bluuebunny/crossref_metadata_2025 huggingface dataset:
Consumption of Alcoholic Beverages and the Prevalence of Metabolic Syndrome and Its Components
Authors: Suliga Edyta , Kozieł Dorota , Ciesla Elzbieta , Rebak Dorota , Głuszek-Osuch Martyna , Głuszek Stanisław
Published: November 2019

The relationship between alcohol consumption and the prevalence of metabolic syndrome is not consistent and may vary between populations, depending on age, sex, ethnicity, cultural traditions and lifestyle. We have hypothesized that moderate alcohol consumption will be associated with the lowest risk of the syndrome. The aim of the present study is to examine the relationship between the current consumption of alcohol and the prevalence of metabolic syndrome and its components. The research material includes data obtained from 12,285 men and women, in the age range of 37–66 years. Multiple logistic regression was used in the statistical analysis. Metabolic syndrome (MetS) was defined according to the International Diabetes Federation. In men, a current consumption of >30 g of alcohol/day was significantly associated with a higher risk of metabolic syndrome (OR = 1.73, 95% CI = 1.25–2.39), high blood pressure (OR = 2.76, 95% CI = 1.64–4.65), elevated glucose concentration (OR = 1.70, 95% CI = 1.24–2.32), and abdominal obesity (OR = 1.77; 95% CI = 1.07–2.92). In women, the consumption from 10.1 to 15.0 g of alcohol was associated only with a higher risk of abnormal glucose concentration (OR = 1.65; 95% CI = 1.14–2.38.) In both sexes, current alcohol consumption was associated with higher high-density lipoproteins (HDL)-cholesterol concentration (p < 0.05). No relationship was found between alcohol consumption and triglyceride concentration. It is difficult to formulate unequivocal recommendations regarding alcohol intake in MetS prophylaxis due to its different association with particular MetS components. In order to explain the causal relationship between alcohol consumption and MetS and its components, prospective studies are necessary.
Hepatitis C Virus among Female Sex Workers: A Cross-Sectional Study Conducted along Rivers and Highways in the Amazon Region
Authors: Oliveira-Filho Aldemir B. , Aires Diego Wendel F. , Cavalcante Natalia S. , Raiol Nairis Costa , Lisboa Brenda Luena A. , Frade Paula Cristina R. , da Costa Luana M. , Pinheiro Luiz Marcelo L. , Machado Luiz Fernando A. , Martins Luisa C. , Silva-Oliveira Gláucia C. , Pinho João Renato R. , Kupek Emil , Lemos José Alexandre R.
Published: November 2019

Background: Previous studies found a high prevalence of pathogens among female sex workers (FSWs) in the Amazon region, and established their parenteral and sexual transmission. This study estimated the prevalence of hepatitis C virus (HCV) infection and associated risk factors, and the frequency of HCV genotypes and resistance-associated substitutions (RASs) in this vulnerable group. Methods: Distinct sampling methods were used to access 412 FSWs in cities and riverside communities in the Amazon region from 2015 to 2018. Three methods for HCV diagnosis were used to determine infection status. HCV genotypes and RASs were identified by sequencing and nucleotide fragment analysis. An association between HCV infection and exposure factors was determined by bivariate and multivariate analysis. Results: In total, 44 (10.7%) FSWs were exposed to HCV, and 32 (7.8%) of them had active infection. Nine socioeconomic characteristics and risky sexual behaviors were associated with HCV exposure, particularly unprotected sex and condom exemption for the clients who paid extra money. Genotype 1 (81.3%) and 3 (18.7%) were detected. The frequency of FSWs with RASs was 23.1% (6/26) for grazoprevir related to the occurrence of substitutions Y56F and S122G. Conclusions: HCV infection among FSWs is highly prevalent and dominated by genotype I. Urgent preventive and treatment measures are required to reduce HCV infection in FSWs and the general population.
Development of Injectable PEGylated Liposome Encapsulating Disulfiram for Colorectal Cancer Treatment
Authors: Najlah Mohammad , Said Suliman Ammar , Tolaymat Ibrahim , Kurusamy Sathishkumar , Kannappan Vinodh , Elhissi Abdelbary M. A. , Wang Weiguang
Published: November 2019

Disulfiram (DS), an anti-alcoholism medicine, shows strong anti-cancer activity in the laboratory, but the application in clinics for anti-cancer therapy has been limited by its prompt metabolism. Conventional liposomes have shown limited ability to protect DS. Therefore, the aim of this study is to develop PEGylated liposomes of DS for enhanced bio-stability and prolonged circulation. PEGylated liposomes were prepared using ethanol-based proliposome methods. Various ratios of phospholipids, namely: hydrogenated soya phosphatidylcholine (HSPC) or dipalmitoyl phosphatidylcholine (DPPC) and N-(Carbonyl-methoxypolyethylenglycol-2000)-1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE-PEG2000) with cholesterol were used. DS was dissolved in the alcoholic solution in different lipid mol% ratios. The size of the resulting multilamellar liposomes was reduced by high-pressure homogenization. Liposomal formulations were characterized by size analysis, zeta potential, drug loading efficiency and stability in horse serum. Small unilamellar vesicles (SUVs; nanoliposomes) were generated with a size of approximately 80 to 120 nm with a polydispersity index (PDI) in the range of 0.1 to 0.3. Zeta potential values of all vesicles were negative, and the negative surface charge intensity tended to increase by PEGylation. PEGylated liposomes had a smaller size (80–90 nm) and a significantly lower PDI. All liposomes showed similar loading efficiencies regardless of lipid type (HSPC or DPPC) or PEGylations. PEGylated liposomes provided the highest drug biostability amongst all formulations in horse serum. PEGylated DPPC liposomes had t1/2 =77.3 ± 9.6 min compared to 9.7 ± 2.3 min for free DS. In vitro cytotoxicity on wild type and resistant colorectal cancer cell lines was evaluated by MTT assay. All liposomal formulations of DS were cytotoxic to both the wild type and resistant colorectal cancer cell lines and were able to reverse chemoresistance at low nanomolar concentrations. In conclusion, PEGylated liposomes have a greater potential to be used as an anticancer carrier for disulfiram.
Exotic Plants Used by the Hmong in Thailand
Authors: Nguanchoo Varangrat , Wangpakapattanawong Prasit , Balslev Henrik , Inta Angkhana
Published: November 2019

Exotic species are an integral part of the plants used by many ethnic groups, but they usually receive little attention and have been considered alien to the ethnobotanical data. Here, we analyze the plants used by Thai Hmong refugees that are not native to their current habitats in Thailand. We attempt to understand the sources of this knowledge. Do people maintain the original traditional knowledge related to exotic species when they migrate to a new region, or does new knowledge originate from acculturation? We interviewed 16 specialist Hmong informants in Nan province, Thailand, about their traditional knowledge of 69 exotic species used. Acquisition of this knowledge has a long history; several species are the same as plants used by the Hmong in China and other countries, others are globally useful species which have become part of the pool of species that the Hmong have developed local knowledge about. However, migration also involves the integration of local knowledge from other cultures, and also adapts them to function in urban settings. This includes using closely related exotic taxa that replace some of the species they used in their original homelands. The migrants’ traditional knowledge in their new habitats is more complicated and also involves the development of local knowledge that is entirely new.
Influence of PGPB Inoculation on HSP70 and HMA3 Gene Expression in Switchgrass under Cadmium Stress
Authors: Begum Nahmina , Hu Zhaoyang , Cai Qingsheng , Lou Laiqing
Published: November 2019

This study aimed to evaluate the gene expression of HSP70 and HMA3 in the switchgrass inoculated with plant-growth-promoting-bacteria (PGPB) under cadmium (Cd) stress and to observe the benefit of PGPB in plant growth and development. Plants were grown in hydroponic culture and treated with PGPB inoculants: Pseudomonas grimontii, Pantoea vagans, Pseudomonas veronii, and Pseudomonas fluorescens with the strains Bc09, So23, E02, and Oj24, respectively. The experimental results revealed that HSP70 and HMA3 genes expressed highly in the PGPB-inoculated plants under Cd stress. In addition, the expression of HSP70 and HMA3 genes was considerably higher in the first two days after successive four-day exposure of Cd in plants compared to the last two days of exposure. Increased biomass and indole-3-acetic-acid production with reduced Cd accumulation were observed in the PGPB-inoculated plants under Cd stress compared to the Cd-control plants. These PGPB, with their beneficial mechanisms, protect plants by modifying the gene expression profile that arises during Cd-toxic conditions and increased the healthy biomass of switchgrass. This demonstrates there is a correlation among the growth parameters under Cd stress. The PGPB in this study may help to intensify agriculture by triggering mechanisms to encourage plant growth and development under heavy metal stress.
Crystalline Characteristics and Their Influence in the Mechanical Performance in Poly(ε-Caprolactone) / High Density Polyethylene Blends
Authors: Blázquez-Blázquez Enrique , Pérez Ernesto , Lorenzo Vicente , Cerrada María L.
Published: November 2019

Blends of poly(ε-caprolactone) (PCL) and high-density polyethylene (HDPE) have been prepared at different compositions in order to assess the effect of HDPE on gas transport and mechanical behaviors of PCL. Previous to this evaluation, a complete morphological, structural, and thermal characterization were performed using techniques, including SEM, contact angle, FTIR, differential scanning calorimetry, and X-ray diffraction with synchrotron radiation at small and wide angles. Low HDPE incorporations allow interactions to be established at interfaces in the amorphous regions and the enhancement of the mechanical performance. Consequently, the addition of a small amount of HDPE (ranging from 5 to 10 wt%) appears to be appropriate in certain bio-applications where a higher mechanical behavior is required.
Quantitative Pore Characterization of Polyurethane Foam with Cost-Effective Imaging Tools and Image Analysis: A Proof-Of-Principle Study
Authors: Yunus Shemmira , Sefa-Ntiri Baah , Anderson Benjamin , Kumi Francis , Mensah-Amoah Patrick , Sonko Sackey Samuel
Published: November 2019

This study investigated the pore characterization of polyurethane (PU) foam as a necessary step in water filtration membrane fabrication. Porous material characterization is essential for predicting membrane performance, strength, durability, surface feel, and to understand the transport mechanisms using modeling and simulations. Most existing pore characterization techniques are relatively costly, time-consuming, subjective, and have cumbersome sample preparations. This study focused on using three relatively inexpensive imaging systems: a black box, Canon camera (EOS760D), and LaserJet scanner (M1132 MFP). Two standard, state-of-the-art imaging systems were used for comparison: a stereomicroscope and a scanning electron microscope. Digital images produced by the imaging systems were used with a MATLAB algorithm to determine the surface porosity, pore area, and shape factor of the polyurethane foam in an efficient manner. The results obtained established the compatibility of the image analysis algorithm with the imaging systems. The black box results were found to be more comparable to both the stereomicroscope and SEM systems than those of the Canon camera and scanner imaging systems. Indeed, the current research effort demonstrates the possibility of substrate characterization with inexpensive imaging systems.
Amphiphilic Block Copolymer Micelles in Selective Solvents: The Effect of Solvent Selectivity on Micelle Formation
Authors: Kumar Labeesh , Horechyy Andriy , Bittrich Eva , Nandan Bhanu , Uhlmann Petra , Fery Andreas
Published: November 2019

We investigated the micellar behavior of a series of asymmetric polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) block copolymers in different P4VP-selective alcoholic solvents. The micellar behavior was further correlated with the spectroscopic ellipsometry results obtained on swelling of PS and P4VP polymer films in the corresponding solvent vapors. The time-resolved (in situ) dynamic light scattering (DLS) measurements, in combination with (ex situ) electron microscopy imaging, revealed information about the aggregation state of PS-b-P4VP BCP in different alcohols and the effect of heat treatment. The ellipsometry measurements allowed us to estimate the difference in solvent selectivity toward PS/P4VP pair. Both DLS and ellipsometric studies suggested that less polar alcohols (i.e., 1-propanol, 1-butanol, and 1-pentanol) are likely to be close to each other in terms of their selectivity toward PS/P4VP pair, whereas more polar ethanol and methanol show the highest and the lowest affinity toward P4VP, respectively.
The Relationship between Sense of Coherence, Stress, Body Image Satisfaction and Eating Behavior in Japanese and Austrian Students
Authors: Kato Yoshiko , Greimel Elfriede , Hu Chenghong , Müller-Gartner Maria , Salchinger Beate , Freidl Wolfgang , Saito Seiichi , Roth Roswith
Published: November 2019

Background: Restrained, emotional, and external eating are related to obesity and eating disorders. A salutogenic model has confirmed sense of coherence (SOC) as a health resource that moderates stress and helps limit the occurrence of overweightness and eating disorders. This study aimed to examine the relationship between SOC, social support, stress, body image satisfaction (BIS) and eating behaviors in different cultural environments. Methods: A total of 371 Austrian (161 men, 210 women) and 398 Japanese (226 men, 172 women) university students participated. The SOC-13 scale, Multidimensional Scale of Perceived Social Support, Dutch Eating Behavior Questionnaire, BMI-Based Silhouette Matching Test and an analogue single-stress item were used as measurements. Results: SOC negatively affected all three types of eating in Austrian students (men: β = −0.227 to −0.215; women: β = −0.262 to −0.214). In Japanese students, SOC negatively affected external eating in both sexes (men: β = −0.150; women: β = −0.198) and emotional eating (β = −0.187) in men. BIS indicated that the desire to become slim predicted restrained eating, women’s emotional eating, and men’s and Austrian women’s external eating. Stress was only predictive of emotional eating in Japanese men. Conclusions: This study found that SOC, BIS and stress might be valuable factors regulating eating behavior in a cultural context. However, the relationship between SOC, BIS, stress and eating behavior differs between cultures.
Pixel-Wise PolSAR Image Classification via a Novel Complex-Valued Deep Fully Convolutional Network
Authors: Cao Yice , Wu Yan , Zhang Peng , Liang Wenkai , Li Ming
Published: November 2019

Although complex-valued (CV) neural networks have shown better classification results compared to their real-valued (RV) counterparts for polarimetric synthetic aperture radar (PolSAR) classification, the extension of pixel-level RV networks to the complex domain has not yet thoroughly examined. This paper presents a novel complex-valued deep fully convolutional neural network (CV-FCN) designed for PolSAR image classification. Specifically, CV-FCN uses PolSAR CV data that includes the phase information and uses the deep FCN architecture that performs pixel-level labeling. The CV-FCN architecture is trained in an end-to-end scheme to extract discriminative polarimetric features, and then the entire PolSAR image is classified by the trained CV-FCN. Technically, for the particularity of PolSAR data, a dedicated complex-valued weight initialization scheme is proposed to initialize CV-FCN. It considers the distribution of polarization data to conduct CV-FCN training from scratch in an efficient and fast manner. CV-FCN employs a complex downsampling-then-upsampling scheme to extract dense features. To enrich discriminative information, multi-level CV features that retain more polarization information are extracted via the complex downsampling scheme. Then, a complex upsampling scheme is proposed to predict dense CV labeling. It employs the complex max-unpooling layers to greatly capture more spatial information for better robustness to speckle noise. The complex max-unpooling layers upsample the real and the imaginary parts of complex feature maps based on the max locations maps retained from the complex downsampling scheme. In addition, to achieve faster convergence and obtain more precise classification results, a novel average cross-entropy loss function is derived for CV-FCN optimization. Experiments on real PolSAR datasets demonstrate that CV-FCN achieves better classification performance than other state-of-art methods.
Next-Generation Gravity Missions: Sino-European Numerical Simulation Comparison Exercise
Authors: Pail Roland , Yeh Hsien-Chi , Feng Wei , Hauk Markus , Purkhauser Anna , Wang Changqing , Zhong Min , Shen Yunzhong , Chen Qiujie , Luo Zhicai , Zhou Hao , Liu Bingshi , Zhao Yongqi , Zou Xiancai , Xu Xinyu , Zhong Bo , Haagmans Roger , Xu Houze
Published: November 2019

Temporal gravity retrieval simulation results of a future Bender-type double pair mission concept, performed by five processing centers of a Sino-European study team, have been inter-compared and assessed. They were computed in a synthetic closed-loop simulation world by five independent software systems applying different gravity retrieval methods, but were based on jointly defined mission scenarios. The inter-comparison showed that the results achieved a quite similar performance. Exemplarily, the root mean square (RMS) deviations of global equivalent water height fields from their true reference, resolved up to degree and order 30 of a 9-day solution, vary in the order of 10% of the target signal. Also, co-estimated independent daily gravity fields up to degree and order 15, which have been co-estimated by all processing centers, do not show large differences among each other. This positive result is an important pre-requisite and basis for future joint activities towards the realization of next-generation gravity missions.
Response of Beech (Fagus sylvatica L.) Trees to Competition—New Insights from Using Fractal Analysis
Authors: Dorji Yonten , Annighöfer Peter , Ammer Christian , Seidel Dominik
Published: November 2019

Individual tree architecture and the composition of tree species play a vital role for many ecosystem functions and services provided by a forest, such as timber value, habitat diversity, and ecosystem resilience. However, knowledge is limited when it comes to understanding how tree architecture changes in response to competition. Using 3D-laser scanning data from the German Biodiversity Exploratories, we investigated the detailed three-dimensional architecture of 24 beech (Fagus sylvatica L.) trees that grew under different levels of competition pressure. We created detailed quantitative structure models (QSMs) for all study trees to describe their branching architecture. Furthermore, structural complexity and architectural self-similarity were measured using the box-dimension approach from fractal analysis. Relating these measures to the strength of competition, the trees are exposed to reveal strong responses for a wide range of tree architectural measures indicating that competition strongly changes the branching architecture of trees. The strongest response to competition (rho = −0.78) was observed for a new measure introduced here, the intercept of the regression used to determine the box-dimension. This measure was discovered as an integrating descriptor of the size of the complexity-bearing part of the tree, namely the crown, and proven to be even more sensitive to competition than the box-dimension itself. Future studies may use fractal analysis to investigate and quantify the response of tree individuals to competition.
Correlation between Ionospheric TEC and the DCB Stability of GNSS Receivers from 2014 to 2016
Authors: Choi Byung-Kyu , Sohn Dong-Hyo , Lee Sang Jeong
Published: November 2019

The Global Navigation Satellite System (GNSS) differential code biases (DCBs) are a major obstacle in estimating the ionospheric total electron content (TEC). The DCBs of the GNSS receiver (rDCBs) are affected by various factors such as data quality, estimation method, receiver type, hardware temperature, and antenna characteristics. This study investigates the relationship between TEC and rDCB, and TEC and rDCB stability during a three-year period from 2014 to 2016. Linear correlations between pairs of variables, measured with Pearson’s coefficient ( R ), are considered. It is shown that the correlation between TEC and rDCB is the smallest in low-latitude regions. The mid-latitude regions exhibit the maximum value of R . In contrast, the correlation between TEC and rDCB root mean square (RMS, stability) was greater in low-latitude regions. A strong positive correlation ( R ≥ 0.90 ) on average between TEC and rDCB RMS was also revealed at two additional GNSS stations in low-latitude regions, where the correlation shows clear latitudinal dependency. We found that the correlation between TEC and rDCB stability is still very strong even after replacing a GNSS receiver.
Detection of Fusarium Head Blight in Wheat Using a Deep Neural Network and Color Imaging
Authors: Qiu Ruicheng , Yang Ce , Moghimi Ali , Zhang Man , Steffenson Brian J. , Hirsch Cory D.
Published: November 2019

Fusarium head blight (FHB) is a devastating disease of wheat worldwide. In addition to reducing the yield of the crop, the causal pathogens also produce mycotoxins that can contaminate the grain. The development of resistant wheat varieties is one of the best ways to reduce the impact of FHB. To develop such varieties, breeders must expose germplasm lines to the pathogen in the field and assess the disease reaction. Phenotyping breeding materials for resistance to FHB is time-consuming, labor-intensive, and expensive when using conventional protocols. To develop a reliable and cost-effective high throughput phenotyping system for assessing FHB in the field, we focused on developing a method for processing color images of wheat spikes to accurately detect diseased areas using deep learning and image processing techniques. Color images of wheat spikes at the milk stage were collected in a shadow condition and processed to construct datasets, which were used to retrain a deep convolutional neural network model using transfer learning. Testing results showed that the model detected spikes very accurately in the images since the coefficient of determination for the number of spikes tallied by manual count and the model was 0.80. The model was assessed, and the mean average precision for the testing dataset was 0.9201. On the basis of the results for spike detection, a new color feature was applied to obtain the gray image of each spike and a modified region-growing algorithm was implemented to segment and detect the diseased areas of each spike. Results showed that the region growing algorithm performed better than the K-means and Otsu’s method in segmenting diseased areas. We demonstrated that deep learning techniques enable accurate detection of FHB in wheat based on color image analysis, and the proposed method can effectively detect spikes and diseased areas, which improves the efficiency of the FHB assessment in the field.
Multisource Point Clouds, Point Simplification and Surface Reconstruction
Authors: Zhu Lingli , Kukko Antero , Virtanen Juho-Pekka , Hyyppä Juha , Kaartinen Harri , Hyyppä Hannu , Turppa Tuomas
Published: November 2019

As data acquisition technology continues to advance, the improvement and upgrade of the algorithms for surface reconstruction are required. In this paper, we utilized multiple terrestrial Light Detection And Ranging (Lidar) systems to acquire point clouds with different levels of complexity, namely dynamic and rigid targets for surface reconstruction. We propose a robust and effective method to obtain simplified and uniform resample points for surface reconstruction. The method was evaluated. A point reduction of up to 99.371% with a standard deviation of 0.2 cm was achieved. In addition, well-known surface reconstruction methods, i.e., Alpha shapes, Screened Poisson reconstruction (SPR), the Crust, and Algebraic point set surfaces (APSS Marching Cubes), were utilized for object reconstruction. We evaluated the benefits in exploiting simplified and uniform points, as well as different density points, for surface reconstruction. These reconstruction methods and their capacities in handling data imperfections were analyzed and discussed. The findings are that (i) the capacity of surface reconstruction in dealing with diverse objects needs to be improved; (ii) when the number of points reaches the level of millions (e.g., approximately five million points in our data), point simplification is necessary, as otherwise, the reconstruction methods might fail; (iii) for some reconstruction methods, the number of input points is proportional to the number of output meshes; but a few methods are in the opposite; (iv) all reconstruction methods are beneficial from the reduction of running time; and (v) a balance between the geometric details and the level of smoothing is needed. Some methods produce detailed and accurate geometry, but their capacity to deal with data imperfection is poor, while some other methods exhibit the opposite characteristics.
Temporal Decorrelation of C-Band Backscatter Coefficient in Mediterranean Burned Areas
Authors: Belenguer-Plomer Miguel A. , Chuvieco Emilio , Tanase Mihai A.
Published: November 2019

Burned area algorithms from radar images are often based on temporal differences between pre- and post-fire backscatter values. However, such differences may occur long past the fire event, an effect known as temporal decorrelation. Improvements in radar-based burned areas monitoring depend on a better understanding of the temporal decorrelation effects as well as its sources. This paper analyses the temporal decorrelation of the Sentinel-1 C-band backscatter coefficient over burned areas in Mediterranean ecosystems. Several environmental variables influenced the radar scattering such as fire severity, post-fire vegetation recovery, water content, soil moisture, and local slope and aspect were analyzed. The ensemble learning method random forests was employed to estimate the importance of these variables to the decorrelation process by land cover classes. Temporal decorrelation was observed for over 32% of the burned pixels located within the study area. Fire severity, vegetation water content, and soil moisture were the main drivers behind temporal decorrelation processes and are of the utmost importance for areas detected as burned immediately after fire events. When burned areas were detected long after fire (decorrelated areas), due to reduced backscatter coefficient variations between pre- to post-fire acquisitions, water content (soil and vegetation) was the main driver behind the backscatter coefficient changes. Therefore, for efficient synthetic aperture radar (SAR)-based monitoring of burned areas, detection, and mapping algorithms need to account for the interaction between fire impact and soil and vegetation water content.
Incremental Pose Map Optimization for Monocular Vision SLAM Based on Similarity Transformation
Authors: Liu Wenlei , Wu Sentang , Wu Zhongbo , Wu Xiaolong
Published: November 2019

The novel contribution of this paper is to propose an incremental pose map optimization for monocular vision simultaneous localization and mapping (SLAM) based on similarity transformation, which can effectively solve the scale drift problem of SLAM for monocular vision and eliminate the cumulative error by global optimization. With the method of mixed inverse depth estimation based on a probability graph, the problem of the uncertainty of depth estimation is effectively solved and the robustness of depth estimation is improved. Firstly, this paper proposes a method combining the sparse direct method based on histogram equalization and the feature point method for front-end processing, and the mixed inverse depth estimation method based on a probability graph is used to estimate the depth information. Then, a bag-of-words model based on the mean initialization K-means is proposed for closed-loop feature detection. Finally, the incremental pose map optimization method based on similarity transformation is proposed to process the back end to optimize the pose and depth information of the camera. When the closed loop is detected, global optimization is carried out to effectively eliminate the cumulative error of the system. In this paper, indoor and outdoor environmental experiments are carried out using open data sets, such as TUM and KITTI, which fully proves the effectiveness of this method. Closed-loop detection experiments using hand-held cameras verify the importance of closed-loop detection. This method can effectively solve the scale drift problem of monocular vision SLAM and has strong robustness.
A Monocular SLAM-based Controller for Multirotors with Sensor Faults under Ground Effect
Authors: Matus-Vargas Antonio , Rodriguez-Gomez Gustavo , Martinez-Carranza Jose
Published: November 2019

Multirotor micro air vehicles can operate in complex and confined environments that are otherwise inaccessible to larger drones. Operation in such environments results in airflow interactions between the propellers and proximate surfaces. The most common of these interactions is the ground effect. In addition to the increment in thrust efficiency, this effect disturbs the onboard sensors of the drone. In this paper, we present a fault-tolerant scheme for a multirotor with altitude sensor faults caused by the ground effect. We assume a hierarchical control structure for trajectory tracking. The structure consists of an external Proportional-Derivative controller and an internal Proportional-Integral controller. We consider that the sensor faults occur on the inner loop and counteract them in the outer loop. In a novel approach, we use a metric monocular Simultaneous Localization and Mapping algorithm for detecting internal faults. We design the fault diagnosis scheme as a logical process which depends on the weighted residual. Furthermore, we propose two control strategies for fault mitigation. The first combines the external PD controller and a function of the residual. The second treats the sensor fault as an actuator fault and compensates with a sliding mode action. In either case, we utilize onboard sensors only. Finally, we evaluate the effectiveness of the strategies in simulations and experiments.
A Multi-Scale Directional Line Detector for Retinal Vessel Segmentation
Authors: Khawaja Ahsan , Khan Tariq M. , Khan Mohammad A. U. , Nawaz Syed Junaid
Published: November 2019

The assessment of transformations in the retinal vascular structure has a strong potential in indicating a wide range of underlying ocular pathologies. Correctly identifying the retinal vessel map is a crucial step in disease identification, severity progression assessment, and appropriate treatment. Marking the vessels manually by a human expert is a tedious and time-consuming task, thereby reinforcing the need for automated algorithms capable of quick segmentation of retinal features and any possible anomalies. Techniques based on unsupervised learning methods utilize vessel morphology to classify vessel pixels. This study proposes a directional multi-scale line detector technique for the segmentation of retinal vessels with the prime focus on the tiny vessels that are most difficult to segment out. Constructing a directional line-detector, and using it on images having only the features oriented along the detector’s direction, significantly improves the detection accuracy of the algorithm. The finishing step involves a binarization operation, which is again directional in nature, helps in achieving further performance improvements in terms of key performance indicators. The proposed method is observed to obtain a sensitivity of 0.8043, 0.8011, and 0.7974 for the Digital Retinal Images for Vessel Extraction (DRIVE), STructured Analysis of the Retina (STARE), and Child Heart And health Study in England (CHASE_DB1) datasets, respectively. These results, along with other performance enhancements demonstrated by the conducted experimental evaluation, establish the validity and applicability of directional multi-scale line detectors as a competitive framework for retinal image segmentation.
Effect of Commercial Off-The-Shelf MAPS on γ-Ray Ionizing Radiation Response to Different Integration Times and Gains
Authors: Xu Shoulong , Velthuis Jaap , Wu Qifan , Han Yongchao , Lin Kuicheng , Beck Lana , Zou Shuliang , Qu Yantao , Li Zengyan
Published: November 2019

We report the γ-ray ionizing radiation response of commercial off-the-shelf (COTS) monolithic active-pixel sensors (MAPS) with different integration times and gains. The distribution of the eight-bit two-dimensional matrix of MAPS output frame images was studied for different parameter settings and dose rates. We present the first results of the effects of these parameters on the response of the sensor and establish a linear relationship between the average response signal and radiation dose rate in the high-dose rate range. The results show that the distribution curves can be separated into three ranges. The first range is from 0 to 24, which generates the first significant low signal peak. The second range is from 25 to 250, which shows a smooth gradient change with different integration times, gains, and dose rates. The third range is from 251 to 255, where a final peak appears, which has a relationship with integral time, gain, and dose rate. The mean pixel value shows a linear dependence on the radiation dose rate, albeit with different calibration constants depending on the integration time and gain. Hence, MAPS can be used as a radiation monitoring device with good precision.
Rectangular Array Electric Current Transducer with Integrated Fluxgate Sensors
Authors: Ripka Pavel , Mlejnek Pavel , Hejda Pavel , Chirtsov Andrey , Vyhnánek Jan
Published: November 2019

Novel rectangular yokeless current transducer with the range 400 A using 16 microfluxgate sensors around the busbar conductor is presented in this paper. Compared to yokeless transducers utilizing the differential pair of magnetic sensors, our solution has much better suppression of the external currents (lower crosstalk). Compared to industrial transducers with yoke, the new transducer has 15-times lower noise, 7-times better temperature stability, and same crosstalk. Sensor design and design of current monitoring system is presented together with the results of long-term field tests. Crosstalk error is examined in dependence on the number of the operating sensors and external current position.
Formal Verification for Task Description Languages. A Petri Net Approach
Authors: López Joaquín , Santana-Alonso Alejandro , Díaz-Cacho Medina Miguel
Published: November 2019

One of the main challenges in verifying robotic systems is its asynchronous interaction with an unstructured environment, observed by imperfect sensors. Autonomous robot systems usually require some language to support task-level control. This paper presents an effective approach to apply formal verification methods for that kind of language. A main contribution of this method is to avoid modeling the robotic system with a specific formalism. The approach translates the task-level control models into a Petri net (PN) based representation. This is used to define new methods to analyze some task properties such as liveness, deadlock-freeness and terminability. The approach has been applied to the Task Description Language (TDL) and it is illustrated by experiments. The final goal is to create new tools within the application development environment to include formal verification as part of the normal software development cycle. The TDL to PN translator uses the Petri Net Markup Language (PNML) as its file format. This format permits interoperability with other Petri net tools that can also be used to analyze the PNs.
An Analytical Model for Describing the Power Coupling Ratio between Multimode Fibers with Transverse Displacement and Angular Misalignment in an Optical Fiber Bend Sensor
Authors: Kam Wern , Ong Yong Sheng , O’Keeffe Sinead , Mohammed Waleed S. , Lewis Elfed
Published: November 2019

The power coupling ratio between step-index multimode fibers caused by combined transversal and angular misalignment is calculated. A theoretical description of the coupling efficiency between two optical fibers based on geometrical optics is provided. The theoretical calculations are collaborated by experiments, determining the power coupling ratio between three output fibers with an axial offset and angular misalignment with a single input fiber. The calculation results are in good agreement with experimental results obtained using a previously fabricated optical fiber sensor for monitoring physiological parameters in clinical environments. The theoretical results are particularly beneficial for optimizing the design of optical fiber bending sensors that are based on power coupling loss (intensity) as the measurement interrogation requires either axial displacement, angular misalignment, or both.
Improved Visual Inspection through 3D Image Reconstruction of Defects Based on the Photometric Stereo Technique
Authors: Huang Sanao , Xu Ke , Li Ming , Wu Mingren
Published: November 2019

Visual inspections of nuclear power plant (NPP) reactors are important for understanding current NPP conditions. Unfortunately, the existing visual inspection methods only provide limited two-dimensional (2D) information due to a loss of depth information, which can lead to errors identifying defects. However, the high cost of developing new equipment can be avoided by using advanced data processing technology with existing equipment. In this study, a three-dimensional (3D) photometric stereo (PS) reconstruction technique is introduced to recover the lost depth information in NPP images. The system uses conventional inspection equipment, equipped with a camera and four light-emitting diodes (LEDs). The 3D data of the object surface are obtained by capturing images under multiple light sources oriented in different directions. The proposed method estimates the light directions and intensities for various image pixels in order to reduce the limitation of light calibration, which results in improved performance. This novel technique is employed to test specimens with various defects under laboratory conditions, revealing promising results. This study provides a new visual inspection method for NPP reactors.
Effects of Two Competitive Soccer Matches on Landing Biomechanics in Female Division I Soccer Players
Authors: Snyder Benjamin J. , Hutchison Randolph E. , Mills Christopher J. , Parsons Stephen J.
Published: November 2019

Fatigue has been proposed to increase the risk of knee injury. This study tracked countermovement jump, knee isometric strength, and kinetics and kinematics in 8 female soccer players (experimental group) during an anticipated sidestep maneuver before and after two matches played over a 43-h period. Time points were: Before and after match 1 (T0 and T1), 12 h after the first match (T2), and immediately after the second match (T3). A control group participated only in practice sessions. Isometric knee extension strength decreased by 14.8% at T2 (p = 0.003), but knee flexion was not affected until T3, declining by 12.6% (p = 0.018). During the sidestep maneuver, knee joint degrees of flexion at initial contact was increased by 17.1% at T3, but maximum knee and hip angle at initial contact were unchanged. Peak resultant ground reaction force (GRF) increased by 12.6% (p = 0.047) at T3 (3.03 xBW) from 2.69 xBW at T0, while posterior GRF was significantly higher than T0 at all three subsequent time points (T1 = 0.82 ± 0.23 xBW, T2 = 0.87 ± 0.22 xBW, T3 = 0.89 ± 0.22 xBW). Anterior tibial shear force increased significantly (p = 0.020) at T3 (1.24 ± 0.12 xBW) compared to T1 (1.15 ± 0.13 xBW), an 8.8% increase. Lateral tibial shear force was significantly higher at both T1 (0.95 ± 0.20 xBW) and T3 (1.15 ± 0.38 xBW) compared to T0 (0.67 ± 0.25 xBW). These findings suggest that participation in a soccer match has significant effects on both physical performance parameters and kinetics/kinematics during a sidestep cut, but these can be more pronounced after a second match with short rest.
Sustainable Development Planning: Master’s Based on a Project-Based Learning Approach
Authors: Cazorla-Montero Adolfo , de los Ríos-Carmenado Ignacio , Pasten Juan Ignacio
Published: November 2019

The educational subject of Sustainable Development Planning in Europe is evolving due to the implementation of the Bologna Agreement across the European Higher Education Area (EHEA). This paper analyses a project-based learning strategy for training Sustainable Development Planning in postgraduate programs, in Spain (Universidad Politécnica de Madrid, UPM). This project-based learning strategy is applied to an International Postgraduate Program for Sustainable Rural Development—Erasmus Mundus, Master’s of Science—with the participation of five European Union universities that formed the Agris Mundus Alliance for Sustainable Development. Using a mixed methods approach, the research examined the program’s implementation through student and staff perceptions, from the technical, behavioral and contextual project management skills. The paper argues that the “Practical Learning platforms” used in the Master’s demonstrate the correct approach of the learning strategy based on teaching–research linked to the professional sphere. The findings that were identified can be categorized as follows: (1) Perspective: holistic thinking and intellectual coherence, defining the contextual skills that must be navigated within and across the broader environment, (2) Practice: experiential learning by reconnecting to real-life situations, and (3) People: Personal and interpersonal skills required to succeed in sustainable projects, programs and portfolios. Reflections on the experience and main success factors in the learning strategy are discussed.
Sustainable Public Procurement: From Law to Practice
Authors: Mendoza Jiménez Javier , Hernández López Montserrat , Franco Escobar Susana Eva
Published: November 2019

This study aims to propose actions to improve the implementation of sustainable public procurement by identifying the problems perceived by public servants and social economy entities. Two types of questionnaires were sent to organizations in Spain and Europe and 217 complete answers were received (152 from the public sector and 65 from the social entities). In addition, 20 semi-structured personal interviews were conducted by phone with managers of social enterprises and four interviews, also by phone, were carried out with relevant people from the public sector. The results of the surveys and the interviews were structured using the analysis of the Strengths, Weaknesses, Opportunities and Threats (SWOT), which was considered consistent with the strategic nature of public procurement. The perceived opportunities for the public sector focus on more efficient use of public resources and improvement of reputation and social equality. For the social entities, more participation in procurement could lead to less dependency on public funds and more visibility. The obstacles for the public sector are related to lack of training and internal resistance to change, as well as, in the case of social entities, to their small size and the tensions with their social object that might derive from bigger competition. The proposed activities focus on two objectives, more training to increase knowledge from the public sector and the readiness of social entities. It is concluded that it is necessary to establish channels of communications between the two groups to avoid possible inefficiencies.
The Relationship between Organizational Commitment and Organizational Citizenship Behaviors in the Public and Private Sectors
Authors: Grego-Planer Dorota
Published: November 2019

Organizational Citizenship Behaviors (OCBs) are activities which are voluntary, go beyond the formal obligations of employees, and significantly affect the efficiency of the entire organization. The literature has devoted a lot of attention to them since the beginning of the 1980s. Not only has the nature of OCBs been studied, but so too have their dimensions and antecedents. However, there is a fairly significant research gap in the area of employee manifestations of citizenship behaviors according to type of organization (private and public sectors). This article addresses the issue of organizational commitment as one of the antecedents of OCBs. The research objective is to identify and assess the level of correlation between individual dimensions of organizational commitment and Organizational Citizenship Behaviors in public and private organizations in Poland. A quantitative study conducted on a sample of 323 employees allowed the hypotheses to be verified. In general, there are similar frequencies of Organizational Citizenship Behaviors in the public and private sectors. In public institutions, however, OCBs in the interpersonal dimension are more frequent, while in private institutions they occur more commonly in the organizational dimension. Most positively correlated with OCBs is the affective dimension of organizational commitment.
Kinetic Determination of Urease Activity in Fresh Pig Feces and Slurry and the Effect on Ammonia Production at Different Conditions
Authors: Hao Chaozhi , Pan Yuepeng , Zhang Zhongyi , Zeng Yang
Published: November 2019

Ammonia (NH3) emissions have become a serious environmental pollution problem, and livestock production is an important source of NH3 emissions, especially pig farming. The origin of NH3 release is the hydrolysis of urea in urine that is catalyzed by urease present in feces. This research determined the urease activity in fresh feces by Michaelis–Menten kinetics and then compared the process of urea hydrolysis and ammonia production in fresh slurry. For feces, the kinetic parameters Vmax and K’m were calculated by determining the concentration of ammonium in initial 5 minutes in closed vessels, and the resulting Vmax and K’m were 26.9 ± 1.2 mmol·[urea]·kg−1·min−1 and 99.7 ± 3.5 mmol·[urea]·l−1, respectively. In fresh slurry, the rate of urea hydrolysis determined directly was higher than the ammonium formation rate in the early stage (0–8 h) and was accompanied by a rapid rise in pH. In addition, we further explored the effects of temperature, pH, and mixing rate on urease activity within different periods (0–5 min, 5 min–2 h and 2 h–8 h). Our observations show that the optimal urease activity occurred at 35 °C, pH 6.71, and 821.83 rpm of stirring, indicating that microbial species and communities associated with urease production are affected by environmental conditions.