4,293 research outputs found
Can VMD improve the estimate of the muon g-2 ?
We show that a VMD based theoretical input allows for a significantly
improved accuracy for the hadronic vacuum polarization of the photon which
contributes to the theoretical estimate of the muon g-2. We also show that the
only experimental piece of information in the decay which cannot be
accounted for is the accepted value for {\rm Br}(\tau \ra \pi \pi \nu_\tau),
while the spectum lineshape is in agreement with expectations from
annihilations.Comment: 6 pages, 1 figure Proceedings of the PhiPsi09, Oct. 13-16, 2009,
Beijing, Chin
Use of Biostimulants as a New Approach for the Improvement of Phytoremediation Performance—A Review
Reconstruction and Particle Identification for a DIRC System
We study the reconstruction and particle identification (PID) problem for
Ring Imaging devices providing a good knowledge of the direction of the
Cerenkov photons, as the DIRC system, on which we specialize. We advocate first
the use of the stereographic projection as a tool allowing a suitable
representation of the photon data, as it allows to represent the Cerenkov cone
always as a circle. We set up an algorithm able to perform reliably a fit of
circle arcs of small angular opening, by minimising a true Chi2 expression. The
system we develop for PID relies on this algorithm and on a procedure able to
remove background photons with a high efficiency. We thus show that, even when
the background is large, it is possible to perform an efficient PID by means of
a fit algorithm which finally provides all the circle parameters; these are
connected with the charged track direction and its Cerenkov angle. It is shown
that background effects can be dealt without spoiling significantly the
reconstruction probability distributions.Comment: 67 pages, 23 figure
Increase in the selenium content of extra virgin olive oil: quantitative and qualitative implications
The biofortification of food crops for human consumption is a direct strategy increasing dietary intake of selenium (Se). The aim of this study was to evaluate the possibility of increasing the Se content of extra virgin olive oil (EVOO) by spraying the olive tree canopy with sodium selenate and the effect of the increase in Se on the chemical properties and sensory characteristics of the EVOO. Se treatments were up to 50 times more effective in enhancing Se content in the EVOO compared with the untreated controls. Se concentration in all the EVOO samples can be considered adequate and useful for providing the human diet with the correct dose of Se. Se-enriched EVOO showed a significant increase in pigment and phenol content. Also, Se treatment does not produce negative effects on fruit characteristics or the sensory quality of EVOO.La biofortificación de cultivos alimenticios para el consumo humano es una estrategia directa para aumentar la ingesta de selenio (Se) en la dieta. El objetivo de este estudio fue evaluar la posibilidad de aumentar el contenido de Se en aceites de oliva virgen extra (AOVE) pulverizando la copa de los olivos con selenato de sodio y el efecto del aumento en el contenido de Se en las propiedades químicas y características sensoriales del AOVE. Los tratamientos con Se fueron muy eficaces consiguiendo aumentar el contenido de Se en el AOVE hasta 50 veces más en comparación con los controles no tratados. La concentración de Se en todas las muestras EVOO puede considerarse adecuada y útil para proporcionar a la dieta humana con la dosis correcta de Se. EVOO-Se enriquecido mostró un aumento significativo en pigmentos y contenido de fenoles. Además, el tratamiento de Se no implica efectos negativos sobre caracteristicas frutales ni sobre la calidad sensorial de AOVE
Triosephosphate Isomerases in Italian Ryegrass (Lolium multiflorum) : Characterization and Susceptibility to Herbicides
The effect of treatments with four herbicides and a safener on the activity of triosephosphate
isomerase (TPI) extracted from shoots of Italian ryegrass was investigated. It was found that
atrazine and fluorodifen, herbicides which interfere with photosynthesis, caused a decrease in
measured enzyme activity. In addition, the in vitro effect of oxidized glutathione (GSSG), a
compound produced in situations of oxidative stress, on TPI activity was investigated. It was shown
that GSSG was a strong inhibitor of enzyme activity, at low concentrations in a dose-timedependent
manner. The enzyme extracts were submitted to chromatographic purifications and to
two-dimensional electrophoresis. Some spots had molecular masses ranging between 20 and 30
kDa and were characterized and identified by LC-ESI-MS/MS as TPIs. The mass spectrometry also
made it possible to identify the presence of cysteine residues that could be subjected to
S-glutathionylation, which regulate the enzyme activity
Impact of different dosing regimens of clopidogrel on systemic oxidative stress in patients undergoing elective percutaneous coronary intervention.
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Piecewise smooth systems near a co-dimension 2 discontinuity manifold: can one say what should happen?
We consider a piecewise smooth system in the neighborhood of a co-dimension 2
discontinuity manifold . Within the class of Filippov solutions, if
is attractive, one should expect solution trajectories to slide on
. It is well known, however, that the classical Filippov
convexification methodology is ambiguous on . The situation is further
complicated by the possibility that, regardless of how sliding on is
taking place, during sliding motion a trajectory encounters so-called generic
first order exit points, where ceases to be attractive.
In this work, we attempt to understand what behavior one should expect of a
solution trajectory near when is attractive, what to expect
when ceases to be attractive (at least, at generic exit points), and
finally we also contrast and compare the behavior of some regularizations
proposed in the literature.
Through analysis and experiments we will confirm some known facts, and
provide some important insight: (i) when is attractive, a solution
trajectory indeed does remain near , viz. sliding on is an
appropriate idealization (of course, in general, one cannot predict which
sliding vector field should be selected); (ii) when loses attractivity
(at first order exit conditions), a typical solution trajectory leaves a
neighborhood of ; (iii) there is no obvious way to regularize the
system so that the regularized trajectory will remain near as long as
is attractive, and so that it will be leaving (a neighborhood of)
when looses attractivity.
We reach the above conclusions by considering exclusively the given piecewise
smooth system, without superimposing any assumption on what kind of dynamics
near (or sliding motion on ) should have been taking place.Comment: 19 figure
Evaluation of microbial contamination of air in two haematology departments equipped with ventilation systems with different filtration devices
Background. Nosocomial infections (NI) are above all due to health-care workers practices, but also the contamination of the environment could lead to their rise in health-care facilities. Introduction. In the last years, the incidence of NI has increased due to a substantial rise in the number of immuno-compromised patients. These patients are often gathered in hospital areas declared at ?high risk? of infection such as Hematology and Bone Marrow Transplant ward. In this study, we evaluated microbial contamination of the air in two divisions with high risk patients, focusing on the validity of the air system with correla- tion to the presence or not of the HEPA absolute filters. Methods. An environmental surveillance study has been carried out in two Divisions of Haematology, in two different Hospitals. Investigations have been performed by sampling air and by analyzing bacterial and fungal growth on microbiology plates after an incubation period. Results. Unit A, without HEPA filters in the ventilation systems, showed a gradual increase in the bacterial load 20 and 60 days after cleaning of the ventilation system. Mycetes and Aspergilli were not present in basal conditions, at 20 or 60 days after decontamination. Unit B, equipped with HEPA filters placed at the inlet vents, showed extremely low values of the bacterial load either in basal conditions or upon inspection 60 days after cleaning. No mycetes were present.
Discussion. From the results obtained, it was evident that fol- lowing the cleaning operation, the quality of the air is excellent in both types of equipment, since no mycetes were present and the bacterial load was inf. 20 CFU/mc in all the sites tested. However, although in subsequent controls mycetes were absent in both types of equipment, a great difference in the suspended bacterial load was found: Unit B was close to sterility whereas in Unit A a progressive increase was observed
Gingival crevicular fluid cytokines in moderate and deep sites of stage III periodontitis patients in different rates of clinical progression
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