bluuebunny/crossref_metadata_2025 huggingface dataset:
Telemedicine as a Modality of Health Care Delivery and its Implications
Authors: Bashshur Rashid L , Shannon Gary W
Published: April 2012

This chapter provides both formal and operational definitions of telemedicine as well as the related concepts of telehealth, e-health, and m-health, and reviews the origin and historical evolution of the nomenclature and content of telemedicine over the last century. The rationale for telemedicine is discussed in terms of potential effects on improving access to care, especially for underserved, remote and isolated populations, redressing inequities in quality and cost containment in terms of greater efficiency and risk avoidance, not only singly but also symbiotically. The current status of telemedicine and the reasons for its limited diffusion to date are discussed. Finally, the empirical evidence is briefly reviewed, selecting one application as an example. The chapter concludes with an optimistic expectation of continued proliferation of the field to serve the common good.
E-Health Behaviors
Authors: Linares Deborah , Subrahmanyam Kaveri
Published: April 2012

E-health (eHealth) is an emerging field of health communication encompassing medical informatics, public health, and business where health information and services are exchanged through electronic processes. The current leading researchers in e-health include: Dr. Gunther Eysenbach from University of Toronto on health information and decision-making; Dr. David Gustafson from University of Wisconsin, Madison on interactive support systems; The Pew Internet and American Life Project on chronicling e-health use; Dr. Neil Coulson from University of Nottingham on online support group communication, and Dr. Elizabeth Murray from University College London, who develops online treatments. This entry summarizes research on e-health behaviors: seeking health information online, the impact of patient-to-patient communication on health, and receiving treatment online. Future directions for research on e-health behaviors include exploring the disadvantages of online support groups, research on minority populations, development of online randomized controlled trial methodology, and longitudinal research examining e-health behaviors over time.
Online Counseling
Authors: Richards Derek , Viganò Noemi
Published: April 2012

Online counseling is defined as the delivery of therapeutic interventions in cyberspace where communication between a trained professional counselor and client(s) is facilitated using computer-mediated communication (CMC) technologies. Research considers aspects of delivering therapeutic interventions online, including process and outcome research, the therapeutic relationship online, the potential benefits and challenges in working online, client suitability for online counseling, therapists’ and clients’ attitudes and experiences of online counseling, professional training for working online with clients, and its very nature and definition as a therapeutic intervention. Understanding the psychology of online behavior as it applies to online counseling includes the effects of apparent anonymity and distance, disinhibition, identity and impression management, writing and emotional expression, presence, and ethical behavior in cyberspace.
Self-Injury Behaviors in Cyber Space
Authors: Duggan Jamie Marie , Whitlock Janis
Published: April 2012

This entry describes the evolution and current state of research related to Non-suicidal self-injury on the Internet across a variety of mediums, including social networking websites, video-sharing websites, and informational websites. Although the full influence of such online behaviours on off-line behaviours and functioning remains relatively unknown, it appears that such activities pose both risks and benefits to mental health and wellbeing. Online activities may provide individuals with a history of or interest in self-injury with guidance and education, informal support, a sense of community, as well as allow for personal expression. However, such activities can also serve to trigger, reinforce, and normalize self-injury and may substitute for off-line relationships. The pervasiveness of self-injury online suggests that regular assessment of on-line activity is an important aspect of self-injury treatment. The chapter concludes with suggestions for utilizing the Internet as a novel approach to self-injury prevention and intervention efforts.
Online Child Pornography
Authors: Marcum Catherine D. , Higgins George E.
Published: April 2012

This entry provides an examination of the past and present prevalence and issues surrounding online child pornography in the United States. Legal definitions of child pornography are explained, followed by an analysis of the current empirical knowledge on the topic, as well as the legal and legislative history. Finally, a brief discussion of the future research directions on the topic will be discussed.
Responses to Online Privacy Risks
Authors: Cho Hichang
Published: April 2012

The increasing use of the Internet and the development of more sophisticated data-mining and surveillance techniques have led to growing levels of public concern about online privacy. This chapter reviews the intellectual history and current knowledge of online privacy risks. It discusses some foundational studies of privacy research. This is followed by literature reviews of empirical studies of online privacy risks. Specifically, this chapter focuses on perceptual and behavioral responses to online privacy risks, such as online privacy concerns, risk perception and optimistic bias, and self-protection behavior. It concludes with implications and directions for future research.
Cyber-Bullying Behaviors
Authors: Li Qing , Lambert Deborah
Published: April 2012

A review of the literature reveals that current research has discovered that the severity of cyberbullying may be a result of the impact of many factors contributing to its prevalence and psychological and emotional effects on both cyberbullies and their victims. Most prominent among these factors include socio-demographic factors such as gender, age, socio-economic status, and the technology-related factor, anonymity. Despite the number of programs and legal procedures being implemented to manage and control cyberbullying, it continues to pose a problem among the youth. Further research is, therefore, needed to determine whether gender, age, socio-economic status, and the technology-related factor, anonymity, are interacting with each other in their impact on cyberbullying or whether other factors, not yet investigated, are interacting with the identified factors to cause the prevalence of cyberbullying.
Lying on the Internet
Authors: Konecny Stepan
Published: April 2012

Mass media often presents a warped image of the Internet as an unreliable environment in which nobody can be trusted. In this entry, the authors describe lying on the Internet both in the context of lying in the real world and with respect to the special properties of computer-mediated communication (CMC). They deal with the most frequent motives for lying online, such as increasing one’s attractiveness or experimenting with identities. They also take into account the various environments of the Internet and their individual effects on various properties of lying. The current methods for detecting lies and the potential for future computer-linguistic analysis of hints for lying in electronic communication are also considered.
E-Participation
Authors: Wells Christopher , Moy Patricia
Published: April 2012

Communication has long been understood as essential to the democratic process; it not only conveys information about politics to citizens, but also enables social deliberation by allowing citizens to communicate with one another and with officials. As digital media have developed and become increasingly ubiquitous in communication, new opportunities for civic and political participation are emerging. This entry considers some of the major trends in e-participation, understood as citizens’ efforts to influence their political environments through various uses of digital media. In particular, the authors explore how digital media are giving rise to new practices in: the consumption and sorting of information from the political world, the expression of political views and deliberation, the creation and sharing of novel content online, and citizen organizing within social movements.
Public Trust in Government, Trust in E-Government, and Use of E-Government
Authors: Goldfinch Shaun
Published: April 2012

The author of this article examines aspects of trust in government generally, and its relationship to trust in e-government. Trust in government has been seen to have positive effects across a number of factors, including economic performance, social cohesion, and the sum of welfare. A specification of different levels of trust in government is outlined. What is the relationship between trust in government and trust in e-government? While there seems to be a relationship between the use of technology and e-government and trust and comfort in its use, recent studies have questioned a simple link between use of e-government and trust in government, and trust in e-government and trust in government generally. Somewhat conflicted findings across studies, however, suggests further research is needed.
Twitter and Political Elections
Authors: Ströhle Fabian , Sprenger Timm
Published: April 2012

The rise of Twitter has changed human communication behavior not only in the political domain, but also in many other fields. Individuals are increasingly using microblogging platforms like Twitter for political deliberation, making full use of the features offered for discussions and social networking. At the same time, politicians and political parties hop on the bandwagon, using Twitter to reach a larger audience and communicate to constituents. As is the case for blogs, the political Twittersphere is fragmented along party lines, but stimulates communication between different ideological clusters. The publicly available discussions on Twitter can serve as a basis for election forecasts and have the potential to complement opinion polls and prediction markets in the future.
The Causes and Consequences of Political Blogging
Authors: Wallsten Kevin
Published: April 2012

“Blogging” has become an incredibly popular activity in recent years. Although political blogging broadly defined as a blog whose “content focuses on issues, events, and policy in a constituency, national, international, or party context” (Ferguson & Griffiths, 2006, p. 366) – constitutes only a small sliver of the overall blogosphere, it has attracted a great deal of attention from political scientists, mass communication specialists, and researchers interested in information technology. The primary focus of this attention has been on four central questions. First, what motivates political bloggers to blog about politics? Second, what is the nature of the politically oriented discussions found on political blogs? Third, what are the political consequences of political blogging? Finally, how have professional politicians used blogs in campaigns and once in office? This entry summarizes the existing literature into each of these questions and points to a number of issues that should be addressed in future studies of the causes and consequences of political blogging.
Political Behavior in Social Network Sites
Authors: Zhang Weiwu , Gearhart Sherice
Published: April 2012

The increasing popularity of social network sites (SNSs), such as Facebook, MySpace, LinkedIn, YouTube, and Twitter, in political campaigns and governance, has captivated researchers in the past several years. This entry aims to provide a comprehensive review and synthesis of the burgeoning empirical research literature on political behavior in SNSs by leading researchers from various fields. Research domains under review include how citizens use SNSs for political purposes and the effects of SNSs on political attitudes and behavior such as social capital, civic engagement, and political participation, how candidates and voters utilize SNSs during election campaigns, how governmental institutions employ SNSs, and the potential dark side of SNSs such as selective exposure and political polarization. Finally, future research directions of the field are discussed.
Cyber Behavior and Social Capital
Authors: Kobayashi Tetsuro
Published: April 2012

This chapter reviews historical development of research on cyber behavior and social capital, based on the definition by Robert D. Putnam, by focusing on the relationship between Information Communication and Technology use with social networks, civic engagement, as well as social trust. Firstly, the intellectual history of studies on cyber behavior and social capital is reviewed. Secondly, important past studies on the relationship between ICT use and social capital are focused from four perspectives: social networks, civic engagement, local community, and mobile phone use. Finally, future research directions are discussed from the perspective of comparative culture and rapidly evolving high-functionality smart phones.
Cyber Conflict and Management
Authors: Ishii Kumi , Black Brittany R.
Published: April 2012

With the diffusion of networked technology in our society, online communication has become an integral part of daily life, and conflict no longer occurs only in face-to-face (FtF) contexts. Many people experience cyber conflict (i.e., a perceived incompatibility of goals among two or more cyber parties over computer-mediated communication (CMC) or online communication) and manages it online. While research in this significant and emerged topic is scattered across contexts and disciplines, this chapter provides preliminary knowledge by discussing the antecedents and outcomes of cyber conflict as well as factors that affect cyber conflict management. The chapter also offers future research directions.
Self-Regulated Learning in Online Mathematical Problem-Solving Discussion Forums
Authors: Kramarski Bracha
Published: April 2012

Online discussion forums have created both opportunities and challenges in the instruction of mathematics. They provide a variety of tools for sharing knowledge during the solution process, which can enhance students’ mathematical problem solving. However, research also indicates that students have difficulty engaging in the processes involved in using discussion forums, which require the ability to coordinate knowledge with solution strategies and control behaviors (i.e., monitoring). This ability is the essence of self-regulated learning (SRL). This article presents how one may stimulate students’ online SRL in mathematical problem-solving discussion forums by using support techniques. An overview of four research fields, along with the leading experts in each field, presents the complexity of mathematical problem-solving online discussion forum tools, SRL models and self-questioning support techniques using the IMPROVE model. Future directions are suggested.
Cybertesting Behaviors
Authors: Stowell Jeffrey R. , Allan Wesley D.
Published: April 2012

Online instruction and computerized testing has attracted a great deal of attention as college and universities increasingly move toward this mode of teaching and assessment. Many concerns have been raised regarding how to ensure these methods are valid and appealing to students and their parents. Researchers have addressed various facets of these issues; in particular, a number of studies have been published regarding how online assessment may affect student performance and test anxiety. We review the literature in this area and provide corresponding practical and ethical recommendations.
Motivation in Online Environments
Authors: Coyle Victoria C. , Newman Dianna L.
Published: April 2012

As the number of Internet users grows, and the opportunities for online activity increase, it is worth considering what motivates or drives people to participate online. Considerable time and effort are spent in online environments; users produce content, play games, and create or maintain relationships. Motivation to participate in online environments can be influenced by the appealing qualities of technology and instantaneous nature of the Internet, which provide incentive for users to create or maintain social connections, seek entertainment, or generate and distribute creative content. Research from the learning sciences, communication sciences, and sociology provide insight into user motivation in online environments. Scholars in these varied fields study the relationship between motivation and online engagement, examining user variables such as personal interest and goals; social and psychological factors that motivate users to fulfill personal goals or needs; and the creation of affiliations that have online as well as offline benefits.
Affective Agents in E-Learning Platforms
Authors: Moridis Christos N. , Economides Anastasios A.
Published: April 2012

During recent decades there has been an extensive progress towards several Artificial Intelligence (AI) concepts, such as that of intelligent agent. Meanwhile, it has been established that emotions play a crucial role concerning human reasoning and learning. Thus, developing an intelligent agent able to recognize and express emotions has been considered an enormous challenge for AI researchers. Embedding a computational model of emotions in intelligent agents can be beneficial in a variety of domains, including e-learning applications. However, until recently emotional aspects of human learning were not taken into account when designing e-learning platforms. Various issues arise when considering the development of affective agents in e-learning environments, such as issues relating to agents’ appearance, as well as ways for those agents to recognize learners’ emotions and express emotional support. Embodied conversational agents (ECAs) with empathetic behaviour have been suggested to be one effective way for those agents to provide emotional feedback to learners’ emotions. There has been some valuable research towards this direction, but a lot of work still needs to be done to advance scientific knowledge.
Cyber-Behaviors and Development Impacts in Latin America
Authors: Chong Alberto , de Mendoza Cecilia
Published: April 2012

While the current scientific literature is quite scarce for most of the developing world, several leading researchers have made great strides in understanding the role of cyber technologies and related information and communication technologies (ICT) in economic development. A good proportion of this work lays on interventions in the regions of South Asia and Africa. However, cyber-behavior research focused on Latin America has been very limited. Very recently, a group of researchers took a bold step to apply rigorous statistical tools in a systematic way to evaluate how these technologies contributed to the success of several development projects in the region of Latin America. This chapter draws on several of the background papers of the book “Development Connections: Unveiling the Impact of Information Technologies,” edited by Alberto Chong, as well as some of the book’s chapters. It summarizes a number of specific cyber-interventions in the areas of finance, education and poverty-reduction that took place in Latin America and that may lead to a better understanding of the impact of interventions to know what works, what does not, and why.
Cyber Behavior of Chinese Internet Users
Authors: He Yurong , Wang Yang
Published: April 2012

While China has the world’s largest Internet population, understanding of this huge group of Internet users still falls short. In this entry, the authors aim to provide an overview of literature on cyber behavior of Chinese Internet users. They focus on characteristics of Chinese Internet users, how they use the Internet and how the Internet influences them. The authors examine different aspects of their cyber behavior: (1) general Internet use, (2) use of specific Internet services such as blogs and social networking sites, (3) online communication and relationships, (4) problematic Internet usage, and (5) cross-cultural comparisons between Internet users in China and in other countries.
Cyber Behavior and its Impact in Japan
Authors: Fuji Kei , Yoshida Fujio
Published: April 2012

With the rapid growth of Internet in Japan, many researches have examined whether Internet use affects social behavior on daily life positively or negatively. Early seminal researches in Japan demonstrated that the negative effects of the Internet are not universal, but such effects are dependent on the circumstances and on how the Internet is utilized by each user. Recent studies have been focusing on various activities on the Internet analyzing “what kind of user is using the Internet for what purpose.” This chapter will introduce these studies in terms of three main characteristics of Internet users in Japan. These three characteristics are: preferences for weblog, participation in online communities, and switching to mobile Internet. At the end of this chapter, future research directions will be discussed, while introducing recently developed scales designed to measure various behaviors on the Internet from three aspects: self-expression, relationships with others, and balance with reality.
Kinetics and Activation Requirements of Contact-Dependent Immune Suppression by Human Regulatory T Cells
Authors: Hagness Morten , Henjum Karen , Landskron Johannes , Brudvik Kristoffer Watten , Bjørnbeth Bjørn Atle , Foss Aksel , Taskén Kjetil , Aandahl Einar Martin
Published: April 2012

Naturally occurring regulatory T cells (Tregs) maintain self tolerance by dominant suppression of potentially self-reactive T cells in peripheral tissues. However, the activation requirements, the temporal aspects of the suppressive activity, and mode of action of human Tregs are subjects of controversy. In this study, we show that Tregs display significant variability in the suppressive activity ex vivo as 54% of healthy blood donors examined had fully suppressive Tregs spontaneously, whereas in the remaining donors, anti-CD3/CD2/CD28 stimulation was required for Treg suppressive activity. Furthermore, anti-CD3/CD2/CD28 stimulation for 6 h and subsequent fixation in paraformaldehyde rendered the Tregs fully suppressive in all donors. The fixation-resistant suppressive activity of Tregs operated in a contact-dependent manner that was not dependent on APCs, but could be fully obliterated by trypsin treatment, indicating that a cell surface protein is directly involved. By add-back of active, fixed Tregs at different time points after activation of responding T cells, the responder cells were susceptible to Treg-mediated immune suppression up to 24 h after stimulation. This defines a time window in which effector T cells are susceptible to Treg-mediated immune suppression. Lastly, we examined the effect of a set of signaling inhibitors that perturb effector T cell activation and found that none of the examined inhibitors affected Treg activation, indicating pathway redundancy or that Treg activation proceeds by signaling mechanisms distinct from those of effector T cells.
ATP Binding Cassette Transporter G1 Deletion Induces IL-17–Dependent Dysregulation of Pulmonary Adaptive Immunity
Authors: Draper David W. , Gowdy Kymberly M. , Madenspacher Jennifer H. , Wilson Rhonda H. , Whitehead Gregory S. , Nakano Hideki , Pandiri Arun R. , Foley Julie F. , Remaley Alan T. , Cook Donald N. , Fessler Michael B.
Published: April 2012

Mice with genetic deletion of the cholesterol transporter ATP binding cassette G1 (ABCG1) have pulmonary lipidosis and enhanced innate immune responses in the airway. Whether ABCG1 regulates adaptive immune responses to the environment is unknown. To this end, Abcg1+/+ and Abcg1−/− mice were sensitized to OVA via the airway using low-dose LPS as an adjuvant, and then challenged with OVA aerosol. Naive Abcg1−/− mice displayed increased B cells, CD4+ T cells, CD8+ T cells, and dendritic cells (DCs) in lung and lung-draining mediastinal lymph nodes, with lung CD11b+ DCs displaying increased CD80 and CD86. Upon allergen sensitization and challenge, the Abcg1−/− airway, compared with Abcg1+/+, displayed reduced Th2 responses (IL-4, IL-5, eosinophils), increased neutrophils and IL-17, but equivalent airway hyperresponsiveness. Reduced Th2 responses were also found using standard i.p. OVA sensitization with aluminum hydroxide adjuvant. Mediastinal lymph nodes from airway-sensitized Abcg1−/− mice produced reduced IL-5 upon ex vivo OVA challenge. Abcg1−/− CD4+ T cells displayed normal ex vivo differentiation, whereas Abcg1−/− DCs were found paradoxically to promote Th2 polarization. Th17 cells, IL-17+ γδT cells, and IL-17+ neutrophils were all increased in Abcg1−/− lungs, suggesting Th17 and non-Th17 sources of IL-17 excess. Neutralization of IL-17 prior to challenge normalized eosinophils and reduced neutrophilia in the Abcg1−/− airway. We conclude that Abcg1−/− mice display IL-17–mediated suppression of eosinophilia and enhancement of neutrophilia in the airway following allergen sensitization and challenge. These findings identify ABCG1 as a novel integrator of cholesterol homeostasis and adaptive immune programs.
Human Th17 Cells Express High Levels of Enzymatically Active Dipeptidylpeptidase IV (CD26)
Authors: Bengsch Bertram , Seigel Bianca , Flecken Tobias , Wolanski Julia , Blum Hubert E. , Thimme Robert
Published: April 2012

Dipeptidylpeptidase IV (CD26) is a multifunctional ectoenzyme involved in T cell activation that has been implicated in autoimmune pathophysiology. Because IL-17–producing CD4+ T cells (Th17 cells) are important mediators of autoimmune disease, we analyzed the expression of CD26 and its enzymatic function on human Th17 cells. Analysis of CD26 expression on different CD4+ T helper subsets showed that CD26 expression is highest on CD4+ T cells producing type 17 cytokines (e.g., IL-22, IL-17, GM-CSF, or TNF) compared with Th1, Th2, and regulatory T cells. Phenotypic analysis revealed that CD26++CD4+ T cells express the type 17 differentiation molecules CD161, CCR6, lL-23R, and retinoic acid-related orphan receptor-γt. Furthermore, sorted CD26++CD4+ T cells contain >90–98% of Th17 cells, indicating that CD26++ T cells harbor the Th17 lineage. A comparison with CD161 and CCR6 indicated that analysis of CD26 coexpression may improve the phenotypic characterization of Th17 cells. Of note, CD26++ Th17 cells are enriched in the inflamed tissue of patients with hepatitis and inflammatory bowel disease. Functional analysis in migration assays revealed that CD26 expressed on Th17 cells is enzymatically active. Indeed, CD26 negatively regulates the chemotactic CD4+ T cell response to the inflammatory chemokines CXCL9–12 that can be restored by pharmacological blockade of the enzymatic center of CD26. In summary, these results strongly suggest that CD26 may contribute to the orchestration of the immune response by Th17 cells in human inflammatory diseases. They also suggest that the phenotypic analysis of Th17 cells may be facilitated by determination of CD26 expression.
A New Preconditioned Generalised AOR Method for the Linear Complementarity Problem Based on a Generalised Hadjidimos Preconditioner
Authors: Liu Cuiyu , Li Chenliang
Published: April 2012

A new generalised Hadjidimos preconditioner and preconditioned generalised AOR method for the solution of the linear complementarity problem are presented. The convergence and convergence rate of the new method are analysed, and numerical experiments demonstrate that it is efficient.
A Comparison of Frictional Resistance between Active and Passive Self-ligating Brackets with Conventional Bracket Systems
Authors: Shivalinga BM , Jyothikiran H , Bansal Sachin , Farhan Azeem
Published: April 2012

Friction, though, is an inseparable and undeniable orthodontic entity that should be minimized, if not eliminated, for obtaining an optimal biological tissue response.

Aim

The present study compared the frictional resistance of active (time- 2, In-Ovation R) and passive (Damon SL-2, Smart clip) self-ligating brackets with conventional titanium, fiberglass and ceramic brackets under dry and wet conditions with artificial saliva using universal testing machine.

Methods

Modified Tidy's jig was constructed to simulate clinical situation. A total of 200 samples were tested. Specimens were divided into two categories which were run under dry and wet conditions, using artificial saliva. Around 10 samples of each active and passive selfligating brackets were dry run and 10 others were used in wet conditions. Around 10 samples of each ceramic, titanium and fiberglass brackets were run using elastomeric ties in both dry and wet conditions and 10 each of them using stainless steel ligatures under dry and wet conditions.

Results

The study revealed that the least frictional resistance was demonstrated by the brackets in the following order, i.e. passive selfligating brackets, active self-ligating brackets, titanium, fiberglass and ceramic brackets in both dry and wet conditions.

Conclusion

The self-ligating brackets seem to be promising in quenching the thirst of orthodontist to have a bracket that is functionally efficient with reduced friction, esthetically pleasing, reduced treatment and chairside time, combined with better oral hygiene maintenance and patient comfort because of absence of ligation.
An in vitro Comparison of Root Canal Measurement in Permanent Teeth by Electronic Apex Locator, Conventional and Digital Radiography
Authors: LNU Alexander , Saeed Musab Hamed , Abtahl Nazil A , Praveen Pradeep A
Published: April 2012

Introduction

In endodontic treatment for permanent teeth, it is important to estimate the working length precisely. Currently, various methods are used in clinical practice for working length estimation. The objective of this study is to compare the accuracy of root canal length in permanent teeth determined by electronic apex locators, conventional and digital radiography.

Materials and methods

A total of 50 single rooted permanent teeth with mature apices were extracted for periodontal reasons and obtained from different sources without caries were studied. The radiographic measurements were done using paralleling technique. Electronic measurements were done next using third generation, DentAport ZX. Actual canal length of each tooth was measured using direct observation of the apical exit of the file. Measurements obtained from radiographic and electronic methods were compared to the actual tooth length. Interclass correlation coefficients and failure rate for each method and their combinations were calculated using STATA 12.0 software.

Results

The measurements obtained through all the three techniques showed high interclass correlation coefficients and excellent level of agreement. The failure rate of measurements obtained through conventional radiography, digital radiography and electronic apex locators was 38, 30 and 22% respectively. Combination of conventional radiography with electronic apex locator showed an accuracy of 90%, while combination of digital radiographs and electronic apex locators given an accuracy of 96%.

Conclusion

A combination of digital radiographic and apex locator methods for determining the root canal length in permanent teeth can be considered safe, reliable and precise.
Association between Socioeconomic Status, Salivary Streptococcus mutans, Lactobacilli and Dental Caries among 12-Year-Old School Children in Belgaum City
Authors: Hebbal Mamata Iranna , Metgud Sharada C
Published: April 2012

Introduction

Aim of the study was to assess dental caries using Modified Dentition Status and Treatment Needs and find its association with salivary Streptococcus mutans and lactobacilli counts among 12-year-old school children of Belgaum city.

Materials and methods

A self-designed, 13 item, open-ended questionnaire given to parents. Children were examined for dental caries using Modified Dentition Status and Treatment Needs. Stimulated saliva was collected and incubated to estimate lactobacilli and Streptococcus mutans colonies. Chi-square test was used to find the association between variables.

Results

When DMFT was recorded it was found that 23% of children were free from dental caries, whereas, only 5% of them were free of dental caries when examined using modified criteria. Most of the children had higher microbial count with 72% and 62% of them having > 105 cfu/μl of Streptococcus mutans and lactobacilli colony count respectively. Modified DMFT was significantly associated with frequency of brushing, lactobacilli and Streptococcus mutans counts (p < 0.05).

Conclusion

The proportion of subjects with dental caries was relatively high in all groups but the number of teeth affected by caries was low. Inclusion of noncavitated incipient lesions could increase sensitivity of index.
Nonsyndromic Bilateral Keratocystic Odontogenic Tumor: A Rare Case
Authors: Kumar Vinod , Babu Chaitanya , Dawar Geetanshu
Published: April 2012

Here, we report a case of keratocystic odontogenic tumor occurring bilaterally in a male patient in fourth decade of life. This case is different from bilateral lesions of keratocystic odontogenic tumor which are most commonly parakeratinized and are associated with syndromes like nevoid basal cell carcinoma syndrome. In our case, we could not find out any syndromic association and furthermore histopathology was in line of orthokeratinization.
Restoration of the Severely Resorbed Maxilla and Mandible using the Multicup Denture
Authors: Chandrakala V
Published: April 2012

A basic concern of edentulous patients is retention of their dentures. This has led to considerable experimentation and research in efforts to perfect dentures that compensate for the loss of natural teeth. The use of multiple miniature suction cups made from a soft material lining the denture satisfies the requirements of retention and stability. A technique describing the fabrication of a maxillary and mandibular multicup dentures which are more beneficial than conventional complete dentures is discussed below with case report.
Fiberoptic Intubation as a Boon in Limited Mouth Opening Surgeries
Authors: Dutt Sunil , Basha Salman
Published: April 2012

Surgery of temporomandibular joint ankylosis under general anesthesia poses a great challenge to anesthesiologists. This surgery falls in the category of difficult intubation as direct vocal cord visualization is difficult due to an inability to open the mouth. The present case report suggests that the fiberoptic intubation has become an essential skill for anesthetists dealing with patients in whom orotracheal intubation is anatomically difficult.
Prosthetic Rehabilitation of Hemimandibulectomy Patient
Authors: Yadav Sandeep , Arora Aman
Published: April 2012

Rehabilitation of patients with mandibular defect requires a multidisciplinary approach involving a head and neck surgeon, maxillofacial prosthodontist and a reconstructive surgeon. A hemimandibulectomy patient can have many debilitating consequences such as eccentric occlusion, disoriented masticatory cycle, facial disfigurement, distorted speech and salivation problem. The aim of this case report is to describe a technique which combines crown with prosthetic rehabilitation to meet the functional and esthetic requirement of the hemimandibulectomy patients.
Br2, BrCl, BrO and surface ozone in coastal Antarctica: a meteorological and chemical analysis
Authors: Buys Z. , Brough N. , Huey G. , Tanner D. , von Glasow R. , Jones A. E.
Published: April 2012

Abstract. There is much debate over the source of bromine radicals in the atmosphere that drives polar boundary layer ozone depletion events (ODEs), but there is strong evidence to suggest a source associated with the sea ice zone. Here we report the first high temporal resolution measurements of Br2, BrCl and BrO in coastal Antarctica, made using a Chemical Ionisation Mass Spectrometer (CIMS). Mixing ratios ranged from instrumental detection limits to 13 pptv for BrO, 45 pptv for Br2, and 6 pptv for BrCl. We find evidence for blowing snow as a source of reactive bromine both directly during a storm and subsequently from recycling of bromide deposited on the continental snowpack. An unusual event of trans-continental air mass transport might have been responsible for severe surface ozone depletion observed at Halley. The halogen source region was the Bellingshausen Sea, to the west of the Antarctic Peninsula, the air mass having spent 3 1/2 days in complete darkness prior to arrival at Halley. We, further, identify an artefact in daytime BrCl measurements arising from conversion of HOBr, similar to that already identified for CIMS observations of Br2. Model calculations using the MISTRA 0-D model suggest a 50–60% conversion of HOBr to Br2, and 5–10% conversion to BrCl. Careful data filtering enabled us to use the halogen observations, in conjunction with the MISTRA model, to explore the temperature dependence of the Br2:BrCl ratio. We find evidence of a ratio shift towards Br2 at temperatures below ~−21 °C, suggesting a relationship with hydrohalite (NaCl.2H2O) precipitation. This suite of Antarctic data provides the first analogue to similar measurements made in the Arctic.
Quality assessment of heterogeneous surface radiation network data
Authors: Becker R. , Behrens K.
Published: April 2012

Abstract. The DWD national radiation measurement network comprises 82 automatic sites, 29 manned sites with shaded and unshaded pyranometer and the BSRN station at Lindenberg. The quality assessment routinely applied takes into account the basic astronomical and empirical considerations as well as some interdependencies like total to diffuse flux relation and cross checking with sunshine duration. A more advanced quality assessment approach attempts to routinely utilise timeseries of clear sky radiative transfer simulations for every site. For that purpose a link to cloud coverage obtained from Meteosat second generation geostationary satellite data, highly resolved in time and space, was established. There is a predefined calibration cycle of 30 month for automatic stations. Data analysis on this timescale allows for the detection of sensor degradation, wrong calibration or configuration and other possible local disturbances. Furthermore using satellite cloud mask enables the identification of larger clear sky regions characterized by similar atmospheric conditions. Thus, in a regionalization step correction or recalibration of moderate quality data to a higher level can be considered. The paper provides an overview of DWD surface radiation network and the current activities to improve automatic quality assessment using remotely sensed data and clear sky modeling for the upgrading of radiation data.
The effect of meter-scale lateral oxygen gradients at the sediment-water interface on selected organic matter based alteration, productivity and temperature proxies
Authors: Bogus K. A. , Zonneveld K. A. F. , Fischer D. , Kasten S. , Bohrmann G. , Versteegh G. J. M.
Published: April 2012

Abstract. A valid assessment of selective aerobic degradation on organic matter (OM) and its impact on OM-based proxies is vital to produce accurate environmental reconstructions. However, most studies investigating these effects suffer from inherent environmental heterogeneities. In this study, we used surface samples collected along two meter-scale transects and one longer transect in the northeastern Arabian Sea to constrain initial OM heterogeneity, in order to evaluate selective aerobic degradation on temperature, productivity and alteration indices at the sediment-water interface. All of the studied alteration indices, the higher plant alkane index, alcohol preservation index, and diol oxidation index, demonstrated that they are sensitive indicators for changes in the oxygen regime. Several export production indices, a cholesterol-based stanol/stenol index and dinoflagellate lipid- and cyst-based ratios, showed significant (more than 20%) change only over the lateral oxygen gradients. Therefore, these compounds do not exclusively reflect surface water productivity, but are significantly altered after deposition. Two of the proxies, glycerol dibiphytanyl glycerol tetraether-based TEX86 sea surface temperature indices and indices based on phytol, phytane and pristane, did not show any trends related to oxygen. Nevertheless, unrealistic sea surface temperatures were obtained after application of the TEX86, TEX86L, and TEX86H proxies. The phytol-based ratios were likely affected by the sedimentary production of pristane. Our results demonstrate the selective impact of aerobic organic matter degradation on the lipid and palynomorph composition of surface sediments along a short lateral oxygen gradient and suggest that some of the investigated proxies may be useful tracers of changing redox conditions at the sediment-water interface.
Dissolved organic matter in sea spray: a transfer study from marine surface water to aerosols
Authors: Schmitt-Kopplin P. , Liger-Belair G. , Koch B. P. , Flerus R. , Kattner G. , Harir M. , Kanawati B. , Lucio M. , Tziotis D. , Hertkorn N. , Gebefügi I.
Published: April 2012

Abstract. Atmospheric aerosols impose direct and indirect effects on the climate system, for example, by absorption of radiation in relation to cloud droplets size, on chemical and organic composition and cloud dynamics. The first step in the formation of Organic primary aerosols, i.e. the transfer of dissolved organic matter from the marine surface into the atmosphere, was studied. We present a molecular level description of this phenomenon using the high resolution analytical tools of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and nuclear magnetic resonance spectroscopy (NMR). Our experiments confirm the chemoselective transfer of natural organic molecules, especially of aliphatic compounds from the surface water into the atmosphere via bubble bursting processes. Transfer from marine surface water to the atmosphere involves a chemical gradient governed by the physicochemical properties of the involved molecules when comparing elemental compositions and differentiating CHO, CHNO, CHOS and CHNOS bearing compounds. Typical chemical fingerprints of compounds enriched in the aerosol phase were CHO and CHOS molecular series, smaller molecules of higher aliphaticity and lower oxygen content, and typical surfactants. A non-targeted metabolomics analysis demonstrated that many of these molecules corresponded to homologous series of oxo-, hydroxy-, methoxy-, branched fatty acids and mono-, di- and tricarboxylic acids as well as monoterpenes and sugars. These surface active biomolecules were preferentially transferred from surface water into the atmosphere via bubble bursting processes to form a significant fraction of primary organic aerosols. This way of sea spray production leaves a selective biological signature of the surface water in the corresponding aerosol that may be transported into higher altitudes up to the lower atmosphere, thus contributing to the formation of secondary organic aerosol on a global scale or transported laterally with possible deposition in the context of global biogeocycling.
First-order estimate of the planktic foraminifer biomass in the modern global oceans
Authors: Schiebel R. , Movellan A.
Published: April 2012

Abstract. Planktic foraminifera are heterotrophic mesozooplankton of global marine abundance. The position of planktic foraminifers in the marine food web is different compared to other protozoans and ranges above the base of heterotrophic consumers. Being secondary producers with an omnivorous diet, which ranges from algae to small metazoans, planktic foraminifers are not limited to a single food source, and are assumed to occur at a balanced abundance displaying the overall marine biological productivity at a regional scale. We have calculated the assemblage carbon biomass from data on standing stocks between the sea surface and 2500 m water depth, based on 754 protein-biomass data of 21 planktic foraminifer species and morphotypes, produced with a newly developed method to analyze the protein biomass of single planktic foraminifer specimens. Samples include symbiont bearing and symbiont barren species, characteristic of surface and deep-water habitats. Conversion factors between individual protein-biomass and assemblage-biomass are calculated for test sizes between 72 and 845 μm (minimum diameter). The calculated assemblage biomass data presented here include 1057 sites and water depth intervals. Although the regional coverage of database is limited to the North Atlantic, Arabian Sea, Red Sea, and Caribbean, our data include a wide range of oligotrophic to eutrophic waters covering six orders of magnitude of assemblage biomass. A first order estimate of the global planktic foraminifer biomass from average standing stocks (>125 μm) ranges at 8.5–32.7 Tg C yr−1 (i.e. 0.008–0.033 Gt C yr−1), and might be more than three time as high including the entire fauna including neanic and juvenile individuals adding up to 25–100 Tg C yr−1. However, this is a first estimate of regional planktic-foraminifer assemblage-biomass (PFAB) extrapolated to the global scale, and future estimates based on larger data-sets might considerably deviate from the one presented here. This paper is supported by, and a contribution to the Marine Ecosystem Data project (MAREDAT). Data are available from www.pangaea.de (http://doi.pangaea.de/10.1594/PANGAEA.777386).
Numerical uncertainty at mesoscale in a Lagrangian model in complex terrain
Authors: Brioude J. , Angevine W. M. , McKeen S. A. , Hsie E.-Y.
Published: April 2012

Abstract. Recently, it has been shown that mass conservation in Lagrangian models is improved by using time-average winds out of Eulerian models. In this study, we evaluate the mass conservation and trajectory uncertainties in complex terrain at mesoscale using the FLEXPART Lagrangian particle dispersion model coupled with the WRF mesoscale model. The specific form of vertical wind used is found to have a large effect. Time average wind with time average sigma dot (σ·), instantaneous wind with geometric cartesian vertical wind (w) and instantaneous wind with σ· are used to simulate mixing ratios of a passive tracer in forward and backward runs using different time interval outputs and horizontal resolutions in California. Mass conservation in the FLEXPART model was not an issue when using time-average wind or instantaneous wind with σ·. However, mass was poorly conserved using instantaneous wind with w, with a typical variation of 25% within 24 h. Uncertainties in surface residence time (a backtrajectory product commonly used in source receptor studies or inverse modeling) calculated for each backtrajectory run were also analyzed. The smallest uncertainties were systematically found when using time-average wind. Uncertainties using instantaneous wind with σ· were slightly larger, as long as the time interval of output was sufficiently small. The largest uncertainties were found when using instantaneous wind with w. Those uncertainties were found to be linearly correlated with the local average gradient of orography. Differences in uncertainty were much smaller when trajectories were calculated over flat terrain. For a typical run at mesoscale in complex terrain, 4 km horizontal resolution and 1 h time interval output, the average uncertainty and bias in surface residence time is, respectively 8.4% and −2.5% using time-average wind, and 13% and −3.7% using instantaneous wind with σ· in complex terrain. The corresponding values for instantaneous wind with cartesian w were 24% and −11%. While the use of time-average wind systematically improves uncertainty in FLEXPART, the improvements are small, and therfore a systematic use of time-average wind in Lagrangian models is not necessarily required. Use of cartesian vertical wind in complex terrain, however, should be avoided.