764 research outputs found
High Pressure Processing of Dairy Foods
End of Project ReportThe term High Pressure Processing (HPP) is used to describe the technology whereby
products are exposed to very high pressures in the region of 50 - 800 MPa (500 - 8000
Atmospheres). The potential application of HPP in the food industry has gained popularity
in recent years, due to developments in the construction of HPP equipment which makes
the technology more affordable. Applying HPP to food products results in modifications to
interactions between individual components, rates of enzymatic reactions and inactivation
of micro-organisms.
The first commercial HPP products appeared on the market in 1991 in Japan, where HPP
is now being used commercially for products such as jams, sauces, fruit juices, rice cakes
and desserts. The pioneering research into the application of HPP to milk dates back to the
end of the 19th century. Application of HPP to milk has been shown to modify its gel
forming characteristics as well as reducing its microbial load. HPP offers the potential to
induce similar effects to those generated by heat on milk protein.
Recent reports have also indicated that HPP could accelerate the ripening of cheese. Much
of the Irish cheese industry is based on the production of Cheddar cheese, the ripening time
for which can vary from 4 - 12 months or more, depending on grade. A substantial portion
of the cost associated with Cheddar manufacture is therefore attributed to storage under
controlled conditions during ripening. Thus, any technology which may accelerate the
ripening of Cheddar cheese while maintaining a balanced flavour and texture is of major
economic significance.
While food safety is a dominant concern, consumers are increasingly demanding foods that
maintain their natural appearance and flavour, while free of chemical preservatives. HPP
offers the food industry the possibility of achieving these twin goals as this technology can
lead to reduced microbial loads without detrimentally effecting the nutritional or sensory
qualities of the product.
The development of food ingredients with novel functional properties offers the dairy
industry an opportunity to revitalise existing markets and develop new ones. HPP can lead
to modifications in the structure of milk components, in particular protein, which may
provide interesting possibilities for the development of high value nutritional and functional
ingredients.
Hence these projects set out to investigate the potential of HPP in the dairy industry and
to identify products and processes to which it could be applied.Department of Agriculture, Food and the Marin
Lepton flavor violation decays in the topcolor-assisted technicolor model and the littlest Higgs model with parity
The new particles predicted by the topcolor-assisted technicolor ()
model and the littlest Higgs model with T-parity (called model) can
induce the lepton flavor violation () couplings at tree level or one loop
level, which might generate large contributions to some processes. Taking
into account the constraints of the experimental data on the relevant free
parameters, we calculate the branching ratios of the decay processes
with = , and
in the context of these two kinds of new physics models. We find
that the model and the model can indeed produce significant
contributions to some of these decay processes.Comment: 24 pages, 7 figure
The Effects of a New Vector Boson on the Top Quark Cross Section at the Tevatron
It has recently been shown that a new neutral vector boson , with a mass
of order 1~TeV and weak couplings to quarks only, could explain both the
anomalous values of and and the apparent excess of large jet
events measured by the CDF collaboration. We calculate the effects of
exchange on the production cross section at Tevatron
collider energies, including next-to-leading-order QCD corrections. We find a
significant enhancement of the cross section and study the resulting
invariant mass distribution, which could provide a decisive test of the
model.Comment: 7 pages, LATEX, 4 figures include
Functional diversity of chemokines and chemokine receptors in response to viral infection of the central nervous system.
Encounters with neurotropic viruses result in varied outcomes ranging from encephalitis, paralytic poliomyelitis or other serious consequences to relatively benign infection. One of the principal factors that control the outcome of infection is the localized tissue response and subsequent immune response directed against the invading toxic agent. It is the role of the immune system to contain and control the spread of virus infection in the central nervous system (CNS), and paradoxically, this response may also be pathologic. Chemokines are potent proinflammatory molecules whose expression within virally infected tissues is often associated with protection and/or pathology which correlates with migration and accumulation of immune cells. Indeed, studies with a neurotropic murine coronavirus, mouse hepatitis virus (MHV), have provided important insight into the functional roles of chemokines and chemokine receptors in participating in various aspects of host defense as well as disease development within the CNS. This chapter will highlight recent discoveries that have provided insight into the diverse biologic roles of chemokines and their receptors in coordinating immune responses following viral infection of the CNS
Rare Charm Decays in the Standard Model and Beyond
We perform a comprehensive study of a number of rare charm decays,
incorporating the first evaluation of the QCD corrections to the short distance
contributions, as well as examining the long range effects. For processes
mediated by the transitions, we show that sensitivity to
short distance physics exists in kinematic regions away from the vector meson
resonances that dominate the total rate. In particular, we find that
and are sensitive to non-universal
soft-breaking effects in the Minimal Supersymmetric Standard Model with
R-parity conservation. We separately study the sensitivity of these modes to
R-parity violating effects and derive new bounds on R-parity violating
couplings. We also obtain predictions for these decays within extensions of the
Standard Model, including extensions of the Higgs, gauge and fermion sectors,
as well as models of dynamical electroweak symmetry breaking.Comment: 45 pages, typos fixed, discussions adde
Simulations of Supercollider Physics
The Standard Model of particle physics makes it possible to simulate complete
events for physics signatures and their backgrounds in high energy collisions.
Knowledge of how the produced particles interact with the materials in a
detector makes it possible to simulate the response of any particular detector
design to these events and so determine whether the detector could observe the
signal. The combination of these techniques has played an important role in the
design of new detectors, particularly those for hadron supercolliders where the
high rates and small signal cross sections make the experiments very difficult.
The technique is reviewed here and illustrated using the simulations of the GEM
detector proposed for the Superconducting Super Collider. Although the
simulations and results described here are somewhat detector-specific, we
believe that they can serve as a useful model for this component of detector
design for future hadron supercolliders.Comment: 99 pages, Plain TeX (macros included), includes gzipped tar file with
56/60 EPS figures for dvips. Get complete version from
http://penguin.phy.bnl.gov/www/hetpapers.html or
ftp://penguin.phy.bnl.gov/pub/papers/gemreview.ps.
Search for composite and exotic fermions at LEP 2
A search for unstable heavy fermions with the DELPHI detector at LEP is
reported. Sequential and non-canonical leptons, as well as excited leptons and
quarks, are considered. The data analysed correspond to an integrated
luminosity of about 48 pb^{-1} at an e^+e^- centre-of-mass energy of 183 GeV
and about 20 pb^{-1} equally shared between the centre-of-mass energies of 172
GeV and 161 GeV. The search for pair-produced new leptons establishes 95%
confidence level mass limits in the region between 70 GeV/c^2 and 90 GeV/c^2,
depending on the channel. The search for singly produced excited leptons and
quarks establishes upper limits on the ratio of the coupling of the excited
fermio
Search for charginos in e+e- interactions at sqrt(s) = 189 GeV
An update of the searches for charginos and gravitinos is presented, based on
a data sample corresponding to the 158 pb^{-1} recorded by the DELPHI detector
in 1998, at a centre-of-mass energy of 189 GeV. No evidence for a signal was
found. The lower mass limits are 4-5 GeV/c^2 higher than those obtained at a
centre-of-mass energy of 183 GeV. The (\mu,M_2) MSSM domain excluded by
combining the chargino searches with neutralino searches at the Z resonance
implies a limit on the mass of the lightest neutralino which, for a heavy
sneutrino, is constrained to be above 31.0 GeV/c^2 for tan(beta) \geq 1.Comment: 22 pages, 8 figure
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