bluuebunny/crossref_metadata_2025 huggingface dataset:
Stepping into the (Social Media) Game
Authors: Sanderson Jimmy
Published: September 2012

This chapter explores how rookie athletes in Major League Baseball (MLB), the National Basketball Association (NBA), National Football League (NFL), and National Hockey League (NHL), used Twitter as an identity expression tool. A representative sample of tweets from athletes selected in the first round of the 2011 amateur draft of each sports league was selected for analysis. Results revealed that identity manifested in the following ways: (a) Athletes as dedicated workers; (b) Athletes as pop culture consumers; (c) Athletes as sports fans; (d) Athletes as motivators; (e) Athletes as information seekers; and (f) Athletes as everyday people. Through social media, athletes can more actively and diversely assert their identity. This action fosters identification, liking, and parasocial interaction with fans as athletes appear more approachable and similar. The ability to construct and disseminate a variety of identities holds important implications for athletes, which are discussed in the concluding section of the chapter.
Self, Self-Presentation, and the Use of Social Applications in Digital Environments
Authors: Ribeiro José Carlos , Silva Tarcízio
Published: September 2012

This chapter discusses the use of social applications in the process of the constitution of the self and the production of the self-presentation in digital environments. It examines two modalities: (1) the use of social applications that promote the comparative analysis of actions, speeches, and performance repercussions taken place in the digital environment, and (2) the use of applications and systems that enable the retrieval of the users’ social information in a systematic, sequential, and historical perspective. It also discusses how these applications present users with different methods of monitoring, controlling, visualizing, and planning information that is published not only by individuals themselves but also by the interacting individuals in the social digital environment.
Social Networking and Identity
Authors: Barker Rachel
Published: September 2012

The realisation that social networks in cyberspace create a different virtual setting where a Technoself can be created by the way an individual shape their self (body and identity) to their own as well as society’s liking, elicits a notion that there was once either an ideal era of bliss or a Utopian promise of universal self-realisation. From a communicative perspective, this chapter propagates how social networks and identity are consequences of the accelerating rate of change and the subsequent ‘cyber revolution’.
The Need for Identity Construction in Computer-Mediated Professional Communication
Authors: Ho Victor
Published: September 2012

This chapter discusses the construction of personal identities by individuals of the same rank through the discourse they constructed while engaging in computer-mediated professional communication in the workplace. First, it discusses the need for the members of three different communities of practice to construct desirable personal identities via their daily computer-mediated professional communication. Second, it discusses how the members constructed these identities through the e-mail discourse they composed by exploiting various discursive strategies. Drawing upon systemic functional grammar, influence tactics, interdiscursivity, and rapport and rapport management, a total of 89 request e-mails were analyzed. The present study intends to bring to the fore the importance of the choice of language in professional communication in general, and in e-mail in particular, thereby enabling professionals to both encode and decode workplace communication in a more comprehensive manner.
A Human Affect Recognition System for Socially Interactive Robots
Authors: McColl Derek , Nejat Goldie
Published: September 2012

This chapter presents a real-time robust affect classification methodology for socially interactive robots engaging in one-on-one human-robot-interactions (HRI). The methodology is based on identifying a person’s body language in order to determine how accessible he/she is to a robot during the interactions. Static human body poses are determined by first identifying individual body parts and then utilizing an indirect 3D human body model that is invariant to different body shapes and sizes. The authors implemented and tested their technique using two different sensory systems in social HRI scenarios to motivate its robustness for the proposed application. In particular, the experiments consisted of integrating the proposed body language recognition and affect classification methodology with imaging-based sensory systems onto the human-like socially interactive robot Brian 2.0 in order for the robot to recognize affective body language during one-on-one interactions.
Just Doesn’t Look Right
Authors: Carpenter Julie
Published: September 2012

This chapter provides a critical analysis of the potential short- and long-term cultural, emotional, and ethical outcomes facing Explosive Ordnance Disposal (EOD) specialists working closely with anthropomorphic robots in daily team situations as viewed through the interdisciplinary lens of Human-Robot Interaction (HRI) research. Effective small group communication and decision-making is especially critical for EOD teams. Communication failures cause immediate safety concerns, potential physical and psychological harm to EOD team members, and similar repercussions for any individuals in close physical proximity of the Unexploded Ordnance (UXO). The complexity of EOD Team duties, coupled with the inherent limitations of human performance, make it gravely important that technicians have tools that aid rather than hamper team goals. The U.S. Military is seeking a refinement of EOD robot design, including the incorporation of some humanlike characteristics such as biped design, upright walking ability, and responsiveness to human voice and gesture commands. These characteristics can be arguably useful for robots to move in human spaces, learn in a humanlike way, dexterously disarm munitions, and communicate efficiently with human users. But while humanoid design may move the role of the robot to one that becomes potentially more effective in some environments, it may complicate emotional and ethical issues in terms of how human team members view the robot – as an extension of self, an external tool, a team member, a pet, or other entity.
Behavioral Analysis of Human-Human Remote Social Interaction Mediated by an Interactive Robot in a Cooperative Game Scenario
Authors: Papadopoulos Fotios , Dautenhahn Kerstin , Ho Wan Ching
Published: September 2012

This book chapter describes the implementation, testing, and evaluation of the first prototype of the “AIBOcom” system, which allows remote users to play an interactive game cooperatively each using a pet-like robot as a social mediator. An exploratory pilot study tested this remote communication system with 10 pairs of participants who were exposed to two experimental conditions characterised by two different modes of synchronisation between the two robots that each interacts locally with the participant. In one mode, the robots incrementally affected each other’s behaviour, while in the other, the robots mirrored each other’s behaviour. Instruments used in this study include questionnaires, video observations and log files for the game state. The authors used various techniques to measure engagement and synchronization such as quantitative (e.g. rate of occurrence and average values) as well as qualitative measurements. In an exploratory data analysis, these multiple sources of data reflecting participant performance and characteristics were analyzed. Significant correlations were found and presented between the participants as well as participants’ preferences and overall acceptance of such communication media. Findings indicate that participants preferred the mirroring mode, and that in this pilot study, robot-assisted remote communication was considered desirable and acceptable to the participants. Furthermore, the existence of interaction variations among different demographic groups was found, while this chapter lists and interprets the most significant effects.
Robot Double
Authors: Sone Yuji
Published: September 2012

This chapter discusses Japanese roboticist Hiroshi Ishiguro’s performance experiments with robotic machines (humanoid and android) as a case study for this book’s theme, “the techno-self.” Ishiguro’s robots are highly sophisticated pieces of engineering intended to replicate human physical movement and appearance. In addition to claims relevant to robot engineering, for Ishiguro, these machines are reflexive tools for investigations into questions of human identity. In Ishiguro’s thinking I identify what I call a “reflexive anthropomorphism,” a notion of the self’s relation to the other that is tied equally to Buddhism and Japanese mythology. Using concepts from Japanese studies and theatre and performance studies, this chapter examines one culturally specific way of thinking about concepts of the self and identity through Ishiguro’s discussion of the human-robot relation.
SaaS Requirements Engineering for Agile Development
Authors: Gill Asif Qumer , Bunker Deborah
Published: September 2012

The emergence of Software as a Service (SaaS) has made it possible to develop dynamic and complex business processes as eServices. The development of business processes as eServices (SaaS) can be assisted by the means of adaptive or agile development processes. The development of business processes in terms of SaaS require to perform SaaS requirements engineering (RE), which is an important phase of a software development process for the success of any project. The challenge here is how best to do SaaS RE (e.g. mapping business process to eServices) and select agile development practices for developing business processes in terms of SaaS. In order to address this challenge, an integrated agile RE model for SaaS project development environments is outlined within this chapter. The purpose of the proposed RE model is to aid in iteratively determining SaaS requirements in short iterations as opposed to the “only first and onetime upfront” phase of a development process. Each identified SaaS requirement or a set of requirements for a given iteration is linked to a single or set of specific agile practices for implementation in short iterations. This model can be used as a guideline by organisations wishing to understand the challenging task of mapping business processes to SaaS and its implementation by using agile software development processes or practices.
The Incremental Commitment Spiral Model for Service-Intensive Projects
Authors: Koolmanojwong Supannika , Boehm Barry , Lane Jo Ann
Published: September 2012

To provide better service to customers and remain competitive in the business environment, a wide variety of ready-to-use software and technologies are available for one to “grab and go” in order to build up software systems at a rapid pace. Currently, a wide variety of Web services are available and ready to use for this purpose. Current software process models also support commercial-off-the-shelf (COTS)-based development processes. However, although COTS and Web Services are similar, they are different in many perspectives. On one hand, there are various software process models that support Web services development. Yet there is no process model that supports the project that uses services provided by others. This chapter introduces the Incremental Commitment Spiral Model (ICSM), a new generation process model that provides development guidelines, from exploring a Web service alternative to deployment and maintenance with case studies.
Improving Lean, Service-Oriented Software Development at Codeweavers Ltd
Authors: Shannon Paul , Kidd Neil , Barrett Paul , Knight Chris , Wessel Sam
Published: September 2012

Following a successful adoption of lean and agile practices, the development team at Codeweavers Ltd has furthered its approach to service-oriented software development for the motor finance and insurance industry. Through iteratively inspecting and adapting their processes over the last twelve months, the team members have seen a change from their Kanban-style single piece flow to multiple work cells developing with separate swim lanes on a work in progress board and within fixed length iterations. The arrival of strong competition to their market led to a positive shift towards customer service and interaction with increased attention on lean planning and agility. This chapter reports on improvement in software craftsmanship with a focus on quality, largely achieved by the use of service-oriented architecture, combined with increased use of mocking for unit-testing. The perspective taken is from software team members, and in the chapter, the developers chart their own observations, improvements, and failures over the course of a year.
Recurrence Quantification Analysis of Financial Markets
Authors: Bastos João A.
Published: September 2012

Recurrence quantification analysis is a nonlinear time series analysis technique that detects deterministic dependencies in time series. This technique is particularly appropriate for modeling financial time series since it requires no assumptions on stationarity, statistical distribution, and minimum number of observations. This chapter illustrates two applications of recurrence quantification analysis to financial data: a set of international stock indices, and zero-coupon yields of US government bonds.
To Be on the Edge of Chaos with Organizational Intelligence and Health
Authors: Erçetin Şefika Şule , Potas Nihan , Kisa Nuray , Açikalin Suay Nilhan
Published: September 2012

This chapter examines how organizations act as self-adapting, complex systems, and how they manage to creatively maintain their existence on the edge of chaos, foster complexity, and renew themselves. The overall shift in academic thought that has given rise to these theories, and this terminology is also examined, with an emphasis on the ways various terms have been used in previous literature. The chapter also reviews the literature on, and develops working definitions of four main characteristic dimensions of organizations: organizational intelligence, organizational stupidity, psychological organizational health, and physical organizational health. Finally, the chapter gives information about research currently being conducted by the authors. This research will attempt to produce a model that represents how organizations are able to exist on the edge of chaos, based on concrete measurements of the four dimensions mentioned above, taken over certain limited time spans.
Teams and Complexity
Authors: Antoniadis Dimitris N
Published: September 2012

The process of structuring teams in projects is not being implemented, and practitioners have lost confidence in the process. In order to improve the current status, there is a need for a major rethink, one that will enable the structuring of teams/complex adaptive systems. Therefore, using deductions drawn from research results, regarding the implementation of the process and the effects of complexity, a tentative proposal for a Finite Structural approach is made for setting up and testing the structure of teams. This is done by integrating a number of progressive theories not only from the field of organisation design but also from engineering, physics, and psychology, with theories such as social network theory, actor-network theory, finite element analysis, complexity, clustering, and cross functional team behaviours. This chapter presents the above and throws the gauntlet for discussion and improvement of the approach that will enable project managers and others to improve the process of structuring of teams.
Drifting into Failure
Authors: Dekker Sidney W. A.
Published: September 2012

The Gaussian copula, an equation first published by David Li in 2000, was a beautiful thing—in isolation. Its intention was to price collaterized debt obligations, and work out whether they were moving in the same direction. The copula was an enabler of mortgaging the most hopeless of homeowner prospects. Millions of securities could be traded on the back of a single number (a security is something that shows ownership, or right of ownership of stocks or bonds, or the right to ownership connected with derivatives that get their value from some underlying asset). As more and more webs of interactions and relationships and interdependencies and feedback loops started growing around it, however, it became part of a complex system. The copula became the trigger of a recession that swelled the number of homeless families in the US by 30% inside of two years (Associated Press, 2010). It ended up bringing global lending to a virtual standstill, triggering a worldwide financial crisis and a deep recession. How did a once good idea like this drift into failure, and how can such a risk of collapse be managed? That is what this chapter is about.
Cognition and Complexity
Authors: Kiel L. Douglas , McCaskill John
Published: September 2012

Contemporary knowledge work places create tremendous challenges for employees and managers. High levels of “cognitive capital” are required to cope with the rapidly evolving complexity of work. This chapter presents an agent-based model of the dynamics of cognitive capital in a simulated workplace. Factors such as stress, sleep insufficiency, and excessive work function to reduce the cognitive capital among workers. The cognitive capital in this microworld is tracked among agents suffering from stress, sleep insufficiency and excessive work. The authors also explore how cognitive capital changes under varying cognitive enrichment scenarios. Simulation results reveal a range of behaviors typical of complex systems, showing evidence of periods of both stability and instability. The authors also see symmetry breaking behavior as the dynamics of cognitive capital create drastic change.
Managing Fisheries in Light of Complexity and Chaos Theories
Authors: Ferreira Manuel Alberto Martins , Filipe José António Candeias Bonito , Coelho Manuel Francisco Pacheco , Pedro Maria Isabel
Published: September 2012

Chaos theory - and models related to non-linear dynamic systems - has increased in importance in recent decades. In fact, chaos is one of the concepts that has most rapidly expanded in research topics. Chaos is ordinarily disorder or confusion; scientifically, it represents a disarray connection, but basically, it involves much more than that. Change and time are closely linked, and they are essential when considered together as chaos theory foundations are intended to be understood. Given the large number of applications in several areas, the goal of this work is to present chaos theory - and dynamical systems such as the theories of complexity - in terms of the interpretation of ecological phenomena. The theory of chaos applied in the context of ecological systems, especially in the context of fisheries, has allowed the recognition of the relevance of this kind of theories to explain fishing events. It raised new advances in the study of marine systems, contributing to the preservation of fish stocks.
Optimal Variability and Complexity
Authors: Haworth Joshua L , Vallabhajosula Srikant , Tzetzis George , Stergiou Nicholas
Published: September 2012

Management seeks to provoke system optimization throughout ever changing environmental and internal conditions. Typically, perturbations to stable organizations are unpredictable and difficult to define, except from within a chaos perspective. How should management staff set up their workforce to be best responsive to these changes? It is proposed that a dynamic systems theoretical approach to the organization of the management system would foster the ideal scenario. This approach lends well to the inclusion of discovery learning strategies that promote the valuable use of optimal variability in the exploration and self-discovery of optimal solutions to existent and novel problems. In this text, the authors walk the reader through a brief history of the development of the systems perspective on human movement optimization. Next, they extend the related discoveries to applications within management systems. It is hoped that a new appreciation for complexity and beneficial aspects of variability is conveyed.
Nonparametric Estimation of Nonlinear Dynamics by Local Linear Approximation
Authors: Shoji Isao
Published: September 2012

This chapter discusses nonparametric estimation of nonlinear dynamical system models by a method of metric-based local linear approximation. By specifying a metric such as the standard metric or the square metric on the Euclidean space and a weighting function based on such as the exponential function or the cut-off function, it is possible to estimate values of an unknown vector field from experimental data. It can be shown the local linear fitting with the Gaussian kernel, or the local polynomial modeling of degree one, is included in the class of the proposed method. In addition, conducting simulation studies for estimating random oscillations, the chapter shows the method numerically works well.
Depletion of Plasmacytoid Dendritic Cells Inhibits Tumor Growth and Prevents Bone Metastasis of Breast Cancer Cells
Authors: Sawant Anandi , Hensel Jonathan A. , Chanda Diptiman , Harris Brittney A. , Siegal Gene P. , Maheshwari Akhil , Ponnazhagan Selvarangan
Published: September 2012

Elevated levels of plasmacytoid dendritic cells (pDC) have been reported in breast cancer patients, but the significance remains undefined. Using three immunocompetent mouse models of breast cancer bone metastasis, we identified a key role for pDC in facilitating tumor growth through immunosuppression and aggressive osteolysis. Following infiltration of macrophages upon breast cancer dissemination, there was a steady increase in pDC within the bone, which resulted in a sustained Th2 response along with elevated levels of regulatory T cells and myeloid-derived suppressor cells. Subsequently, pDC and CD4+ T cells, producing osteolytic cytokines, increased with tumor burden, causing severe bone damage. Microcomputed tomography and histology analyses of bone showed destruction of femur and tibia. The therapeutic significance of this finding was confirmed by depletion of pDC, which resulted in decreased tumor burden and bone loss by activating tumor-specific cytolytic CD8+ T cells and decreasing suppressor cell populations. Thus, pDC depletion may offer a novel adjuvant strategy to therapeutically influence breast cancer bone metastasis.
Insulin Modulates the Inflammatory Granulocyte Response to Streptococci via Phosphatidylinositol 3-Kinase
Authors: Kenzel Sybille , Mergen Miriam , von Süßkind-Schwendi Julius , Wennekamp Julia , Deshmukh Sachin D. , Haeffner Monika , Triantafyllopoulou Antigoni , Fuchs Sebastian , Farmand Susan , Santos-Sierra Sandra , Seufert Jochen , van den Berg Timo K. , Kuijpers Taco W. , Henneke Philipp
Published: September 2012

Group B streptococci (GBS; Streptococcus agalactiae) are a major cause of invasive infections in newborn infants and in patients with type 2 diabetes. Both patient groups exhibit peripheral insulin resistance and alterations in polymorphonuclear leukocyte (PML) function. In this investigation, we studied the PML response repertoire to GBS with a focus on TLR signaling and the modulation of this response by insulin in mice and humans. We found that GBS-induced, MyD88-dependent chemokine formation of PML was specifically downmodulated by insulin via insulin receptor-mediated induction of PI3K. PI3K inhibited transcription of chemokine genes on the level of NF-κB activation and binding. Insulin specifically modulated the chemokine response of PML to whole bacteria, but affected neither activation by purified TLR agonists nor antimicrobial properties, such as migration, phagocytosis, bacterial killing, and formation of reactive oxygen species. The targeted modulation of bacteria-induced chemokine formation by insulin via PI3K may form a basis for the development of novel targets of adjunctive sepsis therapy.
Efficient Xenoengraftment in Severe Immunodeficient NOD/Shi-scidIL2rγnullMice Is Attributed to a Lack of CD11c+B220+CD122+ Cells
Authors: Ito Ryoji , Katano Ikumi , Ida-Tanaka Miyuki , Kamisako Tsutomu , Kawai Kenji , Suemizu Hiroshi , Aiso Sadakazu , Ito Mamoru
Published: September 2012

Xenograft animal models using immunodeficient mice have been widely applied in medical research on various human diseases. NOD/Shi-scid-IL2rγnull (NOG) mice are known to show an extremely high engraftment rate of xenotransplants compared with conventional immunodeficient mice. This high engraftment rate of xenotransplants in NOG mice was substantially suppressed by the transfer of spleen cells from NOD-scid mice that were devoid of NK cells. These results indicate that cell types other than splenic NK cells present in NOD-scid mice but not in NOG mice may be involved in this suppression. To identify the cell types responsible for this effect, we transferred subpopulations of spleen cells from NOD-scid mice into NOG mice and assessed the levels of human cell engraftment after human PBMC (hPBMC) transplantation. These experiments revealed that CD11c+B220+ plasmacytoid dendritic cells (pDCs) from NOD-scid mice markedly inhibited engraftment of human cells. The CD11c+B220+CD122+ cells further fractionated from the pDCs based on the expression of CD122, which is an NK cell marker strongly inhibited during hPBMC engraftment in NOG mice. Moreover, the CD122+ cells in the pDC fraction were morphologically distinguishable from conventional CD122+ NK cells and showed a higher rejection efficiency. The current results suggest that CD11c+B220+CD122+ cells play an important role in xenograft rejection, and their absence in NOG mice may be critical in supporting the successful engraftment of xenotransplants.
Coordinate Stimulation of Macrophages by Microparticles and TLR Ligands Induces Foam Cell Formation
Authors: Keyel Peter A. , Tkacheva Olga A. , Larregina Adriana T. , Salter Russell D.
Published: September 2012

Aberrant activation of macrophages in arterial walls by oxidized lipoproteins can lead to atherosclerosis. Oxidized lipoproteins convert macrophages to foam cells through lipid uptake and TLR signaling. To investigate the relative contributions of lipid uptake and TLR signaling in foam cell formation, we established an in vitro assay using liposomes of defined lipid compositions. We found that TLRs signaling through Toll/IL-1R domain-containing adapter inducing IFN-β promoted foam cell formation by inducing both NF-κB signaling and type I IFN production, whereas TLRs that do not induce IFN, like TLR2, did not enhance foam cell formation. Addition of IFN-α to TLR2 activator promoted robust foam cell formation. TLR signaling further required peroxisome proliferator-activated receptor α, as inhibition of peroxisome proliferator-activated receptor α blocked foam cell formation. We then investigated the ability of endogenous microparticles (MP) to contribute to foam cell formation. We found that lipid-containing MP promoted foam cell formation, which was enhanced by TLR stimulation or IFN-α. These MP also stimulated foam cell formation in a human skin model. However, these MP suppressed TNF-α production and T cell activation, showing that foam cell formation can occur by immunosuppressive MP. Taken together, the data reveal novel signaling requirements for foam cell formation and suggest that uptake of distinct types of MP in the context of activation of multiple distinct TLR can induce foam cell formation.
Targeting the Genital Tract Mucosa with a Lipopeptide/Recombinant Adenovirus Prime/Boost Vaccine Induces Potent and Long-Lasting CD8+ T Cell Immunity against Herpes: Importance of MyD88
Authors: Zhang Xiuli , Dervillez Xavier , Chentoufi Aziz Alami , Badakhshan Tina , Bettahi Ilham , BenMohamed Lbachir
Published: September 2012

Targeting of the mucosal immune system of the genital tract with subunit vaccines has failed to induce potent and durable local CD8+ T cell immunity, which is crucial for protection against many sexually transmitted viral pathogens, including HSV type 2 (HSV-2), which causes genital herpes. In this study, we aimed to investigate the potential of a novel lipopeptide/adenovirus type 5 (Lipo/rAdv5) prime/boost mucosal vaccine for induction of CD8+ T cell immunity to protect the female genital tract from herpes. The lipopeptide vaccine and the rAdv5 vaccine express the immunodominant HSV-2 CD8+ T cell epitope (gB498–505), and both were delivered intravaginally in the progesterone-induced B6 mouse model of genital herpes. Compared with mice immunized with the homologous lipopeptide/lipopeptide (Lipo/Lipo) vaccine, the Lipo/rAdv5 prime/boost immunized mice 1) developed potent and sustained HSV-specific CD8+ T cells, detected in both the genital tract draining nodes and in the vaginal mucosa; 2) had significantly lower virus titers; 3) had decreased overt signs of genital herpes disease; and 4) did not succumb to lethal infection (p < 0.005) after intravaginal HSV-2 challenge. Polyfunctional CD8+ T cells, producing IFN-γ, TNF-α, and IL-2 and exhibiting cytotoxic activity, were associated with protection (p < 0.005). The protective CD8+ T cell response was significantly compromised in the absence of the adapter MyD88 (p = 0.0001). Taken together, these findings indicate that targeting of the vaginal mucosa with a Lipo/rAdv5 prime/boost vaccine elicits a potent, MyD88-dependent, and long-lasting mucosal CD8+ T cell protective immunity against sexually transmitted herpes infection and disease.
Role of Hepatocyte-Derived IL-7 in Maintenance of Intrahepatic NKT Cells and T Cells and Development of B Cells in Fetal Liver
Authors: Liang Bingfei , Hara Takahiro , Wagatsuma Keisuke , Zhang Jia , Maki Kazushige , Miyachi Hitoshi , Kitano Satsuki , Yabe-Nishimura Chihiro , Tani-ichi Shizue , Ikuta Koichi
Published: September 2012

The liver contains a variety of resident immune cells, such as NK cells, NKT cells, T cells, macrophages, and dendritic cells. However, little is known about how IL-7, which is produced by hepatocytes, functions locally in development and maintenance of liver immune cells. To address this question, we established IL-7–floxed mice and crossed them with albumin promoter-driven Cre (Alb-Cre) transgenic mice to establish conditional knockout of IL-7 in hepatocytes. The levels of IL-7 transcripts were reduced 10-fold in hepatocyte fraction. We found that the absolute numbers of NKT and T cells were significantly decreased in adult liver of IL-7f/f Alb-Cre mice compared with IL-7f/f control mice. In contrast, NK cells, dendritic cells, and B cells were unchanged in the IL-7f/f Alb-Cre liver. The number of Vα14+ invariant NKT cells was significantly reduced in liver, but not in thymus and spleen, of IL-7f/f Alb-Cre mice. Furthermore, B cell development was impaired in perinatal liver of IL-7f/f Alb-Cre mice. This study demonstrates that hepatocyte-derived IL-7 plays an indispensable role in maintenance of NKT and T cells in adult liver and development of B cells in fetal liver, and suggests that hepatocytes provide a unique IL-7 niche for intrahepatic lymphocytes.
Affinity and Cross-Reactivity Engineering of CTLA4-Ig To Modulate T Cell Costimulation
Authors: Xu Zhenghai , Juan Veronica , Ivanov Alexander , Ma Zhiyuan , Polakoff Dixie , Powers David B. , DuBridge Robert B. , Wilson Keith , Akamatsu Yoshiko
Published: September 2012

CTLA4-Ig is an Fc fusion protein containing the extracellular domain of CTLA-4, a receptor known to deliver a negative signal to T cells. CTLA4-Ig modulates T cell costimulatory signals by blocking the CD80 and CD86 ligands from binding to CD28, which delivers a positive T cell costimulatory signal. To engineer CTLA4-Ig variants with altered binding affinity to CD80 and CD86, we employed a high-throughput protein engineering method to map the ligand binding surface of CTLA-4. The resulting mutagenesis map identified positions critical for the recognition of each ligand on the three CDR-like loops of CTLA-4, consistent with the published site-directed mutagenesis and x-ray crystal structures of the CTLA-4/CD80 and CTLA-4/CD86 complexes. A number of single amino acid substitutions were identified that equally affected the binding affinity of CTLA4-Ig for both ligands as well as those that differentially affected binding. All of the high-affinity variants showed improved off-rates, with the best one being a 17.5-fold improved off-rate over parental CTLA4-Ig binding to CD86. Allostimulation of human CD4+ T cells showed that improvement of CD80 and CD86 binding activity augmented inhibition of naive and primed T cell activation. In general, increased affinity for CD86 resulted in more potent inhibition of T cell response than did increased affinity for CD80. Optimization of the affinity balance to CD80 and CD86 to particular disease settings may lead to development of a CTLA4-Ig molecule with improved efficacy and safety profiles.
Transient Enhanced IL-2R Signaling Early during Priming Rapidly Amplifies Development of Functional CD8+ T Effector-Memory Cells
Authors: Castro Iris , Dee Michael J. , Malek Thomas R.
Published: September 2012

Much is known concerning the cellular and molecular basis for CD8+ T memory immune responses. Nevertheless, conditions that selectively support memory generation have remained elusive. In this study, we show that an immunization regimen that delivers TCR signals through a defined antigenic peptide, inflammatory signals through LPS, and growth and differentiation signals through the IL-2R initially favors Ag-specific CD8+ T cells to develop rapidly and substantially into T effector-memory cells by TCR transgenic OVA-specific OT-I CD8+ T cells. Amplified CD8+ T memory development depends upon a critical frequency of Ag-specific T cells and direct responsiveness to IL-2. A homologous prime-boost immunization protocol with transiently enhanced IL-2R signaling in normal mice led to persistent polyclonal Ag-specific CD8+ T cells that supported protective immunity to Listeria monocytogenes. These results identify a general approach for amplified T memory development that may be useful to optimize vaccines aimed at generating robust cell-mediated immunity.
A new research journal to understand the interactions of xenobiotics with living organisms
Authors: Gagné François
Published: September 2012

Since its creation in January 2011, the Journal of Xenobiotics (published by PAGEPress, Italy) is devoted to the publication of novel research articles in the fields of the occurrence and biochemical effects of xenobiotics on all living organisms. Although xenobiotics are defined firstly as compounds that are foreign to life, compounds of natural origins occuring at concentrations that are not usually found, could also be considered as foreigners since their enhanced occurrence may affect non-target organisms. In this sense, products derived from natural products are well known to have either a beneficial (natural products used as food additives and many pharmaceuticals) or detrimental (cyanotoxins) impact on the health of an organism. The journal recognizes that these compounds could be either harmful or beneficial to organisms and the interplay between these two aspects is of particular interest...
Feasibility of Computed Tomography Pulmonary Angiography with Low Flow Rates
Authors: Gossner J.
Published: September 2012

Computed tomography pulmonary angiography (CTPA) is the imaging test of choice in suspected pulmonary embolism. High flow rates for the administration of contrast medium are recommended, but these cannot be achieved in a number of patients due to poor peripheral venous access or when using certain central venous catheters. This small feasibility study has examined the CTPA data in a set of 22 patients in whom contrast medium was given at low flow rates (2.0 or 2.5 mL/s). Subjectively, all but one of the patients was judged to be diagnostic. Objectively, enhancement values ≥200 HU were reached in 92% of the examined central vessels (pulmonary trunk, main pulmonary arteries, and lobar arteries). In conclusion, even with a low injection rate CTPA is of diagnostic value in most patients.
Indirect bonding: A literature review
Authors: Aksakalli Sertaç , Demir Abdullah
Published: September 2012

With the increased interest in recently years, indirect bonding became more popular. This technique enhances clinician′s ability to communicate with patients and parents more and enhances chair-time savings. There are many kinds of indirect bonding and new techniques were presented to literature recently. There are so many steps and applications in indirect bonding. So all these are opened to modification and also modified too. With any new development, there will be some trepidation. There is always a natural fear of unknown. In indirect bonding, there were doubts about bond failures but studies revealed that there is no significant difference between direct and indirect technique on bond strength.
Mandibular second premolar with four roots
Authors: Akyuz Sefika Nur , Erdemir Ali
Published: September 2012

Detection of normal and abnormal variation in tooth anatomy is essential for clinical success. It is generally well known that the mandibular second premolar teeth have a single root and canal. However, the mandibular second premolar teeth have sometimes more than one root and root canal. The endodontic treatment of a mandibular second premolar with four roots which separated at different levels along the middle third of the root is presented in this case report. Preoperative radiographs appeared radiolucency and different root anatomy in the region of the mandibular second premolar. The root canals were prepared using Mtwo rotary system (VDW, Munich, Germany) and obturated laterally condensed gutta percha and AH plus (Dentsply De Trey, Konstanz, Germany). After the completion of root canal treatment, the tooth was restored with a posterior composite filling material. On follow-up, the tooth was clinically and radiographically asymptomatic for two years. Clinicians should be aware of the importance of careful clinical and radiographic examination of mandibular premolars during the endodontic treatment. Radiographs exposed at two different horizontal angles and their careful interpretation facilitates the search of additional root canals.
Decadal variations in estimated surface solar radiation over Switzerland since the late 19th century
Authors: Sanchez-Lorenzo A. , Wild M.
Published: September 2012

Abstract. Our knowledge on trends in surface solar radiation (SSR) involves uncertainties due to the scarcity of long-term time series of SSR, especially with records before the second half of the 20th century. Here we study the trends of all-sky SSR from 1885 to 2010 in Switzerland, which have been estimated using a homogenous dataset of sunshine duration series. This variable is shown to be a useful proxy data of all-sky SSR, which can help to solve some of the current open issues in the dimming/brightening phenomenon. All-sky SSR has been fairly stable with little variations in the first half of the 20th century, unlike the second half of the 20th century that is characterized also in Switzerland by a dimming from the 1950s to the 1980s and a subsequent brightening. Cloud cover changes seem to explain the major part of the decadal variability observed in all-sky SSR, at least from 1885 to the 1970s; at this point, a discrepancy in the sign of the trend is visible in the all-sky SSR and cloud cover series from the 1970s to the present. Finally, an attempt to estimate SSR series for clear-sky conditions, based also on sunshine duration records since the 1930s, has been made for the first time. The mean clear-sky SSR series shows no relevant changes between the 1930s to the 1950s, then a decrease, smaller than the observed in the all-sky SSR, from the 1960s to 1970s, and ends with a strong increase from the 1980s up to the present. During the three decades from 1981 to 2010 the estimated clear-sky SSR trends reported in this study are in line with previous findings over Switzerland based on direct radiative flux measurements. Moreover, the signal of the El Chichón and Pinatubo volcanic eruption visible in the estimated clear-sky SSR records further demonstrates the potential to infer aerosol-induced radiation changes from sunshine duration observations.
Aerosol pollution potential from major population centers
Authors: Kunkel D. , Tost H. , Lawrence M. G.
Published: September 2012

Abstract. Major population centers (MPCs) or mega-cities represent the largest of growing urban agglomerations with major societal and environmental implications. In terms of air quality they are seen as localized but strong emission sources of aerosols and trace gases which in turn affect air pollution levels in the city or in downwind regions. In the state-of-the-art atmospheric chemistry general circulation model EMAC, generic aerosol and gas phase tracers with equal emission source strengths at 46 MPC locations are used to study the balance between local pollution build up and pollution export, either vertically into the upper troposphere or horizontally, but remaining in the lower atmosphere. The insoluble gas phase tracers with fixed lifetimes are transported with the atmospheric circulation, while the aerosol tracers also undergo gravitational sedimentation as well as dry and wet deposition processes. The strength of low-level tracer export depends on the location of the emission source and prevailing meteorology, in particular on atmospheric stability and the height of the boundary layer and the mixing out of this layer. In contrast, vertical transport of tracer mass depends on the tracer's solubility: the more soluble a tracer is the less mass reaches altitudes above five kilometers. Hence, the mass of insoluble gas phase tracer above five kilometers can be up to ten times higher than the hydrophilic aerosol mass from the same source. In the case of aerosol tracers, pollution build up around the source is determined by meteorological factors which have only indirect effects on tracer lifetime, like surface wind, boundary layer height, and turbulent mixing as well as those which affect the lifetime of the tracers such as precipitation. The longer a tracer stays in the atmosphere, the lower is the relative importance of the location of the source to the atmospheric mass and thus the lower is the relative local pollution build up. We further use aerosol deposition fields to estimate regions with high deposition, that is more than 1% or more than 5% of the corresponding tracer emission deposited in this region. In doing so, we find that the high deposition areas are larger for larger aerosols, and these differ less between the MPCs than for smaller aerosols due to faster deposition. Furthermore, cities in regions with high precipitation rates or unfavorable geographic location, e.g. in a basin, suffer most of this high deposition. Most of the high deposition occurs over land, although about 50% of the MPCs are located along coastlines. By folding the aerosol deposition fields with geographical distributions of cropland, pasture, and forest, the impact on different land ecosystems is assessed. In general, forest are exhibited most to deposition from MPCs while pasture land is least affected. Moreover, the impact on humans, measured with a threshold exceedance of pollutant surface mixing ratios, is more dependent on population densities than on the size of the area holding a certain mixing ratio.
Near real-time estimation of water vapour in the troposphere using ground GNSS and the meteorological data
Authors: Bosy J. , Kaplon J. , Rohm W. , Sierny J. , Hadas T.
Published: September 2012

Abstract. The near real-time (NRT) high resolution water vapour distribution models can be constructed based on GNSS observations delivered from Ground Base Augmentation Systems (GBAS) and ground meteorological data. Since 2008 in the territory of Poland, a GBAS system called ASG-EUPOS (Active Geodetic Network) has been operating. This paper addresses the problems concerning construction of the NRT model of water vapour distribution in the troposphere near Poland. The first section presents all available GNSS and ground meteorological stations in the area of Poland and neighbouring countries. In this section, data feeding scheme is discussed, together with timeline and time resolution. The high consistency between measured and interpolated temperature value is shown, whereas some discrepancy in the pressure is observed. In the second section, the NRT GNSS data processing strategy of ASG-EUPOS network is discussed. Preliminary results show fine alignment of the obtained Zenith Troposphere Delays (ZTDs) with reference data from European Permanent Network (EPN) processing center. The validation of NRT troposphere products against daily solution shows 15 mm standard deviation of obtained ZTD differences. The last section presents the first results of 2-D water vapour distribution above the GNSS network and application of the tomographic model to 3-D distribution of water vapour in the atmosphere. The GNSS tomography model, working on the simulated data from numerical forecast model, shows high consistency with the reference data (by means of standard deviation 4 mm km−1 or 4 ppm), however, noise analysis shows high solution sensitivity to errors in observations. The discrepancy for real data preliminary solution (measured as a mean standard deviation) between reference NWP data and tomography data was on the level of 9 mm km−1 (or 9 ppm) in terms of wet refractivity.
Characteristics of aerosols over Hyderabad in southern Peninsular India: synergy in the classification techniques
Authors: Sinha P. R. , Kaskaoutis D. G. , Manchanda R. K. , Sreenivasan S.
Published: September 2012

Abstract. The present study focuses on analyzing the seasonal changes in aerosol characteristics using a classification scheme proposed by Gobbi et al. (2007). This scheme is based on the correlation between the Ångström exponent (α) in the 440–870 nm range and the difference in α values [dα = α (440–675 − α(675–870)] including the size of fine-mode particles (Rf) and the fine-mode fraction (η). The classification scheme can therefore provide information on the aerosol characteristics and their modification in transit. Spectral aerosol measurements using the Microtops-II sun photometer (MT-II) have systematically been conducted in Hyderabad, India during April 2009–March 2010 and analysed to study the seasonal effects. The results reveal a seasonal dependence, i.e. the presence of fine-mode aerosols under turbid atmospheres in winter and post-monsoon, a mixture of fine and coarse aerosol types in pre-monsoon and a significant influence of marine mixed with dust air masses during the monsoon season. The identification of the aerosol source type and the modification processes are discussed along with clustered air-mass trajectory analysis. Furthermore, we have also checked the consistency of this scheme with the findings arrived from the columnar size distributions (CSDs) computed by numerical inversion of spectral AOD using King's inversion algorithm and the scatter plot between AOD and spectral α. The comparison clearly demonstrates the usefulness of the classification scheme and highlights its advantages for the monitoring and study of seasonal variation of the aerosol types and the modification processes in the atmosphere.