bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitrogen isotope exchange between NO and NO2 and its implications for δ15N variations in tropospheric NOx and atmospheric nitrate
Authors: Walters Wendell W. , Simonini Damian S. , Michalski Greg 
Published: December 2015

AbstractThe nitrogen (N) isotope exchange between nitric oxide (NO) and nitrogen dioxide (NO2) has been previously suggested to influence N stable isotope compositions (δ15N) of these molecules. However, there is disagreement in the magnitude of the N isotopic fractionation (
) resulting from this exchange process between previous experimental and theoretical studies. To this end, we measured
associated with this exchange reaction at various temperatures. Our results indicate
to be 1.0403 ± 0.0015, 1.0356 ± 0.0015, and 1.0336 ± 0.0014 at 278 K, 297 K, and 310 K, respectively. These measured values are within experimental error of the values we calculated using a modified version of the Bigeleisen‐Mayer equation corrected for accurate zero‐point energies, indicating an agreement between experiment and theory. Modeling of this exchange reaction demonstrates that δ15N‐NO2 may exhibit a diurnal and seasonal profile if N isotopic equilibrium is achieved.
Dynamically combining climate models to “supermodel” the tropical Pacific
Authors: Shen Mao‐Lin , Keenlyside Noel , Selten Frank , Wiegerinck Wim , Duane Gregory S. 
Published: December 2015

AbstractWe construct an interactive ensemble of two different climate models to improve simulation of key aspects of tropical Pacific climate. Our so‐called supermodel is based on two atmospheric general circulation models (AGCMs) coupled to a single ocean GCM, which is driven by a weighted average of the air‐sea fluxes. Optimal weights are determined using a machine learning algorithm to minimize sea surface temperature errors over the tropical Pacific. This coupling strategy synchronizes atmospheric variability in the two AGCMs over the equatorial Pacific, where it improves the representation of ocean‐atmosphere interaction and the climate state. In particular, the common double Intertropical Convergence Zone error is suppressed, and the positive Bjerknes feedback improves substantially to match observations well, and the negative heat flux feedback is also much improved. This study supports the concept of supermodeling as a promising multimodel ensemble strategy to improve weather and climate predictions.
Preindustrial atmospheric ethane levels inferred from polar ice cores: A constraint on the geologic sources of atmospheric ethane and methane
Authors: Nicewonger Melinda R. , Verhulst Kristal R. , Aydin Murat , Saltzman Eric S. 
Published: December 2015

AbstractEthane levels were measured in air extracted from Greenland and Antarctic ice cores ranging in age from 994 to 1918 Common Era (C.E.) There is good temporal overlap between the two data sets from 1600 to 1750 C.E. with ethane levels stable at 397 ± 28 parts per trillion (ppt) (±2 standard error (s.e.)) over Greenland and 103 ± 9 ppt over Antarctica. The observed north/south interpolar ratio of ethane (3.9 ± 0.1, 1σ) implies considerably more ethane emissions in the Northern Hemisphere than in the Southern Hemisphere, suggesting geologic ethane sources contribute significantly to the preindustrial ethane budget. Box model simulations based on these data constrain the global geologic emissions of ethane to 2.2–3.5 Tg yr−1 and biomass burning emissions to 1.2–2.5 Tg yr−1 during the preindustrial era. The results suggest biomass burning emissions likely increased since the preindustrial period. Biomass burning and geologic outgassing are also sources of atmospheric methane. The results place constraints on preindustrial methane emissions from these sources.
Inertia gravity wave in the stratosphere and mesosphere observed by Doppler wind and temperature lidar
Authors: Baumgarten G. , Fiedler J. , Hildebrand J. , Lübken F.‐J. 
Published: December 2015

AbstractWe report on the first observation of persistent inertia gravity wave signatures in the horizontal wind and temperature by Doppler Rayleigh lidar in the middle atmosphere. The observations were performed at the Arctic Lidar Observatory for Middle Atmosphere Research station in northern Norway (69°N,16°E) between 21 and 23 January 2012. The measurements cover the altitude range from 20 km to about 80 km during nighttime and to about 70 km during daytime. We observe amplitudes of 5 to 25 m/s and 1 to 8 K in wind and temperature, respectively. The measured kinetic to potential energy density ratio is about 10, indicating that the majority of variability is due to waves with intrinsic frequencies close to the inertial frequency. The entire wavefield is mainly characterized by the presence of multiple waves; however, quasi‐monochromatic waves could be identified at limited times around 60 km altitude with a mean momentum flux in direction of propagation of 3.8 m2/s2.
A new population of terrestrial gamma‐ray flashes in the RHESSI data
Authors: Østgaard N. , Albrecthsen K. H. , Gjesteland T. , Collier A. 
Published: December 2015

AbstractTerrestrial gamma‐ray flashes (TGFs) are the most energetic photon phenomenon occurring naturally on Earth. An outstanding question is as follows: Are these flashes just a rare exotic phenomenon or are they an intrinsic part of lightning discharges and therefore occurring more frequently than previously thought? All measurements of TGFs so far have been limited by the dynamic range and sensitivity of spaceborne instruments. In this paper we show that there is a new population of weak TGFs that has not been identified by search algorithms. We use the World Wide Lightning Location Network (WWLLN) to identify lightning that occurred in 2006 and 2012 within the 800 km field of view of Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). By superposing 740,210 100 ms RHESSI data intervals, centered at the time of the WWLLN detected lightning, we identify at least 141 and probably as many as 191 weak TGFs that were not part of the second RHESSI data catalogue. This supports the suggestion that the global TGF production rate is larger than previously reported.
North‐south asymmetries in the polar thermosphere‐ionosphere system: Solar cycle and seasonal influences
Authors: Cnossen Ingrid , Förster Matthias 
Published: December 2015

AbstractPrevious studies have revealed that ion drift and neutral wind speeds at ~400 km in the polar cap (>80° magnetic latitude) are on average larger in the Northern Hemisphere (NH) than in the Southern Hemisphere, which is at least partly due to asymmetry in the geomagnetic field. Here we investigate for the first time how these asymmetries depend on season and on solar/geomagnetic activity levels. Ion drift measurements from the Cluster mission show little seasonal dependence in their north‐south asymmetry when all data (February 2001–December 2013) are used, but the asymmetry disappears around June solstice for high solar activity and around December solstice for low solar activity. Neutral wind speeds in the polar cap obtained from the Challenging Minisatellite Payload spacecraft (January 2002–December 2008) are always larger in the summer hemisphere, regardless of solar activity, but the high‐latitude neutral wind vortices at dawn and dusk tend to be stronger in the NH, except around December solstice, in particular, when solar activity is low. Simulations with the Coupled Magnetosphere‐Ionosphere‐Thermosphere (CMIT) more or less capture the behavior of the ion drift speeds, which can be explained as a superposition of seasonal and geomagnetic field effects, with the former being stronger for higher solar activity. The behavior of the neutral wind speed and vorticity is not accurately captured by the model. This is probably due to an incorrect seasonal cycle in plasma density around ~400 km in CMIT, which affects the ion drag force. This must be addressed in future work.
Subduction of Pacific Antarctic Intermediate Water in an eddy‐resolving model
Authors: Hiraike Yuri , Tanaka Yukio , Hasumi Hiroyasu 
Published: December 2015

AbstractThe subduction process of Pacific Antarctic Intermediate Water (PAAIW) in the Pacific is investigated using output from an eddy‐resolving ocean model. Focus is on contribution of eddies to the subduction process. To separate the subduction rate into contributions by eddies and mean flows, the temporal residual mean (TRM) velocity is used. In the mean subduction rate, lateral induction caused by the strong eastward flow of the Antarctic Circumpolar Current (ACC) is dominant. The largest rate is located in the Drake Passage. The estimated eddy‐induced subduction rate is comparable with the mean subduction rate, and it tends to cancel the vertical mean component in many regions. In the west of the Drake Passage, however, the eddy‐induced subduction is larger than the vertical mean component, and this eddy‐induced subduction was not detected in previous studies using the thickness diffusion parameterization and an eddy‐permitting model. Results of idealized sensitivity studies to model resolution suggest that the subduction rate would be larger using a model with higher vertical resolution. Therefore, the vertical resolution should be paid more attention in model studies investigating eddy‐induced subduction, and not just the horizontal resolution.
Record‐breaking temperatures in China during the warming and recent hiatus periods
Authors: Zhang Yuanjie , Gao Zhiqiu , Pan Zaitao , Li Dan , Wan Bingcheng 
Published: December 2015

AbstractThe observed and modeled record‐breaking temperature (RBT) frequency in China is analyzed for different segments of the period 1961–2050 including the hiatus period. It is found that significant changes in the RBT frequency occurred earlier, with greater amplitude, for daily minimum temperatures (TN) compared to maximum temperatures (TX) during the past five decades. Changes in the RBT frequency can be mostly explained by the mean warming trend, especially for TN, while in summer also slightly by variance. Moreover, mean climate change affects more the multiday mean RBT than the single‐day counterpart as RBT occurrence is inversely proportional to variance that is smaller for multiday means. In the hiatus period (1998–2013), the ratios of record highs to lows in summer continue to increase in southern China primarily due to the lower frequency of record lows, since the decreasing temperature variance suppressed the increase in record highs under the summer warming. While the winter ratios decreased significantly across most of the country due to the winter cooling. Model simulations show a much smaller asymmetry of the RBT frequency between TX and TN as compared to the observations. The 28‐model median overestimates the ratios for TX owning to missing the relative cooling in the “warming hole” region and is unable to reproduce the RBT characteristics in the hiatus period. Under a high‐emission scenario, increasing rates of future temperature extremes are projected to accelerate with almost doubling ratio trends in the first half of 21st century compared to the historical results.
Tropical cyclone‐ocean interaction in Typhoon Megi (2010)—A synergy study based on ITOP observations and atmosphere‐ocean coupled model simulations
Authors: Wu Chun‐Chieh , Tu Wei‐Tsung , Pun Iam‐Fei , Lin I‐I. , Peng Melinda S. 
Published: December 2015

AbstractA mesoscale model coupling the Weather Research and Forecasting model and the three‐dimensional Price‐Weller‐Pinkel ocean model is used to investigate the dynamical ocean response to Megi (2010). It is found that Megi induces sea surface temperature (SST) cooling very differently in the Philippine Sea (PS) and the South China Sea (SCS). The results are compared to the in situ measurements from the Impact of Typhoons on the Ocean in the Pacific (ITOP) 2010 field experiment, satellite observations, and ocean analysis field from Eastern Asian Seas Ocean Nowcast/Forecast System of the U.S. Naval Research Laboratory. The uncoupled and coupled experiments simulate relatively accurately the track and intensity of Megi over PS; however, the simulated intensity of Megi over SCS varies significantly among the experiments. Only the experiment coupled with three‐dimensional ocean processes, which generates rational SST cooling, reasonably simulates the storm intensity in SCS. Our results suggest that storm translation speed and upper ocean thermal structure are two main factors responsible for Megi's distinct different impact over PS and over SCS. In addition, it is shown that coupling with one‐dimensional ocean process (i.e., only vertical mixing process) is not enough to provide sufficient ocean response, especially under slow translation speed (~2–3 m s−1), during which vertical advection (or upwelling) is significant. Therefore, coupling with three‐dimensional ocean processes is necessary and crucial for tropical cyclone forecasting. Finally, the simulation results show that the stable boundary layer forms on top of the Megi‐induced cold SST area and increases the inflow angle of the surface wind.
Optimal trait scoring for age estimation
Authors: Konigsberg Lyle W. , Frankenberg Susan R. , Liversidge Helen M. 
Published: December 2015

ABSTRACTObjectivesLittle attention has been paid to questions about the applicability of parametric models to age estimation data and the related problem of how to adjust trait scoring in light of potential deviations from particular parametric models. This article addresses this deficit.MethodsA Lagrange multiplier goodness‐of‐fit test is applied to two datasets to address the question of whether or not attainment ages for stages are log‐normally distributed. The first dataset used in this article consists of scores of the Todd ten‐phase system for the pubic symphysis obtained from 938 individuals with known ages. The second dataset consists of scores for 15 stages of formation for the second mandibular molar scored in 2,304 individuals of known age.ResultsFor the Todd ten‐phase system there is a significant departure from log‐normally distributed ages of attainment. To obtain an acceptable goodness‐of‐fit statistic, Todd scores consequently are collapsed into an eight‐phase system that maintains scores I through VII as individual scores but combines phases VIII through X into one phase. The 15‐stage scoring system for the second mandibular molar has an acceptable fit to the log‐normal distribution for ages of attainment.ConclusionsThe results from the analysis of the Todd pubic symphysis scores show that researchers should use goodness‐of‐fit tests for parametric models before deciding to collapse scores. Further, such goodness‐of‐fit tests are an essential tool in answering questions concerning the suitability of various parametric models. For the 15‐stage scoring of the second mandibular molar, the log‐normal model is appropriate for attainment ages. Am J Phys Anthropol 159:557–576, 2016. © 2015 Wiley Periodicals, Inc.
Brief Report: JNK‐2 Controls Aggrecan Degradation in Murine Articular Cartilage and the Development of Experimental Osteoarthritis
Authors: Ismail Heba M. , Miotla‐Zarebska Jadwiga , Troeberg Linda , Tang Xiaodi , Stott Bryony , Yamamoto Kazuhiro , Nagase Hideaki , Fosang Amanda J. , Vincent Tonia L. , Saklatvala Jeremy 
Published: December 2015

ObjectiveThe pathogenesis of osteoarthritis (OA) is poorly understood. Loss of the proteoglycan aggrecan from cartilage is an early event. Recently, we identified a role for the JNK pathway, particularly JNK‐2, in human articular chondrocytes in vitro in regulating aggrecan degradation. The present study was undertaken to investigate whether JNK‐2 has a similar function in vivo and to examine its role in gene expression.MethodsAggrecan fragments were analyzed by Western blotting. OA was induced by destabilization of the medial meniscus (DMM) and assessed at 4, 8, and 12 weeks after surgery. Knee sections were stained with Safranin O. Medial compartments were scored by histologic grading for aggrecan loss and cartilage damage. RNA was extracted from JNK‐2−/− and wild‐type mouse knees 6 hours after DMM or after interleukin‐1 stimulation of the proximal epiphysis, and expression of 33 DMM‐regulated genes was analyzed with quantitative polymerase chain reaction–customized array cards.ResultsIn vitro, basal and interleukin‐1– or tumor necrosis factor–stimulated release of aggrecanase‐generated aggrecan fragments was greatly reduced in cartilage from JNK‐2−/− mice. In the OA model, JNK‐2−/− mice exhibited significant reduction of aggrecanase‐generated fragments and cartilage damage. Of 33 genes investigated, 13 were significantly down‐regulated in JNK‐2−/−mice compared with wild‐type mice, following DMM. These included Has1, Adamts4, Tnf, Il6, Il18, Il18rap, Il1a, Inhba, Cd68, Ngf, Ccr2, Wnt16, and Tnfaip6, but not Adamts5.ConclusionOur results demonstrate that JNK‐2 regulates aggrecan degradation in cultured murine cartilage and surgically induced OA in vivo following mechanical destabilization of the knee joint. This implicates the JNK signaling pathway in OA and suggests potential novel approaches to therapy.
Using resonance light scattering and UV/vis absorption spectroscopy to study the interaction between gliclazide and bovine serum albumin
Authors: Zhang Qiu‐Ju , Liu Bao‐Sheng , Li Gai‐Xia , Han Rong 
Published: December 2015

AbstractAt different temperatures (298, 310 and 318 K), the interaction between gliclazide and bovine serum albumin (BSA) was investigated using fluorescence quenching spectroscopy, resonance light scattering spectroscopy and UV/vis absorption spectroscopy. The first method studied changes in the fluorescence of BSA on addition of gliclazide, and the latter two methods studied the spectral change in gliclazide while BSA was being added. The results indicated that the quenching mechanism between BSA and gliclazide was static. The binding constant (Ka), number of binding sites (n), thermodynamic parameters, binding forces and Hill's coefficient were calculated at three temperatures. Values for the binding constant obtained using resonance light scattering and UV/vis absorption spectroscopy were much greater than those obtained from fluorescence quenching spectroscopy, indicating that methods monitoring gliclazide were more accurate and reasonable. In addition, the results suggest that other residues are involved in the reaction and the mode ‘point to surface’ existed in the interaction between BSA and gliclazide. Copyright © 2015 John Wiley & Sons, Ltd.
Social impact measurement in social enterprises: An interdependence perspective
Authors: Nguyen Linh , Szkudlarek Betina , Seymour Richard G. 
Published: December 2015

AbstractIn response to recent calls for a better understanding of the connection between social enterprises and their environments, we focus on the influence of funding relationships on social impact measurement in social enterprises in Vietnam. We utilize resource dependence theory and take a multiple case study approach to explore the issue. The findings suggest that in order to understand and explain the social impact measurement behaviours of social enterprises and funding organizations, it is critical to understand the interdependence of the parties rather than focus on the technical issue of measurement alone. The paper contributes to the relatively scant but burgeoning theoretical foundations of the social impact measurement and social entrepreneurship domains. Copyright © 2015 ASAC. Published by John Wiley & Sons, Ltd.
Expression dynamics of NADPH oxidases during early zebrafish development
Authors: Weaver Cory J. , Leung Yuk Fai , Suter Daniel M. 
Published: December 2015

ABSTRACTNicotinamide dinucleotide phosphate oxidases (NOX) control various cellular signaling cascades. In the nervous system, there is recent evidence that NOX‐derived reactive oxygen species (ROS) regulate neurite outgrowth, regeneration, and stem cell proliferation; however, a comprehensive NOX gene expression analysis is missing for all major model systems. Zebrafish embryos provide an excellent model system to study neurodevelopment and regeneration because they develop quickly and are well suited for in vivo imaging and molecular approaches. Although the sequences of five NOX genes (nox1, nox2/cybb, nox4, nox5, and duox) have been identified in the zebrafish genome, nothing is known about their expression pattern. Here, we used quantitative polymerase chain reaction combined with in situ hybridization to develop a catalog of nox1, nox2/cybb, nox5, and duox expression in zebrafish during early nervous system development from 12 to 48 hours post fertilization. We found that expression levels of nox1, nox5, and duox are dynamic during the first 2 days of development, whereas nox2/cybb levels remain remarkably stable. By sectioning in situ hybridized embryos, we found a pattern of broad and overlapping NOX isoform expression at 1 and 1.5 days post fertilization. After 2 days of development, a few brain regions displayed increased NOX expression levels. Collectively, these results represent the first comprehensive analysis of NOX gene expression in the zebrafish and will provide a basis for future studies aimed at determining the functions of NOX enzymes in neurodevelopment and regeneration. J. Comp. Neurol. 524:2130–2141, 2016. © 2015 Wiley Periodicals, Inc.
Microconnectomics of the pretectum and ventral thalamus in the chicken (Gallus gallus)
Authors: Vega‐Zuniga Tomas , Marín Gonzalo , González‐Cabrera Cristian , Planitscher Eva , Hartmann Anja , Marks Vanessa , Mpodozis Jorge , Luksch Harald 
Published: December 2015

ABSTRACTThe avian pretectal and ventrothalamic nuclei, encompassing the griseum tectale (GT), n. lentiformis mesencephali (LM), and n. geniculatus lateralis pars ventralis (GLv), are prominent retinorecipient structures related to optic flow operations and visuomotor control. Hence, a close coordination of these neural circuits is to be expected. Yet the connectivity among these nuclei is poorly known. Here, using intracellular labeling and in situ hybridization, we investigated the detailed morphology, connectivity, and neurochemical identity of neurons in these nuclei. Two different cell types exist in the GT: one that generates an axonal projection to the optic tectum (TeO), LM, GLv, and n. intercalatus thalami (ICT), and a second population that only projects to the LM and GLv. In situ hybridization revealed that most neurons in the GT express the vesicular glutamate transporter (VGluT2) mRNA, indicating a glutamatergic identity. In the LM, three morphological cell types were defined, two of which project axons towards dorsal targets. The LM neurons showed strong VGluT2 expression. Finally, the cells located in the GLv project to the TeO, LM, GT, n. principalis precommisuralis (PPC), and ICT. All neurons in the GLv showed strong expression of the vesicular inhibitory amino acid transporter (VIAAT) mRNA, suggesting a GABAergic identity. Our results show that the pretectal and ventrothalamic nuclei are highly interconnected, especially by glutamatergic and GABAergic neurons from the GT and GLv, respectively. This complex morphology and connectivity might be required to organize orienting visuomotor behaviors and coordinate the specific optic flow patterns that they induce. J. Comp. Neurol. 524:2208–2229, 2016. © 2015 Wiley Periodicals, Inc.