52,292 research outputs found
Bayesian analysis of CCDM Models
Creation of Cold Dark Matter (CCDM), in the context of Einstein Field
Equations, leads to negative creation pressure, which can be used to explain
the accelerated expansion of the Universe. In this work we tested six different
spatially flat models for matter creation using statistical tools, at light of
SN Ia data: Akaike Information Criterion (AIC), Bayesian Information Criterion
(BIC) and Bayesian Evidence (BE). These approaches allow to compare models
considering goodness of fit and number of free parameters, penalizing excess of
complexity. We find that JO model is slightly favoured over LJO/CDM
model, however, neither of these, nor model can be
discarded from the current analysis. Three other scenarios are discarded either
from poor fitting, either from excess of free parameters.Comment: 16 pages, 6 figures, 6 tables. Corrected some text and language in
new versio
First Tests of Gaseous Detectors Made of a Resistive Mesh
We describe here various detectors designs: GEM type, MICROMEGAStype,
PPACtype as well as cascaded detectors made of a resistive mesh manufactured
from a resistive Kapton foil, (20 microns thick, resistivity a few MOhm per
square) by a laser drilling technique. As in any other micropattern detectors
the maximum achievable gas gain of these detectors is restricted by the Raether
limit, however, the resistive mesh makes them and the front end electronics
fully spark protected. This approach could be an alternative or complimentary
to the ongoing efforts in developing MICROMEGAS and GEMs with resistive anode
readout plates and can be especially beneficial in the case of micropattern
detectors combined with a micropixel-type integrated front end electronic
An improved design of spark-protected microstrip gas counters (R-MSGC)
We have developed microstrip gas counters manufactured on standard printed
circuit board and having the following features: resistive cathode strips, thin
(10 micron) metallic anode strips and electrodes protected against surface
discharges by a Coverlay layer at their edges. These features allow the
detector to operate at gas gains as high as can be achieve with the best
microstrip gas counters manufactured on glass substrates. We believe that after
further developments this type of detectors can compete in some applications
with other micropattern detectors, for example MICROMEGAS.Comment: Presented at the 7th RD51 Collaboration meeting, CERN, April 201
The use of genes for performance enhancement: doping or therapy?
Recent biotechnological advances have permitted the manipulation of genetic sequences to treat several diseases in a process called gene therapy. However, the advance of gene therapy has opened the door to the possibility of using genetic manipulation (GM) to enhance athletic performance. In such ‘gene doping’, exogenous genetic sequences are inserted into a specific tissue, altering cellular gene activity or leading to the expression of a protein product. The exogenous genes most likely to be utilized for gene doping include erythropoietin (EPO), vascular endothelial growth factor (VEGF), insulin-like growth factor type 1 (IGF-1), myostatin antagonists, and endorphin. However, many other genes could also be used, such as those involved in glucose metabolic pathways. Because gene doping would be very difficult to detect, it is inherently very attractive for those involved in sports who are prepared to cheat. Moreover, the field of gene therapy is constantly and rapidly progressing, and this is likely to generate many new possibilities for gene doping. Thus, as part of the general fight against all forms of doping, it will be necessary to develop and continually improve means of detecting exogenous gene sequences (or their products) in athletes. Nevertheless, some bioethicists have argued for a liberal approach to gene doping
Synchronization in the presence of memory
We study the effect of memory on synchronization of identical chaotic systems
driven by common external noises. Our examples show that while in general
synchronization transition becomes more difficult to meet when memory range
increases, for intermediate ranges the synchronization tendency of systems can
be enhanced. Generally the synchronization transition is found to depend on the
memory range and the ratio of noise strength to memory amplitude, which
indicates on a possibility of optimizing synchronization by memory. We also
point out on a close link between dynamics with memory and noise, and recently
discovered synchronizing properties of networks with delayed interactions
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