2,053 research outputs found
Long time behaviour and self-similarity in an addition model with slow Input of monomers
We consider a coagulation equation with constant coefficients and a time dependent
power law input of monomers. We discuss the asymptotic behaviour of solutions as , and we prove solutions converge to a similarity profile along the non-characteristic
direction
The Impact of the Malolactic Fermentation in the Volatile Composition of Trincadeira Wine Variety
Use of commercial starters for malolactic fermentation (MLF) is a
common practice, and outcomes of this procedure are very relevant for wine
producers because aroma attributes might change according to the strain
used.
MLF was carried out in the Trincadeira wine variety in three batches:
spontaneously and with inoculation of two different commercial starters. Wine
extracts before and after MLF were obtained through liquid–liquid extraction.
Gas chromatography/ion trap mass spectrometry analysis allowed the detection
of 21 compounds, some of them tentatively identified through electron
impact spectra comparison with a database, through interpretation of multistage
mass spectrometry and chemical ionization mass spectrometry spectra
and confirmation by comprehensive multidimensional gas chromatography/
time of flight-mass spectrometry (GC ¥ GC/ToF-MS).
After MLF, an increase in ethyl lactate, g-butyrolactone and diethyl
succinate and a drop in isoamyl acetate, ethyl octanoate, ethyl decanoate,
2,3-dimethyl-hexan-3-ol, propanol, isobutanol and 2,3-butanediol was
observed. The concentrations of the 10 compounds are statistically different in
wines before and after MLF, and wines after MLF show significant differences
for the nine compounds
Low-frequency connectivity is associated with mild traumatic brain injury
AbstractMild traumatic brain injury (mTBI) occurs from a closed-head impact. Often referred to as concussion, about 20% of cases complain of secondary psychological sequelae, such as disorders of attention and memory. Known as post-concussive symptoms (PCS), these problems can severely disrupt the patient's quality of life. Changes in local spectral power, particularly low-frequency amplitude increases and/or peak alpha slowing have been reported in mTBI, but large-scale connectivity metrics based on inter-regional amplitude correlations relevant for integration and segregation in functional brain networks, and their association with disorders in cognition and behaviour, remain relatively unexplored. Here, we used non-invasive neuroimaging with magnetoencephalography to examine functional connectivity in a resting-state protocol in a group with mTBI (n = 20), and a control group (n = 21). We observed a trend for atypical slow-wave power changes in subcortical, temporal and parietal regions in mTBI, as well as significant long-range increases in amplitude envelope correlations among deep-source, temporal, and frontal regions in the delta, theta, and alpha bands. Subsequently, we conducted an exploratory analysis of patterns of connectivity most associated with variability in secondary symptoms of mTBI, including inattention, anxiety, and depression. Differential patterns of altered resting state neurophysiological network connectivity were found across frequency bands. This indicated that multiple network and frequency specific alterations in large scale brain connectivity may contribute to overlapping cognitive sequelae in mTBI. In conclusion, we show that local spectral power content can be supplemented with measures of correlations in amplitude to define general networks that are atypical in mTBI, and suggest that certain cognitive difficulties are mediated by disturbances in a variety of alterations in network interactions which are differentially expressed across canonical neurophysiological frequency ranges
Integral elastic, electronic-state, ionization, and total cross sections for electron scattering with furfural
8 págs.; 2 figs.; 2 tabs.We report absolute experimental integral cross sections (ICSs) for electron impact excitation of bands of electronic-states in furfural, for incident electron energies in the range 20-250 eV. Wherever possible, those results are compared to corresponding excitation cross sections in the structurally similar species furan, as previously reported by da Costa et al. [Phys. Rev. A 85, 062706 (2012)] and Regeta and Allan [Phys. Rev. A 91, 012707 (2015)]. Generally, very good agreement is found. In addition, ICSs calculated with our independent atom model (IAM) with screening corrected additivity rule (SCAR) formalism, extended to account for interference (I) terms that arise due to the multi-centre nature of the scattering problem, are also reported. The sum of those ICSs gives the IAM-SCAR+I total cross section for electron-furfural scattering. Where possible, those calculated IAM-SCAR+I ICS results are compared against corresponding results from the present measurements with an acceptable level of accord being obtained. Similarly, but only for the band I and band II excited electronic states, we also present results from our Schwinger multichannel method with pseudopotentials calculations. Those results are found to be in good qualitative accord with the present experimental ICSs. Finally, with a view to assembling a complete cross section data base for furfural, some binary-encounter-Bethe-level total ionization cross sections for this collision system are presented.D.B.J. thanks the Australian Research Council (ARC) for
financial support provided through a Discovery Early Career
Research Award, while M.J.B. also thanks the ARC for their
support. M.J.B. acknowledges the Brazilian agency CNPq
for his “Special Visiting Professor” position at the Federal
University of Juiz de Fora. G.G. acknowledges partial financial
support from the Spanish Ministry MINECO (Project No.
FIS2012-31230) and the European Union COST Action No.
CM1301 (CELINA). Finally R.F.C., M.T.doN.V, M.H.F.B,
and M.A.P.L. also acknowledge support from CNPq, while
M.T.doN.V. thanks FAPESPPeer Reviewe
Possibilidades da "previsão" da argila (<0.002mm) pelo método do areómetro
info:eu-repo/semantics/publishedVersio
Schistosome and liver fluke derived catechol-estrogens and helminth associated cancers
Infection with helminth parasites remains a persistent public health problem in developing countries. Three of these pathogens, the liver flukes Clonorchis sinensis, Opisthorchis viverrini and the blood fluke Schistosoma haematobium, are of particular concern due to their classification as Group 1 carcinogens: infection with these worms is carcinogenic. Using liquid chromatography-mass spectrometry (LC-MS/MS) approaches, we identified steroid hormone like (e.g., oxysterol-like, catechol estrogen quinone-like, etc.) metabolites and related DNA-adducts, apparently of parasite origin, in developmental stages including eggs of S. haematobium, in urine of people with urogenital schistosomiasis, and in the adult stage of O. viverrini. Since these kinds of sterol derivatives are metabolized to active quinones that can modify DNA, which in other contexts can lead to breast and other cancers, helminth parasite associated sterols might induce tumor-like phenotypes in the target cells susceptible to helminth parasite associated cancers, i.e., urothelial cells of the bladder in the case of urogenital schistosomiasis and the bile duct epithelia or cholangiocytes, in the case of O. viverrini and C. sinensis. Indeed we postulate that helminth induced cancers originate from parasite estrogen-host epithelial/urothelial cell chromosomal DNA adducts, and here we review recent findings that support this conjecture.José M. Correia da Costa, Maria J. Gouveia, Mónica C.
Botelho, Lúcio L. Santos, and Júlio H. Santos thank FCT for
Pest- OE/AGR/UI0211/2011 and Strategic Project UI211-2011-
2013, Clínica Sagrada Esperança and Hospital Américo Boavida,
Luanda, Angola. Nuno Vale thanks to Fundação para a Ciência
e Tecnologia (FCT, Portugal) and FEDER (European Union) for
funding through project grants CONCREEQ/275/QUI and PEstC/QUI/UI0081/2011.
Nuno Vale also thanks FCT for Post-Doc
grant SFRH/BPD/48345/2008. The research findings reviewed
here were supported by award R01CA155297 (Paul J. Brindley,
Gabriel Rinaldi, Banchob Sripa) from the National Cancer Institute,
NIH and P50 P50AI098639 (Banchob Sripa, Paul J. Brindley)
from the National Institute of Allergy and Infectious Diseases,
NIH
Large-scale collective motion of RFGC galaxies
We processed the data about radial velocities and HI linewidths for 1678 flat
edge-on spirals from the Revised Flat Galaxy Catalogue. We obtained the
parameters of the multipole components of large-scale velocity field of
collective non-Hubble galaxy motion as well as the parameters of the
generalized Tully-Fisher relationship in the "HI line width - linear diameter"
version. All the calculations were performed independently in the framework of
three models, where the multipole decomposition of the galaxy velocity field
was limited to a dipole, quadrupole and octopole terms respectively. We showed
that both the quadrupole and the octopole components are statistically
significant.
On the basis of the compiled list of peculiar velocities of 1623 galaxies we
obtained the estimations of cosmological parameters Omega_m and sigma_8. This
estimation is obtained in both graphical form and as a constraint of the value
S_8=sigma_8(Omega_m/0.3)^0.35 = 0.91 +/- 0.05.Comment: Accepted for publication in Astrophysics and Space Scienc
Convergence of the critical attractor of dissipative maps: Log-periodic oscillations, fractality and nonextensivity
For a family of logistic-like maps, we investigate the rate of convergence to
the critical attractor when an ensemble of initial conditions is uniformly
spread over the entire phase space. We found that the phase space volume
occupied by the ensemble W(t) depicts a power-law decay with log-periodic
oscillations reflecting the multifractal character of the critical attractor.
We explore the parametric dependence of the power-law exponent and the
amplitude of the log-periodic oscillations with the attractor's fractal
dimension governed by the inflexion of the map near its extremal point.
Further, we investigate the temporal evolution of W(t) for the circle map whose
critical attractor is dense. In this case, we found W(t) to exhibit a rich
pattern with a slow logarithmic decay of the lower bounds. These results are
discussed in the context of nonextensive Tsallis entropies.Comment: 8 pages and 8 fig
Large-scale collective motion of RFGC galaxies in curved space-time
We consider large-scale collective motion of flat edge-on spiral galaxies
from the Revised Flat Galaxy Catalogue (RFGC) taking into account the curvature
of space-time in the Local Universe at the scale 100 Mpc/h. We analyse how the
relativistic model of collective motion should be modified to provide the best
possible values of parameters, the effects that impact these parameters and
ways to mitigate them. Evolution of galactic diameters, selection effects, and
difference between isophotal and angular diameter distances are inadequate to
explain this impact. At the same time, measurement error in HI line widths and
angular diameters can easily provide such an impact. This is illustrated in a
toy model, which allows analytical consideration, and then in the full model
using Monte Carlo simulations. The resulting velocity field is very close to
that provided by the non-relativistic model of motion. The obtained bulk flow
velocity is consistent with {\Lambda}CDM cosmology.Comment: 10 pages, 3 figures, 2 table
Urinary Estrogen Metabolites and Self-Reported Infertility in Women Infected with Schistosoma haematobium
Schistosomiasis is a neglected tropical disease, endemic in 76 countries, that afflicts more than 240 million people. The impact of schistosomiasis on infertility may be underestimated according to recent literature. Extracts of Schistosoma haematobium include estrogen-like metabolites termed catechol-estrogens that down regulate estrogen receptors alpha and beta in estrogen responsive cells. In addition, schistosome derived catechol-estrogens induce genotoxicity that result in estrogen-DNA adducts. These catechol estrogens and the catechol-estrogen-DNA adducts can be isolated from sera of people infected with S. haematobium. The aim of this study was to study infertility in females infected with S. haematobium and its association with the presence of schistosome-derived catechol-estrogens
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