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PurposeUsing the theory of planned behavior (TPB) as a theoretical framework, this study investigates individual level psychological determinants of individuals word-of-mouth (WOM) intentions as a way to support corporate social advocacy (CSA).Design/methodology/approachAn online survey (N = 505) using a Qualtrics panel was conducted.FindingsIndividuals' attitudes towards WOM, subjective norms, and self-efficacy was positively associated with their positive WOM intention, whereas perceived controllability over WOM behaviors was not associated with WOM intention. Age was negatively associated with WOM intention.Originality/valueThis study is one of the early attempts to test individual level factors in shaping individuals' WOM intention in response to CSA. This study also employed recent TPB argument and tested the role of self-efficacy and perceived controllability on behavioral intentions in the context of corporate communication. The findings of this study offer theoretical and practical insights to corporations when developing CSA campaigns and designing CSA messages.

Background: It has been a short time since the last wave of the coronavirus disease 2019 pandemic began. The deaths were approximately 6.55M out of 618M confirmed cases. Although future pandemics are inevitable, specific measures could reduce these risks. This study is the first of its kind conducted on this topic in Saudi Arabia aimed at assessing the preparedness and response of the public toward future pandemics in the Qassim region. Methods: An analytical, cross-sectional study was conducted using a pre-validated questionnaire involving 1,200 individuals in the Qassim region, Saudi Arabia. The questionnaire was distributed among the general population in public places. Data entry and statistical analyses were performed using Statistical Package for the Social Sciences software. Results: The results show that people suffered emotionally, psychologically, and economically during the pandemic. A large number of people have tested positive for COVID. They were not ready to stay in lockdown during any future pandemic as they had not yet recovered from the previous economic loss. Conclusion: This survey is a valuable tool for policymakers in public health. This study can help to strengthen the weaknesses of health centers and provide better facilities for people during future pandemics.

Background: Tobacco misuse has not been universally acknowledged as a modifiable risk factor in diabetes preventive or screening methods, despite mounting data revealing substantial epidemiological and mechanistic connections between smoking, hyperglycemia, and the development of type 2 diabetes. Purpose:A growing number of research on the effect of smoking cessation on the development of type 2 diabetes mellitus. The goal of this systematic review was to search the available evidence on the impact of smoking cessation and risk for type 2 diabetes mellitus. Methods: We searched PubMed, Embase, and Scopus (January 1995--October 2022) for prospective observational studies that evaluated the effects smoking and smoking cessation as risk factors for type 2 diabetes mellitus. Results: Type 2 diabetes risk was increased by a factor of 1.37 (95% CI: 1.33 to 1.42) for current smokers, 1.14 (1.10 to 1.18) for ex-smokers, and 1.22 (1.10 to 1.35) for passive smokers, compared to those who had never smoked (7 studies). The associations persisted across all subgroups, and a dose-response relation was discovered between current smoking and diabetes risk, with the RRs (95% CIs) for light, moderate, and heavy smokers, compared with never smokers, being 1.21 (1.10-1.33), 1.34 (1.27-1.41), and 1.57 (1.47-1.66), respectively. If there is a causal relationship between smoking and diabetes, we calculated that 10% in men and 2% in women of all instances of type 2 diabetes globally (about 25 million) may be attributed to smoking. The pooled RR (95% CI) from 10 studies showed that recent ex-smokers (within 5 years) had a lower risk of relapse than never smokers, while long-term ex-smokers (within 10 years) had a lower risk of relapse than current smokers. Conclusion: Both active and passive smoking are strongly connected with higher risks of type 2 diabetes. The risk of diabetes is higher among recent ex-smokers, although it lowers significantly with time.

New conical-shaped geometrical supramolecular H-bonded liquid crystal complexes were formed through 1:2 intermolecular interactions of H-bonding between flexible core (adipic acid, A) and lateral chloro-substituted azopyridines (Bn). The chains of the terminally alkoxy substituted base (n) were changed between 8 and 16 carbons. Mesomorphic and optical examinations of the prepared complexes were measured via differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). Fourier-transform infrared spectroscopy (FT-IR) was used to confirm the Fermi bands of the H- bonding interactions. Induced nematogenic mesophases that cover the whole lengths of alkoxy-chains were detected. The non-linear geometries of the designed supramolecular complexes were also confirmed via Density functional theory (DFT) calculations. It was found that the length of terminal alkoxy chain of the base moiety highly affects the geometrical structure of the investigated complexes. Moreover, it increases the thermodynamic energy and influences the geometrical parameters. The electrical properties of each of the acid component (A), the base (B16) and their 1:2 complex (A/2B16) were evaluated using the Keithley measurement-source unit. The optical properties studies showed that the influences in the optical absorption and the reduction of the energy gap of the complex compared to its individual components made the resulted supramolecular H-bonded complex soft material suitable for solar energy investigations.

Background Many international studies have reported the outcomes and predictors of coronavirus disease 2019 (COVID-19); however, only a few national studies have reported predictors of poor outcomes among adult hospitalized patients with COVID-19. Therefore, this study aimed to describe the clinical characteristics and complications of COVID-19 and identify predictors of poor outcomes. Methods This was a retrospective cohort study. All adult patients confirmed with COVID-19 who were admitted at the King Abdulaziz Medical City (KAMC)-Jeddah between March 1, 2020, and December 31, 2020, were included; pediatric and pregnant patients were excluded. The clinical features and complications of COVID-19 were tested for association with poor outcomes (intensive care unit [ICU] admission or death) using chi-square and Fisher's exact tests. In addition, logistic regression analysis was performed to identify the predictors of poor outcomes. Results A total of 527 patients were included in this study. Forty-two patients (8%) (6-10, 95% confidence interval [CI]) died: 13 in the general wards and 29 in the ICU. Of the 84 patients admitted to the ICU, 65 underwent invasive mechanical ventilation. Poor outcome affected 97 patients (18%) (15-22, 95% CI). Shortness of breath, oxygen saturation92%, and abnormal chest x-ray findings were associated with poor outcomes (P-value0.001). In addition, lymphocyte counts were significantly lower, while c-reactive protein levels were significantly higher among patients with poor outcomes (P-value0.001). The most common complications were acute cardiac (83 patients, 16%), acute kidney (78 patients, 15%), and liver injuries (76 patients, 14%). Predictors of poor outcome were the updated Charlson comorbidity index (CCI) (odds ratio [OR] 1.2 [95% CI 1.1-1.4]), liver injury (OR 2.6 [95% CI 1.3-4.9]), acute kidney injury (OR 4.3 [95% CI 2.3-7.8]), and acute cardiac injury (OR 5.1 [95% CI 2.8-9.4]). Conclusions COVID-19 disease is associated with significant morbidity and mortality. Predictors of poor outcomes among COVID-19 hospitalized patients were the updated CCI, liver injury, acute kidney, and acute myocardial injuries. Subsequently, the risk of poor COVID-19 outcomes is increased among patients with multiple comorbidities and/or multiple COVID-19 complications.

The sudden arrival of COVID-19 called for new technologies to manage the healthcare system and to reduce the burden of patients in the hospitals. Artificial intelligence (AI) which involved using computers to model intelligent behavior became an important choice. Various AI applications helped a lot in the management of healthcare and delivering quick medical consultations and various services to a wide variety of patients. These new technological developments had significant roles in detecting the COVID-19 cases, monitoring them, and forecasting for the future. Artificial intelligence is applied to mimic the functional system of human intelligence. AI techniques and applications are also applied in proper examinations, prediction, analyzing, and tracking of the whereabouts of patients and the projected results. It also played a significant role in recognizing and proposing the generation of vaccines to prevent COVID-19. This study is therefore an attempt to understand the major role and use of AI in healthcare institutions by providing urgent decision-making techniques that greatly helped to manage and control the spread of the COVID-19 disease.

This study adopts the consumer-centric perspective, through the lens of the consumer involvement theory and stakeholder theory, to examine the role of consumer involvement in shaping individuals’ a...

Background: A febrile seizure is the most common type of convulsive disorders in children younger than the age of 5, it occurs in 2%-5% of them, and it is one of the most prevalent causes of emergency hospital admissions in children. The present study aims to understand the general demographics of patients presenting with febrile seizures among pediatrics in the maternity and children’s hospital, Makkah, Saudi Arabia, and to assess the parent’s attitude when managing children with a febrile seizure. Methodology: This study is a cross-sectional study concerned with children presenting with seizures and fever at the pediatric emergency department in the maternity and children’s hospital of Makkah city from May to July 2019. Patients’ parents participated in this study. A validated questionnaire was used for the collection of patients’ data. Data were analyzed using Statistical Package for the Social Sciences, version 10. Summarization of the data was presented using tables and graphs. Results: A total of 71 children patients were included in this study. 70.4% (50) of them were male, while 29.6% (21) were female. 81.7% of the children patients between 6 months and 3-year old. 78.3% had typical convulsions, while the reaming 21.7% had atypical ones. Moreover, 76.9% (20) of the patients’ parents know their children’s diagnosis. Most children, 67.85% (19), were diagnosed with febrile seizures. 42.85% (12) of the participants thought that febrile seizure did not cause epilepsy. Conclusion: The overall attitudes of parents regarding febrile seizures need to be improved; this action will require a well-organized educational program for febrile seizures.

Background: Medication-related osteonecrosis of the jaw (MRONJ) is a complication affecting patients who are being treated with antiresorptive or antiangiogenic medication. These patients require meticulous treatment planning and management strategies. This research aimed to assess the knowledge of dental practitioners and students in their professional years regarding MRONJ. Methods: A cross-sectional study was conducted among 345 dental practitioners and students in their professional years of both genders, in governmental and private dental schools. The data was collected using an electronic and paper-based self-administered structured questionnaire with six sections. The data was entered and analyzed using SPSS Version 23, and a P-value

Background: Preventive oral health of a child is dependent on the parental knowledge toward caries control, care of deciduous tooth, use of space maintainers for malocclusion, and utilization of various procedures available for preventing oral diseases by oral health professionals. This study was aimed to assess the attitude and awareness of preventive dentistry among parents residing in Kingdom of Saudi Arabia. Methodology: A cross-sectional, questionnaire study was conducted among 941 parents. Questionnaire was sent through the use of social media, and responses were collected. Results: The study included 941 participants. Among them there were 692 mothers (73.5%) and 249 fathers (26.5%). The educational level of most of participants was college (n= 576, 61.2%). It is noticed from table one that most of participants agreed with the symptoms listed in the study questionnaire. They strongly agreed on black or brown spots on the teeth is the main symptom of tooth decay. The most prevalent preventive measure was limiting sugary drinks followed by proper teeth brushing. There was statistically significant relationship between proper teeth brushing and level of education (P= 0.001). Conclusion: Awareness about preventive dentistry was more among Saudi parents, but utilization rate was directly correlated to their education and income. After The utilization of preventive procedures was significant according to education (P< 0.05). Keywords:Dental services,malocclusion,preventive procedures,primary teeth

This study investigates the role of consumer–brand congruence and consumer–celebrity congruence in the formation of consumer attitudes toward brands and their impact on behavioral intentions within the context of corporate social advocacy (CSA) involving controversial celebrities. Using a U.S. sample drawn from a Qualtrics panel (N = 372), the results of mediation analyses indicate that attitude toward a brand positively mediates the effects of consumer–brand congruence on consumers’ behavioral intentions, including purchase intention, brand preference, and boycott recommendation. The consumer–celebrity congruence moderated the indirect effect of consumer–brand congruence on brand preference and boycott recommendations, but not purchase intention. The findings of this study contribute to the CSA literature and practices by highlighting the role of consumers’ congruence with a controversial celebrity in determining consumers’ behavioral responses to CSA. When brands practice CSA, consumer–brand congruence rather than consumer–celebrity congruence could play a more important role in shaping consumer behaviors.

Although acute dizziness is a very frequent reason for admissions to emergency care, its differential diagnosis is difficult to establish due to many factors. Dizziness may mean diverse sensations such as vertigo, lightheadedness, presyncope, disequilibrium, or simply feeling unwell. The classical approach to dizziness initiates with characterizing the form of dizziness according to the belief that every kind of dizziness represents a particular underlying etiology: vertigo is vestibular, presyncope is cardiovascular, disequilibrium is neurological, and nonspecific dizziness is psychogenic or metabolic. Development of acute dizziness/vertigo unaccompanied by precipitating features occurs in patients of acute spontaneous dizziness. The dizziness/vertigo mainly presents with autonomic symptoms like imbalance, nausea, and vomiting. Dizziness/vertigo and imbalance are the commonest manifestations in vertebrobasilar ischemia, which accounts for over 20% of all ischemic strokes. It is essential to distinguish between isolated vascular vertigo from less severe disorders related to the inner ear as the treatment plan and prognosis vary among these problems. The development of diffusion-weighted magnetic resonance imaging (MRI) has improved the infarction identification in cases with vascular dizziness/vertigo, particularly from undermined posterior blood flow. Nonetheless, proper bedside neurotologic assessment which includes components such as head impulse/thrust test, head shaking nystagmus test and ocular tilt reaction test demonstrate higher sensitivity than imaging in diagnosing acute cerebrovascular accidents as an etiology of abruptly occurring vertigo lasting longer than one day, particularly in the initial 48 hours.

Background Diabetic peripheral neuropathy (DPN) is a chronic sensorimotor length-dependent and symmetrical polyneuropathy. Some peripheral neuropathies have painful presentations, and some are painless. DPN can have a potential impact on the patient's life. Objectives This study was conducted in order to investigate the frequency of neuropathic sensory symptoms among patients with uncontrolled diabetes mellitus. Methods This is a cross-sectional study conducted in the Security Forces hospital using the Neuropathy Total Symptom Score-6 (NTSS-6) questionnaire. The questionnaire was administered by contacting patients through the phone. Patients with uncontrolled diabetes (HbA1C >9) were included in the study. Results This study included 285 participants; 58.9% had type II diabetes and 41.1% had type I diabetes, 156 (54.7%) were females, and 129 (45.3%) were males. Most of the patients (51.1%) were 45-64 years old and the majority were non-smokers (77.9%). Patients with neuropathic pain were 182 (63.9%); 79 (43.4%) of them were males and 103 (56.6%) were females. The prevalence of neuropathic symptoms was much higher in females than in males. Conclusion The prevalence of painful DPN is high among patients with long-term uncontrolled diabetes mellitus. Older, unemployed, and low-educated patients are at higher risk of developing painful DPN. Proper glycemic control and lifestyle modifications are essential in preventing the progression of this condition.

Background: Self-stigma is one of the three main barriers to treatment and receiving the needed care for people with depression. Additionally, depressed people who have self-stigma have a low expectation for recovery, avoid seeking help and delay or stop treatment early. Objectives: To assess depression literacy, depression self-stigma and relationship between them among secondary school students. Methods: A cross sectional study was conducted in Sabya city, in Jazan among a representative sample of secondary school students. An interview questionnaire was used for data collection. The questionnaire included demographic characteristics of the participants, validated Arabic version of Self-Stigma of Depression Scale and the validated Arabic validated version of the Depression Literacy Questionnaire. Results: Depression literacy is relatively low, correlated negatively with depression personal stigma and positively with perceived depression stigma among secondary school students. Female students were more knowledgeable about depression compared to males. Students` age was negatively correlate with depression stigma scale and score of personal subscale of depression stigma score was significantly high in males in correlation with females. Keywords: Depression, stigma, self-stigma, depression literacy, stigma prevalence.

BACKGROUND Dental professionals are one of the high-risk categories of getting infected with COVID-19 due to their work nature. The study was aimed to evaluate the knowledge, attitude, and practices (KAPs) related to COVID-19 and their clinical practice in the Kingdom of Saudi Arabia. OBJECTIVE 1-To evaluate the level of knowledge and attitude regarding the coronavirus diseases (COVID-19) among dentists in Saudi Arabia . 2-To evaluate the certainty level of dental practitioner in continuing dental practice and the preparedness in screening and dealing of COVID-19 patients . METHODS A cross-sectional online survey was conducted using a pre-tested and validated questionnaire. The questionnaire was comprised of closed-ended items related to KAPs. Participants' correct responses were scored and based on the total scores obtained, each domain was categorized into ‘good’, ‘fair’, and ‘poor’. Relationship with Sociodemographic details and KAP scores were analyzed using Pearson’s Chi-square test. RESULTS Most of the participants showed good scores in KAPs related to COVID-19. Saudi Dentists had comparatively better KAP scores compared to Non-Saudi dentists (p CONCLUSIONS Dentists practice in Saudi Arabia had good knowledge, attitude, and practices towards COVID-19 and its importance in dentistry. Dentists should mandatorily follow all the guidelines and extra precautionary measures to stop the spread of this pandemic.

Smart grid enables two-way communications between operation centers and smart meters to collect power consumption and achieve demand response to improve flexibility, reliability, and efficiency of electricity system. However, power consumption data may contain users’ privacy, e.g., activities, references, and habits. Many smart metering schemes have been proposed utilizing homomorphic encryption for users’ privacy preservation. Unfortunately, some abnormality of smart meter reading, e.g., caused by electricity theft, cannot be discovered since data is encrypted. Meanwhile, operation centers could become curious in reality. To address the above issues, we propose a new privacy-preserving smart metering scheme for smart grid, which supports data aggregation, differential privacy, fault tolerance, and range-based filtering simultaneously. Specifically, we extend lifted ElGamal encryption to aggregate users’ consumption reports at the gateway to reduce communication overhead, while supporting fault tolerance of malfunctioning smart meters effectively. We also leverage zero-knowledge range proof to filter abnormal measurements caused by electricity theft or false data injection attacks without exposing individual measurements. In addition, our scheme can resist differential attacks, by which the curious operation center can violate users’ privacy through comparing two aggregations of the similar data set. Finally, we discuss the properties of the proposed scheme and evaluate its performance in terms of security and efficiency.

Distributed energy resources (ERs), featured with small-scale power generation technologies and renewable energy sources, are considered as necessary supplements for smart grid. To ensure that merged resources contribute effectively to the grid, data generated by consumer side should be shared among the ERs. However, it also introduces challenges of the protection of consumer privacy. To address these difficulties, we propose a new framework to share data in smart grid by leveraging new advances in homomorphic encryption and proxy re-encryption. Our proposed framework allows ERs to analyze consumer data while ensuring consumer privacy. An additional benefit of our proposed framework is that consumer data is transmitted over the smart grid only once. Furthermore, we present a concrete scheme falling into the proposed framework. Extensive analysis shows that the concrete scheme is secure and efficient.

Terahertz (THz) oscillators based on resonant tunneling diodes (RTDs) have relatively low output power, tens to hundreds of microwatts. The conventional designs employ submicron-sized RTDs to reduce the device self-capacitance and, as a result, realize higher oscillation frequencies. However, reducing the RTD device size leads to lower output power. In this article, we present RTD oscillators that can employ one or two RTD devices of relatively large size, 9–25 μm2, for high power and, at the same time, can oscillate at THz frequencies. This is achieved through low resonating inductances realized by microstrip or coplanar waveguide transmission line short stubs with low characteristic impedances ( Z 0), which have lower inductance values per unit length and so compensate the increase of the self-capacitance of large area RTD devices. Thus, fabrication using only photolithography is possible. It is also shown that device sizing, which is limited only by bias stability considerations, does not limit device bandwidth. Further, we report a new way to estimate the RTD oscillator output power with frequency. A series of oscillators with oscillation frequencies in the 245–309 GHz range and output powers from 0.1 to 1 mW have been demonstrated showing the feasibility of the proposed approach.

This paper presents a compact, low power consumption and low cost resonant tunneling diode (RTD) based terahertz (THz) source technology for automotive radar applications. Large RTD sizes of 4×4 μm2 are manufactured using the low cost photolithography technology with a total chip size of 470×530 μm2. The measured oscillation frequency was 260 GHz and the oscillator exhibits a low power consumption of 200 mW and a record output power of 1 mW.

Mobile social network (MSN), which is built upon popular smart phone devices and enables mobile users with similar interests to connect with one another, has received considerable attention in recent years. A common phenomenon that makes the MSN vivid today is mobile users often like to share attractive things to their friends in MSN. In this paper, based on this common phenomenon, we propose an efficient recommendation-based data dissemination (ReDD) protocol for MSN, which can efficiently disseminate high-quality messages in a privacy-preserving way. Specifically, in the proposed ReDD protocol, each mobile user, based on both his or her own view and his or her friends' recommendations, will form his or her personal estimation on the quality of a message. Only if the estimation of quality reaches a threshold, the message will be disseminated. In this way, high-quality messages can be widely spread in the network and occupy more network resources than low-quality ones. In order to check the validity of friends' recommendations, ReDD also employs an efficient anonymous authentication technique, which ensures that only the friends of a user can verify recommendations made by the user. Detailed security analysis demonstrates that ReDD can effectively resist various attacks launched by attackers and ensure identity privacy of nodes, confidentiality of shared keys and integrity of data packets. In addition, extensive simulations are also conducted to evaluate the performance of ReDD in terms of the number of active nodes and the average active time, and the simulation results show that high-quality messages can be disseminated widely and efficiently, while low-quality ones will be eliminated shortly to avoid occupying network resources. Copyright © 2014 John Wiley & Sons, Ltd.

This paper will discuss resonant tunnelling diode (RTD) sources being developed on a European project iBROW (ibrow. project. eu) to enable short-range multi-gigabit wireless links and microwave-photonic interfaces for seamless links to the optical fibre backbone network. The practically relevant output powers are at least 10 mW at 90 GHz, 5 mW at 160 GHz and 1 mW at 300 GHz and simulation and some experimental results show that these are feasible in RTD technology. To date, 75 - 315 GHz indium phosphide (InP) based RTD oscillators with relatively high output powers in the 0.5 - 1.1 mW range have been demonstrated on the project. They are realised in various circuit topologies including those that use a single RTD device, 2 RTD devices and up to 4 RTD devices for increasingly higher output power. The oscillators are realised using only photolithography by taking advantage of the large micron-sized but broadband RTD devices. The paper will also describe properties of RTD devices as photo-detectors which makes this a unified technology that can be integrated into both ends of a wireless link, namely consumer portable devices and fibre-optic supported base-stations (since integration with laser diodes is also possible). info:eu-repo/semantics/publishedVersion

Resonant tunneling diodes (RTDs) have been extensively studied due to their potential applications in very high speed electronics, optical communications, and terahertz generation. In this work, we report the latest results on the characterization of the resonant tunneling diode photo-detectors (RTD-PDs), incorporating InGaAlAs light sensitive layers for sensing at the telecommunication wavelength of lambda = 1310 nm. We have measured responsivities up to 28.8 A/W and light induced voltage shift of 204.8 V/W for light injection powers around 0.25 mW. Fundacao para a Ciencia e a Tecnologia (FCT) [UID/Multi/00631/2013]; European Structural and Investment Funds (FEEI) through the Competitiveness and Internationalization Operational Program (COMPETE); FCT [ALG-01-0145-FEDER-016432/POCI-01-0145-FEDER-016432]; European Commission under the project iBROW [645369] ALG-01-0145-FEDER-016432/POCI-01-0145-FEDER-016432

Radiation from antennas integrated with indium phosphide (InP)-based resonant tunnelling diode (RTD) oscillators is mainly through the substrate because of the effects of the large dielectric constant. Therefore, hemispherical lenses are used to extract the signal from the backside of the substrate. In this study the authors present a broadband bow-tie slot antenna with a tuning stub which is diced and mounted on a ground plane to alleviate the substrate effects. Here, the large dielectric constant substrate around the antenna conductor is removed. In addition, the ground plane underneath the diced substrate acts as a reflector and, ultimately, the antenna radiates to the air-side direction. Antenna integration with RTD oscillators is described in this study as well. Two-port bow-tie slot antennas were designed and characterised and showed the suitability of integration with power combining RTD oscillator circuits which are based on mutual coupling. The antennas were fabricated using electron beam lithography on a semi-insulating InP substrate. Simulated and measured bandwidth almost extends the entire frequency range 230–325 GHz. Simulations shows air-side radiation pattern and antenna gain of around 11 dB at 280 GHz. Simulations also show that the antenna may be fed with a 50-Ω or 30-Ω feed line, i.e. suitable feed lines, without compromising its performance which may prove beneficial for optimum loading of RTD oscillators.

In this paper, we propose an efficient, secure and privacy-preserving scheme for smart grid downlink communication. Specifically, we propose an efficient identity based signcryption scheme, called EIBSC, providing privacy preservation in downlink communication for smart grids. The proposed scheme is characterized by employing the concealing destination technique on a tree network topology to protect consumer privacy in downlink communication. Moreover, the proposed scheme employs identity based signcryption to efficiently achieve downlink message source authentication, data integrity and encryption. Additionally, compared to other identity-based signcryption schemes, the proposed scheme is more efficient in regards to computational overhead and ciphertext size. Furthermore, our security analysis illustrates that the proposed scheme is resilient against various security threats to smart grids.

Radiation from antennas integrated with InP-based resonant tunnelling diode (RTD) oscillators is usually degraded because of the effects of the large dielectric constant substrate. The common solution has been to use hemispherical lenses to extract the signal from the backside of the substrate. In this paper we present a broadband bow-tie slot antenna with tuning stub which is diced and mounted on a ground plane to alleviate the substrate effects. Here, the large dielectric constant substrate around the antenna conductor is removed. In addition, the ground plane underneath the diced substrate acts as a reflector and, ultimately, the antenna radiates to air-side direction. The antenna was designed and fabricated using photolithography techniques to offer wide bandwidth (return loss S11

With more than 1,700 laboratory-confirmed infections, Middle East respiratory syndrome coronavirus (MERS-CoV) remains a significant threat for public health. However, the lack of detailed data on modes of transmission from the animal reservoir and between humans means that the drivers of MERS-CoV epidemics remain poorly characterized. Here, we develop a statistical framework to provide a comprehensive analysis of the transmission patterns underlying the 681 MERS-CoV cases detected in the Kingdom of Saudi Arabia (KSA) between January 2013 and July 2014. We assess how infections from the animal reservoir, the different levels of mixing, and heterogeneities in transmission have contributed to the buildup of MERS-CoV epidemics in KSA. We estimate that 12% [95% credible interval (CI): 9%, 15%] of cases were infected from the reservoir, the rest via human-to-human transmission in clusters (60%; CI: 57%, 63%), within (23%; CI: 20%, 27%), or between (5%; CI: 2%, 8%) regions. The reproduction number at the start of a cluster was 0.45 (CI: 0.33, 0.58) on average, but with large SD (0.53; CI: 0.35, 0.78). It was >1 in 12% (CI: 6%, 18%) of clusters but fell by approximately one-half (47% CI: 34%, 63%) its original value after 10 cases on average. The ongoing exposure of humans to MERS-CoV from the reservoir is of major concern, given the continued risk of substantial outbreaks in health care systems. The approach we present allows the study of infectious disease transmission when data linking cases to each other remain limited and uncertain.

This paper presents a G-band (140 -220 GHz) monolithic microwave/ (millimeter-wave) integrated circuit (MMIC) resonant tunneling diode (RTD) oscillator operating at 205.8 GHz with -14.6 dBm output power. The circuit topology employs two InGaAs/AlAs RTDs in parallel. A new RTD epi-layer material design which will greatly benefit micrometer-sized RTD devices for high output power of millimeterwave oscillators is also presented. It is expected that the oscillator output power will reach several mW for RTD oscillators operating in the G-band. This work shows the promising potential of RTD oscillators as terahertz (THz) sources for a variety of applications including high speed wireless communication.

Background: Health literacy is an essential predictor of health status, disease control and adherence to medications. Objectives: The study goals were to assess the health literacy level of the general population in Saudi Arabia using translated Gulf Arabic version of the short-version of the Test of Functional Health Literacy in Adults (S-TOFHLA) and Single Item Literacy Screener (SILS) tests and to measure the relationship between health literacy and education level. Methods: The study was a cross-sectional with a convenience sample of 123 participants from the general population in Riyadh. Data were collected using the modified (Gulf) Arabic versions of both S-TOFHLA and SILS. Fisher’s Exact test was used to measure the difference of the health literacy scores according to the education degrees and Cronbach’s alpha was used to measure the internal consistency of the S-TOFHLA items. Results: More than half (55.4%) of the participants were male, 50.4% had a middle school or less education level, and we found that 84.4% had adequate health literacy as measured by the S-TOFHLA, compared to 49.6% as measured by SILS. The Fisher’s Exact test showed a significant difference (P

This paper prepents monolithic microwave integrated circuits (MMIC) employing large size resonant tunneling diode (RTD) with high power at high frequencies. This is achieved by proper design of the resonating inductances which are realized by shorted microstrip transmission lines with low characteristic impedances (Z0 = 10.4 Ω). Two oscillators were fabricated using photolithography. Oscillation frequencies of 312 GHz delivering 0.15 mW and 262 GHz delivering 0.19 mW were measured for oscillators employing a single 4 μm × 4 μm and 5 μm × 5 μm RTD devices, respectively.

In this paper, we propose a novel privacy- preserving set aggregation scheme for smart grid communications. The proposed scheme is characterized by employing a group $\mathbb{G}$ of composite order $n=pq$ to achieve two-subset aggregation from a single aggregated data. With the proposed set aggregation scheme, the control center in smart grid is able to obtain more fine- grained data aggregation results for better monitoring and controlling smart grid. Detailed security analysis shows that the proposed scheme can achieve privacy-preserving property with formal proof in the random oracle model. In addition, extensive experiments are conducted, and the results demonstrate the proposed scheme is also efficient in terms of low computational costs and communication overheads.

In smart grid, to monitor, predict and control the power consumption in real time, energy usage data have to be periodically collected through publicly accessible communication channels, and are stored in a centralized operation center. However, electricity consumption data may disclose the privacy information of users. Therefore, protecting privacy of users and validity of power usage reports becomes a crucial security issue. In this paper, we propose a security-enhanced data aggregation scheme for smart grid communications based on homomorphic cryptosystem, trapdoor hash functions and homomorphic authenticators. Our scheme can achieve data confidentiality and integrity against the malicious aggregator (e.g. gateway), meaning that the aggregator is not able to access users' private information or corrupt the power consumption reports during the aggregation process. Through extensive analysis, we demonstrate that our scheme can resist potential threats and be proved secure under cryptographic hard assumptions. It has less computational and communication overheads than existing approaches.