352 research outputs found
Non-existence of equilibria with free elimination
This work is concerned in the existence problem of equilibria for economies with increasing returns to scale. The consequences of relaxing the free disposal assumption are investigated. It is sown that the free disposal assumption can not be dropped, not even relaxed to the assumption of free elimination, without risking that equilibria may fail to exist. This may give new insight to the work of Giraud (2000) and Jouini (1992), because they proved the existence of equilibria for economies without free disposal assuming the production sets to verify (even weaker forms of) free elimination.Free disposal, increasing returns to scale, marginal pricing, non-convex production.
Non-existence of equilibria with free elimination
URL des Cahiers : https://halshs.archives-ouvertes.fr/CAHIERS-MSECahiers de la Maison des Sciences Economiques 2005.57 - ISSN : 1624-0340This work is concerned in the existence problem of equilibria for economies with increasing returns to scale. The consequences of relaxing the free disposal assumption are investigated. It is sown that the free disposal assumption can not be dropped, not even relaxed to the assumption of free elimination, without risking that equilibria may fail to exist. This may give new insight to the work of Giraud (2000) and Jouini (1992), because they proved the existence of equilibria for economies without free disposal assuming the production sets to verify (even weaker forms of) free elimination.Ce travail concerne le problème de l'existence d'équilibre pour des économies aux rendements d'échelle croissants. Les conséquences d'une relaxation de l'hypothèse de la libre disposition sont étudiés. Il est montré que l'hypothèse de la libre disposition ne peut être laisser tombé, même pas relaxé à l'hypothèse de la libre élimination, sans risqué qu'il n'existe plus d'équilibres. Cela peut donner de nouvelles perspicacités aux travaux de Giraud (2000) et de Jouini (1992), car ils démontrent l'existence d'équilibre pour des économies sans libre disposition, supposant que les ensembles de production vérifient (même des formes plus faibles) de l'hypothèse de la libre élimination
Epithelial-mesenchymal transdifferentiation in pediatric lens epithelial cells
PURPOSE. Posterior capsule opacification (PCO) is a complication after cataract surgery, particularly in children. Epithelial-mesenchymal transition (EMT) of lens epithelial cells, mediated by transforming growth factor beta (TGF beta), contributes to PCO. However, its pathogenesis in children is poorly understood. We correlated cell growth in culture with patient characteristics, studied gene expression of pediatric lens epithelial cells (pLEC), and examined the effects of TGF beta-2 on these cells in vitro. METHODS. Clinical characteristics of children with cataracts correlated with growth behavior of pLEC in vitro. mRNA expression of epithelial (alpha B-crystallin, connexin-43) and mesenchymal (alpha(V)-integrin, alpha-smooth muscle actin, collagen-I alpha 2, fibronectin-1) markers was quantified in pLEC and in cell line HLE-B3 in the presence and absence of TGF beta-2. RESULTS. Fifty-four anterior lens capsules from 40 children aged 1 to 180 months were obtained. Cell outgrowth occurred in 44% of the capsules from patients <= 12 months and in 33% of capsules from children aged 13 to 60 months, but in only 6% of capsules from children over 60 months. TGF beta-2 significantly upregulated expression of alpha B-crystallin (HLE-B3), alpha(V)-integrin (HLE-B3), collagen-I alpha 2, and fibronectin-1 (in pLEC and HLE-B3 cells). CONCLUSIONS. Patient characteristics correlated with growth behavior of pLEC in vitro, paralleling a higher clinical incidence of PCO in younger children. Gene expression profiles of pLEC and HLE-B3 suggest that upregulation of alpha(V)-integrin, collagen-I alpha 2, and fibronectin-1 are involved in EMT
A Tangible Solution for Hand Motion Tracking in Clinical Applications
Objective real-time assessment of hand motion is crucial in many clinical applications including technically-assisted physical rehabilitation of the upper extremity. We propose an inertial-sensor-based hand motion tracking system and a set of dual-quaternion-based methods for estimation of finger segment orientations and fingertip positions. The proposed system addresses the specific requirements of clinical applications in two ways: (1) In contrast to glove-based approaches, the proposed solution maintains the sense of touch. (2) In contrast to previous work, the proposed methods avoid the use of complex calibration procedures, which means that they are suitable for patients with severe motor impairment of the hand. To overcome the limited significance of validation in lab environments with homogeneous magnetic fields, we validate the proposed system using functional hand motions in the presence of severe magnetic disturbances as they appear in realistic clinical settings. We show that standard sensor fusion methods that rely on magnetometer readings may perform well in perfect laboratory environments but can lead to more than 15 cm root-mean-square error for the fingertip distances in realistic environments, while our advanced method yields root-mean-square errors below 2 cm for all performed motions.DFG, 414044773, Open Access Publizieren 2019 - 2020 / Technische Universität Berli
Concentration Dependence of Superconductivity and Order-Disorder Transition in the Hexagonal Rubidium Tungsten Bronze RbxWO3. Interfacial and bulk properties
We revisited the problem of the stability of the superconducting state in
RbxWO3 and identified the main causes of the contradictory data previously
published. We have shown that the ordering of the Rb vacancies in the
nonstoichiometric compounds have a major detrimental effect on the
superconducting temperature Tc.The order-disorder transition is first order
only near x = 0.25, where it cannot be quenched effectively and Tc is reduced
below 1K. We found that the high Tc's which were sometimes deduced from
resistivity measurements, and attributed to compounds with .25 < x < .30, are
to be ascribed to interfacial superconductivity which generates spectacular
non-linear effects. We also clarified the effect of acid etching and set more
precisely the low-rubidium-content boundary of the hexagonal phase.This work
makes clear that Tc would increase continuously (from 2 K to 5.5 K) as we
approach this boundary (x = 0.20), if no ordering would take place - as its is
approximately the case in CsxWO3. This behaviour is reminiscent of the
tetragonal tungsten bronze NaxWO3 and asks the same question : what mechanism
is responsible for this large increase of Tc despite the considerable
associated reduction of the electron density of state ? By reviewing the other
available data on these bronzes we conclude that the theoretical models which
are able to answer this question are probably those where the instability of
the lattice plays a major role and, particularly, the model which call upon
local structural excitations (LSE), associated with the missing alkali atoms.Comment: To be published in Physical Review
Parmodulins Inhibit Thrombus Formation Without Inducing Endothelial Injury Caused by Vorapaxar
Protease-activated receptor-1 (PAR1) couples the coagulation cascade to platelet activation during myocardial infarction and to endothelial inflammation during sepsis. This receptor demonstrates marked signaling bias. Its activation by thrombin stimulates prothrombotic and proinflammatory signaling, whereas its activation by activated protein C (APC) stimulates cytoprotective and antiinflammatory signaling. A challenge in developing PAR1-targeted therapies is to inhibit detrimental signaling while sparing beneficial pathways. We now characterize a novel class of structurally unrelated small-molecule PAR1 antagonists, termed parmodulins, and compare the activity of these compounds to previously characterized compounds that act at the PAR1 ligand–binding site. We find that parmodulins target the cytoplasmic face of PAR1 without modifying the ligand-binding site, blocking signaling through Gαq but not Gα13 in vitro and thrombus formation in vivo. In endothelium, parmodulins inhibit prothrombotic and proinflammatory signaling without blocking APC-mediated pathways or inducing endothelial injury. In contrast, orthosteric PAR1 antagonists such as vorapaxar inhibit all signaling downstream of PAR1. Furthermore, exposure of endothelial cells to nanomolar concentrations of vorapaxar induces endothelial cell barrier dysfunction and apoptosis. These studies demonstrate how functionally selective antagonism can be achieved by targeting the cytoplasmic face of a G-protein–coupled receptor to selectively block pathologic signaling while preserving cytoprotective pathways
El trágico fracaso de lo cómico. Lo cómico en el pensamiento estético de Wolgang Heise sobre el teatro y la representación
The purpose of this article is the theoretical discussion of Wolfgang Heise, philosopher and aesthete (Dean of the Institute of Aesthetics at the Humboldt University in Berlin), concerning the comic in the field of the theater and its representation. El propósito de este artículo es la discusión teórica del filósofo y esteta Wolfgang Heise (Decano del Instituto de Estética de la Universidad Humboldt de Berlín) sobre lo cómico en las áreas del teatro y la representación
The influence of cycloplegic in objective refraction
The purpose of this study was to compare refractions measured with an autorefractor and retinoscopy in cycloplegic and non-cycloplegic eyes.
The objective refractions were performed in 199 right eyes from 199 healthy young adults with a mean age of 21.6 ±2.66 years. The measurements were performed first without cycloplegia and repeated 30 minutes later with cycloplegia.
Data were analyzed using Fourier decomposition of the power profile.
More negative values of component M and J0 were give by non-cycloplegic autorefraction compared to cycloplegic autorefraction (p<0.001). However more positive values were given by non-cycloplegic autorefraciton regarding to the J45 vector, althought this differences were not statistically significant (p=0.233).
Regarding retinoscopy, more negative values of component M where obtained with non-cycloplegic retinoscopy (p<0.001); for the cylindrical vectors J0 and J45 the retinoscopy without cycloplegic yields more negative values (p= 0.234; p= 0.112, respectively).
Accepting that differences between cycloplegic and non-cycloplegic retinoscopy are only due to accommodative response, present results confirm that when performed by an experienced clinician, retinoscopy is a more reliable method to obtain objective start point for refraction under non-cycloplegic conditions
Type Traces: For Letterform Lovers
This book was completed for Jan Baker\u27s artists\u27 book class, Printed Books.https://digitalcommons.risd.edu/specialcollections_bookmark_letters/1023/thumbnail.jp
Challenges and opportunities in the care of survivors of adolescent and young adult (AYA) cancers
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