5,404 research outputs found
Phase Transitions in the Early Universe
The physics of the 20th Century is governed by two pillars, Einstein's
relativity principle and the quantum principle. At the beginning of the 21st
Century, it becomes clear that there exist the smallest units of matter, such
as electrons, neutrinos, and quarks; their behaviors are described by the
Standard Model.
It was believed that the temperature of the early Universe was once 300 GeV,
or higher, at , and then going through the electroweak phase
transition. But the mass phase transition happens in the purely imaginary
temperature. Later on, its temperature was 150 MeV at ,
and then going through the "QCD cosmological phase transition". We attempt to
use the Standard Model, a completely dimensionless theory apart from the
negative "ignition" term, to conclude that the EW or mass phase transition {\it
does not exist}.
On the front of QCD cosmological phase transition, the intriguing question
about the latent heat (energy) is discussed and its role is speculated.Comment: 24 pages, 1 figur
Meta-Learning for Phonemic Annotation of Corpora
We apply rule induction, classifier combination and meta-learning (stacked
classifiers) to the problem of bootstrapping high accuracy automatic annotation
of corpora with pronunciation information. The task we address in this paper
consists of generating phonemic representations reflecting the Flemish and
Dutch pronunciations of a word on the basis of its orthographic representation
(which in turn is based on the actual speech recordings). We compare several
possible approaches to achieve the text-to-pronunciation mapping task:
memory-based learning, transformation-based learning, rule induction, maximum
entropy modeling, combination of classifiers in stacked learning, and stacking
of meta-learners. We are interested both in optimal accuracy and in obtaining
insight into the linguistic regularities involved. As far as accuracy is
concerned, an already high accuracy level (93% for Celex and 86% for Fonilex at
word level) for single classifiers is boosted significantly with additional
error reductions of 31% and 38% respectively using combination of classifiers,
and a further 5% using combination of meta-learners, bringing overall word
level accuracy to 96% for the Dutch variant and 92% for the Flemish variant. We
also show that the application of machine learning methods indeed leads to
increased insight into the linguistic regularities determining the variation
between the two pronunciation variants studied.Comment: 8 page
Imunosni odgovor BALB/c miševa oralno imuniziranih rekombinantnim cjepivom od serovara Salmonella Typhimurium s ugrađenim antigenima enterotoksigenog soja Escherichia coli
Salmonella Typhimurium ghost vaccines containing antigens of enterotoxigenic Escherichia coli (ETEC) were obtained by a strain harboring pMMP184, which carries a ghost cassette. The immune responses of BALB/c mice orally vaccinated with these ghost vaccines were determined in this study. Total IgG against S. Typhimurium were highly detected by the oral immunization route in BALB/c mice. IgGs against ETEC antigens in the ghost cells carrying F41 and intimin were detected at 4 weeks after vaccination. However, FedF elicited a delayed induction of IgGs, whereas FedA immune response failed to or barely induced IgGs after vaccination. Proliferations of CD3e/CD4-T cells were observed in splenocytes of BALB/c mice immunized with S. Typhimurium ghost cells carrying FedF. However, CD45R-B220/CD23-B cells were proliferated by ghost cells carrying FedA, F41, and intimin. The immunized BALB/c mice showed 25~50% protection against challenge with wild type S. Typhimurium, when compared to control mice. Therefore, it is assumed that oral vaccination of S. Typhimurium ghost cells has the potential to protect mice against pathogenic E. coli.Salmonella Typhimurium rekombinantna cjepiva što sadrže antigene enterotoksigenih sojeva Escherichia coli (ETEC) proizvedena su od soja koji posjeduje pMMP184 i nosi rekombinantnu kasetu. Istražen je imunosni odgovor BALB/c miševa oralno cijepljenih tim rekombinantnim cjepivima. Ustanovljena je visoka razina ukupnih IgG za S. Typhimurium nakon oralne imunizacije miševa BALB/c. Imunoglobulini IgG za antigene ETEC u rekombinantnom cjepivu koje sadrži F41 i intimin bili su dokazani četiri tjedna nakon cijepljenja. Ipak, FedF je potaknuo kasnu tvorbu imunoglobulina IgG, dok FedA nije potaknuo ili je potaknuo slab imunosni odgovor nakon cijepljenja. Proliferacija CD3e/CD4-T stanica bila je dokazana u splenocitima miševa BALB/c imuniziranih rekombinantnim cjepivom S. Typhimurium s ugrađenim FedF. Međutim, stanice CD45R-B220/CD23-B proliferirale su nakon cijepljenja rekombinantom FedA, F41 i intimin. Imunizirani miševi BALB/c pokazivali su 25~50% zaštitu nakon izazivačke infekcije serovarom S. Typhimurium u usporedbi s necijepljenim kontrolnim miševima. Stoga se pretpostavlja da oralno cijepljenje s rekombinantnim stanicama serovara S. Typhimurium ima potencijal da zaštiti miševe od infekcije patogenim sojevima E. coli
KINEMATIC ANALYSIS OF THE MOVEMENT PATTERNS OF STROKE PATIENTS USING AN AQUA-REHABILITATION PROGRAM
This study analyzed the effect of a BK Aquatic Protocol (aqua-rehabilitation program) on the gait patterns of stroke patients. Seven subjects were divided into three stages on the basis of initial assessment of motor ability. The program varied on the basis of motor ability group. The subjects exercised three times a week for 12 weeks. Each exercise bout lasted 50 minutes. The BK Aquatic Protocol (as the motor skills improved, the graded exercise program appropriately changed) was followed. Four digital camcorders were used to obtain the kinematics of the patients’ gait before and after participation in the aqua-rehabilitation program. Several positive kinematic changes occurred in the gait patterns of the stroke patients from pre- to post test in association with the intervention of the aqua-rehabilitation program
Resilient High Catalytic Performance of Platinum Nanocatalysts with Porous Graphene Envelope.
Despite the innumerable developments of nanosized and well dispersed noble metal catalysts, the degradation of metal nanoparticle catalysts has proven to be a significant obstacle for the commercialization of the hydrogen fuel cell. Here, the formation of Pt nanoparticle catalysts with a porous graphene envelope has been achieved using a single step low temperature vaporization process. While these Pt-Gr core-shell nanoparticles possess superior resilience to degradation, it comes at the cost of degraded overall catalyst efficacy. However, it is possible to combat this lower overall performance through inclusion of low concentrations of nitrogen precursor in the initial stage of single-step synthesis, inhibiting the formation of complete graphene shells, as verified by atomic resolution aberration-corrected transmission electron microscopy (AC-TEM) imaging. The resultant porous graphene encapsulated Pt catalysts are found to have both the high peak performance of the bare Pt nanoparticle catalysts and the increased resilience of the fully shielded Pt-Gr core-shells, with the optimal N-doped Pt-Gr yielding a peak efficiency of 87% compared to bare Pt, and maintaining 90% of its catalytic activity after extended potential cycling. The nitrogen treated Pt-Gr core-shells thus act as an effective substitute catalyst for conventional bare Pt nanoparticles, maintaining their catalytic performance over prolonged use
Condensation and Clustering in the Driven Pair Exclusion Process
We investigate particle condensation in a driven pair exclusion process on
one- and two- dimensional lattices under the periodic boundary condition. The
model describes a biased hopping of particles subject to a pair exclusion
constraint that each particle cannot stay at a same site with its pre-assigned
partner. The pair exclusion causes a mesoscopic condensation characterized by
the scaling of the condensate size and the number of
condensates with the total number of sites .
Those condensates are distributed randomly without hopping bias. We find that
the hopping bias generates a spatial correlation among condensates so that a
cluster of condensates appears. Especially, the cluster has an anisotropic
shape in the two-dimensional system. The mesoscopic condensation and the
clustering are studied by means of numerical simulations.Comment: 4 pages, 5 figure
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