pinecone/core-2020-05-10-deduplication huggingface dataset:
Changes in REIT liquidity 1988 - 2007: Evidence from daily data

In this study, we present panel-data evidence on REIT liquidity and its determinants over the 1988 – 2007 period. We focus upon liquidity measures that do not require micro-structure data (1) to facilitate use of our results as benchmarks for comparisons with results from international markets for which micro-structure data may be unavailable, (2) to provide benchmarks that do not require access to costly (and voluminous) micro-structure data. We find that REIT liquidity improved during the early and mid-1990s, deteriorated during the late 1990s, and then improved dramatically during 2000 – 2006, with the notable exception of 2007. Liquidity improved the most for REITs traded on the NYSE, and was an order of magnitude better than liquidity of REITs traded on the AMEX or NASDAQ. We link the deterioration in liquidity observed in 2007 to the investment portfolio of a REIT. We find that the percentage bid-ask spread is highly correlated with the measure of price impact proposed by Amihud (2002). We provide panel-data evidence on the key determinants of the percentage bid-ask spread that largely confirms the results reported by Bhasin, Cole and Kiely (1997) for 1990 and 1994: the percentage spread is a positive function of the volatility of stock returns, and a negative function of dollar volume turnover, share price and market capitalization. Finally, we provide evidence that these results obtained using daily closing bid- and ask-prices are not qualitatively different from those obtained using market micro-structure data. This suggests that we can use liquidity measures based upon readily available daily return data rather than being forced to rely upon market micro-structure data.
Prewavy instability of nematic liquid crystals in a high-frequency electric field

A kind of electrohydrodynamic instability, the prewavy instability, in nematic liquid crystals is reported. The characteristic of the instability was optically investigated and discussed in comparison with some similar instabilities. Obviously the instability partially shows an isotropic feature around the nematic-isotropic transition temperature. Owing to the characteristic properties of the flow and the spatial periodicity, it should be distinguished from a previously proposed isotropic instability
Theoretical and Experimental Analysis of the Equilibrium Contours of Liquid Bridges of Arbitrary Shape

The equilibrium shape of the liquid bridge interface is analyzed theoretically and experimentally.Both axisymmetric and nonaxisymmetric perturbations are considered. The axisymmetric deviationsare those related to volume effects, the difference between the radii of the disks, and the axial forcesacting on the liquid bridge. The nonaxisymmetric deviations are those due to the eccentricity of thedisk and the action of lateral forces. The theoretical study is performed using three differenttechniques: ~i! an analytical expansion around the cylindrical solution, ~ii! a finite differencescheme, and ~iii! an approximate numerical approach valid only for slight nonaxisymmetricdeviations. The results of the three methods are compared systematically. There is a very goodagreement between the analytical and the numerical approaches for contours which are close tocylindrical, and the agreement extends to configurations with only moderate deviations fromcylindrical. Experiments are performed using the so-called neutral buoyancy or plateau technique.Theoretical and experimental contours are compared considering a wide range of values for theparameters characterizing the perturbations. In general, the finite difference method providesreasonably accurate predictions even for large deviations of the liquid bridge contour fromcylindrical
The zero-removing property in some Hilbert spaces of entire functions arising in sampling theory

In the topic of sampling in reproducing kernel Hilbert spaces, sampling in Paley–Wiener spaces is the paradigmatic example. A natural generalization of Paley–Wiener spaces is obtained by substituting the Fourier kernel with an analytic Hilbert-space-valued kernel K. Thus we obtain a reproducing kernel Hilbert space HKHK of entire functions in which the Kramer property allows to prove a sampling theorem. A necessary and sufficient condition ensuring that this sampling formula can be written as a Lagrange-type interpolation series concerns the stability under removal of a finite number of zeros of the functions belonging to the space HKHK; this is the so-called zero-removing property. This work is devoted to the study of the zero-removing property in HKHK spaces, regardless of the Kramer property, revealing its connections with other mathematical fields
The Epistemic Virtues of the Virtuous Theorist: On Albert Einstein and His Autobiography

Albert Einstein’s practice in physics and his philosophical positions gradually reoriented themselves from more empiricist towards rationalist viewpoints. This change accompanied his turn towards unified field theory and different presentations of himself, eventually leading to his highly programmatic Autobiographical Notes in 1949. Einstein enlisted his own history and professional stature to mold an ideal of a theoretical physicist who represented particular epistemic virtues and moral qualities. These in turn reflected the theoretical ideas of his strongly mathematical unification program and professed Spinozist beliefs
The political economy of natural disaster damage

Economic damage from natural hazards can sometimes be prevented and always mitigated. However, private individuals tend to underinvest in such measures due to problems of collective action, information asymmetry and myopic behavior. Governments, which can in principle correct these market failures, themselves face incentives to underinvest in costly disaster prevention policies and damage mitigation regulations. Yet, disaster damage varies greatly across countries. We argue that rational actors will invest more in trying to prevent and mitigate damage the larger a country's propensity to experience frequent and strong natural hazards. Accordingly, economic loss from an actually occurring disaster will be smaller the larger a country's disaster propensity - holding everything else equal, such as hazard magnitude, the country's total wealth and per capita income. At the same time, damage is not entirely preventable and smaller losses tend to be random. Disaster propensity will therefore have a larger marginal effect on larger predicted damages than on smaller ones. We employ quantile regression analysis in a global sample to test these predictions, focusing on the three disaster types causing the vast majority of damage worldwide: earthquakes, floods and tropical cyclones
Fabrication of luminescent nanostructures by electron-beam direct writing of PMMA resist

We report on the conversion of non-luminescent conventional poly(methylmethacrylate) (PMMA)-based electron-beam resists into luminescent materials when used as negative-tone resists, that is, when exposed to high electron irradiation doses. Raman spectroscopy reveals the chemical transformation induced by electron irradiation which is responsible for the observed luminescence in the visible (blue) region. The emission intensity from exposed PMMA-based patterns can be controlled by the electron irradiation dose employed to create them
A mathematical framework for new fault detection schemes in nonlinear stochastic continuous-time dynamical systems

n this work, a mathematical unifying framework for designing new fault detection schemes in nonlinear stochastic continuous-time dynamical systems is developed. These schemes are based on a stochastic process, called the residual, which reflects the system behavior and whose changes are to be detected. A quickest detection scheme for the residual is proposed, which is based on the computed likelihood ratios for time-varying statistical changes in the Ornstein–Uhlenbeck process. Several expressions are provided, depending on a priori knowledge of the fault, which can be employed in a proposed CUSUM-type approximated scheme. This general setting gathers different existing fault detection schemes within a unifying framework, and allows for the definition of new ones. A comparative simulation example illustrates the behavior of the proposed schemes
How do interactive tabletop systems influence collaboration?

This paper examines some aspects of the usefulness of interactive tabletop systems, if and how these impact collaboration. We chose creative problem solving such as brainstorming as an application framework to test several collaborative media: the use of pen-and-paper tools, the ‘‘around-the-table’’ form factor, the digital tabletop interface, the attractiveness of interaction styles. Eighty subjects in total (20 groups of four members) participated in the experiments. The evaluation criteria were task performance, collaboration patterns (especially equity of contributions), and users’ subjective experience. The ‘‘aroundthe-table’’ form factor, which is hypothesized to promote social comparison, increased performance and improved collaboration through an increase of equity. Moreover, the attractiveness of the tabletop device improved subjective experience and increased motivation to engage in the task. However, designing attractiveness seems a highly challenging issue, since overly attractive interfaces may distract users from the task
One single dose of etomidate negatively influences adrenocortical performance for at least 24 h in children with meningococcal sepsis

Objective: To investigate the effect of one single bolus of etomidate used for intubation on adrenal function in children with meningococcal sepsis. Design: Retrospective study conducted between 1997 and 2004. Setting: University-affiliated paediatric intensive care unit (PICU). Patients and participants: Sixty children admitted to the PICU with meningococcal sepsis, not treated with steroids. Interventions: Adrenal hormone concentrations were determined as soon as possible after PICU admission, and after 12 h and 24 h. To assess disease severity, PRISM score and selected laboratory parameters were determined. Measurements and main results: On admission, before blood was drawn, 23 children had been intubated with etomidate, 8 without etomidate and 29 were not intubated. Children who were intubated had significantly higher disease severity parameters than those not intubated, whereas none of these parameters significantly differed between children intubated with or without etomidate. Children who received etomidate had significantly lower cortisol, higher ACTH and higher 11-deoxycortisol levels than those who did not receive etomidate. Arterial glucose levels were significantly lower in children who were intubated with etomidate than in non-intubated children. When children were intubated with etomidate, cortisol levels were 3.2 times lower for comparable 11-deoxycortisol levels. Eight children died, seven of whom had received etomidate. Within 24 h cortisol/ACTH and cortisol/11-deoxycortisol ratios increased significantly in children who received etomidate, but not in children who did not, resulting in comparable cortisol/ACTH ratios with still significantly lowered cortisol/11-deoxycortisol ratios 24 h after admission. Conclusions: Our data imply that even one single bolus of etomidate negatively influences adrenal function for at least 24 h. It might therefore increase risk of death
Novel haloalkaliphilic methanotrophic bacteria: An attempt for enhancing methane bio-refinery

Producción CientíficaMethane bioconversion into products with a high market value, such as ectoine or hydroxyectoine, can be optimized via isolation of more efficient novel methanotrophic bacteria. The research here presented focused on the enrichment of methanotrophic consortia able to co-produce different ectoines during CH4 metabolism. Four different enrichments (Cow3, Slu3, Cow6 and Slu6) were carried out in basal media supplemented with 3 and 6% NaCl, and using methane as the sole carbon and energy source. The highest ectoine accumulation (∼20 mg ectoine g biomass−1) was recorded in the two consortia enriched at 6% NaCl (Cow6 and Slu6). Moreover, hydroxyectoine was detected for the first time using methane as a feedstock in Cow6 and Slu6 (∼5 mg g biomass−1). The majority of the haloalkaliphilic bacteria identified by 16S rRNA community profiling in both consortia have not been previously described as methanotrophs. From these enrichments, two novel strains (representing novel species) capable of using methane as the sole carbon and energy source were isolated: Alishewanella sp. strain RM1 and Halomonas sp. strain PGE1. Halomonas sp. strain PGE1 showed higher ectoine yields (70–92 mg ectoine g biomass−1) than those previously described for other methanotrophs under continuous cultivation mode (∼37–70 mg ectoine g biomass−1). The results here obtained highlight the potential of isolating novel methanotrophs in order to boost the competitiveness of industrial CH4-based ectoine production.Ministerio de Economía, Industria y Competitividad (Project CTM2015-70442-R project and Red NOVEDAR)Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. UIC71)European Union through the FEDER Funding Program  (PhD Grant contract Nº E-47-2014-0140696
Silica grafted polyethylenimine as heterogeneous catalyst for condensation reactions

Primary amine groups were attached to a silica surface by using α,ω-diamines derivatives
and (3-glycidyloxypropyl)-trimethoxysilane activation. The same activation was used to
graft polyethylenimine, which also contains secondary and tertiary amine groups. These
silica aminated structures were tested as heterogeneous catalysts in nitroaldol
condensation with nitromethane, the derivative with the polyethylenimine moiety being
the more active catalyst. This catalyst also showed efficiency in the Knoevenagel
condensation of benzaldehydes with ethyl cyanoacetate under very mild reaction
conditions and showed much the same efficiency when used in consecutive reaction runs.
A reaction mechanism with participation of the several amine groups of the catalysts is
discussed
The Super-Higgs Mechanism in Fluids

Supersymmetry is spontaneously broken when the field theory stress-energy
tensor has a non-zero vacuum expectation value. In local supersymmetric field
theories the massless gravitino and goldstino combine via the super-Higgs
mechanism to a massive gravitino. We study this mechanism in four-dimensional
fluids, where the vacuum expectation value of the stress-energy tensor breaks
spontaneously both supersymmetry and Lorentz symmetry. We consider both
constant as well as space-time dependent ideal fluids. We derive a formula for
the gravitino mass in terms of the fluid velocity, energy density and pressure.
We discuss some of the phenomenological implications.Comment: 16 page
Variational Multi-Time Green's Functions for Nonequilibrium Quantum
  Fields

The time-dependent variational principle proposed by Balian and Veneroni is
used to provide the best approximation to the generating functional for
multi-time Green's functions of a set of (bosonic) observables $Q_{\mu)$. By
suitably restricting the trial spaces, the computation of the two-time Green's
function, obtained by a second order expansion in the sources, is considerably
simplified. This leads to a tractable formalism suited to quantum fields out of
equilibrium. We propose an illustration on the finite temperature ${\bf\Phi^4}$
theory in curved space and coupled to gravity.Comment: 20 page
An Analytical Model for Repositioning of 6 D.O.F Fixturing System

Lien vers la version éditeur: http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8749247&fulltextType=RA&fileId=S2257777712000164Dimensional errors of the parts from a part family cause the initial misplacement of the workpiece on the ﬁxture aﬀecting the ﬁnal product quality. Even if the part is positioned correctly, the external machining forces and clamping load cause the part to deviate from its position. This deviation depends on the external load and the ﬁxture stiﬀness.
In this article, a comprehensive analytical model of a 3-2-1 ﬁxturing system is proposed, consisting of a kinematic and a mechanical part. The kinematic model relocates the initially misplaced workpiece in the machine reference through the axial advancements of six locators taking all the ﬁxturing elements to be rigid. The repositioned part then shifts again from the corrected position due to the deformation of ﬁxturing elements under clamping and machining forces. The mechanical model calculates this displacement of the part considering the locators and clamps to be elastic.  The rigid cuboid baseplate, used to precisely re-locate the workpiece, is also considered elastic at the interface with the locators. Using small displacement hypothesis with zero friction at the contact points, Lagrangian formulation enables us to calculate the rigid body displacement of the workpiece, deformation of each locator, as well as the stiﬀness matrix and mechanical behavior of the ﬁxturing system.
This displacement of the workpiece is then ﬁnally compensated by the advancement of the six axial locators calculated through the kinematic model
Some aspects of holographic W-gravity

We use the Chern-Simons formulation of higher spin theories in three
dimensions to study aspects of holographic W-gravity. Concepts which were
useful in studies of pure bulk gravity theories, such as the Fefferman-Graham
gauge and the residual gauge transformations, which induce Weyl transformations
in the boundary theory and their higher spin generalizations, are reformulated
in the Chern-Simons language. Flat connections that correspond to conformal and
lightcone gauges in the boundary theory are considered.Comment: 42 page
An Integrated Assessment of changes in the thermohaline circulation

This paper discusses the risks of a shutdown of the thermohaline circulation (THC) for the climate system, for ecosystems in and around the North Atlantic as well as for fisheries and agriculture by way of an Integrated Assessment. The climate model simulations are based on greenhouse gas scenarios for the 21st century and beyond. A shutdown of the THC, complete by 2150, is triggered if increased freshwater input from inland ice melt or enhanced runoff is assumed. The shutdown retards the greenhouse gas-induced atmospheric warming trend in the Northern Hemisphere, but does not lead to a persistent net cooling. Due to the simulated THC shutdown the sea level at the North Atlantic shores rises by up to 80 cm by 2150, in addition to the global sea level rise. This could potentially be a serious impact that requires expensive coastal protection measures. A reduction of marine net primary productivity is associated with the impacts of warming rather than a THC shutdown. Regional shifts in the currents in the Nordic Seas could strongly deteriorate survival chances for cod larvae and juveniles. This could lead to cod fisheries becoming unprofitable by the end of the 21st century. While regional socioeconomic impacts might be large, damages would be probably small in relation to the respective gross national products. Terrestrial ecosystem productivity is affected much more by the fertilization from the increasing CO2 concentration than by a THC shutdown. In addition, the level of warming in the 22nd to 24th century favours crop production in northern Europe a lot, no matter whether the THC shuts down or not. CO2 emissions corridors aimed at limiting the risk of a THC breakdown to 10% or less are narrow, requiring departure from business-as-usual in the next few decades. The uncertainty about THC risks is still high. This is seen in model analyses as well as in the experts' views that were elicited. The overview of results presented here is the outcome of the Integrated Assessment project INTEGRATION
Permeability of rapid prototyped artificial bone scaffold structures.

In this work, various three-dimensional (3D) scaffolds were produced via microstereolithography (m-SLA) and 3D printing (3DP) techniques. This work demonstrates the advantages and disadvantages of these two different rapid prototyping methods for production of bone scaffolds. Compared to 3DP, SLA provides for smaller feature production with better dimensional resolution and accuracy. The permeability of these structures was evaluated experimentally and via numerical simulation utilizing a newly derived Kozeny– Carman based equation for intrinsic permeability. Both experimental and simulation studies took account of porosity percentage, pore size, and pore geometry. Porosity content was varied from 30% to 70%, pore size from 0.34 mm to 3 mm, and pore geometries of cubic and hexagonal closed packed were examined. Two different fluid viscosity levels of 1 mPas and 3.6 mPas were used. The experimental and theoretical results indicated that permeability increased when larger pore size, increased fluid viscosity, and higher percentage porosity were utilized, with highest to lowest degree of significance following the same order. Higher viscosity was found to result in permeabilities 2.2 to 3.3 times higher than for water. This latter result was found to be independent of pore morphology type. As well as demonstrating method for determining design parameters most beneficial for scaffold structure design, the results also illustrate how the variations in patient’s blood viscosity can be extremely important in allowing for permeability through the bone and scaffold structures
Neutronics and activation of the preliminary reaction chamber of HiPER reactor based in a SCLL blanket

The HiPER reactor design is exploring different reaction chambers. In this study, we tackle the neutronicsand activation studies of a preliminary reaction chamber based in the following technologies: unpro-tected dry wall for the First Wall, self-cooled lead lithium blanket, and independent low activation steelVacuum Vessel. The most critical free parameter in this stage is the blanket thickness, as a function ofthe6Li enrichment. After a parametric study, we select for study both a ?thin? and ?thick? blanket, with?high? and ?low?6Li enrichment respectively, to reach a TBR = 1.1. To help to make a choice, we com-pute, for both blanket options, in addition to the TBR, the energy amplification factor, the tritium partialpressure, the203Hg and210Po total activity in the LiPb loop, and the Vacuum Vessel thickness requiredto guarantee the reweldability during its lifetime. The thin blanket shows a superior performance in thesafety related issues and structural viability, but it operates at higher6Li enrichment. It is selected forfurther improvements. The Vacuum Vessel shows to be unviable in both cases, with the thickness varyingbetween 39 and 52 cm. Further chamber modifications, such as the introduction of a neutron reflector,are required to exploit the benefits of the thin blanket with a reasonable Vacuum Vessel