6,586 research outputs found
Red Crossbill Invasion of Northwestern Arkansas during 2012-2013
An irruption of Red Crossbills (Loxia curvirostra) occurred in primarily northwestern Arkansas starting in November of 2012 and lasting to the end of May of 2013. Based on recordings of call notes, most birds around Fayetteville were Type 2, the large-billed ponderosa pine crossbill, associated with a variety of conifer species. Birds recorded in Carroll County were Type 3, the small-billed western hemlock crossbill, and they were associated with small cones on shortleaf pine (Pinus echinata). One recording was obtained in Fayetteville of Type 5, the lodgepole pine crossbill, only the third recording east of the Great Plains. Crossbills at the Fayetteville Country Club were observed eating algae (Cladophora sp.) during the months of December and January, a behavior rarely reported for passerines. During March, crossbills appeared at sunflower bird feeders, which is a relatively recent phenomenon associated with low conifer seed abundance. The first two Arkansas specimens of crossbills (probably Type 3) were obtained from birds that struck windows near feeders. This is only the third recorded irruption of crossbills in Arkansas in the last 43 years, suggesting that crossbills rarely travel this far south in search of cone crops
Unusual Concentration of Summer Tanagers (Piranga rubra) in Northwestern Arkansas during Winter 2015-2016
Cargo of Birds to Arkansas, the Hurricanes in 2008 and the Swept Clean Hypothesis
Three hurricanes in the hurricane season of 2008 brought to Arkansas several unusual marine and other birds from southerly locations. There were 10 species noted, totaling 44 individual birds. Sooty Terns, numbering 15, were the most numerous. Laughing Gulls were next in abundance. In the mix of birds there was only 1 new species for the state, a Least Grebe. The hurricanes brought vastly different cargos of birds, and two hypotheses relating to how hurricanes transport birds are proposed. The findings supported the swept clean hypothesis over the blown through hypothesis
Inelastic Dark Matter in Light of DAMA/LIBRA
Inelastic dark matter, in which WIMP-nucleus scatterings occur through a
transition to an excited WIMP state ~ 100 keV above the ground state, provides
a compelling explanation of the DAMA annual modulation signal. We demonstrate
that the relative sensitivities of various dark matter direct detection
experiments are modified such that the DAMA annual modulation signal can be
reconciled with the absence of a reported signal at CDMS-Soudan, XENON10,
ZEPLIN, CRESST, and KIMS for inelastic WIMPs with masses O(100 GeV). We review
the status of these experiments, and make predictions for upcoming ones. In
particular, we note that inelastic dark matter leads to highly suppressed
signals at low energy, with most events typically occurring between 20 to 45
keV (unquenched) at xenon and iodine experiments, and generally no events at
low (~ 10 keV) energies. Suppressing the background in this high energy region
is essential to testing this scenario. The recent CRESST data suggest seven
observed tungsten events, which is consistent with expectations from this
model. If the tungsten signal persists at future CRESST runs, it would provide
compelling evidence for inelastic dark matter, while its absence should exclude
it.Comment: 27 pages, 17 figures, minor revision
IL-21 receptor expression in human tendinopathy
The pathogenetic mechanisms underlying tendinopathy remain unclear,
with much debate as to whether inflammation or degradation has the prominent
role. Increasing evidence points toward and early inflammatory infiltrate and
associated inflammatory cytokine production in human and animal models of
tendon disease.
The IL-21/IL-21R axis is a proinflammatory cytokine complex that has
been associated with chronic inflammatory diseases including rheumatoid
arthritis and inflammatory bowel disease. This project aimed to investigate the
role and expression of the cytokine/receptor pair IL-21/IL-21R in human
tendinopathy.
We found significantly elevated expression of IL-21 receptor message and
protein in human tendon samples but found no convincing evidence of the
presence of IL-21 at message or protein level. The level of expression of IL-21R
message/protein in human tenocytes was significantly up regulated by
proinflammatory cytokines (TNFα/IL-1ÎČ) in vitro.
These findings demonstrate that IL-21R is present in early human
tendinopathy mainly expressed by tenocytes and macrophages. Despite a lack of
IL-21 expression these data again suggest that early tendinopathy has an
inflammatory/cytokine phenotype, which may provide novel translational targets
in the treatment of tendinopathy
A Unified Account of the Moral Standing to Blame
Recently, philosophers have turned their attention to the question, not when a given agent is blameworthy for what she does, but when a further agent has the moral standing to blame her for what she does. Philosophers have proposed at least four conditions on having âmoral standingâ:
1. Oneâs blame would not be âhypocriticalâ.
2. One is not oneself âinvolved inâ the target agentâs wrongdoing.
3. One must be warranted in believing that the target is indeed blameworthy for the wrongdoing.
4. The targetâs wrongdoing must some of âoneâs businessâ.
These conditions are often proposed as both conditions on one and the same thing, and as marking fundamentally different ways of âlosing standing.â Here I call these claims into question. First, I claim that conditions (3) and (4) are simply conditions on different things than are conditions (1) and (2). Second, I argue that condition (2) reduces to condition (1): when âinvolvementâ removes someoneâs standing to blame, it does so only by indicating something further about that agent, viz., that he or she lacks commitment to the values that condemn the wrongdoerâs action. The result: after we clarify the nature of the non-hypocrisy condition, we will have a unified account of moral standing to blame. Issues also discussed: whether standing can ever be regained, the relationship between standing and our "moral fragility", the difference between mere inconsistency and hypocrisy, and whether a condition of standing might be derived from deeper facts about the "equality of persons"
Solving the Hierarchy Problem with Exponentially Large Dimensions
In theories with (sets of) two large extra dimensions and supersymmetry in
the bulk, the presence of non-supersymmetric brane defects naturally induces a
logarithmic potential for the volume of the transverse dimensions. Since the
logarithm of the volume rather than the volume itself is the natural variable,
parameters of O(10) in the potential can generate an exponentially large size
for the extra dimensions. This provides a true solution to the hierarchy
problem, on the same footing as technicolor or dynamical supersymmetry
breaking. The area moduli have a Compton wavelength of about a millimeter and
mediate Yukawa interactions with gravitational strength. We present a simple
explicit example of this idea which generates two exponentially large
dimensions. In this model, the area modulus mass is in the millimeter range
even for six dimensional Planck scales as high as 100 TeV.Comment: 13 pages, 7 figures, corrected typo
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