185 research outputs found
Aligning Instruction with Extension Professional Competencies for an Enhanced Undergraduate Extension Education Minor
This paper reports on a three-year initiative to enhance the undergraduate Extension Education minor at a state land-grant university. Specific initiatives to improve the undergraduate Extension Education minor curriculum involved (a) revising the Extension Education minor due to varied curriculum and faculty changes and (b) aligning eight Extension Education coursesβ units of study with Extension professional competency domains. The described processes helped understand the Extension Education curriculum by mapping competency domains and showing which domains were and were not taught in the eight courses. A key recommendation is to incorporate the alignment of Extension Education curriculum and Extension professional competencies into the Extension summer internship program, among other uses. Furthermore, it is recommended that faculty engage in a similar effort to map college curricula to professional competencies to ensure that academic minors have a clear purpose in preparing students for careers
THE CHANDRA VARIABLE GUIDE STAR CATALOG
Variable stars have been identified among the optical-wavelength light curves of guide stars used for pointing control of the Chandra X-ray Observatory. We present a catalog of these variable stars along with their light curves and ancillary data. Variability was detected to a lower limit of 0.02 mag amplitude in the 4000-10000 Γ
range using the photometrically stable Aspect Camera on board the Chandra spacecraft. The Chandra Variable Guide Star Catalog (VGUIDE) contains 827 stars, of which 586 are classified as definitely variable and 241 are identified as possibly variable. Of the 586 definite variable stars, we believe 319 are new variable star identifications. Types of variables in the catalog include eclipsing binaries, pulsating stars, and rotating stars. The variability was detected during the course of normal verification of each Chandra pointing and results from analysis of over 75,000 guide star light curves from the Chandra mission. The VGUIDE catalog represents data from only about 9 years of the Chandra mission. Future releases of VGUIDE will include newly identified variable guide stars as the mission proceeds. An important advantage of the use of space data to identify and analyze variable stars is the relatively long observations that are available. The Chandra orbit allows for observations up to 2 days in length. Also, guide stars were often used multiple times for Chandra observations, so many of the stars in the VGUIDE catalog have multiple light curves available from various times in the mission. The catalog is presented as both online data associated with this paper and as a public Web interface. Light curves with data at the instrumental time resolution of about 2 s, overplotted with the data binned at 1 ks, can be viewed on the public Web interface and downloaded for further analysis. VGUIDE is a unique project using data collected during the mission that would otherwise be ignored. The stars available for use as Chandra guide stars are generally 6-11 mag and are commonly spectral types A and later. Due to the selection of guide stars entirely for positional convenience, this catalog avoids the possible bias of searching for variability in objects where it is to be expected. Statistics of variability compared to spectral type indicate the expected dominance of A-F stars as pulsators. Eclipsing binaries are consistently 20%-30% of the detected variables across all spectral types.United States. National Aeronautics and Space Administration (Smithsonian Astrophysical Observatory. Contract NAS8-03060)United States. National Aeronautics and Space Administration (Smithsonian Astrophysical Observatory. Contract SV3-73016
Defining appropriateness in coach-athlete sexual relationships: The voice of coaches
The sporting culture, with omnipotent coaches, fierce competition for recognition and funding, and βwin at all costβ ethos, creates an environment conducive to sexual exploitation of athletes. Recent increased public awareness and the development of child protection policies in sport have led to the questioning of previously accepted coach-athlete relationships. This study is an exploratory investigation into male swimming coachesβ perceptions of appropriateness of coach-athlete sexual relationships. Sexual relationships with athletes under the age of 16 were unanimously considered totally inappropriate. With regard to sexual relationships with athletes above the age of consent for heterosexual sex, opinions ranged from βtotally inappropriateβ to βitβs a question of civil liberties.β These results are discussed in relation to how coaches have adapted their own behaviours in the face of public scrutiny but are still reluctant to restrict the rights of their fellow coaches
The Chandra Source Catalog
The Chandra Source Catalog (CSC) is a general purpose virtual X-ray
astrophysics facility that provides access to a carefully selected set of
generally useful quantities for individual X-ray sources, and is designed to
satisfy the needs of a broad-based group of scientists, including those who may
be less familiar with astronomical data analysis in the X-ray regime. The first
release of the CSC includes information about 94,676 distinct X-ray sources
detected in a subset of public ACIS imaging observations from roughly the first
eight years of the Chandra mission. This release of the catalog includes point
and compact sources with observed spatial extents <~ 30''. The catalog (1)
provides access to the best estimates of the X-ray source properties for
detected sources, with good scientific fidelity, and directly supports
scientific analysis using the individual source data; (2) facilitates analysis
of a wide range of statistical properties for classes of X-ray sources; and (3)
provides efficient access to calibrated observational data and ancillary data
products for individual X-ray sources, so that users can perform detailed
further analysis using existing tools. The catalog includes real X-ray sources
detected with flux estimates that are at least 3 times their estimated 1 sigma
uncertainties in at least one energy band, while maintaining the number of
spurious sources at a level of <~ 1 false source per field for a 100 ks
observation. For each detected source, the CSC provides commonly tabulated
quantities, including source position, extent, multi-band fluxes, hardness
ratios, and variability statistics, derived from the observations in which the
source is detected. In addition to these traditional catalog elements, for each
X-ray source the CSC includes an extensive set of file-based data products that
can be manipulated interactively.Comment: To appear in The Astrophysical Journal Supplement Series, 53 pages,
27 figure
Statistical Characterization of the Chandra Source Catalog
The first release of the Chandra Source Catalog (CSC) contains ~95,000 X-ray
sources in a total area of ~0.75% of the entire sky, using data from ~3,900
separate ACIS observations of a multitude of different types of X-ray sources.
In order to maximize the scientific benefit of such a large, heterogeneous
data-set, careful characterization of the statistical properties of the
catalog, i.e., completeness, sensitivity, false source rate, and accuracy of
source properties, is required. Characterization efforts of other, large
Chandra catalogs, such as the ChaMP Point Source Catalog (Kim et al. 2007) or
the 2 Mega-second Deep Field Surveys (Alexander et al. 2003), while
informative, cannot serve this purpose, since the CSC analysis procedures are
significantly different and the range of allowable data is much less
restrictive. We describe here the characterization process for the CSC. This
process includes both a comparison of real CSC results with those of other,
deeper Chandra catalogs of the same targets and extensive simulations of
blank-sky and point source populations.Comment: To be published in the Astrophysical Journal Supplement Series (Fig.
52 replaced with a version which astro-ph can convert to PDF without issues.
The RS Oph outburst of 2021 monitored in X-rays with NICER
The 2021 outburst of the symbiotic recurrent nova RS Oph was monitored with
the Neutron Star Interior Composition Explorer Mission (NICER) in the 0.2-12
keV range from day one after the optical maximum, until day 88, producing an
unprecedented, detailed view of the outburst development. The X-ray flux
preceding the supersoft X-ray phase peaked almost 5 days after optical maximum
and originated only in shocked ejecta for 21 to 25 days. The emission was
thermal; in the first 5 days only a non-collisional-ionization equilibrium
model fits the spectrum, and a transition to equilibrium occurred between days
6 and 12. The ratio of peak X-rays flux measured in the NICER range to that
measured with Fermi in the 60 MeV-500 GeV range was about 0.1, and the ratio to
the peak flux measured with H.E.S.S. in the 250 GeV-2.5 TeV range was about
100. The central supersoft X-ray source (SSS), namely the shell hydrogen
burning white dwarf (WD), became visible in the fourth week, initially with
short flares. A huge increase in flux occurred on day 41, but the SSS flux
remained variable. A quasi-periodic oscillation every ~35 s was always observed
during the SSS phase, with variations in amplitude and a period drift that
appeared to decrease in the end. The SSS has characteristics of a WD of mass >1
M(solar). Thermonuclear burning switched off shortly after day 75, earlier than
in 2006 outburst. We discuss implications for the nova physics.Comment: Accepted for publication in the Astrophysical Journa
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A low mortality, high morbidity Reduced Intensity Status Epilepticus (RISE) model of epilepsy and epileptogenesis in the rat
Animal models of acquired epilepsies aim to provide researchers with tools for use in understanding the processes underlying the acquisition, development and establishment of the disorder. Typically, following a systemic or local insult, vulnerable brain regions undergo a process leading to the development, over time, of spontaneous recurrent seizures. Many such models make use of a period of intense seizure activity or status epilepticus, and this may be associated with high mortality and/or global damage to large areas of the brain. These undesirable elements have driven improvements in the design of chronic epilepsy models, for example the lithium-pilocarpine epileptogenesis model. Here, we present an optimised model of chronic epilepsy that reduces mortality to 1% whilst retaining features of high epileptogenicity and development of spontaneous seizures. Using local field potential recordings from hippocampus in vitro as a probe, we show that the model does not result in significant loss of neuronal network function in area CA3 and, instead, subtle alterations in network dynamics appear during a process of epileptogenesis, which eventually leads to a chronic seizure state. The modelβs features of very low mortality and high morbidity in the absence of global neuronal damage offer the chance to explore the processes underlying epileptogenesis in detail, in a population of animals not defined by their resistance to seizures, whilst acknowledging and being driven by the 3Rs (Replacement, Refinement and Reduction of animal use in scientific procedures) principles
Immunomodulatory Effects of Streptococcus suis Capsule Type on Human Dendritic Cell Responses, Phagocytosis and Intracellular Survival
Streptococcus suis is a major porcine pathogen of significant commercial importance worldwide and an emerging zoonotic pathogen of humans. Given the important sentinel role of mucosal dendritic cells and their importance in induction of T cell responses we investigated the effect of different S. suis serotype strains and an isogenic capsule mutant of serotype 2 on the maturation, activation and expression of IL-10, IL-12p70 and TNF-Ξ± in human monocyte-derived dendritic cells. Additionally, we compared phagocytosis levels and bacterial survival after internalization. The capsule of serotype 2, the most common serotype associated with infection in humans and pigs, was highly anti-phagocytic and modulated the IL-10/IL-12 and IL-10/TNF-Ξ± cytokine production in favor of a more anti-inflammatory profile compared to other serotypes. This may have consequences for the induction of effective immunity to S. suis serotype 2 in humans. A shielding effect of the capsule on innate Toll-like receptor signaling was also demonstrated. Furthermore, we showed that 24 h after phagocytosis, significant numbers of viable intracellular S. suis were still present intracellularly. This may contribute to the dissemination of S. suis in the body
On the Origin and Spread of the Scab Disease of Apple: Out of Central Asia
Background Venturia inaequalis is an ascomycete fungus responsible for apple scab, a disease that has invaded almost all apple growing regions worldwide, with the corresponding adverse effects on apple production. Monitoring and predicting the effectiveness of intervention strategies require knowledge of the origin, introduction pathways, and population biology of pathogen populations. Analysis of the variation of genetic markers using the inferential framework of population genetics offers the potential to retrieve this information. Methodology/Principal Findings Here, we present a population genetic analysis of microsatellite variation in 1,273 strains of V. inaequalis representing 28 orchard samples from seven regions in five continents. Analysis of molecular variance revealed that most of the variation (88%) was distributed within localities, which is consistent with extensive historical migrations of the fungus among and within regions. Despite this shallow population structure, clustering analyses partitioned the data set into separate groups corresponding roughly to geography, indicating that each region hosts a distinct population of the fungus. Comparison of the levels of variability among populations, along with coalescent analyses of migration models and estimates of genetic distances, was consistent with a scenario in which the fungus emerged in Central Asia, where apple was domesticated, before its introduction into Europe and, more recently, into other continents with the expansion of apple growing. Across the novel range, levels of variability pointed to multiple introductions and all populations displayed signatures of significant post-introduction increases in population size. Most populations exhibited high genotypic diversity and random association of alleles across loci, indicating recombination both in native and introduced areas. Conclusions/Significance Venturia inaequalis is a model of invasive phytopathogenic fungus that has now reached the ultimate stage of the invasion process with a broad geographic distribution and well-established populations displaying high genetic variability, regular sexual reproduction, and demographic expansion.Contexte Venturia inaequalis est un champignon ascomycete responsable de la tavelure du pommier, une maladie qui a envahi presque toutes les rΓ©gions du monde oΓΉ le pommier est cultivΓ© posant ainsi de graves problΓ¨mes en production. PrΓ©venir et enrayer efficacement la rΓ©ussite dβun tel succΓ¨s invasif nΓ©cessite des connaissances approfondies sur lβorigine, les voies dβintroduction, la biologie et la gΓ©nΓ©tique de ces populations invasives. En utilisant le potentiel dβinfΓ©rence de la gΓ©nΓ©tique des populations, lβanalyse de la variation de marqueurs gΓ©nΓ©tiques offre la possibilitΓ© dβaccΓ©der Γ ces informations. MΓ©thodologie et Principaux rΓ©sultats Ici nous prΓ©sentons lβanalyse de donnΓ©es microsatellites obtenues pour 1273 souches de V. inaequalis provenant de 28 vergers prΓ©levΓ©es dans 7 rΓ©gions sur les 5 continents. Lβanalyse de la variance molΓ©culaire rΓ©vΓ¨le que 88% de la variation se retrouve dans les vergers Γ©chantillonnΓ©s, ce qui est compatible avec dβimportantes migrations historiques du champignon entre et Γ lβintΓ©rieur mΓͺme des rΓ©gions. MalgrΓ© cette trΓ¨s faible structuration des populations, les diffΓ©rentes analyses de clustering mettent en Γ©vidence un partage des populations en groupes sΓ©parΓ©s correspondant Γ leur origine gΓ©ographique, montrant ainsi que chaque rΓ©gion hΓ©berge une population distincte du champignon. Ensemble, les rΓ©sultats obtenus sur la comparaison du niveau de variabilitΓ© entre populations, les analyses de coalescence et les modΓ¨les de migration testΓ©s plaident en faveur dβun scΓ©nario dans lequel le champignon aurait Γ©mergΓ© dβAsie Centrale, oΓΉ le pommier a Γ©tΓ© domestiquΓ©, avant dβΓͺtre introduit en Europe puis plus rΓ©cemment dans les autres continents suite Γ lβexpansion de la culture du pommier. Les niveaux de variabilitΓ© indiquent que ces territoires ont subi des introductions multiples et que les populations portent toutes des signatures rΓ©vΓ©lant de fortes expansions dΓ©mographiques aprΓ¨s leur introduction. Enfin, la forte diversitΓ© gΓ©notypique des populations et lβassociation alΓ©atoire des allΓ¨les entre loci suggΓ¨rent que le champignon prΓ©sente une reproduction sexuΓ©e rΓ©guliΓ¨re Γ la fois dans les rΓ©gions oΓΉ il a Γ©tΓ© introduit et dans sa rΓ©gion native. Conclusion et PortΓ©e. Venturia inaequalis est un modΓ¨le de champignons phytopathogΓ¨ne invasif qui a maintenant atteint le stade ultime du processus invasif, cβest Γ dire une trΓ¨s large distribution gΓ©ographique par des populations bien Γ©tablies montrant une grande diversitΓ© gΓ©nΓ©tique, une reproduction sexuΓ©e rΓ©guliΓ¨re et une histoire dβexpansion dΓ©mographique
Genetic Control of Susceptibility to Infection with Candida albicans in Mice
Candida albicans is an opportunistic pathogen that causes acute disseminated infections in immunocompromised hosts, representing an important cause of morbidity and mortality in these patients. To study the genetic control of susceptibility to disseminated C. albicans in mice, we phenotyped a group of 23 phylogenetically distant inbred strains for susceptibility to infection as measured by extent of fungal replication in the kidney 48 hours following infection. Susceptibility was strongly associated with the loss-of-function mutant complement component 5 (C5/Hc) allele, which is known to be inherited by approximately 40% of inbred strains. Our survey identified 2 discordant strains, AKR/J (C5-deficient, resistant) and SM/J (C5-sufficient, susceptible), suggesting that additional genetic effects may control response to systemic candidiasis in these strains. Haplotype association mapping in the 23 strains using high density SNP maps revealed several putative loci regulating the extent of C. albicans replication, amongst which the most significant were C5 (P valueβ=β2.43Γ10β11) and a novel effect on distal chromosome 11 (P valueβ=β7.63Γ10β9). Compared to other C5-deficient strains, infected AKR/J strain displays a reduced fungal burden in the brain, heart and kidney, and increased survival, concomitant with uniquely high levels of serum IFNΞ³. C5-independent genetic effects were further investigated by linkage analysis in an [A/JxAKR/J]F2 cross (nβ=β158) where the mutant Hc allele is fixed. These studies identified a chromosome 11 locus (Carg4, Candida albicans resistance gene 4; LODβ=β4.59), and a chromosome 8 locus (Carg3; LODβ=β3.95), both initially detected by haplotype association mapping. Alleles at both loci were inherited in a co-dominant manner. Our results verify the important effect of C5-deficiency in inbred mouse strains, and further identify two novel loci, Carg3 and Carg4, which regulate resistance to C. albicans infection in a C5-independent manner
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