bluuebunny/crossref_metadata_2025 huggingface dataset:
Ecosystem functioning of canopy- and turf- forming algae: contrasting supply of invertebrate prey to pelagic consumers
Authors: Figueiredo CK , Duarte RC , Flores AAV
Published: July 2020

Macroalgal canopies are declining worldwide and are being replaced by low-lying algal turfs which frequently dominate reefscapes. Their loss may impact reef ecosystems in different ways, including the collapse of small canopy-dwelling invertebrates, and thus the decline of juvenile reef fish that prey on them. To evaluate this potential loss, we assessed (1) the differences between the mobile invertebrate assemblages associated with turf-forming (filamentous and articulated coralline turf) and canopy-forming (Sargassumspp. andDichotomaria marginata) algae, and (2) the mechanisms underlying those contrasts by examining the invertebrate community assembly of filamentous turf andSargassumspp. over the main canopy season. Abundance, biomass and diversity almost always differed between canopies and turfs (although not in a consistent way across sampling sites), while differences within canopy and turf algal types were nearly absent. The structure of invertebrate assemblages differed more consistently between canopies and turfs, with certain hard-bodied and soft-bodied invertebrates characterizing canopies and turfs, respectively. This divergence increased as the canopy season advanced. While no temporal changes occurred in turf invertebrate assemblages, clear temporal dynamics occurred in the invertebrate fauna associated withSargassum.Brittle stars and amphipods were most abundant as early colonizers, followed by hard-shelled gastropods, bivalves and ostracods. By the end of the season, these groups became dominant and decreased diversity in the canopy habitat. As hard-shelled prey are preferred items for the main invertivore fish species in the area, results suggest that canopies may play an important role in the provisioning of trophic resources to pelagic consumers.
Trophic cascades and connectivity in coastal benthic marine ecosystems: a meta-analysis of experimental and observational research
Authors: Eger AM , Baum JK
Published: July 2020

Predators can exert top-down control on lower trophic levels, such that their removal or addition may trigger trophic cascades. Despite coastal ecosystems containing well known trophic cascades, there remains uncertainty about the abiotic and biotic factors governing the occurrence and strength of these cascades. Here, we sought to explain the variability of trophic cascades in benthic marine ecosystems by conducting a meta-analysis of experimental (n = 17) and observational (n = 22) studies that recorded herbivore and producer populations in the presence and absence of a predator. From these data (147 predator-herbivore-producer measurements), we show that predators decreased herbivore populations between 2.1-4.76 times and increased producer populations by 1.62-2.83 times their original biomass, abundance, or density. Contrary to past research, these values are comparable to other ecosystems. Biotic factors related to species body size were most influential in determining herbivore population responses to the presence of predators, while abiotic factors, including nutrient concentration, best determined producer population responses. Our results also show that producers responded more strongly to changes in herbivore populations in high-nutrient and low-temperature environments. We found that herbivore populations in marine reserves were 2.83 times lower on average compared to areas outside the reserve, while producer populations were on average 1.90 times higher. Overall, this work advances understanding of factors modulating trophic cascade strength, demonstrates that reserves can have ecosystem-wide impacts, and provides new information about the average strength of trophic cascades in benthic marine ecosystems.
Environmental Education for Prevent Disaster: A Survey of Students Knowledge in Beginning New Normal of COVID-19
Authors: Ilyasa Feryl , Rahmayanti Henita , Muzani Muzani , Ichsan Ilmi Zajuli , Suhono Suhono
Published: July 2020

The purpose of this study was to determine the importance of implementing disaster mitigation education in schools during the new normal era of coronavirus disease 2019 (COVID-19). The method in this research used descriptive research design using a survey study approach. The research instrument used was a knowledge test with the number of questions as many as 15 items. The sample used was senior high school students who were randomly selected. The level of good and lack of knowledge is determined based on the average total score. A good level of knowledge has a condition> 111.76, while a level of knowledge that lacks a condition <111.76. The results of this study are that the majority of respondents have a total score that is less with a mean score of 101.94, while respondents who have a good number of scores have an average score of 127. Overall respondents have an average of 111.76. Then conducted an Independent Sample t-test with the result that there are differences in the number of good disaster mitigation knowledge scores on respondents with the number of disaster mitigation knowledge scores that are less on respondents with a p-value of 0,000 with a degree of freedom is 95%. The implementation of disaster education in the new normal era is important to continue to prevent transmission of COVID-19. The conclusion of this study is the score of students' knowledge about disaster needs to be improved in the new normal era.

 

Keywords: Disaster Mitigation Education, Disaster Mitigation Knowledge, COVID-19
POLÍTICAS NACIONAIS DE FORMAÇÃO DE PROFESSORES
Authors: MAIA FERNANDA JARDIM , BARROS JUNIOR ARLINDO JOSÉ DE , CUNHA VIRGÍNIA MARA PRÓSPERO DA , BUSSOLOTTI JULIANA MARCONDES
Published: July 2020

Este artigo tem como objetivo analisar políticas públicas de formação docente mais recentes e programas de iniciação à docência provenientes dessas políticas. As escolas de educação básica vêm sofrendo diversas transformações com o passar do tempo por influência de fatores externos, o uso da tecnologia a favor da educação figura como exemplo marcante. Para que a instituição cumpra com excelência essas e outras exigências, a formação docente tanto inicial quanto continuada necessita estar compatível com essas demandas. As instituições de ensino devem estar preparadas para proporcionar situações de aprendizagem adequadas para a oferta de uma educação emancipadora, em que o educando tenha condições de compreender seu papel na sociedade e poder contribuir para transformá-la. A pesquisa a respeito das políticas públicas foi do tipo documental, respaldada com asserções de autores como Gatti, Barretto e André (2011); Tardif (2014) entre outros, no sentido de ponderar os objetivos e aplicabilidade das necessárias alterações da formação inicial docente.
Ecological and Economic Indicators for the Evaluation of Almond (Prunus dulcis L.) Orchard Renewal in Sicily
Authors: Sottile Francesco , Massaglia Stefano , Peano Cristiana
Published: July 2020

Globally, almond production is experiencing a growing trend thanks to a strong interest in the health, gastronomic, and industrial properties that are linked to the fruits and their derivatives. After a constant and marked decline in the second half of the last century, the Mediterranean Basin is thoroughly reassessing this crop, which provides significant results with a modern orchard management. The opportunity determined by the transition from traditional to modern systems have increased the interest in evaluating the different environmental impacts of the two cultivation models that still coexist today. In this work, through the application of the Life Cycle Assessment (LCA) and an economic assessment approach with an in-depth analysis related to the cultivation cycle and the use of resources, the role played by each factor involved in production was determined. Overall, the Greenhouses Gases (GHG) emissions in modern farms are higher (Global Warming Potential (GWP) 0.224 kg CO2 eq.) than those in traditional farms (GWP 0.182 kg CO2 eq.). Regarding the economic assessment, it appears relevant that the modern almond model in the full production phase guarantees significantly higher margins (+84%).The perception of the importance attributed to evaluating economic and environmental aspects by different stakeholders shows relevant differences in the approach coming from growers, dealers, and governmental institutions allows the investigators to positively underline the current innovation in almond orchard systems considering the balance between fruit production and the conservation of environmental resources.
Temporal Responses to Direct and Induced Iron Deficiency in Parietaria judaica
Authors: Tato Liliana , Islam Monirul , Mimmo Tanja , Zocchi Graziano , Vigani Gianpiero
Published: July 2020

Parietaria judaica grows in highly calcareous environments, overcoming the low bioavailability of Fe caused by elevated pH. The aim of this work was to investigate the temporal dynamics of root exudation of P. judaica under Fe deficiency conditions. As high concentrations of bicarbonate and Ca2+ in calcareous soils interfere with the general plant mineral nutrition, two different alkaline growing conditions were applied to distinguish the effects due to the high pH from the responses induced by the presence of high calcium carbonate concentrations. Growth parameters and physiological responses were analyzed during a 7 day time course—shoot and root biomass, chlorophyll and flavonoid contents in leaves, root accumulation, and exudation of organic acids and phenolics were determined. Different responses were found in plants grown in the presence of bicarbonate and in the presence of an organic pH buffer, revealing a time- and condition-dependent response of P. judaica and suggesting a stronger stress in the buffer treatment. The high tolerance to alkaline conditions may be related to an earlier and greater exudation rate of phenolics, as well as to the synergistic effect of phenolics and carboxylic acids in root exudates in the late response. The identification of the main functional traits involved in tolerance to low Fe availability in a wild species could offer crucial inputs for breeding programs for application to crop species.
Study of C, N, P and K Release from Residues of Newly Proposed Cover Crops in a Spanish Olive Grove
Authors: Rodríguez-Lizana Antonio , Repullo-Ruibérriz de Torres Miguel Ángel , Carbonell-Bojollo Rosa , Moreno-García Manuel , Ordóñez-Fernández Rafaela
Published: July 2020

Cover crops (CC)s are increasingly employed by farmers in olive groves. Spontaneous soil cover is the most commonly used CC. Its continuous utilization changes ruderal flora. It is necessary to study new CCs. Living CCs provide C and nutrients to soil during decomposition. Information on this issue in olive groves is scarce. A 4-year field study involving grab sampling of Brachypodium distachyon, Sinapis alba and spontaneous CC residues was conducted to study C and nutrient release from cover crop residues. Throughout the decomposition cycles, C, N and P release accounted for 40 to 58% of the C, N and P amounts in the residues after mowing. Most K was released (80–90%). Expressed in kg per hectare, the release of C and N in Brachypodium (C: 4602, N: 181, P: 29, K: 231) and Sinapis (C: 4806, N: 152, P: 18, K: 195) was greater than that in spontaneous CC (C: 3115, N: 138, P: 21, K: 256). The opposite results were observed for K. The Rickman model, employed to estimate the amount of C, N and P in residues, yielded a good match between the simulated and measured values. In comparison to spontaneous CC, the newly proposed CCs have a higher potential to provide soil with C and N.
Crop Yield Prediction through Proximal Sensing and Machine Learning Algorithms
Authors: Abbas Farhat , Afzaal Hassan , Farooque Aitazaz A. , Tang Skylar
Published: July 2020

Proximal sensing techniques can potentially survey soil and crop variables responsible for variations in crop yield. The full potential of these precision agriculture technologies may be exploited in combination with innovative methods of data processing such as machine learning (ML) algorithms for the extraction of useful information responsible for controlling crop yield. Four ML algorithms, namely linear regression (LR), elastic net (EN), k-nearest neighbor (k-NN), and support vector regression (SVR), were used to predict potato (Solanum tuberosum) tuber yield from data of soil and crop properties collected through proximal sensing. Six fields in Atlantic Canada including three fields in Prince Edward Island (PE) and three fields in New Brunswick (NB) were sampled, over two (2017 and 2018) growing seasons, for soil electrical conductivity, soil moisture content, soil slope, normalized-difference vegetative index (NDVI), and soil chemistry. Data were collected from 39–40 30 × 30 m2 locations in each field, four times throughout the growing season, and yield samples were collected manually at the end of the growing season. Four datasets, namely PE-2017, PE-2018, NB-2017, and NB-2018, were then formed by combing data points from three fields to represent the province data for the respective years. Modeling techniques were employed to generate yield predictions assessed with different statistical parameters. The SVR models outperformed all other models for NB-2017, NB-2018, PE-2017, and PE-2018 dataset with RMSE of 5.97, 4.62, 6.60, and 6.17 t/ha, respectively. The performance of k-NN remained poor in three out of four datasets, namely NB-2017, NB-2018, and PE-2017 with RMSE of 6.93, 5.23, and 6.91 t/ha, respectively. The study also showed that large datasets are required to generate useful results using either model. This information is needed for creating site-specific management zones for potatoes, which form a significant component for food security initiatives across the globe.
The Research on Enhancing the Super-Resolving Effect of Noisy Images through Structural Information and Denoising Preprocessing
Authors: Chang Min , Han Shuai , Chen Guo , Zhang Xuedian
Published: July 2020

Both noise and structure matter in single image super-resolution (SISR). Recent researches have benefited from a generative adversarial network (GAN) that promotes the development of SISR by recovering photo-realistic images. However, noise and structural distortion are detrimental to SISR. In this paper, we focus on eliminating noise and geometric distortion during super-resolving noisy images. It includes a denoising preprocessing module and a structure-keeping branch. At the same time, the advantages of GAN are still used to generate satisfying details. Especially, on the basis of the original SISR, the gradient branch is developed, and the denoising preprocessing module is designed before the SR branch. Denoising preprocessing eliminates noise by learning the noise distribution and utilizing residual-skip. By restoring the high-resolution(HR) gradient maps and combining gradient loss with space loss to guide the parameter optimization, the gradient branch brings additional structural constraints. Experimental results show that we have obtained better Perceptual Index (PI) and Learned Perceptual Image Patch Similarity (LPIPS) performance on the noisy images, and Peak Signal to Noise Ratio(PSNR) and Structure Similarity (SSIM) are equivalent compared with the most reported SR method combined with DNCNN. Taking the Urban100 dataset with noise intensity in 25 as an example, four indexes of the proposed method are respectively 3.6976(PI), 0.1124(LPIPS), 24.652(PSNR) and 0.9481(SSIM). Combined with the performance under different noise intensity and different datasets reflected in box-and-whiskers plots, the values of PI and LPIPS are the best among all comparison methods, and PSNR and SSIM also achieve equivalent effects. Also, the visual results show that the proposed method of enhancing the super-resolving effect of noisy images through structural information and denoising preprocessing(SNS) is not affected by the noise while preserving the geometric structure in SR processing.
Breeding and Economic Aspects of Cytogenetic Screening Studies of Pigs Qualified for Reproduction
Authors: Danielak-Czech Barbara , Kozubska-Sobocińska Anna , Smołucha Grzegorz , Babicz Marek
Published: July 2020

Cytogenetic monitoring allows the identification and early removal of pigs affected by inherited karyotype defects from breeding herds. These abnormalities cause developmental anomalies, considerably reducing the fertility (by several dozen to 100%) and performance parameters of breeding herds, resulting in substantial financial losses. This mainly concerns reciprocal translocations, typical of pigs, which are highly prevalent (about 0.46%), generally occur de novo, and normally result in low breeding soundness of the carriers. Due to the potential spontaneous occurrence of chromosomal aberrations and the rapid spread of these genetic defects in the population, especially under artificial insemination conditions, it is necessary to perform routine karyotype screening of animals qualified for reproduction. The cytogenetic screening program for young boars, carried out using continually refined diagnostic techniques, permits a precise and reliable karyotype assessment, identification of chromosomal abnormalities, and formulation of specific selection guidelines.
Moody Mares—Is Ovariectomy a Solution?
Authors: Melgaard Daniel Taasti , Korsgaard Trine Stokbro , Thoefner Martin Soendergaard , Petersen Morten Roenn , Pedersen Hanne Gervi
Published: July 2020

Unwanted behaviour in mares is a commonly presenting problem to the veterinarian. This behaviour may range from the mare being uncooperative or aggressive when handled on the ground, kicking, bucking or rearing when ridden or being aggressive towards other horses. This purpose of the study was to evaluate whether bilateral ovariectomy in mares with unwanted behaviour improved the mare’s behaviour and/or rideability from the owner’s perspective. The mares were grouped and compared statistically based on their histological classification as having either “normal” or neoplastic ovaries. This study is a retrospective case series report of twenty-eight ovariectomized mares. A semi-quantitative value (1–10) pre- and post-ovariectomy for A) behaviour on ground/in stable and B) rideability was given, based on the owner’s observations. The horses were grouped based on their histopathologic diagnosis as “Normal ovaries” or “Neoplasia”. Following ovariectomy, rideability improved, with a score of ≥5 in 80% (8/10) of mares with normal ovaries and in 57% (8/14) of mares with ovarian neoplasm. A behavioural improvement of ≥5 was observed in 40% (4/10) of mares with normal ovaries, and in 43% (6/14) of mares with ovarian neoplasm. A significant difference was observed between the semi-quantitative value pre- and post-ovariectomy in both groups. No difference was observed in change in behaviour and rideability score between the group with normal ovaries and neoplastic ovaries. Mares with unwanted behaviour not obviously related to the oestrus cycle and to painful conditions may benefit from ovariectomy to alter their behaviour and rideability.
Nociceptive Threshold of Calves and Goat Kids Undergoing Injection of Clove Oil or Isoeugenol for Disbudding
Authors: Frahm Sandra , Di Giminiani Pierpaolo , Stanitznig Anna , Schoiswohl Julia , Krametter-Frötscher Reinhild , Wittek Thomas , Waiblinger Susanne
Published: July 2020

In this preliminary study, we compared changes in mechanical nociceptive thresholds (MNT) of calves and goat kids injected with clove oil or isoeugenol under the horn bud as a potential, more welfare-friendly alternative to hot-iron disbudding. Twenty male calves and goat kids were randomly allocated to clove oil (n = 10 per species) or isoeugenol (n = 10 per species) injection under the horn buds. MNT was measured via a pressure algometer in calves and kids at several locations around the horn buds at several time points before and up to 24 h after injection. In kids, von Frey filaments were used additionally at the same time points. In calves, linear mixed models revealed an effect on MNT of time point (p = 0.010) and side (p = 0.007), but not of injection (p = 0.298), nor of the interaction ‘injection*time point’, MNT waslowest 9 h post-injection. In goats, there was an effect of injection depending on time point (interaction injection*time point, p = 0.03) with MNT being lowest 24 h post-injection for clove oil, while MNT was similar to pre-injection in isoeugenol. In both species, variation in the individual response post-injection was very high. Our results suggest that clove oil and isoeugenol induced hypersensitivity, which was higher for clove oil, in goat kids, but they also suggest a transient anaesthetic effect in some animals and locations.
Determination of Fatty Acids Profile in Original Brown Cows Dairy Products and Relationship with Alpine Pasture Farming System
Authors: Agradi Stella , Curone Giulio , Negroni Daniele , Vigo Daniele , Brecchia Gabriele , Bronzo Valerio , Panseri Sara , Chiesa Luca Maria , Peric Tanja , Danes Doina , Menchetti Laura
Published: July 2020

This study aimed to evaluate the relationships between fatty acids and the pattern that most contributes to discriminate between two farming systems, in which the main difference was the practice, or not, of alpine summer-grazing. Milk and cheese were sampled every month in two farms of Original Brown cows identical under geographical location and management during no grazing season point of view in the 2018 season. Fatty acids concentrations were determined by gas chromatography. The principal component analysis extracted three components (PCs). Mammary gland de novo synthetized fatty acids (C14:0, C14:1 n9, and C16:0) and saturated and monosaturated C18 fatty acids (C18:0, C18:1 n9c) were inversely associated in the PC1; PC2 included polyunsaturated C18 fatty acids (C18:2 n6c, C18:3 n3) and C15:0 while conjugated linoleic acid (CLA n9c, n11t) and fatty acids containing 20 or more carbon atoms (C21:0, C20:5 n3) were associated in the PC3. The processes of rumen fermentation and de novo synthesis in mammary gland that are, in turn, influenced by diet, could explain the relationships between fatty acids within each PC. The discriminant analyses showed that the PC2 included the fatty acids profile that best discriminated between the two farming systems, followed by PC3 and, lastly, PC1. This model, if validated, could be an important tool to the dairy industry.
Monoclonal Antibodies in Cancer Therapy
Authors: Zahavi David , Weiner Louis
Published: July 2020

Monoclonal antibody-based immunotherapy is now considered to be a main component of cancer therapy, alongside surgery, radiation, and chemotherapy. Monoclonal antibodies possess a diverse set of clinically relevant mechanisms of action. In addition, antibodies can directly target tumor cells while simultaneously promoting the induction of long-lasting anti-tumor immune responses. The multifaceted properties of antibodies as a therapeutic platform have led to the development of new cancer treatment strategies that will have major impacts on cancer care. This review focuses on the known mechanisms of action, current clinical applications for the treatment of cancer, and mechanisms of resistance of monoclonal antibody therapy. We further discuss how monoclonal antibody-based strategies have moved towards enhancing anti-tumor immune responses by targeting immune cells instead of tumor antigens as well as some of the current combination therapies.
Antibacterial and Anti-Inflammatory Effects of Novel Peptide Toxin from the Spider Pardosa astrigera
Authors: Shin Min Kyoung , Hwang In-Wook , Kim Yunkyung , Kim Seung Tae , Jang Wonhee , Lee Seungki , Bang Woo Young , Bae Chang-Hwan , Sung Jung-Suk
Published: July 2020

The prevalence of antibiotic-resistant bacteria has become an immediate threat to public health. Antimicrobial peptides are attracting attention as a new source of antibiotics due to their ability to prevent drug-resistances with fewer side effects. Spider venom is composed of various bioactive substances with multiple functionalities such as antimicrobial and anti-inflammatory effects. Here, RNA sequencing was conducted on the venom gland of the spider Pardosa astrigera, and a potential toxin peptide with antibacterial properties was selected via homology and in silico analysis. A novel toxin, Lycotoxin-Pa4a, inhibited both gram-negative and gram-positive bacteria by disrupting the outer and bacterial cytoplasmic membrane. Moreover, the peptide downregulated the expression of pro-inflammatory mediators while upregulating the level of anti-inflammatory cytokine by inactivating mitogen-activated protein kinase signaling in a lipopolysaccharide-stimulated murine macrophage cell line. In this research, we identified a novel peptide toxin, Lycotoxin-pa4a, with antibacterial and anti-inflammatory properties, suggesting its potential for the development of a new antibiotics, as well as offering insights into the utilization of biological resources.
The Effect of the Degree of Anxiety of Learners during the Use of VR on the Flow and Learning Effect
Authors: Kwon Chongsan
Published: July 2020

Virtual reality (VR) learning content that provides negative experiences makes learners anxious. Thus, experimental research was conducted to determine how anxiety felt by learners using VR impacts learning. To measure the learning effects, flow, a leading element of learning effects, was measured. Flow has a positive effect on learning as a scale of how immersed an individual is in the work he or she is currently performing. The evaluation method used the empirical recognition scale by Kwon (2020) and the six-item short-form State-Trait Anxiety Inventory (STAI) from Marteau and Becker (1992), which were used in the preceding study. The difference in flow between high- and low-anxiety groups was explored by measuring the degree the study participants felt using an Fire Safety Education Game based on VR that allows learners to feel the heat and wind of the fire site with their skin. As a result of the experiment, no difference in flow was found between the high- and low-anxiety groups that played the same VR game with cutaneous sensation. However, the high-anxiety group who played the VR game with cutaneous sensation showed a higher flow than the group that played the basic fire safety education VR game. Based on these results, the following conclusions were drawn: the closer to reality the VR learning and training system for negative situations is reproduced, the more realistically the learner feels the anxiety. In other words, the closer to reality the virtual environment is reproduced, the more realistically the learner feels the feelings in the virtual space. In turn, through this realistic experience, the learner becomes immersed in the flow more deeply. In addition, considering that flow is a prerequisite for the learning effect, the anxiety that learners feel in the virtual environment will also have a positive effect on the learning effect. As a result, it can be assumed that the more realistically VR is reproduced, the more effective experiential learning using VR can be.
Phase Transformation, Optical and Emission Performance of Zinc Silicate Glass-Ceramics Phosphor Derived from the ZnO–B2O3–SLS Glass System
Authors: Mohd Shofri Muhammad Faris Syazwan , Mohd Zaid Mohd Hafiz , Matori Khamirul Amin , Fen Yap Wing , Yaakob Yazid , Jaafar Suhail Huzaifa , Wahab Siti Aisyah Abdul , Iwamoto Yuji
Published: July 2020

A new transparent zinc silicate glass-ceramic was derived from the 55ZnO–5B2O3–40SLS glass system via a controlled heat-treatment method. The precursor glass sample was placed through the heat-treatment process at different temperatures to study the progress in phase transformation, optical performance and emission intensity of the zinc silicate glass-ceramics. For this project, material characterization was measured through several tests using densimeter and linear shrinkage measurement, X-ray diffraction (XRD), Fourier transform infrared reflection (FTIR), ultraviolet–visible (UV–Vis) and photoluminescence (PL) spectroscopy. The density and linear shrinkage measurements show that the density of the particular glass-ceramic samples increases with the progression of heating temperature. The XRD analysis displays the result in which the zinc silicate crystal starts to grow after the sample was treated at 700 °C. In addition, the FTIR spectra indicated that the crystallization of the zinc silicate phase occurred with the appearance of SiO4, ZnO4 and Si-O-Zn bands. UV–visible exhibited the small changes when the value for the optical band gap decreased from 3.867 to 3.423 eV, influenced by the temperature applied to the sample. Furthermore, the PL spectroscopy showed an enhancement of broad green emission at 534 nm upon the increased heat-treatment temperature. Thus, it can be concluded there is the progression of crystal growth as the heat-treatment temperature increased; three emission peaks appeared at 529, 570 and 682 nm for the green, yellow and red emissions, respectively.
Influence of the Screw Positioning on the Stability of Locking Plate for Proximal Tibial Fractures: A Numerical Approach
Authors: Ingrassia Tommaso , Nigrelli Vincenzo , Pecorella Daniele , Bragonzoni Laura , Ricotta Vito
Published: July 2020

Tibial fractures are common injuries in people. The proper treatment of these fractures is important in order to recover complete mobility. The aim of this work was to investigate if screw positioning in plates for proximal tibial fractures can affect the stability of the system, and if it can consequently influence the patient healing time. In fact, a more stable construct could allow the reduction of the non-weight-bearing period and consequently speed up the healing process. For that purpose, virtual models of fractured bone/plate assemblies were created, and numerical simulations were performed to evaluate the reaction forces and the maximum value of the contact pressure at the screw/bone interface. A Schatzker type I tibial fracture was considered, and four different screw configurations were investigated. The obtained results demonstrated that, for this specific case study, screw orientation affected the pressure distribution at the screw/bone interface. The proposed approach could be used effectively to investigate different fracture types in order to give orthopaedists useful guidelines for the treatment of proximal tibial fractures.
A Novel Microchip Technique for Quickly Identifying Nanogranules in an Aqueous Solution by Transmission Electron Microscopy: Imaging of Platelet Granules
Authors: Trang Nguyen Thi Thu , Chang Jungshan , Chen Wei-An , Chen Chih-Chun , Chen Hui-Min , Chang Chao-Chien , Fong Tsorng-Harn
Published: July 2020

Ultrastructural observation of biological specimens or nanogranules usually requires the use of electron microscopy. Electron microscopy takes a lot of time, requires many steps, and uses many chemicals, which may affect the native state of biological specimens. A novel microchip (K-kit) was used as a specimen kit for in situ imaging of human platelet granules in an aqueous solution using a transmission electron microscope. This microchip enabled us to observe the native human platelet granules very quickly and easily. The protocols included blood collection, platelet purification, platelet granule isolation, sample loading into this microchip, and then observation by a transmission electron microscope. In addition, these granules could still remain in aqueous solution, and only a very small amount of the sample was required for observation and analysis. We used this microchip to identify the native platelet granules by negative staining. Furthermore, we used this microchip to perform immunoelectron microscopy and successfully label α-granules of platelets with the anti-P-selectin antibody. These results demonstrate that the novel microchip can provide researchers with faster and better choices when using a transmission electron microscope to examine nanogranules of biological specimens in aqueous conditions.
Using Synthetic Data to Improve and Evaluate the Tracking Performance of Construction Workers on Site
Authors: Neuhausen Marcel , Herbers Patrick , König Markus
Published: July 2020

Vision-based tracking systems enable the optimization of the productivity and safety management on construction sites by monitoring the workers’ movements. However, training and evaluation of such a system requires a vast amount of data. Sufficient datasets rarely exist for this purpose. We investigate the use of synthetic data to overcome this issue. Using 3D computer graphics software, we model virtual construction site scenarios. These are rendered for the use as a synthetic dataset which augments a self-recorded real world dataset. Our approach is verified by means of a tracking system. For this, we train a YOLOv3 detector identifying pedestrian workers. Kalman filtering is applied to the detections to track them over consecutive video frames. First, the detector’s performance is examined when using synthetic data of various environmental conditions for training. Second, we compare the evaluation results of our tracking system on real world and synthetic scenarios. With an increase of about 7.5 percentage points in mean average precision, our findings show that a synthetic extension is beneficial for otherwise small datasets. The similarity of synthetic and real world results allow for the conclusion that 3D scenes are an alternative to evaluate vision-based tracking systems on hazardous scenes without exposing workers to risks.
Learning Congruent Triangles through Ethnomathematics: The Case of Students with Difficulties in Mathematics
Authors: Shahbari Juhaina Awawdeh , Daher Wajeeh
Published: July 2020

Ethnomathematics makes school mathematics more relevant and meaningful for students. The current research aims to study the effect of using ethnomathematics in the context of Islamic ornamentation on learning the topic of congruent triangles. To achieve this aim, 30 10th-grade students engaged in ethnomathematics by learning about congruent triangles using Islamic ornamentation. Data was gathered via (a) videotaping and transcribing students’ learning and (b) students answering two parallel questionnaires that included proof questions on the three congruence theorems. The students were required to answer one questionnaire before the learning process and one after it. The main results indicated that the students succeeded in constructing the concepts of congruence and congruent triangles via the ethnomathematics learning process. In addition, the students succeeded in arriving at and formulating the three congruence theorems. Moreover, findings obtained from the questionnaires indicated that the students improved their proving processes as a result of ethnomathematics-based learning. Furthermore, paired sample t-tests indicated significant differences between the students’ mean scores before and after the learning process.
Quartz Enhanced Conductance Spectroscopy for Polymer Nano-Mechanical Thermal Analysis
Authors: Li Shangzhi , Sun Bo , Shang Zhijin , Li Biao , Cui Ruyue , Wu Hongpeng , Dong Lei
Published: July 2020

A fast and highly sensitive polymer nano-mechanical thermal analysis method for determining the melting temperature (Tm) of polymer microwires was proposed. In this method, a small-size, low-cost quartz tuning fork was used as a piezoelectric transducer to analyze the thermodynamics of polymer microwires at the nanogram level without changing its own properties. Due to the thin wire sample, which has a length of 1.2 mm and a diameter of ~5 µm, which is bridged across the prongs of the tuning fork, the nanogram-level sample greatly reduces the thermal equilibrium time for the measurement, resulting in a fast analysis for the melting temperature of the polymer sample. Compared with the traditional method, the analysis method based on the quartz enhanced conductivity spectrum (QECS) does not require annealing before measurement, which is an essential process for conventional thermal analysis to reduce the hardness, refine the grain, and eliminate the residual stress. In this work, the melting temperatures of three of the most commonly used polymers, namely polymers polymethyl methacrylate, high-density polyethylene, and disproportionated rosin, were obtained under the temperature from room temperature to >180 °C, proving the QECS method to be a useful tool for nano-mechanical thermal analysis.
Detectability of Osseous Lesions with a Pre-Programmed Low-Dose Protocol for Cone-Beam Computed Tomography
Authors: Döbelin Quirin , Stadlinger Bernd , Wiedemeier Daniel B. , Bichsel Dominique , Rücker Martin , Valdec Silvio
Published: July 2020

The present study aimed to compare the diagnostic reliability of a pre-set, manufacturer-specific, low-dose mode against a standard-dose mode in the detection of four different osseous lesions in the mandible with cone-beam computed tomography (CBCT). Four types of lesions (periapical lesion, extended periodontal gap, recession of the buccal lamella, sequestrum/fracture) were prepared on 40 pig mandibles. CBCT images were obtained from each mandible, with both the low-dose and standard-dose modes using the Orthophos SL CBCT device (Dentsply-Sirona, Bensheim, Germany). Twelve assessors quantitatively (detection of lesions) and qualitatively (assessment of detectability) evaluated the CBCT images in SIDEXIS 4 (Dentsply-Sirona) using a study-specific digital examination tool. A correct diagnosis was achieved in almost 71% (LD: 70.8%; SD: 70.9%) of 1920 lesions, without a statistically significant difference between the low-dose and standard-dose mode. This finding was consistent across all four lesion types. In conclusion, while low-dose mode and standard-dose mode CBCT scans performed similarly in the detection of four prepared lesions of the mandible, the former may be a promising, user-friendly alternative method of obtaining radiation-optimized, three-dimensional images in accordance with the As Low As Diagnostically Acceptable (ALADA) principle.
Thermoelectric Transport Properties of n-Type Sb-doped (Hf,Zr,Ti)NiSn Half-Heusler Alloys Prepared by Temperature-Regulated Melt Spinning and Spark Plasma Sintering
Authors: Bae Ki Wook , Hwang Jeong Yun , Kim Sang-il , Jeong Hyung Mo , Kim Sunuk , Lim Jae-Hong , Kim Hyun-Sik , Lee Kyu Hyoung
Published: July 2020

Herein we report a significantly reduced lattice thermal conductivity of Sb-doped Hf0.35Zr0.35Ti0.3NiSn half-Heusler alloys with sub-micron grains (grain size of ~300 nm). Polycrystalline bulks of Hf0.35Zr0.35Ti0.3NiSn1−xSbx (x = 0.01, 0.02, 0.03) with a complete single half-Heusler phase are prepared using temperature-regulated melt spinning and subsequent spark plasma sintering without a long annealing process. In these submicron-grained bulks, a very low lattice thermal conductivity value of ~2.4 W m−1 K−1 is obtained at 300 K due to the intensified phonon scatterings by highly dense grain boundaries and point-defects (Zr and Ti substituted at Hf-sites). A maximum thermoelectric figure of merit, zT, of 0.5 at 800 K is obtained in Hf0.35Zr0.35Ti0.3NiSn0.99Sb0.01.
Characterization of Inter-System Biases in GPS + BDS Precise Point Positioning
Authors: Ke Cheng , Zheng Yanning , Wang Shengli
Published: July 2020

With the combination of multi-GNSS data, the precise-point positioning (PPP) technique can improve its accuracy, availability and reliability: Inter-system bias (ISB) is the non-negligible parameter in multi-GNSS PPP. To further enhance the performance of multi-GNSS PPP, it is crucial to analyze the characterization of inter system biases (ISBs) and model them properly. In this contribution, we comprehensively investigate the characterization of ISBs between global positioning system (GPS) and BeiDou navigation satellite system (BDS) in different situations. (1) We estimate ISB by using different precise products from the Center for Orbit Determination (CODE), Deutsches GeoForschungsZentrum (GFZ) and Wuhan University (WHU). The results indicate that the one-day estimates of ISB are stable when using CODE and WHU products, whereas the estimates based on GFZ products vary remarkably. As for the three-day time series of ISB, a sudden jump exists between two adjacent days, which is due to the change of satellite clock datum; (2) We investigate the ISB characterization affected by the ambient environments of the receivers. The result shows that the ISBs estimated from receivers (and antennas) with same type are still inconsistent, which indicates that the ambient environment, probably the temperature, influences the ISB characterization as well, since the receivers are in different areas; (3) We analyze the ISB characterization affected by receiver and antenna type with the same ambient environment. To ensure the same ambient environment, the ultra-short baselines were applied to investigate the ISB characterization affected by the receiver and antenna type. With the insights into ISB characterizations, we carry out combined GPS and BDS PPP with modeling the ISB as time constant, random walk process and white noise. The results suggest that the random walk process outperforms in most cases, since it strengthens the model to some extend and, at the same time, considers the variation of ISBs.
Mechanism of HCB-Modified Asphalt and Dynamic Properties of Mixtures
Authors: Ding Zhan , Su Jinfei , Li Peilong , Bing Hui
Published: July 2020

Hydroxymethyl carbon black (HCB) was prepared as an asphalt modifier with a high oxygen content and active surface chemical properties. The microstructure of HCB was analyzed by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy. The improvement effect of HCB on asphalt’s physical, dynamic shear, rheological, and aging properties was evaluated. To analyze the dynamic properties of the HCB-modified asphalt mixtures, a simple performance test (SPT) was conducted, and then the change laws of the dynamic modulus and phase angle for the HCB mixtures were clarified. The results showed that the surface of HCB is smooth and that the oxygen content increases with the generation of hydroxyl functional groups. Polar oxygen-containing functional groups and hydrogen bonds are helpful in improving the resistance to cracking and aging. The surface activity of HCB is susceptible to temperature and frequency, causing a slight influence of HCB on the viscoelasticity of asphalt mixtures at high and low frequencies. At low temperatures and high frequencies, the HCB enhanced the elasticity characteristics and weakened the viscosity characteristics of asphalt mixtures.
Energy and Exergy Analyses of an Existing Solar-Assisted Combined Cycle Power Plant
Authors: Temraz Ayman , Rashad Ahmed , Elweteedy Ahmed , Alobaid Falah , Epple Bernd
Published: July 2020

Solar-assisted combined cycle power plants (CCPPs) feature the advantages of renewable clean energy with efficient CCPPs. These power plants integrate a solar field with a CCPP. This integration increases the efficiency of solar power plants while decreasing the CO2 emissions of the CCPPs. In this paper, energy and exergy analyses were performed for an existing solar-assisted CCPP. The overall thermal efficiency and the exergetic efficiency of each component in the power plant were calculated for different solar field capacities. Also, a parametric study of the power plant was performed. The analysis indicated that the exergetic efficiency of the power plant components has its lowest value in the solar field while the condenser has the lowest exergetic efficiency in the combined cycle regime of operation. Further, a parametric study revealed that the thermal efficiency and the exergetic efficiency of the power plant as a whole decrease with increasing ambient temperature and have their highest values in the combined cycle regime of operation. Owing to these results, an investigation into the sources of exergy destruction in the solar field was conducted.
Security Requirements Engineering Framework with BPMN 2.0.2 Extension Model for Development of Information Systems
Authors: Zareen Saima , Akram Adeel , Ahmad Khan Shoab
Published: July 2020

With recent advancements of technologies such as Internet of Things and cloud computing, security of information systems has emerged as a critical issue. This has created a need for elicitation and analysis of the security requirements at an early stage of system development. These requirements should also be expressed using visual notations that can encapsulate the vision of different stakeholders related to security. While business process management notation (version 2.0.2) is a widely used graphical representation for business requirements and makes it easier to define and communicate business processes between different stakeholders of the system. Moreover, extension mechanisms are available to model the specific needs of an organization. Due to its flexible structure for defining new extensions, it can be adapted to model security requirements in the information system (IS). Towards this, we propose a threat profile security framework to define the security requirements of manufacturing systems for businesses, which are at a stage of infancy to adapt or evolve the IS with the changing needs of a business environment. In particular, the framework is modeled by extending Business Process Management Notation and is applied in a manufacturing industry process at the shop floor level. We show through a case study example that the threat goal-based framework is broader and, hence, covers a majority of security concerns of organizations.
Release of Antioxidant Compounds of Zingiber officinale by Ultrasound-Assisted Aqueous Extraction and Evaluation of Their In Vitro Bioaccessibility
Authors: Contreras-López Elizabeth , Castañeda-Ovando Araceli , Jaimez-Ordaz Judith , Cruz-Cansino Nelly del Socorro , González-Olivares Luis Guillermo , Rodríguez-Martínez José Sergio , Ramírez-Godínez Juan
Published: July 2020

Ginger rhizome is widely used in culinary preparations and in traditional medicine. Its benefits are associated with its antioxidant properties related to phenolics and terpenoids compounds, which use to be thermolabile. Ultrasound-assisted extraction has been useful for enhancing the release of thermosensitive compounds present in vegetable tissues. Therefore, the aim of this study was to evaluate the influence of ultrasound-assisted extraction on the release of antioxidants from ginger in aqueous media as well as their in vitro bioaccessibility. Central composite rotatable design was applied to obtain the optimal conditions for the extraction; the variables studied were amplitude (80–90%) and temperature (30–50 °C). Total phenolic content, antioxidant capacity (DPPH•, ABTS•+ and FRAP), and in vitro bioaccessibility were determined. Amplitude was the main parameter influencing the extraction of antioxidants. The ginger aqueous extracts showed a bioaccessibility of around 30%. The release of antioxidant compounds from ginger by ultrasound-assisted extraction avoids the use of high temperatures and solvents commonly used in conventional extraction methods.