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Stroke is the second most common cause of death worldwide, with 50% of survivors experiencing long-term disability. For more than two decades, treatment with intravenous thrombolysis (IVT) and mechanical endovascular thrombectomy (MET), the only approved stroke reperfusion therapies, was restricted to patients within the 4.5-6 hour time window, respectively. Therefore, patients who presented with acute ischemic stroke (AIS) beyond the conventional time window were excluded from reperfusion treatment. This narrative review aims to review the scientific literature on the possibilities of reperfusion therapies for patients who present with an unknown time of stroke onset, and those with stroke onset beyond the conventional 4.5-6 hour time window. Beyond the conventional time window, the eligibility of patients for IVT or MET, the two main therapeutic procedures, is decided based on the concept of penumbral imaging. Penumbral imaging identifies patients with hypoperfused but viable brain tissue, who could benefit from reperfusion. On the other hand, clock-based DWI-fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) can detect stroke that has occurred within 4.5 hours in patients with an unknown time of onset, including patients who awaken with stroke. The introduction of penumbral imaging and MRI-based tissue clocking as imaging biomarkers for stroke has revolutionized stroke therapy, potentially allowing for personalized treatment of eligible stroke patients.

With the exponential growth in Internet-of-Things (IoT) devices, security and privacy issues have emerged as critical challenges that can potentially compromise their successful deployment in many data-sensitive applications. Hence, there is a pressing need to address these challenges, given that IoT systems suffer from different limitations, and IoT devices are constrained in terms of energy and computational power, which renders them extremely vulnerable to attacks. Traditional cryptographic algorithms use a static structure that requires several rounds of computations, which leads to significant overhead in terms of execution time and computational resources. Moreover, the problem is compounded when dealing with multimedia contents, since the associated algorithms have stringent QoS requirements. In this paper, we propose a lightweight cipher algorithm based on a dynamic structure with a single round that consists of simple operations, and that targets multimedia IoT. In this algorithm, a dynamic key is generated and then used to build two robust substitution tables, a dynamic permutation table, and two pseudo-random matrices. This dynamic cipher structure minimizes the number of rounds to a single one, while maintaining a high level of randomness and security. Moreover, the proposed cipher scheme is flexible as the dimensions of the input matrix can be selected to match the devices’ memory capacity. Extensive security tests demonstrated the robustness of the cipher against various kinds of attacks. The speed, simplicity and high-security level, in addition to low error propagation, make of this approach a good encryption candidate for multimedia IoT devices.

The study aims to investigate the impact of e-learning readiness on faculty’s performance in their academic works. It also seeks to examine how their information security awareness and technology self-efficacy mediate this primary effect. Due to the COVID-19 pandemic, many academic institutions around the world have closed; and adopted online learning platforms to keep the educational process running. However, the issues about universities readiness and effectiveness of e-learning seem to be motionless and not obviously understood, particularly for a developing country such as Jordan. To achieve the study goals, online questionnaire was distributed as a main tool for data collection from academicians. Sequentially, (383) valid questionnaires were subject to statistical analysis. Data analysis was performed using Partial Least Squares - Structural Equation Modelling (PLS-SEM). The results showed that there is a statistically significant impact of e-learning readiness on the academic staff performance through information security awareness and technology self-efficacy in Jordanian higher education institutions. Based on the results, the study proposed some recommendations, such as improving and supporting e-learning readiness in the Jordanian educational institutions due to its role in improving achieving academic performance.

The Internet of Things (IoT) is a global network of interconnected computing, sensing, and networking devices that can exchange data and information via various network protocols. It can connect numerous smart devices thanks to recent advances in wired, wireless, and hybrid technologies. Lightweight IoT protocols can compensate for IoT devices with restricted hardware characteristics in terms of storage, Central Processing Unit (CPU), energy, etc. Hence, it is critical to identify the optimal communication protocol for system architects. This necessitates an evaluation of next-generation networks with improved characteristics for connectivity. This paper highlights significant wireless and wired IoT technologies and their applications, offering a new categorization for conventional IoT network protocols. It provides an in-depth analysis of IoT communication protocols with detailed technical information about their stacks, limitations, and applications. The study further compares industrial IoT-compliant devices and software simulation tools. Finally, the study provides a summary of the current challenges, along with a broad overview of the future directions to tackle the challenges, in the next IoT generation. This study aims to provide a comprehensive primer on IoT concepts, protocols, and future insights that academics and professionals can use in various contexts.

Protecting the contents of medical records is of paramount importance when it comes to preserving patients’ privacy. Most existing cryptographic-based solutions rely on traditional encryption algorithms having a multi-round structure, which introduces processing latency and requires increased resources. Medical images possess special characteristics compared to other types of images. The main goal of this paper is to leverage these characteristics to design and implement an efficient and secure encryption algorithm for such images. The proposed solution defines three variants of encryption algorithms: (a) full, (b) middle-full, and (c) selective. The full approach encrypts all sub-matrices of an image, while the middle-full variant is a middle solution between the selective and full algorithms and its goal is to just hide the type of the medical image. Selective encryption identifies a set of sub-matrices of an image according to a statistical average test, known as region of interest (ROI). In the three approaches, a high security level is ensured since each image is encrypted independently of the previous and next images. Also, all primitives of the proposed cipher, such as permutation and substitution, depend on a dynamic key. Furthermore, the encryption scheme is efficient since the proposed round function is lightweight and applied for only one round. This reduces the latency and the required resources as compared to traditional cryptographic schemes. The proposed approach is flexible as it can be applied in either selective, middle-full, or full mode. Also, the size of a sub-matrix is variable and can be changed according to the available memory size. Several security and performance tests are conducted to evaluate the effectiveness of the proposed solution. The results validate the robustness of the proposed scheme against almost all considered types of attacks and show an improvement in terms of latency and resources compared to current image-encryption schemes. Also, the results confirm the robustness of the proposed algorithm in protecting the contents of medical images.

The protection of multimedia content has become a key area of research, since very often a user’s privacy and confidentiality can be at risk. Although a large number of image encryption algorithms have recently emerged, only a subset of these algorithms are suitable for real applications. These algorithms however use non-integer operations such as chaotic solutions that introduce a sizeable overhead in terms of latency and resources, in addition to floating-point hardware that is costly to implement. Designing an efficient, lightweight, and secure image encryption algorithm is still a hard challenge; yet, it is crucial to have in order to meet the demands of recent multimedia applications running on energy-limited devices. In this paper, an efficient image encryption scheme based on a dynamic structure is proposed. The structure of the proposed cipher consists of two different lightweight rounds (forward and backward chaining blocks) and a block permutation process. In addition, a key derivation function is proposed to produce a dynamic key based on a secret key and a nonce. This key, according to its configuration, can be changed for each validate time (session) or for each new input image. Then, based on this key, the cipher layers are produced, which are an integer or a binary diffusion matrix and a substitution table S-box, together with a permutation table P-box. The proposed dynamic cipher is designed to provide high robustness against contemporary powerful attacks, and permits reducing the required number of rounds for achieving the lightweight property. Experimental simulations demonstrate the efficiency and robustness levels of the proposed scheme.

Recently, there has been a growing attention for Chaos-based image encryption algorithms. This class of algorithms relies on embedded chaotic maps to ensure a high security level with minimal performance overhead. One such algorithm, which we refer to as NCIES, was proposed recently, and the authors claimed that the algorithm achieves the required cryptographic properties with just a single round. In this paper, we first assess the performance of the NCIES cipher and we show that a single round is not enough for this cipher to ensure the desired cryptographic properties. In this context, we describe how such a cipher is vulnerable to a chosen plaintext/ciphertext attack. Next, we propose a new lightweight dynamic key-dependent cipher scheme that can address and overcome the issues identified in the NCIES cipher and other recent lightweight image encryption schemes. The proposed cipher is designed in a way to achieve a good balance between the latency, the required resources, and the security level when compared to recent chaotic image cipher schemes.

Background Despite the misconceptions regarding E-cigarettes (ECs), only a few studies have been conducted in the Middle East that focused on this topic. This study assesses the knowledge of and attitudes towards ECs in Lebanon, determines how these two measures are associated, and identifies the variables that explain each of these measures. Methods A cross sectional study was conducted on a convenience sample of Lebanese pedestrians aged between 18 and 64 inclusive. A structured self-administered questionnaire comprising of knowledge and attitude scales, and questions on demographical, health and smoking characteristics was used. Results Scores for attitudes and knowledge of ECs were summed and dichotomized using a 75% cutoff, above which the participant was considered to have a positive attitude and good knowledge. Among the 352 participants (56.6% males, 43.3% females, mean age 30.3, 46.2% smokers), 63.3% exhibited a lower level of EC knowledge. More than 50% erroneously thought that ECs are not associated with lung and bladder cancer or impair lung and heart function. 65% falsely thought that it is harmless and not addictive. As for attitude, 43.3, 53.9, and 44.3% thought that it is socially acceptable, helps in smoking cessation, and is a good replacement for cigarettes and an enjoyable recreational device respectively. Our results revealed an inverse correlation between attitude and knowledge scores (Spearman’s correlation = −.30, p  < .001). Predictors of knowledge included health-related occupation ( p  = .010), regular exercise ( p  = .016), healthy diet ( p  = .026), EC use (p = .026), perception that ECs are not harmful ( p  = .001), and help in smoking cessation ( p  = .017). Predictors of attitude included EC use ( p  = .008), sex ( p  = .010), and knowledge that most ECs are addictive ( p  = .006), harmful ( p  = .014), and impair heart and lung function ( p  = .047). Conclusions Our study revealed a gap in EC knowledge, especially among participants who displayed a positive attitude towards ECs. Hence, measures should be undertaken to regulate its use by instituting more stringent laws and holding nationwide awareness campaigns.

The rapid evolution of unmanned technology demands the development of optimized propeller designs that can accommodate a wide range of flight conditions and mission requirements. This article suggests a multi-objective optimization framework for unmanned aircraft during the cruising phase, based on the Multi-Objective Colonial Competitive Method (MOCM). This paper focuses on the maximum thrust-to-weight ratio at hover (T-WHmax) as one of its objective functions, which is associated with the ability to resist wind and maneuver effectively during takeoff and landing. The total energy consumption is the second objective function. Using the suggested framework for the Airbus Vahana unmanned aircraft, the structure of the propeller blade (PB) is optimized and verified through computational fluid dynamics (CFD). A detailed analysis is conducted on the effects of the hover disk loading and cruising speed on the optimization outcome. The findings indicate that T-WHmax greatly influences the outcome of optimization. A comparison with literature results proves the benefits of the optimal PB design in both saving energy and improving takeoff maneuverability. In general, the method and guidelines outlined in this paper endorse the structural optimization of PB design for unmanned aircraft.

The impact of confidentiality and privacy breaches are more pronounced when dealing with multimedia contents. One of the obvious techniques to counter these threats is the use of encryption. A number of algorithms for robust image encryption, targeted for real-time applications with tight resource constraints, has been proposed in the literature. In this paper, first, we analyze two recent cipher schemes for image contents, which are based on two rounds. We show that the schemes are designed to ensure maximum avalanche effect in the whole image by employing the chaining block code mode (CBC) in forward and backward directions. However, they do not lend themselves to parallel implementation and they have a problem with error propagation, which is not desirable for wireless multimedia transmission. As such, we propose to redesign the underlying algorithm to make it practical when used with applications that either suffer from a high error percentage or from real-time constraints. The modified cipher employs the counter mode to eliminate the chaining process (forward and backward), which allows for parallel computations and minimizes the effect of error propagation. According to the security and performance results, the proposed scheme can respond better to the applications and/or system requirements and limitations by ensuring a better performance and an equally high level of security compared to both ciphers in addition to minimum error propagation. To the best of our knowledge, the proposed scheme is the first dynamic key-dependent stream cipher scheme with a pseudo-random key-stream generation for re-ordering of sub-matrices.