bluuebunny/crossref_metadata_2025 huggingface dataset:
RELATIONSHIP AMONG LIFE SATISFACTION, SELF-ESTEEM, AND ACADEMIC PERFORMANCE OF UNIVERSITY STUDENTS IN PAKISTAN
Authors: Perveen Shahnaz , Ikram Hamid , Nisa Qamar Un
Published: May 2021

Abstract

Purpose of the study: This research study explores the relationship between life satisfaction, self-esteem, and academic performance of university students.

Methodology: A quantitative approach was used to explore the relationship among life satisfaction, self-esteem, and academic performance of university students. In this study, a survey method was employed to collect quantitative data on life satisfaction, self-esteem, and academic performance from 575 students studying in three different public universities of Punjab (Pakistan). A self-esteem scale as a survey instrument initially developed by Rosenberg (1965) and a life satisfaction scale developed by Gilligan and Huebner (2002) were used to collect data. A third scale was developed by the researchers to measure the students’ academic performance. The assembled data were statistically examined using descriptive statistics and Pearson correlation by using SPSS 20th Version.

Results: Findings of the study reveal that the level of life satisfaction among university students is comparatively higher than the presence of self-esteem and academic performance. Findings of the study show significant positive associations of university students’ academic performance with their life satisfaction and self-esteem.

Applications of this study: This study helps strengthen the factors that promote university students’ academic performance.

Novelty/Originality of this study: The novelty of this study is to explore the relationship among life satisfaction, self-esteem, and academic performance of university students for strengthening different dimensions of life satisfaction and self-esteem which ultimately promote university students’ academic performance.
RELIGIOUS OBLIGATIONS AND MORAL DILEMMAS: A FEMINISTIC PERSPECTIVE OF IBSEN’S PLAY A DOLL’S HOUSE
Authors: Jaffar Nosheen , Rashid Aniqa , Asghar Ijaz
Published: May 2021

Purpose of the Study: This research paper attempts to examine the play A Doll’s House through the perspective of challenges faced by the protagonist against moral authority and censorship and her resilience in the face of difficulties.

Methodology: The research paper proposes to make use of the secondary data including related articles and web sources. The data collected are words, phrases, clauses, and sentences related to women's problems and their struggles found in the play.

Main Findings: Nora revolts against male-formulated social structure repressing women in the name of religion, conventions, and breaks the framework set up by men and she dashes for a liberated life. The finding of the study is that through the play, we learn how important the interplay of religion and free spirit is to Nora’s evolution.

Applications: This paper can be used by literary scholars and students.

Novelty/Originality of this study: This research paper has used the contrasting forces of moral obligation and the free spirit of Nora to see how they have helped Nora to come out from a rosy-colored view of her dream world. The present study demonstrates how the protagonist feels entrapped and suffocated in her home, forced to live a life of false hope due to the impositions placed on by her husband and the patriarchal society which resultantly creates a feeling of isolation.
Retractions and post-retraction citations in the COVID-19 infodemic: is Academia spreading misinformation?
Authors: Santos-d'Amorim Karen , Ribeiro de Melo Rinaldo , Nonato Macedo dos Santos Raimundo
Published: May 2021

The speed in producing information and the rush to publish scientific articles on COVID-19 in several knowledge areas have resulted in what is known as an infodemic also in the scientific field, potentially producing inaccurate information and sources of misinformation at scholarly communication. This has led to some articles being retracted or withdrawn due to unintentional errors or deliberate misconduct, but they continue to be cited. This article (i) gives an overview of the COVID-19 retracted articles and preprints, and (ii) analyses a set of post-retraction citations in the context of the COVID-19 infodemic. We analyzed 56 retracted articles and preprints by using the list available in the section on “retracted coronavirus (COVID-19) papers” in the Retraction Watch (RW) webpage. We found that 64.3% of these retractions were articles published in journals, 33.9% were uploaded in preprints servers, and 1.8% conference papers. We also analyzed 162 eligible articles out of 612 records identified by using the Google Scholar search engine. This research found that an article from The Lancet continued to be cited even after being retracted. In this case, we identified 214 post-retraction citations, of which 38% were negative (n=81), 32% were neutral (n=69), and 30% were positive citations (n=64)
Consumer Behaviour during Pandemic of COVID-19
Authors: Svajdova Lenka
Published: May 2021

Knowledge of consumer behaviour is an important factor in the success of companies. Knowing how the consumer behaves and what factors influence him enables companies to manage the marketing mix, branding and communication more effectively with customers. Identifying the factors that affect consumers is sometimes very difficult to identify correctly, because very often they are internal factors.The current situation currently prevailing in global markets is mainly influenced by external factors – the COVID-19 pandemic and the effects of political and legislative steps and the economic situation. That is, the factors that both customers and retailers had to adapt to. The author aims to identify changes in consumer behaviour when buying basic products – food, drugstore goods, clothing and footwear and electronics during the pandemic of COVID-19. The aim of this article is based on analysis of primary, secondary data and marketing survey to identify changes in consumer behaviour because of political, legislative, and economic factors caused by the spread of illness COVID-19. The result will be the evaluation of changings in consumer behaviour because of the pandemic of COVID-19.
Miejsce jako czynnik sprawczy w twórczości Gustawa Herlinga-Grudzińskiego (na przykładzie opowiadania Most. Z kroniki naszego miasta)
Authors: Sobota Katarzyna
Published: May 2021

Niniejszy artykuł porusza problem relacji między bohaterem a miejscem w twórczości Gustawa Herlinga-Grudzińskiego na przykładzie opowiadania Most. Z kroniki naszego miasta (1963). Autorka stawia tezę, że miejsca pojawiające się na kartach dzieł pisarza pełnią funkcję czynnika sprawczego wobec postaw, decyzji i zachowania postaci. Omawiane zagadnienie wpisuje się w zakres proponowanej w artykule nowej perspektywy badań nad dorobkiem autora Innego Świata. Opiera się ona na założeniach geopoetyki i ukazuje dokonania literackie pisarza przez pryzmat miejsca, rozumianego zarówno w wymiarze geograficznym, jak i literackim. W toku analizy i interpretacji opowiadania Herlinga-Grudzińskiego starano się wykazać, że tytułowy Most oddziałuje na los, zachowanie i postawę głównego bohatera. Część analityczną artykułu poprzedza prezentacja stanu badań nad problematyką przestrzeni w twórczości pisarza, szkic biograficzny autora Mostu uwzględniający jego doświadczenia związane z miejscami oraz krótka charakterystyka geopoetyki jako perspektywy badawczej, która, zdaniem autorki, umożliwi wydobycie nowych treści z niepowtarzalnego w literaturze polskiej dorobku współtwórcy paryskiej „Kultury”.
Clinical Signs, Activity Indices and Prognostic Indicators in Dogs with Idiopathic Inflammatory Bowel Disease
Authors: Bhavani M. Sandhya , Kavitha S. , Vairamuthu S. , Vijayarani K. , Bhat Abid Ali
Published: May 2021

Background: Canine inflammatory bowel disease (IBD) includes a set of diseases characterized by the presence of recurrent gastrointestinal clinical signs and histologic evidence of intestinal inflammation. Diagnosis can only be made by excluding other possible causes of enteritis. Since the diagnosis of this disease is of great challenge to the veterinarians and currently very little work have been carried out in India, the present study was planned and conducted to study the clinicopathological changes and prognostic indicators of idiopathic inflammatory bowel disease (IBD) in dogs. Methods: After a detailed clinical, laboratoty and endoscopic examination, 33 IBD dogs with signs of chronic gastrointestinal disorders and histologic evidence of mucosal lymphocytic plasmacytic infiltration were selected for the study. Result: Moderate to severe form of IBD with haematochezia as a chief complaint was predominantly recorded. Haematobiochemical changes were not remarkable except a rise in serum alkaline phosphatase level. Decreased IgA expression was observed in serum by flowcytometry indicating impaired mucosal immunity in IBD dogs. It was observed that, increased clinical inflammatory bowel disease activity index score (CIBDAI), increased C-Reactive Protein, decreased cobalamin and folate may act as negative predictors in idiopathic IBD.
In-depth Pedigree Analysis and Inbreeding Effect on Reproduction Traits in Sahiwal Nucleus Herd
Authors: Mumtaz Shabahat , Mukherjee Anupama , Pathak Prajwalita , Parveen Kaiser
Published: May 2021

Background: Loss of genetic diversity is allied with adverse incidents such as inbreeding depression in fitness related traits, addiction of favorable alleles and enhances fluctuation on selection response. Therefore, the study aims to monitor population structure and avoid unfavorable effects of inbreeding for sustainable improvement in breeding programme. Methods: Pedigree information on 3449 animals born from 1955-2018 was analyzed. The effect on inbreeding on Age at first calving (AFC), Service period (SP), Daughter pregnancy rate (DPR), Calving interval (CI) and pregnancy rate was seen by regression analysis. Result: The pedigree completeness index (PCI) were found to be (%) 92.32, 80.26, 65.22, 49.43% and 32.54 respectively from first to fifth generations. The estimated average inbreeding rate was 2.30% and average genetic diversity loss was 2.64%. Study also revealed significant effect of inbreeding on (AFC, CI and SP) with slightly increasing trends. Hence, it is suggested that more precise pedigree recording and planned mating strategies should be adopted to avoid negative effect of inbreeding in future generation.
Influence of Plant Growth Promoting Rhizobium on Growth of Pigeon Pea [Cajanus cajan (L.) Millsp.]
Authors: Harshitha H.A. , Goudar Geeta
Published: May 2021

Background: Symbiotic nitrogen fixation plays a major role in the production of million tons of total biological nitrogen. The Rhizobium not only fixes the nitrogen but also produces plant growth promoting hormones. In this view, the present study was undertaken to characterize the native Rhizobium isolates for their functional properties and evaluate on pigeon pea for their plant growth promotional activities. Methods: The present investigation was carried out during the year 2018-19 at UAS, Dharwad. Five of the native isolates obtained from Northern district of Karnataka were subjected for functional characterization using standard methods. The isolates were also tested for their plant growth promotional activities. Result: The IAA production in the isolates was ranged from 20.50 to 22.85 mg IAA/ml of broth and GA production from 13.40 to 14.51 mg/25ml of broth. ACC deamination activity in the isolates was ranged from 57.50 to 75.5 nmoles of α-ketobutyrate/mg/h of broth. All the isolates exhibited their ability to solubilize P and Zn. Out of ten isolates, four isolates exhibited potential to inhibit mycelial growth of Fusarium oxysporum f. sp. udum and per cent inhibition was ranged from 48.75 to 73.75. All the isolates were found to be positive for siderophore and HCN production. The isolate AMVPR98 performed better with respect to all the growth parameters of pigeon pea. Molecular characterization of isolate AMVPR98 revealed 99% similarity with Rhizobium pusense strain AB3.
Comparison of color difference and reliability of two intraoral spectrophotometers
Authors: Al-Haj Ali Sanaa N. , Farah Ra'fat I, , Aldhefeeri Abdullah , Alduraibi Ibrahim
Published: May 2021

Aim: to evaluate the intra and inter-device reliability of two intraoral spectrophotometers in measuring the Commission Internationale de l’Éclairage (CIE) L*a*b* color coordinates and to compare the color difference (ΔE) between both devices. Methods: the central region of the labial surface of the maxillary central incisor of 31 participants was measured twice by each of the devices (VITA EasyShade and Degudent Shadepilot) by one examiner. CIE L*a*b* color coordinates were obtained for all teeth and ΔE was measured and compared. Intraclass correlation coefficient (ICC) and Mann-whitney U test were used to analyze the data (p<0.05). Results: inter-device reliability ICCs in measuring CIE L*a*b* color coordinates ranged between 0.08-0.49 with significant difference between devices only concerning the b coordinate (p<0.05). While intra device reliability ICCs ranged between 0.86-0.89 for VITA EasyShade and 0.81-0.86 for Degudent Shadepilot. The mean ΔE for CIE L*a*b* color coordinates of VITA EasyShade was 3.61 (±1.93) compared to 3.60 (± 1.45) for Degudent Shadepilot with insignificant difference between both devices (p>0.05). Conclusions: high intra device reliability in measuring CIE L*a*b* color coordinates was achieved particularly of Vita EasyShade, and both devices had clinically acceptable color difference (ΔE <3.7) however, inter device reliability was low to moderate. Consequently, the same spectrophotometer should be used throughout the steps of performing any tooth- colored restoration.
Investment Modelling Using Value at Risk Bayesian Mixture Modelling Approach and Backtesting to Assess Stock Risk
Authors: Miftahurrohmah Brina , Wulandari Catur , Dharmawan Yogantara Setya
Published: May 2021

Background: Stock investment has been gaining momentum in the past years due to the development of technology. During the pandemic lockdown, people have invested more. One the one hand, stock investment has high potential profitability, but on the other, it is equally risky. Therefore, a value at risk (VaR) analysis is needed. One approach to calculate VaR is by using the Bayesian mixture model, which has been proven to be able to overcome heavy-tailed cases. Then, the VaR’s accuracy needs to be tested, and one of the ways is by using backtesting, such as the Kupiec test.Objective: This study aims to determine the VaR model of PT NFC Indonesia Tbk (NFCX) return data using Bayesian mixture modelling and backtesting. On a practical level, this study can provide information about the potential risks of investing that is grounded in empirical evidence.Methods: The data used was NFCX data retrieved from Yahoo Finance, which was then modelled with a mixture model based on the normal and Laplace distributions. After that, the VaR accuracy was calculated and then tested by using backtesting.Results: The test results showed that the VaR with the mixture Laplace autoregressive (MLAR) approach (2;[2],[4]) was accurate at 5% and 1% quantiles while mixture normal autoregressive MNAR (2;[2],[2,4]) was only accurate at 5% quantiles.Conclusion: The better performing NFCX VaR model for this study based on backtesting using Kupiec test is MLAR(2;[2],[4]).
Causal Modeling Between Factors on Quality of Life in Cancer Patients Using S3C-Latent Algorithm
Authors: Nur Yohani Setiya Rafika , Rahmadi Ridho , Effendy Christantie
Published: May 2021

Background: Cancer patients can experience both physical and non-physical problems such as psychosocial, spiritual, and emotional problems, which impact the quality of life. Previous studies on quality of life mostly have employed multivariate analyses. To our knowledge, no studies have focused yet on the underlying causal relationship between factors representing the quality of life of cancer patients, which is very important when attempting to improve the quality of life.  Objective: The study aims to model the causal relationships between the factors that represent cancer and quality of life.Methods: This study uses the S3C-Latent method to estimate the causal model relationships between the factors. The S3C-Latent method combines Structural Equation Model (SEM), a multi objective optimization method, and the stability selection approach, to estimate a stable and parsimonious causal model.Results: There are nine causal relations that have been found, i.e., from physical to global health with a reliability score of 0.73, to performance status with a reliability score of 1, from emotional to global health with a reliability score of 0.71, to performance status with a reliability score of 0.82, from nausea, loss of appetite, dyspnea, insomnia, loss of appetite and from constipation to performance status with reliability scores of 0.76; 1; 0.61; 0.76; 0.72; 0.70, respectively. Moreover, this study found that 15 associations (strong relation where the causal direction cannot be determined from the data alone) between factors with reliability scores range from 0.65 to 1.Conclusion: The estimated model is consistent with the results shown in previous studies. The model is expected to provide evidence-based recommendation for health care providers in designing strategies to increase cancer patients’ life quality. For future research, we suggest studies to include more variables in the model to capture a broader view to the problem.
The Effect of DevOps Implementation on Teamwork Quality in Software Development
Authors: Hermawan Ady , Manik Lindung Parningotan
Published: May 2021

Background: The Agile method, which is claimed to reduce time needed for software development cycle has been widely used. It addresses communication gaps between customers and developers. Today, the DevOps has been extended as part of the Agile process to address communication gaps between developer’s team members. Despite the rising popularity, the effect of DevOps implementation on the teamwork quality in software development is still unknown.Objective: The objective of this research is to conduct a study on the impact of DevOps on teamwork quality. Two software houses, PT X and PT Y, are chosen as the case studies.Methods: This research uses quantitative methods to analyse research data using simple linear regression. The questionnaire technique is used to retrieve respondent data using 62 questions, consisting of 20 DevOps questions from 4 indicators and 42 teamwork quality questions from 6 indicators.Results: The results from various quality tests indicate that all instruments are valid and reliable while hypothesis tests showed that the DevOps implementation variable has an influence on the teamwork quality variable by 75.6%.Conclusion: It can be concluded that the implementation of the DevOps in software development has a positive correlation with the teamwork quality.
INCREASING THE EFFICIENCY OF BLASTING WORKS IN THE QUARRY OF BUILDING MATERIALS
Authors: KOZLOV Sergiy , TERENTIEV Oleg , SERGIENKO Mykola
Published: May 2021

The article is devoted to the urgent problem of increasing the efficiency of blasting operations in open pits in conditions of high water saturation of minerals.

The idea of solving this problem is to use the effect of draining the local area of the water-saturated block of the mineral due to the ordinal explosion of the well charge.  

The purpose of this study was to improve the efficiency of blasting operations on flooded fractured rocks in open pit mining.

Research methodology. The proposed technique makes it possible to determine the parameters of drainage of the watered mass during the explosion of borehole charges and the parameters of an ordinal explosion. This makes it possible to improve the quality of rock crushing and reduce the consumption of explosives per unit cost.

The main direction of research in this work is to reduce the energy intensity of the process of destruction of a water-saturated mineral by using the internal potential of water in the cracks of the massif destroyed by the explosion. The regularities and the role of the drainage funnel in the efficiency of destruction have been established.

The novelty and originality of the work is a developed technology for removing water from the explosion zone, which increases the efficiency of explosion and destruction of rocks using special water-resistant explosives.

The practical value of the work lies in the effectiveness of the proposed method for carrying out blasting operations, which, along with improving the quality of crushing, provides an increase in the output of blasted rock mass from one running meter of the well and reduces the cost of expensive water-resistant explosives.

Conclusions. The introduction of research results and recommendations in open pits made it possible to increase the efficiency of blasting operations in the development of water-saturated rocks. Energy consumption for the destruction of an array of water-saturated minerals is reduced by 10%. The amount of blasted rock mass per running meter of the well increased by 14.1%, and the specific consumption of explosives decreased by (12-14) %.      

 

Keywords: quarry, minerals, well, filtration, water-saturated massif, crushing, explosive,  detonation.
Family rural economy - the development factor of rural tourism in Istria
Authors: Oplanić Milan , Milotić Aldo , Ružić Pavlo
Published: May 2021

In this paper under the title Family Rural Economy- The Development Factor of Rural Tourism in Istria, the family rural economy takes a key role in the development function of rural tourism forms. The necessary data are collected with the method of surveys, and they represent the average family rural economy of Istria, with its material and productive human resources and also with the attitudes and interests of agriculturists about the development of rural-tourism forms. The results of the surveys show that the family rural economy of Istria with its accommodation capacities, human and other resources is a good foundation for development of different rural economy tourism, especially tourism of family rural economy, in the villages of Istria, rural, natural and historical localities. The purpose of this paper is to recognize the possibilities and initiatives for rural tourism development in Istria. This could enrich the tourist supply with new forms suitable for the environment of Istrian villages and family rural economy's resources.
Umweltorientiertes Tourismusmanagement durch die objektive Öko-Kennzeichnung (das Verfahren für die objektive Öko-Kennzeichnung)
Authors: Mihalič Tanja
Published: May 2021

Die natürlichen, kulturellen und sozialen Atraktivitäeten der Tourismusdestination stellen die Anziehungskraft für die touristische Nachfrage dar. Deswegen ist die Umwelttourismusmanagement eine Notwendigkeit für erfolgreiche Tourismus-betriebswirtschaft. Es geht um eine Verstärkung ökologisch orientierten Denkens und Handels, die durch verschiedene Formen erfolgen kann. Ökologische Kennzeichnung stellt eine Möglichkeit dar. Die Autorin unterscheidet drei Arten der Umweltkennzeichnung (Umweltzeichen, Umweltgütezeichen, kombinierte Umweltkennzeichnung). Wesentlich für die Objektivität der Ökokennzeichnung ist die Objektivität der Vergabe. Das objektive Verfahren für Ökokennzeichungvergabe ist vorgeschlagen und am Beispiel der Blauen Flagge dargestellt. Es wird zwischen objektiven und subjektiven (Quasi) öko-Kennzeichen unterschieden.
Carbon, Nitrogen Dynamics and CO2 Efflux in the Calcareous Sandy Loam Soil Treated with Chemically Modified Organic Amendments
Authors: Mohammed-Nour Ahmed , Al-Sewailem Mohamed , El-Naggar Ahmed H. , Hamza Mohamed , Aly Anwar A. , Elfaki Jamal
Published: May 2021

Although carbon (C) efflux from soils treated with organic wastes was widely covered in temperate and cold regions, still such data is not sufficient from arid and semi-arid regions. Saudi Arabia produces more than 335,000 tons/year of cow manure (CM), this CM either left as raw manure or being composted. The application of high C/N amendments is expected to increase soil organic carbon and reduce CO2 fluxes. A 90-day incubation experiment was conducted to study CO2 efflux, organic C microbial biomass C, available NH4+and NO3-when added to agricultural soil. Six manure types were added: cow manure, cow manure compost, cow manure biochar, cow manure stripped ammonia at pH 12 with a temperature of 95oC, cow manure stripped ammonia at pH 9 with a temperature of 95oC and control. The application of CM resulted in a considerable increase in soil available nitrogen, CO2 efflux compared to other treatments. Cow manure biochar showed the lowest CO2 efflux. Cumulative CO2 effluxes of cow manure effluents were lower than CM this possibly due to the relatively high C:N ratio of manure effluent. The content of, P, Fe, Cu, Zn and Mn were decreased as incubation time increased. microbial biomass C of cow manure stripped ammonia at pH 12 with a temperature of 95oC were increased at 7 and 60 days illustrating to temperature effect on the decomposing of manure materials.
Body Mass Index and Birth Weight Improve Polygenic Risk Score for Type 2 Diabetes
Authors: Moldovan Avigail , Waldman Yedael Y. , Brandes Nadav , Linial Michal
Published: May 2021

One of the major challenges in the post-genomic era is elucidating the genetic basis of human diseases. In recent years, studies have shown that polygenic risk scores (PRS), based on aggregated information from millions of variants across the human genome, can estimate individual risk for common diseases. In practice, the current medical practice still predominantly relies on physiological and clinical indicators to assess personal disease risk. For example, caregivers mark individuals with high body mass index (BMI) as having an increased risk to develop type 2 diabetes (T2D). An important question is whether combining PRS with clinical metrics can increase the power of disease prediction in particular from early life. In this work we examined this question, focusing on T2D. We show that an integrated approach combining adult BMI and PRS achieves considerably better prediction than each of the measures on unrelated Caucasians in the UK Biobank (UKB, n=290,584). Likewise, integrating PRS with self-reports on birth weight (n=172,239) and comparative body size at age ten (n=287,203) also substantially enhance prediction as compared to each of its components. While the integration of PRS with BMI achieved better results as compared to the other measurements, the latter are early-life measurements that can be integrated already at childhood, to allow preemptive intervention for those at high risk to develop T2D. Our integrated approach can be easily generalized to other diseases, with the relevant early-life measurements.
Do Remittances Affect Politics in Bangladesh?
Authors: Hassan Gazi Mainul , Rahman Shafiqur
Published: May 2021

This paper examines how remittances contribute to the democratisation process in Bangladesh. The endogeneity issue between remittances and democracy is tackled by employing the Structural VAR (SVAR) approach. It is found that while remittances respond to innovations in the macro-political variables, remittances also have important impact on these variables. Our results build a synergy between two opposing findings in the politics literature where on one hand remittances flows stabilise autocracies, while on the other hand they foster the prospect for democratisation. In particular, we demonstrate that a shock in remittances flows will have a negative but transitory impact on democracy. Initially there will be a bout of autocratic episodes which will be eventually eliminated and democracy will be restored to its original level in three to five years. However, using an alternative measure for democracy with the aid of principal-component analysis, we find that after the fifth year following a shock in remittances flows, a small but positive permanent effect on democracy is observable that do not revert to zero at end of the ten period horizon.
Mathematical Modelling for the Transmission Dynamics of blinding Trachoma
Authors: Muhammad Salisu Muhammad , Hincal Evren
Published: May 2021

Trachsummaroma is an eye infectious disease caused by Chlamydia Trachomatis bacterium, which may lead to irreversible blindness. The disease is spread directly or indirectly by contacting a contaminated material. It can also be transmitted through the disease vector known as “Musca sorbens” or “Bazaar fly”. To curtail the spread of the disease in a population, a meaningful information on the spread and possible control of the disease is required. Mathematical modeling provides efficient tools that can be used to understand and analyze the dynamics of the disease and its control. Several compartmental epidemic models have been proposed in the literature to study the dynamics of trachoma; including SI, SIR and SEIR. However, majority of the existing trachoma models consider only person to person transmission. Thus, the information provided by such models is insufficient since they did not capture the disease vector transmission. The current study proposed a novel SEIR-SEI model that consider both person-person and vector transmission dynamics. The threshold quantity, basic reproduction number R0 is obtained using the next generation matrix, and it was proved that the disease-free equilibrium is asymptotically stable when R0 < 1, and the endemic equilibrium is globally asymptotically stable when R0 > 1. Some simulation results with the aid of mesh plots for the reproductive number as a function of two different biological parameters were obtained. Furthermore, a comprehensive sensitivity analysis is conducted to identify the influence of the individual parameters on the R0. Numerical results show that the vector contact rate has the highest sensitivity with respect to R0, and the value of R0 increases with increase in, hence, the disease can be controlled by decreasing the vector contact rate. Similarly, improving the rate of environmental hygiene and facial cleanliness will decrease the size of R0 and result in the declination of the disease transmission. Moreover, a detailed parameter estimation of the model parameters and model fitting was presented with the use of field data cases from Northern Nigeria using least-square fitting method.

The study provides alternative tools that can be used for planning trachoma control program to achieve global eradication of trachoma as a public heath challenge as targeted by WHO in 2030.
Calculation of the Flux Density Function for Protein Crystals from Small Scale Settling and Filtration Experiments
Authors: Radel Benjamin , Nguyen Tu Hoang , Nirschl Hermann
Published: May 2021

Development and engineering of protein crystals regarding mechanical stability and crystallizability occurs on a small scale. Later in the process chain of industrial production however, filtration properties are important to separate the crystals from mother liquor. Many protein crystals are sensitive to mechanical stress which is why it is important to know the filtration behavior early on. In this study we analyze settling and filtration behavior of isometric, rod-like and needle shaped lysozyme and rod-like alcohol dehydrogenase (ADH) crystals on a small scale using an optical analytical centrifuge. Needle shaped lysozyme and rod-like ADH crystals show compressible material behavior. With the results from settling and filtration experiments the flux density function is calculated and modeled which can be used to describe the whole settling and permeation process in dependency of the solids volume fraction. This is also an issue for simulations of industrial processes.
M87 Supermassive Black Hole Review
Authors: Ganguly Mekhala
Published: May 2021

M87 is a giant elliptical galaxy in the Virgo cluster of galaxies. The radio source has a core which coincides with the nucleus of the galaxy and a jet of emission which is detected from radio to X-ray bands. A supermassive black hole is assumed to be at the centre of M87 which sends out relativistic particles in the form jets along its axis of rotation. Relativistic particles accelerated in a magnetic field, give out synchrotron radiation. The centre is surrounded by an accretion disc, which is the closest that we can probe into a black hole. High resolution observations are needed to examine the nature of the radio emission closest to the centre of M87. An array of millimetre-band telescopes across the globe were used as an interferometer, called the Event Horizon Telescope, (EHT) to probe the nuclear region. The angular resolution of this interferometer array is 25 microarc sec, at a wavelength of 1.3mm and the data was carefully calibrated and imaged. The resulting image shows an asymmetric ring which is consistent with the predictions of strong gravitational lensing of synchrotron emission from hot plasma near the event horizon. In this paper, we review the results of the observations of the radio galaxy, M87, using the Event Horizon Telescope
3x + 1 Problem: Iterative Operations Neither Cause Loops nor Diverge to Infinity
Authors: Jiang Li
Published: May 2021

The 3x+1 problem is a problem of continuous iteration for integers. According to the basic theorem of arithmetic and the way of iteration, we derive a general formula for continuous iteration for odd integers. Through this formula, we can construct a loop iteration equation and obtain the result of the equation: the equation has only one positive integer solution. In addition, this general formula can be converted into a linear indeterminate equation. The process of solving this equation shows that the relationship between the iteration result and the odd number being iterated is linear. Extending this result to all positive even numbers, we get the answer to the 3x + 1 question.
Espacio, acción colectiva e identidad: la Vocacional 7 del Instituto Politécnico Nacional durante el movimiento estudiantil de 1968
Authors: Kuri Pineda Edith Elvira
Published: May 2021

El movimiento estudiantil de 1968 fue producto de una red de alianzas sociopolíticas entre estudiantes de universidades públicas y privadas en México. En este artículo se analizará, desde la sociología de los movimientos sociales y la geografía política y la cultural, cómo se construyó la movilización colectiva en la Vocacional 7, del Instituto Politécnico Nacional; de qué forma se cristalizó el vínculo entre acción colectiva, identidad y espacio; las formas de apropiación material, política y simbólica del mismo, así como qué representa esta escuela para algunos de sus exestudiantes. Para ello, fueron aplicadas dieciocho entrevistas a profundidad a exalumnos de la Vocacional, participantes en este actor colectivo, además de mapas mentales. Como se verá, el espacio fue un recurso de movilización importante, amén de ser un factor que formaba parte de la identidad colectiva.
El general Ángel Flores y el apoyo de los católicos para su campaña a la presidencia de la República en 1924
Authors: González Morfín Juan
Published: May 2021

En 1923, un grupo de católicos promovió la candidatura a la presidencia de la República del general Ángel Flores, revolucionario, con un papel destacado en la política regional y amigo del presidente Álvaro Obregón. Su contendiente era el general Plutarco Elías Calles. A pesar de una campaña intermitente y de escasa penetración, Flores consiguió una gran cantidad de votos y, después de las elecciones, durante algún tiempo se mantuvo viva la posibilidad de un levantamiento armado por parte de sus seguidores. En este artículo se busca profundizar en las motivaciones que condujeron a los católicos a apoyar esta candidatura y mostrar cómo algunos de sus líderes no eran ajenos a la opción de levantarse en armas luego de las elecciones.
Approaches for assessing riverine scour
Authors: Howard Adam , Pak Jang , May David , Gibson Stanford , Haring Chris , Alberto Brian , Haring Michael
Published: May 2021

Calculating scour potential in a stream or river is as much a geomorphological art as it is an exact science. The complexity of stream hydraulics and heterogeneity of river-bed materials makes scour predictions in natural channels uncertain. Uncertain scour depths near high-hazard flood-risk zones and flood-risk management structures lead to over-designed projects and difficult flood-risk management decisions. This Regional Sediment Management technical report presents an approach for estimating scour by providing a decision framework that future practitioners can use to compute scour potential within a riverine environment. This methodology was developed through a partnership with the US Army Engineer Research and Development Center, Hydrologic Engineering Center, and St. Paul District in support of the Lower American River Contract 3 project in Sacramento, CA.
Mutual Impacts and Interactions of Antibiotic Resistance Genes, Microcystin Synthetase Genes, Graphene Oxide, and Microcystis Aeruginosa in Synthetic Wastewater
Authors: Wu Shichao , Ji Xiyan , Li Xin , Ye Jing , Xu Wenwu , Wang Rui , Hou Meifang
Published: May 2021

The physiological impacts and interactions of ARGs abundance, microcystin synthetase genes expression, GO, and M. aeruginosa in synthetic wastewater were investigated. The results demonstrated that the absolute abundance of sul1, sul2, tetW, and tetM in synthetic wastewater dramatically increased to 365.2%, 427.1%, 375.2%, and 231.7%, respectively, when the GO concentration was 0.01 mg/L. Even more interesting is that the sum gene copy numbers of mcyA-J also increased to 243.2%. The appearance of GO made the significant correlation exist between ARGs abundance and mcyA-J expression. Furthermore, M. aeruginosa displayed better photosynthetic performance and more MCs production at 0.01 mg/L GO. There were 65 pairs of positive correlations between the intracellular differential metabolites of M. aeruginosa and the abundance of sul1, sul2, tetM, and tetW with various GO concentrations. The GO will impact the metabolites and metabolic pathway in M. aeruginosa. The metabolic changes impacted the ARGs, microcystin synthetase genes, and physiological characters in algal cells. Furthermore, there were complex correlations among sul1, sul2, tetM, tetW, mcyA-J, MCs, photosynthetic performance parameters, and ROS. The different concentration of GO will aggravate the hazards of M. aeruginosa by promoting the expression of mcyA-J, producing more MCs, simultaneously, it may cause the spread of ARGs.
Expectation Identity of the Discrete Uniform Distribution and Its Application in the Calculations of Higher-Order Origin Moments
Authors: Liu Jia-Lei , Zhang Ying-Ying , Wang Yuan-Quan
Published: May 2021

We provide a novel method to analytically calculate the high-order origin moments of a Discrete Uniform (DU) random variable, that is, the expectation identity method. First, the expectation identity of the DU distribution is discovered and summarized in a theorem. After that, we analytically calculate the first four origin moments and the general kth (k=1,2,…) origin moment of the DU distribution by the expectation identity method. After comparing the corresponding coefficients on both sides of an equation, we obtain a nonhomogeneous linear equations of first degree in k+1 variables. Furthermore, we have provided two ways to solve the nonhomogeneous linear equations. The first way is by matrix inversion, and the second way is by iterative solving. Moreover, the coefficients of the first ten origin moments of the DU distribution are summarized in a table. Finally, we have a proposition for special summations.
New Insight into Mechanism of Cr(VI) Migration and Transformation in Typical Soils of Chromite ore Processing Residue (COPR) Contaminated Sites
Authors: Wei Minghai , Li Wenting , Tang Jie , Zhang Jia , Chen Honghan
Published: May 2021

Chromite ore processing residue (COPR) storage sites are widely distributed all over the world, causing serious soil and groundwater pollution. However, the differences in soil constituents and properties between different regions are significant, and the dynamic migration and transformation of Cr(VI) in different types of soil under alkaline condition of the COPR site is still unclear. In this study, the typical black soil, red soil and loess in different regions of China were chosen to investigate the adsorption kinetics and thermodynamics of Cr(VI) under the original pH conditions of the soil, and then the alkaline Cr(VI) solution was introduced into the soil column to simulate the dynamic migration and transformation process of Cr(VI) at COPR sites. According to the results, the Cr(VI) breakthrough curve predicted by the solid-liquid distribution coefficient Kd based on the static isotherm adsorption experiments significantly underestimated and overestimated the retention effect of black soil and red soil on Cr(VI) dynamic migration, respectively. For the black soil, the retention of Cr(VI) was dominated by Cr(VI) reduction, which is a slow reaction compared with Cr(VI) adsorption. Therefore, the reduction kinetics process during the column experiment cannot be neglected. In respect to the red soil, the outlet Cr(VI) concentration turned to be higher than the inlet concentration with the soil alkalization, which indicated that the adsorbed Cr(VI) desorbed again, and this is the main reason for the overestimation of Cr(VI) retention effect by the red soil. This study shows that the environmental risks of Cr in different types of soil are quite different, mainly related to the valence and occurrence form of Cr that governed by the soil constituents and properties. In addition, the stable form of Cr in the black soil column after the reaction indicates that the soil organic matter can be used as a potential environmentally friendly remediation material for Cr(VI) contaminated soils at COPR sites.
Changes in Urbanization and Urban Heat Island Effect in Dhaka City
Authors: Uddin A S M Shanawaz , Khan Najeebullah , I Abu Reza Md. Towfiqul , Kamruzzaman Mohammad , Shahid Shamsuddin
Published: May 2021

Urbanization changes the local environment, resulting in urban heat island (UHI) effect and deteriorating human life quality. Knowledge of urban environments and temperature changes is important to outline the urban planning process for mitigation of UHI effect. The study aimed to assess the changes in urban areas and UHI effects in Dhaka city, Bangladesh from 2001to 2017, using Moderate Resolution Imaging Spectroradiometer (MODIS) daily day- and nighttime land surface temperature (LST) data from 2001to 2017. The expansion of the city was calculated using the city clustering algorithm (CCA). The temperature of the identified urbanized area was analyzed and compared with the adjacent regions. The changes in urban temperature were estimated using non-parametric statistical methods. The results showed that the Dhaka city area has grown by 19.12% and its inhabitants by 76.65% during 2001–2017. Urban expansion and dense settlements caused an increase in average temperature in some areas of Dhaka city nearly 3°C compared to that at its boundary. The day and night temperatures at Dhaka city's warmest location were nearly 7 and 5ºC, respectively, more than the coolest point outside the city. The city's annual average day- and nighttime temperature was increasing at a rate of 0.03° and 0.023°C/year over the period 2001–2017. The rising temperature would increase the UHI effect in the future, which combined with high humidity, may cause a significant increase in public health risk in the city if mitigation practices are not followed.
Bayesian Model Identification Through Harmonic Balance Method For Hysteresis Prediction in Bolted Joints
Authors: Miguel Luccas Pereira , Teloli Rafael de Oliveira , Silva Samuel da
Published: May 2021

Hysteresis is a nonlinear dissipative phenomenon present in many structures, such as those assembled by bolted joints. However, the approaches for identification are still limited in the literature due to their complexity. Additionally, there are also uncertainties held in bolted structures caused to fluctuations in tightening torque and pressure distribution along the contact surface. Thus, this paper yields a methodology for identifying a stochastic Bouc-Wen model for bolted joints based on the harmonic balance method. Unfortunately, some challenges are encountered when applying conventional series approximation to hysteresis, caused mainly by non-smooth behavior, which induces abrupt transitions between different motion regimes. In this work, previous adaptations were made to split the hysteresis loop in smooth paths and then use a piecewise harmonic balance approach. In this way, it was possible to deal with a deterministic Identification problem based on minimizing the error between the Fourier amplitudes of an experimental signal and those obtained through harmonic balance applying the Cross-Entropy optimization method. So, the results were extended to a stochastic model by applying the Bayesian paradigm, in which the maximized likelihood function was also based on the harmonic balance amplitudes. This methodology was demonstrated to identify Bouc-Wen parameters capable of predicting hysteresis in the BERT benchmark, composed of two aluminum beams jointed by a bolted joint in a cantilever boundary condition. Evaluating the results in the time and frequency domain and the nonlinear behavior through the hysteresis loop, it can be concluded that the method was able to identify an accurate stochastic Bouc-Wen model in predicting the dynamics of bolted structures even taking into account the probable uncertainties of the system.
Fluid migrations and volcanic earthquakes from depolarized ambient noise
Authors: Petrosino Simona , De Siena Luca
Published: May 2021

Ambient noise polarizes inside low-velocity fault zones, yet the spatial and temporal resolution of polarized noise on gas-bearing fluids migrating through stressed volcanic systems is unknown. Pressurized fluids increase stress and lead to volcanic earthquakes; imaging their location in real time would be a giant leap toward forecasting eruptions and monitoring volcanic unrest. Here, we show that depolarized noise detects fluid injections and migrations leading to earthquakes inside the laterally-stressed hydrothermal systems of Campi Flegrei caldera (Southern Italy). A polarized transfer structure connects the deforming centre of the caldera to open hydrothermal vents and extensional caldera-bounding faults during periods of low seismic release. Fluids depolarize the transfer structure and pressurize the hydrothermal system, building up stress before earthquakes and migrating after seismic sequences. During sequences, fluid migration pathways connect the location of the last eruption (Monte Nuovo, 1538AD) with the part of the eastern caldera trapped between transfer and extensional structures. After recent intense seismicity (December 2019-April 2020), the transfer structure appears sealed while fluids stored in the east caldera have moved further east. Depolarized noise has the potential to monitor fluid migrations and earthquakes at stressed volcanoes quasi-instantaneously and with minimum processing.