bluuebunny/crossref_metadata_2025 huggingface dataset:
Using Computational Intelligence for Improved Teleoperation over Wireless Network
Authors: Khan Salman H. , Khan Arsalan H. , Khan Zeashan H.
Published: May 2012

The role of computational intelligence techniques in applied sciences and engineering is becoming popular today. It is essential because the autonomous engineering applications require intelligent decision in real time in order to achieve the desired goal. This chapter discusses some of the approaches to demonstrate various applications of computational intelligence in dependable networked control systems and a case study of teleoperation over wireless network. The results have shown that computational intelligence algorithms can be successfully implemented on an embedded application to offer an improved online performance. The different approaches have been compared and could be chosen as per application requirements.
On the Use of Particle Swarm Optimization Techniques for Channel Assignments in Cognitive Radio Networks
Authors: Abdelsalam Hisham M. , Hamza Haitham S. , Al-Shaar Abdoulraham M. , Hamza Abdelbaset S.
Published: May 2012

Efficient utilization of open spectrum in cognitive radio networks requires appropriate allocation of idle spectrum frequency bands (not used by licensed users) among coexisting cognitive radios (secondary users) while minimizing interference among all users. This problem is referred to as the spectrum allocation or the channel assignment problem in cognitive radio networks, and is shown to be NP-hard. Accordingly, different optimization techniques based on evolutionary algorithms were needed in order to solve the channel assignment problem. This chapter investigates the use of particular swarm optimization (PSO) techniques to solve the channel assignment problem in cognitive radio networks. In particular, the authors study the definitiveness of using the native PSO algorithm and the Improved Binary PSO (IBPSO) algorithm to solve the assignment problem. In addition, the performance of these algorithms is compared to that of a fine-tuned genetic algorithm (GA) for this particular problem. Three utilization functions, namely, Mean-Reward, Max-Min-Reward, and Max-Proportional-Fair, are used to evaluate the effectiveness of three optimization algorithms. Extensive simulation results show that PSO and IBPSO algorithms outperform that fine-tuned GA. More interestingly, the native PSO algorithm outperforms both the GA and the IBPSO algorithms in terms of solution speed and quality.
ACPSO
Authors: Ouadfel Salima , Batouche Mohamed , Ahmed-Taleb Abdlemalik
Published: May 2012

In order to implement clustering under the condition that the number of clusters is not known a priori, the authors propose a novel automatic clustering algorithm in this chapter, based on particle swarm optimization algorithm. ACPSO can partition images into compact and well separated clusters without any knowledge on the real number of clusters. ACPSO used a novel representation scheme for the search variables in order to determine the optimal number of clusters. The partition of each particle of the swarm evolves using evolving operators which aim to reduce dynamically the number of naturally occurring clusters in the image as well as to refine the cluster centers. Experimental results on real images demonstrate the effectiveness of the proposed approach.
Parallel Evolutionary Computation in R
Authors: Gondro Cedric , Kwan Paul
Published: May 2012

Evolutionary Computation (EC) is a branch of Artificial Intelligence which encompasses heuristic optimization methods loosely based on biological evolutionary processes. These methods are efficient in finding optimal or near-optimal solutions in large, complex non-linear search spaces. While evolutionary algorithms (EAs) are comparatively slow in comparison to deterministic or sampling approaches, they are also inherently parallelizable. As technology shifts towards multicore and cloud computing, this overhead becomes less relevant, provided a parallel framework is used. In this chapter the authors discuss how to implement and run parallel evolutionary algorithms in the popular statistical programming language R. R has become the de facto language for statistical programming and it is widely used in biostatistics and bioinformatics due to the availability of thousands of packages to manipulate and analyze data. It is also extremely easy to parallelize routines within R, which makes it a perfect environment for evolutionary algorithms. EC is a large field of research, and many different algorithms have been proposed. While there is no single silver bullet that can handle all classes of problems, an algorithm that is extremely simple, efficient, and with good generalization properties is Differential Evolution (DE). Herein the authors discuss step-by-step how to implement DE in R and how to parallelize it. They then illustrate with a toy genome-wide association study (GWAS) how to identify candidate regions associated with a quantitative trait of interest.
So Into It They Forget What Time It Is?
Authors: Legault Marie-Josée , Ouellet Kathleen
Published: May 2012

This chapter draws on 53 interviews from a case study led in Montreal in 2008 to demonstrate the existence of Unlimited and Unpaid Overtime (UUO) among video game developers and illustrate an emerging workplace regulation model of working time in the videogame industry. It brings to light a sophisticated and efficient system of rewards and sanctions, both material and symbolic, that drives professional workers in these trades to adopt a “free unlimited overtime” behavior despite the Act Respecting Labour Standards. Efficiency of this system is rooted in combined Project Management (PM) as an organisation mode and high international mobility of the workforce that both makes portfolio and reputation utterly important. This chapter focuses on (de)regulation of working time only, but it opens a path to theoretically account for (de)regulation of work among an expanding workforce: the “new professionals” in knowledge work.
The Engineering Project as Story and Narrative
Authors: Henriksen Lars Bo
Published: May 2012

Engineers most often organise their work in projects and consequently project management becomes an essential part of an engineer’s work and working life in general. Even if most engineers are trained in project management, it seems that this is a challenge to most engineers. It also seems that the traditional project management tools are not always sufficient when it comes to managing engineering projects. In this chapter, an engineering project is examined, and it turns out that the language, the stories, and the narratives connected to the project is of greater importance to the engineers than the formal project management tools that were offered to the engineers. It also turns out that the term “project” could itself be a problem when it comes to fulfilling the project goals. Therefore, it is concluded that when working on engineering projects, language, stories, and narratives are just as important to the engineers as any other element in the project.
Excessive Value Creation
Authors: Sköld David , Olaison Lena
Published: May 2012

This chapter demonstrates how contemporary imaginary structures, which urge us to move up in life by making the most of the possibilities we are faced with, may operate in an industrial setting where users are involved in the production of heavy duty vehicles. Opening up new domains for value creation, devoid of established norms and regulations, such an imaginary appeal to elevate ourselves arguably provides little guidance for how to do so. Demanding ever more from those subjected to its call, this appealing power, the chapter suggests, follows the logic of the Lacanian superego, which according to Salecl (2004, p. 51) “commands the subject to enjoy yet at the same time mockingly predicts that he or she will fail in this pursuit of enjoyment.” As such, it makes out a central component in a creative force that feeds excessive outgrowths, which perpetually contribute to pervert, displace, and fragment established grounds for value creating activities within this industrial domain.
Gendered Technology-Based Organizations
Authors: Tran Ben
Published: May 2012

The “glass cliff” is a term coined by Professor Michelle Ryan and Professor Alex Haslam in 2004. Their research demonstrates that once women (or other minority groups) break through the glass ceiling and take on positions of leadership, they often have different experiences from their male counterparts. Specifically, women are more likely to occupy positions that can be described as precarious and thus have a higher risk of failure, either because they are in organizational units that are in crisis, or because they are not given the resources and support needed to thrive. The success of the glass cliff, as a phenomenon, rests on three factors. First, it relies heavily on the quality and quantity of data available, as well as the reliability of the data. Second, it relies heavily on the acceptance, utilization, and application of its existence, for a lack of acknowledgment, acceptance, utilization, and application of any phenomenon, concept, and theory will result in extinction. Third, this phenomenon, in reality, is quite taboo in a male dominated society, regardless of culture. Nevertheless, the glass cliff, as a phenomenon, is quite neoteric, and is typically not spoken of, nor referred to when men communicate, in the same way that men do not usually refer to the glass ceiling, or the glass escalator. The purpose of this chapter is to delve into and explore the concept of the glass cliff faced by women in high-tech corporations, and how the glass cliff affects their career advancement and identity growth through empirical data. The chapter then provides three recommendations on resolving the glass cliff phenomenon, and concludes with whether the glass cliff as a phenomenon is convertible to become a theory.
Design Models for Resource Allocation in Cyber-Physical Energy Systems
Authors: Ranganathan Prakash , Nygard Kendall
Published: May 2012

Today’s and tomorrow’s smart grid systems are made more efficient, cleaner, and reliable by “smart” control mechanisms and decision models that deliver information to consumers so they can better manage energy resources. The rapidly changing needs and opportunities of today’s electric grid market require unprecedented levels of interoperability to integrate diverse information systems to share knowledge and collaborate among sub-devices or sub-systems in the grid. This book chapter focuses on optimal mathematical models for resource allocation. A series of mathematical models is presented in this book chapter for solving large-scale energy allocation problems with partially observable states, utility functions, and constrained action is introduced. The authors’ techniques use a Linear Programming (LP) approach to determine resource allocations among a set of fuzzy rules that allocates Distributed Energy Resources (DER’s) or power sources/sinks and uses to determine improving resource management.
Green IT Project Management
Authors: Bachour Nathalie
Published: May 2012

With the constant evolution of technology and the world critical environmental status, all private and public Information Technology (IT) businesses are moving towards sustainability. Faced with influences from government regulations, market competition and constraints, as well as watchdogs, IT decision makers within organizations are forced to ride the green technology wave with a challenging and uncertain approach. This chapter defines methods to optimize Green IT projects for sustainable value creation within organizations. It only focuses on economic viability and environmental impact, but could be stretched out in the future to social aspects. The contributions of this chapter allow the project management community and decision makers to follow a framework for Green IT project success evaluation and performance follow-up throughout the project life cycle and the three levels of the organization: operational, tactical, and strategic. A macro-model is also developed to aid them in successfully selecting, prioritizing, managing, and aligning their Green IT projects with the corporate and environmental strategies.
The History of CALL
Authors: Butler-Pascoe Mary Ellen
Published: May 2012

It has been over 50 years since the emergence of computer-assisted language learning (CALL) that would forever change how second/foreign languages are taught. This article presents a historical overview of the evolution of CALL from the early years of the mainframe computer to the integrative technologies of the 21st century. It examines the evolution of the dual fields of educational technology and second/foreign language teaching as they intertwined over the last half of the 20th century into present day CALL. The paper describes the paradigm shifts experienced along this journey and the current state of CALL as new technologies rapidly advance language teaching capabilities and challenge practitioners to provide optimum learning environments for the future.
A Review of CALL and L2 Reading
Authors: Askildson Lance R.
Published: May 2012

This paper provides a comprehensive review of the present state of second language reading research and computer-assisted glossing for reading comprehension and vocabulary acquisition. Although computer-assisted language learning, in general, and computer-assisted glossing, in particular, are often cited as facilitative pedagogical and self-study tools for second language reading development (Chun, 2001; Al-Seghayer, 2003; Ko, 2005; Blake, 2007; Stockwell, 2011), the state of computer-assisted glossing research presents a much less compelling and far more nuanced picture of efficacy and facilitation (Ariew & Ercetin, 2004; Bowles, 2004; Taylor, 2006, 2009; AbuSeileek, 2008; Sato & Sazuki, 2010). Research on glossing for reading comprehension presents a mixed collection of findings suggesting facilitation (Leffa, 1992; Lomicka, 1998; Ko, 2005) and inhibition (Hegelheimer, 1997; Plass et al., 2003; Akbulut, 2005; Sakar & Ercetin, 2005), although affective and attentional benefits of glossing for reading comprehension are widely acknowledged. On the other hand, research on incidental vocabulary acquisition as a result of glossing – and particularly multimedia glossing – suggests significant effect and a compelling rationale for ulitization of glossing tools in classroom and self-study contexts (Ariew & Ercetin, 2004; AbuSeileek, 2008; Taylor, 2009; Stockwell, 2011; Aljabri, 2011).
The Nature of ‘Talk’ in Synchronous Computer-Mediated Communication in a Vietnamese Tertiary EFL Context
Authors: Nguyen Long V. , White Cynthia
Published: May 2012

This classroom-based research aims to investigate the nature and quality of talk in synchronous computer-mediated communication (SCMC) among Vietnamese tertiary EFL learners. Participants included 60 students in their sixth semester of an eight-semester BA in TESOL program in a large university in Central Vietnam. Using a sociocultural lens, the nature of discussion was compared in two modes of exchanges, SCMC versus face-to-face (FTF), through analysis of discussion transcripts supported by questionnaire data, interviews and observations. The first level of analysis, participation, revealed that the online students, collaborating in an academic task for the first time via SCMC, produced fewer words, but spent more time, during the discussion process. More equal contribution was a marked feature of the SCMC mode. For the second level of analysis examining the interactional nature and pattern of discussion, transcripts were analyzed according to socioaffective, organizational and sociocognitive themes, and their emergent subcategories. Clear differences were evident between the two settings regarding group processes, leadership, negotiation and consensus. It is argued that for these tertiary Vietnamese EFL learners, the FTF groups were more product-oriented in the discussion task, while the online groups presented a more process-oriented style of learning.
Integrating Online Tools to Motivate Young English Language Learners to Practice English Outside the Classroom
Authors: Terrell Shelly Sanchez
Published: May 2012

Recent research shows that online tools such as: games, wikis, speaking avatars, and interactive stories can be a positive force for English Language Learners (ELLs). It also shows that when ELLs have access to online tools, they are motivated to practice English outside the classroom (Aydin, 2007; Colombo & Colombo, 2007; Son, 2007). Most of this research is undertaken with older learners. This case study attempts to determine if young learners are motivated to practice English outside the classroom if provided with access to various online tools managed via a wiki. A wiki is a free educational web space, which allows a number of people to work together collaboratively on documents with embedded elements and linking. The teacher interviewed parents and kept observational notes. The study results suggest that the online tools improve the listening and speaking skills of young learners.
Assessing Website Effectiveness of Airline Companies
Authors: Vrontis D. , Melanthiou Y.
Published: May 2012

Within the tourism industry, hotels and airlines are encouraging potential customers to make their reservations online. Because of the significant setup costs involved in website development, assessing online behaviour and website effectiveness is necessary. This paper explores the factors influencing online shopping. Moreover, by using three airline company websites as an indicative example, the research identifies whether website best practice principles are utilised and examines visitors’ perceptions of their effectiveness. Further, the results of the current study are compared with the results of a previous study carried out in a similar field to identify similarities/differences over time. Information was collected from both secondary and primary sources. Primary sources included structured interviews, from which 180 responses were collected. The results show that the factors considered when purchasing online are comparable, but with some significant differences, implying that consumers are more confident engaging in online shopping. The limitations of the study are restricted to the non-probability sampling method used. Practitioners are able to use the results from the study as suggested guidelines for their promotional efforts.
Examining the Online Wine Tourism Experience of California Wineries
Authors: Simeon Roblyn , Sayeed Lutfus
Published: May 2012

Online wine tourism is boosting the level of competition among wineries and wine regions around the world. This paper presents and extends a proven framework for examining the strategic orientation of winery web sites. By treating winery web sites as intensive information environments this paper shows how they can have a strategic impact on perceptions. Using a modified AIPD framework and statistical analyses, the authors show how certain California wineries are able to fully project the wine tourism experience online while targeting strategic perception goals that are effective at building virtual brand equity and boosting winery visitations at the same time. The result of this research indicates that it is possible to measure and evaluate both the web experience and the strategic perception aspects of winery web sites.
E-Commerce Adoption by Micro Firms
Authors: Millman Cindy
Published: May 2012

This paper discusses the next stage of Internet usage by micro-businesses in the tourism sector, namely e-Commerce. Motivations for e-Commerce adoptions are examined and the perceived barriers are investigated. Moreover, experiences of the adopters are explored to identify the benefits gained and problems encountered. A qualitative approach is used and a pilot study conducted. In-depth face-to-face interviews with semi-structured questionnaires were conducted with twenty case studies, with a mix of e-Commerce adopters and non-adopters. The Critical Incident technique was used to encourage business owners to identify their experiences with this new business method. Preliminary results show that there are a number of ‘push’ and ‘pull’ factors that reinforce business owners’ decisions in adopting the e-Commerce method. The findings have implications for researchers and policymakers. The diversity of small firms has led to the need to tailor policy initiatives and training programmes. In addition, this study is replicable in other small business sectors that face the next step of development in Internet usage.
Balancing Growth
Authors: Dyerson Romano , Spinelli Riccardo
Published: May 2012

This article analyses the strategic, organisational, and structural conditions for small and medium enterprises (SMEs) to fully exploit the potential of information and communication technology (ICT). The authors build a conceptual framework relating “ICT readiness” (a new construct) to two more common dimensions: “strategic vision of ICT” and “ICT maturity”. Using the framework, the study identifies four distinct groups of SMEs, associated with differing degrees of readiness, before analysing possible evolutionary and regressive development paths among these groups. In discussing the implications of the framework, the authors argue that the framework represents a valid tool of diagnosis and intervention, especially in those circumstances where SMEs cannot fully exploit the potential of ICT. The framework helps identify the underlying causes of limited ICT readiness and supports owner-managers and consultants in choosing and implementing appropriate interventions.
Creating Competitive Advantage by Using Data Mining Technique as an Innovative Method for Decision Making Process in Business
Authors: Bal Mert , Bal Yasemin , Demirhan Ayse
Published: May 2012

Competitive advantage is at the heart of a firm’s performance in today’s challenging and rapidly changing environment. One of the central bases for achieving competitive advantage is the organizational capability to create new knowledge and transfer it across various levels of the organization. Traditional methods of data analysis, based mainly on human dealing directly with the data, simply do not scale to handle with large data sets. This explosive growth in data and databases has generated an urgent need for new techniques and tools that can intelligently and automatically transform the processed data into useful information and knowledge. Consequently, data mining has become a research area with increasing importance. Organizations of all sizes have started to develop and deploy data mining technologies to leverage data resources to enhance their decision making capabilities. Business information received from data analysis and data mining is a critical success factor for companies wishing to maximize competitive advantage. In this study, the importance of gaining knowledge for organizations in today’s competitive environment are discussed and data mining method in decision making process is analyzed as an innovative technique for organizations.
Systems Development Methodology for Mobile Commerce Applications
Authors: Binsaleh Muazzan , Hassan Shahizan
Published: May 2012

There are several systems development methodologies including traditional and agile methodologies being utilized in current systems development. However, it could be argued that when developing mobile commerce applications, suitable development framework should be investigated as these applications are utilized in different contexts from fixed ecommerce applications. This study identifies suitable system development methodology framework for mobile commerce applications. In order to achieve this aim, the practitioners from seven organizations were asked to provide information about their development methodologies by answering the questions regarding mobile commerce application development. The questions were opened and aimed to explore practitioner’s perspectives on the development methodologies. From the practitioner’s perspectives, it was found that there were several development methodologies being used in mobile commerce application development and these can be classified into two different development frameworks which are heavyweight/traditional and lightweight/agile methodologies. The suitable methodology framework for mobile commerce application development thus was identified.
Approximated Simplest Fuzzy Logic Controlled Shunt Active Power Filter for Current Harmonic Mitigation
Authors: Singh Rambir , Singh Asheesh K. , Arya Rakesh K.
Published: May 2012

This paper examines the size reduction of the fuzzy rule base without compromising the control characteristics of a fuzzy logic controller (FLC). A 49-rule FLC is approximated by a 4-rule simplest FLC using compensating factors. This approximated 4-rule FLC is implemented to control the shunt active power filter (APF), which is used for harmonic mitigation in source current. The proposed control methodology is less complex and computationally efficient due to significant reduction in the size of rule base. As a result, computational time and memory requirement are also reduced significantly. The control performance and harmonic compensation capability of proposed approximated 4-rule FLC based shunt APF is compared with the conventional PI controller and 49-rule FLC under randomly varying nonlinear loads. The simulation results presented under transient and steady state conditions show that dynamic performance of approximated simplest FLC is better than conventional PI controller and comparable with 49-rule FLC, while maintaining harmonic compensation within limits. Due to its effectiveness and reduced complexity, the proposed approximation methodology emerges out to be a suitable alternative for large rule FLC.
Semidefinite Programming-Based Method for Implementing Linear Fitting to Interval-Valued Data
Authors: Li Minghuang , Yu Fusheng
Published: May 2012

Building a linear fitting model for a given interval-valued data set is challenging since the minimization of the residue function leads to a huge combinatorial problem. To overcome such a difficulty, this article proposes a new semidefinite programming-based method for implementing linear fitting to interval-valued data. First, the fitting model is cast to a problem of quadratically constrained quadratic programming (QCQP), and then two formulae are derived to develop the lower bound on the optimal value of the nonconvex QCQP by semidefinite relaxation and Lagrangian relaxation. In many cases, this method can solve the fitting problem by giving the exact optimal solution. Even though the lower bound is not the optimal value, it is still a good approximation of the global optimal solution. Experimental studies on different fitting problems of different scales demonstrate the good performance and stability of our method. Furthermore, the proposed method performs very well in solving relatively large-scale interval-fitting problems.
Applying the Linguistic Strategy-Oriented Aggregation Approach to Determine the Supplier Performance with Ordinal and Cardinal Data Forms
Authors: Wang Shih-Yuan , Chang Sheng-Lin , Wang Reay-Chen
Published: May 2012

Supply chain management is a new and evolving paradigm for enterprises to cope with international competition and to improve global logistics efficiency. The suppliers’ performances affect not only supply chain execution results but also the profit capability and business survivability. However, suppliers’ performance assessment always involves a large dimension of supplier behaviors. Information on supplier behaviors is often difficult to be accurately demonstrated as quantitative data. For this reason, the study employs a 2-tuple linguistic variable to perform the initial evaluation and final assessment while keeping track of both linguistic information and data, which can avoid a tied result. Additionally, the modified linguistic ordered weighted averaging (M-LOWA) operator with maximum entropy is used to derive the maximum aggregation value under the current business strategy to reflect on the criteria. The focal company can then rapidly rely on the assessment results to represent the performance of suppliers and provide integrated information to decision makers. This study draws the complete framework for the issue of supplier performance assessment without limitations on categories of variables and scales.
A Comparative Study of SIP Overload Control Algorithms
Authors: Hong Yang , Huang Changcheng , Yan James
Published: May 2012

Recent collapses of SIP servers in the carrier networks indicates two potential problems of SIP: (1) the current SIP design does not easily scale up to large network sizes, and (2) the built-in SIP overload control mechanism cannot handle overload conditions effectively. In order to help carriers prevent widespread SIP network failure effectively, this chapter presents a systematic investigation of current state-of-the-art overload control algorithms. To achieve this goal, this chapter first reviews two basic mechanisms of SIP, and summarizes numerous experiment results reported in the literatures which demonstrate the impact of overload on SIP networks. After surveying the approaches for modeling the dynamic behaviour of SIP networks experiencing overload, the chapter presents a comparison and assessment of different types of SIP overload control solutions. Finally it outlines some research opportunities for managing SIP overload control.
Management of Service Level Agreement for Service-Oriented Content Adaptation Platform
Authors: Fudzee Mohd Farhan Md , Abawajy Jemal H.
Published: May 2012

It is paramount to provide seamless and ubiquitous access to rich contents available online to interested users via a wide range of devices with varied characteristics. Recently, a service-oriented content adaptation scheme has emerged to address this content-device mismatch problem. In this scheme, content adaptation functions are provided as services by third-party providers. Clients pay for the consumed services and thus demand service quality. As such, negotiating for the QoS offers, assuring negotiated QoS levels and accuracy of adapted content version are essential. Any non-compliance should be handled and reported in real time. These issues elevate the management of service level agreement (SLA) as an important problem. This chapter presents prior work, important challenges, and a framework for managing SLA for service-oriented content adaptation platform.
Enabling Frameworks for Autonomic Adaptation of Protocols in Future Internet Systems
Authors: Gazis Vangelis , Patouni Eleni , Alonistioti Nancy
Published: May 2012

The emergence of several networking standards has been continuous over the last decade. Engineering creativity spawned a wide gamut of innovative technologies for wireless and wireline communications. This increase in technological portfolios, in combination with the requirement to migrate legacy systems and to maximize the use of large investments in network installations, resulted in the design of multiple network evolution paths. Combined with the increasing sophistication of networking technologies, this variety of choice in design has run counter to the simplification – and the efficiency – of management procedures. The task of managing network infrastructures is confronted with an increasingly disharmonious Babel of standards involving interfaces, protocols, topologies, and versions. As a result, there has been a turn of research interest towards an autonomous mode of management where the elements of the managed system display individualistic proactive behavior that strives to maintain their modus operandi within specific bounds. The umbrella term autonomic computing and communications refers to a capability set that includes a system’s ability to monitor selected aspects of its own operation, collect, and record any data resulting from these observations, evaluate its performance under the light of its own operational history, possibly also identifying trends and recurring patterns in the process, and, in the case of subpar performance, undertaking corrective actions targeted to achieve a satisfactory level of performance. To this end, dynamically adaptable protocol stack offer a systemic capacity for change during runtime according to current operational requirements, thus providing an essential framework feature of autonomic systems.
Is ethylene binding after treatment of pre-climacteric bananas to stimulate ripening reversible or permanent?
Authors: Tong René , Whitehead Charles S.
Published: May 2012

The results of this study indicate that the binding of ethylene to its receptors after a short exposure to ethylene is reversible, while exposure for a longer time period results in irreversible binding. However, if exposure to ethylene exceeds a certain threshold time period, the ethylene binding becomes permanent.
The impact of herbivory and fire on the survival of certain perennial herbs along the Sabie River, Kruger National Park
Authors: Myburgh H. , Siebert F. , Van Coller H.
Published: May 2012

Herbivory and fire could be regarded as important drivers for perennial plant diversity, since their absence causes an increase in plant biomass, which was proven to suppress individual numbers of perennial species.
A survey and DNA barcoding of the molluscs and barnacles of Robben Island
Authors: Van der Bank F.H. , Greenfield R.
Published: May 2012

This study was done to identify the alien, native and introduced species that inhabit the island. DNA barcoding will ensure correct identification of the species.
Aggressive surgical palliation for advanced girdle tumours
Authors: Burd Andrew , Wong KC , Kumta Shekhar M.
Published: May 2012

Background: The surgical management of advanced, incurable, malignant disease presents particular ethical and technical challenges. The clear goal is palliation and the surgical futility must be avoided. This case series presents some particular challenges in end-of-life surgery. Materials and Methods: Fifteen patients referred with advanced malignant disease involving a limb girdle were reviewed. Results: In one case, a patient pleaded for surgery after initially requesting a delay to seek treatment from a Chinese Traditional Herbalist. The increase in tumour bulk led to problems with surgery and the patient died in a hospital a few weeks later. This case illustrates ′futility′ not recognized and encountered. The remaining 14 patients exhibited positive palliation with improved quality of dying and appreciation expressed by patients, relatives and staff. Conclusion: In selected cases, with a skilled and experienced surgical team, patients with advanced malignant disease can still benefit from aggressive surgical palliation. The margin of error is small between palliation being attempted and futility being achieved. This considerably adds to the challenge of end-of-life surgery.
Binder′s syndrome (maxillonasal dysplasia) different treatment modalities: Our experience
Authors: Deshpande Sanjeev N. , Juneja Manpreet H.
Published: May 2012

Aim: Being an uncommon congenital condition, the treatment modalities of maxillonasal dysplasia are not clearly defined. Our aim is to discuss the availability and utility of various treatment options to achieve optimum results. In patients with Binder′s syndrome, the midface appears flattened, the columella is short and the upper lip slants backwards. Materials and Methods: We report here 15 patients with Binder′s syndrome who were operated over a period of 5 years. Different treatment options in the form of correction of the depressed nasal dorsum and maxillary hypoplasia with split cranial bone graft or synthetic materials such as high-density porous polyethylene implant were used. Two patients with Angle class III malocclusion underwent a Le Fort I osteotomy for maxillary advancement. The patients were followed over a period of 3 years. Results: We achieved a reasonable augmentation of the nose and the maxilla in our patients. We faced complications in two of our patients; in one patient there was fracture of the dorsal nasal bone graft and the other patient had protrusion of paranasal screws into the palate, which were removed. Conclusion: In this series of cases, we were able to utilise various treatment modalities appropriately to achieve satisfactory outcome with no significant complications.
Improvement of a long random skin flap survival by application of vascular endothelial growth factor in various ways of local administration in a rat model
Authors: Vourtsis Spyridon A. , Papalois Apostolos E. , Agrogiannis George D. , Spyriounis Petros K. , Patsouris Efstratios , Ionac Mihai
Published: May 2012

Background: Vascular endothelial growth factor (VEGF) is a heparin-binding glycoprotein which plays a significant role in angiogenesis and vascular permeability. The effect of various ways of local administration of VEGF on random skin flap survival was studied, using flaps with a relatively high length (L) to width (W) ratio (5:1). Materials and Methods: An 1.5 × 7.5 cm dorsal skin flap with the pedicle orientated, centered, and remaining attached between the lower angles of the scapulae was elevated in 45 Wistar rats in different phases, depending on the group. Rats were divided in five groups of nine. In group A, injections of saline were administered, in equally divided spaces, into flap′s fascia and transposed to a created skin defect. In group B, injections of VEGF were applied subdermally, in equally divided spaces, within the limits of a predesigned flap, a week prior to flap dissection and transposition. In group C, injections of VEGF were applied into a recipient bed′s fascia just before flap raising and transposition. In group D, injections of VEGF were applied subdermally, only in the distal third of the flap and then the flap was transposed to a recipient area. Finally, in group E, injections of VEGF were applied in the flap intrafascially and in equally divided spaces and then again, the flap was transposed to a recipient area. A week after final flap raising and positioning, rats were euthanatised and flaps were excised. Specimens were photographed, measured, put in formalin 10% and were sent for histological and image analysis. Results: Mean flap survival percentage was 35.4% in group A, and 33.7% in group B. In groups C and D, the mean survival area was 56.3% and 80.4%, respectively. In group E, the mean flap survival percentage was 28.3%. Histological analysis demonstrated increased angiogenesis in groups C and D. Conclusions: VEGF application improved skin flap survival when injected subdermally in the distal third of a random skin flap or into the fascia of a recipient area even though the length-to-width ratio was high.
An uncommon case of upper limb pterygia
Authors: Deodhar Avinash
Published: May 2012

Reporting images in a case of a 9-year-old boy who presented with bilateral congenital webbing (pterygium) of axillae and elbows. This deformity was restricting his axilla and elbow movements. This was successfully treated on one side with multiple Z-plasty. An outline of multiple pterygium syndrome is given herewith.
Single stage reconstructions in head and neck surgery using deltopectoral and pectoralis major myocutaneous flaps
Authors: Nayak Bibhuti B. , Nilamani Mohanty
Published: May 2012

Even though free tissue transfers are a routine in many centres, pedicle flaps still have a huge roll to play in our country. There are many centres in the country where pedicle flaps are in use because of logistic problems. Deltopectoral and pectoralis muscle flaps are usually preferred for composite cheek defects. When both these flaps are used in combination it is a two-staged procedure. We describe a single-stage procedure to reconstruct a composite cheek defect with pectoralis major myocutaneous flap for lining and single-stage deltopectoral flap for cover. In the available literature search, single-stage DP and PMMC have not been described for management of composite cheek defect.
Utility of the omentum in sacral reconstruction following total sacrectomy due to recurrent and irradiated giant cell tumour of the spine
Authors: Unal Cigdem , Eren Guler Gamze , Isil Eda , Alponat Ahmet , Sarlak Ahmet
Published: May 2012

Reconstruction of the lumbosacral region after surgical excision of irradiated and recurrent spinal giant cell tumours remains a challenging problem. In this case report, we describe the use of the pedicled omentum flap in reconstruction of an irradiated and infected wide sacral defect of a 19-year-old male patient. The patient had radiotherapy and subsequent wide surgical resection after recurrence of the tumour. A myocutaneous flap from the gluteal area had failed previously. Local flap options could not be used because of the recent radiotherapy to the gluteal area. Since the patient had a laparotomy for tumour resection and a colostomy, abdominal muscles were not considered reliable for reconstructive procedures. A pedicled omentum flap was chosen as a reconstructive option because of its rich blood supply, large surface area, and angiogenic capacity. This report aims to describe the use of the pedicled omentum flap for reconstruction of the lumbosacral area following surgical resection of a spinal tumour, when gluteal and abdominal flap options for reconstruction are jeopardised.
Skin markings methods and guidelines: A reality in image guidance radiotherapy era
Authors: Rathod Shrinivas , Munshi Anusheel , Agarwal Jaiprakash
Published: May 2012

Preparation of site of radiation delivery is an important process in radiation treatment planning and plays a crucial role during a course of radiotherapy to achieve reproducibility of set-up and accuracy of treatment delivery. The preparation of treatment area is done by markings of field center, field edge or other reference point of planned field. Both non-invasive (marker pen, henna) and invasive methods (tattoo) are available for marking with limitations of each. Tattoo with a needle pricked at angle of 30° to 1-2 mm depth to create tattoo 2-3 mm diameter in size is an ideal procedure. Visibility, permanent nature, social-religious belief, and mobility of skin are one of the main concerns about tattoo. Tattoo removal can be done performed if desirable by patients by various modern ways, which will be esthetically available. Dermabrasion, cryotherapy, surgery, QSRL (Q-switched ruby laser) are common methods of tattoo removal. Esthetic dissatisfaction, allergy, dermatoses, keloids, infection, fanning/fading of tattoo are associated problems. In IMRT and IGRT treatment, delivery dependence on tattoo in reduced and use of surrogate markers including particularly for bony set-up and implanted markers (e.g. gold seeds) for tumor localization and treatment verification is increasing. However, these are complex procedures and require an expertise. Ease of set-up and less time required for tattooing are one of the main advantages of tattoo as compared to external or internal marker set-up. Tattoo still remains a crucial method of positioning, especially in developing countries and in palliative treatment settings.
Metastatic renal cell carcinoma: Current scenario and future trends
Authors: Bharthuar Anubha
Published: May 2012

An improved understanding of the biology of renal cell carcinoma (RCC) has led to the development of a number of targeted agents, which has resulted in a paradigm shift in the management of metastatic RCC. We review the current therapeutic strategies for metastatic RCC and present a synopsis of the novel agents in use today with a discussion of the phase III trials that demonstrated their clinical benefit. The management of RCC continues to evolve. The introduction of VEGF and mTOR inhibitors has markedly expanded our drug armamentarium and improved the outcome of a disease that has always been challenging to treat. Knowledge from upcoming trials will help us utilize these drugs for maximum clinical efficacy with optimal dosing and sequencing, either individually or in combination therapy.
Nitrogen deposition to the United States: distribution, sources, and processes
Authors: Zhang L. , Jacob D. J. , Knipping E. M. , Kumar N. , Munger J. W. , Carouge C. C. , van Donkelaar A. , Wang Y. X. , Chen D.
Published: May 2012

Abstract. We simulate nitrogen deposition over the US in 2006–2008 by using the GEOS-Chem global chemical transport model at 1/2°×2/3° horizontal resolution over North America and adjacent oceans. US emissions of NOx and NH3 in the model are 6.7 and 2.9 Tg N a−1 respectively, including a 20% natural contribution for each. Ammonia emissions are a factor of 3 lower in winter than summer, providing a good match to US network observations of NHx (≡NH3 gas + ammonium aerosol) and ammonium wet deposition fluxes. Model comparisons to observed deposition fluxes and surface air concentrations of oxidized nitrogen species (NOy) show overall good agreement but excessive wintertime HNO3 production over the US Midwest and Northeast. This suggests a model overestimate N2O5 hydrolysis in aerosols, and a possible factor is inhibition by aerosol nitrate. Model results indicate a total nitrogen deposition flux of 6.5 Tg N a−1 over the contiguous US, including 4.2 as NOy and 2.3 as NHx. Domestic anthropogenic, foreign anthropogenic, and natural sources contribute respectively 78%, 6%, and 16% of total nitrogen deposition over the contiguous US in the model. The domestic anthropogenic contribution generally exceeds 70% in the east and in populated areas of the west, and is typically 50–70% in remote areas of the west. Total nitrogen deposition in the model exceeds 10 kg N ha−1 a−1 over 35% of the contiguous US.
Does precipitation susceptibility vary with increasing cloud thickness in marine stratocumulus?
Authors: Terai C. R. , Wood R. , Leon D. C. , Zuidema P.
Published: May 2012

Abstract. The relationship between precipitation rate and accumulation mode aerosol concentration in marine stratocumulus-topped boundary layers is investigated by applying the precipitation susceptibility metric to aircraft data obtained during the VOCALS Regional Experiment. A new method to calculate the precipitation susceptibility that incorporates non-precipitating clouds is introduced. The mean precipitation rate R over a segment of the data is expressed as the product of a drizzle fraction f and a drizzle intensity I (mean rate for drizzling columns). The susceptibility Sx is then defined as the fractional decrease in precipitation variable x = {R, f, I} per fractional increase in the concentration of aerosols with dry diameter >0.1 μm, with cloud thickness h held fixed. The precipitation susceptibility SR is calculated using data from both precipitating and non-precipitating cloudy columns to quantify how aerosol concentrations affect the mean precipitation rate of all clouds of a given h range and not just the mean precipitation of clouds that are precipitating. SR systematically decreases with increasing h, and this is largely because Sf decreases with h while SI is approximately independent of h. In a general sense, Sf can be thought of as the effect of aerosols on the probability of precipitation, while SI can be thought of as the effect of aerosols on the intensity of precipitation. Since thicker clouds are likely to precipitate regardless of ambient aerosol concentration, we expect Sf to decrease with increasing h. The results are broadly insensitive to the choice of horizontal averaging scale. Similar susceptibilities are found for both cloud base and near-surface drizzle rates. The analysis is repeated with cloud liquid water path held fixed instead of cloud thickness. Simple power law relationships relating precipitation rate to aerosol concentration or cloud droplet concentration do not capture this observed behavior.