bluuebunny/crossref_metadata_2025 huggingface dataset:
Sealing Ability of Alkaline Endodontic Cements versus Resin Cements
Authors: Teoh Yu-Yao , Athanassiadis Basil , Walsh Laurence
Published: October 2017

Penetration of oral bacteria through root fillings leads to their long term failure. Dimensionally stable alkaline cements have been developed. A saliva challenge model was used to compare resistance to bacterial penetration of these alkaline cements to conventional root fillings that combine gutta percha (GP) with epoxy resin sealers. A sample of 140 human roots with single straight canals prepared to standard length and canal size were obturated with mineral trioxide aggregate (MTA) (Nex MTA or MTAmix), with an alkaline calcium hydroxide hard setting cement (Supercal), or with GP and a resin cement (either AH-Plus or Zirmix). Negative control roots were sealed with wax, while positive controls were left open. The test assemblies were gamma sterilised, then the coronal root face was exposed daily to fresh stimulated human saliva diluted in broth. Bacterial penetration was determined by assessing growth in sterile brain-heart infusion (BHI) medium in contact with the root apex. Using Kaplan–Meier survival analysis, in order of performance from highest to lowest: Negative control, Supercal, Nex MTA, Zirmix, MTAmix, GP + AH-Plus, and the positive control. In addition, statistically significant differences were noted between Supercal and AH-Plus, and between the two MTA cements. It can be concluded that alkaline cements, particularly Supercal, can show considerable resistance to bacterial penetration from constant saliva challenge, and provide superior sealing ability in comparison to resin cements. While this property is due mostly to dimensional stability, the release of hydroxide ions could be a contributing factor to impaired bacterial survival, and this aspect should be explored further.
Ameliorative Effect of Caffeic Acid on Capecitabine-Induced Hepatic and Renal Dysfunction: Involvement of the Antioxidant Defence System
Authors: Olayinka Ebenezer , Ola Olaniyi , Ore Ayokanmi , Adeyemo Oluwatobi
Published: October 2017

Background: It has been postulated that during liver and kidney damage there is a decreased in the antioxidant status associated with a simultaneous increase in the reactive oxygen species and lipid peroxidation. In consonant with this, Capecitabine, an oral chemotherapy and inactive non-cytotoxic fluoropyrimidine considered for the treatment of advance colorectal cancer, has also been shown to induce oxidative stress in liver tissues. Caffeic acid, a typical hydroxycinnamic, has been claimed to be effective against oxidative stress. Therefore, this present work studied the protective effect of caffeic acid on oxidative stress-induced liver and kidney damage by the administration of capecitabine. Methods: Twenty-four male Wistar strain rats were randomly divided into four treatment groups: A. control, B. capecitabine (CPTB)-treated group (30 mg/kg b.w. CPTB), C. caffeic acid (CFA)-treated group (100 mg/kg b.w. CFA) and D. co-treated group with CFA (100 mg/kg b.w.) and CPTB (30 mg/kg b.w.). Results: Caffeic acid administration significantly ameliorated the elevated plasma biomarkers of hepatic and renal tissue damage induced by the capecitabine and improved enzymatic and non-enzymatic antioxidant levels in liver organ. Conclusions: The protective effect of caffeic acid could be attributed to its ability to boost the antioxidant defence system and reduce lipid peroxidation.
Global Potential of Rare Earth Resources and Rare Earth Demand from Clean Technologies
Authors: Zhou Baolu , Li Zhongxue , Chen Congcong
Published: October 2017

Rare earth elements (REE) are widely used in high technologies, medical devices, and military defense systems, and are especially indispensable in emerging clean energy. Along with the growing market of green energy in the next decades, global demand for REE will increase continuously, which will put great pressure on the current REE supply chain. The global REE production is currently mainly concentrated in China and Australia; they respectively contributed 85% and 10% in 2016. However, there are 178 deposits widely distributed in the world, and reported REE resources as of 2017 totaled 478 megaton (Mt) rare earth oxides (REO); 58% of these deposits contained exceed 0.1 Mt REO; 59 deposits have been technically assessed. These resources could sustain the global REE production at the current pace for more than a hundred years. It is noted that REE demand from clean technologies will reach 51.9 thousand metric tons (kt) REO in 2030, Nd and Dy, respectively, comprising 75% and 9%, while these two elements comprise 15% and 0.52% of the global REE resources, respectively. This indicates that Nd and Dy will strongly influence the development of exploring new REE projects and clean technologies in the next decades.
Solution Based Methods for the Fabrication of Carbon Nanotube Modified Atomic Force Microscopy Probes
Authors: Slattery Ashley , Shearer Cameron , Shapter Joseph , Quinton Jamie , Gibson Christopher
Published: October 2017

High aspect ratio carbon nanotubes are ideal candidates to improve the resolution and lifetime of atomic force microscopy (AFM) probes. Here, we present simple methods for the preparation of carbon nanotube modified AFM probes utilising solvent evaporation or dielectrophoresis. Scanning electron microscopy (SEM) of the modified probes shows that the carbon nanotubes attach to the probe apex as fibres and display a high aspect ratio. Many of the probes made in this manner were initially found to exhibit anomalous feedback characteristics during scanning, which rendered them unsuitable for imaging. However, we further developed and demonstrated a simple method to stabilise the carbon nanotube fibres by scanning with high force in tapping mode, which either shortens or straightens the carbon fibre, resulting in stable and high quality imaging AFM imaging.
Influence of VO2 Nanoparticle Morphology on the Colorimetric Assay of H2O2 and Glucose
Authors: Tian Rui , Sun Jiaheng , Qi Yanfei , Zhang Boyu , Guo Shuanli , Zhao Mingming
Published: October 2017

Nanozyme-based colorimetric sensors have received considerable attention due to their unique properties. The size, shape, and surface chemistry of these nanozymes could dramatically influence their sensing behaviors. Herein, a comparative study of VO2 nanoparticles with different morphologies (nanofibers, nanosheets, and nanorods) was conducted and applied to the sensitive colorimetric detection of H2O2 and glucose. The peroxidase-like activities and mechanisms of VO2 nanoparticles were analyzed. Among the VO2 nanoparticles, VO2 nanofibers exhibited the best peroxidase-like activity. Finally, a comparative quantitative detections of H2O2 and glucose were done on fiber, sheet, and rod nanoparticles. Under the optimal reaction conditions, the lower limit of detection (LOD) of the VO2 nanofibers, nanosheets, and nanorods for H2O2 are found to be 0.018, 0.266, and 0.41 mM, respectively. The VO2 nanofibers, nanosheets, and nanorods show the linear response for H2O2 from 0.025–10, 0.488–62.5, and 0.488–15.625 mM, respectively. The lower limit of detection (LOD) of the VO2 nanofibers, nanosheets, and nanorods for glucose are found to be 0.009, 0.348, and 0.437 mM, respectively. The VO2 nanofibers, nanosheets, and nanorods show the linear response for glucose from 0.01–10, 0.625–15, and 0.625–10 mM, respectively. The proposed work will contribute to the nanozyme-based colorimetric assay.
Precision Nutrition and Omega-3 Polyunsaturated Fatty Acids: A Case for Personalized Supplementation Approaches for the Prevention and Management of Human Diseases
Authors: Chilton Floyd , Dutta Rahul , Reynolds Lindsay , Sergeant Susan , Mathias Rasika , Seeds Michael
Published: October 2017

Background: Dietary essential omega-6 (n-6) and omega-3 (n-3) 18 carbon (18C-) polyunsaturated fatty acids (PUFA), linoleic acid (LA) and α-linolenic acid (ALA), can be converted (utilizing desaturase and elongase enzymes encoded by FADS and ELOVL genes) to biologically-active long chain (LC; >20)-PUFAs by numerous cells and tissues. These n-6 and n-3 LC-PUFAs and their metabolites (ex, eicosanoids and endocannabinoids) play critical signaling and structural roles in almost all physiologic and pathophysiologic processes. Methods: This review summarizes: (1) the biosynthesis, metabolism and roles of LC-PUFAs; (2) the potential impact of rapidly altering the intake of dietary LA and ALA; (3) the genetics and evolution of LC-PUFA biosynthesis; (4) Gene–diet interactions that may lead to excess levels of n-6 LC-PUFAs and deficiencies of n-3 LC-PUFAs; and (5) opportunities for precision nutrition approaches to personalize n-3 LC-PUFA supplementation for individuals and populations. Conclusions: The rapid nature of transitions in 18C-PUFA exposure together with the genetic variation in the LC-PUFA biosynthetic pathway found in different populations make mal-adaptations a likely outcome of our current nutritional environment. Understanding this genetic variation in the context of 18C-PUFA dietary exposure should enable the development of individualized n-3 LC-PUFA supplementation regimens to prevent and manage human disease.
Ion Conduction and Its Activation in Hydrated Solid Polyelectrolyte Complexes
Authors: De Souvik , Ostendorf Annika , Schönhoff Monika , Cramer Cornelia
Published: October 2017

For the first time, temperature-dependent conductivities at constant water content for a series of solid polyelectrolyte complexes with varying mixing ratios of anionic poly(sodium 4-styrene sulfonate) and poly(diallyldimethylammonium chloride) are presented. For water absorption, the samples are first equilibrated at an ambient temperature and at fixed relative humidity (RH). During the conductivity measurements, the so achieved water content of the samples is kept constant. At all of the hydration levels, the dc conductivities of the hydrated polyelectrolyte complexes (PEC) display Arrhenius behavior with activation enthalpies that are significantly lower than those of dry complexes. The activation enthalpy decreases linearly with water content. The lower activation enthalpies in case of hydrated as compared to dried complexes are attributed to a lowering of the energy barriers for ion motion. Finally, it is shown that the temperature-dependent conductivity spectra at constant water content obey the time-temperature superposition principle. Additionally, temperature-dependent conductivities at constant water content are compared to data sets determined in a separate study with constant RH at all of the temperatures. For the latter case, the influence of the type of alkali ion is also considered. Using the broad variety of data sets, the influences of water content and temperature on the conductivity mechanism can be separated from each other.
Photosensitive Layer-by-Layer Assemblies Containing Azobenzene Groups: Synthesis and Biomedical Applications
Authors: Akiba Uichi , Minaki Daichi , Anzai Jun-ichi
Published: October 2017

This review provides an overview of the syntheses of photosensitive layer-by-layer (LbL) films and microcapsules modified with azobenzene derivatives and their biomedical applications. Photosensitive LbL films and microcapsules can be prepared by alternate deposition of azobenzene-bearing polymers and counter polymers on the surface of flat substrates and microparticles, respectively. Azobenzene residues in the films and microcapsules exhibit trans-to-cis photoisomerization under UV light, which causes changes in the physical or chemical properties of the LbL assemblies. Therefore, azobenzene-functionalized LbL films and microcapsules have been used for the construction of photosensitive biomedical devices. For instance, cell adhesion on the surface of a solid can be controlled by UV light irradiation by coating the surface with azobenzene-containing LbL films. In another example, the ion permeability of porous materials coated with LbL films can be regulated by UV light irradiation. Furthermore, azobenzene-containing LbL films and microcapsules have been used as carriers for drug delivery systems sensitive to light. UV light irradiation triggers permeability changes in the LbL films and/or decomposition of the microcapsules, which results in the release of encapsulated drugs and proteins.
Noise Maps for Quantitative and Clinical Severity Towards Long-Term ECG Monitoring
Authors: Everss-Villalba Estrella , Melgarejo-Meseguer Francisco , Blanco-Velasco Manuel , Gimeno-Blanes Francisco , Sala-Pla Salvador , Rojo-Álvarez José , García-Alberola Arcadi
Published: October 2017

Noise and artifacts are inherent contaminating components and are particularly present in Holter electrocardiogram (ECG) monitoring. The presence of noise is even more significant in long-term monitoring (LTM) recordings, as these are collected for several days in patients following their daily activities; hence, strong artifact components can temporarily impair the clinical measurements from the LTM recordings. Traditionally, the noise presence has been dealt with as a problem of non-desirable component removal by means of several quantitative signal metrics such as the signal-to-noise ratio (SNR), but current systems do not provide any information about the true impact of noise on the ECG clinical evaluation. As a first step towards an alternative to classical approaches, this work assesses the ECG quality under the assumption that an ECG has good quality when it is clinically interpretable. Therefore, our hypotheses are that it is possible (a) to create a clinical severity score for the effect of the noise on the ECG, (b) to characterize its consistency in terms of its temporal and statistical distribution, and (c) to use it for signal quality evaluation in LTM scenarios. For this purpose, a database of external event recorder (EER) signals is assembled and labeled from a clinical point of view for its use as the gold standard of noise severity categorization. These devices are assumed to capture those signal segments more prone to be corrupted with noise during long-term periods. Then, the ECG noise is characterized through the comparison of these clinical severity criteria with conventional quantitative metrics taken from traditional noise-removal approaches, and noise maps are proposed as a novel representation tool to achieve this comparison. Our results showed that neither of the benchmarked quantitative noise measurement criteria represent an accurate enough estimation of the clinical severity of the noise. A case study of long-term ECG is reported, showing the statistical and temporal correspondences and properties with respect to EER signals used to create the gold standard for clinical noise. The proposed noise maps, together with the statistical consistency of the characterization of the noise clinical severity, paves the way towards forthcoming systems providing us with noise maps of the noise clinical severity, allowing the user to process different ECG segments with different techniques and in terms of different measured clinical parameters.
Assessing Managerial Efficiency of Educational Tourism in Agriculture: Case of Dairy Farms in Japan
Authors: Ohe Yasuo
Published: October 2017

Many rural areas face difficulty in how to motivate farmers to embark on diversified activities, such as tourism, while raising managerial efficiency. Thus, this paper conceptually and empirically evaluated how a farmer’s identity correlates with managerial efficiency since the connection between the two has not been explored fully. We have addressed this issue through examining farmers’ efforts in providing an emerging new educational tourism service by focusing on the Educational Dairy Farms in Japan. Conceptually, this paper classified farmers’ identity into two types: traditional identity as a simple farm producer offering an educational service as a volunteer, and, enlarged identity, which is oriented toward viability of a new service activity. Empirically, data envelopment analysis revealed that those with the enlarged identity realized a higher managerial efficiency although there was much room for improvement in overall managerial efficiency. Consequently, support measures with a wider perspective that include identity issues should be designed for capacity building of farmers who are conducting tourism.
Evolution of Urban Socio-Spatial Structure in Modern Times in Xi’an, China
Authors: Wang Yanjun , Liu Kewei
Published: October 2017

Urban socio-spatial structure has been extensively studied in the Western context but is less researched in Chinese cities, particularly those in less developed regions. To clarify its evolution and evolutionary mechanisms, the city of Xi’an is considered as an empirical case, using factor ecological analysis for modern times. Research results are concluded as follows: the types and affecting factors of social space continued to increase. Urban socio-spatial structure evolved from single-core pattern to single-core pattern with enclaves, and later showed a more mosaic tendency. The political and socio-economic backgrounds of different periods have had a great influence on the urban socio-spatial structure. The research results have theoretical significance for optimizing socio-spatial structure and understanding the urban space of Xi’an. Compared with studies of other cities in China and cities in western countries, the evolution of urban socio-spatial structure in China shows the characteristics of circle expansion and the gradual and stable transition under socialist ideology.
Precoding Design and Power Allocation in Two-User MU-MIMO Wireless Ad Hoc Networks
Authors: Chen Haole , Xiao Lin , Li Yinfeng , Yang Dingcheng , Zhou Xiaoxiao
Published: October 2017

In this paper, we consider the precoding design and power allocation problem for multi-user multiple-input multiple-output (MU-MIMO) wireless ad hoc networks. In the first timeslot, the source node (SN) transmits energy and information to a relay node (RN) simultaneously within the simultaneous wireless information and power transfer (SWIPT) framework. Then, in the second timeslot, based on the decoder and the forwarding (DF) protocol, after reassembling the received signal and its own signal, the RN forwards the information to the main user (U1) and simultaneously sends its own information to the secondary user (U2). In this paper, when the transmission rate of the U1 is restricted, the precoding, beamforming, and power splitting (PS) transmission ratio are jointly considered to maximize the transmission rate of U2. To maximize the system rate, we design an optimal beamforming matrix and solve the optimization problem by semi-definite relaxation (SDR), considering the high complexity of implementing the optimal solution. Two sub-optimal precoding programs are also discussed: singular value decomposition and block diagonalization. Finally, the performance of the optimization and sub-optimization schemes are compared using a simulation.
CPT and Lorentz Violation in the Photon and Z-Boson Sector
Authors: Colladay Donald , Noordmans Jacob , Potting Robertus
Published: October 2017

Violation of CPT and Lorentz symmetry in the photon sector is described within the minimal Standard-Model Extension by a dimension-3 Chern–Simons-like operator parametrized by a four-vector parameter k A F that has been very tightly bounded by astrophysical observations. On the other hand, in the context of the S U ( 2 ) × U ( 1 ) electroweak gauge sector of the Standard-Model Extension, CPT and Lorentz violation is described similarly, by dimension-3 operators parametrized by four-vector parameters k 1 and k 2 . In this work, we investigate in detail the effects of the resulting CPT and Lorentz violation in the photon and Z-boson sectors upon electroweak-symmetry breaking. In particular, we show that, for the photon sector, the relevant Lorentz-violating effects are described at the lowest order by the k A F term, but that there are higher-order momentum-dependent effects due to photon-Z boson mixing. As bounds on CPT and Lorentz violation in the Z sector are relatively weak, these effects could be important phenomenologically. We investigate these effects in detail in this work.
An Ecological Dynamics Perspective on Adventure Tourism
Authors: Peacock Suzanne , Brymer Eric , Davids Keith , Dillon Michelle
Published: October 2017

Traditional definitions for adventure tourism have focused on the adventure tourism activity or the adventure tourism environment. In these cases the activity is most often associated with risk and the environment associated with unfamiliarity and natural terrains. Critiques of these
definitions have pointed out that this traditional perspective is limited. The risk focus is paradoxical as clients purchase adventure experiences involving risk and uncertainty, whereas tour operators must minimize the risk and emphasize safety. Additionally, adventure tourism can also take
place in urban or man-made environments. Furthermore, the traditional definitions mostly ignore the lived experience of the adventure consumer. Individuals undertake adventure for a variety of reasons, including risk and thrills, health and well-being, connection to others and nature, recreational
mastery, and personal development. We propose a nuanced conceptual understanding of adventure tourism within an ecological dynamics perspective that considers the relationship between the person, the adventure activity and the surrounding environment, and the recognition of affordances that
support well-being. This theoretical approach provides a useful framework for operators and researchers that encourages a more personalized and meaningful experience for the tourist.
Quasi-periodic Oscillations in Flares and Coronal Mass Ejections Associated with Magnetic Reconnection
Authors: Takahashi Takuya , Qiu Jiong , Shibata Kazunari
Published: October 2017

We propose a mechanism for quasi-periodic oscillations of both coronal mass ejections (CMEs) and flare loops as related to magnetic reconnection in eruptive solar flares. We perform two-dimensional numerical MHD simulations of magnetic flux rope eruption, with three different values of the global Lundquist number. In the low Lundquist number run, no oscillatory behavior is found. In the moderate Lundquist number run, on the other hand, quasi-periodic oscillations are excited both at the bottom of the flux rope and at the flare loop top. In the high Lundquist number run, quasi-periodic oscillations are also excited; in the meanwhile, the dynamics become turbulent owing to the formation of multiple plasmoids in the reconnection current sheet. In high and moderate Lundquist number runs, thin reconnection jets collide with the flux rope bottom or flare loop top and dig them deeply. Steep oblique shocks are formed as termination shocks where reconnection jets are bent (rather than decelerated) in the horizontal direction, resulting in supersonic backflows. The structure becomes unstable, and quasi-periodic oscillations of supersonic backflows appear at locally confined high-beta regions at both the flux rope bottom and flare loop top. We compare the observational characteristics of quasi-periodic oscillations in erupting flux ropes, post-CME current sheets, flare ribbons, and light curves with corresponding dynamical structures found in our simulation.
IFN-λ4 Attenuates Antiviral Responses by Enhancing Negative Regulation of IFN Signaling
Authors: Obajemu Adeola A. , Rao Nina , Dilley Kari A. , Vargas Joselin M. , Sheikh Faruk , Donnelly Raymond P. , Shabman Reed S. , Meissner Eric G. , Prokunina-Olsson Ludmila , Onabajo Olusegun O.
Published: October 2017

Type III IFNs are important mediators of antiviral immunity. IFN-λ4 is a unique type III IFN because it is produced only in individuals who carry a dG allele of a genetic variant rs368234815-dG/TT. Counterintuitively, those individuals who can produce IFN-λ4, an antiviral cytokine, are also less likely to clear hepatitis C virus infection. In this study, we searched for unique functional properties of IFN-λ4 that might explain its negative effect on hepatitis C virus clearance. We used fresh primary human hepatocytes (PHHs) treated with recombinant type III IFNs or infected with Sendai virus to model acute viral infection and subsequently validated our findings in HepG2 cell line models. Endogenous IFN-λ4 protein was detectable only in Sendai virus–infected PHHs from individuals with the dG allele, where it was poorly secreted but highly functional, even at concentrations < 50 pg/ml. IFN-λ4 acted faster than other type III IFNs in inducing antiviral genes, as well as negative regulators of the IFN response, such as USP18 and SOCS1. Transient treatment of PHHs with IFN-λ4, but not IFN-λ3, caused a strong and sustained induction of SOCS1 and refractoriness to further stimulation with IFN-λ3. Our results suggest unique functional properties of IFN-λ4 that can be important in viral clearance and other clinical conditions.
Faculty Development on Clinical Teaching Skills: An Effective Model for the Busy Clinician
Authors: Damp Julie B. , Dewey Charlene M. , Wells Quinn , Horn Leora , Kroop Susan F. , Mendes Lisa
Published: October 2017

Introduction

The authors developed and evaluated a faculty development program on clinical teaching skills to address barriers to participation and to impact teaching behaviors.

Methods

Four one-hour workshops were implemented over five months. Evaluation included participant satisfaction and pre/post self-assessment. Pre/post faculty teaching ratings by trainees were compared.

Results

A total of 82% of faculty ( N = 41) attended. Participants rated workshops highly (mean, 4.43/5.00). Self-assessment of skills and comfort with teaching activities improved. A total of 59% of residents and 40% of fellows felt that teaching received from participating faculty was highly effective. The majority observed targeted teaching behaviors by the faculty. Teaching ratings improved after the workshops ( P = 0.042).

Conclusion

Our series of short workshops during a standing conference time was associated with increased self-assessed skill and comfort and an increase in faculty ratings on teaching evaluations. Effective faculty development programs can be implemented in flexible formats and overcome common barriers to participation.
A Convergence of Traditions: Saint Lawrence Chapel, by Avanto Architects
Authors: Millán-Gómez Antonio
Published: October 2017

Debates on the actuality of modern architecture by new contributions could be considered by critics as a deviation from its essence. In such a context, some works by Finnish studies exhibited at the Museum of Finnish Architecture in Spring, 2015 provide fresh approaches with their proposals and interest us here to reconsider architectural modernity with alterative readings. Project ideas are fused and converge towards new proposals in a process of continuity, from which only the concrete buildings experience, with enlightening phenomenal qualities, redeem us. We concentrate on a chapel by Avanto Architects in which interests from the second generation of modern architecture and the masters of Nordic Architecture can be appreciated.
Hacia una arquitectura pragmática. El caso de Tous y Fargas
Authors: Hernandez Falagan David
Published: October 2017

Tous & Fargas were a unique case in the field of Spanish architecture of the second half of the 20th century. From the technical and industrial experimentation of their first works, they developed a nonconformist architecture within the realistic conditions characteristic of the time, propitiated by the economic, political and social context. Despite of this, they achieved a remarkable success carrying out designs of technological type and giving support to the industrial innovation of constructive systems. However, during the last stage of their collaboration, traits characteristic of the pragmatic drift are visible to which much of the architecture of the last quarter of the 20th century was subjected. The excess of mercantile concern for the real estate product, the excessive systematization of the typological models and the constructive systems, the lack of a consistent theoretical discourse or the abandonment of the technical investigation as a priority of innovation are some of the symptoms that characterize the pragmatic architecture of their latest works.
Characteristics of intercontinental transport of tropospheric ozone from Africa to Asia
Authors: Han Han , Liu Jane , Yuan Huiling , Zhu Ye , Wu Yue , Yan Yuhan , Ding Aijun
Published: October 2017

Abstract. Based on 20-year simulations using a global chemical transport model, GEOS-Chem, and a trajectory model, HYSPLIT, the transport of ozone produced in the African troposphere to Asia is investigated. The study shows that the influence of African ozone on Asia varies largely in time and space. In the middle and upper troposphere, the inflow of African ozone to Asia peaks around 25° N, being the largest in boreal winter and early spring (> 10 ppbv) and the lowest in boreal summer (
Water vapor increase in the northern lower stratosphere by the Asian monsoon anticyclone observed during TACTS/ESMVal campaigns
Authors: Rolf Christian , Vogel Bärbel , Hoor Peter , Afchine Armin , Günther Gebhard , Krämer Martina , Müller Rolf , Müller Stefan , Spelten Nicole , Riese Martin
Published: October 2017

Abstract. The impact of air masses from Asia influenced by the Asian monsoon anticyclone on the northern hemispheric stratosphere is investigated based on in-situ measurements. An statistical significant increase in water vapor of about 0.5 ppmv (11 %) and methane up to 20 ppbv (1.2 %) in the extra-tropical stratosphere above a potential temperature of 380 K was detected between August and September 2012 by in-situ instrumentation in the northern hemisphere during the HALO aircraft mission TACTS and ESMVal. We investigate the origin of this water vapor and methane increase with the help of the three-dimensional Lagrangian chemistry transport model CLaMS. We assign the source of the moist air masses in the Asian region (North and South India, East China, South East Asia and tropical Pacific) based on tracers of airmass origin used in CLaMS. The water vapor increase is correlated to an increase of the simulated Asian monsoon air mass contribution from 10 % in August to 20 % in September, which corresponds to a doubling of the influence of air masses affected by the Asian monsoon region. Additionally, back trajectories starting at the aircraft flight paths are used to differentiate between transport from the Asian monsoon anticyclone and other source regions by calculating the Lagrangian cold point (LCP). The geographic location of the LCPs, which indicates the region where the imprint of water vapor concentration along these trajectories occur, can be exclusively attributed to the Asian monsoon region.
Greenhouse gas measurements from a UK network of tall towers: technical description and first results
Authors: Stanley Kieran M. , Grant Aoife , O'Doherty Simon , Young Dickon , Manning Alistair J. , Stavert Ann R. , Spain T. Gerard , Salameh Peter K. , Harth Christina M. , Simmonds Peter G. , Sturges William T. , Oram David E. , Derwent Richard G.
Published: October 2017

Abstract. A network of tall tower measurement stations was set up in 2012 across the United Kingdom to expand measurements made at the long-term background northern hemispheric site, Mace Head, Ireland. Reliable and precise in situ greenhouse gas (GHG) analysis systems were developed and deployed at three sites in the UK with automated custom-built instrumentation measuring a suite of GHGs. The UK Deriving Emissions linked to Climate Change (UK DECC) network uses tall (165–230 m) open lattice telecommunications towers, which provide a convenient platform for boundary layer trace gas sampling. In this paper we describe the automated measurement system and first results from the UK DECC network for CO2, CH4, N2O, SF6, CO and H2. CO2 and CH4 are measured at all of the UK DECC sites by cavity ring-down spectroscopy (CRDS) with multiple inlet heights at two of the three tall tower sites to assess for boundary layer stratification. The long-term 1-minute mean precisions (1σ) of CRDS measurements at background mole fractions for January 2012 to September 2015 is
Mesospheric OH layer altitude at midlatitudes: variability over the Sierra Nevada Observatory in Granada, Spain (37° N, 3° W)
Authors: García-Comas Maya , López-González María José , González-Galindo Francisco , de la Rosa José Luis , López-Puertas Manuel , Shepherd Marianna G. , Shepherd Gordon G.
Published: October 2017

Abstract. The mesospheric OH layer varies on several timescales, primarily driven by variations in atomic oxygen, temperature, density and transport (advection). Vibrationally excited OH airglow intensity, rotational temperature and altitude are closely interrelated and thus accompany each other through these changes. A correct interpretation of the OH layer variability from airglow measurements requires the study of the three variables simultaneously. Ground-based instruments measure excited OH intensities and temperatures with high temporal resolution, but they do not generally observe altitude directly. Information on the layer height is crucial in order to identify the sources of its variability and the causes of discrepancies in measurements and models. We have used SABER space-based 2002–2015 data to infer an empirical function for predicting the altitude of the layer at midlatitudes from ground-based measurements of OH intensity and rotational temperature. In the course of the analysis, we found that the SABER altitude (weighted by the OH volume emission rate) at midlatitudes decreases at a rate of 40 m decade−1, accompanying an increase of 0.7 % decade−1 in OH intensity and a decrease of 0.6 K decade−1 in OH equivalent temperature. SABER OH altitude barely changes with the solar cycle, whereas OH intensity and temperature vary by 7.8 % per 100 s.f.u. and 3.9 K per 100 s.f.u., respectively. For application of the empirical function to Sierra Nevada Observatory SATI data, we have calculated OH intensity and temperature SATI-to-SABER transfer functions, which point to relative instrumental drifts of −1.3 % yr−1 and 0.8 K yr−1, respectively, and a temperature bias of 5.6 K. The SATI predicted altitude using the empirical function shows significant short-term variability caused by overlapping waves, which often produce changes of more than 3–4 km in a few hours, going along with 100 % and 40 K changes in intensity and temperature, respectively. SATI OH layer wave effects are smallest in summer and largest around New Year's Day. Moreover, those waves vary significantly from day to day. Our estimations suggest that peak-to-peak OH nocturnal variability, mainly due to wave variability, changes within 60 days at least 0.8 km for altitude in autumn, 45 % for intensity in early winter and 6 K for temperature in midwinter. Plausible upper limit ranges of those variabilities are 0.3–0.9 km, 40–55 % and 4–7 K, with the exact values depending on the season.
Variations of Mediterranean–Atlantic exchange across the late Pliocene climate transition
Authors: García-Gallardo Ángela , Grunert Patrick , Piller Werner E.
Published: October 2017

Abstract. Mediterranean-Atlantic exchange through the Strait of Gibraltar plays a significant role in the global ocean-climate dynamics in two ways. On one side, the injection of the saline and warm Mediterranean Outflow Water (MOW) contributes to North Atlantic deep-water formation. In return, the Atlantic inflow is considered a sink of less saline water for the North Atlantic Ocean. However, while the history of MOW is the focus of numerous studies, the latter has received little attention so far. The present study provides an assessment of the Mediterranean–Atlantic exchange with focus on the Atlantic inflow strength and its response to regional and global climate from 3.33 to 2.60 Myrs. This time interval comprises the mid-Pliocene warm period (MPWP, 3.29–2.97 Myr) and the onset of the Northern Hemisphere Glaciation (NHG). For this purpose, gradients in surface δ18O records of the planktonic foraminifer Globigerinoides ruber between the Integrated Ocean Drilling Program (IODP) Hole U1389E (Gulf of Cadiz) and ODP Site 978 (Alboran Sea) have been evaluated. Interglacial stages and warm glacials of the MPWP revealed steep and reversed (relative to the present) W-E δ18O gradients suggesting a weakening of Mediterranean–Atlantic exchange likely caused by high levels of relative humidity in the Mediterranean region. In contrast, periods of stronger inflow are indicated by flat δ18O gradients due to more intense arid conditions during the severe glacial Marine Isotope Stage (MIS) M2 and the initiation of the NHG (MIS G22, G14, G6–104). Intensified Mediterranean–Atlantic exchange in cold periods is linked to the occurrence of ice-rafted debris (IRD) at low latitudes and weakening of the Atlantic Meridional Overturning Circulation (AMOC). Our results thus suggest the development of a negative feedback between AMOC and exchange rates at the Strait of Gibraltar in the latest Pliocene as it has been proposed for the late Quaternary.
Construction of surface air temperature series of Qingdao in China for the period 1899 to 2014
Authors: Li Yan , Tinz Birger , von Storch Hans , Wang Qingyuan , Zhou Qingliang
Published: October 2017

Abstract. We present a homogenized time series surface air temperature at 2 meters (SAT) for the city of Qingdao in China from 1899 to 2014. This series is derived from three data sources: newly digitized and homogenized observations of German National Meteorological Service from 1899 to 1913; National observation data of China Meteorological Administration (CMA) from 1961–2014 and a gridded data set of Willmott and Matsuura in Delaware to fill the gap from 1914 to 1959. Based on this new series, long-term trends are described. The SAT in Qingdao has a significant warming trend of 0.11 °C (10 yr)-1 during 1899–2014. The coldest period occurred in 1909–1918 and the warmest period occurred in 1999–2008. For the seasonal mean SAT, the most significant warming can be found in spring, followed by winter. Access to the data is provided in excel and archived by Deutscher Wetterdienst (DWD) web page under overseas stations of the Deutsche Seewarte (http://www.dwd.de/EN/ourservices/overseas_stations/ueberseedoku/doi_qingdao.html) or be freely available at https://doi.org/10.5676/DWD/Qing_v1.
Scenario-based impacts of land use and climate changes on the hydrology of a lowland rainforest catchment in Ghana, West Africa
Authors: Aduah Michael S. , Jewitt Graham P. W. , Toucher Michele L. W.
Published: October 2017

Abstract. This study analysed the separate and the combined impacts of climate and land use changes on hydrology on the Bonsa catchment in Ghana, West Africa, using the ACRU hydrological model. The study used five RCP8.5 climate change scenarios (wet, 25th percentile, 75th percentile, dry and a multi-model median of nine GCMs) from the CMIP5 AR5 models for near (2020–2039) and far (2060–2079) future time slices. Change factors were used to downscale the GCM scenarios to the local scale, using observed climate data for the control period of 1990 to 2009. The land use of 1991 and 2011 were used as the baseline and current land use as well as three future land use scenarios (BAU, EG, EGR) for two time slices (2030 and 2070) were used. The study showed that under all separate climate change scenarios, overall flows reduced, but under combined climate and land use changes, streamflows increased. Under the combined scenarios, streamflow responses due to the different future land use scenarios were not substantially different. Also, land use is the dominant controlling factor in streamflow changes in the Bonsa catchment under a dry climate change, but under a wet climate change, climate controls streamflow changes. The spatial variability of catchment streamflow changes under combined land use and climate changes were greater than the spatial variability of streamflow changes under climate change. The range of plausible future streamflows changes derived in this study provides natural resources and environmental managers of the Bonsa catchment, the first ever and the most current information to develop suitable adaptation and mitigation strategies, to prepare adequately for climate and land use changes.
AGENT BASED MODELING: FINE-SCALE SPATIO-TEMPORAL ANALYSIS OF PERTUSSIS
Authors: Mills D. A.
Published: October 2017

Abstract. In epidemiology, spatial and temporal variables are used to compute vaccination efficacy and effectiveness. The chosen resolution and scale of a spatial or spatio-temporal analysis will affect the results. When calculating vaccination efficacy, for example, a simple environment that offers various ideal outcomes is often modeled using coarse scale data aggregated on an annual basis. In contrast to the inadequacy of this aggregated method, this research uses agent based modeling of fine-scale neighborhood data centered around the interactions of infants in daycare and their families to demonstrate an accurate reflection of vaccination capabilities. Despite being able to prevent major symptoms, recent studies suggest that acellular Pertussis does not prevent the colonization and transmission of Bordetella Pertussis bacteria. After vaccination, a treated individual becomes a potential asymptomatic carrier of the Pertussis bacteria, rather than an immune individual. Agent based modeling enables the measurable depiction of asymptomatic carriers that are otherwise unaccounted for when calculating vaccination efficacy and effectiveness. Using empirical data from a Florida Pertussis outbreak case study, the results of this model demonstrate that asymptomatic carriers bias the calculated vaccination efficacy and reveal a need for reconsidering current methods that are widely used for calculating vaccination efficacy and effectiveness.
MAKING TEMPORAL SEARCH MORE CENTRAL IN SPATIAL DATA
INFRASTRUCTURES
Authors: Corti P. , Lewis B.
Published: October 2017

Abstract. A temporally enabled Spatial Data Infrastructure (SDI) is a framework of geospatial data, metadata, users, and tools intended to provide an efficient and flexible way to use spatial information which includes the historical dimension. One of the key software components of an SDI is the catalogue service which is needed to discover, query, and manage the metadata. A search engine is a software system capable of supporting fast and reliable search, which may use any means necessary to get users to the resources they need quickly and efficiently. These techniques may include features such as full text search, natural language processing, weighted results, temporal search based on enrichment, visualization of patterns in distributions of results in time and space using temporal and spatial faceting, and many others. In this paper we will focus on the temporal aspects of search which include temporal enrichment using a time miner - a software engine able to search for date components within a larger block of text, the storage of time ranges in the search engine, handling historical dates, and the use of temporal histograms in the user interface to display the temporal distribution of search results.
BUILDING A BILLION SPATIO-TEMPORAL OBJECT SEARCH AND VISUALIZATION
PLATFORM
Authors: Kakkar D. , Lewis B.
Published: October 2017

Abstract. With funding from the Sloan Foundation and Harvard Dataverse, the Harvard Center for Geographic Analysis (CGA) has developed a prototype spatio-temporal visualization platform called the Billion Object Platform or BOP. The goal of the project is to lower barriers for scholars who wish to access large, streaming, spatio-temporal datasets. The BOP is now loaded with the latest billion geo-tweets, and is fed a real-time stream of about 1 million tweets per day. The geo-tweets are enriched with sentiment and census/admin boundary codes when they enter the system. The system is open source and is currently hosted on Massachusetts Open Cloud (MOC), an OpenStack environment with all components deployed in Docker orchestrated by Kontena. This paper will provide an overview of the BOP architecture, which is built on an open source stack consisting of Apache Lucene, Solr, Kafka, Zookeeper, Swagger, scikit-learn, OpenLayers, and AngularJS. The paper will further discuss the approach used for harvesting, enriching, streaming, storing, indexing, visualizing and querying a billion streaming geo-tweets.
Devising Effective Policies for Bug-Bounty Platforms and Security Vulnerability Discovery
Authors: Zhao Mingyi , Laszka Aron , Grossklags Jens
Published: October 2017

Bug-bounty programs have the potential to harvest the effort and diverse knowledge of thousands of independent security researchers, but running them at scale is challenging due to misaligned incentives and misallocation of effort. In our research, we discuss these challenges in detail and present relevant empirical data. We develop an economic framework consisting of two models that focus on evaluating different policies for improving the effectiveness of bug-bounty programs. Further, we discuss regulatory policy challenges and questions related to vulnerability research and disclosure, such as mandatory bug bounties and the relation to other cybersecurity policies.
Reconstrução e reforma do estado
Authors: Miranda Lara Caxico Martins
Published: October 2017

ALBUQUERQUE, Roberto Cavalcanti de. Reconstrução e reforma do Estado. IN: VELOSO, João Paulo dos Reis; ALBUQUERQUE, Roberto Cavalcanti de (coord.). Governabilidade e Reformas. Rio de Janeiro: José Olympio, 1995. p. 129-198.
Nutrient Composition of Cereals-based Complementary Flour and its Nutritional Adequacy in Infants Nutrition
Authors: Makori Nyabasi , Kassim Neema , Kinabo Joyce , Matemu Athanasia
Published: October 2017

Evaluation of the quality of complementary flour and its nutritional adequacy in relation to infant’s nutritional requirements was done to four different types of complementary flour (composite cereals with groundnuts, maize, millet and sorghum). The collected samples were analysed for determination of macronutrient, micronutrients and phytate content. The mean protein content in all types of complementary flour was 7.30 ± 2.52 g/100 g. A significant difference in protein content between composite cereals (p ≤ 0.001) and other types of cereals-based foods was observed. Fat and iron content were found to be inadequate in all types of complementary flours. Phytate content ranged from 59.47 - 1176.8 mg/100 g, the highest content was observed in sorghum. On the other hand, the mean iron and zinc content in all types of complementary flour was 5.25 ± 1.35 mg/100 g and 2.99 ± 1.36 mg/100 g respectively. The molar ratios of phytate:iron and phytate:zinc were at a level that would tend to inhibit bioavailability of iron and zinc in 97% and 45% of analysed samples respectively. An association between anaemia and phytate:iron molar ratio (AOR = 4.2, 95%, 1.2 - 6.9) was observed. The quality and adequacy of nutrients in cereal-based complementary flour has shown to be inadequate and likely to be compromised by the presence of phytate.