bluuebunny/crossref_metadata_2025 huggingface dataset:
Exercise ventilatory inefficiency in mild to end-stage COPD
Authors: Neder J. Alberto , Arbex Flavio F. , Alencar Maria Clara N. , O’Donnell Conor D.J. , Cory Julia , Webb Kathy A. , O’Donnell Denis E.
Published: October 2014

Ventilatory inefficiency during exercise is a key pathophysiological feature of chronic obstructive pulmonary disease. Currently, it is unknown how this physiological marker relates to clinically relevant outcomes as resting ventilatory impairment progresses across disease stages.

Slope and intercept of the linear region of the ventilation–carbon dioxide output relationship and the ratio between these variables, at the lowest point (nadir), were contrasted in 316 patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages 1–4 (forced expiratory volume in 1 s, ranging from 148% pred to 12% pred) and 69 aged- and gender-matched controls,

Compared to controls, slope and intercept were higher in GOLD stages 1 and 2, leading to higher nadirs (p<0.05). Despite even larger intercepts in GOLD stages 3 and 4, slopes diminished as disease evolved (from mean±sd35±6 in GOLD stage 1 to 24±5 in GOLD stage 3, p<0.05). As a result, there were no significant differences in nadirs among patient groups. Higher intercepts, across all stages (p<0.01), and to a lesser extent lower slopes in GOLD stages 2–4 (p<0.05), were related to greater mechanical constraints, worsening pulmonary gas exchange, higher dyspnoea scores, and poorer exercise capacity.

Increases in the ventilation intercept best indicate the progression of exercise ventilatory inefficiency across the whole spectrum of chronic obstructive pulmonary disease severity.
An a posteriori Fourier regularization method for identifying the unknown source of the space-fractional diffusion equation
Authors: Li Xiao-Xiao , Lei Jin Li , Yang Fan
Published: October 2014

In this paper, we identify the unknown source which depends only on spatial variable for a fractional diffusion equation using the Fourier method. Not alike the previous literature, we propose to choose the regularization parameter by an a posteriori rule, with which we can obtain error estimate of Hölder type between the exact solution and the regularized approximation. Numerical simulations show that the proposed scheme is effective and stable.

MSC: 35R30, 47A52, 65M30, 65M32.
Some results in quasi-b-metric-like spaces
Authors: Zhu Chuanxi , Chen Chunfang , Zhang Xiaozhi
Published: October 2014

In this paper, we introduce a new concept of quasi-b-metric-like spaces as a generalization of b-metric-like spaces and quasi-metric-like spaces. Some fixed point theorems are investigated in quasi-b-metric-like spaces. Moreover, an example is given to support one of our results.

MSC:47H10, 54H25.
Square-like functions generated by the Laplace-Bessel differential operator
Authors: Keleş Şeyda , Bayrakçı Simten
Published: October 2014

We introduce a wavelet-type transform associated with the Laplace-Bessel differential operator

Δ
B

=

∑

k
=
1

n

∂
2

∂

x
k

+

2

ν
k

∂

x
k

∂

∂

x
k

and the relevant square-like functions. An analogue of the Calderón reproducing formula and the

L

2
,
ν

boundedness of the square-like functions are obtained.

MSC:47G10, 42C40, 44A35.
An optimized disaggregation method for human lung tumors that preserves the phenotype and function of the immune cells
Authors: Quatromoni Jon G , Singhal Sunil , Bhojnagarwala Pratik , Hancock Wayne W , Albelda Steven M , Eruslanov Evgeniy
Published: October 2014

Careful preparation of human tissues is the cornerstone of obtaining accurate data in immunologic studies. Despite the essential importance of tissue processing in tumor immunology and clinical medicine, current methods of tissue disaggregation have not been rigorously tested for data fidelity. Thus, we critically evaluated the current techniques available in the literature that are used to prepare human lung tumors for immunologic studies. We discovered that these approaches are successful at digesting cellular attachments and ECMs; however, these methods frequently alter the immune cell composition and/or expression of surface molecules. We thus developed a novel approach to prepare human lung tumors for immunologic studies by combining gentle mechanical manipulation with an optimized cocktail of enzymes used at low doses. This enzymatic digestion cocktail optimized cell yield and cell viability, retrieved all major tumor-associated cell populations, and maintained the expression of cell-surface markers for lineage definition and in vivo effector functions. To our knowledge, we present the first rigorously tested disaggregation method designed for human lung tumors.
Sadness and mild cognitive impairment as predictors for interferon-alpha-induced depression in patients with hepatitis C
Authors: Sarkar Susanne , Sarkar Rahul , Berg Thomas , Schaefer Martin
Published: October 2014

Background

Antiviral therapy with interferon-alpha (IFN-α) for hepatitis C virus (HCV) infection is associated with increased risk for depression.

Aims

To identify clinical predictors for IFN-α-induced depression during antiviral therapy for HCV infection.

Method

Depression (defined with the Montgomery–åsberg Depression Rating Scale (MADRS)) was evaluated before and during antiviral treatment in 91 people with chronic HCV infection without a history of psychiatric disorders. Cognitive function was evaluated using the Trail Making Test A/B (TMT A/B). (Trial registration at ClinicalTrials.gov: NCT00136318.)

Results

Depression during antiviral therapy was significantly associated with a baseline MADRS score of 3 or higher (P= 0.006). In total, 89% (n= 16) of patients who had a baseline score >0 for the single item sadness developed depression. Poor baseline performance in the TMT A (P= 0.027) and TMT B (P=0.033) was predictive for severe depression.

Conclusions

Pre-treatment screening for subthreshold depressive and cognitive symptoms will help to identify those at risk for IFN-α-associated depression among patients with chronic hepatitis C.
Rational Design Spectra for Structural Reliability Assessment Using the Response Spectrum Method
Authors: Loth Christophe , Baker Jack W.
Published: October 2014

Current design spectra, which approximate uniform hazard or risk spectra, are known to have shortcomings, but no alternative has been proven superior for the purposes of design checks. In this work, we use response spectrum method analysis to show that the “design point” associated with a structural reliability assessment is a rational choice for a design spectrum. When the response parameter of interest is sensitive to excitation at a particular period, the design point corresponds to a conditional mean spectrum (CMS) conditioned on that period. In the case where there are multiple structural response parameters of interest, or it is unknown what excitation periods are important to the structural response, the CMS can be used by considering multiple conditioning periods and taking the maximum structural response from any of the spectra for design checks. This observation is used to justify the CMS as a target response spectrum for design checks.
A White Russian in the Green Hell: Military Science, Ethnography, and Nation Building
Authors: Chesterton Bridget María , Isaenko Anatoly V.
Published: October 2014

This article considers how Juan Belaieff's experiences in the Caucasus of Russia during the early twentieth century shaped his later work with the Paraguayan military in the Chaco region. His Russian training in both military science and ethnography prepared him for his scouting work in the Chaco, a territory contested by both Bolivia and Paraguay. This work, done with the native population of the Chaco, helped secure victory over the Bolivians during the Chaco War (1932–1935). It also played a key role in his broader project of incorporating the native peoples of the Chaco into the Paraguayan nation-state, a project that drew upon his work on behalf of Russia with the populations of the Caucasus. Significantly, his postwar efforts and ethnographic studies directly led to rights and considerations for Paraguay's indigenous population. Belaieff's work demonstrates how both the Paraguayan military and society (long considered by historians as isolated) were influenced by outside ideas and people.
Ezh2-mediated repression of a transcriptional pathway upstream of Mmp9 maintains integrity of the developing vasculature
Authors: Delgado-Olguín Paul , Dang Lan T. , He Daniel , Thomas Sean , Chi Lijun , Sukonnik Tatyana , Khyzha Nadiya , Dobenecker Marc-Werner , Fish Jason E. , Bruneau Benoit G.
Published: October 2014

Maintenance of vascular integrity is required for embryogenesis and organ homeostasis. However, the gene expression programs that stabilize blood vessels are poorly understood. Here, we show that the histone methyltransferase Ezh2 maintains integrity of the developing vasculature by repressing a transcriptional program that activates expression of Mmp9. Inactivation of Ezh2 in developing mouse endothelium caused embryonic lethality with compromised vascular integrity and increased extracellular matrix degradation. Genome-wide approaches showed that Ezh2 targets Mmp9 and its activators Fosl1 and Klf5. In addition, we uncovered Creb3l1 as an Ezh2 target that directly activates Mmp9 gene expression in the endothelium. Furthermore, genetic inactivation of Mmp9 rescued vascular integrity defects in Ezh2-deficient embryos. Thus, epigenetic repression of Creb3l1, Fosl1, Klf5 and Mmp9 by Ezh2 in endothelial cells maintains the integrity of the developing vasculature, potentially linking this transcriptional network to diseases with compromised vascular integrity.
An adhesome comprising laminin, dystroglycan and myosin IIA is required during notochord development in Xenopus laevis
Authors: Buisson Nicolas , Sirour Cathy , Moreau Nicole , Denker Elsa , Le Bouffant Ronan , Goullancourt Aline , Darribère Thierry , Bello Valérie
Published: October 2014

Dystroglycan (Dg) is a transmembrane receptor for laminin that must be expressed at the right time and place in order to be involved in notochord morphogenesis. The function of Dg was examined in Xenopus laevis embryos by knockdown of Dg and overexpression and replacement of the endogenous Dg with a mutated form of the protein. This analysis revealed that Dg is required for correct laminin assembly, for cell polarization during mediolateral intercalation and for proper differentiation of vacuoles. Using mutations in the cytoplasmic domain, we identified two sites that are involved in cell polarization and are required for mediolateral cell intercalation, and a site that is required for vacuolation. Furthermore, using a proteomic analysis, the cytoskeletal non-muscle myosin IIA has been identified for the first time as a molecular link between the Dg-cytoplasmic domain and cortical actin. The data allowed us to identify the adhesome laminin-Dg-myosin IIA as being required to maintain the cortical actin cytoskeleton network during vacuolation, which is crucial to maintain the shape of notochordal cells.
An interplay of geometry and signaling enables robust lung branching morphogenesis
Authors: Menshykau Denis , Blanc Pierre , Unal Erkan , Sapin Vincent , Iber Dagmar
Published: October 2014

Early branching events during lung development are stereotyped. Although key regulatory components have been defined, the branching mechanism remains elusive. We have now used a developmental series of 3D geometric datasets of mouse embryonic lungs as well as time-lapse movies of cultured lungs to obtain physiological geometries and displacement fields. We find that only a ligand-receptor-based Turing model in combination with a particular geometry effect that arises from the distinct expression domains of ligands and receptors successfully predicts the embryonic areas of outgrowth and supports robust branch outgrowth. The geometry effect alone does not support bifurcating outgrowth, while the Turing mechanism alone is not robust to noisy initial conditions. The negative feedback between the individual Turing modules formed by fibroblast growth factor 10 (FGF10) and sonic hedgehog (SHH) enlarges the parameter space for which the embryonic growth field is reproduced. We therefore propose that a signaling mechanism based on FGF10 and SHH directs outgrowth of the lung bud via a ligand-receptor-based Turing mechanism and a geometry effect.
A complex of p190RhoGAP and anillin modulates RhoGTP and the cytokinetic furrow in human cells
Authors: Manukyan Arkadi , Ludwig Kirsten , Sanchez-Manchinelly Sergio , Parsons Sarah J. , Stukenberg P. Todd
Published: October 2014

The cytokinetic furrow (CF) is organized by the RhoA GTPase, which recruits actin and myosin II to the furrow and drives contractility. Here we show a role for the RhoGAP, p190, in cytokinesis and its involvement in regulating Rho GTP levels and contractility. Cells depleted of p190RhoGAP (p190) accumulate high levels of RhoGTP and markers of high Rho activity in the furrow, resulting in failure of the CF to progress to abscission. The loss of p190 can be rescued by a low dose of the myosin II inhibitor blebbistatin, suggesting that cells fail cytokinesis because they have too much myosin activity. p190RhoGAP binds the cytokinetic organizer anillin, and mutants of p190 that are unable to bind anillin or unable to inactivate Rho fail to rescue cytokinesis defects in p190-depleted cells. Together these data demonstrate that a complex of p190RhoGAP and anillin modulates RhoGTP levels in the CF to ensure robust cytokinesis.
Hsp90α forms a stable complex at cilia neck for signal molecules interaction in cilia-mediated IGF-1 receptor signaling
Authors: Wang Hongzhong , Zou Xinle , Wei Zhuang , Wu Yuan , Li Rongxia , Zeng Rong , Chen Zhengjun , Liao Kan
Published: October 2014

Primary cilium is composed of an axoneme protruded on cell surface, a basal body beneath the membrane and a transition neck in between. It is considered as a sensory organelle on plasma membrane to mediate extracellular signals. The transition neck region contains the microtubules from triplet to doublet transition, the transition fibres crosslinking the axoneme with membrane and the necklace proteins regulating molecules being transported into and out of cilium. In this protein-enriched complex area it is important to maintain all these proteins in proper assembly. Here, through immunofluorescence staining and protein isolation, we identified that the molecular chaperone, Hsp90α, clustered at periciliary base. At transition neck region the phosphorylated Hsp90α formed a stable ring around axoneme. Heat shock treatment dissipated Hsp90α and induced cilia resorption. We further identified that Hsp90α at transition neck region represented a signalling platform on which IRS-1 interacted with intracellular downstream signal molecules for IGF-1 receptor signalling.
Epidermal Growth Factor Receptor substrate 8 (Eps8) controls Src/FAK-dependent phenotypes in squamous carcinoma cells
Authors: Schoenherr Christina , Serrels Bryan , Proby Charlotte , Cunningham Debbie L. , Findlay Jane E. , Baillie George S. , Heath John K. , Frame Margaret C.
Published: October 2014

Eps8 is an actin regulatory scaffold protein increased in Squamous Cell Carcinoma (SCC) cells. It forms a complex with both Focal Adhesion Kinase (FAK) and c-Src in SCC cells derived from the DMBA/TPA model of skin carcinogenesis. Here, we describe two new roles for Eps8. Firstly, it controls the spatial distribution of active c-Src in a FAK-dependent manner. Specifically, Eps8 participates in, and regulates, a biochemical complex with c-Src and drives c-Src's trafficking to autophagic structures that SCC cells use to cope with high levels of active c-Src when FAK is absent. Secondly, when FAK is expressed in SCC cells, so tethering active c-Src at focal adhesion complexes, Eps8 is also recruited to focal adhesions and is required for FAK-dependent polarization and invasion. Therefore, Eps8 is a critical mediator of Src/FAK-regulated processes; it participates in specific biochemical complexes and promotes actin re-arrangements that determine c-Src's spatial localization and Src/FAK functions in invasive migration.
Effects of unsaturated fatty acids on torpor frequency and diet selection in Djungarian hamsters (Phodopus sungorus)
Authors: Diedrich Victoria , Steinlechner Stephan , Scherbarth Frank
Published: October 2014

Essential polyunsaturated fatty acids (PUFA) have been shown to play a beneficial role in hibernating mammals. High amounts of dietary PUFA led to an earlier hibernation onset, deeper and longer hibernation bouts and a higher proportion of hibernating animals in several species. In contrast, the relevance of dietary PUFA for daily heterotherms exhibiting only brief and shallow torpor bouts is less well studied. Therefore, diets differing in PUFA composition were used to examine the effects on the frequency of spontaneous daily torpor in Djungarian hamsters (Phodopus sungorus). In contrast to earlier studies, we were interested whether the ratio of n-6 to n-3 PUFA affects torpor expression, also in comparison with a diet rich in monounsaturated fatty acids (MUFA). Although we found a positive effect on torpor frequency in hamsters fed a diet rich in n-6 PUFA compared with the groups fed diets either rich in n-3 PUFA or MUFA, the latter did not show unusually low torpor frequencies. The results of the additional diet choice experiment indicated that hamsters in short photoperiod select food with only a slight excess of n-6 PUFA compared with n-3 PUFA (ratio 1 to 1.5). However, there was no significant difference in torpor frequency between the diet choice group and hamsters fed on standard chow with a sevenfold excess of n-6 PUFA. In summary, the present data strongly indicate that the dietary composition of unsaturated fatty acids plays a minor role in the occurrence of spontaneous daily torpor in Djungarian hamsters.
Active Vibration Control of Container Cranes against Earthquake by the Use of Delay-Dependent H∞ Controller under Consideration of Actuator Saturation
Authors: Yazici Hakan , Azeloglu C. Oktay , Kucukdemiral I. Beklan
Published: October 2014

This paper studies the design of a state-feedback delay-dependent H∞ controller for vibration attenuation problem of a seismic-excited container crane subject to having time-varying actuator delay, L2 type disturbances and actuator saturation. First, a sufficient delay-dependent stability criterion is developed by choosing a Lyapunov-Krasovskii functional candidate based on matrix inequalities for a stabilizing H∞ synthesis. To convexify the Bilinear Matrix Inequality (BMI) based optimization problem involved in the delay dependent conditions; a cone complementary linearization method is adopted to find a sub-optimal solution. The proposed method also utilizes convex description of nonlinear saturation phenomenon by means of convex hull of some linear feedback which leads to a few additional ellipsoidal conditions in terms of Linear Matrix Inequalities (LMIs). By use of the proposed method, a suboptimal controller with maximum allowable delay bound and minimum allowable disturbance attenuation level can be easily obtained by a convex optimization technique. In order to show effectiveness of the proposed approach, a five Degrees-of-Freedom (DOF) container crane structure is modeled using a spring-mass-damper subsystem. The system is then simulated against the real ground motions of Kobe and Northridge earthquakes. Finally, the time history of the crane parts displacements, accelerations, control forces and frequency responses of the both uncontrolled and controlled cases are presented. Additionally, the performance of the proposed controller is also compared with a nominal state-feedback H∞ controller performance. Simulation results show that, in spite of the actuator saturation, the designed controller is all effective in reducing vibration amplitudes of crane parts and guarantees stability at maximum actuator delay.
Robust Control for Ride Comfort Improvement of an Active Suspension System considering Uncertain Driver's Biodynamics
Authors: Gudarzi M. , Oveisi A.
Published: October 2014

This paper presents a robust output feedback control design for a half-car active suspension system by considering driver's biodynamics. Because of different kinds of passengers there is a wide range of variations in biodynamics' parameters, and an appropriate robust control design approach, μ-synthesis approach, is used to tackle these parametric uncertainties. The performance of active suspension system with designed controller is compared with the open loop one in both frequency and time domain simulations. The results show that μ-synthesis based controller achieves great performance in ride comfort. In addition, suspension deflections, road holding and actuators force remain in reasonable regions. Finally, analysis of robust performance indicating that the μ-synthesis controller remains stable in a wide range of frequency domain despite parametric uncertainties, which is also validated by a specific case in this paper.
Dynamic Characteristics and Stability of Axially Moving Viscoelastic Plate with Piezoelectric Layer
Authors: Wang Yan , Cao Xiaoshan , Jing Tao , Wu Jimei
Published: October 2014

The dynamic stability of the moving viscoelastic plate with the piezoelectric layer is studied. On the basis of the thin plate theory and the two-dimensional viscoelastic differential constitutive relation, the differential equation of the axially moving viscoelastic rectangular plate with piezoelectric layer in the Laplace domain is formulated, the equation is suitable for various viscoelastic differential models. Then, the differential equation of motion of the viscoelastic plate with elastic dilatation and Kelvin–Voigt distortion in time domain is derived, with the piezoelectric effect. The complex eigenvalue equations of axially moving viscoelastic plate are established by the differential quadrature method. The generalized eigenvalue equations are solved, and the force excited by the piezoelectric layer due to external voltage is modeled as the follower tensile force; this force is used to improve the stability of the axially moving viscoelastic plate. Via numerical calculation, the results for the instability type and the corresponding critical moving speed of viscoelastic plate are presented to show the variations in these factors with respect to the dimensionless moving speed, the dimensionless delay time and the applied voltages. The dynamic stability of the axially moving viscoelastic plates can be effectively improved by the determination of the optimal location for the piezoelectric layers and the most favorable voltage assignment.
Optimized T-Shape and Y-Shape Inclined Sound Barriers for Railway Noise Mitigation
Authors: Karimi Mostafa , Younesian Davood
Published: October 2014

Performance of T-shape and Y-shape inclined noise barriers in railway noise mitigation is studied in this paper. Control of the noise attenuation and sound-map behind two conventional barriers is performed by optimal adjusting their inclination angle. Logarithmic averaging of the noise attenuation in different heights is adopted to be the objective function. A numerical model is constructed and the Steepest Descent Method (SDM) is adopted as the optimization algorithm. Validly of the modeling and solution procedure is verified by use of experimental results. Field measurements are performed and the frequency responses of different trains are loaded into the model. Optimal inclination angel is subsequently obtained for each configuration. It is found that the inclination angle can play a significant role in noise mitigation level remarkably in high elevation back regions.
Vibroacoustic Response of an Annular Sandwich Electrorheological Disc
Authors: Hasheminejad Seyyed M. , Afsharmanesh Bahram
Published: October 2014

The steady-state sound radiation characteristics of a rigidly-baffled clamped-free sandwich annular disc with a tunable electrorheological fluid (ERF) core is studied. Hamilton's principle is employed to derive the governing equations of motion for the composite plate along with the associated boundary conditions in general form. The classical Galerkin procedure is subsequently utilized to reduce the structural problem into a linear system of algebraic equations for the unknown displacement coefficients. A modal summation approach based on Rayleigh integral formula along with the proper integral representation of the cylindrical Bessel functions are used to arrive at a useful single integral relation for the far-field modal radiated sound pressure and subsequently determine the radiation power and efficiency. Numerical results reveal the imperative influence of the applied electric field strength (0–3.5kV/mm) on controlling acoustic radiation from the adaptive panel in a wide frequency range. In particular, an effort is made to find the optimal electric field which yields improved sound radiation characteristics for each excitation frequency. Limiting cases are considered and good agreements with the calculations made by using a commercial finite element package as well as with the solutions available in the literature are obtained.
Systematic and Logical Problems in Global Warming Science
Authors: Gould Laurence I.
Published: October 2014

Arguments put forth in favor of anthropogenic global warming (AGW) are frequently lacking in objectivity due to the use of imprecise terms and unwarranted extrapolations. A salient characteristic of such arguments is, moreover, the seemingly arbitrary attribution of causes to certain phenomena [Singer, 2012a]. As a result, such arguments run counter to the reasoning that is a hallmark of the scientific method. The purpose of this paper is to reason about some of those erroneous arguments in order to better inform people about pitfalls from a misuse of the scientific method in arguments about AGW.

In a time when many scientists, scientific organizations, and educators have apparently been compromising their honesty and their integrity [Ball 2014a], S. Fred Singer stands out: As a rallying point for those who haven't compromised, as a trusted source seeking the truth, and as a beacon for those who seek moral support to carry on the grand tradition of science. It is my pleasure to dedicate this essay to Fred (a scientist for all seasons), with gratitude and admiration, on his 90th birthday.
HPC Parallelisation of Boundary Conditions in Multiscale Methods
Authors: Asproulis Nikolaos , Drikakis Dimitris
Published: October 2014

This paper investigates two numerical implementations of continuum boundary conditions in parallel high performance computing (HPC) systems in conjunction with multiscale modelling comprising molecular dynamics (MD) and computational fluid dynamics (CFD) methods. The multiscale method provides the best compromise in terms of accuracy and computational cost in mesoscale regimes, however, there are still algorithmic challenges preventing the practical application of these methods. The present study investigates some of these challenges, namely different domain decompositions of the momentum transferred from the continuum domain to the atomistic region in conjunction with HPC parallelisation.
Collaboration for rare disease drug discovery research
Authors: Litterman Nadia K. , Rhee Michele , Swinney David C. , Ekins Sean
Published: October 2014

Rare disease research has reached a tipping point, with the confluence of scientific and technologic developments that if appropriately harnessed, could lead to key breakthroughs and treatments for this set of devastating disorders. Industry-wide trends have revealed that the traditional drug discovery research and development (R&D) model is no longer viable, and drug companies are evolving their approach. Rather than only pursue blockbuster therapeutics for heterogeneous, common diseases, drug companies have increasingly begun to shift their focus to rare diseases. In academia, advances in genetics analyses and disease mechanisms have allowed scientific understanding to mature, but the lack of funding and translational capability severely limits the rare disease research that leads to clinical trials. Simultaneously, there is a movement towards increased research collaboration, more data sharing, and heightened engagement and active involvement by patients, advocates, and foundations. The growth in networks and social networking tools presents an opportunity to help reach other patients but also find researchers and build collaborations. The growth of collaborative software that can enable researchers to share their data could also enable rare disease patients and foundations to manage their portfolio of funded projects for developing new therapeutics and suggest drug repurposing opportunities. Still there are many thousands of diseases without treatments and with only fragmented research efforts. We will describe some recent progress in several rare diseases used as examples and propose how collaborations could be facilitated. We propose that the development of a center of excellence that integrates and shares informatics resources for rare diseases sponsored by all of the stakeholders would help foster these initiatives.
Are Preschool Teachers Committed to Implement Objectives of the Federal State Educational Standard of Preschool Education? (As exemplified by the “Cognitive development” educational field)
Authors: Румянцева  , Rumyantseva Irina
Published: October 2014

The paper summarizes the findings of surveys among teachers of preschool educational institutions on issues concerning the arrangement of

integrated educational activities of preschool children. The author provides quantitative and qualitative analyses of the teachers’ level of readiness

to practice integrated teaching; assesses the degree of teachers’ commitment to practice this kind of teaching; reveals the main obstacles, the

teachers encounter in the course of integrated educational activities.
Research Note—Perceived Firm Attributes and Intrinsic Motivation in Sponsored Open Source Software Projects
Authors: Spaeth Sebastian , von Krogh Georg , He Fang
Published: October 2014

Voluntary contributions are crucial to the success of open source software (OSS) projects. Firms sponsoring OSS projects may face substantial challenges in soliciting such contributions, since volunteer participants are neither regulated by an employment contract nor offered financial incentives. Although prior work has shown the positive impact of motivation on the effort expended by volunteer participants, there is limited understanding of how specific firm attributes shape volunteers’ intrinsic motivation. We offer a theoretical model of how the perceived community-based credibility and openness of the sponsoring firm have a positive impact on the intrinsic motivation of volunteer participants. The model is explored using survey data on volunteer participants from two sponsored OSS projects. Results show that a sponsoring firm’s community-based credibility (OSS developers’ perception of its expertise and trustworthiness) and openness (its mutual knowledge exchange with the community) strengthen the volunteer participants’ social identification with the firm-sponsored community, which in turn reinforces their intrinsic motivation to participate. Moreover, the perceived community-based credibility of a sponsoring firm directly enhances volunteer participants’ intrinsic motivation, whereas perceived openness fails to affect motivation without the mediating mechanism of social identification. Implications for firms seeking voluntary contributions for their sponsored OSS projects are discussed.
Erratum to “Optimal Reverse-Pricing Mechanisms” by Martin Spann, Robert Zeithammer, and Gerald Häubl
Authors: Spann Martin , Zeithammer Robert , Häubl Gerald
Published: October 2014

In our paper about optimal reverse pricing mechanisms [Spann M, Zeithammer R, Häubl G (2010) Optimal reverse-pricing mechanisms. Marketing Sci. 29(6):1058–1070] (hereafter, ORPM), some of the mathematical derivations implicitly assume that the name-your-own-price seller interprets the outside-market posted price p differently than the buyers. This note shows that all of the qualitative results in ORPM continue to hold under the more natural assumption of common knowledge that p is the upper bound of wholesale cost. Interestingly, the proofs and algebraic expressions are often simpler than those in ORPM.
Analysis of Tailored Base-Surge Policies in Dual Sourcing Inventory Systems
Authors: Janakiraman Ganesh , Seshadri Sridhar , Sheopuri Anshul
Published: October 2014

We study a model of a firm managing its inventory of a single product by sourcing supplies from two supply sources, a regular supplier who offers a lower unit cost and a longer lead time than a second, emergency, supplier. A practically implementable policy for such a firm is a tailored base-surge (TBS) policy [Allon G, Van Mieghem JA (2010) Global dual sourcing: Tailored base-surge allocation to near- and offshore production. Management Sci. 56(1):110–124] to manage its inventory. Under this policy, the firm procures a constant quantity from the regular supplier in every period and dynamically makes procurement decisions for the emergency supplier. Allon and Van Mieghem describe this practice as using the regular supplier to meet a base level of demand and the emergency supplier to manage demand surges, and they conjecture that this practice is most effective when the lead time difference between the two suppliers is large. We confirm these statements in two ways. First, we show the following analytical result: when demand is composed of a base demand random component plus a surge demand random component, which occurs with a certain small probability, the best TBS policy is close to optimal (over all policies) in a well-defined sense. Second, we also numerically investigate the cost effectiveness of the best TBS policy on a test bed of problem instances. The emphasis of this investigation is the study of the effect of the lead time difference between the two suppliers. Our study reveals that the cost difference between the best TBS policy and the optimal policy decreases dramatically as the lead time of the regular supplier increases. On our test bed, this cost difference decreases from an average (over the test bed) of 21% when the lead time from the regular supplier is two periods (the emergency supplier offers instant delivery) to 3.5% when that lead time is seven periods.

This paper was accepted by Martin Lariviere, operations management.
Rational Information Leakage
Authors: Indjejikian Raffi , Lu Hai , Yang Liyan
Published: October 2014

Empirical evidence suggests that information leakage in capital markets is common. We present a trading model to study the incentives of an informed trader (e.g., a well-informed insider) to voluntarily leak information about an asset’s value to one or more independent traders. Our model shows that, although leaking information dissipates the insider’s information advantage about the asset’s value, it enhances his information advantage about the asset’s execution price relative to other informed traders. The profit impact of these two effects are countervailing. When there are a sufficient number of other informed traders, the profit impact from enhanced information dominates. Hence, the insider has incentives to leak some of his private information. We label this rational information leakage and discuss its implications for the regulation of insider trading.

This paper was accepted by Mary Barth, accounting.
Do Tips Increase Workers' Income?
Authors: Shy Oz
Published: October 2014

This paper constructs a model of service providers who compete in service and labor markets simultaneously to analyze the effects of tipping on hourly wages and total tip-inclusive hourly worker compensation. An increase in the tipping rate reduces hourly wages. Total worker compensation increases at different rates depending on the market structure, market coverage, and employment level, with the exception of price-taking (competitive) service providers, where the tip-inclusive hourly income declines with the tipping rate. The paper develops an index of “effective tipping” that measures the net percentage change in total hourly worker compensation associated with each tipping rate.

This paper was accepted by John List, behavioral economics.
Trading as Gambling
Authors: Dorn Anne Jones , Dorn Daniel , Sengmueller Paul
Published: October 2014

This paper offers evidence from three different samples consistent with investors substituting between playing the lottery and gambling in financial markets. In the United States, increases in the jackpots of the multistate lotteries Powerball and Mega Millions are associated with significant reductions in small trade participation in the stock market. California-based discount brokerage clients and German discount brokerage clients are significantly less likely to trade during weeks with larger lottery prizes in the California and German lotteries, respectively. Variation in lottery prizes affects speculative trading in more lottery-like securities such as individual stocks and options, but not trading in bonds and mutual funds. Trading that is likely associated with long-term savings motives, such as trading in retirement accounts, does not respond to lottery jackpots, either. The negative relation between trading activity and jackpots is stronger for individuals who are more likely to play the lottery.

This paper was accepted by Brad Barber, finance.
Contractual vs. Actual Separation Pay Following CEO Turnover
Authors: Goldman Eitan Moshe , Huang Peggy Peiju
Published: October 2014

Using hand-collected data, we document the details of the ex ante severance contracts and the ex post separation pay given to S&P 500 chief executive officers (CEOs) upon departing from their companies. We analyze what determines whether or not a CEO receives separation pay in excess of the amount specified in the severance contract. We find that discretionary separation pay is given to about 40% of departing CEOs and is, on average, $8 million, which amounts to close to 242% of a CEO’s annual compensation. We investigate the determinants of discretionary separation pay and find, for example, that discretionary separation pay positively correlates with weak internal governance in cases of voluntary CEO turnover but not when the CEO is forced out. We also find that discretionary pay is higher when the CEO has a noncompete clause in her ex ante severance contract. Event study analysis suggests that shareholders benefit from discretionary separation pay in forced turnovers but not in voluntary ones. Our overall results help to shed light on the complex role of discretionary separation pay in the bargaining game between boards and departing executives.

This paper was accepted by Itay Goldstein, finance.
Can Noise Create the Size and Value Effects?
Authors: Arnott Robert D. , Hsu Jason C. , Liu Jun , Markowitz Harry
Published: October 2014

If the price of a stock differs from its intrinsic value by a random noise, then value stocks are more likely to have negative noise; they are thus more likely undervalued and have higher expected return than justified by risk. The same intuition applies to small capitalization stocks. We formally verify and explore this intuition by using a standard noise-in-price model. This intuition is different from the Jensen’s inequality effect studied by Blume and Stambaugh [Blume ME, Stambaugh RF (1983) Biases in computed returns: An application to the size effect. J. Financial Econom. 12(3):387–404]. Our model is parsimonious: the value premium as well as size premium are computed in closed form and depend on only four parameters: mean of stock return, volatility of stock return, volatility of the price-to-dividend ratio, and noise volatility. We emphasize that only a moderate volatility of price noise is needed to generate the observed value premium. However, the model cannot generate the observed size premium.

This paper was accepted by Wei Jiang, finance.
Of Age, Sex, and Money: Insights from Corporate Officer Compensation on the Wage Inequality Between Genders
Authors: Newton David , Simutin Mikhail
Published: October 2014

This paper shows that the gender and age of the wage setter are crucial determinants of the disparity in wages between sexes. We document our findings using a data set on compensation of corporate officers that is uniquely suited for this analysis because officer wages are set by chief executive officers (CEOs). We show that CEOs pay officers of the opposite gender less than officers of their own gender, even when controlling for job characteristics. Older and male CEOs exhibit the greatest propensity to differentiate on the basis of sex. Female officers receive smaller raises if the firm is headed by a man. Our results suggest that CEO gender and age are economically more important determinants of officer compensation than are firm stock performance, stock volatility, or return on assets.

This paper was accepted by Uri Gneezy, behavioral economics.
Collaboration and Multitasking in Networks: Architectures, Bottlenecks, and Capacity
Authors: Gurvich Itai , Van Mieghem Jan A.
Published: October 2014

Motivated by the trend toward more collaboration in work flows, we study networks where some activities require the simultaneous processing by multiple types of multitasking human resources. Collaboration imposes constraints on the capacity of the process because multitasking resources have to be simultaneously at the right place. We introduce the notions of collaboration architecture and unavoidable bottleneck idleness to study the maximal throughput or capacity of such networks. Collaboration and multitasking introduce synchronization requirements that may inflict unavoidable idleness of the bottleneck resources: even when the network is continuously busy (processing at capacity), bottleneck resources can never be fully utilized. The conventional approach that equates network capacity with bottleneck capacity is then incorrect because the network capacity is below that of the bottlenecks. In fact, the gap between the two can grow linearly with the number of collaborative activities. Our main result is that networks with nested collaboration architectures have no unavoidable bottleneck idleness. Then, regardless of the processing times of the various activities, the standard bottleneck procedure correctly identifies the network capacity. We also prove necessity in the sense that, for any nonnested architecture, there are values of processing times for which unavoidable idleness persists. The fundamental trade-off between collaboration and capacity does not disappear in multiserver networks and has important ramifications to service-system staffing. Yet, even in multiserver networks, a nested collaboration architecture still guarantees that the bottleneck capacity is achievable. Finally, simultaneous collaboration, as a process constraint, may limit the benefits of flexibility. We study the interplay of flexibility and unavoidable idleness and offer remedies derived from collaboration architectures.
Limit Theorems for Markovian Bandwidth-Sharing Networks with Rate Constraints
Authors: Reed Josh , Zwart Bert
Published: October 2014

Bandwidth-sharing networks provide a natural modeling framework for describing the dynamic flow-level interaction among elastic data transfers in computer and communication systems, and can be used to develop traffic pricing/charging mechanisms. At the same time, such models are exciting from an operations research perspective because their analysis requires techniques from stochastic modeling and optimization.

In this paper, we develop a framework to approximate bandwidth-sharing networks under the assumption that the number of users as well as the capacities of the system are large, and the assumption that the traffic that each user is allowed to submit is bounded above by some rate, which is standard in practice. We also assume that customers on each route in the network abandon according to exponential patience times. Under Markovian assumptions, we develop fluid and diffusion approximations, which are quite tractable: for most parameter combinations, the invariant distribution is multivariate normal, with mean and diffusion coefficients that can be computed in polynomial time as a function of the size of the network.
Supervising Across Borders: The Case of Multinational Hierarchies
Authors: Zhou Yue Maggie
Published: October 2014

This paper examines how multinational corporations (MNCs) selectively assign supervisory responsibilities to units in countries with varying levels of institutional quality. Arbitraging across institutional contexts is an important function of MNCs, but it also creates coordination challenges. The choice of organization structure, such as the differential assignment of supervisory responsibilities, is an important tool for managing these coordination challenges. Using data on the business activities and supervision relationships within U.S. multinational manufacturers in 1996–2008, I find that frontline subsidiaries in countries with weaker institutions are more likely to be supervised by foreign rather than domestic supervisory units. Foreign supervision is even more likely when subsidiaries in weak-institution countries conduct activities that are more central to or interdependent with their parents’ global operations. These findings confirm that MNCs use differential supervision to enhance global coordination. The paper highlights one of the most unique features of MNCs: a multinational hierarchy that resides within a firm’s boundary but across national borders. It also connects MNCs’ hierarchical structure with institutional imperfections that give rise to the emergence of the firm in the first place.
Round-Based Public Transit Routing
Authors: Delling Daniel , Pajor Thomas , Werneck Renato F.
Published: October 2014

We study the problem of computing all Pareto-optimal journeys in a dynamic public transit network for multiple criteria, such as arrival time and number of transfers. Existing algorithms consider this as a graph problem and solve it using various graph search algorithms. Unfortunately, this leads to either high query times or suboptimal solutions. We take a different approach. We introduce RAPTOR, our novel round-based public transit router. Unlike previous algorithms, it is not Dijkstra-based, looks at each route (such as a bus line) in the network at most once per round, and can be made even faster with simple pruning rules and parallelization using multiple cores. Because it does not rely on preprocessing, RAPTOR works in fully dynamic scenarios. Starting from arrival time and number of transfers as criteria, it can be easily extended to handle flexible departure times or arbitrary additional criteria. As practical examples we consider fare zones and reliability of transfers. When run on complex public transportation networks (such as London), RAPTOR computes all Pareto-optimal journeys between two random locations an order of magnitude faster than previous approaches, which easily enables interactive applications.
Look out for each other
Authors: Goose Philip
Published: October 2014

Teachers have a vital part to play in raising awareness about the dangers posed to children on our roads. Participating in Road Safety Week is a good way to start.
Get to know your place in the world
Authors: Davis John
Published: October 2014

Key stage 1 pupils can start to develop their knowledge of place by exploring areas close to home. They can then apply the same principles to exploring further afield.
‘Colour the roses of Lancaster and York’
Authors: Bosley Rachel , Bosley Mark
Published: October 2014

Use this hands-on tutorial using Scratch programming to construct graphics linked to the Tudor period, and provide a springboard for pupils to learn about history.
Start learning this Important life skill
Authors: Francis-Pester Dawn
Published: October 2014

Dawn Francis-Pester examines why primary schools are teaching British Sign Language, where it fits on the curriculum and how to find teachers and resources.