bluuebunny/crossref_metadata_2025 huggingface dataset:
Building Knowledge through the Cyber space
Authors: Zhang Jianwei , Chen Jingping
Published: April 2012

Knowledge building refers to social and collaborative processes to advance knowledge and ideas of value to a community, with individual learning and growth of members as an important by-product. Cyber environments to support knowledge building (e.g. Knowledge Forum) provide networked knowledge spaces where members contribute ideas and continually improve the ideas through collaborative discourse and other inquiry activities. Research on knowledge building using cyber environments sheds light on socio-cognitive and cultural dynamics underpinning knowledge building and technology-based designs to support such dynamics. In the context of education, research results demonstrate the possibility and benefits of engaging students in knowledge building early on to develop deep understanding in core subject areas and high-order competencies that are essential to 21st century careers.
Online Knowledge Sharing
Authors: Ma Will W.K.
Published: April 2012

The concept of knowledge sharing finds historical support in theories on the acquisition and creation of knowledge. While the key to knowledge sharing depends on frequent and regular social interaction, the recent rapid development of the Internet has enhanced much of the social interaction taking place among individuals at any time, at any place, and with any person. Through a review of the literature, this chapter defines online knowledge sharing, discusses the effects of intrinsic and extrinsic motivational factors in explaining online knowledge behavior, explores the various forms of knowledge sharing in different online learning environments, and reviews the measurement of online knowledge sharing. The chapter also discusses online knowledge-sharing issues that should be addressed in future.
Online Friendship
Authors: Tang Lijun
Published: April 2012

This entry reviews and discusses several issues regarding online friendship. After introducing two opposite perspectives: the cues-filtered-out perspective and the social information process theory, it examines empirical studies with particular focuses on online friendships development, comparisons between online friendship and its offline counterpart, and the impacts of online friendship on the offline life.
Consumers’ Adoption of Online Shopping
Authors: Cai Yi , Cude Brenda J.
Published: April 2012

Online shopping is a broadly defined activity that includes searching for product information, buying products or services, and communicating with retailers and other consumers. It has been described as a “flow experience:” consumers’ goal-directed as well as experiential activities on the Internet. Four factors, namely consumer characteristics, consumer perceptions, e-tailer attributes, and product characteristics, have been identified as the determinants of consumers’ adoption of online shopping. Researchers have developed and applied several theories and models, such as diffusion of innovation, theory of reasoned action, theory of planned behavior, and technology acceptance model, to explain why and how consumers shop online.
Cyber Behavior in Marketing
Authors: Varnali Kaan
Published: April 2012

Emerging online environments not only provide the most pertinent tools to enhance efficiency and effectiveness in a variety of daily and business-oriented tasks, but also drive and shape expectations, norms, lifestyle, and culture of the emerging crowd of postmodern consumers. These changes inflict a tremendous impact on the universe of marketing; hence, online human behavior has been drawing increasing attention from marketing scholars. The research of cyber behavior in marketing merits come from the relevant bodies of literature in multiple disciplines, including sociology, computer-mediated-communication, and Information Systems. The present chapter aims to present an overview of this accumulated scientific knowledge and highlight latest research trends on human behavior in cyber environments with a marketing-oriented focus.
E-Recruitment
Authors: Harman Reanna Poncheri , Thompson Lori Foster
Published: April 2012

E-recruitment uses the Internet to identify and attract prospective employees through media such as internet job boards (e.g., monster.com), organizational websites, and more recently, social media such as Twitter and LinkedIn.com. There are many advantages associated with the shift toward e-recruitment, such the ability to easily reach prospective applicants worldwide. However, there are also drawbacks, such as the time and effort required to sift through materials submitted by large numbers of unqualified applicants. Research conducted to date is limited but provides important first steps in understanding internet recruiting. It can be categorized into two main areas: 1) employer adoption of e-recruitment, and 2) applicant reactions to e-recruitment. Research is particularly limited when it comes to the employer’s perspective, while relatively more research has focused on applicant reactions to recruitment websites’ form, content, and function.
Physicians’ Acceptance of E-Health
Authors: Egea José Manuel Ortega
Published: April 2012

Physicians’ acceptance of e-health refers to physicians’ voluntary or intended use of e-health services or applications—defined as ‘‘health services and information delivered or enhanced through the Internet and related technologies” (Eysenbach, 2001). Physicians exert a crucial influence on the successful diffusion and implementation of health information technology, largely because of their service-generating role in health care. Drawing on the Technology Acceptance Model—TAM (Davis, Bagozzi, & Warshaw, 1989) and its extended/adapted versions, empirical evidence has accumulated to suggest the importance of cognitive instrumental processes—especially usefulness perceptions—in accounting for physicians’ acceptance of e-health. This chapter discusses physicians’ acceptance of four e-health applications: (1) Electronic prescriptions—i.e., IT-based management and automation of drug prescriptions; (2) EHCR systems—viewed as IT systems for electronic recording and storage of patient information; (3) Patient-physician and physician-physician online communication; and (iv) Telemonitoring applications—i.e., IT systems enabling remote monitoring of patients.
Cyber Support Venues for Cancer
Authors: Blank Thomas O. , Schmidt Steven D.
Published: April 2012

In recent years, many cancer patients and families have turned to the Internet for information and support. Cyber support venues to serve those needs vary from small newsgroups to discussion areas as part of comprehensive eHealth support systems. Two decades of research studies, mostly on breast and/or prostate cancer venues, indicate a range of users, including both patients and family members, and reveal both advantages and disadvantages compared to face-to-face support groups. Researchers have shown consistent differences about how breast and prostate sites are used, apparently due to both gender-based approaches to communication and support and different issues related to the different cancer types. Limited research indicates mostly positive psychological well-being impacts of participating on these venues. Future research is needed to further explore gender differences and examine how newer cyber venues, such as blogs, Facebook, and Twitter, become utilized by those facing cancer.
Internet Gambling Addiction
Authors: Kuss Daria J. , Griffiths Mark
Published: April 2012

As the Internet offers a new venue for gambling, the risks for engaging in pathological behaviors are potentially increased. In light of this, a systematic literature review was conducted in order to shed further light on the relationship between gambling on the Internet and possible addiction by assessing Internet gambling in general and addictive gambling on the Internet specifically. Based on previous research, it is argued that a combination of individual, situational, and structural characteristics determine whether and to what extent individuals engage in Internet gambling. The results suggest that there are more problem gamblers on the Internet than in land-based venues. A reason for this may be the structural characteristics of the Internet inherent to this technology, namely availability, ease of access, anonymity, and convenience. In conclusion, however, the Internet cannot be claimed to be addictive per sé, but rather to facilitate the engagement in addictive behaviors, including gambling.
Computer Vision Syndrome among Internet Users
Authors: Hu Liang , Lu Fan
Published: April 2012

The chapter is intended to introduce Computer Vision Syndrome (CVS), a widely spreading but largely unknown epidemic among professional and ordinary computer users, especially internet users. Dr. Sheedy and Dr. Anshel are two leading researchers in the ergonomics and optometry fields, and CVS has been extensively studied in these fields. The authors have summarized their views about CVS, including five major symptoms of CVS, three key contributing factors of CVS, and basic preventive and treatment strategies. Future researches are needed to continue the advancement of current knowledge regarding computer screens, computer task, and computer environments, and to expand research in diverse computer user populations, especially younger computer users.
Internet Crimes against Children
Authors: Durkin Keith F. , DeLong Ronald L.
Published: April 2012

Internet crimes against children are a contemporary social problem which has drawn a great deal of attention from the parents, educators, legislators, and law enforcement officials. This phenomenon has captured national attention in the United States with a number of media reports of this phenomenon. These crimes include child pornography offenses, as well as adults soliciting minors for sexual purposes on line. Drawing upon data from recent national surveys, the characteristics of offenses, offenders, and victims are examined. A multitude of issues related to the assessment and classification of the individuals who commit Internet crimes against children are also explored. Strategies for the prevention of this behavior and enforcement of laws protecting children online are discussed.
Unwanted Online Sexual Solicitation and Online Sexual Risk Behavior
Authors: Baumgartner Susanne E. , Valkenburg Patti M. , Peter Jochen
Published: April 2012

In recent years, there have been growing concerns about online sexual solicitations and online sexual risk behaviors. Recent studies suggest that only a minority of adolescents is confronted with online sexual solicitations or engages in online sexual risk behavior. Whereas more girls encounter incidences of online sexual solicitations, gender differences in online sexual risk behavior are relatively small. Older adolescents are more at risk of receiving online sexual solicitations and are also more likely to engage in online sexual risk behavior. Adolescents do not engage in online sexual risk behavior more frequently than adults, and they seem to be quite aware of the potential negative consequences of this behavior. Adolescents who encounter online sexual solicitations or engage in online sexual risk behavior typically also encounter problems in their offline lives.
Online Abuse
Authors: Bossler Adam M. , Holt Thomas J.
Published: April 2012

The development of computers, cell phones, and the Internet allows individuals to connect with one another with ease in a variety of ways in near real time. The beneficial impact of these resources, however, has been adulterated by some to engage in abusive communications while online. Specifically, individuals now use email, text messaging, and social networking sites to spread hurtful or malicious information about others. This entry summarizes the problem of online abuse via cyberbullying, online harassment, and stalking by discussing the prevalence of these phenomena as well as the prospective predictors of victimization.
Internet Safety
Authors: Sasaki Yuriko , Hobbs Jon
Published: April 2012

Internet safety has become a great concern in daily life. This entry provides information about Internet safety in terms of: (1) psychological well-being; (2) online privacy; (3) cyberbullying; and (4) exposure to sexual content. As part of the narrative, the authors discuss problematic Internet use, online communication and psychological factors, breaches of online privacy, privacy concerns, privacy protection behaviors (online privacy), cyberbullying (Internet harassment), online pornography, and sexual offenders. For each topic, the authords identify factors that are related to Internet safety and the potential for harm in online and offline contexts.
The Democratic Divide
Authors: Min Seong-Jae
Published: April 2012

The democratic divide, or the political participation gap in cyberspace, raises a critical social question as it suggests that new communication technologies, which are expected to contribute to the development of all humans, actually widen the political inequalities among different segments of people. Studies of the democratic divide show that human behavior in cyberspace is not equal, as individuals possess different levels of digital literacy and political motivation. The democratic divide will likely persist in a variety of forms.
E-learning Behaviors in Middle School
Authors: Guinee Kathleen
Published: April 2012

E-learning occurs throughout the middle school curriculum. Children use computers and the Internet to learn skills, complete assignments, and deepen their understanding of concepts. Supplementary computer software helps students build literacy skills, while digital texts provide affordances and challenges for comprehension and learning. During Web-based research, students leverage literacy and technical skills to accumulate knowledge. Students can use word processing or multimedia to demonstrate their learning. Simulations help create authentic learning experiences in the content areas and promote the transfer of learned skills. Even with the introduction of new technologies, teacher quality and classroom structure are important for student learning. Home video game and computer use also impacts students’ academic performance. Future research should continue to investigate the impact of e-learning on middle school students’ learning and development.
Cyber Behavior in Social Studies Education
Authors: Berson Michael J. , Sheffield Caroline C.
Published: April 2012

Events throughout the world have demonstrated the powerful use of technology to shape political ideas, give people a voice, and impact human behavior. The field of social studies education has long been a proponent for the use of technology; however, educators continue to be eluded by a paucity of studies to validate the effectiveness of implementation through longitudinal and outcome-based research. Key areas of focus for the social studies include digital citizenship, the evolution of the electronic republic, the Internet’s impact on political elections and movements, the rise of participatory democracy in cyberspaces, the power of the Internet to transform society through social networks, and the potential to transcend physical boundaries to promote community building and global interaction.
Learning Languages in Cyberspace
Authors: Meskill Carla , Guan Shuyi , Ryu Dongwan
Published: April 2012

A great deal of formal and informal language learning and teaching is taking place in cyberspace. A number of theoretically motivated affordances for online language learning point to why this is the case. In the last decade, these affordances have been identified and empirically examined in a number of studies. This entry synthesizes the extant research on these online language education activities and the state of current understanding regarding the potential of teaching and learning languages in cyberspace.
Students’ Cyber-Plagiarism
Authors: Kakkonen Tuomo , Mozgovoy Maxim
Published: April 2012

Educational institutions fight against students’ plagiarism, because plagiarizing contradicts the most basic learning principles. Among ways of countering student plagiarism include understanding the reasons behind it and developing measures to detect and prevent it. Wide availability of text and other resources on the Internet makes plagiarizing easy and, thus, commonplace among students. Students’ cyber-plagiarism sets new challenges to educational institutions. Computers and technology, however, also provide solutions to the problem; plagiarism detection and prevention can be supported by automatic detection technologies that help to reveal instances of plagiarism. Ongoing research in student cyber-plagiarism is also concerned with the various ethical questions that plagiarism and its detection arise.
The Origin and Current Status of Cyberpsychology in Russia
Authors: Voiskounsky Alexander
Published: April 2012

Theory, history (several decades long), and the current status of the studies in cyberpsychology in the USSR and later in Russia are presented in a condensed form. Socio-historic theory of psychic development, introduced by Vygotsky in 1930s, and particularly ideas of semiotic mediation, seem to offer the best perspectives in cyberpsychological studies. A brief historic overview in this article combines general conclusions and personal memories. Directions of the current studies are briefly described as well. This section starts with studies made within the new communities which emerged with the advance of information technologies; special attention is given to hackers and gamers. The section proceeds with the studies of children’s behavior on the Internet. Finally, research in the field of Internet Addiction Disorder is discussed. The current status of cyberpsychology as a non-universally accepted discipline, in which new generations of specialists are deeply interested, is discussed. Methodological work is presented as the major source of progress in the near future. The reference section includes publications in English and several recommended books which are available exclusively in Russian.
Fyn Promotes Th17 Differentiation by Regulating the Kinetics of RORγt and Foxp3 Expression
Authors: Ueda Aki , Zhou Liang , Stein Paul L.
Published: April 2012

Th17 cells constitute a proinflammatory CD4+ T cell subset that is important for microbial clearance, but also are implicated as propagators of various autoimmune pathologies. Evidence suggests that Th17 cells share common progenitors with immunosuppressive CD4+ inducible regulatory T cells (TREG) and that the developmental pathways of these two subsets are reciprocally regulated. In this study, we show evidence that the Src family tyrosine kinase Fyn helps regulate this Th17/TREG balance. When placed under Th17-skewing conditions, CD4+ T cells from fyn−/− mice had decreased levels of IL-17, but increased expression of the TREG transcription factor Foxp3. The defect in IL-17 expression occurred independently of the ectopic Foxp3 expression and correlated with a delay in retinoic acid-related orphan receptor γt upregulation and an inability to maintain normal STAT3 activation. Fyn-deficient Th17 cells also exhibited delayed upregulation of Il23r, Il21, Rora, and Irf4, as well as aberrant expression of Socs3, suggesting that Fyn may function upstream of a variety of molecular pathways that contribute to Th17 polarization. The fyn−/− mice had fewer IL-17+CD4+ T cells in the large intestinal lamina propria compared with littermate controls. Furthermore, after transfer of either wild-type or fyn−/− naive CD4+ T cells into Rag1−/− hosts, recipients receiving fyn−/− cells had fewer IL-17–producing T cells, indicating that Fyn may also regulate Th17 differentiation in vivo. These results identify Fyn as a possible novel regulator of the developmental balance between the Th17 cell and TREG subsets.
Regulation of Cytosolic Phospholipase A2 Phosphorylation by Proteolytic Cleavage of Annexin A1 in Activated Mast Cells
Authors: Kwon Joon Hyun , Lee Jea Hwang , Kim Ki Soon , Chung Youn Wook , Kim Ick Young
Published: April 2012

Annexin A1 (ANXA1) is cleaved at the N terminal in some activated cells, such as macrophages, neutrophils, and epithelial cells. We previously observed that ANXA1 was proteolytically cleaved in lung extracts prepared from a murine OVA-induced asthma model. However, the cleavage and regulatory mechanisms of ANXA1 in the allergic response remain unclear. In this study, we found that ANXA1 was cleaved in both Ag-induced activated rat basophilic leukemia 2H3 (RBL-2H3) cells and bone marrow-derived mast cells. This cleavage event was inhibited when intracellular Ca2+ signaling was blocked. ANXA1-knockdown RBL-2H3 cells produced a greater amount of eicosanoids with simultaneous upregulation of cytosolic phospholipase A2 (cPLA2) activity. However, there were no changes in degranulation activity or cytokine production in the knockdown cells. We also found that cPLA2 interacted with either full-length or cleaved ANXA1 in activated mast cells. cPLA2 mainly interacted with full-length ANXA1 in the cytosol and cleaved ANXA1 in the membrane fraction. In addition, introduction of a cleavage-resistant ANXA1 mutant had inhibitory effects on both the phosphorylation of cPLA2 and release of eicosanoids during the activation of RBL-2H3 cells and bone marrow-derived mast cells. These data suggest that cleavage of ANXA1 causes proinflammatory reactions by increasing the phosphorylation of cPLA2 and production of eicosanoids during mast-cell activation.
Protein Kinase C-θ Inhibits Inducible Regulatory T Cell Differentiation via an AKT-Foxo1/3a–Dependent Pathway
Authors: Ma Jian , Ding Yan , Fang Xianfeng , Wang Ruiqing , Sun Zuoming
Published: April 2012

Protein kinase C (PKC)-θ has been shown to be a critical TCR signaling molecule that promotes the activation and differentiation of naive T cells into inflammatory effector T cells. In this study, we demonstrate that PKC-θ–mediated signals inhibit inducible regulatory T cell (iTreg) differentiation via an AKT-Foxo1/3A pathway. TGF-β–induced iTreg differentiation was enhanced in PKC-θ−/− T cells or wild-type cells treated with a specific PKC-θ inhibitor, but was inhibited by the PKC-θ activator PMA, or by CD28 crosslinking, which enhances PKC-θ activation. PKC-θ−/− T cells had reduced activity of the AKT kinase, and the expression of a constitutively active form of AKT in PKC-θ−/− T cells restored the ability to inhibit iTreg differentiation. Furthermore, knockdown or overexpression of the AKT downstream targets Foxo1 and Foxo3a was found to inhibit or promote iTreg differentiation in PKC-θ−/− T cells accordingly, indicating that the AKT-Foxo1/3A pathway is responsible for the inhibition of iTreg differentiation of iTregs downstream of PKC-θ. We conclude that PKC-θ is able to control T cell-mediated immune responses by shifting the balance between the differentiation of effector T cells and inhibitory Tregs.
Dendritic Cell-Specific Ablation of the Protein Tyrosine Phosphatase Shp1 Promotes Th1 Cell Differentiation and Induces Autoimmunity
Authors: Kaneko Tetsuya , Saito Yasuyuki , Kotani Takenori , Okazawa Hideki , Iwamura Hiroko , Sato-Hashimoto Miho , Kanazawa Yoshitake , Takahashi Satoshi , Hiromura Keiju , Kusakari Shinya , Kaneko Yoriaki , Murata Yoji , Ohnishi Hiroshi , Nojima Yoshihisa , Takagishi Kenji , Matozaki Takashi
Published: April 2012

Dendritic cells (DCs) promote immune responses to foreign Ags and immune tolerance to self-Ags. Deregulation of DCs is implicated in autoimmunity, but the molecules that regulate DCs to protect against autoimmunity have remained unknown. In this study, we show that mice lacking the protein tyrosine phosphatase Shp1 specifically in DCs develop splenomegaly associated with more CD11c+ DCs. Splenic DCs from the mutant mice showed upregulation of CD86 and CCR7 expression and of LPS-induced production of proinflammatory cytokines. The mice manifested more splenic Th1 cells, consistent with the increased ability of their DCs to induce production of IFN-γ by Ag-specific T cells in vitro. The number of splenic CD5+CD19+ B-1a cells and the serum concentrations of Igs M and G2a were also increased in the mutant mice. Moreover, aged mutant mice developed glomerulonephritis and interstitial pneumonitis together with increased serum concentrations of autoantibodies. Shp1 is thus a key regulator of DC functions that protects against autoimmunity.
Dental Bleaching with 35 and 38% Hydrogen Peroxide and Immersion in Soft Drink: Analysis by Reflectance and Fourier Transform-Raman Spectroscopy
Authors: Torres Carlos Rocha Gomes , Jeronymo Raffaela Di Iorio , da Silva Eduardo Galera , Huhtala Maria Filomena Rocha Lima , Gomes Ana Paula Martins , de Luca Alves Gustavo , Munin Egberto
Published: April 2012

Objective

The aim of this study was to evaluate the effects of dental bleaching with 35 and 38% hydrogen peroxide and soft drink immersion on the chemistry and color of the bovine enamel fragments before and after treatment using reflectance and Fourier transform-Raman spectroscopy (FT-Raman spectroscopy).

Materials and methods

Sixty bovine enamel fragments were prepared and randomly divided into six experimental groups according to the hydrogen peroxide gel concentration or immersion in soft drink (n = 10): G1-Whiteness HP Maxx; G2-Whiteness HP Maxx + light lemon coke immersion; G3-Opalescence Xtra Boost; G4-Opalescence Xtra Boost + light lemon coke immersion; G5-Whiteform Perox Red Form gel; G6-Whiteform Perox Red Form gel + light lemon coke immersion. The bleaching treatment was performed in two sessions with a 7 days interval and the analysis before treatments were used as control (baseline). Samples were submitted to reflectance and FT-Raman spectroscopy analysis to evaluate surface mineral content and the reflectance before and after treatments.

Results

There was no significant statistical difference among the bleaching agents in the reflectance analysis (p = 0.63). The FT-Raman spectroscopy data showed significant loss in enamel mineral content after immersion in the light lemon coke and statistical significant differences for the interactions between ‘bleaching agent’ and ‘immersion in soft drink’ (p = 0.03) and between ‘bleaching agent’ and ‘time’ (p = 0.04). With regards to the whitened specimens, the Opalescence Xtra Boost agent demonstrated the greatest loss in enamel mineral content.

Conclusion

All bleaching agents exhibited great bleaching potential in reflectance analysis. This highly concentrated hydrogen peroxide gel (38%) changed significantly the enamel mineral content with or without immersion in soft drink. The specimens immersed in soft drink showed significant loss in enamel mineral content.

Clinical relevance

Some investigations have shown that hydrogen peroxide and beverages can modify enamel dental components, but more studies are necessary to explain its effects.
Management of Animal Bite Wounds on Face: Our Experience
Authors: Anup Kumar G , Mathur Abhishek , Ramesh Keerthi
Published: April 2012

Bite wounds are among the commonest types of trauma to which the man is subjected. Infection is the most common complication in animal bite wounds. The surgical treatment of facial animal bites remains a source of controversy. The controversies continue to center on the timing of wound debridement and primary wound closure as well as the use of antibiotic prophylaxis and primary plastic reconstruction. We report 30 cases of animal bites treated in our department and our protocol in the management of the same.
Nanostructure of Crystal Hydroxyapatite from Fluorosis: Affected Enamel
Authors: Nasution Abdillah Imron
Published: April 2012

Fluorosis is a condition due to ingestion of excessive amounts of fluor which can cause the change the teeth structure and strength. Currently, a little explanation was available to describe the surface and change of nanostructure crystal hydroxyapatite which contribute to influence the macrocharacteristic of fluorosis enamel.

Aims and objectives

To describe the change of surface structure, c-axis, a-axis and grain size of crystal hydroxyapatite on fluorosis enamel.

Materials and methods

This research was carried out the fluorosis and normal enamel specimen by using scanning electron microscopy/ energy disperse X-ray (SEM/EDX) to determine fluor concentration and the surfaces structure of fluorosis enamel, and powder X-ray diffraction (XRD) to determine change of c- and a-axis of hydroxyapatite of fluorosis enamel.

Results

Fluor concentration were higher in fluorosis enamel and the surface increasingly roughness and porous. SEM/EDX also confirmed gaps areas between enamel rods and visible aprismatic zone in some regions. The axis on fluorosis enamel was a-axis = 9.3786 Å and c-axis = 6.8836 Å. The a-axis on normal enamel was = 9.4148 Å and c-axis = 6.8791 Å. Grain size of fluorosis enamel was 19.59 nm and normal enamel was 20.30 nm.

Conclusion

Fluor as most electronegative element changes the c-axis, a-axis, and grain size of crystal hydroxyapatite and generates the internal atomic bonding which influences the stability of enamel strength.
Immunofluorescence in Oral Pathology: Part I—Methodology
Authors: Premalatha BR , Rao Roopa S , Mysorekar Vijaya
Published: April 2012

Immunofluorescence is an immunological method used to demonstrate the presence of antigen and antibodies in tissues or serum. Immunofluorescence techniques have become indispensable in modern pathology laboratories and have greatly contributed to the diagnosis, treatment and understanding of autoimmune bullous diseases, hereditary bullous diseases, collagen-vascular diseases, many inflammatory dermatosis and cutaneous tumors. This review emphasizes the basics of immunofluorescence techniques, methodology, interpretation of the results and the newer advancements in the field.

The application of immunofluorescence techniques in various vesiculobullous disorders will be extensively discussed in the subsequent parts. Part II will deal with the pemphigus group and other dermatological conditions with oral involvement and part III with subepidermal immunobullous diseases.
When the Unthinkable Happens: Universal Work Precautions and Postexposure Prophylaxis in HIV
Authors: Ramdurg Praveen , Kambale Sharanappa , Mendigeri Vijaylaxmi B , Fayyaz Mohammad
Published: April 2012

Postexposure prophylaxis (PEP) with antiretrovirals is now widely used worldwide after either occupational contact (with blood or another blood-containing fluid), or nonoccupational contact (mainly sexual or injection-drug use). It is assumed to reduce the risk of HIV transmission by at least 80%, although its efficacy has not been completely proven. Several countries have issued guidelines to help the clinician in their decision to offer PEP and to improve its cost-effectiveness. This article reviews the different antiretroviral combinations used, their safety profile, the recommendations and indications of PEP.
Prosthetic Full Mouth Rehabilitation in a Case of Xerostomia following Radiation Therapy for Carcinoma of Esophagus: A Clinical Case Report
Authors: Shetty Karunakar B , Jayashankar Deepa
Published: April 2012

Aim of the study

Complete rehabilitation of a 38-year-old female patient with radiation caries and xerostomia postirradiation therapy for the treatment of carcinoma of esophagus, by a multidisciplinary approach involving specialties of periodontics, endodontics and prosthodontics.

This 38-year-old female patient presented with missing teeth, ill fitting prosthesis, radiation caries and xerostomia as a consequence of radiation therapy. In addition, the patient was severely psychologically affected not just due to the carcinoma, but also due to the adverse effects of cancer therapy. Therefore, rehabilitation of such a patient was aimed not just at careful oral reconstruction of lost and damaged structures but also towards providing a boost to her self-esteem. The outcome of this multidisciplinary approach led to a completely wellrehabilitated patient, both orally as well as psychologically.
Dentin Bonding Agents I: Complete Classification—A Review
Authors: Kakar Surbhi , Kanase Anoop
Published: April 2012

Traditional mechanical methods of retaining restorative materials have been replaced to a large extent by tooth conserving adhesive restorative techniques. Bonding techniques allow more conservative tooth preparation. Less reliance on macromechanical retention and less removal of unsupported enamel because adhesives have been evolving, so rapidly for the last few years, as the timing is right for evaluating the clinical status of present day adhesives. The purpose of this article is to provide a concise, comprehensive and updated classification of dentin bonding agents. Current products are highlighted to improve clinical use and performance of the materials.
Silane Films Modified with Yttrium Oxide Nanoparticles for Improved Corrosion Resistance of AA6061-T6
Authors: Zhang S.-L. , Zhang M.-M. , Yao Y. , Sun F.
Published: April 2012

The present work strives to evaluate the corrosion resistance of aluminum alloy (AA)6061-T6 (UNS A96061) pretreated with bis-1,2-[triethoxysiyl]ethane silane (BTSE) solution containing different contents of yttrium oxide (Y2O3) nanoparticles. The corrosion resistance of the pretreated AA6061-T6 substrates was investigated with potentiodynamic polarization curves and the neutral salt spray (NSS) test. The morphologies of the silane film were observed using scanning electron microscopy (SEM). The results indicated that the presence of small amounts of Y2O3 nanoparticles in BTSE solutions can increase the corrosion resistance of the silane films in 3.5% sodium chloride (NaCl) solution. Y2O3 nanoparticles do not change the behavior of the electrode reaction. The formed silane film acts as a physical barrier for the protection of aluminum alloy. The SEM images indicated that the surface morphologies of silane films formed were flat and compact, when the contents of the Y2O3 nanoparticles in BTSE solutions were between 10 ppm and 20 ppm.
Unusually low ozone, HCl, and HNO3 column measurements at Eureka, Canada during winter/spring 2011
Authors: Lindenmaier R. , Strong K. , Batchelor R. L. , Chipperfield M. P. , Daffer W. H. , Drummond J. R. , Duck T. J. , Fast H. , Feng W. , Fogal P. F. , Kolonjari F. , Manney G. L. , Manson A. , Meek C. , Mittermeier R. L. , Nott G. J. , Perro C. , Walker K. A.
Published: April 2012

Abstract. As a consequence of dynamically variable meteorological conditions, springtime Arctic ozone levels exhibit significant interannual variability in the lower stratosphere. In winter 2011, the polar vortex was strong and cold for an unusually long time. Our research site, located at Eureka, Nunavut, Canada (80.05° N, 86.42° W), was mostly inside the vortex from October 2010 until late March 2011. The Bruker 125HR Fourier transform infrared spectrometer installed at the Polar Environment Atmospheric Research Laboratory at Eureka acquired measurements from 23 February to 6 April during the 2011 Canadian Arctic Atmospheric Chemistry Experiment Validation Campaign. These measurements showed unusually low ozone, HCl, and HNO3 total columns compared to the previous 14 yr. To remove dynamical effects, we normalized these total columns by the HF total column. The normalized values of the ozone, HCl, and HNO3 total columns were smaller than those from previous years, and confirmed the occurrence of chlorine activation and chemical ozone depletion. To quantify the chemical ozone loss, a three-dimensional chemical transport model, SLIMCAT, and the passive subtraction method were used. The chemical ozone depletion was calculated as the mean percentage difference between the measured ozone and the SLIMCAT passive ozone, and was found to be 35%.
Missing OH source in a suburban environment near Beijing: observed and modelled OH and HO2 concentrations in summer 2006
Authors: Lu K. D. , Hofzumahaus A. , Holland F. , Bohn B. , Brauers T. , Fuchs H. , Hu M. , Häseler R. , Kita K. , Kondo Y. , Li X. , Lou S. R. , Oebel A. , Shao M. , Zeng L. M. , Wahner A. , Zhu T. , Zhang Y. H. , Rohrer F.
Published: April 2012

Abstract. Measurements of ambient OH and HO2 radicals were performed by laser induced fluorescence (LIF) during CAREBeijing2006 (Campaigns of Air Quality Research in Beijing and Surrounding Region 2006) at the suburban site Yufa in the south of Beijing in summer 2006. On most days, local air chemistry was influenced by aged air pollution that was advected by a slow, almost stagnant wind from southern regions. Observed daily maxima of OH and HO2* were in the range of (4–17) × 106 cm−3 and (2–24) × 108 cm−3, respectively. During daytime, OH reactivities were generally high (10–30 s−1) and mainly contributed by VOCs and their oxidation products. The comparison of modelled and measured HOx concentrations reveals a systematic underprediction of OH as a function of NO. A large discrepancy of a factor 2.6 is found at the lowest NO concentration encountered (0.1 ppb), whereas the discrepancy becomes insignificant above 1 ppb NO. This study extends similar observations from the Pearl-River Delta (PRD) in South China to a more urban environment. The OH discrepancy at Yufa can be resolved, if NO-independent additional OH recycling is assumed in the model. The postulated Leuven Isoprene Mechanism (LIM) has the potential to explain the gap between modelled and measured OH at Beijing taking into account conservative error estimates, but still lacks experimental confirmation. This and the hereby unresolved discrepancy at PRD suggest that other VOCs besides isoprene might be involved in the required, additional OH recycling. Fast primary production of ROx radicals up to 7 ppb h−1 was determined at Beijing which was dominated by the photolysis of O3, HONO, HCHO, and dicarbonyls. For a special case, 20 August, when the plume of Beijing city was encountered, a missing primary HOx source (≈ 3 ppb h−1) was determined under high NOx conditions similar to other urban areas like Mexico city. CAREBeijing2006 emphasizes the important role of OVOCs as a radical source and sink, and the need for further investigation of the chemical degradation of VOCs in order to better understand radical chemistry in VOC-rich air.
Trends of particulate matter (PM2.5) and chemical composition at a regional background site in the Western Mediterranean over the last nine years (2002–2010)
Authors: Cusack M. , Alastuey A. , Pérez N. , Pey J. , Querol X.
Published: April 2012

Abstract. The time variability and long term trends of PM2.5 (particulate matter of diameter <2.5 μm) at various regional background (RB) sites across Europe are studied and interpreted in this work. Long-term trends of PM2.5 concentrations are relatively scarce across Europe, with few studies outlining the changes measured in PM2.5 concentrations over a significant period of time. To this end, data on mean annual levels of PM2.5 measured at Montseny (MSY, North East Spain) and various RB sites in Spain and Europe are evaluated and compared, and subsequently analysed for statistically significant trends. The MSY site registered higher average PM2.5 levels than those measured at a selection of other RB sites across Spain, Portugal, Germany and Scandinavia, but lower than those measured in Switzerland, Italy and Austria. Reductions in PM2.5 were observed across all stations in Spain and Europe to varying degrees. MSY underwent a statistically significant reduction since measurements began, indicating a year-on-year gradual decrease (−3.7 μg m−3, calculated from the final year of data compared to the mean). Similar trends were observed in other RB sites across Spain (−1.9 μg m−3). Reductions recorded in PM2.5 across Europe were varied, with many experiencing gradual, year-on-year decreases (−1.8 μg m−3). These reductions have been attributed to various causes: the introduction and implementation of pollution abatement strategies in EU member states, the effect of the current economic crisis on emissions of PM2.5 and the influence of anomalous meteorology observed during the winters of 2009 and 2010. The North Atlantic Oscillation (NAO), a large scale meteorological phenomenon most prevalent during winter, was observed to influence the frequency of Saharan dust intrusions across the Iberian Peninsula. Chemical composition of PM2.5 at MSY is characterised by high levels of organic matter (OM) and sulphate, followed by crustal material, nitrate and ammonia. Sea Spray and finally elemental carbon (EC) comprised a minor part of the total PM2.5 mass. Statistical trend analysis was performed on the various chemical components of PM2.5 recorded at MSY to determine which components were accountable for the decrease in PM2.5 concentration. It is shown that OM underwent the largest decrease over the time period with a statistically significant trend (−1.3 μg m−3 of the mean), followed by sulphate (−0.8 μg m−3), ammonium (−0.5 μg m−3) and nitrate (−0.4 μg m−3). Conversely, sea spray, EC and crustal material reductions were found to be negligible.
Determination of optical and microphysical properties of thin warm clouds using ground based hyper-spectral analysis
Authors: Hirsch E. , Agassi E. , Koren I.
Published: April 2012

Abstract. Clouds play a critical role in the Earth's radiative budget as they modulate the atmosphere by reflecting shortwave solar radiation and absorbing long wave IR radiation emitted by the Earth's surface. Although extensively studied for decades, cloud modelling in global circulation models is far from adequate, mostly due to insufficient spatial resolution of the circulation models. In addition, measurements of cloud properties still need improvement, since the vast majority of remote sensing techniques are focused in relatively large, thick clouds. In this study, we utilize ground based hyperspectral measurements and analysis to explore very thin water clouds. These clouds are characterized by liquid water path (LWP) that spans from as high as ~50g m−2 and down to 65 mg m−2 with a minimum of about 0.01 visible optical depth. The retrieval methodology relies on three elements: a detailed radiative transfer calculations in the longwave IR regime, signal enhancement by subtraction of a clear sky reference, and spectral matching method which exploits fine spectral differences between water droplets of different radii. A detailed description of the theoretical basis for the retrieval technique is provided along with a comprehensive discussion regarding its limitations. The proposed methodology was validated in a controlled experiment where artificial clouds were sprayed and their effective radii were both measured and retrieved simultaneously. This methodology can be used in several ways: (1) the frequency and optical properties of very thin water clouds can be studied more precisely in order to evaluate their total radiative forcing on the Earth's radiation budget. (2) The unique optical properties of the inter-region between clouds (clouds' "twilight zone") can be studied in order to more rigorously understanding of the governing physical processes which dominate this region. (3) Since the optical thickness of a developed cloud gradually decreases towards its edges, the proposed methodology can be used to study the spatial microphysical behaviour of these edges. (4) A spatial-temporal analysis can be used to study mixing processes in clouds' entrainment zone.
Water supply patterns in two agricultural areas of Central Germany under climate change conditions
Authors: Tölle M. H. , Moseley C. , Panferov O. , Busch G. , Knohl A.
Published: April 2012

Abstract. Increasing emissions of greenhouse gases and increasing prices for fossil fuels have highlighted the demand for CO2 "neutral" renewable energy sources, e.g. short rotation forestry systems used for bioenergy. These systems might be vulnerable to changes in temperature, precipitation and occurrence of extreme weather events. To estimate success or failure of such short rotation coppices in a certain area we need regional climate projections and risk assessment. Changes of water supply patterns in two agriculturally extensively used regions in Central Germany (around Göttingen and Großfahner) with different climate conditions but both in the temperate climate zone are explored. The study is carried out under present conditions as well as under projected climate change conditions (1971–2100) using A1B and B1 climate scenarios downscaled for Europe. Analysis of precipitation bias shows regional differences: a strong bias in Göttingen area and a weaker bias in the Großfahner area. A bias correction approach, Quantile mapping, is applied to the ensemble results for both areas for winter and summer seasons. By using quantile regression on the seasonal Standardized Precipitation Indices (SPIs) as indicator for water supply conditions we found that precipitation is expected to increase in winter in all quantiles of the distribution for Göttingen area during the 21th century. Heavy precipitation is also expected to increase for Großfahner area suggesting a trend to wetter extremes in winter for the future. This winter precipitation increase could trigger runoff and soil erosion risk enhancing the severity of floods. Increasing winter availability of water could enhance local water supply in spring. For both areas no significant change in summer was found over the whole time period. Although the climate change signal of the SPI indicate mild dryer conditions in summer at the end of the 21st century which may trigger water shortage and summer drying associated with above–average temperatures in the future. Even though both study areas are close together Großfahner area was found to be the least affected one by changes indicating that small spatial scale differences matter. These developments were found in all examined simulation runs. This study highlighted the regional differences in the vulnerability to water surplus or deficit risks in a temperate system which emphasizes the need in impact studies to focus on proper consideration of local and regional environmental conditions as well as adaption and mitigation of management for agriculture.