3,632 research outputs found
Huge right-handed current effects in B->K*(K pi)l+l- in supersymmetry
Transverse asymmetries in the decay B->K*(K pi)l+l- are an extremely
sensitive probe of right-handed flavour-changing neutral currents. We show how
to include the contribution from the chiral partner of the electromagnetic
operator on the transverse asymmetries at NLO in QCD factorization. We then
consider supersymmetric models with non-minimal flavour violation in the
down-squark sector. We include all the relevant experimental constraints and
present a numerical formula for B->Xs gamma that takes into account the most
recent NNLO calculations. We show that the flavour-changing parameters of these
models are poorly constrained by present data and allow for large effects on
the transverse asymmetries that we consider.Comment: 12 pages, 4 figures, version to appear on JHE
Gamma-ray absorption in the microquasar SS433
We discuss the gamma-ray absorption in the inner region of the microquasar
SS433. Our investigation includes several contributions to the opacity of this
system. They result from the ambient fields generated by the primary star,
possibly an A-type supergiant, and a very extended disk around the black hole.
Besides the sharp and dramatic absorption effect that occurs every time the
star crosses the emission zone, we find in the UV photon field from the
extended disk an important source of absorption for very high energy
gamma-rays. This results in periodic gamma-ray observational signatures.Comment: 8 pages, 9 figures, to appear in Astropart.Phy
Combining Full-Shape and BAO Analyses of Galaxy Power Spectra: A 1.6% CMB-independent constraint on H0
We present cosmological constraints from a joint analysis of the pre- and
post-reconstruction galaxy power spectrum multipoles from the final data
release of the Baryon Oscillation Spectroscopic Survey (BOSS). Geometric
constraints are obtained from the positions of BAO peaks in reconstructed
spectra, analyzed in combination with the unreconstructed spectra in a
full-shape (FS) likelihood using a joint covariance matrix, giving stronger
parameter constraints than FS-only or BAO-only analyses. We introduce a new
method for obtaining constraints from reconstructed spectra based on a
correlated theoretical error, which is shown to be simple, robust, and
applicable to any flavor of density-field reconstruction. Assuming CDM
with massive neutrinos, we analyze data from two redshift bins
and obtain constraints on the Hubble
constant , using only a single prior on the current baryon density
from Big Bang Nucleosynthesis (BBN) and no knowledge of the power
spectrum slope . This gives , with the inclusion of BAO
data sharpening the measurement by , representing one of the strongest
current constraints on independent of cosmic microwave background data.
Restricting to the best-fit slope from Planck (but without additional
priors on the spectral shape), we obtain a measurement of . We find strong constraints on the
cosmological parameters from a joint analysis of the FS, BAO, and Planck data.
This sets new bounds on the sum of neutrino masses (at confidence) and the effective number of
relativistic degrees of freedom , though
contours are not appreciably narrowed by the inclusion of BAO data.Comment: 42 pages, 12 figures, accepted by JCAP, likelihoods available at
https://github.com/Michalychforever/lss_montepython (minor typo corrected
Negotiating from the margins: how the UN shapes the rules of the WTO
World Trade Organization (WTO) rules on agriculture are among the most contentious issues in the international political economy due to agriculture’s importance in the production of tradable commodities as well as economic development and food security in developing countries. In this article, I analyse a surprising and unexpected actor playing an important role in shaping WTO rules on agriculture – the United Nations (UN). While UN actors do not have a seat at the bargaining table, I argue that they invoke their delegated and moral authority and initiate actions to shape global trade rule-making. I demonstrate that UN actors have influenced the discourse, agenda and outcomes of trade negotiations by analysing three cases: 1) the Food and Agriculture Organization (FAO) orchestrating a Uruguay Round agreement in favour of food insecure developing countries; 2) the World Food Programme’s (WFP) blocking of trade rules on international food aid during the Doha Round negotiations; and 3) a proposal by the UN Special Rapporteur on the right to food for a legal waiver to protect public food stockholding that was taken up by WTO member states in 2013
Backdoor Bargaining: How the European Union Navigates the Food Aid Regime Complex
Scholars have long observed that states play off overlapping international institutions against one another in an effort to advance their policy objectives. This article identifies a strategy utilized by the EU in response to regime complexity that I term "backdoor bargaining." Unlike forum-shopping, regime-shifting, and competitive-regime creation strategies, which states use to move multilateral negotiations to an institution that they expect will produce a more favorable outcome, backdoor bargaining involves a state using negotiations within one institution to gain an advantage in negotiations taking place at another distinct institution in a regime complex. I demonstrate the plausibility of backdoor bargaining by showing that the EU used the renegotiation of the Food Aid Convention as a strategy to gain bargaining leverage in the agriculture negotiations at the World Trade Organization. The article also offers insights into the potential consequences of international regime complexity for the EU as a global actor and the coherence of its foreign policies
Modelling the spinning dust emission from LDN 1780
We study the anomalous microwave emission (AME) in the Lynds Dark Nebula
(LDN) 1780 on two angular scales. Using available ancillary data at an angular
resolution of 1 degree, we construct an SED between 0.408 GHz to 2997 GHz. We
show that there is a significant amount of AME at these angular scales and the
excess is compatible with a physical spinning dust model. We find that LDN 1780
is one of the clearest examples of AME on 1 degree scales. We detected AME with
a significance > 20. We also find at these angular scales that the
location of the peak of the emission at frequencies between 23-70 GHz differs
from the one on the 90-3000 GHz map. In order to investigate the origin of the
AME in this cloud, we use data obtained with the Combined Array for Research in
Millimeter-wave Astronomy (CARMA) that provides 2 arcmin resolution at 30 GHz.
We study the connection between the radio and IR emissions using morphological
correlations. The best correlation is found to be with MIPS 70m, which
traces warm dust (T50K). Finally, we study the difference in radio
emissivity between two locations within the cloud. We measured a factor
of difference in 30 GHz emissivity. We show that this variation can
be explained, using the spinning dust model, by a variation on the dust grain
size distribution across the cloud, particularly changing the carbon fraction
and hence the amount of PAHs.Comment: 14 pages, 11 figures, submitted to MNRA
“Mommy, is being brown bad?” : Critical Race Parenting in a Post-Race Era
This article looks at the counter-pedagogical processes that may disrupt how children learn about race by positing a pedagogical process called Critical Race Parenting. By drawing upon counterstories of parenting I posit how Critical Race Parenting (CRP) becomes an educational praxis that can engage both parent and child in a mutual process of teaching and learning about race, especially ones that debunk dominant messages about race. And, in doing so, both parents and children have a deeper commitment to racial realism that does not allow for colorblind rhetoric to reign supreme
Dispersal and population structure at different spatial scales in the subterranean rodent Ctenomys australis
This study was funded by grants from Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET, PIP5838), Agencia de Promoción Científica y Tecnológica de la Argentina (PICTO1-423, BID-1728/OC-AR), and the programme ECOS-Sud France/Argentina (A05B01).Background: The population genetic structure of subterranean rodent species is strongly affected by demographic (e.g. rates of dispersal and social structure) and stochastic factors (e.g. random genetic drift among subpopulations and habitat fragmentation). In particular, gene flow estimates at different spatial scales are essential to understand genetic differentiation among populations of a species living in a highly fragmented landscape. Ctenomys australis (the sand dune tuco-tuco) is a territorial subterranean rodent that inhabits a relatively secure, permanently sealed burrow system, occurring in sand dune habitats on the coastal landscape in the south-east of Buenos Aires province, Argentina. Currently, this habitat is threatened by urban development and forestry and, therefore, the survival of this endemic species is at risk. Here, we assess population genetic structure and patterns of dispersal among individuals of this species at different spatial scales using 8 polymorphic microsatellite loci. Furthermore, we evaluate the relative importance of sex and habitat configuration in modulating the dispersal patterns at these geographical scales. Results: Our results show that dispersal in C. australis is not restricted at regional spatial scales (similar to 4 km). Assignment tests revealed significant population substructure within the study area, providing support for the presence of two subpopulations from three original sampling sites. Finally, male-biased dispersal was found in the Western side of our study area, but in the Eastern side no apparent philopatric pattern was found, suggesting that in a more continuous habitat males might move longer distances than females. Conclusions: Overall, the assignment-based approaches were able to detect population substructure at fine geographical scales. Additionally, the maintenance of a significant genetic structure at regional (similar to 4 km) and small (less than 1 km) spatial scales despite apparently moderate to high levels of gene flow between local sampling sites could not be explained simply by the linear distance among them. On the whole, our results support the hypothesis that males disperse more frequently than females; however they do not provide support for strict philopatry within females.Publisher PDFPeer reviewe
Biodiesel Mandate Laws in Argentina and Brazil: An Estimation of Soybean Oil Foregone Export Revenues
Replaced with revised version of paper 02/22/08.Research and Development/Tech Change/Emerging Technologies,
Categorização das respostas às questões do questionário views on science-technology-society (vosts) realizada por professores/pesquisadores brasileiros
Esta pesquisa contou com a colaboração de 22 professores/pesquisadores brasileiros das áreas de Ciências Humanas, Naturais e Exatas, que categorizaram as opções de respostas às questões do questionário Views on Science-Technology-Society (VOSTS) referentes às dimensões: Construção social da Tecnologia e Influência da Sociedade na Ciência e na Tecnologia. Esse processo consistiu em analisar opções de respostas das questões e as categorizarem em realista, plausível e simplista. Com esse método estabeleceu-se validez ao processo de categorização, pois este foi realizado pela comunidade científica. Com a análise dos dados constatou-se que não é simples observar consenso por parte dos analistas nas frases categorizadas em realista e plausível, visto que desde a construção do VOSTS as controvérsias em relação aos assuntos abordados em suas questões se ampliaram muito
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