542 research outputs found
Continuum Double Exchange Model
We present a continuum model for doped manganites which consist of two
species of quantum spin 1/2 fermions interacting with classical spin fields.
The phase structure at zero temperature turns out to be considerably rich:
antiferromagnetic insulator, antiferromagnetic two band conducting, canted two
band conducting, canted one band conducting and ferromagnetic one band
conducting phases are identified, all of them being stable against phase
separation. There are also regions in the phase diagram where phase separation
occurs.Comment: 14 pages, LaTeX2e file, two eps included figures. Published versio
MicroRNAs of Gallid and Meleagrid herpesviruses show generally conserved genomic locations and are virus-specific
AbstractMany herpesviruses, including Marek's disease viruses (MDV1 and MDV2), encode microRNAs. In this study, we report microRNAs of two related herpesviruses, infectious laryngotracheitis virus (ILTV) and herpesvirus of turkeys (HVT), as well as additional MDV2 microRNAs. The genome locations, but not microRNA sequences, are conserved among all four of these avian herpesviruses. Most are clustered in the repeats flanking the unique long region (I/TRL), except in ILTV which lacks these repeats. Two abundant ILTV microRNAs are antisense to the immediate early gene ICP4. A homologue of host microRNA, gga-miR-221, was found among the HVT microRNAs. Additionally, a cluster of HVT microRNAs was found in a region containing two locally duplicated segments, resulting in paralogous HVT microRNAs with 96–100% identity. The prevalence of microRNAs in the genomic repeat regions as well as in local repeats suggests the importance of genetic plasticity in herpesviruses for microRNA evolution and preservation of function
Framework for Leadership and Training of Biosafety Level 4 Laboratory Workers
One-sentence summary for table of contents: Training should include theoretical consideration of biocontainment principles, practical hands-on training, and mentored on-the-job experience
Spin Waves in Canted Phases: An Application to Doped Manganites
We present the effective lagrangian for low energy and momentum spin waves in
canted phases at next to leading order in the derivative expansion. The
symmetry breaking pattern SU(2) --> 1 of the internal spin group and that of
the crystallographic space group imply that there is one ferromagnetic and one
antiferromagnetic spin wave. The interaction of the spin waves with the charge
carriers is also discussed for canted, ferromagnetic and antiferromagnetic
phases. All this together allows us to write the doping dependence of the
dispersion relation parameters for doped manganites. We point out that the spin
waves posses distinctive characteristics which may allow us to experimentally
differentiate canted phases from phase separation regions in doped manganites.Comment: 34 pages, latex file, 1 eps included figure. Minor changes, published
versio
Prospects for heavy supersymmetric charged Higgs boson searches at hadron colliders
We investigate the production of a heavy charged Higgs boson at hadron
colliders within the context of the MSSM. A detailed study is performed for all
important production modes and basic background processes for the
t\bar{t}b\bar{b} signature. In our analysis we include effects of initial and
final state showering, hadronization, and principal detector effects. For the
signal production rate we include the leading SUSY quantum effects at high
\tan\beta>~ mt/mb. Based on the obtained efficiencies for the signal and
background we estimate the discovery and exclusion mass limits of the charged
Higgs boson at high values of \tan\beta. At the upgraded Tevatron the discovery
of a heavy charged Higgs boson (MH^+ >~ 200 GeV) is impossible for the
tree-level cross-section values. However, if QCD and SUSY effects happen to
reinforce mutually, there are indeed regions of the MSSM parameter space which
could provide 3\sigma evidence and, at best, 5\sigma charged Higgs boson
discovery at the Tevatron for masses M_H^+<~ 300 GeV and M_H^+<~ 250 GeV,
respectively, even assuming squark and gluino masses in the (500-1000) GeV
range. On the other hand, at the LHC one can discover a H^+ as heavy as 1 TeV
at the canonical confidence level of 5\sigma; or else exclude its existence at
95% C.L. up to masses ~ 1.5 TeV. Again the presence of SUSY quantum effects can
be very important here as they may shift the LHC limits by a few hundred GeV.Comment: Latex2e, 44 pages, 15 figures, 6 tables, uses JHEP3.sty, axodraw.sty.
Comments added. Discussion on QCD factors clarified. Added discussion on
uncertainties. Change of presentation of Tables 4 and 5 and Fig.6. Results
and conclusions unchanged. Version accepted in JHE
Some Like It Fat: Comparative Ultrastructure of the Embryo in Two Demosponges of the Genus Mycale (Order Poecilosclerida) from Antarctica and the Caribbean
0000-0002-7993-1523© 2015 Riesgo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License [4.0], which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published version of the article
Different paths to the modern state in Europe: the interaction between domestic political economy and interstate competition
Theoretical work on state formation and capacity has focused mostly on early modern Europe and on the experience of western European states during this period. While a number of European states monopolized domestic tax collection and achieved gains in state capacity during the early modern era, for others revenues stagnated or even declined, and these variations motivated alternative hypotheses for determinants of fiscal and state capacity. In this study we test the basic hypotheses in the existing literature making use of the large date set we have compiled for all of the leading states across the continent. We find strong empirical support for two prevailing threads in the literature, arguing respectively that interstate wars and changes in economic structure towards an urbanized economy had positive fiscal impact. Regarding the main point of contention in the theoretical literature, whether it was representative or authoritarian political regimes that facilitated the gains in fiscal capacity, we do not find conclusive evidence that one performed better than the other. Instead, the empirical evidence we have gathered lends supports to the hypothesis that when under pressure of war, the fiscal performance of representative regimes was better in the more urbanized-commercial economies and the fiscal performance of authoritarian regimes was better in rural-agrarian economie
Testing the running of the cosmological constant with Type Ia Supernovae at high z
Within the Quantum Field Theory context the idea of a "cosmological constant"
(CC) evolving with time looks quite natural as it just reflects the change of
the vacuum energy with the typical energy of the universe. In the particular
frame of Ref.[30], a "running CC" at low energies may arise from generic
quantum effects near the Planck scale, M_P, provided there is a smooth
decoupling of all massive particles below M_P. In this work we further develop
the cosmological consequences of a "running CC" by addressing the accelerated
evolution of the universe within that model. The rate of change of the CC stays
slow, without fine-tuning, and is comparable to H^2 M_P^2. It can be described
by a single parameter, \nu, that can be determined from already planned
experiments using SNe Ia at high z. The range of allowed values for \nu follow
mainly from nucleosynthesis restrictions. Present samples of SNe Ia can not yet
distinguish between a "constant" CC or a "running" one. The numerical
simulations presented in this work show that SNAP can probe the predicted
variation of the CC either ruling out this idea or confirming the evolution
hereafter expected.Comment: LaTeX, 51 pages, 13 figures, 1 table, references added, typos
corrected, version accepted in JCA
Melflufen and dexamethasone in heavily pretreated relapsed and refractory multiple myeloma
Clinical trial information: NCT02963493Altres ajuts: Oncopeptides A
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