bluuebunny/crossref_metadata_2025 huggingface dataset:
A Survey on Attitude Towards Quality Monitoring System of Linguistic Landscape
Authors: Lu Bin
Published: November 2019

This study aims at investigating the difference between attitude towards the construction of quality monitoring system on linguistic landscape of Chinese tourism, and the current situation on regional special linguistic landscape program. By analyzing the degree of participation in serving for improvement the quality of local linguistic landscape, this survey carries out quantitative analysis of attitude research on constructing the benchmark indicators, program management, process control and quality evaluation; explores a sustainable development mode on linguistic landscape assessment for national tourism; promotes the formulation, implementation and promotion of the quality monitoring system on linguistic landscape tourism from 520 feedbacks of respondents. And the objectives of this research were to 1) to investigate the attitudes towards social influence and implementation of series of Standards and Guidance for English Translation and Usage in Public Service(2017-2019); 2) to study the factors that influence different attitudes and opinions; 3) to explore quality evaluation system of linguistic landscape, and promote linguistic landscape evaluation indicators and modes. The conclusion is that the governments should construct the common understanding of program mode and collaborative development on quality monitoring system.
The Role of Memory in Dyslexia
Authors: Ghazzai Alsulami Sami
Published: November 2019

This paper examines what the literature proffers regarding the relationship between dyslexia and memory deficiencies. Dyslexia is a well-known learning disability that has been recognized since the late 1800’s and has grown in notoriety since it was first discovered (Javier, 2015). It is especially notable due to its current prevalence among school aged children as well as adults and because of the detrimental nature that impaired literacy can have on their ability to read, write and excel academically. Discussed here are a history of dyslexia, along with a general exploration of the functions of memory and how it has to do with the processing and output of information within the mind. Two research studies are examined that help draw a direct correlation between a deficit in short-term and working memory with the phonological difficulties suffered by those who experience dyslexia. By better understanding the role of memory in dyslexia, educators may be more efficient at assisting and implementing early intervention for those children who need it.
Postgraduate Students’ Perception of Massive Open Online Courses (MOOCs) in Enhancing their Learning Experience
Authors: Abd Majid Faizah , Kamarudin Rafidah , Mohd Zamin Ainul Azmin
Published: November 2019

MOOCs first became a phenomenon in the higher education landscape in 2008. Ever since, various researches have been conducted to explore the potential of MOOCs as an alternative in the learning and teaching process, and the way forward in delivering the courses effectively. Despite the growing interest in MOOCs applicability in higher education, very little is known about how postgraduate students perceive the use of MOOCs in their programme. Postgraduate students are synonymous with the concept of adult learners. One of the characteristics of adult learners is their motivation, which is driven by intrinsic and instrumental factors. As past research have concentrated on the undergraduates, this paper uncovers the postgraduates’ perceptions of MOOCs. A total of 51 respondents took part in a survey conducted in one of the Malaysian public universities. Quantitative data yielded findings similar to past research findings. However, what is new is the need for MOOC providers to cater to the needs of the postgraduate students who are adult learners particularly in determining the following; MOOCs’ attributes, learning process and learning outcomes. It is expected that the postgraduate students, their educators and the MOOC developers would find the findings helpful.
Examining High School Students’ Writing Self-efficacy Perceptions
Authors: Volkan Demi̇rel Mehmet , Seçkin Aydin İbrahim
Published: November 2019

The aim of this study was to investigate whether high school students’ writing self-efficacy perceptions differ based on their gender, grade level, type of high school and the number of books they read annually. A total of 585 students (Females = 270; and Males = 315) studying in the ninth and tenth grade classes from high schools of different type participated in the study. The results showed that high school students’ self-efficacy perceptions differed based on their gender, grade level, school type and the number of book they read annually. This difference was observed in the writing stages of planning, drafting, revision and modification. Consequently, it was concluded that reading books positively affected individuals’ writing self-efficacy.
Nationalism, Patriotism and Global Citizenship: A Comparison in between the Social Studies Teacher Candidates in the US and Turkey
Authors: Altıkulaç Ali , Yontar Alper
Published: November 2019

The aim of this research is to introduce the opinions of the social studies teachers who receive education in USA and Turkey in relation to the concepts of nationalism, patriotism and global citizenship comparatively. The basic research design belonging to the research is of a case study model. The multiple techniques have been used to transform the data sets to findings. According to the results of the research, it becomes evident that the constructive patriotism attitudes that belong to the participants from both countries are high and if comparison is made, the blind patriotism attitudes that belong to the participants from Turkey are higher than the participants from USA. On the other hand, if the global citizenship attitudes are taken as a basis, the participants from USA are more prone to global citizenship in comparison to the participants from Turkey.
Level of Civic Knowledge and Attitude as Antidotes of Civic Engagement among Secondary School Students in Oyo State, Nigeria
Authors: Bilqees Olayinka Abdu-Raheem , Sola Elijah Olorunda
Published: November 2019

The study investigated the level of civic knowledge and attitude as antidotes of civic engagement of secondary institution students in Oyo State. It also examined their attitude towards civic engagement. The research design is descriptive of the survey type. Population comprised all 411,912 public schools in urban and rural areas in Oyo State. Sample was 600 public school students selected using multistage sampling procedure. The instrument used was titled ‘Students’ Civic Engagement Questionnaire’ (SCEQ). The instrument was validated through face and content validity while reliability of the tool was established using Cronbach’s alpha method and a coefficient of 0.72 was obtained. Data were analysed using descriptive statistics for the research questions raised. It was found that the level of secondary school students’ civic knowledge and engagement was moderate, while their attitude towards civic engagement was negative. Based on the results it is suggested that students be enlightened to take part in civic obligations in order to develop positive attitudes towards civic engagement. Additionally, non- governmental organisations should intensify efforts in campaigning and promoting civic duties as this could increase the awareness of the citizens.
Senior Meets Junior Digital Natives: TESLians Integrating Technology in their Teaching Practice
Authors: Kien Men Loo , Noordin Nooreen
Published: November 2019

The younger generations of students called Digital Natives learn via technology. The Malaysia Education Blueprint 2013-2025 has taken the initiatives to implement Information and Communication Technology (ICT) in learning in bid to cater to their learning styles. However, the implementation has not been smooth-sailing as most teachers have not been integrating ICT in their lessons seamlessly. Goldberg’s (1981) Big Five Model of Personality can explain various usage of ICT based on their respective trait but TESL (Teaching English as Second Language) undergraduates in the Malaysian context had not been studied before. The researcher purposively selected 72 TESL undergraduates from the Faculty of Educational Studies in a public university in Malaysia for the study using a questionnaire and semi-structured interview. The findings reported high levels of ICT integration and motivation in integrating it. Next, they scored the highest in Openness to experience towards ICT integration in L2 teaching while low in Neuroticism. There was also a statistically significant, moderate, positive relationship between their level of motivation, Agreeableness, Conscientiousness, Extraversion and Openness traits and their ICT integration in L2 teaching. These findings present vital implications for TESL program and course coordinators to facilitate their pre-service teachers to leverage ICT in their teaching practice.
Digital Storytelling in Secondary School Turkish Courses in Turkey
Authors: Ertan Özen Nesime , Duran Erol
Published: November 2019

This study aimed to evaluate the digital story-telling activities in Secondary School Turkish textbooks and curriculum. It also sought to determine the learners and teachers’ opinions about digital storytelling activities. The study was designed using the basic qualitative model. The research had two different study groups consisting of students and Turkish language teachers. The data were obtained through the 2018 Turkish curriculum, Turkish textbooks and interview forms. Content and descriptive analysis techniques were used. According to the results, a total of eight learning objectives were found in the 2018 Turkish Curriculum about story writing skills. However, there were no learning objectives related to digital storytelling. No text and activity related to the ability to create digital stories were encountered in the textbooks. Most of the teachers stated that the activities that would be done by creating digital stories would contribute to the language development of the students, and that the ability to create digital stories should be included in the Turkish curriculum. It was found that most of the students wanted to have digital story production activities in Turkish courses, and that they would be interested in preparing their stories with computers. They preferred creating a story by computers instead of writing a story in traditional ways.
Fostering Students’ High Order Thinking Skills through the Use of Interpretation Cards
Authors: Asari Slamet , Husniah Rohmy , Ma’rifah Ulfatul , Anwar Khoirul
Published: November 2019

In teaching and learning process particularly at university level, High Order Thinking Skills (HOTS) should be an integral element to foster students’s critical and creative thinking. It should not only be designed for assessment purposes but also be implemented within classroom teaching process. This study is aimed at analyzing students’ HOTS encompassing three cognitive domains as parameters to identify students’ HOTS namely; analysing, evaluating, and creating. This is a mixed method study which is descriptively presented. The data collection was conducted by employing three observations during teaching learning process and distributing questionnaires to 32 students of English department in semester 5. In addition, students were selected using snowball technique and were interviewed. Both qualitative and quantitative approaches were used to data analysis. The finding reveals that indicators and characteristics of HOTS are presented very consistently during classroom teaching. Students frequently show critical and creative thinking through variety of ways when participating in the classroom teaching process. The Interpretation Card works so effectively and contributes vividly to the HOTS of the students.
Empowerment Programmes of Faith-Based Organisations (FBOs) and Socio-economic Well-being of Members in Yenagoa Community, Bayelsa State, Nigeria
Authors: Oghenekohwo Jonathan E. , Tonunarigha Young D.
Published: November 2019

This is an investigation on the empowerment programmes of faith-based organizations (FBOs) and socio-economic well-being of members in Yenegoa Communities of Bayelsa. This study lay to rest the controversy surrounding FBOs, whether they are empowering members or exploiting them and the extent to which such organisations have met its goals especially that of capacity building, charity and giving. The survey research method was used for the study. From a population of 12,565 FBOs leaders and members in Yenegoa communities, a sample of 659 participants was selected through proportional random sampling method. Data were collected with a face and content validated self-structured instrument title: Faith-Based Organisations Empowerment Scales (FBOES), (r=0.88). Four research questions were raised and answered using the mean, standard deviation and multiple regression statistics analysis. Results showed that, faith-based organisations provided skills acquisition programmes for member’s empowerment. Majority of the FBOs were actively involved in the empowerment of youth, women and the most vulnerable members of the affiliates and even the host communities. Faith-based organisations derived its goals from the teaching on social capital investment elements of trust, cooperation, mutuality, compromise, reciprocity, courage, integrity, networking, mentoring, and communication for peace building and community development. It was concluded that faith-based organisations empowerment programmes had positive impacts on members’ social and economic well-being. In view of these findings, it was recommended that leaders of FBOs in the communities should moderate their lifestyles, emulate and enhance the example of service, humanness and sacrifice in their engagement.
The Relations Among University Students’ Academic Self-efficacy, Academic Motivation, and Self-control and Self-management Levels
Authors: ARIK Soner
Published: November 2019

Self-control and self-management, academic motivation and academic self-efficacy are among several variables that affect academic achievement. Although they are widely studied in literature, there is lack of study that deals with them together in one study. This study investigates the relations between self-control and self-management, academic motivation and academic self-efficacy levels of university students. A group of 588 students at a state university in Turkey participated in the study. The data were collected through ‘Academic Motivation Scale’, ‘Academic Self-Efficacy Scale’, ‘Self-Control and Self-Management Scale’ and a Personal Profile Form that was prepared by the researcher. In line with the purpose of the research, a structural equation model regarding the predictive power of Academic Self-Efficacy level on Academic Motivation and Self-Control and Self-Management levels, and the predictive power of Academic Motivation level on Self-Control and Self-Management level was set. According to the results of the research, it is clear that academic self-efficacy is a significant predictor of both academic motivation and self-control and self-management of university students but academic motivation does not predict self-control and self-management. The research results were discussed within the literature and several recommendations were made in accordance with them.
Principals’ Role in Promoting Teachers’ Professional Development and Learners’ Performance In Secondary Schools in Murang’a and Kirinyaga Counties, Kenya
Authors: Mwihaki Irungu Cecilia , Josphat N Kagema , Wambugu Gachahi Michael
Published: November 2019

Students’ overall performance in country wide national examinations in Kenya has recorded below mean achievement as attested by Kenya Certificate of Secondary Education (KCSE) results. The number of students scoring grade D+ and below has consistently remained high compared with those attaining grade C+ and above which is the country’s minimum university entry. Concerns have been raised regarding this trend in students’ achievement. This study examined the performance of the principals’ role in promoting teachers’ professional development and learners’ performance in Kirinyaga and Murang’a counties, Kenya. The study involved a sample of 205 principals and 367 teachers selected from secondary schools in the two counties. Researchers used validated questionnaires and interview schedules to collect data from teachers and principals and analysed data using descriptive and inferential statistics. The hypothesis was tested at p>0.5 level of significance using Pearson Product Moment Correlation. The study established that there was no statistically significant relationship between principals’ role in promoting teachers’ professional development and learners’ performance. The study recommended that principals should ensure that teachers put into practice knowledge and skills learnt during in-service courses so that students benefit from the investment. The Ministry of Education should also take keen interest in how in-service courses are conducted.
Excelling in Exam Through Narrative Writing: A Connection of Creative and Descriptive Expressions
Authors: David Roseline , Alagiaraj Thambu Raj Joseph
Published: November 2019

This paper discusses the impacts of an action research on how students can excel in writing skills regardless of their level of competency especially for those taking the English Language paper (SPM 1119) in the Malaysian Secondary School Public Exam in 2018. This action research aims to exert the need for realigning our focus to incorporate an approach of teaching and learning at upper secondary level. The research was carried out from January to October in a secondary school in Kota Kinabalu, Sabah. Two classes of 37 Limited English Proficiency students and 24 High English Proficiency Students who were sitting for SPM 1119 in 2018 were the subjects. The students were exposed to creative expressions under various topics which were then emphasized to be utilized in continuous writing. As a result, the performance of students had improved significantly in their continuous writing where they eventually scored 100 percent pass in SPM1119 in 2018. All 24 Highly Competent students were able to score ranging from “A-” to “A+” with grade A being the median grade. On the other hand, all the students from the Limited English Proficiency students passed with grades ranging from “A”+ to “E” (minimum passing grade) with grade “B” as the median.
The Relationship between Classroom Management Skills and Self-confidence of Social Studies Teachers
Authors: BAŞ Kenan
Published: November 2019

This study investigated the relationship between classroom management skills, and self-confidence of social studies teachers. To this end and through a general survey, social studies teachers’ classroom management skills and their self-confidence for education were examined in terms of Gender, Professional Seniority, and Class Size. The population was constituted by 67 social studies teachers working in various secondary schools within the boundaries of the province of Elazig, Turkey, in the spring semester of the 2018 and 2019 academic years. The instruments used were a Personal Information Form, a Classroom Management Skills Scale and a Self-Confidence Scale for Education. The findings of the research were analyzed using SPSS (version 22) and revealed that the social studies teachers did not have a statistically significant difference in terms of both classroom management skills and levels of self-confidence for education related to variables of Gender, Professional Seniority and Class Size. On the other hand, it was found that there was a significant positive relationship between the classroom management skills and levels of self-confidence of the social studies teachers. The results are discussed within the framework of the relevant literature and the study concludes by presenting suggestions for future research.
Labeling English Learners: Teachers’ Perceptions and Implications
Authors: Byfield Lavern
Published: November 2019

In the U. S., given the growing number of students who are speakers of languages other than English, this article brings attention to a need for a nuanced perspective on the definition of English learners. The study was designed to investigate teachers’ perceptions of English learners and the implications for classroom instruction. Teachers classified English learners as Latinos and conflated race and ethnicity with language proficiency. Although Amish students were included on classroom demographic forms, race/ethnicity and language were confused in teachers’ explanations of their accommodations for linguistically diverse students. In conflating language with race/ethnicity there are several implications for the Latina/o community and likewise for White bilingual communities with mostly deficit frames that are enacted in pedagogy for Latinos.
A different Analysis with the Literature Circles: Teacher Candidates’ Perspectives on the Profession
Authors: Çetinkaya Fatih Çetin , Topçam Abdurrahman Baki
Published: November 2019

This study aimed to determine the perceptions of teacher candidates and to use the literature circles method to help them to develop a positive attitude towards the profession. Given that the study of literature circles in the national literature is only for a specific area, this study is the first study in which the literature circles are used for a different purpose. The research was carried out with eight teacher candidates who were studying in two different undergraduate programs of a public university in the spring term of the 2018-2019 academic year. Participants were selected by using convenience sampling and purposeful sampling methods. In the study, which was formed by selecting the case study from qualitative research designs, data were analyzed by the content analysis method. Findings from the books and sessions performed within the literature circles show that the process has a positive effect on the teacher candidates’ perspectives.
Physical Activity Counseling in Kinesiology Curricula: What is Offered in Ontario?
Authors: Wilson Philip M. , Kelly Caitlin , Mack Diane E. , Wierts Colin
Published: November 2019

Background: Physical activity counseling (PAC) is a viable approach for individualizing behavior change yet it is unclear if training opportunities in this area constitute a portion of the curriculum offered to university students by kinesiology departments. Objectives: The purpose of this study was to describe the availability of courses in PAC within the curricular offered by kinesiology departments at the post-secondary level. Methods: Data were extracted from the 2018-2019 undergraduate calendars published by kinesiology departments from universities in Ontario, Canada. Results: Seventeen of the 22 universities (77.3%) reported a department of kinesiology (or equivalent). Every kinesiology department offered courses in human biomechanics and human psychomotor learning or neuroscience. Less than half (n = 7; 41.2%) of these kinesiology departments offered PAC courses. Conclusions: Overall, this study makes it apparent that university students completing a kinesiology degree may have limited access to formal training opportunities devoted exclusively to PAC in comparison to other knowledge domains (e.g., human biomechanics). Based on these results, it seems reasonable to contend that kinesiology programs may warrant reconfiguring to meet the occupational demands of exercise professionals who use PAC to combat physical inactivity.
Effects of Drop Height on Drop Jump Performance
Authors: Addie Cameron D. , Arnett Jocelyn E. , Neltner Tyler J. , Straughn Marisa K. , Greska Eric K. , Cosio-Lima Ludmila , Brown Lee E.
Published: November 2019

Background: Drop jumps (DJ) are commonly implemented in plyometric training programs in an attempt to enhance jump performance. However, it is unknown how different drop heights (DH) affect reactive strength index (RSI), jump height (JH) and ground contact time (GCT). Objectives: The purpose of this study was to assess the effect of various DHs on RSI, JH, and GCT. Methods: Twenty volunteers with a history of plyometric training (Males = 13, Females = 7; age: 22.80 ± 2.69 yr, height: 175.65 ± 11.81 cm, mass: 78.32 ± 13.50 kg) performed DJs from 30 cm (DJ30), 45 cm (DJ45), 60 cm (DJ60), 76 cm (DJ76), and 91 cm (DJ91) and a countermovement jump (0 cm). A 16-camera Vicon system was used to track reflective markers to calculate JH; a Kistler force plate was used to record GCT. RSI was calculated by dividing JH by GCT. RSI and GCT were compared using a 2x5 (sex x DH) mixed factor repeated measures ANOVA, while JH was compared using a 2x6 (sex x DH) repeated measures ANOVA. Results: There were no interactions, but there was a main effect for sex for both JH (M>F) and GCT (F>M). JH demonstrated no main effect for DH: DJ30 (0.49 ± 0.11 m), DJ45 (0.50 ± 0.11 m), DJ60 (0.49 ± 0.12 m), DJ76 (0.50 ± 0.11 m), and DJ91 (0.48 ± 0.12 m). However, GCT showed a main effect where DJ30 (0.36 ± 0.10 s), DJ45 (0.36 ± 0.12 s), and DJ60 (0.37 ± 0.10 s) were not significantly different but were less than DJ76 (0.40 ± 0.12 s) and DJ91 (0.42 ± 0.12 s). Conclusions: Increasing DH beyond 60 cm increased GCT but did not affect JH, resulting in decreased RSI. Therefore, practitioners designing plyometric training programs that implement DJs may utilize DHs up to 60 cm, thereby minimizing GCT without compromising JH.
The Effects of Including Aerobic Exercise in the Treatment Protocol of Concussions: A Systemic Review and Meta-analysis
Authors: Wandel Sofie De , Sulak Tracey , Willoughby Darryn S.
Published: November 2019

Background of Study: More research studies are being completed advocating for the use of exercise as an intervention and form of treatment for concussions. However, exercise can include many forms of physical activity, intensities, and durations. This systemic review and meta-analysis focused on the use of aerobic exercise, such as cycling or walking, as an intervention and form of treatment for children and young adults suffering from a concussion. Objective: The purpose of this systematic review and meta-analysis was to determine if the addition of aerobic exercise to an individual concussion treatment makes a significant difference when compared to treatments using flexibility as a form of physical activity or traditional methods of treatment following guidelines from the 2016 Berlin Consensus Statement on Concussion in Sport. Method: The search conducted for articles generated 472 studies. Out of these, 5 studies were selected based from the inclusion criteria. Results: Aerobic exercise was shown to significantly decrease the absolute risk difference for the development of prolonged post-concussion symptoms in children and adolescents with concussions when compared to those who reported no physical activity. The mean risk difference for the independent variable (IV) was -0.12 with a 95% confidence interval was reported to be -0.17 to -0.07 and an effect size of Z = 4.94 (P < 0.00001). Aerobic exercise was also shown to have an effect on the change in post-concussion symptom scale scores. The mean IV difference was 8.7 with a 95% confidence interval of 2.05 to 14.35 and an effect size of Z=3.02 (p=0.003). Conclusion: In conclusion, while there is evidence that aerobic exercise is beneficial for children and adolescents with a concussion, more studies need to be completed focusing on this age group and the effects of aerobic exercise on concussion recovery.
Helmet Prototype Response Time Assessment using NCAA Division 1 Collegiate Football Athletes
Authors: Shelly Zachary , Stewart Ethan , Fonville Tate , Burch V Reuben F. , Chander Harish , Strawderman Lesley , May David , Smith JohnEric , Carruth Daniel , Bichey Cory
Published: November 2019

Background: With advances in concussion research, an increasing amount of resources are being allocated to advancing football helmet technology. Objective: This study assesses the claim that a new modified helmet prototype provides greater field of view for the user as compared to a commonly worn helmet by players. Method: The helmets—Riddell SpeedFlex and the modified helmet—were compared based on user response time while performing a response test task using the FITLIGHT Trainer system, actual helmet field of view blockage, users’ subjective perception of field of view, and balance tests. Eighteen National Collegiate Athletic Association (NCAA) Division 1 American football student-athletes completed the response test task and questionnaire. Results: The results demonstrate evidence that the SpeedFlex helmet provided by the equipment staff significantly increases wearers’ response times, F(2,20) = 5.646, p < 0.05. Also, while the quantification of the field of view perception was similar across helmet types, the student-athlete participants perceived the modified helmet to have significantly more field of view while performing the response test task, 1.56 v. 2.56; p < 0.05 for frontal vision and 2.83 v. 5.39; p < 0.05 for peripheral vision. Conclusion: In addition to the findings, this study also lays out a response time test protocol using the FITLIGHT Trainer system that can be used for assessment of response time testing of football and other helmets in future studies.
Risk Factors for Retinopathy in Young Adults With Type 1 Diabetes
Authors: Seyed Ahmadi Shilan , Ludvigsson Johnny , Imberg Henrik , Nyström Thomas , Lind Marcus
Published: December 2024

This cohort study investigates whether risk factors other than glucose control are associated with the development of diabetic retinopathy.
Progressive Eyelid Lesions in a Woman With Essential Thrombocythemia
Authors: Legala Akshara R. , Shoji Marissa K. , Kikkawa Don O.
Published: December 2024

A 75-year-old woman with a history of essential thrombocythemia presented with 3 months of progressively enlarging right upper eyelid lesions. Examination revealed a thickened eyelid margin, madarosis, and erythema with some tenderness to palpation but an otherwise normal ocular examination. What would you do next?
Digital Predistortion for Power Amplifiers
Authors: Gilabert Pere L. , Montoro Gabriel
Published: December 2024

This chapter provides a comprehensive overview of the principles of digital predistortion (DPD) linearization, a crucial technique for enhancing the performance of radiofrequency power amplifiers (PAs). The chapter delves into the inherent trade‐off between linearity and efficiency in PAs, highlighting the challenges of maintaining both high efficiency and linearity in wireless communication systems. It explores various power amplifier behavioral models and the methods used for parameter identification. The chapter also discusses the learning approaches employed for the parameter identification of the DPD, focusing on how they optimize the predistortion process. Regularization techniques, which are crucial for preventing overfitting and improving modeling performance, are examined in detail. Additionally, an overview of feature selection and feature extraction techniques is provided, emphasizing their importance in enhancing the accuracy and efficiency, in terms of computational complexity, of DPD algorithms. By integrating these topics, the chapter offers a detailed guide to understanding and implementing DPD linearization, making it a valuable resource for researchers and engineers working to cope with the inherent PA trade‐off between linearity and power efficiency in modern communication systems.
Polarization
Authors: Maybell Michael J.
Published: December 2024

Polarization is the property of a plane wave that completely describes the magnitude, direction, and angle of the phasor electric field in the plane transverse to propagation over one RF cycle. People working on antennas, communications, or propagation need to understand this fundamental property of electromagnetic waves to be able to efficiently solve common problems. This document introduces the fundamental concepts of electromagnetic wave polarization. It begins with the mathematical description of a phasor plane wave broken up into two orthogonal components and shows how when these are superimposed, the tip of the electric field traces an ellipse once each RF cycle. The principal constituent parts of the polarization ellipse are described which are the ratio of major to minor ellipse axis (axial ratio or AR), major axis tilt angle (
τ
), and direction of rotation (sense). The Poincaré sphere is introduced which provides a powerful, intuitive, and convenient method for representing polarization and doing polarization computations. The polarization ratio is described which provides a convenient means with which to measure, characterize, and compute polarization‐related parameters. The ellipse, sphere, and polarization ratios are documented and key formulas are presented in a single sheet “Polarization Basics Diagram.” How this diagram may be used to do most all polarization computations without further equations is described. Additional helpful equations are documented. Several numerical examples are presented using the material in this chapter.
Evaluation of binding activities of a putative lipoprotein LIC_13355 of Leptospira spp.
Authors: Silva Igor R. M. , Takahashi Maria B. , Teixeira Aline F. , Nascimento Ana L. T. O.
Published: December 2024

Pathogenic Leptospira is the etiological cause of the zoonotic life‐threatening infection called leptospirosis. The disease is spread worldwide with higher risk in tropical regions. Although leptospirosis represents a burden to the health of humans and animals, the pathogenic mechanisms of Leptospira infection are yet to be clarified. Leptospirosis infection is multifactorial, involving functionally redundant proteins with the capability to invade, disseminate, and escape the host's immune response. In this work, we describe a putative lipoprotein encoded by the gene LIC_13355, genome annotated as hypothetical of unknown function. The coding sequence is conserved among pathogenic Leptospira spp. with high percentage of coverage and identity. The recombinant protein, rLIC_13355, was expressed in Escherichia coli host system in its insoluble form. The circular dichroism spectrum of the refolded protein showed it containing a mixture of secondary structures. rLIC_13355 interacts with extracellular matrix (ECM) component laminin and binds plasminogen (PLG), generating plasmin (PLA), thus possibly participating during the adhesion and dissemination processes. The rLIC_13355 has the ability to interact with Ea.hy926 and HMEC‐1 endothelial cells either in monolayer or suspension. The binding of rLIC_13355 with monolayer cells is dose‐dependent on protein concentration. Taken together, our data suggest that this is presumably an adhesion lipoprotein that may play diverse roles in host–Leptospira interactions by mediating the interaction with host components and with endothelial cell.
Interfacial Engineering of β‐Ketoenamine‐Based COFs/Urea‐Linked Perylene Diimide for Overall Photosynthesis of H2O2 in Seawater
Authors: Shi Xiaoyu , You Yang , Huang Liang , Zhao Jie , Ji Wen , Li Libo , Bu Donglei , Huang Shaoming
Published: December 2024

High‐efficiently non‐sacrificial H2O2 production is challenging due to the sluggish kinetics of ORR and WOR and severe electron‐hole recombination. Via interfacial engineering, a series of non‐metal photocatalysts are rationally designed and constructed, covalently bonded TpDT‐COF (TP) and urea‐PDI (UP), to achieve high non‐sacrificially photocatalytic H2O2 production in seawater. Experimental and theoretical analysis has revealed that an interfacial electric field is formed between covalently bonded TP and UP, which provides an internal driving force to enhance the electron‐hole separation. Further mechanistic studies reveal that the H2O2 production follows a simultaneous two‐step 2e− ORR and 4e− OER route. Moreover, the activity toward OER of the active center at the UP is significantly promoted due to a net charge transfer from UP to TP after covalently bonding. As a result, a high non‐sacrificial H2O2 production rate of 3846 µmol gh−1 in seawater is achieved. Furthermore, a 4.7 mM H2O2 is obtained after a 13 h‐continuous photocatalytic reaction, which can be directly used to purify dye and phenol contaminated water. Notably, the strategy of creating interfacial electric field coupled with desired charge transfer provides a universal approach for non‐sacrificial photosynthesis by enhancing the electron‐hole separation and activity of catalytic centers simultaneously.
Hollow Polyaniline Microspheres Decorated Fabric Sensor with Electromagnetic Wave‐Absorbing and Multimodal Sensing Toward Human–Machine Interaction
Authors: Wang Jun , Yan Kai , Li Xiao , Zong Yan , Xu Qunna , Sun Xiaodan
Published: December 2024

Developing comfortable, protective, and reliable monitoring wearable devices is of great significance for next‐generation electronic devices. However, previously reported fabrics have proven inadequate for cross‐mechanism sensing integration and electromagnetic wave (EMW) protection. To address these, an electromagnetic wave‐absorbing flexible wearable device with multimodal sensing capabilities is fabricated based on cotton fabric through polypyrrole (PPy) in situ growth as well as dip‐coating with polyaniline hollow microspheres (PHMs) and amino silane modified polyurethane. It demonstrates excellent electromagnetic wave‐absorbing properties (Reflection loss peak: −48.20 dB, Effective absorption bandwidth:4.2 GHz). Remarkably, three sensing units have been all integrated by a multimodal sensing principle (strain, temperature, and triboelectric nanogenerator) in an all‐in‐one structural configuration. The motion sensing unit shows quick response (225 ms) and recovery (285 ms) times with high sensitivity (Gage factor ≈9.2). The temperature sensing unit has a sensitivity of 0.59% K−1. The self‐powered tactile sensing unit exhibits high output voltage (41 V), maximum instantaneous power density (1.9 W m−2), and detects touching incentive within 0.3 s. Smart human–machine interaction is demonstrated in applications like morse code, temperature, and touching detection. This study serves as a proof‐of‐concept for new smart textiles, showcasing potential for integrated flexible wearable devices, artificial intelligence, and human–machine interactions.
A Gym for Cells—Direct Laser Writing of Magnetic Multilayered Micro Actuators for Mechanical Stimulation of Cells
Authors: Geid Nicolas , Husari Ayman , Galli Eleonora , Leffler Lukas , Tomakidi Pascal , Rühe Jürgen
Published: December 2024

Mechanical forces play a crucial role in many biological processes, including cell–cell and cell–matrix interactions. The generation of surface‐attached multilayer micromagnet systems fabricated by two‐photon lithography and the use of such systems to perform single‐cell actuation are presented. The actuators are generated by two‐photon crosslinking and consist of a soft and flexible surface‐attached hydrogel layer swollen in aqueous medium and a hydrophobic polymer filled with magnetic nanoparticles. To this, thin copolymer bilayers containing a photoreactive crosslinking moiety are deposited on a solid substrate. The crosslinker units are activated by two‐photon excitation and react via a C,H insertion reaction with any nearby aliphatic C,H bonds. This leads to crosslinking and surface‐attachment of the forming structures so that arrays of micromagnetic pillars with spatially controlled cell adhesion behavior are formed in a single step. Cells are placed on the pillars and actuation is induced by an external magnetic field allowing for highly controllable dynamic and static actuation. Geometric differences can be used to vary cell morphogenesis and movement of the actuators to stretch the cells resulting in highly customizable actuator systems for specific cell growth and actuation control and the study of cell behavior on the molecular level.
Synergistic Target‐Attacking Tumor Cells and M2 Macrophages via a Triple‐Responsive Nanoassembly for Complete Metastasis Blocking
Authors: Wang Bei , Cheng Hao , Ji Zhongsheng , Jiang Zijun , Wang Rong , Ding Yang , Ni Jiang
Published: December 2024

Collaboration of cancerous cells and microenvironment is the root for tumor spreading, leading to difficulty in complete metastasis blockage via mono‐intervention. Herein, a triple‐responsive nanoassembly is designed for orienting tumor cells and migration‐driving M2 tumor associated macrophages (TAMs) in microenvironment for efficient anti‐metastatic therapy. Structurally, a reactive oxygen species (ROS)‐responsive crosslinked short‐chain polyquaternium is synthesized to bridge graphene oxide (GO) scaffold with apolipoprotein A‐I crown via borate‐crosslinking, electrostatic adherence, and coordinative coupling. The protein‐crowning polymeric GO nanoparticles could give multimodal shielding and triple‐responsive release of doxorubicin and Snail‐targeted siRNA. Tailor‐made apolipoprotein A‐I crown fulfills nanoparticles synergistically attacking tumor cells and M2 TAMs via binding with overexpressed scavenger receptors. The findings witness the targeted accumulation and potent cytotoxicity of the hybrid nanoparticles for M2 TAMs and tumor cells; especially, elimination of M2 TAMs in tumor microenvironment holds back Snail‐enhancing transforming growth factor (TGF)‐β signal pathway, which collaborates with Snail silencing in tumor cells to reverse epithelial mesenchymal transition (EMT) and metastasis‐promoting niche. Collectively, the synergistic targeting therapeutic platform could provide a promising solution for metastatic tumor treatment.
A Multisynergistic Strategy for Bone Tumor Treatment: Orchestrating Oxidative Stress and Autophagic Flux Inhibition by Environmental‐Response Nanoparticle
Authors: Chen Xiaochen , Tian Pengfei , Chai Wenwen , Zhang Liyan , Qin Muyan , Fan Mengke , Liang Na , Kim Jua , Wang Yansong , Lu Weijia William , Wang Deping , Cui Xu , Pan Haobo
Published: December 2024

Tumor therapy has advanced significantly in recent years, but tumor cells can still evade and survive the treatment through various mechanisms. Notably, tumor cells use autophagy to sustain viability by removing impaired mitochondria and clearing excess reactive oxygen species (ROS). In this study, the aim is to amplify intracellular oxidative stress by inhibiting mitochondrial autophagic flux. Multisynergistic environmental‐response nanoparticles (ERNs) are engineered by integrating gold nanoparticles and copper peroxide with borosilicate bioactive glass. The controlled release of copper and inhibition of autophagy flux triggered an overabundance and accumulation of oxidative stress within the tumor cells. This stress triggered immunogenic tumor cell death, believed to initiate a systemic immune response. The tumor microenvironment (TME) transitioned back to a normal physiological state as tumor cells are ablated. ERNs responded to the microenvironment changes by depositing hydroxyapatite on the surface and spontaneously enhancing bone regeneration. This innovative formulation facilitates the functional transition of ERNs from “anti‐tumor therapy” to “biomineralization” that kills cancers and induces new bone formation. Overall, it is shown that the ERNs effectively eradicate cancers by utilizing chemodynamic therapy, starvation therapy, and immunotherapy.
Nanofiber‐based Multifunctional Microspheres for Rapid Hemostasis and Microorganism Removal of Water
Authors: Li Qing , Ye Lingjun , Leng Yanqiu , Yu Kun , Hu Enling , Lu Fei , Xie Ruiqi , Jiang Sha , Gao Hang , Bao Rong , Dai Fangyin , Lan Guangqian
Published: December 2024

Constructing hemostats capable of effectively controlling severe hemorrhage from irregular wounds presents significant challenges and imperatives. In this study, a novel approach is introduced using nanofibrous chitin microspheres (NCM) that are compressed to 60% strain (NCM‐60%) to amplify their water‐initiated expansion performance. This unique capacity allows NCM‐60% to efficiently conform to and fill irregular bleeding cavities, even those of varying depths and curvatures, thereby promoting rapid blood coagulation at deep hemorrhage sites. NCM‐60% exhibits effective control of severe femoral artery and “J”‐shaped liver hemorrhages in 151 ± 6 s and 68 ± 15 s, respectively, revealing its exceptional hemostatic efficacy. Furthermore, NCM‐60% exhibited promising capabilities in removing microbes from water, achieving removal rates of over 96% of bacteria. Blood compatibility assessments and cytotoxicity tests further confirmed the favorable biocompatibility of NCM‐60%. Importantly, NCM‐60% is found to biodegrade and be absorbed in vivo within 12 weeks. This study represents the first instance of leveraging chitin nanofiber‐based biomaterials to design water‐initiated expansion micro‐hemostat, and integrate hemostatic functions with waterborne microorganism removal, thereby expanding the potential applications of micro‐nanostructural materials in emergency first‐aid scenarios.
Suspending Light‐Absorbing Nanoparticles in Silica Aerogel Enables Numerous Superblacks
Authors: Li Guangyong , Wang Leyi , Ji Xiaofei , Zhang Xuetong
Published: December 2024

Current strategies for constructing sparse nanostructures for fabricating superblacks are only suitable for a few light‐absorbing materials, severely limiting their applications. Herein, ultra‐low reflective silica aerogels with ultra‐high light transparency are used as solid smokes to individually or simultaneously suspend at least 100 species of light‐absorbing nanoparticles with a volume fraction as low as 0.005%, for creating > 100 superblacks in practice and one billion superblacks in theory if taken permutation and combination among these 0D, 1D, or 2D nanoparticles into account. Depending on the composition of suspended nanoparticles and the structure of solid smoke, the resulting mechanically robust superblacks with supplementary properties including magnetism, full‐spectrum absorption, high thermal stability, and excellent mechanical strength, are first observed. The wide choice of metallic or semiconductive LNs allows as‐made superblacks to glitter in different catalytic reactions, and the resulting superblacks have been on‐demand modified for endowing the self‐cleaning performance in some contaminable environments. Benefiting from the superblack feature and porous network, these superblack monoliths have shown high‐efficiency solar‐heat conversion in some emerging light harvesting and managing fields. This powerful synthetic strategy for superblacks is expected to inspire researchers to conduct in‐depth investigations on super‐black optics, functional materials, etc.
2D Conjugated Metal‐Organic Frameworks for New Generation Flexible Multicolor Electrochromic Devices
Authors: Zhao Qi , Yang Jing , Wang Qing , Zhang Yong‐Wei , Wang John
Published: December 2024

There has been considerable interest in 2D conductive conjugated MOFs (2D c‐MOFs) for their potential applications in sensors, opto‐electronics, catalysis, and energy storage, owing to their ultra‐high specific surface area, relatively high electrical conductivity, and tunable pore channel sizes for ion/charge diffusion/adsorption. The unique advantages brought by systematic tunings in the metal nodes and organic ligands enable the creation of highly accessible and remarkable structures with diverse chemical and physical behaviors. While the 2D c‐MOFs are being explored for the rapid widening spectrum of applications, in this work, the great potential of multicolor transitions and functional properties of these 2D c‐MOFs are examined for the new generation of flexible multicolor electrochromic devices (FMEDs). Despite the rather limited and yet steady progress that has been made so far, 2D c‐MOFs offer great opportunities in addressing the monotonous color switching, undesirable stability, as well as the sluggish kinetics of electron/ion transportation, which are typically encountered by the conventional electrochromic materials. Together with the main challenges that are being faced, this perspective provides a timely re‐visit to the expected transition in the near future from the proof‐of‐concept demonstration to the eventual industrial‐scale implementation of 2D c‐MOFs in the new generation FEMDs.