370 research outputs found
Realizations of Causal Manifolds by Quantum Fields
Quantum mechanical operators and quantum fields are interpreted as
realizations of timespace manifolds. Such causal manifolds are parametrized by
the classes of the positive unitary operations in all complex operations, i.e.
by the homogenous spaces \D(n)=\GL(\C^n_\R)/\U(n) with for mechanics
and for relativistic fields. The rank gives the number of both the
discrete and continuous invariants used in the harmonic analysis, i.e. two
characteristic masses in the relativistic case. 'Canonical' field theories with
the familiar divergencies are inappropriate realizations of the real
4-dimensional causal manifold \D(2). Faithful timespace realizations do not
lead to divergencies. In general they are reducible, but nondecomposable - in
addition to representations with eigenvectors (states, particle) they
incorporate principal vectors without a particle (eigenvector) basis as
exemplified by the Coulomb field.Comment: 36 pages, latex, macros include
Simplicial quantum dynamics
Present-day quantum field theory can be regularized by a decomposition into
quantum simplices. This replaces the infinite-dimensional Hilbert space by a
high-dimensional spinor space and singular canonical Lie groups by regular spin
groups. It radically changes the uncertainty principle for small distances.
Gaugeons, including the gravitational, are represented as bound fermion-pairs,
and space-time curvature as a singular organized limit of quantum
non-commutativity.
Keywords: Quantum logic, quantum set theory, quantum gravity, quantum
topology, simplicial quantization.Comment: 25 pages. 1 table. Conference of the International Association for
Relativistic Dynamics, Taiwan, 201
A case series on the value of tau and neurofilament protein levels to predict and detect delirium in cardiac surgery patients
BACKGROUND: Delirium following cardiac surgery is a relevant complication in the majority of elderly patients but its prediction is challenging. Cardiopulmonary bypass, essential for many interventions in cardiac surgery, is responsible for a severe inflammatory response leading to neuroinflammation and subsequent delirium. Neurofilament light protein (NfL) and tau protein (tau) are specific biomarkers to detect neuroaxonal injury as well as glial fibrillary acidic protein (GFAP), a marker of astrocytic activation. METHODS: We thought to examine the perioperative course of these markers in a case series of each three cardiac surgery patients under off-pump cardiac arterial bypass without evolving delirium (OPCAB-NDEL), patients with a procedure under cardio-pulmonary bypass (CPB) without delirium (CPB-NDEL) and delirium after a CPB procedure (CPB-DEL). Delirium was diagnosed by the Confusion Assessment Method for the ICU and chart reviews. RESULTS: We observed increased preoperative levels of tau in patients with later delirium, whereas values of NfL and GFAP did not differ. In the postoperative course, all biomarkers increased multi-fold. NfL levels sharply increased in patients with CPB reaching the highest levels in the CPB-DEL group. CONCLUSION: Tau and NfL might be of benefit to identify patients in cardiac surgery at risk for delirium and to detect patients with the postoperative emergence of delirium
First Measurement of the Transverse Spin Asymmetries of the Deuteron in Semi-Inclusive Deep Inelastic Scattering
First measurements of the Collins and Sivers asymmetries of charged hadrons
produced in deep-inelastic scattering of muons on a transversely polarized
6-LiD target are presented. The data were taken in 2002 with the COMPASS
spectrometer using the muon beam of the CERN SPS at 160 GeV/c. The Collins
asymmetry turns out to be compatible with zero, as does the measured Sivers
asymmetry within the present statistical errors.Comment: 6 pages, 2 figure
Gluon polarization in the nucleon from quasi-real photoproduction of high-pT hadron pairs
We present a determination of the gluon polarization Delta G/G in the
nucleon, based on the helicity asymmetry of quasi-real photoproduction events,
Q^2<1(GeV/c)^2, with a pair of large transverse-momentum hadrons in the final
state. The data were obtained by the COMPASS experiment at CERN using a 160 GeV
polarized muon beam scattered on a polarized 6-LiD target. The helicity
asymmetry for the selected events is = 0.002 +- 0.019(stat.) +-
0.003(syst.). From this value, we obtain in a leading-order QCD analysis Delta
G/G=0.024 +- 0.089(stat.) +- 0.057(syst.) at x_g = 0.095 and mu^2 =~ 3
(GeV}/c)^2.Comment: 10 pages, 3 figure
Measurement of the Spin Structure of the Deuteron in the DIS Region
We present a new measurement of the longitudinal spin asymmetry A_1^d and the
spin-dependent structure function g_1^d of the deuteron in the range 1 GeV^2 <
Q^2 < 100 GeV^2 and 0.004< x <0.7. The data were obtained by the COMPASS
experiment at CERN using a 160 GeV polarised muon beam and a large polarised
6-LiD target. The results are in agreement with those from previous experiments
and improve considerably the statistical accuracy in the region 0.004 < x <
0.03.Comment: 10 pages, 6 figures, subm. to PLB, revised: author list, Fig. 4,
details adde
Tectono-stratigraphic response of the Sandino Forearc Basin (N-Costa Rica and W-Nicaragua) to episodes of rough crust and oblique subduction
The southern Central American active margin is a world-class site where past and
present subduction processes have been extensively studied. Tectonic erosion/accretion
and oblique/orthogonal subduction are thought to alternate in space and time
along the Middle American Trench. These processes may cause various responses
in the upper plate, such as uplift/subsidence, deformation, and volcanic arc migration/
shut-off. We present an updated stratigraphic framework of the Late Cretaceous–
Cenozoic Sandino Forearc Basin (SFB) which provides evidence of
sedimentary response to tectonic events. Since its inception, the basin was predominantly
filled with deep-water volcaniclastic deposits. In contrast, shallow-water
deposits appeared episodically in the basin record and are considered as tectonic
event markers. The SFB stretches for about 300 km and varies in thickness from
5 km (southern part) to about 16 km (northern part). The drastic, along-basin, thickness
variation appears to be the result of (1) differential tectonic evolutions and (2)
differential rates of sediment supply. (1) The northern SFB did not experience major
tectonic events. In contrast, the reduced thickness of the southern SFB (5 km) is the
result of at least four uplift phases related to the collision/accretion of bathymetric
reliefs on the incoming plate: (i) the accretion of a buoyant oceanic plateau (Nicoya
Complex) during the middle Campanian; (ii) the collision of an oceanic plateau (?)
during the late Danian–Selandian; (iii) the collision/accretion of seamounts during
the late Eocene–early Oligocene; (iv) the collision of seamounts and ridges during
the Pliocene–Holocene. (2) The northwestward thickening of the SFB may have
been enhanced by high sediment supply in the Fonseca Gulf area which reflects
sourcing from wide, high relief drainage basins. In contrast, sedimentary input has
possibly been lower along the southern SFB, due to the proximity of the narrow,
lowland isthmus of southern Central America. Moreover, two phases of strongly
oblique subduction affected the margin, producing strike-slip faulting in the forearc
basin: (1) prior to the Farallon Plate breakup, an Oligocene transpressional phase
caused deformation and uplift of the basin depocenter, triggering shallowing-upward
of the Nicaraguan Isthmus in the central and northern SFB; (2) a Pleistocene–Holocene transtensional phase drives the NW-directed motion of a forearc sliver
and reactivation of the graben-bounding faults of the late Neogene Nicaraguan
Depression. We discuss arguments in favour of a Pliocene development of the
Nicaraguan Depression and propose that the Nicaraguan Isthmus, which is the
apparent rift shoulder of the depression, represents a structure inherited from the Oligocene
transpressional phase
Insight into the proteome of the hyperthermophilic Crenarchaeon Ignicoccus hospitalis: the major cytosolic and membrane proteins
Ignicoccus hospitalis, a hyperthermophilic, chemolithoautotrophic Crenarchaeon, is the host of Nanoarchaeum equitans. Together, they form an intimate association, the first among Archaea. Membranes are of fundamental importance for the interaction of I. hospitalis and N. equitans, as they harbour the proteins necessary for the transport of macromolecules like lipids, amino acids, and cofactors between these organisms. Here, we investigated the protein inventory of I. hospitalis cells, and were able to identify 20 proteins in total. Experimental evidence and predictions let us conclude that 11 are soluble cytosolic proteins, eight membrane or membrane-associated proteins, and a single one extracellular. The quantitatively dominating proteins in the cytoplasm (peroxiredoxin; thermosome) antagonize oxidative and temperature stress which I. hospitalis cells are exposed to at optimal growth conditions. Three abundant membrane protein complexes are found: the major protein of the outer membrane, which might protect the cell against the hostile environment, forms oligomeric complexes with pores of unknown selectivity; two other complexes of the cytoplasmic membrane, the hydrogenase and the ATP synthase, play a key role in energy production and conversion
Inhibition of HCV 3a core gene through Silymarin and its fractions
Hepatitis C is a major health problem affecting 270 million individuals in world including Pakistan. Current treatment regimen, interferon alpha and ribavirin only cure half of patients due to side effects and high cost.
In the present study Silybum marianum (Milk thistle) seeds were collected, extracted and analyzed against HCV 3a core gene by transiently transfecting the liver cells with HCV core plasmid. Our results demonstrated that Silymarin (SM) dose dependently inhibit the expression or function of HCV core gene at a non toxic concentration while the GAPDH remained constant. To identify the active ingredient, SM was fractioned by thin layer chromatography (TLC), column chromatography and HPLC. Purified fractions were tested for HCV core gene and western blotting results showed that two factions of SM (S1 and S2) inhibit HCV 3a core expression or function in liver cells
Our results suggest SM and its fractions (S1 and S2) inhibit HCV core gene of 3a genotype and combination of SM and its fractions with interferon will be a better option to treat HCV infection
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