bluuebunny/crossref_metadata_2025 huggingface dataset:
Bioseparation of Four Proteins fromEuphorbia characiasLatex: Amine Oxidase, Peroxidase, Nucleotide Pyrophosphatase/Phosphodiesterase, and Purple Acid Phosphatase
Authors: Medda Rosaria , Pintus Francesca , Spanò Delia , Floris Giovanni
Published: October 2011

This paper deals with the purification of four proteins fromEuphorbia characiaslatex, a copper amine oxidase, a nucleotide pyrophosphatase/phosphodiesterase, a peroxidase, and a purple acid phosphatase. These proteins, very different in molecular weight, in primary structure, and in the catalyzed reaction, are purified using identical preliminary steps of purification and by chromatographic methods. In particular, the DEAE-cellulose chromatography is used as a useful purification step for all the four enzymes. The purification methods here reported allow to obtain a high purification of all the four proteins with a good yield. This paper will give some thorough suggestions for researchers busy in separation of macromolecules from different sources.
Composite Holomorphic Functions and Normal Families
Authors: Bing Xiao , Qifeng Wu , Wenjun Yuan
Published: October 2011

We study the normality of families of holomorphic functions. We prove the following result. Let α(z),   ai(z),   i = 1,2, …, p, be holomorphic functions and ℱ a family of holomorphic functions in a domain D, P(z, w): = (w − a1(z))(w − a2(z))⋯(w − ap(z)),   p ≥ 2. If Pw∘f(z) and Pw∘g(z) share α(z) IM for each pair f(z),   g(z) ∈ ℱ and one of the following conditions holds: (1) P(z0, z) − α(z0) has at least two distinct zeros for any z0 ∈ D; (2) there exists z0 ∈ D such that P(z0, z) − α(z0) has only one distinct zero and α(z) is nonconstant. Assume that β0 is the zero of P(z0, z) − α(z0) and that the multiplicities l and k of zeros of f(z) − β0 and α(z) − α(z0) at z0, respectively, satisfy k ≠ lp, for all f(z) ∈ ℱ, then ℱ is normal in D. In particular, the result is a kind of generalization of the famous Montel′s criterion. At the same time we fill a gap in the proof of Theorem 1.1 in our original paper (Wu et al., 2010).
On the Dynamics of a Higher‐Order Rational Difference Equation
Authors: Ahmed A. M.
Published: October 2011

The aim of this paper is to investigate the global asymptotic stability and the periodic character for the rational difference equation , where the parameters α, β, γ, pl, pl+1, …, pk are nonnegative real numbers, and l, k are nonnegative integers such that l ≤ k.
Random Attractors for the Stochastic Discrete Long Wave‐Short Wave Resonance Equations
Authors: Xin Jie , Lu Hong
Published: October 2011

We prove the existence of the random attractor for the stochastic discrete long wave‐short wave resonance equations in an infinite lattice. We prove the asymptotic compactness of the random dynamical system and obtain the random attractor.
A LabVIEW-Based Virtual Instrument System for Laser-Induced Fluorescence Spectroscopy
Authors: Wu Qijun , Wang Lufei , Zu Lily
Published: October 2011

We report the design and operation of a Virtual Instrument (VI) system based on LabVIEW 2009 for laser-induced fluorescence experiments. This system achieves synchronous control of equipment and acquisition of real-time fluorescence data communicating with a single computer via GPIB, USB, RS232, and parallel ports. The reported VI system can also accomplish data display, saving, and analysis, and printing the results. The VI system performs sequences of operations automatically, and this system has been successfully applied to obtain the excitation and dispersion spectra ofα-methylnaphthalene. The reported VI system opens up new possibilities for researchers and increases the efficiency and precision of experiments. The design and operation of the VI system are described in detail in this paper, and the advantages that this system can provide are highlighted.
Studies on the ns-IR-Laser-Induced Plasma Parameters in the Vanadium Oxide
Authors: Sarkar Arnab , Shah Raju V. , Alamelu D. , Aggarwal Suresh K.
Published: October 2011

We report spectroscopic studies of laser-induced plasma (LIP) produced by ns-IR-Nd:YAG laser light pulses of different energies onto four different oxides of vanadium (VO, V2O3, VO2, and V2O5) in air under atmospheric pressure. For each oxide with a different oxidation state of vanadium, both electron density and plasma temperature were calculated for different time delays and laser pulse energies. The plasma temperature was determined from Boltzmann plot method, whereas the electron number density was estimated from the Saha equation. The decay rates for plasma temperature as well as electron density were observed to follow power law and were independent of the nature of vanadium oxide. These investigations provide an insight to optimize various parameters during LIBS analysis of vanadium-based matrices.
The Role of Synthetic Biology in the Design of Microbial Cell Factories for Biofuel Production
Authors: Colin Verónica Leticia , Rodríguez Analía , Cristóbal Héctor Antonio
Published: October 2011

Insecurity in the supply of fossil fuels, volatile fuel prices, and major concerns regarding climate change have sparked renewed interest in the production of fuels from renewable resources. Because of this, the use of biodiesel has grown dramatically during the last few years and is expected to increase even further in the future. Biodiesel production through the use of microbial systems has marked a turning point in the field of biofuels since it is emerging as an attractive alternative to conventional technology. Recent progress in synthetic biology has accelerated the ability to analyze, construct, and/or redesign microbial metabolic pathways with unprecedented precision, in order to permit biofuel production that is amenable to industrial applications. The review presented here focuses specifically on the role of synthetic biology in the design of microbial cell factories for efficient production of biodiesel.
Atrioventricular Cross-Talk Leading to Ventricular Pacing Inhibition in a Dual-Chamber ICD
Authors: Debie Luuk , Broers Bernard , van Opstal Jurren , van Gelder Berry M.
Published: October 2011

We report atrio-ventricular cross talk in a patient with a dual chamber ICD leading to ventricular pacing inhibition. This was observed in an ICD without the ventricular safety pace option, which normally is a sufficient protection against this phenomenon. Cross talk could be prevented effectively by reprogramming ventricular sensitivity to a less sensitive setting.
Achieving Closed‐Loop Control Simulation of Human‐Artefact Interaction: A Comparative Review
Authors: van der Vegte Wilhelm Frederik , Horváth Imre
Published: October 2011

To include user interactions in simulations of product use, the most common approach is to couple human subjects to simulation models, using hardware interfaces to close the simulation‐control loop. Testing with virtual human models could offer a low‐cost addition to evaluation with human subjects. This paper explores the possibilities for coupling human and artefact models to achieve fully software‐based interaction simulations. We have critically reviewed existing partial solutions to simulate or execute control (both human control and product‐embedded control) and compared solutions from literature with a proof‐of‐concept we have recently developed. Our concept closes all loops, but it does not rely on validated algorithms to predict human decision making and low‐level human motor control. For low‐level control, validated solutions are available from other approaches. For human decision making, however, validated algorithms exist only to predict the timing but not the reasoning behind it. To identify decision‐making schemes beyond what designers can conjecture, testing with human subjects remains indispensable.
An Intelligent Information Retrieval Approach Based on Two Degrees of Uncertainty Fuzzy Ontology
Authors: Hourali Maryam , Montazer Gholam Ali
Published: October 2011

In spite of the voluminous studies in the field of intelligent retrieval systems, effective retrieving of information has been remained an important unsolved problem. Implementations of different conceptual knowledge in the information retrieval process such as ontology have been considered as a solution to enhance the quality of results. Furthermore, the conceptual formalism supported by typical ontology may not be sufficient to represent uncertainty information due to the lack of clear-cut boundaries between concepts of the domains. To tackle this type of problems, one possible solution is to insert fuzzy logic into ontology construction process. In this article, a novel approach for fuzzy ontology generation with two uncertainty degrees is proposed. Hence, by implementing linguistic variables, uncertainty level in domain's concepts (Software Maintenance Engineering (SME) domain) has been modeled, and ontology relations have been modeled by fuzzy theory consequently. Then, we combined these uncertain models and proposed a new ontology with two degrees of uncertainty both in concept expression and relation expression. The generated fuzzy ontology was implemented for expansion of initial user's queries in SME domain. Experimental results showed that the proposed model has better overall retrieval performance comparing to keyword-based or crisp ontology-based retrieval systems.
Basidiobolomycosis of the Colon Masquerading as Stenotic Colon Cancer
Authors: Rabie M. Ezzedien , El Hakeem Ismail , Al-Shraim Mubarak , Al Skini M. Saad , Jamil Salim
Published: October 2011

Basidiobolus ranarumis a widespread saprophyte fungus with pathogenic potential. It affects mainly the subcutaneous tissues of the trunk and limbs. Relatively recently, occasional reports of gastrointestinal basidiobolomycosis appeared in the literature. Due to the rarity of the condition and the nonspecific presenting features, the correct diagnosis is usually hard to reach. In this paper, we describe the clinical course of an otherwise healthy female, who presented with a colonic mass. She received subtotal colectomy followed by oral itraconazole, with successful outcome.
Investigating a Case of Recurrent Pleural Effusion
Authors: Rodrigues Patrícia , Neves Maria , Ferreira João Pedro , Abreu Miguel Araújo , Almeida Fernanda
Published: October 2011

We describe the case of a patient with long-standing Parkinson's disease and recurrent bilateral pleural effusions. The pleural fluid was an exudate, rich in normal lymphocytes, and the echocardiogram, chest computerized axial tomography, and immunological, microbiological and cytological studies were negative. The patient had been taking bromocriptine, which can be related to chronic pleural effusions. Using Pubmed, we found about 40 cases of pleuropulmonary changes or constrictive pericarditis that were related to bromocriptine. We decided to suspend this drug, with resolution of the pleural effusion and respiratory complaints for more than a year now. We discuss possible underlining mechanisms for this and emphasize the importance of collecting the past medical history and medication and of considering possible iatrogenic effects.
Biomechanical Study of the Pullout Resistance in Screws of a Vertebral Fixation System
Authors: Fakhouri Sarah F. , Zamarioli Ariane , Wichr Célia R. G. , Araujo Cleudmar A. , Defino Helton L. A. , Shimano Antônio C.
Published: October 2011

The purpose of this study was to investigate the effect of varying the outer diameter of screws of a vertebral fixation system by submitting them to mechanical tests and photoelasticity. The pullout mechanical test was performed in 20 swine lumbar vertebrae, divided into two groups based on the screw outer diameter: 5.0 and 6.0 mm. The maximal pullout strengths and stiffness were evaluated. For the photoelasticity, eight models were used and divided into the same groups. The maximal pullout strength was 974.12 ± 144.44 N in the 5.0 mm screws and 1537.42 ± 326.95 N in the 6.0 mm screws ( P ┼ 0.001). The stiffness was 418.60 ± 62.58 103N/m in the 5.0 mm screws and 502.12 ± 133.45 103N/m in the 6.0 mm screws ( P = 0.09). The mean ± SD shear stress of the 5.0 mm screws was 12.90 ± 1.87 KPa and 11.99 ± 2.01 KPa for the 6.0 mm screws. Thus, the 5.0 mm screw had lower pullout and higher shear stress, suggesting that this screw is more susceptible to loosening.
Trees and the City: Diversity and Composition along a Neotropical Gradient of Urbanization
Authors: Ortega-Álvarez Rubén , Rodríguez-Correa Hernando A. , MacGregor-Fors Ian
Published: October 2011

In this study we assessed tree species richness, density, and composition patterns along a gradient of urbanization of a megacity. Our results show that total, native, and exotic tree densities were highest in green areas where larger spaces are considered for greening purposes. Conversely, total, native, and exotic tree species richness were highest in land uses with intermediate levels of urban development (residential, residential-commercial areas). Not finding highest tree species richness in less developed urban areas suggests that cultural factors may shape the array of species that are planted within cities. Supporting this, tree composition analyses showed that green areas are comprised of different tree species when compared to the rest of the studied urban land uses. Thus, our results suggest that, to increase the ecological quality of cities, residents and managers should be encouraged to select a greater variety of trees to promote heterogeneous green areas.
Mechanical Action of Inhomogeneously Polarized Optical Fields and Detection of the Internal Energy Flows
Authors: Bekshaev A. Ya. , Angelsky O. V. , Sviridova S. V. , Zenkova C. Yu.
Published: October 2011

We analyze numerically correspondence between the mechanical action, experienced by a spherical microparticle, and the internal energy flows in the light field incident on the particle. The inhomogeneous incident field is modelled by superposition of two plane waves; the mechanical action is calculated via the Mie theory for dielectric and conducting particles of different sizes and optical properties. It is shown that both spin and orbital components of the field momentum can produce the mechanical action whose value and sign depend on many additional details of the field-particle interaction. Besides, forces that are not associated with any sort of the energy flow (e.g., the gradient force owing to the inhomogeneous intensity and the polarization-dependent dipole force emerging due to inhomogeneous polarization) can strongly modify the observed mechanical action. The polarization-dependent mechanical action on particles can be treated as a form of the spin-orbit interaction of light.
Topological Conjugacy between Two Kinds of Nonlinear Differential Equations via Generalized Exponential Dichotomy
Authors: Chen Xiaodan , Xia Yonghui
Published: October 2011

Based on the notion of generalized exponential dichotomy, this paper considers the topological decoupling problem between two kinds of nonlinear differential equations. The topological equivalent function is given.
Nonparametric Estimation of ATE and QTE: An Application of Fractile Graphical Analysis
Authors: Montes-Rojas Gabriel V.
Published: October 2011

Nonparametric estimators for average and quantile treatment effects are constructed using Fractile Graphical Analysis, under the identifying assumption that selection to treatment is based on observable
characteristics. The proposed method has two steps: first, the propensity score is estimated, and, second, a blocking estimation procedure using this estimate is used to compute treatment effects. In both cases, the estimators are proved to be consistent. Monte Carlo results show a better performance than other procedures based on the propensity score. Finally, these estimators are applied to a job training dataset.
Th2 Regulation of Viral Myocarditis in Mice: Different Roles for TLR3 versus TRIF in Progression to Chronic Disease
Authors: Abston Eric D. , Coronado Michael J. , Bucek Adriana , Bedja Djahida , Shin Jaewook , Kim Joseph B. , Kim Eunyong , Gabrielson Kathleen L. , Georgakopoulos Dimitrios , Mitzner Wayne , Fairweather DeLisa
Published: October 2011

Viral infections are able to induce autoimmune inflammation in the heart. Here, we investigated the role of virus-activated Toll-like receptor (TLR)3 and its adaptor TRIF on the development of autoimmune coxsackievirus B3 (CVB3) myocarditis in mice. Although TLR3- or TRIF-deficient mice developed similarly worse acute CVB3 myocarditis and viral replication compared to control mice, disease was significantly worse in TRIF compared to TLR3-deficient mice. Interestingly, TLR3-deficient mice developed an interleukin (IL)-4-dominant T helper (Th)2 response during acute CVB3 myocarditis with elevated markers of alternative activation, while TRIF-deficient mice elevated the Th2-associated cytokine IL-33. Treatment of TLR3-deficient mice with recombinant IL-33 improved heart function indicating that elevated IL-33 in the context of a classic Th2-driven response protects against autoimmune heart disease. We show for the first time that TLR3 versus TRIF deficiency results in different Th2 responses that uniquely influence the progression to chronic myocarditis.
Analysis of Static Instability of an Asymmetric, Rotating Sand-Wich Beam
Authors: Dash P. R. , Ray K. , Sarangi S. K. , Pradhan P. K.
Published: October 2011

The static stability of an asymmetric, rotating sandwich beam subjected to an axial pulsating load has been investigated for pinned-pinned and fixed-free boundary conditions. The equations of motion and associated boundary conditions have been obtained by using the Hamilton's energy principle. Then, these equations of motion and the associated boundary conditions have been nondimensionalised. A set of Hill's equations are obtained from the nondimensional equations of motion by the application of the general Galerkin method. The static buckling loads have been obtained from Hill's equations. The influences of geometric parameters and rotation parameters on the nondimensional static buckling loads have been investigated.
Nuclear Transport: A Switch for the Oxidative Stress—Signaling Circuit?
Authors: Kodiha Mohamed , Stochaj Ursula
Published: October 2011

Imbalances in the formation and clearance of reactive oxygen species (ROS) can lead to oxidative stress and subsequent changes that affect all aspects of physiology. To limit and repair the damage generated by ROS, cells have developed a multitude of responses. A hallmark of these responses is the activation of signaling pathways that modulate the function of downstream targets in different cellular locations. To this end, critical steps of the stress response that occur in the nucleus and cytoplasm have to be coordinated, which makes the proper communication between both compartments mandatory. Here, we discuss the interdependence of ROS-mediated signaling and the transport of macromolecules across the nuclear envelope. We highlight examples of oxidant-dependent nuclear trafficking and describe the impact of oxidative stress on the transport apparatus. Our paper concludes by proposing a cellular circuit of ROS-induced signaling, nuclear transport and repair.
Exploring Multiple Potential Energy Surfaces: Photochemistry of Small Carbonyl Compounds
Authors: Maeda Satoshi , Ohno Koichi , Morokuma Keiji
Published: October 2011

In theoretical studies of chemical reactions involving multiple potential energy surfaces (PESs) such as photochemical reactions, seams of intersection among the PESs often complicate the analysis. In this paper, we review our recipe for exploring multiple PESs by using an automated reaction path search method which has previously been applied to single PESs. Although any such methods for single PESs can be employed in the recipe, the global reaction route mapping (GRRM) method was employed in this study. By combining GRRM with the proposed recipe, all critical regions, that is, transition states, conical intersections, intersection seams, and local minima, associated with multiple PESs, can be explored automatically. As illustrative examples, applications to photochemistry of formaldehyde and acetone are described. In these examples as well as in recent applications to other systems, the present approach led to discovery of many unexpected nonadiabatic pathways, by which some complicated experimental data have been explained very clearly.
Multiple-Pulse Operation and Bound States of Solitons in Passive Mode-Locked Fiber Lasers
Authors: Komarov A. , Amrani F. , Dmitriev A. , Komarov K. , Meshcheriakov D. , Sanchez F.
Published: October 2011

We present results of our research on a multiple-pulse operation of passive mode-locked fiber lasers. The research has been performed on basis of numerical simulation. Multihysteresis dependence of both an intracavity energy and peak intensities of intracavity ultrashort pulses on pump power is found. It is shown that the change of a number of ultrashort pulses in a laser cavity can be realized by hard as well as soft regimes of an excitation and an annihilation of new solitons. Bound steady states of interacting solitons are studied for various mechanisms of nonlinear losses shaping ultrashort pulses. Possibility of coding of information on basis of soliton trains with various bonds between neighboring pulses is discussed. The role of dispersive wave emitted by solitons because of lumped intracavity elements in a formation of powerful soliton wings is analyzed. It is found that such powerful wings result in large bounding energies of interacting solitons in steady states. Various problems of a soliton interaction in passive mode-locked fiber lasers are discussed.
Bernstein Widths of Some Classes of Functions Defined by a Self‐Adjoint Operator
Authors: Feng Guo
Published: October 2011

We consider the classes of periodic functions with formal self‐adjoint linear differential operators Wp(ℒr), which include the classical Sobolev class as its special case. Using the iterative method of Buslaev, with the help of the spectrum of linear differential equations, we determine the exact values of Bernstein width of the classes Wp(ℒr) in the space Lq for 1 < p ≤ q < ∞.
Self-Monitoring of Blood Pressure in Hypertension: A UK Primary Care Survey
Authors: Baral-Grant S. , Haque M. S. , Nouwen A. , Greenfield S. M. , McManus R. J.
Published: October 2011

This study aimed to determine the prevalence of Self-Monitoring Blood Pressure amongst people with hypertension using a cross-sectional survey. Of the 955 who replied (53%), 293 (31%) reported that they self-monitored blood pressure. Nearly 60% (198/331) self-monitored at least monthly. Diabetic patients monitoring their blood glucose were five times more likely than those not monitoring to monitor their blood pressure. Self-monitoring is less common in the UK than internationally, but is practiced by enough people to warrant greater integration into clinical practice.
Metabolic Syndrome and Triple-Negative Breast Cancer: A New Paradigm
Authors: Davis Andrew A. , Kaklamani Virginia G.
Published: October 2011

Triple-negative breast cancers (TNBCs) are aggressive tumors with poor prognosis compared to other breast cancer subtypes. The evidence linking TNBC with the metabolic syndrome, which consists of central obesity, insulin resistance, impaired glucose tolerance, dyslipidemia, and hypertension, has emerged from clinical studies and experiments using cell lines and mouse models. Epidemiological studies have associated abdominal obesity with increased incidence of TNBC. Additionally, insulin resistance, dyslipidemia, and hypertension are associated with increased incidence of breast cancer across all subtypes. The insulin-leptin-adiponectin axis has been implicated mechanistically in breast cancer tumorigenesis. Specifically, increased leptin and decreased adiponectin levels disrupt homeostatic signaling pathways involved in cell proliferation, survival, cell-cycle regulation, and angiogenesis. Insulin, insulin-like growth factor I (IGF-I), and epidermal growth factor receptor (EGFR) may mediate interactions between these two hormones. Further research will facilitate the development of targeted therapeutics and programs to modify lifestyle factors to modulate the insulin-leptin-adiponectin axis for TNBC.
Modern Detection of Prostate Cancer's Bone Metastasis: Is the Bone Scan Era Over?
Authors: Tombal Bertrand , Lecouvet Frederic
Published: October 2011

Prostate cancer cells have an exquisite tropism for bone, which clinically translates into the highest rate of bone metastases amongst male cancers. Although in the latest years there has been an active development of new “bone targeted” therapies, modern diagnostic techniques for bone metastases still relies mostly on bone scanning (BS) and plain X-ray. BS dramatically lacks specificity and sensitivity. Recent publications using modern imaging technologies have clearly pinpointed that BS grossly underestimates the true prevalence of bone metastasis. In addition BS does not allow tumour measurement and is, therefore, not appropriate to monitor response to therapy. This might be extremely important in patients harbouring high-risk localized disease that are eventually candidate for local therapy. Here we reviewed what are the emerging imaging strategies that are likely to supplant BS and to what extent they can be used in the clinic already.
Multipotent Mesenchymal Stromal Stem Cell Expansion by Plating Whole Bone Marrow at a Low Cellular Density: A More Advantageous Method for Clinical Use
Authors: Mareschi Katia , Rustichelli Deborah , Calabrese Roberto , Gunetti Monica , Sanavio Fiorella , Castiglia Sara , Risso Alessandra , Ferrero Ivana , Tarella Corrado , Fagioli Franca
Published: October 2011

Mesenchymal stem cells (MSCs) are a promising source for cell therapy due to their pluripotency and immunomodulant proprieties. As the identification of “optimal” conditions is important to identify a standard procedure for clinical use. Percoll, Ficoll and whole bone marrow directly plated were tested from the same sample as separation methods. The cells were seeded at the following densities: 100 000, 10 000, 1000, 100, 10 cells/cm2. After reaching confluence, the cells were detached, pooled and re-plated at 1000, 500, 100, and 10 cells/cm2. Statistical analyses were performed. Cumulative Population Doublings (PD) did not show significant differences for the separation methods and seeding densities but only for the plating density. Some small quantity samples plated in T25 flasks at plating densities of 10 and 100 cells/cm2did not produce any expansion. However, directly plated whole bone marrow resulted in a more advantageous method in terms of CFU-F number, cellular growth and minimal manipulation. No differences were observed in terms of gross morphology, differentiation potential or immunophenotype. These data suggest that plating whole bone marrow at a low cellular density may represent a good procedure for MSC expansion for clinical use.
Relabeling Heads: A Unified Account for Relativization Structures
Authors: Donati Caterina , Cecchetto Carlo
Published: October 2011

A tenet of any version of phrase structure theory is that a lexical item can transmit its label when merged with another category. We assume that if it is internally merged, a lexical item can turn a clause into a nominal phrase. If the relabeling lexical item is a wh-word, a free relative results; if it is an N, a full relative results; if it is a non-wh D, a pseudorelative results. It follows that the head of a relative construction cannot be more complex than a lexical item. We show massive evidence that when it is otherwise (e.g., the book about Obama that you bought), the modifier is late-merged after the noun has moved and relabeled the structure.
Predicting Performance
Authors: Sandholtz Judith Haymore , Shea Lauren M.
Published: October 2011

The implementation of teaching performance assessments has prompted a range of concerns. Some educators question whether these assessments provide information beyond what university supervisors gain through their formative evaluations and classroom observations of candidates. This research examines the relationship between supervisors’ predictions and candidates’ performance on a summative assessment based on a capstone teaching event, the Performance Assessment for California Teachers. The study, based on records for 337 teacher candidates over a 2-year period, specifically addresses the following questions: To what extent do university supervisors predict candidates’ total scores? On which questions and categories of the assessment do supervisors most accurately predict their candidates’ scores? Do supervisors predict scores more accurately for high- and low-performing candidates? The findings indicate that university supervisors’ perspectives did not always correspond with outcomes on the performance assessment, particularly for high and low performers.
Is chess the drosophila of artificial intelligence? A social history of an algorithm
Authors: Ensmenger Nathan
Published: October 2011

Since the mid 1960s, researchers in computer science have famously referred to chess as the ‘drosophila’ of artificial intelligence (AI). What they seem to mean by this is that chess, like the common fruit fly, is an accessible, familiar, and relatively simple experimental technology that nonetheless can be used productively to produce valid knowledge about other, more complex systems. But for historians of science and technology, the analogy between chess and drosophila assumes a larger significance. As Robert Kohler has ably described, the decision to adopt drosophila as the organism of choice for genetics research had far-reaching implications for the development of 20th century biology. In a similar manner, the decision to focus on chess as the measure of both human and computer intelligence had important and unintended consequences for AI research. This paper explores the emergence of chess as an experimental technology, its significance in the developing research practices of the AI community, and the unique ways in which the decision to focus on chess shaped the program of AI research in the decade of the 1970s. More broadly, it attempts to open up the virtual black box of computer software – and of computer games in particular – to the scrutiny of historical and sociological analysis.
Calciphylaxis in a patient with systemic lupus erythematosus without renal insufficiency or hyperparathyroidism
Authors: Aliaga LG , Barreira JC
Published: October 2011

Calciphylaxis is a frequent entity in patients with chronic renal failure of diverse etiology. The main pathogenic mechanism of calciphylaxis is impairment of either calcium and phosphate metabolism or plasma levels of parathyroid hormone. There are communications of patients with normal renal function, and in some cases with chronic inflammatory diseases such as rheumatoid arthritis, systemic lupus erythematosus (SLE) and antiphospholipid syndrome. We report a patient with SLE and no renal failure or hyperparathyroidism who developed severe calciphylaxis.
Protein-losing enteropathy as initial manifestation of systemic lupus erythematosus
Authors: Carneiro FOAA , Sampaio LR , Brandão LAR , Braga LLBC , Rocha FAC
Published: October 2011

Protein-losing enteropathy is a rare manifestation of systemic lupus erythematosus. We report the case of an 18-year-old woman that presented initially with diarrhoea and anasarca. During evaluation, there was low serum albumin of 1.6 g/dl (3.5–5.2 g/dl) and a positive antinuclear antibody test (1:2560). Anti-Sm antibodies (ELISA) were positive in addition to low serum C3 of 35 mg/dl. A scintigraphy using 99mTc-labelled albumin was positive for abdominal protein loss. A diagnosis of systemic lupus erythematosus related protein-losing enteropathy was made. She was started on prednisolone 40 mg/day without amelioration; a month later, azathioprine (100 mg/day) was added, leading to normalization of serum albumin and resolution of symptoms within 4 months. After 1.5 years, the patient developed a 2.9 g 24-h proteinuria while still in remission of the protein-losing enteropathy, receiving 5 mg prednisone and 100 mg azathioprine daily.
Process Evaluation Results From an Environmentally Focused Worksite Weight Management Study
Authors: DeJoy David M. , Wilson Mark G. , Padilla Heather M. , Goetzel Ron Z. , Parker Kristin B. , Della Lindsay J. , Roemer Enid C.
Published: October 2011

There is currently much interest in exploring environmental approaches to combat weight gain and obesity. This study presents process evaluation results from a workplace-based study that tested two levels of environmentally focused weight management interventions in a manufacturing setting. The moderate treatment featured a set of relatively simple, low-cost environmental modifications designed to facilitate healthy eating and physical activity; the intense treatment added elements intended to actively involve and engage management in program efforts. Fidelity varied across the 11 interventions comprising the two treatment conditions but did not vary systematically by treatment condition (moderate vs. intense). Environmental assessments showed improvements in workplace supports for weight management and significant differences by treatment level. Positive shifts in health climate perceptions also occurred, but sites receiving the intense treatment were not perceived as more supportive by employees. Challenges and limitations associated with environmental interventions are discussed with specific reference to activating management support.
Probabilistic approach to growth and detection of a truncated distribution of initial crack lengths based on Paris' law
Authors: Cohen Moshe L , Kulkarni Salil S , Achenbach Jan D
Published: October 2011

A method for incorporating probabilistic considerations into fatigue life prognosis based on experimental information for Paris' law is presented in this article. A truncated probability distribution of initial crack lengths is introduced to obviate a complication of the use of Paris' law. This formulation allows the calculation of several probabilities for various values of the truncation length, including the probability of the existence of a crack larger than a predetermined critical crack length and the probability of a crack in a prescribed domain of crack lengths, and the effect of an inspection on these probabilities. A probabilistic consideration for the fact that the Paris' law parameters are not constants but distributions is also addressed using a stochastic version of Paris' law and a Monte Carlo simulation. Finally, a novel Bayesian approach which highlights the effect of probability of detection, critical crack length, and applied stress versus the number of elapsed fatigue cycles is presented and ramifications explored. This article provides insight on how various factors affect diagnosis and prognosis in a probabilistic manner.
Subclavian Steal Syndrome
Authors: Viduetsky Alexander
Published: October 2011

Duplex sonography of extracranial arteries is one of the best tools for identifying stenoses and other diseases of the carotid, vertebral, and subclavian arteries. Abnormal Doppler waveforms in vertebral arteries could be evidence of subclavian steal syndrome. The difference of 15 to 20 mm Hg or more in systolic bilateral brachial arterial blood pressure measurements provides important clinical information in patients with subclavian steal syndrome. Complementary to duplex sonographic scanning, radiologists use computerized tomography angiography, magnetic resonance angiography, and digital subtraction angiography for preoperative planning.
Conserved valproic-acid-induced lipid droplet formation in Dictyostelium and human hepatocytes identifies structurally active compounds
Authors: Elphick Lucy M. , Pawolleck Nadine , Guschina Irina A. , Chaieb Leila , Eikel Daniel , Nau Heinz , Harwood John L. , Plant Nick J. , Williams Robin S. B.
Published: October 2011

Lipid droplet formation and subsequent steatosis (the abnormal retention of lipids within a cell) has been reported to contribute to hepatotoxicity and is an adverse effect of many pharmacological agents including the antiepileptic drug valproic acid (VPA). In this study, we have developed a simple model system (Dictyostelium discoideum) to investigate the effects of VPA and related compounds in lipid droplet formation. In mammalian hepatocytes, VPA increases lipid droplet accumulation over a 24-hour period, giving rise to liver cell damage, and we show a similar effect in Dictyostelium following 30 minutes of VPA treatment. Using 3H-labelled polyunsaturated (arachidonic) or saturated (palmitic) fatty acids, we shown that VPA treatment of Dictyostelium gives rise to an increased accumulation of both types of fatty acids in phosphatidylcholine, phosphatidylethanolamine and non-polar lipids in this time period, with a similar trend observed in human hepatocytes (Huh7 cells) labelled with [3H]arachidonic acid. In addition, pharmacological inhibition of β-oxidation in Dictyostelium phenocopies fatty acid accumulation, in agreement with data reported in mammalian systems. Using Dictyostelium, we then screened a range of VPA-related compounds to identify those with high and low lipid-accumulation potential, and validated these activities for effects on lipid droplet formation by using human hepatocytes. Structure-activity relationships for these VPA-related compounds suggest that lipid accumulation is independent of VPA-catalysed teratogenicity and inositol depletion. These results suggest that Dictyostelium could provide both a novel model system for the analysis of lipid droplet formation in human hepatocytes and a rapid method for identifying VPA-related compounds that show liver toxicology.
Chasing a Moving Target: Exploitation and Exploration in Dynamic Environments
Authors: Posen Hart E. , Levinthal Daniel A.
Published: October 2011

A common justification for organizational change is that the circumstances in which the organization finds itself have changed, thereby eroding the value of utilizing existing knowledge. On the surface, the claim that organizations should adapt by generating new knowledge seems obvious and compelling. However, this standard wisdom overlooks the possibility that the reward to generating new knowledge may itself be eroded if change is an ongoing property of the environment. This observation in turn suggests that environmental change is not a self-evident call for strategies of greater exploration. Indeed, under some conditions the appropriate response to environmental change is a renewed focus on exploiting existing knowledge and opportunities. We develop a computational model based on the canonical multiarmed bandit formulation of exploration and exploitation. We endeavor to understand the mechanisms by which environmental change acts to make purposeful efforts at organizational adaptation less (or more) valuable.

This paper was accepted by Jesper Sørensen, organizations.
Density Forecasting of Intraday Call Center Arrivals Using Models Based on Exponential Smoothing
Authors: Taylor James W.
Published: October 2011

A key input to the call center staffing process is a forecast for the number of calls arriving. Density forecasts of arrival rates are needed for analytical call center models, which assume Poisson arrivals with a stochastic arrival rate. Density forecasts of call volumes can be used in simulation models and are also important for the analysis of outsourcing contracts. A forecasting method, which has previously shown strong potential, is Holt–Winters exponential smoothing adapted for modeling the intraday and intraweek cycles in intraday data. To enable density forecasting of the arrival volume and rate, we develop a Poisson count model, with gamma distributed arrival rate, which captures the essential features of this exponential smoothing method. The apparent stationary level in our data leads us to develop versions of the new model for series with stationary levels. We evaluate forecast accuracy up to two weeks ahead using data from three organizations. We find that the stationary level models improve prediction beyond approximately two days ahead, and that these models perform well in comparison with sophisticated benchmarks. This is confirmed by the results of a call center simulation model, which demonstrates the use of arrival rate density forecasting to support staffing decisions.

This paper was accepted by Yossi Aviv, operations management.
Verification Theorems for Models of Optimal Consumption and Investment with Retirement and Constrained Borrowing
Authors: Dybvig Philip H. , Liu Hong
Published: October 2011

Proving verification theorems can be tricky for models with both optimal stopping and state constraints. We pose and solve two alternative models of optimal consumption and investment with an optimal retirement date (optimal stopping) and various wealth constraints (state constraints). The solutions are parametric in closed form up to at most a constant. We prove the verification theorem for the main case with a nonnegative wealth constraint by combining the dynamic programming and Slater condition approaches. One unique feature of the proof is the application of the comparison principle to the differential equation solved by the proposed value function. In addition, we also obtain analytical comparative statics.
The Value of Collaborative Forecasting in Supply Chains
Authors: Kurtuluş Mümin , Ülkü Sezer , Toktay Beril L.
Published: October 2011

Motivated by the mixed evidence concerning the adoption level and value of collaborative forecasting (CF) implementations in retail supply chains, in this paper, we explore the conditions under which CF offers the highest potential. We consider a two-stage supply chain with a single supplier selling its product to consumers through a single retailer. We assume that both the supplier and the retailer can improve the quality of their demand forecasts by making costly forecasting investments to gather and analyze information. First, we consider a noncollaborative model where the supplier and the retailer can invest in forecasting but do not share forecast information. Next, we examine a collaborative forecasting model where the supplier and the retailer combine their information to form a single shared demand forecast. We investigate the value of CF by comparing each party's profits in these scenarios under three contractual forms that are widely used in practice (two variations of the simple wholesale price contract as well as the buyback contract). We show that for a given set of parameters, CF may be Pareto improving for none to all three of the contractual structures, and that the Pareto regions under all three contractual structures can be expressed with a unifying expression that admits an intuitive interpretation. We observe that these regions are limited and explain how they are shaped by the contractual structure, power balance, and relative forecasting capability of the parties. To determine the specific value of collaborative forecasting as a function of different factors, we carry out a numerical analysis and observe the following. First, under noncoordinating contracts, improved information as a result of CF has the added benefit of countering the adverse effects of double marginalization in addition to reducing the cost of supply–demand mismatch. Second, one may expect the value of CF to increase with bargaining power, however this does not hold in general: The value of CF for the newsvendor first increases and then decreases in his bargaining power. Finally, whereas one may expect CF to be more valuable under coordinating contracts, rather than a simple wholesale price contract that is prone to double marginalization, the magnitude of the gain from CF is in many cases higher in the absence of quantity coordination.
The Potential Value of Hybrid Positron Emission Tomography/Dual-Source Computed Tomography Imaging in Coronary Bypass Surgery
Authors: Plass Andre , Emmert Maximilian Y. , Gaemperli Oliver , Alkadhi Hatem , Kaufmann Philipp , Falk Volkmar , Gr�nenfelder J�rg
Published: October 2011

Background: We evaluated how comprehensive assessment of coronary artery lesions and their hemodynamic relevance by means of hybrid positron emission tomography (PET) and computed tomography (CT) imaging would affect decision-making in coronary artery bypass surgery (CABG), compared with using invasive coronary angiography (ICA) alone.

Methods: After undergoing ICA, 27 patients (21 men and 6 women; mean SD age, 66 � 10 years) planned for cardiac surgery were scheduled for myocardial perfusion stress/rest evaluation with [13N]ammonia PET and CT coronary angiography. Only ICA was available to the surgeon. Postoperatively, the performed CABG was compared with the hypothetical strategy based on hybrid PET/CT findings (regional coronary flow reserve [CFR], myocardial perfusion defects). Procedures included CABG (n = 18) alone, CABG combined with valve replacement (n = 6), and CABG combined with isolated valve replacement (n = 3). A total of 56 bypass grafts (28 venous and 28 arterial) and 66 distal anastomoses were placed.

Results: CT evaluation showed 93% concordance (66/71) with ICA regarding significant stenoses, with sensitivity, specificity, positive predictive value, and negative predictive value of 93.1%, 98.7%, 94.4%, and 98.4%, respectively. In the PET scan, 16 patients had 1 ischemic region, and 12 patients had 1 scar region, including 5 patients who presented with mixed conditions (scar and ischemia). One patient had a completely normal myocardium. Compared with the performed surgery, PET/CT fusion evaluation showed that of the performed anastomoses, 48% had documented ischemia (with a CFR <2 in 86%), 38% were nonischemic (although a CFR value <2 was found in 78%), and 14% had scar tissue (fixed perfusion defect).

Conclusions: Although <50% of bypasses were placed to areas with myocardial ischemia, the CFR was low in the majority of nonischemic regions, a finding that may have important prognostic relevance. PET/CT fusion imaging could potentially influence planning for CABG and provide incremental prognostic information.
The relationships between economic growth and intellectual capital: A study in the European Union
Authors: Alfaro J. , Lopez V. , Nevado D.
Published: October 2011

We are immersed in a knowledge society that calls for indicators to go beyond economic factors to measure the development of a country. In this paper we use an adapted microeconomic model that determines the value of a country’s intellectual capital. For this, we consider intangibles such as human development, economic structure, international trade, foreign image and innovation. This measurement of intellectual capital is divided into human and structural capital and is used to analyse the relationship between these capitals and the economic development of the 27 countries in the European Union (EU27). The results show that when we consider aspects other than economic variables, the differences between countries are larger. Moreover, there is an inverse relationship between the management of intangibles and economic growth, which is why the former progresses after the latter have occurred.