104 research outputs found
Just Looking and Staring Back: Challenging Ableism through Disability Performance Art
This article advocates for art curriculum to be guided by the goal of challenging the discrimination, stigmatization, marginalization, and medicalization of disabled people The Disability Arts Movement provides an important site through which to engage students in exploring the sociopolitical issue of ableism in art curriculum The pedagogical strategies of disability performance artists Carrie Sandahl, Mary Duffy, and Petra Kuppers are examined for the purposes of establishing an affirmative model that focuses upon the cultural contributions of disabled people rather than an orientation that focuses upon individual functional limitations It is suggested that the strategies of critical appropriation and autobiography used by these artists offer ways through which to conceptualize disability as a sociopolitical issue in art curriculum In its conclusions, this article suggests that an integration of the sociopolitical orientation and affirmative model of disability in the classroom be employed guided by the important work of the Disability Arts Movement in order to challenge ableist ideologie
Nutrient Availability Controls the Impact of Mammalian Herbivores on Soil Carbon and Nitrogen Pools in Grasslands
Grasslands are subject to considerable alteration due to human activities globally, including widespread changes in populations and composition of large mammalian herbivores and elevated supply of nutrients. Grassland soils remain important reservoirs of carbon (C) and nitrogen (N). Herbivores may affect both C and N pools and these changes likely interact with increases in soil nutrient availability. Given the scale of grassland soil fluxes, such changes can have striking consequences for atmospheric C concentrations and the climate. Here, we use the Nutrient Network experiment to examine the responses of soil C and N pools to mammalian herbivore exclusion across 22 grasslands, under ambient and elevated nutrient availabilities (fertilized with NPK + micronutrients). We show that the impact of herbivore exclusion on soil C and N pools depends on fertilization. Under ambient nutrient conditions, we observed no effect of herbivore exclusion, but under elevated nutrient supply, pools are smaller upon herbivore exclusion. The highest mean soil C and N pools were found in grazed and fertilized plots. The decrease in soil C and N upon herbivore exclusion in combination with fertilization correlated with a decrease in aboveground plant biomass and microbial activity, indicating a reduced storage of organic matter and microbial residues as soil C and N. The response of soil C and N pools to herbivore exclusion was contingent on temperature â herbivores likely cause losses of C and N in colder sites and increases in warmer sites. Additionally, grasslands that contain mammalian herbivores have the potential to sequester more N under increased temperature variability and nutrient enrichment than ungrazed grasslands. Our study highlights the importance of conserving mammalian herbivore populations in grasslands worldwide. We need to incorporate localâscale herbivory, and its interaction with nutrient enrichment and climate, within globalâscale models to better predict landâatmosphere interactions under future climate change
Reddening and Extinction Toward the Galactic Bulge from OGLE-III: The Inner Milky Way's Rv ~ 2.5 Extinction Curve
We combine VI photometry from OGLE-III with VVV and 2MASS measurements of
E(J-K_{s}) to resolve the longstanding problem of the non-standard optical
extinction toward the Galactic bulge. We show that the extinction is well-fit
by the relation A_{I} = 0.7465*E(V-I) + 1.3700*E(J-K_{s}), or, equivalently,
A_{I} = 1.217*E(V-I)(1+1.126*(E(J-K_{s})/E(V-I)-0.3433)). The optical and
near-IR reddening law toward the inner Galaxy approximately follows an R_{V}
\approx 2.5 extinction curve with a dispersion {\sigma}_{R_{V}} \approx 0.2,
consistent with extragalactic investigations of the hosts of type Ia SNe.
Differential reddening is shown to be significant on scales as small as as our
mean field size of 6', with the 1{\sigma} dispersion in reddening averaging 9%
of total reddening for our fields. The intrinsic luminosity parameters of the
Galactic bulge red clump (RC) are derived to be (M_{I,RC}, \sigma_{I,RC,0},
(V-I)_{RC,0}, \sigma_{(V-I)_{RC}}, (J-K_{s})_{RC,0}) = (-0.12, 0.09, 1.06,
0.121, 0.66). Our measurements of the RC brightness, brightness dispersion and
number counts allow us to estimate several Galactic bulge structural
parameters. We estimate a distance to the Galactic center of 8.20 kpc,
resolving previous discrepancies in distance determinations to the bulge based
on I-band observations. We measure an upper bound on the tilt {\alpha} \approx
40{\deg}. between the bar's major axis and the Sun-Galactic center line of
sight, though our brightness peaks are consistent with predictions of an N-body
model oriented at {\alpha} \approx 25{\deg}. The number of RC stars suggests a
total stellar mass for the Galactic bulge of 2.0*10^{10} M_{\odot}, if one
assumes a Salpeter IMF.Comment: 61 Pages, 21 Figures, 4 Tables, Submitted to The Astrophysical
Journal and modified as per a referee report. Includes reddening, reddening
law, differential reddening, mean distance, dispersion in distance, surface
density of stars and errors thereof for ~9,000 bulge sightlines. For a brief
video explaining the key result of this paper, see
http://www.youtube.com/user/OSUAstronom
Chronic exposure to arsenic in the drinking water alters the expression of immune response genes in mouse lung
This paper is not subject to U.S. copyright. The definitive version was published in Environmental Health Perspectives 117 (2009): 1108-1115, doi:10.1289/ehp.0800199.Chronic exposure to drinking water arsenic is a significant worldwide environmental health concern. Exposure to As is associated with an increased risk of lung disease, which may make it a unique toxicant, because lung toxicity is usually associated with inhalation rather than ingestion.
The goal of this study was to examine mRNA and protein expression changes in the lungs of mice exposed chronically to environmentally relevant concentrations of As in the food or drinking water, specifically examining the hypothesis that As may preferentially affect gene and protein expression related to immune function as part of its mechanism of toxicant action.
C57BL/6J mice fed a casein-based AIN-76A defined diet were exposed to 10 or 100 ppb As in drinking water or food for 5â6 weeks.
Whole genome transcriptome profiling of animal lungs revealed significant alterations in the expression of many genes with functions in cell adhesion and migration, channels, receptors, differentiation and proliferation, and, most strikingly, aspects of the innate immune response. Confirmation of mRNA and protein expression changes in key genes of this response revealed that genes for interleukin 1ÎČ, interleukin 1 receptor, a number of toll-like receptors, and several cytokines and cytokine receptors were significantly altered in the lungs of As-exposed mice.
These findings indicate that chronic low-dose As exposure at the current U.S. drinking-water standard can elicit effects on the regulation of innate immunity, which may contribute to altered disease risk, particularly in lung.This work was supported by National Institute of Environmental Health Science grant P42 ES007373 [J.W.H., Superfund Basic Research Program (SBRP) project 2]. C.D.K., A.P.N., and J.A.G. were supported by graduate and postdoctoral fellowships from P42 ES007373 (SBRP, Training Core). C.D.K. was also supported by National Institutes of Health training grant predoctoral fellowship T32-DF007301. P.L.E. and D.J.W. were supported by Cystic Fibrosis Foundation Research grant HL081289
The JWST Galactic Center Survey -- A White Paper
The inner hundred parsecs of the Milky Way hosts the nearest supermassive
black hole, largest reservoir of dense gas, greatest stellar density, hundreds
of massive main and post main sequence stars, and the highest volume density of
supernovae in the Galaxy. As the nearest environment in which it is possible to
simultaneously observe many of the extreme processes shaping the Universe, it
is one of the most well-studied regions in astrophysics. Due to its proximity,
we can study the center of our Galaxy on scales down to a few hundred AU, a
hundred times better than in similar Local Group galaxies and thousands of
times better than in the nearest active galaxies. The Galactic Center (GC) is
therefore of outstanding astrophysical interest. However, in spite of intense
observational work over the past decades, there are still fundamental things
unknown about the GC. JWST has the unique capability to provide us with the
necessary, game-changing data. In this White Paper, we advocate for a JWST
NIRCam survey that aims at solving central questions, that we have identified
as a community: i) the 3D structure and kinematics of gas and stars; ii)
ancient star formation and its relation with the overall history of the Milky
Way, as well as recent star formation and its implications for the overall
energetics of our galaxy's nucleus; and iii) the (non-)universality of star
formation and the stellar initial mass function. We advocate for a large-area,
multi-epoch, multi-wavelength NIRCam survey of the inner 100\,pc of the Galaxy
in the form of a Treasury GO JWST Large Program that is open to the community.
We describe how this survey will derive the physical and kinematic properties
of ~10,000,000 stars, how this will solve the key unknowns and provide a
valuable resource for the community with long-lasting legacy value.Comment: This White Paper will be updated when required (e.g. new authors
joining, editing of content). Most recent update: 24 Oct 202
Dominant native and non-native graminoids differ in key leaf traits irrespective of nutrient availability
Aim: Nutrient enrichment is associated with plant invasions and biodiversity loss. Functional trait advantages may predict the ascendancy of invasive plants following nutrient enrichment but this is rarely tested. Here, we investigate (a) whether dominant native and non-native plants differ in important morphological and physiological leaf traits, (b) how their traits respond to nutrient addition, and (c) whether responses are consistent across functional groups. Location: Australia, Europe, North America and South Africa. Time period: 2007â2014. Major taxa studied: Graminoids and forbs. Methods: We focused on two types of leaf traits connected to resource acquisition: morphological features relating to light-foraging surfaces and investment in tissue (specific leaf area, SLA) and physiological features relating to internal leaf chemistry as the basis for producing and utilizing photosynthate. We measured these traits on 503 leaves from 151 dominant species across 27 grasslands on four continents. We used an identical nutrient addition treatment of nitrogen (N), phosphorus (P) and potassium (K) at all sites. Sites represented a broad range of grasslands that varied widely in climatic and edaphic conditions. Results: We found evidence that non-native graminoids invest in leaves with higher nutrient concentrations than native graminoids, particularly at sites where native and non-native species both dominate. We found little evidence that native and non-native forbs differed in the measured leaf traits. These results were consistent in natural soil fertility levels and nutrient-enriched conditions, with dominant species responding similarly to nutrient addition regardless of whether they were native or non-native. Main conclusions: Our work identifies the inherent physiological trait advantages that can be used to predict non-native graminoid establishment, potentially because of higher efficiency at taking up crucial nutrients into their leaves. Most importantly, these inherent advantages are already present at natural soil fertility levels and are maintained following nutrient enrichment
Nutrient availability controls the impact of mammalian herbivores on soil carbon and nitrogen pools in grasslands
Grasslands are subject to considerable alteration due to human activities globally,
including widespread changes in populations and composition of large mammalian
herbivores and elevated supply of nutrients. Grassland soils remain important reservoirs of carbon (C) and nitrogen (N). Herbivores may affect both C and N pools and
these changes likely interact with increases in soil nutrient availability. Given the scale
of grassland soil fluxes, such changes can have striking consequences for atmospheric
C concentrations and the climate. Here, we use the Nutrient Network experiment
to examine the responses of soil C and N pools to mammalian herbivore exclusion
across 22 grasslands, under ambient and elevated nutrient availabilities (fertilized
with NPK + micronutrients). We show that the impact of herbivore exclusion on soil
C and N pools depends on fertilization. Under ambient nutrient conditions, we observed no effect of herbivore exclusion, but under elevated nutrient supply, pools are
smaller upon herbivore exclusion. The highest mean soil C and N pools were found in
grazed and fertilized plots. The decrease in soil C and N upon herbivore exclusion in
combination with fertilization correlated with a decrease in aboveground plant biomass and microbial activity, indicating a reduced storage of organic matter and microbial residues as soil C and N. The response of soil C and N pools to herbivore exclusion
was contingent on temperature â herbivores likely cause losses of C and N in colder
sites and increases in warmer sites. Additionally, grasslands that contain mammalian
herbivores have the potential to sequester more N under increased temperature variability and nutrient enrichment than ungrazed grasslands. Our study highlights the
importance of conserving mammalian herbivore populations in grasslands worldwide.
We need to incorporate local-scale herbivory, and its interaction with nutrient enrichment and climate, within global-scale models to better predict landâatmosphere
interactions under future climate change.National Science Foundation Research Coordination Network,
Long Term Ecological Research,
Institute on the Environment,
Strategic Resources of the Netherlands Institute of Ecology,
Research Foundation Flanders,
VENI grant,
NWO-RUBICON grant,
NWO-VENI grant,
German Centre for Integrative Biodiversity Research,
German Research Foundation (FZT 118).http://wileyonlinelibrary.com/journal/gcbpm2021Mammal Research InstituteZoology and Entomolog
Global impacts of fertilization and herbivore removal on soil net nitrogen mineralization are modulated by local climate and soil properties
Soil nitrogen (N) availability is critical for grassland functioning. However, human activities have increased the supply of biologically limiting nutrients, and changed the density and identity of mammalian herbivores. These anthropogenic changes may alter net soil N mineralization (soil net Nmin), that is, the net balance between N mineralization and immobilization, which could severely impact grassland structure and functioning. Yet, to date, little is known about how fertilization and herbivore removal individually, or jointly, affect soil net Nmin across a wide range of grasslands that vary in soil and climatic properties. Here we collected data from 22 grasslands on five continents, all part of a globally replicated experiment, to assess how fertilization and herbivore removal affected potential (laboratoryâbased) and realized (fieldâbased) soil net Nmin. Herbivore removal in the absence of fertilization did not alter potential and realized soil net Nmin. However, fertilization alone and in combination with herbivore removal consistently increased potential soil net Nmin. Realized soil net Nmin, in contrast, significantly decreased in fertilized plots where herbivores were removed. Treatment effects on potential and realized soil net Nmin were contingent on siteâspecific soil and climatic properties. Fertilization effects on potential soil net Nmin were larger at sites with higher mean annual precipitation (MAP) and temperature of the wettest quarter (T.q.wet). Reciprocally, realized soil net Nmin declined most strongly with fertilization and herbivore removal at sites with lower MAP and higher T.q.wet. In summary, our findings show that anthropogenic nutrient enrichment, herbivore exclusion and alterations in future climatic conditions can negatively impact soil net Nmin across global grasslands under realistic field conditions. This is an important contextâdependent knowledge for grassland management worldwide
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