) or the T allele of GLRX (rs12109442) was 0.23 (95%CI: 0.12, 0.42; p = 1.09 × 10−6) and 0.27 (95%CI: 0.14, 0.50; p = 2.06 × 10−5) times the risk among children who inherited a maternal copy of the same allele. The paternally inherited copy of the GSR (rs7818511) A allele had a 0.31 (95%CI: 0.18, 0.53; p = 9.94 × 10−6] risk of CTHD compared to children with the maternal copy of the same allele. The risk of CTHD is less influenced by variants in paternal genes involved in the folate, homocysteine, or transsulfuration pathways than variants in maternal genes in those pathways.
Selective Transformation of β‐Disubstituted Enones and Ynones in the Presence of β‐Monosubstituted Enones
Authors: Morita Kenta , Ohta Reiya , Watanabe Kei , Fujioka Hiromichi
Published: February 2018

α,β‐Unsaturated carbonyl groups are found in many natural products and functional molecules. The reactivity of nucleophiles towards α,β‐unsaturated carbonyls, such as β‐monosubstituted and disubstituted α,β‐unsaturated ketones (enones) and ynones, is similar. Therefore, the development of a method to selectively convert α,β‐unsaturated carbonyls is desirable. In this study, selective one‐pot reductions and allylations of β‐disubstituted enones or ynones were accomplished in the presence of β‐monosubstituted enones using an in situ protection methodology. β‐Monosubstituted enones selectively reacted with a combination of triphenylphosphine and trimethylsilyl triflate in the presence of β‐disubstituted enones or ynones to produce phosphonium silyl enol ethers, which acted as enone protecting groups during the reduction and allylation of the remaining β‐disubstituted enone or ynone. The substrate was then easily deprotected in the workup to regenerate the parent enone.
Metal‐Free Sensitizers with a Perfluorohexyl Side Chain for Dye‐Sensitized Solar Cells: Properties Alien to Alkyl Chains
Authors: Liang Chia‐Jung , Kumar CH. Pavan , Li Chun‐Ting , Lin Jiann T.
Published: February 2018

New fluorene dyes containing a perfluorohexyl or an n‐hexyl side chain in the conjugated spacer (thiophene) were synthesized for application in dye‐sensitized solar cells. The perfluoro dyes more effectively suppress the charge recombination than their congeners containing a hexyl chain, which leads to a higher open‐circuit voltage (VOC). The more efficient dark current suppression afforded by the perfluorohexyl‐containing dyes was also confirmed by electrochemical impedance spectroscopy. A perfluoro‐containing dye exhibited the best power conversion efficiency of the synthesized compounds, which was further improved to 6.73 % by the addition of chenodeoxycholic acid (10 mm) as a co‐adsorbant. The hydrophobic perfluorohexyl‐containing dyes are more resistant to leaching due to the presence of moisture, leading to higher temporal stability of the DSSCs.
Tris(2‐aminoethyl)amine‐based ferrocene‐terminated dendrimers as burning rate catalysts for ammonium perchlorate‐based propellant decomposition
Authors: Zain‐ul‐Abdin  , Wang Li , Yu Haojie , Khan Rizwan Ullah , Ullah Raja Summe , Haroon Muhammad
Published: February 2018

Ferrocene‐based derivatives show potential application as burning rate catalysts (BRCs) for solid composite propellants. However, migration problems of simple ferrocene‐based derivatives limit their application as BRCs in solid composite propellants. To overcome the migration problems of ferrocene‐based BRCs and to enhance the burning rate of ammonium perchlorate (AP)‐based propellants, zero‐ to second‐generation tris(2‐aminoethyl)amine‐based ferrocene‐terminated dendrimers (G0, G1 and G2) were synthesized. The structures of G0, G1 and G2 were confirmed using 1H NMR, Fourier transform infrared and UV–visible spectroscopies. The electrochemical behavior of G0, G1 and G2 was investigated using cyclic voltammetry. It was found that G0, G1 and G2 showed redox behavior due to the presence of ferrocene and this redox behavior was diffusion controlled over the investigated scan range. The burning rate catalytic effect of G0, G1 and G2 on thermal decomposition of AP was investigated using thermogravimetry and differential thermogravimetry. G0, G1 and G2 showed good catalytic effect on the thermal decomposition of AP. Anti‐migration studies showed that migration of G0, G1 and G2 was much slower than that of 2,2‐bis(ethylferrocenyl)propane (catocene) and ferrocene.
Mechanistic investigation of imine formation in ruthenium‐catalyzed N‐alkylation of amines with alcohols
Authors: Yu Xiaojun , Li Yaqiu , Fu Haiyan , Zheng Xueli , Chen Hua , Li Ruixiang
Published: February 2018

Imines are observed frequently in ruthenium‐catalyzed N‐alkylation of amines with alcohols. Herein, nitrogen–phosphine functionalized carbene ligands were developed and used in ruthenium‐catalyzed N‐alkylation to explore the mechanism of imine formation. The results showed that strongly electron‐donating ligands were beneficial for imine formation and alcohol dehydrogenation to generate acid. In addition, with an increase of electron density of nitrogen atom in substituted amines, the yield of imines in N‐alkylation was improved. At the same time, with electron‐rich imines as substrates, the transfer hydrogenation of imines became difficult. It is suggested that strongly electron‐donating ligands and substrates caused an increase of electron density on the ruthenium center, which resulted in the elimination of hydrogen atoms in active species [LRuH2] as hydrogen gas rather than transfer onto the imine coordinated with the ruthenium center.
Liposome Microencapsulation for the Surface Modification and Improved Entrapment of Cytochrome c for Targeted Delivery
Authors: Kajimoto Kazuaki , Katsumi Tatsuhito , Nakamura Takashi , Kataoka Masatoshi , Harashima Hideyoshi
Published: February 2018

In this study, we established a procedure based on the microencapsulation vesicle (MCV) method for preparing surface‐modified liposomes, using polyethylene glycol (PEG) and a site‐directed ligand, with high entrapment efficiency of cytochrome c (Cyt c). For preparing a water‐in‐oil (W/O) emulsion, egg phosphatidylcholine and cholesterol were dissolved in organic solvents (O phase) and emulsified by sonication with aqueous solution of Cyt c (W1). Although the dispersion stability of the W1/O emulsion was low when n‐hexane was used to dissolve the lipids in the O phase, it was substantially improved by using mixed solvents consisting of n‐hexane and other organic solvents, such as ethanol and dichloromethane (DCM). The W1/O emulsion was then added to another water phase (W2) to prepare the W1/O/W2 emulsion. PEG‐ and/or ligand‐modified lipids were introduced into the W2 phase as external emulsifiers not only for stabilizing the W1/O/W2 emulsion but also for modifying the surface of liposomes obtained later. After solvent evaporation and extrusion for downsizing the liposomes, approximately 50% of Cyt c was encapsulated in the liposomes when the mixed solvent consisting of n‐hexane and DCM at a volume ratio of 75/25 was used in the O phase. Finally, the fluorescence‐labeled liposomes, with a peptide ligand having affinity to the vasculature in adipose tissue, were prepared by the MCV method and intravenously injected into mice. Confocal microscopy showed the substantial accumulation of these liposomes in the adipose tissue vessels. Taken together, the MCV technique, along with solvent optimization, could be useful for generating surface‐modified liposomes with high drug entrapment efficiency for targeted delivery.
Apoptosis of posterior silk gland of Bombyx mori during spinning period and the role of PI3K/Akt pathway
Authors: Hu Jia‐Huan , Cheng Xiao‐Yu , Li Jin‐Xin , Xue Bin , Tian Jiang‐Hai , Hu Jing‐Sheng , Li Bing
Published: February 2018

Bombyx mori is an economic insect of the Lepidoptera. Its posterior silk gland (PSG) is an important organ for fibroin synthesis. In order to study the occurrence of apoptosis in PSG and the role of PI3K/Akt signaling pathway during spinning period, changes in morphology of silk gland, expressions of fibroin components Fib‐H, Fib‐L and P25 and Akt, TOR2, P70S6K and S6 in PI3K/Akt pathway, expressions of apoptosis related genes caspase‐3, caspase‐9 and activity of caspase‐3 were explored. The results showed that the morphology of silk gland dramatically degenerated; transcription of Fib‐H, Fib‐L, and P25 gradually declined with time; and Fib‐L protein level reduced by 0.6‐fold at 72 h. Moreover, the transcription levels of Akt, TOR2, P70S6K, and S6 also decreased by 0.3‐, 0.8‐, 0.7‐, and 0.1‐fold, respectively, indicating that the downregulation of PI3K/Akt signaling pathway could lead to reduction in fibroin synthesis. In addition, the transcription levels of caspase‐3 and caspase‐9 increased by 1.3‐ and 3.6‐fold, respectively, and the enzyme activity of caspase‐3 grew at a maximum of 1.6‐fold. The results showed the occurrence of apoptosis in PSG during spinning period. In conclusion, the present study indicated that both the decline in fibroin components and the increase in apoptosis‐related genes were regulated by PI3K/Akt signaling pathway during spinning period, which shed new light on the functions of PI3K/Akt signaling pathway.
Synthesis, docking, in vitro and in vivo antidiabetic activity of pyrazole‐based 2,4‐thiazolidinedione derivatives as PPAR‐γ modulators
Authors: Naim Mohd. Javed , Alam Ozair , Alam Md. Jahangir , Shaquiquzzaman Mohammad , Alam Md. Mumtaz , Naidu Vegi Ganga Modi
Published: February 2018

The design, synthesis, structure–activity relationship, and biological activity of 2,4‐thiazolidinedione derivatives as peroxisome proliferator‐activated receptor‐γ (PPAR‐γ) modulators for antidiabetic activity are reported. Fifteen 2,4‐thiazolidinedione derivatives clubbed with pyrazole moiety were docked into the ligand binding domain of PPAR‐γ by the Glide XP module of Schrodinger. Eight derivatives (5a, 5b, 5d, 5f, 5i, 5l, 5n, 5o) having Glide XP scores > −8 as compared to the standard drug, rosiglitazone (Glide XP score = −9.165), showed almost similar interaction with the amino acids such as HIS 449, TYR 473, TYR 327, HIS 323, and SER 289 in the molecular docking studies. These eight derivatives were further screened for PPAR‐γ transactivation and in vivo blood glucose lowering activity in the streptozotocin‐induced diabetic rat model. Compounds 5o, 5n, 5a, 5i, and 5b showed 52.06, 51.30, 48.65, 43.13, and 40.36% PPAR‐γ transactivation as compared to the reference drugs rosiglitazone and pioglitazone with 85.30 and 65.22% transactivation, respectively. The data analysis showed significant blood glucose lowering effects (hypoglycemia) of compounds 5o, 5n, and 5a (140.1 ± 4.36, 141.4 ± 6.15, and 150.7 ± 4.15, respectively), along with reference drugs pioglitazone (135.2 ± 4.91) and rosiglitazone (141.1 ± 5.88) as compared to the diabetic control. Furthermore, the most potent compound 5o also elevated the PPAR‐γ gene expression by 2.35‐fold as compared to rosiglitazone (1.27‐fold) and pioglitazone (1.6‐fold). It also significantly lowered the AST, ALT, and ALP levels and caused no damage to the liver.
The birth of collective memories: Analyzing emerging entities in text streams
Authors: Graus David , Odijk Daan , de Rijke Maarten
Published: February 2018

We study how collective memories are formed online. We do so by tracking entities that emerge in public discourse, that is, in online text streams such as social media and news streams, before they are incorporated into Wikipedia, which, we argue, can be viewed as an online place for collective memory. By tracking how entities emerge in public discourse, that is, the temporal patterns between their first mention in online text streams and subsequent incorporation into collective memory, we gain insights into how the collective remembrance process happens online. Specifically, we analyze nearly 80,000 entities as they emerge in online text streams before they are incorporated into Wikipedia. The online text streams we use for our analysis comprise of social media and news streams, and span over 579 million documents in a time span of 18 months. We discover two main emergence patterns: entities that emerge in a “bursty” fashion, that is, that appear in public discourse without a precedent, blast into activity and transition into collective memory. Other entities display a “delayed” pattern, where they appear in public discourse, experience a period of inactivity, and then resurface before transitioning into our cultural collective memory.