3,691 research outputs found
Seawater acclimation causes independent alterations in Na \u3csup\u3e+\u3c/sup\u3e/TK\u3csup\u3e+\u3c/sup\u3e- And H\u3csup\u3e+\u3c/sup\u3e-ATPase activity in isolated mitochondria-rich cell subtypes of the rainbow trout gill
Mitochondria-rich cells (MR cells) of the gills of rainbow trout undergo changes in relative distribution and biochemical function during acclimation to partial-strength (10‰) and full-strength (30‰) seawater. In isolated total gill cells, Na+/K+-ATPase activity increased fivefold and H+-ATPase activity decreased fourfold when trout were acclimated to either 10‰ or 30‰ seawater. When total MR gill cells were separated based on differential binding to peanut lectin agglutinin (PNA), the PNA subtypes underwent a change in relative distribution in seawater-acclimated fish. In freshwater, the ratio of PNA-: PNA+ was 65:35 while in seawater the distribution changed to 20:80 PNA-:PNA+. Additionally, differential changes in Na +/K+-ATPase and H+-ATPase activity in each of the independent cell types occurred during seawater acclimation; Na +/K+-ATPase activity in the PNA- cells increased by 197% while in PNA+ cells Na+TK +-ATPase decreased by 57%. However, H+-ATPase activity was decreased in both PNA- (84%) and PNA+ (72%) subtypes during acclimation to seawater
MW and sin^2\theta_eff in Split SUSY: present and future expectations
We analyse the precision electroweak observables MW and sin^2\theta_eff and
their correlations in the recently proposed Split SUSY model. We compare the
results with the Standard Model and Minimal Supersymmetric Standard Model
predictions, and with present and future experimental accuracies. Present
experimental accuracies in (MW, sin^2\theta_eff) do not allow constraints to be
placed on the Split SUSY parameter space. We find that the shifts in (MW,
sin^2\theta_eff) induced by Split SUSY can be larger than the anticipated
accuracy of the GigaZ option of the International Linear Collider, and that the
most sensitive observable is sin^2\theta_eff. These large shifts are possible
also for large chargino masses in scenarios with small tan(\beta) =~ 1.Comment: LaTeX, 13 pages, 4 figures. Comments adde
Precision Calculations for Future Colliders
I discuss the motivations for, and the status of, precision calculations for
the Large Hadron Collider (LHC) and the planned International Linear Collider
(ILC).Comment: latex, uses ws-ijmpe.cls, 19 pages, 9 figures, 1 table, based on a
talk given at the symposium "50 Years of High Energy Physics at UB", to
appear in International Journal of Modern Physics
Localization and characterization of phenamil-sensitive Na\u3csup\u3e+\u3c/sup\u3e influx in isolated rainbow trout gill epithelial cells
Percoll density-gradient separation, combined with peanut lectin agglutinin (PNA) binding and magnetic bead separation, was used to separate dispersed fish gill cells into sub-populations. Functional characterization of each of the sub-populations was performed to determine which displayed acid-activated phenamil- and bafilomycin-sensitive Na+ uptake. Analysis of the mechanism(s) of 22Na+ influx was performed in control and acid-activated (addition of 10 mmoll-1 proprionic acid) cells using a variety of Na+ transport inhibitors (ouabain, phenamil, HOE-694 and bumetanide) and a V-type ATPase inhibitor (bafilomycin). We found that cells migrating to a 1.03-1.05 g ml-1 Percoll interface [pavement cells (PVCs)] possessed the lowest rates of Na+ uptake and that influx was unchanged during either bafilomycin (10 nmoll-1) treatment or internal acidification with addition of proprionic acid (10 mmoll-1). Mitochondria-rich (MR) cells that migrated to the 1.05-1.09 g ml-1 interface of the Percoll gradient demonstrated acidification-activated bafilomycin and phenamil-sensitive Na+ influx. Further separation of the MR fraction into PNA+ and PNA- fractions using magnetic separation demonstrated that only the PNA- cells (α-MR cells) demonstrated phenamiland bafilomycin-sensitive acid-activated 22Na+ uptake. We confirm the coupling of a V-type H+-ATPase with phenamil-sensitive Na+ uptake activity and conclude that high-density α-MR cells function in branchial Na+ uptake in freshwater fish
The Road Towards the ILC: Higgs, Top/QCD, Loops
The International Linear e+e- Collider (ILC) could go into operation in the
second half of the upcoming decade. Experimental analyses and theory
calculations for the physics at the ILC are currently performed. We review
recent progress, as presented at the LCWS06 in Bangalore, India, in the fields
of Higgs boson physics and top/QCD. Also the area of loop calculations,
necessary to achieve the required theory precision, is included.Comment: 7 pages, 1 figure. Plenary talk given at the LCWS06 March 2006,
Bangalore, India. Top part slightly enlarged, references adde
Physics at International Linear Collider (ILC)
International Linear Collider (ILC) is an electron-positron collider with the
initial center-of-mass energy of 500 GeV which is upgradable to about 1 TeV
later on. Its goal is to study the physics at TeV scale with unprecedented high
sensitivities. The main topics include precision measurements of the Higgs
particle properties, studies of supersymmtric particles and the underlying
theoretical structure if supersymmetry turns out to be realized in nature,
probing alternative possibilities for the origin of mass, and the cosmological
connections thereof. In many channels, Higgs and leptonic sector in particular,
ILC is substantially more sensitive than LHC, and is complementary to LHC
overall. In this short article, we will have a quick look at the capabilities
of ILC.Comment: To appear in JPSJ Vol76 No1
Electroweak Precision Observables in the MSSM with Non-Minimal Flavor Violation
The leading corrections to electroweak precision observables in the MSSM with
non-minimal flavor violation (NMFV) are calculated and the effects on M_W and
sin^2 theta_eff are analyzed. The corrections are obtained by evaluating the
full one-loop contributions from the third and second generation scalar quarks,
including the mixing in the scalar top and charm, as well as in the scalar
bottom and strange sector. Furthermore the leading corrections to the mass of
the lightest MSSM Higgs boson, m_h, is obtained. The electroweak one-loop
contribution to M_W can amount up to 140 MeV and up to 70x10^{-5} for sin^2
theta_eff, allowing to set limits on the NMFV parameters. The corrections for
m_h are not significant for moderate generation mixing.Comment: LaTeX, 21 pages, 8 figures. Complete one-loop effects from scalar
quark generation mixing (beyond Delta rho) included for M_W and sin^2
theta_ef
Master integrals for massive two-loop Bhabha scattering in QED
We present a set of scalar master integrals (MIs) needed for a complete
treatment of massive two-loop corrections to Bhabha scattering in QED,
including integrals with arbitrary fermionic loops. The status of analytical
solutions for the MIs is reviewed and examples of some methods to solve MIs
analytically are worked out in more detail. Analytical results for the pole
terms in epsilon of so far unknown box MIs with five internal lines are given.Comment: 23 pages, 5 tables, 12 figures, references added, appendix B enlarge
Potentially bioavailable iron delivery by iceberg-hosted sediments and atmospheric dust to the polar oceans
Iceberg-hosted sediments and atmospheric dust transport potentially bioavailable iron to the Arctic and Southern oceans as ferrihydrite. Ferrihydrite is nanoparticulate and more soluble, as well as potentially more bioavailable, than other iron (oxyhydr)oxide minerals (lepidocrocite, goethite, and hematite). A suite of more than 50 iceberghosted sediments contain a mean content of 0.076 wt% Fe as ferrihydrite, which produces iceberg-hosted Fe fluxes ranging from 0.7 to 5.5 and 3.2 to 25 Gmoles yr 1 to the Arctic and Southern oceans respectively. Atmospheric dust (with little or no combustion products) contains a mean ferrihydrite Fe content of 0.038 wt% (corresponding to a fractional solubility of 1 %) and delivers much smaller Fe fluxes (0.02–0.07 Gmoles yr 1 to the Arctic Ocean and 0.0– 0.02 Gmoles yr 1 to the Southern Ocean). New dust flux data show that most atmospheric dust is delivered to sea ice where exposure to melting/re-freezing cycles may enhance fractional solubility, and thus fluxes, by a factor of approximately 2.5. Improved estimates for these particulate sources require additional data for the iceberg losses during fjord transit, the sediment content of icebergs, and samples of atmospheric dust delivered to the polar regions
Electroweak Physics at the ILC
Some aspects of electroweak physics at the International Linear Collider
(ILC) are reviewed. The importance of precision measurements in the Higgs
sector and in top-quark physics is emphasized, and the physics potential of the
GigaZ option of the ILC is discussed. It is shown in particular that even in a
scenario where the states of new physics are so heavy that they would be
outside of the reach of the LHC and the first phase of the ILC, the GigaZ
precision on the effective weak mixing angle may nevertheless allow the
detection of quantum effects of new physics.Comment: 5 pages, contribution to the proceedings of EPS0
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