bluuebunny/crossref_metadata_2025 huggingface dataset:
METACOGNITIVE STRATEGY AND STUDENT’S READING COMPREHENSION: AN EXPERIMENTAL STUDY AT SMK N 1 KOTA BENGKULU
Authors: Syafrianti Herlina , Suwarno Bambang , . Elfrida
Published: August 2019

This research aimed to know the effect of using metacognitive strategy towards student’s reading comprehension. The design was quasi-experimental. The sample consists of 69 students in two classes. The instrument consists of reading test which was tried out. The treatment for the experiment group was metacognitive strategy and for the control group was the strategy that the teacher use in the class. The data were collected through pre-test and post-test. The activity in the classroom during six meetings, two meetings for pre-test and post-test and four meetings for teaching in the classroom. The data was analyzed by The Wilcoxon Test and The Mann-Whitney Test. The Wilcoxon Test for the control group showed that there was no significant difference between pre-test and post-test. The Wilcoxon test for the experiment group showed that there was significant difference between pre-test and post-test. The Mann-Whitney test for pre-test showed that there was no significant difference between experiment and control class. The Mann-Whitney test for post-test showed that there was significant difference between experiment and control class. Finding of the research showed that, there was significant difference between pre-test and post-test for the experiment class and there was significant differece between experiment and control class for post-test result. This result indicated that there was an effect of metacognitive strategy towards student’s reading comprehension
LANGUAGE LEARNING STRATEGIES USED BY SUCCESSFUL STUDENTS OF THE ENGLISH EDUCATION STUDY PROGRAM AT UNIVERSITY OF BENGKULU
Authors: Sari Purnama Yulian , Sofyan Dedi , Hati Gita Mutiara
Published: August 2019

This research is aimed at finding the language learning strategy used by successful students that is categorized into six kinds of strategies; memory, cognitive, metacognitive, affective, compensation, and social strategy suggested by Oxford (1990). The population of the research are students of English study program University Bengkulu year 2014 and 2015 that have GPA 3.51 to 4.00. Methodology of this research is descriptive quantitative. Data were collected by using questionnaires as the instruments. The questionnaires consist of 50 items based on Oxford’s Strategy Inventory for Language Learning (SILL) version 7.0 about language learning strategy. The data were processed by using Microsoft Excel 2013 to find the most dominant strategy used by the students. The results showed that the successful students use more than one language learning strategy or mixed strategy, including memory, cognitive, metacognitive, affective, compensation, and social strategy. The dominant strategy used by successful students was metacognitive with mean score 3.94 followed by compensation (3.81), cognitive (3.59), social (3.43), memory (3.31), and affective strategy (3.30). Metacognitive strategies have positive and significant influence toward academic achievement on successful students in learning a language. Metacognitive strategies can help the students to develop good thinking management ability. It also create good academic achievement. In the other hand, the choice of lowest strategy seems to be affected by technology advances, curriculum, feelings, mood, and attitude of the students which is unpredictable.
The Correlation between Reading Self-Efficacy and Reading Comprehension
Authors: Fitri E. Dona Rahma , Sofyan Dedi , Jayanti Fernandita Gusweni
Published: August 2019

AbstractThe purpose of this research was to find out the correlation between reading self-efficacy and reading comprehension. The research applied correlational study which used quantitative design. The sample was 273 of twelfth grade students of science class at SMAN 5 Bengkulu. The data were collected by using two instruments: (1) the reading self-efficacy questionnaire which was used to measure the students’ reading self-efficacy and (2) reading comprehension test which was used to know the students’ reading comprehension. The correlation between the two variables was calculated by using Pearson Product Moment in SPSS 15. The result shows that there is a significant correlation between reading self-efficacy and reading comprehension. The score of significance level is < 0.05 (0.000 < 0.05) which means that H1 was accepted and H0 was rejected. So, it can be inferred that the higher the reading self-efficacy, the higher the reading comprehension. Keywords: Reading Comprehension; Self-Efficacy
Factors Affecting Students’ Difficulties in Speaking Performance of The Tenth Grade Students of SMA Negeri 1 Tiworo Kepulauan
Authors: Afebri Hendriati , . Aderlaepe , Muhsin Khusnun
Published: August 2019

Students’ speaking performance could be affected by factors that come from performance conditions (time pressure, planning, standard of performance and amount of support), affective factors (such as motivation, confidence and anxiety), listening ability, topical knowledge and feedback during speaking activities. The purpose of this study was to analyze, describe and determine factors affecting students’ difficulties in speaking performance of the tenth-grade students of SMA Negeri 1 Tiworo Kepulauan. This study employed quantitative design in the form of survey. The samples were 30 students of X MIA 2 which were taken by using random sampling. The data were collected by using close ended questionnaire and were analyzed by using SPSS version 16. The results of this research showed that of the three factors affecting students’ difficulties in speaking, the highest percentage was linguistic factors including grammar, vocabulary and pronunciation. It was concluded that the students got difficulties in performing speaking task. Keywords: Speaking Performance, Students’ Difficulties
The Effect of Guided Question Technique on Students’ Writing Ability in Descriptive Text
Authors: Indriani Rizka , . Zahrida , Hardiah Mei
Published: August 2019

The objective of this research is to find out whether or not there is a significant effect using guided question technique on students’ writing ability in descriptive text. This research is a quasi experimental design. The population of this research is the seventh grade students at SMPN 3 Kota Bengkulu. The sample in this research are about 60 students divided into 2 classes, VII 2 consists of 30 students as the experimental group and VII 3 that consist of 30 students as the control group. The treatment is given only for the experimental group. The data are collected by using two writing tests: pre-test and post-test. The result of the research showed the mean score of experimental group (31.34) was higher than mean score of control group (23.35). This indicated that the guided question technique could give a significant positive effect to the students’ writing ability in descriptive text.
The Analysis of English Pronunciation Errors by English Education Students of FKIP UMSU
Authors: Yusriati Yusriati , Hasibuan Selamat Husni
Published: August 2019

Pronunciation is one important thing that must be mastered by the students who studies English. Good Pronunciation makes students’ English speaking skills becomes better. This research aimed at analyzing the errors made by students of English education department of FKIP UMSU in pronouncing English words. The objectives of this study were 1) to describe the opinions of English education students about their English pronunciation skills so far; 2). to analyze the forms of English pronunciation errors made by the students; 3) to explore strategies or efforts made by students to improve their English pronunciation skills; 4) to Identify obstacles found by the students in English pronunciation. Descriptive qualitative design was used  in this research. The data were obtained by doing the interview and asking the students to pronounce some English words in specific topic. The findings of this research revealed that students had various opinion about their ability in English pronunciation. Some students thought that they had good English pronunciation skills; some students thought that their ability in pronouncing English words was better than before and some other students still thought that their English pronunciation skills were not good. Based on the analysis of data, the students still made some errors in pronouncing English words. In order to improve their pronunciation, the students used some strategies such as watching YouTube in English and using google voice application.
FOREIGNIZATION AND DOMESTICATION IN THE MINISTERIAL WEBSITE LOCALIZATION
Authors: Nasution Ely Hayati , Silalahi Roswita , Nasution Vivi Adryani
Published: August 2019

The translation is a representation of the effect of developing technology on language. Translated website or website localization with the easiness of accessibility is considered as the most efficient space for transferring the information nowadays. It certainly involves the appropriate translation strategies in order to provide reliable information required. This research aims to identify the translation strategy involved under foreignization and domestication reference in the official website localization of Ministry of Health of Republic of Indonesia, to find out the most dominant translation strategy used, and to analyze the reasons to what extent foreignization and domestication applied, by referring the classifications proposed by Venuti (2008). The source of data was taken from five (5) popular news along 2018 which were broken down into 191 data analyzed, consisting of 5 headlines in the form of phrases and sentences, contents totally written in 161 sentences, and 25 sub-contents in the form of words, phrases, clauses, and sentences. The research found that the translator used all eight (8) translation strategies under domestication and foreignization reference including literal translation, transliteration, borrowing, transference, transposition, omission, addition, and adaptation, simultaneously or separately. Literal translation becomes the most dominant translation strategy used and it can indicate that the website localization is translated into source text-oriented.
THE EFFECT OF GENRE-BASED MENTORING ON LINGUISTIC FEATURE QUALITY OF RESEARCH ARTICLE ABSRACTS BY INDONESIAN LECTURERS IN SOCIAL SCIENCES AND HUMANITIES
Authors: Jasrial Dedi , Arsyad Safnil , Arono Arono
Published: August 2019

Meta-discourse is one of the linguistic features that have gotten considerable attention in writing a research article abstract recently. It is because the meta-discourse serves as a textual and interpersonal marker that can help readers to organize, classify, interpret, evaluate, and react to the contents of a propositions or meanings of sentences in the research article abstracts. However, Indonesian authors still have a problem in the use of meta-discourse based on its function in writing a research article abstract that meets to reputable international journals. The purpose of this study is to help improve the linguistic feature quality of research article abstracts written by Indonesian lecturers in social sciences and humanities in terms of the appropriate use of meta-discourse devices. This study used three stages of genre-based method following Hyland (2003): modeling, joint construction, and independent construction to mentor 20 lecturers in improving their research article abstract quality in terms of the appropriate use of meta-discourse devices in the sentences. The meta-discourse devices in the lecturers’ research article abstracts was evaluated following the frameworks of meta-discourse based on its function as suggested by Hyland (2005). The result revealed that there is an important improvement on the linguistic feature quality of Indonesian lecturers’ research article abstracts in terms of the appropriate use of meta-discourse devices. It implies that genre-based mentoring method has been quite effective in helping Indonesian lecturers in social sciences and humanities in writing their RA abstracts in using meta-discourse devices for a reputable international journal.
Adaptive-Size Dictionary Learning Using Information Theoretic Criteria
Authors: Dumitrescu Bogdan , Giurcăneanu Ciprian Doru
Published: August 2019

Finding the size of the dictionary is an open issue in dictionary learning (DL). We propose an algorithm that adapts the size during the learning process by using Information Theoretic Criteria (ITC) specialized to the DL problem. The algorithm is built on top of Approximate K-SVD (AK-SVD) and periodically removes the less used atoms or adds new random atoms, based on ITC evaluations for a small number of candidate sub-dictionaries. Numerical experiments on synthetic data show that our algorithm not only finds the true size with very good accuracy, but is also able to improve the representation error in comparison with AK-SVD knowing the true size.
Evaluation of Consumers’ WTP for Service Recovery in Restaurants: Waiting Time Perspective
Authors: Ting Chung-Te , Huang Yu-Sheng , Lin Cheng-Te , Pan Szu-Chin
Published: August 2019

Restaurant service quality assessment has generally focused on the dining service. However, restaurant service begins with waiting for the meal. When service failure occurs due to a long waiting time, restaurant managers should adopt appropriate service recovery measures to retain consumers and reduce loss. This approach would allow them to mitigate customer dissatisfaction and negative impressions. In this study, we explore the importance of pre-processing service in the context of possible restaurant service crises and construct a restaurant service recovery model for willingness to pay (WTP) through the contingent valuation method (CVM) to measure the effects before and after implementing service recovery. Overall, several psychological and tangible service recovery measures are provided to enhance people’s willingness to extend their waiting time. Within our study group, relatively young participants showed a high willingness to extend their waiting time. Furthermore, the opportunity cost of high-income people in the waiting process was relatively high. Compared with psychological service recovery programs, our results show that tangible service recovery programs prompt respondents to wait for an additional ~10 min. This paper offers support for restaurant managers to manage consumer relationships.
Extending the View on Project Performance
Authors: Molaei Maedeh , Bosch-Rekveldt Marian , Bakker Hans
Published: August 2019

The main aim of this study is to gain insights into project management professionals’ perception of how project success can be achieved. The Q-methodology was followed in this research. Based on an extensive literature review and validation through expert judgment, a framework consisting of 33 factors increasing the likelihood of success was developed. A total of 34 practitioners in three different sectors (real estate, urban development, and infrastructure) in the Netherlands were asked to rank the statements contributing to the success of their projects. Four different perspectives of how project success can be achieved were distinguished in this study: “seeking the best match”, “being adaptive and open”, “keeping the team focused”, and “preparing for opportunities”. The perception of different practitioners of how success can be obtained may stem from factors of project context rather than sector and complexity. This highlights further research opportunities in taking a contingent approach when investigating project performance. The study helps to grasp the subjectivity of practitioners’ viewpoints regarding the potential ways to enhance project performance by understanding the similarity and differences of these viewpoints.
Value Chains and Diet Quality: A Review of Impact Pathways and Intervention Strategies
Authors: Ridoutt Bradley , Bogard Jessica R. , Dizyee Kanar , Lim-Camacho Lilly , Kumar Shalander
Published: August 2019

Low and middle-income countries increasingly face a triple burden of malnutrition encompassing undernutrition, micronutrient deficiency, and excessive energy consumption contributing to overweight and obesity. Food systems are also becoming more complex, supported by investments in food processing and retailing. Traditional approaches addressing hunger, typically based on agricultural development, are deemed insufficient alone to address the problem and attention is now being directed to food value chains, although experience is currently limited. To assess the state of science and identify knowledge gaps, an integrative review of the broad topic of value chains and diet quality was undertaken, with particular focus on interventions and their related impact pathways. Interventions were classified according to their primary orientation: to increase the availability, accessibility, or desirability of nutritious food. We identified 24 separate interventions associated with 10 different impact pathways, demonstrating the numerous entry points and large potential for value chain interventions to influence diet quality. However, case study evidence regarding effectiveness remains scant. Most studies addressed individual nutrient-rich commodities that could address a nutritional deficiency in the community of interest. Rarely was overall diet quality assessed, and future studies could benefit from taking a wider perspective of dietary patterns and food substitutions. The value chain analytical approach was deemed valuable due to its consumer orientation that seeks to understand how food products are used and what motivates their choice. The systems perspective is also important as it considers the roles of actors involved in food production, distribution, marketing, and regulation. However, few studies directly engaged with the subject of the local food environment as the bridge connecting food production and food choice. The challenge is to combat the increasing prevalence of processed foods of low nutritional value through interventions that lead to nutritious food becoming more conveniently available, affordable, and desirable.
Influence of Pasture on Stearoyl-CoA Desaturase and miRNA 103 Expression in Goat Milk: Preliminary Results
Authors: Tudisco Raffaella , Morittu Valeria Maria , Addi Laura , Moniello Giuseppe , Grossi Micaela , Musco Nadia , Grazioli Raffaella , Mastellone Vincenzo , Pero Maria Elena , Lombardi Pietro , Infascelli Federico
Published: August 2019

The effect of pasture on the stearoyl-CoA desaturase (SCD) and miRNA 103 expression was evaluated on dairy goats divided into two homogeneous groups (G, grazing, and S, stable). Group S was housed in a stall and received alfalfa hay as forage, while group G was led to pasture. The goats of both the groups received the same amount of concentrate. Milk yield did not differ statistically between the groups. Group G showed significantly higher fat (4.10% vs. 2.94%, p < 0.01) and protein percentage (3.43% vs. 3.25%; p < 0.05) than group S. Among milk fatty acids, group S showed significantly higher levels of saturated fatty acids (SFA) and lower values of mono-unsaturated fatty acid (MUFA). The percentages of polyunsaturated fatty acid (PUFA) were not different between groups even if pasture significantly affected the percentages of C18:3 and total omega 3. In group G, total CLAs were twice than in group S (0.646% vs. 0.311%; p < 0.01) mainly due to the differences in CLA cis9 trans 11 (0.623% vs. 0.304%; p < 0.01). Milk total CLA in grazing group was significantly (p < 0.01) higher in August according to the highest value of both linoleic and α-linolenic acids in the pasture. In grazing animals, SCD expression decreased from April to June, increased in July and decreased again in August, while it was almost unvaried along the trial in group S. By contrast, the expression of miRNA 103 showed a similar trend for both groups, decreasing from April to June, increasing in July and falling down in August. To our knowledge, this is the first observation of the effects of pasture on miRNA expression in milk from ruminant species.
Polyphenolic Composition and Antioxidant Activity of Uncaria tomentosa Commercial Bark Products
Authors: Navarro Mirtha , Arnaez Elizabeth , Moreira Ileana , Hurtado Alonso , Monge Daniela , Monagas Maria
Published: August 2019

Uncaria tomentosa, which is widely commercialized as an herbal medicine, constitutes an important source of secondary metabolites with diverse biological activities. For instance, we have previously reported, for the first time, of a polyphenolic profile rich in proanthocyanidins from extracts of U. tomentosa plants, as well as their antioxidant capacity, antimicrobial activity on aerial bacteria, and cytotoxicity on cancer cell lines. These promising results prompted this research to evaluate the polyphenolic contents of U. tomentosa commercial products. We report a detailed study on the polyphenolic composition of extracts from U. tomentosa bark products (n = 18) commercialized in Costa Rica and Spain. Using HPLC-DAD/TQ-ESI-MS, a total of 25 polyphenolic compounds were identified, including hydroxybenzoic and hydroxycinnamic acids, flavan-3-ol monomers, procyanidin dimers, procyanidin trimers, as well as propelargonidin dimers. Our findings on the polyphenolic profile for all commercial samples show analogous composition to previous reports on U. tomentosa bark material, for instance a 41–49% content of procyanidin dimers and the presence of propelargonidin dimers (8–15%). However, most of the 18 commercial samples exhibit low proanthocyanidin contents (254.8–602.8 µg/g), more similar to previous U. tomentosa inner bark reports, while some exhibit better results, with one sample (SP-2) showing the highest contents (2386.5 µg/g) representing twice the average value of all 18 commercial products. This sample also exhibits the highest total phenolics (TP) and total proanthocyanidins (PRO) contents, as well as the highest Oxygen Radical Absorbance Capacity (ORAC) value (1.31 µg TE/g). One-way Analysis of Variance (ANOVA) with a Tukey post hoc test indicated significant difference (p < 0.05) between products from Costa Rica and Spain for TP and PRO findings, with samples from Spain exhibiting a higher average value. In addition, Pearson correlation analysis results showed a positive correlation (p < 0.05) between TP, PRO, and ORAC results, and an especially important correlation between ORAC antioxidant values and procyanidin dimers (r = 0.843, p < 0.05), procyanidin trimers (r = 0.847, p < 0.05), and propelargonidin dimers (r = 0.851, p < 0.05) contents. Finally, Principal Component Analysis (PCA) results indicated some variability in the composition regardless of their origin. However, only one sample (SP-2) stands out significatively, showing the highest PC1 because of its particularly high proanthocyanidins contents, which could be attributed to the 15% bark polyphenolic extract labeled in this commercial product, which differentiate this sample from all other 17 commercial samples. Therefore, our findings confirmed previous results on the value of extracts in the elaboration of potential commercial products from U. tomentosa, rich in proanthocyanidins and exhibiting high antioxidant activity.
Increase of 4-Hydroxybenzoic, a Bioactive Phenolic Compound, after an Organic Intervention Diet
Authors: Hurtado-Barroso Sara , Quifer-Rada Paola , Marhuenda-Muñoz María , Rinaldi de Alvarenga Jose Fernando , Tresserra-Rimbau Anna , Lamuela-Raventós Rosa M.
Published: August 2019

Consumption of organic products is increasing yearly due to perceived health-promoting qualities. Several studies have shown higher amounts of phytochemicals such as polyphenols and carotenoids in foods produced by this type of agriculture than in conventional foods, but whether this increase has an impact on humans still needs to be assessed. A randomized, controlled and crossover study was carried out in nineteen healthy subjects aged 18–40 years, who all followed an organic and conventional healthy diet, both for a 4-week period. Analysis of biological samples revealed a significant increase on the excretion of 4-hydroxybenzoic acid (4-HBA), a phenolic metabolite with biological activity, after the organic intervention. However, no changes were observed in the other variables analyzed.
Vitamin D Attenuates Oxidative Damage and Inflammation in Retinal Pigment Epithelial Cells
Authors: Tohari Ali Mohammad , Alhasani Reem Hasaballah , Biswas Lincoln , Patnaik Sarita Rani , Reilly James , Zeng Zhihong , Shu Xinhua
Published: August 2019

Age-related macular degeneration (AMD), the most common visual disorder in elderly people, is characterized by the formation of deposits beneath the retinal pigment epithelium (RPE) and by dysfunction of RPE and photoreceptor cells. The biologically active form of vitamin D, 1,25-(OH)2D3 (VITD), is categorized as a multifunctional steroid hormone that modulates many transcriptional processes of different genes and is involved in a broad range of cellular functions. Epidemiological and genetic association studies demonstrate that VITD may have a protective role in AMD, while single nucleotide polymorphisms in the vitamin D metabolism gene (CYP24A1) increase the risk of AMD. However, the functional mechanisms of VITD in AMD are not fully understood. In the current study, we investigated the impact of VITD on H2O2-induced oxidative stress and inflammation in human RPE cells. We demonstrate that exposure to H2O2 caused significantly reduced cell viability, increased production of reactive oxygen species (ROS), lowered expression of antioxidant enzymes and enhanced inflammation. VITD exposure notably counteracted the above H2O2-induced effects. Our data suggest that VITD protects the RPE from oxidative damage and elucidate molecular mechanisms of VITD deficiency in the development of AMD.
Anti-Inflammatory, Anti-Arthritic and Anti-Nociceptive Activities of Nigella sativa Oil in a Rat Model of Arthritis
Authors: Nasuti Cinzia , Fedeli Donatella , Bordoni Laura , Piangerelli Marco , Servili Maurizio , Selvaggini Roberto , Gabbianelli Rosita
Published: August 2019

This study investigated the preventive efficacy of the crude oil extracted from Nigella sativa seeds in a rat model of arthritis induced by using complete Freund’s adjuvant (CFA). Nigella sativa oil at 1.82 mL/kg or 0.91 mL/kg (corresponding to 1596 and 798 mg/kg, respectively) was orally administered for 25 days from the day of immunization. One immunized group was treated orally with indomethacin (3 mg/kg) as a reference drug. Body weight growth rate, paw swelling, arthritis score, mechanical allodynia, locomotor activity and anxiety-like behavior were observed, and the levels of Interleukin 6 (IL-6), C-reactive protein, albumin and total cholesterol in plasma were measured on days 15 and 25. Nigella sativa oil showed anti-inflammatory, anti-arthritic and anti-nociceptive activities that were significant as compared to untreated arthritic rats but less than indomethacin. These results indicated that Nigella sativa oil significantly attenuated adjuvant-arthritis in rats and the higher dose (1.82 mL/kg) prevented the development of arthritis with an inhibition of 56%.
The Evolution of Interfacial Microstructure and Fracture Behavior of Short Carbon Fiber Reinforced 2024 Al Composites at High Temperature
Authors: Zhang Chi , Wu Jinhao , Meng Qingnan , Sun Youhong , Wen Mao
Published: August 2019

The short carbon fiber reinforced 2024 Al composites were fabricated through powder metallurgy. The effect of short carbon fiber content on the interfacial microstructure and fracture behavior of the composites at different temperatures were investigated. The results showed that the dislocation accumulation was formed in the aluminum matrix due to the thermal expansion mismatch between carbon fiber and aluminum matrix. With the testing temperature increasing, the size of interfacial product Al4C3 and precipitates Al2Cu became larger, and the segregation of Al2Cu was found coarsening around Al4C3. The addition of short carbon fiber improved the hardness and modulus of the aluminum matrix in the vicinity of the interface between carbon fiber and aluminum matrix. Compared to the matrix 2024 Al, the yield strength and ultimate tensile strength of the composites first increased and then decreased with increasing short carbon fiber content at room temperature 423 Kand 523 K. The fracture surface of the composites at room temperature was characterized by shear failure of fiber, while the interface debonding and fiber pulled-out became predominant fracture morphologies for the fracture surface at increased temperatures.
A Deep Learning Based Method for the Non-Destructive Measuring of Rock Strength through Hammering Sound
Authors: Han Shuai , Li Heng , Li Mingchao , Rose Timothy
Published: August 2019

Hammering rocks of different strengths can make different sounds. Geological engineers often use this method to approximate the strengths of rocks in geology surveys. This method is quick and convenient but subjective. Inspired by this problem, we present a new, non-destructive method for measuring the surface strengths of rocks based on deep neural network (DNN) and spectrogram analysis. All the hammering sounds are transformed into spectrograms firstly, and a clustering algorithm is presented to filter out the outliers of the spectrograms automatically. One of the most advanced image classification DNN, the Inception-ResNet-v2, is then re-trained with the spectrograms. The results show that the training accurate is up to 94.5%. Following this, three regression algorithms, including Support Vector Machine (SVM), K-Nearest Neighbor (KNN), and Random Forest (RF) are adopted to fit the relationship between the outputs of the DNN and the strength values. The tests show that KNN has the highest fitting accuracy, and SVM has the strongest generalization ability. The strengths (represented by rebound values) of almost all the samples can be predicted within an error of [−5, 5]. Overall, the proposed method has great potential in supporting the implementation of efficient rock strength measurement methods in the field.
Additive Friction Stir-Enabled Solid-State Additive Manufacturing for the Repair of 7075 Aluminum Alloy
Authors: Griffiths R. Joey , Petersen Dylan T. , Garcia David , Yu Hang Z.
Published: August 2019

The repair of high strength, high performance 7075 aluminum alloy is essential for a broad range of aerospace and defense applications. However, it is challenging to implement it using traditional fusion welding-based approaches, owing to hot cracking and void formation during solidification. Here, the use of an emerging solid-state additive manufacturing technology, additive friction stir deposition, is explored for the repair of volume damages such as through -holes and grooves in 7075 aluminum alloy. Three repair experiments have been conducted: double through-hole filling, single through-hole filling, and long, wide-groove filling. In all experiments, additive friction stir deposition proves to be effective at filling the entire volume. Additionally, sufficient mixing between the deposited material and the side wall of the feature is always observed in the upper portions of the repair. Poor mixing and inadequate repair quality have been observed in deeper portions of the filling in some scenarios. Based on these observations, the advantages and disadvantages of using additive friction stir deposition for repairing volume damages are discussed. High quality and highly flexible repairs are expected with systematic optimization work on process control and repair strategy development in the future.
A Review of Biochar Properties and Their Utilization in Crop Agriculture and Livestock Production
Authors: Kalus Kajetan , Koziel Jacek , Opaliński Sebastian
Published: August 2019

When it comes to the use of biochar in agriculture, the majority of research conducted in the last decade has focused on its application as a soil amendment and for soil remediation. This treatment improves soil quality, increases crops yields, and sequestrates atmospheric carbon to the soil. Another widely studied aspect connecting biochar with agriculture is the composting processes of various agricultural waste with the addition of biochar. Obtaining the material via the pyrolysis of agricultural waste, including animal manure, has also been investigated. However, given the remarkable properties of biochar, its application potential could be utilized in other areas not yet thoroughly investigated. This review paper summarizes the last decade of research on biochar and its use in crop agriculture and livestock production. Knowledge gaps are highlighted, such as using biochar for the mitigation of odorous emissions from animal manure and by feeding the biochar to animals.
Multiscale Entropy Analysis with Low-Dimensional Exhaustive Search for Detecting Heart Failure
Authors: Chao Hsuan-Hao , Yeh Chih-Wei , Hsu Chang Francis , Hsu Long , Chi Sien
Published: August 2019

Multiscale entropy (MSE) is widely used to analyze heartbeat signals. Even though cardiologists do not use MSE to diagnose heart failure at present, these studies are of importance and have potential clinical applications. In previous studies, MSE discrimination between old congestive heart failure (CHF) and healthy individuals has remained controversial. Few studies have been published on the discrimination between them, using only MSE with machine learning for automatic multidimensional analysis, with reported testing accuracies of less than 86%. In this study, we determined the optimal MSE scales for discrimination by using a low-dimensional exhaustive search along with three classifiers—linear discriminant analysis (LDA), support vector machine (SVM), and k-nearest neighbor (KNN). In younger people (<55 years), the results showed an accuracy of up to 95.5% with two optimal MSE scales (2D) and up to 97.7% with four optimal MSE scales (4D) in discriminating between young CHF and healthy participants. In older people (≥55 years), the discrimination accuracy reached 90.1% using LDA in 2D, SVM in 3D (three optimal MSE scales), and KNN in 5D (five optimal MSE scales). LDA with a 3D exhaustive search also achieved 94.4% accuracy in older people. Therefore, the results indicate that MSE analysis can differentiate between CHF and healthy individuals of any age.
Having a Smarter City through Digital Urban Interfaces: An Evaluation Method
Authors: Aceves Gutierrez Luis C. , Martin Gutierrez Jorge , Del-Rio-Guerra Marta Sylvia
Published: August 2019

This paper appraises a tool developed to evaluate user experiences of urban digital interfaces. The authors propose an evaluation method that uses 14 guidelines to analyze questions pertaining to efficiency, assistance and instructions, content structure, resemblance to reality, feedback interface, visual design, cognitive processes, internationalization, and perceptive access. The proposed tool serves to identify obstacles that once identified can then be tackled and resolved in the design phase. Addressing obstacles in the design phase serves to prevent the creation of inefficient interfaces that would lead to poor user experiences, or, likewise, the rejection of these interfaces by users. To verify the effectiveness of the proposed guidelines in a real-world environment a field study has been conducted in which eight urban interfaces located in different cities and countries were observed. The study reveals the issues typically encountered by users that prevent them from having satisfactory or enjoyable experiences when using digital urban interfaces. The paper concludes by identifying and discussing areas of opportunity for further research and improvements to the proposed guidelines.
A Biased-Randomized Iterated Local Search Algorithm for Rich Portfolio Optimization
Authors: Kizys  Renatas , Juan Angel , Sawik Bartosz , Calvet  Laura
Published: August 2019

This research develops an original algorithm for rich portfolio optimization (ARPO), considering more realistic constraints than those usually analyzed in the literature. Using a matheuristic framework that combines an iterated local search metaheuristic with quadratic programming, ARPO efficiently deals with complex variants of the mean-variance portfolio optimization problem, including the well-known cardinality and quantity constraints. ARPO proceeds in two steps. First, a feasible initial solution is constructed by allocating portfolio weights according to the individual return rate. Secondly, an iterated local search framework, which makes use of quadratic programming, gradually improves the initial solution throughout an iterative combination of a perturbation stage and a local search stage. According to the experimental results obtained, ARPO is very competitive when compared against existing state-of-the-art approaches, both in terms of the quality of the best solution generated as well as in terms of the computational times required to obtain it. Furthermore, we also show that our algorithm can be used to solve variants of the portfolio optimization problem, in which inputs (individual asset returns, variances and covariances) feature a random component. Notably, the results are similar to the benchmark constrained efficient frontier with deterministic inputs, if variances and covariances of individual asset returns comprise a random component. Finally, a sensitivity analysis has been carried out to test the stability of our algorithm against small variations in the input data.
Spatial Predictability of Heavy Rainfall Events in East China and the Application of Spatial-Based Methods of Probabilistic Forecasting
Authors: Zhuang Xiaoran , Zhu Haonan , Min Jinzhong , Zhang Liu , Wu Naigen , Wu Zhipeng , Wang Shiqi
Published: August 2019

One of the major issues in developing convective-scale ensemble forecasts is what is widely known as under-dispersion. This can be addressed through the consideration of spatial uncertainties via post-processing, motivating the development of various techniques to represent the spatial uncertainties of ensembles. In this study, a recently developed fraction-based approach (the ensemble agreement scale, EAS) is applied to characterize the spatial predictability and spread–skill performances of precipitation forecasts using a WRF-EnKF convective-scale ensemble forecast system over the Yangtze and Huai river valleys, China. Fourteen heavy rainfall events during the Meiyu season of 2013 and 2014 were classified into two categories—strong forcing (SF) and weak forcing (WF)—using the convective adjustment timescale. The results show that the spatial predictability and spread–skill relationship are highly regime-dependent and that both exhibit lower values under WF. Furthermore, a new object-based probabilistic approach (OBJ_NEP) is proposed as a supplement to traditional neighborhood ensemble probability (NEP) and a recently proposed fraction-based approach (EAS_NEP). The results of the application of OBJ_NEP are evaluated, and a comparison is made between NEP and EAS_NEP for the analysis of experiments involving both idealized and ‘real’ events by using objective verification methods. The results imply that OBJ_NEP can be effectively employed under different large-scale forcings. Consequently, these results can aid the understanding of spatial-based approaches to probabilistic forecasting, which has been widely applied to post-processing processes of convective-scale ensemble forecast systems (CSEFs) in recent years.
Wind Stress in the Coastal Zone: Observations from a Buoy in Southwestern Norway
Authors: Flügge Martin , Bakhoday-Paskyabi Mostafa , Reuder Joachim , El Guernaoui Omar
Published: August 2019

Several studies have focused on the investigation of the wind stress in open ocean conditions where coastal processes were negligible. However, the direction and magnitude of the wind stress vector in coastal areas are still not fully known due to the low number of available measurement datasets. Here, we present new observations of the wind stress magnitude and its deviation from the mean wind direction. The data were recorded from a surface buoy during a five-day measurement campaign in southwestern Norway and cover wind speeds up to 10 m s−1 and significant wave heights up to 3.5 m in a coastal area with a steeply sloping sea floor. The adjustment of the wind stress vector due to changes in the wind and the wave conditions is illustrated and discussed by means of seven sample cases associated with both wind-following swell, cross-swell and counter-swell conditions. For this purpose, the stress vector computed in the sonic anemometer’s orthogonal coordinate system is projected into a non-orthogonal wind-swell coordinate system with its components aligned with: (1) the local wind-generated waves propagating in the wind direction; and (2) the swell wave direction. The wind stress direction was found to deviate from the wind direction by more than 20° for 46% of the recorded wind-following swell and cross-swell cases and for 54% of the counter-swell cases. The wind stress magnitude was observed to approach zero during the counter-swell period, which suggest a decoupling between the sea surface and the atmospheric surface layer. This was further investigated by means of an idealized Large Eddy Simulation results. The results in this study provide additional experimental evidence that the wind stress direction in coastal areas with a steeply sloping sea floor is influenced by the swell waves, the wave age and the wave steepness when the wind blows from undisturbed open ocean directions. For landward wind directions, the influence of the land boundary layer can, possibly in combination with atmospheric stability, adjust the magnitude and direction of the wind stress.
Characterising Particulate Organic Nitrogen at A Savannah-Grassland Region in South Africa
Authors: Booyens Wanda , Van Zyl Pieter G. , Beukes Johan P. , Ruiz-Jimenez Jose , Kopperi Matias , Riekkola Marja-Liisa , Vakkari Ville , Josipovic Miroslav , Kulmala Markku , Laakso Lauri
Published: August 2019

Although atmospheric organic N compounds are considered to be important, especially in new particle formation and their contribution to brown carbon, these species are not that well understood. This can be partially attributed to their chemical complexity. Therefore, the aim of this study was to assess the characteristics of organic N compounds utilising comprehensive two-dimensional gas chromatography coupled with a time-of-flight mass spectrometer (GCxGC-TOFMS) in aerosol samples that were collected at a savanna-grassland background region and to determine the possible sources. 135 atmospheric organic N compounds were tentatively characterised and semi-quantified, which included amines, nitriles, amides, urea, pyridine derivatives, amino acids, nitro-and nitroso compounds, imines, cyanates and isocyanates, and azo compounds. Amines contributed to 51% of the semi-quantified concentrations, while nitriles, pyridine derivatives, and amides comprised 20%, 11%, and 8%, respectively, of the semi-quantified concentrations. Amines, nitriles, amides, and pyridine derivatives concentrations were higher during the dry season, which were attributed to meteorology and open biomass burning. Anthropogenic sources impacting air masses measured at Welgegund, as well as regional agricultural activities, were considered as the major sources of amines, while the regional influence of household combustion was most likely the main source of nitriles, amides, and pyridine derivatives. The other organic N species were most likely related to the influence of local and regional agricultural activities.
New Particle Formation: A Review of Ground-Based Observations at Mountain Research Stations
Authors: Sellegri Karine , Rose Clemence , Marinoni Angela , Lupi Angelo , Wiedensohler Alfred , Andrade Marcos , Bonasoni Paolo , Laj Paolo
Published: August 2019

New particle formation (NPF) was predicted to contribute to a major fraction of free tropospheric particle number and cloud condensation nuclei (CCN) concentrations by global models. At high altitudes, pre-existing particle concentrations are low, leading to limited condensational sinks for nucleation precursor gases, and temperatures are cooler compared to lower altitudes, whereas radiation is higher. These factors would all be in favor of nucleation to occur with an enhanced frequency at high altitudes. In the present work, long term data from six altitude stations (and four continents) at various altitudes (from 1465 to 5240 m a.s.l) were used to derive statistically relevant NPF features (frequency, formation rates, and growth rates) and seasonal variability. The combined information together with literature data showed that the frequencies of NPF events at the two Southern hemisphere (SH) stations are some of the highest reported thus far (64% and 67%, respectively). There are indications that NPF would be favored at a preferential altitude close to the interface of the free troposphere (FT) with the planetary boundary layer (PBL) and/or at the vicinity with clouds, which otherwise inhibit the occurrence of NPF. Particle formation rates are found to be lower at high altitudes than at low altitude sites, but a higher fraction of particles are formed via the charged pathway (mainly related to positive ions) compared to boundary layer (BL) sites. Low condensational sinks (CS) are not necessarily needed at high altitudes to promote the occurrence of NPF. For stations at altitudes higher than 1000 m a.s.l., higher CSs favor NPF and are thought to be associated with precursor gases needed to initiate nucleation and early growth.
Carbidopa Alters Tryptophan Metabolism in Breast Cancer and Melanoma Cells Leading to the Formation of Indole-3-Acetonitrile, a Pro-Proliferative Metabolite
Authors: Duarte Diana , Amaro Filipa , Silva Isabel , Silva Dany , Fresco Paula , Oliveira José C. , Reguengo Henrique , Gonçalves Jorge , Vale Nuno
Published: August 2019

Carbidopa is used for the treatment of Parkinson’s disease (PD) as an inhibitor of DOPA decarboxylase, and PD patients taking carbidopa have a lower incidence of various tumors, except for breast cancer and melanoma. Recently, it was shown that carbidopa inhibits tryptophan-2,3-dioxygenase (TDO) and kynureninase enzymes. In the present study, the effect of carbidopa on the viability and metabolic profile of breast cancer MCF-7 and melanoma A375 cells was investigated. Carbidopa was not effective in inhibiting MCF-7 and A375 proliferation. Liquid chromatography and mass spectrometry revealed a new compound, identified as indole-3-acetonitrile (IAN), which promoted a concentration-dependent increase in the viability of both cell lines. The results suggest that treatment with carbidopa may alter tryptophan (Trp) metabolism in breast cancer and melanoma leading to the formation of a pro-proliferative Trp metabolite, which may contribute to its failure in reducing breast cancers and melanoma incidence in PD patients taking carbidopa.
Herbal Tea for the Management of Pharyngitis: Inhibition of Streptococcus pyogenes Growth and Biofilm Formation by Herbal Infusions
Authors: Wijesundara Niluni M. , Rupasinghe H. P. Vasantha
Published: August 2019

Herbal teas are becoming popular as functional beverages due to their various health promotional properties. This study aimed at assessing 13 hot water infusions (HWIs) from different herbs against streptococcal pharyngitis (strep throat). Licorice root exhibited the lowest minimum inhibitory concentrations (MIC) of 1.56 mg/mL, followed by barberry root, thyme, and oregano flowering shoots, with a MIC of 3.13 mg/mL. At their respective minimum bactericidal concentrations (MBC), licorice showed the bactericidal effect on S. pyogenes within 12 h after exposure while others need 24 h for a similar outcome. The HWIs exhibited inhibitory activity on biofilm formation, ranging from 1.56 to 6.25 mg/mL, which confirmed by ruptured cells or clusters of dead cell debris observed in scanning electron microscope (SEM). Overall, non-toxic concentrations of efficacious HWIs from licorice root, barberry root, thyme, and oregano flowering shoots may provide potential sources for developing herbal teas or biomedicine for the management of S. pyogenes infections.