829 research outputs found
User's Guide for ERB 7 Matrix. Volume 1: Experiment Description and Quality Control Report for Year 1
The Nimbus 7 ERB MATRIX Tape is a computer program in which radiances and irradiances are converted into fluxes which are used to compute the basic scientific output parameters, emitted flux, albedo, and net radiation. They are spatially averaged and presented as time averages over one-day, six-day, and monthly periods. MATRIX data for the period November 16, 1978 through October 31, 1979 are presented. Described are the Earth Radiation Budget experiment, the Science Quality Control Report, Items checked by the MATRIX Science Quality Control Program, and Science Quality Control Data Analysis Report. Additional material from the detailed scientific quality control of the tapes which may be very useful to a user of the MATRIX tapes is included. Known errors and data problems and some suggestions on how to use the data for further climatologic and atmospheric physics studies are also discussed
Force balance in canonical ensembles of static granular packings
We investigate the role of local force balance in the transition from a
microcanonical ensemble of static granular packings, characterized by an
invariant stress, to a canonical ensemble. Packings in two dimensions admit a
reciprocal tiling, and a collective effect of force balance is that the area of
this tiling is also invariant in a microcanonical ensemble. We present
analytical relations between stress, tiling area and tiling area fluctuations,
and show that a canonical ensemble can be characterized by an intensive
thermodynamic parameter conjugate to one or the other. We test the equivalence
of different ensembles through the first canonical simulations of the force
network ensemble, a model system.Comment: 9 pages, 9 figures, submitted to JSTA
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Function of B cells expressing a human immunoglobulin M rheumatoid factor autoantibody in transgenic mice.
We have generated transgenic mice that express the immunoglobulin (Ig)M heavy chain and kappa light chain genes coding for a human IgM rheumatoid factor (RF), Les. Transgenic B cells expressing human IgM RF show striking similarities to their counterparts in normal humans. They comprise a significant proportion of the adult B cell population, but secrete only low levels of RF into the serum. The RF transgene-expressing B cells localize to primary B cell follicles and the mantle zone regions of secondary follicles in the spleen. Using these mice we have been able to show that one of the central functions of normal RF-expressing B cells may be to act as highly efficient antigen-presenting cells for low concentrations of immune-complexed antigen. High levels of secretion of IgM RF can not be induced under normal circumstances, although RF-expressing B cells proliferate well in vitro to both aggregated human IgG and anti-human IgM antibodies. However, these mice are not intrinsically secretion deficient. By crossing the RF transgenic mice with the autoimmune MRL/lpr background, we find a dramatic increase, > 200-fold, in levels of serum RF. The results strongly suggest that a major function of normal resting RF B cells is unrelated to antibody secretion. Rather, the RF B cells in the follicles may play a role in antigen presentation and regulation of immune responses to antibody-bound nonself-, and possibly self-antigens. This physiologic role of RF B cells may be disrupted in RF-associated autoimmune disease
Training for the Bar - Educational (R)evolution
On 25th June 2013, the Legal Education and Training Review published its report on the legal education landscape and made 26 recommendations for change. Over the past 5 years the legal regulators have considered these recommendations and developed and consulted on new education and training pathways and assessment strategies. This article focusses on the Bar Standards Board’s Future Bar Training Programme and provides commentary, explanation and a rationale for training for the Bar from 2020
Relaxations and rheology near jamming
We determine the form of the complex shear modulus in soft sphere
packings near jamming. Viscoelastic response at finite frequency is closely
tied to a packing's intrinsic relaxational modes, which are distinct from the
vibrational modes of undamped packings. We demonstrate and explain the
appearance of an anomalous excess of slowly relaxing modes near jamming,
reflected in a diverging relaxational density of states. From the density of
states, we derive the dependence of on frequency and distance to the
jamming transition, which is confirmed by numerics.Comment: 4 pages, 3 figure
Angoricity and compactivity describe the jamming transition in soft particulate matter
The application of concepts from equilibrium statistical mechanics to
out-of-equilibrium systems has a long history of describing diverse systems
ranging from glasses to granular materials. For dissipative jammed systems--
particulate grains or droplets-- a key concept is to replace the energy
ensemble describing conservative systems by the volume-stress ensemble. Here,
we test the applicability of the volume-stress ensemble to describe the jamming
transition by comparing the jammed configurations obtained by dynamics with
those averaged over the ensemble as a probe of ergodicity. Agreement between
both methods suggests the idea of "thermalization" at a given angoricity and
compactivity. We elucidate the thermodynamic order of the jamming transition by
showing the absence of critical fluctuations in static observables like
pressure and volume. The approach allows to calculate observables such as the
entropy, volume, pressure, coordination number and distribution of forces to
characterize the scaling laws near the jamming transition from a statistical
mechanics viewpoint.Comment: 27 pages, 13 figure
High-resolution imaging at the SOAR telescope
Bright single and binary stars were observed at the 4.1-m telescope with a
fast electron-multiplication camera in the regime of partial turbulence
correction by the visible-light adaptive optics system. We compare the angular
resolution achieved by simple averaging of AO-corrected images (long-exposure),
selection and re-centering (shift-and-add or "lucky" imaging) and speckle
interferometry. The effect of partial AO correction, vibrations, and image
post-processing on the attained resolution is shown. Potential usefulness of
these techniques is evaluated for reaching the diffraction limit in
ground-based optical imaging. Measurements of 75 binary stars obtained during
these tests are given and objects of special interest are discussed. We report
tentative resolution of the astrometric companion to Zeta Aqr B. A concept of
advanced high-resolution camera is outlined.Comment: Accepted for publication in PASP. 14 pages, 9 figures, 2 tabl
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