bluuebunny/crossref_metadata_2025 huggingface dataset:
Development and Efficacy of Lateral Flow Point-of-Care Testing Devices for Rapid and Mass COVID-19 Diagnosis by the Detections of SARS-CoV-2 Antigen and Anti-SARS-CoV-2 Antibodies
Authors: Hsieh Wen-Yeh , Lin Cheng-Han , Lin Tzu-Ching , Lin Chao-Hsu , Chang Hui-Fang , Tsai Chin-Hung , Wu Hsi-Tien , Lin Chih-Sheng
Published: September 2021

The COVID-19 pandemic is an ongoing global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 2020–2021. COVID-19 is becoming one of the most fatal pandemics in history and brings a huge challenge to the global healthcare system. Opportune detection, confinement, and early treatment of infected cases present the first step in combating COVID-19. Diagnosis via viral nucleic acid amplification tests (NAATs) is frequently employed and considered the standard procedure. However, with an increasing urge for point-of-care tests, rapid and cheaper immunoassays are widely utilized, such as lateral flow immunoassay (LFIA), which can be used for rapid, early, and large-scale detection of SARS-CoV-2 infection. In this narrative review, the principle and technique of LFIA applied in COVID-19 antigen and antibody detection are introduced. The diagnostic sensitivity and specificity of the commercial LFIA tests are outlined and compared. Generally, LFIA antigen tests for SARS-CoV-2 are less sensitive than viral NAATs, the “gold standard” for clinical COVID-19 diagnosis. However, antigen tests can be used for rapid and mass testing in high-risk congregate housing to quickly identify people with COVID-19, implementing infection prevention and control measures, thus preventing transmission. LFIA anti-SARS-CoV-2 antibody tests, IgM and/or IgG, known as serology tests, are used for identification if a person has previously been exposed to the virus or vaccine immunization. Notably, advanced techniques, such as LFT-based CRISPR-Cas9 and surface-enhanced Raman spectroscopy (SERS), have added new dimensions to the COVID-19 diagnosis and are also discussed in this review.
Clinical and Histopathological Factors Influencing IgA Nephropathy Outcome
Authors: Konieczny Andrzej , Donizy Piotr , Gołębiowski Tomasz , Tukiendorf Andrzej , Hałoń Agnieszka , Kusztal Mariusz , Augustyniak-Bartosik Hanna , Krajewska Magdalena
Published: September 2021

IgA nephropathy (IgAN) is the most frequent primary glomerulonephritis worldwide. Due to its heterogenicity, there is a need to establish robust biomarkers for IgAN, to support treatment decisions and evaluate the risk of progression to end-stage renal disease. Using both clinical and histopathological data, derived from renal biopsies, we aimed to find predictors of renal function deterioration and proteinuria reduction. Clinical and histopathological data of 80 patients with biopsy proven IgAN were analyzed. In a multivariate logarithmic regression model, the presence of endocapillary hypercellularity (E1) predicted a decline in estimated glomerular filtration rate (eGFR)of at least 50% with an odds ratio (OR) of 15.2, whereas serum albumin concentration had a negative influence on eGFR deterioration (OR 0.2). In the second multivariate model, the extent of interstitial fibrosis predicted the worsening of eGFR by 50% (OR 1.1) and serum albumin concentration had a protective impact (OR 0.1). In the univariate logarithmic regression, both the extent of interstitial fibrosis and the presence of endocapillary hypercellularity negatively correlated with the reduction in proteinuria below 1.0 g/24 h with an OR of 0.2 and 0.9, respectively. In our paper, we confirmed the utility of histopathological variables, especially endocapillary hypercellularity and interstitial fibrosis, and clinical parameters, particularly serum albumin concentration, in the prediction of both a decline in eGFR and a reduction in proteinuria in IgA nephropathy.
Association of Adiponectin, Leptin and Resistin Plasma Concentrations with Echocardiographic Parameters in Patients with Coronary Artery Disease
Authors: Puchałowicz Kamila , Kłoda Karolina , Dziedziejko Violetta , Rać Monika , Wojtarowicz Andrzej , Chlubek Dariusz , Safranow Krzysztof
Published: September 2021

The imbalanced network of adipokines may contribute to the development of systemic low-grade inflammation, metabolic diseases and coronary artery disease (CAD). In the last decade, three classic adipokines—adiponectin, leptin and resistin—have been of particular interest in studies of patients with CAD due to their numerous properties in relation to the cardiovascular system. This has directed our attention to the association of adipokines with cardiac structure and function and the development of heart failure (HF), a common end effect of CAD. Thus, the purpose of this study was to analyse the associations of plasma concentrations of adiponectin, leptin and resistin with parameters assessed in the echocardiographic examinations of CAD patients. The presented study enrolled 167 Caucasian patients (133 male; 34 female) with CAD. Anthropometric, echocardiographic and basic biochemical measurements, together with plasma concentrations of adiponectin, leptin and resistin assays, were performed in each patient. Adiponectin concentrations were negatively associated with left ventricular ejection fraction (LVEF) and shortening fraction (LVSF), and positively associated with mitral valve E/A ratio (E/A), left ventricular end-diastolic volume (LVEDV), left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter LVESD, and left atrium diameter (LAD). Resistin concentrations were negatively associated with E/A. Leptin concentrations, although correlated with HF severity assessed by the New York Heart Association (NYHA) Functional Classification, were not independently associated with the echocardiographic parameters of cardiac structure or function. In conclusion, adiponectin and resistin, but not leptin, are associated with the echocardiographic parameters of cardiac remodelling and dysfunction. These associations suggest that adiponectin and resistin might be involved in mechanisms of cardiac remodelling or compensative response. We also suggest the possible benefits of adiponectin and resistin level measurements in the monitoring of patients with CAD.
Clinical Uses and Short-Term Safety Profile of Ethiodized Poppy Seed Oil Contrast Agent in the Diagnosis and Treatment of Vascular Anomalies and Tumors
Authors: Clemens Robert K. , Sebastian Tim , Kerr Cindy , Alomari Ahmad I.
Published: September 2021

Background: There is a sparsity of data on the use of ethiodized poppy seed oil (EPO) contrast agent (Lipiodol) in patients. We investigated the safety of EPO in children, adolescents, and some adults for diagnostic and therapeutic interventions. Methods: All patients who underwent procedures with EPO between 1995 and 2014 were retrospectively included. Demographic characteristics, diagnosis, dose, route of administration, preparation of EPO in combination with other agents, and complications were recorded. Results: In 1422 procedures, EPO was used for diagnostic or treatment purposes performed in 683 patients. The mean patient age was 13.4 years (range: 2 months–50 years); 58% of patients were female. Venous malformations (n = 402, 58.9%) and arteriovenous malformations (n = 60, 8.8%) were the most common diagnosis. Combined vascular anomalies included capillary–lymphatic–venous malformations, fibroadipose vascular anomalies (n = 54, 7.9%), central conducting lymphatic anomalies (n = 31, 4.5%), lymphatic malformations (n = 24, 3.5%), aneurysmal bone cysts (n = 22, 3.2%), and vascularized tumors (n = 11, 1.6%). In 1384 procedures (96%), EPO was used in various combinations with sclerosing and embolization agents, including sodium tetradecyl sulfate, ethanol, and glue. The mean volume of EPO used in interventions was 3.85 mL (range: 0.1–25 mL) per procedure with a mean patient weight of 45.9 kg (range: 3.7–122.6 kg) and a weight-adjusted dose of 0.12 mL/kg (range: 0.001–1.73 mL/kg). In 56 procedures (4%), EPO was used as a single agent for diagnostic lymphangiography. The mean volume was 4.8 mL (range: 0.3–13 mL) per procedure with a mean patient weight of 27.4 kg (range: 2.4–79.3 kg) and a weight-adjusted dose of 0.2 mL/kg (range: 0.04–0.54 mL/kg). Procedural-related complications occurred in 25 (1.8%) procedures. The 20 minor and 5 major complications were related to the primary treatment agents. None of them were directly related to EPO. No allergic reactions were noted. Conclusion: The use of an ethiodized poppy seed oil contrast agent in children, adolescents, and adults for diagnostic or therapeutic purposes is safe.
Societal Criticism towards COVID-19: Assessing the Theory of Self-Diagnosis Contrasted to Medical Diagnosis
Authors: Mouliou Dimitra S. , Pantazopoulos Ioannis , Gourgoulianis Konstantinos I.
Published: September 2021

Background: Coronavirus disease 2019 (COVID-19) has emerged as a pandemic introducing the mass autodiagnosis via rapid antigen testing methods, and self-tests were important for several populaces, yet with several neglected issues. In addition, hospital diagnosis was a target of many people or media, as the various COVID-19 clinical phenotypes trammel the precise emergency physicians’ response. Methods: A web-based questionnaire was disseminated through social media in the first half of August 2021 in the Greek populace, assessing the societal criticism for autodiagnosis and medical diagnosis and their issues, just before the occurrence of the fourth pandemic wave in the country. Results: Two thirds of the responders characterized self-tests as unreliable and two fifths reported them dangerous. Reliability (OR 1.335; CI 0.060–0.300; p = 0.000) and danger (OR 5.068; CI 3139–8184; p = 0.000) were significant predictors for the population-based sample’s volition for a self-test. Reversely, regarding medical diagnosis, half of the responders reported the lack of reliability and effectiveness in the emergency departments, which had a significant impact on willingness to visit a hospital if needed (OR 3.207; CI 1987–5182; p = 0.000 and OR 3.506; CI 2167–5670; p = 0.000). Conclusions: The importance of community-based questionnaires is highlighted for assessing people’s criticism and improving the highlighted points in several topics.
Clinical Pilot Series of Non-Self-Contained Periodontal Infrabony Defects Treated with a Slowly Resorbable Bovine Pericardium Membrane in Combination with Low-Temperature-Treated Decellularized Bovine Bone Particles
Authors: Rojas Mariana A. , Marini Lorenzo , Russo Paola , Blardi Vittorio , Schmidlin Patrick R. , Pilloni Andrea
Published: September 2021

The aim of this case series was to present the clinical outcomes of non-contained intrabony periodontal defects (IPDs) treated by means of papillary preservation flaps in association with a slowly resorbable bovine pericardium membrane (BPM) and a low-temperature-treated bovine bone graft (BBG). Eight healthy, non-smoking patients (two males and six females, mean age 48 ± 8 years) with stage 3 periodontitis and at least one site with residual probing depth (PD) ≥ 6 mm associated with a non-contained IPD ≥ 3 mm were treated. Two weeks after surgery, no adverse events were observed, and an early wound healing score (EHS) of 8.1 ± 1.0 was recorded. After 1 year, the mean probing depth (PD) reduction and mean clinical attachment level gain (CAL-gain) accounted for 4.8 ± 0.7 and 3.5 ± 0.7 mm, respectively, whereas the mean gingival recession (REC) was of 1.2 ± 0.3 mm. Radiographic bone fill was observed in all cases. In conclusion, the treatment of non-contained IPDs with a slowly resorbable BPM and a low-temperature-treated BBG could be considered safe and may result in significant clinical improvements 1 year after surgery.
Comparison of Different Methods of Education in the Adoption of Oral Health Care Knowledge
Authors: Gavic Lidia , Marcelja Martina , Gorseta Kristina , Tadin Antonija
Published: September 2021

Aim: The scope of this study was to determine if there is a critical distinction in the usage of lectures, videos, and pamphlets as educational material utilized in the adoption of oral health care knowledge. Materials and methods: Three-hundred and thirty children from ages 11 to 13 from the city of Split, Croatia completed the questionnaire on oral health care knowledge. Consequently, they were educated by randomly using a method: lecture, pamphlet, or video. Finally, after education, their knowledge was tested again. Results: Different statistical tests were used for comparison of different sets of data. The Wilcoxon signed-rank test showed a statistically significant difference (p ˂ 0.001) compared to the results before and after education. The Kruskal–Wallis test comparing knowledge outcomes after three different types of education: video, lecture, and pamphlet, showed a statistically significant difference in the final knowledge between groups (p ˂ 0.05). A pairwise comparison between different types of education showed a significant statistical difference between education conducted by pamphlet and video material (p = 0.003) and pamphlet and lecture (p = 0.006). No difference was observed between the level of knowledge acquired through video material education and lectures (p = 0.928). Conclusion: Videos and lectures as means of education showed equal effectiveness in the adoption of oral health care knowledge, while the pamphlet was a method that proved to be less effective.
Meta-Strategy for Learning Tuning Parameters with Guarantees
Authors: Meunier Dimitri , Alquier Pierre
Published: September 2021

Online learning methods, similar to the online gradient algorithm (OGA) and exponentially weighted aggregation (EWA), often depend on tuning parameters that are difficult to set in practice. We consider an online meta-learning scenario, and we propose a meta-strategy to learn these parameters from past tasks. Our strategy is based on the minimization of a regret bound. It allows us to learn the initialization and the step size in OGA with guarantees. It also allows us to learn the prior or the learning rate in EWA. We provide a regret analysis of the strategy. It allows to identify settings where meta-learning indeed improves on learning each task in isolation.
Adequacy Evaluation of an Islanded Microgrid
Authors: Kjær Martin , Wang Huai , Blaabjerg Frede
Published: September 2021

The reliability of power converters has been extensively examined in terms of component- and converter level. However, in case of multiple generation units, the evaluation of the performance of power systems requires system-level modeling. This paper aims to merge the prior art of reliability modeling of power converters with the adequacy evaluation of power systems through an extensive design and evaluation analysis of a microgrid based case study. The methodology proposed in the paper integrates the device-level analysis into the domain of the conventional power system reliability analysis while outlining the steps needed to deal with non-exponential distributed failures of power electronic-based generation units. A replacement policy of the power electronic-based units is adopted by means of evaluating the system risk of not supplying system loads, and, finally, an approach on how to ensure a desired replacement frequency is outlined.
Securing Publisher–Subscriber Smart Grid Infrastructure
Authors: Orr Fraser , Nafees Muhammad Nouman , Saxena Neetesh , Choi Bong Jun
Published: September 2021

The security of communication protocols in the smart grid system is a crucial concern. An adversary can exploit the lack of confidentiality and authentication mechanism to cause damaging consequences. In the substation automation systems that rely on multicast communication between various intelligent electronic devices, the lack of security features in the standard IEC61850 and IEC62351 can invite attackers to manipulate the integrity of the employed publisher–subscriber communication paradigm to their advantage. Consequently, many researchers have introduced various approaches offering authenticity and confidentiality. However, such schemes and methods for the aforesaid standards have computational limitations in compliance with the stringent timing requirements of specific applications in the smart grid. In this paper, we propose an approach that can fully secure the publisher–subscriber communication against confidentiality attacks. In this direction, we develop a demo tool to validate the performance of our proposed security approach for potential factors such as timing requirements and the size of the messages. Finally, we evaluate our scheme considering the requirements of the GOOSE, SMV, and MMS protocols in the substation automation systems.
Forecast of Distribution and Thickness of Gas Hydrate Stability Zone at the Bottom of the Caspian Sea
Authors: Bogoyavlensky Vasily , Yanchevskaya Alisa , Kishankov Aleksei
Published: September 2021

The Caspian Sea is a region of active hydrocarbon production, where apart from conventional accumulations, gas hydrates (GH) are known to exist. GH are a potential future source of energy, however, currently they pose danger for development of conventional fields. The goal of this research was to determine the area of GH distribution and thickness of their stability zone in the Caspian Sea using numerical modeling and to define how certain parameters affect the calculated thickness. As a result of the research, cartographic schemes were created for the South and Middle Caspian, where GH were predicted. For the South Caspian, conditions for methane hydrates formation exist at depths of more than 419–454 m, and for the Middle Caspian, more than 416–453 m. The maximal thicknesses of methane hydrates stability zones for the South Caspian can reach 900–956 m, and for the Middle Caspian, 226–676 m. Variations of parameters of seafloor depth, geothermal gradient and gas composition can significantly change the resulting thickness of GH stability zone.
Thermodynamics, Energy Dissipation, and Figures of Merit of Energy Storage Systems—A Critical Review
Authors: Michaelides Efstathios E.
Published: September 2021

The path to the mitigation of global climate change and global carbon dioxide emissions avoidance leads to the large-scale substitution of fossil fuels for the generation of electricity with renewable energy sources. The transition to renewables necessitates the development of large-scale energy storage systems that will satisfy the hourly demand of the consumers. This paper offers an overview of the energy storage systems that are available to assist with the transition to renewable energy. The systems are classified as mechanical (PHS, CAES, flywheels, springs), electromagnetic (capacitors, electric and magnetic fields), electrochemical (batteries, including flow batteries), hydrogen and thermal energy storage systems. Emphasis is placed on the magnitude of energy storage each system is able to achieve, the thermodynamic characteristics, the particular applications the systems are suitable for, the pertinent figures of merit and the energy dissipation during the charging and discharging of the systems.
A Study of Blockage Effects at the Wind Turbine and Wind Farm Scales
Authors: Popescu Mihaela , Flåtten Tore
Published: September 2021

The paper provides novel insights into the physics behind the wind turbine and wind farm blockages as well as their effects on the energy yield based on the momentum and energy balance. The current work presents blockage effects at two scales: the local scale and the wind farm scale. We clarify the combined effect of local blockages when more than one turbine is present. The work demonstrates why two turbines, which are positioned one behind the other, induce a mutual decrease in energy yield. When the turbines are placed in a row, there is an increase of energy from the end to the middle of the row because of the restriction of the expansion flow. As in the case of two turbines placed behind each other, back rows induce a power decrease for the rows in front of them and the effect increases from the edge to the center. The work also elucidates for the first time how the power output of an isolated row has a maximum in the center, whereas, in a wind farm, wind turbines on the edge of the first row could have maximum power. The findings are supported by CFD.
Load Profile-Based Residential Customer Segmentation for Analyzing Customer Preferred Time-of-Use (TOU) Tariffs
Authors: Jang Minseok , Jeong Hyun-Cheol , Kim Taegon , Joo Sung-Kwan
Published: September 2021

Smart meters and dynamic pricing are key factors in implementing a smart grid. Dynamic pricing is one of the demand-side management methods that can shift demand from on-peak to off-peak. Furthermore, dynamic pricing can help utilities reduce the investment cost of a power system by charging different prices at different times according to system load profile. On the other hand, a dynamic pricing strategy that can satisfy residential customers is required from the customer’s perspective. Residential load profiles can be used to comprehend residential customers’ preferences for electricity tariffs. In this study, in order to analyze the preference for time-of-use (TOU) rates of Korean residential customers through residential electricity consumption data, a representative load profile for each customer can be found by utilizing the hourly consumption of median. In the feature extraction stage, six features that can explain the customer’s daily usage patterns are extracted from the representative load profile. Korean residential load profiles are clustered into four groups using a Gaussian mixture model (GMM) with Bayesian information criterion (BIC), which helps find the optimal number of groups, in the clustering stage. Furthermore, a choice experiment (CE) is performed to identify Korean residential customers’ preferences for TOU with selected attributes. A mixed logit model with a Bayesian approach is used to estimate each group’s customer preference for attributes of a time-of-use (TOU) tariff. Finally, a TOU tariff for each group’s load profile is recommended using the estimated part-worth.
On-Line EIS Measurement for High-Power Fuel Cell Systems Using Simulink Real-Time
Authors: Han Soo-Bin , Oh Hwanyeong , Lee Won-Yong , Won Jinyeon , Chae Suyong , Baek Jongbok
Published: September 2021

Impedance measurements by EIS are used to build a physical circuit-based model that enables various fault diagnostics and lifetime predictions. These research areas are becoming increasingly crucial for the safety and preventive maintenance of fuel cell power systems. It is challenging to apply the impedance measurement up to commercial applications at the field level. Although EIS technology has been widely used to measure and analyze the characteristics of fuel cells, EIS is applicable mainly at the single-cell level. In the case of stacks constituting a power generation system in the field, it is difficult to apply EIS due to various limitations in the high-power condition with uncontrollable loads. In this paper, we present a technology that can measure EIS on-line by injecting the perturbation current to fuel cell systems operating in the field. The proposed EIS method is developed based on Simulink Real-Time so that it can be applied to embedded devices. Modeling and simulation of the proposed method are presented, and the procedures from the simulation in virtual space to the real-time application to physical systems are described in detail. Finally, actual usefulness is shown through experiments using two physical systems, an impedance hardware simulator and a fuel cell stack with practical considerations.
Quasi-Boundary Method for Design Consideration of Resonant DC-DC Converters
Authors: Hinov Nikolay
Published: September 2021

The paper presents a new unified method for designing the two basic types of serial resonant DC-DC converters (series and with a parallel-loaded capacitor). The method is based on the use of a simplified generalized approach for the analysis of this type of power electronic devices. It is characterized by the fact that regardless of the specific operating mode, with a control frequency below or above the resonant of the series resonant circuit to determine the relationship between input and output voltage or current, it is assumed that the converter operates in resonance. In this sense, it is called a quasi-boundary method for analysis and design. The use of the quasi-boundary method significantly accelerates and facilitates the design of the considered power circuits, which is very useful for the purposes of engineering practice, as well as in the training of power electronics. The applicability of this approach is proven by the methods of mathematical modeling and computer simulations.
Assessment of Carbon Stock in Forest Biomass and Emission Reduction Potential in Malaysia
Authors: Raihan Asif , Begum Rawshan Ara , Mohd Said Mohd Nizam , Pereira Joy Jacqueline
Published: September 2021

Malaysia has a large extent of forest cover that plays a crucial role in storing biomass carbon and enhancing carbon sink (carbon sequestration) and reducing atmospheric greenhouse gas emissions, which helps to reduce the negative impacts of global climate change. This article estimates the economic value of forest carbon stock and carbon value per hectare of forested area based on the price of removing per ton CO2eq in USD from 1990 to 2050. The economic value of biomass carbon stored in the forests is estimated at nearly USD 51 billion in 2020 and approximately USD 41 billion in 2050, whereas carbon value per hectare forest area is estimated at USD 2885 in 2020 and USD 2388 in 2050. If the BAU scenario of forest loss (converting forests to other land use) continues, the projected estimation of carbon stock and its economic value might fall until 2050 unless further initiatives on proper planning of forest management and ambitious policy implementation are taken. Instead, Malaysia’s CO2 emission growth started to fall after 2010 due to rising forest carbon sink of 282 million tons between 2011 and 2016, indicating a huge potential of Malaysian forests for future climate change mitigation. The estimated and projected value of carbon stock in Malaysian forest biomass, annual growth of forest carbon, forest carbon density and carbon sink would be useful for the better understanding of enhancing carbon sink by avoiding deforestation, sustainable forest management, forest conservation and protection, accurate reporting of national carbon inventories and policy-making decisions. The findings of this study could also be useful in meeting emission reduction targets and policy implementation related to climate change mitigation in Malaysia.
Thinning Influences Wood Properties of Plantation-Grown Eucalyptus nitens at Three Sites in Tasmania
Authors: Gendvilas Vilius , Downes Geoffrey M. , Neyland Mark , Hunt Mark , Harrison Peter A. , Jacobs Andrew , Williams Dean , O’Reilly-Wapstra Julianne
Published: September 2021

Thinning of forestry plantations is a common silviculture practice to increase growth rates and to produce larger dimension logs. The wood properties, basic density and stiffness, are key indicators of the suitability of timber for particular purposes and ultimately determine timber value. The impact of thinning operations on wood properties is, therefore, of considerable interest to forest growers and timber producers. To date, studies examining the impact of thinning on wood properties have produced variable results and understanding the consistency of the effects of thinning treatments across various sites for important plantation species is limited. Two non-destructive assessment techniques, drilling resistance and acoustic wave velocity, were used to examine the impact of thinning on basic density and stiffness in 19–21-year-old plantation grown Eucalyptus nitens across three sites. Commercial thinning to 300 trees ha−1 decreased the stiffness of standing trees and this effect was consistent across the sites. Reduction in stiffness due to thinning ranged from 3.5% to 11.5%. There was no difference in wood properties between commercially and non-commercially thinned trees to 300 trees ha−1 and no difference in wood properties when thinned to 500 trees ha−1. Basic density was not affected by thinning. The site had significant effects on both basic density and stiffness, which were lowest at the highest precipitation and highest elevation site. The results indicate that wood properties are influenced both by silviculture and site environmental differences. This knowledge can be used for the better management of E. nitens resources for solid wood production.
Chemical Signals in Tree Rings from Northern Patagonia as Indicators of Calbuco Volcano Eruptions since the 16th Century
Authors: Bertin Lizette J. , Christie Duncan A. , Sheppard Paul R. , Muñoz Ariel A. , Lara Antonio , Alvarez Claudio
Published: September 2021

The Calbuco volcano ranks third in the specific risk classification of volcanoes in Chile and has a detailed eruption record since 1853. During 2015, Calbuco had a sub-Plinian eruption with negative impacts in Chile and Argentina, highlighting the need to determine the long-term history of its activity at a high-resolution time scale to obtain a better understanding of its eruptive frequency. We developed a continuous eruptive record of Calbuco for the 1514–2016 period by dendrochemical analysis of Fitzroya cupressoides tree rings at a biennium resolution using inductively coupled plasma–mass spectrometry. After comparing the chemical record of 20 elements contained in tree rings with historical eruptions, one group exhibited positive anomalies during (Pb/Sn) and immediately after (Mo/P/Zn/Cu) eruptions, with a Volcanic Explosivity Index (VEI) ≥ 3, and so were classified as chemical tracers of past eruptions (TPE). The tree-ring width chronology also exhibited significant decreases in tree growth associated with eruptions of VEI ≥ 3. According to these records, we identified 11 new eruptive events of Calbuco, extending its eruptive chronology back to the 16th century and determining a mean eruptive frequency of ~23 years. Our results show the potential to use dendrochemical analysis to infer past volcanic eruptions in Northern Patagonia. This information provides a long-term perspective for assessing eruptive history in Northern Patagonia, with implications for territorial planning.
The Harvest Operability Index (HOI): A Decision Support Tool for Mechanized Timber Harvesting in Mountainous Terrain
Authors: Phelps Keith , Hiesl Patrick , Hagan Donald , Hotaling Hagan Althea
Published: September 2021

Forest operations have become increasingly reliant on mechanized harvesting equipment due to their increased production capacities in competitive markets. However, operating heavy machinery in mountainous terrain poses numerous operational and accessibility challenges from steep slopes, erosion risk, and poor road access. Geographic Information Systems (GIS) have effectively been used in various studies to identify areas in mountainous landscapes that pose no or reduced constraints for harvesting equipment operation. This study introduces the Harvest Operability Index (HOI), which rates a landscape for wheel-based equipment suitability (i.e., operability) and assesses its application in 13,118 ha of the Jocassee Gorges Natural Resource Area, situated on the Southern Blue Ridge Escarpment in Northwestern South Carolina, USA. The HOI incorporated slope, distance from roads, cost distance from major highways, primary Streamside Management Zones (SMZ), stand age, and soil suitability ratings for harvesting equipment operation. Upon reclassification to a 5-tier suitability scale, the HOI revealed 60% (7824 ha) of the case study area was in a Slope Exclusion Zone, or land area inoperable for wheel-based equipment due to steep slopes. Values of Very Poor and Poor Operability occupied less than 1% (213 ha) of land area whereas Moderate Operability values were 9% of the land area (1257 ha). Values of Good Operability occupied 18% (2442 ha) of the study area and values of Very Good Operability occupied 10% (1381 ha). These results reflected the challenges of mechanized harvesting in the study area due to a preponderance of steep slopes and poorly suited soil. Our model delineated areas of high equipment operability in two locations in the study area, despite a lack of recent logging activity around them. Results of the HOI analysis offer an accessible way for forest managers to better prioritize logging operations in areas that are highly operable and therefore more likely to possess lower overall harvesting costs, for wheel-based harvesting systems. The HOI can also be used as an asset for other forest management priorities, such as identifying highly operable areas that can use timber harvesting for fuel reduction and ecological restoration in fire-dependent forests. This model can be applied to various other regions where mountainous terrain poses a limitation to wheel-based harvesting equipment operation- and where wheel-based equipment is essential to advance the pace and scale of harvesting for ecological restoration.
Effect of Bamboo Nodes on the Mechanical Properties of P. edulis (Phyllostachys edulis) Bamboo
Authors: Liu Pengcheng , Zhou Qishi , Fu Feiyang , Li Wei
Published: September 2021

In the context of global sustainable development, the use of natural and renewable bamboo as a building material is of great significance for building engineering. As an important part of bamboo, there is still a lack of systematic research on the effect of bamboo nodes on the mechanical properties of bamboo. In this paper, compression parallel to the grain of the bamboo, bending, tensile parallel to the grain, shear parallel to the grain, compression perpendicular to the grain and tensile perpendicular to the grain tests of an entire bamboo culm of P. edulis bamboo were carried out, and the effects of bamboo nodes on moisture content, bearing capacity and mechanical properties were analyzed. The relationship between the mechanical properties and standardized parameters of the node and internode specimens was established. A conversion method of mechanical properties of the same test type was proposed, and a conversion method among different mechanical properties was proposed. The bamboo was graded by tensile strength parallel to the grain. The results show that bamboo nodes have an obvious effect on the moisture content. Bamboo nodes have different effects on the bearing capacity and mechanical properties of different types of specimens. The mechanical properties of P. edulis bamboo can be predicted by the relationship between the mechanical properties and the standardized parameters and the mechanical property conversion method. The strength classification of P. edulis bamboo can be predicted by standardized parameters.
Comparative Transcriptome Analysis of Stage-Specific Changes in Gene Expression during Larval Development in Monochamus alternatus Hope
Authors: Huang Jing , Guo Yajie , Weng Xiaoqian , Sun Yunzhu , Carballar-Lejarazú Rebeca , Hu Xia , Wang Rong , Liang Guanghong , Zhang Feiping , Wu Songqing
Published: September 2021

Monochamus alternatus Hope (Coleoptera: Cerambycidae) is an important trunk borer of pine trees and a major vector of pine wilt disease. Although chemicals are widely used in forest pest control, new strategies based on insect biology are offering promising approaches to manage the disease. Although there have been important research advances in this respect, there has not yet been a deep sequence analysis of M. alternatus describing the transcriptome, and no information is available about the gene function of this insect vector. We used next generation sequencing technology to provide a full transcriptome from the four larval instars of M. alternatus and successfully built an M. alternatus transcriptome database. In total, 67,456 unigenes were obtained with trinity software, information for 11,858 classified unigenes was obtained with the Clusters of Orthologous Groups (COGs) database, and 13,007 unigenes matched predicted pathways using the Kyoto Encyclopedia of Genes and Genomes (KEGG). In addition, genes related to lignocellulose, and putative Bt receptors and genes related to digestion are described. Additionally, the differential gene expression of these genes in different larval stages was analyzed. This study provides valuable information to underpin the development of new molecular tools for M. alternatus control strategies.
Populus euphratica Phenology and Its Response to Climate Change in the Upper Tarim River Basin, NW China
Authors: Li Hualin , Feng Jianzhong , Bai Linyan , Zhang Jianjun
Published: September 2021

Quantifying the phenological variations of Populus euphratica Olivier (P. euphratica) resulting from climate change is vital for desert ecosystems. There has previously been great progress in the influence of climate change on vegetation phenology, but knowledge of the variations in P. euphratica phenology is lacking in extremely arid areas. In this study, a modified method was proposed to explore P. euphratica phenology and its response to climate change using 18-year Global Land Surface Satellite (GLASS) leaf area index (LAI) time series data (2000–2017) in the upper Tarim River basin. The start of the growing season (SOS), length of the growing season (LOS), and end of the growing season (EOS) were obtained with the dynamic threshold method from the reconstructed growth time series curve by using the Savitzky–Golay filtering method. The grey relational analysis (GRA) method was utilized to analyze the influence between the phenology and the key climatic periods and factors. Importantly, we also revealed the positive and negative effects between interannual climate factors and P. euphratica phenology using the canonical correlation analysis (CCA) method, and the interaction between the SOS in spring and EOS in autumn. The results revealed that trends of P. euphratica phenology (i.e., SOS, EOS, and LOS) were not significant during the period from 2000–2017. The spring temperature and sunshine duration (SD) controlled the SOS, and the EOS was mainly affected by the temperature and SD from June–November, although the impacts of average relative humidity (RH) and precipitation (PR) on the SOS and EOS cannot be overlooked. Global warming may lead to SOS advance and EOS delay, and the increase in SD and PR may lead to earlier SOS and later EOS. Runoff was found to be a more key factor for controlling P. euphratica phenology than PR in this region.
School Culture and Digital Technologies: Educational Practices at Universities within the Context of the COVID-19 Pandemic
Authors: González-Nieto Noé Abraham , García-Hernández Caridad , Espinosa-Meneses Margarita
Published: September 2021

The pandemic caused by COVID-19 led schools to continue their work by relying on digital technologies. Changes in this matter are observed within three dimensions in the theoretical and conceptual background: (a) the influence of ITC in education, (b) the macrosocial changes in the educational systems and public policy derived from the COVID-19 pandemic, and (c) the impact of the COVID-19 pandemic in higher education and its role for the future. The general objective of this research was to characterize the educational practices executed by the university community (students, professors, and managers) during the emerging remote classes derived from the pandemic at the Universidad Autonoma Metropolitana, Cuajimalpa Campus, a public educational institution in Mexico (through an explanation for each educational actor profile). As specific research objectives, this paper: (a) examines whether the professors and students had enough digital technology to continue with the classes, (b) defines the obstacles they had in the use of said digital technology, and (c) recognizes the existence of innovative educational practices and determines whether stated learning was achieved in educational programs. For this purpose, a mixed methodology was chosen, comprising the application of surveys to students and professors and semi-structured interviews with managers, professors, and students. It was found that there was innovation in the area of resources (material–economic dimension) and in the area of relationships (socio-political dimension), while the discursive dimension (cultural-discursive dimension) was negatively impacted. Based on the above, we conclude that the school culture of the UAM-C is solid and that it has the necessary technological resources to continue with the teaching–learning process. The educational practice was transformed, which resulted in advantages and disadvantages, but despite these situations, most students developed their learning.
EconLedger: A Proof-of-ENF Consensus Based Lightweight Distributed Ledger for IoVT Networks
Authors: Xu Ronghua , Nagothu Deeraj , Chen Yu
Published: September 2021

The rapid advancement in artificial intelligence (AI) and wide deployment of Internet of Video Things (IoVT) enable situation awareness (SAW). The robustness and security of IoVT systems are essential for a sustainable urban environment. While blockchain technology has shown great potential in enabling trust-free and decentralized security mechanisms, directly embedding cryptocurrency oriented blockchain schemes into resource-constrained Internet of Video Things (IoVT) networks at the edge is not feasible. By leveraging Electrical Network Frequency (ENF) signals extracted from multimedia recordings as region-of-recording proofs, this paper proposes EconLedger, an ENF-based consensus mechanism that enables secure and lightweight distributed ledgers for small-scale IoVT edge networks. The proposed consensus mechanism relies on a novel Proof-of-ENF (PoENF) algorithm where a validator is qualified to generate a new block if and only if a proper ENF-containing multimedia signal proof is produced within the current round. The decentralized database (DDB) is adopted in order to guarantee efficiency and resilience of raw ENF proofs on the off-chain storage. A proof-of-concept prototype is developed and tested in a physical IoVT network environment. The experimental results validated the feasibility of the proposed EconLedger to provide a trust-free and partially decentralized security infrastructure for IoVT edge networks.
OLP—A RESTful Open Low-Code Platform
Authors: da Cruz Mauro A. A. , de Paula Heitor T. L. , Caputo Bruno P. G. , Mafra Samuel B. , Lorenz Pascal , Rodrigues Joel J. P. C.
Published: September 2021

Low-code is an emerging concept that transforms visual representations into functional software, allowing anyone to be a developer. However, building a low-code platform from scratch can be challenging concerning the scarce available literature about the topic. In this sense, this paper proposes an Open Low-Code Platform (OLP), a low-code solution that enables regular users to create applications. Furthermore, it presents low-code’s functional and nonfunctional requirements, as well as its similarities and its differences with the no-code concept. The experience obtained while developing OLP was translated into a pipeline that details how code was transformed from the visual representations into a fully fledged application. The paper demonstrates the solution’s viability and is especially useful for building a low-code platform from scratch or improving an existing one.
The Influence of Environmental Conditions on the Antagonistic Activity of Lactic Acid Bacteria Isolated from Fermented Meat Products
Authors: Łepecka Anna , Szymański Piotr , Rutkowska Sylwia , Iwanowska Kinga , Kołożyn-Krajewska Danuta
Published: September 2021

The aim of this study was to determine the impact of environmental conditions on the antimicrobial properties of 21 lactic acid bacteria strains in the selected indicator bacteria. To assess the antimicrobial activity of the whole bacteria culture (WBC), the agar well diffusion method was used. The interference of LAB strains with the growth of the selected indicator bacteria was evaluated by incubating co-cultures in the food matrix. Based on the conducted research, it was found that environmental conditions have a significant impact on the antimicrobial activity of lactic acid bacteria strains. The highest antimicrobial activity was recorded under optimal conditions for the development of LAB, the incubation time being different depending on the indicator strain used. The tested LAB strains were characterized by a high ability to inhibit indicator strains, especially in the food matrix. These results led us to further characterize and purify the antimicrobial compound produced by lactic acid bacteria taking into account changing environmental conditions.
Organic Foods Purchase Behavior among Generation Y of Bangladesh: The Moderation Effect of Trust and Price Consciousness
Authors: Zheng Guang-Wen , Akter Nazma , Siddik Abu Bakkar , Masukujjaman Mohammad
Published: September 2021

This study aims to identify the factors influencing the purchase behavior of organic foods among young generation customers in Bangladesh. The study adopted the theory of planned behavior as a base and developed 11 hypotheses based on the extant empirical literature. Adopting the purposive sampling method, the primary data were obtained from a cross-sectional sample of 464 young Bangladeshi consumers using a survey method. In order to identify the key relationship among the study variables, the structural equation modeling (SEM) approach was employed using AMOS software, version 25. The study employed a purposive sampling method to pick young respondents through online media. The study revealed that health consciousness, environmental consciousness, food safety consciousness, price consciousness, novelty consciousness, and trust are factors that significantly affect purchase intention and subsequently, the actual purchase of organic foods. The novelty consciousness factor got the highest predicting power, followed by food safety concerns among Generation Y. The research also found that trust and price consciousness exhibit positive and negative moderating effects, respectively, on the relationship between purchase intention and actual purchase. However, the study did not find any moderating role of price consciousness on the association between environmental consciousness and purchase intention. As policy recommendations, informing and educating young consumers about organic products, their novelty, and other benefits of consuming is critical for fostering their purchase.
Fatty Acids and Nutraceutical Properties of Lipids in Fallow Deer (Dama dama) Meat Produced in Organic and Conventional Farming Systems
Authors: Kilar Janusz , Kasprzyk Anna
Published: September 2021

The aim of the study was to assess the fatty acid profile and nutraceutical properties of lipids contained in fallow deer (Dama dama) meat produced in organic and conventional farming systems. Longissimus lumborum (LL) and semimembranosus (SM) muscles from 24 fallow deer carcasses were selected for the study. The fallow deer meat from the organic farming system was characterized by significantly lower intramuscular fat content. The fatty acid profile in the organic meat was characterized by a particularly high proportion (p < 0.0001) of conjugated linoleic acid—CLA (LL—2.29%, SM—2.14%), alpha-linolenic acid—ALA (LL—4.32%, SM—3.87%), and docosahexaenoic acid—DHA (LL—2.83%, SM—2.60%). The organic system had a beneficial effect (p < 0.0001) on the amount of polyunsaturated fatty acids (PUFAs), including n-3 PUFAs, which resulted in a more favorable n-6 PUFA (polyunsaturated fatty acid)/n-3 PUFA ratio. The significantly higher nutritional quality of organic meat lipids was confirmed by such nutraceutical indicators as the thrombogenic index (TI), ∆9-desaturase C16, elongase, and docosahexaenoic acid+eicosapentaenoic acid (DHA+EPA) in the LL and SM and cholesterol index (CI), and the cholesterol-saturated fat index (CSI) indices in the SM. LL was characterized by higher overall quality.