713 research outputs found
The State Of Higher Education In 2012
The higher education sector is experiencing an escalating pace of change. Even colleges and universities with the greatest resources and strongest brands are confronting change, particularly as a result of the digital revolution that is radically impacting modes of learning and accessibility to knowledge. These changes are driven by market pressures — i.e., by the demands and expectations of students and faculty. At the same time, all of higher education continues its evolution in response to ongoing price pressures, to reduced governmental support, to growing competition from the for-profit higher education sector, to its own ethical challenges, and to changes in the regulatory environment. Boards, presidents, provosts and CFOs are addressing these risks and challenges with new strategies and unique action plans that are a far cry from traditional approaches to higher education
Revisiting a classical theory of sensory specificity:assessing consistency and stability of thermosensitive spots
Opposing roles for striatonigral and striatopallidal neurons in dorsolateral striatum in consolidating new instrumental actions.
Comparatively little is known about how new instrumental actions are encoded in the brain. Using whole-brain c-Fos mapping, we show that neural activity is increased in the anterior dorsolateral striatum (aDLS) of mice that successfully learn a new lever-press response to earn food rewards. Post-learning chemogenetic inhibition of aDLS disrupts consolidation of the new instrumental response. Similarly, post-learning infusion of the protein synthesis inhibitor anisomycin into the aDLS disrupts consolidation of the new response. Activity of D1 receptor-expressing medium spiny neurons (D1-MSNs) increases and D2-MSNs activity decreases in the aDLS during consolidation. Chemogenetic inhibition of D1-MSNs in aDLS disrupts the consolidation process whereas D2-MSN inhibition strengthens consolidation but blocks the expression of previously learned habit-like responses. These findings suggest that D1-MSNs in the aDLS encode new instrumental actions whereas D2-MSNs oppose this new learning and instead promote expression of habitual actions
Towards Direct Simulation of Future Tropical Cyclone Statistics in a High-Resolution Global Atmospheric Model
We present a set of high-resolution global atmospheric general circulation model (AGCM) simulations focusing on the model's ability to represent tropical storms and their statistics. We find that the model produces storms of hurricane strength with realistic dynamical features. We also find that tropical storm statistics are reasonable, both globally and in the north Atlantic, when compared to recent observations. The sensitivity of simulated tropical storm statistics to increases in sea surface temperature (SST) is also investigated, revealing that a credible late 21st century SST increase produced increases in simulated tropical storm numbers and intensities in all ocean basins. While this paper supports previous high-resolution model and theoretical findings that the frequency of very intense storms will increase in a warmer climate, it differs notably from previous medium and high-resolution model studies that show a global reduction in total tropical storm frequency. However, we are quick to point out that this particular model finding remains speculative due to a lack of radiative forcing changes in our time-slice experiments as well as a focus on the Northern hemisphere tropical storm seasons
A Radial Velocity Survey of the Cygnus OB2 Association
We conducted a radial velocity survey of the Cygnus OB2 Association over a 6
year (1999 - 2005) time interval to search for massive close binaries. During
this time we obtained 1139 spectra on 146 OB stars to measure mean systemic
radial velocities and radial velocity variations. We spectroscopically identify
73 new OB stars for the first time, the majority of which are likely to be
Association members. Spectroscopic evidence is also presented for a B3Iae
classification and temperature class variation (B3 - B8) on the order of 1 year
for Cygnus OB2 No. 12. Calculations of the intial mass function with the
current spectroscopic sample yield Gamma = -2.2 +/- 0.1. Of the 120 stars with
the most reliable data, 36 are probable and 9 are possible single-lined
spectroscopic binaries. We also identify 3 new and 8 candidate double-lined
spectroscopic binaries. These data imply a lower limit on the massive binary
fraction of 30% - 42%. The calculated velocity dispersion for Cygnus OB2 is
2.44 +/- km/s, which is typical of open clusters. No runaway OB stars were
found.Comment: 56 pages, 23 figures, 5 tables, accepted for publication in the
Astrophysical Journa
From START to FINISH : the influence of osmotic stress on the cell cycle
Peer reviewedPublisher PD
Teaching Hospital Five-Year Mortality Trends in the Wake of Duty Hour Reforms
Background
The Accreditation Council for Graduate Medical Education (ACGME) implemented duty hour regulations for residents in 2003 and again in 2011. While previous studies showed no systematic impacts in the first 2 years post-reform, the impact on mortality in subsequent years has not been examined. OBJECTIVE
To determine whether duty hour regulations were associated with changes in mortality among Medicare patients in hospitals of different teaching intensity after the first 2 years post-reform. DESIGN
Observational study using interrupted time series analysis with data from July 1, 2000 to June 30, 2008. Logistic regression was used to examine the change in mortality for patients in more versus less teaching-intensive hospitals before (2000–2003) and after (2003–2008) duty hour reform, adjusting for patient comorbidities, time trends, and hospital site. PATIENTS
Medicare patients (n = 13,678,956) admitted to short-term acute care non-federal hospitals with principal diagnoses of acute myocardial infarction (AMI), gastrointestinal bleeding, or congestive heart failure (CHF); or a diagnosis-related group (DRG) classification of general, orthopedic, or vascular surgery. MAIN MEASURE
All-location mortality within 30 days of hospital admission. KEY RESULTS
In medical and surgical patients, there were no consistent changes in the odds of mortality at more vs. less teaching intensive hospitals in post-reform years 1–3. However, there were significant relative improvements in mortality for medical patients in the fourth and fifth years post-reform: Post4 (OR 0.88, 95 % CI [0.93–0.94]); Post5 (OR 0.87, [0.82–0.92]) and for surgical patients in the fifth year post-reform: Post5 (OR 0.91, [0.85–0.96]). CONCLUSIONS
Duty hour reform was associated with no significant change in mortality in the early years after implementation, and with a trend toward improved mortality among medical patients in the fourth and fifth years. It is unclear whether improvements in outcomes long after implementation can be attributed to the reform, but concerns about worsening outcomes seem unfounded
SARS-CoV-2 Viral Load in Saliva Rises Gradually and to Moderate Levels in Some Humans
Transmission of SARS-CoV-2 in community settings often occurs before symptom onset, therefore testing strategies that can reliably detect people in the early phase of infection are urgently needed. Early detection of SARS-CoV-2 infection is especially critical to protect vulnerable populations who require frequent interactions with caretakers. Rapid COVID-19 tests have been proposed as an attractive strategy for surveillance, however a limitation of most rapid tests is their low sensitivity. Low-sensitivity tests are comparable to high sensitivity tests in detecting early infections when two assumptions are met: (1) viral load rises quickly (within hours) after infection and (2) viral load reaches and sustains high levels (>10⁵ - 10⁶ RNA copies/mL). However, there are no human data testing these assumptions. In this study, we document a case of presymptomatic household transmission from a healthy college student to his brother and father. Participants prospectively provided twice-daily saliva samples. Samples were analyzed by RT-qPCR and RT-ddPCR and we measured the complete viral load profiles throughout the course of infection of the brother and father. This study provides evidence that in at least some human cases of SARS-CoV-2, viral load rises slowly (over days, not hours) and not to such high levels to be detectable reliably by any low-sensitivity test. Additional viral load profiles from different samples types across a broad demographic must be obtained to describe the early phase of infection and determine which testing strategies will be most effective for identifying SARS-CoV-2 infection before transmission can occur
Barred Galaxies in the Abell 901/2 Supercluster with STAGES
We present a study of bar and host disk evolution in a dense cluster
environment, based on a sample of ~800 bright (MV <= -18) galaxies in the Abell
901/2 supercluster at z~0.165. We use HST ACS F606W imaging from the STAGES
survey, and data from Spitzer, XMM-Newton, and COMBO-17. We identify and
characterize bars through ellipse-fitting, and other morphological features
through visual classification. (1) We explore three commonly used methods for
selecting disk galaxies. We find 625, 485, and 353 disk galaxies, respectively,
via visual classification, a single component S'ersic cut (n <= 2.5), and a
blue-cloud cut. In cluster environments, the latter two methods miss 31% and
51%, respectively, of visually-identified disks. (2) For moderately inclined
disks, the three methods of disk selection yield a similar global optical bar
fraction (f_bar-opt) of 34% +10%/-3%, 31% +10%/-3%, and 30% +10%/-3%,
respectively. (3) f_bar-opt rises in brighter galaxies and those which appear
to have no significant bulge component. Within a given absolute magnitude bin,
f_bar-opt is higher in visually-selected disk galaxies that have no bulge as
opposed to those with bulges. For a given morphological class, f_bar-opt rises
at higher luminosities. (4) For bright early-types, as well as faint late-type
systems with no evident bulge, the optical bar fraction in the Abell 901/2
clusters is comparable within a factor of 1.1 to 1.4 to that of field galaxies
at lower redshifts (5) Between the core and the virial radius of the cluster at
intermediate environmental densities, the optical bar fraction does not appear
to depend strongly on the local environment density and varies at most by a
factor of ~1.3. We discuss the implications of our results for the evolution of
bars and disks in dense environments.Comment: accepted for publication in ApJ, abstract abridged, for high
resolution figures see
http://www.as.utexas.edu/~marinova/STAGES/STAGES_bars.pd
Insights into the cultured bacterial fraction of corals
Bacteria associated with coral hosts are diverse and abundant, with recent studies suggesting involvement of these symbionts in host resilience to anthropogenic stress. Despite their putative importance, the work dedicated to culturing coral-associated bacteria has received little attention. Combining published and unpublished data, here we report a comprehensive overview of the diversity and function of culturable bacteria isolated from corals originating from tropical, temperate, and cold-water habitats. A total of 3,055 isolates from 52 studies were considered by our metasurvey. Of these, 1,045 had full-length 16S rRNA gene sequences, spanning 138 formally described and 12 putatively novel bacterial genera across the Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria phyla. We performed comparative genomic analysis using the available genomes of 74 strains and identified potential signatures of beneficial bacterium-coral symbioses among the strains. Our analysis revealed \u3e 400 biosynthetic gene clusters that underlie the biosynthesis of antioxidant, antimicrobial, cytotoxic, and other secondary metabolites. Moreover, we uncovered genomic features-not previously described for coral-bacterium symbioses-potentially involved in host colonization and host-symbiont recognition, antiviral defense mechanisms, and/or integrated metabolic interactions, which we suggest as novel targets for the screening of coral probiotics. Our results highlight the importance of bacterial cultures to elucidate coral holobiont functioning and guide the selection of probiotic candidates to promote coral resilience and improve holistic and customized reef restoration and rehabilitation efforts
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