4,484 research outputs found
The effects of matter density uncertainties on neutrino oscillations in the Earth
We compare three different methods to evaluate uncertainties in the Earth's
matter density profile, which are relevant to long baseline experiments, such
as neutrino factories.Comment: 3 pages, 1 figure. Talk given at the NuFact'02 Workshop, London, 1-6
July, 200
Resource Management in Diffserv On DemAnd (RODA) PHR
The purpose of this draft is to present the Resource Management in Diffserv (RMD) On DemAnd (RODA) Per Hop Reservation (PHR) protocol. The RODA PHR protocol is used on a per-hop basis in a Differentiated Services (Diffserv) domain and extends the Diffserv Per Hop Behavior (PHB) with resource provisioning and control
Antimicrobial resistance and Neisseria gonorrhoeae multiantigen sequence typing (NG-MAST) genotypes in N. gonorrhoeae during 2012-2014 in Karachi, Pakistan
Background: Globally, increasing antimicrobial resistance (AMR) in Neisseria gonorrhoea has led to decreased treatment options for gonorrhoea. Continuous monitoring of resistance is crucial to determine evolving resistance trends in Neisseria gonorrhoea and to suggest treatment recommendations. Quality assured gonococcal AMR data from Pakistan are mainly lacking. This study was performed to determine prevalence and trends of gonococcal AMR and molecular epidemiology of local strains during 2012-2014 in Karachi, Pakistan.
Methods: Gonococcal isolates (nâ=â100) were obtained from urogenital specimens submitted to the Aga Khan University Laboratory, Karachi, Pakistan. Antimicrobial susceptibility was determined using Etest and molecular epidemiology was assessed by N. gonorrhoeae multiantigen sequence typing (NG-MAST). Quality control was performed using N. gonorrhoeae WHO reference strains C, F, G, K, L, M, N, O, and P, and ATCC 49226.
Results: Susceptibility to spectinomycin, ceftriaxone and cefixime was 100 % and to azithromycin was 99 %. All isolates had low ceftriaxone MICs, i.e., â€0.032 mg/L. Resistance to ciprofloxacin, tetracycline and penicillin G were 86 %, 51 % and 43 %, respectively. NG-MAST analysis identified 74 different sequence types (STs).
Conclusions: A highly diversified gonococcal population, 74 NG-MAST STs (62 novel STs) with an increased resistance to penicillin G, ciprofloxacin and tetracycline circulated in Karachi, Pakistan. Fortunately, no resistance to ceftriaxone was detected. Accordingly, ceftriaxone can continuously be recommended as the treatment of choice. However it is recommended to increase the dose of ceftriaxone from 125 mg intramuscularly to 250 mg intramuscularly due to ceftriaxone MIC creep and emerging resistance reported in the region. Furthermore, due to the high level of resistance to ciprofloxacin (86 %) it is essential to exclude ciprofloxacin from the recommended first-line therapy. It is imperative to significantly broaden the gonococcal AMR monitoring with participation from other laboratories and cities in Pakistan
Taxonomy and evolutionary relationships within species of section Rimosae (Inocybe) based on ITS, LSU and mtSSU sequence data
The present study aimed at elucidating the structure of Inocybe subg. Inosperma sect. Rimosae but included also representatives from subg. Mallocybe and the genus Auritella. Phylogenetic relationships were inferred using ITS, LSU and mtSSU sequence data. The analyses recovered the ingroup as a monophyletic, strongly supported clade. The results indicate that recognizing Auritella on the genus level renders Inocybe paraphyletic. The species traditionally placed in sect. Rimosae were found to be distributed over two strongly supported clades, Maculata and Rimosae s.s. The Maculata clade clusters with sect. Cervicolores and the two represent subg. Inosperma in a strict sense. Rimosae s.s. emerges as an independent, supported clade well separated from Inosperma s.s. Twenty-one terminal groups were correlated with morphologically distinct species. In addition several taxa on single branches and minor less supported clades were recovered. A key to the identified species of the Maculata and Rimosae s.s. clades which occur in Northwest Europe is provided
Resource Management in Diffserv (RMD) Framework
This draft presents the work on the framework for the Resource Management in Diffserv (RMD) designed for edge-to-edge resource reservation in a Differentiated Services (Diffserv) domain. The RMD extends the Diffserv architecture with new resource reservation concepts and features. Moreover, this framework enhances the Load Control protocol described in [WeTu00].\ud
\ud
The RMD framework defines two architectural concepts:\ud
- the Per Hop Reservation (PHR)\ud
- the Per Domain Reservation (PDR)\ud
\ud
The PHR protocol is used within a Diffserv domain on a per-hop basis to augment the Diffserv Per Hop Behavior (PHB) with resource reservation. It is implemented in all nodes in a Diffserv domain. On the other hand, the PDR protocol manages the resource reservation per Diffserv domain, relying on the PHR resource reservation status in all nodes. The PDR is only implemented at the boundary of the domain (at the edge nodes).\ud
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The RMD framework presented in this draft describes the new reservation concepts and features. Furthermore it describes the:\ud
- relationship between the PHR and PHB\ud
- interaction between the PDR and PHR\ud
- interoperability between the PDR and external resource reservation schemes\ud
\ud
This framework is an open framework in the sense that it provides the basis for interoperability with other resource reservation schemes and can be applied in different types of networks as long as they are Diffserv domains. It aims at extreme simplicity and low cost of implementation along with good scaling properties
Production of a C-15 radioactive ion beam based on O-18(n, alpha)
.In the context of the SPIRAL2 radioactive beam facility the production rate of the neutron-rich C-15 nucleus by O-18(n,) has been investigated. In a water target of 20 cm(3), enriched in O-18 and placed behind the neutron converter, a rate of a few 10(10) nuclei per second can be reached with 1mA of 40MeV deuterons. A O-18(n,) cross-section based on the activation method is proposed. It is intermediate between the highest and lowest evaluations available to date.Peer reviewe
Neutrino tomography - Learning about the Earth's interior using the propagation of neutrinos
Because the propagation of neutrinos is affected by the presence of Earth
matter, it opens new possibilities to probe the Earth's interior. Different
approaches range from techniques based upon the interaction of high energy
(above TeV) neutrinos with Earth matter, to methods using the MSW effect on the
neutrino oscillations of low energy (MeV to GeV) neutrinos. In principle,
neutrinos from many different sources (sun, atmosphere, supernovae, beams etc.)
can be used. In this talk, we summarize and compare different approaches with
an emphasis on more recent developments. In addition, we point out other
geophysical aspects relevant for neutrino oscillations.Comment: 22 pages, 9 figures. Proceedings of ``Neutrino sciences 2005:
Neutrino geophysics'', December 14-16, 2005, Honolulu, USA. Minor changes,
some references added. Final version to appear in Earth, Moon, and Planet
Design of a high power production target for the Beam Dump Facility at CERN
The Beam Dump Facility (BDF) project is a proposed general-purpose facility
at CERN, dedicated to beam dump and fixed target experiments. In its initial
phase, the facility is foreseen to be exploited by the Search for Hidden
Particles (SHiP) experiment. Physics requirements call for a pulsed 400 GeV/c
proton beam as well as the highest possible number of protons on target (POT)
each year of operation, in order to search for feebly interacting particles.
The target/dump assembly lies at the heart of the facility, with the aim of
safely absorbing the full high intensity Super Proton Synchrotron (SPS) beam,
while maximizing the production of charmed and beauty mesons. High-Z materials
are required for the target/dump, in order to have the shortest possible
absorber and reduce muon background for the downstream experiment. The high
average power deposited on target (305 kW) creates a challenge for heat
removal. During the BDF facility Comprehensive Design Study (CDS), launched by
CERN in 2016, extensive studies have been carried out in order to define and
assess the target assembly design. These studies are described in the present
contribution, which details the proposed design of the BDF production target,
as well as the material selection process and the optimization of the target
configuration and beam dilution. One of the specific challenges and novelty of
this work is the need to consider new target materials, such as a molybdenum
alloy (TZM) as core absorbing material and Ta2.5W as cladding.
Thermo-structural and fluid dynamics calculations have been performed to
evaluate the reliability of the target and its cooling system under beam
operation. In the framework of the target comprehensive design, a preliminary
mechanical design of the full target assembly has also been carried out,
assessing the feasibility of the whole target system.Comment: 17 pages, 18 figure
Khovanov-Rozansky Homology and Topological Strings
We conjecture a relation between the sl(N) knot homology, recently introduced
by Khovanov and Rozansky, and the spectrum of BPS states captured by open
topological strings. This conjecture leads to new regularities among the sl(N)
knot homology groups and suggests that they can be interpreted directly in
topological string theory. We use this approach in various examples to predict
the sl(N) knot homology groups for all values of N. We verify that our
predictions pass some non-trivial checks.Comment: 25 pages, 2 figures, harvmac; minor corrections, references adde
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