165 research outputs found
Influence of short- and long-term administration of Melengestrol acetate on estrus activity and reproductive performance of nulliparous Barki ewes
In Egypt, research focusing on estrous synchronization in small ruminants based on Melengestrol acetate (MGA) supplementation, particularly in nulliparous ewes, is still lacking. The present work aimed to evaluate effect of long-term and short-term administration of melengestrol acetate (MGA) treatments on estrus synchronization and reproductive performance of nulliparous Barki Ewes. This study was performed in Siwa Oasis Research Station (Tegzerty Experimental Farm for animal production), belonged to Desert Research Center, Egypt. Forty five nulliparous Barki ewes with age ranging from 15.5 to 16.5 months, and 38 ± 0.23 kg average live body weight were assigned to one of three groups: (1) control (C, n = 15); (2) long-term treatment with MGA (n = 15, 0.22 mg/ewe/d for 14 days) and (3) short-term treatment with MGA (n = 15, 0.22 mg/ewe/d for 7 days). At the end of MGA treatment (14 or 7 d) all treated ewes were injected by 600 IU PMSG intramuscularly. The results showed that, ewes treated with MGA exhibited highest (
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Combined sensitivity to the neutrino mass ordering with JUNO, the IceCube Upgrade, and PINGU
The ordering of the neutrino mass eigenstates is one of the fundamental open questions in neutrino physics. While current-generation neutrino oscillation experiments are able to produce moderate indications on this ordering, upcoming experiments of the next generation aim to provide conclusive evidence. In this paper we study the combined performance of the two future multi-purpose neutrino oscillation experiments JUNO and the IceCube Upgrade, which employ two very distinct and complementary routes toward the neutrino mass ordering. The approach pursued by the 20 kt medium-baseline reactor neutrino experiment JUNO consists of a careful investigation of the energy spectrum of oscillated νe produced by ten nuclear reactor cores. The IceCube Upgrade, on the other hand, which consists of seven additional densely instrumented strings deployed in the center of IceCube DeepCore, will observe large numbers of atmospheric neutrinos that have undergone oscillations affected by Earth matter. In a joint fit with both approaches, tension occurs between their preferred mass-squared differences Δm312=m32-m12 within the wrong mass ordering. In the case of JUNO and the IceCube Upgrade, this allows to exclude the wrong ordering at >5σ on a timescale of 3-7 years - even under circumstances that are unfavorable to the experiments' individual sensitivities. For PINGU, a 26-string detector array designed as a potential low-energy extension to IceCube, the inverted ordering could be excluded within 1.5 years (3 years for the normal ordering) in a joint analysis
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Design and performance of the first IceAct demonstrator at the South Pole
In this paper we describe the first results of IceAct, a compact imaging air-Cherenkov telescope operating in coincidence with the IceCube Neutrino Observatory (IceCube) at the geographic South Pole. An array of IceAct telescopes (referred to as the IceAct project) is under consideration as part of the IceCube-Gen2 extension to IceCube. Surface detectors in general will be a powerful tool in IceCube-Gen2 for distinguishing astrophysical neutrinos from the dominant backgrounds of cosmic-ray induced atmospheric muons and neutrinos: the IceTop array is already in place as part of IceCube, but has a high energy threshold. Although the duty cycle will be lower for the IceAct telescopes than the present IceTop tanks, the IceAct telescopes may prove to be more effective at lowering the detection threshold for air showers. Additionally, small imaging air-Cherenkov telescopes in combination with IceTop, the deep IceCube detector or other future detector systems might improve measurements of the composition of the cosmic ray energy spectrum. In this paper we present measurements of a first 7-pixel imaging air Cherenkov telescope demonstrator, proving the capability of this technology to measure air showers at the South Pole in coincidence with IceTop and the deep IceCube detector
Prevalence of Pseudoexfoliation Syndrome and Pseudoexfoliation Glaucoma in Upper Egypt
<p>Abstract</p> <p>Background</p> <p>Pseudoexfoliation (PXF) is a recognized risk factor for developing cataract, glaucoma and lens dislocation. PXF is also associated with increased risk of complications during cataract surgery due to poor mydriasis and zonular weakness. The aim of this study is to report the prevalence of pseudoexfoliation among Upper Egyptians attending the ophthalmology clinic of Assiut University Hospital.</p> <p>Methodology</p> <p>A retrospective, chart review study conducted in the period from February 2002 to August 2009. A total of 7738 patients aged 40 years or older attending the general ophthalmic clinics were included in this study. A detailed evaluation including ophthalmic and general history, slit lamp biomicroscopy, intraocular pressure measurement, gonioscopy and dilated eye examination were performed. Patients with pseudoexfoliative material on the anterior lens surface and ⁄ or the pupillary margin in either or both eyes were labeled as having PXF.</p> <p>Results</p> <p>Out of the 7738 patients included, three hundred twenty (4.14%) subjects had PXF. Mean age of PXF group was 68.15 years (SD 8.16, range 40-92 years). PXF was bilateral in 82.2% of cases. It was significantly associated with cataract, glaucoma and hearing loss. Of the PXF patients, 65% had cataract, 30.3% had glaucoma and 8.1% had hearing loss.</p> <p>Conclusion</p> <p>Pseudoexfoliation appears to be a common disorder in older individuals in Upper Egypt.</p
Fulminant Staphylococcus lugdunensis septicaemia following a pelvic varicella-zoster virus infection in an immune-deficient patient: a case report
<p>Abstract</p> <p>Introduction</p> <p>The deadly threat of systemic infections with coagulase negative <it>Staphylococcus lugdunensis </it>despite an appropriate antibiotic therapy has only recently been recognized. The predominant infectious focus observed so far is left-sided native heart valve endocarditis, but bone and soft tissue infections, septicaemia and vascular catheter-related bloodstream infections have also been reported. We present a patient with a fatal <it>Staphylococcus lugdunensis </it>septicaemia following zoster bacterial superinfection of the pelvic region.</p> <p>Case presentation</p> <p>A 71-year old male diagnosed with IgG kappa plasmocytoma presented with a conspicuous weight loss, a hypercalcaemic crisis and acute renal failure. After initiation of haemodialysis treatment his condition improved rapidly. However, he developed a varicella-zoster virus infection of the twelfth thoracic dermatome requiring intravenous acyclovir treatment. Four days later the patient presented with a fulminant septicaemia. Despite an early intravenous antibiotic therapy with ciprofloxacin, piperacillin/combactam and vancomycin the patient died within 48 hours, shortly before the infective isolate was identified as <it>Staphylococcus lugdunensis </it>by polymerase chain reaction.</p> <p>Conclusion</p> <p>Despite <it>S. lugdunensis </it>belonging to the family of coagulase-negative staphylococci with an usually low virulence, infections with <it>S. lugdunensis </it>may be associated with an aggressive course and high mortality. This is the first report on a <it>Staphylococcus lugdunensis </it>septicaemia following a zoster bacterial superinfection of the pelvic region.</p
Search for Quantum Gravity Using Astrophysical Neutrino Flavour with IceCube
Along their long propagation from production to detection, neutrino states
undergo quantum interference which converts their types, or flavours.
High-energy astrophysical neutrinos, first observed by the IceCube Neutrino
Observatory, are known to propagate unperturbed over a billion light years in
vacuum. These neutrinos act as the largest quantum interferometer and are
sensitive to the smallest effects in vacuum due to new physics. Quantum gravity
(QG) aims to describe gravity in a quantum mechanical framework, unifying
matter, forces and space-time. QG effects are expected to appear at the
ultra-high-energy scale known as the Planck energy, ~giga-electronvolts (GeV). Such a high-energy universe would have
existed only right after the Big Bang and it is inaccessible by human
technologies. On the other hand, it is speculated that the effects of QG may
exist in our low-energy vacuum, but are suppressed by the Planck energy as
(~GeV), (~GeV), or its higher powers. The coupling of particles to these
effects is too small to measure in kinematic observables, but the phase shift
of neutrino waves could cause observable flavour conversions. Here, we report
the first result of neutrino interferometry~\cite{Aartsen:2017ibm} using
astrophysical neutrino flavours to search for new space-time structure. We did
not find any evidence of anomalous flavour conversion in IceCube astrophysical
neutrino flavour data. We place the most stringent limits of any known
technologies, down to ~GeV, on the dimension-six operators
that parameterize the space-time defects for preferred astrophysical production
scenarios. For the first time, we unambiguously reach the signal region of
quantum-gravity-motivated physics.Comment: The main text is 7 pages with 3 figures and 1 table. The Appendix
includes 5 pages with 3 figure
Measurement of atmospheric neutrino mixing with improved IceCube DeepCore calibration and data processing
We describe a new data sample of IceCube DeepCore and report on the latest measurement of atmospheric neutrino oscillations obtained with data recorded between 2011–2019. The sample includes significant improvements in data calibration, detector simulation, and data processing, and the analysis benefits from a sophisticated treatment of systematic uncertainties, with significantly greater level of detail since our last study. By measuring the relative fluxes of neutrino flavors as a function of their reconstructed energies and arrival directions we constrain the atmospheric neutrino mixing parameters to be sin2θ23=0.51±0.05 and Δm232=2.41±0.07×10−3 eV2, assuming a normal mass ordering. The errors include both statistical and systematic uncertainties. The resulting 40% reduction in the error of both parameters with respect to our previous result makes this the most precise measurement of oscillation parameters using atmospheric neutrinos. Our results are also compatible and complementary to those obtained using neutrino beams from accelerators, which are obtained at lower neutrino energies and are subject to different sources of uncertainties
IceCat-1: The IceCube Event Catalog of Alert Tracks
We present a catalog of likely astrophysical neutrino track-like events from the IceCube Neutrino Observatory. IceCube began reporting likely astrophysical neutrinos in 2016, and this system was updated in 2019. The catalog presented here includes events that were reported in real time since 2019, as well as events identified in archival data samples starting from 2011. We report 275 neutrino events from two selection channels as the first entries in the catalog, the IceCube Event Catalog of Alert Tracks, which will see ongoing extensions with additional alerts. The Gold and Bronze alert channels respectively provide neutrino candidates with a 50% and 30% probability of being astrophysical, on average assuming an astrophysical neutrino power-law energy spectral index of 2.19. For each neutrino alert, we provide the reconstructed energy, direction, false-alarm rate, probability of being astrophysical in origin, and likelihood contours describing the spatial uncertainty in the alert\u27s reconstructed location. We also investigate a directional correlation of these neutrino events with gamma-ray and X-ray catalogs, including 4FGL, 3HWC, TeVCat, and Swift-BAT
Measurement of Atmospheric Neutrino Mixing with Improved IceCube DeepCore Calibration and Data Processing
We describe a new data sample of IceCube DeepCore and report on the latest
measurement of atmospheric neutrino oscillations obtained with data recorded
between 2011-2019. The sample includes significant improvements in data
calibration, detector simulation, and data processing, and the analysis
benefits from a detailed treatment of systematic uncertainties, with
significantly higher level of detail since our last study. By measuring the
relative fluxes of neutrino flavors as a function of their reconstructed
energies and arrival directions we constrain the atmospheric neutrino mixing
parameters to be and , assuming a normal mass ordering. The
resulting 40\% reduction in the error of both parameters with respect to our
previous result makes this the most precise measurement of oscillation
parameters using atmospheric neutrinos. Our results are also compatible and
complementary to those obtained using neutrino beams from accelerators, which
are obtained at lower neutrino energies and are subject to different sources of
uncertainties
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