We consider various symmetries present in the collinear effective theory and their implications. There are collinear, soft and ultrasoft gauge symmetries and we discuss transformation properties of a collinear quark and gauge fields under these gauge transformations. If we require the gauge invariance order by order, the gauge fields have definite transformation properties. We also probe repara...

Urmia Lake has been designated as an international park by the United Nations. The lake occupies a 5700 km2 depression in northwestern Iran. Thirteen permanent rivers flow into the lake. Water level in the lake has been decreased 3.5 m in the last decade due to a shortage of precipitation and progressively dry climate. Geologically the lake basin is considered to be a graben of tectonic origin....

We consider effects of symmetries on renormalization properties of the collinear effective theory. We investigate which types of operators are possible in the effective theory satisfying gauge invariance, reparameterization invariance and residual energy invariance. Each symmetry puts a constraint on the possible structure of the theory, and there can appear only specific combinations of operat...

We study the normalization of perturbative QCD corrections to the inclusive B → Xsγ decay. We propose to set the renormalization scale using the Brodsky-Lepage-Mackenzie (BLM) method. In the proposed method the scale is determined by absorbing the vacuum polarization correction from light fermions to renormalization scale but not including the anomalous dimensions. The BLM scale depends in gene...

Two issues dominate the school choice debate: whether competition would make schools more productive, and whether choice would result in sorting or stratification. In trying to answer these questions, economists have generally focused on the consequences of voucher systems, yet inter-district or Tiebout choice is, and is likely to remain, the main form of school choice in the United States. Sur...

Small firms in developing countries are typically modeled as facing a frictionless market for workers, characterized by low search costs, full information, and a lack of regulation. We report the results of a field experiment that randomly placed unemployed young people as apprentices with small firms in Ghana. The program provided a novel worker screening technology to firms (in addition to si...

We consider the azimuthal asymmetries in semi-inclusive deep inelastic leptoproduction arising due to both perturbative and nonperturbative effects at HERMES energies and show that the k2 T /Q 2 order corrections to 〈cos φ〉 and 〈cos 2φ〉 are significant. We also reconsider the results of perturbative effects for 〈cosφ〉 at large momentum transfers [1] using the more recent sets of scale-dependent...

N-[(3-fluorophenyl)methyl]glycyl-N-{3-[((3-aminophenyl)sulfonyl)2-(aminophenyl)amino]-(1S,2S)-2-hydroxy-1-(phenylmethyl)propyl}3-methyl-L-valinamide (DPC 681, DPC) on oral coadministration with ritonavir (RTV) in rats caused a significant increase in systemic exposure to DPC. Following a single oral dose of [C]DPC with and without RTV pretreatment in rats, and subsequent analysis of whole-body ...