31 research outputs found
Biogenic Amines in Wine: Understanding the Headache
The presence of biogenic amines in wine is becoming increasingly important to consumers and producers alike,due to the potential threats of toxicity to humans and consequent trade implications. In the scientific field, biogenicamines have the potential to be applied as indicators of food spoilage and/or authenticity. Biogenic amines can beformed from their respective amino acid precursors by various microorganisms present in the wine, at any stageof production, ageing or storage. To understand the large number of factors that could influence the formation ofbiogenic amines, the chemical, biochemical, enzymatic and genetic properties relating to these compounds have tobe considered. Analytical and molecular methods to detect biogenic amines in wine, as well as possibilities that couldenable better control over their production levels in wine will also be explored in this review
Environmental Stress and Aroma Production During Wine Fermentation
The sensory description of wine uses the widest range of descriptive terminology of all food products, reflecting the complex nature of a product whose character depends on the balance of hundreds of individual flavour-active compounds. There are many tools that can influence flavour profiles or wine styles, one of which is the choice of a specific yeast strain. Yeasts contribute to wine flavour by producing volatile metabolites with different flavour profiles. The impact of changing environmental conditions on the production of flavour compounds by yeast strains remains largely unexplored. This is the first study investigating the impact of two mild fermentation stresses, hyperosmotic and temperature stress, on aroma production in synthetic must by commercial Saccharomyces cerevisiae wine strains. Hyperosmotic stress was imposed by cultivation of the yeast for 21 days in the must containing either 0.3 or 0.5 M sorbitol. The transient temperature stresses were applied for 16 h at 8° or 37°C for either two or eight days after commencement of the fermentation. Greater glycerol and acetic acid levels were produced by most yeasts when only hyperosmotic stress was applied. Hyperosmotic and temperature stress conditions produced a limited number of significant changes to the profile of the esters, higher alcohols and volatile fatty acids. These changes differed significantly for each strain and stress treatment, suggesting that the fermentation conditions can significantly alter the aromatic profile of a wine, although these stress impacts cannot be predicted in general. The changes to the aromatic profile are specific to each individual wine yeast strain
Lattice QCD Simulations in External Background Fields
We discuss recent results and future prospects regarding the investigation,
by lattice simulations, of the non-perturbative properties of QCD and of its
phase diagram in presence of magnetic or chromomagnetic background fields.
After a brief introduction to the formulation of lattice QCD in presence of
external fields, we focus on studies regarding the effects of external fields
on chiral symmetry breaking, on its restoration at finite temperature and on
deconfinement. We conclude with a few comments regarding the effects of
electromagnetic background fields on gluodynamics.Comment: 31 pages, 10 figures, minor changes and references added. To appear
in Lect. Notes Phys. "Strongly interacting matter in magnetic fields"
(Springer), edited by D. Kharzeev, K. Landsteiner, A. Schmitt, H.-U. Ye
Green function techniques in the treatment of quantum transport at the molecular scale
The theoretical investigation of charge (and spin) transport at nanometer
length scales requires the use of advanced and powerful techniques able to deal
with the dynamical properties of the relevant physical systems, to explicitly
include out-of-equilibrium situations typical for electrical/heat transport as
well as to take into account interaction effects in a systematic way.
Equilibrium Green function techniques and their extension to non-equilibrium
situations via the Keldysh formalism build one of the pillars of current
state-of-the-art approaches to quantum transport which have been implemented in
both model Hamiltonian formulations and first-principle methodologies. We offer
a tutorial overview of the applications of Green functions to deal with some
fundamental aspects of charge transport at the nanoscale, mainly focusing on
applications to model Hamiltonian formulations.Comment: Tutorial review, LaTeX, 129 pages, 41 figures, 300 references,
submitted to Springer series "Lecture Notes in Physics
Synaptic processes and immune-related pathways implicated in Tourette syndrome.
Tourette syndrome (TS) is a neuropsychiatric disorder of complex genetic architecture involving multiple interacting genes. Here, we sought to elucidate the pathways that underlie the neurobiology of the disorder through genome-wide analysis. We analyzed genome-wide genotypic data of 3581 individuals with TS and 7682 ancestry-matched controls and investigated associations of TS with sets of genes that are expressed in particular cell types and operate in specific neuronal and glial functions. We employed a self-contained, set-based association method (SBA) as well as a competitive gene set method (MAGMA) using individual-level genotype data to perform a comprehensive investigation of the biological background of TS. Our SBA analysis identified three significant gene sets after Bonferroni correction, implicating ligand-gated ion channel signaling, lymphocytic, and cell adhesion and transsynaptic signaling processes. MAGMA analysis further supported the involvement of the cell adhesion and trans-synaptic signaling gene set. The lymphocytic gene set was driven by variants in FLT3, raising an intriguing hypothesis for the involvement of a neuroinflammatory element in TS pathogenesis. The indications of involvement of ligand-gated ion channel signaling reinforce the role of GABA in TS, while the association of cell adhesion and trans-synaptic signaling gene set provides additional support for the role of adhesion molecules in neuropsychiatric disorders. This study reinforces previous findings but also provides new insights into the neurobiology of TS
Measurement of event-shape observables in Z→ℓ+ℓ− events in pp collisions at √ s=7 TeV with the ATLAS detector at the LHC
Event-shape observables measured using charged particles in inclusive
-boson events are presented, using the electron and muon decay modes of the
bosons. The measurements are based on an integrated luminosity of of proton--proton collisions recorded by the ATLAS detector at the
LHC at a centre-of-mass energy TeV. Charged-particle
distributions, excluding the lepton--antilepton pair from the -boson decay,
are measured in different ranges of transverse momentum of the boson.
Distributions include multiplicity, scalar sum of transverse momenta, beam
thrust, transverse thrust, spherocity, and -parameter, which are
in particular sensitive to properties of the underlying event at small values
of the -boson transverse momentum. The Sherpa event generator shows larger
deviations from the measured observables than Pythia8 and Herwig7. Typically,
all three Monte Carlo generators provide predictions that are in better
agreement with the data at high -boson transverse momenta than at low
-boson transverse momenta and for the observables that are less sensitive to
the number of charged particles in the event.Comment: 36 pages plus author list + cover page (54 pages total), 14 figures,
4 tables, submitted to EPJC, All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2014-0
Evaluating the Influence of Malolactic Fermentation Inoculation Practices and Ageing on Lees on Biogenic Amine Production in Wine
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Regionale differentiatie in het nieuwe GLB : Een aanvullende analyse op de houtskool-SWOT
For the period 2021-2027, the EU member states have the obligation to point out in a National Strategic Plan (NSP) how their policy efforts will contribute to the goals for the Common Agricultural Policy as formulated by the European Commission. The Dutch ministry of Agriculture has decided to have a SWOT-analysis on the main issues developed in order to prepare the NSP. In the first phase, a SWOT-analysis on the main issues (‘Draft SWOT’) has been performed. In the second phase, the final SWOT-analysis will be performed. This report contains an additional analysis on the ‘Draft SWOT’, with a focus on the question whether, to which extent and how the NSP needs to take regional differences into account
Variation in content of tyramine, histamine, 2‐phenylethylamine, tryptamine and their precursor amino acids in a Chardonnay wine by using different commercial active dry yeasts and nitrogen sources
Influence of ICP etching on surface morphology of InP substrates
We have investigated the effect of Inductively Coupled Plasma (ICP) etching using a C12-CHrH2 chemistry on the surface morphology of InP substrates. We have observed a strong dependence of the surface morphology on the etching times of semi-insulating ( s i ) InP-wafers. Pillars are formed after a sufficient etching time. Photoluminescence characterization revealed a strong correlation between morphology and PL signal intensity