1,342 research outputs found
Experiential Research and Practical Application: A Case of Student Affairs Partnering with Academic Affairs
Excerpt:
Learning occurs everywhere. Jernstadt (2004) suggests learning occurs on a continuum comprised of knowledge, recognition, application, and extrapolation (as cited in Keeling, 2006). âIn our need to put things into categories, we have classified some parts of higher education as curricular, and other parts as co-curricular, but students just call it collegeâ (Keeling & Associates, 2006, p. vii). Learning Reconsidered argued for the integrated use of higher educationâs resources in the education and preparation of the whole student. One of the most critical elements required to accomplish this was the creation or enhancement of strong, collaborative working relationships among academic and student affairs educators. (Steffes & Keeling, 2006, p. 69
A lower limit of dz > 0.06 for the duration of the reionization epoch
Observations of the 21-centimetre line of atomic hydrogen in the early
Universe directly probe the history of the reionization of the gas between
galaxies. The observations are challenging, though, because of the low expected
signal strength (~10 mK), and contamination by strong (>100 K) foreground
synchrotron emission in the Milky Way and extragalactic continuum sources2. If
reionization happened rapidly, there should be a characteristic signature
visible against the smooth foreground in an all-sky spectrum. Here we report an
all-sky spectrum between 100 and 200 MHz, corresponding to the redshift range 6
< z < 13 for the 21-centimetre line. The data exclude a rapid reionization
timescale of dz < 0.06 at the 95% confidence level.Comment: 8 pages, 2 figures, Published in Nature, Volume 468, Issue 7325, pp.
796-798 (2010
The stigmatisation of people with chronic back pain
This study responded to the need for better theoretical understanding of experiences that shape the beliefs, attitudes and needs of chronic back patients attending pain clinics. The aim was explore and conceptualise the experiences of people of working age who seek help from pain clinics for chronic back pain. Methods. This was a qualitative study, based on an interpretative phenomenological approach (IPA). During in-depth interviews in their homes, participants were invited to 'tell their story' from the time their pain began. Participants were twelve male and six female patients, aged between 28 and 62 years, diagnosed as having chronic benign back pain. All had recently attended one of two pain clinics as new referrals. The interview transcripts were analysed thematically. Findings. Stigmatisation emerged as a key theme from the narrative accounts of participants. The findings expose subtle as well as overt stigmatising responses by family, friends, health professionals and the general public which appeared to have a profound effect on the perceptions, self esteem and behaviours of those interviewed. Conclusions. The findings suggest that patients with chronic back pain feel stigmatised by the time they attend pain clinics and this may affect their attitudes and behaviours towards those offering professional help. Theories of chronic pain need to accommodate these responses, while pain management programmes need to address the realities and practicalities of dealing with stigma in everyday life
The signature of the first stars in atomic hydrogen at redshift 20
Dark and baryonic matter moved at different velocities in the early Universe,
which strongly suppressed star formation in some regions. This was estimated to
imprint a large-scale fluctuation signal of about 2 mK in the 21-cm spectral
line of atomic hydrogen associated with stars at a redshift of 20, although
this estimate ignored the critical contribution of gas heating due to X-rays
and major enhancements of the suppression. A large velocity difference reduces
the abundance of halos and requires the first stars to form in halos of about a
million solar masses, substantially greater than previously expected. Here we
report a simulation of the distribution of the first stars at z=20 (cosmic age
of ~180 Myr), incorporating all these ingredients within a 400 Mpc box. We find
that the 21-cm signature of these stars is an enhanced (10 mK) fluctuation
signal on the 100-Mpc scale, characterized by a flat power spectrum with
prominent baryon acoustic oscillations. The required sensitivity to see this
signal is achievable with an integration time of a thousand hours with an
instrument like the Murchison Wide-field Array or the Low Frequency Array but
designed to operate in the range of 50-100 MHz.Comment: 27 pages, 5 figures, close (but not exact) match to accepted version.
Basic results unchanged from first submitted version, but justification
strengthened, title and abstract modified, and substantial Supplementary
Material added. Originally first submitted for publication on Oct. 12, 201
Macrofossil evidence for a rapid and severe CretaceousâPaleogene mass extinction in Antarctica
Debate continues about the nature of the CretaceousâPaleogene (KâPg) mass extinction event. An abrupt crisis triggered by a bolide impact contrasts with ideas of a more gradual extinction involving flood volcanism or climatic changes. Evidence from high latitudes has also been used to suggest that the severity of the extinction decreased from low latitudes towards the poles. Here we present a record of the KâPg extinction based on extensive assemblages of marine macrofossils (primarily new data from benthic molluscs) from a highly expanded CretaceousâPaleogene succession: the LoÌpez de Bertodano Formation of Seymour Island, Antarctica. We show that the extinction was rapid and severe in Antarctica, with no significant biotic decline during the latest Cretaceous, contrary to previous studies. These data are consistent with a catastrophic driver for the extinction, such as bolide impact, rather than a significant contribution from Deccan Traps volcanism during the late Maastrichtian
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Results from EDGES High-Band. III. New Constraints on Parameters of the Early Universe
We present new constraints on parameters of cosmic dawn and the epoch of
reionization derived from the EDGES High-Band spectrum ( MHz). The
parameters are probed by evaluating global cm signals generated with the
recently developed Global21cm tool. This tool uses neural networks trained and
tested on spectra produced with semi-numerical simulations that
assume the standard thermal evolution of the cosmic microwave background and
the intergalactic medium. From our analysis, we constrain at (1) the
minimum virial circular velocity of star-forming halos to km
s, (2) the X-ray heating efficiency of early sources to , and (3) the low-energy cutoff of the X-ray spectral energy
distribution to keV. We also constrain the star-formation
efficiency (), the electron scattering optical depth (), and
the mean-free path of ionizing photons (). We re-compute the
constraints after incorporating into the analysis four estimates for the
neutral hydrogen fraction from high- quasars and galaxies, and a prior on
from Planck . The largest impact of the external
observations is on the parameters that most directly characterize reionization.
Specifically, we derive the combined constraints
and Mpc. The external observations also have a significant
effect on due to its degeneracy with , while the
constraints on , , and , remain primarily
determined by EDGES
Induction of humoral immune response to multiple recombinant Rhipicephalus appendiculatus antigens and their effect on tick feeding success and pathogen transmission
BACKGROUND: Rhipicephalus appendiculatus is the primary vector of Theileria parva, the etiological agent of East Coast fever (ECF), a devastating disease of cattle in sub-Saharan Africa. We hypothesized that a vaccine targeting tick proteins that are involved in attachment and feeding might affect feeding success and possibly reduce tick-borne transmission of T. parva. Here we report the evaluation of a multivalent vaccine cocktail of tick antigens for their ability to reduce R. appendiculatus feeding success and possibly reduce tick-transmission of T. parva in a natural host-tick-parasite challenge model.
METHODS: Cattle were inoculated with a multivalent antigen cocktail containing recombinant tick protective antigen subolesin as well as two additional R. appendiculatus saliva antigens: the cement protein TRP64, and three different histamine binding proteins. The cocktail also contained the T. parva sporozoite antigen p67C. The effect of vaccination on the feeding success of nymphal and adult R. appendiculatus ticks was evaluated together with the effect on transmission of T. parva using a tick challenge model.
RESULTS: To our knowledge, this is the first evaluation of the anti-tick effects of these antigens in the natural host-tick-parasite combination. In spite of evidence of strong immune responses to all of the antigens in the cocktail, vaccination with this combination of tick and parasite antigens did not appear to effect tick feeding success or reduce transmission of T. parva.
CONCLUSION: The results of this study highlight the importance of early evaluation of anti-tick vaccine candidates in biologically relevant challenge systems using the natural tick-host-parasite combination
Structural evolution and flip-flop recombination of chloroplast DNA in the fern genus Osmunda
The evolution and recombination of chloroplast genome structure in the fern genus Osmunda were studied by comparative restriction site mapping and filter hybridization of chloroplast DNAs (cpDNAs) from three species â 0. cinnamomea, 0. claytoniana and 0. regalis . The three 144 kb circular genomes were found to be colinear in organization, indicating that no major inversions or transpositions had occurred during the approximately 70 million years since their radiation from a common ancestor. Although overall size and sequence arrangement are highly conserved in the three genomes, they differ by an extensive series of small deletions and insertions, ranging in size from 50 bp to 350 by and scattered more or less at random throughout the circular chromosomes. All three chloroplast genomes contain a large inverted repeat of approximately 10 kb in size. However, hybridizations using cloned fragments from the 0. cinnamomea and 0. regalis genomes revealed the absence of any dispersed repeats in at least 50% of the genome. Analysis with restriction enzymes that fail to cleave the 10 kb inverted repeat indicated that each of the three fern chloroplast genomes exists as an equimolar population of two isomeric circles differing only in the relative orientation of their two single copy regions. These two inversion isomers are inferred to result from high frequency intramolecular recombination between paired inverted repeat segments. In all aspects of their general organization, recombinational heterogeneity, and extent of structural rearrangement and length mutation, these fern chloroplast genomes resemble very closely the chloroplast genomes of most angiosperms.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46956/1/294_2004_Article_BF00418530.pd
A Corpus of Potentially Contradictory Research Claims from Cardiovascular Research Abstracts
Background: Research literature in biomedicine and related fields contains a huge number
of claims, such as the effectiveness of treatments. These claims are not always consistent and
may even contradict each other. Being able to identify contradictory claims is important for
those who rely on the biomedical literature. Automated methods to identify and resolve them
are required to cope with the amount of information available. However, research in this area
has been hampered by a lack of suitable resources. We describe a methodology to develop a
corpus which addresses this gap by providing examples of potentially contradictory claims and
demonstrate how it can be applied to identify these claims from Medline abstracts related to the
topic of cardiovascular disease.
Methods A set of systematic reviews concerned with four topics in cardiovascular disease were
identified from Medline and analysed to determine whether the abstracts they reviewed contained
contradictory research claims. For each review, annotators were asked to analyse these abstracts
to identify claims within them that answered the question addressed in the review. The annotators
were also asked to indicate how the claim related to that question and the type of the claim.
Results: A total of 259 abstracts associated with 24 systematic reviews were used to form
the corpus. Agreement between the annotators was high, suggesting that the information they
provided is reliable.
Conclusions: The paper describes a methodology for constructing a corpus containing contradictory
research claims from the biomedical literature. The corpus is made available to enable
further research into this area and support the development of automated approaches to contradiction
identification
The Effect of Map Boundary on Estimates of Landscape Resistance to Animal Movement
BACKGROUND: Artificial boundaries on a map occur when the map extent does not cover the entire area of study; edges on the map do not exist on the ground. These artificial boundaries might bias the results of animal dispersal models by creating artificial barriers to movement for model organisms where there are no barriers for real organisms. Here, we characterize the effects of artificial boundaries on calculations of landscape resistance to movement using circuit theory. We then propose and test a solution to artificially inflated resistance values whereby we place a buffer around the artificial boundary as a substitute for the true, but unknown, habitat. METHODOLOGY/PRINCIPAL FINDINGS: We randomly assigned landscape resistance values to map cells in the buffer in proportion to their occurrence in the known map area. We used circuit theory to estimate landscape resistance to organism movement and gene flow, and compared the output across several scenarios: a habitat-quality map with artificial boundaries and no buffer, a map with a buffer composed of randomized habitat quality data, and a map with a buffer composed of the true habitat quality data. We tested the sensitivity of the randomized buffer to the possibility that the composition of the real but unknown buffer is biased toward high or low quality. We found that artificial boundaries result in an overestimate of landscape resistance. CONCLUSIONS/SIGNIFICANCE: Artificial map boundaries overestimate resistance values. We recommend the use of a buffer composed of randomized habitat data as a solution to this problem. We found that resistance estimated using the randomized buffer did not differ from estimates using the real data, even when the composition of the real data was varied. Our results may be relevant to those interested in employing Circuitscape software in landscape connectivity and landscape genetics studies
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