Age effect on presence, susceptibility and treatment of erosive tooth wear

Indiana University-Purdue University Indianapolis (IUPUI)Erosive tooth wear (ETW) is a growing dental condition often associated with aging. This in-vitro project comprised three studies aiming to investigate the impact of tooth age on ETW susceptibility and prevention. In the first study, un-identified extracted premolars were collected and had their ages estimated using validated dental forensic methods. The premolars were examined to investigate the relationship between age and presence and severity of ETW, as well as other main dental-hard tissues conditions. ETW, dental caries, fluorosis, extrinsic staining and tooth color were evaluated using established clinical indices. In the second study, the tooth age impact on ETW susceptibility and response to preventive treatments (Sn+F, NaF, and de-ionized water control) were evaluated using representative samples from the initial study. Enamel and dentin specimens were prepared and subjected to daily erosion-treatmentremineralization cycling procedure. Surface loss (SL) was determined during and after the cycling, by optical profilometry. Similar protocol was adopted in the third study with the addition of toothbrushing abrasion to the model, in order to explore the interplay between age and toothpaste abrasivity on erosion-abrasion development. SL was measured during and after the erosion-toothbrushing-remineralization cycling. The relationships between age and the investigated variables were assessed using linear regression models. In conclusion: 1. The presence and severity of ETW, dental caries, and extrinsic staining increased with age, while of enamel fluorosis decreased. Tooth also showed to be darker with age. 2. Susceptibility of enamel and dentin to demineralization increased with age. Sn+F showed the highest anti-erosive efficacy, and was not affected by age. NaF showed lower efficacy on dentin, which increased with age. 3. Enamel and dentin SL increased with toothpaste abrasivity level. Dentin SL also increased with age. Age effect on enamel SL was observed only with low abrasive toothpaste. Age-related changes on enamel and dentin affected ETW development.2020-05-1

Policing internet fraud in Saudi Arabia : the mediation of risk in a theocratic society

This thesis aims to contribute to current debates on the policing of Internet fraud by introducing the Saudi Arabian experience. Drawing on the findings of field research focusing on the capital city of Riyadh, this study assesses the extent to which the Saudi state response to Internet fraud fits in with contemporary debates on cybercrime control within a late-modern penal framework as theorised in Western literature. At the same time, the study provides a detailed micro-sociological account of how the policing of Internet fraud is carried out in different police units within the city in which the case study was conducted. This involves an in-depth investigation into both the organisational and operational dimensions of the Saudi police response to such criminal activity. In this respect, the thesis explores and analyses how this new aspect of policing activity fits in with not only the existing organisational practices, but also the occupational and individual concerns of frontline officers (McCahill, 2002). Moreover, the study considers the implications of the Arab, Islamic and specifically Saudi culture, social norms, values and political environment for police responses to Internet fraud.An interpretive approach was adopted, employing a single case study strategy, which utilised two methods, i.e. participant observation and semi- structured interviews, to collect the required data. The observational data was generated from seven police departments that are directly involved in the policing of Internet fraud in Riyadh. Interviews were conducted with 41 participants, including representatives of both the managerial and operational levels at the units targeted in the observational work, officers from supporting departments and officers with key roles in planning, controlling and supervising the implementation of police policies and strategies in relation to Internet fraud, at both national and local levels.The findings revealed that the only way in which Saudi control strategies in response to cybercrime can be aligned with those followed by Western authorities is in relation to the state’s ‘expressive gestures’ (Garland, 1996, 2001). In this regard, evidence demonstrated that the legal and organisational innovations introduced by the Saudi state, ostensibly to address informational crimes, had serious limitations in achieving their declared purposes and were perceived by police participants as intended only to create and sustain a favourable global image. In contrast, the study failed to find a clear and wide application of plural policing of Internet fraud, which is characterised by networks of calculation through deploying instrumental ordering practices and risk management technologies. In addition to the limited relevance in an autocratic society such as Saudi Arabia of the ideological, socio-economic and political conditions that facilitated the emergence of the notion of plural policing in Western societies, the Saudi police organisation also appeared unready to engage in networked policing of Internet fraud.Moreover, it was shown how the policing response to Internet fraud was shaped by specific moral principles and cultural values. The findings of this thesis emphasise not only the persistent influence of ‘old’ cultural traditions and moral principles on officers’ perception of risk in Internet fraud and, consequently, their decision to respond to incidents brought to their attention, but also how police commitment to these cultural and religious values can place limits on the ability of technological systems to facilitate preventive policing of online fraudulent activities. Based on these findings, it is argued that policing of Internet fraud in Saudi Arabia, and the extent to which it aligns with the principles of crime control in late modernity, can only be understood by examining and analysing how new policing modes and cultural traditions merge and integrate to shape police response to such a novel criminal phenomenon as Internet fraud

Quantitative economics of security: software vulnerabilities and data breaches

Includes bibliographical references.2016 Summer.Security vulnerabilities can represent enormous risks to society and business organizations. A large percentage of vulnerabilities in software are discovered by individuals external to the developing organization. These vulnerabilities are often exchanged for monetary rewards or a negotiated selling price, giving rise to vulnerability markets. Some of these markets are regulated, while some are unregulated. Many buyers in the unregulated markets include individuals, groups, or government organizations who intend to use the vulnerabilities for potential attacks. Vulnerabilities traded through such markets can cause great economic, organizational, and national security risks. Vulnerability markets can reduce risks if the vulnerabilities are acquitted and remedied by the software developers. Studying vulnerability markets and their related issues will provide an insight into their underlying mechanisms, which can be used to assess the risks and develop approaches for reducing and mitigating the potential risks to enhance the security against the data breaches. Some of the aspects of vulnerability—discovery, dissemination, and disclosure—have received some recent attention. However, the role of interaction among the vulnerability discoverers and vulnerability acquirers has not yet been adequately addressed. This dissertation suggests that a major fraction of discoverers, a majority in some cases, are unaffiliated with the software developers and thus are free to disseminate the vulnerabilities they discover in any way they like. As a result, multiple vulnerability markets have emerged. In recent vulnerability discovery literature, the vulnerability discoverers have remained anonymous. Although there has been an attempt to model the level of their efforts, information regarding their identities, modes of operation, and what they are doing with the discovered vulnerabilities has not been explored. Reports of buying and selling the vulnerabilities are now appearing in the press; however, the nature of the actual vulnerability markets needs to be analyzed. We have attempted to collect detailed information. We have identified the most prolific vulnerability discoverers throughout the past decade and examined their motivation and methods. A large percentage of these discoverers are located outside of the US. We have contacted several of the most prolific discoverers in order to collect firsthand information regarding their techniques, motivations, and involvement in the vulnerability markets. We examine why many of the discoverers appear to retire after a highly successful vulnerability-finding career. We found that the discoverers had enough experience and good reputation to work officially with a good salary in some well- known software development companies. Many security breaches have been reported in the past few years, impacting both large and small organizations. Such breaches may occur through the exploitation of system vulnerabilities. There has been considerable disagreement about the overall cost and probability of such breaches. No significant formal studies have yet addressed this issue of risk assessment, though some proprietary approaches for evaluating partial data breach costs and probabilities have been implemented. These approaches have not been formally evaluated or compared and have not been systematically optimized. This study proposes a consolidated approach for identifying key factors contributing to the breach cost by minimizing redundancy among the factors. Existing approaches have been evaluated using the data from some of the well-documented breaches. It is noted that the existing models yield widely different estimates. The reasons for this variation are examined and the need for better models is identified. A complete computational model for estimating the costs and probabilities of data breaches for a given organization has been developed. We consider both the fixed and variable costs and the economy of scale. Assessing the impact of data breaches will allow organizations to assess the risks due to potential breaches and to determine the optimal level of resources and effort needed for achieving target levels of security

Autonomous Vehicles:The Cybersecurity Vulnerabilities and Countermeasures for Big Data Communication

The possible applications of communication based on big data have steadily increased in several industries, such as the autonomous vehicle industry, with a corresponding increase in security challenges, including cybersecurity vulnerabilities (CVs). The cybersecurity-related symmetry of big data communication systems used in autonomous vehicles may raise more vulnerabilities in the data communication process between these vehicles and IoT devices. The data involved in the CVs may be encrypted using an asymmetric and symmetric algorithm. Autonomous vehicles with proactive cybersecurity solutions, power-based cyberattacks, and dynamic countermeasures are the modern issues/developments with emerging technology and evolving attacks. Research on big data has been primarily focused on mitigating CVs and minimizing big data breaches using appropriate countermeasures known as security solutions. In the future, CVs in data communication between autonomous vehicles (DCAV), the weaknesses of autonomous vehicular networks (AVN), and cyber threats to network functions form the primary security issues in big data communication, AVN, and DCAV. Therefore, efficient countermeasure models and security algorithms are required to minimize CVs and data breaches. As a technique, policies and rules of CVs with proxy and demilitarized zone (DMZ) servers were combined to enhance the efficiency of the countermeasure. In this study, we propose an information security approach that depends on the increasing energy levels of attacks and CVs by identifying the energy levels of each attack. To show the results of the performance of our proposed countermeasure, CV and energy consumption are compared with different attacks. Thus, the countermeasures can secure big data communication and DCAV using security algorithms related to cybersecurity and effectively prevent CVs and big data breaches during data communication

Susceptibility to Social Engineering in Social Networking Sites: The Case of Facebook

Past research has suggested that social engineering poses the most significant security risk. Recent studies have suggested that social networking sites (SNSs) are the most common source of social engineering attacks. The risk of social engineering attacks in SNSs is associated with the difficulty of making accurate judgments regarding source credibility in the virtual environment of SNSs. In this paper, we quantitatively investigate source credibility dimensions in terms of social engineering on Facebook, as well as the source characteristics that influence Facebook users to judge an attacker as credible, therefore making them susceptible to victimization. Moreover, in order to predict users’ susceptibility to social engineering victimization based on their demographics, we investigate the effectiveness of source characteristics on different demographic groups by measuring the consent intentions and behavior responses of users to social engineering requests using a role-play experiment

Efficacy of stannous, fluoride and their their combination in dentin erosion prevention in vitro

The aim of this study was to compare the protective effects of solutions containing stannous (Sn), fluoride (F) and their combination in the prevention of dentin erosion. Forty bovine root dentin specimens (4’4’2 mm3) were prepared and randomly assigned to 4 groups (n = 10): SnCl2 (800 ppm/6.7 mM Sn), NaF (250 ppm/13 mM F), NaF/SnCl2 (800 ppm/6.7 mM Sn; 250 ppm/13 mM F), and deionized water (DIW) as a negative control. An acquired pellicle was formed on dentin samples by incubation in clarified, pooled, stimulated human saliva for 24 hours. The specimens were subjected to 5 daily cycles, each consisting of 5 of min demineralization (0.3%/15.6 mM citric acid, pH 2.6, 6’/day) and 60 min of re-mineralization in clarified human saliva. Thirty minutes after the 1st, 3rd and 5th demineralization episodes of each day, the specimens were treated with one of the test solutions for 2 min. Surface loss was measured via optical profilometry. Mixed-model ANOVA followed by Tukey’s test were used for the statistical analysis. Sn, F, and their combination significantly reduced the dentin surface loss by 23%, 36%, and 60% compared with DIW, respectively. All groups were significantly different (p < 0.05). The combination of Sn and F significantly reduced the amount of dentin surface loss compared with all other groups. The F group also significantly reduced surface loss compared with Sn and DIW, followed by the Sn group, which showed significantly greater protection compared with the DIW control. The daily use of a combined fluoride and stannous solution is promising for preventing dentin erosion

Character-level word encoding deep learning model for combating cyber threats in phishing URL detection

A cyber threat is generally a malicious activity that damages or steals data, or something that disrupts digital life. Such threats include viruses, security breaches, DoS attacks, and data theft. Phishing is a type of cyber threat whereby the attackers mimic a genuine URL or a webpage and steal user data, 21% fall into the phishing category. The novel approach of using the character-level encoding of URLs is introduced. Unlike word-level encoding, the use of character-level encoding decreases the discrete workspace and can be effective even in an energy-constrained environment. The experimental results of comparisons to other state-of-the-art methods demonstrate that the proposed method achieved 98.12% of true positive instances. Moreover, Conclusions: An experimental evaluation was performed to demonstrate the efficiency, and it was observed that the accuracy reached an all-time high of 98.13%. the experiments prove that the proposed method can operate efficiently even in energy-saving modes of phishing detection systems

Market orientation in higher education and innovativeness as a mediating variable

Market orientation (MO) is an operationalization of a marketing concept and considered vital to enhance organization profitability and sustainability especially for businesses. However, efforts to investigate MO in the educational context have not been extensively conducted in comparison to those in the business settings. This research assessed the influence of top management emphasis and internal market orientation (IMO) as antecedents to MO in higher education institutions (HEIs). It also examined the effect of IMO and MO on HEIs perceived performance. In addition, the mediation role of innovativeness to the relationship of MO and perceived performance was investigated. The unit of analysis in this research was an educational institution that provides tertiary education under the supervision of the Ministry of Education in Saudi Arabia. In this quantitative cross sectional study, the whole population was targeted and data was collected online. There were 263 usable responses from 537, representing 48.97% response rate. The findings of this research indicated that there is a positive relationship between top management emphasis and IMO, as well as with MO. Results also showed that IMO was found to be positively related to MO. On the contrary, the relationship between IMO and HEIs perceived performance was found to be insignificant. Besides that, the study disclosed that MO is positively related to HEIs perceived performance. In this study, innovativeness was found to be partially mediating the relationship between MO and perceived performance. The research has illustrated the application of MO in the educational setting of a developing country. Additionally, the findings of the study will help academic managers and education policy makers in Saudi Arabia to develop market oriented strategies to improve HEIs performance

A Machine Learning Framework for Optimising File Distribution Across Multiple Cloud Storage Services

Storing data using a single cloud storage service may lead to several potential problems for the data owner. Such issues include service continuity, availability, performance, security, and the risk of vendor lock-in. A promising solution is to distribute the data across multiple cloud storage services , similarly to the manner in which data are distributed across multiple physical disk drives to achieve fault tolerance and to improve performance . However, the distinguishing characteristics of different cloud providers, in term of pricing schemes and service performance, make optimising the cost and performance across many cloud storage services at once a challenge. This research proposes a framework for automatically tuning the data distribution policies across multiple cloud storage services from the client side, based on file access patterns. The aim of this work is to explore the optimisation of both the average cost per gigabyte and the average service performance (mainly latency time) on multiple cloud storage services . To achieve these aims, two machine learning algorithms were used: 1. supervised learning to predict file access patterns. 2. reinforcement learning to learn the ideal file distribution parameters. File distribution over several cloud storage services . The framework was tested in a cloud storage services emulator, which emulated a real multiple-cloud storage services setting (such as Google Cloud Storage, Amazon S3, Microsoft Azure Storage, and Rack- Space file cloud) in terms of service performance and cost. In addition, the framework was tested in various settings of several cloud storage services. The results of testing the framework showed that the multiple cloud approach achieved an improvement of about 42% for cost and 76% for performance. These findings indicate that storing data in multiple clouds is a superior approach, compared with the commonly used uniform file distribution and compared with a heuristic distribution method