1,456 research outputs found
How environmental sustainability labels affect food choices: Assessing consumer preferences in southern Italy
This paper assesses consumer preferences and willingness to pay for three different environmental sustainability
labels (EU Organic Farming, Rainforest Alliance, ‘Per il Clima-Legambiente’) and information cues about the
origin displayed on a processed food product, namely tomato puree. Using a choice experiment and conditional
logit models, the results show that: i) preferences for the environmental sustainability labelled product increase
when consumers have proper knowledge about the meaning of the labels; ii) the information cue about the
product’s domestic origin is important for all consumers, regardless of their education, unlike environmental
sustainability labels that are more appreciated by well-educated consumers; iii) consumers’ willingness to pay is
higher for labels with greater market penetration, regardless of certification by private or public organisations.
Findings suggest that the adoption of environmental sustainability labels by food producers should be combined
with effective information policies aimed at increasing consumer awareness
Note sulla didattica del progetto
RIFLESSIONI SUL PROGETTO ARCHITETTONICO DALLE ESPERIENZE DI ALCUNI DOCENTI DELLA FACOLTÁ DI ARCHITETTURA DI PALERM
Comment on ``Quasiparticle Spectra around a Single Vortex in a d-wave Superconductor''
In a recent Letter Morita, Kohmoto and Maki analyzed the structure of
quasiparticle states near a single vortex in a d-wave superconductor using an
approximate version of the Bogoliubov - de Gennes theory. Their principal
result is the existence of a bound state within the core region at finite
energy with full rotational symmetry, which they assert explains the recent
scanning tunneling microscopy results on YBCO single crystals. Here we argue
that the approximation used in this work is fundamentally inadequate for the
description of a d-wave vortex and that the obtained circular symmetry of the
local density of states is an unphysical artifact of this approximation.Comment: 1 page REVTeX, to appear in PR
Study of nuclear recoils in liquid argon with monoenergetic neutrons
For the development of liquid argon dark matter detectors we assembled a
setup in the laboratory to scatter neutrons on a small liquid argon target. The
neutrons are produced mono-energetically (E_kin=2.45 MeV) by nuclear fusion in
a deuterium plasma and are collimated onto a 3" liquid argon cell operating in
single-phase mode (zero electric field). Organic liquid scintillators are used
to tag scattered neutrons and to provide a time-of-flight measurement. The
setup is designed to study light pulse shapes and scintillation yields from
nuclear and electronic recoils as well as from {\alpha}-particles at working
points relevant to dark matter searches. Liquid argon offers the possibility to
scrutinise scintillation yields in noble liquids with respect to the
populations of the two fundamental excimer states. Here we present experimental
methods and first results from recent data towards such studies.Comment: 9 pages, 8 figures, proceedings of TAUP 2011, to be published in
Journal of Physics: Conference Series (JCPS
Design and Performance of the XENON10 Dark Matter Experiment
XENON10 is the first two-phase xenon time projection chamber (TPC) developed
within the XENON dark matter search program. The TPC, with an active liquid
xenon (LXe) mass of about 14 kg, was installed at the Gran Sasso underground
laboratory (LNGS) in Italy, and operated for more than one year, with excellent
stability and performance. Results from a dark matter search with XENON10 have
been published elsewhere. In this paper, we summarize the design and
performance of the detector and its subsystems, based on calibration data using
sources of gamma-rays and neutrons as well as background and Monte Carlo
simulations data. The results on the detector's energy threshold, energy and
position resolution, and overall efficiency show a performance that exceeds
design specifications, in view of the very low energy threshold achieved (<10
keVr) and the excellent energy resolution achieved by combining the ionization
and scintillation signals, detected simultaneously
Exotic fermion multiplets as a solution to baryon asymmetry, dark matter and neutrino masses
We propose an extension to the standard model where three exotic fermion
5-plets and one scalar 6-plet are added to the particle content. By demanding
that all interactions are renormalizable and standard model gauge invariant, we
show that the lightest exotic particle in this model can be a dark matter
candidate as long as the new 6-plet scalar does not develop a nonzero vacuum
expectation value. Furthermore, light neutrino masses are generated radiatively
at one-loop while the baryon asymmetry is produced by the CP-violating decays
of the second lightest exotic particle. We have demonstrated using concrete
examples that there is a parameter space where a consistent solution to the
problems of baryon asymmetry, dark matter and neutrino masses can be obtained.Comment: 17 pages, 2 figures (REVTeX4.1), v2: some refs added, v3: typos
corrected, Sec.VI.B, C modified, this version to appear in PR
In-water synthesis of isocyanides under micellar conditions
An in-water dehydration of N-formamides to afford isocyanides using micellar conditions at room temperature is reported. This method allows for the preparation of aliphatic isocyanides in an environmental friendly manner. The replacement of undesirable components such as phosphorous oxychloride, triethyl amine and dichloromethane (the classical combination used for the dehydration of N-formamides), by p-toluen sulphonyl chloride, sodium hydrogen carbonate and water makes this transformation really sustainable and safe
Sequence Specificity in the Entropy-Driven Binding of a Small Molecule and a Disordered Peptide
Approximately one-third of the human proteome is made up of proteins that are entirely disordered or that contain extended disordered regions. Although these disordered proteins are closely linked with many major diseases, their binding mechanisms with small molecules remain poorly understood, and a major concern is whether their specificity can be sufficient for drug development. Here, by studying the interaction of a small molecule and a disordered peptide from the oncogene protein c-Myc, we describe a "specific-diffuse" binding mechanism that exhibits sequence specificity despite being of entropic nature. By combining NMR spectroscopy, biophysical measurements, statistical inference, and molecular simulations, we provide a quantitative measure of such sequence specificity and compare it to the case of the interaction of urea, which is diffuse but not specific. To investigate whether this type of binding can generally modify intermolecular interactions, we show that it leads to an inhibition of the aggregation of the peptide. These results suggest that the binding mechanism that we report may create novel opportunities to discover drugs that target disordered proteins in their monomeric states in a specific manner.G.T.H. is supported by the Churchill Scholarship and the Gates Cambridge Trust Scholarship
Theory of vortex excitation imaging via an NMR relaxation measurement
The temperature dependence of the site-dependent nuclear spin relaxation time
T_1 around vortices is studied in s-wave and d-wave superconductors.Reflecting
low energy electronic excitations associated with the vortex core, temperature
dependences deviate from those of the zero-field case, and T_1 becomes faster
with approaching the vortex core. In the core region, T_1^{-1} has a new peak
below T_c. The NMR study by the resonance field dependence may be a new method
to prove the spatial resolved vortex core structure in various superconductors.Comment: 5 pages, 3 figure
Imaging the essential role of spin-fluctuations in high-Tc superconductivity
We have used scanning tunneling spectroscopy to investigate short-length
electronic correlations in three-layer Bi2Sr2Ca2Cu3O(10+d) (Bi-2223). We show
that the superconducting gap and the energy Omega_dip, defined as the
difference between the dip minimum and the gap, are both modulated in space
following the lattice superstructure, and are locally anti-correlated. Based on
fits of our data to a microscopic strong-coupling model we show that Omega_dip
is an accurate measure of the collective mode energy in Bi-2223. We conclude
that the collective mode responsible for the dip is a local excitation with a
doping dependent energy, and is most likely the (pi,pi) spin resonance.Comment: 4 pages, 4 figure
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