266 research outputs found
RAPD and SCAR markers as potential tools for detection of milk origin in dairy products: adulterant sheep breeds in Serra da Estrela cheese production
Available online 17 May 2016Serra da Estrela Protected Designation of Origin (PDO) cheese is the most famous Portuguese cheese and has a high commercial value. However, the adulteration of production with cheaper/lower-quality milks from non-autochthones ovine breeds compromises the quality of the final product and undervalues the original PDO cheese. A Randomly Amplified Polymorphic DNA (RAPD) method was developed for efficient detection of adulterant breeds in milk mixtures used for fraudulent production of this cheese. Furthermore, Sequence Characterized Amplified Region (SCAR) markers were designed envisioning the detection of milk adulteration in processed dairy foods. The RAPD-SCAR technique is here described, for the first time, to be potentially useful for detection of milk origin in dairy products. In this sense, our findings will play an important role on the valorization of Serra da Estrela cheese, as well as on other high-quality dairy products prone to adulteration, contributing to the further development of the dairy industry.This work was financially supported by
the project ‘‘Valor Queijo” (CENTRO-07-0202-FEDER-030372)
funded by FCT/MCTES (PIDDAC) and co-funded by ‘‘Fundo Europeu
de Desenvolvimento Regional” (FEDER) through ‘‘COMPETE – Programa
Operacional Factores de Competitividade” (POFC). This
study was supported by the Portuguese Foundation for Science
and Technology (FCT) under the scope of the Strategic Project of
UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-
FEDER-006684) and the project RECI/BBB-EBI/0179/2012
(FCOMP-01-0124-FEDER-027462)
The three-dimensional randomly dilute Ising model: Monte Carlo results
We perform a high-statistics simulation of the three-dimensional randomly
dilute Ising model on cubic lattices with . We choose a
particular value of the density, x=0.8, for which the leading scaling
corrections are suppressed. We determine the critical exponents, obtaining , , , and ,
in agreement with previous numerical simulations. We also estimate numerically
the fixed-point values of the four-point zero-momentum couplings that are used
in field-theoretical fixed-dimension studies. Although these results somewhat
differ from those obtained using perturbative field theory, the
field-theoretical estimates of the critical exponents do not change
significantly if the Monte Carlo result for the fixed point is used. Finally,
we determine the six-point zero-momentum couplings, relevant for the
small-magnetization expansion of the equation of state, and the invariant
amplitude ratio that expresses the universality of the free-energy
density per correlation volume. We find .Comment: 34 pages, 7 figs, few correction
Pressure-driven instabilities in astrophysical jets
Astrophysical jets are widely believed to be self-collimated by the
hoop-stress due to the azimuthal component of their magnetic field. However
this implies that the magnetic field is largely dominated by its azimuthal
component in the outer jet region. In the fusion context, it is well-known that
such configurations are highly unstable in static columns, leading to plasma
disruption. It has long been pointed out that a similar outcome may follow for
MHD jets, and the reasons preventing disruption are still not elucidated,
although some progress has been accomplished in the recent years.
In these notes, I review the present status of this open problem for
pressure-driven instabilities, one of the two major sources of ideal MHD
instability in static columns (the other one being current-driven
instabilities).
I first discuss in a heuristic way the origin of these instabilities.
Magnetic resonances and magnetic shear are introduced, and their role in
pressure-driven instabilities discussed in relation to Suydam's criterion. A
dispersion relation is derived for pressure-driven modes in the limit of large
azimuthal magnetic fields, which gives back the two criteria derived by
Kadomtsev for this instability. The growth rates of these instabilities are
expected to be short in comparison with the jet propagation time.
What is known about the potential stabilizing role of the axial velocity of
jets is then reviewed. In particular, a nonlinear stabilization mechanism
recently identified in the fusion literature is discussed.
Key words: Ideal MHD: stability, pressure-driven modes; Jets: stabilityComment: 20 pages, 3 figures. Lecture given at the JETSET European school
"Numerical MHD and Instabilities". To be published by Springer in the
"Lectures notes in physics" serie
SiPMs coated with TPB : coating protocol and characterization for NEXT
Silicon photomultipliers (SiPM) are the photon detectors chosen for the
tracking readout in NEXT, a neutrinoless {\beta}{\beta} decay experiment which
uses a high pressure gaseous xenon time projection chamber (TPC). The
reconstruction of event track and topology in this gaseous detector is a key
handle for background rejection. Among the commercially available sensors that
can be used for tracking, SiPMs offer important advantages, mainly high gain,
ruggedness, cost-effectiveness and radio-purity. Their main drawback, however,
is their non sensitivity in the emission spectrum of the xenon scintillation
(peak at 175 nm). This is overcome by coating these sensors with the organic
wavelength shifter tetraphenyl butadienne (TPB). In this paper we describe the
protocol developed for coating the SiPMs with TPB and the measurements
performed for characterizing the coatings as well as the performance of the
coated sensors in the UV-VUV range.Comment: Submitted to the Journal of Instrumentation on december 26th 201
- …