bluuebunny/crossref_metadata_2025 huggingface dataset:
Clustered Proppant Design Optimization Utilizing Advanced Geomechanics-Flow-Reservoir Modeling
Authors: Huang Jian , Deshpande Kedar M. , Safari Reza , Fragachan Francisco , Ma Xiaodan , Smith Clayton , Mutlu Uno
Published: August 2015

Fracture potential of a formation is governed by its ability to create high quality/extensive fracture networks that can remain open during production and maintain conductivity. In permeability challenged reservoirs, overall success of the hydraulic fracture operation is measured by this fracture conductivity. Different techniques have been used to increase fracture conductivity by employing a variety of proppant placement strategies. One strategy is to involve alternating (i.e. pulsed) stages of proppant-containing fluids and proppant-free fluids to form heterogeneously distributed proppant clusters and highly conductive flow channels in between each cluster. If engineered accurately, proppant clusters can withstand closure stresses (reducing embedment or crush risk), and result in longer effective fracture length(s) with improved conductivity.

While there are a number of approaches to modify or adjust treatment schedules to optimize clustered proppant placement, many of these suffer from a consideration of only one or two aspects of a fracturing operation. There is a need for a physics based integrated methodology which couples advanced flow and geomechanical models (with production analysis) to optimize engineering design and proppant placement. In this study, clustered proppant design optimization is demonstrated within the framework of an integrated geomechanics-flow-reservoir workflow. The workflow combines quick look analysis (i.e. candidate screening) with advanced computational models (i.e. geomechanical, flow and reservoir models). Candidate screening process utilizes response surface(s) to asses fracture closure risk for multiple well(s) or formation(s). Following the screening procedure, computational fluid dynamics (CFD) flow analysis, geomechanical and reservoir modelling are performed on specific well(s). These results are then used to (i) adjust treatment schedule, perforation geometry, pulse frequency, flow rate, drawdown, (ii) optimize proppant cluster transport/configuration within fractures, and (iii) quantify conductivity & production uplift from multiple scenarios. The formulated workflow indicates that clustered proppant placement design can be optimized, proppant configuration/transport can be customized and operational parameters can be adjusted to maximize production.
Improved solution reliability through generalised finite integral methods
Authors: Barnett A. G.
Published: August 2015

Model solution reliability is shown to be important for applications, where the computational method should accommodate a wide range of flow conditions through each model run without failure through instability or excessive run times. Such difficulties are linked to the use of poor assumptions in the derivation of models, in particular those neglecting energy solutions and the proper treatment of gradient discontinuities and shocks. Finite integral methods are introduced as a formal extension of longstanding traditional hydraulic analysis, leading through Control Element Lifetime Locus (CELL) Integral analysis to a new set of fundamental balance equations, the Full Hydraulic equations. These are then formulated for hydraulic streamtube analysis and discretised for separate numerical solutions for momentum and energy balances. Case studies for steady flow are referenced, where CELL energy balances improve solution robustness through a variable weighting scheme, accelerating convergence in comparison with widely used fixed weighting Upstream Differencing and Central Differencing schemes. A standard dambreak case study is then used to show the same robust system also copes with severe unsteady flow discontinuities, even while Courant Numbers are varied by orders of magnitude.
Influence of bath temperature and pH on the structure of electrodeposited cobalt nanowires
Authors: Mehmood Tahir , Khan Babar Shahzad , Mukhtar Aiman , Tan Ming
Published: August 2015

To fully understand the mechanism of forming fcc Co in electrodeposition, the effect of bath temperature and pH on the structure of electrodeposited Co nanowires is studied by means of X-ray diffraction and scanning electron microscopy. At −3.0 V and pH 2.5, the fraction of fcc Co decreases with increasing temperature, ranging from 1 (25 °C, pure fcc Co) to 0 (45 °C, pure hcp Co). The formation of hcp Co can be attributed to larger critical clusters formed at higher temperatures. The pH value has no appreciable effect on the formation of fcc Co nanowires. This is because the H adatoms produced at the cathodic surface can penetrate quickly through the thin Au film and desorb into air.
Microstructural evolution during solidification of Al–Cu-based alloys
Authors: Zaki Gergis A. , Samuel Agnes M. , Doty Herbert W. , Samuel Fawzy H.
Published: August 2015

The present study focuses on the effect of alloying elements, namely, strontium, titanium, zirconium, scandium and silver, individually or in combination, on the performance of a newly developed Al-2 %Cu-based alloy. A total of thirteen alloy compositions were used in the study. Castings were prepared employing the low pressure die casting technique. The microstructures of selected samples were examined using optical microscopy and electron probe microanalysis. Hardness measurements were also carried out on these alloys using a Brinell hardness tester. The results showed that adding Ti in the amount of 0.15 wt.% in the form of Al-5 %Ti-1 %B master alloy is sufficient to refine the grains in the cast structure in the presence of 200 ppm Sr (0.02 wt.%). Addition of Zr and Sc did not contribute further to the grain refining effect. The main role of addition of these two elements appeared in the formation of complex compounds with Al and Ti. The results obtained from the low pressure die casting samples were compared with those produced using traditional gravity die casting. No heat treatment was applied.
ALS-Linked P56S-VAPB Mutation Impairs the Formation of Multinuclear Myotube in C2C12 Cells
Authors: Tokutake Yukako , Yamada Keita , Ohata Masaki , Obayashi Yoshihito , Tsuchiya Megumi , Yonekura Shinichi
Published: August 2015

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disorder that affects upper and lower motor neurons. Since motor neurons target skeletal muscles, the maintenance system of muscles is disturbed in ALS; however, the mechanism by which this occurs is unknown. In the present study, we investigated the effects of ALS-associated P56S-vesicle-associated membrane protein-associated protein B (VAPB) (P56S-VAPB) on the IRE1-XBP1 pathway, which is involved in the unfolded protein response (UPR) of the mouse myoblast cell line (C2C12 cells). Experiments with C2C12 cells transfected with wild-type wt-VAPB and P56S-VAPB expression vectors showed reduced myotube formation and aberrant myonuclear position in cells expressing P56S-VAPB. Activity of the IRE1-XBP1 pathway in the cells visualized with the ERAI system revealed that the pathway was disrupted in cells expressing P56S-VAPB, whereas the IRE1-XBP1 pathway activity was enhanced in the differentiation process of normal C2C12 cells. These results suggest that disruption of the IRE1-XBP1 pathway is a cause for the reduced myotube formation in P56S-VAPB-expressing cells. The expression level of the VAPB protein has been reported to be reduced in the neurons of patients with ALS. Therefore, it is expected that the IRE1-XBP1 pathway is also impaired in muscle tissues of patients with ALS, which causes a disturbance in the muscle maintenance system.
Modelling Deforestation and Land Cover Transitions of Tropical Peatlands in Sumatra, Indonesia Using Remote Sensed Land Cover Data Sets
Authors: Elz Ian , Tansey Kevin , Page Susan , Trivedi Mandar
Published: August 2015

In Southeast Asia land use change associated with forest loss and degradation is a major source of greenhouse gas (GHG) emissions. This is of particular concern where deforestation occurs on peat soils. A business-as-usual (BAU) land change model was developed using Dinamica EGO© for a REDD+ Demonstration Activity area in south-east Jambi Province, Sumatra, Indonesia containing Berbak National Park (NP). The model output will be used as baseline land change predictions for comparison with alternative land cover management scenarios as part of a REDD+ feasibility study. The study area is approximately 376,000 ha with approximately 50% on peat soils. The model uses published 2000 and 2010 land cover maps as input and projects land cover change for thirty years until 2040. The model predicted that under a BAU scenario the forest area, 185,000 ha in 2010, will decline by 37% by 2040. In protected forest areas, approximately 50% of the study area, forest cover will reduce by 25%. Peat swamp forest will reduce by almost 37%. The greatest land cover category increases are plantation/regrowth areas (which includes oil palm) and open areas which each increase by 30,000 ha. These results indicate that the site has great potential as an Indonesian REDD+ Demonstration Activity.
Can Stabilization and Inhibition of Aquaporins Contribute to Future Development of Biomimetic Membranes?
Authors: To Janet , Torres Jaume
Published: August 2015

In recent years, the use of biomimetic membranes that incorporate membrane proteins, i.e., biomimetic-hybrid membranes, has increased almost exponentially. Key membrane proteins in these systems have been aquaporins, which selectively permeabilize cellular membranes to water. Aquaporins may be incorporated into synthetic lipid bilayers or to more stable structures made of block copolymers or solid-state nanopores. However, translocation of aquaporins to these alien environments has adverse consequences in terms of performance and stability. Aquaporins incorporated in biomimetic membranes for use in water purification and desalination should also withstand the harsh environment that may prevail in these conditions, such as high pressure, and presence of salt or other chemicals. In this respect, modified aquaporins that can be adapted to these new environments should be developed. Another challenge is that biomimetic membranes that incorporate high densities of aquaporin should be defect-free, and this can only be efficiently ascertained with the availability of completely inactive mutants that behave otherwise like the wild type aquaporin, or with effective non-toxic water channel inhibitors that are so far inexistent. In this review, we describe approaches that can potentially be used to overcome these challenges.
Mapping US Urban Extents from MODIS Data Using One-Class Classification Method
Authors: Wan Bo , Guo Qinghua , Fang Fang , Su Yanjun , Wang Run
Published: August 2015

Urban areas are one of the most important components of human society. Their extents have been continuously growing during the last few decades. Accurate and timely measurements of the extents of urban areas can help in analyzing population densities and urban sprawls and in studying environmental issues related to urbanization. Urban extents detected from remotely sensed data are usually a by-product of land use classification results, and their interpretation requires a full understanding of land cover types. In this study, for the first time, we mapped urban extents in the continental United States using a novel one-class classification method, i.e., positive and unlabeled learning (PUL), with multi-temporal Moderate Resolution Imaging Spectroradiometer (MODIS) data for the year 2010. The Defense Meteorological Satellite Program Operational Linescan System (DMSP-OLS) night stable light data were used to calibrate the urban extents obtained from the one-class classification scheme. Our results demonstrated the effectiveness of the use of the PUL algorithm in mapping large-scale urban areas from coarse remote-sensing images, for the first time. The total accuracy of mapped urban areas was 92.9% and the kappa coefficient was 0.85. The use of DMSP-OLS night stable light data can significantly reduce false detection rates from bare land and cropland far from cities. Compared with traditional supervised classification methods, the one-class classification scheme can greatly reduce the effort involved in collecting training datasets, without losing predictive accuracy.
Distributed Wireless Monitoring System for Ullage and Temperature in Wine Barrels
Authors: Zhang Wenqi , Skouroumounis George , Monro Tanya , Taylor Dennis
Published: August 2015

This paper presents a multipurpose and low cost sensor for the simultaneous monitoring of temperature and ullage of wine in barrels in two of the most important stages of winemaking, that being fermentation and maturation. The distributed sensor subsystem is imbedded within the bung of the barrel and runs on battery for a period of at least 12 months and costs around $27 AUD for all parts. In addition, software was designed which allows for the remote transmission and easy visual interpretation of the data for the winemaker. Early warning signals can be sent when the temperature or ullage deviates from a winemakers expectations so remedial action can be taken, such as when topping is required or the movement of the barrels to a cooler cellar location. Such knowledge of a wine’s properties or storage conditions allows for a more precise control of the final wine quality.
Plann: A command‐line application for annotating plastome sequences
Authors: Huang Daisie I. , Cronk Quentin C. B.
Published: August 2015

Premise of the study:

Plann automates the process of annotating a plastome sequence in GenBank format for either downstream processing or for GenBank submission by annotating a new plastome based on a similar, well‐annotated plastome.

Methods and Results:

Plann is a Perl script to be executed on the command line. Plann compares a new plastome sequence to the features annotated in a reference plastome and then shifts the intervals of any matching features to the locations in the new plastome. Plann's output can be used in the National Center for Biotechnology Information's tbl2asn to create a Sequin file for GenBank submission.

Conclusions:

Unlike Web‐based annotation packages, Plann is a locally executable script that will accurately annotate a plastome sequence to a locally specified reference plastome. Because it executes from the command line, it is ready to use in other software pipelines and can be easily rerun as a draft plastome is improved.
Cross-metathesis reaction of α- and β-vinyl C-glycosides with alkenes
Authors: Šnajdr Ivan , Parkan Kamil , Hessler Filip , Kotora Martin
Published: August 2015

Cross-metathesis of α- and β-vinyl C-deoxyribosides and α-vinyl C-galactoside with various terminal alkenes under different conditions was studied. The cross-metathesis of the former proceeded with good yields of the corresponding products in ClCH2CH2Cl the latter required the presence of CuI in CH2Cl2 to achieve good yields of the products. A simple method for the preparation of α- and β-vinyl C-deoxyribosides was also developed. In addition, feasibility of deprotection and further transformations were briefly explored.
Mados ir asmens individualumo raiška šiuolaikinėje vartotojiškoje visuomenėje
Authors: Valivonytė Ieva Mantė
Published: August 2015

The article deals with the concept of creative industries, fashion and its prevalence among consumer society. It analyzes the evolution of consumer culture and its relationship with fashion as well as fashion and style concept of value. The article represents theorist’s insight and reflection on the consumer society and the search for individuality in vogue. Also it reviews the role of fashion in the consumer society as diverse and complex phenomenon, which with the certain character and non-verbal language communicates about some of their values and their impact on the user and groups.
New data on the rare Afrotropical scarab beetles Orphnus drumonti Frolov and Delopleurus naviauxi Frolov et Cambefort (Coleoptera, Scarabaeidae, Orphninae and Scarabaeinae)
Authors: Frolov Andrey , Akhmetova Lilia
Published: August 2015

The scarab beetle genera Orphnus Macleay and Delopleurus Boheman are most speciose in the Afrotropical region. However, a number of species are only known from type specimens, sometimes only from one sex.

New locality records of Orphnus drumonti Frolov (Orphninae) and Delopleurus naviauxi Frolov et Cambefort (Scarabaeinae) are given. The previously unknown female of the former and male of the latter species are described.
Use of Targeted Liposome-based Chemotherapeutics to Treat Breast Cancer
Authors: Khan David R. , Webb Maggie N. , Cadotte Thomas H. , Gavette Madison N.
Published: August 2015

The use of nanocarriers such as liposomes to deliver anticancer drugs to tumors can significantly enhance the therapeutic index of otherwise unencapsulated cytotoxic agents. This is in part because of the fact that the phospholipid bilayer can protect healthy sensitive tissue from the damaging effects of these types of drugs. Furthermore, the ease with which the phospholipid bilayer surface can be modified to allow for polyethylene glycol incorporation resulting in pegylated liposomes allow for increased circulation times in vivo, and thus an overall increase in the concentration of the drug delivered to the tumor site. This explains the clinical success of the liposomal-based drug Doxil, which has proven to be quite efficacious in the treatment of breast cancer. However, significant challenges remain involving poor drug transfer between the liposome and tumor cells with this type of nontargeted drug delivery system. Thus, future work involves the development of “smart” drugs, or targeted drug delivery intended for improved colocalization between the drug and cancerous cells. While it is not possible to entirely discuss such a rapidly growing field of study involving many different types of chemotherapeutics here, in this review, we discuss some of the recent advancements involving the development of targeted liposome-based chemotherapeutics to treat breast cancer.
Weed control in soybean using pyroxasulfone and sulfentrazone
Authors: Belfry Kimberly D. , McNaughton Kristen E. , Sikkema Peter H.
Published: August 2015

Belfry, K. D., McNaughton, K. E. and Sikkema, P. H. 2015. Weed control in soybean using pyroxasulfone and sulfentrazone. Can. J. Plant Sci. 95: 1199–1204. Pyroxasulfone and sulfentrazone are new herbicides currently being evaluated for weed control in soybean [Glycine max (L.) Merr.] in Ontario, Canada. Seven experiments were conducted over a 3-yr period (2011 to 2013) at Ridgetown and Exeter, Ontario, to evaluate weed management using pyroxasulfone, sulfentrazone and their tank-mixes relative to the industry standard, imazethapyr plus metribuzin. Tank-mixing pyroxasulfone and sulfentrazone provided up to 97, 46, 60, 100 and 71% control of common lambsquarters (Chenopodium album L.), common ragweed (Ambrosia artemisiifolia L.), green foxtail [Setaria viridis (L.) Beauv.], Powell amaranth [Amaranthus powellii (S.) Wats.] and velvetleaf (Abutilon theophrasti Medic.), respectively, at 2 wk after treatment. Control with pyroxasulfone and sulfentrazone was improved when tank-mixed, relative to application of each herbicide separately. Although control was variable across weed species, no difference in control was identified between pyroxasulfone plus sulfentrazone and imazethapyr plus metribuzin. Soybean yield was up to 2.7, 2.4 and 2.9 t ha−1 for pyroxasulfone, sulfentrazone and pyroxasulfone plus sulfentrazone application, yet imazethapyr plus metribuzin provided the highest yield (3.3 t ha−1). This research demonstrates that pyroxasulfone plus sulfentrazone may be used as a valuable weed control option in soybean; however, weed community composition may limit herbicidal utility.
Trace metal characterization of aerosol particles and cloud water during HCCT 2010
Authors: Fomba K. W. , van Pinxteren D. , Müller K. , Iinuma Y. , Lee T. , Collett J. L. , Herrmann H.
Published: August 2015

Abstract. Trace metal characterization of bulk and size-resolved aerosol and cloud water samples were performed during the Hill Cap Cloud Thuringia (HCCT) campaign. Cloud water was collected at the top of Mt. Schmücke while aerosol samples were collected at two stations upwind and downwind of Mt. Schmücke. Fourteen trace metals including Ti, V, Fe, Mn, Co, Zn, Ni, Cu, As, Sr, Rb, Pb, Cr, and Se were investigated during four full cloud events (FCEs) that fulfilled the conditions of a continuous air mass flow through the three stations. Aerosol particle trace metal concentrations were found to be lower than those observed in the same region during previous field experiments but were within a similar range to those observed in other rural regions in Europe. Fe and Zn were the most abundant elements with concentration ranges of 0.2–111.6 and 1.1–32.1 ng m−3, respectively. Fe, Mn, and Ti were mainly found in coarse mode aerosols while Zn, Pb, and As were mostly found in the fine mode. Correlation and enrichment factor analysis of trace metals revealed that trace metals such as Ti and Rb were mostly of crustal origin while trace metals such as Zn, Pb, As, Cr, Ni, V, and Cu were of anthropogenic origin. Trace metals such as Fe and Mn were of mixed origins including crustal and combustion sources. Trace metal cloud water concentration decreased from Ti, Mn, Cr, to Co with average concentrations of 9.18, 5.59, 5.54, and 0.46 μg L−1, respectively. A non-uniform distribution of soluble Fe, Cu, and Mn was observed across the cloud drop sizes. Soluble Fe and Cu were found mainly in cloud droplets with diameters between 16 and 22 μm, while Mn was found mostly in larger drops greater than 22 μm. Fe(III) was the main form of soluble Fe especially in the small and larger drops with concentrations ranging from 2.2 to 37.1 μg L−1. In contrast to other studies, Fe(II) was observed mainly in the evening hours, implying its presence was not directly related to photochemical processes. Aerosol–cloud interaction did not lead to a marked increase in soluble trace metal concentrations; rather it led to differences in the chemical composition of the aerosol due to preferential loss of aerosol particles through physical processes including cloud drop deposition to vegetative surfaces.
A comparison of chemical mechanisms using tagged ozone production potential (TOPP) analysis
Authors: Coates J. , Butler T. M.
Published: August 2015

Abstract. Ground-level ozone is a secondary pollutant produced photochemically from reactions of NOx with peroxy radicals produced during volatile organic compound (VOC) degradation. Chemical transport models use simplified representations of this complex gas-phase chemistry to predict O3 levels and inform emission control strategies. Accurate representation of O3 production chemistry is vital for effective prediction. In this study, VOC degradation chemistry in simplified mechanisms is compared to that in the near-explicit Master Chemical Mechanism (MCM) using a box model and by "tagging" all organic degradation products over multi-day runs, thus calculating the tagged ozone production potential (TOPP) for a selection of VOCs representative of urban air masses. Simplified mechanisms that aggregate VOC degradation products instead of aggregating emitted VOCs produce comparable amounts of O3 from VOC degradation to the MCM. First-day TOPP values are similar across mechanisms for most VOCs, with larger discrepancies arising over the course of the model run. Aromatic and unsaturated aliphatic VOCs have the largest inter-mechanism differences on the first day, while alkanes show largest differences on the second day. Simplified mechanisms break VOCs down into smaller-sized degradation products on the first day faster than the MCM, impacting the total amount of O3 produced on subsequent days due to secondary chemistry.
Identification of particulate organosulfates in three megacities at the middle and lower reaches of the Yangtze River
Authors: Wang X. K. , Rossignol S. , Ma Y. , Yao L. , Wang M. Y. , Chen J. M. , George C. , Wang L.
Published: August 2015

Abstract. PM2.5 filter samples have been collected in three megacities i.e., Wuhan (WH), Nanjing (NJ), and Shanghai (SH) at the middle and lower reaches of the Yangtze River, respectively. Analysis of those samples using an ultra-high performance liquid chromatography (UHPLC) coupled to an orbitrap mass spectrometer (MS) allowed detection of about two hundred particulate organosulfates (OSs), including dozens of nitrooxy-organosulfates, at each location. While aliphatic OSs represented more than 78 % of the detected OSs at the three locations, aromatic OSs were much less abundant. OSs with two to four isomers accounted for about 50 % of the total OSs on average in these megacities, and the percentage of OSs with six and more isomers in WH was more significant than those in SH and NJ. The average molecular weight, and the degrees of oxidation and saturation of OSs in the WH summer samples were greater than those in WH winter samples. In SH, the average molecular weight and the degree of oxidation of OSs in summer samples were greater than those in winter samples, but the degree of saturation was similar between the two seasons. In summer, the average molecular weight, and the degrees of oxidation and unsaturation of OSs were smallest in WH among the three cities. Between NJ and SH, the average molecular weight and the degree of saturation of OSs were close and the degree of oxidation of OSs in NJ was smaller. Kendrick mass defect diagrams and Van Krevelen diagrams indicated that the characteristics of identified OSs between in NJ and in SH shared better similarity. In addition, the identity and abundance of OSs in SH showed clear seasonal and diurnal variations. OSs in summer were more abundant than they were in winter due to stronger photochemical reactions in summer. The relative abundance of OSs at night was greater than that in the daytime and more nitrooxy-OSs existed at night, probably because of active NO3 radical chemistry at night. In SH summer samples, OSs with 5 and 10 carbons (C5 and C10) were the most abundant, indicating the importance of isoprene and monoterpenes as precursors of OSs, whereas the relative abundances of OSs with 8, 9, and more than 14 carbons (C8, C9, and C14+) were also high in SH winter samples, urging the need to further understand the precursors of OSs.
Distinguishing the drivers of trends in land carbon fluxes and plant volatile emissions over the past three decades
Authors: Yue X. , Unger N. , Zheng Y.
Published: August 2015

Abstract. The terrestrial biosphere has experienced dramatic changes in recent decades. Estimates of historical trends in land carbon fluxes remain uncertain because long-term observations are limited on the global scale. Here, we use the Yale Interactive terrestrial Biosphere (YIBs) model to estimate decadal trends in land carbon fluxes and emissions of biogenic volatile organic compounds (BVOCs) and to identify the key drivers for these changes during 1982–2011. Driven with hourly meteorology from WFDEI (WATCH Forcing Data methodology applied to ERA-Interim data), the model simulates an increasing trend of 297 Tg C a−2 in gross primary productivity (GPP) and 185 Tg C a−2 in the net primary productivity (NPP). CO2 fertilization is the main driver for the flux changes in forest ecosystems, while meteorology dominates the changes in grasslands and shrublands. Warming boosts summer GPP and NPP at high latitudes, while drought dampens carbon uptake in tropical regions. North of 30° N, increasing temperatures induce a substantial extension of 0.22 day a−1 for the growing season; however, this phenological change alone does not promote regional carbon uptake and BVOC emissions. Nevertheless, increases of LAI at peak season accounts for ~ 25 % of the trends in GPP and isoprene emissions at the northern lands. The net land sink shows statistically insignificant increases of only 3 Tg C a−2 globally because of simultaneous increases in soil respiration. In contrast, driven with alternative meteorology from MERRA (Modern Era-Retrospective Analysis), the model predicts significant increases of 59 Tg C a−2 in the land sink due to strengthened uptake in the Amazon. Global BVOC emissions are calculated using two schemes. With the photosynthesis-dependent scheme, the model predicts increases of 0.4 Tg C a−2 in isoprene emissions, which are mainly attributed to warming trends because CO2 fertilization and inhibition effects offset each other. Using the MEGAN (Model of Emissions of Gases and Aerosols from Nature) scheme, the YIBs model simulates global reductions of 1.1 Tg C a−2 in isoprene and 0.04 Tg C a−2 in monoterpene emissions in response to the CO2 inhibition effects. Land use change shows limited impacts on global carbon fluxes and BVOC emissions, but there are regional contrasting impacts over Europe (afforestation) and China (deforestation).
Improved stratospheric aerosol extinction profiles from SCIAMACHY: validation and sample results
Authors: von Savigny C. , Ernst F. , Rozanov A. , Hommel R. , Eichmann K.-U. , Rozanov V. , Burrows J. P. , Thomason L. W.
Published: August 2015

Abstract. Stratospheric aerosol extinction profiles have been retrieved from SCIAMACHY/Envisat measurements of limb-scattered solar radiation. The retrieval is an improved version of an algorithm presented earlier. The retrieved aerosol extinction profiles are compared to co-located aerosol profile measurements with the SAGE II solar occultation instrument at a wavelength of 525 nm. Comparisons were carried out with two versions of the SAGE II data set (version 6.2 and the new version 7.0). In a global average sense the SCIAMACHY and the SAGE II version 7.0 extinction profiles agree to within about 10 % for altitudes above 15 km. Larger relative differences (up to 40 %) are observed at specific latitudes and altitudes. We also find differences between the two SAGE II data versions of up to 40 % for specific latitudes and altitudes. Sample results on the latitudinal and temporal variability of stratospheric aerosol extinction and optical depth during the SCIAMACHY mission period are presented. The results indicate that a series of volcanic eruptions is responsible for the increase in stratospheric aerosol optical depth from 2002 to 2012. Above about 28 km altitude volcanic eruptions are found to have negligible impact in the period 2002 to 2012.
Influence of timing of sea ice retreat on phytoplankton size during marginal ice zone bloom period in the Chukchi and Bering shelves
Authors: Fujiwara A. , Hirawake T. , Suzuki K. , Eisner L. , Imai I. , Nishino S. , Kikuchi T. , Saitoh S. I.
Published: August 2015

Abstract. Timing of sea ice retreat (TSR) as well as cell size of primary producers (i.e., phytoplankton) plays crucial roles in seasonally ice-covered marine ecosystem. Thus, it is important to monitor the temporal and spatial distribution of phytoplankton community size structure. Prior to this study, an ocean color algorithm has been developed to derive phytoplankton size index FL, which is defined as the ratio of chlorophyll a derived from the cells larger than 5 μm to the total chl a using satellite remote sensing for the Chukchi and Bering shelves. Using this method, we analyzed pixel-by-pixel relationships between FL during marginal ice zone (MIZ) bloom period and TSR over a period of 1998–2013. The influence of TSR on sea surface temperature (SST) and changes in ocean heat content (ΔOHC) during the MIZ bloom period were also investigated. A significant negative relationship between FL and TSR was widely found in the shelf region during MIZ bloom season. On the other hand, we found a significant positive (negative) relationship between SST (ΔOHC) and TSR. That is, earlier sea-ice retreat was associated with a dominance of larger phytoplankton during a colder and weakly stratified MIZ bloom season, suggesting that duration of nitrate supply, which is important for large-sized phytoplankton growth in this region (i.e., diatoms), can change according to TSR. In addition, under-ice phytoplankton blooms are likely to occur in years with late ice retreat, because sufficient light for phytoplankton growth can pass through the ice and penetrate into the water columns due to an increase in solar radiation toward the summer solstice. Moreover, we found not only the length of ice-free season but also annual median of FL positively correlated with annual net primary production (APP). Thus, both phytoplankton community composition and growing season are important for APP in the study area. Our findings showed quantitative relationship between the inter-annual variability of FL, TSR and APP suggesting satellite remote sensing of phytoplankton community size structure is suitable to document the impact of recent rapid sea ice loss on ecosystem of the study region.
Estimating greenhouse gas emissions from travel – a GIS-based study
Authors: Kuonen S.
Published: August 2015

Abstract. Conferences, meetings and congresses are an important part of today's economic and scientific world. But the environmental impact, especially from greenhouse gas emissions associated with travel, can be extensive. Anthropogenic greenhouse gas (GHG) emissions account for the warming of the atmosphere and oceans. This study draws on the need to quantify and reduce greenhouse gas emissions associated with travel activities and aims to give suggestions for organizers and participants on possible ways to reduce greenhouse gas emissions, demonstrated on the example of the European Geography Association (EGEA) Annual Congress 2013 in Wasilkow, Poland. The lack of a comprehensive methodology for the estimation of greenhouse gas emissions from travel led to an outline of a methodology that uses geographic information systems (GIS) to calculate travel distances. The calculation of travel distances in GIS is adapted from actual transportation infrastructure, derived from the open-source platform OpenStreetMap. The methodology also aims to assess the possibilities to reduce GHG emissions by choosing different means of transportation and a more central conference location. The results of the participants of the EGEA congress, who shared their travel data for this study, show that the total travel distance adds up to 238 000 km, with average travel distance of 2429 km per participant. The travel activities of the participants in the study result in total GHG emissions of 39 300 kg CO2-eq including both outward and return trip. On average a participant caused GHG emissions of 401 kg CO2-eq. In addition, the analysis of the travel data showed differences in travel behaviour depending on the distance between conference site and point of origin. The findings on travel behaviour have then been used to give an estimation of total greenhouse gas emissions from travel for all participants of the conference, which result in a total amount of 79 711 kg CO2-eq. The potential for reducing greenhouse gas emissions by substituting short flights with train rides and car rides with bus and train rides is limited. Only 6 % of greenhouse gas emissions could be saved by applying these measures. Further considerable savings could only be made by substituting longer flights (32.6 %) or choosing a more central conference location (26.3 %).
The activation of IgM- or isotype-switched IgG- and IgE-BCR exhibits distinct mechanical force sensitivity and threshold
Authors: Wan Zhengpeng , Chen Xiangjun , Chen Haodong , Ji Qinghua , Chen Yingjia , Wang Jing , Cao Yiyun , Wang Fei , Lou Jizhong , Tang Zhuo , Liu Wanli
Published: August 2015

B lymphocytes use B cell receptors (BCRs) to sense the physical features of the antigens. However, the sensitivity and threshold for the activation of BCRs resulting from the stimulation by mechanical forces are unknown. Here, we addressed this question using a double-stranded DNA-based tension gauge tether system serving as a predefined mechanical force gauge ranging from 12 to 56 pN. We observed that IgM-BCR activation is dependent on mechanical forces and exhibits a multi-threshold effect. In contrast, the activation of isotype-switched IgG- or IgE-BCR only requires a low threshold of less than 12 pN, providing an explanation for their rapid activation in response to antigen stimulation. Mechanistically, we found that the cytoplasmic tail of the IgG-BCR heavy chain is both required and sufficient to account for the low mechanical force threshold. These results defined the mechanical force sensitivity and threshold that are required to activate different isotyped BCRs.
On the view of dielectric properties in microwave‐assisted activated carbon preparation
Authors: Alias Norulaina , Zaini Muhammad Abbas Ahmad
Published: August 2015

Dielectric properties are important in the conversion of agro‐wastes into activated carbon as they indicate the suitability of materials to be heated under microwave. However, dielectric properties of materials in microwave‐assisted process are very much neglected in much of published literature. This paper aims to offer perspectives on the characteristics and dielectric properties of some agro‐wastes in microwave heating. Issues involving the microwave‐assisted activation strategies and the characteristics of the derived activated carbon are also discussed. © 2015 Curtin University of Technology and John Wiley & Sons, Ltd.
One Question, Multiple Answers: Biochemical and Biophysical Screening Methods Retrieve Deviating Fragment Hit Lists
Authors: Schiebel Johannes , Radeva Nedyalka , Köster Helene , Metz Alexander , Krotzky Timo , Kuhnert Maren , Diederich Wibke E. , Heine Andreas , Neumann Lars , Atmanene Cedric , Roecklin Dominique , Vivat‐Hannah Valérie , Renaud Jean‐Paul , Meinecke Robert , Schlinck Nina , Sitte Astrid , Popp Franziska , Zeeb Markus , Klebe Gerhard
Published: August 2015

Fragment‐based lead discovery is gaining momentum in drug development. Typically, a hierarchical cascade of several screening techniques is consulted to identify fragment hits which are then analyzed by crystallography. Because crystal structures with bound fragments are essential for the subsequent hit‐to‐lead‐to‐drug optimization, the screening process should distinguish reliably between binders and non‐binders. We therefore investigated whether different screening methods would reveal similar collections of putative binders. First we used a biochemical assay to identify fragments that bind to endothiapepsin, a surrogate for disease‐relevant aspartic proteases. In a comprehensive screening approach, we then evaluated our 361‐entry library by using a reporter‐displacement assay, saturation‐transfer difference NMR, native mass spectrometry, thermophoresis, and a thermal shift assay. While the combined results of these screening methods retrieve 10 of the 11 crystal structures originally predicted by the biochemical assay, the mutual overlap of individual hit lists is surprisingly low, highlighting that each technique operates on different biophysical principles and conditions.
Lower crosslinking density enhances functional nucleus pulposus‐like matrix elaboration by human mesenchymal stem cells in carboxymethylcellulose hydrogels
Authors: Lin Huizi A. , Gupta Michelle S. , Varma Devika M. , Gilchrist M. Lane , Nicoll Steven B.
Published: August 2015

Engineered constructs represent a promising treatment for replacement of nucleus pulposus (NP) tissue. Recently, photocrosslinked hydrogels comprised of methacrylated carboxymethylcellulose (CMC) were shown to support chondrogenic differentiation of encapsulated human mesenchymal stem cells (hMSCs) and promote accumulation of NP‐like extracellular matrix (ECM). The objective of this study was to investigate the influence of CMC crosslinking density, by varying macromer concentration and modification (i.e., methacrylation) percentage, on NP‐like differentiation of encapsulated hMSCs. Constructs of lower macromer concentration (2%, w/v) exhibited significantly greater collagen II accumulation, more homogeneous distribution of ECM macromolecules, and a temporal increase in mechanical properties compared to hydrogels of higher macromer concentration (4%, w/v). Constructs of higher modification percentage (25%) gave rise to significantly elevated collagen II content and the formation of cell clusters within the matrix relative to samples of lower modification percentage (10% and 15%). These differences in functional ECM accumulation and distribution are likely attributed to the distinct crosslinked network structures of the various hydrogel formulations. Overall, CMC constructs of lower macromer concentration and modification percentage were most promising as scaffolds for NP tissue engineering based on functional ECM assembly. Optimization of such hydrogel fabrication parameters may lead to the development of clinically relevant tissue‐engineered NP replacements. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 165–177, 2016.
Cellular Response to Linear and Branched Poly(acrylic acid)
Authors: Whitty Elizabeth G. , Maniego Alison R. , Bentwitch Sharon A. , Guillaneuf Yohann , Jones Mark R. , Gaborieau Marianne , Castignolles Patrice
Published: August 2015

Poly(acrylic acid‐co‐sodium acrylate) (PNaA) is a pH‐responsive polymer with potential in anticancer drug delivery. The cytotoxicity and intracellular effects of 3‐arm star, hyperbranched and linear PNaA were investigated with L1210 progenitor leukemia cells and L6 myoblast cells. Free solution capillary electrophoresis demonstrated interactions of PNaA with serum proteins. In a 72 h MTT assay most PNaAs exhibited a IC50 between 7 and 14 mmol L−1, showing that precipitation may be a sufficient purification for PNaA dilute solutions. Dialyzed 3‐arm star and hyperbranched PNaA caused an increase in L6 cell viability, challenging the suitability of MTT as cytotoxicity assay for PNaA. Fluorescent confocal microscopy revealed merging of cellular lipids after exposure to PNaA, likely caused by serum starvation.
1H NMR spectra of alcohols in hydrogen bonding solvents: DFT/GIAO calculations of chemical shifts
Authors: Lomas John S.
Published: August 2015

Proton nuclear magnetic resonance (NMR) shifts of aliphatic alcohols in hydrogen bonding solvents have been computed on the basis of density functional theory by applying the gauge‐including atomic orbital method to geometry‐optimized alcohol/solvent complexes. The OH proton shifts and hydrogen bond distances for methanol or ethanol complexed with pyridine depend very much on the functional employed and very little on the basis set, provided it is sufficiently large to give the correct quasi‐linear hydrogen bond geometry. The CH proton shifts are insensitive to both the functional and the basis set. NMR shifts for all protons in several alcohol/pyridine complexes are calculated at the Perdew, Burke and Ernzerhof PBE0/cc‐pVTZ//PBE0/6‐311 + G(d,p) level in the gas phase. The results correlate with the shifts for the pyridine‐complexed alcohols, determined by analysing data from the NMR titration of alcohols against pyridine. More pragmatically, computed shifts for a wider range of alcohols correlate with experimental shifts in neat pyridine. Shifts for alcohols in dimethylsulfoxide, based on the corresponding complexes in the gas phase, correlate well with the experimental values, but the overall root mean square difference is high (0.23 ppm), shifts for the OH, CHOH and other CH protons being systematically overestimated, by averages of 0.42, 0.21 and 0.06 ppm, respectively. If the computed shifts are corrected accordingly, a very good correlation is obtained with a gradient of 1.00 ± 0.01, an intercept of 0.00 ± 0.02 ppm and a root mean square difference of 0.09 ppm. This is a modest improvement on the result of applying the CHARGE programme to a slightly different set of alcohols. Some alcohol complexes with acetone and acetonitrile were investigated both in the gas phase and in a continuum of the relevant solvent. Copyright © 2015 John Wiley & Sons, Ltd.
Optically controlled switch‐mode current‐source amplifiers for on‐coil implementation in high‐field parallel transmission
Authors: Gudino Natalia , Duan Qi , de Zwart Jacco A. , Murphy‐Boesch Joe , Dodd Stephen J. , Merkle Hellmut , van Gelderen Peter , Duyn Jeff H.
Published: August 2015

Purpose

We tested the feasibility of implementing parallel transmission (pTX) for high‐field MRI using a radiofrequency (RF) amplifier design to be located on or in the immediate vicinity of an RF transmit coil.

Method

We designed a current‐source switch‐mode amplifier based on miniaturized, nonmagnetic electronics. Optical RF carrier and envelope signals to control the amplifier were derived, through a custom‐built interface, from the RF source accessible in the scanner control. Amplifier performance was tested by benchtop measurements as well as with imaging at 7T (300 MHz) and 11.7 T (500 MHz). The ability to perform pTX was evaluated by measuring interchannel coupling and phase adjustment in a two‐channel setup.

Results

The amplifier delivered in excess of 44 W RF power and caused minimal interference with MRI. The interface derived accurate optical control signals with carrier frequencies ranging from 64 to 750 MHz. Decoupling better than 14 dB was obtained between two coil loops separated by only 1 cm. Application to MRI was demonstrated by acquiring artifact‐free images at 7 T and 11.7 T.

Conclusion

We propose an optically controlled miniaturized RF amplifier for on‐coil implementation at high fields that should facilitate implementation of high‐density pTX arrays. Magn Reson Med 76:340–349, 2016. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.
Innovative and Established Strategies for the Surface Analysis of Nitrogen and Oxygen‐Rich Plasma Polymer Films by XPS: An Introductory Guide
Authors: Girard‐Lauriault Pierre‐Luc , Unger Wolfgang E. S. , Dietrich Paul M. , Holländer Andreas
Published: August 2015

Nitrogen‐ and oxygen‐based plasma polymer films are materials with a complex and partially elusive surface chemistry. We present an overview of innovative and established X‐ray photoelectron spectroscopy (XPS)‐based analysis strategies developed to elucidate the surface chemistry of such films. We focus on both experimental methods and data analysis strategies and include the following topics: high‐resolution spectra curve fitting, aging, chemical derivatization, and depth profiling by angle‐ and energy‐resolved XPS.
A joint latent class analysis for adjusting survival bias with application to a trauma transfusion study
Authors: Ning Jing , Rahbar Mohammad H. , Choi Sangbum , Hong Chuan , Piao Jin , del Junco Deborah J. , Fox Erin E. , Rahbar Elaheh , Holcomb John B.
Published: August 2015

There is no clear classification rule to rapidly identify trauma patients who are severely hemorrhaging and may need substantial blood transfusions. Massive transfusion (MT), defined as the transfusion of at least 10 units of red blood cells within 24 h of hospital admission, has served as a conventional surrogate that has been used to develop early predictive algorithms and establish criteria for ordering an MT protocol from the blood bank. However, the conventional MT rule is a poor proxy, because it is likely to misclassify many severely hemorrhaging trauma patients as they could die before receiving the 10th red blood cells transfusion. In this article, we propose to use a latent class model to obtain a more accurate and complete metric in the presence of early death. Our new approach incorporates baseline patient information from the time of hospital admission, by combining respective models for survival time and usage of blood products transfused within the framework of latent class analysis. To account for statistical challenges, caused by induced dependent censoring inherent in 24‐h sums of transfusions, we propose to estimate an improved standard via a pseudo‐likelihood function using an expectation‐maximization algorithm with the inverse weighting principle. We evaluated the performance of our new standard in simulation studies and compared with the conventional MT definition using actual patient data from the Prospective Observational Multicenter Major Trauma Transfusion study. Copyright © 2015 John Wiley & Sons, Ltd.