1,044 research outputs found
Evolution of the energy spacing in odd-mass K, Cl and P isotopes for
The energy of the first excited state in the neutron-rich N=28 nucleus 45Cl
has been established via in-beam gamma-ray spectroscopy following proton
removal. This energy value completes the systematics of the
E(1/2^+_1)-E(3/2^+_1) level spacing in odd-mass K, Cl and P isotopes for
N=20-28. The results are discussed in the framework of shell-model calculations
in the sd-fp model space. The contribution of the central, spin-orbit and
tensor components is discussed from a calculation based on a proton single-hole
spectrum from G-matrix and pi + rho meson exchange potentials. A composite
model for the proton 0d_{3/2}-1s_{1/2} single-particle energy shift is
presented.Comment: Phys. Rev. C, in pres
The Power to Resist: Mobilization and the Logic of Terrorist Attacks in Civil War
Existing research has argued that terrorism is common in civil war because it is "effective." Surprisingly, however, only some groups use terrorism during civil wars, while many refrain altogether. We also see considerable variation in the use of terrorism over time. This article presents a theory of terrorism as a mobilization strategy in civil war, taking into account benefits, costs, and temporal dynamics. We argue that the choice and the timing of terrorism arise from the interaction between conditions for effective mobilization and battlefield dynamics. Terrorism can mobilize support when it provokes indiscriminate government repression or when it radicalizes rebels' constituency by antagonizing specific societal groups. The timing of attacks, however, is in uenced by battlefield losses, which increase rebels' need to rally civilian support. The analyses of new disaggregated data on rebels' terrorist attacks during con icts (1989-2009) and of ISIS tactics in Iraq and Syria support our theoretical argument
Plasmodium berghei Hsp90 contains a natural immunogenic I-A<sup>b</sup>-restricted antigen common to rodent and human Plasmodium species
Thorough understanding of the role of CD4 T cells in immunity can be greatly assisted by the study of responses to defined specificities. This requires knowledge of Plasmodium-derived immunogenic epitopes, of which only a few have been identified, especially for the mouse C57BL/6 background. We recently developed a TCR transgenic mouse line, termed PbT-II, that produces CD4+ T cells specific for an MHC class II (I-Ab)-restricted Plasmodium epitope and is responsive to both sporozoites and blood-stage P. berghei. Here, we identify a peptide within the P. berghei heat shock protein 90 as the cognate epitope recognised by PbT-II cells. We show that C57BL/6 mice infected with P. berghei blood-stage induce an endogenous CD4 T cell response specific for this epitope, indicating cells of similar specificity to PbT-II cells are present in the naĂŻve repertoire. Adoptive transfer of in vitro activated TH1-, or particularly TH2-polarised PbT-II cells improved control of P. berghei parasitemia in C57BL/6 mice and drastically reduced the onset of experimental cerebral malaria. Our results identify a versatile, potentially protective MHC-II restricted epitope useful for exploration of CD4 T cell-mediated immunity and vaccination strategies against malaria
Conditional probabilities in quantum theory, and the tunneling time controversy
It is argued that there is a sensible way to define conditional probabilities
in quantum mechanics, assuming only Bayes's theorem and standard quantum
theory. These probabilities are equivalent to the ``weak measurement''
predictions due to Aharonov {\it et al.}, and hence describe the outcomes of
real measurements made on subensembles. In particular, this approach is used to
address the question of the history of a particle which has tunnelled across a
barrier. A {\it gedankenexperiment} is presented to demonstrate the physically
testable implications of the results of these calculations, along with graphs
of the time-evolution of the conditional probability distribution for a
tunneling particle and for one undergoing allowed transmission. Numerical
results are also presented for the effects of loss in a bandgap medium on
transmission and on reflection, as a function of the position of the lossy
region; such loss should provide a feasible, though indirect, test of the
present conclusions. It is argued that the effects of loss on the pulse {\it
delay time} are related to the imaginary value of the momentum of a tunneling
particle, and it is suggested that this might help explain a small discrepancy
in an earlier experiment.Comment: 11 pages, latex, 4 postscript figures separate (one w/ 3 parts
Preparation of anti-vicinal amino alcohols: asymmetric synthesis of D-erythro-Sphinganine, (+)-spisulosine and D-ribo-phytosphingosine
Two variations of the Overman rearrangement have been developed for the highly selective synthesis of anti-vicinal amino alcohol natural products. A MOM-ether directed palladium(II)-catalyzed rearrangement of an allylic trichloroacetimidate was used as the key step for the preparation of the protein kinase C inhibitor D-erythro-sphinganine and the antitumor agent (+)-spisulosine, while the Overman rearrangement of chiral allylic trichloroacetimidates generated by asymmetric reduction of an alpha,beta-unsaturated methyl ketone allowed rapid access to both D-ribo-phytosphingosine and L-arabino-phytosphingosine
Phosphine-Catalyzed Formation of Carbon-Sulfur Bonds: Catalytic Asymmetric Synthesis of gamma-Thioesters
Supporting Information Available: Experimental procedures and compound characterization data. This material is available free of charge via the Internet at http://pubs.acs.org.A method for catalytic asymmetric Îł sulfenylation of carbonyl compounds has been developed. In the presence of an appropriate catalyst, thiols not only add to the Îł position of allenoates, overcoming their propensity to add to the ÎČ position in the absence of a catalyst, but do so with very good enantioselectivity. Sulfur nucleophiles are now added to the three families of nucleophiles (carbon, nitrogen, and oxygen) that had earlier been shown to participate in catalyzed Îł additions. The phosphine catalyst of choice, TangPhos, had previously only been employed as a chiral ligand for transition metals, not as an efficient enantioselective nucleophilic catalyst.National Institutes of Health (U.S.)National Institute of General Medical Sciences (U.S.) (R01-GM57034)Merck & Co.Novartis (Firm
Measurement of E2 transition strengths in Mg32,34
The degree of collectivity in the neutron-rich nuclei Mg32 and Mg34 has been determined via intermediate-energy Coulomb excitation in inverse kinematics. Measured energies of the first excited 2+ states and reduced electric quadrupole transition probabilities B(E2;0g.s.+â21+) are presented for Mg32 and Mg34. The results agree with previous measurements and confirm the placement of both nuclei within the "island of inversion.
Breaks and the Statistical Process of Inflation:The Case of Estimating the âModernâ Long-Run Phillips Curve*
Stock markets and effective exchange rates in European countries: threshold cointegration findings
© 2015, Eurasia Business and Economics Society. The nexus between stock markets and exchange rates is examined in the case of eight European countries. The sample consists of four economies with national currencies and four that have adopted the euro. Thus, if differences between the two groups in the relationship governing the two markets exist, they will be unveiled. To this effect, a threshold cointegration methodology is adopted that allows for more reliable inferences to be drawn for both the short and long run nexus between the two markets. Monthly data is used covering the period 01/2000â12/2014. The findings reported herein offer support in favor of the portfolio approach thesis over the recent economic crisis period, but this finding is not the case for the entire sample. Bidirectional causality is found for Norway and the UK, pointing to a currency effect on stock markets. In view of the findings reported herein, policies aiming at reducing uncertainty in the stock markets can exert beneficial effects on currency markets
A three-miRNA signature as promising non-invasive diagnostic marker for gastric cancer
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