bluuebunny/crossref_metadata_2025 huggingface dataset:
A posteriori error estimates of spectral method for the fractional optimal control problems with non-homogeneous initial conditions
Authors: Ye Xingyang ,   School of Science, Jimei University, 361021 Xiamen, China, Xu Chuanju ,   School of Mathematical Sciences and Fujian Provincial Key Laboratory of Mathematical Modeling and High Performance Scientific Computing, Xiamen University, 361005 Xiamen, China
Published: August 2021

In this paper we consider an optimal control problem governed by a space-time fractional diffusion equation with non-homogeneous initial conditions. A spectral method is proposed to discretize the problem in both time and space directions. The contribution of the paper is threefold: (1) A discussion and better understanding of the initial conditions for fractional differential equations with Riemann-Liouville and Caputo derivatives are presented. (2) A posteriori error estimates are obtained for both the state and the control approximations. (3) Numerical experiments are performed to verify that the obtained a posteriori error estimates are reliable.
Black Hole, Neutron Star and Numerical Relativity
Authors: KIM Jinho
Published: August 2021

Compact stars, e.g., black holes and neutron stars, are the most energetic objects in astrophysics. These objects are accompanied by extremely strong gravity and a high velocity, which approaches the speed of light. Therefore, compact objects should be dealt with in Einstein’s relativity. This article will briefly introduce a numerical method that will allow us to obtain general solutions in general relativity. Several applications using numerical relativistic simulations will also be presented.
Modified Concrete Mixes for Monolithic Construction
Authors: Kastornykh Lubov , Kholodnyak Mikhail , Osipchuk Igor , Kaklyugin Alexander
Published: August 2021

The effect of the multifunctional supplement Linamix PCX and mineral fillers of microsilica and expanded clay dust on the characteristics of concrete mixtures pumped by concrete pumps is investigated. The evaluation of highly mobile and self-compacting concrete mixtures’ properties was carried out according to pumpability criteria that simulate the elastic-viscous structured system flow. The physical and mechanical characteristics of the hardened concrete were determined using standard and generally accepted methods. The ability of the modified concrete to resist tensile stresses was determined by the crack resistance coefficient. The water-reducing efficiency of the superplasticizer was evaluated by the specific consumption of cement per unit of concrete strength. The performed studies have established that the polyfunctional superplasticizer Linamix PCX is an effective modifier of concrete mixtures, rheologically compatible with cements of various material composition. A significant effect of the fine aggregate grain size composition on the properties of highly mobile concrete mixtures and the formation of the hardened concrete structure has been revealed. Evaluation of the modified concretes’ strength characteristics showed that it is rational to use the mixtures with Linamix superplasticizer PCX and microsilica, providing high strength concrete with a minimum specific consumption of cement for concreting massive monolithic structures in order to slow down heat generation during concrete hardening.
Association of digital media exposure and addiction with child development and behavior
Authors: Anitha Fatima Shirly , Narasimhan Udayakumar , Janakiraman Abhinayaa , Janakarajan Nivetha , Tamilselvan Priyadharshini
Published: August 2021

Background:

Media exposure which was traditionally restricted only to television has now broadened to include various handheld devices and constant internet access. Although high quality educational and interactive screen time is beneficial, excessive addiction and early introduction of such media use has various deleterious consequences.

Aim:

To estimate the exposure of media among Indian children and its influence on early child development and behaviour.

Settings and Design:

A tertiary care hospital based cross-sectional study.

Materials and Methods:

We included 613 children between 18 months and 12 years who visited the paediatric out-patient department for a well or a sick visit. Their media exposure was extensively analysed along with Problematic Media Use Measure Short Form (PMUM-SF). They were screened for behaviour problems using the Child Behaviour Checklist (CBCL) and Strengths and Difficulties Questionnaire (SDQ) accordingly. Those under five years were also subjected to a screening using Ages and Stages Questionnaire (ASQ3).

Results:

The most common gadget used was television followed immediately by smartphones. The average daily screen time was 2.11 hours, Mean+SD=2.11+1.53, 95% CI 2.11+ 0.12, found in (40.1%) of the study population. The prevalence of screen addiction was 28.1%, majority being boys. Increased screen time and media addiction were significantly associated with concerns in communication, problem-solving and personal-social domains, as well as conduct, hyperactivity and pervasive developmental disorder (PDD) problems.

Conclusion:

We conclude that media exposure among children should be enquired as a routine. This helps to curtail unhealthy digital media practices at the earliest to ensure a digital safe environment for children.
Parental experiences of telerehabilitation for children with special needs
Authors: Hameed Noufal Thadathukunnel , Satheesan Sisira Chalapurath , Santhamma Jameela Padmalayam
Published: August 2021

Context:

The COVID-19 pandemic's emergence necessitated that clinic/hospital-based rehabilitation is replaced or substituted by other modes. Using telecommunication devices was found a convenient alternative.

Aims:

Present study explored the telerehabilitation experiences of the parents of children with developmental disabilities (CDD).

Settings and Design:

The study was conducted among the service users of a not-for-profit NGO located in Kerala. Parents of children with one or more developmental disabilities formed the population of the present study. The present study was a cross-sectional exploratory survey.

Subjects and Methods:

A total of 205 parents took part in the study using a brief open-ended survey. The majority of the participants were females (65%).

Statistical Analysis Used:

The sociodemographic data were analyzed using frequency and percentage. The qualitative data were analyzed using thematic analysis.

Results:

Overall, the study found that parents experienced more challenges in telerehabilitation compared to face-to-face interventions. Perceived challenges included externalizing problems, reduced effectiveness, logistical issues, multiple disabilities, and the child's lack of interest in gadgets. Perceived advantages included the child's liking for the device and increased availability of time.

Conclusion:

In short, the study throws light on the various challenges experienced by parents in implementing telerehabilitation for their CDD. The findings strongly recommend fine-tuning telerehabilitation programs to meet these challenges to provide optimal care to our children with special needs.
Reason for improper simple hysterectomy in invasive cervical cancer in Northeast India
Authors: Liegise Haelom , Barmon Debabrata , Baruah Upasana , Begum Dimpy , Kataki Amal Chandra , Chhangte Zirsangliana
Published: August 2021

Objective:

The objective of the study was to determine the reasons for improper simple hysterectomy in the presence of invasive cervical cancer in Northeast India.

Materials and Methods:

The medical records of 52 patients who had undergone improper simple hysterectomy in the presence of invasive cervical cancer and were referred to a tertiary regional cancer Institute at Guwahati, Assam, between January 2015 and December 2019 were reviewed.

Results:

Most of the patients presented with abnormal vaginal bleeding (40.4%). The failure to perform cervical cytology before the operation was quite high at 48.1% (25 patients). Interestingly, normal cytologic smear could still be found in 15.4% (8 patients) despite the presence of invasive cervical cancer. Failure to perform preoperative Papanicolaou smear, incomplete evaluation of cervical intraepithelial neoplasia (CIN) on cervical biopsy, and negative Papanicolaou smear accounted for 75% of the patients undergoing inappropriate simple hysterectomy. The most common indications for inappropriate operation were abnormal vaginal bleeding (40.4%) and CIN (19.2%). The reasons for inappropriate simple hysterectomy included lack of preoperative cervical cytology (48.1%), false-negative cervical cytology (15.4%), incomplete evaluation of cervical dysplasia or microinvasion on biopsy (11.5%). failure to perform indicated conization(5.8%), emergency hysterectomy (3.8%), errors in colposcopic examination (3.8%), incomplete evaluation of an abnormal cervical cytology (3.8%), failure to review slide (3.8%) and failure to biopsy a gross cervica lesion (3.8%).

Conclusion:

Most improper simple hysterectomy resulted from deviation from guideline for cervical cancer detection protocols. Improper simple hysterectomy in the presence of invasive cervical cancer can be avoided if one sticks to the diagnostic guideline for patients with an abnormal cervical cytology.
Evaluation of cytotoxic effects of fungal origin nanosilver particles on oral cancer cell lines
Authors: Halkai Kiran R. , Halkai Rahul , Patil Supriya , Alawadi Jameela , Alawadhi Wafa Saeed , Marukala Narender Reddy , Mohammad Albar Nassreen Hassan , Indi Shreeshail
Published: August 2021

Background:

Oral cancer is often associated with poor prognosis and it is found that conventional treatment options cause severe side effects, adjacent tissue disfigurement, and loss of function. Recently, silver nanoparticles (AgNPs) paved their path for cancer treatment.

Aim:

This study aimed to investigate cytotoxic effects of fungal procured AgNPs on oral squamous cell carcinoma (SCC-9) cell line using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.

Methodology:

The silver nanoparticles were biosynthesized using the fungi Fusarium semitectum. Cell lines were cultured in a 1:1 ratio of Dulbecco's Modified Eagle's medium and Ham's F12 medium and subcultured in a T-75 cm2 flask. Cell count was adjusted to 1 × 105 cells/ml; 50,000 cells/well were seeded into a 96 well plate and incubated at 37°C, for 24 h in 5% CO2 humidified conditions. AgNPs (1.75–50 μl/ml) were added to the plates and further incubated at 37°C for another 24 h. Medium containing cells without AgNPs were used as a control group. Later, 20 μl of MTT was added to each well and incubated for 6 h at above-mentioned conditions. About 0.1 mL of Dulbecco's Modified Eagle's Medium solution was added to each well to solubilize formazan. The absorbance was measured using a Tecan reader at 540 nm. The experiment was repeated thrice independently. The percentage (%) inhibition of growth and the AgNP's concentration that prevents the cell growth by 50% (IC50) were determined.

Results:

Significant dose-dependent inhibition of the growth of SCC-9 cell lines was seen and IC50 was found at 12 μl/ml concentration of AgNPs.

Conclusion:

Biosynthesized AgNPs of fungal origin exhibit effective anticancer properties against the SCC-9 cell line.
Immunoexpression of claudin-4 and correlation with estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2-neu in breast cancer
Authors: Kumar Niranjan , Tandon Megha , Chintamani CM , Saxena Sunita
Published: August 2021

Background:

Claudins are important transmembrane proteins in tight junction. The role of intercellular tight junctions in breast epithelial cells is traditionally thought to be in maintaining polarity and barrier function. However, claudin-4, a tight junction protein, is overexpressed in breast tumor cells compared to normal epithelial cells, which generally corresponds to loss in polarity and can provide valuable information about biology of the tumor. A prospective clinical study was conducted to assess the expression claudin-4 in patients with breast cancer and its correlation with hormone receptors – estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2)-neu.

Materials and Methods:

The study included 102 biopsy-proven breast carcinoma patients. The biopsy samples were evaluated immunohistochemistry for expression of ER, PR, HER2-neu, and claudin-4. The expression of claudin-4 was correlated with ER, PR, and HER2-neu.

Results:

In the study, we found that out of 26 cases of high claudin-4, 25 cases (96.15%) were ER negative and P < 0.001, which was significant. Similar results were found with PR-negative cases. Whereas, out of 76 cases with low claudin-4, 54 cases (71.05%) were HER2-neu negative and P = 0.022, which was significant.

Conclusions:

Claqudin-4 expression has a negative correlation with ER and PR and has a positive correlation with HER2-neu. Hence, it can be effectively utilized as a prognostic and therapeutic marker in breast cancer in the future.
Single step “See and Treat” strategy might be replacing the “conventional three step strategy” in management of preinvasive cervical lesions at tertiary center
Authors: Sachan Rekha , Shukla Ayushi , Patel Munna Lal , Sachan Pushplata , Verma Manjulata , Singh Uma
Published: August 2021

Introduction:

The aim of this study was to compare overtreatment rates of see and treat colposcopy-based single step protocol with cytology and colposcopy-guided biopsy-based conventional three-step protocol using loop electrosurgical excision procedure (LEEP) for treatment of preinvasive lesions of cervix.

Materials and Methods:

Prospective interventional study was carried out over a period of 1 year. Recruitment of cases was done from the 664 diagnostic colposcopies performed for various gynecological indications. Among 496 colposcopies performed exclusively for unhealthy cervix on per speculum examination, 74 women had high-grade colposcopy (Swede score ≥5). Subsequently, 50 women were enrolled under the see and treat arm, arm 1 and underwent LEEP. In study arm 2, conventional three-step strategy, concurrently 22 women with abnormal cytology. ≥ Atypical squamous cells of undetermined significance and unhealthy cervix were enrolled for colposcopy and if indicated, guided biopsy was obtained and tissue was sent for histopathology. Only 12 such women having HPE reports of cervical intraepithelial neoplasia (CIN) 2 or 3 were subjected to LEEP. Overtreatment was defined as CIN 1 or less on final LEEP tissue histopathology.

Results:

The overtreatment rate in See and Treat protocol was 44% when colposcopy Swede score cutoff was considered 5, which fell down to 0% when Swede score cutoff was taken 7. Conventional three step protocol had an overtreatment rate of 8.3%. Incidentally diagnosed high-grade CIN or invasive cancer was found in 24%. Discrepancy between biopsy tissue and LEEP tissue histopathology was 50% in conventional arm.

Conclusion:

Women with unhealthy cervix having high-grade colposcopy (Swede score ≥7) can be directly subjected to LEEP without waiting for results of any initial screening modality. Advantages include minimal over treatment coupled with reduced patient visits and interventions.
Varicella Infection in an Immunized Pediatric Living Donor Liver-Transplant Recipient
Authors: Mehta Vibha , Ramachandran Krithiga , Agarwal Reshu , Alam Seema , Pamecha Viniyendra , Gupta Ekta
Published: August 2021

Varicella-zoster virus (VZV) is a DNA virus belonging to the Herpesviridae family. Primary infection causes chickenpox followed by latency in the sensory ganglia, which can sometimes reactivate leading to herpes zoster. Chicken pox is generally a mild disease of childhood with a secondary attack rate of >85%, but disseminated VZV infection with visceral involvement and fatal outcome may occur in immunocompromised individuals. Indian Academy of Pediatrics recommends two doses of live-attenuated varicella vaccine in healthy unexposed children at 15–18 months and then at 4–6 years of age. The effectiveness of a single dose of vaccine is around 85% and with a two-dose schedule is as high as 92%. Despite the vaccine-induced protection, community-acquired VZV infections still remain a problem in immunocompromised population. We hereby report a case of a previously immunized pediatric liver-transplant recipient who acquired VZV infection. This case report clearly highlights the importance of strict environmental infection control practices, early suspicion, diagnosis, and management in such cases.
Association between Cholera Outbreak and Traditional Gold Mining in Northern State, Sudan 2017
Authors: Alzain Mohamed Ali , Haruwn Mogahid Hassan , Abdelaziz Mohamed Osman , Elsheikh Mohamed , Asweto Collins Otieno , Algahtani Fahad D. , Adeboye Adeniyi Abolaji , Elhassan Najm Eldinn Elsser , Itumalla Ramaiah
Published: August 2021

Introduction:

Cholera is one of the health problems causing considerable morbidity and mortality. The Northern State of Sudan experienced a recent cholera outbreak, however, there are limited data on the outbreak.

Methods:

The objective of this study was to assess the magnitude and risk factors associated with the cholera outbreak in the Northern State of Sudan. A retrospective case series study was conducted in the Northern State of Sudan, which involved tracing cases of cholera outbreak of 2017. Data were collected through reports and interviews. A geographical information system was used to map all cases during the outbreak. Chi-square test and logistic regression were used to identify associated factors.

Results:

There were 957 cholera cases reported in the state with an attack rate of 14.2/10,000 persons. Dalgo locality had the highest number (415) of cases reported with an attack rate of 167.2/10,000 persons. About 78% of cases were adult males, while 56.2% of cases were immigrants from other states. Immigrants in Halfa and Dalgo localities were four times (odds ratio [OR] = 4.031, 95% confidence interval [CI]: 2.482–6.547) and eight times (OR = 8.318, 95% CI: 5.674–12.193), respectively, at risk of cholera infection compared to immigrants in Dongola locality. The overall case-fatality rate was 1.9%. This was significantly higher in younger (5.8%) and older (22.7%) age groups (P < 0.05).

Conclusions:

The study revealed that the cholera outbreak spread highly along with traditional gold mining areas due to poor sanitation. Therefore, improving sanitation services and establishing an effective surveillance system in these areas are essential to prevent future occurrence of outbreaks.
Unusual Mechanism and Unusual Combination of Two Common Diseases
Authors: Parashar Satish K. , Mukherjee Samanjoy
Published: August 2021

Balloon mitral valvuloplasty (BMV) is an accepted treatment for certain subsets of patients of mitral stenosis. Prior to BMV, a full clinical and echocardiographic evaluation is done. This 36-years old lady of severe mitral stenosis had two BMV's including a three-dimensional transesophageal echocardiography at leading cardiac centers. However, an important echocardiographic finding was missed which would have altered the course of management. These details are discussed.
Indian Academy of Echocardiography Guidelines for Performance of Transesophageal Echocardiography in Adults
Authors: Burkule Nitin J. , Bansal Manish , Govind Satish C. , Alagesan R. , Ponde Chandrashekhar K. , Parashar Satish K. , Shrivastava Sameer , Raghu K. , Kasliwal Ravi R.
Published: August 2021

Transesophageal echocardiography (TEE) has unique advantages over conventional transthoracic echocardiography (TTE). Compared with TTE, TEE generally provides excellent quality images, especially of the posteriorly situated cardiac structures, such as atria, pulmonary veins, mitral valve, and left atrial appendage. TEE also offers a useful alternative to TTE in patients in whom transthoracic acoustic windows are suboptimal. Furthermore, TEE is the most suited imaging modality for use in the operating rooms and cardiac catheterization labs for guiding cardiac surgical or interventional procedures. However, specific training and competence are required for performing TEE successfully, smoothly, safely and with minimum patient discomfort. This document describes the basic principles of TEE examination, including patient selection and preparation, periprocedural monitoring, and probe handling and maneuvers. Commonly recommended views and the techniques to obtain these views are described in detail, followed by evaluation of specific cardiac structures. Finally, the role of TEE in certain specific clinical settings, such as during advanced circulatory support, is also discussed.
Information-Seeking Behavior on Coronavirus Disease-19 Vaccine on the Internet
Authors: Mondal Shaikat , Mondal Himel , Samantaray Ritushri
Published: August 2021

Background:

A significant portion of the global population seeks health-related information on the Internet. The world is searching for an effective vaccine to control the coronavirus disease-19. Knowing the information-seeking behavior of the population helps in designing an awareness program.

Aim:

This study aimed to explore the information-seeking behavior of the global and Indian population by analyzing Internet search trends.

Materials and Methods:

This cross-sectional study was conducted from April to November 2020. We used fully anonymous data available in the public domain (https://trends.google.com/trends). The phrase “COVID vaccine” was searched with “schedule,” “when,” “cost,” “where,” and “side effect” to compare the trends. The global and Indian data were categorized month-wise and statistically tested by the Chi-square test.

Results:

Global Internet users seek information on “when” the COVID vaccine would be available followed by “where” to get the vaccine. The “schedule,” “cost,” and “side effect” come later. Indian search trend is similar for “when” and “where.” However, the third query was the “cost” followed by “schedule” and “side effect.”

Conclusion:

The Internet search trend showed that people around the world want to know when they would get a vaccine and where to get it. The least search volume was about the side effects of the vaccine. Primary care physicians, government, and nongovernment stakeholders may use this finding for optimum dissemination of information both online and offline.
Dynamic Health Information System
Authors: Singh Mitasha , Goswami Shweta
Published: August 2021

The ongoing pandemic of Covid 19 is different from previous ones in the sense that the data science combined with statistical analysis has countless applications in epidemiology of the disease. The final product of data analysis is usually of interest to the readers. However, through this article we bring forth the process of the data collection, movement and management at the ground level. The data generators and collectors are usually the health workers who were also the care givers during the pandemic. The duplication of record maintenance and data flow at multiple places by the burnt-out workers deteriorates the quality of data. Integrated database is the need of hour for quality health management system.
A Rare Case of Horseshoe Kidney with Unilateral Chronic Pyelonephritis in a Cadaver
Authors: Balasubramanian R , Pattanshetti Sheetal Vishwanath , Kangle Ranjit , Gosavi Manasi , Srevatsa Karthik , Virupaxi Rajendra D , Pattanshetti Vishwanath M
Published: August 2021

Horseshoe kidney is one of the most common congenital urologic anomalies, with an incidence of 1 in 400 live births. The presence of this type of fusion anomaly of kidneys with resultant progression to renal pathology sometimes may remain obscured or dormant, due to the person being asymptomatic for years, only to be incidentally encountered during an autopsy, or during a cadaveric dissection. Similarly, during routine cadaveric dissection, we came across with a list of variations along with congenital anomalous horseshoe kidney. In this case report, we discuss about anatomical variation and pathological findings of horseshoe kidney.
Sparse versions of the Cayley–Bacharach theorem
Authors: Matusevich Laura Felicia , Reznick Bruce
Published: August 2021

We give combinatorial generalizations of the Cayley–Bacharach theorem and induced map.
The set of numerical semigroups of a given multiplicity and Frobenius number
Authors: Branco Manuel B. , Ojeda Ignacio , Rosales José Carlos
Published: August 2021

We study the structure of the family of numerical semigroups with fixed multiplicity and Frobenius number. We give an algorithmic method to compute all the semigroups in this family. As an application we compute the set of all numerical semigroups with given multiplicity and genus.
Analysis of a bulk-surface thermistor model for large-area organic LEDs
Authors: Glitzky Annegret , Liero Matthias , Nika Grigor
Published: August 2021

The existence of a weak solution for an effective system of partial differential equations describing the electrothermal behavior of large-area organic light-emitting diodes (OLEDs) is proved. The effective system consists of the heat equation in the threedimensional bulk glass substrate and two semilinear equations for the current flow through the electrodes coupled to algebraic equations for the continuity of the electrical fluxes through the organic layers. The electrical problem is formulated on the (curvilinear) surface of the glass substrate where the OLED is mounted. The source terms in the heat equation are due to Joule heating and are hence concentrated on the part of the boundary where the current-flow equation is posed. The existence of weak solutions to the effective system is proved via Schauder’s fixed-point theorem. Moreover, since the heat sources are a priori only in

L^1

, the concept of entropy solutions is used.
Recent increase in pertussis incidence in Korea: an age-period-cohort analysis
Authors: Kim Chanhee , Yi Seonju , Cho Sung-il
Published: August 2021

OBJECTIVES: Pertussis or whooping cough—one of the most contagious diseases—is caused by the Gram-negative bacterium Bordetella pertussis. Despite a high vaccination rate, Korea recently experienced a resurgence of pertussis. This study explores patterns and possible explanations for this resurgence through an age-period-cohort analysis.METHODS: Using secondary data from the infectious disease portal of the Korea Disease Control and Prevention Agency and the Korea Statistical Information Service of Statistics Korea, this study analyzed the incidence of pertussis in Korea to determine which factors contributed to the recent increase using an age-period-cohort model.RESULTS: Analysis of the age effect indicated that the age group most vulnerable to pertussis was 0-year to 2-year-olds. Analysis of the period effect showed a sharp increase in the incidence rate after 2016. Analysis of the cohort effect showed a significant decrease in incidence beginning with the 1955 birth cohort, with the risk increasing again with the 2000s birth cohort.CONCLUSIONS: Previous studies have suggested 3 main possible explanations for our results. First, the increased incidence rate can be attributed to contact rates. Second, the rate of immunity through natural exposure has decreased due to the low number of circulating pathogens, in turn affecting the trend of infection. Lastly, variations in pathogens may have also contributed to the increase in incidence. Given that the most significant increase in incidence was observed among infants younger than 1 year old, sufficient maternal immunity must be prioritized to provide passive immunity to newborns via the placenta.
FACTORES DE DIFERENCIACIÓN EN AGENCIAS DE SERVICIOS TURÍSTICOS DUALES. OPORTUNIDADES DE INNOVACIÓN DESDE LO LOCAL
Authors: Macías-Arteaga Miryan Irina , Vélez-Moreira Estefanía Monserrate
Published: August 2021

La investigación tiene como objeto primordial analizar los factores de diferenciación en agencias de servicios turísticos duales, en la que se procura conocer los factores de diferenciación que permiten la generación de oportunidades de negocio turístico a través de estas operadoras; la investigación se plantea desde los cantones Portoviejo y Manta, ambos de la provincia de Manabí, Ecuador. Se tiene como informantes clave a una representante del Ministerio de Turismo del Ecuador y agencias de servicios turísticos duales. La investigación es de enfoque cualitativo, con un nivel analítico descriptivo; de carácter documental y acercamiento al campo, no experimental. Su método inductivo permite un adecuado acercamiento desde la observación directa, así como la revisión de teorías que emergen desde lo sustantivo. Como técnica de acompañamiento en el levantamiento de la información está la entrevista en profundidad, y como técnica de análisis de los resultados se utilizaron las estrategias propuestas por la teoría fundamentada, facilitando el proceso de la interpretación de las categorías y emerger de descriptores. La investigación concluye como una propuesta en que los operadores turísticos duales incorporen oportunidades desde la innovación para la atracción de turistas a la localidad y al crecimiento económico para la provincia de Manabí.

Palabras clave: operadores turísticos duales, innovación, diferenciación.
Development of Integrated Media for Promoting of Thai Cuisine to Global Market
Authors: Kheerajit Cherdpong , Paisarnsombat Sarinya , Rampai Nattaphon , Sompong Narong
Published: August 2021

The research aims to develop suitable integrated media for public relations of Thai food innovations created under the research project Thai Food to Global Market. The sample group is 257 tourists. The research tools are 1) integrated media for public relations of Thai food to Global Market including website, video, mobile application, and AR publication, 2) media evaluation form for Thai food and public relations media expert, and 3) satisfactory survey of tourist on the integrated media. The results indicate that 1) quality of the integrated media developed under the research has met the standard with a Very Good score level evaluated by media experts, and 2) tourists are satisfied with the integrated media with the highest satisfactory level, in which online media and mobile application are the most satisfied media by tourists both in term of content presentation and its accessibility. The research also illustrated that the convergent media concept can be performed in order to enhance its accessibility and target of the media itself. The procedure used to develop the media in the researches has indicated a significant outcome suggested from the quality of the media and satisfactory level of the media receivers.
Development of Logistics Management and Relationship with Industry
Authors: Erdoğdu Mehmet
Published: August 2021

Today, the internet is in contact with everything in the world. Since it is impossible to think of production and logistics separately, Industry 4.0 is expected to redefine business processes in the logistics sector. The main purpose of the study; It is to reveal the innovations it will bring to the logistics sector by examining the Industry 4.0 revolution in detail, which contributes to the development of the logistics management This study, which was prepared as a conceptual framework, was supported by a survey study to raise awareness about the effects of Industry 4.0 on the logistics sector and to reveal a new perspective in terms of theory and practice. In the last 15 years, the transportation/transportation activities in the sector have been carried out with a more scientific and contemporary perspective, increasing the impact of logistics on transportation systems day by day and has started to play an important role in the development of Turkish foreign trade. The purpose of the study in your hand; The logistics sector, which has been developing rapidly, "Does the logistics performance of Turkey in the last 15 years, which has developed with the contribution of industry 4.0, digitalization and the internet, differ according to the descriptive characteristics of the participants and businesses?" and “How does Industry 4.0, digitalization and internet contribute to Turkey's logistics performance in the last 15 years? It is to reveal it by evaluating it with ANOVA analysis for searching the answers of the problem in the form.
You’ve Got Mail! – Written Communication and Feedback in Mathematics
Authors: Barbosa Ana , Vale Isabel
Published: August 2021

This paper describes a study that aims to understand and characterize the written communication of future teachers through a pen pal experience with elementary education students, in particular the nature of their feedback. To carry out this investigation we followed a qualitative methodology and collected data through observation, interviews and written productions. The participants were seven pre-service teachers that attended a Master’s Degree Course in Primary Education (6-12 years old) who interacted through letter correspondence with 3rd grade students. Results show that the pre-service teachers valued this experience, considering it useful and effective in the development of written communication. They also had the opportunity to identify the importance of more general aspects, such as the adequacy of the discourse, the need to acknowledge the curricular guidelines and the features of the educational context. The type of feedback given in the written commentaries was diversified, trying to meet the main characteristics of evaluative writing, being intentional, personalized and identifying aspects to improve through self-regulation.
Digital Humanities and Virtual Reality: A Review of Theories and Best Practices for Art History
Authors: Hutson James , Olsen Trent
Published: August 2021

The technology of virtual reality (VR) has had proven educational benefits over the last three decades. Yet, most research conducted on these benefits has been confined to the sciences, especially in Computer Science. The application of VR technology for the Digital Humanities is only now beginning to receive attention, but more study needs to be conducted on its uses within various humanistic disciplines. In order to expand on the research at a pivotal time in education when modalities expand to incorporate more hybrid, distance education, and online learning, this study reviews the literature and theories behind the educational use of VR as a tool to reinforce learning outcomes in the field of art history. Through the review, theories and best practices are presented for practical adoption at various level of instruction at other institutions, as well as a list of recommendations for integrating VR technology specifically within art history instruction.
Investigation of University Students’ Smartphone Usage Levels and Effects
Authors: Kaysi Feyzi , Yavuz Mehmet , Aydemir Emrah
Published: August 2021

Smartphones are among the most used devices. Considering the high rate of usage by university students, these devices' intended usage is a matter of curiosity. The purpose of this study is to determine the smartphones usage duration and purpose of using for university students. The study was carried out with a qualitative design. In the first stage of the study, smartphones' usage duration were obtained from 29 participants via a smartphone application. Considering these data, in the second stage, data were collected from seven participants via semi-structured interview form. Among the study results, it was determined that smartphones and smartphone applications were used extensively. Although this intensive usage causes on students' physical problems, there is no change in use intensity. According to the results, it was determined that the level of use of smartphones for following the educational processes or for improving learning is in the last place. Besides, problems were identified in students' participation in learning processes and focusing on lessons. The most used application types are messaging, social networks, video watching and editing, and game applications. Among the study's suggestions, reducing students' intensively usage and guiding students for using smartphone applications that support learning processes are stated.
A Dual-Band and Low-Cost Microstrip Patch Antenna for 5G Mobile Communications
Authors: Kaburcuk Fatih , Kalinay Gurkan , Chen Yiming , Elsherbeni Atef , Demir Veysel
Published: August 2021

This paper investigates the numerical and experimental analysis of a low-cost and dual-band microstrip patch antenna for the fifth generation (5G) mobile communications. The numerical analysis of the proposed antenna is performed using the computational
electromagnetic simulator (CEMS) software which is based on the finite-difference time-domain (FDTD) and CST software which is based on the finite integration technique (FIT). The performance of the proposed antenna designed and fabricated on a low-cost FR-4
substrate is verified with the simulated and measured results. The antenna operates at dual frequency bands which are 24 and 28 GHz. The antenna maximum gain values are 3.20 dBi and 3.99 dBi in the x-y plane at 24 and 28 GHz, respectively. The proposed antenna provides almost omni-directional patterns suitable for 5G mobile communication devices.
Vortex Beam Optimization Design of Concentric Uniform Circular Array Antenna with Improved Array Factor
Authors: Feng Qiang , Lin Yifeng , Zheng Yushan , Li Long
Published: August 2021

In this paper, an improved array factor of the concentric uniform circular array (CUCA) antenna is proposed for the orbital angular momentum (OAM) vortex beam optimization design. From the perspective of the radiation pattern’s power conservation principle, a
correction factor is introduced to the conventional array factor of CUCA. Then, based on the improved array factor, by adjusting the rings’ radii parameters of the CUCA, we optimize the vortex beam’s sidelobe level through the generic algorithm (GA). Two different CUCA antenna model are calculated as examples to further illustrate the effectiveness of the improved array factor. Subsequently, an electromagnetic simulation
model of two rings CUCA antenna is built at C band for generating low sidelobe vortex beam carrying OAM mode. The electromagnetic simulation model of the designed CUCA antenna is also fabricated and measured. The corresponding antenna far-field vortex
beam radiation pattern and near-field vortex wave electric field distributions are measured. The simulation results and the measurement results are in good agreement. The proposed designs of antenna and OAM vortex beam regulation are expected to be used for 5G and 6G communications applications
Reflectarray Resonant Element based on a Dielectric Resonator Antenna for 5G Applications
Authors: Sallehuddin Nur , Jamaluddin Mohd , Kamarudin Muhammad , Dahri Muhammad
Published: August 2021

The performance of a proposed cross hybrid dielectric resonator antenna (DRA) element for dual polarization configuration operating at 26 GHz for 5G applications is presented in this paper. The new cross hybrid DRA unit cell is introduced which combines a cross shape DRA with a bottom loading cross microstrip patch. This technique of a bottom loading cross microstrip patch is chosen as the tuning mechanism (varying the length of the microstrip to tune the phase) instead of changing the DRA dimensions because of
their ease of implementation and fabrication. By doing so, high reflection phase range with low reflection loss performance can be obtained, which is essential for a high bandwidth and high gain reflectarray for 5G applications. The design and simulation have been done using commercial software of CST MWS. The reflection loss, reflection phase and slope variation were analyzed and compared. A metallic cross microstrip patch of varying length placed beneath the DRA to act as the phase shifter to tune the phase and give smooth variation in slope with a large phase range. The proposed cross
hybrid DRA unit cell provides a high reflection phase range of 342º and 1.8 dB reflection loss. The computed results are compared with experimental results revealing
reasonable agreement, thereby confirming the viability of the design.
Design of W-band PIN Diode SPDT Switch with Low Loss
Authors: Jiang Yun , Ye Yuan , Li Daotong , Huang Zhaoyu , Wang Chao , Huang Jingjian , Yuan Naichang
Published: August 2021

A W-band PIN diode single pole double throw (SPDT) switch with low insertion loss (IL) was successfully developed using a hybrid integration circuit (HIC) of microstrip and coplanar waveguide (CPW) in this paper. In order to achieve low loss of the SPDT switch, the beam-lead PIN diode 3D simulation model was accurately established in Ansys High Frequency Structure Simulator (HFSS) and the W-band H-plane waveguide-microstrip transition was realized based on the principle of the magnetic field coupling. The key of the proposed method is to design the H-plane waveguide-microstrip transition, it not only realizes the low IL of the SPDT switch, but also the direct current (DC) bias of the PIN diode can be better grounded. In order to validate the proposed design method, a W-band PIN diode SPDT switch is fabricated and measured. The measurement results show that the IL of the SPDT switch is less than 2 dB in the frequency range of 85 to 95 GHz, while the isolation of the SPDT switch is greater than 15 dB in the frequency range of 89.5 to 94 GHz. In the frequency range of 92 to 93 GHz, the IL of the SPDT switch is less than 1.65 dB, and its isolation is higher than 22 dB. Switch rise time and switch fall time of the SPDT switch are smaller than 29ns and 19ns, respectively. Good agreement between the simulations and measurements validates the design method.
Ultra-wideband Transmissive Linear Polarization Device Based on Graphene
Authors: Guo Liwei , Li Simin , Jiang Xing , Liao Xin , Peng Lin
Published: August 2021

In order to achieve both adjustable wideband and high Polarization Conversion Rate (PCR) of the transmitted waves, a novelty tri-layered structure is proposed for terahertz applications. The Rhombus Hollow Square (RHS) is built up by top and bottom gold gratings on Silicon Dioxide and Polyamide substrate with graphene strips. The proposed polarizer broadens the bandwidth and has well performance. As chemical potential increases, the bandwidth is also broadened by adjusting the graphene. From 0.5 THz to 3 THz, the PCR is greater than 90%, and the relative bandwidth up to 142.9%. The transmission and absorption of polarizer are analyzed at the oblique incidence with chemical potential 0.1eV. By simulating and analyzing the performance, a new result of maintaining broadband and high transmittance in oblique incidence is obtained.
Fast Analysis of Broadband Electromagnetic Scattering Characteristics of Electrically Large Targets using Precorrected Fast Fourier Transform Algorithm based on Near Field Matrix Interpolation Method
Authors: Kong Wei , Yang Xiao , Zhou Feng , Xie Jia , Chen Chuan , Li Na , Yang Wen
Published: August 2021

In this paper, a new method is proposed to analyze the broadband electromagnetic characteristics of electrically large targets by combining the precorrected-FFT algorithm (P-FFT) with the near-field matrix interpolation technique. The proposed method uses the
precorrected-FFT algorithm to reduce the storage and accelerate the matrix vector product of the far field. In order to make the precorrected-FFT algorithm can calculate the broadband characteristics of electrically large targets more quickly, the matrix interpolation method is used to interpolate the near-field matrix of the precorrected-FFT algorithm to improve the efficiency of calculation. The numerical results obtained validate
the proposed method and its implementation in terms of accuracy and runtime performance.
EFFECTS OF NITROGEN AND ZINC TREATMENTS AT DIFFERENT DOSES ON MAIZE YIELD AND YIELD COMPONENTS UNDER KAHRAMANMARAŞ CONDITIONS
Authors: Yururdurmaz Cengiz , Turan Ali
Published: August 2021

This study was carried out in 2019 in Kahramanmaraş University Field Crops Department to determine nitrogen and zinc fertilizer needs of maize plants in Kahramanmaraş Region. Experiments were conducted in split-plots design with 3 replications. Soil nitrogenous fertilizer (Urea) treatments were arranged as: 0 kg/da (N0), 15 kg/da (N15), 30 kg/da (N30). Foliar zinc treatments were arranged as 0 ppm (Zn0), 2500 ppm (Zn5), 5000 ppm (Zn10). Dekalp DKC6890 hybrid maize variety was used as the plant material of the experiments. Present findings revealed that nitrogen and zinc treatments had significant effects on the first cob height, cob length, cob thickness, number of rows per cob, number of kernels per cob and kernel yield of maize plants, but the effects of nitrogen and zinc treatments on plant height and thousand kernel weight were not found to be significant.
Rekreatif amaçlı dağcılık ve doğa sporları yapan bireylerin COVID-19 fobilerine yönelik tutumları
Authors: Karaca Yasin , Can Kalaycı Metin
Published: August 2021

Amaç: Bu araştırmada, rekreatif amaçlı dağcılık ve doğa sporu yapan bireylerin COVID-19 fobilerinin cinsiyet, medeni durum, maske takma durumu, yakınlarına COVID-19 tanısı konulması ve COVID-19'a ilişkin bilgilendirme ve haberleri izleme durumlarına göre incelenmesi amaçlandı.

Gereç ve Yöntem: Araştırmada genel tarama modeli kullanıldı. Veri grubunu X kentinde yaşayan, uygun örnekleme yöntemine göre seçilmiş gönüllü 123 rekreatif amaçlı dağcılık ve doğa sporu yapan bireyler oluşturdu. Araştırmada "COVID-19 Fobisi ölçeği" kullanıldı. Araştırmanın veri analizinde, betimsel istatistik için frekans ve yüzde analizi; ilişkisiz ölçümlerde ortalama puanların karşılaştırılması için Varyans analizi (One-way ANOVA, bağımsız örneklem t-testi), anlamlı farklılığın hangi gruplar arasında olduğunu belirlemek için Tukey testi kullanıldı.

Bulgular: Araştırma sonucunda rekreatif amaçlı dağcılık ve doğa sporu yapan bireylerin COVID-19 fobilerinin cinsiyet, medeni durum, maske takma, yakınlarına COVID-19 teşhisi konulması, COVID-19'a ilişkin bilgilendirmeler ve haberleri takip etme durumlarına göre anlamlı farklılıklar gösterdiği saptandı.

Sonuç: COVID-19 kaynaklı stres, korku ve tedirginliğin araştırmaya katılan bireylerde çeşitli fobilere neden olduğu belirlendi.