bluuebunny/crossref_metadata_2025 huggingface dataset:
Children’s Pictorial Expression of Plant Life and Its Connection with School-Based Greenness
Authors: Zaballa Ilargi , Merino Maria , Villarroel José Domingo
Published: April 2021

Previous research highlights the positive influence that experiences in nature have on children’s physical, emotional and conceptual development. There is also evidence that indicates that the availability of green areas on school grounds is associated with pupils’ better academic performance as well as with their comprehension of wildlife. This study examines the drawings that 152 children completed with the objective of expressing their understanding of the plant world. Approximately half of the drawings were depicted by children that attend a school with green areas within the school site as well as in the surrounding area. The remaining half of the sample includes the illustrations that children attending an educational centre with, virtually, no green areas within the school premises or in the immediate vicinity. Notwithstanding the fact that the two schools involved in the study belong to a similar social context and they are relatively close to each other, the results show relevant differences between the drawings by the two groups compared, in terms of the pictorial content and the utilisation of colour. The results are discussed in light of the growing number of studies that emphasise the positive impact that close contact with nature has on children’s everyday life at school.
Socio-Economic and Spatial Characteristics of Wielkopolski National Park: Application of the Hedonic Pricing Method
Authors: Chwiałkowski Cyprian , Zydroń Adam
Published: April 2021

The study aimed to determine the influence of the proximity of Wielkopolski National Park (WNP) on the value of dwelling units in Mosina municipality. The research was conducted based on 1182 residential property transactions in the period from 2014 to 2018. The input data were subjected to spatial and statistical analysis. The main part of the analysis was performed with the use of the hedonic price method (HPM)—WLS (weighted least squares). The use of statistical tools made it possible to find undeniable evidence that the housing prices are positively related to the presence of Wielkopolski National Park, which has also been confirmed by previous research works conducted in other parts of the world.
Sustainable Leadership in Frontier Asia Region: Managerial Discretion and Environmental Innovation
Authors: Iqbal Qaisar , Ahmad Noor Hazlina , Li Yongmei
Published: April 2021

Climate change brings severe impact to frontier Asia in the shape of its significant negative effect on workability and livability. Drawing on the upper echelon theory (UET), this study aims to investigate the mechanism and conditional factors of a sustainable leadership–environmental performance relationship. Employing cluster sampling, this study has collected data from small and medium enterprises in frontier Asian countries—Pakistan, India, and Bangladesh. In this study, the authors have collected 245 valid responses with a response rate of 41%. The authors have employed Structural Equation Modelling (SEM) analysis to test the proposed hypothesis. The present empirical findings confirm the significant effect of sustainable leadership on environmental innovation and the significant effect of environmental innovation on environmental performance. The current study confirms that sustainable leaders indirectly influence environmental performance through environmental innovation. Nevertheless, its effect on environmental innovations does not amplify in the presence of managerial discretion. To the best of our knowledge, this study is the first in its nature that has explored the integrated role of sustainable leadership, environmental innovation, managerial discretion, and environmental performance. Limitations and implications have been listed at the end of the study.
Effects of an Autonomy Support Intervention on the Involvement of Higher Education Students
Authors: Lozano-Jiménez José Eduardo , Huéscar Elisa , Moreno-Murcia Juan Antonio
Published: April 2021

Intervention studies based on Self-Determination Theory (SDT) in educational contexts prove the importance of the teacher’s motivating interpersonal style, promoting positive results in students’ motivation. However, college practices and processes have new challenges. This study examines the repercussions of an intervention program with autonomy support on students’ involvement. The sample was randomly divided into two groups, an intervention group composed of 12 teachers, aged between 25 and 56 years (M = 35.38; SD = 7.71) and 113 students, aged between 18 and 28 years (M = 20.53; SD = 2.42); and a control group consisting of 12 teachers, aged between 25 and 44 years (M = 35.11; SD = 5.79), 107 students, aged between 18 and 39 years (M = 21; SD = 3.68). Quantitative and qualitative data were collected on the motivating interpersonal style, satisfaction of basic psychological needs, academic motivation and student involvement. The results demonstrate in general the effectiveness of the intervention on the perception of autonomy support to improve student involvement; this relationship is mediated by the improvement of psychological needs and academic motivation. The results are discussed around the recommendation of motivational strategies that the higher education teacher should implement to promote students’ involvement.
The Differences in the Propensity of Providing Smart Services by SMEs from the Electrical Engineering Industry with Regard to Their Cooperation and Innovation Flexibility
Authors: Kaňovská Lucie , Bumberová Veronika
Published: April 2021

There is still a lack of empirical evidence about smart service in general, and more particularly, in small and medium sized firms (SMEs). For SMEs, where the implementation of smart technologies is more demanding, the importance of cooperation with other business partners and innovation flexibility increases dramatically. The purpose of this article is to determine how the cooperation and innovation flexibility of SMEs affect the propensity to provide smart services in the electrical engineering industry. This paper also contributes a deeper insight into the intensity scale of collaboration within SME providers of smart services regarding the types of smart services offered. The empirical evidence is based on quantitative and firm-level data gathered through an email questionnaire which yielded 112 SME companies from the electrical engineering industry in the Czech Republic. The analysis is based on factor analysis, non-parametric tests, and binary logistic regression to identify the differences and effects of collaboration and innovation flexibility. The results of the factors affected confirmed external cooperation flexibility with customers and innovative flexibility in relation to the products as significant with inverse relationships between external collaboration with customers and the propensity to provide smart services. It is evident that weak ties in external customer cooperation flexibility operate as incentives or driving forces in the provision of smart services to establish closer relationships. The deeper research insights as well as the theoretical and practical implications are discussed at the end of the paper.
Design of a Model for Risk Reduction in Project Management in Small and Medium-Sized Enterprises
Authors: Nagyová Anna , Pačaiová Hana , Markulik Štefan , Turisová Renáta , Kozel Róbert , Džugan Ján
Published: April 2021

In general, it can be said that a project is a means of change so that the organization or individual obtain something they do not currently have, and which, in some respects, can ensure its functioning within the system in society, in the market, etc. Organizations often use different tools and techniques in project implementation to help manage projects. The selection of the optimal method requires a thorough systematic analysis. The chosen method must cover the requirements of project management with regard to its size and nature. One such tool is the ISO 21500 Guidance on project management standard, which defines the basic processes and documents needed for project management. The aim of this article is to propose a model through which it would be possible to effectively manage projects in small and medium enterprises (SMEs), i.e., where generally available international methodologies for project management are not introduced. The proposed model (referred to as Model B) was verified on projects in different SMEs in Slovakia. Mathematical evaluation presented in the paper as well as the knowledge and experience from this verification were summarized and the proposed Model B was modified (referred to as SMEPM: small and medium enterprises project management) so that it can be used in the implementation of other projects in the conditions of SMEs.
Individuals with Unilateral Mild-to-Moderate Hip Osteoarthritis Exhibit Lower Limb Kinematic Asymmetry during Walking But Not Sit-to-Stand
Authors: Higgs Jeremy P. , Diamond Laura E. , Saxby David J. , Constantinou Maria , Barrett Rod S.
Published: April 2021

Asymmetry during gait is associated with the evolution of secondary osteoarthritis. Kinematic asymmetry has been reported in advanced stages of hip osteoarthritis but has not been evaluated in earlier stages of the disease or has it been directly compared with unilateral and bilateral hip osteoarthritis. Our objective was to evaluate within-group symmetry and compare between-group asymmetry for three-dimensional pelvis, hip, knee, and ankle kinematics during walking and sit-to-stand in individuals with unilateral mild-to-moderate hip OA, bilateral mild-to-moderate hip osteoarthritis, and healthy controls. Twelve individuals with unilateral mild-to-moderate hip OA, nine individuals with bilateral mild-to-moderate symptomatic and radiographic hip OA, and 21 age-comparable healthy controls underwent three-dimensional motion analysis during walking and sit-to-stand. Pelvis and lower limb joint angles were calculated using inverse kinematics and between-limb symmetry was assessed for each group. Any resulting asymmetries (most affected minus contralateral limb) were compared between groups. Participants with unilateral hip osteoarthritis exhibited significantly less hip extension (7.90°), knee flexion (4.72°), and anterior pelvic tilt (3.38°) on their affected limb compared with the contralateral limb during the stance phase of walking. Those with unilateral hip osteoarthritis were significantly more asymmetrical than controls for sagittal plane hip and pelvis angles. No significant asymmetries were detected within- or between-groups for sit-to-stand. Individuals with unilateral hip osteoarthritis exhibited lower limb asymmetries consistent with those reported in advanced stages of disease during walking, but not sit-to-stand. Consideration of the possible negative effects of gait asymmetry on the health of the affected and other compensating joints appears warranted in the management of hip OA.
Analysis of an Electrical Circuit Using Two-Parameter Conformable Operator in the Caputo Sense
Authors: Piotrowska Ewa , Sajewski Łukasz
Published: April 2021

The problem of voltage dynamics description in a circuit containing resistors, and at least two fractional order elements such as supercapacitors, supplied with constant voltage is addressed. A new operator called Conformable Derivative in the Caputo sense is used. A state solution is proposed. The considered operator is a generalization of three derivative definitions: classical definition (integer order), Caputo fractional definition and the so-called Conformable Derivative (CFD) definition. The proposed solution based on a two-parameter Conformable Derivative in the Caputo sense is proven to be better than the classical approach or the one-parameter fractional definition. Theoretical considerations are verified experimentally. The cumulated matching error function is given and it reveals that the proposed CFD–Caputo method generates an almost two times lower error compared to the classical method.
Enhancement of Polymer Structural Ordering in Polymer-Stabilised Blue Phases for Improved Electro-Optical Properties
Authors: Kikuchi Hirotsugu , Ashimine Takahiro , Qin Zehui , Higuchi Hiroki , Anan Shizuka , Okumura Yasushi
Published: April 2021

Polymer-stabilised blue phase (PSBP) could be employed in novel fast response optical and photonic devices. It is inferred that inside PSBPs, the polymers are selectively aggregated by location in −1/2 disclinations, which are defects coexisting with the blue phase as a periodic lattice, thereby extending the temperature range of the blue phase. The polymer aggregate structure in PSBPs strongly affects their physical properties. In this study, we employed a non-destructive synchrotron ultra-small-angle X-ray diffraction analysis to investigate the effect of polymerisation rates on the polymer aggregate structure in PSBPs prepared with monomers of different polymerisation rates and examined the structure formation process of the polymer during polymerisation. When methacrylate monomers, which exhibit a relatively low polymerisation rate, were used to form polymers in PSBP, the resulting polymer was more selectively aggregated at disclinations in the PSBP. Furthermore, the electro-optical effect in the PSBP was successfully improved by reducing the polymer concentration in the PSBPs prepared with the optimised monomer combinations.
Development and Limitations of Exposure Biomarkers to Dietary Contaminants Mycotoxins
Authors: Turner Paul C. , Snyder Jessica A.
Published: April 2021

Mycotoxins are toxic secondary fungal metabolites that frequently contaminate cereal crops globally, presenting exposure hazards to humans and livestock in many settings. The heterogeneous distribution of mycotoxins in food restricts the usefulness of food sampling and intake estimates for epidemiological studies, making validated exposure biomarkers better tools for informing epidemiological investigations. While biomarkers of exposure have served important roles for understanding the public health impact of mycotoxins such as aflatoxins (AF), the science of biomarkers must continue advancing to allow for better understanding of mycotoxins’ roles in the etiology of disease and the effectiveness of mitigation strategies. This review will discuss mycotoxin biomarker development approaches over several decades for four toxins of significant public health concerns, AFs, fumonisins (FB), deoxynivalenol (DON), and ochratoxin A (OTA). This review will also highlight some knowledge gaps, key needs and potential pitfalls in mycotoxin biomarker interpretation.
In-Host Emergence of Linezolid Resistance in a Complex Pattern of Toxic Shock Syndrome Toxin-1-Positive Methicillin-Resistant Staphylococcus aureus Colonization in Siblings with Cystic Fibrosis
Authors: Boudet Agathe , Jay Alexandre , Dunyach-Remy Catherine , Chiron Raphaël , Lavigne Jean-Philippe , Marchandin Hélène
Published: April 2021

Methicillin-resistant Staphylococcus aureus (MRSA) can cause chronic lung infections in patients with Cystic Fibrosis (CF). One option for managing them is the use of linezolid. We hereby report the in-host emergence of linezolid resistance (LR) in MRSA in CF siblings via a population analysis. A collection of 171 MRSA strains from 68 samples were characterized by determining their linezolid Minimal Inhibitory Concentrations (MICs), analyzing the locus of staphylococcal protein A (spa) and whole genome sequencing. Courses of linezolid were retraced. Strains belonged to three spa types (t002, t045, t127) and two sequence types (ST1, ST5). Emergence of LR occurred under treatment, one year apart in both siblings, in the CC5-MRSA-I Geraldine clone harboring the toxic shock syndrome toxin-1-encoding gene. Resistance was related to a G2576T substitution present in a variable number of 23S rRNA gene copies. Susceptible and resistant strains were co-isolated within samples. Single Nucleotide Polymorphism-based analysis revealed complex colonizations by highly diversified, clonally related populations. LR remains rare in MRSA and there are very few longitudinal analyses documenting its emergence. Analyzing a large MRSA collection revealed new aspects of LR emergence: it emerges in specific subclonal lineages resulting from adaptive diversification of MRSA in the CF lung and this heterogeneity of intra-sample resistance may contribute to compromising antibiotic management.
Mechanistic Insight into the Peptide Binding Modes to Two M. tb MazF Toxins
Authors: Chen Ran , Zhou Jie , Xie Wei
Published: April 2021

Tuberculosis (TB) is a contagious disease caused by Mycobacterium tuberculosis (M. tb). It is regarded as a major health threat all over the world, mainly because of its high mortality and drug-resistant nature. Toxin-antitoxin (TA) systems are modules ubiquitously found in prokaryotic organisms, and the well-studied MazEF systems (MazE means “what is it?” in Hebrew) are implicated in the formation of “persister cells” in the M. tb pathogen. Here, we report cocrystal structures of M. tb MazF-mt1 and -mt9, two important MazF members responsible for specific mRNA and tRNA cleavages, respectively, in complexes with truncated forms of their cognate antitoxin peptides. These peptides bind to the toxins with comparable affinities to their full-length antitoxins, which would reduce the RNA-cleavage capacities of the toxins in vitro. After structural analysis of the binding modes, we systemically tested the influence of the substitutions of individual residues in the truncated MazE-mt9 peptide on its affinity. This study provides structural insight into the binding modes and the inhibition mechanisms between the MazE/F-mt TA pairs. More importantly, it contributes to the future design of peptide-based antimicrobial agents against TB and potentially relieves the drug-resistance problems by targeting novel M. tb proteins.
N-Linked Glycosylation on Anthrax Toxin Receptor 1 Is Essential for Seneca Valley Virus Infection
Authors: Jayawardena Nadishka , Miles Linde A. , Burga Laura N. , Rudin Charles , Wolf Matthias , Poirier John T. , Bostina Mihnea
Published: April 2021

Seneca Valley virus (SVV) is a picornavirus with potency in selectively infecting and lysing cancerous cells. The cellular receptor for SVV mediating the selective tropism for tumors is anthrax toxin receptor 1 (ANTXR1), a type I transmembrane protein expressed in tumors. Similar to other mammalian receptors, ANTXR1 has been shown to harbor N-linked glycosylation sites in its extracellular vWA domain. However, the exact role of ANTXR1 glycosylation on SVV attachment and cellular entry was unknown. Here we show that N-linked glycosylation in the ANTXR1 vWA domain is necessary for SVV attachment and entry. In our study, tandem mass spectrometry analysis of recombinant ANTXR1-Fc revealed the presence of complex glycans at N166, N184 in the vWA domain, and N81 in the Fc domain. Symmetry-expanded cryo-EM reconstruction of SVV-ANTXR1-Fc further validated the presence of N166 and N184 in the vWA domain. Cell blocking, co-immunoprecipitation, and plaque formation assays confirmed that deglycosylation of ANTXR1 prevents SVV attachment and subsequent entry. Overall, our results identified N-glycosylation in ANTXR1 as a necessary post-translational modification for establishing stable interactions with SVV. We anticipate our findings will aid in selecting patients for future cancer therapeutics, where screening for both ANTXR1 and its glycosylation could lead to an improved outcome from SVV therapy.
Age, Disease Severity and Ethnicity Influence Humoral Responses in a Multi-Ethnic COVID-19 Cohort
Authors: Smith Muneerah , Abdesselem Houari B. , Mullins Michelle , Tan Ti-Myen , Nel Andrew J. M. , Al-Nesf Maryam A. Y. , Bensmail Ilham , Majbour Nour K. , Vaikath Nishant N. , Naik Adviti , Ouararhni Khalid , Mohamed-Ali Vidya , Al-Maadheed Mohammed , Schell Darien T. , Baros-Steyl Seanantha S. , Anuar Nur D. , Ismail Nur H. , Morris Priscilla E. , Mamat Raja N. R. , Rosli Nurul S. M. , Anwar Arif , Ellan Kavithambigai , Zain Rozainanee M. , Burgers Wendy A. , Mayne Elizabeth S. , El-Agnaf Omar M. A. , Blackburn Jonathan M.
Published: April 2021

The COVID-19 pandemic has affected all individuals across the globe in some way. Despite large numbers of reported seroprevalence studies, there remains a limited understanding of how the magnitude and epitope utilization of the humoral immune response to SARS-CoV-2 viral anti-gens varies within populations following natural infection. Here, we designed a quantitative, multi-epitope protein microarray comprising various nucleocapsid protein structural motifs, including two structural domains and three intrinsically disordered regions. Quantitative data from the microarray provided complete differentiation between cases and pre-pandemic controls (100% sensitivity and specificity) in a case-control cohort (n = 100). We then assessed the influence of disease severity, age, and ethnicity on the strength and breadth of the humoral response in a multi-ethnic cohort (n = 138). As expected, patients with severe disease showed significantly higher antibody titers and interestingly also had significantly broader epitope coverage. A significant increase in antibody titer and epitope coverage was observed with increasing age, in both mild and severe disease, which is promising for vaccine efficacy in older individuals. Additionally, we observed significant differences in the breadth and strength of the humoral immune response in relation to ethnicity, which may reflect differences in genetic and lifestyle factors. Furthermore, our data enabled localization of the immuno-dominant epitope to the C-terminal structural domain of the viral nucleocapsid protein in two independent cohorts. Overall, we have designed, validated, and tested an advanced serological assay that enables accurate quantitation of the humoral response post natural infection and that has revealed unexpected differences in the magnitude and epitope utilization within a population.
Identification of Highly Conserved SARS-CoV-2 Antigenic Epitopes with Wide Coverage Using Reverse Vaccinology Approach
Authors: Hisham Yasmin , Ashhab Yaqoub , Hwang Sang-Hyun , Kim Dong-Eun
Published: April 2021

One of the most effective strategies for eliminating new and emerging infectious diseases is effective immunization. The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) warrants the need for a maximum coverage vaccine. Moreover, mutations that arise within the virus have a significant impact on the vaccination strategy. Here, we built a comprehensive in silico workflow pipeline to identify B-cell- and T-cell-stimulating antigens of SARS-CoV-2 viral proteins. Our in silico reverse vaccinology (RV) approach consisted of two parts: (1) analysis of the selected viral proteins based on annotated cellular location, antigenicity, allele coverage, epitope density, and mutation density and (2) analysis of the various aspects of the epitopes, including antigenicity, allele coverage, IFN-γ induction, toxicity, host homology, and site mutational density. After performing a mutation analysis based on the contemporary mutational amino acid substitutions observed in the viral variants, 13 potential epitopes were selected as subunit vaccine candidates. Despite mutational amino acid substitutions, most epitope sequences were predicted to retain immunogenicity without toxicity and host homology. Our RV approach using an in silico pipeline may potentially reduce the time required for effective vaccine development and can be applicable for vaccine development for other pathogenic diseases as well.
AAV-HDV: An Attractive Platform for the In Vivo Study of HDV Biology and the Mechanism of Disease Pathogenesis
Authors: Maestro Sheila , Gómez-Echarte Nahia , Camps Gracián , Usai Carla , Suárez Lester , Vales África , Olagüe Cristina , Aldabe Rafael , González-Aseguinolaza Gloria
Published: April 2021

Hepatitis delta virus (HDV) infection causes the most severe form of viral hepatitis, but little is known about the molecular mechanisms involved. We have recently developed an HDV mouse model based on the delivery of HDV replication-competent genomes using adeno-associated vectors (AAV), which developed a liver pathology very similar to the human disease and allowed us to perform mechanistic studies. We have generated different AAV-HDV mutants to eliminate the expression of HDV antigens (HDAgs), and we have characterized them both in vitro and in vivo. We confirmed that S-HDAg is essential for HDV replication and cannot be replaced by L-HDAg or host cellular proteins, and that L-HDAg is essential to produce the HDV infectious particle and inhibits its replication. We have also found that lack of L-HDAg resulted in the increase of S-HDAg expression levels and the exacerbation of liver damage, which was associated with an increment in liver inflammation but did not require T cells. Interestingly, early expression of L-HDAg significantly ameliorated the liver damage induced by the mutant expressing only S-HDAg. In summary, the use of AAV-HDV represents a very attractive platform to interrogate in vivo the role of viral components in the HDV life cycle and to better understand the mechanism of HDV-induced liver pathology.
Increased Risk of Age-Related Macular Degeneration with Chronic Hepatitis C Virus Infection: A Nationwide Population-Based Propensity Score-Matched Cohort Study in Taiwan
Authors: Yeh Chih-Ching , Wu Meei-Maan , Wu Chia-Min , Sung Fung-Chang , Muo Chih-Hsin , Te Arlene , Su Fu-Hsiung
Published: April 2021

Studies evaluating the association between age-related macular degeneration (AMD) risk and HCV infection are scant. In this population-based cohort study, 13,300 patients newly diagnosed as having HCV (HCV cohort) and 26,600 propensity score-matched patients without HCV (non-HCV cohort) were identified from the Taiwan National Health Insurance Research Database between 2000 and 2013. Furthermore, 1,983 patients with HCV who received pegylated interferon and ribavirin treatment (HCV-treated cohort) and propensity score-matched patients with HCV (matched at a ratio of 1:2) who did not receive this treatment (HCV-untreated cohort) were selected from the HCV cohort. Cox proportional hazards regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) associated with the risk of AMD in the HCV and non-HCV cohorts. The adjusted HR (aHR) for AMD in the HCV cohort was 1.22 (95% CI = 1.09–1.35). This significant association was observed only for nonexudative AMD (aHR = 1.22, 95% CI = 1.09–1.37). Compared with the HCV-untreated cohort, the HCV-treated cohort showed no significant association with any type of AMD (aHR = 1.07, 95% CI = 0.81–1.43). Age and sex did not modify AMD development after the exposure and treatment of chronic HCV infection. Our findings revealed that patients with chronic HCV infection had an increased risk of AMD.
In Vitro Lung Models and Their Application to Study SARS-CoV-2 Pathogenesis and Disease
Authors: Heinen Natalie , Klöhn Mara , Steinmann Eike , Pfaender Stephanie
Published: April 2021

SARS-CoV-2 has spread across the globe with an astonishing velocity and lethality that has put scientist and pharmaceutical companies worldwide on the spot to develop novel treatment options and reliable vaccination for billions of people. To combat its associated disease COVID-19 and potentially newly emerging coronaviruses, numerous pre-clinical cell culture techniques have progressively been used, which allow the study of SARS-CoV-2 pathogenesis, basic replication mechanisms, and drug efficiency in the most authentic context. Hence, this review was designed to summarize and discuss currently used in vitro and ex vivo cell culture systems and will illustrate how these systems will help us to face the challenges imposed by the current SARS-CoV-2 pandemic.
Complement’s C1 Complex, Factor H and the X Factor: A Personal Tribute to Prof. Robert B. Sim
Authors: Kishore Uday
Published: April 2021

It is with great sadness that I am writing this obituary for my mentor, colleague and friend, Bob, i [...]
Channeling Water Conflicts through the Legislative Branch in Colombia
Authors: Páez Angela M. , Vallejo Piedrahíta Catalina
Published: April 2021

This paper answers the question: has the Colombian Congress been effective at addressing relevant water conflicts and making them visible? While courts and social movements have been key for the advancement of social rights in Latin America, the role of legislators remains unclear. We conduct content analysis of all water-related bills, proposed bills, and constitutional amendments filed in Colombia from 1991 to 2020; we also analyzed Congress hearings of political control related to water, and the statutes of political parties who hold majority of seats in Congress; we also conducted interviews with key actors on water governance in Colombia. We find that only three bills have passed in the 30-year time frame and that relevant water conflicts have not been addressed by Colombian legislators. We find that water conflicts are not reaching the political agenda of Congress, yet through political control hearings, it has given some late visibility to critical territorial conflicts in which water is a key element. We analyze our data in light of literature on legislative politics and legal mobilization in Latin America. This study adds to global research on the role of legislators in advancing the human right to water, particularly in Latin America.
Changes in the Soil–Plant–Water System Due to Biochar Amendment
Authors: Horel Ágota , Tóth Eszter
Published: April 2021

The aim of this study was to do a complex examination of the soil–plant–water system and soil greenhouse gas emissions when biochar is applied to soil planted with sweet corn (Zea mays L. var. saccharata). The study covers two consecutive vegetation periods. We investigated (i) the changes in plant growth, (ii) soil water and temperature at different depths, (iii) greenhouse gas (GHG) emissions (CO2 and N2O) after biochar application, and (iv) the soil water, chemistry, and plant interactions. We used discrete measurements for plant growth, biomass production, and soil chemistry, while continuously monitoring the soil water content and temperature, and the state of plant health (i.e., using spectral reflectance sensors). Plant response in the control plot showed higher values of normalized difference vegetation index (NDVI; 0.3%) and lower values for photochemical reflectance index (PRI) and fraction of absorbed photosynthetically active radiation (fAPAR) by 26.8% and 2.24%, respectively, than for biochar treatments. We found significant negative correlations between fAPAR and soil water contents (SWC), and NDVI and SWC values (−0.59 < r < −0.30; p < 0.05). Soil temperature at the depth of 15 cm influenced soil CO2 emissions to a larger extent (r > 0.5; p < 0.01) than air temperature (0.21 < r < 0.33) or soil water content (r < 0.06; p > 0.05). Our data showed strong connections between GHG production and soil chemical parameters of soil pH, nitrogen, potassium, or phosphate concentrations. Biochar application increased soil CO2 emissions but reduced N2O emissions. Our results demonstrated that biochar amendment to soils can help plant growth initially, but might not result in enhanced crop yield. The plant parameters were substantially different between the investigated years for both control and biochar amended parcels; therefore, long-term studies are essential to document the lasting effects of these treatments.
Fabrication of Manganese-Supported Activated Alumina Adsorbent for Defluoridation of Water: A Kinetics and Thermodynamics Study
Authors: You Kun , Li Peijie , Fu Jinxiang , Kang Ning , Gao Yujia , Cheng Xiaoxiang , Yang Yuehong , Yu Furui
Published: April 2021

Fluoride pollution frequently occurs in many underground drinking water sources due to discrepancies in the geological environment. To address this problem, a manganese-supported activated alumina (MnOOH-supported AA) adsorbent was proposed in the present study. The adsorbent was prepared with an impregnation method, then the morphology and microstructure were systematically characterized. Further, the adsorption kinetics and thermodynamics were systematically explored through static experiments to confirm the adsorption mechanism. The results showed that MnOOH was successfully loaded on the activated alumina (AA), and irregular and convex spinous structures were formed on the surface of particles. Compared with the AA, MnOOH-supported AA exhibited a significantly higher defluoridation rate, which has been doubled. The kinetic behavior of fluoride adsorption on MnOOH-supported AA was governed by the quasi-second-order kinetics model with regression coefficients of 0.9862, 0.9978 and 0.9956, respectively. The adsorption rate was mainly ascribed to the intra-particle diffusion. Additionally, the Freundlich isotherm equation fitted the adsorption thermodynamic process reasonably well compared with the Langmuir adsorption model. Specifically, the correlation coefficients were 0.9614, 0.9383 and 0.9852 at 25 °C, 35 °C and 45 °C, respectively. The adsorption–desorption isotherm plot was similar to the Type V isotherm. The whole fluoride adsorption was a spontaneous endothermic reaction, and controlled by chemical adsorption. These results demonstrated that MnOOH-supported AA as an alternative to the conventional AA showed promising potential for defluoridation in drinking water treatment.
Optimizing the Hydrothermal Carbonization of Sewage Sludge—Response Surface Methodology and the Effect of Volatile Solids
Authors: Blach Tobias , Engelhart Markus
Published: April 2021

This study focuses on identifying the optimum conditions of sewage sludge hydrothermal carbonization by Box–Behnken Design and on the effects of volatile solids on heating value and on process water load. To get insight into the solid and process water characteristics, we applied the Box–Behnken Design on the hydrothermal reaction temperature (190, 220, 250 °C), reaction time (0.5, 2.25, 4 h) and pH (3.9, 5, 6.1). The response surface of the liquid phase revealed decreasing dissolved organic carbon (DOC) concentrations with increasing temperature from 9446 mg/L (190 °C) to 7402 mg/L (250 °C) at 4 h reaction time. For the same hydrothermal conditions, NH4-N concentration increased from 754 to 1230 mg/L. Reaction temperature was identified as the most important process parameter, whereas reaction time and pH had only minor effects. Moreover, linear coefficients of the models were more decisive than the interrelation and quadratic coefficients. Volatile solids (VS) of the feedstock were found to significantly influence both the load of the process water and the change in heating value of the hydrochars. Process water load increased steadily with higher VS. The heating value only increased with more than around 65–80% VS in feedstock.
Comparison of Different Magnesium Hydroxide Coatings Applied on Concrete Substrates (Sewer Pipes) for Protection against Bio-Corrosion
Authors: Merachtsaki Domna , Tsardaka Eirini-Chrysanthi , Anastasiou Eleftherios K. , Yiannoulakis Haris , Zouboulis Anastasios
Published: April 2021

Several coatings and linings have been examined and used for the protection of sewer concrete pipes, against mainly biogenic-provoked corrosion due to the production of bio-sulfuric acid, leading to the degradation of the pipes’ structure and eventually, to their collapse and need for costly replacement. This study aimed to examine the potential differences between five different magnesium hydroxide coatings, prepared from powders presenting different purity, surface area and pore size distribution, when applied as corrosion protection agents. These coatings were tested by using accelerated sulfuric acid spraying tests, both in dry and wet coating conditions. The coating adhesion ability and their microstructure were examined by the application of pull-off measurements and of SEM analysis, respectively and were found to present certain differences, regarding the adhesion ability and the surface morphologies. During the acid spraying procedure, the surface pH and the mass change of coated concrete specimens were recorded daily. The surface pH was reduced towards acidic values and the mass reduction approached almost −20% in comparison with the initial coating mass for certain cases. Additionally, the hardness and roughness of concrete surface under the coating layer (i.e., the interface between the coating and the surface) after four days of acid spraying, exhibited much smaller changes (due to protection) in contrast to the uncoated concrete specimens (used as blank/comparison experiments), which were found to be highly affected/corroded. The formation of concrete corrosion and coating by-products, as noticed after the respective chemical reactions, was recorded by X-ray diffraction (XRD) measurements and the respective quantification of obtained results. In all the coated specimens only very small amounts of the major by-product (gypsum) was observed, indicating that the concrete surface was sufficiently protected from sulfuric acid attack.
Probabilistic Approach to Precipitation-Runoff Relation in a Mountain Catchment: A Case Study of the Kłodzka Valley in Poland
Authors: Perz Adam , Sobkowiak Leszek , Wrzesiński Dariusz
Published: April 2021

On the basis of daily precipitation and discharges recorded in 1974–2013 relations between precipitation and runoff in the Kłodzka Valley (KV) in south-western Poland were analyzed. The degree of synchronicity between them was determined using the bivariate Archimedean copulas. This study aims at identifying and then describe in a probabilistic way the precipitation and runoff relations in the area playing an important role in the formation of water resources, but also particularly exposed to flooding. It was found that isolines of the synchronous occurrence of precipitation and total runoff in the Nysa Kłodzka catchment controlled by gauge Kłodzko had a zonal distribution, with the synchronicity values decreasing from south-east to north-west of the study area. This proves that its eastern part is more hydrologically active, compared to the western part, and as such it determines the amount of water resources of the study area. The decrease in synchronicity is influenced by the type and spatial distribution of precipitation, the structure of water supply, and the geological structure of the study area. Moreover, probabilistic methods applied in this research differ from those used in previous research on the hydrology of KV, as we propose using the copula functions. The method presented can be used to evaluate the availability of water resources in areas playing a key role in their formation on different scales.
Validation of a Swimming Direction Model for the Downstream Migration of Atlantic Salmon Smolts
Authors: Szabo-Meszaros Marcell , Silva Ana , Bærum Kim , Baktoft Henrik , Alfredsen Knut , Hedger Richard , Økland Finn , Gjelland Karl , Fjeldstad Hans-Petter , Calles Olle , Forseth Torbjørn
Published: April 2021

Fish swimming performance is strongly influenced by flow hydrodynamics, but little is known about the relation between fine-scale fish movements and hydrodynamics based on in-situ investigations. In the presented study, we validated the etho-hydraulic fish swimming direction model presented in the River Mandal from Southern Norway, using similar behavioral and hydraulic data on salmon smolts from the River Orkla in Central Norway. The re-parametrized model explained the variation of the swimming direction of fish in the Orkla system in same degree as the original model performed in the Mandal system (R2: 84% in both cases). The transferability of the model when using it from one river to predict swimming direction in the other river was lower (R2: 21% and 26%), but nevertheless relatively high given that the two localities differed in hydraulic conditions. The analyses thus provide support for the fact that the identified hydraulic parameters and their interaction affected smolt behavior in a similar way at the two sites, but that local parametrization of the base model is required. The developed etho-hydraulic models can provide important insights into fish behavior and fish migration trajectories and can be developed into prediction models important for the future development of behavioral downstream migration solutions.
Sulfur Isotope and Stoichiometry–Based Source Identification of Major Ions and Risk Assessment in Chishui River Basin, Southwest China
Authors: Ge Xin , Wu Qixin , Wang Zhuhong , Gao Shilin , Wang Tao
Published: April 2021

Hydrochemistry and sulfur isotope (δ34S–SO42−) of Chishui River watershed in Southwest China were measured to identify the sources of riverine solutes, the potential impact of human activities, water quality, and health risk. The main findings indicated that the HCO3− (2.22 mmol/L) and Ca2+ (1.54 mmol/L) were the major ions, with the cation order of Ca2+ (71 ± 6%) > Mg2+ (21 ± 6%) > Na+ + K+ (8 ± 3%) and the anion sequence of HCO3− (55 ± 9%) > SO42− (41 ± 9%) > Cl− (4 ± 3%). The riverine δ34S–SO42− values fluctuated from −7.79‰ to +22.13‰ (average +4.68‰). Overall, the water samples from Chishui River presented a hydrochemical type of Calcium–Bicarbonate. The stoichiometry and PCA analysis extracted three PCs that explained 79.67% of the total variances. PC 1 with significantly positive loadings of K+, Mg2+, F−, HCO3− and relatively strong loading of Ca2+ revealed the natural sources of rock weathering inputs (mainly carbonate). PC 2 (Na+ and Cl−) was primarily explained as atmospheric contribution, while the human inputs were assuaged by landscape setting and river water mixing processes. The strongest loadings of SO42− and NO3− were found in PC 3, which could be defined as the anthropogenic inputs. The H2SO4–involved weathering processes significantly impacted (facilitated weathering) the concentrations of riverine total ions. Sulfur isotope compositions further indicated that riverine SO42− were mainly controlled by anthropogenic inputs SO42− compared to the sulfide oxidation derived SO42−, and the atmospheric contribution was very limited. The results of risk and water quality assessment demonstrated that Chishui River water was desirable for irrigation and drinking purposes due to low hazard quotient values (<1, ignorable risk), but long–term monitoring is still worthy under the circumstances of global environmental change.
Hydraulic Dynamic Calculation and Simulation
Authors: Aricò Costanza
Published: April 2021

Hydraulic dynamics is emerging as a basic concept with applications and important implications for many industrial, civil, and environmental engineering problems [...]
Online and telephone access to general practice: a cross-sectional patient survey
Authors: Bryce Carol , O'Connell Matthew DL , Dale Jeremy , Underwood Martin , Atherton Helen
Published: April 2021

Background

Improving access to primary health care in the UK has focused on the use of telephone and online access, but little is known about how awareness of and use varies between different patient groups.

Aim

To determine how patients are interacting with telephone and online channels for accessing general practice services and information, and to analyse how this varies according to patient characteristics and health status.

Design & setting

A cross-sectional self-administered survey of adult patients in general practices across the West Midlands, UK.

Method

Descriptive statistics were used to show participants’ awareness of and interaction with online information sources and remote access. Multivariable logistic regression was used to model the relationships between demographic and health characteristics, and awareness and use of online services and alternatives to face-to-face consultations (for example, telephone).

Results

A total of 2789 patients (19.0% response rate) from 43 general practices participated. The study found 60.8% (n = 1651/2715) of participants were aware of online services and 30.3% (n = 811/2674) reported having used one. Daily internet usage and frequently visiting the GP showed the strongest associations with knowledge and use of online services.

Conclusion

The study shows that there is the potential for inequitable awareness and use of telephone and online services in general practice populations. Given that their use has greatly increased owing to the COVID-19 pandemic, future service design will need to ensure equity is taken into account.
Procesos de la gestión financiera en las empresas de servicio metalmecánico del occidente de Venezuela.
Authors: Piñero Nairen
Published: April 2021

El presente artículo tuvo como propósito describir los procesos de la gestión financiera llevados a cabo por las empresas de servicio metalmecánico del occidente de Venezuela. La metodología fue descriptiva, con un diseño no experimental, transeccional y de campo, esta permitió interpretar la diversidad de escenarios que se presentan en estas empresas, analizando el comportamiento de los gerentes de finanzas e inversión. Se aplicó la encuesta, utilizando un cuestionario de 9 ítems, con 5 opciones de respuestas. La validez se hizo bajo el juicio de expertos. Para la confiabilidad, se empleó el Método Alfa de Cronbach, obteniendo un resultado de 0,83. El análisis de los datos se realizó mediante la estadística descriptiva, a través del análisis de frecuencias. Se concluyó alta aplicación de dichos procesos, otorgándole una leve fortaleza; evidenciándose muy alta aplicación del control y seguimiento; y alta aplicación de los procesos de planificación y organización.
Producción agrícola intensiva: una estrategia de tecnificación agrícola modelo Almería
Authors: Soruco Parada Paola Daniela
Published: April 2021

A nivel mundial existe preocupación por la capacidad de abastecimiento de la producción agrícola. El objetivo de este artículo científico fue proponer un Modelo de Tecnificación Agrícola de alto rendimiento para el municipio de Sucre (Bolivia) que permita cubrir los requerimientos de productos alimenticios de la región. El estudio asumió un enfoque mixto que consistió en realizar un diagnóstico de la producción agrícola de esta región, para identificar las posibilidades de adecuación del modelo de agricultura intensiva vigente en el municipio de Almería (España). Como resultado se propuso una estrategia de implantación que implica el trabajo sistemático en siete áreas fundamentales: recursos naturales, recursos humanos, infraestructura y equipamiento, innovación tecnológica, capacitación y asistencia técnica, respeto al medio ambiente y cooperación institucional. El documento concluye probando mejoras en el rendimiento de la producción agrícola, mediante un ejemplo teórico referido a la producción de tomate en los distritos 7 y 8 de Sucre.