bluuebunny/crossref_metadata_2025 huggingface dataset:
Loss of Ubiquitin Carboxy-Terminal Hydrolase L1 Impairs Long-Term Differentiation Competence and Metabolic Regulation in Murine Spermatogonial Stem Cells
Authors: Alpaugh Whitney F. , Voigt Anna L. , Dardari Rkia , Su Lin , Al Khatib Iman , Shin Wisoo , Goldsmith Taylor M. , Coyle Krysta M. , Tang Lin A. , Shutt Timothy E. , Klein Claudia , Biernaskie Jeff , Dobrinski Ina
Published: September 2021

Spermatogonia are stem and progenitor cells responsible for maintaining mammalian spermatogenesis. Preserving the balance between self-renewal of spermatogonial stem cells (SSCs) and differentiation is critical for spermatogenesis and fertility. Ubiquitin carboxy-terminal hydrolase-L1 (UCH-L1) is highly expressed in spermatogonia of many species; however, its functional role has not been identified. Here, we aimed to understand the role of UCH-L1 in murine spermatogonia using a Uch-l1−/− mouse model. We confirmed that UCH-L1 is expressed in undifferentiated and early-differentiating spermatogonia in the post-natal mammalian testis. The Uch-l1−/− mice showed reduced testis weight and progressive degeneration of seminiferous tubules. Single-cell transcriptome analysis detected a dysregulated metabolic profile in spermatogonia of Uch-l1−/− compared to wild-type mice. Furthermore, cultured Uch-l1−/− SSCs had decreased capacity in regenerating full spermatogenesis after transplantation in vivo and accelerated oxidative phosphorylation (OXPHOS) during maintenance in vitro. Together, these results indicate that the absence of UCH-L1 impacts the maintenance of SSC homeostasis and metabolism and impacts the differentiation competence. Metabolic perturbations associated with loss of UCH-L1 appear to underlie a reduced capacity for supporting spermatogenesis and fertility with age. This work is one step further in understanding the complex regulatory circuits underlying SSC function.
Aging and Cancer: The Waning of Community Bonds
Authors: Laconi Ezio , Cheri Samuele , Fanti Maura , Marongiu Fabio
Published: September 2021

Cancer often arises in the context of an altered tissue landscape. We argue that a major contribution of aging towards increasing the risk of neoplastic disease is conveyed through effects on the microenvironment. It is now firmly established that aged tissues are prone to develop clones of altered cells, most of which are compatible with a normal histological appearance. Such increased clonogenic potential results in part from a generalized decrease in proliferative fitness, favoring the emergence of more competitive variant clones. However, specific cellular genotypes can emerge with reduced cooperative and integrative capacity, leading to disruption of tissue architecture and paving the way towards progression to overt neoplastic phenotypes.
Synthesis and Self-Assembling Properties of Peracetylated β-1-Triazolyl Alkyl D-Glucosides and D-Galactosides
Authors: Sharma Pooja , Chen Anji , Wang Dan , Wang Guijun
Published: September 2021

Carbohydrate-based low-molecular-weight gelators (LMWGs) are useful classes of compounds due to their numerous applications. Among sugar-based LMWGs, certain peracetylated sugar beta-triazole derivatives were found to be effective organogelators and showed interesting self-assembling properties. To further understand the structural influence towards molecular assemblies and obtain new functional materials with interesting properties, we designed and synthesized a library of tetraacetyl beta-1-triazolyl alkyl-D-glucosides and D-galactosides, in which a two or three carbon spacer is inserted between the anomeric position and the triazole moiety. A series of 16 glucose derivatives and 14 galactose derivatives were synthesized and analyzed. The self-assembling properties of these new triazole containing glycoconjugates in different solvents were analyzed. Several glucose derivatives were found to be effective LMWGs, with compound 7a forming gels in a variety of organic solvents as well as in the presence of metal ions in aqueous solutions. The organogels formed by several compounds were characterized using optical microscopy, atomic force microscopy (AFM) and UV-vis spectroscopy, etc. The co-gels formed by compound 7a with the Fmoc derivative 7i showed interesting fluorescence enhancement upon gelation. Several gelators were also characterized using powder X-ray diffraction and FT-IR spectroscopy. The potential applications of these sugar-based gelators for drug delivery and dye removal were also studied.
Active Ingredients from Euodia ruticarpa Steam Distilled Essential Oil Inhibit PC-3 Prostate Cancer Cell Growth via Direct Action and Indirect Immune Cells Conditioned Media In Vitro
Authors: Yeh Tzu-He , Lin Jin-Yuarn
Published: September 2021

Active constituents isolated from Euodia ruticarpa (ER) steam distilled essential oil (SDEO) against PC-3 prostate cancer cell growth remain unclear. To clarify the puzzle, ER SDEO was extracted and further resolved into six isolated fractions ERF1–F6 with Sephadex LH-20 gel filtration chromatography to analyze their biological activities. Active ingredients in the isolated fractions were analyzed with GC-MS. Potential isolated fractions were selected to treat PC-3 cells with direct action and indirect treatment by mouse splenocyte- (SCM) and macrophage-conditioned media (MCM). The relationship between PC-3 cell viabilities and corresponding total polyphenols, flavonoid contents as well as Th1/Th2 cytokine profiles in SCM was analyzed using the Pearson product–moment correlation coefficient (r). As a result, ERF1–F3 was abundant in total polyphenols and flavonoids contents with diverse active ingredients. Treatments with ERF1–F3 at appropriate concentrations more or less inhibit PC-3 cell growth in a direct action manner. Only SCM, respectively, cultured with ER SDEO and ERF1–F3 markedly enhanced the effects to inhibit PC-3 cell growth, suggesting that secretions by splenocytes might involve anti-PC-3 effects. There are significantly negative correlations between PC-3 cell viabilities and IL-2, IL-10 as well as IL-10/IL-2 ratios in the corresponding SCM. Total polyphenol and flavonoid contents in the media cultured with ER SDEO isolated fractions positively correlated with IL-10 (Th2) and IL-10/IL-2 (Th2/Th1) cytokine secretion ratios by splenocytes, indicating that polyphenol and flavonoid components in ER SDEO isolated fractions promote Th2-polarized and anti-inflammatory characteristics. These new findings concluded that the inhibitory effects against PC-3 prostate cancer cell growth are attributed to active anti-inflammatory ingredients in ER SDEO and its active ERF1–F3 fractions through direct action and indirect treatment by modulating splenocytes’ cytokine secretion profiles.
Lateral Deformation Capacity and Plastic Hinge Length of RC Columns Confined with Textile Reinforced Mortar Jackets
Authors: Parvin Azadeh , Alhusban Mohannad
Published: September 2021

This paper presents a nonlinear finite element analysis (FEA) of textiles reinforced mortars (TRM)-confined reinforced concrete (RC) columns through jacketing, under combined axial and cyclic loadings. The FEA models were validated with an experimental study in the literature that was conducted on full-scale square columns reinforced with continuous steel bars (no lap splices). Subsequently, parametric study was performed on the validated FEA models. The parameters considered include various jacket’s lengths and mortar strengths. Moreover, semiempirical models were developed to evaluate the plastic hinge length (LP) and the ultimate drift ratio of RC columns confined with TRM and FRP jackets, while considering the jacket length effect. The FEA models and experimental results were in good agreement. The finite element results revealed that the increase in the jacket length improved the lateral deformation capacity and increased the plastic hinge length linearly up to a confinement ratio of 0.2. Beyond this point, the plastic hinge length shortened as the confinement ratio raised. Moreover, mortars with higher flexural strength resulted in a slightly higher deformation capacity. However, the difference in the mortar compressive strength did not affect the ultimate lateral deformation capacity. The semiempirical models show that the average difference in the predicted LP and the ultimate drift ratio values as compared to the experimental and simulated columns was 3.19 and 16.06%, respectively.
Numerical Investigations on Non-Rectangular Anchor Groups under Shear Loads Applied Perpendicular or Parallel to an Edge
Authors: Bokor Boglárka , Sharma Akanshu
Published: September 2021

Anchorages of non-rectangular configuration, though not covered by current design codes, are often used in practice due to functional or architectural needs. Frequently, such anchor groups are placed close to a concrete edge and are subjected to shear loads. The design of such anchorages requires engineering judgement and no clear rules are given in the codes and standards. In this work, numerical investigations using a nonlinear 3D FE analysis code are carried out on anchor groups with triangular and hexagonal anchor patterns to understand their behavior under shear loads. A microplane model with relaxed kinematic constraint is utilized as the constitutive law for concrete. Two different orientations are considered for both triangular and hexagonal anchor groups while no hole clearance is considered in the analysis. Two loading scenarios are investigated: (i) shear loading applied perpendicular and towards the edge; and (ii) shear loading applied parallel to the edge. The results of the analyses are evaluated in terms of the load-displacement behavior and failure modes. A comparison is made between the results of the numerical simulations and the analytical calculations according to the current approaches. It is found that, similar to the rectangular anchorages, and also for such non-rectangular anchorages without hole clearance, it may be reasonable to calculate the concrete edge breakout capacity by assuming a failure crack from the back anchor row. Furthermore, the failure load of the investigated groups loaded in shear parallel to the edge may be considered as twice the failure load of the corresponding groups loaded in shear perpendicular to the edge.
Resilient Predictive Control Coupled with a Worst-Case Scenario Approach for a Distributed-Generation-Rich Power Distribution Grid
Authors: Dkhili Nouha , Eynard Julien , Thil Stéphane , Grieu Stéphane
Published: September 2021

In a context of accelerating deployment of distributed generation in power distribution grid, this work proposes an answer to an important and urgent need for better management tools in order to ‘intelligently’ operate these grids and maintain quality of service. To this aim, a model-based predictive control (MPC) strategy is proposed, allowing efficient re-routing of power flows using flexible assets, while respecting operational constraints as well as the voltage constraints prescribed by ENEDIS, the French distribution grid operator. The flexible assets used in the case study—a low-voltage power distribution grid in southern France—are a biogas plant and a water tower. Non-parametric machine-learning-based models, i.e., Gaussian process regression (GPR) models, are developed for intraday forecasting of global horizontal irradiance (GHI), grid load, and water demand, to better anticipate emerging constraints. The forecasts’ quality decreases as the forecast horizon grows longer, but quickly stabilizes around a constant error value. Then, the impact of forecasting errors on the performance of the control strategy is evaluated, revealing a resilient behaviour where little degradation is observed in terms of performance and computation cost. To enhance the strategy’s resilience and minimise voltage overflow, a worst-case scenario approach is proposed for the next time step and its contribution is examined. This is the main contribution of the paper. The purpose of the min–max problem added upstream of the main optimisation problem is to both anticipate and minimise the voltage overshooting resulting from forecasting errors. In this min–max problem, the feasible space defined by the confidence intervals of the forecasts is searched, in order to determine the worst-case scenario in terms of constraint violation, over the next time step. Then, such information is incorporated into the decision-making process of the main optimisation problem. Results show that these incidents are indeed reduced thanks to the min–max problem, both in terms of frequency of their occurrence and the total surface area of overshooting.
Excellent Seizure and Friction Properties Achieved with a Combination of an a-C:H:Si DLC-Coated Journal and an Aluminum Alloy Plain Bearing
Authors: Iwata Takumi , Oikawa Masakuni , Chida Riki , Ishii Daijiro , Ogihara Hidemi , Mihara Yuji , Kano Makoto
Published: September 2021

Friction occurring between the crank journal and main bearings accounts for a large share of the mechanical losses of automotive engines. The effects of higher in-cylinder pressures and narrower bearings have raised the specific load applied to bearings, making it essential to secure sufficient seizure resistance as well. For the purpose of meeting both requirements, we have endeavored to reduce friction and improve seizure resistance by applying a diamond-like carbon (DLC) coating to the crank journal. In the present study, a bearing tester was used that has received international standard certification from the International Organization for Standardization for reproducing the sliding behavior occurring between the crank journal and main bearings in actual engines. Test results indicated that a silicon-containing hydrogenated amorphous carbon (a-C:H:Si) DLC-coated journal showed a definite friction reduction and a marked improvement in seizure resistance. An acoustic emission (AE) analysis revealed that an adhesion-induced AE peak observed for a steel journal was not seen for the DLC-coated journal. Additionally, tin and aluminum elements in the bearing material that were transferred to and observed on the sliding surface of the steel journal were not seen on the DLC-coated journal. Accordingly, the low affinity of the DLC coating with these metal elements presumably led to the clear friction reduction and superior seizure resistance displayed by the DLC coating.
Application of Whey Protein-Based Edible Films and Coatings in Food Industries: An Updated Overview
Authors: Kandasamy Sujatha , Yoo Jayeon , Yun Jeonghee , Kang Han-Byul , Seol Kuk-Hwan , Kim Hyoun-Wook , Ham Jun-Sang
Published: September 2021

The recent surge in environmental awareness and consumer demand for stable, healthy, and safe foods has led the packaging and food sectors to focus on developing edible packaging materials to reduce waste. Edible films and coatings as a modern sustainable packaging solution offer significant potential to serve as a functional barrier between the food and environment ensuring food safety and quality. Whey protein is one of the most promising edible biopolymers in the food packaging industry that has recently gained much attention for its abundant nature, safety, and biodegradability and as an ecofriendly alternative of synthetic polymers. Whey protein isolate and whey protein concentrate are the two major forms of whey protein involved in the formation of edible films and coatings. An edible whey film is a dry, highly interacting polymer network with a three-dimensional gel-type structure. Films/coatings made from whey proteins are colorless, odorless, flexible, and transparent with outstanding mechanical and barrier properties compared with polysaccharide and other-protein polymers. They have high water vapor permeability, low tensile strength, and excellent oxygen permeability compared with other protein films. Whey protein-based films/coatings have been successfully demonstrated in certain foods as vehicles of active ingredients (antimicrobials, antioxidants, probiotics, etc.), without considerably altering the desired properties of packaging films that adds value for subsequent industrial applications. This review provides an overview of the recent advances on the formation and processing technologies of whey protein-based edible films/coatings, the incorporation of additives/active ingredients for improvement, their technological properties, and potential applications in food packaging.
An Exploratory Study of Consumers’ Knowledge and Attitudes about Lignin-Based Sunscreens and Bio-Based Skincare Products
Authors: Sajinčič Nežka , Gordobil Oihana , Simmons Amy , Sandak Anna
Published: September 2021

Daily consumption of synthetic sunscreens is harmful to the environment and consumers’ health, so greener alternatives need to be produced. Lignin is a multifunctional and widely available biopolymer that can replace several ingredients, but its dark color and low sun protection limit its perceived usefulness. With a survey made for this study, we explored the knowledge and attitudes of 230 consumers towards lignin-based sunscreen, their motives and barriers to purchase it, and how it relates to their environmental and health consciousness. Participants were also asked about their sunscreen habits, their familiarity with the environmental and health impacts of skincare, their perceptions of bio-based ingredients in general, and their skincare product purchasing decisions. Those who are more familiar with environmental issues have a positive attitude towards bio-based ingredients, are accustomed to purchasing more environmentally friendly skincare, and are likelier to be interested in a lignin product. Consumers are welcoming towards a natural, healthy, and environmentally friendly sunscreen alternative but are worried about the lower SPF. Because organic is perceived as luxurious, they are concerned about its price, and some are apprehensive about its pigmentation. While a lignin-based sunscreen at this stage of development is unlikely to take on the role of primary sunscreen on warm, sunny days, it may be more useful as a general-purpose, everyday product that can offer some protection, moisture, and coverage.
Salicylic Acid Pretreatment Modulates Wheat Responses to Glyphosate
Authors: Shopova Elena , Brankova Liliana , Katerova Zornitsa , Dimitrova Ljudmila , Todorova Dessislava , Sergiev Iskren , Talaat Neveen B.
Published: September 2021

Glyphosate is an extensively used herbicide because of its non-selective action for weed control. Salicylic acid (SA) is a phenolic compound that has the potential to increase plant tolerance to diverse stresses. To test SA ability to modulate plant responses to glyphosate we used young wheat (Triticum aestivum L.) seedlings grown as a water culture. Plants were sprayed with 1 mM SA, and 24 h later with 0.5 mM glyphosate. All measurements were performed 14 days after herbicide treatment. Wheat growth was reduced by glyphosate. Stress markers (proline and malondialdehyde) were significantly increased by glyphosate showing oxidative damages. Incapacity of wheat to cope with the oxidative stress was evidenced by reduction in thiols and phenolics content, accompanied by slight induction of superoxide dismutase and catalase activities. Enhanced activities of peroxidase, glutathione reductase and glutathione-S-transferase were expected to participate in glyphosate detoxification. SA applied alone had no important effects on measured parameters. SA pretreatment decreased stress markers and caused additional amplification of antioxidant defense systems in glyphosate-treated plants. Growth was partially restored in combine-treated plants due to SA application. SA probably triggered antioxidant defense to cope with the herbicide stress.
Using DFT to Calculate the Parameters of the Crystal Field in Mn2+ Doped Hydroxyapatite Crystals
Authors: Shurtakova Daria Vladimirovna , Grishin Peter Olegovich , Gafurov Marat Revgerovich , Mamin Georgy Vladimirovich
Published: September 2021

Crystal field parameters for two nonequivalent positions Ca (I) and Ca (II) for hydroxyapatite (HAp) crystals from the density functional theory (DFT) are calculated. Calculations are compared with the experimental electron paramagnetic resonance (EPR) spectra (registered at two microwave frequencies) for the synthesized Mn-HAp powders Ca9.995Mn0.005(PO4)6(OH)2. It is found that in the investigated species, the manganese is redistributed between both calcium sites with prevalence in Ca (I). Agreement between the calculated and experimental data proves that crystal field parameters in HAp can be calculated in the classical DFT model using the distributed electron density.
Ultrasound in Continuous Tubular Crystallizers: Parameters Affecting the Nucleation Rate
Authors: Vancleef Arne , Van Gerven Tom , Thomassen Leen C. J. , Braeken Leen
Published: September 2021

Ultrasound has proven to be an important tool for controlling nucleation in continuous tubular crystallizers. However, insufficient information is available about the parameters controlling the nucleation rate in a continuous ultrasonic process. Previous research has studied parameters related to the nucleation rate, but has not measured the nucleation rate directly or continuously. In this work, the nucleation rate is measured continuously and inline to solve this problem and achieve a better process understanding. The results indicate that the ultrasound-assisted nucleation process is presumably dominated by secondary nucleation. Additionally, the supersaturation, residence time and flow rate have a strong influence on the nucleation rate. On the other hand, the influence of the ultrasonic power is crucial but levels off once a certain amount of power is reached. The static pressure in the system determines the effective ultrasonic power and is therefore also important for the nucleation rate. Finally, maintaining an equal power per unit of volume and an equal residence time by increasing the tubing diameter seems to be a good scale-up method. These results will improve understanding of ultrasonic tubular crystallizers and how to control them.
Characterization of Terrihabitans soli gen. nov., sp. nov., a Novel 0.2 μm-Filterable Soil Bacterium Belonging to a Widely Distributed Lineage of Hyphomicrobiales (Rhizobiales)
Authors: Nakai Ryosuke , Naganuma Takeshi , Tazato Nozomi , Kunihiro Tadao , Morohoshi Sho , Koide Tomomi , Kusada Hiroyuki , Tamaki Hideyuki , Narihiro Takashi
Published: September 2021

We previously showed that novel filterable bacteria remain in “sterile” (<0.2 μm filtered) terrestrial environmental samples from Japan, China, and Arctic Norway. Here, we characterized the novel filterable strain IZ6T, a representative strain of a widely distributed lineage. Phylogenetic analysis showed that this strain was affiliated with the Rhizobiales (now proposed as Hyphomicrobiales) of Alphaproteobacteria, but distinct from any other type strains. Strain IZ6T shared the following chemotaxonomic features with the closest (but distantly) related type strain, Flaviflagellibacter deserti SYSU D60017T: ubiquinone-10 as the major quinone; phosphatidylethanolamine, phosphatidylcholine, and phosphatidylglycerol as major polar lipids; and slightly high G+C content of 62.2 mol%. However, the cellular fatty acid composition differed between them, and the unsaturated fatty acid (C18:1ω7c/C18:1ω6c) was predominantly found in our strain. Moreover, unlike methyrotrophs and nitrogen-fixers of the neighboring genera of Hyphomicrobiales (Rhizobiales), strain IZ6T cannot utilize a one-carbon compound (e.g., methanol) and fix atmospheric nitrogen gas. These findings were consistent with the genome-inferred physiological potential. Based on the phylogenetic, physiological, and chemotaxonomic traits, we propose that strain IZ6T represents a novel genus and species with the name Terrihabitans soli gen. nov., sp. nov. (=NBRC 106741T = NCIMB 15058T). The findings will provide deeper insight into the eco-physiology of filterable microorganisms.
Body Condition Score, Rumination, Intake, Milk Production and Milk Composition of Grazing Dairy Cows Supplemented with Rumen-Protected Lysine and Methionine
Authors: Cheng Long , Balogun Razaq , Meng Fanzeng , Dunshea Frank R. , Cullen Brendan
Published: September 2021

The study utilised a pasture grazing based, voluntary traffic automatic milking system to investigate milk production of cows fed a pasture-based diet and supplemented with a pellet formulated with vs. without rumen-protected lysine and methionine (RPLM). The study adopted a switch-over design (over two periods of 5 and 10 weeks, respectively) and used 36 cows and equally allocated them into two experimental groups. The RPLM (Trial) pellet had 2% lower crude protein, but similar metabolizable energy content compared to the Control pellet. Pellet intake was 10.0 and 9.4 kg/day/cow. Milk yield was 36.2 and 34.4 kg/day/cow (p = 0.23), and energy corrected milk was 35.1 and 33.8 kg/day/cow (p = 0.076), and milk solids was 2.55 and 2.46 kg/cow/day (p = 0.073) in the Control and Trial groups, respectively. Milk fat%, milk protein%, milk fat: protein ratio, milking frequency and rumination time were not different between the two groups (p > 0.05). In period 1, plasma glucose was 3.1 mmol/L for both groups and milk urea were 150 and 127 mg/L in the Control and Trial groups, respectively. Both plasma glucose (as a proxy for energy supply) and milk urea (as a proxy for nitrogen use efficiency; NUE) were not different between groups (p > 0.05). This study showed that under a grazing pasture system, feeding lactating dairy cows a low protein pellet with RPLM supplementation, maintained milk production performance and NUE, compared with cows fed a high protein Control pellet diet with no RPLM. Further research should assess the long-term (seasonal) effects of feeding a diet formulated with RPLM on cow intake, health and reproductive performance.
The Non-Cancer Specific Elevation of the Serum Squamous Cell Carcinoma Antigen during the Post-Radiotherapy Follow-Up of Cervical Cancer Patients
Authors: Oike Tae , Oike Takahiro , Ando Ken , Iwase Akira , Ohno Tatsuya
Published: September 2021

The elevation of the serum squamous cell carcinoma (SCC) antigen unrelated to disease progression occurs during the follow-up of patients with cervical cancer treated with radiotherapy. Although known empirically, the incidence and characteristics of this non-cancer specific elevation in SCC remain unclear. Here, we examined the post-treatment kinetics of SCC in 143 consecutive patients with squamous cell carcinoma of the cervix treated with definitive radiotherapy; in all patients, progression-free disease status was confirmed by periodic monitoring for at least 36 months (median, 61 months). We found that the 5-year cumulative incidence of post-treatment SCC elevation was unexpectedly high at 37.3% (59/143 patients), and that 59.3% (35/59) of event-positive patients experienced multiple events. The median peak SCC level for a given event was 2.0 ng/mL (interquartile range, 1.7–2.9 ng/mL). The multivariate analysis showed that renal dysfunction was associated significantly with a greater incidence of SCC elevation (p = 0.046). In addition, the 5-year cumulative incidence of SCC elevation was significantly greater in patients with renal dysfunction than in those without (54.8% vs. 32.9%, respectively; hazard ratio, 2.1 [95% confidence interval, 1.1–4.2]; p = 0.028). These data will be useful for monitoring cervical cancer patients treated with radiotherapy.
Flap Thickness and the Risk of Complications in Mechanical Microkeratome and Femtosecond Laser In Situ Keratomileusis: A Literature Review and Statistical Analysis
Authors: Kanclerz Piotr , Khoramnia Ramin
Published: September 2021

Introduction: A recent Cochrane review found no difference in visual acuity outcomes between femtosecond-assisted laser in situ keratomileusis (LASIK) and LASIK using mechanical microkeratomes (MMKs). This study compares the flap thickness and risk of complications related to flap creation using femtosecond lasers and MMKs. Methods: PubMed and the Web of Science are used to search the medical literature. An extensive search is performed to identify the flap thickness and complications of LASIK as reported up to 15 July 2021. The following keywords are used in various combinations: Corneal flap, femtosecond laser, laser in situ keratomileusis, laser-assisted in situ keratomileusis, LASIK, mechanical microkeratome. Results: After removing duplicates and irrelevant studies, 122 articles were included for review. Pooled differences for intended vs. postoperative flap thickness using MMKs and femtosecond laser were −4.07 μm (95% CI: −19.55, 3.24 μm) in studies on the MMK and 5.43 μm (95% CI: 2.30, 7.84 μm; p < 0.001), respectively. After removing the studies evaluating outcomes of the old generation Hansatome MMKs (which had a significantly greater variation of flap thickness), the pooled difference for newer MMKs was 4.97 μm (95% CI: 0.35, 9.58 μm; p < 0.001), but the results still favored the femtosecond laser. Uncommon and mild complications unique for the femtosecond LASIK are epithelial gas breakthrough, opaque bubble layer, transient light sensitivity syndrome, and rainbow glare. A single study reported a very low, but stastically different risk of postoperative flap slippage (0.033% for MMK LASIK, and 0.003% for femtosecond LASIK, respectively). Conclusion: In both manual microkeratome and femtosecond LASIK, intra- and postoperative complications were uncommon. The evidence of the superiority of one technique in terms of complications over another cannot be indisputably stated.
Level of Inclusiveness of People with Disabilities in Ghanaian Health Policies and Reports: A Scoping Review
Authors: Seidu Abdul-Aziz , Malau-Aduli Bunmi S. , McBain-Rigg Kristin , Malau-Aduli Aduli E. O. , Emeto Theophilus I.
Published: September 2021

(1) Background: Globally, persons with disabilities (PWDs) face numerous challenges including access to healthcare. This scoping review sought to assess the level of inclusiveness in Ghanaian health policies and reports for PWDs; (2) Methods: An extensive search and scoping review of health policies/reports in Ghanaian government websites and Google was conducted. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for scoping reviews were followed in selecting and reporting the policies/reports. The program evaluation and policy design framework was employed for content analysis; (3) Results: Fifteen policies and reports with political recognition, objectives, and specific resources needed to execute stipulated plans were included. Although these policies and reports had collaborative partnerships with various institutions and organisations in development and implementation plans, the level of inclusiveness of disability issues was very low. Only eight out of the fifteen policies/reports (53%) reviewed considered PWDs, indicating a low level of inclusion. The definition of disability was also limited.; (4) Conclusions: To achieve the sustainable development goal of ‘leaving no one behind’ in line with the provisions of the United Nations Convention on the Right of Persons with Disabilities and the Disability Act 715 of Ghana, it is recommended that subsequent health policies should have an in-depth engagement with PWDs from the conceptual design stage right through to implementation and evaluation.
An Algorithm for Local Dynamic Map Generation for Safe UAV Navigation
Authors: Lee Jin-Woo , Lee Wonjai , Kim Kyoung-Dae
Published: September 2021

For safe UAV navigation and to avoid collision, it is essential to have accurate and real-time perception of the environment surrounding the UAV, such as free area detection and recognition of dynamic and static obstacles. The perception system of the UAV needs to recognize information such as the position and velocity of all objects in the surrounding local area regardless of the type of object. At the same time, a probability based representation taking into account the noise of the sensor is also essential. In addition, a software design with efficient memory usage and operation time is required in consideration of the hardware limitations of the UAVs. In this paper, we propose a 3D Local Dynamic Map (LDM) generation algorithm for a perception system for UAVs. The proposed LDM uses a circular buffer as a data structure to ensure low memory usage and fast operation speed. A probability based occupancy map is created using sensor data and the position and velocity of each object are calculated through clustering between grid voxels using the occupancy map and velocity estimation based on a particle filter. The objects are predicted using the position and velocity of each object and this is reflected in the occupancy map. This process is continuously repeated and the flying environment of the UAV can be expressed in a three-dimensional grid map and the state of each object. For the evaluation of the proposed LDM, we constructed simulation environments and the UAV for outdoor flying. As an evaluation factor, the occupancy grid is accuracy evaluated and the ground truth velocity and the estimated velocity are compared.
Shannon Entropy and Diffusion Coefficient in Parity-Time Symmetric Quantum Walks
Authors: Tian Zhiyu , Liu Yang , Luo Le
Published: September 2021

Non-Hermitian topological edge states have many intriguing properties, however, to date, they have mainly been discussed in terms of bulk–boundary correspondence. Here, we propose using a bulk property of diffusion coefficients for probing the topological states and exploring their dynamics. The diffusion coefficient was found to show unique features with the topological phase transitions driven by parity–time (PT)-symmetric non-Hermitian discrete-time quantum walks as well as by Hermitian ones, despite the fact that artificial boundaries are not constructed by an inhomogeneous quantum walk. For a Hermitian system, a turning point and abrupt change appears in the diffusion coefficient when the system is approaching the topological phase transition, while it remains stable in the trivial topological state. For a non-Hermitian system, except for the feature associated with the topological transition, the diffusion coefficient in the PT-symmetric-broken phase demonstrates an abrupt change with a peak structure. In addition, the Shannon entropy of the quantum walk is found to exhibit a direct correlation with the diffusion coefficient. The numerical results presented herein may open up a new avenue for studying the topological state in non-Hermitian quantum walk systems.
Educational Innovation in the Evaluation Processes within the Flipped and Blended Learning Models
Authors: Yangari Monserrath , Inga Esteban
Published: September 2021

Nowadays, several institutions and universities have employed Flipped and Blended Learning models in the educational context. Consequently, these models advance correctly in the classrooms; students become more able to build their knowledge and develop their skills with technological innovation that could be compared with studies based on technological achievements and accessible data Tics. Therefore, this article proposes educational innovation in the evaluation processes within the FL and BL learning models to ensure active and interactive education. In this work, a bibliometric analysis of 2000 scientific articles from the Web of Science and Scopus databases has been carried out, thus making it possible to identify countries and universities with constant and relevant use of these learning models, as well as a comparison with these databases of articles, citations and their global impact. On the other hand, a survey was conducted with 41 teachers of different subjects and 385 students from elementary school to high school using the Likert scale. The questions were represented in perception values with their respective analysis of results and evaluations about these learning models, technological resources, flexible curriculum, learning before class, autonomous learning, and future professional competencies, which will help us know the existing motivation between them.
The Education of Informal Educators
Authors: Jeffs Tony , Smith Mark K.
Published: September 2021

No undergraduate or postgraduate programmes currently exist for the professional education of informal educators. The authors outline the development of previous programmes and consider the emergence of informal education as a discrete concept. The article then highlights some key failings in the professional education of informal educators and outlines some changes in the orientation and content of programmes.
Resilience in Higher Education: A Complex Perspective to Lecturers’ Adaptive Processes in Response to the COVID-19 Pandemic
Authors: Bento Fabio , Giglio Bottino Andréa , Cerchiareto Pereira Felipe , Forastieri de Almeida Janimayri , Gomes Rodrigues Fabiana
Published: September 2021

The present article discusses the dynamics of system resilience, focusing on the case of a university college in Brazil. It investigates the experience of lecturers of this educational institution in the initial months of the COVID-19 pandemic. This is exploratory basic qualitative research, aiming at understanding how the university college self-organized in this period. This research focused on local adaptation processes and was conducted through interviews with a sample of lecturers from the study programs offered by the university college. A text analysis software was used to analyze the data generated according to the three aspects of social-ecological resilience. The analytical framework of this research applies the concept of resilience in a socio-ecological system to discuss emergent organizational changes and learning in higher education. Systems resilience highlights adaptation processes characterized by an interplay of previous experience and emerging new knowledge. The findings describe the emergence of new practices and learning as faculty members encountered challenges brought on by the pandemic. Beyond learning new technological tools, the pandemic raised awareness of students’ socio-economic backgrounds in the context of inequality in Brazil. However, resilience requires open communication among staff and across organizational levels about adaptation processes that have taken place during the pandemic.
Multiple Drone Navigation and Formation Using Selective Target Tracking-Based Computer Vision
Authors: Upadhyay Jatin , Rawat Abhishek , Deb Dipankar
Published: September 2021

Autonomous unmanned aerial vehicles work seamlessly within the GPS signal range, but their performance deteriorates in GPS-denied regions. This paper presents a unique collaborative computer vision-based approach for target tracking as per the image’s specific location of interest. The proposed method tracks any object without considering its properties like shape, color, size, or pattern. It is required to keep the target visible and line of sight during the tracking. The method gives freedom of selection to a user to track any target from the image and form a formation around it. We calculate the parameters like distance and angle from the image center to the object for the individual drones. Among all the drones, the one with a significant GPS signal strength or nearer to the target is chosen as the master drone to calculate the relative angle and distance between an object and other drones considering approximate Geo-location. Compared to actual measurements, the results of tests done on a quadrotor UAV frame achieve 99% location accuracy in a robust environment inside the exact GPS longitude and latitude block as GPS-only navigation methods. The individual drones communicate to the ground station through a telemetry link. The master drone calculates the parameters using data collected at ground stations. Various formation flying methods help escort other drones to meet the desired objective with a single high-resolution first-person view (FPV) camera. The proposed method is tested for Airborne Object Target Tracking (AOT) aerial vehicle model and achieves higher tracking accuracy.
Power System Zone Partitioning Based on Transmission Congestion Identification Using an Improved Spectral Clustering Algorithm
Authors: Hu Yifan , Xun Peng , Kang Wenjie , Zhu Peidong , Xiong Yinqiao , Shi Weiheng
Published: September 2021

The ever-expanding power system is developed into an interconnected pattern of power grids. Zone partitioning is an essential technique for the operation and management of such an interconnected power system. Owing to the transmission capacity limitation, transmission congestion may occur with a regional influence on power system. If transmission congestion is considered when the system is decomposed into several regions, the power consumption structure can be optimized and power system planning can be more reasonable. At the same time, power resources can be properly allocated and system safety can be improved. In this paper, we propose a power system zone partitioning method where the potential congested branches are identified and the spectral clustering algorithm is improved. We transform the zone partitioning problem into a graph segmentation problem by constructing an undirected weighted graph of power system where the similarities between buses are measured by the power transfer distribution factor (PTDF) corresponding to the potential congested branches. Zone partitioning results show that the locational marginal price (LMP) in the same zone is similar, which can represent regional price signals and provide regional auxiliary decisions.
Automated Memory Corruption Detection through Analysis of Static Variables and Dynamic Memory Usage
Authors: Park Jihyun , Choi Byoungju , Kim Yeonhee
Published: September 2021

Various methods for memory fault detection have been developed through continuous study. However, many memory defects remain that are difficult to resolve. Memory corruption is one such defect, and can cause system crashes, making debugging important. However, the locations of the system crash and the actual source of the memory corruption often differ, which makes it difficult to solve these defects using the existing methods. In this paper, we propose a method that detects memory defects in which the location causing the defect is different from the actual location, providing useful information for debugging. This study presents a method for the real-time detection of memory defects in software based on data obtained through static and dynamic analysis. The data we used for memory defect analysis were (1) information of static global variables (data, address, size) derived through the analysis of executable binary files, and (2) dynamic memory usage information obtained by tracking memory-related functions that are called during the real-time execution of the process. We implemented the proposed method as a tool and applied it to applications running on the Linux. The results indicate the defect-detection efficacy of our tool for this application. Our method accurately detects defects with different cause and detected-fault locations, and also requires a very low overhead for fault detection.
3D Expression-Invariant Face Verification Based on Transfer Learning and Siamese Network for Small Sample Size
Authors: Li Zhenye , Zou Hongyan , Sun Xinyan , Zhu Tingting , Ni Chao
Published: September 2021

Three-dimensional (3D) face recognition has become a trending research direction in both industry and academia. However, traditional facial recognition methods carry high computational costs and face data storage costs. Deep learning has led to a significant improvement in the recognition rate, but small sample sizes represent a new problem. In this paper, we present an expression-invariant 3D face recognition method based on transfer learning and Siamese networks that can resolve the small sample size issue. First, a landmark detection method utilizing the shape index was employed for facial alignment. Then, a convolutional network (CNN) was constructed with transfer learning and trained with the aligned 3D facial data for face recognition, enabling the CNN to recognize faces regardless of facial expressions. Following that, the weighted trained CNN was shared by a Siamese network to build a 3D facial recognition model that can identify faces even with a small sample size. Our experimental results showed that the proposed method reached a recognition rate of 0.977 on the FRGC database, and the network can be used for facial recognition with a single sample.
Projected Near-Surface Wind Speed Trends in Lithuania
Authors: Jankevičienė Justė , Kanapickas Arvydas
Published: September 2021

Developing wind energy in Lithuania is one of the most important ways to achieve green energy goals. Observational data show that the decline in wind speeds in the region may pose challenges for wind energy development. This study analyzed the long-term variation of the observed 2006–2020 and projected 2006–2100 near-surface wind speed at the height of 10 m over Lithuanian territory using data of three models included in the Coupled Model Intercomparison Project phase 5 (CMIP5). A slight decrease in wind speeds was found in the whole territory of Lithuania for the projected wind speed data of three global circulation models for the scenarios RCP2.6, RCP4.5, and RCP8.5. It was found that the most favorable scenario for wind energy production is RCP2.6, and the most unfavorable is the RCP4.5 scenario under which the decrease in wind speed may reach 12%. At the Baltic Sea coastal region, the decline was smaller than in the country’s inner regions by the end of the century. The highest reduction in speed is characteristic of the most severe RCP8.5 scenario. Although the analysis of wind speeds projected by global circulation models (GCM) confirms the downward trends in wind speeds found in the observational data, the projected changes in wind speeds are too small to significantly impact the development of wind farms in Lithuania.
Investigation of Opto-Electronic Properties and Stability of Mixed-Cation Mixed-Halide Perovskite Materials with Machine-Learning Implementation
Authors: Filipoiu Nicolae , Mitran Tudor , Anghel Dragos , Florea Mihaela , Pintilie Ioana , Manolescu Andrei , Nemnes George
Published: September 2021

The feasibility of mixed-cation mixed-halogen perovskites of formula AxA’1−xPbXyX’zX”3−y−z is analyzed from the perspective of structural stability, opto-electronic properties and possible degradation mechanisms. Using density functional theory (DFT) calculations aided by machine-learning (ML) methods, the structurally stable compositions are further evaluated for the highest absorption and optimal stability. Here, the role of the halogen mixtures is demonstrated in tuning the contrasting trends of optical absorption and stability. Similarly, binary organic cation mixtures are found to significantly influence the degradation, while they have a lesser, but still visible effect on the opto-electronic properties. The combined framework of high-throughput calculations and ML techniques such as the linear regression methods, random forests and artificial neural networks offers the necessary grounds for an efficient exploration of multi-dimensional compositional spaces.