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Improving survival of probiotic bacteria using bacterial poly-γ-glutamic acid
A major hurdle in producing a useful probiotic food product is bacterial survival during storage and ingestion. The aim of this study was to test the effect of γ-PGA immobilisation on the survival of probiotic bacteria when stored in acidic fruit juice. Fruit juices provide an alternative means of probiotic delivery, especially to lactose intolerant individuals. In addition, the survival of γ-PGA-immobilised cells in simulated gastric juice was also assessed. Bifidobacteria strains (B. longum, B. breve), immobilised on 2.5 % γ-PGA, survived significantly better (P < 0.05) in orange and pomegranate juice for 39 and 11 days respectively, compared to free cells. However, cells survived significantly better (P < 0.05) when stored in orange juice compared to pomegranate juice. Moreover, both strains, when protected with 2.5 % γ-PGA, survived in simulated gastric juice (pH 2.0) with a marginal reduction (<0.47 log CFU/ml) or no significant reduction in viable cells after four hours, whereas free cells died within two hours. In conclusion, this research indicates that γ-PGA can be used to protect Bifidobacteria cells in fruit juice, and could also help improve the survival of cells as they pass through the harsh conditions of the gastrointestinal tract (GIT). Following our previous report on the use of γ-PGA as a cryoprotectant for probiotic bacteria, this research further suggests that γ-PGA could be used to improve probiotic survival during the various stages of preparation, storage and ingestion of probiotic cells
Report on the off-flavoured oil sardine, Sardinella longiceps, caught off Mangalore coast in may, 1991
The oil sardine, Sardinella longiceps is one of the principal species caught by the purse
seiners operating from Mangalore. On 3- 5- '91, 4 purse seine boats which operated off Panambur, Hejmadi and Kaup (located north of Mangalore) at a depth of 10-15 m landed an estimated 20 tonnes of oil sardine
Phase transitions and rare-earth magnetism in hexagonal and orthorhombic DyMnO single crystals
The floating-zone method with different growth ambiances has been used to
selectively obtain hexagonal or orthorhombic DyMnO single crystals. The
crystals were characterized by X-ray powder diffraction of ground specimen and
a structure refinement as well as electron diffraction. We report magnetic
susceptibility, magnetisation, and specific heat studies of this multiferroic
compound in both the hexagonal and the orthorhombic structure. The hexagonal
DyMnO shows magnetic ordering of Mn (S =2) spins on a triangular
Mn lattice at = 57 K characterized by a cusp in the
specific heat. This transition is not apparent in the magnetic susceptibility
due to the frustration on the Mn triangular lattice and the dominating
paramagnetic susceptibility of the Dy (S=9/2) spins. At = 3 K, a partial antiferromagnetic order of Dy moments has been
observed. In comparison, the magnetic data for orthorhombic DyMnO display
three transitions. The data broadly agree with results from earlier neutron
diffraction experiments, which allows for the following assignment: a
transition from an incommensurate antiferromagnetic ordering of Mn spins
at = 39 K, a {\textit{lock--in}} transition at = 16 K and a second antiferromagnetic transition at = 5 K due to the ordering of Dy moments. Both the hexagonal and the
orthorhombic crystals show magnetic anisotropy and complex magnetic properties
due to 4 and 4 couplings.Comment: 15 figure
Loss of Landau Damping in the LHC
Loss of Landau damping leading to a single bunch longitudinal instability has been observed in the LHC during the ramp and on the 3.5 TeV flat top for small injected longitudinal emittances. The first measurements are in reasonable agreement with the threshold calculated for the expected longitudinal reactive impedance budget of the LHC as well as with the threshold dependence on beam energy. The cure is a controlled longitudinal emittance blow-up during the ramp which for a constant threshold through the cycle should provide an emittance proportional to the square root of energy
Search for associated Higgs boson production using like charge dilepton events in p(p)over-bar collisions at root s=1.96 TeV
We present a search for associated Higgs boson production in the process p (p) over bar -> W/ZH -> l(+/-)l'(+/-) + X in ee, e mu, and mu mu final states. The search is based on data collected by the D0 experiment at the Fermilab Tevatron Collider at root s = 1.96 TeV corresponding to 5.3 fb(-1) of integrated luminosity. We require two isolated leptons (electrons or muons) with the same electric charge and additional kinematic requirements. No significant excess above background is observed, and we set 95% C. L. observed (expected) upper limits on ratio of the production cross section to the standard model prediction of 6.4 (7.3) for a Higgs boson mass of 165 GeV and 13.5 (19.8) for a mass of 115 GeV
Low Temperature Transport and Specific Heat Studies of Nd_{1-x}Pb_{x}MnO_{3} Single Crystals
Electrical transport and specific heat properties of Nd_{1-x}Pb_{x}MnO_{3}
single crystals for 0.15 < x 0.5 have been studied in low temperature regime.
The resistivity in the ferromagnetic insulating (FMI) phase for x < 0.3 has an
activated character. The dependence of the activation gap Delta on doping x has
been determined and the critical concentration for the zero-temperature
metal-insulator transition was determined as x_{c} ~ 0.33. For a metallic
sample with x=0.42, a conventional electron-electron (e-e) scattering term
proportional T^{2} is found in the low-temperature electrical resistivity,
although the Kadowaki-Woods ratio is found to be much larger for this manganite
than for a normal metal. For a metallic sample with x=0.5, a resistivity
minimum is observed for x= 0.5. The effect is attributed to weak localization
and can be described by a negative T^{1/2} weak-localization contribution to
resistivity for a disordered three-dimensional electron system. The specific
heat data have been fitted to contributions from free electrons (gamma), spin
excitations (beta_{3/2}), lattice and a Schottky-like anomaly related to the
rare-earth magnetism of the Nd ions. The value of gamma is larger than for
normal metals, which is ascribed to magnetic ordering effects involving Nd.
Also, the Schottky-like anomaly appears broadened and weakened suggesting
inhomogeneous molecular fields at the Nd-sites.Comment: 14 pages, 8 figure
Study of Zγ events and limits on anomalous ZZγ and Zγγ couplings in pp̄ collisions at s=1.96TeV
We present a measurement of the Zγ production cross section and limits on anomalous ZZγ and Zγγ couplings for form-factor scales of Λ=750 and 1000 GeV. The measurement is based on 138 (152) candidates in the eeγ (μμγ) final state using 320(290)pb-1 of pp̄ collisions at s=1.96TeV. The 95% C.L. limits on real and imaginary parts of individual anomalous couplings are |h10,30Z|<0.23, |h20,40Z|<0.020, |h10,30γ|<0.23, and |h20,40γ|<0.019 for Λ=1000GeV. © 2005 The American Physical Society
Multiwavelength Intraday Variability of the BL Lac S5 0716+714
We report results from a 1 week multi-wavelength campaign to monitor the BL
Lac object S5 0716+714 (on December 9-16, 2009). In the radio bands the source
shows rapid (~ (0.5-1.5) day) intra-day variability with peak amplitudes of up
to ~ 10 %. The variability at 2.8 cm leads by about 1 day the variability at 6
cm and 11 cm. This time lag and more rapid variations suggests an intrinsic
contribution to the source's intraday variability at 2.8 cm, while at 6 cm and
11 cm interstellar scintillation (ISS) seems to predominate. Large and
quasi-sinusoidal variations of ~ 0.8 mag were detected in the V, R and I-bands.
The X-ray data (0.2-10 keV) do not reveal significant variability on a 4 day
time scale, favoring reprocessed inverse-Compton over synchrotron radiation in
this band. The characteristic variability time scales in radio and optical
bands are similar. A quasi-periodic variation (QPO) of 0.9 - 1.1 days in the
optical data may be present, but if so it is marginal and limited to 2.2
cycles. Cross-correlations between radio and optical are discussed. The lack of
a strong radio-optical correlation indicates different physical causes of
variability (ISS at long radio wavelengths, source intrinsic origin in the
optical), and is consistent with a high jet opacity and a compact synchrotron
component peaking at ~= 100 GHz in an ongoing very prominent flux density
outburst. For the campaign period, we construct a quasi-simultaneous spectral
energy distribution (SED), including gamma-ray data from the FERMI satellite.
We obtain lower limits for the relativistic Doppler-boosting of delta >= 12-26,
which for a BL\,Lac type object, is remarkably high.Comment: 16 pages, 15 figures, table 2; Accepted for Publication in MNRA
Ligand-Receptor Interactions
The formation and dissociation of specific noncovalent interactions between a
variety of macromolecules play a crucial role in the function of biological
systems. During the last few years, three main lines of research led to a
dramatic improvement of our understanding of these important phenomena. First,
combination of genetic engineering and X ray cristallography made available a
simultaneous knowledg of the precise structure and affinity of series or
related ligand-receptor systems differing by a few well-defined atoms. Second,
improvement of computer power and simulation techniques allowed extended
exploration of the interaction of realistic macromolecules. Third, simultaneous
development of a variety of techniques based on atomic force microscopy,
hydrodynamic flow, biomembrane probes, optical tweezers, magnetic fields or
flexible transducers yielded direct experimental information of the behavior of
single ligand receptor bonds. At the same time, investigation of well defined
cellular models raised the interest of biologists to the kinetic and mechanical
properties of cell membrane receptors. The aim of this review is to give a
description of these advances that benefitted from a largely multidisciplinar
approach
Bioactive Compounds of Rambutan (Nephelium lappaceum L.)
Rambutan, a widely popular tropical fruit encompasses rich amount of bioactive compounds.
All parts of this plant (leaves, bark, root, fruits, fruit skin, pulp and seeds) finds traditional
usage, and are linked with high therapeutic values. Rambutan fruits parts like that of peel, pulp
and seeds have been scientifically investigated in-depth and is reported to encompass high
amounts of bioactive compounds (such as polyphenol, flavonoid, alkaloid, essential mineral,
dietary fiber). These compounds contribute towards antioxidant, antimicrobial, anticancer,
antidiabetic and anti-obesity activities. However, literature pertaining towards potential
industrial applications (food, cosmetics, pharmaceutical) of rambutan fruits are limited. In the
present chapter, it is intended to document some of the interesting research themes published
on rambutan fruits, and identify the existing gaps to open up arena for future research work.This chapter theme is based on our ongoing project—VALORTECH,
which has received funding from the European Union’s Horizon 2020 research and innovation
program under grant agreement No 810630
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