Common security issues and challenges in wireless sensor networks and IEEE 802.11 wireless mesh networks

Both Wireless Mesh Network (WMN) and Wireless Sensor Network (WSN) are multi-hop wireless networks. WMN is an emerging community based integrated broadband wireless network which ensures high bandwidth ubiquitous internet provision to users, while, WSN is application specific and ensures large scale real-time data processing in complex environment. Both these wireless networks have some common vulnerable features which may increase the chances of different sorts of security attacks. Wireless sensor nodes have computation, memory and power limitations, which do not allow for implementation of complex security mechanism. In this paper, we discuss the common limitations and vulnerable features of WMN and WSN, along with the associated security threats and possible countermeasures. We also propose security mechanisms keeping in view the architecture and limitations of both. This article will serve as a baseline guide for the new researchers who are concern with the security aspects of WMN and WSN

Denial of service attacks and challenges in broadband wireless networks

Broadband wireless networks are providing internet and related services to end users. The three most important broadband wireless technologies are IEEE 802.11, IEEE 802.16, and Wireless Mesh Network (WMN). Security attacks and vulnerabilities vary amongst these broadband wireless networks because of differences in topologies, network operations and physical setups. Amongst the various security risks, Denial of Service (DoS) attack is the most severe security threat, as DoS can compromise the availability and integrity of broadband wireless network. In this paper, we present DoS attack issues in broadband wireless networks, along with possible defenses and future directions

Multi-view convolutional recurrent neural networks for lung cancer nodule identification

Screening via low-dose Computer Tomography (CT) has been shown to reduce lung cancer mortality rates by at least 20%. However, the assessment of large numbers of CT scans by radiologists is cost intensive, and potentially produces varying and inconsistent results for differing radiologists (and also for temporally-separated assessments by the same radiologist). To overcome these challenges, computer aided diagnosis systems based on deep learning methods have proved an effective in automatic detection and classification of lung cancer. Latterly, interest has focused on the full utilization of the 3D information in CT scans using 3D-CNNs and related approaches. However, such approaches do not intrinsically correlate size and shape information between slices. In this work, an innovative approach to Multi-view Convolutional Recurrent Neural Networks (MV-CRecNet) is proposed that exploits shape, size and cross-slice variations while learning to identify lung cancer nodules from CT scans. The multiple-views that are passed to the model ensure better generalization and the learning of robust features. We evaluate the proposed MV-CRecNet model on the reference Lung Image Database Consortium and Image Database Resource Initiative and Early Lung Cancer Action Program datasets; six evaluation metrics are applied to eleven comparison models for testing. Results demonstrate that proposed methodology outperforms all of the models against all of the evaluation metrics

Acute-on-chronic Liver Failure: MELD Score 30-day Mortality Predictability and Etiology in a Pakistani Population

Background: Cirrhosis is a pathological condition that ultimately leads to liver failure. Acute on chronic liver failure (ACLF) has a high short term mortality rate. Viral hepatitis is the most common cause of liver failure in our local population. We carried out this study to identity the 30-day mortality and etiology of patients presenting with ACLF using Model for End-Stage Liver Disease (MELD) score predictability. Methodology: This was a descriptive case series, conducted at Sheikh Zayed Hospital, Lahore, Pakistan from January 31, 2018 to July 30, 2018. One hundred and eighty five patients who met the inclusion criteria were enrolled using 95% confidence level and 4% margin of error. Data was entered and analyzed with SPSS version 23.0. Numerical variables including age was presented by Mean ± S.D. Categorical variables i.e. gender, etiology of acute-on-chronic liver failure and 30-day mortality were presented by frequency and percentage. Data was stratified for age, gender, duration of chronic liver disease and MELD grade to address the effect modifiers. Post-stratification chi-square test was calculated using 95% significance (p≤0.05). Results: Majority of the enrolled patients were male (74.6%) while only 25.4% of the patients were female. One hundred and thirty patients (70.3%) had underlying viral hepatitis while twelve patients (6.5%) and forty three patients (23.2%) presented with alcoholic liver disease and drug-induced ACLF, respectively. Eighty patients (43.2%) died within 30 days of admission.The 30-day mortality with respect to MELD grade was statistically significant (p<0.001) with the highest mortality noted in grade-IV and thirty five patients (43.8%) dying within 30 days of admission (p<0.001). Grade-II and III MELD scores also contributed to the 30-day mortality with twenty three patients (28.8%) and nineteen patients (23.8%) dying within 30 days of admission (p<0.001). Conclusion: MELD scores are able to accurately predict the short-term mortality in patients with ACLF and viral hepatitis was the most common etiology in our population. Early detection and use of appropriate prognostic models may alleviate mortality and morbidity in paitents with ACLF

Wet chemical synthesis and characterisation of Ba0.5Sr0.5Ce0.6Zr0.2Gd0.1Y0.1O3 − δ proton conductor

M. N. Khan would like to thank University of Brunei Darussalam for a Graduate Research Scholarship. L.C. Lim and P. Hing thank UBD, and Government of Brunei Darussalam (S&T 17) for a generous research grant under the UBD Energy programme.Ba0.5Sr0.5Ce0.6Zr0.2Gd0.1Y0.1O3 − δ (BSCZGY) proton conducting electrolyte material for intermediate temperature solid oxide fuel cells (IT-SOFCs) has been synthesized by a sol-gel modified Pechini process and its sinterability, thermal expansion, microstructure, ionic conductivity and chemical stability have been investigated. Ionic conductivity at 700 °C was measured to be ~ 8 × 10− 3 S cm− 1 in wet 5 vol.% H2/Ar atmospheres. Chemical stability test in pure CO2 up to 1200 °C shows that the material is highly stable; better than the stability of BaZr0.3Ce0.5Y0.1Yb0.1O3 − δ.PostprintPeer reviewe

Endourological Management of Urolithiasis in Donor Kidneys prior to Renal Transplant

Background. We present our centres successful endourological methodology of ex vivo ureteroscopy (EVFUS) in the management of these kidneys prior to renal transplantation. Patient and Methods. A retrospective analysis was performed of all living donors (n = 157) identified to have asymptomatic incidental renal calculi from January 2004 until December 2008. The incidence of asymptomatic renal calculi was 3.2% (n = 5). Donors were subdivided into 2 groups depending on whether theydonated the kidney with the renal calculus (Group 1) versus the opposite calculus-free kidney (Group 2). Results. All donors in Group 1 underwent a left laparoscopic donor nephrectomy. The calculi were extracted in all 3 cases using a 7.5 Fr flexible ureteroscope either prior to transplant (n = 2) or on revascularization (n = 1). There were no urological complications in either group. At a mean followup at 64 months there was no recurrent calculi formation in the recipient in Group 1. However, 1 recipient formed a calculus in group 2 at a follow up of 72 months. Conclusions. Renal calculi can be successfully retrieved during living-related transplantation at the time of transplant itself using EVUS. This is technically feasible and is associated with no compromise in ureteral integrity or renal allograft function

Techniques - Ultrasound-guided percutaneous nephrolithotomy: How we do it.

Ultrasonography has emerged as an alternative to fluoroscopy for image-guided percutaneous nephrolithotomy (PCNL) in many countries. Compared to fluoroscopy-guided PCNL (F-PCNL), ultrasound-guided PCNL (US-PCNL) is easier to learn and reduces radiation exposure to patients and providers. Despite these advantages, uptake of ultrasound-guided PCNL (US-PCNL) in Canada has been almost nonexistent, largely because it is not incorporated into urologists' training. In this article, we seek to familiarize Canadian urologists with this approach by describing our step-by-step technique for US-PCNL. Additionally, we provide keys to successful implementation of this technique

Tit for tat: Abusive supervision and knowledge hiding - The role of psychological contract breach and psychological ownership

The extant literature has focused on individuals' knowledge-sharing behavior and its driving factors, which stimulate the knowledge transmission and exchange in organizations. However, little research has focused on factors that inhibit knowledge sharing and encourage individuals to hide their knowledge. Therefore, based on social exchange and displaced aggression theories, the study proposed and checked a model that examined the effect of abusive supervision on knowledge hiding (KH) via a psychological contract breach (PCB). The Psychological ownership was regarded as a boundary condition on abusive supervision and KH relationship. Using a time-lagged method, we recruited 344 full-time employees enrolled in an executive development program in a large university in China. The findings show that PCB mediates the association between abusive supervision and KH. Similarly, psychological ownership moderates the association between abusive supervision and KH. Employees with high psychological ownership minimized the effect of abusive supervision on KH. Based on study findings, contributions to theory and practice, limitations, and future directions are discussed

Effect of Moringa oleifera (Lam.) pods as feed additive on egg antioxidants, chemical composition and performance of commercial layers

The present study was designed to investigate the influence of Moringa oleifera (Lam.) pod meal (MPM) on production, immunity, and functional food index of chicken eggs. Two hundred HyLine W36 layer birds aged 50 weeks, 1469 ± 46.63 g, were assigned to four treatments in a completely randomized design, with five replicates and ten birds each. Diets A, B, C, and D were formulated with the same caloric and protein levels, but with differing MPM dose levels of 0, 5, 10, and 15g MPM/kg finisher diet, respectively. Data for production performance, quality, and chemical composition of eggs were analysed by one-way ANOVA, and means were compared with Duncan’s multiple range test. As a result of this study, feed conversion ratio (FCR) and egg mass (EM) were significantly decreased and recorded lowest in Group B, which was offered 5 g/kg above the basal diet. Bioactives such as β-carotene, quercetin, and selenium levels were increased (540, 121, & 72.21μg/100g of yolk, respectively), whereas cholesterol levels in egg yolk and serum were decreased significantly, that is, 201.87 mg/100g and 8.47 mg/dl, respectively. Serum biochemical indicators, including serum glutamic-pyruvic transaminase (SGPT), glucose, creatinine and cholesterol levels, were lowered significantly. Proximate analysis of egg yolk showed that moisture and ether extract were decreased, whereas crude protein (CP), ash and minerals, sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), and phosphorus (P) contents were increased. The outcomes of this study showed that MPM supplementation affects EM, serum biochemistry and bioactive compounds of the egg yolk positively. Keywords: Antibody titers, β-carotene, cholesterol, egg quality, quercetin, seleniu