605 research outputs found
A conceptual design of an advanced 23 m diameter IACT of 50 tons for ground-based gamma-ray astronomy
A conceptual design of an advanced Imaging Air Cherenkov Telescope with a 23
m diameter mirror and of 50 tons weight will be presented. A system photon
detection efficiency of 15-17%, averaged over 300-600 nm, is aimed at to lower
the threshold to 10-20 GeV. Prospects for a second generation camera with
Geiger-mode Avalanche Photo Diodes will be discussed.Comment: 4 pages, 1 figure, to appear in the proceedings of the 31th
International Cosmic Ray Conference, Lodz, Poland, 200
Using the Resected Kidney for Transplantation After Nephrectomy for Nutcracker Syndrome
Nutcracker syndrome (NCS) is the clinical manifestation of unilateral renal venous hypertension. It develops secondary to the nutcracker phenomenon caused by compression of the left renal vein between the superior mesenteric artery and the aorta. We present the case of a 43-year-old female with a history of left flank pain, pelvic congestion, and hematuria secondary to NCS. The patient frequently required high-dose non-steroidal anti-inflammatory medications with minimal relief. She initiated a kidney donor evaluation after electing to undergo a nephrectomy for the possible long-term resolution of NCS symptoms. If diagnosed early, NCS does not generate pathology within the kidney. This finding allows an individual with medically refractory NCS to avoid the morbidity of a complex surgical procedure by instead donating their kidney. Attention to this treatment modality could provide individuals with NCS resolution of symptoms while providing someone with end-stage renal disease with a life-saving organ
Acoustic barriers as an acoustic deterrent for native potamodromous migratory fish species
This study focused on the use of sound playbacks as acoustic deterrents to direct native potamodromous
migratory species away from all kind of traps. The effects of two acoustic treatments,
a repeated sine sweep up to 2 kHz (sweep-up stimulus) and an intermittent 140 Hz tone,
were tested in three fish species native to Iberia: Salmo trutta, Pseudochondrostoma duriense and
Luciobarbus bocagei. In contrast with S. trutta, the endemic cyprinids P. duriense and L. bocagei
exhibited a strong repulse reaction to the frequency sweep-up sound. The 140 Hz stimulus did
not seem to alter significantly the behaviour of any of the studied species. These results highlight
the potential of acoustic stimuli as fish behavioural barriers and their application to in situ
conservation measures of native Iberian fish populations, to protect them from hydropower
dams. In addition, this study shows that acoustic deterrents can be used selectively on target
species.The project n 13737: Original Solutions - ENI
and CITAB-UTAD was funded project:
ANI/QREN/FEDER. The Science and
Technology Foundation, Portugal funded
M.C.P.A. (strategic projects
UID/MAR/04292/2013 granted to MARE) and
P.J.F. (UID/BIA/00329/2013 granted to cE3c).
The scientific plan was achieved under
European Investment Funds by FEDER/
COMPETE/POCI– Operational
Competitiveness and Internationalization
Programme, under Project POCI-
01-0145-FEDER-006958 and National Funds
by FCT - Portuguese Foundation for Science
and Technology, under the project
UID/AGR/04033.info:eu-repo/semantics/publishedVersio
Uhlmann's geometric phase in presence of isotropic decoherence
Uhlmann's mixed state geometric phase [Rep. Math. Phys. {\bf 24}, 229 (1986)]
is analyzed in the case of a qubit affected by isotropic decoherence treated in
the Markovian approximation. It is demonstrated that this phase decreases
rapidly with increasing decoherence rate and that it is most fragile to weak
decoherence for pure or nearly pure initial states. In the unitary case, we
compare Uhlmann's geometric phase for mixed states with that occurring in
standard Mach-Zehnder interferometry [Phys. Rev. Lett. {\bf 85}, 2845 (2000)]
and show that the latter is more robust to reduction in the length of the Bloch
vector. We also describe how Uhlmann's geometric phase in the present case
could in principle be realized experimentally.Comment: New ref added, refs updated, journal ref adde
The Combination of Neutrophil–Lymphocyte Ratio and Platelet–Lymphocyte Ratio with Liquid Biopsy Biomarkers Improves Prognosis Prediction in Metastatic Pancreatic Cancer
Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with a highly inflammatory microenvironment and liquid biopsy has emerged as a promising tool for the noninvasive analysis of this tumor. In this study, plasma was obtained from 58 metastatic PDAC patients, and neutrophil–lymphocyte ratio (NLR), platelet–lymphocyte ratio (PLR), circulating cell-free DNA (cfDNA) concentration, and circulating RAS mutation were determined. We found that NLR was significantly associated with both overall survival (OS) and progression-free survival. Remarkably, NLR was an independent risk factor for poor OS. Moreover, NLR and PLR positively correlated, and combination of both inflammatory markers significantly improved the prognostic stratification of metastatic PDAC patients. NLR also showed a positive correlation with cfDNA levels and RAS mutant allelic fraction (MAF). Besides, we found that neutrophil activation contributed to cfDNA content in the plasma of metastatic PDAC patients. Finally, a multi-parameter prognosis model was designed by combining NLR, PLR, cfDNA levels, RAS mutation, RAS MAF, and CA19-9, which performs as a promising tool to predict the prognosis of metastatic PDAC patients. In conclusion, our study supports the idea that the use of systemic inflammatory markers along with circulating tumor-specific markers may constitute a valuable tool for the clinical management of metastatic PDAC patients
Weakly-Bound Three-Body Systems with No Bound Subsystems
We investigate the domain of coupling constants which achieve binding for a
3-body system, while none of the 2-body subsystems is bound. We derive some
general properties of the shape of the domain, and rigorous upper bounds on its
size, using a Hall--Post decomposition of the Hamiltonian. Numerical
illustrations are provided in the case of a Yukawa potential, using a simple
variational method.Comment: gzipped ps with 11 figures included. To appear in Phys. Rev.
Diagnostic and therapeutic approach to cardioinhibitory reflex syncopeA complex and controversial issue
Syncope is defined as a transient loss of consciousness due to global cerebral hypoperfusion and is one of the leading causes of emergency department admission. The initial approach should focus on excluding non‐syncopal causes for loss of consciousness and risk stratification for cardiac cause, in order to ensure an appropriate etiological investigation and therapeutic approach. Vasovagal syncope (VVS), the most common type of syncope, should be assumed once other causes are excluded. Pathophysiologically, the vasovagal reflex is the result of a paradoxical autonomic response, leading to hypotension and/or bradycardia. VVS has not been shown to affect mortality, but morbidity may be considerable in those with recurrent syncopal episodes. The management of VVS includes both non‐pharmacological and pharmacological measures that act on various levels of the reflex arc that triggers the syncopal episode. However, most are of uncertain benefit given the scarcity of high‐quality supporting evidence. Pacemaker therapy may be considered in recurrent refractory cardioinhibitory reflex syncope, for which it is currently considered a robust intervention, as noted in the European guidelines. Non‐randomized and unblinded studies have shown a potential benefit of pacing in recurrent VVS, but double‐blinded randomized controlled trials have not consistently demonstrated positive results. We performed a comprehensive review of the current literature and recent advances in cardiac pacing and pacing algorithms in VVS, and discuss the diagnostic and therapeutic approach to the complex patient with recurrent VVS and reduced quality of life.publishersversionpublishe
Entanglement, Bell Inequalities and Decoherence in Particle Physics
We demonstrate the relevance of entanglement, Bell inequalities and
decoherence in particle physics. In particular, we study in detail the features
of the ``strange'' system as an example of entangled
meson--antimeson systems. The analogies and differences to entangled spin--1/2
or photon systems are worked, the effects of a unitary time evolution of the
meson system is demonstrated explicitly. After an introduction we present
several types of Bell inequalities and show a remarkable connection to CP
violation. We investigate the stability of entangled quantum systems pursuing
the question how possible decoherence might arise due to the interaction of the
system with its ``environment''. The decoherence is strikingly connected to the
entanglement loss of common entanglement measures. Finally, some outlook of the
field is presented.Comment: Lectures given at Quantum Coherence in Matter: from Quarks to Solids,
42. Internationale Universit\"atswochen f\"ur Theoretische Physik,
Schladming, Austria, Feb. 28 -- March 6, 2004, submitted to Lecture Notes in
Physics, Springer Verlag, 45 page
Unfolding of differential energy spectra in the MAGIC experiment
The paper describes the different methods, used in the MAGIC experiment, to
unfold experimental energy distributions of cosmic ray particles (gamma-rays).
Questions and problems related to the unfolding are discussed. Various
procedures are proposed which can help to make the unfolding robust and
reliable. The different methods and procedures are implemented in the MAGIC
software and are used in most of the analyses.Comment: Submitted to NIM
Implementation of the Random Forest Method for the Imaging Atmospheric Cherenkov Telescope MAGIC
The paper describes an application of the tree classification method Random
Forest (RF), as used in the analysis of data from the ground-based gamma
telescope MAGIC. In such telescopes, cosmic gamma-rays are observed and have to
be discriminated against a dominating background of hadronic cosmic-ray
particles. We describe the application of RF for this gamma/hadron separation.
The RF method often shows superior performance in comparison with traditional
semi-empirical techniques. Critical issues of the method and its implementation
are discussed. An application of the RF method for estimation of a continuous
parameter from related variables, rather than discrete classes, is also
discussed.Comment: 16 pages, 8 figure
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