Showing papers by "University of Memphis published in 2019"

Blockchain-Based Decentralized Trust Management in Vehicular Networks

Abstract: Vehicular networks enable vehicles to generate and broadcast messages in order to improve traffic safety and efficiency. However, due to the nontrusted environments, it is difficult for vehicles to evaluate the credibilities of received messages. In this paper, we propose a decentralized trust management system in vehicular networks based on blockchain techniques. In this system, vehicles can validate the received messages from neighboring vehicles using Bayesian Inference Model. Based on the validation result, the vehicle will generate a rating for each message source vehicle. With the ratings uploaded from vehicles, roadside units (RSUs) calculate the trust value offsets of involved vehicles and pack these data into a “block.” Then, each RSU will try to add their “blocks” to the trust blockchain which is maintained by all the RSUs. By employing the joint proof-of-work (PoW) and proof-of-stake consensus mechanism, the more total value of offsets (stake) is in the block, the easier RSU can find the nonce for the hash function (PoW). In this way, all RSUs collaboratively maintain an updated, reliable, and consistent trust blockchain. Simulation results reveal that the proposed system is effective and feasible in collecting, calculating, and storing trust values in vehicular networks.

The evolution and genomic basis of beetle diversity.

Abstract: The order Coleoptera (beetles) is arguably the most speciose group of animals, but the evolutionary history of beetles, including the impacts of plant feeding (herbivory) on beetle diversification, remain poorly understood. We inferred the phylogeny of beetles using 4,818 genes for 146 species, estimated timing and rates of beetle diversification using 89 genes for 521 species representing all major lineages and traced the evolution of beetle genes enabling symbiont-independent digestion of lignocellulose using 154 genomes or transcriptomes. Phylogenomic analyses of these uniquely comprehensive datasets resolved previously controversial beetle relationships, dated the origin of Coleoptera to the Carboniferous, and supported the codiversification of beetles and angiosperms. Moreover, plant cell wall-degrading enzymes (PCWDEs) obtained from bacteria and fungi via horizontal gene transfers may have been key to the Mesozoic diversification of herbivorous beetles—remarkably, both major independent origins of specialized herbivory in beetles coincide with the first appearances of an arsenal of PCWDEs encoded in their genomes. Furthermore, corresponding (Jurassic) diversification rate increases suggest that these novel genes triggered adaptive radiations that resulted in nearly half of all living beetle species. We propose that PCWDEs enabled efficient digestion of plant tissues, including lignocellulose in cell walls, facilitating the evolution of uniquely specialized plant-feeding habits, such as leaf mining and stem and wood boring. Beetle diversity thus appears to have resulted from multiple factors, including low extinction rates over a long evolutionary history, codiversification with angiosperms, and adaptive radiations of specialized herbivorous beetles following convergent horizontal transfers of microbial genes encoding PCWDEs.

The Potential of Additive Manufacturing in the Smart Factory Industrial 4.0: A Review

Abstract: Additive manufacturing (AM) or three-dimensional (3D) printing has introduced a novel production method in design, manufacturing, and distribution to end-users. This technology has provided great freedom in design for creating complex components, highly customizable products, and efficient waste minimization. The last industrial revolution, namely industry 4.0, employs the integration of smart manufacturing systems and developed information technologies. Accordingly, AM plays a principal role in industry 4.0 thanks to numerous benefits, such as time and material saving, rapid prototyping, high efficiency, and decentralized production methods. This review paper is to organize a comprehensive study on AM technology and present the latest achievements and industrial applications. Besides that, this paper investigates the sustainability dimensions of the AM process and the added values in economic, social, and environment sections. Finally, the paper concludes by pointing out the future trend of AM in technology, applications, and materials aspects that have the potential to come up with new ideas for the future of AM explorations.

A fully resolved backbone phylogeny reveals numerous dispersals and explosive diversifications throughout the history of Asteraceae

Abstract: The sunflower family, Asteraceae, comprises 10% of all flowering plant species and displays an incredible diversity of form. Asteraceae are clearly monophyletic, yet resolving phylogenetic relationships within the family has proven difficult, hindering our ability to understand its origin and diversification. Recent molecular clock dating has suggested a Cretaceous origin, but the lack of deep sampling of many genes and representative taxa from across the family has impeded the resolution of migration routes and diversifications that led to its global distribution and tremendous diversity. Here we use genomic data from 256 terminals to estimate evolutionary relationships, timing of diversification(s), and biogeographic patterns. Our study places the origin of Asteraceae at ∼83 MYA in the late Cretaceous and reveals that the family underwent a series of explosive radiations during the Eocene which were accompanied by accelerations in diversification rates. The lineages that gave rise to nearly 95% of extant species originated and began diversifying during the middle Eocene, coincident with the ensuing marked cooling during this period. Phylogenetic and biogeographic analyses support a South American origin of the family with subsequent dispersals into North America and then to Asia and Africa, later followed by multiple worldwide dispersals in many directions. The rapid mid-Eocene diversification is aligned with the biogeographic range shift to Africa where many of the modern-day tribes appear to have originated. Our robust phylogeny provides a framework for future studies aimed at understanding the role of the macroevolutionary patterns and processes that generated the enormous species diversity of Asteraceae.

Sunflower pan-genome analysis shows that hybridization altered gene content and disease resistance

Abstract: Domesticated plants and animals often display dramatic responses to selection, but the origins of the genetic diversity underlying these responses remain poorly understood. Despite domestication and improvement bottlenecks, the cultivated sunflower remains highly variable genetically, possibly due to hybridization with wild relatives. To characterize genetic diversity in the sunflower and to quantify contributions from wild relatives, we sequenced 287 cultivated lines, 17 Native American landraces and 189 wild accessions representing 11 compatible wild species. Cultivar sequences failing to map to the sunflower reference were assembled de novo for each genotype to determine the gene repertoire, or 'pan-genome', of the cultivated sunflower. Assembled genes were then compared to the wild species to estimate origins. Results indicate that the cultivated sunflower pan-genome comprises 61,205 genes, of which 27% vary across genotypes. Approximately 10% of the cultivated sunflower pan-genome is derived through introgression from wild sunflower species, and 1.5% of genes originated solely through introgression. Gene ontology functional analyses further indicate that genes associated with biotic resistance are over-represented among introgressed regions, an observation consistent with breeding records. Analyses of allelic variation associated with downy mildew resistance provide an example in which such introgressions have contributed to resistance to a globally challenging disease.

Enabling Efficient and Geometric Range Query With Access Control Over Encrypted Spatial Data

Abstract: As a basic query function, range query has been exploited in many scenarios such as SQL retrieves, location-based services, and computational geometry Meanwhile, with explosive growth of data volume, users are increasingly inclining to store data on the cloud for saving local storage and computational cost However, a long-standing problem is that the user’s data may be completely revealed to the cloud server because it has full data access right To cope with this problem, a frequently-used method is to encrypt raw data before outsourcing them, but the availability and operability of data will be reduced significantly In this paper, we propose an efficient and geometric range query scheme (EGRQ) supporting searching and data access control over encrypted spatial data We employ secure KNN computation, polynomial fitting technique, and order-preserving encryption to achieve secure, efficient, and accurate geometric range query over cloud data Then, we propose a novel spatial data access control strategy to refine user’s rights in our EGRQ To improve the efficiency, R-tree is adopted to reduce the searching space and matching times in whole search process Finally, we theoretically prove the security of our proposed scheme in terms of confidentiality of spatial data, privacy protection of index and trapdoor, and the unlinkability of trapdoors In addition, extensive experiments demonstrate the high efficiency of our proposed model compared with existing schemes

A Selective Review of Multi-Level Omics Data Integration Using Variable Selection.

Abstract: High-throughput technologies have been used to generate a large amount of omics data. In the past, single-level analysis has been extensively conducted where the omics measurements at different levels, including mRNA, microRNA, CNV and DNA methylation, are analyzed separately. As the molecular complexity of disease etiology exists at all different levels, integrative analysis offers an effective way to borrow strength across multi-level omics data and can be more powerful than single level analysis. In this article, we focus on reviewing existing multi-omics integration studies by paying special attention to variable selection methods. We first summarize published reviews on integrating multi-level omics data. Next, after a brief overview on variable selection methods, we review existing supervised, semi-supervised and unsupervised integrative analyses within parallel and hierarchical integration studies, respectively. The strength and limitations of the methods are discussed in detail. No existing integration method can dominate the rest. The computation aspects are also investigated. The review concludes with possible limitations and future directions for multi-level omics data integration.

Epigenome-wide meta-analysis of DNA methylation and childhood asthma

Abstract: Background Epigenetic mechanisms, including methylation, can contribute to childhood asthma. Identifying DNA methylation profiles in asthmatic patients can inform disease pathogenesis. Objective We sought to identify differential DNA methylation in newborns and children related to childhood asthma. Methods Within the Pregnancy And Childhood Epigenetics consortium, we performed epigenome-wide meta-analyses of school-age asthma in relation to CpG methylation (Illumina450K) in blood measured either in newborns, in prospective analyses, or cross-sectionally in school-aged children. We also identified differentially methylated regions. Results In newborns (8 cohorts, 668 cases), 9 CpGs (and 35 regions) were differentially methylated (epigenome-wide significance, false discovery rate Conclusion Novel loci differentially methylated in newborns represent potential biomarkers of risk of asthma by school age. Cross-sectional associations in children can reflect both risk for and effects of disease. Asthma-related differential methylation in blood in children was substantially replicated in eosinophils and respiratory epithelium.

Stimuli-Responsive Drug Release from Smart Polymers

Abstract: Over the past 10 years, stimuli-responsive polymeric biomaterials have emerged as effective systems for the delivery of therapeutics. Persistent with ongoing efforts to minimize adverse effects, stimuli-responsive biomaterials are designed to release in response to either chemical, physical, or biological triggers. The stimuli-responsiveness of smart biomaterials may improve spatiotemporal specificity of release. The material design may be used to tailor smart polymers to release a drug when particular stimuli are present. Smart biomaterials may use internal or external stimuli as triggering mechanisms. Internal stimuli-responsive smart biomaterials include those that respond to specific enzymes or changes in microenvironment pH; external stimuli can consist of electromagnetic, light, or acoustic energy; with some smart biomaterials responding to multiple stimuli. This review looks at current and evolving stimuli-responsive polymeric biomaterials in their proposed applications.

Meta-analysis of epigenome-wide association studies in neonates reveals widespread differential DNA methylation associated with birthweight

Abstract: Birthweight is associated with health outcomes across the life course, DNA methylation may be an underlying mechanism. In this meta-analysis of epigenome-wide association studies of 8,825 neonates from 24 birth cohorts in the Pregnancy And Childhood Epigenetics Consortium, we find that DNA methylation in neonatal blood is associated with birthweight at 914 sites, with a difference in birthweight ranging from -183 to 178 grams per 10% increase in methylation (PBonferroni < 1.06 x 10-7). In additional analyses in 7,278 participants, <1.3% of birthweight-associated differential methylation is also observed in childhood and adolescence, but not adulthood. Birthweight-related CpGs overlap with some Bonferroni-significant CpGs that were previously reported to be related to maternal smoking (55/914, p = 6.12 x 10-74) and BMI in pregnancy (3/914, p = 1.13x10-3), but not with those related to folate levels in pregnancy. Whether the associations that we observe are causal or explained by confounding or fetal growth influencing DNA methylation (i.e. reverse causality) requires further research.

Comparative financing analysis and political economy of noncommunicable diseases.

Abstract: The pandemic of chronic non-communicable diseases (NCDs) poses substantial challenges to the health financing sustainability in high-income and low/middle income countries (LMICs). The aim of this review is to identify the bottle neck inefficiencies in NCDs attributable spending and propose sustainable health financing solutions. The World Health Organization (WHO) introduced the "best buy" concept to scale up the core intervention package against NCDs targeted for LMICs. Population- and individual-based NCD best buy interventions are projected at US$170 billion over 2011-2025. Appropriately designed health financing arrangements can be powerful enablers to scale up the NCD best buys. Rapidly developing emerging nations dominate the landscape of LMICs. Their capability and willingness to invest resources for eradicating NCDs could strengthen WHO outreach efforts in Asia, Africa, and Latin America, much beyond current capacities. There has been a declining trend in international donor aid intended to cope with NCDs over the past decade. There is also a serious misalignment of these resources with the actual needs of recipient countries. Globally, the momentum towards the financing of intersectoral actions is growing, and this presents a cost-effective solution. A budget discrepancy of 10:1 in WHO and multilateral agencies remains in donor aid in favour of communicable diseases compared to NCDs. LMICs are likely to remain a bottleneck of NCDs imposed financing sustainability challenge in the long-run. Catastrophic household health expenditure from out of pocket spending on NCDs could plunge almost 150 million people into poverty worldwide. This epidemiological burden coupled with population ageing presents an exceptionally serious sustainability challenge, even among the richest countries which are members of the Organization for Economic Co-operation and Development (OECD). Strategic and political leadership of WHO and multilateral agencies would likely play essential roles in the struggle that has just begun.

A survey of blockchain from security perspective

Abstract: The report starts with an overview of the blockchain security system and then highlights the specific security threats and summarizes them. We review with some comments and possible research direction. This survey, we examines the security issues of blockchain model related technologies and their applications. The blockchain is considered a still growing like the internet in 1990. It has the potential to disrupt so many technology areas in the future. But as a new underdeveloped field, it is suffering many setbacks mostly resulting from the security area. Its security concerns coming not only from distributed/decentralized computing issue or Cryptography algorithm issue, from some unexpected field too. Here, in this paper, we tried to classify the security concerns for the blockchain based on our survey from recent research papers. We also tried to show which way blockchain development trends are going.

The development of the Awe Experience Scale (AWE-S): A multifactorial measure for a complex emotion

Abstract: Awe is a complex emotion composed of an appraisal of vastness and a need for accommodation The purpose of this study was to develop a robust state measure of awe, the Awe Experience Scale (AWE-S),

IoMT-SAF: Internet of Medical Things Security Assessment Framework

Abstract: The emergence of the Internet of Medical Things (IoMT) has introduced a monumental change in facilitating the management of diseases, improving diseases diagnosis and treatment methods, and reducing healthcare cost and errors. This change has greatly impacted the quality of healthcare for both patients and all frontline healthcare workers. However, the IoMT is far from being immune to security and privacy breaches due to the wide variety IoMT vendors and products available on the market as well as the massive number of devices transmitting sensitive medical data wirelessly to the cloud. The lack of security awareness among healthcare users (e.g., patients, medical staff) aggravates the deficiencies and can facilitate attacks that jeopardize the patients’ lives. Therefore, ensuring the security and privacy of the IoMT becomes an urgent issue worthy of further investigation and resolution. Security cannot be planned for, managed, monitored, or controlled if it cannot be measured. However, security assessment poses problems for novice IoMT adopters when choosing security measures that are both sufficient and robust. Accordingly, we developed a web-based IoMT Security Assessment Framework (IoMT-SAF) based on a novel ontological scenario-based approach to recommend security features in IoMT and assess protection and deterrence in IoMT solutions. IoMT-SAF supports the selection of a solution that matches the stakeholder's security objectives and supports the decision-making process. The novelty of IoMT-SAF lies in its granularity, extensibility, as well as its ability to adapt to new stakeholders, and conformance to technology and medical standards.

Fe3O4 Nanoparticles Dispersed on Douglas Fir Biochar for Phosphate Sorption

Abstract: Surface area, particle aggregation, pressure drop in columns, nanotoxicity, and commercialization difficulties limit the use of nanoparticle adsorbents. Magnetic primary nano-Fe3O4 particles (∼16.7...

Are the Quantity and Quality of Sustainability Disclosures Associated with the Innate and Discretionary Earnings Quality

Abstract: Voluntary disclosures of sustainability information have recently received considerable attention by investors, regulators, and public companies in improving reliability and integrity of corporate reporting. We examine the association between the quantity and quality of sustainability disclosures and earnings quality in the context of corporate ethical value and culture. We posit that sustainability disclosures of environmental, social, and governance (ESG) performance reports are linked to earnings quality, because of the importance of both earnings quality and ESG sustainability disclosures to investors and trustworthiness of corporate reporting. We collect our sample of 35,110 firm-year observations between 1999 and 2015. Using both difference-in-difference tests and OLS regression, we find that sustainability disclosure quantity is positively associated with innate earnings quality and negatively correlated with discretionary earnings quality in mitigating managerial earnings manipulation and unethical opportunistic reporting behavior. Further tests illustrate that sustainability disclosure quality can strengthen the positive relation between innate earnings quality and sustainability disclosure quantity and mitigate the negative relation between discretionary earnings quality and sustainability disclosure quantity. Finally, additional tests suggest that the relation between earnings quality and sustainability disclosure quantity is moderated by corporate structure and prior-year sustainability performance. Our results provide policy, practical, and research implications as ESG sustainability reporting is being integrated into corporate culture and business models.

KDD Cup 99 Data Sets: A Perspective on the Role of Data Sets in Network Intrusion Detection Research

Abstract: Many consider the KDD Cup 99 data sets to be outdated and inadequate. Therefore, the extensive use of these data sets in recent studies to evaluate network intrusion detection systems is a matter of concern. We contribute to the literature by addressing these concerns.

Meaning reconstruction in bereavement: Development of a research program

Abstract: The death of a significant person, especially when it comes tragically or prematurely, can shake the foundations of our assumptive and relational world and lead to anguished attempts to find meaning in the loss and in our lives in its aftermath. In this article, I review one program of research focused on this attempt at meaning reconstruction, describe recently developed measures of meaning in mourning, and discuss several therapeutic techniques for helping clients make sense of the death and rework their attachment relationship to the deceased. I conclude by illustrating some of this work in my therapy with a couple grieving the loss of not one but two children to tragic accidents, as they try to adapt to a compound traumatic bereavement.

Data Security Issues in Deep Learning: Attacks, Countermeasures, and Opportunities

Abstract: Benefiting from the advancement of algorithms in massive data and powerful computing resources, deep learning has been explored in a wide variety of fields and produced unparalleled performance results. It plays a vital role in daily applications and is also subtly changing the rules, habits, and behaviors of society. However, inevitably, data-based learning strategies are bound to cause potential security and privacy threats, and arouse public as well as government concerns about its promotion to the real world. In this article, we mainly focus on data security issues in deep learning. We first investigate the potential threats of deep learning in this area, and then present the latest countermeasures based on various underlying technologies, where the challenges and research opportunities on offense and defense are also discussed. Then, we propose SecureNet, the first verifiable and privacy-preserving prediction protocol to protect model integrity and user privacy in DNNs. It can significantly resist various security and privacy threats during the prediction process. We simulate SecureNet under a real dataset, and the experimental results show the superior performance of SecureNet for detecting various integrity attacks against DNN models.

Coating Techniques for Functional Enhancement of Metal Implants for Bone Replacement: A Review

Abstract: To facilitate patient healing in injuries and bone fractures, metallic implants have been in use for a long time. As metallic biomaterials have offered desirable mechanical strength higher than the stiffness of human bone, they have maintained their place. However, in many case studies, it has been observed that these metallic biomaterials undergo a series of corrosion reactions in human body fluid. The products of these reactions are released metallic ions, which are toxic in high dosages. On the other hand, as these metallic implants have different material structures and compositions than that of human bone, the process of healing takes a longer time and bone/implant interface forms slower. To resolve this issue, researchers have proposed depositing coatings, such as hydroxyapatite (HA), polycaprolactone (PCL), metallic oxides (e.g., TiO2, Al2O3), etc., on implant substrates in order to enhance bone/implant interaction while covering the substrate from corrosion. Due to many useful HA characteristics, the outcome of various studies has proved that after coating with HA, the implants enjoy enhanced corrosion resistance and less metallic ion release while the bone ingrowth has been increased. As a result, a significant reduction in patient healing time with less loss of mechanical strength of implants has been achieved. Some of the most reliable coating processes for biomaterials, to date, capable of depositing HA on implant substrate are known as sol-gel, high-velocity oxy-fuel-based deposition, plasma spraying, and electrochemical coatings. In this article, all these coating methods are categorized and investigated, and a comparative study of these techniques is presented.

The rhythm of memory: how breathing shapes memory function

Abstract: The mammalian olfactory bulb displays a prominent respiratory rhythm, which is linked to the sniff cycle and is driven by sensory input from olfactory receptors in the nasal sensory epithelium. In rats and mice, respiratory frequencies occupy the same band as the hippocampal θ-rhythm, which has been shown to be a key player in memory processes. Hippocampal and olfactory bulb rhythms were previously found to be uncorrelated except in specific odor-contingency learning circumstances. However, many recent electrophysiological studies in both rodents and humans reveal a surprising cycle-by-cycle influence of nasal respiration on neuronal activity throughout much of the cerebral cortex beyond the olfactory system, including the prefrontal cortex, hippocampus, and subcortical structures. In addition, respiratory phase has been shown to influence higher-frequency oscillations associated with cognitive functions, including attention and memory, such as the power of γ-rhythms and the timing of hippocampal sharp wave ripples. These new findings support respiration's role in cognitive function, which is supported by studies in human subjects, in which nasal respiration has been linked to memory processes. Here, we review recent reports from human and rodent experiments that link respiration to the modulation of memory function and the neurophysiological processes involved in memory in rodents and humans. We argue that respiratory influence on the neuronal activity of two key memory structures, the hippocampus and prefrontal cortex, provides a potential neuronal mechanism behind respiratory modulation of memory.

Design and Design Thinking in STEM Education

Abstract: Design and design thinking are vital to creativity and innovation, and have become increasingly important in the current movement of developing and implementing integrated STEM education. In this editorial, we build on existing research on design and design thinking, and discuss how students’ learning and design thinking can be developed through design activities in not only engineering and technology, but also other disciplines as well as integrated STEM education.

Conserved transcriptomic profiles underpin monogamy across vertebrates.

Abstract: Social monogamy, typically characterized by the formation of a pair bond, increased territorial defense, and often biparental care, has independently evolved multiple times in animals. Despite the independent evolutionary origins of monogamous mating systems, several homologous brain regions and neuropeptides and their receptors have been shown to play a conserved role in regulating social affiliation and parental care, but little is known about the neuromolecular mechanisms underlying monogamy on a genomic scale. Here, we compare neural transcriptomes of reproductive males in monogamous and nonmonogamous species pairs of Peromyscus mice, Microtus voles, parid songbirds, dendrobatid frogs, and Xenotilapia species of cichlid fishes. We find that, while evolutionary divergence time between species or clades did not explain gene expression similarity, characteristics of the mating system correlated with neural gene expression patterns, and neural gene expression varied concordantly across vertebrates when species transition to monogamy. Our study provides evidence of a universal transcriptomic mechanism underlying the evolution of monogamy in vertebrates.