bluuebunny/crossref_metadata_2025 huggingface dataset:
A quantification method for methylglyoxal oligomers and its application on 1,3,5-
trimethylbenzene SOA
Authors: Rodigast Maria , Mutzel Anke , Herrmann Hartmut
Published: August 2016

Abstract. Methylglyoxal is often described to form oligomeric compounds in the aqueous particle phase which might have a significant contribution to the formation of aqueous secondary organic aerosol (aqSOA). Thus-far, no suitable method for the quantification of methylglyoxal oligomers is available despite the great effort spent for structure elucidation. In the present study a simplified method was developed to quantify methylglyoxal oligomers as a sum parameter. The method is based on the thermal decomposition of oligomers into methylglyoxal monomers. Formed methylglyoxal monomers were detected using PFBHA (o-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride) derivatisation and gas chromatography/mass spectrometry (GC/MS) analysis. The method development was focused on the heating time (varied between 15 and 48 hours), pH during the heating process (pH = 1 − 7), and heating temperature (50 °C, 100 °C) and optimised values for these conditional parameters are presented. The developed method was applied to quantify methylglyoxal oligomers formed during the OH-radical oxidation of 1,3,5-TMB in the Leipziger aerosol chamber (LEAK). Oligomer formation was investigated as a function of seed particle acidity and relative humidity. A fraction of methylglyoxal oligomers of up to 8 % of the produced organic particle mass was found, highlighting the importance of those oligomers formed solely by methylglyoxal for SOA formation. Overall, the present study provides a new and suitable method for quantification of methylglyoxal oligomers in the aqueous particle phase.
Factors Controlling Black Carbon Distribution in the Arctic
Authors: Qi Ling , Li Qinbin , Li Yingrui , He Cenlin
Published: August 2016

Abstract. We investigate the sensitivity of black carbon (BC) in the Arctic, including BC in snow (BCsnow, ng g−1) and surface air (BCair, μg m−3), to emissions, dry deposition and wet scavenging using a global 3-D chemical transport model (CTM) GEOS-Chem. We find that the model underestimates BCsnow in the Arctic by 40 % on average (median = 11.8 ng g−1). Natural gas flaring substantially increases total BC emissions in the Arctic (by ~ 70 %). The flaring emissions lead to up to 49 % increases (0.1–8.5 ng g−1) in Arctic BCsnow, dramatically improving model comparison with observations (50 % reduction in discrepancy) near flaring source regions (Western Extreme North of Russia). Ample observations suggest that BC dry deposition velocities over snow and ice in current CTMs (0.03 cm s−1 in GEOS-Chem) are exceedingly small. We apply the resistance-in-series method to compute the dry deposition velocity that varies with local meteorological and surface conditions. The resulting velocity is significantly larger and varies by a factor of eight in the Arctic (0.03–0.24 cm s−1), increases the fraction of dry to total BC deposition (16 % to 25 %), yet leaves the total BC deposition and BCsnow in the Arctic unchanged. This is largely explained by the offsetting higher dry and lower wet deposition fluxes. Additionally, we account for the effect of the Wegener-Bergeron-Findeisen (WBF) process in mixed-phase clouds, which releases BC particles from condensed phases (water drops and ice crystals) back to the interstitial air and thereby substantially reduces the scavenging efficiency of BC (by 43–76 % in the Arctic). The resulting BCsnow is up to 80 % higher, BC loading is considerably larger (from 0.25 to 0.43 mg  m−2), and BC lifetime is markedly prolonged (from 9 to 16 days) in the Arctic. Over all, flaring emissions increase BCair in the Arctic (by ~ 20 ng m−3), the updated dry deposition velocity more than halves BCair (by ~ 20 ng  m−3), and the WBF effect increases BCair by 25–70 % during winter and early spring. The resulting model simulation of BCsnow is substantially improved (within 10 % of the observations) and the discrepancies of BCair are much smaller during snow season at Barrow, Alert and Summit (from −67 %–−47 % to −46 %–3 %). Our results point toward an urgent need for better characterization of flaring emissions of BC (e.g. the emission factors, temporal and spatial distribution), extensive measurements of both the dry deposition of BC over snow and ice, and the scavenging efficiency of BC in mixed-phase clouds.
The CAIRN method: automated, reproducible calculation of catchment-averaged denudation rates from cosmogenic nuclide concentrations
Authors: Mudd Simon Marius , Harel Marie-Alice , Hurst Martin D. , Grieve Stuart W. D. , Marrero Shasta M.
Published: August 2016

Abstract. We report a new program for calculating catchment-averaged denudation rates from cosmogenic nuclide concentrations. The method (Catchment-Averaged denudatIon Rates from cosmogenic Nuclides: CAIRN) bundles previously reported production scaling and topographic shielding algorithms. In addition, it calculates production and shielding on a pixel-by-pixel basis. We explore the effect of sampling frequency across both azimuth (Δθ) and altitude (Δϕ) angles for topographic shielding and show that in high relief terrain a relatively high sampling frequency is required, with a good balance achieved between accuracy and computational expense at Δθ = 8° and Δϕ = 5°. CAIRN includes both internal and external uncertainty analysis, and is packaged in freely available software in order to facilitate easily reproducible denudation rate estimates. CAIRN calculates denudation rates but also automates catchment averaging of shielding and production, and thus can be used to provide reproducible input parameters for the CRONUS family of online calculators.
Background error covariance with balance constraints for aerosol species and
applications in variational data assimilation
Authors: Zang Zengliang , Hao Zilong , Li Yi , Pan Xiaobin , You Wei , Li Zhijin , Chen Dan
Published: August 2016

Abstract. Balance constraints are important for background error covariance (BEC) in data assimilation to spread information between different variables and produce balance analysis fields. Using statistical regression, we develop a balance constraint for the BEC of aerosol variables and apply it to a three-dimensional variational data assimilation system in the WRF/Chem model; 1-month forecasts from the WRF/Chem model are employed for BEC statistics. The cross-correlations between the different species are generally high. The largest correlation occurs between elemental carbon and organic carbon with as large as 0.9. After using the balance constraints, the correlations between the unbalanced variables reduce to less than 0.2. A set of data assimilation and forecasting experiments is performed. In these experiments, surface PM2.5 concentrations and speciated concentrations along aircraft flight tracks are assimilated. The analysis increments with the balance constraints show spatial distributions more complex than those without the balance constraints, which is a consequence of the spreading of observation information across variables due to the balance constraints. The forecast skills with the balance constraints show substantial and durable improvements from the 2nd hour to the 16th hour compared with the forecast skills without the balance constraints. The results suggest that the developed balance constraints are important for the aerosol assimilation and forecasting.
Impact of LUCC on Streamflow using the SWAT Model over the Wei
River Basin on the Loess Plateau of China
Authors: Wang Hong , Sun Fubao
Published: August 2016

Abstract. Under the Grain for Green project in China, vegetation recovery constructions have been widely implemented on the Loess Plateau for the purpose of soil and water conservation. Now it becomes controversial whether the recovery constructions of vegetation, particularly forest, is reducing streamflow in rivers of the Yellow River Basin. In this study, we choose the Wei River, the largest branch of the Yellow River and implemented with revegetation constructions, as the study area. To do that, we apply the widely used Soil and Water Assessment Tool (SWAT) model for the upper and middle reaches of the – Wei River basin. The SWAT model was forced with daily observed meteorological forcings (1960–2009), calibrated against daily streamflow for 1960–1969, validated for the period of 1970–1979 and used for analysis for 1980–2009. To investigate the impact of the LUCC (Land Use and land Cover Change) on the streamflow, we firstly use two observed land use maps of 1980 and 2005 that are based on national land survey statistics emerged with satellite observations. We found that the mean streamflow generated by using the 2005 land use map decreased in comparison with that using the 1980 one, with the same meteorological forcings. Of particular interest here, we found the streamflow decreased in agricultural land but increased in forest area. More specifically, the surface runoff, soil flow and baseflow all decreased in agricultural land, while the soil flow and baseflow of forest were increased. To investigate that, we then designed five scenarios including (S1) the present land use (1980), (S2) 10 %, (S3) 20 %, (S4) 40 % and (S5) 100 % of agricultural land was converted into forest. We found that the streamflow consistently increased with agricultural land converted into forest by about 7.4 mm per 10 %. Our modeling results suggest that forest recovery constructions have positive impact on both soil flow and base flow compensating reduced surface runoff, which leads to a slight increase in streamflow in the Wei River with mixed landscapes of Loess Plateau and earth-rock mountain.
Identification of hydrological model parameters variation using
ensemble Kalman filter
Authors: Deng Chao , Liu Pan , Guo Shenglian , Li Zejun , Wang Dingbao
Published: August 2016

Abstract. Hydrological model parameters play an important role in the ability of model prediction. In a stationary context, parameters of hydrological models are treated as constants; however, model parameters may vary with time under climate change and human activities. The technique of ensemble Kalman filter (EnKF) is proposed to identify the temporal variation of parameters for a two-parameter monthly water balance model (TWBM) by assimilating the runoff observations. Through a synthetic experiment, the proposed method is evaluated with time-invariant (i.e., constant) parameters and different types of parameter variations, including trend, abrupt change, and periodicity. Various levels of observation uncertainty are designed to examine the performance of the EnKF. The results show that the EnKF can successfully capture the temporal variations of the model parameters. The application to the Wudinghe basin shows that the water storage capacity (SC) of the TWBM model has an apparent increasing trend during the period from 1958 to 2000. The identified temporal variation of SC is explained by land use and land cover changes due to soil and water conservation measures. Whereas, the application to the Tongtianhe basin shows that the estimated SC has no significant variation during the simulation period of 1982–2013, corresponding to the relatively stationary catchment characteristics. The evapotranspiration parameter (C) has temporal variations while no obvious change patterns exist. The proposed method provides an effective tool for quantifying the temporal variations of the model parameters, thereby improving the accuracy and reliability of model simulations and forecasts.
Report on ICDP workshop CONOSC (COring the NOrth Sea Cenozoic)
Authors: Westerhoff Wim , Donders Timme , Luthi Stefan
Published: August 2016

Abstract. ICDP workshop COring the NOrth Sea Cenozoic focused on the scientific objectives and the technical aspects of drilling and sampling. Some 55 participants attended the meeting, ranging from climate scientists, drilling engineers, and geophysicists to stratigraphers and public outreach experts. Discussion on the proposed research sharpened the main research lines and led to working groups and the necessary technical details to compile a full proposal that was submitted in January 2016.
Soil moisture redistribution and its effect on inter-annual active
layer temperature and thickness variations in a dry loess terrace in
Adventdalen, Svalbard
Authors: Schuh C. , Frampton A. , Christiansen H. H.
Published: August 2016

Abstract. High resolution field data for the period 2000–2014 consisting of active layer and permafrost temperature, active layer soil moisture, and thaw depth progression from the UNISCALM research site in Adventdalen, Svalbard, is combined with a physically-based coupled cryotic and hydrogeological model to investigate active layer dynamics. The site is a loess-covered river terrace characterized by dry conditions with little to no summer infiltration and an unsaturated active layer. A range of soil moisture characteristic curves consistent with loess sediments are considered and their effects on ice and moisture redistribution, heat flux, energy storage through latent heat transfer, and active layer thickness is investigated and quantified based on hydro-climatic site conditions. Results show that soil moisture retention characteristics exhibit notable control of ice distribution and circulation within the active layer by cryosuction subject to seasonal variability and site-specific surface temperature variations. The retention characteristics also impact unfrozen water and ice content in the permafrost. Although these effects lead to differences in thaw progression rates, the resulting inter-annual variability in active layer thickness is not large. Field data analysis reveals that variations in summer degree days do not notably affect the active layer thaw depths; instead, a cumulative winter degree day index is found to more significantly control inter-annual active layer thickness variation at this site. A tendency of increasing winter temperatures is found to cause a general warming of the subsurface down to 10 m depth (0.05 to 0.26 ˚C/yr, observed and modelled) including an increasing active layer thickness (0.8 cm/yr, observed and 0.3 to 0.8 cm/yr, modelled) during the 14-year study period.
Providing Orthopaedic Care for the Incarcerated: Obstacles and Challenges
Authors: Sraj Shafic A.
Published: August 2016

Scant information on healthcare delivery to inmates is available in the medical literature. Healthcare provision to inmates has different rules than that for the general population and presents particular challenges for orthopaedic surgeons because of the nature of this population and restrictions imposed by their confinement. This population is typically of a lower socioeconomic status and is less well educated, has accumulated injuries over a lifetime, and has a considerable prevalence of communicable and blood-borne diseases, along with a high prevalence of smoking and high-risk behavior, such as drug-seeking, abuse, and self-inflicted injury. These variables add levels of complexity of care, including the determination of medical necessity for orthopaedic referral, the logistics of transportation and follow-up, access to durable medical equipment and ancillary services, and the choices the orthopaedic provider must make to optimize care within these limitations.
Management of Spinal Deformity in Adult Patients With Neuromuscular Disease
Authors: Protopsaltis Themistocles S. , Boniello Anthony J. , Schwab Frank J.
Published: August 2016

A wide range of neuromuscular diseases, including Parkinson disease, cerebral palsy, multiple sclerosis, and myopathy, are associated with spinal deformities. The most common postural deformities include anterocollis, Pisa syndrome (pleurothotonus), scoliosis, and camptocormia. Nonsurgical management of spinal deformity in patients with neuromuscular disease centers on maximizing the medical management of the underlying neurodegenerative pathology before surgical intervention is contemplated. Surgical management can include decompression alone, or decompression and fusion with short or long fusion constructs. Patients with neuromuscular disease are susceptible to postoperative medical complications, such as delirium, epidural hematomas, pulmonary emboli, and cardiac events. Compared with outcomes in the typical patient with spinal deformity, postoperative outcomes in patients with neuromuscular disease have higher rates of surgical complications, such as instrumentation failure, proximal junctional kyphosis, loss of correction, and the need for revision surgery, regardless of the magnitude of surgical treatment.
The Use of MRI in Evaluating Knee Pain in Patients Aged 40 Years and Older
Authors: Adelani Muyibat A. , Mall Nathan A. , Brophy Robert H. , Halstead Mark E. , Smith Matthew V. , Wright Rick W.
Published: August 2016

Introduction: The use of MRI is increasing when evaluating patients with knee pain because it is highly sensitive for detecting intra-articular pathology. However, such changes can be associated with degenerative joint disease, which may be demonstrated with weight-bearing radiographs. The purpose of this study was to determine how often MRI was obtained before orthopaedic referral in patients aged ≥40 years with knee pain, how often weight-bearing radiographs were obtained before MRI, and whether such imaging influenced treatment recommendations.

Methods: In a study of 599 new patients, participating physicians documented the presence of a prereferral MRI and/or plain radiographic studies, the results of weight-bearing radiographs, treatment recommendations, and the impact of any prereferral imaging.

Results: Prereferral use of MRI occurred in 130 patients (22%). Of these patients, plain radiographic studies were obtained for 58% before MRI and 13% had weight-bearing radiographs. Ultimately, 17% had weight-bearing radiographs that demonstrated >50% loss of joint space. Forty-eight percent of prereferral MRIs did not contribute to treatment recommendations. In patients with >50% loss of joint space, MRI was considered unnecessary in 95% of the cases.

Discussion: Many prereferral MRIs do not contribute to clinical decision making. Weight-bearing radiographs can help identify those patients in whom MRI is unlikely to be helpful.

Level of Evidence: Level III
Management of Osteochondritis Dissecans of the Femoral Condyle
Authors: Shea Kevin G. , Carey James L. , Brown Gregory A. , Murray Jayson N. , Pezold Ryan , Sevarino Kaitlyn S.
Published: August 2016

The American Academy of Orthopaedic Surgeons has developed the Appropriate Use Criteria (AUC) document Management of Osteochondritis Dissecans of the Femoral Condyle. Evidence-based information, in conjunction with the clinical expertise of physicians, was used to develop the criteria to improve patient care and obtain the best outcomes while considering the subtleties and distinctions necessary in making clinical decisions. The AUC clinical patient scenarios were derived from patient indications that generally accompany osteochondritis dissecans of the femoral condyle, as well as from current evidence-based clinical practice guidelines and supporting literature. The 64 patient scenarios and 12 treatments were developed by the Writing Panel, a group of clinicians who are specialists in this AUC topic. Lastly, a separate, multidisciplinary Voting Panel (made up of specialists and nonspecialists) rated the appropriateness of treatment of each patient scenario using a 9-point scale to designate a treatment as Appropriate (median rating, 7 to 9), May Be Appropriate (median rating, 4 to 6), or Rarely Appropriate (median rating, 1 to 3).
Graph Layout with Versatile Boundary Constraints
Authors: Zhang Yani , Pang Alex
Published: August 2016

Graph layouts are in general data dependent and help to reveal structural
and attribute relationships in the data set. However, there are situations
when one may wish to alter the layout e.g. to emphasize parts of the data set
or for aesthetic reasons. This paper strives to meet that need for the case
of force-directed graph layout algorithms. Our approach is to add boundary
constraints to specify where graph nodes may or may not be positioned. Users
can interactively draw one or more boundaries. Boundaries may self-intersect
and define different topology e.g. donut or figure eight shapes.
Additional control, subject to the density of nodes,
can impart different density distributions within defined boundaries.
We tested the feasibility of this concept on several data sets and
different boundary constraints.
Interactions cognition-émotion et personnalité psychopathique : des trajectoires distinctes vers les comportements antisociaux et violents
Authors: Verona Edelyn
Published: August 2016

Les chercheurs ont depuis longtemps reconnu l’hétérogénéité des individus présentant des comportements antisociaux et violents. Or, l’étude de la personnalité psychopathique (ou psychopathie), par l’examen de ses différentes facettes, peut aider à mieux comprendre cette hétérogénéité. Plus particulièrement, la distinction entre les corrélats des traits interpersonnels et affectifs (Facteur 1) et ceux des traits impulsifs et antisociaux (Facteur 2) de la psychopathie suggère l’existence d’au moins deux trajectoires pouvant mener aux comportements antisociaux. Basée sur diverses études en neurosciences cognitives et affectives, nous proposons une revue ciblée, non exhaustive, des travaux identifiant les mécanismes biopsychologiques impliqués dans ces deux trajectoires, avec une attention particulière accordée aux études utilisant la méthode des potentiels évoqués (PE). Plus spécifiquement, nous présentons une série d’études portant sur les processus cognitifs et affectifs permettant de distinguer, parmi un groupe de délinquants, ceux ayant des traits psychopathiques élevés, en mettant en évidence les altérations des interactions entre émotion et cognition associées à chaque facteur de la psychopathie. L’ensemble de ces résultats mène aux conclusions suivantes. Le Facteur 1, associé à une réponse émotionnelle diminuée exacerbée par des anomalies attentionnelles, correspond à un profil de délinquance caractérisé par des conduites délibérées et une insensibilité émotionnelle. À l’opposé, le Facteur 2 comporte des dérégulations émotionnelles et comportementales, de même que des troubles de contrôle cognitif, particulièrement en contexte émotionnel. Les implications de l’identification de ces processus étiologiques seront ensuite présentées dans la perspective d’une meilleure compréhension des comportements violents et antisociaux.
Crises psychogènes non épileptiques : état des connaissances et apports de l’évaluation des traitements émotionnels
Authors: Rutka Roman , Denis Anne , Vercueil Laurent , Hot Pascal
Published: August 2016

Des crises psychogènes non épileptiques (CPNE) sont des manifestations transitoires d’allure neurologique pouvant évoquer, à tort, le diagnostic de crise épileptique, mais qui n’en présentent en réalité pas l’origine neurologique. Les CPNE ont rencontré ces cinq dernières années un intérêt croissant tant dans la description de la population concernée, que des origines du trouble et du substrat neuronal qui pourraient les sous-tendre. L’existence d’un profil particulier de traitements émotionnels constitue à ce jour une piste prometteuse de caractérisation de cette population qui a reçu une série de confirmations récentes. Nous présentons ici les données issues de différents domaines allant de la psychologie clinique aux neurosciences affectives et examinant les spécificités de traitements émotionnels rapportés dans les CPNE, ainsi que les pistes d’études à développer afin de mieux les caractériser.
Réactivité physiologique et conscience intéroceptive dans les troubles anxieux pédiatriques : une revue conceptuelle et empirique
Authors: Rossignol Mandy , Philippot Pierre , Vögele Claus
Published: August 2016

L’intéroception, correspondant à la capacité de prendre conscience des sensations corporelles (SC) et réponses physiologiques, est supposée jouer un rôle majeur dans l’émergence de la réponse anxieuse. Chez les adultes, différentes études ont montré une altération des processus intéroceptifs en lien avec l’anxiété, qui s’associe à une sensibilité intéroceptive accrue et, paradoxalement, à une surestimation de l’activité physiologique du corps. Dans la mesure où les modèles cognitifs de l’anxiété insistent sur le rôle de ces processus dans l’étiologie et le maintien de l’anxiété et des troubles anxieux, l’étude de ces processus chez l’enfant souffrant d’anxiété est de premier intérêt. Dans cette revue empirique, nous nous intéresserons à la conscience que l’enfant anxieux a de ses SC et au rôle que celle-ci joue dans la pathogenèse du trouble. Dans la mesure où l’intéroception s’appuie sur la conscience de l’expérience physiologique et notamment des réponses cardiovasculaires, nous commencerons par présenter les données relatives à la réactivité cardiaque dans les troubles anxieux pédiatriques. Après une mise au point conceptuelle, nous synthétiserons ensuite les connaissances actuelles provenant des études ayant investigué les processus intéroceptifs chez l’enfant anxieux. Nous conclurons ce travail par une série de propositions pour les recherches futures.
Transmittance characteristics of plasmonic graphene ribbons with a wing
Authors: Yuan Lin , Yan Xin , Wang Yueke , Sang Tian , Yang Guofeng
Published: August 2016

We numerically investigate the transmittance characteristics of graphene ribbons with a wing by the finite element method. By determining the dispersion relation of edge graphene plasmon (EGP) modes and analyzing the mode distributions, it is considered that the transmission dips originate from the resonances of three EGP modes, namely, the symmetrical EGPs, antisymmetrical EGPs, and EGPs of a semi-infinite sheet. By changing the width and length of the wing, it was further confirmed that transmission dips originate from the EGP modes. Owing to the tunable permittivity of graphene by adjusting the gate voltage, the transmittance dips can be easily tuned.
Nanocontact printing of Au nanoarray onto atomically stepped ultrasmooth polymer sheets
Authors: Shimada Kodai , Tan Goon , Nozawa Yasuhisa , Urakami Tatsuhiro , Koyama Koji , Kaneko Satoru , Matsuda Akifumi , Yoshimoto Mamoru
Published: August 2016

Large area Au nanoparticle arrays of dots or meshes were produced onto 0.3-nm-high stepped ultrasmooth poly(methyl methacrylate) (PMMA) sheets by applying a nanocontact-printing technique using a Au-film-coated pillar or mesh molds. The ultrasmooth PMMA sheets were fabricated by thermal nanoimprinting using the atomically stepped sapphire templates. The partial Au ultrathin layer near the protruding area of the mold was adhered onto the PMMA sheet under imprinting conditions (loading of 0.4–2 MPa at 80 °C for 300 s).
Predicting the mineral composition of dust aerosols: Insights from elemental composition measured at the Izaña Observatory
Authors: Pérez García‐Pando Carlos , Miller Ron L. , Perlwitz Jan P. , Rodríguez Sergio , Prospero Joseph M.
Published: August 2016

Regional variations of dust mineral composition are fundamental to climate impacts but generally neglected in climate models. A challenge for models is that atlases of soil composition are derived from measurements following wet sieving, which destroys the aggregates potentially emitted from the soil. Aggregates are crucial to simulating the observed size distribution of emitted soil particles. We use an extension of brittle fragmentation theory in a global dust model to account for these aggregates. Our method reproduces the size‐resolved dust concentration along with the approximately size‐invariant fractional abundance of elements like Fe and Al in the decade‐long aerosol record from the Izaña Observatory, off the coast of West Africa. By distinguishing between Fe in structural and free forms, we can attribute improved model behavior to aggregation of Fe and Al‐rich clay particles. We also demonstrate the importance of size‐resolved measurements along with elemental composition analysis to constrain models.
Overestimating climate warming‐induced methane gas escape from the seafloor by neglecting multiphase flow dynamics
Authors: Stranne C. , O'Regan M. , Jakobsson M.
Published: August 2016

Continental margins host large quantities of methane stored partly as hydrates in sediments. Release of methane through hydrate dissociation is implicated as a possible feedback mechanism to climate change. Large‐scale estimates of future warming‐induced methane release are commonly based on a hydrate stability approach that omits dynamic processes. Here we use the multiphase flow model TOUGH + hydrate (T + H) to quantitatively investigate how dynamic processes affect dissociation rates and methane release. The simulations involve shallow, 20–100 m thick hydrate deposits, forced by a bottom water temperature increase of 0.03°C yr−1 over 100 years. We show that on a centennial time scale, the hydrate stability approach can overestimate gas escape quantities by orders of magnitude. Our results indicate a time lag of > 40 years between the onset of warming and gas escape, meaning that recent climate warming may soon be manifested as widespread gas seepages along the world's continental margins.
Dynamics of water vapor and energy exchanges above two contrasting Sudanian climate ecosystems in Northern Benin (West Africa)
Authors: Mamadou Ossénatou , Galle Sylvie , Cohard Jean‐Martial , Peugeot Christophe , Kounouhewa Basile , Biron Romain , Hector Basile , Zannou Arnaud Bruno
Published: August 2016

Natural ecosystems in sub‐Saharan Africa are experiencing intense changes that will probably modify land surface feedbacks and consequently the regional climate. In this study, we have analyzed water vapor (QLE) and sensible heat (QH) fluxes over a woodland (Bellefoungou, BE) and a cultivated area (Nalohou, NA) in the Sudanian climate of Northern Benin, using 2 years (from July 2008 to June 2010) of eddy covariance measurements. The evaporative fraction (EF) response to environmental and surface variables was investigated at seasonal scale. Soil moisture was found to be the main environmental factor controlling energy partitioning. During the wet seasons, EF was rather stable with an average of 0.75 ± 0.07 over the woodland and 0.70 ± 0.025 over the cultivated area. This means that 70–75% of the available energy was changed into actual evapotranspiration during the investigated wet seasons depending on the vegetation type. The cumulative annual actual evapotranspiration (AET) varied between 730 ± 50 mm yr−1 at the NA site and 1040 ± 70 mm yr−1 at the BE site. With similar weather conditions at the two sites, the BE site showed 30% higher AET values than the NA site. The sensible heat flux QH at the cultivated site was always higher than that of the woodland site, but observed differences were much less than those of QLE. In a land surface conversion context, these differences are expected to impact both atmospheric dynamics and the hydrological cycle.
Modeling hydrological process in a glacier basin on the central Tibetan Plateau with a distributed hydrology soil vegetation model
Authors: Zhang Guoshuai , Kang Shichang , Cuo Lan , Qu Bin
Published: August 2016

A mass and energy balance‐based glacier melt module was coupled with the spatially distributed hydrological soil vegetation model and used to simulate the basin‐scale water and energy balance in the Zhadang glacier basin. Observed hourly meteorological data from 2011 to 2014 were used as model forcing data. The basin‐scale simulations were evaluated at both the point and areal scales using albedo, temperature, and height change on the glacier surface, as well as the mass balance and streamflow of the whole basin. The analysis showed that the model could effectively reproduce the key elements of the energy and mass balance of the Zhadang basin. The analysis demonstrates that radiation was the most important energy component accounting for 80% of total surface energy. On average, glacier runoff contributed to 64% of the total basin discharge during the study period. The overall streamflow was controlled by the glacier mass balance in 2012 and 2014, while temperature and precipitation affected hydrological processes the most during 2011 and 2013. Both high temperature and precipitation resulted in high total basin streamflow but via different mechanisms. High temperatures increase glacier mass loss and glacier melt runoff, whereas high precipitation decreases glacier melt runoff but produces high runoff in nonglacier areas. The early onset of the Indian monsoon with high snowfall reduces glacier surface melt but sustains basin discharge, positively affecting for water resources.
Understanding and optimization of chemical reactor performance for bimodal reaction sequences
Authors: Poissonnier Jeroen , Thybaut Joris W. , Marin Guy B.
Published: August 2016

The relative contributions of heterogeneously catalyzed and homogeneous bulk phase reactions in bimodal reaction sequences have been assessed via 1D reactor simulations. Starting from a reaction network only comprising two parallel, irreversible heterogeneously catalyzed and homogeneous bulk phase steps, complementary consecutive steps were included with the option of being reversible. The final product formed after a minimum number of homogeneous bulk phase reactions is obtained with high yields in continuous flow fixed bed reactors. The products obtained after a higher number of homogeneous bulk phase reactions generally dominate in slurry reactors. Yields of the latter may exhibit an optimum as a function of the catalyst amount in the reactor. The adsorption enthalpies of the intermediates in the reaction network critically determine the position and shape of this maximum. The reversibility of the homogeneous bulk phase steps provides specific opportunities to tune the product yields in bimodal reaction sequences. © 2016 American Institute of Chemical Engineers AIChE J, 63: 111–119, 2017
Redox‐Neutral C1 Functionalization of Unprotected Tetrahydroisoquinolines with Diazo Carbonyl Compounds
Authors: Huang Jun , Li Linyong , Xiao Tiebo , Mao Zong‐wan , Zhou Lei
Published: August 2016

A silver or acid‐mediated three‐component reaction of tetrahydroisoquinolines, benzaldehydes, and diazo compounds has been developed. The reaction provides a novel route to β‐amino‐α‐diazo compounds through redox‐neutral C1 functionalization of unprotected THIQs with diazo carbonyl motifs with high regioselectivity.
Paranasal sinus opacification‐to‐pneumatization ratio applied as a rapid and validated clinician assessment
Authors: Marino Michael J. , Riley Charles A. , Patel Amit S. , Pou Jason D. , Kessler Raymond H. , McCoul Edward D.
Published: August 2016

Background

The utility of clinician‐applied instruments, particularly the Lund‐Mackay score, in the assessment of paranasal sinus computed tomography (CT) in chronic rhinosinusitis (CRS) remains incompletely defined. The purpose of this study was to determine if a new approach to the evaluation of sinus CT could accurately predict the extent of opacification while remaining simple for clinician use.

Methods

Twenty‐four sinus CT scans were measured for the percent of sinus opacification using three‐dimensional (3D) volumetric analyses. The same scans were also evaluated using the Lund‐Mackay score to measure opacification and the Assessment of Pneumatization of the Paranasal Sinuses (APPS) score to measure total sinus volume (TSV). Correlation analysis was performed for the Lund‐Mackay to APPS score ratio as a predictor of percent opacification. Validation analysis was also performed to determine the optimal orientation for Lund‐Mackay scoring, which has not previously been described.

Results

The Lund‐Mackay to APPS score ratio was very strongly correlated with the percentage of sinus opacification measured by 3D volumetric analysis (r = 0.862, r2 = 0.743, p < 0.001). Lund‐Mackay scoring was not statistically different between axial‐only, coronal‐only, or triplanar groups for interrater (p = 0.379) and intrarater reliability (p = 0.312).

Conclusion

The Lund‐Mackay score is validated for rater reliability in multiple orientations. Using the APPS score as a measure of TSV, the Lund‐Mackay‐to‐APPS ratio very strongly correlates with the percentage of sinus opacification by 3D volumetric analysis. Further study will be required to determine if this ratio is predictive of symptom severity.
Promotion of Organic Reactions by Non‐Benzenoid Carbocyclic Aromatic Ions
Authors: Lyons Demelza J. M. , Crocker Reece D. , Blümel Marcus , Nguyen Thanh V.
Published: August 2016

The first three primary members of the non‐benzenoid carbocyclic aromatic ion family, namely cyclopropenium, cyclopentadienide, and cycloheptatrienium (tropylium) ions, have planar cyclic structures with (4n+2)π electrons in fully conjugated systems. They fulfill Hückel's rule for aromaticity and hence possess extraordinary stability. Since the historic discovery of tropylium bromide in the late 19th Century, these non‐benzenoid aromatic ions have attracted a lot of attention because of their unique combination of stability and reactivity. The charge on the aromatic ions makes them more prone to nucleophilic/electrophilic reactions than the neutral benzenoid counterparts. Within the last seven years, there has been a large number of investigations in utilizing aromatic ions to mediate organic reactions. This Review highlights these recent developments and discusses the potential of aromatic ions in promoting synthetically useful organic transformations.
Experimental and theoretical investigations of the antioxidant activity of 2,2′‐methylenebis(4,6‐dialkylphenol) compounds
Authors: Al Zoubi Wail , Karabet François , Al Bandakji Rana , Hussein Khansaa
Published: August 2016

The antioxidant activity of two primary antioxidants, 2,2′‐methylenebis(4‐methyl‐6‐tert‐butylphenol) (MMBPH2) and 2,2′‐methylenebis(4,6‐di‐tert‐butylphenol) (MDBPH2), has been studied using the 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) method. The synthesized compounds have been successfully characterized systematically using elemental analyses, infrared, 1H NMR and 13C NMR spectra and GC–MS. Importantly, it has been found that the compound MMBPH2 in particular is more active in DPPH radical scavenging. In addition, density functional theory calculations (B3LYP) have been used to predict the antioxidant activity and predict structural geometries of the compounds in the gas phase.
Randomized clinical trial of single-incision versus multiport laparoscopic colectomy
Authors: Watanabe J , Ota M , Fujii S , Suwa H , Ishibe A , Endo I
Published: August 2016

Background

The efficacy and safety of single-incision laparoscopic colectomy (SILC) for colonic cancer remain unclear. The aim of this study was to determine the outcomes of SILC compared with multiport laparoscopic colectomy (MPLC) for colonic cancer.

Methods

Patients with histologically proven colonic carcinoma located in the caecum, ascending, sigmoid or rectosigmoid colon, clinically diagnosed as stage 0–III by CT, were eligible for this study. Patients were randomized before surgery and underwent tumour dissection with complete mesocolic excision. Safety analyses were conducted according to randomization groups.

Results

A total of 200 patients were enrolled and randomized to the MPLC (100 patients) or SILC (100 patients) arm. Surgical outcomes were similar between the MPLC and SILC arms, including duration of operation (mean 162 versus 156 min respectively; P = 0·273), blood loss (mean 8·8 versus 21·4 ml; P = 0·102), conversion to open laparotomy (2·0 versus 1·0 per cent; P = 0·561), reoperation (3·0 versus 3·0 per cent; P = 1·000), time to first flatus (both median 1 day; P = 0·155) and postoperative hospital stay (both median 6; P = 0·372). The total skin incision length was significantly shorter in the SILC arm (mean 4·4 cm versus 6·8 cm in the MPLC arm; P < 0·001). The median duration of analgesia use was 5 days in the MPLC and 4 days in the SILC arm (P = 0·485). Overall complication rates were equivalent (15·0 versus 12·0 per cent respecitvely; P = 0·680).

Conclusion

SILC is not superior to MPLC. Registration number: UMIN000007220 (http://www.umin.ac.jp/ctr/index.htm).
Employing a Nickel‐Containing Supramolecular Framework as Ni Precursor for Synthesizing Robust Supported Ni Catalysts for Dry Reforming of Methane
Authors: Li Weizuo , Zhao Zhongkui , Guo Xinwen , Wang Guiru
Published: August 2016

This work presents a facile and efficient approach for preparing well dispersed supported Ni catalyst (HMA@Ni/SBA‐15) for dry reforming of methane (DRM) through the modified impregnation method by using a hexamethylenetetramine (HMA) Ni(II) complex, a three‐dimensional hydrogen‐bonded supramolecular framework, as Ni precursor. By employing this method, the NiII cation was discretely impregnated into the mesoporous channels of SBA‐15 support by the “obstacle effect” of the HMA coordination shell of the Ni complex; and then the Ni nanoparticles were stabilized inside the mesoporous channels of SBA‐15 by the confinement effect. The developed HMA@Ni/SBA‐15 catalyst demonstrated much higher catalytic activity and much better catalytic stability than the traditional Ni/SBA‐15 towards this reaction. The superior catalytic activity was suggested to be associated with the enhanced Ni dispersion and the improved reduction degree of NiO. In addition, the confinement effect of mesopore channels and strengthened interaction between Ni and support by improved Ni dispersion contributed to stabilizing Ni particles during the reduction and reaction process at high temperature. The strengthened Ni–support interaction of HMA@Ni/SBA‐15 favored the formation of whisker‐like carbon, which did not depress the accessibility of Ni active sites. However, owing to the weaker Ni–support interaction, the clearly observed shell‐like carbon closely encapsulated on Ni nanoparticles of spent Ni/SBA‐15 would significantly depress the accessibility of Ni active sites to reactants. The combination of stabilized Ni nanoparticles and well‐kept Ni accessibility of HMA@Ni/SBA‐15 catalyst allows it to show outstanding catalytic stability for DRM reaction. The much superior catalytic activity and stability of the developed HMA@Ni/SBA‐15 catalyst to the traditional Ni/SBA‐15 make it a promising candidate for producing synthesis gas through DRM reaction.
Gutmann's Donor Numbers Correctly Assess the Effect of the Solvent on the Kinetics of SNAr Reactions in Ionic Liquids
Authors: Alarcón‐Espósito Jazmín , Contreras Renato , Tapia Ricardo A. , Campodónico Paola R.
Published: August 2016

We report an experimental study on the effect of solvents on the model SNAr reaction between 1‐chloro‐2,4‐dinitrobenzene and morpholine in a series of pure ionic liquids (IL). A significant catalytic effect is observed with reference to the same reaction run in water, acetonitrile, and other conventional solvents. The series of IL considered include the anions, NTf2−, DCN−, SCN−, CF3SO3−, PF6−, and FAP− with the series of cations 1‐butyl‐3‐methyl‐imidazolium ([BMIM]+), 1‐ethyl‐3‐methyl‐imidazolium ([EMIM]+), 1‐butyl‐2,3‐dimethyl‐imidazolium ([BM2IM]+), and 1‐butyl‐1‐methyl‐pyrrolidinium ([BMPyr]+). The observed solvent effects can be attributed to an “anion effect”. The anion effect appears related to the anion size (polarizability) and their hydrogen‐bonding (HB) abilities to the substrate. These results have been confirmed by performing a comparison of the rate constants with Gutmann's donicity numbers (DNs). The good correlation between rate constants and DN emphasizes the major role of charge transfer from the anion to the substrate.
Erweiterung des Semenov‐Kriteriums auf konzentrationsabhängige Reaktionen
Authors: Hugo Peter
Published: August 2016

Exotherme Flüssigphase‐Reaktionen werden technisch vielfach in gekühlten Batch‐Reaktoren durchgeführt. Ein mögliches Runaway kann bei geeigneter Wahl der Reaktions‐ und Betriebsbedingungen vermieden werden. Es wird gezeigt, dass für Reaktionen in flüssiger Phase anstelle des Semenov‐Kriteriums zur Beurteilung die Sensitivität mit Berücksichtigung der Konzentrationsabhängigkeit verwendet werden muss. Die theoretischen Zusammenhänge werden auf der Grundlage der Stoff‐ und Wärmebilanz abgeleitet. Sie werden anschließend anhand von numerischen Berechnungen veranschaulicht.
Facile Synthesis of Carbon‐Supported Ultrasmall Ag@Pd Core‐Shell Nanocrystals with Superior Electrocatalytic Activity for Direct Formic Acid Fuel Cell Application
Authors: Cao Jianyu , Zhu Zhentao , Zhao Weifang , Xu Juan , Chen Zhidong
Published: August 2016

To design electrocatalysts with excellent performance, morphology, composition and structure is a decisive influential factor. In this work, ultrasmall Ag@Pd core‐shell nanocrystals supported on Vulcan XC72R carbon with different Ag/Pd atomic ratios are synthesized via a facile successive reduction approach with formaldehyde and ethylene glycol as reducing agents, respectively. The Ag‐core/Pd‐shell nanostructures are revealed by high‐resolution transmission electron microscopy (HRTEM). Ag@Pd core‐shell nanocrystals possess a narrow size distribution with an average size of ca. 4.3 nm. In comparison to monometallic Pd/C and commercial Pd black catalysts, such Ag@Pd core‐shell nanocrystals display excellent electrocatalytic activities for formic acid oxidation, which may be due to high Pd utilization derived from the formation of Ag@Pd core‐shell nanostructure and the strong interaction between Ag and Pd.
A propensity score matching analysis of dasatinib and nilotinib as a frontline therapy for patients with chronic myeloid leukemia in chronic phase
Authors: Takahashi Koichi , Kantarjian Hagop M. , Yang Yulong , Sasaki Koji , Jain Preetesh , DellaSala Sara , Ravandi Farhad , Kadia Tapan , Pemmaraju Naveen , Daver Naval , Borthakur Gautam , Garcia‐Manero Guillermo , Jabbour Elias , Cortes Jorge E.
Published: August 2016

BACKGROUND

Both dasatinib and nilotinib are approved frontline therapy for chronic myeloid leukemia in chronic phase (CML‐CP) based on randomized trials compared with imatinib. However, no head‐to‐head comparison of dasatinib and nilotinib has been conducted in patients with newly diagnosed CML‐CP.

METHODS

The authors conducted a propensity score (PS) matched comparison of patients with CML‐CP who received frontline therapy with either dasatinib (N = 102) or nilotinib (N = 104) under the respective phase 2 trials conducted in parallel.

RESULTS

PS matching resulted in 87 patients from each trial being matched for pretreatment characteristics. The 3‐month BCR‐ABL1/ABL1 ratio <10% rate was 93% with dasatinib and 94% with nilotinib (P = .25); the rates of major molecular response at 12 months were 77% and 85%, respectively (P = .13); and the rates of molecular response with 4.5‐log reduction in the ratio at 36 months were 66% and 64%, respectively (P = .96). All other clinically relevant responses were similar between the 2 treatment cohorts. The 3‐year probability of event‐free survival was 89% among the patients who received dasatinib and 87% among those who received nilotinib (P = .99), and the corresponding 3‐year overall survival probabilities were 99% and 93%, respectively (P = .95). No statistical difference was observed between the dasatinib and nilotinib groups in any of the other survival endpoints. The treatment discontinuation rate also was similar between the 2 cohorts (dasatinib group, 18%; nilotinib group, 19%; P = .82).

CONCLUSIONS

In a PS‐matched cohort of patients with newly diagnosed CML‐CP, dasatinib and nilotinib offer similar response and survival outcomes. Both drugs can be considered reasonable standard‐of‐care options as first‐line therapy for patients with CML‐CP. Cancer 2016;122:3336–3343. © 2016 American Cancer Society.