bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolutionary Optimization Strategy for Indoor Position Estimation Using Smartphones
Authors: Grottke Jan , Blankenbach Jörg
Published: March 2021

Due to their distinctive presence in everyday life and the variety of available built-in sensors, smartphones have become the focus of recent indoor localization research. Hence, this paper describes a novel smartphone-based sensor fusion algorithm. It combines the relative inertial measurement unit (IMU) based movements of the pedestrian dead reckoning with the absolute fingerprinting-based position estimations of Wireless Local Area Network (WLAN), Bluetooth (Bluetooth Low Energy—BLE), and magnetic field anomalies as well as a building model in real time. Thus, a step-based position estimation without knowledge of any start position was achieved. For this, a grid-based particle filter and a Bayesian filter approach were combined. Furthermore, various optimization methods were compared to weigh the different information sources within the sensor fusion algorithm, thus achieving high position accuracy. Although a particle filter was used, no particles move due to a novel grid-based particle interpretation. Here, the particles’ probability values change with every new information source and every stepwise iteration via a probability-map-based approach. By adjusting the weights of the individual measurement methods compared to a knowledge-based reference, the mean and the maximum position error were reduced by 31%, the RMSE by 34%, and the 95-percentile positioning errors by 52%.
J-CO: A Platform-Independent Framework for Managing Geo-Referenced JSON Data Sets
Authors: Psaila Giuseppe , Fosci Paolo
Published: March 2021

Internet technology and mobile technology have enabled producing and diffusing massive data sets concerning almost every aspect of day-by-day life. Remarkable examples are social media and apps for volunteered information production, as well as Open Data portals on which public administrations publish authoritative and (often) geo-referenced data sets. In this context, JSON has become the most popular standard for representing and exchanging possibly geo-referenced data sets over the Internet.Analysts, wishing to manage, integrate and cross-analyze such data sets, need a framework that allows them to access possibly remote storage systems for JSON data sets, to retrieve and query data sets by means of a unique query language (independent of the specific storage technology), by exploiting possibly-remote computational resources (such as cloud servers), comfortably working on their PC in their office, more or less unaware of real location of resources. In this paper, we present the current state of the J-CO Framework, a platform-independent and analyst-oriented software framework to manipulate and cross-analyze possibly geo-tagged JSON data sets. The paper presents the general approach behind the J-CO Framework, by illustrating the query language by means of a simple, yet non-trivial, example of geographical cross-analysis. The paper also presents the novel features introduced by the re-engineered version of the execution engine and the most recent components, i.e., the storage service for large single JSON documents and the user interface that allows analysts to comfortably share data sets and computational resources with other analysts possibly working in different places of the Earth globe. Finally, the paper reports the results of an experimental campaign, which show that the execution engine actually performs in a more than satisfactory way, proving that our framework can be actually used by analysts to process JSON data sets.
Automatic Classification of Monosyllabic and Multisyllabic Birds Using PDHF
Authors: Alghamdi Abdullah , Mehtab Tooba , Iqbal Rizwan , Leeza Mona , Islam Noman , Hamdi Mohammed , Shaikh Asadullah
Published: March 2021

Bioacoustics plays an important role in the conservation of bird species. Bio-acoustic surveys based on autonomous audio recording are both cost-effective and time-efficient. However, there are many bird species with different patterns of vocalization, and it is a challenging task to deal with them. Previous studies have revealed that many authors focus on the segmentation of bird audio without considering specific patterns of bird vocalization. Based on the existing literature, currently there is no work on the segmentation of monosyllabic and multisyllabic birds, separately. Therefore, this research addresses the aforementioned concern and also proposes a collection of audio features named ‘Perceptual, Descriptive, and Harmonic Features (PDHFs)’ that gives promising results in the classification of bird vocalization. Moreover, the classification results improved when monosyllabic and multisyllabic birds were classified separately. To analyze the performance of PDHFs, different classifiers were used in which Artificial neural network (ANN) outperformed other classifiers and demonstrated an accuracy of 98%.
Design and Implementation Procedure of a High-Gain Three-Input Step-Up 1 kW Converter
Authors: Netzahuatl-Huerta Edgardo , Hernandez-Gonzalez Leobardo , Cortes Domingo , Ramirez-Hernandez Jazmin
Published: March 2021

The use of different sources to energize a load is convenient in many applications, particularly those where two or more renewable energy sources are employed, such as energy harvesting, hybrid vehicles, and off-grid systems. In these cases, a multi-input converter is able to admit sources with different characteristics and, if necessary, select the output power of each source. Several topologies of multi-input converters have been proposed to this aim; however, most of them are based on multistage designs, which decreases efficiency and increases control complexity, particularly when more than two sources are used. In this work, a three-input step-up converter, easy to control in open loop condition, is analyzed. A designed procedure is described, and experimental results are presented for a 1 kW power converter. The implemented converter results in a higher voltage gain and less storage element, keeping high efficiency compared to similar topologies. Using the procedure here proposed, this converter that was initially designed for photovoltaic applications is enabled to be used in medium- and high-power applications, for example, when renewable energy sources are used.
Control-Oriented, Data-Driven Models of Thermal Dynamics
Authors: Boskic Ljuboslav , Mezic Igor
Published: March 2021

We investigate data-driven, simple-to-implement residential environmental models that can serve as the basis for energy saving algorithms in both retrofits and new designs of residential buildings. Despite the nonlinearity of the underlying dynamics, using Koopman operator theory framework in this study we show that a linear second order model embedding, that captures the physics that occur inside a single or multi zone space does well when compared with data simulated using EnergyPlus. This class of models has low complexity. We show that their parameters have physical significance for the large-scale dynamics of a building and are correlated to concepts such as the thermal mass. We investigate consequences of changing the thermal mass on the energy behavior of a building system and provide best practice design suggestions.
Microplastics Contamination versus Inorganic Particles: Effects on the Dynamics of Marine Dissolved Organic Matter
Authors: Boldrini Amedeo , Galgani Luisa , Consumi Marco , Loiselle Steven Arthur
Published: March 2021

Microplastic contamination has been linked to a range of impacts on aquatic environments. One important area that is only beginning to be addressed is the effect of microplastics on marine carbon cycling and how these compare to the effects related to inorganic particles typically present in ocean waters. The present study explores these impacts on dissolved organic matter dynamics by comparing three scenarios: a particle-free environment, a particle-enriched system with polystyrene microplastics, and a particle-enriched system with inorganic particles (water insoluble SiO2). Natural marine organic matter was obtained by culturing a non-axenic strain of Chaetoceros socialis in 2 L flasks under each of three scenarios. Following the diatom growth phase, filtered samples from the three flasks containing dissolved organic matter and bacteria were incubated separately in the dark for 5 days to monitor changes in dissolved organic matter. Chromophoric dissolved organic matter (CDOM), a bulk optical property, was monitored daily to examine changes in its quality and quantity and to compare degradation dynamics in the three systems. CDOM absorbance (quantity) remained higher in the control with respect to particle-enriched systems, suggesting that the presence of particles led to different rates of CDOM production and degradation. Using indicators for CDOM that could be related to microbial activity, results showed a higher CDOM alteration in the particle-enriched systems. These results indicate that microplastics have a potential role in modifying marine organic matter dynamics, on a similar magnitude to that of biogenic inorganic particles. Given their increasing concentrations of marine ecosystems, their role in marine microbial processing of organic matter needs to be better understood.
Magneto-Bioconvection Flow of Williamson Nanofluid over an Inclined Plate with Gyrotactic Microorganisms and Entropy Generation
Authors: Yusuf Tunde A. , Mabood Fazle , Prasannakumara B. C. , Sarris Ioannis E.
Published: March 2021

The fluid flow through inclined plates has several applications in magneto-aerodynamics, materials processing and magnetohydrodynamic propulsion thermo-fluid dynamics. Inspired by these applications, the rate of entropy production in a bio-convective flow of a magnetohydrodynamic Williamson nanoliquid over an inclined convectively heated stretchy plate with the influence of thermal radiation, porous materials and chemical reaction has been deliberated in this paper. The presence of microorganisms aids in stabilizing the suspended nanoparticles through a bioconvection process. Also, the thermal radiation assumed an optically thick limit approximation. With the help of similarity transformations, the coupled partial differential equations are converted to nonlinear ordinary differential equations and the resulting model is numerically tackled using the shooting method. The influences of the determining thermo-physical parameters on the flow field are incorporated and extensively discussed. The major relevant outcomes of the present analysis are that the upsurge in values of Schmidt number decays the mass transfer characteristics, but the converse trend is depicted for boost up values of the thermophoresis parameter. Enhancement in bioconvection Peclet and Schmidt numbers deteriorates the microorganism density characteristics. Further, the upsurge in the Williamson parameter declines the Bejan number and irreversibility ratio.
Physical Background, Computations and Practical Issues of the Magnetohydrodynamic Pressure Drop in a Fusion Liquid Metal Blanket
Authors: Smolentsev Sergey
Published: March 2021

In blankets of a fusion power reactor, liquid metal (LM) breeders, such as pure lithium or lead-lithium alloy, circulate in complex shape blanket conduits for power conversion and tritium breeding in the presence of a strong plasma-confining magnetic field. The interaction of the magnetic field with induced electric currents in the breeder results in various magnetohydrodynamic (MHD) effects on the flow. Of them, high MHD pressure losses in the LM breeder flows is one of the most important feasibility issues. To design new feasible LM breeding blankets or to improve the existing blanket concepts and designs, one needs to identify and characterize sources of high MHD pressure drop, to understand the underlying physics of MHD flows and to eventually define ways of mitigating high MHD pressure drop in the entire blanket and its sub-components. This article is a comprehensive review of earlier and recent studies of MHD pressure drop in LM blankets with a special focus on: (1) physics of LM MHD flows in typical blanket configurations, (2) development and testing of computational tools for LM MHD flows, (3) practical aspects associated with pumping of a conducting liquid breeder through a strong magnetic field, and (4) approaches to mitigation of the MHD pressure drop in a LM blanket.
The Senescence-Associated Endonuclease, PhENDO1, Is Upregulated by Ethylene and Phosphorus Deficiency in Petunia
Authors: Jones Michelle , Bai Shuangyi , Lin Yiyun , Chapin Laura
Published: March 2021

The upregulation of endonuclease activities and subsequent decreases in the nucleic acid content of leaves and petals are characteristics of senescence that allow for nutrient remobilization from dying organs. We previously identified a 43-kDa endonuclease activity (PhNUC1) that was upregulated in Petunia × hybrida petals during senescence. PhNUC1 has optimal activity at neutral pH, is enhanced by Co2+, and degrades both DNA and RNA. The peptide sequence of a 43-kDa endonuclease identified from senescing petals by 2-dimensional gel electrophoresis was used to clone the gene (PhENDO1) encoding the senescence-associated protein. PhENDO1 expression was upregulated in petals during the senescence of unpollinated and pollinated flowers and by ethylene treatment. When petunias were grown under nutrient deficient conditions, P-starvation, and to a lesser extent N-starvation, induced expression of PhENDO1. The endogenous expression of PhENDO1 was down regulated using virus induced gene silencing (VIGS), and in-gel endonuclease assays confirmed that the activity of the 43-kDa PhNUC1 was decreased in senescing corollas from PhENDO1-silenced (pTRV2:PhCHS:PhENDO1) plants compared to controls (pTRV2:PhCHS). Down regulating PhENDO1 in petunias did not alter flower longevity. While PhENDO1 may be involved in nucleic acid catabolism during senescence, down regulating this gene using VIGS was not sufficient to delay flower senescence.
Psychological Adjustment of Children and Adolescents with 22q11.2 Deletion Syndrome and Their Mothers’ Stress and Coping—A Longitudinal Study
Authors: Briegel Wolfgang , Andritschky Christoph
Published: March 2021

At present, there is a lack of longitudinal studies on the psychological adjustment of both children and adolescents with 22q11.2 deletion syndrome (22q11.2DS) and their primary caregivers. To fill this gap, we performed a four-year follow-up study. Mothers filled out the Child Behavior Checklist 4–18, the Social Orientation of Parents with Handicapped Children questionnaire to assess maternal stress and coping strategies, and the Freiburger Personality Inventory-Revised—subscales strain and life satisfaction. Fifty-five subjects with 22q11.2DS (26 males and 29 females; age: M = 10.79 years, SD = 3.56 years) and their biological mothers (age: M = 40.84 years, SD = 4.68 years) were included in this study. Significantly higher levels of behavior problems than in the general population and an increase in these problems, especially internalizing ones, over time could be found. In contrast, maternal stress did not change significantly over time, but mothers demonstrated increased levels of strain and reduced life satisfaction at T2. Thus, careful monitoring as well as early and adequate interventions, if indicated, should be offered to families with a child with 22q11.2DS, not only for somatic complaints but also for problems with psychological adjustment.
The Impact of Using a Larger Forearm Artery for Percutaneous Coronary Interventions on Hand Strength: A Randomized Controlled Trial
Authors: Lewandowski Pawel , Zuk Anna , Slomski Tomasz , Maciejewski Pawel , Ramotowski Bogumil , Budaj Andrzej
Published: March 2021

(1) Background: The exact mechanism underlying hand strength reduction (HSR) after coronary angiography with transradial access (TRA) or transulnar access (TUA) remains unknown. (2) Methods: This study aimed to assess the impact of using a larger or smaller forearm artery access on the incidence of HSR at 30-day follow-up. This was a prospective randomized trial including patients referred for elective coronary angiography or percutaneous coronary intervention. Based on the pre-procedural ultrasound examination, the larger artery was identified. Patients were randomized to larger radial artery (RA) or ulnar artery (UA) or a group with smaller RA/UA. The primary endpoint was the incidence of HSR, while the secondary endpoint was the incidence of subjective HSR, paresthesia, and any hand pain. (3) Results: We enrolled 200 patients (107 men and 93 women; mean age 68 ± 8 years) between 2017 and 2018. Due to crossover between TRA and TUA, there were 57% (n = 115) patients in larger RA/UA and 43% (n = 85) patients in smaller RA/UA. HSR occurred in 29% (n = 33) patients in larger RA/UA and 47% (n = 40) patients in smaller RA/UA (p = 0.008). Subjective HSR was observed in 10% (n = 12) patients in larger RA/UA and 21% (n = 18) patients in smaller RA/UA (p = 0.03). Finally, paresthesia was noted in 7% (n = 8) patients in larger RA/UA and 22% (n = 15) in smaller RA/UA (p = 002). Independent factors of HSR were larger RA/UA (OR 0.45; 95% CI, 0.24–0.82; p < 0.01) and the use of TRA (OR 1.87; 95% CI, 1.01–34; p < 0.05). (4) Conclusions: The use of a larger artery as vascular access was associated with a lower incidence of HSR at 30-day follow-up.
Adult Spinal Cord Injury without Major Bone Injury: Effects of Surgical Decompression and Predictors of Neurological Outcomes in American Spinal Injury Association Impairment Scale A, B, or C
Authors: Na Bo-Ram , Seo Hyoung-Yeon
Published: March 2021

The cervical spine can be injured even in the absence of radiographic abnormality, and the best surgical treatment for adult spinal cord injury without bone injury is debated. The aim of this study was to retrospectively investigate the effect of surgical decompression for severe adult spinal cord injury without major bone injury and to establish predictors of good neurological outcome. We analyzed 11 patients who underwent surgical decompression in severe adult spinal cord injury without major bone injury patients classified as American Spinal Injury Association Impairment Scale (AIS) grade A, B, or C. Neurological assessments were performed using AIS at preoperative and postoperative 1-year follow-up. Radiological evaluations were performed using cervical magnetic resonance imaging (MRI) at preoperative. Seven cases were classified as AIS grade A; two cases as AIS grade B; and two cases as AIS grade C. Five of 11 (45.5%) patients showed improved neurological grade 1-year postoperatively. Intramedullary lesion length (IMLL) (p = 0.047) and compression rate (p = 0.045) had the most powerful effect on AIS grade conversion. This study shows that the fate of the injured spinal cord is determined at the time of the injury, but adequate decompression may have limited contribution to the recovery of neurological function. Compression rate and IMLL on MRI can be used as a predictor of neurological recovery.
Real-World Efficacy of Midostaurin in Aggressive Systemic Mastocytosis
Authors: Szudy-Szczyrek Aneta , Bachanek-Mitura Oliwia , Gromek Tomasz , Chromik Karolina , Mital Andrzej , Szczyrek Michał , Krupski Witold , Szumiło Justyna , Kanduła Zuzanna , Helbig Grzegorz , Hus Marek
Published: March 2021

In April 2017 midostaurin was approved by the US Food and Drug Administration for the treatment of patients with aggressive systemic mastocytosis (ASM). So far, very limited real world data on its efficacy is available. Thirteen patients aged from 48 to 79 years, who received midostaurin in the early access program, were included in the study. Midostaurin was used both in first (n = 5) and subsequent lines of treatment (n = 8). The median duration of exposure was 9 months. Most patients (77%, n = 10) had a clinical improvement already as soon as the second month of therapy. Objective response was noted in 4 (50%) of eight evaluated patients. Among responders, we observed a decrease in serum tryptase level (median 74.14%) and bone marrow infiltration by mast cells (median 50%) in the sixth month of treatment. In one case, in the 10th month of treatment, allogenic stem cell transplantation was performed, achieving complete remission. Five patients died, three due to progression of disease, one in the course of secondary acute myeloid leukemia and one due to reasons not related to mastocytosis. Treatment is ongoing in seven patients. We found that midostaurin therapy is beneficial to patients with ASM.
Platelet Phenotyping and Function Testing in Thrombocytopenia
Authors: Jurk Kerstin , Shiravand Yavar
Published: March 2021

Patients who suffer from inherited or acquired thrombocytopenia can be also affected by platelet function defects, which potentially increase the risk of severe and life-threatening bleeding complications. A plethora of tests and assays for platelet phenotyping and function analysis are available, which are, in part, feasible in clinical practice due to adequate point-of-care qualities. However, most of them are time-consuming, require experienced and skilled personnel for platelet handling and processing, and are therefore well-established only in specialized laboratories. This review summarizes major indications, methods/assays for platelet phenotyping, and in vitro function testing in blood samples with reduced platelet count in relation to their clinical practicability. In addition, the diagnostic significance, difficulties, and challenges of selected tests to evaluate the hemostatic capacity and specific defects of platelets with reduced number are addressed.
Four Decades of COPD Mortality Trends: Analysis of Trends and Multiple Causes of Death
Authors: Fernández-García Alberto , Pérez-Ríos Mónica , Fernández-Villar Alberto , Naveira Gael , Candal-Pedreira Cristina , Santiago-Pérez María Isolina , Represas-Represas Cristina , Malvar-Pintos Alberto , Cerdeira-Caramés Sara , Ruano-Raviña Alberto
Published: March 2021

There is little information on chronic obstructive pulmonary disease (COPD) mortality trends, age of death, or male:female ratio. This study therefore sought to analyze time trends in mortality with COPD recorded as the underlying cause of death from 1980 through 2017, and with COPD recorded other than as the underlying cause of death. We conducted an analysis of COPD deaths in Galicia (Spain) from 1980 through 2017, including those in which COPD was recorded other than as the underlying cause of death from 2015 through 2017. We calculated the crude and standardized rates, and analyzed mortality trends using joinpoint regression models. There were 43,234 COPD deaths, with a male:female ratio of 2.4. Median age of death was 82 years. A change point in the mortality trend was detected in 1996 with a significant decrease across the sexes, reflected by an annual percentage change of −3.8%. Taking deaths into account in which COPD participated or contributed without being the underlying cause led to an overall 42% increase in the mortality burden. The most frequent causes of death when COPD was not considered to be the underlying cause were bronchopulmonary neoplasms and cardiovascular diseases. COPD mortality has decreased steadily across the sexes in Galicia since 1996, and age of death has also gradually increased. Multiple-cause death analysis may help prevent the underestimation of COPD mortality.
Delivering into the Mounting Evidence of a Probable Link between Maternal Hypothyroidism and Breech Presentation at Term: What Do We Know until Now?
Authors: Peitsidis Panagiotis , Vrachnis Nikolaos
Published: March 2021

Approximately 3–5% of all women at term have a breech baby [...]
High Cortico-Trabecular Transitional Zone Porosity and Reduced Trabecular Density in Men and Women with Stress Fractures
Authors: Zendeli Afrodite , Bui Minh , Fischer Lukas , Ghasem-Zadeh Ali , Schima Wolfgang , Seeman Ego
Published: March 2021

To determine whether stress fractures are associated with bone microstructural deterioration we quantified distal radial and the unfractured distal tibia using high resolution peripheral quantitative computed tomography in 26 cases with lower limb stress fractures (15 males, 11 females; mean age 37.1 ± 3.1 years) and 62 age-matched healthy controls (24 males, 38 females; mean age 35.0 ± 1.6 years). Relative to controls, in men, at the distal radius, cases had smaller cortical cross sectional area (CSA) (p = 0.012), higher porosity of the outer transitional zone (OTZ) (p = 0.006), inner transitional zone (ITZ) (p = 0.043) and the compact-appearing cortex (CC) (p = 0.023) while trabecular vBMD was lower (p = 0.002). At the distal tibia, cases also had a smaller cortical CSA (p = 0.008). Cortical porosity was not higher, but trabecular vBMD was lower (p = 0.001). Relative to controls, in women, cases had higher distal radial porosity of the OTZ (p = 0.028), ITZ (p = 0.030) not CC (p = 0.054). Trabecular vBMD was lower (p = 0.041). Distal tibial porosity was higher in the OTZ (p = 0.035), ITZ (p = 0.009), not CC. Stress fractures are associated with compromised cortical and trabecular microstructure.
Association between Sudden Sensorineural Hearing Loss and Lyme Disease
Authors: Sowula Klaudia , Szaleniec Joanna , Stolcman Kamila , Ceranowicz Piotr , Kocoń Sebastian , Tomik Jerzy
Published: March 2021

Objectives: Sudden sensorineural hearing loss (SSNHL) is defined as sensorineural hearing loss of 30 dB or more over at least three adjacent audiometric frequencies occurring within a 72-h period of time. One of the causes of SSNHL could be the progressive inflammatory state caused by an infection. The aim of this study was to assess the prevalence of SSNHL caused by various factors, most importantly those potentially related to Lyme disease. Material and Methods: The study includes a group of 86 patients between the ages of 20 and 70 who were hospitalized due to SSNHL between 2017 and 2018. All of these patients underwent a detailed medical interview and an otolaryngological examination, including audiological and diagnostic tests. Additionally, ELISA and Western blot tests were performed to confirm the diagnosis of Lyme disease. Results: In this group of 86 patients, nine patients presented with positive antibodies toward Borrelia burgdorferi sensu lato. This group was treated with antibiotics and experienced partial or complete regression of their deafness. This may suggest a relationship between SSNHL and Lyme disease. Conclusion: Infections caused by Borrelia burgdorferi may contribute to the development of inflammatory and angiopathic lesions, which are a possible cause of SSNHL. The longer the duration of the infection, the greater the likelihood of permanent and irreversible changes in the vessels of the cochlea or auditory nerve. Therefore, serological tests for Borrelia burgdorferi should be performed during the diagnosis of SSNHL as a possible cause of this illness.
Haptoglobin and Its Related Protein, Zonulin—What Is Their Role in Spondyloarthropathy?
Authors: Chmielińska Magdalena , Olesińska Marzena , Romanowska-Próchnicka Katarzyna , Szukiewicz Dariusz
Published: March 2021

Haptoglobin (Hp) is an acute phase protein which supports the immune response and protects tissues from free radicals. Its concentration correlates with disease activity in spondyloarthropathies (SpAs). The Hp polymorphism determines the functional differences between Hp1 and Hp2 protein products. The role of the Hp polymorphism has been demonstrated in many diseases. In particular, the Hp 2-2 phenotype has been associated with the unfavorable course of some inflammatory and autoimmune disorders. Its potential role in modulating the immune system in SpA is still unknown. This article contains pathophysiological considerations on the potential relationship between Hp, its polymorphism and SpA.
Analytical Solution for Static and Dynamic Analysis of Graphene-Based Hybrid Flexoelectric Nanostructures
Authors: Shingare Kishor Balasaheb , Naskar Susmita
Published: March 2021

Owing to their applications in devices such as in electromechanical sensors, actuators and nanogenerators, the consideration of size-dependent properties in the electromechanical response of composites is of great importance. In this study, a closed-form solution based on the linear piezoelectricity, Kirchhoff’s plate theory and Navier’s solution was developed, to envisage the electromechanical behaviors of hybrid graphene-reinforced piezoelectric composite (GRPC) plates, considering the flexoelectric effect. The governing equations and respective boundary conditions were obtained, using Hamilton’s variational principle for achieving static deflection and resonant frequency. Moreover, the different parameters considering aspect ratio, thickness of plate, different loadings (inline, point, uniformly distributed load (UDL), uniformly varying load (UVL)), the combination of different volume fraction of graphene and piezoelectric lead zirconate titanate are considered to attain the desired bending deflection and frequency response of GRPC. Different mode shapes and flexoelectric coefficients are also considered and the results reveal that the proper addition of graphene percentage and flexoelectric effect on the static and dynamic responses of GRPC plate is substantial. The obtained results expose that the flexoelectric effect on the piezoelastic response of the bending of nanocomposite plates are worth paying attention to, in order to develop a nanoelectromechanical system (NEMS). Our fundamental study sheds the possibility of evolving lightweight and high-performance NEMS applications over the existing piezoelectric materials.
A Brief Overview of Recent Progress in Porous Silica as Catalyst Supports
Authors: Shinde Preeti S. , Suryawanshi Pradnya S. , Patil Kanchan K. , Belekar Vedika M. , Sankpal Sandeep A. , Delekar Sagar D. , Jadhav Sushilkumar A.
Published: March 2021

Porous silica particles have shown applications in various technological fields including their use as catalyst supports in heterogeneous catalysis. The mesoporous silica particles have ordered porosity, high surface area, and good chemical stability. These interesting structural or textural properties make porous silica an attractive material for use as catalyst supports in various heterogeneous catalysis reactions. The colloidal nature of the porous silica particles is highly useful in catalytic applications as it guarantees better mass transfer properties and uniform distribution of the various metal or metal oxide nanocatalysts in solution. The catalysts show high activity, low degree of metal leaching, and ease in recycling when supported or immobilized on porous silica-based materials. In this overview, we have pointed out the importance of porous silica as catalyst supports. A variety of chemical reactions catalyzed by different catalysts loaded or embedded in porous silica supports are studied. The latest reports from the literature about the use of porous silica-based materials as catalyst supports are listed and analyzed. The new and continued trends are discussed with examples.
Efficient Rank-Based Diffusion Process with Assured Convergence
Authors: Guimarães Pedronette Daniel Carlos , Pascotti Valem Lucas , Latecki Longin Jan
Published: March 2021

Visual features and representation learning strategies experienced huge advances in the previous decade, mainly supported by deep learning approaches. However, retrieval tasks are still performed mainly based on traditional pairwise dissimilarity measures, while the learned representations lie on high dimensional manifolds. With the aim of going beyond pairwise analysis, post-processing methods have been proposed to replace pairwise measures by globally defined measures, capable of analyzing collections in terms of the underlying data manifold. The most representative approaches are diffusion and ranked-based methods. While the diffusion approaches can be computationally expensive, the rank-based methods lack theoretical background. In this paper, we propose an efficient Rank-based Diffusion Process which combines both approaches and avoids the drawbacks of each one. The obtained method is capable of efficiently approximating a diffusion process by exploiting rank-based information, while assuring its convergence. The algorithm exhibits very low asymptotic complexity and can be computed regionally, being suitable to outside of dataset queries. An experimental evaluation conducted for image retrieval and person re-ID tasks on diverse datasets demonstrates the effectiveness of the proposed approach with results comparable to the state-of-the-art.
Identification of the Antidepressant Function of the Edible Mushroom Pleurotus eryngii
Authors: Park Yong-Sung , Jang Subin , Lee Hyunkoo , Kang Suzie , Seo Hyewon , Yeon Seoyeong , Lee Dongho , Yun Cheol-Won
Published: March 2021

Pleurotus eryngii produces various functional molecules that mediate physiological functions in humans. Recently, we observed that P. eryngii produces molecules that have antidepressant functions. An ethanol extract of the fruiting body of P. eryngii was obtained, and the extract was purified by XAD-16 resin using an open column system. The ethanol eluate was separated by HPLC, and the fraction with an antidepressant function was identified. Using LC-MS, the molecular structure of the HPLC fraction with antidepressant function was identified as that of tryptamine, a functional molecule that is a tryptophan derivative. The antidepressant effect was identified from the ethanol extract, XAD-16 column eluate, and HPLC fraction by a serotonin receptor binding assay and a cell-based binding assay. Furthermore, a forced swimming test (FST) showed that the mice treated with purified fractions of P. eryngii exhibited decreased immobility time compared with nontreated mice. From these results, we suggest that the extract of P. eryngii has an antidepressant function and that it may be employed as an antidepressant health supplement.
Determinants of Differentiation of Cost of Risk (CoR) among Polish Banks during COVID-19 Pandemic
Authors: Korzeb Zbigniew , Niedziółka Paweł
Published: March 2021

The aim of the paper is to assess the evolution of the cost of credit risk (CoR) of Polish banks as a result of the COVID-19 pandemic in the first three quarters of 2020 as well as its microeconomic determinants. We analysed the structural diversity of the sample of the 13 largest Polish commercial banks in terms of the evolution of their CoR. For this purpose, a diagraphic method of Jan Czekanowski was used. It allowed us to distinguish two groups of banks displaying features characteristic of multi-object structures and three groups consisting of individual banks characterized by atypical CoR developments, significantly different from the structures of objects classified to the first and second groups. In the second part of the research, in order to identify the determinants of the observed trends, a multiple regression model was used in which the explanatory variable was the dynamics of CoR in the first three quarters of 2020. The parameters of return on capital (ROE) at the end of 2019, Non-Performing Loans (NPLs) at the end of 2019 and the dynamics of write-offs in the period 2017–2019 proved to be important explanatory variables.
Informal Land Rights and Infrastructure Retrofit: A Typology of Land Rights in Informal Settlements
Authors: Mesgar Mahsa , Ramirez-Lovering Diego
Published: March 2021

Informal settlements represent a challenging operational context for local government service providers due to precarious contextual conditions. Location choice and land procurement for public infrastructure raise the complicated question: who has the right to occupy, control, and use a piece of land in informal settlements? There is currently a dearth of intelligence on how to identify well-located land for public infrastructure, spatially and with careful consideration for safeguarding the claimed rights and preventing conflicts. Drawing on a case study of green infrastructure retrofit in seven informal settlements in Makassar, Indonesia, we classify the informal settlers’ land rights into four types: ownership, use, control, and management. This exploratory study uses a typological approach to investigate the spatial dimension of land rights in informal settlements. We introduce non-registrable land interests and the partial, dynamic, and informal land use rights that impact the land procurement for infrastructure retrofit. We also create a simple spatial matrix describing the control/power, responsibilities and land interests of different stakeholders involved in the location decision making for public infrastructure. We argue that without sufficient understanding of non-formal land rights, land procurement proposals for the public infrastructure upgrades can be frustrated by the individual or group claims on the land, making the service provision impossible in informal settlements.
A Tale of Two Protected Areas: “Value and Nature Conservation” in Comparable National Parks in Estonia and Russia
Authors: Järv Henri , Shkaruba Anton , Likhacheva Olga , Kireyeu Viktar , Ward Raymond , Sepp Kalev
Published: March 2021

This study explores how local communities reflect on institutional frameworks and protected area governance in two national parks (NPs) with similar nature values in Estonia and Russia, and aims to understand the role of value systems in these interactions. It is based on 50 in-depth interviews with a broad range of stakeholders, and a desktop analysis of relevant regulation and plans. Interview questions reflect on various aspects of well-being (including fairness of governance solutions), awareness of NPs’ function and restrictions, related value aspects, and covered basic personal data needed to interpret the interviews. The study reconfirms the pivotal role of social justice as a driver of wellbeing. In particular, it articulates the significance of value systems playing the role of filters between governance inputs and specific management activities of communities. It underlines the vulnerability of such systems at a community level, most of all to the impacts related to various instances of “centralization”. They are manifested through the choice of restrictive measures and top-down arrangements at the expense of transparency and inclusiveness (in Russia), as well as through the removal of governance autonomy from NPs and transferring monitoring and enforcement functions to local communities without clear mandates or sufficient capacity (in Estonia).
A Personal View of Microstructure and Properties of Al Alloys
Authors: Campbell John
Published: March 2021

This paper presents a personal view by the author of the role of bifilms in Al alloys. The mantra ‘microstructure determines properties’ is widely accepted as a truism, but is here critically assessed and found wanting. The case is made that bifilms from the casting process, while often invisible in the microstructure, are usually at least as important, if not of far greater importance, because they are often present as a dense population of cracks throughout the metal. The bifilm population controls the morphology of many features of cast and wrought structures. For cast alloys, bifilm control of pore morphology and Si morphology in Al–Si alloys is discussed, as is dendrite arm spacing (DAS). The tensile property benefits of grain refinement are seen to be mainly bifilm controlled. The properties ductility and fatigue appear to be especially dominated by bifilm content, as are invasive corrosion processes such as pitting, intergranular corrosion, hydrogen blistering and cracking. Bifilm control is proposed as a new concept permitting the improvement and control of metallurgical properties.
On the Discretization of Continuous Probability Distributions Using a Probabilistic Rounding Mechanism
Authors: Tovissodé Chénangnon Frédéric , Honfo Sèwanou Hermann , Doumatè Jonas Têlé , Glèlè Kakaï Romain
Published: March 2021

Most existing flexible count distributions allow only approximate inference when used in a regression context. This work proposes a new framework to provide an exact and flexible alternative for modeling and simulating count data with various types of dispersion (equi-, under-, and over-dispersion). The new method, referred to as “balanced discretization”, consists of discretizing continuous probability distributions while preserving expectations. It is easy to generate pseudo random variates from the resulting balanced discrete distribution since it has a simple stochastic representation (probabilistic rounding) in terms of the continuous distribution. For illustrative purposes, we develop the family of balanced discrete gamma distributions that can model equi-, under-, and over-dispersed count data. This family of count distributions is appropriate for building flexible count regression models because the expectation of the distribution has a simple expression in terms of the parameters of the distribution. Using the Jensen–Shannon divergence measure, we show that under the equidispersion restriction, the family of balanced discrete gamma distributions is similar to the Poisson distribution. Based on this, we conjecture that while covering all types of dispersions, a count regression model based on the balanced discrete gamma distribution will allow recovering a near Poisson distribution model fit when the data are Poisson distributed.
Gaussian Pseudorandom Number Generator Using Linear Feedback Shift Registers in Extended Fields
Authors: Cotrina Guillermo , Peinado Alberto , Ortiz Andrés
Published: March 2021

A new proposal to generate pseudorandom numbers with Gaussian distribution is presented. The generator is a generalization to the extended field GF(2n) of the one using cyclic rotations of linear feedback shift registers (LFSRs) originally defined in GF(2). The rotations applied to LFSRs in the binary case are no longer needed in the extended field due to the implicit rotations found in the binary equivalent model of LFSRs in GF(2n). The new proposal is aligned with the current trend in cryptography of using extended fields as a way to speed up the bitrate of the pseudorandom generators. This proposal allows the use of LFSRs in cryptography to be taken further, from the generation of the classical uniformly distributed sequences to other areas, such as quantum key distribution schemes, in which sequences with Gaussian distribution are needed. The paper contains the statistical analysis of the numbers produced and a comparison with other Gaussian generators.
Designing Tasks for a Dynamic Online Environment: Applying Research into Students’ Difficulties with Linear Equations
Authors: Elkjær Morten , Jankvist Uffe Thomas
Published: March 2021

Despite almost half a century of research into students’ difficulties with solving linear equations, these difficulties persist in everyday mathematics classes around the world. Furthermore, the difficulties reported decades ago are the same ones that persist today. With the immense number of dynamic online environments for mathematics teaching and learning that are emerging today, we are presented with a perhaps unique opportunity to do something about this. This study sets out to apply the research on lower secondary school students’ difficulties with equation solving, in order to eventually inform students’ personalised learning through a specific task design in a particular dynamic online environment (matematikfessor.dk). In doing so, task design theory is applied, particularly variation theory. The final design we present consists of eleven general equation types—ten types of arithmetical equations and one type of algebraic equation—and a broad range of variations of these, embedded in a potential learning-trajectory-tree structure. Besides establishing this tree structure, the main theoretical contribution of the study and the task design we present is the detailed treatment of the category of arithmetical equations, which also involves a new distinction between simplified and non-simplified arithmetical equations.
Global Persistence of the Unit Eigenvectors of Perturbed Eigenvalue Problems in Hilbert Spaces: The Odd Multiplicity Case
Authors: Benevieri Pierluigi , Calamai Alessandro , Furi Massimo , Pera Maria Patrizia
Published: March 2021

We study the persistence of eigenvalues and eigenvectors of perturbed eigenvalue problems in Hilbert spaces. We assume that the unperturbed problem has a nontrivial kernel of odd dimension and we prove a Rabinowitz-type global continuation result. The approach is topological, based on a notion of degree for oriented Fredholm maps of index zero between real differentiable Banach manifolds.
Feature Selection for Colon Cancer Detection Using K-Means Clustering and Modified Harmony Search Algorithm
Authors: Bae Jin Hee , Kim Minwoo , Lim J.S. , Geem Zong Woo
Published: March 2021

This paper proposes a feature selection method that is effective in distinguishing colorectal cancer patients from normal individuals using K-means clustering and the modified harmony search algorithm. As the genetic cause of colorectal cancer originates from mutations in genes, it is important to classify the presence or absence of colorectal cancer through gene information. The proposed methodology consists of four steps. First, the original data are Z-normalized by data preprocessing. Candidate genes are then selected using the Fisher score. Next, one representative gene is selected from each cluster after candidate genes are clustered using K-means clustering. Finally, feature selection is carried out using the modified harmony search algorithm. The gene combination created by feature selection is then applied to the classification model and verified using 5-fold cross-validation. The proposed model obtained a classification accuracy of up to 94.36%. Furthermore, on comparing the proposed method with other methods, we prove that the proposed method performs well in classifying colorectal cancer. Moreover, we believe that the proposed model can be applied not only to colorectal cancer but also to other gene-related diseases.
The Potentials of Melatonin in the Prevention and Treatment of Bacterial Meningitis Disease
Authors: Zhang Dong , Xu Shu , Wang Yiting , Zhu Guoqiang
Published: March 2021

Bacterial meningitis (BM) is an acute infectious central nervous system (CNS) disease worldwide, occurring with 50% of the survivors left with a long-term serious sequela. Acute bacterial meningitis is more prevalent in resource-poor than resource-rich areas. The pathogenesis of BM involves complex mechanisms that are related to bacterial survival and multiplication in the bloodstream, increased permeability of blood–brain barrier (BBB), oxidative stress, and excessive inflammatory response in CNS. Considering drug-resistant bacteria increases the difficulty of meningitis treatment and the vaccine also has been limited to several serotypes, and the morbidity rate of BM still is very high. With recent development in neurology, there is promising progress for drug supplements of effectively preventing and treating BM. Several in vivo and in vitro studies have elaborated on understanding the significant mechanism of melatonin on BM. Melatonin is mainly secreted in the pineal gland and can cross the BBB. Melatonin and its metabolite have been reported as effective antioxidants and anti-inflammation, which are potentially useful as prevention and treatment therapy of BM. In bacterial meningitis, melatonin can play multiple protection effects in BM through various mechanisms, including immune response, antibacterial ability, the protection of BBB integrity, free radical scavenging, anti-inflammation, signaling pathways, and gut microbiome. This manuscript summarizes the major neuroprotective mechanisms of melatonin and explores the potential prevention and treatment approaches aimed at reducing morbidity and alleviating nerve injury of BM.