bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechatronics Technology for Solar Cells
Authors: Zhang H. Henry , Rodriguez Danny , Li Qiong
Published: September 2013

A mechatronic real-time solar tracker is developed with National Instruments Compact Rio programming module, photoresistors sensor, stepper motors, and a set of nickel metal hydride (NiMH) cells. The tracking array is able to pivot on two axes by way of the stepper motors to reflect the effect of daily and seasonal trajectories of the sun. This design will keep the solar cell perpendicular to the sunlight. This project furthers the application of mechatronics to the field of renewable energy.
Transforming Technical Services
Authors: Hsiung Lai Ying , Wei Wei
Published: September 2013

The current economic downturn has resulted in constantly shrinking budgets and drastic staff reduction at the University of California, Santa Cruz (UCSC) Library. Meanwhile, rapid shifting to digital formats as well as dramatic growth in social networking, mobile applications and cloud computing continues. To face these challenges, the Technical Services (TS) at the university library at UCSC need a transformation. This chapter discusses how the authors have adopted the strategy of maximizing technology in utilizing “robot-like” batch processing tools in house to minimize the risk of becoming ineffective or irrelevant. In aligning human resources to apply those tools to achieve our goals in tandem with the mission of the library, the authors learn to work with the various issues and the barriers that we have encountered during the past decade. The authors are examining the changes brought to the department through the process, highlighting a plan of action, and providing guidance for those interested in bringing about a technological transformation that will continue into the future.
Medical Robotics
Authors: Azar Ahmad Taher , Eljamel M. Sam
Published: September 2013

Medical robotics is an interdisciplinary field that focuses on developing electromechanical devices for clinical applications. The goal of this field is to enable new medical techniques by providing new capabilities to the physician or by providing assistance during surgical procedures. Medical robotics is a relatively young field, as the first recorded medical application occurred in 1985 for a brain biopsy. It has tremendous potential for improving the precision and capabilities of physicians when performing surgical procedures, and it is believed that the field will continue to grow as improved systems become available. This chapter offers a comprehensive overview about medical robotics field and its applications. It begins with an introduction to robotics, followed by a historical review of their use in medicine. Clinical applications in several different medical specialties are discusssed. The chapter concludes with a discussion of technology challenges and areas for future research.
Making Use of Multi-Modal Synchrony
Authors: Wrede Britta , Schillingmann Lars , Rohlfing Katharina J.
Published: September 2013

If they are to learn and interact with humans, robots need to understand actions and make use of language in social interactions. Hirsh-Pasek and Golinkoff (1996) have emphasized the use of language to learn actions when introducing the idea of acoustic packaging in human development. This idea suggests that acoustic information, typically in the form of narration, overlaps with action sequences, thereby providing infants with a bottom-up guide to attend to relevant parts and to find structure within them. The authors developed a computational model of the multimodal interplay of action and language in tutoring situations. This chapter presents the results of applying this model to multimodal parent-infant interaction data. Results are twofold and indicate that (a) infant-directed interaction is more structured than adult-directed interaction in that it contains more packages, and these packages have fewer motion segments; and (b) the synchronous structure within infant-directed packages contains redundant information making it possible to solve the reference problem when tying color adjectives to a moving object.
Developmental Language Learning from Human/Humanoid Robot Social Interactions
Authors: Arsénio Artur M.
Published: September 2013

This chapter presents work on developmental machine learning strategies applied to robots for language acquisition. The authors focus on learning by scaffolding and emphasize the role of the human caregiver for robot learning. Indeed, language acquisition does not occur in isolation, neither can it be a robot’s “genetic legacy.” Rather, they propose that language is best acquired incrementally, in a social context, through human-robot interactions in which humans guide the robot, as if it were a child, through the learning process. The authors briefly discuss psychological models related to this work and describe and discuss computational models that they implemented for robot language acquisition. The authors aim to introduce robots into our society and treat them as us, using child development as a metaphor for robots’ developmental language learning.
The Mediating Role of Context in an Urban After-School Robotics Program
Authors: Baker John Y.
Published: September 2013

The purpose of this chapter is to illustrate the usefulness of cultural-historical activity theory in understanding how context mediates youth activity in a successful urban after-school robotics program. Youth activity is analyzed using activity systems, uncovering the role of tools, rules, community, and division of labor in youth engagement with a set of open-ended engineering tasks. The program supported the youth in making sense of the engineering tasks using their own intuitive methods, and it also helped them to see a purpose for disciplinary practices. The author illustrates that the social context, made up of elements from in and out of school, supported youth in drawing on knowledge from across different settings. A use of activity systems is proposed for practitioners in the design of out-of-school-time educational programs.
The Impact of Educational Robotics on Student STEM Learning, Attitudes, and Workplace Skills
Authors: Nugent Gwen C. , Barker Bradley S. , Grandgenett Neal
Published: September 2013

This chapter discusses findings from a National Science Foundation (NSF) project funded by the Innovative Technologies Experiences for Student and Teachers (ITEST) program. The project has an ongoing research agenda focusing on the impact of robotics summer camps and competitions targeted at middle school youth. The research focused on the impact of the interventions on youth a) learning of computer programming, mathematics, and engineering concepts, b) science, technology, engineering, and math (STEM) attitudes, c) workplace skills, and d) STEM career interest. Results show that robotics camps and competitions appear to be viable strategies to increase student STEM learning, robotics self-efficacy, and problem solving skills.
Stereo Vision Depth Estimation Methods for Robotic Applications
Authors: Nalpantidis Lazaros , Gasteratos Antonios
Published: September 2013

Vision is undoubtedly the most important sense for humans. Apart from many other low and higher level perception tasks, stereo vision has been proven to provide remarkable results when it comes to depth estimation. As a result, stereo vision is a rather popular and prosperous subject among the computer and machine vision research community. Moreover, the evolution of robotics and the demand for vision-based autonomous behaviors has posed new challenges that need to be tackled. Autonomous operation of robots in real working environments, given limited resources requires effective stereo vision algorithms. This chapter presents suitable depth estimation methods based on stereo vision and discusses potential robotic applications.
Self-Calibration of Eye-to-Hand and Workspace for Mobile Service Robot
Authors: Hu Jwu-Sheng , Chang Yung-Jung
Published: September 2013

The geometrical relationships among robot arm, camera, and workspace are important to carry out visual servo tasks. For industrial robots, the relationships are usually fixed and well calibrated by experienced operators. However, for service robots, particularly in mobile applications, the relationships might be changed. For example, when a mobile robot attempts to use the visual information from environmental cameras to perform grasping, it is necessary to know the relationships before taking actions. Moreover, the calibration should be done automatically. This chapter proposes a self-calibration method using a laser distance sensor mounted on the robot arm. The advantage of the method, as compared with pattern-based one, is that the workspace coordinate is also obtained at the same time using the projected laser spot. Further, it is not necessary for the robot arm to enter the view scope of the camera for calibration. This increases the safety when the workspace is unknown initially.
Ad Hoc Communications for Wireless Robots in Indoor Environments
Authors: Del Río Laura Victoria Escamilla , Díaz Juan Michel García
Published: September 2013

This chapter presents a theoretical and experimental comparison of electromagnetic propagation models for indoor robot communication using mobile ad-hoc IEEE802.11 and IEEE802.15.4. The analysis includes the behavior of the electromagnetic signal using the abovementioned standards in two scenarios, both located inside the building of the College of Telematics of the University of Colima. The results of the propagation of the electromagnetic signals in the two scenarios were then compared with the mathematical model.
Collaborative Exploration based on Simultaneous Localization and Mapping
Authors: Puig Domenec
Published: September 2013

This chapter focuses on the study of SLAM taking into account different strategies for modeling unknown environments, with the goal of comparing several methodologies and test them in real robots even if they are heterogeneous. The purpose is to combine them in order to reduce the exploration time. Indubitably, it is not an easy work because it is important to take into account the problem of integrating the information related with the changes into the map. In this way, it is necessary to obtain a representation of the surrounding in an efficiently way. Furthermore, the author is interested in the collaboration between robots, because it is well-known that a team of robots is capable of completing a given task faster than a single robot. This assumption will be checked by using both simulations and real robots in different experiments. In addition, the author combines the benefits of both vision-based and laser-based systems in the integration of the algorithms.
Biorobotics
Authors: Menciassi Arianna , Laschi Cecilia
Published: September 2013

Biorobotics is an emerging discipline that merges biomedical engineering and robotics. Biorobotics is the science and engineering of robotics applied in the Biomedical field, with the development of biomedical devices for surgery and rehabilitation, as well as with the modeling of biological systems. In this sense, biorobotics is also the construction of physical models of the biological systems, as bioinspired and biomimetic robots. Although most technologies are derived from robotics at large, biorobotics possesses some distinguishing features in terms of methodology of design that deserve to be approached apart from robotics. Biorobotics represents today a field of evolution for biomedical engineering and for robotics, and the ideal ground for educating young engineers, by breaking the traditional barriers among the engineering sectors and those of biological sciences and medicine.
Mobile Laboratory Model for Next-Generation Heterogeneous Wireless Systems
Authors: Ngom Ibrahima , Saliah-Hassane Hamadou , Lishou Claude
Published: September 2013

Failure to integrate heterogeneous wireless systems generally makes it difficult, if not impossible, for the continuation of remote working or remote experiments when human operators and equipment coexist through networks in a collaborative environment. Mobile laboratories using ubiquitous mobile communication for next-generation heterogeneous wireless systems have prospects for increasing the operation of distributed communication and mobile ubiquitous systems. All “technology assessors” concur that tomorrow's society will have access to smart objects (mobile devices or apparatuses, mobile equipment, e.g. robots) that contain “programs” that will assist with communication in everyday life. However one of the tomorrow’s challenges will consist of programming those objects to cooperate with and control telecommunications technologies. For a Mobile Laboratory to ensure consistent mobility in an environment, it must combine various wireless networks as a single integrated system. In this chapter we propose a Mobile Laboratory Model with mobile devices that take advantage of multiple mobile gateways by using Internet Protocol (IP) as the interconnection protocol to achieve the objective stated above.
Understanding the Human-Machine Interface in a Time of Change
Authors: Orange Erica
Published: September 2013

The author presents an overview of how the ubiquitous nature of technology has led to a monumental shift in human evolution, a change involving language, thought, and feeling. The interrelationship between humans and technology will undoubtedly alter the way in which we define what it truly means to be human in a world of complexities. As systems, networks, and programs become more complex, our ability to interface with these machines that play such a prominent and vital role in our day-to-day lives is becoming increasingly difficult. It used to be the human was in charge; able to manipulate the machine to perform a desired outcome. But it is no longer simply about input and output measures. Now the roles are reversing, and it is becoming harder to determine where power and control ultimately resides. Consequently, our ability to manage machines and robots will become more vulnerable. The intimate connection and interoperability of human intelligence with machine intelligence, has undoubtedly impacted the human experience and our process of self-identification.
Social Influence Online
Authors: Okdie Bradley M. , Guadagno Rosanna E. , Petrova Petia K. , Shreves Wyley B.
Published: September 2013

This study examined the extent to which communicator salience manipulated by varying communication modes, authority-based social influence, and gender affect persuasion in online environments by utilizing a 2 by 2 between subjects design. Participants of the experiment were either presented with an authority-based influence attempt or no influence attempt. They then engaged in a persuasive interaction with a same-sex confederate via computer-mediated communication (CMC) or face-to-face. Results revealed that men in the Authority condition who interacted via CMC were more persuaded then men in the Peer condition who interacted via CMC. Additionally, men reported more confidence when interacting via CMC and reported that their decision was more influenced by the confederate online. Moreover, perceptions of the confederate varied by gender and communication mode. Analysis suggests that authority based influence tactics via CMC are more effective for men than for women.
Facebook History Collector
Authors: Guadagno Rosanna E. , Loewald Tonio A. , Muscanell Nicole L. , Barth Joan M. , Goodwin Melissa K. , Yang Yang
Published: September 2013

Social networking sites are a rich source of untapped data. While much research has focused on Facebook and other social networks, less has done so by collecting information straight from the source. The purpose of this paper is to present a new and innovative means of gathering raw data from Facebook via a software program the authors call the Facebook History Collector. Initially developed to study Facebook activity in the wake of a destructive tornado that occurred in Tuscaloosa, Alabama on April 27, 2011, this tool allows for retrieving massive amounts of text, photographs, and videos directly from Facebook during a period of time set by the researcher. In this article, the authors argue that the new method has broad implications for use within the research community as it allows capturing real-time social media interactions. The process of software development, data collection, technical details, and ethical considerations are discussed.
Cooperative Space Time Coding for Semi Distributed Detection in Wireless Sensor Networks
Authors: Al-Jarrah Mohammad A. , Al-Ababneh Nedal K. , Al-Ibrahim Mohammad M. , Al-Jarrah Rami A.
Published: September 2013

Parallel distributed detection in wireless sensor networks (WSNs) is considered in this paper. In parallel architecture, sensors process the observations to make local decisions and send them to a central device called fusion center. Parallel architecture is assumed in this paper with cooperative sensors in order to obtain Alamouti space time block codes (STBCs). A similar idea was discussed by Vosoughi and Ahmadi (2009). Although the likelihood ratio provided in that paper is correct, the simulation results don’t make sense. In this paper, we are going to prove that the results provided in (Vosoughi & Ahmadi, 2009) are not correct. Upper bound for the detection performance is also derived. Furthermore, suboptimal fusion rules are derived to support our results. Moreover, correct results are shown in this paper.
Extended Cell Planning for Capacity Expansion and Power Optimization by Using MEMETIC Algorithm
Authors: Saini Hemraj , Sharma L. K. , Panda T. C. , Pratihari H. N.
Published: September 2013

In the current era of cellular world, cell planning plays an important role to achieve better performance of the cellular network. Capacity expansion and cost optimization of a newly activated base station by placing it at an optimized location is one of the primary objectives of the current manuscript. The locations of the new as well as the existing base stations are directly correlated to the required capacity demand and the power of the received signal at the base station which becomes the sensitive parameter for the cell planning. Therefore, cell planning is to be modeled to optimize the location of the base stations in the form of a linear programming problem. Further, the MEMETIC algorithm has to be used for the optimization of the multi-objectives of the scenario. The simulated results show that there is a significant enhancement in the capacity of the base stations (1% to 5%) as compared with the orientation of base stations achieved by random deployment.
Heterogeneous Dynamic Priority Scheduling in Time Critical Applications
Authors: Viswanathan Arvind , Murthy Garimella Rama , Chilamkurti Naveen
Published: September 2013

In the unlicensed band, the notion of primary user and secondary user (To implement cognitive radio) is not explicit. By dynamic priority assignment the authors propose to implement cognitive radio in the unlicensed band. In time critical events, the data which is most important, has to be given the time slots. Wireless Sensor nodes in the authors’ case are considered to be mobile, and hence make it difficult to prioritize one over another. A node may be out of the reach of the cluster head or base station by the time it is allotted a time slot and hence mobility is a constraint. With the data changing dynamically and factors such as energy and mobility, which are major constraints, assigning priority to the nodes becomes difficult. In this paper, the authors have discussed about how Wireless Sensor Networks are able to allocate priorities to nodes in the unlicensed band with multiple parameters being posed. They have done simulations on NS-2 and have shown the implementation results.
Mobile Web 2.0 Integration
Authors: Cochrane Thomas , Flitta Isaac
Published: September 2013

Web 2.0 tools provide a wide variety of collaboration and communication tools that can be appropriated within education to facilitate student-generated learning contexts and sharing student-generated content as key elements of social constructivist learning environments or Pedagogy 2.0. “Social software allows students to participate in distributed research communities that extend spatially beyond their classroom and school, temporally beyond a particular class session or term, and technologically beyond the tools and resources that the school makes available to the students.” (Mejias, 2006, p1). This paper illustrates this by describing and evaluating the impact of the introduction of web 2.0 and mlearning to facilitate student eportfolios within the context of a first year Bachelor of Design and Visual Arts course in New Zealand (Unitec). Core web 2.0 (social software) tools used in establishing students’ web 2.0 eportfolios included: Vox, Qik, Picasaweb, Prezi, Google Docs, and YouTube. The participating lecturers and the technology steward also used these web 2.0 tools to collaborate on the design of the project. The paper reflects upon the impact of the participants’ previous web 2.0 experience and the use of these tools to facilitate student-generated content and at the same time to act as catalysts for pedagogical change. The project is evaluated as an action research cycle within a framework of longitudinal action research investigating the impact of mobile web 2.0 on higher education from 2006 to the present.
Automatic Usability Evaluation of Mobile Web Pages with XML
Authors: Kohli Ankita , Zhao Chunying , Kong Jun
Published: September 2013

Recently, mobile browsing on the World Wide Web is growing rapidly. The growth has created a surge in the number of Web pages designed for mobile devices. To increase the usability of mobile browsing, the Mobile Web Best Practices have been proposed to guide the development of mobile-friendly Web pages. In this paper, the mobileOK checker, a free service provided by W3C, is used to automatically inspect the conformance of 46 popular mobile Web sites to the Mobile Web Best Practices. We analyze the evaluation results and provide suggestions for improving the design of mobile Web sites. In mobile browsing, different mobile devices have different screen sizes, layout structures, and styles to represent Web contents. Furthermore, mobile devices are developing fast. The diversity and fast development of mobile devices cause the mobile design guidelines changing over time. However, the mobileOK checker is not flexible to include new guidelines or customize a best practice rule to fit a specific mobile browsing scenario. To solve this problem, this paper presents a generic approach to represent the mobile design guidelines through an XML schema. Using the XML schema provides the flexibly to support evolving guidelines in an open format. To evaluate our approach, a prototype, WPChecker, has been developed.
Intelligent Bandwidth Allocation of IPTV Streams with Bitstream Complexity Measures
Authors: Moiron Sandro , Razavi Rouzbeh , Fleury Martin , Ghanbari Mohammed
Published: September 2013

IPTV video services are increasingly being considered for delivery to mobile devices over broadband wireless access networks. The IPTV streams or channels are multiplexed together for transport across an IP core network prior to distribution across the access network. According to the type of access network, prior bandwidth constraints exist that restrict the multiplex data-rate. This paper presents a bandwidth allocation scheme based on content complexity to equalize the overall video quality of the IPTV sub-streams, in effect a form of statistical multiplexing. Bandwidth adaptation is achieved through a bank of bit-rate transcoders. Complexity metrics serve to estimate the appropriate bandwidth share for each stream, prior to distribution over a wireless or ADSL access network. These metrics are derived after entropy decoding of the input compressed bit-streams, without the delay resulting from a full decode. Fuzzy-logic control serves to adjust the balance between spatial and temporal coding complexity. The paper examines constant and varying bandwidth scenarios. Experimental results show a significant overall gain in video quality in comparison to a fixed bandwidth allocation.
Context-Aware Multimedia Distribution to Mobile Social Communities
Authors: Pinto Filipe Cabral , Carapeto Nuno , Videira António , Frazão Teresa , Homem Mário
Published: September 2013

The work here presented introduces a next generation context-aware architecture for social networking multimedia distribution. It enhances the Multimedia Broadcast Multicast Service (MBMS) and the Evolved MBMS (E-MBMS) systems by adding users’ situation knowledge on their assessments allowing Mobile Operators to offer personalized services delivered over optimized networks. Furthermore, it evolves IP Multimedia Subsystem (IMS) with specific functionalities to control the context information and to manage MBMS and E-MBMS bearers. The proposed framework was tested and the results are here presented. A clever content sharing in mobile communities can be the basis of the famous killer application that Mobile Operators are still looking for.
Evaluating the Effectiveness of Information Security Governance Practices in Developing Nations
Authors: Yaokumah Winfred
Published: September 2013

The purpose of this empirical study is to evaluate the extent to which information security governance domain practices: strategic alignment, value delivery, resource management, risk management, and performance measurement relate to information security governance effectiveness. Random sampling technique was employed and data were collected via web survey from Ghanaian organizations. Employing three multiple regression models, the results showed there were statistically significant positive linear relationship between information security governance domain practices and information security governance effectiveness. Overall, the model produced R2 = .505, indicating that 50.5% of the variance in information security governance effectiveness was explained by information security governance domain practices. The results highlighted resource management, performance measurement and risk management practices as the predictors of organizational information security governance effectiveness while strategic alignment contributed only marginally to the models. Therefore, to attain higher information security governance effectiveness, organizations should focus on strategic alignment between the business and information security attributes.
The Benefits Management and Balanced Scorecard Strategy Map
Authors: Gomes Jorge , Romão Mário , Caldeira Mário
Published: September 2013

We are living in a period of enormous technological transformations and the organizations face new opportunities that the systems and information technology (IS/IT) implementations provide with the hope that these investments will help to increase productivity and business prosperity, meanwhile, several studies performed in public and private sectors have proven that the investments done in IS/IT have not brought the expected benefits. Some authors argue that the result of the studies that related investments in IS/IT and the increasing performance of the organizations in the last thirty years were far from true. In this paper the authors propose a link between the Benefits Dependency Network, from a Benefits Management approach, and a Strategy Map, from Balanced Scorecard, to improve the management of business benefits and to ensure that actions taken along the investment life-cycle lead to foreseen benefits realization. The goal of this integration is to build a framework that combines useful features of both methods. The authors sustain that they can be complementary. As a Strategy Map is committed with strategic alignment, communication and monitoring of strategy execution at all levels of an organization, a Benefits Dependency Network is aimed at explaining how benefits are going to be obtained through organizational change. Using the results of a case-study research, the authors explain how a Strategy Map can cross with the Benefits Dependency Network. The integrated contribution is meant to increase the investments effectiveness, giving to stakeholders the confidence on a clearer delivery path for their expected benefits.
Impact Evaluation of Customer Knowledge Process on Customer Knowledge Expansion
Authors: Alhawari Samer
Published: September 2013

The paper aim is to investigate how Customer Knowledge Processes used in practice by Jordanian banks to achieve customer knowledge expansion. The empirical study is based on a sample of the data collected from 165 respondents, drawn randomly from six banks. The results show that the seven selected factors (Customer Knowledge Codification, Customer Knowledge Representation, Customer Knowledge Sharing, Customer Knowledge Application, Design of Customer Knowledge, Execution of Knowledge from Customer, and Verify of Knowledge from Customer) have a significant impact on Customer Knowledge Expansion. The findings did reveal the potential relationship between the customer knowledge processes and customer knowledge expansion. It also provides advice for the Information Technology (IT) Industry as to how an analytical knowledge process from customers should be taken into account in developing countries to attain proper customer knowledge expansion because of cultural, social and educational disparities.
Electronic Logistics Services
Authors: Wu Yen-Chun Jim , Chang Chan-Lan , Dong Tse-Ping
Published: September 2013

This study begins with discussing the relationship between the marketers’ organizational performance and E-marketing performance in the Taiwan’s mobile phone industry. From the perspective of dealers, this study discovers the effects on Relationship Quality, which generated by expected benefits derived from implementing the interorganizational information system on the management of marketing activities. The authors conducted Structural Equation Modeling approach on marketers and dealers respectively. The quality of the information system will affect marketers’ intention to use. Research findings also suggest that the system quality and information quality will affect marketers’ satisfaction and then will affect the Relationship Quality among dealers. From the implementation of information systems, the Relationship Quality has positive effects on the expected strategic benefits, informational benefits and transactional benefits. Therefore, combining the two perspectives from marketers and dealers, this study examines how the E-marketing channel contributes the effects of Relationship Quality on both marketers and dealers.
A Conceptualization of Music Sound Recordings and Its Representation in an Ontology
Authors: Albuquerque Marcelo de O. , Siqueira Sean Wolfgand M. , Braz Maria Helena Lima Baptista
Published: September 2013

Music is a domain with several dimensions and some specific characteristics. When different types of music are considered, modeling this domain becomes even more challenging. This paper presents some of the characteristics that makes music such an interesting domain to model and summarizes a conceptualization process based on the Dahlberg conceptual triangle for guiding the construction of an ontology proposal for representing music sound recordings. This ontology can provide a global representation that might be used to support music information systems’ interoperability as well as data integration, contributing to worldwide music dissemination in nowadays knowledge society. Some possible mappings to other representational schemes for music sound recordings are identified to enable interoperability and integration with other similar systems. An interview with domain specialists indicates the right coverage of the necessary concepts, and evidences the importance of the proposal.
Endovascular therapy in acute ischemic stroke: The way forward after results from the IMS 3, SYNTHESIS and MR Rescue trials
Authors: Menon Bijoy , Goyal Mayank
Published: September 2013

Endovascular therapy (EVT) has gained vogue in the management of patients with acute stroke. Newer stent-retriever devices have led to better recanalization rates. In many centers, EVT is slowly being used as an add on to or in some instances, even as an alternative to intravenous tissue plasminogen activator (IV tPA). The publication of the results of the SYNTHESIS expansion, Interventional Management of Stroke III and Mechanical Retrieval Recanalization of Stroke Clots Using Embolectomy trials in 2013 has questioned the enthusiastic use of EVT in acute stroke. They demonstrate that EVT (using a variety of devices) is no superior to IV tPA in the management of acute stroke. In the light of these controversial findings, we review the current status of EVT in the management of acute stroke.
Endoscopic posterior decompression of lumbar canal stenosis
Authors: Yadav Nishtha , Parihar Vijay , Kher Yatin , Ratre Shailendra , Yadav Yad
Published: September 2013

Lumbar canal stenosis (LCS) is quite common. Surgery is indicated when patient fails to improve after conservative treatment. Endoscopic technique can be used in LCS and lateral recess stenosis. It can be performed in degenerative canal stenosis or with disc bulges. Bilateral severe bony canal stenosis and unstable spine are the contraindications. This procedure should be avoided in patients with a history of trauma. Detailed history and thorough physical examination should be performed to find out exact level of pathology responsible for symptoms. Patient’s symptoms must correlate with radiological findings. Magnetic resonance imaging is the investigation of choice because of its superior visualization of soft-tissue. Computed tomography scan does give a more accurate and detailed picture of the bony anatomy. Although the operative time and the complication rate could be more in the initial learning curve, the results of endoscopic decompression are comparable with conventional open procedures with the additional benefit of decreased complications and lower morbidity, when sufficient experience is gained. Complications in endoscopic surgery for LCS could be dural tears, hematomas and root and facet injury. This procedure is also associated with limitations such as steep learning curve and the contra lateral decompression may not be as good as ipsilateral side. Some of the limitations of this technique can be overcome by attending live operative workshop, practice on models and hands on cadaveric dissection. Conversion to an open procedure may be required when there is disorientation, management of dural tear and for control of bleeding.
Factors influencing shunt malfunction in patients with tuberculous meningitis
Authors: Ambekar Sudheer , Pandey Paritosh , Sampath Somanna , Bangalore Chandramouli , Indira Devi , Srinivas Dwarakanath
Published: September 2013

Hydrocephalus secondary to tuberculous meningitis (TBM) is a challenging condition to treat. Though ventriculo-peritoneal (VP) shunt is an accepted modality of treatment for hydrocephalus in TBM, there is a high rate of complications associated with the same.

The study was planned to evaluate various factors associated with shunt malfunction in patients undergoing VP shunt surgery for hydrocephalus due to TBM.

A retrospective review of all the patients undergoing VP shunt and shunt revision for TBM between 2004 and 2008 was performed. 449 VP shunt surgeries were performed in 432 patients for hydrocephalus due to TBM. Among these 70 shunt revisions were performed in 53 patients.

Shunt malfunction rate in our series was 16.2%. High cerebrospinal fluid (CSF) protein concentration (>200 mg/dL) was associated with 5 times increased incidence of shunt malfunction. Patients with hyponatremia (Na+ <130 mEq/dL) prior to surgery had a 3 times increased incidence of shunt malfunction (P < 0.05). Other factors such as duration of symptoms, presence of neurological deficits, Evan’s index, third ventricular diameter, thickness of exudates, presence of infarcts, anemia, CSF cellularity and CSF glucose concentration were not associated with increased incidence of shunt malfunction. Analysis showed that shunt viability was longest in patients with normal serum sodium levels and CSF protein concentration less than 200 mg/dL and shortest in patients with low serum sodium and CSF protein concentration more than 200 mg/dL.

Patients with pre-operative hyponatremia and high CSF protein concentration have a higher incidence of shunt malfunction and need to be followed-up closely.
Suicidal rare craniocerebral injury and its complications
Authors: Kaushal Sona , Gupta Uday , Gupta Pradeep
Published: September 2013

The authors here describe a rare cranio-cerebral injury, which occurred due to a self-inflicted suicidal attempt by the patient, who hammered an 8 cm long nail into his skull. This patient was a known case of schizophrenia. The nail entered in the region of the left parafalx area and reached almost up to the base of skull of the patient. This nail was removed by a mid-line craniotomy. Approximately six months later, the patient presented with the symptoms of raised intra cranial pressure and right hemi paresis. Repeat computed tomography scan showed a large brain abscess at the site of the previous surgery and the patient was re-explored through the previous incision; the abscess was drained and the wall was excised. The patient then made a good recovery.
Transarterial onyx embolization of arteriovenous malformation in the infratemporal fossa and parotid region
Authors: Huang Qinghai , Liu Jianmin , Chen Xinpu
Published: September 2013

Maxillofacial arteriovenous malformation (AVM) is a rare, but potentially life-threatening entity. Surgical excision usually associates with a high rate of significant blood loss and cosmetic defects. We report a patient who had an AVM involving infratemporal fossa and parotid region, supplied by an enlarged branch of the left ophthalmic artery, cavernous internal carotid artery, middle meningeal artery, and internal maxillary. Successful treatment of this lesion was achieved by transarterial embolization with Onyx. Less invasive transarterial embolization with Onyx is rewarding when curing certain types of maxillofacial AVMs.
Balance sheet recession as the ‘other half’ of macroeconomics
Authors: Koo Richard C.
Published: September 2013

Once every several decades, the private sector loses its mind in a bubble, leverages itself up to the hilt, and is forced into debt minimization in order to remove its debt overhang following the crash. When the private sector as a whole is deleveraging, even at record low interest rates, monetary policy is largely ineffective while fiscal policy becomes absolutely essential in keeping both the economy and money supply from shrinking. The superior effectiveness of monetary policy during private sector profit maximization and of fiscal policy during private sector debt minimization indicates that the latter was the long-overlooked ‘other half’ of macroeconomics.
Can the new French economic policy be successful?
Authors: Mathieu Catherine , Sterdyniak Henri
Published: September 2013

In early 2013, the French economy, like many other EU economies, faces tough challenges. French GDP is 9 per cent below the level it would have reached had it continued to grow at its pre-crisis trend. France has committed to cut the public deficit to 3 per cent in 2013 and 0 per cent in 2017 which would imply dramatic public spending cuts and fiscal tightening, reducing GDP growth even further. France has to choose between strengthening its specificity, its social model and its State-interventionist tradition, and imitating the best pupils of globalization in the world or in Europe by implementing liberal or social-liberal strategies. The paper deals with the French government strategy since the 2012 presidential elections and tries to assess its chances of success. In many areas – fiscal strategy, social issues, banking and industrial policies – there is a significant risk that the announced proactive strategy will be replaced by policies accepting the constraints imposed by European institutions and financial markets.
Gattopardo economics: the crisis and the mainstream response of change that keeps things the same
Authors: Palley Thomas I.
Published: September 2013

Gattopardo constitutes change that keeps things the same. Gattopardo is relevant for understanding the economics profession's response to the financial crash of 2008. This paper explores gattopardo economics as it applies to the issues of the macroeconomics of income distribution; the global financial imbalances; and inflation policy. Gattopardo economics adopts ideas developed by critics of mainstream economics, but it does so in a way that ignores the thrust of the original critique and leaves mainstream analysis unchanged. Gattopardo economics makes change more difficult because it deceives people into thinking change has taken place. By masquerading as change, it crowds-out space for real change. That makes exposing gattopardo economics a matter of vital importance.
Capital gains, total returns and saving rates
Authors: Hudson Michael
Published: September 2013

To focus on the dynamics of how financial wealth is created, obtained, and valued, this paper (1) distinguishes capital gains from income by measuring total returns, and (2) contrasts the capitalized value of rentier income (rent extraction rights and privileges from land, natural resources, and monopolies) from that of industrial profits on tangible capital investment.
Should post-Keynesians make a behavioural turn?
Authors: King John E.
Published: September 2013

This paper deals with the relationship between post-Keynesian and behavioural economics. I begin by responding critically to Paul Davidson's claim that Keynes was the first behavioural economist. Then I discuss some recent work in behavioural macroeconomics, which reveals some important strengths but also some fundamental weaknesses. Next I outline what (Old) behavioural economists have had to say about macroeconomics, beginning with the father of the school, Herbert Simon, and considering the contributions of some of his disciples. I then reverse the question and ask what post-Keynesians have had to say about behavioural economics, Old and New. I conclude by identifying some potential sources of difficulty and also suggesting some areas of macroeconomics where cooperation between post-Keynesians and behavioural economists seems especially promising.
Numerical analysis of the chemical kinetic mechanisms of ozone depletion and halogen release in the polar troposphere
Authors: Cao L. , Sihler H. , Platt U. , Gutheil E.
Published: September 2013

Abstract. In recent years, the role of halogen species (e.g. Br, Cl) in the troposphere of polar regions is investigated after the discovery of their importance for boundary layer ozone destruction in the polar spring. Halogen species take part in an auto-catalytic chemical cycle including key self reactions. In this study, several chemical reaction schemes are investigated, and the importance of specific reactions and their rate constants is identified by a sensitivity analysis. A category of heterogeneous reactions related to HOBr activate halogen ions from sea salt aerosols, fresh sea ice or snow pack, driving the "bromine explosion". In the Arctic, a small amount of NOx may exist, which comes from nitrate contained in the snow, and this NOx may have a strong impact on ozone depletion. The heterogeneous reaction rates are parameterized by considering the aerodynamic resistance, a reactive surface ratio, β, i.e. ratio of reactive surface area to total ground surface area, and the boundary layer height, Lmix. It is found that for β = 1, the ozone depletion process starts after five days and lasts for 40 h for Lmix = 200 m. Ozone depletion duration becomes independent of the height of the boundary layer for about β≥20, and it approaches a value of two days for β=100. The role of nitrogen and chlorine containing species on the ozone depletion rate is studied. The calculation of the time integrated bromine and chlorine atom concentrations suggests a value in the order of 103 for the [Br] / [Cl] ratio, which reveals that atomic chlorine radicals have minor direct influence on the ozone depletion. The NOx concentrations are influenced by different chemical cycles over different time periods. During ozone depletion, the reaction cycle involving the BrONO2 hydrolysis is dominant. A critical value of 0.002 of the uptake coefficient of the BrONO2 hydrolysis reaction at the aerosol and saline surfaces is identified, beyond which the existence of NOx species accelerate the ozone depletion event – for lower values, deceleration occurs.
Strong sensitivity of Southern Ocean carbon uptake and nutrient cycling to wind stirring
Authors: Rodgers K. B. , Aumont O. , Mikaloff Fletcher S. E. , Plancherel Y. , Bopp L. , Boyer Montégut C. de , Iudicone D. , Keeling R. F. , Madec G. , Wanninkhof R.
Published: September 2013

Abstract. Here we test the hypothesis that winds have an important role in determining the rate of exchange of CO2 between the atmosphere and ocean through wind stirring over the Southern Ocean. This is tested with a sensitivity study using an ad hoc parameterization of wind stirring in an ocean carbon cycle model. The objective is to identify the way in which perturbations to the vertical density structure of the planetary boundary in the ocean impacts the carbon cycle and ocean biogeochemistry. Wind stirring leads to reduced uptake of CO2 by the Southern Ocean over the period 2000–2006, with differences of order 0.9 Pg C yr−1 over the region south of 45° S. Wind stirring impacts not only the mean carbon uptake, but also the phasing of the seasonal cycle of carbon and other species associated with ocean biogeochemistry. Enhanced wind stirring delays the seasonal onset of stratification, and this has large impacts on both entrainment and the biological pump. It is also found that there is a strong sensitivity of nutrient concentrations exported in Subantarctic Mode Water (SAMW) to wind stirring. This finds expression not only locally over the Southern Ocean, but also over larger scales through the impact on advected nutrients. In summary, the large sensitivity identified with the ad hoc wind stirring parameterization offers support for the importance of wind stirring for global ocean biogeochemistry, through its impact over the Southern Ocean.
Phenology as a strategy for carbon optimality: a global model
Authors: Caldararu S. , Purves D. W. , Palmer P. I.
Published: September 2013

Abstract. Phenology is essential to our understanding of biogeochemical cycles and the climate system. We develop a global mechanistic model of leaf phenology based on the hypothesis that phenology is a strategy for optimal carbon gain at the canopy level so that trees adjust leaf gains and losses in response to environmental factors such as light, temperature and soil moisture, to achieve maximum carbon assimilation. We fit this model to five years of satellite observations of leaf area index (LAI) using a Bayesian fitting algorithm. We show that our model is able to reproduce phenological patterns for all vegetation types and use it to explore variations in growing season length and the climate factors that limit leaf growth for different biomes. Phenology in wet tropical areas is limited by leaf age physiological constraints while at higher latitude leaf seasonality is limited by low temperature and light availability. Leaf growth in grassland regions is limited by water availability but often in combination with other factors. This model will advance the current understanding of phenology for ecosystem carbon models and our ability to predict future phenological behaviour.