4,938 research outputs found
Rare and charmless decays of b-hadrons at Tevatron
I report the most recent results from the CDF and DØ Collaborations on the search for rare-decay modes of the b-hadrons. The results involve the current best limit on B0
(s)→ μ+μ− and B0(s)→ e+μ− decay modes, further results in
charmless decays are expected soon
Manganese-56 coincidence-counting facility precisely measures neutron-source strength
Precise measurement of neutron-source strength is provided by a manganese 56 coincidence-counting facility using the manganese-bath technique. This facility combines nuclear instrumentation with coincidence-counting techniques to handle a wide variety of radioisotope-counting requirements
The development of Integrated Real Time Control to optimise storm water management for the combined sewer system of Rome
Increasing urbanisation and intensification of human activities are common
trends all over the world. The higher portion of impermeable urban surfaces
often leads to well known effects on storm water runoff and its polluting
potential for receiving waters. Despite the variety of structural solutions and
management practices proposed to mitigate the operational and environmental
impact of urban runoff, their application on existing drainage systems can often
be either ineffective at a metropolitan scale or unfeasible for a densely urbanised
territory. Among all the proposed alternatives, the real time control (RTC) of
drainage systems is proving more and more promising to dynamically regulate
the system capacity in response to intense rainfall. The combined sewer network
of Rome, historically built with high-capacity pipes to collect storm water from
both urban and natural catchments, holds significant potential for RTC of online
storage and combined sewer overflows, to optimise the global drainage capacity
and reduce the impact of discharges on local river quality. To assess the real
benefits, the potential limits and the feasibility of such a system for the city
sewers, a pilot study has been conducted on a 3,000 hectare sub-catchment. It
involved the development of a fast-response hydrodynamic simulation tool for
the sewer network, the definition and evaluation of RTC strategies and the
implementation of an environmental integrated telemetry system. As described
here, the study has highlighted significant margins for the optimisation of the
global network capacity without any major interventions on the physical assets,
as well as some critical issues to solve for a fully operational RTC application
Sediment Transport in Sewers: The Cesarina Combined Sewer Network
The polluting effects of storm water runoff on the receiving waterbodies
represent an increasingly relevant problem in developing urban areas. In
combined sewer pipes, transiting flood waves cause the alternation of sediment
erosion and deposition of the solid material transported by the flow. Combined
sewer deposit, mainly generated as an effect of such phenomena during the dry
weather period between two rain events, is generally a mix of sand and highly
polluting materials. Accumulation of sediments along a combined sewer network
is often the cause of dysfunctions in the drainage system itself and negative
impacts on the quality of receiving waters, due to the resuspension and overflow
of pollutants. Both aspects have been investigated for the combined sewer of
Rome thanks to an experimental catchment of about 2800 ha in the Cesarina –
S. Basilio area. Based on the simulations conducted, structural solutions were
proposed and evaluated, aimed at reducing the operational and environmental
problems related to sewer sediment. The results show noticeable margins for the
optimisation of the whole sewer system and for the reduction of its
environmental impact
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The pgip family in soybean and three other legume species: evidence for a birth-and-death model of evolution
Polygalacturonase-inhibiting proteins (PGIPs) are leucine-rich repeat (LRR) plant cell wall glycoproteins involved in plant immunity. They are typically encoded by gene families with a small number of gene copies whose evolutionary origin has been poorly investigated. Here we report the complete characterization of the full complement of the pgip family in soybean (Glycine max [L.] Merr.) and the characterization of the genomic region surrounding the pgip family in four legume species. Results: BAC clone and genome sequence analyses showed that the soybean genome contains two pgip loci. Each locus is composed of three clustered genes that are induced following infection with the fungal pathogen Sclerotinia sclerotiorum (Lib.) de Bary, and remnant sequences of pgip genes. The analyzed homeologous soybean genomic regions (about 126 Kb) that include the pgip loci are strongly conserved and this conservation extends also to the genomes of the legume species Phaseolus vulgaris L., Medicago truncatula Gaertn. and Cicer arietinum L., each containing a single pgip locus. Maximum likelihood-based gene trees suggest that the genes within the pgip clusters have independently undergone tandem duplication in each species. Conclusions: The paleopolyploid soybean genome contains two pgip loci comprised in large and highly conserved duplicated regions, which are also conserved in bean, M. truncatula and C. arietinum. The genomic features of these legume pgip families suggest that the forces driving the evolution of pgip genes follow the birth-and-death model, similar to that proposed for the evolution of resistance (R) genes of NBS-LRR-type
Intraluminal recanalization of long infrainguinal chronic total occlusions using the Crosser system
Purpose: To assess the safety and efficacy of a device for vibrational angioplasty in the
percutaneous intraluminal recanalization of long infrainguinal chronic total occlusions (CTO).
Technique: The Crosser CTO Recanalization System is a mechanical recanalization device
that uses high-frequency vibrational energy to disrupt and channel through fibrocalcific
plaque without harming the vessel wall, thus assisting in the recanalization of an occluded
artery. In 12 diabetic patients (7 men; median age 71 years, range 58–80) with critical limb
ischemia owing to long (median length 26 cm, range 21–32) infrainguinal CTOs resistant to
conventional guidewire techniques, the Crosser CTO Recanalization System was
successful in intraluminally crossing the occlusion in 9 (75%) patients in ,5 minutes
(mean 4:03 minutes). The safety endpoint (distal lumen guidewire position with no vessel
perforation or dissection) was achieved in all successful cases.
Conclusion: In our preliminary experience, the Crosser CTO Recanalization Catheter
decreased crossing time, was safe, and achieved a high rate of intraluminal recanalization
of long infrainguinal CTOs.
J Endovasc Ther. 2009;16:23–27
Key words: critical limb ischemia, chronic total occlusion, percutaneous interventions,
infrainguinal occlusion, intraluminal recanalization, vibrational energ
Feasibility of a storage ring for polar molecules in strong-field-seeking states
We show, through modeling and simulation, that it is feasible to construct a
storage ring that will store dense bunches of strong-field-seeking polar
molecules at 30 m/s (kinetic energy of 2K) and hold them, for several minutes,
against losses due to defocusing, oscillations, and diffusion. The ring, 3 m in
diameter, has straight sections that afford access to the stored molecules and
a lattice structure that may be adapted for evaporative cooling. Simulation is
done using a newly-developed code that tracks the particles, in time, through
400 turns; it accounts for longitudinal velocity changes as a function of
external electric field, focusing and deflection nonlinearities, and the
effects of gravity. An injector, decelerator, and source are included and
intensities are calculated.Comment: 6 pages 5 figures, 3 table
Current management of herpes zoster: The European view
The overall incidence of herpes zoster in Europe is approximately 3 per 1000 people per year and more than 10 per 1000 people per year in those aged >80 years. Post herpetic neuralgia (PHN) is a common debilitating complication of herpes zoster, particularly in patients aged >50 years, in persons with severe pain or rash at presentation, and in those with significant prodromal symptoms. Antiviral drugs can effectively control acute symptoms and, if used early enough in the course of the illness, can help prevent the development of PHN and other complications. However, despite this, many patients do not receive such treatment. The economic impact of zoster and PHN is largely underestimated in Europe. Furthermore, there is considerable variation throughout Europe in the management of herpes zoster. Use of antiviral therapy including the newer potent antiviral agents such as brivudin, which requires less frequent administration than acyclovir, is improving patient outcomes in some European countries. However, in many countries, patient awareness of herpes zoster and, as a result, overall antiviral use is low. Guidelines recommending the use of antiviral agents, particularly in patients at risk of developing PHN, are available but are not widely used. More needs to be done to educate the general public and increase awareness among primary healthcare providers of the benefits of timely and appropriate pharmacological therapy in patients with herpes zoster. © 2005 Adis Data Information BV. All rights reserved
A criterion for optimal management of water distribution networks
The management of water supply systems is based on fundamental principles, set
by international and national legislations; the general target for water utilities is
to offer a reliable and effective service following efficiency criteria. In this
context, losses in distribution networks are one of the main problems to tackle:
their reduction implies a general decrease in operational costs and in the need for
a limited resource such as water. Numerous solutions have been proposed to
reduce non revenue water, from simple leak detection to structural interventions
on distribution systems, based on new design criteria which favour district-based
networks over redundant ones. The present work proposes a new procedure to
restructure a water supply network starting from its hydraulic model, comparing
different types of intervention and evaluating their feasibility, limits and
effectiveness in terms of the global system efficiency, as measured by the
infrastructure leakage index (ILI). The possibility to use excessive pressure in
specific parts of a network for the production of electricity is also examined, as it
offers an additional resource to improve the system performance. The procedure
has been tested for the water network in the municipalities of Tarcento and
Magnano in Riviera, near Udine in Italy. Thanks to a specific hydraulic model,
simulations were performed to identify the optimal interventions on the system
aimed at reducing water losses and improving performances and efficiency
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