6,193 research outputs found
Employing and Accommodating Workers with Psychiatric Disabilities
This brochure on The Americans with Disabilities Act (ADA) and individuals with psychiatric disabilities is one of a series on human resources practices and workplace accommodations for persons with disabilities edited by Susanne M. Bruyère, Ph.D., CRC, SPHR, Director, Program on Employment and Disability, School of Industrial and Labor Relations – Extension Division, Cornell University.
Cornell University was funded in the early 1990’s by the U.S. Department of Education National Institute on Disability and Rehabilitation Research as a National Materials Development Project on the employment provisions (Title I) of the ADA (Grant #H133D10155). These updates, and the development of new brochures, have been funded by Cornell’s Program on Employment and Disability, the Pacific Disability and Business Technical Assistance Center, and other supporters
Assessing the tilt of the solar magnetic field axis through Faraday rotation observations
Context: Faraday rotation measurements of extragalactic radio sources during
coronal occultation allow assessment of both the electron density distribution
and the three-dimensional magnetic field topology in the outer solar corona.
Aims: We simulate the three-dimensional structure of both the coronal magnetic
field and the electron density distribution in order to reproduce the excess
Faraday rotation measures (RMs) of the occulted radio sources observed during
solar activity minimum. In particular, we infer the tilt of the solar magnetic
axis with respect to the rotation axis. Methods: We compare the output of the
model with Very Large Array (VLA) radio polarimetric measurements of a sample
of extragalactic sources observed in May 1997. Information on the magnetic
field geometry can be retrieved by fine-tuning the set of model free parameters
that best describe the observations. Results: We find that predicted and
observed Faraday rotation measures are in excellent agreement, thus supporting
the model. Our best-fitting model yields a tilt angle
of the solar magnetic axis with respect to the solar rotation axis around
Carrington Rotation 1923. This result is consistent with analogous but
independent estimates computed from the expansion coefficients of the
photospheric field observed at the Wilcox Solar Observatory (WSO).Comment: 8 pages, 5 figures, accepted for publication in A&
Rejection of randomly coinciding events in ZnMoO scintillating bolometers
Random coincidence of events (particularly from two neutrino double beta
decay) could be one of the main sources of background in the search for
neutrinoless double beta decay with cryogenic bolometers due to their poor time
resolution. Pulse-shape discrimination by using front edge analysis, mean-time
and methods was applied to discriminate randomly coinciding events in
ZnMoO cryogenic scintillating bolometers. These events can be effectively
rejected at the level of 99% by the analysis of the heat signals with rise-time
of about 14 ms and signal-to-noise ratio of 900, and at the level of 92% by the
analysis of the light signals with rise-time of about 3 ms and signal-to-noise
ratio of 30, under the requirement to detect 95% of single events. These
rejection efficiencies are compatible with extremely low background levels in
the region of interest of neutrinoless double beta decay of Mo for
enriched ZnMoO detectors, of the order of counts/(y keV kg).
Pulse-shape parameters have been chosen on the basis of the performance of a
real massive ZnMoO scintillating bolometer. Importance of the
signal-to-noise ratio, correct finding of the signal start and choice of an
appropriate sampling frequency are discussed
Representing and analysing molecular and cellular function in the computer
Determining the biological function of a myriad of genes, and understanding how they interact to yield a living cell, is the major challenge of the post genome-sequencing era. The complexity of biological systems is such that this cannot be envisaged without the help of powerful computer systems capable of representing and analysing the intricate networks of physical and functional interactions between the different cellular components. In this review we try to provide the reader with an appreciation of where we stand in this regard. We discuss some of the inherent problems in describing the different facets of biological function, give an overview of how information on function is currently represented in the major biological databases, and describe different systems for organising and categorising the functions of gene products. In a second part, we present a new general data model, currently under development, which describes information on molecular function and cellular processes in a rigorous manner. The model is capable of representing a large variety of biochemical processes, including metabolic pathways, regulation of gene expression and signal transduction. It also incorporates taxonomies for categorising molecular entities, interactions and processes, and it offers means of viewing the information at different levels of resolution, and dealing with incomplete knowledge. The data model has been implemented in the database on protein function and cellular processes 'aMAZE' (http://www.ebi.ac.uk/research/pfbp/), which presently covers metabolic pathways and their regulation. Several tools for querying, displaying, and performing analyses on such pathways are briefly described in order to illustrate the practical applications enabled by the model
The radial profile of the inner heliospheric magnetic field as deduced from Faraday rotation observations
Faraday rotation measures (RMs) of the polarized emission from extragalactic
radio sources occulted by the coronal plasma were used to infer the radial
profile of the inner heliospheric magnetic field near solar minimum activity.
By inverting LASCO/SOHO polarized brightness (pB) data taken during the days of
observations on May 1997, we retrieved the electron density distribution along
the lines of sight to the sources, thus allowing to disentangle the two plasma
properties that contribute to the observed RMs. By comparing the observed RM
values to those theoretically predicted by a power-law model of the radial
component of the coronal magnetic field, using a best-fitting procedure, we
found that the radial component of the inner heliospheric magnetic field can be
nicely approximated by a power-law of the form B_r = 3.76 r^{-2.29} G in a
range of heights from about 5 to 14 solar radii. Finally, our analysis suggests
that the radial computation of the potential field source surface (PFSS) model
from the Wilcox Solar Observatory (WSO), assuming a radial field in the
photosphere and a source surface located at R_{ss} = 2.5 solar radii, is the
preferred choice near solar minimum.Comment: 17 pages, 5 figures, submitted for publication in A&
Assembly of the Auditory Circuitry by a Hox Genetic Network in the Mouse Brainstem
Rhombomeres (r) contribute to brainstem auditory nuclei during development. Hox genes are determinants of rhombomere-derived fate and neuronal connectivity. Little is known about the contribution of individual rhombomeres and their associated Hox codes to auditory sensorimotor circuitry. Here, we show that r4 contributes to functionally linked sensory and motor components, including the ventral nucleus of lateral lemniscus, posterior ventral cochlear nuclei (VCN), and motor olivocochlear neurons. Assembly of the r4-derived auditory components is involved in sound perception and depends on regulatory interactions between Hoxb1 and Hoxb2. Indeed, in Hoxb1 and Hoxb2 mutant mice the transmission of low-level auditory stimuli is lost, resulting in hearing impairments. On the other hand, Hoxa2 regulates the Rig1 axon guidance receptor and controls contralateral projections from the anterior VCN to the medial nucleus of the trapezoid body, a circuit involved in sound localization. Thus, individual rhombomeres and their associated Hox codes control the assembly of distinct functionally segregated sub-circuits in the developing auditory brainstem
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