123 research outputs found
The Ugly Side of America: Institutional Oppression and Race
This manuscript examines structural racism through a socio-historical context of institutional oppression and its effects on modern society. The epistemological framework of intersectionality is used to focus on the overlap of oppression, structural racism, and implicit bias evident in the stereotypes and perceptions of the African American male population in the United States. Four eras of socio-historical significance are addressed: 1. Foundations of Racial Oppression; 2. Racism: Reconstruction and Jim Crow; 3. Renewal: Civil Rights and Civil Disobedience; 3. Reckoning: Embedded Racism and the Criminal Justice System
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Spatial Analysis of Poverty, Tourism, and Opportunity in North Carolina
This study collected online secondary data in terms of tourism economic impact, human development, natural amenities, and self-employment income at the county level in the State of North Carolina and used GIS to conduct a spatial analysis of the distribution of and the interaction between tourism, poverty, and micro-entrepreneurship. It is aimed at identifying the areas where tourism( can( be( utilized( to( cope( with( poverty( by( creating( employment( and( tax( revenues(and(where(tourism(micro8entrepreneurship(might(have(an(important(role(in(enabling( individuals( to( earn( their( way( to( equitable( and( sustainable( prosperity.( ( The results show variations across the counties and the four geographic regions in North Carolina. Tourism business startup factors, the ways to achieve success in business, and the potential of tourism micro-entrepreneurship as a strategy for enabling sustainable livelihoods at the state or national scale are also examined based on the findings
Parvalbumin Interneurons of Hippocampus Tune Population Activity at Theta Frequency
SummaryHippocampal theta rhythm arises from a combination of recently described intrinsic theta oscillators and inputs from multiple brain areas. Interneurons expressing the markers parvalbumin (PV) and somatostatin (SOM) are leading candidates to participate in intrinsic rhythm generation and principal cell (PC) coordination in distal CA1 and subiculum. We tested their involvement by optogenetically activating and silencing PV or SOM interneurons in an intact hippocampus preparation that preserves intrinsic connections and oscillates spontaneously at theta frequencies. Despite evidence suggesting that SOM interneurons are crucial for theta, optogenetic manipulation of these interneurons modestly influenced theta rhythm. However, SOM interneurons were able to strongly modulate temporoammonic inputs. In contrast, activation of PV interneurons powerfully controlled PC network and rhythm generation optimally at 8 Hz, while continuously silencing them disrupted theta. Our results thus demonstrate a pivotal role of PV but not SOM interneurons for PC synchronization and the emergence of intrinsic hippocampal theta
Assessment of the Activity of Ceftaroline Against Clinical Isolates of Penicillin-Intermediate and Penicillin-Resistant \u3cem\u3eStreptococcus pneumoniae\u3c/em\u3e with elevated MICs of Ceftaroline Using an In Vitro Pharmacodynamic Model
Objectives This study assessed the pharmacodynamics of ceftaroline against penicillin-intermediate and penicillin-resistant Streptococcus pneumoniae with elevated MICs of ceftaroline using an in vitro pharmacodynamic model.
Methods Nine isolates of S. pneumoniae, including one penicillin-susceptible isolate, one penicillin-intermediate isolate and seven penicillin-resistant isolates, were tested. The pharmacodynamic model was inoculated with a concentration of 1 × 106 cfu/mL and ceftaroline was dosed twice daily (at 0 and 12 h) to simulate the fCmax (maximum free concentration in serum) and t1/2 (half-life in serum) obtained after 600 mg intravenous doses every 12 h (fCmax, 16 mg/L; t1/2, 2.6 h). Ceftaroline was compared with ceftriaxone dosed once daily to simulate the fCmax and t1/2 obtained after a 1 g dose (fCmax, 18 mg/L; t1/2, 8.0 h). Samples were collected over 24 h to assess viable growth and possible changes in ceftaroline MICs over time.
Results Ceftaroline fT\u3eMIC (time of free serum concentration over the MIC) of 100% (ceftaroline MICs, ≤0.5 mg/L) was bactericidal (≥3 log10 killing) against all isolates at 6 h and completely eradicated all organisms at 12 and 24 h. No bacterial regrowth occurred over the study period and no changes in ceftaroline MICs were observed. Upon ceftriaxone exposure, S. pneumoniae isolates with ceftriaxone MICs of 0.12 and 0.25 mg/L were eradicated, but isolates with ceftriaxone MICs of 1–8 mg/L resulted in initial bacterial reduction at 6 h with organism regrowth at 12 h and no reduction in organism concentration, relative to the starting inoculum, at 24 h.
Conclusions Ceftaroline fT\u3eMIC of 100% (ceftaroline MICs, ≤0.5 mg/L) was bactericidal (≥3 log10 killing) and eradicated all S. pneumoniae at 12 and 24 h with no regrowth
Photometric Supernova Cosmology with BEAMS and SDSS-II
Supernova cosmology without spectroscopic confirmation is an exciting new
frontier which we address here with the Bayesian Estimation Applied to Multiple
Species (BEAMS) algorithm and the full three years of data from the Sloan
Digital Sky Survey II Supernova Survey (SDSS-II SN). BEAMS is a Bayesian
framework for using data from multiple species in statistical inference when
one has the probability that each data point belongs to a given species,
corresponding in this context to different types of supernovae with their
probabilities derived from their multi-band lightcurves. We run the BEAMS
algorithm on both Gaussian and more realistic SNANA simulations with of order
10^4 supernovae, testing the algorithm against various pitfalls one might
expect in the new and somewhat uncharted territory of photometric supernova
cosmology. We compare the performance of BEAMS to that of both mock
spectroscopic surveys and photometric samples which have been cut using typical
selection criteria. The latter typically are either biased due to contamination
or have significantly larger contours in the cosmological parameters due to
small data-sets. We then apply BEAMS to the 792 SDSS-II photometric supernovae
with host spectroscopic redshifts. In this case, BEAMS reduces the area of the
(\Omega_m,\Omega_\Lambda) contours by a factor of three relative to the case
where only spectroscopically confirmed data are used (297 supernovae). In the
case of flatness, the constraints obtained on the matter density applying BEAMS
to the photometric SDSS-II data are \Omega_m(BEAMS)=0.194\pm0.07. This
illustrates the potential power of BEAMS for future large photometric supernova
surveys such as LSST.Comment: 25 pages, 15 figures, submitted to Ap
Results from the Supernova Photometric Classification Challenge
We report results from the Supernova Photometric Classification Challenge
(SNPCC), a publicly released mix of simulated supernovae (SNe), with types (Ia,
Ibc, and II) selected in proportion to their expected rate. The simulation was
realized in the griz filters of the Dark Energy Survey (DES) with realistic
observing conditions (sky noise, point-spread function and atmospheric
transparency) based on years of recorded conditions at the DES site.
Simulations of non-Ia type SNe are based on spectroscopically confirmed light
curves that include unpublished non-Ia samples donated from the Carnegie
Supernova Project (CSP), the Supernova Legacy Survey (SNLS), and the Sloan
Digital Sky Survey-II (SDSS-II). A spectroscopically confirmed subset was
provided for training. We challenged scientists to run their classification
algorithms and report a type and photo-z for each SN. Participants from 10
groups contributed 13 entries for the sample that included a host-galaxy
photo-z for each SN, and 9 entries for the sample that had no redshift
information. Several different classification strategies resulted in similar
performance, and for all entries the performance was significantly better for
the training subset than for the unconfirmed sample. For the spectroscopically
unconfirmed subset, the entry with the highest average figure of merit for
classifying SNe~Ia has an efficiency of 0.96 and an SN~Ia purity of 0.79. As a
public resource for the future development of photometric SN classification and
photo-z estimators, we have released updated simulations with improvements
based on our experience from the SNPCC, added samples corresponding to the
Large Synoptic Survey Telescope (LSST) and the SDSS, and provided the answer
keys so that developers can evaluate their own analysis.Comment: accepted by PAS
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