5,219 research outputs found
Wnt/Lef1 signaling acts via Pitx2 to regulate somite myogenesis
AbstractWnt signaling has been implicated in somite, limb, and branchial arch myogenesis but the mechanisms and roles are not clear. We now show that Wnt signaling via Lef1 acts to regulate the number of premyogenic cells in somites but does not regulate myogenic initiation in the limb bud or maintenance in the first or second branchial arch. We have also analysed the function and regulation of a putative downstream transcriptional target of canonical Wnt signaling, Pitx2. We show that loss-of-function of Pitx2 decreases the number of myogenic cells in the somite, whereas overexpression increases myocyte number particularly in the epaxial region of the myotome. Increased numbers of mitotic cells were observed following overexpression of Pitx2 or an activated form of Lef1, suggesting an effect on cell proliferation. In addition, we show that Pitx2 expression is regulated by canonical Wnt signaling in the epaxial somite and second branchial arch, but not in the limb or the first branchial arch. These results suggest that Wnt/Lef1 signaling regulates epaxial myogenesis via Pitx2 but that this link is uncoupled in other regions of the body, emphasizing the unique molecular networks that control the development of various muscles in vertebrates
An Anglo-Saxon execution cemetery at Walkington Wold, Yorkshire
This paper presents a re-evaluation of a cemetery excavated over
30 years ago at Walkington Wold in east Yorkshire. The cemetery is
characterized by careless burial on diverse alignments, and by the fact that
most of the skeletons did not have associated crania. The cemetery has been
variously described as being the result of an early post-Roman massacre, as
providing evidence for a âCelticâ head cult or as an Anglo-Saxon execution
cemetery. In order to resolve the matter, radiocarbon dates were acquired and
a re-examination of the skeletal remains was undertaken. It was confirmed that
the cemetery was an Anglo-Saxon execution cemetery, the only known example
from northern England, and the site is set into its wider context in the paper
Diamond Line - Fall 2020
In following up the premier issue of The Diamond Line, the fall 2020 editorial staff had big shoes to fill. We took on the challenge of creating something that would uphold the framework of Issue 1 while simultaneously branching out from its margins.
Like the editors before us, we had a vision, but ours took a new form â bright, warm colors. Sunset colors. Moons. Playful lines. Isolation and introspection. A stroll through an art gallery. A coming-of-age story bound between two groovy orange bookends. While Issue 2 does not have an overarching theme, we chose the cover art, âPandemic Promâ by Autumn Blaylock, because it beautifully encompassed the pages within and the vision we were working toward
Diamond Line - Fall 2020
In following up the premier issue of The Diamond Line, the fall 2020 editorial staff had big shoes to fill. We took on the challenge of creating something that would uphold the framework of Issue 1 while simultaneously branching out from its margins.
Like the editors before us, we had a vision, but ours took a new form â bright, warm colors. Sunset colors. Moons. Playful lines. Isolation and introspection. A stroll through an art gallery. A coming-of-age story bound between two groovy orange bookends. While Issue 2 does not have an overarching theme, we chose the cover art, âPandemic Promâ by Autumn Blaylock, because it beautifully encompassed the pages within and the vision we were working toward
Priorities for social science and humanities research on the challenges of moving beyond animal-based food systems
Increasingly high-profile research is being undertaken into the socio-environmental challenges associated with the over-production and consumption of food from animals. Transforming food systems to mitigate climate change and hidden hunger, ensure food security and good health all point to reducing animal-based foods as a key lever. Moving beyond animal-based food systems is a societal grand challenge requiring coordinated international research by the social sciences and humanities. A 'selective openness' to this range of disciplines has been observed within multi-discipline research programmes designed to address societal grand challenges including those concerned with the sustainability of food systems, inhibiting the impact of social sciences and humanities. Further, existing research on animal-based foods within these disciplines is largely dispersed and focused on particular parts of food systems. Inspired by the 'Sutherland Method' this paper discusses the results of an iterative research prioritisation process carried out to enhance capacity, mutual understanding and impact amongst European social sciences and humanities researchers. The process produced 15 research questions from an initial list of 100 and classified under the following five themes: (1) debating and visioning food from animals; (2) transforming agricultural spaces; (3) framing animals as food; (4) eating practices and identities; and (5) governing transitions beyond animal-based food systems. These themes provide an important means of making connections between research questions that invite and steer research on key challenges in moving beyond animal-based food systems. The themes also propose loci for future transdisciplinary research programmes that join researchers from the natural sciences, social sciences, and humanities and stakeholders from beyond academia to develop cooperative research and implementation initiatives. The experiences gained from the prioritisation process draw attention to the value of spending time to discuss and collaboratively steer research enquiry into emergent and controversial matters of concern. Fundamental, ethical questions around the continuation or complete cessation of the use of animals for food was a key tension. The positioning of research towards these questions affects not only the framing of the research area but also the partners with whom the research can be carried out and for whom it may be of benefit.peerReviewe
Social Class
Discussion of class structure in fifth-century Athens, historical constitution of theater audiences, and the changes in the comic representation of class antagonism from Aristophanes to Menander
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A Search for Dark Higgs Bosons
Recent astrophysical and terrestrial experiments have motivated the proposal
of a dark sector with GeV-scale gauge boson force carriers and new Higgs
bosons. We present a search for a dark Higgs boson using 516 fb-1 of data
collected with the BABAR detector. We do not observe a significant signal and
we set 90% confidence level upper limits on the product of the Standard
Model-dark sector mixing angle and the dark sector coupling constant.Comment: 7 pages, 5 postscript figures, published version with improved plots
for b/w printin
Duffy antigen receptor for chemokines mediates chemokine endocytosis through a macropinocytosis-like process in endothelial cells
Background: The Duffy antigen receptor for chemokines (DARC) shows high affinity binding to multiple inflammatory CC and CXC chemokines and is expressed by erythrocytes and endothelial cells. Recent evidence suggests that endothelial DARC facilitates chemokine transcytosis to promote neutrophil recruitment. However, the mechanism of chemokine endocytosis by DARC remains unclear. Methodology/Principal Findings: We investigated the role of several endocytic pathways in DARC-mediated ligand internalization. Here we report that, although DARC co-localizes with caveolin-1 in endothelial cells, caveolin-1 is dispensable for DARC-mediated 125I-CXCL1 endocytosis as knockdown of caveolin-1 failed to inhibit ligand internalization. 125I-CXCL1 endocytosis by DARC was also independent of clathrin and flotillin-1 but required cholesterol and was, in part, inhibited by silencing Dynamin II expression. 125I-CXCL1 endocytosis was inhibited by amiloride, cytochalasin D, and the PKC inhibitor GÜ6976 whereas Platelet Derived Growth Factor (PDGF) enhanced ligand internalization through DARC. The majority of DARC-ligand interactions occurred on the endothelial surface, with DARC identified along plasma membrane extensions with the appearance of ruffles, supporting the concept that DARC provides a high affinity scaffolding function for surface retention of chemokines on endothelial cells. Conclusions/Significance: These results show DARC-mediated chemokine endocytosis occurs through a macropinocytosis-like process in endothelial cells and caveolin-1 is dispensable for CXCL1 internalization. Š 2011 Zhao et al
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
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