From Conventional to State-of-the-Art IoT Access Control Models

open access articleThe advent in Online Social Networks (OSN) and Internet of Things (IoT) has created a new world of collaboration and communication between people and devices. The domain of internet of things uses billions of devices (ranging from tiny sensors to macro scale devices) that continuously produce and exchange huge amounts of data with people and applications. Similarly, more than a billion people are connected through social networking sites to collaborate and share their knowledge. The applications of IoT such as smart health, smart city, social networking, video surveillance and vehicular communication are quickly evolving people’s daily lives. These applications provide accurate, information-rich and personalized services to the users. However, providing personalized information comes at the cost of accessing private information of users such as their location, social relationship details, health information and daily activities. When the information is accessible online, there is always a chance that it can be used maliciously by unauthorized entities. Therefore, an effective access control mechanism must be employed to ensure the security and privacy of entities using OSN and IoT services. Access control refers to a process which can restrict user’s access to data and resources. It enforces access rules to grant authorized users an access to resources and prevent others. This survey examines the increasing literature on access control for traditional models in general, and for OSN and IoT in specific. Challenges and problems related to access control mechanisms are explored to facilitate the adoption of access control solutions in OSN and IoT scenarios. The survey provides a review of the requirements for access control enforcement, discusses several security issues in access control, and elaborates underlying principles and limitations of famous access control models. We evaluate the feasibility of current access control models for OSN and IoT and provide the future development direction of access control for the sam

Activity of Compounds from Temperate Propolis against Trypanosoma brucei and Leishmania mexicana

Ethanolic extracts of samples of temperate zone propolis, four from the UK and one from Poland, were tested against three strains and displayed EC values < 20 µg/mL. The extracts were fractionated, from which 12 compounds and one two-component mixture were isolated, and characterized by NMR and high-resolution mass spectrometry, as 3-acetoxypinobanksin, tectochrysin, kaempferol, pinocembrin, 4'-methoxykaempferol, galangin, chrysin, apigenin, pinostrobin, cinnamic acid, coumaric acid, cinnamyl ester/coumaric acid benzyl ester (mixture), 4',7-dimethoxykaempferol, and naringenin 4',7-dimethyl ether. The isolated compounds were tested against drug-sensitive and drug-resistant strains of and , with the highest activities ≤ 15 µM. The most active compounds against were naringenin 4',7 dimethyl ether and 4'methoxy kaempferol with activity of 15-20 µM against the three strains. The most active compounds against were 4',7-dimethoxykaempferol and the coumaric acid ester mixture, with EC values of 12.9 ± 3.7 µM and 13.1 ± 1.0 µM. No loss of activity was found with the diamidine- and arsenical-resistant or phenanthridine-resistant strains, or the miltefosine-resistant strain; no clear structure activity relationship was observed for the isolated compounds. Temperate propolis yields multiple compounds with anti-kinetoplastid activity

The instability of non-Newtonian boundary-layer flows over rough rotating disks

We are concerned with the local linear convective instability of the incompressible boundary-layer flows over rough rotating disks for non-Newtonian fluids. Using the Carreau model for a range of shear-thinning and shear-thickening fluids, we determine, for the first time, steady-flow profiles under the partial-slip model for surface roughness. The subsequent linear stability analyses of these flows (to disturbances stationary relative to the disk) indicate that isotropic and azimuthally-anisotropic (radial grooves) surface roughness leads to the stabilisation of both shear-thinning and -thickening fluids. This is evident in the behaviour of the critical Reynolds number and growth rates of both Type I (inviscid cross flow) and Type II (viscous streamline curvature) modes of instability. The underlying physical mechanisms are clarified using an integral energy equation

Lymphomas driven by Epstein-Barr virus nuclear antigen-1 (EBNA1) are dependant upon Mdm2

Epstein-Barr virus (EBV)-associated Burkitt's lymphoma is characterised by the deregulation of c-Myc expression and a restricted viral gene expression pattern in which the EBV nuclear antigen-1 (EBNA1) is the only viral protein to be consistently expressed. EBNA1 is required for viral genome propagation and segregation during latency. However, it has been much debated whether the protein plays a role in viral-associated tumourigenesis. We show that the lymphomas which arise in EµEBNA1 transgenic mice are unequivocally linked to EBNA1 expression and that both C-Myc and Mdm2 deregulation are central to this process. Tumour cell survival is supported by IL-2 and there is a skew towards CD8-positive T cells in the tumour environment, while the immune check-point protein PD-L1 is upregulated in the tumours. Additionally, several isoforms of Mdm2 are upregulated in the EµEBNA1 tumours, with increased phosphorylation at ser166, an expression pattern not seen in Eµc-Myc transgenic tumours. Concomitantly, E2F1, Xiap, Mta1, C-Fos and Stat1 are upregulated in the tumours. Using four independent inhibitors of Mdm2 we demonstrate that the EµEBNA1 tumour cells are dependant upon Mdm2 for survival (as they are upon c-Myc) and that Mdm2 inhibition is not accompanied by upregulation of p53, instead cell death is linked to loss of E2F1 expression, providing new insight into the underlying tumourigenic mechanism. This opens a new path to combat EBV-associated disease

Assessing disparities in medical students’ knowledge and attitude about monkeypox: a cross-sectional study of 27 countries across three continents

Background and aimsThe recent monkeypox (Mpox) outbreak confirmed by the World Health Organization (WHO) underscores the importance of evaluating the knowledge and attitude of medical students toward emerging diseases, given their potential roles as healthcare professionals and sources of public information during outbreaks. This study aimed to assess medical students’ knowledge and attitude about Mpox and to identify factors affecting their level of knowledge and attitude in low-income and high-income countries.MethodsA cross-sectional study was conducted on 11,919 medical students from 27 countries. A newly-developed validated questionnaire was used to collect data on knowledge (14 items), attitude (12 items), and baseline criteria. The relationship between a range of factors with knowledge and attitude was studied using univariate and multivariate analyses.Results46% of the study participants were males; 10.7% were in their sixth year; 54.6% knew about smallpox; 84% received the coronavirus disease 2019 (COVID-19) vaccine; and 12.5% had training on Mpox. 55.3% had good knowledge of Mpox and 51.7% had a positive attitude towards it. Medical students in their third, fifth, or sixth year high- income countries who obtained information on Mpox from friends, research articles, social media and scientific websites were positive predictors for good knowledge. Conversely, being male or coming from high-income countries showed a negative relation with good knowledge about Mpox. Additionally, a positive attitude was directly influenced by residing in urban areas, being in the fifth year of medical education, having knowledge about smallpox and a history of receiving the coronavirus disease 2019 (COVID-19) vaccine. Receiving information about Mpox from social media or scientific websites and possessing good knowledge about Mpox were also predictors of a positive attitude. On the other hand, being male, employed, or receiving a training program about Mpox were inversely predicting positive attitude about Mpox.ConclusionThere were differences in knowledge and attitude towards Mpox between medical students in low and high-income countries, emphasizing the need for incorporating epidemiology of re-emerging diseases like Mpox into the medical curriculum to improve disease prevention and control

Global overview of the management of acute cholecystitis during the COVID-19 pandemic (CHOLECOVID study)

Background: This study provides a global overview of the management of patients with acute cholecystitis during the initial phase of the COVID-19 pandemic. Methods: CHOLECOVID is an international, multicentre, observational comparative study of patients admitted to hospital with acute cholecystitis during the COVID-19 pandemic. Data on management were collected for a 2-month study interval coincident with the WHO declaration of the SARS-CoV-2 pandemic and compared with an equivalent pre-pandemic time interval. Mediation analysis examined the influence of SARS-COV-2 infection on 30-day mortality. Results: This study collected data on 9783 patients with acute cholecystitis admitted to 247 hospitals across the world. The pandemic was associated with reduced availability of surgical workforce and operating facilities globally, a significant shift to worse severity of disease, and increased use of conservative management. There was a reduction (both absolute and proportionate) in the number of patients undergoing cholecystectomy from 3095 patients (56.2 per cent) pre-pandemic to 1998 patients (46.2 per cent) during the pandemic but there was no difference in 30-day all-cause mortality after cholecystectomy comparing the pre-pandemic interval with the pandemic (13 patients (0.4 per cent) pre-pandemic to 13 patients (0.6 per cent) pandemic; P = 0.355). In mediation analysis, an admission with acute cholecystitis during the pandemic was associated with a non-significant increased risk of death (OR 1.29, 95 per cent c.i. 0.93 to 1.79, P = 0.121). Conclusion: CHOLECOVID provides a unique overview of the treatment of patients with cholecystitis across the globe during the first months of the SARS-CoV-2 pandemic. The study highlights the need for system resilience in retention of elective surgical activity. Cholecystectomy was associated with a low risk of mortality and deferral of treatment results in an increase in avoidable morbidity that represents the non-COVID cost of this pandemic

Current Knowledge, Satisfaction, and Use of E-Health Mobile Application (Seha) Among the General Population of Saudi Arabia: A Cross-Sectional Study

BACKGROUND: General population knowledge, satisfaction, and barriers to using Seha app have not been evaluated from a large-scale perspective. Therefore, this study aimed to explore current knowledge, satisfaction, and barriers of using Seha app and identify the most common mobile health application used among the general population in Saudi Arabia. METHODS: A cross-sectional online survey, consisting of 25 questions, was distributed among the general population of Saudi Arabia. Descriptive statistics were used to describe the respondents’ characteristics. Categorical variables were reported as frequencies and percentages. A chi-square (χ 2) test was conducted to assess the statistical difference between respondents’ demographic characteristics and their knowledge and use of the app. RESULTS: Overall, 5008 respondents, both Saudi (3723: 74%) and non-Saudi (1285: 26%) as well as male 2142 (43%) and female 2866 (57%), across the Kingdom of Saudi Arabia completed the online survey. A total of 2921 (58%) had heard of the Seha app, although only 1286 (25%) had used the app. Higher percentages of users were from the western region, females and those within the age group of ≥ 51 years old, 388 users (29%: P< 0.001), 804 (28%; P< 0.001) and 67 (35%; P=0.013), respectively. Consulting a doctor was the most frequently utilized service, 576 users (58%). Respondents strongly agreed 402 (41%) that Seha was easy to use, and 538 (54%) strongly agreed that they would recommend Seha to others. The most common barrier of using Seha was a lack of knowledge about the app and its benefits, at 1556 (35%). Overall, the Tawakkalna app was the most utilized mobile health application provided by MOH used 2170 (48%). CONCLUSIONS: Utilization of the Seha app is quite low due to a lack of knowledge about the app and its benefits. Thus, the MOH should promote public awareness about the app and its benefits

Statistical Study of Nonthermal Plasma-Assisted ZnO Coating of Cotton Fabric through Ultrasonic-Assisted Green Synthesis for Improved Self-Cleaning and Antimicrobial Properties

Nonthermal plasma processing is a dry, environment-friendly and chemical-free method of improving the wettability, adhesion, self-cleaning and dying quality of fabrics without affecting their bulk properties. This study presents a green synthesis and coating method for the immobilization of nanoparticles of ZnO on the nonthermal plasma functionalized cotton fabric. The self-cleaning activity of ZnO-coated cotton was then optimized statistically. The ultraviolet protection and antimicrobial activity of the optimized and a control sample were also elaborated in this study. Psidium guajava Linn (guava) plant extract and zinc chloride were used in the ultrasonic biosynthesis of ZnO nanoparticles and concurrent immobilization over plasma functionalized cotton. Sodium hydroxide was used as a reaction accelerator. Statistical complete composite design (CCD) based on the amount of ZnCl2, NaOH and plasma exposure time was used to optimize the role of input parameters on the self-cleaning ability of the coated cotton. Methylene blue in water was used as a sample pollutant in the self-cleaning study. The ZnO-coated cotton showed notably high self-cleaning activity of 94% and a UV protection factor of 69.87. The antimicrobial activity against E. Coli and S. Aureus bacteria was also appreciably high compared to the control