The Digital Disconnect: The Widening Gap Between Internet Savvy Students and Their Schools

Presents findings from a survey of public middle and high school students from thirty schools across the U.S. Looks at how students rely on the Internet to help them do their schoolwork, in addition to dozens of other education related tasks

Constructive Ontology Engineering

The proliferation of the Semantic Web depends on ontologies for knowledge sharing, semantic annotation, data fusion, and descriptions of data for machine interpretation. However, ontologies are difficult to create and maintain. In addition, their structure and content may vary depending on the application and domain. Several methods described in literature have been used in creating ontologies from various data sources such as structured data in databases or unstructured text found in text documents or HTML documents. Various data mining techniques, natural language processing methods, syntactical analysis, machine learning methods, and other techniques have been used in building ontologies with automated and semi-automated processes. Due to the vast amount of unstructured text and its continued proliferation, the problem of constructing ontologies from text has attracted considerable attention for research. However, the constructed ontologies may be noisy, with missing and incorrect knowledge. Thus ontology construction continues to be a challenging research problem. The goal of this research is to investigate a new method for guiding a process of extracting and assembling candidate terms into domain specific concepts and relationships. The process is part of an overall semi automated system for creating ontologies from unstructured text sources and is driven by the user’s goals in an incremental process. The system applies natural language processing techniques and uses a series of syntactical analysis tools for extracting grammatical relations from a list of text terms representing the parts of speech of a sentence. The extraction process focuses on evaluating the subject predicate-object sequences of the text for potential concept-relation-concept triples to be built into an ontology. Users can guide the system by selecting seedling concept-relation-concept triples to assist building concepts from the extracted domain specific terms. As a result, the ontology building process develops into an incremental one that allows the user to interact with the system, to guide the development of an ontology, and to tailor the ontology for the user’s application needs. The main contribution of this work is the implementation and evaluation of a new semi- automated methodology for constructing domain specific ontologies from unstructured text corpus

An Overview on a Promising Root Canal Irrigation Solution: QMix

Due to the complex micro-anatomy of the root canal system, mechanical instrumentation leaves significant portions of the root canal walls untouched; therefore, complete elimination of bacteria from the root canal by cleaning with instrumentation alone is unlikely. It has long been postulated but not demonstrated, that any pulp tissue left in the root canals can serve as bacterial/fungal/viral (microorganism nutrients) nutrients. Furthermore, tissue remnants also impede the antimicrobial effects of root canal irrigants and medicaments and prevent intimate adaptation of the root canal filling to the dentin. Therefore, specific irrigation/disinfection procedures are necessary to remove tissue from the root canals and to kill microorganisms, respectively. The purpose of this paper was to review different aspects of a promising root canal irrigant; QMix. This is a relatively new root canal irrigant composed of traditional materials like chlorhexidine (CHX), ethylele diamine tetraacetic acid (EDTA), saline and a detergent. QMix is antibacterial, antifungal and has antibiofilm activities, it displays substantivity, smear layer removing ability; moreover, its effect on dentin and retention of fiber posts etc. has been reviewed. There have been strong reports that show the chemical design of QMix prevents precipitation of CHX when together with EDTA and mixing with sodium hypochlorite does not produce the orange-brown precipitate. Furthermore, the smear layer removal ability of QMix is comparable to that of 17% EDTA and the antibacterial activity of QMix was greater than 1% and 2% sodium hypochlorite (NaOCl) and 2% CHX

The role of culture economics in social health: the case of cultural diversity in Iran

Background: The culture economy usually deals with the economy in the field of art and culture, and due to the cultural diversity in Iran, its effects on the social health have always been controversial. The purpose of this study was to determine the role of the cultural economy on social health with respect to cultural diversity in Iran.Methods: A comprehensive search had been done in the following databases: web of science, PubMed, SciVerse Scopus, Google scholar and MEDLINE, using keywords including, culture economics, social health, and cultural diversity. Library research was carried out either. A total of 48 articles related to the topic of the study were found. Among them, 24 articles were found to be precisely related to the topic of the study. Findings were criticized and analyzed. Results: The economy of society could be affected by any changes in culture. On the other hand, cultural diversity also obviously affects the various aspects of mental health, including health and disease perceptions, coping styles, treatment patterns, the impact of history, racism, bias and stereotypes, gender and family, shame and discrimination. Cultural diversity provides many opportunities for working in a unique and effective way in the field of positive mental health.Conclusion: If the economy of society moves on the basis of the development of profit and social capital, it will create a context for growth and development of culture. Cultural diversity is also in line with the economics of culture as a motivating factor for the development not, only in the economic arena but also in the expansion of intellectual and creative spheres and social health

Externalizing the Latent Structure of Computer Games: Effect on game play, reasoning and implication for design

Computer games have initially and primarily been used for entertainment purposes. Recently, however, computer games have gained popularity in the educational and training arena. Epistemic computer games require players to think hard while entertaining them at the same time. Designing good epistemic computer games is complex and difficult. This thesis aims to further our understanding of how to design good epistemic computer games. Super Maze is a puzzle game that requires players to navigate through a maze picking up things on the way. At each junction, players can move either up, down, left or right. Four different versions of Super Maze were created. These versions differ from each other with respect to the representation of the maze and the way players interact with the maze to move through and finish it. The alternative representation to the traditional maze representation externalizes the internal structure of the maze as a tree diagram. An exploratory usability study was conducted to investigate how externalizing the internal structure of the game affects thinking and reasoning and if and how externalizing the internal structure of the game affects the gaming experienc

Effect of hydroxyapatite and bovine serum albumin on the antibacterial activity of MTA

INTRODUCTION: The purpose of this study was to compare the inhibitory effect of bovine serum albumin (BSA) and hydroxyapatite (HA) on the antibacterial activity of white-colored MTA (WMTA) against Staphylococcus (S.) aureus and Streptococcus (S.) mutans after 24 and 72 hours.MATERIALS & METHODS: All materials were prepared according to the manufacturer’s directions immediately before testing. The antibacterial effect of each group (WMTA, WMTA+BSA and WMTA+HA) was determined by measuring the diameter of zone of inhibition in millimeters after incubation at 37°C for 24 and 72 hours in a humid atmosphere. Each test was repeated three times. Data were analyzed using ANOVA and Tukey’s test. RESULTS: In the 24 hours samples as well as in 72 hours samples, the antibacterial activity of MTA+HA group was significantly greater than two other groups against S. aureus (P < 0.05). However, the antibacterial activity of MTA+HA group against S. mutans was not significantly different from the MTA group in 24 hours as well as 72 hours samples. BSA reduced the antibacterial activity of MTA against both tested bacteria in the 24 and 72 hour samples (P < 0.05).CONCLUSION: The products studied exhibited antibacterial activity. However, in both time intervals, the MTA+HA group exerted the greatest activity against S. mutans and S. aureus.

Is chlorhexidine an ideal vehicle for calcium hydroxide?

Microorganisms play a major role in the initiation and perpetuation of pulpal and periapical disease. In order to predictably achieve a bacteria-free root canal system, it is necessary to use intracanal medicaments. Calcium hydroxide is the most common intracanal medicaments. It is effective against primary infections. However, its effectiveness against Enterococcus faecalis and Candida albicans is controversial. On the other hand, chlorhexidine is a potent agent against Enterococcus faecalis and Candida albicans. For this reason, it has been combination of calcium hydroxide and chlorhexidine has been suggested as an intracanal medicament. The purpose of this article was to a brief review antimicrobial efficacy of calcium hydroxide, chlorhexidine, and their combination

The Effect of Social Media on Iranian Citizens’ Electoral Participation and Political Action

The present age is called the age of communication. Undoubtedly, in all matters of the world, the most incredible information is on the shoulders of the mass media. Today, the media have influenced the identity of contemporary man by expanding geographical, cultural and political boundaries so that the identity of modern man can be called media identity. The increasing role of new means of mass communication in various parts of human life has led to multiple fields. One area that social media have influenced in the present age is political participation. The present paper sought to test the effect of social media on the Iranian citizens’ willingness to electoral participation political actions using the World Values Survey (WVS) wave 7 data release (49 countries/territories). The results show that social media indirectly, through the mediator variable of political trust, reduces the willingness of individuals to participate in elections. Moreover, the results show that social media, both directly and indirectly, increases citizens’ willingness to engage in political protests

Quantifying Security Risks in Cloud Infrastructures:A Data-driven Approach

Businesses increasingly outsource their ICT services to cloud environments, mostly driven by considerations about costs, processes and security. However concerns around cloud exposure against cyber-security attacks are also growing. This bring about the question if the cloud really makes us more secure, or if it merely changes the type of threats we are exposed to. This PhD project aims at addressing this question by focusing on cloud infrastructure security. Using Internet measurements, we will take a data-driven approach to identify vulnerabilities and single points of failure in cloud infrastructure. Based on our analysis, we will propose solutions to mitigate these vulnerabilities and enhance the overall security of cloud environments