Dvali-Gabadadze-Porrati Cosmology in Bianchi I brane

The dynamics of Dvali-Gabadadze-Porrati Cosmology (DGP) braneworld with an anisotropic brane is studied. The Friedmann equations and their solutions are obtained for two branches of anisotropic DGP model. The late time behavior in DGP cosmology is examined in the presence of anisotropy which shows that universe enters a self-accelerating phase much later compared to the isotropic case. The acceleration conditions and slow-roll conditions for inflation are obtained

Fresh and mechanical properties of self compacting concrete containing copper slag as fine aggregates

An investigation is carried out on the development of Self Compacting Concrete (SCC) using copper slag (CS) as fine aggregates with partial and full replacement of sand. Six different SCC mixes (60% OPC and 40% Fly Ash) with 0% as control mix, 20%, 40%, 60%, 80% and 100% of copper slag substituting sand with constant w/b ratio of 0.45 were cast and tested for fresh properties of SCC. Compressive strength and splitting tensile strength were evaluated at different ages and microstructural analysis was observed at 120 days. It has been observed that the fluidity of SCC mixes was significantly enhanced with the increment of copper slag. The test results showed that the compressive strength increases up to 60% copper slag as replacement of sand, beyond which decrease in strength was observed. The highest compressive strength was obtained at 20% copper slag substitution at different curing ages among all the mixes, except for 7 days curing. The splitting tensile strength of the CS substituted mixes in comparison to control concrete was found to increase at all the curing ages but the remarkable achievement of strength was detected at 60% copper slag replacement. The microscopic view from Scanning electron microscopy (SEM) demonstrated more voids, capillary channels, and micro cracks with the increment of copper slag as substitution of sand as compared to the control mix

Technologies and solutions for location-based services in smart cities: past, present, and future

Location-based services (LBS) in smart cities have drastically altered the way cities operate, giving a new dimension to the life of citizens. LBS rely on location of a device, where proximity estimation remains at its core. The applications of LBS range from social networking and marketing to vehicle-toeverything communications. In many of these applications, there is an increasing need and trend to learn the physical distance between nearby devices. This paper elaborates upon the current needs of proximity estimation in LBS and compares them against the available Localization and Proximity (LP) finding technologies (LP technologies in short). These technologies are compared for their accuracies and performance based on various different parameters, including latency, energy consumption, security, complexity, and throughput. Hereafter, a classification of these technologies, based on various different smart city applications, is presented. Finally, we discuss some emerging LP technologies that enable proximity estimation in LBS and present some future research areas

Therapeutic hypothermia and ischemic stroke: A literature review

BACKGROUND: Ischemic stroke is the fifth leading cause of death in the US. Clinical techniques aimed at helping to reduce the morbidity associated with stroke have been studied extensively, including therapeutic hypothermia. In this study, the authors review the literature regarding the role of therapeutic hypothermia in ischemic stroke to appreciate the evolution of hypothermia technology over several decades and to critically analyze several early clinical studies to validate its use in ischemic stroke. METHODS: A comprehensive literature search was performed using PubMed and Google Scholar databases. Search terms included hypothermia and ischemic stroke and therapeutic hypothermia. A comprehensive search of the current clinical trials using clinicaltrials.gov was conducted using the keywords stroke and hypothermia to evaluate early and ongoing clinical trials utilizing hypothermia in ischemic stroke. RESULTS: A comprehensive review of the evolution of hypothermia in stroke and the current status of this treatment was performed. Clinical studies were critically analyzed to appreciate their strengths and pitfalls. Ongoing and future registered clinical studies were highlighted and analyzed compared to the reported results of previous trials. CONCLUSION: Although hypothermia has been used for various purposes over several decades, its efficacy in the treatment of ischemic stroke is debatable. Several trials have proven its safety and feasibility; however, more robust, randomized clinical trials with large volumes of patients are needed to fully establish its utility in the clinical setting

Clinicopathological Features of Melanocytic Nevi and Their Correlation to Cutaneous Melanoma among Patients Attending King Abdulaziz University Hospital, Jeddah, Saudi Arabia

Melanocytic nevi (MN) pose diagnostic difficulty due to their heterogeneous clinical, biological and molecular characteristics. Their recognition is also important because cutaneous melanomas are known to arise in pre-existing MN. Aim: This retrospective study aims to examine the clinical features and histopathological types of MN among patients attending King Abdulaziz University Hospital between January 2000 and December 2017. It also aims to examine the correlation of their number to cutaneous melanoma. Materials and Methods: All biopsy specimen data of pigmented skin lesions were collected through an electronic search of the Anatomic Pathology archives. Age, gender and site distribution and histological features were studiedfor different MN and their relation to cutaneous melanoma if associated. Results: MN were most common in the third decade of life affecting females more than males. The most frequent anatomic location was the head region, 176 (45.3%), with face being most frequent site, 45 (25.5%). Histologically the most common MN wasintradermal type accounting for 217 (56%). Two dysplastic nevi and one congenital nevus was associated with cutaneous melanoma. Conclusion: MN most commonly affected patients in their third decade of life .Females were more affected than males. Histologically most MN were of intradermal type and were rarely associated with cutaneous melanoma

Shrink or Substitute: Handling Process Failures in HPC Systems using In-situ Recovery

Efficient utilization of today's high-performance computing (HPC) systems with complex hardware and software components requires that the HPC applications are designed to tolerate process failures at runtime. With low mean time to failure (MTTF) of current and future HPC systems, long running simulations on these systems require capabilities for gracefully handling process failures by the applications themselves. In this paper, we explore the use of fault tolerance extensions to Message Passing Interface (MPI) called user-level failure mitigation (ULFM) for handling process failures without the need to discard the progress made by the application. We explore two alternative recovery strategies, which use ULFM along with application-driven in-memory checkpointing. In the first case, the application is recovered with only the surviving processes, and in the second case, spares are used to replace the failed processes, such that the original configuration of the application is restored. Our experimental results demonstrate that graceful degradation is a viable alternative for recovery in environments where spares may not be available.Comment: 26th Euromicro International Conference on Parallel, Distributed and network-based Processing (PDP 2018