bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular Basis of Alcohol-Related Gastric and Colon Cancer
Authors: Na Hye-Kyung , Lee Ja
Published: May 2017

Many meta-analysis, large cohort studies, and experimental studies suggest that chronic alcohol consumption increases the risk of gastric and colon cancer. Ethanol is metabolized by alcohol dehydrogenases (ADH), catalase or cytochrome P450 2E1 (CYP2E1) to acetaldehyde, which is then further oxidized to acetate by aldehyde dehydrogenase (ALDH). Acetaldehyde has been classified by the International Agency for Research on Cancer (IARC) as a Group 1 carcinogen to humans. The acetaldehyde level in the stomach and colon is locally influenced by gastric colonization by Helicobacter pylori or colonic microbes, as well as polymorphisms in the genes encoding tissue alcohol metabolizing enzymes, especially ALDH2. Alcohol stimulates the uptake of carcinogens and their metabolism and also changes the composition of enteric microbes in a way to enhance the aldehyde level. Alcohol also undergoes chemical coupling to membrane phospholipids and disrupts organization of tight junctions, leading to nuclear translocation of β-catenin and ZONAB, which may contributes to regulation of genes involved in proliferation, invasion and metastasis. Alcohol also generates reactive oxygen species (ROS) by suppressing the expression of antioxidant and cytoprotective enzymes and inducing expression of CYP2E1 which contribute to the metabolic activation of chemical carcinogens. Besides exerting genotoxic effects by directly damaging DNA, ROS can activates signaling molecules involved in inflammation, metastasis and angiogenesis. In addition, alcohol consumption induces folate deficiency, which may result in aberrant DNA methylation profiles, thereby influencing cancer-related gene expression.
Stability Profiles and Therapeutic Effect of Cu/Zn Superoxide Dismutase Chemically Coupled to O-Quaternary Chitosan Derivatives against Dextran Sodium Sulfate-Induced Colitis
Authors: Zhao Nan , Feng Zhaolong , Shao Meng , Cao Jichao , Wang Fengshan , Liu Chunhui
Published: May 2017

Superoxide dismutase (SOD) has attracted considerable attention on treatment of reactive oxygen species (ROS)-related disorders. We previously conjugated Cu/Zn SOD to O-quaternary chitosan derivatives (O-HTCC) to yield a polymer–enzyme conjugate O-HTCC-SOD that demonstrated superior therapeutic effect to native SOD. The present study demonstrated that O-HTCC-SOD had wider pH activity range, better thermal stability, excellent long-term stability for storage, as well as unique reinstatement of activity exposure to proteolytic degradation that was helpful for longer half-life in vivo. O-HTCC-SOD exerted significant anti-inflammatory effects on lipopolysaccharides (LPS)-stimulated mouse peritoneal macrophages by down-regulating production of pro-inflammatory cytokines and intracellular ROS. O-HTCC-SOD significantly attenuated dextran sodium (DSS)-induced colitis in mice as observed by the colitis severity, neutrophil infiltration and histopathological damage, whereas native SOD failed to do so. In conclusion, conjugation of O-HTCC conferred SOD with better stability and enhanced therapeutic potential, offering a promising option in treatment of inflammatory bowel disease.
Correction of Outliers in Temperature Time Series Based on Sliding Window Prediction in Meteorological Sensor Network
Authors: Ma Li , Gu Xiaodu , Wang Baowei
Published: May 2017

In order to detect outliers in temperature time series data for improving data quality and decision-making quality related to design and operation, we proposed an algorithm based on sliding window prediction. Firstly, the time series are segmented based on the sliding window. Then, the prediction model is established based on the history data to predict the future value. If the difference between a predicted value and a measured value is larger than the preset threshold value, the sequence point will be judged to be an outlier and then corrected. In this paper, the sliding window and parameter settings of the algorithm are discussed and the algorithm is verified on actual data. This method does not need to pre classify the abnormal points and perform fast, and can handle large scale data. The experimental results show that the proposed algorithm can not only effectively detect outliers in the time series of meteorological data but also improves the correction efficiency notoriously.
The Rejuvenating Effect in Hot Asphalt Recycling by Mortar Transfer Ratio and Image Analysis
Authors: Wang Fusong , Wang Zipeng , Li Chao , Xiao Yue , Wu Shaopeng , Pan Pan
Published: May 2017

Using a rejuvenator to improve the performance of asphalt pavement is an effective and economic way of hot asphalt recycling. This research analyzes the rejuvenating effect on aged asphalt by means of a Mortar Transfer Ratio (MTR) test, which concerns the ratio of asphalt mortar that moves from recycled aggregates (RAP aggregates) to fresh added aggregates when aged asphalt is treated with a regenerating agent and comes into contact with fresh aggregates. The proposed MTR test analyzes the regeneration in terms of the softening degree on aged asphalt when the rejuvenator is applied. The covered area ratio is studied with an image analyzing tool to understand the possibility of mortar transferring from RAP aggregates to fresh aggregates. Additionally, a micro-crack closure test is conducted and observed through a microscope. The repairing ability and diffusion characteristics of micro-cracks can therefore be analyzed. The test results demonstrate that the proposed mortar transfer ratio is a feasible way to evaluate rejuvenator diffusion during hot recycling. The mortar transfer ratio and uncovered area ratio on fresh aggregates are compatible, and can be used to quantify the contribution of the rejuvenator. Within a certain temperature range, the diffusing effect of the rejuvenator is better when the diffusing temperature is higher. The diffusion time of the rejuvenator is optimum when diffusion occurs for 4–8 h. When the rejuvenator is properly applied, the rough and cracking surface can be repaired, resulting in better covered aggregates. The micro-closure analysis visually indicates that rejuvenators can be used to repair the RAP aggregates during hot recycling.
Effect of Current on Structure and Macrosegregation in Dual Alloy Ingot Processed by Electroslag Remelting
Authors: Liu Yu , Zhang Zhao , Li Guangqiang , Wang Qiang , Wang Li , Li Baokuan
Published: May 2017

Macrosegregation is a very common problem for the quality control of all cast ingots. The effect of current on the structure and macrosegregation in dual alloy ingot processed by electroslag remelting (ESR) was investigated experimentally with various analytical methods. In this study, the electrode consisted of NiCrMoV alloy bar (upper part) and CrMoV alloy (lower part) with a diameter of 55 mm, was remelted in a laboratory-scale ESR furnace with the slag containing 30 mass pct alumina and 70 mass pct calcium fluoride under an open air atmosphere. The results show that the macrostructures of three ingots processed by electroslagremelting with different currents are nearly similar. The thin equiaxed grains region and the columnar grains region are formed under the ingot surface, the latter region is the dominant part of the ingot. The typical columnar structure shows no discontinuity among the NiCrMoV alloy zone, the CrMoV alloy zone, and the transition zone in three ingots. With the increase of the current, the grain growth angle increases due to the deeper molten metal pool. The secondary dendrite arm spacing (SDAS) firstly decreases, then increases. The SDAS is dominated by the combined effect of the local solidification rate and the width of mushy region. With the current increasing from 1500 A to 1800 A and 2100 A, the width of the transition zone decreases from 147 mm to 115 mm and 102 mm. The macrosegregation becomes more severe due to the fiercer flows forced by the Lorentz force and the thermal buoyancy force. The cooling rate firstly increases, then decreases, due to the effect of the flows between the mushy region and metal pool and the temperature gradient at the mushy zone of the solidification front. With a current of 1800 A, the SDAS is the smallest and cooling rate is the fastest, indicating that less dendrite segregation and finer precipitates exist in the ingot. Under the comprehensive consideration, the dual alloy ingot processed by the ESR with a current of 1800 A is the best because it has the smallest SDAS, the appropriate grain growth angle, moderate macrosegregation and thickness of the transition zone.
Phase Selection during Solidification of Ni-10.95 at. % and B-3.23 at. % Si Alloy
Authors: Fraga-Chávez Karla , Castro-Román Manuel , Herrera-Trejo Martín , Ramírez-Vidaurri Luciano , Aguilera-Luna Israel
Published: May 2017

To gain insight into the solidification of the Ni-10.95 at. % and B-3.23 at. % Si alloy, 29 cast samples extracted from a casting of this alloy were remelted under an Ar atmosphere, using either DSC or an in-house thermal analysis apparatus. Ni(fcc) and Ni3B phases were identified by X-ray diffraction of both the remelted and original cast samples; however, microstructural differences were observed between the two. These microstructural differences are associated with the high undercooling observed during the eutectic reaction in the remelted samples. This high undercooling results from the difficulty of Ni3B nucleation, which allows the formation of a NixBy metastable phase. Metallographic inspection shows that the metastable phase solidifies at least partially through a non-cooperative growth mechanism. This metastable phase may be the elusive Ni23B6 phase. The melting temperature of the metastable phase is 985 °C, and it solidifies below 943 °C under the experimental conditions used in this study. The temperature of solid transformation of the metastable constituent to Ni3B and Ni is strongly dependent on the amount of Ni3B formed during solidification. The minimal temperature of such transformation, 834 °C, corresponds to samples where Ni3B solidification was not detected in the thermal curves.
Large-Scale Fabrication of Porous Gold Nanowires via Laser Interference Lithography and Dealloying of Gold–Silver Nano-Alloys
Authors: Chauvin Adrien , Stephant Nicolas , Du Ke , Ding Junjun , Wathuthanthri Ishan , Choi Chang-Hwan , Tessier Pierre-Yves , El Mel Abdel-Aziz
Published: May 2017

In this work, we report on an efficient approach to fabricating large-area and uniform planar arrays of highly ordered nanoporous gold nanowires. The approach consists in dealloying Au–Ag alloy nanowires in concentrated nitric acid. The Au–Ag alloy nanowires were obtained by thermal annealing at 800 °C for 2 h of Au/Ag stacked nanoribbons prepared by subsequent evaporation of silver and gold through a nanograted photoresist layer serving as a mask for a lift-off process. Laser interference lithography was employed for the nanopatterning of the photoresist layer to create the large-area nanostructured mask. The result shows that for a low Au-to-Ag ratio of 1, the nanowires tend to cracks during the dealloying due to the internal residual stress generated during the dealloying process, whereas the increase of the Au-to-Ag ratio to 3 can overcome the drawback and successfully leads to the obtainment of an array of highly ordered nanoporous gold nanowires. Nanoporous gold nanowires with such well-regulated organization on a wafer-scale planar substrate are of great significance in many applications including sensors and actuators.
Effects of Commercial Apple Varieties on Human Gut Microbiota Composition and Metabolic Output Using an In Vitro Colonic Model
Authors: Koutsos Athanasios , Lima Maria , Conterno Lorenza , Gasperotti Mattia , Bianchi Martina , Fava Francesca , Vrhovsek Urska , Lovegrove Julie , Tuohy Kieran
Published: May 2017

Apples are a rich source of polyphenols and fiber. A major proportion of apple polyphenols escape absorption in the small intestine and together with non-digestible polysaccharides reach the colon, where they can serve as substrates for bacterial fermentation. Animal studies suggest a synergistic interaction between apple polyphenols and the soluble fiber pectin; however, the effects of whole apples on human gut microbiota are less extensively studied. Three commercial apple varieties—Renetta Canada, Golden Delicious and Pink Lady—were digested and fermented in vitro using a batch culture colonic model (pH 5.5–6.0, 37 °C) inoculated with feces from three healthy donors. Inulin and cellulose were used as a readily and a poorly fermentable plant fiber, respectively. Fecal microbiota composition was measured by 16S rRNA gene Illumina MiSeq sequencing (V3-V4 region) and Fluorescence in Situ Hybridization. Short chain fatty acids (SCFAs) and polyphenol microbial metabolites were determined. The three apple varieties significantly changed bacterial diversity, increased Actinobacteria relative abundance, acetate, propionate and total SCFAs (p < 0.05). Renetta Canada and Golden Delicious significantly decreased Bacteroidetes abundance and increased Proteobacteria proportion and bifidobacteria population (p < 0.05). Renetta Canada also increased Faecalibacterium prausnitzii, butyrate levels and polyphenol microbial metabolites (p < 0.05). Together, these data suggest that apples, particularly Renetta Canada, can induce substantial changes in microbiota composition and metabolic activity in vitro, which could be associated with potential benefits to human health. Human intervention studies are necessary to confirm these data and potential beneficial effects.
Implicit Bias, Stereotype Threat, and Political Correctness in Philosophy
Authors: Hermanson Sean
Published: May 2017

This paper offers an unorthodox appraisal of empirical research bearing on the question of the low representation of women in philosophy. It contends that fashionable views in the profession concerning implicit bias and stereotype threat are weakly supported, that philosophers often fail to report the empirical work responsibly, and that the standards for evidence are set very low—so long as you take a certain viewpoint.
Polyolefins, a Success Story
Authors: Sauter Dominique , Taoufik Mostafa , Boisson Christophe
Published: May 2017

This paper reports the principal discoveries which have played a major role in the polyolefin field and have positioned polyolefins as the most produced plastics. The early development of polyolefins covering the production of LDPE (Low density polyethylene) at ICI (Imperial Chemical Industries) and the discovery of Phillips or Ziegler-Natta catalysts are highlighted in the first section. In the second part, the impact of the implementation of molecular catalysts on the research in polyolefins is discussed together with the most recent advances leading to high-performance tailor-made resins.
Effect of High Salt Concentration (HSC) on Structural, Morphological, and Electrical Characteristics of Chitosan Based Solid Polymer Electrolytes
Authors: Aziz Shujahadeen B. , Abdullah Omed Gh. , Rasheed Mariwan A. , Ahmed Hameed M.
Published: May 2017

Chitosan (CS) films doped with sodium triflate (NaTf) were prepared by the solution cast technique. The structural and morphological behaviors of the samples were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The XRD patterns were deconvoluted to estimate the degree of crystallinity of the samples. The SEM micrograph showed the crystalline structure of the sample contained 50 wt % of NaTf salt. The disappearance of broad peaks of chitosan at 2θ ≈ 21° and 2θ ≈ 32° confirmed the occurrence of ion association at 50 wt % of NaTf salt. In impedance plots, a low frequency spike region and a high frequency semicircle, were distinguishable for low salt concentrations. The highest ambient temperature direct current (DC) electrical conductivity obtained for CS:NaTf was found to be 2.41 × 10−4 S/cm for the sample containing 40 wt % of NaTf salt. The role of lattice energy of salts on DC ionic conductivity was also discussed. The temperature dependence of DC conductivity was found to follow the well-known Arrhenius relationship. From the alternating current (AC) conductivity spectra, three distinct regions were recognized for the samples with NaTf salt concentration ranging from 10 wt % to 30 wt %. The plateau region of AC spectra was used to estimate the DC conductivity.
Economic Inequality and the New School of American Economics
Authors: Leccese Stephen
Published: May 2017

This essay analyzes economic inequality in the Gilded Age, roughly from 1865 to 1900. It focuses specifically on a group of economists who identified working-class consumption as an economic stimulus, and accordingly advocated an increase in wages to bring this about. It is structured in three sections: first, it demonstrates how industrialization in the late-nineteenth century sparked social tensions, convincing observers that there was a crisis of inequality; second, it explains how these tensions produced a “New School” of economics who sought to alleviate these issues by changing economic doctrine; it concludes by noting how this New School exerted an influence on public policy in the Progressive Era. In their conception, economics should be redesigned to promote a more equal distribution of wealth. Therefore, higher wages would stimulate working-class consumption, which would stabilize the economy and overall alleviate class conflict. This story offers a unique way to view the development of consumerism and social reform in American history.
Augmented Reality Guidance with Multimodality Imaging Data and Depth-Perceived Interaction for Robot-Assisted Surgery
Authors: Wen Rong , Chng Chin-Boon , Chui Chee-Kong
Published: May 2017

Image-guided surgical procedures are challenged by mono image modality, two-dimensional anatomical guidance and non-intuitive human-machine interaction. The introduction of Tablet-based augmented reality (AR) into surgical robots may assist surgeons with overcoming these problems. In this paper, we proposed and developed a robot-assisted surgical system with interactive surgical guidance using tablet-based AR with a Kinect sensor for three-dimensional (3D) localization of patient anatomical structures and intraoperative 3D surgical tool navigation. Depth data acquired from the Kinect sensor was visualized in cone-shaped layers for 3D AR-assisted navigation. Virtual visual cues generated by the tablet were overlaid on the images of the surgical field for spatial reference. We evaluated the proposed system and the experimental results showed that the tablet-based visual guidance system could assist surgeons in locating internal organs, with errors between 1.74 and 2.96 mm. We also demonstrated that the system was able to provide mobile augmented guidance and interaction for surgical tool navigation.
Assessment of Chlorophyll-a Remote Sensing Algorithms in a Productive Tropical Estuarine-Lagoon System
Authors: Lins Regina , Martinez Jean-Michel , Motta Marques David , Cirilo José , Fragoso Carlos
Published: May 2017

Remote estimation of chlorophyll-a in turbid and productive estuaries is difficult due to the optical complexity of Case 2 waters. Although recent advances have been obtained with the use of empirical approaches for estimating chlorophyll-a in these environments, the understanding of the relationship between spectral reflectance and chlorophyll-a is based mainly on temperate and subtropical estuarine systems. The potential to apply standard NIR-Red models to productive tropical estuaries remains underexplored. Therefore, the purpose of this study is to evaluate the performance of several approaches based on multispectral data to estimate chlorophyll-a in a productive tropical estuarine-lagoon system, using in situ measurements of remote sensing reflectance, Rrs. The possibility of applying algorithms using simulated satellite bands of modern and recent launched sensors was also evaluated. More accurate retrievals of chlorophyll-a (r2 > 0.80) based on field datasets were found using NIR-Red three-band models. In addition, enhanced chlorophyll-a retrievals were found using the two-band algorithm based on bands of recently launched satellites such as Sentinel-2/MSI and Sentinel-3/OLCI, indicating a promising application of these sensors to remotely estimate chlorophyll-a for coming decades in turbid inland waters. Our findings suggest that empirical models based on optical properties involving water constituents have strong potential to estimate chlorophyll-a using multispectral data from satellite, airborne or handheld sensors in productive tropical estuaries.
Satellite-Based Sea Ice Navigation for Prydz Bay, East Antarctica
Authors: Hui Fengming , Zhao Tiancheng , Li Xinqing , Shokr Mohammed , Heil Petra , Zhao Jiechen , Zhang Lin , Cheng Xiao
Published: May 2017

Sea ice adversely impacts nautical, logistical and scientific missions in polar regions. Ship navigation benefits from up-to-date sea ice analyses at both regional and local scales. This study presents a satellite-based sea ice navigation system (SatSINS) that integrates observations and scientific output from remote sensing and meteorological data to develop optimum marine navigational routes in sea ice-covered waters, especially in areas where operational ice information is usually scarce. The system and its applications are presented in the context of a decision-making process to optimize the routing of the RV Xuelong during her passage through Prydz Bay, East Antarctica during three trips in the austral spring of 2011–2013. The study assesses scientifically-generated remote sensing ice parameters for their operational use in marine navigation. Evaluation criteria involve identification of priority parameters, their spatio-temporal requirements in relation to navigational needs, and their level of accuracy in conjunction with the severity of ice conditions. Coarse-resolution ice concentration maps are sufficient to delineate ice edge and develop a safe route when ice concentration is less than 70%, provided that ice dynamics, estimated from examining the cyclonic pattern, is not severe. Otherwise, fine-resolution radar data should be used to identify and avoid deformed ice. Satellite data lagging one day behind the actual location of the ship was sufficient in most cases although the proposed route may have to be adjusted. To evaluate the utility of SatSINS, deviation of the actual route from the proposed route was calculated and found to range between 165 m to about 16.0 km with standard deviations of 2.8–6.1 km. Growth of land-fast ice has proven to be an essential component of the system as it was estimated using a thermodynamic model with input from a meteorological station.
Dynamic Monitoring of the Largest Freshwater Lake in China Using a New Water Index Derived from High Spatiotemporal Resolution Sentinel-1A Data
Authors: Tian Haifeng , Li Wang , Wu Mingquan , Huang Ni , Li Guodong , Li Xiang , Niu Zheng
Published: May 2017

Poyang Lake is the largest freshwater lake in China and is well known for its ecological function and economic importance. However, due to the influence of clouds, it is difficult to dynamically monitor the changes in water surface areas using optical remote sensing. To address this problem, we propose a novel method to monitor these changes using Sentinel-1A data. First, the Sentinel-1A water index (SWI) was built using a linear model and a stepwise multiple regression analysis method with Sentinel-1A and Landsat-8 imagery acquired on the same day. Second, water surface areas of Poyang Lake from 24 May 2015 to 14 November 2016 were extracted by the threshold method utilizing time-series SWI data with an interval of 12 days. The results showed that the SWI threshold classification method could be applied to different regions during different periods with high quantity accuracy (approximately 99%). The water surface areas ranged between 1726.73 km2 and 3729.19 km2 during the study periods, indicating an extreme variability in the short term. The maximum and average values of the changed areas were 875.57 km2 (with a change rate of 35%) and 197.58 km2 (with a change rate of 8.2%), respectively, after 12 days. The changes in the mid-western region of Poyang Lake were more dramatic. These results provide baseline data for high-frequency monitoring of the ecological environment and wetland management in Poyang Lake.
A Monitoring System for Laying Hens That Uses a Detection Sensor Based on Infrared Technology and Image Pattern Recognition
Authors: Zaninelli Mauro , Redaelli Veronica , Luzi Fabio , Bontempo Valentino , Dell’Orto Vittorio , Savoini Giovanni
Published: May 2017

In Italy, organic egg production farms use free-range housing systems with a big outdoor area and a flock of no more than 500 hens. With additional devices and/or farming procedures, the whole flock could be forced to stay in the outdoor area for a limited time of the day. As a consequence, ozone treatments of housing areas could be performed in order to reduce the levels of atmospheric ammonia and bacterial load without risks, due by its toxicity, both for hens and workers. However, an automatic monitoring system, and a sensor able to detect the presence of animals, would be necessary. For this purpose, a first sensor was developed but some limits, related to the time necessary to detect a hen, were observed. In this study, significant improvements, for this sensor, are proposed. They were reached by an image pattern recognition technique that was applied to thermografic images acquired from the housing system. An experimental group of seven laying hens was selected for the tests, carried out for three weeks. The first week was used to set-up the sensor. Different templates, to use for the pattern recognition, were studied and different floor temperature shifts were investigated. At the end of these evaluations, a template of elliptical shape, and sizes of 135 × 63 pixels, was chosen. Furthermore, a temperature shift of one degree was selected to calculate, for each image, a color background threshold to apply in the following field tests. Obtained results showed an improvement of the sensor detection accuracy that reached values of sensitivity and specificity of 95.1% and 98.7%. In addition, the range of time necessary to detect a hen, or classify a case, was reduced at two seconds. This result could allow the sensor to control a bigger area of the housing system. Thus, the resulting monitoring system could allow to perform the sanitary treatments without risks both for animals and humans.
Thermochemical Humidity Detection in Harsh or Non-Steady Environments
Authors: Bridgeman Devon , Tsow Francis , Xian Xiaojun , Chang Qinan , Liu Yongming , Forzani Erica
Published: May 2017

We present a new method of chemical quantification utilizing thermal analysis for the detection of relative humidity. By measuring the temperature change of a hydrophilically-modified temperature sensing element vs. a hydrophobically-modified reference element, the total heat from chemical interactions in the sensing element can be measured and used to calculate a change in relative humidity. We have probed the concept by assuming constant temperature streams, and having constant reference humidity (~0% in this case). The concept has been probed with the two methods presented here: (1) a thermistor-based method and (2) a thermographic method. For the first method, a hydrophilically-modified thermistor was used, and a detection range of 0–75% relative humidity was demonstrated. For the second method, a hydrophilically-modified disposable surface (sensing element) and thermal camera were used, and thermal signatures for different relative humidity were demonstrated. These new methods offer opportunities in either chemically harsh environments or in rapidly changing environments. For sensing humidity in a chemically harsh environment, a hydrophilically-modified thermistor can provide a sensing method, eliminating the exposure of metallic contacts, which can be easily corroded by the environment. On the other hand, the thermographic method can be applied with a disposable non-contact sensing element, which is a low-cost upkeep option in environments where damage or fouling is inevitable. In addition, for environments that are rapidly changing, the thermographic method could potentially provide a very rapid humidity measurement as the chemical interactions are rapid and their changes are easily quantified.
The Effect of Leaf Stacking on Leaf Reflectance and Vegetation Indices Measured by Contact Probe during the Season
Authors: Neuwirthová Eva , Lhotáková Zuzana , Albrechtová Jana
Published: May 2017

The aims of the study were: (i) to compare leaf reflectance in visible (VIS) (400–700 nm), near-infrared (NIR) (740–1140 nm) and short-wave infrared (SWIR) (2000–2400 nm) spectral ranges measured monthly by a contact probe on a single leaf and a stack of five leaves (measurement setup (MS)) of two broadleaved tree species during the vegetative season; and (ii) to test if and how selected vegetation indices differ under these two MS. In VIS, the pigment-related spectral region, the effect of MS on reflectance was negligible. The major influence of MS on reflectance was detected in NIR (up to 25%), the structure-related spectral range; and weaker effect in SWIR, the water-related spectral range. Vegetation indices involving VIS wavelengths were independent of MS while indices combining wavelengths from both VIS and NIR were MS-affected throughout the season. The effect of leaf stacking contributed to weakening the correlation between the leaf chlorophyll content and selected vegetation indices due to a higher leaf mass per area of the leaf sample. The majority of MS-affected indices were better correlated with chlorophyll content in both species in comparison with MS-unaffected indices. Therefore, in terms of monitoring leaf chlorophyll content using the contact probe reflectance measurement, these MS-affected indices should be used with caution, as discussed in the paper. If the vegetation indices are used for assessment of plant physiological status in various times of the vegetative season, then it is essential to take into consideration their possible changes induced by the particular contact probe measurement setup regarding the leaf stacking.
A New Calibration Method for Commercial RGB-D Sensors
Authors: Darwish Walid , Tang Shenjun , Li Wenbin , Chen Wu
Published: May 2017

Commercial RGB-D sensors such as Kinect and Structure Sensors have been widely used in the game industry, where geometric fidelity is not of utmost importance. For applications in which high quality 3D is required, i.e., 3D building models of centimeter‑level accuracy, accurate and reliable calibrations of these sensors are required. This paper presents a new model for calibrating the depth measurements of RGB-D sensors based on the structured light concept. Additionally, a new automatic method is proposed for the calibration of all RGB-D parameters, including internal calibration parameters for all cameras, the baseline between the infrared and RGB cameras, and the depth error model. When compared with traditional calibration methods, this new model shows a significant improvement in depth precision for both near and far ranges.
Fabric Sol–gel Phase Sorptive Extraction Technique: A Review
Authors: Kazantzi Viktoria , Anthemidis Aristidis
Published: May 2017

Since the introduction in 2014 of fabric phase sorptive extraction (FPSE) as a sample preparation technique, it has attracted the attention of many scientists working in the field of separation science. This novel sorbent extraction technique has successfully utilized the benefits of sol–gel derived hybrid sorbents and a plethora of fabric substrates, resulting in a highly efficient, sensitive and green sample pretreatment methodology. The proposed procedure is an easy and efficient pathway to extract target analytes from different matrices providing inherent advantages such as high sample loading capacity and short pretreatment time. The present review mainly focuses on the background and sol–gel chemistry for the preparation of new fabric sorbents as well as on the applications of FPSE for extracting target analytes, from the time that it was first introduced. New modes of FPSE including stir FPSE, stir-bar FPSE, dynamic FPSE, and automated on-line FPSE are also highlighted and commented upon in detail. FPSE has been effectively applied for the determination of various organic and inorganic analytes in different types of environmental and biological samples in high throughput analytical, environmental, and toxicological laboratories.
Assessing the Impact of Mobile Technology on Exhibition Attendees’ Unplanned Booth Visit Behaviour
Authors: Chung Namho , Koo Chulmo , Lee Kyungmin
Published: May 2017

This study examines the effect of the booth Recommender system (BRS) embedded in a mobile device on the goals of exhibition attendees, based on two main theories that are unplanned behaviour and goal frame theories. Previous studies have overlooked the importance of the unplanned behavioural effectiveness of IT devices for understanding motivation and delivering unexpected outcomes at exhibitions. The BRS offers customized, personalized, and advanced information to attendees; experiences with the BRS lead to unplanned behaviour. In this paper, we distinguish several goal frames, including hedonic, gain, and normative goals, which contribute to the relationship between continued BRS use and unplanned booth visits. Continued BRS use directly influences revisit intentions to an exhibition and contributes to unplanned booth visits. We analysed data from 508 attendees at a franchise exhibition using structural equation modelling (SEM) method. Our research empirically determined that goal framing theory and unplanned behaviour via continued BRS use embedded in a mobile device are connected. Continued BRS use in an exhibition can contribute to attendees’ impulsive behaviour and can induce them to return to an exhibition. The results and implications are discussed.
The Route to Sustainability—Prospects and Challenges of the Bio-Based Economy
Authors: Bennich Therese , Belyazid Salim
Published: May 2017

The bio-based economy has been increasingly recognized in the sustainability debate over the last two decades, presented as a solution to a number of ecological and social challenges. Its premises include climate change mitigation, cleaner production processes, economic growth, and new employment opportunities. Yet, a transition to a bio-based economy is hampered by risk factors and uncertainties. In this paper, we explore the concept of a bio-based economy, focusing on opportunities of achieving sustainability, as well as challenges of a transition. Departing from an understanding of sustainability provided by the weak and strong sustainability paradigms, we first outline the definition and development of the bio-based economy from a theoretical perspective. Second, we use Sweden as an example of how a transition towards a bio-based economy has been evolving in practice. The review indicates that the proposed direction and strategies of the bio-based economy are promising, but sometimes contradictory, resulting in different views on the actions needed for its premises to be realized. Additionally, current developments adhere largely to the principles of the weak sustainability paradigm. In order for the bio-based economy to develop in accordance with the notion of strong sustainability, important steps to facilitate a transition would include acknowledging and addressing the trade-offs caused by biophysical and social limits to growth.
Testbed for Multilayer Conformal Additive Manufacturing
Authors: Kutzer Michael , DeVries Levi
Published: May 2017

Over the last two decades, additive manufacturing (AM) or 3D printing technologies have become pervasive in both the public and private sectors. Despite this growth, there has been little to no deviation from the fundamental approach of building parts using planar layers. This undue reliance on a flat build surface limits part geometry and performance. To address these limitations, a new method of applying material onto or around existing surfaces with multilayer, thick features will be explored. Prior work proposes algorithms for defining conformal layers between existing and desired surfaces, however this work does not address the derivation of deposition paths, trajectories, or required hardware to achieve this new type of deposition. This paper presents (1) the derivation of deposition paths given a prescribed set of layers; (2) the design, characterization, and control of a proof-of-concept testbed; and (3) the derivation and application of time evolving trajectories subject to the material deposition constraints and mechanical constraints of the testbed. Derivations are presented in a general context with examples extending beyond the proposed testbed. Results show the feasibility of conformal material deposition (i.e., onto and around existing surfaces) with multilayer, thick features.
Optimizing Sediment Diversion Operations: Working Group Recommendations for Integrating Complex Ecological and Social Landscape Interactions
Authors: Peyronnin Natalie , Caffey Rex , Cowan James , Justic Dubravko , Kolker Alexander , Laska Shirley , McCorquodale Alex , Melancon Earl , Nyman John , Twilley Robert , Visser Jenneke , White John , Wilkins James
Published: May 2017

Future conditions of coastal Louisiana are highly uncertain due to the dynamic nature of deltas, climate change, tropical storms, and human reliance on natural resources and ecosystem services. Managing a system in which natural and socio-economic components are highly integrated is inherently difficult. Sediment diversions are a unique restoration tool that would reconnect the Mississippi River to its deltaic plain to build and sustain land. Diversions are innately adaptable as operations can be modified over time. An expert working group was formed to explore how various operational strategies may affect the complex interactions of coastal Louisiana’s ecological and social landscape and provide preliminary recommendations for further consideration and research. For example, initial operations should be gradually increased over 5 to 10 years to facilitate the development of a distributary channel network, reduce flood risk potential to communities, limit erosion of adjacent marshes and reduce stress to vegetation and fish and wildlife species. Diversions should operate over winter peaks to capture the highest sediment concentration, reduce vegetation loss while dormant, and reduce detrimental effects to fish and wildlife. Operations during the spring/summer should occur over shorter periods to capture the highest sediment load during the rising limb of the flood peak and minimize impacts to the ecosystem. Operational strategies should strive to build and sustain as much of the coastal landscape as possible while also balancing the ecosystem and community needs.
Magnetically Modulated Heat Transport in a Global Simulation of Solar Magneto-convection
Authors: Cossette Jean-Francois , Charbonneau Paul , Smolarkiewicz Piotr K. , Rast Mark P.
Published: May 2017

We present results from a global MHD simulation of solar convection in which the heat transported by convective flows varies in-phase with the total magnetic energy. The purely random initial magnetic field specified in this experiment develops into a well-organized large-scale antisymmetric component undergoing hemispherically synchronized polarity reversals on a 40 year period. A key feature of the simulation is the use of a Newtonian cooling term in the entropy equation to maintain a convectively unstable stratification and drive convection, as opposed to the specification of heating and cooling terms at the bottom and top boundaries. When taken together, the solar-like magnetic cycle and the convective heat flux signature suggest that a cyclic modulation of the large-scale heat-carrying convective flows could be operating inside the real Sun. We carry out an analysis of the entropy and momentum equations to uncover the physical mechanism responsible for the enhanced heat transport. The analysis suggests that the modulation is caused by a magnetic tension imbalance inside upflows and downflows, which perturbs their respective contributions to heat transport in such a way as to enhance the total convective heat flux at cycle maximum. Potential consequences of the heat transport modulation for solar irradiance variability are briefly discussed.
The Dynamics of Inhomogeneous Dark Energy
Authors: Tian Shuxun , Cao Shuo , Zhu Zong-Hong
Published: May 2017

In this paper, by analyzing the dynamics of inhomogeneous quintessence dark energy, we find that the gradient energy of dark energy will oscillate and gradually vanish, which indicates the gradient energy of the scalar field present in the early universe does not affect the current dynamics of the universe. Moreover, with the decaying of gradient energy, there exists a possible mutual transformation between kinetic energy and gradient energy. In the framework of interacting dark energy models, we argue that inhomogeneous dark energy may have a significant effect on the evolution of the cosmic background, the investigation of which still requires fully relativistic N-body numerical simulations in the future.
A Polarization Sequence for Type Ia Supernovae?
Authors: Meng X. , Zhang J. , Han Z.
Published: May 2017

Early polarization observations of type Ia supernovae (SNe Ia) may reveal the geometry of supernova ejecta, and then put constraints on their explosion mechanism and their progenitor model. We performed a literature search of SNe Ia with polarization measurements and determined the polarization and relative equivalent width (REW) of the Si ii 635.5 nm absorption feature at −5 days after the maximum light. We found that either the distribution of observed polarization degree is bimodal, i.e., the broad-line SNe Ia have systematically higher polarization than all other SNe Ia, or that all types of SNe Ia share the same polarization sequence, i.e., the polarization of the Si ii 635.5 nm absorption feature increases with the REW. We also discussed the potential effects that the discovery might have on the explosion mechanism and progenitor model of SNe Ia.
Scenarios for Ultrafast Gamma-Ray Variability in AGN
Authors: Aharonian F. A. , Barkov M. V. , Khangulyan D.
Published: May 2017

We analyze three scenarios to address the challenge of ultrafast gamma-ray variability reported from active galactic nuclei. We focus on the energy requirements imposed by these scenarios: (i) external cloud in the jet, (ii) relativistic blob propagating through the jet material, and (iii) production of high-energy gamma-rays in the magnetosphere gaps. We show that while the first two scenarios are not constrained by the flare luminosity, there is a robust upper limit on the luminosity of flares generated in the black hole magnetosphere. This limit depends weakly on the mass of the central black hole and is determined by the accretion disk magnetization, viewing angle, and the pair multiplicity. For the most favorable values of these parameters, the luminosity for 5-minute flares is limited by

, which excludes a black hole magnetosphere origin of the flare detected from IC 310. In the scopes of scenarios (i) and (ii), the jet power, which is required to explain the IC 310 flare, exceeds the jet power estimated based on the radio data. To resolve this discrepancy in the framework of scenario (ii), it is sufficient to assume that the relativistic blobs are not distributed isotropically in the jet reference frame. A realization of scenario (i) demands that the jet power during the flare exceeds by a factor 102 the power of the radio jet relevant to a timescale of 108 years.
Properties of Turbulence in the Reconnection Exhaust: Numerical Simulations Compared with Observations
Authors: Pucci F. , Servidio S. , Sorriso-Valvo L. , Olshevsky V. , Matthaeus W. H. , Malara F. , Goldman M. V. , Newman D. L. , Lapenta G.
Published: May 2017

The properties of the turbulence that develops in the outflows of magnetic reconnection have been investigated using self-consistent plasma simulations, in three dimensions. As commonly observed in space plasmas, magnetic reconnection is characterized by the presence of turbulence. Here we provide a direct comparison of our simulations with reported observations of reconnection events in the magnetotail, investigating the properties of the electromagnetic field and the energy conversion mechanisms. In particular, simulations show the development of a turbulent cascade consistent with spacecraft observations, statistics of the dissipation mechanisms in the turbulent outflows similar to the ones observed in reconnection jets in the magnetotail, and that the properties of turbulence vary as a function of the distance from the reconnecting X-line.
The Stellar Metallicity Distribution of the Galactic Halo Based on SCUSS and SDSS Data
Authors: Zuo Wenbo , Du Cuihua , Jing Yingjie , Gu Jiayin , Newberg Heidi Jo , Wu Zhenyu , Ma Jun , Zhou Xu
Published: May 2017

Based on the Sloan Digital Sky Survey and South Galactic Cap u-band Sky Survey (SCUSS), we simulate the photometric metallicity distribution functions (MDFs) of stars in the Galactic halo. The photometric metallicity of stars was estimated by a new Monte-Carlo method. Due to the use of a more reliable metallicity calibration method and more accurate u-band deep measurements from SCUSS, we can obtain more accurate MDFs of a large sample of distant stars in the Galactic halo. In this study, we select 78,092 F/G main-sequence turnoff stars (MSTO) in the south Galactic cap, with 0.2 < (g − r)0 < 0.4, as tracers of the stellar MDFs in the Galactic halo. The sample stars are divided into two height intervals above the Galactic plane: −8 < z < −4 kpc and −12 < z < −8 kpc. The MDFs of selected stars in each interval are well fit by a three-Gaussian model, with peaks at [Fe/H] ≈ −0.63, −1.45, and −2.0. The two metal-poor components correspond to the inner halo and outer halo, respectively. The fraction of the metal-rich component, which may be contributed by the substructure (such as Sagittarius stream or other streams) is about 10%. With limited kinematic estimation, we find the correlations between metallicity and kinematics. Our results provide additional supporting evidence of duality of the Galactic halo.
Constraining the Single-degenerate Channel of Type Ia Supernovae with Stable Iron-group Elements in SNR 3C 397
Authors: Dave Pranav , Kashyap Rahul , Fisher Robert , Timmes Frank , Townsley Dean , Byrohl Chris
Published: May 2017

Recent Suzaku X-ray spectra of supernova remnant (SNR) 3C 397 indicate enhanced stable iron group element abundances of Ni, Mn, Cr, and Fe. Seeking to address key questions about the progenitor and explosion mechanism of 3C 397, we compute nucleosynthetic yields from a suite of multidimensional hydrodynamics models in the near-Chandrasekhar-mass, single-degenerate paradigm for Type Ia supernovae (SNe Ia). Varying the progenitor white dwarf (WD) internal structure, composition, ignition, and explosion mechanism, we find that the best match to the observed iron peak elements of 3C 397 are dense (central density ≥6 × 109 g cm−3), low-carbon WDs that undergo a weak, centrally ignited deflagration, followed by a subsequent detonation. The amount of 56Ni produced is consistent with a normal or bright normal SNe Ia. A pure deflagration of a centrally ignited, low central density (≃2 × 109 g cm−3) progenitor WD, frequently considered in the literature, is also found to produce good agreement with 3C 397 nucleosynthetic yields, but leads to a subluminous SN Ia event, in conflict with X-ray line width data. Additionally, in contrast to prior work that suggested a large supersolar metallicity for the WD progenitor for SNR 3C 397, we find satisfactory agreement for solar- and subsolar-metallicity progenitors. We discuss a range of implications our results have for the single-degenerate channel.