1,403 research outputs found
Dark Universe and distribution of Matter as Quantum Imprinting: the Quantum Origin of Universe
In this paper we analyze the Dark Matter problem and the distribution of
matter through two different approaches, which are linked by the possibility
that the solution of these astronomical puzzles should be sought in the quantum
imprinting of the Universe. The first approach is based on a cosmological model
formulated and developed in the last ten years by the first and third authors
of this paper; the so-called Archaic Universe. The second approach was
formulated by Rosen in 1933 by considering the Friedmann-Einstein equations as
a simple one-dimensional dynamical system reducing the cosmological equations
in terms of a Schroedinger equation. As an example, the quantum memory in
cosmological dynamics could explain the apparently periodic structures of the
Universe while Archaic Universe shows how the quantum phase concernts not only
an ancient era of the Universe, but quantum facets permeating the entire
Universe today.Comment: 18 page
Selection and characterization of indigenous hydrocarbon-degrading bacteria from tourist ports in the Mediterranean Sea Basin
A general theorem on the divergence of vortex beams
The propagation and divergence properties of beams carrying orbital angular
momentum (OAM) play a crucial role in many applications. Here we present a
general study on the divergence of optical beams with OAM. We show that the
mean absolute value of the OAM imposes a lower bound on the value of the beam
divergence. We discuss our results for two different definitions of the
divergence, the so called rms or encircled-energy. The bound on the rms
divergence can be expressed as a generalized uncertainty principle, with
applications in long-range communication, microscopy and 2D quantum systems.Comment: RevTex, published versio
QuantEYE: The Quantum Optics Instrument for OWL
QuantEYE is designed to be the highest time-resolution instrument on ESO:s
planned Overwhelmingly Large Telescope, devised to explore astrophysical
variability on microsecond and nanosecond scales, down to the quantum-optical
limit. Expected phenomena include instabilities of photon-gas bubbles in
accretion flows, p-mode oscillations in neutron stars, and quantum-optical
photon bunching in time. Precise timescales are both variable and unknown, and
studies must be of photon-stream statistics, e.g., their power spectra or
autocorrelations. Such functions increase with the square of the intensity,
implying an enormously increased sensitivity at the largest telescopes.
QuantEYE covers the optical, and its design involves an array of
photon-counting avalanche-diode detectors, each viewing one segment of the OWL
entrance pupil. QuantEYE will work already with a partially filled OWL main
mirror, and also without [full] adaptive optics.Comment: 7 pages; Proceedings from meeting 'Instrumentation for Extremely
Large Telescopes', held at Ringberg Castle, July 2005 (T.Herbst, ed.
Mycobacterium tuberculosis Drives Expansion of Low-Density Neutrophils Equipped With Regulatory Activities
In human tuberculosis (TB) neutrophils represent the most commonly infected phagocyte but their role in protection and pathology is highly contradictory. Moreover, a subset of low-density neutrophils (LDNs) has been identified in TB, but their functions remain unclear. Here, we have analyzed total neutrophils and their low-density and normal-density (NDNs) subsets in patients with active TB disease, in terms of frequency, phenotype, functional features, and gene expression signature. Full-blood counts from Healthy Donors (H.D.), Latent TB infected, active TB, and cured TB patients were performed. Frequency, phenotype, burst activity, and suppressor T cell activity of the two different subsets were assessed by flow cytometry while NETosis and phagocytosis were evaluated by confocal microscopy. Expression analysis was performed by using the semi-quantitative RT-PCR array technology. Elevated numbers of total neutrophils and a high neutrophil/lymphocyte ratio distinguished patients with active TB from all the other groups. PBMCs of patients with active TB disease contained elevated percentages of LDNs compared with those of H.D., with an increased expression of CD66b, CD33, CD15, and CD16 compared to NDNs. Transcriptomic analysis of LDNs and NDNs purified from the peripheral blood of TB patients identified 12 genes differentially expressed: CCL5, CCR5, CD4, IL10, LYZ, and STAT4 were upregulated, while CXCL8, IFNAR1, NFKB1A, STAT1, TICAM1, and TNF were downregulated in LDNs, as compared to NDNs. Differently than NDNs, LDNs failed to phagocyte live Mycobacterium tuberculosis (M. tuberculosis) bacilli, to make oxidative burst and NETosis, but caused significant suppression of antigen-specific and polyclonal T cell proliferation which was partially mediated by IL-10. These insights add a little dowel of knowledge in understanding the pathogenesis of human TB
An innovative speech-based user interface for smarthomes and IoT solutions to help people with speech and motor disabilities
A better use of the increasing functional capabilities of home automation systems and Internet of Things (IoT) devices to support the needs of users with disability, is the subject of a research project currently conducted by Area Ausili (Assistive Technology Area), a department of Polo Tecnologico Regionale Corte Roncati of the Local Health Trust of Bologna (Italy), in collaboration with AIAS Ausilioteca Assistive Technology (AT) Team. The main aim of the project is to develop experimental low cost systems for environmental control through simplified and accessible user interfaces. Many of the activities are focused on automatic speech recognition and are developed in the framework of the CloudCAST project. In this paper we report on the first technical achievements of the project and discuss future possible developments and applications within and outside CloudCAST
Kinetics and metabolism of Bifidobacterium adolescentis MB 239 growing on glucose, galactose, lactose, and galactooligosaccharides
The kinetics and the metabolism of Bifidobacterium adolescentis MB 239 growing on galactooligosaccharides (GOS), lactose, galactose, and glucose were investigated. An unstructured unsegregated model for growth in batch cultures was developed, and kinetic parameters were calculated with a recursive algorithm. The growth rate and cellular yield were highest on galactose, followed by lactose and GOS, and were lowest on glucose. Lactate, acetate, and ethanol yields allowed the calculation of carbon fluxes toward fermentation products. Distributions between two- and three-carbon products were similar on all the carbohydrates (55 and 45%, respectively), but ethanol yields were different on glucose, GOS, lactose, and galactose, in decreasing order of production. Based on the stoichiometry of the fructose-6-phosphate shunt and on the carbon distribution among the products, the ATP yield was calculated. The highest yield was obtained on galactose, while the yields were 5, 8, and 25% lower on lactose, GOS, and glucose, respectively. Therefore, a correspondence among ethanol production, low ATP yields, and low biomass production was established, demonstrating that carbohydrate preferences may result from different distributions of carbon fluxes through the fermentative pathway. During the fermentation of a GOS mixture, substrate selectivity based on the degree of polymerization was exhibited, since lactose and the trisaccharide were the first to be consumed, while a delay was observed until longer oligosaccharides were utilized. Throughout the growth on both lactose and GOS, galactose accumulated in the cultural broth, suggesting that beta(1-4) galactosides can be hydrolyzed before they are taken up
The Hurst Exponent of Fermi GRBs
Using a wavelet decomposition technique, we have extracted the Hurst exponent
for a sample of 46 long and 22 short Gamma-ray bursts (GRBs) detected by the
Gamma-ray Burst Monitor (GBM) aboard the Fermi satellite. This exponent is a
scaling parameter that provides a measure of long-range behavior in a time
series. The mean Hurst exponent for the short GRBs is significantly smaller
than that for the long GRBs. The separation may serve as an unbiased criterion
for distinguishing short and long GRBs.Comment: Accepted for publication in Monthly Notices of the Royal Astronomical
Societ
Photon Orbital Angular Momentum and Mass in a Plasma Vortex
We analyse the Anderson-Higgs mechanism of photon mass acquisition in a
plasma and study the contribution to the mass from the orbital angular momentum
acquired by a beam of photons when it crosses a spatially structured charge
distribution. To this end we apply Proca-Maxwell equations in a static plasma
with a particular spatial distribution of free charges, notably a plasma
vortex, that is able to impose orbital angular momentum (OAM) onto light. In
addition to the mass acquisition of the conventional Anderson-Higgs mechanism,
we find that the photon acquires an additional mass from the OAM and that this
mass reduces the Proca photon mass.Comment: Four pages, no figures. Error corrections, improved notation, refined
derivation
- …
