bluuebunny/crossref_metadata_2025 huggingface dataset:
Polycentric Phoenix
Authors: Leslie Timothy F. , HUallacháin Breandán Ó
Published: August 2010

Abstract: Sun Belt cities have a reputation for sprawling disarray. Although Phoenix is often depicted as the ultimate large fast‐growing, low‐density Sun Belt metropolis, we found considerable order in the location of business establishments. We tested spatial pattern to show that establishments in a variety of sectors are significantly clustered and found that while clustering declines outside the central business district (CBD) and subcenters, all sectors remain significantly clustered in the suburbs. A new method that we developed to assess spatial relationships of establishments across sectors revealed that spatial intersectoral associations are evident between some intermediate‐sector establishments and within final demand. These intersectoral associations mostly carry over to portions of the urbanized area beyond the CBD and subcenters. A cartographic analysis details sectoral locational patterns across the metropolitan area and the relationships between the function of subcenters and the transportation network. We compare the economic structure of the CBD and five subcenters. Phoenix has a distinctively specialized CBD. Some subcenters are functionally diversified, while others are specialized. The rank‐size rule is a good approximation of the size order of centers. We conclude that continued forces of accessibility, externality, and regulation shape the spatial structure of Phoenix.
The Regional Environment and a Firm's Innovative Performance: A Plea for a Multilevel Interactionist Approach
Authors: Beugelsdijk Sjoerd
Published: August 2010

Abstract: Following the recent critical debate on the role of the firm versus that of the region, this article contends that for a true test of the importance of the role of the region for a firm's innovative performance firm‐specific heterogeneity needs to be minimized. Empirical studies have tended to deduce that the region matters from the macrophenomenon of regional clusters of economic activity. This deduction has led to an ecological fallacy, in which global phenomena or data aggregates that are actual representations of lower‐level phenomena cannot be generalized to those lower levels. This article argues that if researchers want to analyze how a firm's environment affects its performance, they need to include firm‐level strategy and structure. As an empirical illustration of this argument, the article presents a test—controlling for a number of firm‐specific factors—of whether regional characteristics like the intensity of regional research and development (R&D), the number of R&D workers in the region, and the presence of a research institute are significantly related to a firm's ability to produce innovations. The findings suggest that the firm‐specific drivers of innovation are more important than is a firm's regional environment. The article concludes that a renewed focus on the main actors and their interrelationships is needed, particularly those that involve the exchange of knowledge, to assess the extent to which such interactions are carried out within bounded territories.
Countervailing Immigration and Domestic Migration in Gateway Cities: Australian and Canadian Variations on an American Theme
Authors: Ley David
Published: August 2010

Abstract: This article addresses the spatial regularity of countervailing population flows of immigration and net domestic migration, respectively, into and out of large gateway cities. This regularity has been noted most often in the United States, and the argument presented here makes two new contributions. First, it extends the analysis to the principal Australian and Canadian gateway cities of Sydney and Toronto, making use of an extended time series of annual data. Second, it argues for the importance of the neglected effects of housing markets, in contrast to conventional accounts that stress cultural avoidance or labor market competition, in differentiating the two demographic streams. The article shows how trends in the housing market separate the locational preferences of immigrants from two diverse groups of domestic migrants.
Roepke Lecture in Economic Geography—Regional Context and Global Trade
Authors: Storper Michael
Published: August 2010

abstract

How should we think of the role of regions in relation to the global economy? Theory has surprising gaps when it comes to building a unified vision of these two scales of development. Two contributions to such a vision are proposed in this article. First, the relationship between geographic concentration and the regional economic specialization it underpins and globalization should be theorized as a dynamic process. Standard location and trade theory is not adequate for this task; instead, the dynamic relationship can be captured through growth theory. But capturing this dynamic relationship requires correcting growth theory to separate its local and its global components, which are, respectively, Marshall‐Arrow and Romer externalities. Second, the missing element in all theories of geographic concentration and locally specialized development is an element labeled “context” here. A theory of context, in turn, raises important new questions about the dynamic welfare and developmental effects of contemporary processes of fragmenting and relocating production at a global scale.
Relational Economic Geography: A Partial Understanding or a New Paradigm?
Authors: Sunley Peter
Published: August 2010

Relational approaches in economic geography have grown in popularity and influence, but have not been critically evaluated or discussed. This article argues that poststructural and network‐based versions of relational economic geography undoubtedly open up new research issues and provide tools for certain purposes, but questions whether they provide a coherent research agenda and new theoretical paradigm that can guide the reconceptualization of economic geography. The article addresses two main cases for a relational approach: its correspondence with a knowledge‐ and network‐based capitalism and the claim that it provides an improved philosophy and ontology. It finds problems with both cases and argues that the approach provides an imprecise and selective ontology that is preoccupied with microscale processes. As a result, relational economic geography does not lend itself to causal explanations and schemas, is incapable of discriminating among different economic theories, and could become immune to empirical evaluation. In many cases, it seems to disregard many of the valuable insights of institutionalist and critical realist approaches, including the implications of emergence. The article concludes that instead of searching for a microlevel relational perspective or a new vocabulary, economic geography's analysis of connections and relations would be better set within an evolutionary and historical institutionalism that understands economic relations as forms of institutional rules and practices and does not privilege ties and networks over nodes and agents.
Innovation and Peripherality: An Empirical Comparative Study of SMEs in Six European Union Member Countries
Authors: Copus Andrew , Skuras Dimitris , Tsegenidi Kyriaki
Published: August 2010

This article examines the rates of innovative activity of small and medium‐sized enterprises (SMEs) in central areas and equally developed but less accessible areas in six European Union member states. The probability of innovating is well predicted by the observable characteristics of firms, entrepreneurial characteristics, and business networks. More accessible areas consistently present higher rates of innovative activity than do their peripheral counterparts. The difference in the rates of peripheral and central areas is decomposed into observable and non‐observable factors. The entire innovation gap is attributed to nonobservable factors that constitute a combination of behavior and environment. Innovation policy for SMEs should aim to meet businesses' specific needs (firm‐specific factors) and to sustain and improve the innovative environment.
Accumulation by Decarbonization and the Governance of Carbon Offsets
Authors: Bumpus Adam G. , Liverman Diana M.
Published: August 2010

This article examines the governance of international carbon offsets, analyzing the political economy of the origins and governance of offsets. We examine how the governance structures of the Kyoto Protocol's Clean Development Mechanism and unregulated voluntary carbon offsets differ in regulation and in complexity of the chain that links consumers and reducers of carbon, with specific consequences for carbon reductions, development, and the ability to provide “accumulation by decarbonization.” We show how carbon offsets represent capital‐accumulation strategies that devolve governance over the atmosphere to supranational and nonstate actors and to the market.
Yet Another Turn? The Evolutionary Project in Economic Geography
Authors: Grabher Gernot
Published: August 2010

abstract

What does the economic in economic geography stand for? For much of the 1990s up to the more recent past, answers to this pertinent question frequently referred to the embeddedness‐network paradigm of the new economic sociology. At the same time, economic geography more and more drew inspiration, metaphors, and practices from an increasingly diverse range of schools. In terms of the disciplinary orientation, economic geography, on the one hand, remains firmly engaged with sociology, although interest seems to expand from the Granovetterian paradigm to the poststructuralism of Latour and Callon. On the other hand, economic geography's interest in heterodox economic geography is gaining new momentum. Above all, evolutionary approaches have attracted considerable attention that most recently culminated in a range of programmatic statements to develop a distinct evolutionary economic geography. It is these attempts to develop a collective agenda that Danny MacKinnon, Andrew Cumbers, Andy Pike, Kean Birch, and Robert McMaster take issue with. Subsequently, Ron Boschma and Koen Frenken, Jürgen Essletzbichler, and Geoffrey Hodgson comment on this “sympathetic critique.” A rejoinder by Andy Pike and his coauthors concludes this symposium.
Agency, Institutions, and Darwinism in Evolutionary Economic Geography
Authors: Hodgson Geoffrey M.
Published: August 2010

abstract

The article by Danny MacKinnon, Andrew Cumbers, Andy Pike, Kean Birch, and Robert McMaster continues the dialogue on evolutionary ideas within economic geography. In response, I argue that the word “evolution” has a variety of meanings and that more precision is required. This commentary also addresses the possibility of generalizing Darwinian principles to evolving social phenomena. It upholds that institutions and power fit into this Darwinian framework and that it does not undermine the importance of agency, deliberation, or choice. A word such as “determinism” should also be used more carefully, as it has multiple meanings.
The Expansion of the Finance Industry and Its Impact on the Economy: A Territorial Approach Based on Swiss Pension Funds
Authors: Corpataux José , Crevoisier Olivier , Theurillat Thierry
Published: August 2010

abstract

A new economic geography of finance is emerging, and the current “financialization” of contemporary economies has contributed greatly to the reshaping of the economic landscape. How can these changes be understood and interpreted, especially from a territorial point of view? There are two contradictory economic theories regarding the tangible effects of the rise of the finance industry. According to neoclassical financial theorists, the finance industry's success is based on its positive effects on the real economy through its capacity to allocate financial resources efficiently. An alternative approach, adopted here, posits that finance does not merely mirror the real economy and that the financial economy, far from being a simple instrument for the allocation of capital, has its own autonomy, its own logic of development and expansion. A series of complex, and sometimes contradictory, connections link financial markets and the real economy, and there are some tensions between them, calling into question the coherence of the regional and national economies that follow from them. Moreover, the territorial approach shows how the mobility/liquidity of capital and the changing dimensions of new regions and countries are central to the finance industry's functioning. This article builds an understanding of the financial system through the lens of pension funds and highlights the impact of such a system on the real economy and its geography.
Guest Editorial: Introduction to the Creative Class in European City Regions
Authors: Asheim Bjørn
Published: August 2010

abstract

This special issue presents the results of a European research project on the creative class in European city regions. In this introduction, the need for contextualizing the approach is underlined, taking into account the differences between the United States, where Richard Florida's ideas were developed, and Europe. In modifying the approach to suit European conditions, varieties of capitalism and social capital perspectives were applied.
Does Geography Still Matter? Evidence on the Portfolio Turnover of Large Equity Investors and Varieties of Capitalism
Authors: Dupuy Claude , Lavigne Stéphanie , Nicet‐Chenaf Dalila
Published: August 2010

abstract

This article investigates the geography of finance through a study of the behavior of large equity investors who are key actors in capitalism. The main argument is based on their expectations in “finance‐driven” capitalism: large equity investors require high returns on invested capital in a shorter time and are said to be impatient. The article focuses on their portfolio turnover in relation to geographic factors and their attachment to a specific model of capitalism. The U.S. “market‐based” model is presented as a benchmark, since U.S. investors trade securities most frequently relative to other international equity investors. Our empirical findings on the proximity of investors in various models of capitalism with U.S. “impatient” investors contribute to a growing literature on the economic importance of geography in understanding global finance.
Phase Characteristics of Self-Excited Chatter in Cutting
Authors: Kasahara N. , Sato H. , Tani Y.
Published: August 2010

The behavior of the self-excited chatter in cutting was investigated from the space phase point of view; the space phase is defined as that between outer and inner modulation. Records of oscillation for the horizontal motion of the work and those for the horizontal component of the cutting force were stored in a newly developed measurement system. The amplitude of the vibration increases for decreasing cutting speed and vice versa, the amplitude for the cutting force does not increase as the amplitude of the work motion does. Amplified and damped amplitudes for the decreasing and the increasing cutting speed are shown to be closely related to decreasing and increasing space phases, respectively. The mechanism of this phenomenon was analyzed on the complex plane by taking the cutting dynamics and the structural compliance into account. Attempts to suppress the chatter amplitude were conducted on the basis of these phenomena.
Predictive Control of a Robotic Grinding System
Authors: Kurfess T. R. , Whitney D. E.
Published: August 2010

This paper describes a modified predictive controller that has been interfaced with the robotic weld bead grinding system currently under development at The Charles Stark Draper Laboratory. The objective of the predictive control in the grinding system is to invert the previously modeled grinding dynamics. This is accomplished via a link between the controller and a grinding simulator that has been developed, based on an exchange of geometric and force data used by both algorithms. The interface utilizes vision data obtained from previous grinding passes to generate a force trajectory used by the robot on the subsequent pass. This trajectory is precomputed by the predictive controller to yield a specific weld bead shape. Due to system limitations, measurement noise, and modelling errors, the beads are not ground perfectly flat. However, their cross sectional area (or height) variations are reduced significantly. Thus, the bead is flattened although not completely.
On-Line Roundness Error Compensation via P-Integrator Learning Control
Authors: Li C. J. , Li S. Y.
Published: August 2010

The work described is the result of a research project for developing a roundness error compensation scheme in turning processes based on the p-integrator learning controller and an on-line metrology system. The objective is to eliminate the repeatable error in turning operations. The scheme was realized on a CNC lathe. The effectiveness of the scheme is supported by the experimental results obtained through workpiece inspections.
Three Dimensional Printing: Rapid Tooling and Prototypes Directly from a CAD Model
Authors: Sachs E. , Cima M. , Williams P. , Brancazio D. , Cornie J.
Published: August 2010

Three Dimensional Printing is a process for the manufacture of tooling and functional prototype parts directly from computer models. Three Dimensional Printing functions by the deposition of powdered material in layers and the selective binding of the powder by “ink-jet” printing of a binder material. Following the sequential application of layers, the unbound power is removed, resulting in a complex three-dimensional part. The process may be applied to the production of metal, ceramic, and metal-ceramic composite parts. An experiment employing continuous-jet ink-jet printing technology has produced a three-dimensional ceramic part constructed of 50 layers, each 0.005 in. thick. The powder is alumina and the binder is colloidal silica. The minimum feature size is 0.017 in., and features intended to be 0.5000 in. apart average 0.4997 in. apart in the green state and 0.5012 in. apart in the cured state, with standard deviations of 0.0005 in. and 0.0018 in., respectively. Future research will be directed toward the direct fabrication of cores and shells for metal casting, and toward the fabrication of porous ceramic preforms for metal-ceramic composite parts.
Modelling and Optimization of the NO Formation in an Industrial Glass Furnace
Authors: Carvalho M. G. , Semia˜o V. S. , Coelho P. J.
Published: August 2010

The effects of combustion excess-air level, air preheating, and fuel composition on the nitric oxide emissions from an industrial glass furnace are studied through the use of a mathematical model. The mathematical model is based on the solution of the time-averaged form of the governing conservation equations for mass, momentum, energy, and chemical species. The k-ε turbulence model is employed for modelling the turbulence fluxes. The flame is modelled as a turbulent diffusion one and the chemical reactions associated with the heat release are assumed to be fast. The fluctuations of scalar properties are accounted for by use of a clipped-Gaussian probability density function. The thermal radiation, playing the dominant role in the heat-transfer process, is modelled using the discrete transfer method. Because of the high temperatures at which industrial glass furnaces operate a considerable amount of thermal NO is formed. The present work presents a model, based on a chemical kinetic approach, to predict the nitric oxide emissions from industrial glass furnaces. The Zeldovich mechanism, retaining the reverse reactions, is incorporated in the model in order to predict the instantaneous NO net formation rate from atmospheric nitrogen. The whole procedure is applied to a cross-fired regenerative furnace. A set of parametric studies is carried out, demonstrating the ability of the model to evaluate the influence of changes in operating conditions on the NO emissions.
Coupled for Cross-Presentation in Tumor Immunotherapy
Authors: Pang Baoxu , Neefjes Jacques
Published: August 2010

Bacterial infection–induced gap junctions in melanoma cells shuttle tumor antigens to immune cells and spur a successful antitumor immune response.
Rebuilding Broken Bones with Bioactive Ceramics
Authors: Ng Kenneth W.
Published: August 2010

Novel bioactive ceramics may allow orthopedic trauma surgeons to better repair shattered bones.
The Combination of Rifampin plus Moxifloxacin Is Synergistic for Suppression of Resistance but Antagonistic for Cell Kill ofMycobacterium tuberculosisas Determined in a Hollow-Fiber Infection Model
Authors: Drusano G. L. , Sgambati Nicole , Eichas Adam , Brown David L. , Kulawy Robert , Louie Arnold
Published: August 2010

Moxifloxacin is under development for expanded use againstMycobacterium tuberculosis. Rifampin is a mainstay of therapy. We examined the interaction of moxifloxacin plus rifampin for log-phase and nonreplicating persister (NRP) organisms. For this evaluation, we employed our hollow-fiber infection model, in which organisms are exposed to clinically relevant drug concentration-time profiles and the impact on bacterial cell kill and resistant subpopulation amplification is determined. In log phase, resistance emergence was observed in all monotherapy regimens and in no combination therapy regimen. No difference was seen in time to a 3-log reduction in the bacterial burden; there was a significant difference in time to resistance emergence (P= 0.0006). In the NRP experiment, no resistance emergence was seen. There was a significant difference between the monotherapy and combination therapy regimens in time to a 3-log reduction in the bacterial burden (P= 0.042). The combination is efficacious for suppressing resistant organisms but is antagonistic for cell kill.

IMPORTANCEM. tuberculosisinfects one-third of the world’s population. Multiresistant organisms have become more frequent, threatening our ability to provide adequate chemotherapy. Moxifloxacin has been seen as an important new agent with the potential to supplant isoniazid or add to the rifampin/isoniazid combination.M. tuberculosisalso exists in different physiological states, including the NRP phenotype. We examined the moxifloxacin/rifampin combination in a newin vitrosystem to allow judgment of how moxifloxacin would interact with rifampin and allow its performance in clinical trials to be placed into perspective. Importantly, the combination suppressed resistance emergence, but at the price of slightly slowing bacterial cell kill. This new combination is a welcome addition to the physician’s armamentarium.
Programmed cell death 4 (PDCD4) expression during multistep Barrett's carcinogenesis
Authors: Fassan Matteo , Pizzi Marco , Battaglia Giorgio , Giacomelli Luciano , Parente Paola , Bocus Paolo , Ancona Ermanno , Rugge Massimo
Published: August 2010

Aim

To test the contribution of programmed cell death 4 (PDCD4) tumour suppressor gene in Barrett's carcinogenesis.

Methods

PDCD4 immunohistochemical expression was assessed in 88 biopsy samples obtained from histologically proven long-segment Barrett's mucosa (BM; 25 non-intestinal columnar metaplasia, 25 intestinal metaplasia (IM), 16 low-grade intraepithelial neoplasia (LG-IEN), 12 high-grade IEN (HG-IEN) and 10 Barrett's adenocarcinoma (BAc)). As controls, 25 additional samples of native oesophageal mucosa (N) were obtained from patients with dyspepsia. To further support the data, the expression levels of miR-21, an importantPDCD4expression regulator, in 14 N, 5 HG-IEN and 11 BAc samples were determined by quantitative real-time PCR analysis.

Results

PDCD4 immunostaining decreased progressively and significantly with the progression of the phenotypic changes occurring during Barrett's carcinogenesis (p<0.001). Normal basal squamous epithelial layers featured strong PDCD4 nuclear immunoreaction (mostly coexisting with weak–moderate cytoplasmic staining). Non-intestinal columnar metaplasia and intestinal metaplasia preserved a strong nuclear immunostaining; conversely, a significant decrease in PDCD4 nuclear expression was seen in dysplastic (LG-IEN and HG-IEN) and neoplastic lesions. Weak–moderate cytoplasmic immunostaining was evident in cases of LG-IEN, while HG-IEN and BAc samples showed weak cytoplasmic or no protein expression. As expected, miR-21 expression was significantly upregulated in HG-IEN and BAc samples, consistently withPDCD4dysregulation.

Conclusions

These data support a significant role forPDCD4downregulation in the progression of BM to BAc, and confirm miR-21 as a negative regulator ofPDCD4in vivo. Further efforts are needed to validatePDCD4as a potential prognostic marker in patients with Barrett's oesophagus.
SCALAR CURVATURE OF HYPERSURFACES WITH CONSTANT MEAN CURVATURE IN UNIT SPHERES
Authors: CHEN GANGYI , LI HAIZHONG
Published: August 2010

Let M be an n-dimensional closed hypersurface with constant mean curvature H in a unit sphere Sn+1, n ≤ 8, and S the squared length of the second fundamental form of M. If |H| ≤ ε(n), then there exists a positive constant α(n, H), which depends only on n and H, such that if S0 ≤ S ≤ S0 + α(n, H), then S ≡ S0 and M is isometric to a Clifford hypersurface, where ε(n) is a positive constant depending only on n and [Formula: see text].
MAGNETIC INTERACTIONS IN FERROMAGNET-ENCAPSULATED POLYANILINE NANOTUBES
Authors: FRIEDMAN ADAM L. , BRITTAIN DERRICK , MENON LATIKA
Published: August 2010

We demonstrate Co , Fe , and Ni encapsulated polyaniline (PAni) nanotubes using a three-step anodization and electrodeposition process. The electrodeposition process is used to create the tubes, as well as the wires, in a highly reliable manner. The metal-filled PAni structures embedded inside nanoporous alumina templates are fabricated in the form of an array. The magnetic properties of these structures are investigated as a function of temperature. These results are compared with the magnetic properties of nanowires embedded inside nanoporous alumina templates.
STABILITY AND SIZE EFFECT ANALYSIS OF THIN MAGNESIUM NANOWIRES
Authors: KUMAR SANJEEV , SRIVASTAVA PANKAJ
Published: August 2010

The stability and size effect analysis of different isomeric structures of Mg n(n = 1–5) nanowires have been investigated by employing ab-initio approach. We have considered various geometrical structures up to five atoms to explore the minimum energy configuration. In the present study, we have calculated various physical properties in large energy interval for all structures. In particular, we have analyzed the effect of shape and size on these calculated values and investigated density of states (DOS) in four different ways to see the microscopic changes in their nature of peaks. We predict that five atom tetrahedral structure is stable having highest binding energy and DOS. The band structure calculations of all wires reflect the possibility of sufficient number of channels for quantum conduction and are metallic in character. In addition, we have also analyzed the effect of hydrogen adsorption on most stabilized geometrical structure of magnesium ( Mg ) nanowire which shows no evidence of better stability in comparison to pure Mg nanowires.
FULL ANALYSIS OF AN ALL-OPTICAL PHOTONIC CRYSTAL SWITCH
Authors: LIMA A. WIRTH , SOMBRA A. S. B.
Published: August 2010

We analyze and propose an all-optical switch working over the C-band of the International Telecommunication Union (ITU), which is based on nonlinear switching cells made of photonic crystal (PhC). Indeed, the nonlinear switching cells are directional couplers (DCs) embedded in PhC, which can work over the C-band of the ITU (wavelength from 1530 to 1565 nm). The nonlinear switching method uses a relatively low-power external command signal for obtaining nonlinear effects. This external command signal is inserted in the central coupling region of the DC, which acts as another waveguide. The switching process is based on the change from the cross state to the bar state owing to the external command signal. In our simulations we used the plane-wave expansion (PWE), finite-difference time-domain (FDTD), and our own binary propagation method (BiPM).
Typing linear constraints
Authors: Ruggieri Salvatore , Mesnard Fred
Published: August 2010

We present a type system for linear constraints over the reals intended for reasoning about the input-output directionality of variables. Types model the properties of definiteness, range width or approximation, lower and upper bounds of variables in a linear constraint. Several proof procedures are presented for inferring the type of a variable and for checking validity of type assertions. We rely on theory and tools for linear programming problems, linear algebra, parameterized polyhedra and negative constraints. An application of the type system is proposed in the context of the static analysis of constraint logic programs. Type assertions are at the basis of the extension of well-moding from pure logic programming. The proof procedures (both for type assertion validity and for well-moding) are implemented and their computational complexity is discussed. We report experimental results demonstrating the efficiency in practice of the proposed approach.
e-Learning Helps Women Survive Eclampsia
Authors: Little Bob
Published: August 2010

Between 300,000 and 500,000 women die each year from problems related to pregnancy. Ninety-nine percent of these deaths, which are often preventable, occur in developing countries. One of the leading causes of maternal death in the developing world is pre-eclampsia, a pregnancy condition that is characterized by high blood pressure and protein in the urine. In an effort to drastically reduce cases of pre-eclampsia, Italy-based Giunti Labs is helping the Nuffield Department of Obstetrics & Gynaecology and the Oxford Maternal & Perinatal Health Institute (Green Templeton College) at the University of Oxford in the U.K. develop educational material on maternal health for midwives, nurses, and doctors in developing countries, notably India, Mexico, and Nigeria. The material, delivered via e-learning, focuses on pre-eclampsia.
Injecting Errors for Fun and Profit
Authors: Chessin Steve
Published: August 2010

It is an unfortunate fact of life that anything with moving parts eventually wears out and malfunctions, and electronic circuitry is no exception. In this case, of course, the moving parts are electrons. In addition to the wear-out mechanisms of electromigration (the moving electrons gradually push the metal atoms out of position, causing wires to thin, thus increasing their resistance and eventually producing open circuits) and dendritic growth (the voltage difference between adjacent wires causes the displaced metal atoms to migrate toward each other, just as magnets will attract each other, eventually causing shorts), electronic circuits are also vulnerable to background radiation. These fast-moving charged particles knock electrons out of their orbits, leaving ionized trails in their wake. Until those electrons find their way back home, a conductive path exists where there once was none.
Related organizations
Authors: Halavais Alexander
Published: August 2010

This is a new Computers & Society feature, in which we provide reports and descriptions about professional and advocacy organizations that have goals in common with SIGCAS. If you are a member of an organization that fits this description, or know individuals or colleagues who are members of different groups, please consider contributing a piece to this section.
Computers in developing nations
Authors: Dickson-Deane Camille
Published: August 2010

In 1976, Edward L. Robertson was part of a panel that discussed the overarching topic of Computers in Developing Nations. At the time, computers were slowly being introduced into mainstream society and thoughts of access or even use was the focus of many discussions. Today, not only has computers and its associated technology evolved but so too has the descriptor "developing nations". Since 1976, computers have moved from being desktops, to being portable and hand-held, thus becoming extremely accessible to the general public. In the same vein, the classification of a country's development has since been modified to include another category --- the emerging market. This newly defined category delineates nations that have rapidly growing societies or business markets from those that are still slowly growing. The participants' contributing to this article are all from countries that are identified by the International Monetary Fund (IMF) as being either an emerging market or a developing country. Another Non-Governmental Organization (NGO), the World Bank only recognizes Oman as being a developed country. To follow the [previous] panels' discussion on the importance of computers in developing nations some questions were revisited and new ones were introduced to provide an up-to-date view of computers as seen by specific countries.
Revisiting Moor's
Towards a Theory of Privacy in the Information Age
Authors: Appel Florence
Published: August 2010

Back in 1988, when my department chair encouraged me to pursue my interest in developing a course on the social and ethical impact of computing, I was thrilled at the prospect but had no idea how difficult it would be to find resources to support my teaching. I did some pre-Web digging and found two organizations that delivered on their promises to provide me with valuable sources of material: ACM SIGCAS (ACM's Special Interest Group for Computers and Society, and the publisher of this newsletter) and CPSR (Computer Professionals for Social Responsibility). I quickly joined each group, subscribed to each one's publications, and the rest, as they say, is history. Over the past twenty years, I have enjoyed a rich and rewarding career in the area of computer ethics and its pedagogy, and have benefited professionally and personally through my affiliation with a vibrant interdisciplinary community of computer ethics scholars. I am happy to report that Computers and Society continues to provide my students with thought-provoking material, and is now part of a large and growing body of literature.
Hypothesis Testing in Econometrics
Authors: Romano Joseph P. , Shaikh Azeem M. , Wolf Michael
Published: August 2010

This article reviews important concepts and methods that are useful for hypothesis testing. First, we discuss the Neyman-Pearson framework. Various approaches to optimality are presented, including finite-sample and large-sample optimality. Then, we summarize some of the most important methods, as well as resampling methodology, which is useful to set critical values. Finally, we consider the problem of multiple testing, which has witnessed a burgeoning literature in recent years. Along the way, we incorporate some examples that are current in the econometrics literature. While many problems with well-known successful solutions are included, we also address open problems that are not easily handled with current technology, stemming from such issues as lack of optimality or poor asymptotic approximations.
Models of Growth and Firm Heterogeneity
Authors: Luttmer Erzo G.J.
Published: August 2010

Although employment at individual firms tends to be highly nonstationary, the employment size distribution of all firms in the United States appears to be stationary. It closely resembles a Pareto distribution. There is a lot of entry and exit, mostly of small firms. This review surveys general equilibrium models that can be used to interpret these facts and explores the role of innovation by new and incumbent firms in determining aggregate growth. The existence of a balanced growth path with a stationary employment size distribution depends crucially on assumptions made about the cost of entry. Some type of labor must be an essential input in setting up new firms.
The Changing Nature of Financial Intermediation and the Financial Crisis of 2007–2009
Authors: Adrian Tobias , Shin Hyun Song
Published: August 2010

The current financial crisis has highlighted the changing role of financial institutions and the growing importance of the shadow banking system, which grew on the back of the securitization of assets and the integration of banking with capital market developments. This trend has been most pronounced in the United States but has had a profound influence on the global financial system as a whole. In a market-based financial system, banking and capital market developments are inseparable, and funding conditions are closely tied to the fluctuations in leverage of market-based financial intermediaries. Balance-sheet growth of market-based financial intermediaries provides a window on liquidity in the sense of the availability of credit, whereas financial crises tend to be associated with contractions of balance sheets. We describe the changing nature of financial intermediation in the market-based financial system, chart the course of the recent financial crisis, and outline the policy responses that have been implemented by the Federal Reserve and other central banks to counter it.
Microeconomics of Technology Adoption
Authors: Foster Andrew D. , Rosenzweig Mark R.
Published: August 2010

Differences in technology levels across countries account for a large component of the differences in wages and per-capita GDP across countries worldwide. This article reviews micro studies of the adoption of new technologies and the use of inputs complementary with new technologies to shed light on the barriers to technology diffusion in low-income countries. Among the factors examined affecting decisions pertaining to technology choice and input allocations are the financial and nonfinancial returns to adoption, one's own learning and social learning, technological externalities, scale economies, schooling, credit constraints, risk and incomplete insurance, and departures from behavioral rules implied by simple models of rationality.
Health, Human Capital, and Development
Authors: Bleakley Hoyt
Published: August 2010

How much does disease depress development in human capital and income around the world? I discuss a range of micro evidence, which finds that health is both human capital itself and an input to producing other forms of human capital. I use a standard model to integrate these results and suggest a reinterpretation of much of the micro literature. I then discuss the aggregate implications of micro estimates but note the complications in extrapolating to general equilibrium, especially because of health's effect on population size. I also review the macro evidence on this topic, which consists of either cross-country comparisons or measuring responses to health shocks. Micro estimates are one to two orders of magnitude smaller than the cross-country relationship but nevertheless imply high benefit-to-cost ratios from improving certain forms of health.
Dynamics of a Birth‐Pulse Single‐Species Model with Restricted Toxin Input and Pulse Harvesting
Authors: Ma Yi , Liu Bing , Feng Wei
Published: August 2010

We consider a birth‐pulses single‐species model with restricted toxin input and pulse harvesting in a polluted environment. Pollution accumulates as a slowly decaying stock and is assumed to affect the growth of the renewable resource population. Firstly, by using the discrete dynamical system determined by the stroboscopic map, we obtain an exact 1‐period solution of system whose birth function is Ricker function or Beverton‐Holt function and obtain the threshold conditions for their stability. Furthermore, we show that the timing of harvesting has a strong impact on the maximum annual sustainable yield. The best timing of harvesting is immediately after the birth pulses. Finally, we investigate the effect of the amount of toxin input on the stable resource population size. We find that when the birth rate is comparatively lower, the population size is decreasing with the increase of toxin input; that when the birth rate is high, the population size may begin to rise and then drop with the increase of toxin input.
Numerical Exploration of Kaldorian Interregional Macrodynamics: Enhanced Stability and Predominance of Period Doubling under Flexible Exchange Rates
Authors: Asada Toichiro , Douskos Christos , Kalantonis Vassilis , Markellos Panagiotis
Published: August 2010

We present a discrete two‐regional Kaldorian macrodynamic model with flexible exchange rates and explore numerically the stability of equilibrium and the possibility of generation of business cycles. We use a grid search method in two‐dimensional parameter subspaces, and coefficient criteria for the flip and Hopf bifurcation curves, to determine the stability region and its boundary curves in several parameter ranges. The model is characterized by enhanced stability of equilibrium, while its predominant asymptotic behavior when equilibrium is unstable is period doubling. Cycles are scarce and short‐lived in parameter space, occurring at large values of the degree of capital movement β. By contrast to the corresponding fixed exchange rates system, for cycles to occur sufficient amount of trade is required together with high levels of capital movement. Rapid changes in exchange rate expectations and decreased government expenditure are factors contributing to the creation of interregional cycles. Examples of bifurcation and Lyapunov exponent diagrams illustrating period doubling or cycles, and their development into chaotic attractors, are given. The paper illustrates the feasibility and effectiveness of the numerical approach for dynamical systems of moderately high dimensionality and several parameters.
Emerging Spatiotemporal Patterns from Discrete Migration Dynamics of Heterogeneous Agents
Authors: Shin J. K. , Mansury Yuri
Published: August 2010

We propose a discrete agent‐based model to investigate the migration dynamics of heterogeneous individuals. Compatibility among agents of different types is expressed in terms of homophily parameters capturing the extent to which similar individuals are attracted to, or dissimilar individuals are repelled by, each other. Based on agent‐based simulations, we establish the connection between emerging spatiotemporal patterns and the homophily parameters. Key results are presented in a novel phase diagram, which reveals a wide range of spatial patterns including the cell, worm, herd, amoeba, and swarm modes under the dynamic regime and the separation, ghetto, and integration modes under the stationary one. Our model thus provides a generalized framework encompassing both static equilibrium and nonstationary systems to investigate the impact of agent heterogeneity on population dynamics. We demonstrate potential applications of our model to social systems using sexual segregation of ungulate habitats as a case study.
Ferroportin and Erythroid Cells: An Update
Authors: Cianetti Luciano , Gabbianelli Marco , Sposi Nadia Maria
Published: August 2010

In recent years there have been major advances in our knowledge of the regulation of iron metabolism that have had implications for understanding the pathophysiology of some human disorders like beta-thalassemia and other iron overload diseases. However, little is known about the relationship among ineffective erythropoiesis, the role of iron-regulatory genes, and tissue iron distribution in beta-thalassemia. The principal aim of this paper is an update about the role of Ferroportin during human normal and pathological erythroid differentiation. Particular attention will be given to beta-thalassemia and other diseases with iron overload. Recent discoveries indicate that there is a potential for therapeutic intervention in beta-thalassemia by means of manipulating iron metabolism.
Large Solutions for Semilinear Parabolic Equations Involving Some Special Classes of Nonlinearities
Authors: Niculescu Constantin P. , Rovenţa Ionel
Published: August 2010

We consider a new class of nonlinearities for which a nonlocal parabolic equation with Neumann boundary conditions has finite time blow‐up solutions. Our approach is inspired by previous work done by Jazar and Kiwan (2008) and El Soufi et al. (2007).
Multiple Attractors and Nonlinear Dynamics in an Overlapping Generations Model with Environment
Authors: Naimzada Ahmad , Sodini Mauro
Published: August 2010

This paper develops a one‐sector productive overlapping generations model with environment where a CES technology is assumed. Relying
on numerical and geometrical approaches, various dynamic properties of the proposed model are explored: the existence of the phenomenon of multistability or the coexistence of different attractors was demonstrated. Finally, we describe a nontypical global bifurcation which determines the appearance of an attracting cycle.
Levosimendan as Treatment Option in Severe Verapamil Intoxication: A Case Report and Review of the Literature
Authors: Osthoff Mirjam , Bernsmeier Christine , Marsch Stephan C. , Hunziker Patrick R.
Published: August 2010

Cardiovascular shock due to verapamil intoxication is often refractory to standard resuscitation methods. Recommended therapy includes prevention of further absorption of the drug, inotropic therapy, calcium gluconate, and hyperinsulinemia/euglycemia therapy. Often further measures are needed such as ventricular pacing or mechanical circulatory support. Still, mortality remains high. Levosimendan, an inotropic agent, that enhances myofilament response to calcium, increases myocardial contraction and could therefore be beneficial in verapamil intoxication. Here, we report the case of a 60-year-old patient with clinically severe verapamil poisoning who presented with shock, bradycardia, and sopor. Standard therapy including high-dose inotropes failed to ameliorate the signs of intoxication. But additional therapy with levosimendan led to rapid improvement. Based on this observation, the literature is reviewed focusing on utilization of levosimendan in the treatment of calcium channel blocker overdose. We suggest to consider levosimendan as additional treatment option in patients with cardiovascular shock due to verapamil intoxication that are refractory to standard management.
From Melanocyte to Metastatic Malignant Melanoma
Authors: Bandarchi Bizhan , Ma Linglei , Navab Roya , Seth Arun , Rasty Golnar
Published: August 2010

Malignant melanoma is one of the most aggressive malignancies in human and is responsible for almost 60% of lethal skin tumors. Its incidence has been increasing in white population in the past two decades. There is a complex interaction of environmental (exogenous) and endogenous, including genetic, risk factors in developing malignant melanoma. 8–12% of familial melanomas occur in a familial setting related to mutation of the CDKN2A gene that encodes p16. The aim of this is to briefly review the microanatomy and physiology of the melanocytes, epidemiology, risk factors, clinical presentation, historical classification and histopathology and, more in details, the most recent discoveries in biology and genetics of malignant melanoma. At the end, the final version of 2009 AJCC malignant melanoma staging and classification is presented.
Physician-Controlled Wire-Guided Cannulation of the Minor Papilla
Authors: Maple John T. , Mansour Lilah , Ammar Tarek , Ansstas Michael , Coté Gregory A. , Azar Riad R.
Published: August 2010

Background. Minor papilla (MiP) cannulation is frequently performed using specialized small-caliber accessories. Outcomes data for MiP cannulation with standard-sized accessories are lacking.
Methods. This is a case series describing MiP cannulation outcomes in consecutive patients treated by two endoscopists between July 2005 and November 2008 at two tertiary referral centers. MiP cannulation was attempted using a 4.4 Fr tip sphincterotome loaded with a , 260 cm hydrophilic-tip guidewire, using a wire-guided technique under physician control.
Results. 25 patients were identified (14 women, mean age 45). Procedure indications included recurrent acute pancreatitis in 16 patients (64%) and chronic pancreatitis in 2 (8%), among other indications. MiP cannulation was successful in 24 patients (96%). Sphincterotomy followed by pancreatic stent placement was performed in 21 patients (84%). Mild post-ERCP pancreatitis occurred in 3 patients (12%).
Conclusion. Physician-controlled wire-guided MiP cannulation using a 4.4 Fr sphincterotome and guidewire is an effective and safe technique.