403 research outputs found
Depolarizing metrics for plant samples imaging
Optical methods, as fluorescence microscopy or hyperspectral imaging, are commonly used for plants visualization and characterization. Another powerful collection of optical techniques is the so-called polarimetry, widely used to enhance image contrast in multiple applications. In the botanical applications framework, in spite of some works have already highlighted the depolarizing print that plant structures left on input polarized beams, the potential of polarimetric methods has not been properly exploited. In fact, among the few works dealing with polarization and plants, most of them study light scattered by plants using the Degree of Polarization (DoP) indicator. Other more powerful depolarization metrics are nowadays neglected. In this context, we highlight the potential of different depolarization metrics obtained using the Mueller matrix (MM) measurement: the Depolarization Index and the Indices of Polarimetric Purity. We perform a qualitative and quantitative comparison between DoP- and MM-based images by studying a particular plant, the Hedera maroccana. We show how Mueller-based metrics are generally more suitable in terms of contrast than DoP-based measurements. The potential of polarimetric measurements in the study of plants is highlighted in this work, suggesting they can be applied to the characterization of plants, plant taxonomy, water stress in plants, and other botanical studies
Unification of gauge couplings and the tau neutrino mass in Supergravity without R-parity
Minimal R-parity violating supergravity predicts a value for
smaller than in the case with conserved R-parity, and therefore closer to the
experimental world average. We show that the R-parity violating effect on the
prediction comes from the larger two-loop b-quark Yukawa contribution
to the renormalization group evolution of the gauge couplings which
characterizes R-parity violating supergravity. The effect is correlated to the
tau neutrino mass and is sensitive to the initial conditions on the soft
supersymmetry breaking parameters at the unification scale. We show how a few
percent effect on may naturally occur even with tau neutrino
masses as small as indicated by the simplest neutrino oscillation
interpretation of the atmospheric neutrino data from Super-Kamiokande.Comment: Latex, 21 pages including 2 figure
Systems biology of antioxidants
Understanding the role of oxidative injury will allow for therapy with agents that scavenge ROS (reactive oxygen species) and antioxidants in the management of several diseases related to free radical damage. The majority of free radicals are generated by mitochondria as a consequence of the mitochondrial cycle, whereas free radical accumulation is limited by the action of a variety of antioxidant processes that reside in every cell. In the present review, we provide an overview of the mitochondrial generation of ROS and discuss the role of ROS in the regulation of endothelial and adipocyte function. Moreover, we also discuss recent findings on the role of ROS in sepsis, cerebral ataxia and stroke. These results provide avenues for the therapeutic potential of antioxidants in a variety of diseases
Inflationary Cosmology with Five Dimensional SO(10)
We discuss inflationary cosmology in a five dimensional SO(10) model
compactified on , which yields below the compactification scale. The gauge
symmetry is preserved on one of the fixed points, while
``flipped'' is on the other fixed point. Inflation is
associated with breaking, and is implemented through -term scalar
potentials on the two fixed points. A brane-localized Einstein-Hilbert term
allows both branes to have positive tensions during inflation. The scale of
breaking is fixed from measurements to be around
GeV, and the scalar spectral index . The inflaton field
decays into right-handed neutrinos whose subsequent out of equilibrium decay
yield the observed baryon asymmetry via leptogenesis.Comment: 1+19 pages, improved discussion of 5D cosmology, Version to appear in
PR
Search for composite and exotic fermions at LEP 2
A search for unstable heavy fermions with the DELPHI detector at LEP is
reported. Sequential and non-canonical leptons, as well as excited leptons and
quarks, are considered. The data analysed correspond to an integrated
luminosity of about 48 pb^{-1} at an e^+e^- centre-of-mass energy of 183 GeV
and about 20 pb^{-1} equally shared between the centre-of-mass energies of 172
GeV and 161 GeV. The search for pair-produced new leptons establishes 95%
confidence level mass limits in the region between 70 GeV/c^2 and 90 GeV/c^2,
depending on the channel. The search for singly produced excited leptons and
quarks establishes upper limits on the ratio of the coupling of the excited
fermio
Search for lightest neutralino and stau pair production in light gravitino scenarios with stau NLSP
Promptly decaying lightest neutralinos and long-lived staus are searched for
in the context of light gravitino scenarios. It is assumed that the stau is the
next to lightest supersymmetric particle (NLSP) and that the lightest
neutralino is the next to NLSP (NNLSP). Data collected with the Delphi detector
at centre-of-mass energies from 161 to 183 \GeV are analysed. No evidence of
the production of these particles is found. Hence, lower mass limits for both
kinds of particles are set at 95% C.L.. The mass of gaugino-like neutralinos is
found to be greater than 71.5 GeV/c^2. In the search for long-lived stau,
masses less than 70.0 to 77.5 \GeVcc are excluded for gravitino masses from 10
to 150 \eVcc . Combining this search with the searches for stable heavy leptons
and Minimal Supersymmetric Standard Model staus a lower limit of 68.5 \GeVcc
may be set for the stau mas
HTLV-1 infection in solid organ transplant donors and recipients in Spain
Background: HTLV-1 infection is a neglected disease, despite infecting 10–15 million people worldwide and
severe illnesses develop in 10% of carriers lifelong. Acknowledging a greater risk for developing HTLV-1
associated illnesses due to immunosuppression, screening is being widely considered in the transplantation
setting. Herein, we report the experience with universal HTLV testing of donors and recipients of solid organ
transplants in a survey conducted in Spain.
Methods: All hospitals belonging to the Spanish HTLV network were invited to participate in the study. Briefly, HTLV
antibody screening was performed retrospectively in all specimens collected from solid organ donors and recipients
attended since the year 2008.
Results: A total of 5751 individuals were tested for HTLV antibodies at 8 sites. Donors represented 2312
(42.2%), of whom 17 (0.3%) were living kidney donors. The remaining 3439 (59.8%) were recipients. Spaniards
represented nearly 80%.
Overall, 9 individuals (0.16%) were initially reactive for HTLV antibodies. Six were donors and 3 were recipients.
Using confirmatory tests, HTLV-1 could be confirmed in only two donors, one Spaniard and another from
Colombia. Both kidneys of the Spaniard were inadvertently transplanted. Subacute myelopathy developed
within 1 year in one recipient. The second recipient seroconverted for HTLV-1 but the kidney had to be
removed soon due to rejection. Immunosuppression was stopped and 3 years later the patient remains in
dialysis but otherwise asymptomatic.
Conclusion: The rate of HTLV-1 is low but not negligible in donors/recipients of solid organ transplants in
Spain. Universal HTLV screening should be recommended in all donor and recipients of solid organ
transplantation in Spain. Evidence is overwhelming for very high virus transmission and increased risk along
with the rapid development of subacute myelopath
A First Search for coincident Gravitational Waves and High Energy Neutrinos using LIGO, Virgo and ANTARES data from 2007
We present the results of the first search for gravitational wave bursts
associated with high energy neutrinos. Together, these messengers could reveal
new, hidden sources that are not observed by conventional photon astronomy,
particularly at high energy. Our search uses neutrinos detected by the
underwater neutrino telescope ANTARES in its 5 line configuration during the
period January - September 2007, which coincided with the fifth and first
science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed
for candidate gravitational-wave signals coincident in time and direction with
the neutrino events. No significant coincident events were observed. We place
limits on the density of joint high energy neutrino - gravitational wave
emission events in the local universe, and compare them with densities of
merger and core-collapse events.Comment: 19 pages, 8 figures, science summary page at
http://www.ligo.org/science/Publication-S5LV_ANTARES/index.php. Public access
area to figures, tables at
https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=p120000
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