960 research outputs found
Editorial: Geospace Observation of Natural Hazards
This collection of technical papers aims to bring recent data from many sources into the study of natural hazards. They represent a multi-instrumental approach using both ground observations: Global Navigation Satellite System (GNSS); and Low Earth Orbiting Electromagnetic (LEO EM) satellites missions together with Earth Observations (EO), which could reveal new information. Results from latest satellite missions, [(NPP/NASA/NOAA(US), CENTINEL, Swarm/ESA (EU), HIMAWARI (JMA, Japan), FORMOSAT-5 (Taiwan, August 2017), CSES1 (China/Italy, Feb 2018), and FORMOSAT-7/COSMIC-2 (Taiwan/United States, May 2019)], are represented in this volume
Solvable Optimal Velocity Models and Asymptotic Trajectory
In the Optimal Velocity Model proposed as a new version of Car Following
Model, it has been found that a congested flow is generated spontaneously from
a homogeneous flow for a certain range of the traffic density. A
well-established congested flow obtained in a numerical simulation shows a
remarkable repetitive property such that the velocity of a vehicle evolves
exactly in the same way as that of its preceding one except a time delay .
This leads to a global pattern formation in time development of vehicles'
motion, and gives rise to a closed trajectory on -
(headway-velocity) plane connecting congested and free flow points. To obtain
the closed trajectory analytically, we propose a new approach to the pattern
formation, which makes it possible to reduce the coupled car following
equations to a single difference-differential equation (Rondo equation). To
demonstrate our approach, we employ a class of linear models which are exactly
solvable. We also introduce the concept of ``asymptotic trajectory'' to
determine and (the backward velocity of the pattern), the global
parameters associated with vehicles' collective motion in a congested flow, in
terms of parameters such as the sensitivity , which appeared in the original
coupled equations.Comment: 25 pages, 15 eps figures, LaTe
The rectifying developable and the spherical Darboux image of a space curve
In this paper we study singularities of certain surfaces and curves associated with the family of rectifying planes along space curves. We establish the relationships between singularities of these subjects and geometric invariants of curves which are deeply related to the order of contact with helices
Lung Carcinogenic Bioassay of CuO and TiO2 Nanoparticles with Intratracheal Instillation Using F344 Male Rats
Toxicity assessment of nanoparticles, now widespread in our environment, is an important issue. We have focused attention on the carcinogenic potential of copper oxide (CuO) and titanium dioxide (TiO2). In experiment 1, a sequential pilot study, the effectiveness of a carcinogenic bioassay featuring intraperitoneal injection (i.p.) of 20 mg 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) or 0.1% N-bis(2-hydroxypropyl)nitrosamine (DHPN) in drinking water for 2 weeks was examined. Based on the results, DHPN, as the lung carcinogen, and evaluation at week 30 were selected as the most appropriate for our purposes in Experiment 1. In experiment 2, the carcinogenic bioassay was used to assess the carcinogenic potentials of instilled nanoparticles of CuO and TiO2. There were no significant intergroup differences in the lung neoplastic lesions induced by DHPN, although the neoplastic lesions induced by the nanoparticles in the CuO or TiO2 intratracheal instillation (i.t.) groups, demonstrated a tendency to increase compared with the microparticles administration. At the very least, the carcinogenic bioassay with DHPN proved useful for assessment of the modifying effects of instilled particles, and further assessment of the carcinogenic potential of nanoparticles appears warranted
Novel Approach to Super Yang-Mills Theory on Lattice - Exact fermionic symmetry and "Ichimatsu" pattern -
We present a lattice theory with an exact fermionic symmetry, which mixes the
link and the fermionic variables. The staggered fermionic variables may be
reconstructed into a Majorana fermion in the continuum limit. The gauge action
has a novel structure. Though it is the ordinary plaquette action, two
different couplings are assigned in the ``Ichimatsu pattern'' or the checkered
pattern. In the naive continuum limit, the fermionic symmetry survives as a
continuum (or an ) symmetry. The transformation of the fermion is
proportional to the field strength multiplied by the difference of the two
gauge couplings in this limit. This work is an extension of our recently
proposed cell model toward the realization of supersymmetric Yang-Mills theory
on lattice.Comment: 26 pages, 4 figure
Lipid profile disturbances are highly prevalent in Japanese-Brazilians
Alta prevalência de diabetes em população nipo-brasileira de Bauru/SP foi previamente relatada. Visando a complementar a avaliação do risco cardiometabólico, este estudo analisou distúrbios no perfil lipídico de 1.330 nipo-brasileiros (46% homens) > 30 anos. Definiu-se hipercolesterolemia por níveis de colesterol total > 240 mg/dL; hipertrigliceridemia por valores > 150 mg/dL e HDL-colesterol baixo por valores < 40 mg/dL e < 50 mg/dL para homens e mulheres, respectivamente. A prevalência desses distúrbios foi comparada pelo qui-quadrado, estratificando-se por sexos e categorias glicêmicas. As médias dos lipídeos e lipoproteínas foram comparadas entre sexos pelo teste t de Student. A prevalência de hipertrigliceridemia foi de 66,0% (IC95%:63,5 - 68,5%), sendo mais comum em homens e aumentando com a piora da categoria glicêmica; a trigliceridemia média foi 235,7 ± 196,3 mg/dL. A prevalência de hipercolesterolemia foi 24,4% (IC95%:22,1 - 26,7%); HDL-C baixo foi observado em 43,0% (IC95%:39,4 - 46,6%] das mulheres e 17,5% (IC95%:14,5 - 20,5%) dos homens, porém a razão colesterol total/HDL-C foi menor em mulheres (4,23 ± 0,68 vs. 4,40 ± 0,73; p < 0,001). Em nipo-brasileiros, a hipertrigliceridemia é a anormalidade lipídica mais comum, em concordância com a elevada prevalência de diabetes. Os homens apresentaram pior perfil lipídico que as mulheres. Sugere-se que hábitos de vida ocidental possam estar deteriorando a saúde desses indivíduos.High prevalence of diabetes has been previously reported in Japanese-Brazilians. In an attempt to better estimate the cardiometabolic risk, this study evaluated lipid disorders in 1,330 Japanese-Brazilians (46% men) aged >30 years. Hypercholesterolemia was defined as serum cholesterol > 240 mg/dL, hypertriglyceridemia as values > 150 mg/dL and low-HDL-C as values <40 mg/dL and <50 mg/dl for men and women respectively. The prevalence of dyslipidemias was compared by the chi-square test between gender and glycemic category. Mean and Standard Deviation of lipids and lipoproteins were compared by the Student t-Test between gender. Hypertriglyceridemia was detected in 66.0% [95% CI: 63.5-68.5] of the population, being more common in men and increasing with deterioration of glucose metabolism. Mean level of triglycerides was 235.7±196.3 mg/dL. The prevalence of hypercholesterolemia was 24.4% [95% CI: 22.1- 26.7]. Low HDL-C was observed in 17.5% [95% CI: 14.5-20.5] of men and 43.0% [95% CI: 39.4- 46.6] of women but total / HDL-cholesterol ratio was lower in women (4.23 ± 0.68 vs. 4.40 ± 0.73, p<0.001). In Japanese-Brazilians, hypertriglyceridemia is the commonest dyslipidemia, in agreement with the high prevalence of diabetes. Men showed a worse lipid profile than women; it was suggested that the Western diet and living habits could be deteriorating their health.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
Dynamical simulations of an electronically induced solid-solid phase transformation in tungsten
The rearrangement of a material's electron density during laser irradiation leads to modified nonthermal forces on the atoms that may lead to coherent atomic motions and structural phase transformation on very short time scales. We present ab initio molecular dynamics simulations of a martensitic solid-solid phase transformation in tungsten under conditions of strong electronic excitation. The transformation is ultrafast, taking just over a picosecond, and follows the tetragonal Bain path. To examine whether a solid-solid bcc-fcc phase transformation could occur during laser irradiation, we use two-temperature molecular dynamics (2T-MD) simulations with a specially developed potential dependent on the electronic temperature. Our simulations show that the occurrence of the solid-solid phase transformation is in competition with ultrafast nonthermally assisted melting with the strength of the electron-phonon coupling determining the lifetime of the new solid phase. In tungsten the melting transition is predicted to occur too rapidly for the fcc phase to be detectable during laser irradiation
Crystalline ground state in chiral Gross-Neveu and Cooper pair models at finite densities
We study the possibility of spatially non-uniform ground state in
(1+1)-dimensional models with quartic fermi interactions at finite fermion
densities by introducing chemical potential \mu. We examine the chiral
Gross-Neveu model and the Cooper pair model as toy models of the chiral
symmetry breaking and the difermion pair condensates which are presumed to
exist in QCD. We confirm in the chiral Gross-Neveu model that the ground state
has a crystalline structure in which the chiral condensate oscillates in space
with wave number 2\mu. Whereas in the Cooper pair model we find that the vacuum
structure is spatially uniform. Some discussions are given to explain this
difference.Comment: 18 pages, REVTeX, 3 eps figure
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