452 research outputs found
Cellular response to empty and palladium-conjugated amino-polystyrene nanospheres uptake: A proteomic study.
Mergers and Acquisitions in Latin America: Industrial Productivity and Corporate Governance
This paper examines the impact of industrial productivity on transnationals M&As from OECD countries towards Latin American countries in the period 1996 to 2010. It also analyzes the relationship between external mechanism of corporate governance and transnational M&As. For this purpose we use a gravitational model at the industry level. We find that industry productivity and higher standards of corporate governance in the country of origin promote transnational M&As activity. However, it is also found that higher levels of capital and technological productivity decreases transnational M&As activity
Genetic dissection reveals diabetes loci proximal to the gimap5 lymphopenia gene
rats are protected from type 1 diabetes (T1D) by 34 Mb of F344 DNA introgressed proximal to the gimap5 lymphopenia gene. To dissect the genetic factor(s) that confer protection from T1D in the DRF. f/f rat line, DRF. f/f rats were crossed to inbred BBDR or DR. lyp/lyp rats to generate congenic sublines that were genotyped and monitored for T1D, and positional candidate genes were sequenced. All (100%) DR. f/f congenic sublines further refined the RNO4 region 1 interval to ϳ670 kb and region 2 to the 340 kb proximal to gimap5. All congenic DRF. f/f sublines were prone to low-grade pancreatic mononuclear cell infiltration around ducts and vessels, but Ͻ20% of islets in nondiabetic rats showed islet infiltration. Coding sequence analysis revealed TCR V 8E, 12, and 13 as candidate genes in region 1 and znf467 and atp6v0e2 as candidate genes in region 2. Our results show that spontaneous T1D is controlled by at least two genetic loci 7 Mb apart on rat chromosome 4. type 1 diabetes; BB rat; T cell receptor; autoimmune CHARACTERISTICS OF TYPE 1 DIABETES (T1D) in both human and the BioBreeding spontaneously diabetes-prone (BBDP) rat include polyuria, hyperglycemia, ketoacidosis, insulitis, and insulin dependency for life. As in human T1D, islets are infiltrated by mononuclear cells at the time of onset with rapid hyperglycemia due to a complete loss of islet -cells (32). The genetic etiology of human T1D remains complex and although the major histocompatibility complex (MHC) (HLA DQ) on chromosome 6 accounts for ϳ40% of T1D risk, the number of non-HLA genetic factors is increasing steadily (2, 7). The BB rat offers a powerful model to dissect both genetic contributions and mechanisms by which immunemediated beta cell killing induces T1D (3, 4, 15, 17-21, 27, 28, 46). As in humans, the major genetic determinant of susceptibility in the BB rat is the MHC (Iddm1) on rat chromosome (RNO) 20. The class II MHC locus RT1B/D. u/u ), an ortholog of human HLA DQ (9), is necessary but not sufficient for T1D in the BBDP rat and other RT1. u/u -related rat strains with spontaneous (24, 47) or induced T1D (8, 43). In BBDP, a null mutation in the gimap5 gene (lyp; Iddm2) on RNO4 (14, 27) causes lymphopenia and is tightly linked to spontaneous T1D development. The DR. lyp/lyp rat with 2 Mb of BBDP DNA encompassing gimap5 introgressed into the genome of related BBDR rats (BioBreeding resistant to spontaneous T1D) are also 100% lymphopenic and 100% spontaneously diabetic (11). With complete T1D penetrance and tight regulation of onset, the congenic DR. lyp/lyp rat line offers distinct advantages in identification of genes responsible for disease progression. It is possible to induce T1D in BBDR rats (32) and related RT1 u/u rats (8) by administration of polyinosinic: polycytidylic acid (poly I:C, an activator of innate immunity), the T reg depleting cytotoxic DS4.23 anti-ART2.1 (formerly RT6) monoclonal antibody or by viral infection (34). This indicates that the BBDR has an underlying genetic susceptibility to T1D. In crosses between WF and either BBDP or BBDR rats, a quantitative trait locus (QTL) important for induced T1D (Iddm14, previously designated Iddm4) was mapped to RNO4 (6, Interestingly, F344 DNA introgressed between D4Rat253 and D4Rhw6 into the congenic DR. lyp/lyp genetic background resulted in a lymphopenic but nondiabetic rat (designated DRF. f/f ) (11). Protection from T1D in the DRF. f/f congenic rat line led us to conclude that spontaneous T1D in the BB rat is controlled, in part, by a diabetogenic factor(s) independent of the gimap5 mutation (76.84 Mb) on RNO4. This congenic interval is encompassed within Iddm14, raising the possibility that the Iddm14 locus could be required for both spontaneous and induced T1D in the BB rat. The aim of this study was to cross the DRF. f/f rat to BBDR and DR. lyp/lyp rats and produce recombinant sublines that could be assessed for both lymphopenia and diabetes and to estimate the number of independent genes on RNO4 that control spontaneous T1D
Specific Heat Discontinuity, deltaC, at Tc in BaFe2(As0.7P0.3)2 - Consistent with Unconventional Superconductivity
We report the specific heat discontinuity, deltaC/Tc, at Tc = 28.2 K of a
collage of single crystals of BaFe2(As0.7P0.3)2 and compare the measured value
of 38.5 mJ/molK**2 with other iron pnictide and iron chalcogenide (FePn/Ch)
superconductors. This value agrees well with the trend established by Bud'ko,
Ni and Canfield who found that deltaC/Tc ~ a*Tc**2 for 14 examples of doped
Ba1-xKxFe2As2 and BaFe2-xTMxAs2, where the transition metal TM=Co and Ni. We
extend their analysis to include all the FePn/Ch superconductors for which
deltaC/Tc is currently known and find deltaC/Tc ~ a*Tc**1.9 and a=0.083
mJ/molK**4. A comparison with the elemental superconductors with Tc>1 K and
with A-15 superconductors shows that, contrary to the FePn/Ch superconductors,
electron-phonon-coupled conventional superconductors exhibit a significantly
different dependence of deltaC on Tc, namely deltaC/Tc ~ Tc**0.9. However
deltaC/gamma*Tc appears to be comparable in all three classes (FePn/Ch,
elemental and A-15) of superconductors with, e. g., deltaC/gamma*Tc=2.4 for
BaFe2(As0.7P0.3)2. A discussion of the possible implications of these
phenomenological comparisons for the unconventional superconductivity believed
to exist in the FePn/Ch is given.Comment: some disagreement in reference and footnote numbering with the
published versio
Pressure-dependence of electron-phonon coupling and the superconducting phase in hcp Fe - a linear response study
A recent experiment by Shimizu et al. has provided evidence of a
superconducting phase in hcp Fe under pressure. To study the
pressure-dependence of this superconducting phase we have calculated the phonon
frequencies and the electron-phonon coupling in hcp Fe as a function of the
lattice parameter, using the linear response (LR) scheme and the full potential
linear muffin-tin orbital (FP-LMTO) method. Calculated phonon spectra and the
Eliashberg functions indicate that conventional s-wave
electron-phonon coupling can definitely account for the appearance of the
superconducting phase in hcp Fe. However, the observed change in the transition
temperature with increasing pressure is far too rapid compared with the
calculated results. For comparison with the linear response results, we have
computed the electron-phonon coupling also by using the rigid muffin-tin (RMT)
approximation. From both the LR and the RMT results it appears that
electron-phonon interaction alone cannot explain the small range of volume over
which superconductivity is observed. It is shown that
ferromagnetic/antiferromagnetic spin fluctuations as well as scattering from
magnetic impurities (spin-ordered clusters) can account for the observed values
of the transition temperatures but cannot substantially improve the agreeemnt
between the calculated and observed presure/volume range of the superconducting
phase. A simplified treatment of p-wave pairing leads to extremely small ( K) transition temperatures. Thus our calculations seem to rule out
both - and - wave superconductivity in hcp Fe.Comment: 12 pages, submitted to PR
Particle-yield modification in jet-like azimuthal di-hadron correlations in Pb-Pb collisions at = 2.76 TeV
The yield of charged particles associated with high- trigger
particles ( GeV/) is measured with the ALICE detector in
Pb-Pb collisions at = 2.76 TeV relative to proton-proton
collisions at the same energy. The conditional per-trigger yields are extracted
from the narrow jet-like correlation peaks in azimuthal di-hadron correlations.
In the 5% most central collisions, we observe that the yield of associated
charged particles with transverse momenta GeV/ on the
away-side drops to about 60% of that observed in pp collisions, while on the
near-side a moderate enhancement of 20-30% is found.Comment: 15 pages, 2 captioned figures, 1 table, authors from page 10,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/350
Strange particle production in proton-proton collisions at TeV with ALICE at the LHC
The production of mesons containing strange quarks (K, ) and both
singly and doubly strange baryons (, Anti-, and
+Anti-) are measured at central rapidity in pp collisions at
= 0.9 TeV with the ALICE experiment at the LHC. The results are
obtained from the analysis of about 250 k minimum bias events recorded in 2009.
Measurements of yields (dN/dy) and transverse momentum spectra at central
rapidities for inelastic pp collisions are presented. For mesons, we report
yields () of 0.184 0.002 stat. 0.006 syst. for K and
0.021 0.004 stat. 0.003 syst. for . For baryons, we find
= 0.048 0.001 stat. 0.004 syst. for , 0.047
0.002 stat. 0.005 syst. for Anti- and 0.0101 0.0020 stat.
0.0009 syst. for +Anti-. The results are also compared with
predictions for identified particle spectra from QCD-inspired models and
provide a baseline for comparisons with both future pp measurements at higher
energies and heavy-ion collisions.Comment: 33 pages, 21 captioned figures, 10 tables, authors from page 28,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/387
Elliptic flow of charged particles in Pb-Pb collisions at 2.76 TeV
We report the first measurement of charged particle elliptic flow in Pb-Pb
collisions at 2.76 TeV with the ALICE detector at the CERN Large Hadron
Collider. The measurement is performed in the central pseudorapidity region
(||<0.8) and transverse momentum range 0.2< < 5.0 GeV/. The
elliptic flow signal v, measured using the 4-particle correlation method,
averaged over transverse momentum and pseudorapidity is 0.087 0.002
(stat) 0.004 (syst) in the 40-50% centrality class. The differential
elliptic flow v reaches a maximum of 0.2 near = 3
GeV/. Compared to RHIC Au-Au collisions at 200 GeV, the elliptic flow
increases by about 30%. Some hydrodynamic model predictions which include
viscous corrections are in agreement with the observed increase.Comment: 10 pages, 4 captioned figures, published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/389
Two-pion Bose-Einstein correlations in central Pb-Pb collisions at = 2.76 TeV
The first measurement of two-pion Bose-Einstein correlations in central Pb-Pb
collisions at TeV at the Large Hadron Collider is
presented. We observe a growing trend with energy now not only for the
longitudinal and the outward but also for the sideward pion source radius. The
pion homogeneity volume and the decoupling time are significantly larger than
those measured at RHIC.Comment: 17 pages, 5 captioned figures, 1 table, authors from page 12,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/388
Suppression of charged particle production at large transverse momentum in central Pb-Pb collisions at TeV
Inclusive transverse momentum spectra of primary charged particles in Pb-Pb
collisions at = 2.76 TeV have been measured by the ALICE
Collaboration at the LHC. The data are presented for central and peripheral
collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross
section. The measured charged particle spectra in and GeV/ are compared to the expectation in pp collisions at the same
, scaled by the number of underlying nucleon-nucleon
collisions. The comparison is expressed in terms of the nuclear modification
factor . The result indicates only weak medium effects ( 0.7) in peripheral collisions. In central collisions,
reaches a minimum of about 0.14 at -7GeV/ and increases
significantly at larger . The measured suppression of high- particles is stronger than that observed at lower collision energies,
indicating that a very dense medium is formed in central Pb-Pb collisions at
the LHC.Comment: 15 pages, 5 captioned figures, 3 tables, authors from page 10,
published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/98
- …