bluuebunny/crossref_metadata_2025 huggingface dataset:
Standing at the Crossroads – the Future of a Strong Common Agricultural Policy is at Stake  A la croisée des chemins – l’avenir d’une politique agricole commune forte est en jeu  Am Scheideweg – die Zukunft einer starken Gemeinsamen Agrarpolitik steht auf dem Spiel
Authors: Fazekas Sándor
Published: December 2010

Standing at the Crossroads – the Future of a Strong Common Agricultural Policy is at Stake

The issues and targets in the European Union’s agenda are largely in line with Hungarian objectives; job creation for example is one of the main targets of the Europe 2020 strategy and also of the Hungarian Government. Hungary’s development and competitiveness are linked to the internal development and global competitiveness of the European Union; and so our primary objective is to strengthen the integration process and to obtain a strong Common Agricultural Policy. The CAP has reached the highest level of integration among EU policies and its original objectives have been reinforced by the Lisbon Treaty. Europe needs a strong and common agricultural policy beyond 2013; the main task of agriculture will be to ensure the security of food supplies. The future success of the CAP requires appropriate financial support to secure future targets. Rural development has already become an integral part of the CAP structure; but rural areas will not be viable without an evolving agriculture. Without the provision of a proper level of income subsidies many farms would be forced to stop production. CAP adjustments should promote the catching up of new Member States and eliminate the current system of direct subsidies that disadvantage the new members.
Russia’s Agricultural Imports: Will the High Growth of the 2000s Continue?  Les importations agricoles russes : la forte croissance des années 2000 va‐t‐elle se poursuivre ?  Russlands Agrarimporte: Wird das starke Wachstum aus den 2000er Jahren anhalten?
Authors: Liefert William M. , Liefert Olga , Shane Mathew
Published: December 2010

summary

Russia’s Agricultural Imports: Will the High Growth of the 2000s Continue?

Russia is the EU region’s second largest foreign market for agricultural goods, after the United States, and in 2007 took 10 per cent of the EU’s agricultural exports, worth €7.7 billion. During the 2000s, Russian total agricultural imports have grown considerably, from €7.4 billion in 2000 to €19.2 billion in 2007, and imports from the EU have increased accordingly. The import growth has made Russia the second largest agricultural importer among emerging markets, after China. The main imports are meat, highly processed goods, fruits, and vegetables. The main reasons for the import rise are macroeconomic in nature ─ high Russian GDP growth which has increased consumer income and purchasing power, and a rise in the value of the ruble in real (inflation‐adjusted) terms, which makes imports less expensive vis‐à‐vis domestically produced goods. The economic crisis that hit Russia in autumn 2008 makes the outlook for the country’s agricultural imports uncertain. Nonetheless, the Russian economy will probably stabilise within the next few years, such that annual GDP growth could rebound to 3–5 per cent. If so, agricultural imports should resume growth, though at a lower rate than in the recent past.
Economic Outcomes among Latino Migrants to Spain and the United States: Differences by Source Region and Legal Status
Authors: Connor Phillip , Massey Douglas S.
Published: December 2010

Using representative national surveys, this paper compares economic outcomes among Latin American migrants to Spain and the United States in the first cross-national comparison using quantitative data. Considering the geographic location and social proximity of each country with respect to Latin America, we detect a critical selection effect whereby the majority of Latin American migrants to Spain originate in South America from middle class backgrounds, whereas most migrants to the United States are Central Americans of lower class origins. This selection effect accounts for cross-national differences in the probability of employment, occupational attainment, and wages earned. Despite differences in the origins and characteristics of Latino immigrants to each country, demographic and human and social capital factors appear to operate similarly in both places; and when models are estimated separately by legal status, we find that effects are more accentuated for undocumented compared with documented migrants, especially in the United States.
Immigration and the Transformation of American Unionism
Authors: Burgoon Brian , Fine Janice , Jacoby Wade , Tichenor Daniel
Published: December 2010

Does immigration hamper union organizing in the United States? The prevailing literature strongly suggests that it does and for two reasons: first, immigrants increase the labor pool and diminish union influence over the labor market. And second, immigrants may be harder to organize than native workers. In this dominant view, unions are well served to restrict immigration and have always done so. But how, then, to explain the fact that American labor has long been deeply divided over the response to immigration? Drawing on new archival research and interviews, this paper uncovers a neglected side of American labor history in which many union leaders have extended solidarity to immigrants and sought to organize them. Moreover, analysis of time series data on immigration and union density corroborates the implicit theory of this alternate account of labor history: immigration has, in fact, no statistically significant effect – either positive or negative – on union density over time. Depending on specific conditions and strategies, unions can and have been successful in organizing during periods of high immigration.
Inappropriate Use of D‐Values for Determining Biocidal Activity of Various Antimicrobials
Authors: Hines Jesse D. , McKelvey Pamela J. , Bodnaruk Peter W.
Published: December 2010

Abstract:  The objective of this study was to investigate the application of established D‐value calculations to survival curves for various bacteria using the following antimicrobials: acidified sodium chlorite, triclosan, octanoic acid, and sodium hydroxide. D‐values can be calculated in 3 ways, a linear regression, an endpoint calculation, or an average of multiple endpoint calculations. The assumption made in calculating a D‐value is that the rate of kill follows 1st‐order kinetics under specified treatment conditions. Each antimicrobial solution was challenged with approximately 108 CFU/mL of Staphylococcus aureus, Listeria monocytogenes, Salmonella enterica subsp. enterica, and Escherichia coli independently and in triplicate. Test systems were sampled at each of the 10 time points over a period of 7 min, neutralized, pour plated then incubated at 35 °C for 48 h (AOAC official method 960.09). Survival curves using the log‐transformed data were calculated using regression analysis. Correlations coefficients for all linear regression analyses ranged between 0.291 and 0.982, with 6 of the 16 different treatment systems having an R2 value below 0.7. Methods used for calculating D‐values should lead to the same result if the survival curve in a given condition is linear. The calculated D‐values were different using endpoint analysis (Stumbo method), linear regression, and average of multiple endpoints. This study demonstrates the nonlinearity of inactivation curves of antimicrobials. D‐value estimations cannot be reliably used to illustrate biocidal activity in antimicrobial test systems.
Kinetic Analysis of E. coli Inactivation by High Hydrostatic Pressure with Salts
Authors: Ueno Shigeaki , Shigematsu Toru , Hasegawa Toshimi , Higashi Jun , Anzai Mayumi , Hayashi Mayumi , Fujii Tomoyuki
Published: December 2010

Abstract:  Inactivation of E. coli by high hydrostatic pressure (250 to 400 MPa) with salts was investigated based on kinetic analysis. At concentrations from 0.074 to 0.145 M and from 0.240 to 0.290 M, both the absolute activation volumes and the preexponential factors were similar in KCl, NaCl, and LiCl solutions, suggesting that pressure inactivation is not salt‐specific. On the other hand, in the intermediate salt‐concentration range of 0.145 to 0.240 M, inactivation kinetics in the presence of the Na+ and K+ differed significantly from those in the presence of Li+ (P < 0.05). In this concentration range, effect of salt stress and osmotic stress differed significantly from those in concentrations below 0.145 M or above 0.240 M. The cellular response to pressure varies with salt type and salt concentration. These novel findings provide important clues to distinguish between salt stress and osmotic stress in the inactivation of E. coli.
Genetic structure, behaviour and invasion history of the Argentine ant supercolony in Australia
Authors: Suhr Elissa L. , O’Dowd Dennis J. , McKechnie Stephen W. , Mackay Duncan A.
Published: December 2010

Biological invasions have significant ecological, evolutionary and economic consequences. Ants are exemplary invaders and their invasion success is frequently attributed to a shift in social structure between native and introduced populations. Here, we use a multidisciplinary approach to determine the social structure, origin and expansion of the invasive Argentine ant, Linepithema humile, in Australia by linking behavioural and genetic studies with indicators of dispersal pathways and propagule pressure. Behavioural assays revealed a complete absence of aggression within and between three cities – Melbourne, Adelaide and Perth – spanning 2700 km across Australia. Microsatellite analyses showed intracity genetic homogeneity and limited but significant intercity genetic differentiation. Exceptions were two Perth nests that likely represent independent translocations from Adelaide. These patterns suggest efficient local gene flow with more limited jump dispersal via transport corridors between cities. Microsatellite analyses of L. humile from potential source regions, combined with data from port interceptions, trade pathways and the timeline of spread within Australia, implicate the main European supercolony as the source of L. humile in Melbourne. Such an introduction probably then redistributed across Australia and spread to New Zealand to form an expansive Australasian supercolony.
Conglomerate Structure and Capital Market Timing
Authors: Chang Xin , Hilary Gilles , Shih Chia Mei , Tam Lewis H.K.
Published: December 2010

We examine the effects of keiretsu structure on capital market‐timing. Keiretsu groups offer a hybrid structure between fully integrated conglomerates and stand‐alone firms. We find that past market conditions affect the capital structure of keiretsu firms more than they affect the capital structure of unaffiliated firms. The decision to issue equity is more correlated with market conditions for keiretsu members than it is for unaffiliated firms. The stock returns of keiretsu firms following the issuance of equity decrease with the size of the issuance. These results suggest that keiretsu members time the issuance of equity more so than stand‐alone firms.
Financial Flexibility, Investment Ability, and Firm Value: Evidence from Firms with Spare Debt Capacity
Authors: Marchica Maria‐Teresa , Mura Roberto
Published: December 2010

We document, for the first time, that a conservative leverage policy directed at maintaining financial flexibility can enhance investment ability. Our analysis reveals that following a period of low leverage, firms make larger capital expenditures and increase abnormal investment. We find that these new investments are financed through new issues of debt. The impact of financial flexibility is both statistically significant and economically sizable. Further, long‐run performance tests reveal that financially flexible firms not only invest more but also invest better. Our results are consistent with the view that financial flexibility in the form of untapped reserves of borrowing power is a crucial missing link in capital structure theory.
What Matters in Venture Capital? Evidence from Entrepreneurs’ Stated Preferences
Authors: Bengtsson Ola , Wang Frederick
Published: December 2010

We study how entrepreneurs evaluate the ability of different US venture capitalists (VCs) to add value to start‐up companies. Analyzing a large data set of entrepreneurs’ stated preferences regarding VCs, we demonstrate that entrepreneurs view independent partnership VCs more favorably than other VC types (e.g., corporate, financial, and government sponsored VCs). Although entrepreneurs are able to correctly identify VCs with better track records, they do not believe them to be more desirable investors. We also find that an entrepreneur's rankings are affected by their overall exposure to VCs, emphasizing the role of experiential learning in the venture capital market.
The Effects of Ambiguous Information on Initial and Subsequent IPO Returns
Authors: Arnold Tom , Fishe Raymond P.H. , North David
Published: December 2010

Newly public companies must disclose significant risk factors in the offering prospectus. These disclosures are examples of “soft” or ambiguous information. Ambiguity models predict that investors will alter their portfolio weights and react to subsequent signals about such information. We test for these effects in a sample of 1,398 initial public offerings (IPOs) using word count ratios between soft and hard information as measures of ambiguity. We find a significant relationship between the soft information on risk and both initial and ex post measures of returns. These results support the view that soft information embeds ambiguity and that it influences investors’ portfolio choices.
Acquisition Activity and IPO Underpricing
Authors: Boulton Thomas J. , Smart Scott B. , Zutter Chad J.
Published: December 2010

We propose an “M&A activity” hypothesis as a partial explanation for initial public offering (IPO) underpricing. When going public during active corporate control markets, managers may take actions to safeguard their control. In support of this conjecture, we find that pre‐IPO M&A activity directly explains IPO underpricing. We also find that underpricing and ownership dispersion are positively correlated, as are ownership dispersion and the probability of remaining independent. Considering the possibility that some managers take their firms public to be acquired, we find that the positive link between M&A activity and underpricing is not robust for firms that are viewed as likely targets.
Management Quality and Equity Issue Characteristics: A Comparison of SEOs and IPOs
Authors: Chemmanur Thomas J. , Paeglis Imants , Simonyan Karen
Published: December 2010

We use hand‐collected data on the management quality of firms making seasoned equity offerings (SEOs) or initial public offerings (IPOs) to analyze the relationship between management quality and equity issue characteristics, and to compare the effect of management quality on SEOs versus IPOs. We hypothesize that higher quality managers are more credible to equity market investors, thereby reducing the information asymmetry they face in the market and outsiders’ information production costs. Therefore, the equity issues of higher management quality firms will have more reputable underwriters, smaller underwriting spreads, and other expenses, and smaller SEO discounts. Further, since better managers will be able to select better projects, higher management quality firms will have larger offer sizes. Finally, since SEO firms are likely to suffer from less information asymmetry compared to IPO firms, these effects will be smaller for SEOs than for IPOs. Our findings support the above hypotheses. Our direct tests of the relationship between management quality and information asymmetry, and our comparison of information asymmetry in SEOs versus IPOs provide further support for these hypotheses.
A Competing Risks Analysis of Corporate Survival
Authors: He Qing , Chong Terence Tai‐Leung , Li Li , Zhang Jun
Published: December 2010

This paper investigates how the characteristics of a Hong Kong‐listed firm influence its odds of going bankrupt, being acquired, and going private. A competing risks model is estimated. Our results reveal that larger firms are more vulnerable to bankruptcy, and that fast‐growing firms are more likely to be acquired. We also demonstrate that undervaluation is a key driver of going private. Despite the low agency cost due to the concentrated ownership structure, the propensity of Hong Kong‐listed firms to go private still increases with the level of free cash flow.
Medical Malpractice: A Cardiovascular Perspective
Authors: Tan S. Y.
Published: December 2010

This article reviews the elements of medical malpractice, informed consent, and affirmative defense; and discusses the legal risks associated with the diagnosis and therapy of cardiovascular disease.
Therapeutic Potential of Kainate Receptors
Authors: Matute Carlos
Published: December 2010

Glutamate receptors are key mediators of brain communication. Among ionotropic glutamate receptors, kainate receptors (KARs) have been least explored and their relevance to pathophysiology is relatively obscure. This is in part due to the relatively low abundance of KARs, the regulatory function in network activity they play, the lack of specific agonists and antagonists for this receptor subtype, as well as to the absence of striking phenotypes in mice deficient in KAR subunits. Nonetheless, it is now well established that KARs are located presynaptically whereby they regulate glutamate and GABA release, and thus, excitability and participate in short‐term plasticity. In turn, KARs are also located postsynaptically and their activation contributes to synaptic integration. The development of specific novel ligands is helping to further investigate the contribution of KARs to health and disease. In this review, I summarize current knowledge about KAR physiology and pharmacology, and discuss their involvement in cell death and disease. In addition, I recapitulate the available data about the use of KAR antagonists and receptor subunit deficient mice in experimental paradigms of brain diseases, as well as the main findings about KAR roles in human CNS disorders. In sum, subunit specific antagonists have therapeutic potential in neurodegenerative and psychiatric diseases as well as in epilepsy and pain. Knowledge about the genetics of KARs will also help to understand the pathophysiology of those and other illnesses.
Untangling the multiple monooxygenases of Mycobacterium chubuense strain NBB4, a versatile hydrocarbon degrader
Authors: Coleman Nicholas V. , Yau Sheree , Wilson Neil L. , Nolan Laura M. , Migocki Margaret D. , Ly Mai‐anh , Crossett Ben , Holmes Andrew J.
Published: December 2010

Mycobacterium strain NBB4 was isolated on ethene as part of a bioprospecting study searching for novel monooxygenase (MO) enzymes of interest to biocatalysis and bioremediation. Previous work indicated that strain NBB4 contained an unprecedented diversity of MO genes, and we hypothesized that each MO type would support growth on a distinct hydrocarbon substrate. Here, we attempted to untangle the relationships between MO types and hydrocarbon substrates. Strain NBB4 was shown to grow on C2–C4 alkenes and C2–C16 alkanes. Complete gene clusters encoding six different monooxygenases were recovered from a fosmid library, including homologues of ethene MO (etnABCD), propene MO (pmoABCD), propane MO (smoABCD), butane MO (smoXYB1C1Z), cytochrome P450 (CYP153; fdx‐cyp‐fdr) and alkB (alkB‐rubA1‐rubA2). Catabolic enzymes involved in ethene assimilation (EtnA, EtnC, EtnD, EtnE) and alkane assimilation (alcohol and aldehyde dehydrogenases) were identified by proteomics, and we showed for the first time that stress response proteins (catalase/peroxidase, chaperonins) were induced by growth on C2–C5 alkanes and ethene. Surprisingly, none of the identified MO genes could be specifically associated with oxidation of small alkanes, and thus the nature of the gaseous alkane MO in NBB4 remains mysterious.
The extent and nature of dental fear and phobia in Australia
Authors: Armfield JM
Published: December 2010

Background:  For the general dental practitioner, fearful patients are harder and more stressful to treat and are most likely to attend irregularly. This study presents updated and refined dental fear and phobia prevalence estimates in Australia as well as information on the nature of dental fear and phobia.

Methods:  A total of 1084 Australian adults (response rate = 71.7%) completed a mailed questionnaire. The survey contained four measures of dental fear and phobia, as well as questions regarding potentially anxiety‐eliciting dental stimuli and past aversive dental experiences.

Results:  The prevalence of high dental fear ranged from 7.8% to 18.8%, and more incapacitating dental phobia from 0.9% to 5.4%, depending upon the scale, cut‐point and specific criteria used. Dental phobia was significantly associated with blood‐injection‐injury (BII) concerns. The cost of dental treatment was endorsed as the most anxiety‐eliciting dental situation (64.5%), followed by fear of needles/injections (46.0%) and painful or uncomfortable procedures (42.9%). Anxiety‐eliciting stimuli and the type of aversive dental experiences varied significantly by gender, age, income, education, language spoken at home and dental visiting frequency.

Conclusions:  High dental fear and dental phobia are common in Australia although prevalence estimates are highly dependent on both the scale and cut‐points used.
Effect of bleaching versus repolishing on colour and surface topography of stained resin composite
Authors: Elhamid M Abd , Mosallam R
Published: December 2010

Background:  The aim of this study was to examine the effect of ozonated gel, carbamide peroxide bleaching agent and polishing paste on the colour and surface topography of stained resin composite.

Methods:  Ninety disc‐shaped resin composite specimens were used in this study. They were randomly divided into three groups of 30 specimens each according to the immersion solutions used, i.e., tea, cola or artificial saliva. Each group was further subdivided into three equal subgroups (n = 10) according to the type of whitening treatment applied; 30% carbamide peroxide, ozonated KY gel or polishing paste. Colour and surface roughness was measured at baseline, after immersion, also following whitening procedures by using a stereomicroscope. The results were recorded, tabulated and statistically analysed.

Results:  The colour values of artificial saliva displayed the highest statistically significant mean colour difference compared to cola and tea. However, there was no statistically significant difference in surface roughness. Also, a superior whitening effect was demonstrated with ozonated gel. Ozonated gel showed statistically significant lowest roughness compared to both carbamide peroxide and polishing paste.

Conclusions:  Immersion solutions have a positive influence on the colour of resin composite. Also, ozonated gel is an efficient bleaching agent with the least adverse effect on surface roughness.
Simulation of medical emergencies in dental practice: development and evaluation of an undergraduate training programme
Authors: Newby JP , Keast J , Adam WR
Published: December 2010

Background:  The evidence available suggests that many dentists on graduation do not feel competent managing medical emergencies; a problem requiring improved undergraduate training. This study developed a comprehensive simulation based training programme for final year undergraduate dental students and assessed student attitudes towards training.

Methods:  Final year dental students (n = 52) from The University of Melbourne were required to complete simulation training incorporating an interactive tutorial and realistic, simulated emergency scenarios conducted in the students’ real clinical environment. A post‐participation questionnaire utilizing a 5‐point Likert scale (1 = strongly disagree, 5 = strongly agree) assessed student attitudes.

Results:  Student responses supported simulation training, evidenced by the following selected questionnaire responses: achieved greater confidence in managing emergencies 4.65 ± 0.48 (n = 52); prefer lecture to simulation 1.46 ± 0.74 (n = 52); simulation training is important in undergraduate teaching 4.86 ± 0.35 (n = 43).

Conclusions:  Realistic simulation training in management of medical emergencies for dental students is an effective adjunct to traditional lecture style teaching. Given the importance of this subject, this mode of training would benefit students if incorporated into undergraduate dental courses.
GUIDELINES FOR THEORIZING ABOUT REALIZATION
Authors: Morris Kevin
Published: December 2010

abstract

Realization can be roughly understood as a kind of role‐playing, a relationship between a property that plays a role and a property characterized by that role. This rough sketch previously received only moderate elaboration; recently, however, several substantive theories of realization have been proposed. But are there any general constraints on a theory of realization? What is a theory of realization supposed to accomplish? I first argue that a view of realization is viable, in part, to the extent that physical realization under that view explains or accounts for why instances of realized properties are necessitated by how things are physically in a modally strong sense. In this sense, I claim that physical realization should explain physical supervenience. I then call into question two alternative desiderata and raise a challenge for attempts to explicate realization in terms of isomorphism or analogy. Finally, I explain how a causal‐functional account of realization, as well as less demanding accounts, can meet the preferred desideratum.
LOYALTY AND THE ART OF WISE LIVING: THE INFLUENCE OF PLATO ON THE MORAL PHILOSOPHY OF JOSIAH ROYCE
Authors: Shew Melissa , Foust Mathew A.
Published: December 2010

abstract

This essay investigates Josiah Royce's sustained interest in the Platonic dialogues by focusing not only on Royce's explicit commentary on Socrates and Plato but also on significant philosophical connections between Royce and these figures. In section 1, we explain the nature of loyalty according to Royce and how Socratic loyalty exemplifies Royce's ideas in both evident and surprising ways. In section 2, we claim that Royce's treatment of “lost causes” (particularly truth as a lost cause) relates to Socrates' dedication to the logos; the Platonic dialogues are reinvestigated in order to make this point. In section 3, we explain the nature of “cause” both in Royce's thought and in the Platonic dialogues in order to see how loyalty to a cause culminates in the art of wise living—Socrates' philosophical practice.
Direct and indirect control of orexin/hypocretin neurons by glycine receptors
Authors: Karnani Mahesh M. , Venner Anne , Jensen Lise T. , Fugger Lars , Burdakov Denis
Published: December 2010

Non‐technical summary

Normal wakefulness relies on brain cells called orexin/hypocretin neurons. Activity of these cells stimulates awakening while their loss produces the sleep disorder narcolepsy. By studying what makes orexin/hypocretin cells more or less active, we can thus gain insights into how the brain switches between different states of consciousness. We describe a new way to turn orexin/hypocretin cells off using a chemical called glycine. We show that glycine shuts down the electrical activity of orexin/hypocretin neurons from the adult brain, but has the opposite effect in the very young brain. Apart from these direct actions on orexin/hypocretin cells, glycine also enhances the ability of other nerve cells to communicate with orexin/hypocretin neurons. These data shed new light on the basic chemical and physical mechanisms regulating orexin/hypocretin neurons, which may also be useful in improving therapeutic strategies for disorders such as insomnia.
A Manipulator for Medical Applications: Design and Control
Authors: Yousef Basem Fayez , Patel Rajni V. , Moallem Mehrdad
Published: December 2010

An actuated robot arm is designed for use as a gross positioning macro-manipulator that can carry, appropriately orient, precisely position, and firmly “lock” in place different types of micro-robots and surgical tools necessary for applications in minimally invasive therapy. With a simple manipulation protocol, the clinician can easily operate the robot in manual mode. A remote control mode can also be enabled for teleoperation of the robot. The robot’s normally locked braking system and the simple quick-release joint enhance its safety features for emergencies and power shutdown. Robot workspace analysis showed that the singularity regions are outside the usable work envelope of the robot. Performance analysis showed that the robot operates with an average displacement accuracy of 0.58 mm and a roll, pitch, and yaw angular accuracies of 0.26 deg, 0.26 deg, and 0.38 deg, respectively. The sophisticated configuration and joint architecture of the arm enable it to perform and interact efficiently with the constrained and limited workspace of surgical environments. The special features of the proposed robot make it well suited for use with new surgical tools and micro-robots for a range of medical interventions.
On the Dynamic Modeling of a Bevel-Geared Surgical Robotic Mechanism
Authors: Zhang Xiaoli , Nelson Carl A.
Published: December 2010

The use of robotics to enhance visualization and tissue manipulation capabilities contributes to the advancement of minimally invasive surgery. For the development of surgical robot manipulators, the use of advanced dynamic control is an important aspect at the design stage to determine the driving forces and/or torques, which must be exerted by the actuators in order to produce a desirable trajectory of the end effector. Therefore, this study focuses on the generation of inverse dynamic models for a spherical bevel-geared mechanism called Compact Bevel-geared Robot for Advanced Surgery (CoBRASurge), which is used as a surgical tool manipulator. For given typical trajectories of end effectors in clinical experiments, the motion of each element in the mechanism can be derived using the inverse kinematic equations. The driving torques exerted by actuators can be determined according to the presented inverse dynamic formulations. The simulation results of CoBRASurge reveal the nature of the driving torques in spherical bevel-geared mechanisms. In addition, sensitivity analysis of mass contribution has been performed to evaluate the effect of individual elements on the peak driving torques. Dynamic models, such as the one presented, can be used for the design of advanced dynamic control systems, including gravity compensation and haptic interfaces for enhanced surgical functionality. The accompanying sensitivity analysis also provides a solid guideline for the design of the next generation CoBRASurge prototype. The present dynamic modeling methodology also gives a general dynamic analysis approach for other spherical articulated linkage mechanisms.
A Process for Design, Verification, Validation, and Manufacture of Medical Devices Using Immersive VR Environments
Authors: Keefe Daniel F. , Sotiropoulos Fotis , Interrante Victoria , Runesha H. Birali , Coffey Dane , Staker Molly , Lin Chi-Lun , Sun Yi , Borazjani Iman , Le Trung , Rowe Nancy , Erdman Arthur
Published: December 2010

This paper presents a framework and detailed vision for using immersive virtual reality (VR) environments to improve the design, verification, validation, and manufacture of medical devices. Major advances in medical device design and manufacture currently require extensive and expensive product cycles that include animal and clinical trials. The current design process limits opportunities to thoroughly understand and refine current designs and to explore new high-risk, high-payoff designs. For the past 4 years, our interdisciplinary research group has been working toward developing strategies to dramatically increase the role of simulation in medical device engineering, including linking simulations with visualization and interactive design. Although this vision aligns nicely with the stated goals of the FDA and the increasingly important role that simulation plays in engineering, manufacturing, and science today, the interdisciplinary expertise needed to realize a simulation-based visual design environment for real-world medical device design problems makes implementing (and even generating a system-level design for) such a system extremely challenging. In this paper, we present our vision for a new process of simulation-based medical device engineering and the impact it can have within the field. We also present our experiences developing the initial components of a framework to realize this vision and applying them to improve the design of replacement mechanical heart valves. Relative to commercial software packages and other systems used in engineering research, the vision and framework described are unique in the combined emphasis on 3D user interfaces, ensemble visualization, and incorporating state-of-the-art custom computational fluid dynamics codes. We believe that this holistic conception of simulation-based engineering, including abilities to not just simulate with unprecedented accuracy but also to visualize and interact with simulation results, is critical to making simulation-based engineering practical as a tool for major innovation in medical devices. Beyond the medical device arena, the framework and strategies described may well generalize to simulation-based engineering processes in other domains that also involve simulating, visualizing, and interacting with data that describe spatially complex time-varying phenomena.
Optimal Fiducial Configuration in Image-Guided Neurosurgery Using a Genetic Algorithm
Authors: Gastaldi Laura , Battezzato Alessandro , Bernucci Claudio , Mannino Marco , Pastorelli Stefano
Published: December 2010

Image-guided neurosurgery allows surgeons to navigate and localize lesion through the patient’s cranium with a 3D image guidance. The model of the head is reconstructed using preoperative computed tomography or magnetic resonance images and real and virtual spaces are aligned by means of fiducial markers placed on the patient. In this paper, a new method for the optimal placement of the fiducial markers in order to reduce misalignment is presented. Using routine diagnostic images, a customized 3D model of the patient’s cranium is reconstructed. A genetic algorithm calculates optimal positions of the marker in order to minimize the target registration error. The fiducial set is shown to the surgeons on the 3D model to help him/her in placement of them.
Clinical Characteristics of Bloodstream Infections Due to Ampicillin-Sulbactam-Resistant, Non-Extended- Spectrum-β-Lactamase-Producing
Escherichia coli
and the Role of TEM-1 Hyperproduction
Authors: Waltner-Toews Rebecca I. , Paterson David L. , Qureshi Zubair A. , Sidjabat Hanna E. , Adams-Haduch Jennifer M. , Shutt Kathleen A. , Jones Mark , Tian Guo-Bao , Pasculle Anthony W. , Doi Yohei
Published: December 2010

Ampicillin-sulbactam is commonly used as an empirical therapy for invasive infections where
Escherichia coli
is a potential pathogen. We evaluated the clinical and microbiologic characteristics of bloodstream infection due to
E. coli
, with focus on cases that were nonsusceptible to ampicillin-sulbactam and not producing extended-spectrum β-lactamase (ESBL). Of a total of 357 unique bacteremic cases identified between 2005 and 2008, 111 (31.1%) were intermediate or resistant to ampicillin-sulbactam by disk testing. In multivariate analysis, a history of liver disease, organ transplant, peptic ulcer disease, and prior use of ampicillin-sulbactam were independent risk factors for bloodstream infection with ampicillin-sulbactam-nonsusceptible
E. coli
. Among cases that received ampicillin-sulbactam as an empirical therapy, an early clinical response was observed in 65% (22/34) of susceptible cases but in only 20% (1/5) of nonsusceptible cases. Among 50 ampicillin-sulbactam-resistant isolates examined, there was no clonal relatedness and no evidence of production of inhibitor-resistant TEM (IRT). Instead, the resistance was attributed to hyperproduction of TEM-1 β-lactamase in the majority of isolates. However, promoter sequences of
bla
TEM-1
did not predict resistance to ampicillin-sulbactam. While the plasmid copy number did not differ between representative resistant and susceptible isolates, the relative expression of
bla
TEM-1
was significantly higher in two of three resistant isolates than in three susceptible isolates. These results suggest high-level
bla
TEM-1
expression as the predominant cause of ampicillin-sulbactam resistance and also the presence of yet-unidentified factors promoting overexpression of
bla
TEM-1
in these isolates.
Characterization of the E138K Resistance Mutation in HIV-1 Reverse Transcriptase Conferring Susceptibility to Etravirine in B and Non-B HIV-1 Subtypes
Authors: Asahchop Eugene L. , Oliveira Maureen , Wainberg Mark A. , Brenner Bluma G. , Moisi Daniela , Toni Thomas d'Aquin , Tremblay Cecile L.
Published: December 2010

We have selected for resistance to etravirine (ETR) and efavirenz (EFV) in tissue culture using three subtype B, three subtype C, and two CRF02_AG clinical isolates, grown in cord blood mononuclear cells. Genotypic analysis was performed at baseline and at various weeks of selection. Phenotypic resistance in regard to ETR, EFV, and nevirapine (NVP) was evaluated at weeks 25 to 30 for all ETR-selected viruses and in viral clones that contained specific resistance mutations that were inserted by site-directed mutagenesis into pNL-4.3 and AG plasmids. The results show that ETR selected mutations at positions V90I, K101Q, E138K, V179D/E/F, Y181C, V189I, G190E, H221H/Y, and M230L and that E138K was the first of these to emerge in most instances. The time to the emergence of resistance was longer in the case of ETR (18 weeks) compared to EFV (11 weeks), and no differences in the patterns of emergent mutations could be documented between the B and non-B subtypes. Viral clones containing E138K displayed low-level phenotypic resistance to ETR (3.8-fold) and modestly impaired replication capacity (2-fold) compared to wild-type virus. ETR-selected virus showed a high degree of cross-resistance to NVP but not to EFV. We identified K101Q, E138K, V179E, V189I, G190E, and H221Y as mutations not included among the 17 currently recognized resistance-associated mutations for ETR.
P-012 Solitaire FR in acute ischemic stroke: preliminary experience in a consecutive series of 21 cases
Authors: Bonafe A , Machi P , Costalat V , Riquelme C , Arquizan C
Published: December 2010

Background and purpose

Prompt recanalization of occluded brain arteries in patient victims of acute ischemic stroke (AIS) is associated with a better clinical outcome. Several trials have assessed the efficacy and safety of intra-arterial (IA) mechanical thrombectomy combined with intravenous (IV) administration of thrombolytic drugs in the therapy of AIS. The aim of this work is to evaluate the efficacy and the safety of Solitaire™ FR (SFR) (ev3 Inc, Irvine, California, USA) as a revascularization device in the treatment of AIS in combination with IV administration of thrombolytic drugs.

Materials and methods

Data from 21 patients treated with SFR within 7 h of AIS symptom onset in the setting of a prospectively defined IV–IA combined therapy were analyzed.

Results

SFR was successful in achieving complete recanalization in 19 patients (90.4%) with a final score of 3 according to the Thrombolysis in Myocardial Infarction classification (TIMI). Partial recanalization (TIMI 2) was obtained in one patient (4.7%). Treatment failure was observed (TIMI 0) in one patient (4.7%).

Four adverse events were recorded (21%): two intraprocedural thromboembolic events (10.5%) and two symptomatic intracranial hemorrhagic infarctions (10.5%). One patient died during the hospitalization due to massive brainstem infarction.

Marked improvement of National Institutes of Health Stroke Scale from baseline to 24 h after recanalization was obtained in 12 patients (57.1%).

Conclusions

SFR was effective in achieving a high rate of complete artery recanalization with a low rate of complications. SFR may be considered a promising tool for endovascular cerebral thrombectomy.
P-017 ‘Double barrel’ stent reconstruction of a symptomatic fusiform basilar artery aneurysm
Authors: Bain M , Hussain M , Spiotta A , Vivekananda G , Sivapatham T , Moskowitz S , Gupta R
Published: December 2010

Objective and importance

Giant fusiform aneurysms of the basilar artery are associated with a high rate of morbidity and mortality. Treatment of these lesions can be difficult especially when there are poor anatomic collaterals such as posterior communicating arteries. Often times these lesions have no acceptable treatment. We present a case of a patient with a large, symptomatic, fusiform basilar artery aneurysm successfully treated with a side by side, telescoping stent construct and coiling of the giant basilar artery aneurysm.

Clinical presentation

A 56-year-old man presented with chief complaints of dysarthria and left-sided hemiparesis. MRI and conventional catheter based angiography revealed a dolichoectatic basilar artery with three large fusiform aneurysms throughout its length. Flow through the patient's aneurysm was successfully reduced with a side by side stent construct and coiling of the proximal aneurysm dilation. The patient experienced stabilization of his ischemic events and neurologic recovery.

Intervention and technique

A total of eight Neuroform-2 4.5×30 mm stents were navigated and positioned from the proximal posterior cerebral arteries to the distal vertebral arteries in a side by side, telescoping manner. These were deployed simultaneously by two operators to oppose the stent struts as well as the arterial wall. Next, the proximal aneurysmal dilation was coiled to near occlusion.

Conclusion

We present a novel, endovascular stenting technique for successfully treating symptomatic, giant basilar artery aneurysms. The above patient at 4 months was living independently with no further neurologic events or decline.

Abstract P-017 Figure 1
P-018 Curative transvenous embolization of craniofacial arteriovenous malformation
Authors: Feng L , Mattson-Gates G , Sosa V , Baker C
Published: December 2010

Background

Craniofacial arteriovenous malformation (AVM) is a challenging disease to eradicate, often requiring the combination of embolization and reconstructive surgery. The tortuosity of distal feeding arteries and the presence of abundant collaterals make it difficult to obliterate the nidus with transarterial embolization. In this small case series, we report curative transvenous embolization of craniofacial AVM under transient arrest of arterial inflow.

Materials and methods

Four patients with craniofacial AVMs (two in the scalp, one in the face and one in the forehead) were embolized transvenously with Onyx. In all cases, the dominant feeding arteries were first embolized with Onyx to reduce arterial inflow. The major draining veins were then accessed transfemorally or via direct puncture. Detachable coils were placed in the venous pouches to further obstruct outflow from the AVM nidus. After arterial inflow was completely stopped with the placement of a tourniquet on the head or inflation of a balloon catheter in the external carotid artery, we injected Onyx into the venous pouch to retrogradely fill the entire AVM nidus. Follow-up angiograms were performed 1 year later.

Results

Angiographic cure was achieved in all four patients. The mass effect from the Onyx cast was not disfiguring. No patient had skin necrosis or a visible black mark on the skin. The first two patients underwent surgical removal of the Onyx cast which was scheduled before embolization. The next two patients declined surgery because they were not bothered by the Onyx cast. No recurrence was found at the 1 year follow-up angiogram.

Conclusion

Head and neck AVM can be safely cured with transvenous embolization using Onyx.

Abstract P-018 Figure 1

Angiogram of a facial arteriovenous malformation before and after embolization.

Abstract P-018 Figure 2

Transvenous embolization with Onyx after partial coiling and transient occlusion of the external carotid artery with a balloon (A). Onyx cast showing the nidus and numerous small feeders (B).
P-020 The transcirculation treatment of cerebral aneurysms
Authors: Albuquerque F , McDougall C
Published: December 2010

Introduction

Unfavorable anatomy can preclude embolization of intracranial aneurysms. Transcirculation techniques, in which a catheter is navigated from one side of the brain to the other or from the anterior to the posterior circulation, are alternative pathways for primary or balloon/stent assisted coiling. We report the largest experience in coil embolization of aneurysms using these techniques.

Methods

We prospectively reviewed our collected database from 2006 to 2009 and identified 20 patients who had aneurysms treated with transcirculation techniques.

Results

Eight patients had anterior and 12 had posterior circulation aneurysms. Overall, nine patients required stent assisted coiling and 10 required balloon assisted coiling, including two patients treated with a ‘kissing balloon’ technique. Of the 10 patients, two requiring balloon assistance were also treated with stenting at the conclusion of aneurysm coiling. One patient with a left V4 aneurysm was treated with a bilateral vertebral artery (VA) approach. In 14 patients, the anterior communicating and posterior communicating arteries were used as conduits. In six patients, both VA were traversed to treat two V4 aneurysms, two posterior inferior cerebellar artery aneurysms, one basilar apex aneurysm and one basilar trunk aneurysm. Overall, two (10%) permanent complications occurred as a result of treatment: one death and one minor stroke. Complete or near complete (>95%) embolization was achieved in all patients.

Conclusions

Trancirculation techniques are effective pathways for embolization of complex aneurysms. Although technically challenging, these techniques are associated with an acceptably low rate of complications when compared with the natural history of the treated lesion.

Abstract P-020 Figure 1