2,638 research outputs found
The multilevel trigger system of the DIRAC experiment
The multilevel trigger system of the DIRAC experiment at CERN is presented.
It includes a fast first level trigger as well as various trigger processors to
select events with a pair of pions having a low relative momentum typical of
the physical process under study. One of these processors employs the drift
chamber data, another one is based on a neural network algorithm and the others
use various hit-map detector correlations. Two versions of the trigger system
used at different stages of the experiment are described. The complete system
reduces the event rate by a factor of 1000, with efficiency 95% of
detecting the events in the relative momentum range of interest.Comment: 21 pages, 11 figure
The cyclin-dependent kinase inhibitor p57(Kip2) is epigenetically regulated in carboplatin resistance and results in collateral sensitivity to the CDK inhibitor seliciclib in ovarian cancer
Carboplatin remains a first-line agent in the management of epithelial ovarian cancer (EOC). Unfortunately, platinum-resistant disease ultimately occurs in most patients. Using a novel EOC cell line with acquired resistance to carboplatin: PEO1CarbR, genome-wide micro-array profiling identified the cyclin-dependent kinase inhibitor p57(Kip2) as specifically downregulated in carboplatin resistance. Presently, we describe confirmation of these preliminary data with a variety of approaches
An integrated view on monitoring and compensation for dynamic optical networks: from management to physical layer
A vertical perspective, ranging from management and routing to physical layer options, concerning dynamic network monitoring and compensation of impairments (M&C), is given. Feasibility, reliability, and performance improvements on reconfigurable transparent networks are expected to arise from the consolidated assessment of network management and control specifications, as a more accurate evaluation of available M&C techniques. In the network layer, physical parameters aware algorithms are foreseen to pursue reliable network performance. In the physical layer, some new M&C methods were developed and rating of the state-of-the-art reported in literature is given. Optical monitoring implementation and viability is discussed.Publicad
Phenomenological analysis of D-brane Pati-Salam vacua
In the present work we perform a phenomenological analysis of the effective
low energy models with Pati-Salam (PS) gauge symmetry derived in the context of
D-branes. A main issue in these models arises from the fact that the
right-handed fermions and the PS-symmetry breaking Higgs field transform
identically under the PS symmetry, causing unnatural matter-Higgs mixing
effects. We argue that this problem could be solved in particular D-brane
setups where these fields arise in different intersections. We further observe
that whenever a large Higgs mass term is generated in a particular class of
mass spectra, a splitting mechanism -reminiscent of the doublet triplet
splitting- may protect the neutral Higgs components from a heavy mass term. We
analyze the implications of each individual representation which in principle
is available in these models in order to specify the minimal spectrum required
to build up a consistent PS model which reconciles the low energy data. A short
discussion is devoted on the effects of stringy instanton corrections,
particularly those generating missing Yukawa couplings and contributing to the
fermion mass textures. We discuss the correlations of the intersecting D-brane
spectra with those obtained from Gepner constructions and analyze the
superpotential, the resulting mass textures and the low energy implications of
some examples of the latter along the lines proposed above.Comment: 50 pages, 3 figures (v2 - Minor corrections
Phase Separation of Crystal Surfaces: A Lattice Gas Approach
We consider both equilibrium and kinetic aspects of the phase separation
(``thermal faceting") of thermodynamically unstable crystal surfaces into a
hill--valley structure. The model we study is an Ising lattice gas for a simple
cubic crystal with nearest--neighbor attractive interactions and weak
next--nearest--neighbor repulsive interactions. It is likely applicable to
alkali halides with the sodium chloride structure. Emphasis is placed on the
fact that the equilibrium crystal shape can be interpreted as a phase diagram
and that the details of its structure tell us into which surface orientations
an unstable surface will decompose. We find that, depending on the temperature
and growth conditions, a number of interesting behaviors are expected. For a
crystal in equilibrium with its vapor, these include a low temperature regime
with logarithmically--slow separation into three symmetrically--equivalent
facets, and a higher temperature regime where separation proceeds as a power
law in time into an entire one--parameter family of surface orientations. For a
crystal slightly out of equilibrium with its vapor (slow crystal growth or
etching), power--law growth should be the rule at late enough times. However,
in the low temperature regime, the rate of separation rapidly decreases as the
chemical potential difference between crystal and vapor phases goes to zero.Comment: 16 pages (RevTex 3.0); 12 postscript figures available on request
([email protected]). Submitted to Physical Review E. SFU-JDSDJB-94-0
Palliative care interventions in intensive care unit patients - a systematic review protocol
Background: Even though data suggest that palliative care (PC) improves patient quality of life, caregiver burden, cost,
and intensive care unit (ICU) length of stay, integration of PC in the ICU is far from being universally accepted. Poor
understanding of what PC provides is one of the barriers to the widespread implementation of their services in ICU.
Evidence suggests that the availability of specialist PC is lacking in most European countries and provided differently
depending on geographical location. The aim of this systematic review is to compare the numbers and types of PC
interventions and gauge their impact on stakeholder outcomes and ICU resource utilisation.
Methods: We will undertake a systematic review of the published peer-reviewed journal articles; our search will be
carried out MEDLINE, Embase, Cochrane, CINAHL, and PsycINFO. The search strategy will include variations in the term
âpalliative careâ and âintensive careâ. All studies with patient populations undergoing palliative care interventions will be
selected. Only full-text articles will be considered, and conference abstracts excluded. There will be no date restrictions
on the year of publications or on language. The primary aim of the present study is to compare the numbers and
types of PC interventions in ICU and their impact on stakeholder (patient, family, clinician, other) outcomes. Reporting
of findings will follow the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) guidelines.
Discussion: This review will provide insight into the implementation of palliative care in ICU, elucidate differences
between countries and health systems, reveal most effective models, and contribute to identifying research priorities to
improve outcomes
Business Models and E-Services: an Ontological Approach in a Cross-border Environment
Monograph's chapter
Search for Branons at LEP
We search, in the context of extra-dimension scenarios, for the possible
existence of brane fluctuations, called branons. Events with a single photon or
a single Z-boson and missing energy and momentum collected with the L3 detector
in e^+ e^- collisions at centre-of-mass energies sqrt{s}=189-209$ GeV are
analysed. No excess over the Standard Model expectations is found and a lower
limit at 95% confidence level of 103 GeV is derived for the mass of branons,
for a scenario with small brane tensions. Alternatively, under the assumption
of a light branon, brane tensions below 180 GeV are excluded
Study of Spin and Decay-Plane Correlations of W Bosons in the e+e- -> W+W- Process at LEP
Data collected at LEP at centre-of-mass energies \sqrt(s) = 189 - 209 GeV are
used to study correlations of the spin of W bosons using e+e- -> W+W- -> lnqq~
events. Spin correlations are favoured by data, and found to agree with the
Standard Model predictions. In addition, correlations between the W-boson decay
planes are studied in e+e- -> W+W- -> lnqq~ and e+e- -> W+W- -> qq~qq~ events.
Decay-plane correlations, consistent with zero and with the Standard Model
predictions, are measured
- âŠ