bluuebunny/crossref_metadata_2025 huggingface dataset:
Using GIS and the Diversity Indices: A Combined Approach to Woody Plant Diversity in the Urban Landscape
Authors: Gül Doğan Tuba , Eroğlu Engin
Published: April 2021

Thanks to their recreational and psychological functions as well as plant diversity, open and green spaces in a city improve the life quality of the urban inhabitants. Woody plant diversity has significant value in urban green systems. The main purpose of this study was to determine the biodiversity values and the potential of the urban green infrastructure via floristic and spatial analyses of woody plant diversity. To this aim, field studies were carried out on the open and green infrastructure in selected areas of Duzce, having different spatial characteristics. The contribution of the identified species to urban biodiversity was examined as well as the spatial characteristics of the species in terms of landscape architecture. In this study, both statistical analyses (alpha and beta diversity of the species) and GIS analyses (species density and spatial distribution) were carried out. According to the results of the research, the most common of the 173 plant species detected were Cupressocyparis leylandii and Tilia tomentosa, found in the open green areas. As a result of the study, it was found that using the floristic diversity indices and GIS jointly enabled the UFD (Urban Floristic Diversity) of the city to be defined both statistically and positionally.
The Internet of Things Space Infrastructure. Current State and Development Prospects
Authors: Ilchenko Mikhail , Narytnyk Teodor , Prisyazhny Vladimir , Kapshtyk Segii , Matvienko Sergey
Published: April 2021

This chapter presents an overview of possibilities for existing Satellite Communication Systems utilization to provide Internet of Things Services. It is shown that existing Satellite Communication Systems provide traffic transmission for Internet of Things Systems with Cloud Architecture. The propositions on possibility of Fog and Edge computing implementation in Satellite Communication Systems are proposed. The ways for Low-Earth Orbit and Geostationary Orbit Satellite Communication Systems modernization for Fog and Edge computing implementation for the Internet of Things Systems are presented. To increase the efficiency of IoT data processing and the reliability of Internet of Things Data Storage, it is proposed to generate an Orbital Cloud Data Storage in Geostationary Orbit, which consists of several Geostationary Orbit Satellites - Cloud Computing Data Centers. Methods for access provision to the Orbital Cloud Data Storage using Geostationary Orbit High-Throughput Satellites and satellites from the structure of Low-Earth Orbit Satellite Communication Systems are proposed. The issues of interaction between Orbital Cloud Data Storage and ground-based Cloud Data Processing and Storage Infrastructure are briefly considered. The orbital slots in Geostationary Orbit are proposed for location of Geostationary Orbit Satellites - Cloud Computing Data Centers.
A Food Recommender Based on Frequent Sets of Food Mining Using Image Recognition
Authors: Tangpong Thunchanok , Leanghirun Somkiet , Hansuebsai Aran , Takano Kosuke
Published: April 2021

Food recommendation is an important service in our life. To set a system, we searched a set of food images from social network which were shared or reviewed on the web, including the information that people actually chose in daily life. In the field of representation learning, we proposed a scalable architecture for integrating different deep neural networks (DNNs) with a reliability score of DNN. This allowed the integrated DNN to select a suitable recognition result obtained from the different DNNs that were independently constructed. The frequent set of foods extracted from food images was applied to Apriori data mining algorithm for the food recommendation process. In this study, we evaluated the feasibility of our proposed method.
Nanomaterials Characterisation through Magnetic Field Dependent AFM
Authors: Coïsson Marco , Barrera Gabriele , Celegato Federica , Tiberto Paola
Published: April 2021

Atomic force microscopy is a versatile technique allowing to exploit many different physical effects for measuring a number of materials properties. The magnetic properties of surfaces and thin films are traditionally accessed through magnetic force microscopy, which produces magnetic field gradient maps generated by the magnetisation distribution at the surface of the sample. However, more advanced techniques can be derived from this fundamental setup, allowing for a richer characterisation of magnetic samples. In this chapter, we will describe how to extend a magnetic force microscope to allow magnetic field-dependent characterisations. Magnetisation reversal processes, as well as full hysteresis loops, can be investigated with such a technique, with field resolution adequate for identifying significant features such as domains reversal, nucleation or annihilation of domains, and other irreversible mechanisms. The same principle can also be exploited for the measurement of magnetostriction on thin films, and can be taken as guideline for other advanced applications of atomic force microscopy.
Usability of Computerised Gaming Simulation for Experiential Learning
Authors: Becu Nicolas
Published: April 2021

This chapter examines the impacts of computerization of gaming simulations on their usability. Simulation and gaming is an interdisciplinary domain which rallies, among others, the disciplines of education and modelling, and which aim at helping groups of participants to acquire knowledge and skills on complex topics. Gaming simulations can take the form of haptic games or computerised simulations. Yet, the later form may slow down the learning potential for the users. The chapter describes the different types of computerization of gaming simulations. It then examines the effects of computerization, both from the users’ perspective (accessibility, captive effect, and flexibility of use) and from the developers’ perspective (material, human, and time requirements). Some paths to overcome barriers to experiential learning of computerised gaming simulation are finally presented.
The Influence of Economic Activity of Women in Malaysia and Guatemala on National Development
Authors: Habrich Verena , Bobek Vito , Horvat Tatjana
Published: April 2021

Emerging markets are amongst some of the fastest-growing economies on the globe. However, it is necessary to enhance human capital to enable the long-term development of a nation. The theory states that the increase in workforce participation favorably impacts GDP per capita. Additionally, developing markets can grow even further if they increase women’s rates in the labor market. The authors’ desire is to determine the main obstacles for women in the job market and identify the impact of female participation on national development. The authors applied the following methods of work: description and compilation of different literature and deduction method to show which relevant factors are recommended to make higher women’s economic activity to impacts the economy in a broader sense. The results show that Emerging markets must overcome gender inequalities, properly enforce female-related regulations, and invest in human development. The results also point out the relevance of a country’s level of development, culture, education, female-related laws, and their influence on women’s decision or ability to work. The discussion demonstrates that the rate of women in the workforce is increasing, but it is still severely lower than the men’s rate. The main issues are cultural stereotypes, limited access to the job market, and difficulties with combining work and childcare. When it comes to infrastructure and educational possibilities, remote areas are still underdeveloped. Furthermore, gender bias is still deeply rooted in rural society. The elimination of these stereotypes and the improvement (and enforcement) of women-related policies will contribute to higher female workforce participation in the future.
Changes in Airway Dimensions After Face-Mask Therapy in Cleft Lip and Palate and Non-cleft Patients: Systematic Review and Meta-Analysis
Authors: Shafaee Hooman , Mazloumhoseini Bahareh , Bardideh Erfan , Dadgarmoghaddam Maliheh
Published: April 2021

Context: Maxillary deficiency can lead to the reduction of airway space and increase the chances of development of obstructive airway disorders. Facemask therapy is one of the main treatment protocols in developing maxillary deficient patients. Objectives: The purpose of this systematic review and meta-analysis was to assess the changes in the airway dimensions after face-mask therapy in both cleft lip and palate and non-cleft patients. Methods: A systematic search in different electronic databases (EMBASE, Pubmed, Cochrance Central register of controlled trials), IADR proceedings and a hand search by October 2020 were conducted and a meta-analysis and systematic review was performed. Results: In patients without cleft lip and palate, upper pharyngeal width was significantly increased by mean of 2.05 mm (CI = 95%, 0.61 - 3.50) following facemask therapy in comparison to patients who did not receive the treatment. Other upper pharyngeal (nasopharyngeal) measurements also showed a statistically significant improvement after therapy: S-PNS by 4.64 mm (CI = 95%, 3.34 - 5.94), AD1-PNS by 3.81 mm (CI = 95%, 2.40 - 5.21), AD2-PNS by 2.90 mm (CI = 95%, 0.13 - 5.67) and Pm’-SPL by 2.53 (CI = 95%, 0.54 - 4.51). Lower pharyngeal measurments did not show any significant changes after the treatment (P > 0.05). In the analysis of studies with 3D imaging modalities, upper pharyngeal volume was also significantly increased by 499.29 mm3 (CI = 95%, 69.58-929.00) after the treatment. In addition, a review of articles that included cleft lip and palate patients also showed after the treatment, the upper pharyngeal measurements all showed a significant improvement (P < 0.05), whereas the oropharyngeal region was relatively stable. Conclusions: In maxillary deficient patients with or without an orofacial cleft, facemask therapy can improve the nasopharyngeal area dimensions; however, this treatment protocol appears not to have an effect on the oropharyngeal area of the airway tract.
Comparison of five commercial anti-SARS-CoV-2 total antibodies and IgG immunoassays after vaccination with BNT162b2 mRNA
Authors: Danese Elisa , Montagnana Martina , Salvagno Gian , Gelati Matteo , Peserico Denise , Pighi Laura , de Nitto , Henry Brandon , Porru Stefano , Lippi Giuseppe
Published: April 2021

Background: Since universal vaccinations represents the most effective strategy to mitigate coronavirus disease 2019 (COVID-19), baseline assessment and post-vaccine monitoring of anti-SARS-CoV-2 neutralizing antibodies are essential to vaccination programs. Therefore, this study aimed to compare data of five commercial anti-SARS-CoV2 immunoassays after administration of an mRNA vaccine. Methods: Venous blood was collected from three healthcare workers, receiving a double (30 g) dose of BNT162b2 mRNA Covid-19 vaccine (Comirnaty, Pfizer), on the day of the first vaccine dose and then at fixed intervals for the following 2 months. Anti-SARS-CoV-2 neutralizing antibody response was assayed with Roche Total Ig anti-RBD (receptor binding domain), DiaSorin TrimericS IgG (spike trimer), Beckman Coulter IgG anti-RBD, SNIBE IgG anti-RBD and Technogenetics IgG anti-N/S1. Results: A total number of 45 samples were drawn at the end of the 2-month study period. The Spearman's correlations of absolute anti-SARS-CoV-2 antibodies were always excellent (all p<0.001), comprised between 0.967-0.994. Satisfactory results were also observed when absolute antiSARS-CoV-2 antibodies values of the five methods were compared with the mean consensus value, with correlations always higher than 0.979 (all p<0.001). The agreement of anti-SARS-CoV-2 antibodies positivity versus the consensus median positivity ranged between 0.764 and 1.000 (always p<0.001), but become always >0.900 after readjustment of one assay cutoff. Conclusions: All the immunoassays evaluated in this study appear suitable for monitoring anti-SARS-CoV-2 neutralizing antibodies response in subjects undergoing mRNA COVID-19 vaccination.
Decision Tree for Key Comparisons
Authors: Possolo Antonio , Koepke Amanda , Newton David , Winchester Michael R.
Published: April 2021

This contribution describes a Decision Tree intended to guide the
selection of statistical models and data reduction procedures in key
comparisons (KCs). The Decision Tree addresses a specific need of
the Inorganic Analysis Working Group (IAWG) of the Consultative
Committee (CC) for Amount of Substance, Metrology in Chemistry and
Biology (CCQM), of the International Committee for Weights and
Measures (CIPM), and it is likely to address similar needs of other
working groups and consultative committees.

Because the portfolio of KCs previously organized by the CCQM-IAWG
affords a full range of opportunities to demonstrate the
capabilities of the Decision Tree, the majority of the illustrative
examples of application of the Decision Tree are from this working
group. However, the Decision Tree is widely applicable in other
areas of metrology, as illustrated in examples of application to
measurements of radionuclides and of the efficiency of a thermistor
power sensor.

The Decision Tree is intended for use after choices will have been
made about the measurement results that qualify for inclusion in the
calculation of the key comparison reference value (KCRV), and about
the measurement results for which degrees of equivalence should be
produced. Both these choices should be based on substantive
considerations, not on purely statistical criteria. However, the
Decision Tree does not require that the measurement results selected
for either purpose be mutually consistent.

The Decision Tree should be used as a guide, not as the sole and
autonomous determinant of the model that should be selected for the
measurement results obtained in a KC, or of the procedure that
should be employed to reduce these results. The scientists running
the KCs ultimately have the freedom and responsibility to make the
corresponding choices that they deem most appropriate and that best
fit the purpose of each KC.

The Decision Tree involves three statistical tests, and comprises
five terminal leaves, which correspond to as many alternative ways
in which the KCRV, its associated uncertainty, and the degrees of
equivalence (DoEs) may be computed.

This contribution does not purport to suggest that any of the KCRVs,
associated uncertainties, or DoEs, presented in previously approved
final reports issued by working groups of the CCs should be
modified. Neither do the alternative results question existing,
demonstrated calibration and measurement capabilities (CMCs), nor do
they support any new CMCs.
Iris recognition on Noah Kalina s Everyday
Authors: Matey James R
Published: April 2021

In January 2000, Noah Kalina began taking a photograph of himself every day and has continued for more than 20 years. A time-lapse video of his images can be seen online: EveryDay. These images, and images from similar projects, provide us with interesting opportunities to explore the effects of time lapse on iris recognition employed on images that were not originally intended for iris recognition. NIST obtained a license from Kalina to use a subset (7 half years from 2009-2015) of original, high resolution, digital images in biometric studies. This paper is our first published analysis of those images. Our license does not permit redistribution of the high resolution images. Our analysis demonstrates that over a period of at least 6 years, even though the majority of the images in this dataset did not provide solid matches, there are instances where mated iris image pairs from visible light images that were not obtained for the purpose of iris recognition match with match scores corresponding to a false match rate of 0:1% at a true accept rate of 1% . Though such performance is not useful in applications such as access control, there are cases where it may be useful. We note that the algorithms used in this analysis were not designed to work with the iris images that we extracted from the EveryDay project.
How cells determine the number of polarity sites
Authors: Chiou Jian-geng , Moran Kyle D , Lew Daniel J
Published: April 2021

The diversity of cell morphologies arises, in part, through regulation of cell polarity by Rho-family GTPases. A poorly understood but fundamental question concerns the regulatory mechanisms by which different cells generate different numbers of polarity sites. Mass-conserved activator-substrate (MCAS) models that describe polarity circuits develop multiple initial polarity sites, but then those sites engage in competition, leaving a single winner. Theoretical analyses predicted that competition would slow dramatically as GTPase concentrations at different polarity sites increase toward a ‘saturation point’, allowing polarity sites to coexist. Here, we test this prediction using budding yeast cells, and confirm that increasing the amount of key polarity proteins results in multiple polarity sites and simultaneous budding. Further, we elucidate a novel design principle whereby cells can switch from competition to equalization among polarity sites. These findings provide insight into how cells with diverse morphologies may determine the number of polarity sites.
Model for Simulating the Financial Viability of a Just-in-Time Maintenance Program in an Agribusiness Company
Authors: Fontanini Carlos Augusto Candeo , Wollmann Dewey
Published: April 2021

Research Question: The objective of this article is to present the model for simulating the financial viability of a Just-in-Time Maintenance Program in an agribusiness company.  Motivation: Maintenance management in agro-industrial environments lacks effective systems to optimize the production process. The existing maintenance program have proven to be ineffective, from the point of view that unscheduled production downtime continues to occur. It is important to highlight that the types of maintenance used today, considering that their characteristics are not able to reduce or minimize the errors caused by human limited capacity, which has contributed to the increase of unscheduled production stoppages, causing equipment unavailability, low quality of final products and, mainly, failing to deliver products as agreed with customers. Idea: The maintenance program called Just-In-Time Maintenance Program - Maintenance Just in Time – consists of an integrated system for monitoring physical phenomena, with sensors installed in the equipment, connected to a central diagnosis able to predict failures in real time. With this program, it is possible to know in advance what may happen, taking the necessary measures regarding the acquisition of parts, repairs, and personnel allocation, among others, making these stops compatible or readjusting them with the production plan to minimize the undesirable stops. Data: The choice of the company participating in the research is made due to its continuous production process. The present study used a non-probabilistic sample for convenience with that provided by the observed company. The information collected in the agribusiness regarding the selling price, cost of raw material, cost of electricity, and total expenditure on maintenance, refer to the year 2020. Tools: A mathematical model was developed that estimates variations in the company's productivity and the consequent financial impacts. The results, operational and financial, of the model allow assessing the feasibility of implementing each of these programs. Findings: The results obtained indicate losses with the current maintenance program and show the potential for implementing the Just-In-Time Maintenance Program. This research concludes that it is possible to reduce unscheduled stoppages that cause production interruptions, increasing profit, with the implementation of the Just-In-Time Maintenance Program. Contribution: This article contributes to the literature as it presents an equipment maintenance model based on operational conditions, in contrast to other existing maintenance programs.
Public Debt Threshold in the Republic of North Macedonia
Authors: Kjosev Sasho , Noveski Martin , Mojsova Kjoseva Nina
Published: April 2021

Research question: Is there a non-linear relationship between public debt and economic growth in North Macedonia, in the form of an inverted U-shape? Motivation: Government consumption plays an important role in the stability of the national economy, especially in periods of economic crisis. However, a rapidly growing public debt is a concerning issue nowadays, since it might jeopardize economic growth perspectives. Economic theory suggests that public debt has non-linear impact on economic growth in the form of an inverted U-shape. In other words, it is believed that after a certain threshold, the public debt will have deleterious impact on economic growth. Idea: Given that such threshold varies significantly across countries, the aim of this paper is to calculate the turning point of the public debt impact in the Republic of North Macedonia. Tools: For this purpose, we use non-linear multiple regression model for the real GDP growth rate as a dependent variable, general government public debt-to-GDP ratio (in nominal and squared terms) as a key independent variable, as well as several other controlling variables. Since theory also suggests reverse causality between economic growth and public debt, we use two different estimation techniques (Ordinary Least Squares and Generalized Method of Moments) to deal with potential endogeneity, and to cross-validate the results. Data: In this regard, we use annual data for the period 1998 – 2019, for 14 variables in total, obtained from several different data sources. Findings: Our results show that general government debt in the Republic of North Macedonia positively affects economic growth until it reaches around 30% of GDP, whereas further indebtedness after that turning point will most likely have a negative impact. Contribution: Given that current debt level is far above the estimated turning point, the need of urgent fiscal consolidation inevitably arises. This is especially important in the light of the ongoing COVID-19 crisis, which imposed the need for strong government intervention and pointed out the importance of the fiscal space for such matter.
Towards an Integrative Framework of Relationship Quality in a Retail Setting: Evidence from an Emerging Economy
Authors: Dado Jaroslav , Taborecka–Petrovicova Janka , Rajic Tamara
Published: April 2021

Research question: This study aims to propose and empirically examine a relationship quality model in a grocery retail setting in Serbia. Motivation: Whereas relationship quality has been extensively studied in B2B settings and in developed economies, far less research attention has been devoted to the formation and effects of relationship quality in B2C exchange relations in developing economies. This especially holds true for Eastern Eupean emerging economies and the present research aims to fill this gap. Idea: Building upon previous research in service settings, this study proposes customer orientation as an antecedent to relationship quality, comprising relationship satisfaction, customer trust and commitment to a retailer, and attitudinal and behavioural loyalty as consequences of relationship quality. Data: The study has been performed on a convenience sample of 453 grocery retail customers in Serbia, by means of structured questionnaire. Tools: Upon supporting constructs’ validity, structural equation modelling (SEM) has been applied to examine the proposed relationships. Findings: The results of the study indicate significant direct impact of employees’ customer orientation on trust and relationship satisfaction. Commitment to a retailer and relationship satisfaction emerged as direct antecedents to attitudinal and behavioural loyalty, whereas trust emerged as an indirect determinant of loyalty constructs. In terms of total effect, relationship satisfaction emerged as the most influential determinant of both facets of customer loyalty. Contribution: The findings of the study which indicate significant indirect contribution of front-line employees’ customer orientation to attitudinal and behavioural loyalty of customers provide valuable insights for HR management of retail enterprises. In addition, by addressing relationship quality construct and its antecedents and effects in a B2C setting in thus far largely under-studied context, such as an emerging European economy, this study’s findings add to the growing body of knowledge on Relationship Marketing.
HiCEnterprise: identifying long range chromosomal contacts in Hi-C data
Authors: Kranas Hanna , Tuszynska Irina , Wilczynski Bartek
Published: April 2021

Motivation

Computational analysis of chromosomal contact data is currently gaining popularity with the rapid advance in experimental techniques providing access to a growing body of data. An important problem in this area is the identification of long range contacts between distinct chromatin regions. Such loops were shown to exist at different scales, either mediating relatively short range interactions between enhancers and promoters or providing interactions between much larger, distant chromosome domains. A proper statistical analysis as well as availability to a wide research community are crucial in a tool for this task.

Results

We present HiCEnterprise, a first freely available software tool for identification of long range chromatin contacts not only between small regions, but also between chromosomal domains. It implements four different statistical tests for identification of significant contacts for user defined regions or domains as well as necessary functions for input, output and visualization of chromosome contacts.

Availability

The software and the corresponding documentation are available at: github.com/regulomics/HiCEnterprise.

Supplementary information

Supplemental data are available in the online version of the article and at the website regulomics.mimuw.edu.pl/wp/hicenterprise.
Experiencing fear during the pandemic: validation of the fear of COVID-19 scale in Polish
Authors: Pilch Irena , Kurasz Zofia , Turska-Kawa Agnieszka
Published: April 2021

Background

The Fear of COVID-19 Scale (FCV-19S) is a brief self-report measure developed at the beginning of the coronavirus pandemic. The scale evaluates the emotional responses to COVID-19. To date, the FCV-19S has been translated and validated in about 20 languages and has been used in many published research. The current study aimed to validate the Polish version of the FCV-19S.

Method

The FCV-19S was translated into Polish using forward- and back-translation. From May 15th to June 15th 2020, a total of 708 community members (Sample 1: 383 persons, 209 females, Sample 2: 325 persons, 198 females) participated in the online study. The participants were recruited using online advertisements in social media. Participation was anonymous, voluntary, and without compensation. A confirmatory factor analysis was performed to test the one-factor structure of the FCV-19S. Then, measurement invariance was analyzed across samples, gender and age groups. To assess the validity of the scale, correlations between the FCV-19S and the remaining scales were computed.

Results

Internal consistency of the FCV-19S was good in both samples (Cronbach’s alpha 0.89 and 0.85). The CFA showed that the one-factor model fits the data well (RMSEA = 0.067, 90% CI [0.059–0.094], CFI = 0.977, TLI = 0.965, GFI = 0.986). The criteria for configural, metric, scalar and strict invariance were met for all models tested. The FCV-19S scores correlated significantly with age, subjective vulnerability to the disease, neuroticism, self-reported compliance with the pandemic measures, and three kinds of preventive behavior (i.e., social distancing, hand hygiene, and disinfecting things).

Conclusion

The Polish version of the FCV-19S had a unidimensional structure, good reliability, and correlated as predicted with other variables. With the FCV-19S and the obtained results, healthcare professionals, researchers, and the government can gain more valuable information about people who may be at risk for negative psychological outcomes during the pandemic or who are not implementing protective behavior. The tool can be used in hospitals to quickly screen the level of fear in patients and minimize its severe adverse consequences.
The effect of curing conditions on the mechanical properties of SIFCON
Authors:   Niğde Ömer Halisdemir Üniversitesi, Akçaözoğlu Kubilay , Kıllı Adem ,   Niğde Ömer Halisdemir University
Published: April 2021

In this study, the effect of curing conditions on the mechanical properties of slurry infiltrated fiber reinforced concrete (SIFCON) was investigated. For this purpose, SIFCON samples containing 4% and 8% steel fiber with two different aspect ratios were produced. The samples were subjected to three different curing types, namely standard, dry and accelerated curing methods. Ultrasonic wave velocity, flexural strength, fracture toughness, compressive strength, impact resistance and capillary water absorption tests were performed on the samples. The highest flexural strength was found to be achieved in the samples with an aspect ratio of 55 and a content of 8% steel fiber. The most suitable curing method was determined as the standard curing method and the best flexural strength was achieved at the rate of 8%. According to the test results, the best strength properties were achieved in the samples exposed to the standard curing method. In addition, the samples exposed to the accelerated curing method showed satisfactory values. The accelerated curing method can be used as an alternative in SIFCON production especially in applications requiring mass production.
Development of hybrid steel-basalt fiber reinforced concrete – in aspects of flexure, fracture and microstructure
Authors:   ThiagarajarCollege of Engineering, Department of Civil Engineering (India), Vinotha Jenifer J. , Brindha D. ,   ThiagarajarCollege of Engineering, Department of Civil Engineering (India)
Published: April 2021

The conventional concrete is considered to be critical in various constructional applications due to its setbacks such as service load failures, brittle property, low ductility and low tensile capacity. Apart from the natural bridging mechanism (aggregate bridging), an additional bridging mechanism is necessary to overcome the existing setbacks in plain cement concrete. Thus concrete with one or more types of fibers in suitable combinations can augment the mechanical performance of concrete causing a positive synergy effect. Along with the two control mixes with and without copper slag as partial replacement of fine aggregate, two different groups of hybrid combination of fibers such as steel and basalt were cast with 3 different groups of coarse aggregate proportions of sizes 20 mm and 12.5 mm. The hybridization of fibers is assessed in this study under compression, tension, flexure and fracture. Stress-strain data were recorded under compression to validate the strain capacity of the mixtures. The mechanical properties were analyzed for the positive hybrid effect and the influencing factors were copper slag, hybrid fiber combination and coarse aggregate proportions. The optimum volume fraction of fibers and mix proportions were highlighted based on various behaviors of concrete. Steel as macro fibers and basalt as microfibers were examined under microstructural studies (SEM and EDX). The results from the flexural toughness showcased the potential of hybrid fibers with greater energy absorption capacity ensuring the ductile property of the proposed hybrid fiber reinforced concrete.
Impact of Agricultural R&D on Sectoral Economic Growth
Authors: Ouru Lawrence , Mose Naftaly
Published: April 2021

Public and private investment in agricultural research and development (R&D) creates preconditions for the implementation of more advanced and better technologies. It enables the introduction of new production processes and products which can result in higher earnings and potential sectoral economic growth in Agriculture. Despite the fact that accelerated agricultural research and development is a catalyst for the beginning of the long-run economic activity, its importance is not widely investigated at regional levels. The East Africa economies have defined strategies that view innovation as an essential element in stimulating growth and job creation. The goal of this study is to establish the role of agricultural R&D in fostering sectoral economic growth of East Africa states. The data used in this research were panel data of the East Africa Countries for the period from 2001 to 2015. The result showed that agricultural sector R&D is important factor in explaining sectoral economic growth in East Africa. Therefore, only innovation through increasing Agricultural R&D expenditure and strengthening institutions can sufficiently drive sustainable sectoral output growth and development in East Africa economies. Thus, East Africa nations need to strengthen and build their agricultural research and development capacity while aligning of policies and procedures of research organizations to achieve sustainable sectoral economic growth.
Modelling of Biphasic Biogas Production Process from Mixtures of Livestock Manure Using Bi-logistic Function and Modified Gompertz Equation
Authors: Opurum Christian C. , Nweke Christian O. , Nwanyanwu Christopher E. , Nwogu Nkemakolam A.
Published: April 2021

In this study, anaerobic digestion (AD) of three livestock manure: (poultry manure (PM), pig dung (PD), and cow dung (CD) was conducted at different mixed ratios under mesophilic (25-35°C) conditions. Two kinetic models, the modified Gompertz and bi-logistic function model were used to simulate the cumulative biogas yield from the experiments, and model parameters simultaneously obtained. The biogas production profile appeared diauxic-like or biphasic with multiple peaks, revealing the complexity and multi-component nature of the substrates. There was an increase in biogas yield from the treatments, PD/CD 1:1; 37.25 dm3 (3.47%), PD/CD 3:1; 38.41 dm3 (6.96%), CD/PM 1:1; 26.76 dm3 (16.80%) and CD/PM 3:1 24.31 dm3 (6.11%), whereas PD/CD 2:1 (15.41 dm3) and CD/PM 2:1 (22.57 dm3) exhibited inhibitory effect. However, statistical analysis (ANOVA) indicated a significant difference in biogas yield from PD alone (36 dm3) compared to CD alone (22.91 dm3). The two models showed good performance in the simulation of the AD process, with high correlation coefficients, an indication of a very strong relationship between experimental data and model parameters. However, the bi-logistic function model showed a better fit in the simulation of the experimental values, as it was able to capture the curves in the plots, with a higher correlation coefficient R2 (0.9920 - 0.9985) than the modified Gompertz model (0.9797 - 0.9968). This work has shown that the phenomenon of diauxic growth in the anaerobic digestion of complex organic substrates could be captured quantitatively in the kinetic model using bi-logistic function model.
Evaluation of Secondary Metabolites and Antioxidant Activity of Water, Ethyl Acetate and Hexane Fractions from the Mangrove Young Leaves Sonneratia alba
Authors: Dotulong Verly , Wonggo Djuhria , Montolalu Lita A. D. Y.
Published: April 2021

The fractions from young leaves of mangrove Sonneratia alba was studied for its associated secondary metabolites and antioxidant activities. The objective of this study was to determine the secondary metabolite components and antioxidant activity of water, ethyl acetate, and hexane fractions of the young leaves of mangrove S. alba. The fraction was obtained from dry powder of young leaf S.alba using continuous fractionation of crude extracts. The crude extract was attained by 2 extraction methods (soxhlet and maceration) and 2 extraction solvents (methanol and ethanol). Secondary metabolites analyses were qualitatively conducted to detect the presence or absence of phenols, flavonoid, tannin, steroid, triterpenoid and alkaloid. Total phenols were measured using Folin Ciocalteau reagents and gallic acid standard curves whereas antioxidant activity were analyzed using DPPH method (1- 1-diphenil-2-picrihydrasil). Results showed that all fractions contained secondary metabolite components tested. The highest rendement was found in the water fraction fromsoxhletation extract with methanol (6.36±0.29%). The total phenol values were found the highest in the ethylacetatefraction from macerated extract with ethanol (352±9.77 mgGAE/g). Stronger antioxidant activity was also found in ethylacetate  fraction as indicated by the small value of IC50 DPPH namely the ethylacetate fraction with soxhletation extract with ethanol  (3.43±0.25 µg / mL). The results of this study indicate that the semipolar fraction (ethylacetate fraction) has more potential as a source of natural antioxidants.
Comparative Analysis of Some Existing Models for Estimating the Time of Concentration for Watersheds in Anambra State, Nigeria
Authors: Agunwamba J. C. , Mmonwuba N. C.
Published: April 2021

This study considered the estimation of the time of concentration (TC) using 30 different watersheds in Anambra State, Nigeria. The study assessed the performance of some existing models for the estimation of time of concentration in the study area. Data for this research were collected from watersheds located at Awka-South Local Government in Anambra State. A measured time of concentration values was also obtained by using a tracer at the watershed divide and the time it took the tracer to get the outlet of the watershed was recorded. This was carried out on all the 30 watersheds at the same time. The length, slope and area of the 30 watersheds were also measured. Thereafter, the time of concentration was estimated using the 30 existing models. The extent of linear association between the observed and estimated time of concentration for the different models was determined. The outcome of the study revealed that the Ventura model (Tc12) developed in Italy recorded the highest correlation coefficient with a measure of 0.681, followed by DNOS model (Tc14) with a coefficient measure of 0.661 while the least performing model was Picking model (Tc13) with -0.423 correlation measure. There was also an obvious difference in the values of the time of concentration calculated using the different models. Therefore there is always a need to verify any model to be used for estimating the time of concentration in other to have a more robust design.
Flood Flow Probability Distribution Model Selection on Niger/Benue River Basins in Nigeria
Authors: Ologhadien Itolima
Published: April 2021

Flood frequency analysis is a crucial component of flood risk management which seeks to establish a quantile relationship between peak discharges and their exceedance (or non-exceedance) probabilities, for planning, design and management of infrastructure in river basins. This paper evaluates the performance of five probability distribution models using the method of moments for parameter estimation, with five GoF-tests and Q-Q plots for selection of best –fit- distribution. The probability distributions models employed are; Gumbel (EV1), 2-parameter lognormal (LN2), log Pearson type III (LP3), Pearson type III(PR3), and Generalised Extreme Value( GEV). The five statistical goodness – of – fit tests, namely; modified index of agreement (Dmod), relative root mean square error (RRMSE), Nash – Sutcliffe efficiency (NSE), Percent bias (PBIAS), ratio of RMSE and standard deviation of the measurement (RSR) were used to identify the most suitable distribution models. The study was conducted using annual maximum series of nine gauge stations in both Benue and Niger River Basins in Nigeria. The study reveals that GEV was the best – fit distribution in six gauging stations, LP3 was best – fit distribution in two gauging stations, and PR3 is best- fit distribution in one gauging station. This study has provided a significant contribution to knowledge in the choice of distribution models for predicting extreme hydrological events for design of water infrastructure in Nigeria. It is recommended that GEV, PR3 and LP3 should be considered in the development of regional flood frequency using the existing hydrological map of Nigeria.
Discovery of Small Anti‐ACE2 Peptides to Inhibit SARS‐CoV‐2 Infectivity
Authors: Adhikary Pratik , Kandel Sashi , Mamani Umar‐Farouk , Mustafa Bahaa , Hao Siyuan , Qiu Jianming , Fetse John , Liu Yanli , Ibrahim Nurudeen Mohammed , Li Yongren , Lin Chien‐Yu , Omoscharka Evanthia , Cheng Kun
Published: April 2021

COVID‐19 is caused by the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), which infects host cells by binding its viral spike protein receptor‐binding domain (RBD) to the angiotensin converting enzyme 2 (ACE2) on host cells. Blocking the SARS‐CoV‐2‐RBD/ACE2 interaction is, therefore, a potential strategy to inhibit viral infections. Using a novel biopanning strategy, a small anti‐ACE2 peptide is discovered, which shows high affinity and specificity to human ACE2. It blocks not only the SARS‐CoV‐2‐RBD/ACE2 interaction but also the SARS‐CoV‐1‐RBD/ACE2 interaction. Moreover, it inhibits SARS‐CoV‐2 infection in Vero‐E6 cells. The peptide shows negligible cytotoxicity in Vero‐E6 cells and Huh7 cells. In vivo short‐term lung toxicity study also demonstrates a good safety of the peptide after intratracheal administration. The anti‐ACE2 peptide can be potentially used as a prophylactic or therapeutic agent for SARS‐CoV‐2 or other ACE2‐mediated viruses. The strategy used in this study also provides a fast‐track platform to discover other antiviral peptides, which will prepare the world for future pandemics.
Inelastic Tunnel Transport and Nanoscale Junction Thermoelectricity with Varying Electrode Topology
Authors: Roy Talem Rebeda , J John Donald Raj , Sen Arijit
Published: April 2021

Intricacies in the charge transport behavior of single‐molecule junctions often revolve around the complex nature of orbital hybridization stemming from diversified metal‐molecule coupling at interfaces. It will hence be pertinent to fathom the myriad aspect of inelastic charge transport and nanoscale thermoelectricity in single‐molecule junctions. It is examined from first‐principles, achiral and chiral quasi‐1D electrodes to understand the role of junction heterogeneity in overall thermoelectric behavior during charge transport. This calculated inelastic electron tunneling spectra exhibit intense peaks in the low‐frequency regime (< 25 meV) with characteristic bending and rocking modes, which auger well with the available measured data. It is subsequently found that the thermopower can be as high as 212 µV K−1 for σ‐saturated molecular moieties, depending strongly on the configuration of electrodes. Besides, a majority of such single‐molecule junctions turn out to deviate from the Wiedemann–Franz law, leading to anomalies in the electronic thermal conductance. The authors' analysis suggests that as nanoscale electrodes, Au(111) nanowires are likely to render a relatively high thermoelectric figure of merit (ZT > 1) for a small molecular junction at room temperature. Discerning the diversity as driven exigently by the electrode topology may thus augment the device performance in terms of thermal stability at molecular scale.
Introduction to P‐TRAP software for designing phosphorus removal structures
Authors: Penn Chad J. , Frankenberger James , Livingston Stanley
Published: April 2021

Phosphorus (P) removal structures are a new best management practice for filtering dissolved P in non‐point drainage from legacy P soils through use of P sorption materials (PSMs). Structures must be designed according to characteristics of the site (hydrology and constraints) and PSMs to be utilized, as well as user‐defined goals (P removal, lifetime, and flow rate), making it a cumbersome process. A freely available P Transport Reduction App (P‐TRAP) allows users to quickly produce a custom design or evaluate a hypothetical or existing structure. The software includes a library of P removal flow‐through curves for many different PSMs conducted under various conditions of inflow P concentration and retention time. Design output includes the necessary PSM mass and orientation, pipe requirement, and a table of annual P removal. The software enables conservationists and engineers to quickly compare cost and efficiency among possible designs.

Phosphorus Transport Reduction App (P‐Trap) software is used to evaluate and design site‐specific P removal structures based on (a) user inputs regarding site and P sorption material (PSM) characteristics and (b) P removal performance goals.

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Phosphorus Transport Reduction App (P‐Trap) software is used to evaluate and design site‐specific P removal structures based on (a) user inputs regarding site and P sorption material (PSM) characteristics and (b) P removal performance goals.
Development of a support for Black Lives Matter measure among racially–ethnically diverse college students
Authors: Yoo Hyung Chol , Atkin Annabelle L. , Seaton Eleanor K. , Gabriel Abigail K. , Parks Sarah J.
Published: April 2021

This paper developed and validated a new measure of support for the Black Lives Matter (BLM) movement among a racially–ethnically diverse sample of college students. The measure focuses on the movement’s principles of Black liberation, intersectionality, and alliance building. Participants included 1934 college students (75% female) from a large public Southwestern university. The factor structure was supported by exploratory and confirmatory factor analyses, resulting in an 18‐item measure, Support for Black Lives Matter, with two underlying factors. Black Liberation includes 12 items representing support for BLM because of awareness of and challenging structural inequality and racism experienced by Black individuals. Intersectional Values includes six items representing support for BLM because it embraces and affirms marginalized populations within the Black community, especially disabled Blacks, queer Blacks, Black women, and Black families with children. Evidence of criterion‐related validity was demonstrated with racial group differences in support of BLM factors. Evidence of convergent validity was supported by significant positive correlations between support for BLM factors and critical consciousness (including awareness of racism, classism, and heterosexism), and negative correlations between support for BLM factors and subtle racist attitudes toward Blacks. Measurement invariance was evident between White, Black, Asian American, Latinx, and Multiracial participants. Implications and suggestions for use of the new measure are discussed.
Enzyme kinetic parameters estimation: A tricky task?
Authors: Aledo Juan C.
Published: April 2021

We are living in the Big Data era, and yet we may have serious troubles when dealing with a handful of kinetic data if we are not properly instructed. The aim of this paper, related to enzyme kinetics, is to illustrate how to determine the Km and Vmax of a michaelian enzyme avoiding the pitfalls in which we often fall. To this end, we will resort to kinetic data obtained by second‐year Biochemistry students during a laboratory experiment using β‐galactosidase as an enzyme model, assayed at different concentrations of its substrate. When these data were analyzed using conventional linear regression of double‐reciprocal plots, the range of Km and Vmax values obtained by different students varied widely. Even worse, some students obtained negative values for the kinetic parameters. Although such a scenario could make us think of a wide inter‐student variability regarding their skills to obtain reliable data, the reality was quite different: when properly analyzed (accounting for error propagation) the data obtained by all the students were good enough to allow a correct estimation of the Km (2.8 ± 0.3 mM) and Vmax (179 ± 27 mM/min) with a reduced intergroup standard deviation. A student‐accessible discussion of the importance of weighted linear regression in biochemical sciences is provided.