bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient Hierarchical and Time-Sensitive Data Sharing with User Revocation in Mobile Crowdsensing
Authors: Zhang Jiawei , Ma Jianfeng , Li Teng , Jiang Qi
Published: February 2021

Recently, cloud-based mobile crowdsensing (MCS) has developed into a promising paradigm which can provide convenient data sensing, collection, storage, and sharing services for resource-constrained terminates. Nevertheless, it also inflicts many security concerns such as illegal access toward user secret and privacy. To protect shared data against unauthorized accesses, many studies on Ciphertext-Policy Attribute-Based Encryption (CP-ABE) have been proposed to achieve data sharing granularity. However, providing a scalable and time-sensitive data-sharing scheme across hierarchical users with compound attribute sets and revocability remains a big issue. In this paper, we investigate this challenge and propose a hierarchical and time-sensitive CP-ABE scheme, named HTR-DAC, which is characteristics of time-sensitive data access control with scalability, revocability, and high efficiency. Particularly, we propose a time-sensitive CP-ABE for hierarchical structured users with recursive attribute sets. Moreover, we design a robust revocable mechanism to achieve direct user revocation in our scheme. We also integrate verifiable outsourced decryption to improve efficiency and guarantee correctness in decryption procedure. Extensive security and performance analysis is presented to demonstrate the security requirement satisfaction and high efficiency for our data-sharing scheme in MCS.
Antioxidant and Anti‐inflammatory Effect of Cannabidiol Contributes to the Decreased Lipid Peroxidation of Keratinocytes of Rat Skin Exposed to UV Radiation
Authors: Jastrząb Anna , Jarocka-Karpowicz Iwona , Markowska Agnieszka , Wroński Adam , Gęgotek Agnieszka , Skrzydlewska Elżbieta
Published: February 2021

There is a great need for compounds with antioxidant and anti‐inflammatory properties for protection against UV radiation, which is the most prooxidative physical factor that skin cells are exposed to everyday. Therefore, the aim of the study was to evaluate the mechanism of phytocannabinoid‐cannabidiol (CBD) action in vivo on lipid metabolism in keratinocytes of rat skin exposed to UVA/UVB radiation. Our results show that CBD protects keratinocytes against the effects of UVA/UVB radiation by reducing lipid peroxidation products: 4‐HNE and 8‐isoPGF2α. In addition, CBD significantly increases the level of endocannabinoids, such as anandamide, 2‐arachidonylglycerol, and palmitoylethanolamide, and the activation of their receptors CB1/2 or TRPV1. The above changes are due to the protective effect of CBD against the UVA/UVB‐induced decrease in the level/activity of superoxide dismutase and the components of the thioredoxin and glutathione systems. CBD also increases the in vivo transcriptional activity of Nrf2 and the expression of its Bach1 inhibitor as well as preventing the UVA/UVB‐induced increase in the expression of Nrf2 activators p21, p62, p38, and KAP1 and proinflammatory factors such as NFκB and TNFα. By counteracting oxidative stress and changes in lipid structure in keratinocytes, CBD prevents cellular metabolic disturbances, protecting the epidermis against UV damage.
A Real-Time Detection Method for Abnormal Data of Internet of Things Sensors Based on Mobile Edge Computing
Authors: Liu Xuguang
Published: February 2021

Aiming at the anomaly detection problem in sensor data, traditional algorithms usually only focus on the continuity of single-source data and ignore the spatiotemporal correlation between multisource data, which reduces detection accuracy to a certain extent. Besides, due to the rapid growth of sensor data, centralized cloud computing platforms cannot meet the real-time detection needs of large-scale abnormal data. In order to solve this problem, a real-time detection method for abnormal data of IoT sensors based on edge computing is proposed. Firstly, sensor data is represented as time series; K-nearest neighbor (KNN) algorithm is further used to detect outliers and isolated groups of the data stream in time series. Secondly, an improved DBSCAN (Density Based Spatial Clustering of Applications with Noise) algorithm is proposed by considering spatiotemporal correlation between multisource data. It can be set according to sample characteristics in the window and overcomes the slow convergence problem using global parameters and large samples, then makes full use of data correlation to complete anomaly detection. Moreover, this paper proposes a distributed anomaly detection model for sensor data based on edge computing. It performs data processing on computing resources close to the data source as much as possible, which improves the overall efficiency of data processing. Finally, simulation results show that the proposed method has higher computational efficiency and detection accuracy than traditional methods and has certain feasibility.
Dynamic Network Security Mechanism Based on Trust Management in Wireless Sensor Networks
Authors: Zheng Guiping , Gong Bei , Zhang Yu
Published: February 2021

Wireless sensor network is a key technology in Internet of Things. However, due to the large number of sensor nodes and limited security capability, aging nodes and malicious nodes increase. In order to detect the untrusted nodes in the network quickly and effectively and ensure the reliable operation of the network, this paper proposes a dynamic network security mechanism. Firstly, the direct trust value of the node is established based on its behavior in the regional information interaction. Then, the comprehensive trust value is calculated according to the trust recommendation value and energy evaluation value of other high‐trust nodes. Finally, node reliability and management nodes are updated periodically. Malicious nodes are detected and isolated according to the credibility to ensure the dynamic, safe, and reliable operation of the network. Simulation results and analysis show that the node trust value calculated by this mechanism can reflect its credibility truly and accurately. In terms of reliable network operation, the mechanism can effectively detect malicious nodes, with higher detection rate, avoid the risk of malicious nodes as management nodes, reduce the energy consumption of nodes, and also play a defensive role in DOS attacks in wireless sensor networks.
miR‐145‐5p Inhibits the Proliferation, Migration, and Invasion of Esophageal Carcinoma Cells by Targeting ABRACL
Authors: Fan Shengming , Chen Pei , Li Shugang
Published: February 2021

Objective. The study is aimed at investigating the regulatory relationship between miR‐145‐5p and ABRACL, and has tried at clarifying the mechanisms underlying the proliferation, migration, and invasion of esophageal carcinoma (EC) cells. Methods. Gene expression data related to EC were accessed from TCGA database, and the “edgeR” package was used to screen differentially expressed genes. TargetScan, miRDB, and miRTarBase databases were used to predict potential targets for the target miRNA miR‐145‐5p. qRT‐PCR and Western blot were performed to assess the expression of miR‐145‐5p and ABRACL in EC cells. Dual‐luciferase reporter assay was performed to validate the targeting relationship between miR‐145‐5p and ABRACL. Functional experiments including CCK‐8 assay, Transwell migration, and invasion assays were used to detect the proliferation, migration, and invasion of EC cells. Results. The expression of miR‐145‐5p was significantly decreased in EC, while ABRACL was remarkably increased. In addition, there was a negative correlation identified between miR‐145‐5p and ABRACL mRNA. Overexpressing miR‐145‐5p was able to suppress cell proliferation, migration, and invasion, whereas silencing miR‐145‐5p posed an opposite effect. In the meantime, ABRACL was identified as a direct target of miR‐145‐5p by dual‐luciferase reporter assay. Furthermore, miR‐145‐5p could inhibit the expression of ABRACL, in turn inhibiting the proliferation, migration, and invasion of EC cells. Conclusion. miR‐145‐5p functions on the proliferation, migration, and invasion of EC cells via targeting ABRACL, and it may be a novel therapeutic target in EC treatment.
Experimental Study of Joint Roughness Influence on Fractured Rock Mass Seepage
Authors: Tian Zhongxi , Dai Chunquan , Zhao Qingshuang , Meng Zhaobo , Zhang Baoliang
Published: February 2021

Surrounding rock pressure, water pressure, and joint roughness are the important factors that affect the fractured rock mass seepage. It is of great significance to quantify the influence of these factors through experiments. In this study, rock fracture joint surfaces were measured. Next, 3D coordinates of joint surfaces were extracted with using the Geomagic software, and joint roughness was described using the mean variance of protrusion height and equidistant fluctuation angle, which were acquired through calculation. Stress-seepage coupling test was then conducted on the samples on a triaxial apparatus, and the effects of confining stress and water pressure on the permeability of single-fracture rock were investigated. On the basis of the relationship between the parameters in data fitting expression and the mean variance of protrusion height and equidistant fluctuation angle, the calculation formula of the permeability coefficient including joint roughness, confining pressure, and seepage pressure difference was derived.
Investigation on the Influences of Curing Time on the Cracking Resistance of Semiflexible Pavement Mixture
Authors: Tan Hua , Xiong Zijia , Gong Minghui , Chen Jie , Hong Jinxiang
Published: February 2021

Semiflexible pavement (SFP) is constructed by pouring grouting material into porous asphalt (PA) mixture. SFP has been widely used to address the rutting distress issues across China in recent years. However, studies on its cracking resistance are limited and the failure mechanism of the SFP mixture has not been fully explored nor understood in a comprehensive way. Moreover, the influences of the curing time on the cracking property of the SFP mixture are still not clear. To this end, the strength development and shrinkage properties of grouting materials are determined by utilizing the three‐point beam bending test and the shrinkage test. The semicircular bending (SCB) test and the scanning electron microscope‐energy‐dispersive spectrum (SEM‐EDS) are conducted in this study to investigate the cracking resistance and failure mechanism of SFP mixtures with different curing days. Results show that both the strength and shrinkage of grouting materials would develop as the curing time was extended from 0 days to 14 days. SCB test results show that SFP mixtures have higher tensile strength but a lower flexibility index (FI) than PA mixture. It is found that the cracking resistance of SFP mixture is influenced by both the grouting materials’ strength and shrinkage. SEM‐EDS analysis demonstrates that the cement‐asphalt interface is a stress concentration site and therefore is the weak zone where cracks would initially develop. The microcracks found in the interface zone with different curing days may contribute to the decline of the SFP mixture’s anticracking ability. This study sheds light on the further application of SFP in practical projects.
Differences in the Cardiovascular Risk Assessment in Cardiology Outpatients in Mali: Comparison between Framingham Body Mass Index-Based Tool and Low-Information World Health Organization Chart
Authors: Oumar Bâ Hamidou , Ibrahima Sangaré , Youssouf Camara , Noumou Sidibé , Souleymane Coulibaly , Yacouba Cissoko , Samba Sidibé , Massama Konaté , Kéita Maiga Asmaou , Thiam Doumbia Coumba , Mamadou Touré , Mamadou Diakité , Ichaka Menta , Bella Diall Ilo
Published: February 2021

Objective. This study aimed to compare 2 laborless tools, namely, the body mass index-based Framingham (bmi-Frm) and low-information WHO- (li-WHO-) based risk scores, and assess their agreement in outpatients in a cardiology department. Methodology. Data stem from a cross-sectional previous study performed from May to September 2016 in the Cardiology Department of University Hospital Gabriel Touré (UH-GT) in Bamako. All patients aged 40 and more were included in the study allowing the assessment of bmi-Frm and li-WHO prediction charts. The cardiovascular risk (CVR) was evaluated using a calculator prepared by D‘Agostino et al. for the bmi-Frm and the li-WHO chart for the Afro-D region of the WHO. The risk score for both ranged from <10 to ≥40. The data were entered in an ACCESS 2010 database, then processed by MS Excel 2010, and finally analysed using IBM SPSS Statistics 20. Continuous variables were presented as means and standard deviations, and categorical variables were presented as frequencies with percentages.

P
<
0.05

was considered the statistical significance level. After sample description, the risk score was assessed using bmi-Frm and li-WHO prediction tools. Finally, a kappa test was performed to check for the interreliability of both methods. For weighted kappa, coefficients were given all five classes of risk groups in 0, 25 steps from 1 for total concordance to 0 for total discordance. Results. This study involved 793 outpatients, 63.7% being female, 35.1% of them younger than 50 years, 57.9% with no formal education, and 67.7% with no medical insurance. Means for age, body mass index (BMI), and systolic blood pressure (SBP) were, respectively, 53.81 ± 16.729 years, 25.29 ± 06.151 kg/m2, and 139.49 ± 27.110 mm Hg. Using the li-WHO prediction chart gives a much higher proportion of low-risk patients compared to bmi-Frm (83.6 vs. 37.7). Sociodemographic characteristics such as education or income level were not different in risk score neither for the bmi-Frm nor for the li-WHO risk score. The percentage of agreement between both tools was 40.4%, and agreement (kappa of 0.1 and weighted kappa of 0.2) was found to be slight. Conclusion. Using the bmi-Frm and li-WHO tool gives a similar risk estimation in younger female patients. Older patients must be evaluated using high-information tools with cholesterol, e.g., versions of the Framingham risk equation or WHO using cholesterol. These must be confirmed in further studies and compared to data from prospective studies
Public Key Cryptosystem Based on Optimized Chaos-Based Image Encryption
Authors: Khaitan Supriya , Sagar Shrddha , Agarwal Rashi
Published: March 2021

Now is the era of online data and transaction, all this happens on an unsecured channel. With this huge data transfer, comes the need of protecting this data. Thus, to achieve security during transmission, several symmetric key encryption algorithms have been proposed. Inspired from
researchers, we propose an asymmetric key image security algorithm based on chaotic tent map integrated with Optimized Salp Swarm Algorithm (SSA) for key generation and encryption for gray scale images. Diffusion and confusion are carried out in each round to mix plain text and key to it more
secure. Experimental analysis shown by SSA are encouraging and is secure enough to resist brute force, differential cryptoanalysis and key sensitivity analysis attack and is suitable for practical application.
Time Variant Multi Feature Census Analysis for Efficient Prediction of Migration Risks in Agriculture
Authors: Sasikala V. , Venkatesan G.
Published: March 2021

The changing dynamics of life and other activities has encouraged the human society to move or migrate between regions of any country. The population in different region and state of India gets increasing and it is necessary for the planning commission to monitor the migrations incur
in every year. Number of approaches available for the prediction and analysis of migrations to perform several decision making but suffer to achieve higher performance. In this paper, an efficient time variant multi feature census analysis algorithm is presented. The method keeps track of
migrations made in every time stamp. The reasons and purpose of migration also being recorded every year like study, business, work, marriage and others. Using these features the method performs analysis on the ratio of migration in different aspects and predicts the ratio of migration. The
result of analysis would be used to perform several planning activities by the government. The method introduces higher performance in migration prediction.
Bacteriophages immunomodulate the response of monocytes
Authors: Perea Lídia , Rodríguez-Rubio Lorena , Nieto Juan C , Zamora Carlos , Cantó Elisabet , Soriano German , Poca Maria , Blanco-Picazo Pedro , Navarro Ferran , Muniesa Maite , Vidal Silvia
Published: February 2021

Bacteriophages are present in fluids from cirrhosis patients. However, their effect on the immune response is unknown. In this work, we explore the role of phages in the phenotype, function, and cytokine production of monocytes. We stimulated healthy monocytes with five different butanol-purified phage suspensions infective for Gram-negative and Gram-positive bacteria. We studied the expression of the monocyte markers involved in lipopolysaccharide recognition (LPS; CD14), antigen presentation (HLA-DR) and co-stimulation (CD86), and the concentration of induced cytokines (TNF-α, IFN-α, and IL-10) by phages. To confirm the direct role of phages without the interference of contaminating soluble LPS in phage suspensions, polymyxin B was added to the cell cultures. Phagocytosis experiments were assessed by flow cytometry using labeled phage suspensions. We observed that butanol-purified phages reduced the surface levels of CD14 and CD86 in monocytes and increased the secreted levels of TNF-α and IL-10 compared with the control sample containing only butanol buffer. All phage suspensions showed downregulation of HLA-DR expression but only Staphylococcus aureus phage contaminated with Escherichia coli reached statistical significance. The addition of polymyxin B did not restore the monocytic response induced by phages, suggesting that the effect was not caused by the presence of LPS. Monocytes were able to phagocyte phages in a dose- and time-dependent manner. To conclude, the phagocytosis of butanol-purified phages altered the phenotype and cytokine production of monocytes suggesting they become tolerogenic.
The cardiovascular complications in COVID-19: Focus on acute cardiac injury
Authors: Saeed Sahrai , Rajani Ronak
Published: February 2021

At the end of 2019 a novel coronavirus was identified in Wuhan, China. The disease caused by the severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2) was designated COVID-19 (corona virus disease 2019) by the World Health Organization in early 2020. Up to 80% of patients with COVID-19 experience mild symptoms with severe or critical disease occurring in the remaining 20%. Severe disease is manifested by the development of pneumonia, hypoxia and radiographic lung involvement while critical disease indicates multiorgan involvement with significant respiratory or cardiac compromise. The current estimated case fatality rate from COVID-19 is approximately 1%. Epidemiological studies have shown that advanced age, male gender, previous chronic lung disease, cardiovascular and kidney disease, obesity and diabetes are risk factors for the severity of disease course. In the current focused review, we present an overview of the acute cardiovascular complications of COVID-19, their detection and impact upon prognosis.

doi: https://doi.org/10.12669/pjms.37.3.4063

How to cite this:Saeed S, Rajani R. The cardiovascular complications in COVID-19: Focus on acute cardiac injury. Pak J Med Sci. 2021;37(3):908-912. doi: https://doi.org/10.12669/pjms.37.3.4063

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
The ultimate guide: PPE and skin health hacks
Authors: Matthews Annette
Published: March 2021

Annette Matthews shares some insider tips on how to survive mask-wearing whilst maintaining a healthy, flawless appearance
Kingella kingae septic arthritis
Authors: Khattak Mohammed , Vellathussery Chakkalakumbil Sujith , Stevenson Robert A. , Bryson David J. , Reidy Michael J. , Talbot Christopher L. , George Harvey
Published: February 2021

Aims

The aim of this study was to determine the extent to which patient demographics, clinical presentation, and blood parameters vary in Kingella kingae septic arthritis when compared with those of other organisms, and whether this difference needs to be considered when assessing children in whom a diagnosis of septic arthritis is suspected.

Methods

A prospective case series was undertaken at a single UK paediatric institution between October 2012 and November 2018 of all patients referred with suspected septic arthritis. We recorded the clinical, biochemical, and microbiological findings in all patients.

Results

A total of 160 patients underwent arthrotomy for a presumed septic arthritis. Of these, no organism was identified in 61 and only 25 of these were both culture- and polymerase chain reaction (PCR)-negative. A total of 36 patients did not undergo PCR analysis. Of the remaining 99 culture- and PCR-positive patients, K. kingae was the most commonly isolated organism (42%, n = 42). The knee (n = 21), shoulder (n = 9), and hip (n = 5) were the three most commonly affected joints. A total of 28 cases (66%) of K. kingae infection were detected only on PCR. The mean age of K. kingae-positive cases (16.1 months) was significantly lower than that of those whose septic arthitis was due to other organisms (49.4 months; p < 0.001). The mean CRP was significantly lower in the K. kingae group than in the other organism group (p < 0.001). The mean ESR/CRP ratio was significantly higher in K. kingae (2.84) than in other infections (1.55; p < 0.008). The mean ESR and ESR/CRP were not significantly different from those in the 'no organism identified' group.

Conclusion

K. kingae was the most commonly isolated organism from paediatric culture- and/or PCR-positive confirmed septic arthritis, with only one third of cases detected on routine cultures. It is important to develop and maintain a clinical suspicion for K. kingae infection in young patients presenting atypically. Routine PCR testing is recommended in these patients. Cite this article: Bone Joint J 2021;103-B(3):584–588.
Prediction of 90-day mortality after total hip arthroplasty
Authors: Garland Anne , Bülow Erik , Lenguerrand Erik , Blom Ashley , Wilkinson Mark , Sayers Adrian , Rolfson Ola , Hailer Nils P.
Published: February 2021

Aims

To develop and externally validate a parsimonious statistical prediction model of 90-day mortality after elective total hip arthroplasty (THA), and to provide a web calculator for clinical usage.

Methods

We included 53,099 patients with cemented THA due to osteoarthritis from the Swedish Hip Arthroplasty Registry for model derivation and internal validation, as well as 125,428 patients from England and Wales recorded in the National Joint Register for England, Wales, Northern Ireland, the Isle of Man, and the States of Guernsey (NJR) for external model validation. A model was developed using a bootstrap ranking procedure with a least absolute shrinkage and selection operator (LASSO) logistic regression model combined with piecewise linear regression. Discriminative ability was evaluated by the area under the receiver operating characteristic curve (AUC). Calibration belt plots were used to assess model calibration.

Results

A main effects model combining age, sex, American Society for Anesthesiologists (ASA) class, the presence of cancer, diseases of the central nervous system, kidney disease, and diagnosed obesity had good discrimination, both internally (AUC = 0.78, 95% confidence interval (CI) 0.75 to 0.81) and externally (AUC = 0.75, 95% CI 0.73 to 0.76). This model was superior to traditional models based on the Charlson (AUC = 0.66, 95% CI 0.62 to 0.70) and Elixhauser (AUC = 0.64, 95% CI 0.59 to 0.68) comorbidity indices. The model was well calibrated for predicted probabilities up to 5%.

Conclusion

We developed a parsimonious model that may facilitate individualized risk assessment prior to one of the most common surgical interventions. We have published a web calculator to aid clinical decision-making. Cite this article: Bone Joint J 2021;103-B(3):469–478.
Mapping suitability for Buruli ulcer at fine spatial scales across Africa: A modelling study
Authors: Simpson Hope , Tabah Earnest Njih , Phillips Richard O. , Frimpong Michael , Maman Issaka , Ampadu Edwin , Timothy Joseph , Saunderson Paul , Pullan Rachel L. , Cano Jorge
Published: March 2021

Buruli ulcer (BU) is a disabling and stigmatising neglected tropical disease (NTD). Its distribution and burden are unknown because of underdiagnosis and underreporting. It is caused by Mycobacterium ulcerans, an environmental pathogen whose environmental niche and transmission routes are not fully understood. The main control strategy is active surveillance to promote early treatment and thus limit morbidity, but these activities are mostly restricted to well-known endemic areas. A better understanding of environmental suitability for the bacterium and disease could inform targeted surveillance, and advance understanding of the ecology and burden of BU. We used previously compiled point-level datasets of BU and M. ulcerans occurrence, evidence for BU occurrence within national and sub-national areas, and a suite of relevant environmental covariates in a distribution modelling framework. We fitted relationships between BU and M. ulcerans occurrence and environmental predictors by applying regression and machine learning based algorithms, combined in an ensemble model to characterise the optimal ecological niche for the disease and bacterium across Africa at a resolution of 5km x 5km. Proximity to waterbodies was the strongest predictor of suitability for BU, followed potential evapotranspiration. The strongest predictors of suitability for M. ulcerans were deforestation and potential evapotranspiration. We identified patchy foci of suitability throughout West and Central Africa, including areas with no previous evidence of the disease. Predicted suitability for M. ulcerans was wider but overlapping with that of BU. The estimated population living in areas predicted suitable for the bacterium and disease was 46.1 million.

These maps could be used to inform burden estimations and case searches which would generate a more complete understanding of the spatial distribution of BU in Africa, and may guide control programmes to identify cases beyond the well-known endemic areas.
A high-affinity RBD-targeting nanobody improves fusion partner’s potency against SARS-CoV-2
Authors: Yao Hebang , Cai Hongmin , Li Tingting , Zhou Bingjie , Qin Wenming , Lavillette Dimitri , Li Dianfan
Published: March 2021

A key step to the SARS-CoV-2 infection is the attachment of its Spike receptor-binding domain (S RBD) to the host receptor ACE2. Considerable research has been devoted to the development of neutralizing antibodies, including llama-derived single-chain nanobodies, to target the receptor-binding motif (RBM) and to block ACE2-RBD binding. Simple and effective strategies to increase potency are desirable for such studies when antibodies are only modestly effective. Here, we identify and characterize a high-affinity synthetic nanobody (sybody, SR31) as a fusion partner to improve the potency of RBM-antibodies. Crystallographic studies reveal that SR31 binds to RBD at a conserved and ‘greasy’ site distal to RBM. Although SR31 distorts RBD at the interface, it does not perturb the RBM conformation, hence displaying no neutralizing activities itself. However, fusing SR31 to two modestly neutralizing sybodies dramatically increases their affinity for RBD and neutralization activity against SARS-CoV-2 pseudovirus. Our work presents a tool protein and an efficient strategy to improve nanobody potency.
Communicative Approach in the Five Curricula of English Subject for Secondary Schools: A Paradox in English Language Teaching in Indonesia
Authors: MASDUQI HARITS , Prihananto Novi
Published: February 2021

The English curriculum implemented in the Indonesian secondary schools has undergone some development in the past few decades. The development is meant to ensure that the curriculum remains up to date with the development of English language teaching theories and practices in the world. This paper discusses the English curricula which were developed in 1984, 1994, 2004, and 2006 and critically analyses the communicative approach that has been implemented in Indonesian secondary schools. The newest 2013 curriculum is also discussed, but only superficially as the curriculum was just officially implemented at national level in the end of 2019. The writers finally offer some recommendations for future curriculum developers and government officials in order to improve English language teaching and learning in Indonesia.
Energy analysis of image descriptors in texture classification
Authors: Kiani Faeze
Published: February 2021

Texture play important role in image description process. Texture classification is one of the problems which have been paid much attention on by computer vision scientists in last decade. If texture classification is done accurately, it can be used in many problems such as skin detection, surface defect detection, medical image analysis, gender identification, human identification, etc. Since now, many approaches are proposed to perform it. Most of them have tried to extract discriminative features to separate different texture types accurately. This paper has proposed an approach based on energy analysis of some efficient image descriptors such as median binary pattern, Local binary pattern and Gray Level Co-occurrence matrix. Next, by concatenating extracted features, a discriminative feature vector is defined. Finally, classifier is used to classify texture types. Although, this approach is a general one and is could be used in different applications. In the result part the proposed approach has been evaluated on some benchmark dataset. Next, the results have been compared with some of state-of-the-art approaches to prove the quality of the proposed approach.
The Nicholson's conjecture
Authors: Feliksiak Jan
Published: February 2021

This research paper discusses the distribution of prime numbers, from the point of view of the Nicholson's conjecture of 2013. The proof of the conjecture, permits to develop and establish a Supremum bound, on the difference of terms of the conjecture. Nicholson's conjecture belongs to the class of the strongest bounds on maximal prime gaps.
Genesis and phytodiversity in the enclave pico do jabre in the brazilian semiarid
Authors: Gomes Aureliana Santos , Marques Ailson De Lima , Vieira Cauê Souto , Moura Débora Coelho , Rodrigues Erimágna De Morais , Sousa Gabryelle De Farias , Costa Cássio Ricardo Gonçalves da
Published: February 2021

Dentre os elementos que compõem as áreas paisagísticas da Caatinga, encontram-se os chamados "brejos de altitude" ou "enclaves de floresta úmida", o que pode ter explicado sua gênese a partir da hipótese de mudanças climáticas quaternárias. Este trabalho tem como objetivo retratar a fitodiversidade e a origem do maciço residual Pico do Jabre, localizado na região Nordeste, semi-árido brasileiro. Como resultado, verificou-se que o Pico do Jabre corresponde a um maciço residual, assente na zona geotectónica de Teixeira ou Pluton Teixeira, e teve a sua origem na erosão diferencial entre as rochas xistosas do pediplano e as rochas graníticas do maciço. Sua fitodiversidade se distribui em altitudes onde o afloramento do planalto abriga espécies de cavernas, a dimensão entre 900 e 1100 metros corresponde à área de floresta semidecidual montana, e Caatinga abaixo de 900 metros.
Handling a double-edged sword: Controlling rhetoric in early China
Authors: Richter Matthias L.
Published: February 2021

The present essay discusses rhetorics as an instrument of both persuasion and deception. Early Chinese political thought shows a keen awareness of the deceptive potential immanent in rhetorical skills. Multiple texts warn against certain types of rhetorical behaviour that entail a potential threat to the ruler's control over political power. Yet, at the same time rhetorical skills were also a desirable qualification. While most texts from early China discuss rhetorical skills in general terms as an asset or a threat to the ruler's power, some texts reflect rhetorical skills in more detail, describing specific types of rhetorical behaviour. This essay introduces examples of such texts that were probably first composed as pragmatic texts for application in political practice, before they were integrated into larger compilations or literary texts for argumentative purposes. The essay also shows that these pragmatic texts used a set of technical terms, some of which were no longer recognized in the later transmission, which often led to changes in the texts.
Species separation within the Lessonia nigrescens complex (Phaeophyceae, Laminariales) is mirrored by ecophysiological traits
Authors: Koch Kristina , Thiel Martin , Tellier Florence , Hagen Wilhelm , Graeve Martin , Tala Fadia , Laeseke Philipp , Bischof Kai
Published: February 2021

Lessonia nigrescens used to be an abundant kelp species along the Chilean coast, but recent molecular studies revealed the existence of a L. nigrescens species complex, which includes the two cryptic species Lessonia berteroana and Lessonia spicata. Since these species have different distributions (16°S–30°S for L. berteroana and 29°S–42°S for L. spicata), they experience differences in environmental conditions, such as solar irradiance, seawater temperature and air exposure during low tide. This study tested to what extent the genetic distinctness of each of the two species [identified by a mitochondrial marker (atp8/trnS)] is reflected by ecophysiological traits (total lipids, fatty acid composition, phlorotannins, pigments and variable chlorophyll a fluorescence of PSII) in response to the respective environmental conditions, prevailing along the latitudinal gradient. We studied algal individuals from eight populations (27°S–32°S, including the species overlapping zone). Phlorotannins, pigments and Chl a fluorescence of PSII were most crucial for species-specific adaptations at the respective growth sites, whereas changes in total lipids and fatty acid compositions were negligible. Hence, species differentiation within the L. nigrescens complex is also manifested at the ecophysiological level. These findings may help to predict kelp responses towards future environmental changes.
Innus: A God of Archaic Latium and His Sanctuary at Fosso dell’Incastro (Ardea)
Authors: Torelli Mario
Published: February 2021

In 2006, the Soprintendenza Archeologica del Lazio began an excavation at the site of Fosso dell’Incastro on the coastline of Ardea. A well-preserved settlement buried under huge sand dunes was discovered, featuring a Roman castrum created in the fourth century BCE around a sanctuary dating back to the mid-sixth century BCE. Its characteristics not only suggested that the ancient site was Castrum Inui, previously known only through the ancient literary sources (e.g., Virgil, Servius and Macrobius), but also that its sanctuary could be attributed to an inconspicuous local deity, Inuus—often correlated with Pan and Sol. In its final phase (the early Imperial period), the sanctuary housed three sacred buildings: Temple A, Temple B, and a small shrine dedicated to Aesculapius. Temple B, the site of Inuus’ worship, was constructed in the Etrusco-Italic style during the first quarter of the fifth century BCE, while Temple A was built during the mid-second century BCE. Temple B was oriented to the southwest, one typical for religious buildings connected to chthonic cults; two altars built during the fourth century BCE were placed along the façade of the temple, one facing the east and on the axis of the temple, the second close to its southwest corner. It was also enhanced with an acroterion depicting the head of a warrior with the skin and horns of a goat or cow over his helmet, a motif that establishes a connection between Innus, Pan and Faunus. Temple A, on the other hand, faced the northeast and was enhanced with a sculpted pediment in high relief showing an assembly of gods and possibly Aeneas. Both its orientation and the iconography of the pediment suggest that it was dedicated to Aeneas Indiges, a pan-Latin version of the old cult of Inuus.
Excavations at Poggio Civitate (Murlo) During the 2012--2013 Seasons: Domestic Architecture and Selected Finds From the Civitate A Property Zone
Authors: Tuck Anthony , Kreindler Kate , Huntsman Theresa
Published: February 2021

Excavations over the course of the 2012 and 2013 seasons at Poggio Civitate (Murlo) have revealed the presence of domestic architecture in an area immediately to the southwest of the Piano del Tesoro plateau, the portion of Poggio Civitate that preserves evidence of monumental building from the Orientalizing and Archaic phases of the site’s occupation. At least two building phases have been discovered in the eastern extent of the hill’s Civitate A property zone and they reveal that a small rectilinear structure dating to the late seventh century BCE was superimposed on an earlier, curvilinear structure. These architectural discoveries indicate that the opulent Orientalizing structures on the Piano del Tesoro plateau were not only visible to people on nearby hilltops, but also to a community that stood to its immediate west. While additional excavation is needed to clarify a number of questions about Civitate A, it is striking that its inhabitants appear to have had access to at least a few items of notable quality and potential social value, many of which were also used by the social elite living on the plateau. In addition, the number of planed, cut and carved antler, horn and bone objects and fragments recovered within the interior area of Structure 1 raises the possibility that artisans employed in the service of Poggio Civitate’s ruling elite created similar artifacts for their own domestic arena. Future excavations both in Civitate A as well as on other hilltop settlements in the region of Murlo should provide even greater insight into these and many other questions concerning this remarkably well-preserved site and the activities of its ancient inhabitants.
Dogon reported discourse markers: The Ben Tey quotative topicalizer
Authors: Hantgan Abbie
Published: February 2021

The purpose of this study is to re-evaluate the interpretation of a particle that has hitherto been analyzed as a marker either of addressee or the subject of a quoted clause in Ben Tey (Dogon, Mali). As both of these interpretations are typologically rare if not unique, a broader conceptualization for the particle as a quotative topic marker is proposed here. Data are from a newly compiled cross-linguistic annotated corpus of discourse reports within textual contexts. Along with data presentation and analysis, a methodology is illustrated for multilingual comparative corpus construction for the analysis of discourse reporting strategies.
Sturm's Theorem for Equations with Delayed Argument
Authors: Domoshnitsky A.
Published: February 2021

Sturm's type theorems on separation of zeros of solutions are proved for the second order linear differential equations with delayed argument.
On Two-Point Boundary Value Problems for Systems of Higher-Order Ordinary Differential Equations with Singularities
Authors: Kiguradze I. , Tskhovrebadze G.
Published: February 2021

The sufficient conditions of solvability and unique solvability of the two-point boundary value problems of Vallèe-Poussin and Cauchy-Niccoletti have been found for a system of ordinary differential equations of the form

u
(n) = ƒ(t, u, u′, . . . , u
(n – 1)),

where the vector function has nonintegrable singularities with respect to the first argument at the points a and b.
Measures of Controllability
Authors: Lions J. L.
Published: February 2021

We introduce here a new notion, the measure of controllability aimed at expressing that one system is ”more controllable” than another one. First estimates are given.
On Structure of Solutions of a System of Four Differential Inequalities
Authors: Bartušek Miroslav
Published: February 2021

The aim of the paper is to study a global structure of solutions of four differential inequalities

with respect to their zeros. The structure of an oscillatory solution is described, and the number of points with trivial Cauchy conditions is investigated.
On a Spatial Problem of Darboux Type for a Second-Order Hyperbolic Equation
Authors: Kharibegashvili S.
Published: February 2021

The theorem of unique solvability of a spatial problem of Darboux type in Sobolev space is proved for a second-order hyperbolic equation.
Applications of the Method of Barriers II. Some Singularly Perturbed Problems
Authors: Sushko V. G. , Rozov N. Kh.
Published: February 2021

The method of barriers is used to justify asymptotic representations of solutions of two-point boundary value problems for singularly perturbed quasilinear equations of the second and the third order. This paper is a continuation of [Rozov and Sushko, Georgian Math. J. 2: 99-110, 1995].
On a Problem of Littlewood
Authors: Khazaradze M.
Published: February 2021

The theorem on the tending to zero of coefficients of a trigonometric series is proved when the L
1-norms of partial sums of this series are bounded. It is shown that the analog of Helson's theorem does not hold for orthogonal series with respect to the bounded orthonormal system. Two facts are given that are similar toWeis' theorem on the existence of a trigonometric series which is not a Fourier series and whose L
1-norms of partial sums are bounded.
Criteria of Strong Type Two-Weighted Inequalities for Fractional Maximal Functions
Authors: Gogatishvili A. , Kokilashvili V.
Published: February 2021

A strong type two-weight problem is solved for fractional maximal functions defined in homogeneous type general spaces. A similar problem is also solved for one-sided fractional maximal functions.
Weighted Composition Operators on Bergman and Dirichlet Spaces
Authors: Mirzakarimi G. , Seddighi K.
Published: February 2021

Let 𝐻(Ω) denote a functional Hilbert space of analytic functions on a domain Ω. Let 𝑤 : Ω → 𝐂 and ϕ : Ω → Ω be such that 𝑤 𝑓 ○ ϕ is in 𝐻(Ω) for every 𝑓 in 𝐻(Ω). The operator 𝑤𝐶
ϕ
Given by 𝑓 → 𝑤 𝑓 ○ ϕ is called a weighted composition operator on 𝐻(Ω). In this paper we characterize such operators and those for which (𝑤𝐶
ϕ
)* is a composition operator. Compact weighted composition operators on some functional Hilbert spaces are also characterized. We give sufficient conditions for the compactness of such operators on weighted Dirichlet spaces.
Internal Categories in a Left Exact Cosimplicial Category
Authors: Pataraia D.
Published: February 2021

The notion of an internal category in a left exact cosimplicial category is introduced. For any topos over sets a certain left exact cosimplicial category is constructed functorially and the category of internal categories in it is investigated. The notion of a fundamental group is defined for toposes admitting the notion of “a discrete category.”
Boundary Properties of First-Order Partial Derivatives of the Poisson Integral for the Half-Space
Authors: Topuria S.
Published: February 2021

Boundary properties of first-order partial derivatives of the Poisson integral are studied in the half-space .
On Some Properties of Multiple Moduli of Continuity
Authors: Panjikidze L.
Published: February 2021

For functions of several variables a property is established similar to the well-known result of S. B. Stechkin about the metric property of almost increasing functions. In the case of one variable the proof is easier than the known one.
On the Universal C*-Algebra Generated by Partial Isometry
Authors: Kandelaki T.
Published: February 2021

A universal C*-algebra is constructed which is generated by a partial isometry. Using grading on this algebra we construct an analog of Cuntz algebras which gives a homotopical interpretation of KK-groups. It is proved that this algebra is homotopy equivalent up to stabilization by 2×2 matrices to M
2(C). Therefore those algebras are KK-isomorphic.
Summation of Singular Series Corresponding to Representations of Numbers by Some Quadratic Forms in Twelve Variables
Authors: Lomadze G.
Published: February 2021

Formulas for calculating the sum of singular series corresponding to the number of representations of integers by some quadratic forms in 12 variables with integral coefficient are derived.
Solution of Some Weight Problems for the Riemann–Liouville and Weyl Operators
Authors: Meskhi A.
Published: February 2021

The necessary and sufficient conditions are found for the weight function 𝑣, which provide the boundedness and compactness of the Riemann–Liouville operator 𝑅
α
from 𝐿𝑝 to . The criteria are also established for the weight function 𝑤, which guarantee the boundedness and compactness of the Weyl operator 𝑊
α
from to 𝐿𝑞.
Characterization of a Two-Weighted Vector-Valued Inequality for Fractional Maximal Operators
Authors: Rakotondratsimba Y.
Published: February 2021

We give a characterization of the weights 𝑢(·) and 𝑣(·) for which the fractional maximal operator 𝑀𝑠 is bounded from the weighted Lebesgue spaces 𝐿𝑝(𝑙𝑟, 𝑣𝑑𝑥) into 𝐿𝑞(𝑙𝑟, 𝑢𝑑𝑥) whenever 0 ≤ 𝑠 < 𝑛, 1 < 𝑝, 𝑟 < ∞, and 1 ≤ 𝑞 < ∞.
On Some Rings of Arithmetical Functions
Authors: Bhattacharjee D.
Published: February 2021

In this paper we consider several constructions which from a given 𝐵-product *𝐵 lead to another one . We shall be interested in finding what algebraic properties of the ring 𝑅𝐵 = 〈𝐶ℕ, +, *𝐵〉 are shared also by the ring . In particular, for some constructions the rings 𝑅𝐵 and will be isomorphic and therefore have the same algebraic properties.
On Estimating Integral Moduli of Continuity of Functions of Several Variables in Terms of Fourier Coefficients
Authors: Gogoladze L.
Published: February 2021

Inequalities are derived which enable one to estimate integral moduli of continuity of functions of several variables in terms of Fourier coefficients.
Positive Solutions to Second Order Singular Differential Equations Involving the One-Dimensional M-Laplace Operator
Authors: Tanigawa Tomoyuki
Published: February 2021

We consider a class of second order quasilinear differential equations with singular ninlinearities. Our main purpose is to investigate in detail the asymptotic behavior of their solutions defined on a positive half-line. The set of all possible positive solutions is classified into five types according to their asymptotic behavior near infinity, and sharp conditions are established for the existence of solutions belonging to each of the classified types.
Oscillation and Nonoscillation Criteria for a Second Order Linear Equation
Authors: Chantladze T. , Kandelaki N. , Lomtatidze A.
Published: February 2021

New oscillation and nonoscillation criteria are established for the equation

𝑢″ + 𝑝(𝑡)𝑢 = 0,

where 𝑝 : ]1, + ∞[ → 𝑅 is the locally integrable function. These criteria generalize and complement the well known criteria of E. Hille, Z. Nehari, A. Wintner, and P. Hartman.
Derivative Uniform Sampling via Weierstrass σ(z). Truncation Error Analysis in
Authors: Pogány Tibor K.
Published: February 2021

In the entire functions space consisting of at most second order functions such that their type is less than πq/(2s
2) it is valid the q-order derivative sampling series reconstruction procedure, reading at the von Neumann lattice {s(m + ni)| (m, n) ∈ } via the Weierstrass σ(·) as the sampling function, s > 0. The uniform convergence of the sampling sums to the initial function is proved by the circular truncation error upper bound, especially derived for this reconstruction procedure. Finally, the explicit second and third order sampling formulæ are given.
On Periodic Solutions of Autonomous Difference Equations
Authors: Ronto A. N. , Rontó M. , Samoilenko A. M. , Trofimchuk S. I.
Published: February 2021

We establish conditions necessary for the existence of non-constant periodic solutions of non-linear autonomous difference equations with Lipschitzian right-hand sides.