379 research outputs found
Anomalous quartic couplings in collisions at the LHeC and the FCC-he
We conducted a study on measuring production and on the sensitivity
limits at Confidence Level on thirteen anomalous couplings obtained by
dimension-8 operators which are related to the anomalous quartic
couplings. We consider the main reaction with the sub-process at
the Large Hadron electron Collider (LHeC) and the Future Circular
Collider-hadron electron (FCC-he). For the LHeC, energies of the beams
are taken to be and 140 GeV and the energy of the beams is taken
to be TeV. For the FCC-he, energies of the beams are taken to
be and 140 GeV and the energy of the beams is taken to be TeV, respectively. It is interesting to notice that the LHeC and the FCC-he
will lead to model-independent limits on the anomalous quartic
couplings which are one order of magnitude stringent than the CMS Collaboration
limits, in addition to being competitive with other limits reported in the
literature.Comment: 28 pages, 10 Figures and 13 Table
Regulation and competition in the Turkish telecommunications industry: an update
This chapter provides an overview of the state of liberalization, competition and regulation of major segments of the telecommunications industry in Turkey. It shows that the competitive stance of the regulatory authority and the development of actual competition has been uneven across segments. Specifically, the degree of competition has been higher in the mobile segment relative to fixed telephony or broadband. The chapter also discusses the new Electronic Communications Law and argues that although not perfect, it provides a coherent basis on which the regulatory authority can pursue competitive objectives in a more even manner. However, the actual development of competition will depend a lot on how the law and the ensuing secondary legislation are actually implemented
Optical properties of radially-polarised twisted light
We show that, in general, any type of radially-polarised paraxial twisted
optical mode carries only an axial total optical angular momentum (AM) where is the winding number and
is a constant. This mode, however, is shown to have zero spin angular momentum
(SAM), so it is endowed only with orbital angular momentum (OAM) and no SAM.
The helicity is found to be proportional to , hence radially-polarised
modes display chirality. When applied to a Laguerre-Gaussian (LG) mode our
treatment leads to a total helicity equal to , where
is the action constant. The factor , depends on
the sign, not the magnitude of and so the result holds for any
radially-polarised LG mode however large the magnitude of its winding number
is. The magnitude of the action constant and hence the
helicity are diminished for all such LG modes of large beam waist .Comment: 4 figure
Search for the anomalous and gauge couplings through the process with unpolarized and polarized beams
This work offers the constraints on the anomalous neutral triple gauge
couplings (aNTGC) for the process at the CLIC with
TeV. The realistic CLIC detector environments and their effects
are considered in our analysis. The study is planned for the decays of
producted bosons to a pair of charged leptons (electrons or muons) and
neutrino pairs. The bounds on the aNTGCs defining -conserving
coupling and three -violating
, , and couplings
are obtained. Also, the effects and advantages of polarization for incoming
electron beams in these calculations are investigated.Comment: 21 pages, 14 figure
Anticipation via canards in excitable systems
Neurons can anticipate incoming signals by exploiting a physiological mechanism that is not well understood. This article offers a novel explanation on how a receiver neuron can predict the sender’s dynamics in a unidirectionally-coupled configuration, in which both sender and receiver follow the evolution of a multi-scale excitable system. We present a novel theoretical viewpoint based on a mathematical object, called canard, to explain anticipation in excitable systems. We provide a numerical approach, which allows to determine the transient effects of canards. To demonstrate the general validity of canard-mediated anticipation in the context of excitable systems, we illustrate our framework in two examples, a multi-scale radio-wave circuit (the van der Pol model) that inspired a caricature neuronal model (the FitzHugh-Nagumo model) and a biophysical neuronal model (a 2-dimensional reduction of the Hodgkin-Huxley model), where canards act as messengers to the senders’ prediction. We also propose an experimental paradigm that would enable experimental neuroscientists to validate our predictions. We conclude with an outlook to possible fascinating research avenues to further unfold the mechanisms underpinning anticipation. We envisage that our approach can be employed by a wider class of excitable systems with appropriate theoretical extensions.ERC Advanced Grant NerVi no. 227747
Ikerbasque (The Basque Foundation for Science
A comparative study on the antioxidant activity of fringe tree (Chionanthus virginicus L.) extracts
Fringe tree (Chionanthus virginicus L.) is used as a raw material by pharmaceutical industries for the preparation of homeopathy tinctures. In this study, antioxidant activity of methanol extract (MEFT) andethylacetate extract (EEFT) from root bark of fringe tree (C. virginicus L.) were evaluated. 2,2-Azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging, 1,1-diphenyl-2-picryl-hydrazyl freeradical (DPPH.) scavenging, superoxide anion (O2 •-) radical scavenging, total antioxidant activity, reducing activity, hydrogen peroxide (H2O2) scavenging and ferrous metal chelating activities were for used antioxidant evaluation of MEFT and EEFT. The both extracts neutralized the activities of radicals and inhibited the peroxidation reactions of linoleic acid emulsion. Total antioxidant activity wasmeasured according to ferric thiocyanate method. Butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), á-tocopherol and trolox, a water-soluble analogue of tocopherol, were used as thereference antioxidant compounds. MEFT and EEFT showed 69.4, 79.3, 72.3 and 83.7% inhibition on lipid peroxidation of linoleic acid emulsion, respectively, at the 10 and 20 ìg/mL concentrations. On the other hand, 20 ìg/mL of á-tocopherol, trolox, BHA and BHT exhibited 54.7, 20.1, 74.4 and 71.2% inhibition on peroxidation of linoleic acid emulsion, respectively. Also, MEFT and EEFT have effective DPPH•, ABTS•+ and superoxide anion radicals scavenging, hydrogen peroxide scavenging, total reducing power and metal chelating on ferrous ions activities
Study of the projected sensitivity on the anomalous quartic gauge couplings via production at the CLIC
Gauge boson self-couplings are completely defined by the non-Abelian gauge
symmetry of the Standard Model (SM), thus direct search for these couplings are
extremely significant in understanding the gauge structure of the SM. The
possible deviation from the SM predictions of gauge boson self-couplings would
be a sign of the presence of new physics beyond the SM. In this work, we study
the sensitivities on the anomalous couplings defined by dimension-8 operators
related to the and quartic vertices
through the process with Z-boson decaying to charged
leptons at the Compact Linear Collider (CLIC). We analyze the center-of-mass
energy of 3 TeV, integrated luminosities of ,
systematic uncertainties of , and unpolarized and
polarized electron beams for extraction of expected sensitivity on the
anomalous couplings at confidence level, which are
especially sensitive to the channel. It is clear from the
results that if the systematic error is improved, we expect better limits on
the couplings. The best limits obtained on the anomalous quartic couplings for
the process with TeV,
and can be approximately improved up to about
two times better than the limits obtained with . Our
sensitivities on the anomalous quartic couplings with can
set more stringent sensitivity by two orders of magnitude concerning the best
sensitivity derived from the current experimental limits. Finally, with initial
electron beam polarization, the sensitivity of the anomalous quartic couplings
improves by almost a factor of 1.2.Comment: 38 pages, 22 figure
Study on the anomalous quartic couplings of electroweak bosons in collisions at the LHeC and the FCC-he
In this paper, a study is carried out on the production to probe quartic couplings
using 10, 100 of collisions data at = 1.30,
1.98 GeV at the Large Hadron electron Collider (LHeC) and 100, 1000 with = 3.46, 5.29 GeV at the Future Circular
Collider-hadron electron (FCC-he). Production cross-sections are determined for
both at leptonic and hadronic decay channel of the -boson. With the data
from future colliders, it is possible to obtain sensitivity measures at
C.L. on the anomalous and
couplings which are competitive with the limits obtained by the LHC, as well as
with others limits reported in the literature. The production mode in collisions offers a window for
study the quartic electroweak bosons couplings at the LHeC
and the FCC-he, which provides a much cleaner collision environment than the
LHC.Comment: 27 pages , 10 figure
Association of the Asn306Ser variant of the SP4 transcription factor and an intronic variant in the β-subunit of transducin with digenic disease
Purpose SP4 is a transcription factor abundantly expressed in retina that binds to the GC promoter region of photoreceptor signal transduction genes. We have previously shown that SP4 may be involved in the transcriptional activation of these genes alone or together with other transcription factors such as SP1, neural retina leucine zipper protein (NRL), and cone-rod homeobox gene (CRX). Since mutations in NRL and CRX are involved in inherited retinal degenerations, SP4 was considered a good candidate for mutation screening in patients with this type of diseases. The purpose of this work, therefore, was to investigate possible mutations in SP4 in a cohort of patients affected with different forms of retinal degenerations. Methods 270 unrelated probands with various forms of retinal degeneration including autosomal dominant and autosomal recessive retinitis pigmentosa (RP), autosomal dominant and autosomal recessive cone-rod dystrophy (CRD), and Leber's congenital amaurosis (LCA), were screened for mutations in the SP4 gene. Single strand conformation polymorphism (SSCP) analysis was performed on the six SP4 gene exons including flanking regions followed by direct sequencing of SSCP variants. Results Nine different sequence variants were found in 29 patients, four in introns and five in exons. Many of the probands were previously screened for mutations in the genes encoding the α-, β- and γ-subunits of rod-specific cGMP phosphodiesterase (PDE6A, PDE6B, PDE6G), the β-subunit of rod-specific transducin (GNB1), and peripherin/rds (RDS). One group of seven probands of Hispanic background that included five with arRP, one with RP of unknown inheritance (isolate) and 1 with arCRD carried an Asn306Ser mutation in SP4. Of the seven, the isolate case was homozygous and the other 6 heterozygous for the variant. Two arRP and the arCRD probands carried an additional intronic GNB1 variant. DNA from the family members of the arCRD proband could not be obtained, but for the other two families, all affected members and none of the unaffected carried both the SP4 Asn306Ser allele and the GNB1 intronic variant. Conclusions If mutations in SP4 do cause retinal degenerative disease, their frequency would be low. While digenic disease with the SP4 Asn306Ser and the GNB1 intronic variant alleles has not been established, neither has it been ruled out. This leaves open the possibility of a cooperative involvement of SP4 and GNB1 in the normal function of the retina.PubMedWo
- …