11,879 research outputs found
QCD--Instanton Induced Final States in Deep Inelastic Scattering
We report briefly on a broad and systematic study of possible manifestations
of QCD-instantons at HERA. We concentrate on the high multiplicity final state
structure, reminiscent of an isotropically decaying ``fireball''. First results
of a Monte Carlo simulation are presented, with emphasis on the typical
event-structure and the transverse energy, muon and flows.Comment: 10 pages, latex, epsfig, 9 uuencoded figure
The pentaquark in K-plus-d total cross section data
An analysis of -d total cross section data is undertaken to explore
possible effects of the recently observed resonance in the S=+1 hadronic system
with mass around 1.55 GeV. It is found that a structure corresponding to the
resonance is visible in the data. The width consistent with the observed
deviation from background is found to be MeV and the mass is
GeV/c for spin-parity \h^+ and \
GeV/c for \h^-. The errors are one standard deviation and statistical
only.
\Comment: 10 pages, 5 figures Replaced to correct references, add and correct
text. No change in content. More discussion of errors, increased error on
width, corrected one figur
Protective Refractory Coatings on Titanium Metal
The problem undertaken in this thesis concerns the development of a newer phase of metallurgy, namely the adaption of the strong, lightweight metal titanium to high-temperature uses. The primary objective of the investigation is to determine whethÂer the application of refractory coatings to titanium will proÂtect the metal from chemical reactions and corrosion at high temperatures
Randomized Clinical Trial of Intrapartum Clindamycin Cream for Reduction of Group B Streptococcal Maternal and Neonatal Colonization
Objective: In a randomized trial, we sought to determine whether 2% clindamycin cream administered
intravaginally during labor to group B streptococcal-colonized pregnant women without risk
factors would decrease maternal and neonatal colonization
A novel method for evaluating the critical nucleus and the surface tension in systems with first order phase transition
We introduce a novel method for calculating the size of the critical nucleus
and the value of the surface tension in systems with first order phase
transition. The method is based on classical nucleation theory, and it consists
in studying the thermodynamics of a sphere of given radius embedded in a frozen
metastable surrounding. The frozen configuration creates a pinning field on the
surface of the free sphere. The pinning field forces the sphere to stay in the
metastable phase as long as its size is smaller than the critical nucleus. We
test our method in two first-order systems, both on a two-dimensional lattice:
a system where the parameter tuning the transition is the magnetic field, and a
second system where the tuning parameter is the temperature. In both cases the
results are satisfying. Unlike previous techniques, our method does not require
an infinite volume limit to compute the surface tension, and it therefore gives
reliable estimates even by using relatively small systems. However, our method
cannot be used at, or close to, the critical point, i.e. at coexistence, where
the critical nucleus becomes infinitely large.Comment: 12 pages, 15 figure
Epeoloides pilosulus (Cresson) Rediscovered in Michigan, with Notes on the Distribution and Status of its Macropis hosts.
Epeoloides pilosulus (Cresson 1878) is one of the rarest bees in North America with only a handful of records since 1960. The last collection in Michigan was made in 1944. Epeoloides pilosulus is a brood parasite of Macropis bees, which until recently had not been collected in Michigan for several decades. Bee surveys in Midland County, Michigan have led to the rediscovery of E. pilosulus in this state – the first record in 74 years. Michigan becomes the fourth state where E. pilosulus has been rediscovered after Connecticut in 2006, New York in 2014 and Maine in 2016, and the sixth region in North America after Nova Scotia in 2002 and Alberta in 2010. State-wide bee surveys have also shown that the principal host, Macropis nuda (Provancher 1882), remains widespread in Michigan, and that Macropis patellata Patton 1880 is newly recorded for the state
Pion double charge exchange on 4He
The doubly differential cross sections for the He
reaction were calculated using both a two-nucleon sequential single charge
exchange model and an intranuclear cascade code. Final state interactions
between the two final protons which were the initial neutrons were included in
both methods. At incident pion energies of 240 and 270 MeV the low-energy peak
observed experimentally in the energy spectrum of the final pions can be
understood only if the contribution of pion production is included. The
calculated cross sections are compared with data.Comment: 25 pages, 9 figure
Differential expression and biochemical activity of the immune receptor Tim-3 in healthy and malignant human myeloid cells
The T cell immunoglobulin and mucin domain 3 (Tim-3) is a plasma membrane-associated receptor which is involved in a variety of biological responses in human immune cells. It is highly expressed in most acute myeloid leukaemia (AML) cells and therefore may serve as a possible target for AML therapy. However, its biochemical activities in primary human AML cells remain unclear. We therefore analysed the total expression and surface presence of the Tim-3 receptor in primary human AML blasts and healthy primary human leukocytes isolated from human blood. We found that Tim-3 expression was significantly higher in primary AML cells compared to primary healthy leukocytes. Tim-3 receptor molecules were distributed largely on the surface of primary AML cells, whereas in healthy leukocytes Tim-3 protein was mainly expressed intracellularly. In primary human AML blasts, both Tim-3 agonistic antibody and galectin-9 (a Tim-3 natural ligand) significantly upregulated mTOR pathway activity. This was in line with increased accumulation of hypoxia-inducible factor 1 alpha (HIF-1α) and secretion of VEGF and TNF-α. Similar results were obtained in primary human healthy leukocytes. Importantly, in both types of primary cells, Tim-3-mediated effects were compared with those induced by lipopolysaccharide (LPS) and stem cell factor (SCF). Tim-3 induced comparatively moderate responses in both AML cells and healthy leukocytes. However, Tim-3, like LPS, mediated the release of both TNF-α and VEGF, while SCF induced mostly VEGF secretion and did not upregulate TNF-α release
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