Every planar graph with the Liouville property is amenable

We introduce a strengthening of the notion of transience for planar maps in order to relax the standard condition of bounded degree appearing in various results, in particular, the existence of Dirichlet harmonic functions proved by Benjamini and Schramm. As a corollary we obtain that every planar non-amenable graph admits Dirichlet harmonic functions

The impact of active workstations on workplace productivity and performance: a systematic review

Active workstations have been recommended for reducing sedentary behavior in the workplace. It is important to understand if the use of these workstations has an impact on worker productivity. The aim of this systematic review was to examine the effect of active workstations on workplace productivity and performance. A total of 3303 articles were initially identified by a systematic search and seven articles met eligibility criteria for inclusion. A quality appraisal was conducted to assess risk of bias, confounding, internal and external validity, and reporting. Most of the studies reported cognitive performance as opposed to productivity. Five studies assessed cognitive performance during use of an active workstation, usually in a single session. Sit-stand desks had no detrimental effect on performance, however, some studies with treadmill and cycling workstations identified potential decreases in performance. Many of the studies lacked the power required to achieve statistical significance. Three studies assessed workplace productivity after prolonged use of an active workstation for between 12 and 52 weeks. These studies reported no significant effect on productivity. Active workstations do not appear to decrease workplace performance

Kinetic energies of fragment ions produced by dissociative photoionization of NO

The kinetic energies of ions produced by dissociative photoionization of NO have been measured at the discrete resonance lines of He (584A) and Ne (736A), and with undispersed synchrotron radiation. O sup + ions were identified with energies from 0 to approximately 0.5 eV and two groups of N sup + ions one with energy of 0.36 eV and another with energies between 0.9 and 1.5 eV, apparently produced by predissociation of the C sup 3 P 1 and B'1 sigma states respectively

The free energy in a class of quantum spin systems and interchange processes

We study a class of quantum spin systems in the mean-field setting of the complete graph. For spin $S=\tfrac12$ the model is the Heisenberg ferromagnet, for general spin $S\in\tfrac12\mathbb{N}$ it has a probabilistic representation as a cycle-weighted interchange process. We determine the free energy and the critical temperature (recovering results by T\'oth and by Penrose when $S=\tfrac12$). The critical temperature is shown to coincide (as a function of $S$) with that of the $q=2S+1$ state classical Potts model, and the phase transition is discontinuous when $S\geq1$.Comment: 22 page

A test for the search for life on extrasolar planets: Looking for the terrestrial vegetation signature in the Earthshine spectrum

We report spectroscopic observations (400 to 800nm, R = approx 100) of Earthshine in June, July and October 2001 from which normalised Earth albedo spectra have been derived. The resulting spectra clearly show the blue colour of the Earth due to Rayleigh diffusion in its atmosphere. They also show the signatures of oxygen, ozone and water vapour. We tried to extract from these spectra the signature of Earth vegetation. A variable signal (4 to 10 +/-3%) around 700nm has been measured in the Earth albedo. It is interpreted as being due to the vegetation red edge, expected to be between 2 to 10% of the Earth albedo at 700nm, depending on models. We discuss the primary goal of the present observations: their application to the detection of vegetation-like biosignatures on extrasolar planets.Comment: 7 pages, 7 figures. A&A, accepted 6 May 200

Self-other agreement measures of acceptance in predicting academic achievement: A longitudinal analysis

This research focused on sed light to the process that surrounded accuracy perception of acceptance status during adolescence from a non-componential view of social perception. With a longitudinal data of adolescents, mediational models are proposed in order to understand the different types of accuracy measures developed, and how they worked to finally predict academic achievement..

Phase-Induced Amplitude Apodization of Telescope Pupils for Extrasolar Terrestrial Planet Imaging

In this paper, an alternative to the classical pupil apodization techniques (use of an amplitude pupil mask) is proposed. It is shown that an apodized pupil suitable for imaging of Extrasolar planets can be obtained by reflection of an unapodized flat wavefront on 2 mirrors. By carefully choosing the shape of these 2 mirrors, it is possible to obtain a contrast better than 10^{9} at a distance smaller than 2 \lambda/d from the optical axis. Because this technique preserves both the angular resolution and light gathering capabilities of the unapodized pupil, it allows efficient detection of terrestrial extrasolar planets with a 1.5m telescope in the visible.Comment: 9 pages, 9 figures, Accepted for publication in A&A. Postscript file with full-resolution figures can be found at http://www.naoj.org/staff/guyon/publications/PIAA.p

Gaucher\u27s Disease: Case Report with Stress on Eye Findings

This interesting case report comes from an alumnus of Henry Ford Hospital - Dr. Carlos Petrozzi who was a medical resident here from July 1961 to 1964. The findings may be of interest to opththalmologists and others because of the rather specific changes in the bulbar conjunctiva which can be easily seen without special ophthalmic instruments

Alkali activation of fly ashes part II: Mechanochemical pre-processing as way to optimize the reactivity

Good quality fly ash is in demand in the cement and concrete industries due to its ability to replace clinker Portland in blended cements and Portland cements in concrete. In this paper the authors show how by mechanochemical activation of fly ashes it is possible to increase the amount of fly ashes added to cement and concrete. The objective pursued in this study was to determine the mechanical properties and mineralogical characteristics of some mortars and concretes containing a high percentage of fly ash additions (50%): A= original fly ash; B= mechanically activated fly ash, C= mechanochemically activated fly ash. The mechanical strength of mortars prisms (4x4x16cm) were determined at early and long ages (1, 2, 7, 28, 90 and 180 days) at room temperature; also some concrete cubes (15x15x15cm) were analysed. The setting time and the heat flow released in the hydration process were additionally determined