bluuebunny/crossref_metadata_2025 huggingface dataset:
A Weakly Synchronous and Distributed Coordination Function for QoS Management in CSMA/CA Wireless Access Networks
Authors: Vesco Andrea , Scopigno Riccardo
Published: October 2012

Moreover a signalling architecture is here designed, for the first time, to enable dynamic and distributed resource reservation over the wireless network by means of two protocols: the Resource Reservation Protocols with Traffic Engineering (RSVP-TE), properly extended to work in TD-uCSMA networks and the new Resource State Management Protocol (RSMP). The TD-uCSMA operating principles and the signalling architecture are then validated by simulation over many scenarios comprising multi-hop wireless access networks. Finally the chapter addresses the issue of prototyping TD-uCSMA by open source IEEE 802.11 legacy drivers.
MAC and PHY-Layer Network Coding for Applications in Wireless Communications Networks
Authors: Bartoli Giulio , Chiti Francesco , Fantacci Romano , Marabissi Dania , Tassi Andrea
Published: October 2012

Network coding (NC) is a promising technique recently proposed to improve network performance in terms of maximum throughput, minimum delivery delay, and energy consumption. The original proposal highlighted the advantages of NC for multicast communications in wire-line networks. Recently, network coding has been considered as an efficient approach to improve performance in wireless networks, mainly in terms of data reliability and lower energy consumption, especially for broadcast communications. The basic idea of NC is to remove the typical requirement that different information flows have to be processed and transmitted independently through the network. When NC is applied, intermediate nodes in the network do not simply relay the received packets, but they combine several received packets before transmission. As a consequence, the output flow at a given node is obtained as a linear combination of its input flows. This chapter deals with the application of network coding principle at different communications layers of the protocol stack, specifically, the Medium Access Control (MAC) and physical (PHY) Layers for wireless communication networks.
Precoding for Multiuser MIMO
Authors: Saeid Elsadig , Jeoti Varun , Samir Brahim Belhaouari
Published: October 2012

Future Wireless Networks are expected to adopt multi-user multiple input multiple output (MU-MIMO) systems whose performance is maximized by making use of precoding at the transmitter. This chapter describes the recent advances in precoding design for MU-MIMO and introduces a new technique to improve the precoder performance. Without claiming to be comprehensive, the chapter gives deep introduction on basic MIMO techniques covering the basics of single user multiple input multiple output (SU-MIMO) links, its capacity, various transmission strategies, SU-MIMO link precoding, and MIMO receiver structures. After the introduction, MU-MIMO system model is defined and maximum achievable rate regions for both MU-MIMO broadcast and MU-MIMO multiple access channels are explained. It is followed by critical literature review on linear precoding design for MU-MIMO broadcast channel. This paves the way for introducing an improved technique of precoding design that is followed by its performance evaluation.
CORM
Authors: Hassan Hoda Mamdouh
Published: October 2012

Designing future computer networks dictates an eclectic vision capable of encompassing ideas and concepts developed in contemporary research unfettered by today’s operational and technological constraints. However, unguided by a clear articulation of core design principles, the process of network design may be at stake of falling into similar pitfalls and limitations attributed to current network realizations. This chapter presents CORM: a clean-slate Concern-Oriented Reference Model for architecting future computer networks. CORM stands as a guiding framework from which several network architectures can be derived. CORM represents a pioneering attempt within the network realm, and to the author’s knowledge, CORM is the first reference model that is bio-inspired, accounts for complex system characteristics, and applies a software engineering approach to network design. Moreover, CORM’s derivation process conforms to the Function-Behavior-Structure (FBS) engineering framework, which is credited to be applicable to any engineering discipline for reasoning about, and explaining the process of design.
Localizing Persons Using Body Area Sensor Network
Authors: Guo Cheng , Prasad R. Venkatesha , Wang Jing , Rao Vijay Sathyanarayana , Niemegeers Ignas
Published: October 2012

Context awareness is an important aspect in many ICT applications. For example, in an intelligent home network, location of the user enables session transfer, lighting, and temperature control, et cetera. In fact, in a body area sensor network (BASN), location estimation of a user helps in realizing realtime monitoring of the person (especially those who require help) for better health supervision. In this chapter the authors first introduce many localization methods and algorithms from the literature in BASNs. They also present classification of these methods. Amongst them, location estimation using signal strength is one of the foremost. In indoor environments, the authors found that the signal strength based localization methods are usually not accurate, since signal strength fluctuates. The fluctuation in signal strength is due to deficient antenna coverage and multi-path interference. Thus, localization algorithms usually fail to achieve good accuracy. The authors propose to solve this problem by combining multiple receivers in a body area sensor network to estimate the location with a higher accuracy. This method mitigates the errors caused by antenna orientations and beam forming properties. The chapter evaluates the performance of the solution with experiments. It is tested with both range-based and range-free localization algorithm that we developed. The chapter shows that with spatial diversity, the localization accuracy is improved compared to using single receiver alone. Moreover, the authors observe that range-based algorithm has a better performance.
Workforce Diversity at the Lagos Business School, Pan-African University, Nigeria
Authors: Ogunyemi Kemi
Published: October 2012

The School has a fair distribution of people from different ethnic groups. It also has a mission that identifies expressly with the Christian view of human nature and yet is open to people of all religious inclinations. As an academic environment, there is also the inevitable risk of distance between academic staff and administrative staff and between lecturers and students. The purpose of this chapter is to highlight the positive practices at the LBS that help them leverage workforce diversity and to make a few suggestions for improvement. This chapter will also highlight how the school reflects the importance of leveraging diversity in its academic curriculum.
Leveraging Multinational Firm Performance through the Use of Diversified Top Management Teams
Authors: Alpay Güven , Büyükbalci Pinar
Published: October 2012

This chapter discusses the theoretical framework covering the relationship between top management team diversity determinants and certain organization-level variables in order to capture the essence of possible strategic outcomes. Accordingly, it attempts to summarize and clarify the theoretical and empirical literature regarding the effects of diversity on the functioning of top management teams. In this sense, the main aim of this study is to contribute to and improve the current literature on diversity through the viewpoint of strategic international business literature by directly focusing on the organizational unit—top management teams—which is responsible for formulating and implementing strategies that will leverage organizational performance in the long run.
Leveraging Workforce Diversity and Team Development
Authors: Zaballero Aileen G. , Tsai Hsin-Ling , Acheampong Philip
Published: October 2012

This chapter will emphasize the importance of collaborative team-based work groups among diverse settings. First, the authors will discuss the factors of diverse teams and identify the stages of group development focusing on Tuckman’s Model. In addition, Gert Hofstede’s cultural dimension will be addressed. Finally, organizational contexts that impact the performance of diverse teams such will be explored.
Leveraging Intergenerational Diversity to Meet Business Goals
Authors: Jackson Sherita L.
Published: October 2012

In recent years, the concept of generational diversity has gained increasing recognition in the United States. Each generation is shaped by historical, social, and cultural events that are unique to that particular age cohort. The purpose of this chapter is to help scholars, researchers, organizational leaders, practitioners, and graduate students understand diversity among generational cohorts and employ practices to utilize the wealth of knowledge that exists within today’s multigenerational workforce. This chapter will describe the four generations in today’s workplace and discuss gaps that can cause conflict. This chapter also provides tips and best practices for leveraging intergenerational diversity as well as scenarios and examples that demonstrate best practices. The result is a cohesive and productive workplace that respects multigenerational perspectives.
Leveraging Workforce Diversity
Authors: Zaballero Aileen G. , Asino Tutaleni I. , Briskin Jessica
Published: October 2012

This chapter connects technology and diversity and argues that technology can be leveraged to contribute to the diversification of a workforce. The authors discuss the changing global economy as it pertains to the diminution of labor market boundaries and diversified consumers, as well as current trends in technology usage and innovation as a means to accomplishing organizational goals. In addition, the authors analyze organizational learning and organizational performance, regarding the use of technology as a tool to overcome the challenges of a diverse workforce.
The Power of EA Taxonomies in Enhancing Portfolio Visibility and Optimising Decision Making
Authors: Ashdown Don , Douglas-Savage Vanessa , Harte Kirsten , Low Ee-Kuan
Published: October 2012

This chapter describes the power of using Enterprise Architecture (EA) taxonomies in making sense of an organisation and its components to support portfolio visibility and optimise decision-making. It describes the use of taxonomies in a manner that has been successfully applied across a range of medium to large organisations particularly at a whole-of-government level within the Queensland Government, the Gold Coast City Council, and at an agency level within the Queensland Department of Justice and Attorney-General. These taxonomies enable increased visibility of an organisation’s investment portfolio to support more structured decision-making and provide a basis for evidence-based policy development. At the whole-of-government level, this supports optimisation of information and IT investments across the entire connected government portfolio.
Integrating Agency Enterprise Architecture into Government-Wide Enterprise Architecture
Authors: Lee Young-Joo , Shin Shinae
Published: October 2012

Since the Korean government mandated public entities to adopt Enterprise Architecture (EA) in 2005, 75.8% of central agencies, municipal governments, and other public organizations have adopted EA. Following a two-year project, which defined all government-level architecture components and collected relevant data from each agency’s EA, the Korean Government-Wide EA (KGEA) was rolled out. As of the end of 2010, KGEA manages IT projects, information systems, work processes, data, hardware, and other related information of 809 agencies in a single repository. All information is shared with all the agencies through the KGEA portal (www.geap.or.kr). This chapter illustrates a case of how EA works for aligning an agency’s IT resources with the national IT agenda and enhances IT investment management at a government-wide level. By applying the analytical framework suggested by Janssen and Hjort-Madsen (2007), the development and accomplishments of KGEA are then discussed in terms of connected government—specifically national IT investment and resource management, public service improvements, and interoperability across agencies. This case may offer practical guidance to government CIOs of other countries when implementing Government-Wide EA (GEA).
An Investigative Assessment of the Role of Enterprise Architecture in Realizing E-Government Transformation
Authors: Anthopoulos Leonidas
Published: October 2012

In this chapter, some important e-strategies are investigated concerning the existence and the contribution of an EA to strategic implementation and transformation. Different EAs are compared, and architectures are aligned to strategic and to transformation objectives, via Connected Government. Moreover, the necessity of the alignment of an EA to the strategic update is underlined, and an EA maturity roadmap to Connected Government is considered.
Architecting for Connected Healthcare
Authors: Tambo Torben , Hoffmann-Petersen Nikolai , Bejder Karsten
Published: October 2012

The healthcare system is in many countries operated by the governments, and interaction with the healthcare system is one of the most frequent interactions between citizen and government. Demographic, medical, and technological changes are likely to bring new aspects of connectedness into the everyday life of people and place healthcare and homecare professionals in new roles. A transformation is taking place where hospital best practices are constantly reducing patient’s in-hospital stays to alternative, less-costly care—notably at home. Telemedicine, telehealth, eHealth, home monitoring, and self-care are essential aspects of this transformation. Many issues are influencing this transformation, and new barriers are showing up where others are removed. A broadly oriented enterprise architecture effort is presented for the underpinning of the change process. The architectural approach encompasses views of the citizen, the healthcare system, the information infrastructure, and the citizen-oriented technology. A case of telemonitoring and self-care is presented using mobile hypertension measurement on a large-scale population cohort. Evaluation of the acceptance and success of the solutions is done within a combined understanding including technology, economy, organization, and culture.
Moving towards the Connected Transformational Government
Authors: Mansor Dzaharudin , Mansor Dzaharudin , Mokhtar Mohd. Rosmadi , Azman Azlina
Published: October 2012

This chapter provides insights into interoperability from the point of view of delivering government services. It shows that today, technology and the industry have progressed to such an extent that the technical barriers to interoperability can be overcome in many ways. The real challenge is to address business interoperability that involves the interplay of technical, architectural, strategic, organizational, policy, and legal dimensions. This, in turn, has influenced the evolution of government interoperability frameworks, where some governments have incorporated Enterprise Architecture approaches. Today, new socio-economic challenges require policy makers to rethink their approaches in ways that will enable them to constantly improve and evolve citizen-centric services powered by an ICT-enabled Connected Transformational Government.
Location-Based Services and Navigation in Smart Phones
Authors: Pei Ling , Liu Zhengjun
Published: October 2012

The ubiquitous positioning ability and abundant computation capability of a smart phone allow the provision of a variety of location-based services (LBSs). This chapter focuses on the fundamental elements and principles of LBS in a smart phone. First, the basic concept of LBS is introduced. Second, the state-of-the-art smart phones and communication networks are described. Afterwards, the smart phone positioning technologies are presented as three groups: satellite-based technologies, network-based solutions, and sensor-based approaches. Then, the location relevant services, contents, data, and context in a smart phone are explained. Furthermore, in the perspective of the new generation of LBS, the emerging features and technical solutions are discussed. Finally, three examples show how the above elements are integrated into the LBS applications in a smart phone.
Mobile Geographic Information Systems
Authors: Li Yang , Brimicombe Allan J.
Published: October 2012

This chapter introduces the concept of Mobile Geographical Information Systems (Mobile GIS) as an evolution of conventional GIS to being available on wireless mobile devices such as smart phones. The evolution of the technology and its applications are charted in this chapter. The main elements of Mobile GIS are then discussed. This focuses on: GIS servers; wireless mobile telecommunication networks; wireless mobile devices; location-awareness technology; and gateway services. This is followed by a discussion of the main features in terms of the services and usage of Mobile GIS: mobility; real-time connectivity; location-awareness; broadened usage. Mobile Geographical Information Systems are an important facilitating technology for Location-Based Services (LBS). A range of applications of Mobile GIS for smart phones are described. The chapter closes with a discussion of the prospects and challenges for Mobile GIS. Challenges derive from four broad areas: limitations that derive from the technologies being used; areas of GIScience that still need to be adequately researched; users; and business models for a sustainable presence.
Web Services Compositions Modelling and Choreographies Analysis
Authors: Rouached Mohsen , Fdhila Walid , Godart Claude
Published: October 2012

In Rouached et al. (2006) and Rouached and Godart (2007) the authors described the semantics of WSBPEL by way of mapping each of the WSBPEL (Arkin et al., 2004) constructs to the EC algebra and building a model of the process behaviour. With these mapping rules, the authors describe a modelling approach of a process defined for a single Web service composition. However, this modelling is limited to a local view and can only be used to model the behaviour of a single process. The authors further the semantic mapping to include Web service composition interactions through modelling Web service conversations and their choreography. This paper elaborates the models to support a view of interacting Web service compositions extending the mapping from WSBPEL to EC, and including Web service interfaces (WSDL) for use in modelling between services. The verification and validation techniques are also exposed while automated induction-based theorem prover is used as verification back-end.
Protocol-Level Service Composition Mismatches
Authors: Xiong PengCheng , Pu Calton , Zhou MengChu
Published: October 2012

Protocol-level mismatch is one of the most important problems in service composition. The state-of-the-art method to deal with protocol mismatch is to generate adaptors to check deadlock-freeness based on a reachability graph. When this property is violated, the generation process will repeat itself until no deadlock state is found; however, the main drawback of this method is that it does not take into account the future deadlock state and requires many interactions with a developer. In this regard, it suffers from low efficiency. In this paper, the authors model multiple web service interaction with a Petri net called Composition net (C-net). The protocol-level mismatch problem is transformed into the empty siphon problem of a C-net. The authors take future deadlock states into consideration through this model, while finding the optimal solution that involves fewest interactions with a developer. The proposed method is proved to achieve higher efficiency for resolving protocol-level mismatch issues than traditional ones.
Managing the Replaceability of Web Services Using Underlying Semantics
Authors: Peng Dunlu , Wang Xiaoling , Zhou Aoying
Published: October 2012

In the context of web services, service replaceability refers to the ability of substituting one service for another. With the bloom of service-oriented computing, the effective management of service replaceability is important to make the applications unaffected once the requested service cannot work. This work studies the quantitative aspect of the replaceability of web services. FCA (Formal Concept Analysis) method is applied to reveal the pairwise replaceable relationship among web services. A novel structure, called RSLattice, is proposed to index web services on the basis of the underlying semantics, and the replaceability among services at the operation level is represented accurately. It ensures that the services having mutual replaceability are organized in the same path of RSLattice. Based on this property, we can greatly reduce the search space when retrieving the replaceable services in RSLattice. Experimental evaluation shows that RSLattice is an efficient and flexible structure for service replaceability management.
Satisfying End User Constraints in Service Composition by Applying Stochastic Search Methods
Authors: Lecue Freddy , Mehandjiev Nikolay
Published: October 2012

Semantic web service compositions must be aligned with requirements from the target users in terms of quality requirements. Given a set of quality requirements, one can choose to either find the optimal composition or a “good enough” composition, which satisfies these requirements. Since optimizing compositions of semantic services under quality constraints is known to be NP-hard, it is unsuitable for realistic problems within large search spaces. The authors address the issue by using the “good enough” approach, selecting the first composition that passes their quality threshold. Firstly, this paper defines quality constraints within an innovative and extensible model designed to balance semantic fit (or functional quality) with quality of service (QoS) metrics. The semantic fit criterion evaluates the quality of semantic links between the semantic descriptions of Web services parameters, while QoS focuses on non-functional criteria of services. User quality requirements are met by selecting a valid composition. To allow the use of this model with a large number of candidate services as foreseen by the strategic EC-funded project SOA4All the authors formulate the selection problem as a Constraint Satisfaction Problem and test the use of a stochastic search method.
The MACE Approach for Caching Mashups
Authors: Hassan Osama Al-Haj , Ramaswamy Lakshmish , Miller John
Published: October 2012

In recent years, Web 2.0 applications have experienced tremendous growth in popularity. Mashups are a key category of Web 2.0 applications, which empower end-users with a highly personalized mechanism to aggregate and manipulate data from multiple sources distributed across the Web. Surprisingly, there are few studies on the performance and scalability aspects of mashups. In this paper, the authors study caching-based approaches to improve efficiency and scalability of mashups platforms. This paper presents MACE, a caching framework specifically designed for mashups. MACE embodies three major technical contributions. First, the authors propose a mashup structure-aware indexing scheme that is used for locating cached data efficiently. Second, taxonomy awareness into the system is built and provides support for range queries to further improve caching effectiveness. Third, the authors design a dynamic cache placement technique that takes into consideration the benefits and costs of caching at various points within mashups workflows. This paper presents a set of experiments studying the effectiveness of the proposed mechanisms.
Behavioral Attestation for Web Services Based Business Processes
Authors: Alam Masoom , Nauman Mohammad , Zhang Xinwen , Ali Tamleek , Hung Patrick , Alam Quratulain
Published: October 2012

Service Oriented Architecture (SOA) is an architectural paradigm that enables dynamic composition of heterogeneous, independent, multi-vendor business services. A prerequisite for such inter-organizational workflows is the establishment of trustworthiness, which is mostly achieved through non-technical measures, such as legislation, and/or social consent that businesses or organizations pledge themselves to adhere. A business process can only be trustworthy if the behavior of all services in it is trustworthy. Trusted Computing Group (TCG) has defined an open set of specifications for the establishment of trustworthiness through a hardware root-of-trust. This paper has three objectives: firstly, the behavior of individual services in a business process is formally specified. Secondly, to overcome the inherent weaknesses of trust management through software alone, a hardware root of-trust devised by the TCG, is used for the measurement of the behavior of individual services in a business process. Finally, a verification mechanism is detailed through which the trustworthiness of a business process can be verified.
Recent Advances in Cardiovascular Research: Systems Biology
Authors: D'Alessandro Raffaella , Sepe Joseph
Published: October 2012

The authors describe different bioinformatic approaches to cardiovascular research, focusing on: (i) the complexity of cardiovascular diseases; (ii) how does systems biology work and its application to cardiology; (iii) new systems research in cardiology; (iv) clinical cardiological practice; (v) perspectives and limitations of systems biology in cardiology.
The Dilemma of Treating Vertebrobasilar Dolichoectasia
Authors: Lin Yu-Wei , Chen Chih-Hung , Lai Ming-Liang
Published: October 2012

Vertebrobasilar dolichoectasia (VBD) is a common phenomenon among people over 50 years old, and the related clinical expressions are varied. One of our VBD patients presented with brainstem infarction initially, received low molecular weight heparin treatment, and developed rupture of the dolichoectasia segment. Another patient with a similar-sized VBD experienced recurrent brainstem infarction three times over 2 years, despite higher bleeding tendency and long-term antiplatelet treatment. The third patient with a smallersized VBD, had left hemiplegia and received intravenous recombinant tissue plasminogen activator within 3 h, totally recovered with no lesions detected on brain Magnetic Resonance Imaging (MRI). The pathophysiology of VBD is unique, its prevalence and risks of ischemic stroke and intracranial hemorrhage both increase as the degree of arterial dolichoectasia extends, making the strategy of management quite a challenge. The best management of VBD is controlling arterial hypertension and following up with image studies regularly to detect the early extension of VBD degree.
Optimizing healthy ageing in disadvantaged communities: insights into older people’s use of health and social care services
Authors: Tetley Josephine
Published: October 2012

The European Year of Healthy Ageing recognizes that health care systems need to be improved and reorganized if services are to optimize the opportunities for people to stay healthy and well in their own homes for as long as possible. However, current services tend to be fragmented and insensitive to the needs of older people and their carers resulting in services being underused or refused leading to increased admissions into acute hospital care that could have been prevented. The main aim of the study reported in this paper was to identify the factors that affected older peoples’ decision and choice-making processes, when using or contemplating the use of care services. Using a constructivist methodology, this study used participant observation and 23 interviews in three study settings: an African Caribbean support service, day centers for people with memory and cognition problems and luncheon clubs for older people. An inductive analysis of the data revealed that when older community dwelling people found themselves struggling with certain aspects of their daily care needs; they used adapting, coping and seeking as strategies to manage. Additional issues of how well services were able to meet individual’s aspirations for care and support were identified through themes of match-mismatch, fair-unfair, independence-dependence. The findings reported in this study provide important insights as to how people’s needs are complex yet are negatively affected by rigid state controlled services that ultimately affect individual decisions to use or refuse services.
Optimising automation of a manual enzyme-linked immunosorbent assay
Authors: De Beer Corena , Esser Monika , Preiser Wolfgang
Published: October 2012

Objective: Enzyme-linked immunosorbent assays (ELISAs) are widely used to quantify immunoglobulin levels induced by infection or vaccination. Compared to conventional manual assays, automated ELISA systems offer more accurate and reproducible results, faster turnaround times and cost effectiveness due to the use of multianalyte reagents.Design: The VaccZyme™ Human Anti-Haemophilus influenzae type B (Hib) kit (MK016) from The Binding Site Company was optimised to be used on an automated BioRad PhD™ system in the Immunology Laboratory (National Health Laboratory Service) in Tygerberg, South Africa.Methods: An automated ELISA system that uses individual well incubation was compared to a manual method that uses whole-plate incubation.Results: Results were calculated from calibration curves constructed with each assay. Marked differences in calibration curves were observed for the two methods. The automated method produced lower-than-recommended optical density values and resulted in invalid calibration curves and diagnostic results. A comparison of the individual steps of the two methods showed a difference of 10 minutes per incubation cycle. All incubation steps of the automated method were subsequently increased from 30 minutes to 40 minutes. Several comparative assays were performed according to the amended protocol and all calibration curves obtained were valid. Calibrators and controls were also included as samples in different positions and orders on the plate and all results were valid.Conclusion: Proper validation is vital before converting manual ELISA assays to automated or semi-automated methods.
Characteristics of seizure frequency among Malaysian children diagnosed with structural– metabolic epilepsy
Authors: Salih Muhannad RM , Bahari Mohd Baidi , Ahmad Hassali Mohamed Azmi , Shafie Asrul Akmal , Al-lela Omer Qutaiba B , Abd Arwa Y , Ganesan Vigneswari M
Published: October 2012

Introduction: Seizure-free patients or substantial reduction in seizure frequency are the most important outcome measures in the management of epilepsy. The study aimed to evaluate the patterns of seizure frequency and its relationship with demographics, clinical characteristics, and outcomes. Materials and Methods: A retrospective cohort study was conducted at the Pediatric Neurology Clinic, Hospital Pulau Pinang. Over a period of 6 months, the required data were extracted from the medical records using a pre-designed data collection form. Results: Seizure frequency showed no significant association with patient’s demographics and clinical characteristic. However, significant reduction in seizure frequency from the baseline to the last follow-up visit was only seen in certain subgroups of patients including Malays, females, patients <4 years of age, patients with global developmental delay/intellectual disability, and patients with focal seizure. There was no significant association between seizure frequency and rate of adverse events. Polytherapy visits were associated with higher seizure frequency than monotherapy visits (27.97 ± 56.66, 10.94 ± 30.96 attack per month, respectively) (P < 0.001). There was a clear tendency to get antiepileptic drugs used at doses above the recommended range in polytherapy (8.4%) rather than in monotherapy (1.4%) visits (P < 0.001). A significant correlation was found between seizure frequency and number of visits per patient per year (r = 0.450, P < 0.001). Conclusion: Among children with structural–metabolic epilepsy, Malays, females, patients <4 years of age, patients with global developmental delay/intellectual disability and patients manifested with focal seizure are more responsive antiepileptic drug therapy than the other subgroups of patients.
Anthropometric parameters as indicators of metabolic derangements in schizophrenia patients stabilized on olanzapine in an Indian rural population
Authors: Rout Jayanta Kumar , Dasgupta Anindya , Singh Om Prakash , Banerjee Ushasi , Das Brahmarshi
Published: October 2012

Context: For any given body mass, Asian Indians have higher central obesity than Europeans. A periodic measurement of body mass index (BMI) and waist hip ratio (WHR) is practically more feasible than other parameters of metabolic syndrome by repeated blood collection. However, few studies are available on the relative importance of BMI and WHR as markers of dyslipidemia and insulin resistance in schizophrenia patients stabilized on second generation antipsychotics in Indian population. Aim: We conducted the present study on such patients to examine whether BMI or WHR can better predict dyslipidemia and insulin resistance in these patients in a rural area. Settings and Design: The study was a hospital based case control study under rural settings on 38 schizophrenia patients stabilized on olanzapine and 30 matched controls. Materials and Methods: Fasting concentrations of blood glucose, lipid parameters and serum insulin were assessed. Data for Homeostatic model for assessment of insulin resistance (HOMAIR), BMI, and WHR were obtained to assess the insulin resistance, overall body fat distribution and abdominal fat dispensation respectively. Statistical analysis used: ‘t’ test was performed to assay any difference in corresponding mean values between cases and controls. Dependence of HOMA-IR on key parameters was assessed by analysis of co-variance (ANCOVA) study. Results: Cases exhibited significantly higher values for HOMA-IR, serum triglyceride and low density lipoprotein cholesterol (LDLc) with a significantly lower high density lipoprotein cholesterol (HDLc) level. ANCOVA study reflected that irrespective of age and sex, HOMA-IR was dependent on serum triglyceride level and WHR (F=8.3 and 5.7 respectively, P<0.05), but not on BMI (F<0.001, P=0.997). Conclusions: Central obesity could be more closely associated with the pathogenesis of prediabetic state in our case group. So, WHR is a better anthropometric parameter than BMI for an early assessment of insulin resistance and dyslipidemia in schizophrenia patients stabilized on olanzapine in our region.
Investigation of in vitro cytotoxicity of the redox state of ionic iron in neuroblastoma cells
Authors: Singh Ajay Vikram , Vyas Varun , Montani Erica , Cartelli Daniele , Parazzoli Dario , Oldani Amanda , Zeri Giulia , Orioli Elisa , Gemmati Donato , Zamboni Paolo
Published: October 2012

Background: there is an intimate relation between transition metals and cell homeostasis due to the physiological necessity of metals in vivo. Particularly, iron (ferrous and ferric state) is utilized in many physiological processes of the cell but in excess has been linked with negative role contributing in many neurodegenerative processes. Objective: the aim of this study was to investigate which oxidation state of ionic iron (Ferrous (II) versus Ferric (III)) is more toxic to neuronal cells (SHSY5Y). Materials and Methods: The neuroblastoma (SHSY5Y) cells were exposed to varying concentration of ferric and ferrous iron. Morphological studies using immunofluorescence staining and microscopic analysis as confirmed by intracellular glutathione (GSH) test demonstrated oxidative stress to cells in iron microenvironment. In addition, MTT assay was performed to evaluate the viability and metabolic state of the cells. Results: the results showed that ferrous form has significantly higher toxicity compared to the ferric ionic state of higher concentration. In addition, microscopic analysis shows cell fenestration at higher concentrations and swelling at intermediate ferric dosages as demonstrated by atomic force microscopy (AFM). Interestingly, the addition of a differentiation inducing factor, trans-retinoic rcid (RA) retains significant viability and morphological features of the cells irrespective of the ionic state of the iron. AFM images revealed clustered aggregates arising from iron chelation with RA. Conclusions: the results indicate that Fe (II) has more toxic effects on cells. In addition, it could be an interesting finding with respect to the antioxidant properties of RA as a chelating agent for the neurodegenerative therapeutics.
Intracranial meningiomas managed at Memfys hospital for neurosurgery in Enugu, Nigeria
Authors: Mezue Wilfred C , Ohaegbulam Samuel C , Ndubuisi Chika C , Chikani Mark C , Achebe David S
Published: October 2012

Introduction: The epidemiology and pathology of meningioma in Nigeria are still evolving and little has been published about this tumor in Nigeria, especially in the southeast region. The aim of this paper is to compare the characteristics of intracranial meningioma managed in our center with the pattern reported in the literature worldwide. Materials and Methods: Retrospective analysis of prospectively recorded data of patients managed for intracranial meningioma between January 2002 and December 2010 at a Private neurosurgery Hospital in Enugu, Nigeria. We excluded patients whose histology results were inconclusive. Results: Meningiomas constituted 23.8% of all intracranial tumors seen in the period. The male to female ratio was 1:1.1. The peak age range for males and females were in the fifth and sixth decades, respectively. The most common location is the Olfactory groove in 26.5% of patients followed by convexity in 23.5%. Presentation varied with anatomical location of tumor. Patients with olfactory groove meningioma (OGM) mostly presented late with personality changes and evidence of raised ICP. Tuberculum sellar and sphenoid region tumors presented earlier with visual impairment with or without hormonal abnormalities. Seizures occurred in 30.9% of all patients and in 45% of those with convexity meningiomas. Only 57.4% of the patients were managed surgically and there was no gender difference in this group. WHO grade1 tumors were the most common histological types occurring in 84.6%. One patient had atypical meningioma and two had anaplastic tumors. Conclusion: The pattern of meningioma in our area may have geographical differences in location and histology. Childhood meningioma was rare.
Unilateral contiguous two level thoracic ossified hypertrophied facet joints with compressive myelopathy
Authors: Thotakura Amit Kumar , Patibandla Mohana Rao , Panigrahi Manas Kumar , Marabathina Nageswara Rao
Published: October 2012

Ossified hypertrophy of the facet joints in the thoracic region is very uncommon. We present a rare case of thoracic unilateral ossified hypertrophied facet joints with compressive myelopathy in a patient with scoliosis. The diagnosis is made with computed tomography and magnetic resonance imaging studies of the dorsal spine. Decompressive laminectomy and medial facetectomy was performed. Patient improved neurologically to normal status within 2 months. We present the review of the literature on the facet joint hypertrophy producing dorsal myelopathy.
Unusual complications of ventriculo peritoneal shunt surgery
Authors: Teegala Ramesh , Kota Laxmi Prasanna
Published: October 2012

Ventriculo peritoneal (VP) shunt surgery is one of the common neurosurgical procedures employed in the management of hydrocephalus. Numerous complications related to this procedure are reported in the literature. Peritoneal catheterrelated complications are the usual causes of the shunt malfunction. We report three unusual cases of peritoneal shunt catheter migration in children. Two cases are of anal and one vaginal extrusion. Possible mechanisms of migration and management strategies were discussed.
Choroid plexus papilloma of the fourth ventricle in a septuagenarian
Authors: Umredkar Alok A. , Chhabra Rajesh , Bal Aman , Das Ashim
Published: October 2012

Choroid plexus papillomas (CPP) are most commonly found in children and rarely in adult. A very few cases are reported in geriatric population. We present a case of 72-year-old man with posterior fossa lesion operated with provisional diagnosis of metastasis, but turn out to be CPP.
Determination of Some Heavy Metal Pollutants in Sediments of the Seybouse River in Annaba, Algeria
Authors: Louhi Achour , Hammadi Atika , Achouri Mabrouka
Published: October 2012

This study was conducted in order to fight against pollution of the environment. The study concerns river sediment of the Seybouse River in northeastern Algeria. Northeastern Algeria is known for its various industries (steel, fertilizer, metal processing, etc), and the sediment deposited by the Seybouse River, is probably polluted by heavy metals.

For this study, we used two protocols of digestion of sediments, the first, using a mixture of hydrofluoric acid and perchloric acid, and the second, using aqua regia. The comparison of these two protocols will help us to find the best solubilization and thus facilitate the extraction and determination of heavy metals in sediment.

Before determining the concentration of some heavy metals (Fe, Zn, Mn, Sn, Ni, Cr, Pb and Cu), we first analyzed parameters of sediments such as pH and organic matter. We used atomic absorption spectrometry (AAS) to measure these heavy metals. The functional groups characteristic of organic matter and particularly clays were identified by infrared spectroscopy.

The average concentrations of metals exceeded acceptable standards for sediment pollution with heavy metals. Maximum concentrations in mg/kg respectively of the elements studied (Fe, Zn, Mn, Sn, Ni, Cr, Pb and Cu) were, respectively, 2460.20 ± 74.8; 1140.65 ± 38.2; 3.60 ± 1.2; 1.20 ± 0.5; 16.80 ± 2.6; 9.50 ± 3.2; 476.31 ± 21.6 and 145.15 ± 35.2. These results clearly show that the sediments deposited by the Seybouse River are heavily polluted.
European Inflation and the New Keynesian Phillips Curve
Authors: Mazumder Sandeep
Published: October 2012

The majority of macroeconomists who have studied inflation dynamics in Europe argue that the New Keynesian Phillips Curve (NKPC) provides a good way to describe changes in the price level from the 1970 on. However the vast majority of these articles estimate the NKPC using the labor income share as the proxy for real marginal cost. This article argues that the labor share cannot serve as a proxy for real marginal cost because of its countercyclicality and the lack of labor adjustment costs. Once we account for labor adjustment costs, we are able to derive a new marginal cost proxy that is indeed procyclical; however, we find that the NKPC fails to produce coefficients consistent with its underlying structural parameters when a procyclical marginal cost proxy is used. This casts serious doubt whether the NKPC is empirically applicable to Europe or, for that matter, any other country.
Optimization of the Experimental Variables Influencing the Corrosion Rate of Aluminum Using Response Surface Methodology
Authors: Bingöl Deniz , Zor Sibel
Published: October 2012

The effects of temperature and sodium dodecyl benzene sulfonate (SDBS) concentration in hydrochloric acid (HCl) solution on aluminum corrosion rate were investigated using the response surface methodology (RSM) with central composite design (CCD). Optimization studies are an essential tool used in the corrosion systems. RSM is a statistical technique frequently used in most studies involving optimization. RSM was used to optimize the corrosion current density (icorr) of aluminum determined using the potentiodynamic polarization method and to evaluate the effects and the interactions of temperature and SDBS concentration. The lowest icorr was found as SDBS concentration at 130 mg/L and temperature at 24°C. This methodology was first applied successfully in optimizing the conditions that are needed to attain the minimum icorr of aluminum under tested conditions in this study.
Using Silane Films to Produce an Alternative for Chromate Conversion Coatings
Authors: Zaferani S.H. , Peikari M. , Zaarei D. , Danaee I. , Fakhraei J.M. , Mohammadi M.
Published: October 2012

Recently, many efforts have been made to find environmentally friendly substitutes for carcinogen Cr6+ in the pre-treatments of metal substrates. Silane films are one of the important candidates for this purpose. The use of silane films on metallic substrates provides corrosion protection as a result of excellent adhesion and good barrier properties. Their corrosion protection can be improved by adding suitable dopants. There are various methods for applying these films on the metal substrates (sol-gel dip coatings and electrodeposited coating). In this review, several main researches in the field of silane films have been indicated and their results have been analyzed.
Influence of Surface Mechanical Attrition Treatment Attrition Media on the Surface Contamination and Corrosion of Magnesium
Authors: Fabijanic D. , Taylor A. , Ralston K.D. , Zhang M.-X. , Birbilis N.
Published: October 2012

Surface mechanical attrition treatment (SMAT) is a mechanical peening process used to generate ultrafine grain surfaces on a metal. SMAT was carried out on pure magnesium using different attrition media (zirconia [ZiO2], alumina [Al2O3], and steel balls) to observe the effect on microstructure, surface residual stress, surface composition, and corrosion. Surface contamination from SMAT was characterized using glow discharge optical emission spectroscopy (GDOES). The SMAT process produced a refined grain structure on the surface of Mg but resulted in a region of elemental contamination extending ~10 μm into the substrate, regardless of the media used. Consequently, SMAT-treated surfaces showed an increased corrosion rate compared to untreated Mg, primarily through increased cathodic kinetics. This study highlights the issue of contamination resulting from the SMAT process, which is a penalty that accompanies the significant grain refinement of the surface produced by SMAT. This must be considered if attempting to exploit grain refinement for improving corrosion resistance.
Quantification of Sensitization in AA5083-H131 via Imaging Ga-Embrittled Fracture Surfaces
Authors: Birbilis N. , Zhang R. , Lim M.L.C. , Gupta R.K. , Davies C.H.J. , Lynch S.P. , Kelly R.G. , Scully J.R.
Published: October 2012

Sensitization of 5xxx series Al alloys involving precipitation of β phase (Mg2Al3) at grain boundaries was studied for different exposure times at 100°C upon AA5083-H131 (UNS A95083). In this work, we reveal that fracture surfaces prepared by liquid gallium embrittlement can yield a quantification of grain boundary β phase with significant statistics on β phase size and spacing. This information is a necessary first step toward development of quantitative damage models to describe inter-granular corrosion (IGC) and stress corrosion (IGSCC).