80 research outputs found
Correlation of Clinical Symptoms with Temporal and Frontoparietal Lobe Response During an Auditory \u27Odball\u27 Task of Chronic and First Episode Schizophrenia Patients (N=190)
The disorder of schizophrenia is defined by the presence of positive and negative clinical symptoms. One of the hallmark positive symptoms is the presence of auditory hallucinations which have previously been studied to involve bilateral temporal lobe anamolies. Our study seeks to further define and potentially quantify these anamolies in temporal lobe response by looking at the correlation of clinical symptoms with temporal lobe activation. To accomplish this task we have subjected 22 first episode and 64 chronic patients along with 104 matched healthy controls to a functional MRI scan while undergoing an auditory oddball\u27 task. Analysis of this data is unique in the use of independent component analysis (ICA) via Matlab toolbox (GIFT). Results showed expected positive activation patterns for temporal lobe activity across all participants but revealed no statistically significant differences within patient populations (first episode (FE) vs. chronic) or between patients and matched healthy controls. We observed strong correlation coefficients for both patient groups as positive symptoms were negatively correlated to temporal lobe response (FE rho = -0.31, chronic rho = -0.20). Negative symptoms were positively correlated but only statistically significant for first episode patients (rho = +0.23). This data is consistent with other studies involving EEG recordings of P300 amplitude response. Finally, in analyzing frontoparietal (FP) lobe activation we showed statistically signficant activation differences between patients and controls. This result could potentially be used as a future diagnostic test. In addition, we uncovered another point of asymmetry in first episode patients whose right FP lobe showed a nearly two-fold correlation coefficient value versus the left FP lobe for negative symptoms. This unique asymmetry could offer a new area of focus for future researchers into the pathophysiology of schizophrenia.\u2
The CFEPS Kuiper Belt Survey: Strategy and Pre-survey Results
We present the data acquisition strategy and characterization procedures for
the Canada-France Ecliptic Plane Survey (CFEPS), a sub-component of the
Canada-France-Hawaii Telescope Legacy Survey. The survey began in early 2003
and as of summer 2005 has covered 430 square degrees of sky within a few
degrees of the ecliptic. Moving objects beyond the orbit of Uranus are detected
to a magnitude limit of =23 -- 24 (depending on the image quality). To
track as large a sample as possible and avoid introducing followup bias, we
have developed a multi-epoch observing strategy that is spread over several
years. We present the evolution of the uncertainties in ephemeris position and
orbital elements as the objects progress through the epochs. We then present a
small 10-object sample that was tracked in this manner as part of a preliminary
survey starting a year before the main CFEPS project.
We describe the CFEPS survey simulator, to be released in 2006, which allows
theoretical models of the Kuiper Belt to be compared with the survey
discoveries since CFEPS has a well-documented pointing history with
characterized detection efficiencies as a function of magnitude and rate of
motion on the sky. Using the pre-survey objects we illustrate the usage of the
simulator in modeling the classical Kuiper Belt.Comment: to be submitted to Icaru
Rural Revitalization in New Mexico
The Rural Education Bureau of the New Mexico Public Education Department has established a program to address the special needs of schools and communities in the extensive rural areas of the state. High poverty rates, depopulation and a general lack of viable economic opportunity have marked rural New Mexico for decades. The program underway aims at establishing holistic community socioeconomic revitalization at the grass roots level with the schools playing a leading role. Initiatives include community conversations with key leaders to determine necessary steps to take in encouraging economic growth and attracting businesses, the institution of entrepreneurship within the community, the transformation of the school into a community resource and the encouragement of place-based education within schools. In the second year of this program there are 13 school districts actively involved in the enhancement of their schools and community. The program adopted many of the principles for rural revitalization seen in the remote communities of South Australia
Is Forest Structure Related to Fire Severity? Yes, No, and Maybe : Methods and Insights in Quantifying the Answer
Wildfires in 2000 burned over 500,000 forested ha in the Northern Rocky Mountains. In 2001, National Fire Plan funding became available to evaluate the influence of pre-wildfire forest structure on post wildfire fire severity. Results from this study will provide information on forest structures that are resilient to wild- fire. Three years of data (558 plots) have been collected from forested areas that burned in 2000, 2001, and 2002. Forests used in this study include dry ponderosa pine/Douglas-fir, cold lodgepole pine/subalpine fir, and moist western larch forests. Probability sampling of all areas within a particular fire perimeter was used to locate study sites and a sampling matrix was used to capture variation in weather, topographic setting, and pre-wildfire forest structure of which the fires represented. Fire severity (current state of soils and vegetation after the wildfire) was quantified on adjacent paired plots, with each plot representing a different forest structure. Classification trees and cluster analysis identified relations among forest structure characteristics, physical setting, and fire severity. Probability of a particular forest structure relating to fire severity was computed. This paper describes methodology used in the project, discusses challenges associated with conducting this type of study, and uses preliminary results (probabilities) from the first two years of data collection to show how forest structure relates to both crown and soil surface fire severity
Phase curves of small bodies from the SLOAN Moving Objects Catalog
Context. Extensive photometric surveys continue to produce enormous stores of data on small bodies. These data are typically sparsely obtained at arbitrary (or unknown) rotational phases. Therefore, new methods for processing such data need to be developed to make the most of these vast catalogs.
Aims. We aim to produce a method of recreating the phase curves of small bodies by considering the uncertainties introduced by the nominal errors in the magnitudes and the effect introduced by rotational variations. We use the SLOAN Moving Objects Catalog data as a benchmark to construct phase curves of all small bodies in u′, g′, r′, i′, and z′ filters. From the phase curves, we obtain the absolute magnitudes and we use them to set up the absolute colors, which are the colors of the asteroids that are not affected by changes in the phase angle.
Methods. We selected objects with ≥3 observations taken in at least one filter and spanning over a minimum of 5 degrees in the phase angle. We developed a method that combines Monte Carlo simulations and Bayesian inference to estimate the absolute magnitudes using the HG photometric system.
Results. We obtained almost 15 000 phase curves, with about 12 000 of these including all five filters. The absolute magnitudes and absolute colors are compatible with previously published data that support our method.
Conclusions. The method we developed is fully automatic and well suited for a run based on large amounts of data. Moreover, it includes the nominal uncertainties in the magnitudes and the whole distribution of possible rotational states of the objects producing what are possibly less precise values, that is, larger uncertainties, but more accurate, namely, closer to the actual value. To our knowledge, this work is the first to include the effect of rotational variations in such a manner
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