1,983 research outputs found
A Two-Dimensional CA Traffic Model with Dynamic Route Choices Between Residence and Workplace
The Biham, Middleton and Levine (BML) model is extended to describe dynamic
route choices between the residence and workplace in cities. The traffic
dynamic in the city with a single workplace is studied from the velocity
diagram, arrival time probability distribution, destination arrival rate and
convergence time. The city with double workplaces is also investigated to
compared with a single workplace within the framework of four modes of urban
growth. The transitional region is found in the velocity diagrams where the
system undergoes a continuous transition from a moving phase to a completely
jamming phase. We perform a finite-size scaling analysis of the critical
density from a statistical point of view and the order parameter of this
jamming transition is estimated. It is also found that statistical properties
of urban traffic are greatly influenced by the urban area, workplace area and
urban layout.Comment: 18 pages, 13 figure
Gorbachev's Vladivostok initiatives
In July 1986, sixteen months after becoming General Secretary of the Communist Party of the Soviet Union (CPSU), Mikhail sergeyevich Gorbachov made a three-week tour of the Soviet Far East. He visited main cities and town, industrial centers, agricultural communities, as well as military and naval installations. Most importantof all, Gorbachev delivered an important speech at Vladivostok on July 28. Apart from a lengthy consideration of domestic policy issues, Gorbachev defined in his speech Soviet interests, attitudes and aims in Asia and the Pacific in a fresh light, taking Asian convictions and views (as he saw them) into consideration. Gorbachev came to power at a time when the Soviet Union urgently needed economic reinvigoration at home, yet his predecessors, especialy Brezhnev, had given insufficient attention to developing a comprehensive strategy for the Asian-Pacific region. Soviet leaders, as Ross Babbage argued, had failed to appreciate the region's economic dynamism and had tended to be overly pre-occupied with security issues. Their drive to build up their military power in the region had created serious political obstacles in external relations with neighbouring countries as important as China, Japan and the Unites States. As a result, the Soviet Union was rather isolated in the region
Use of Biocides and Soy Oil in Preservative Treatment of Structural Flakeboard
Many uses of structural wood composite panels require preservative treatment to increase decay resistance. The most cost-effective way to treat structural flakeboard is done during manufacturing, but it is difficult to accomplish because of incompatibility between adhesive resins and preservatives. The objective of this study was to evaluate physical properties and decay resistance of flakeboard made with phenolic wood adhesive resins blended with biocides dissolved in soybean oil. The blended phenolic adhesive resins contained equal parts of iodo-propynyl butyl carbamate, propiconazole, and tebuconazole. Hybrid poplar flakeboards were made at the combined biocide retention levels of 0, 0.51, 0.81, and 1.63 kg/m3. Results indicated that the strength and dimensional stability properties of flakeboard were not affected by the in-process preservative treatment. The biocides were stable and maintained their efficacy against decay after pressing boards at 200°C for 7 min. Boards treated with 1.63 kg/m3 biocides sustained 2.5% to 5.0% weight loss after exposing to the brown-rot fungus (Postia placenta) for 12 wk compared with over 27% weight loss of nontreated boards
spectroscopy using the modified Rovibrational model
Mass spectra of quarkonium systems can be described by different
phenomenological potentials. In the present work, the {\color{black}resonance}
states of heavy quarkonium like ( and ) are considered as
the rovibrational states. We study a parameterized rovibrational model derived
from the empirical solution of the nonrelativistic Schr\"{o}dinger equation
with Morse potential, the corrections are composed of colour hyperfine
interaction and spin-orbit interaction of mesons. We {\color{black}obtain} the
high excited state mass spectra of charmonium and bottomonium comparing the
results in reasonable agreement with the present experimental data.Comment: 6 pages, 4 figure
Search for the Contamination Source of Butyltin Compounds in Wine: Agglomerated Cork Stoppers
A possible butyltin contamination source in wine was studied in this paper. Agglomerated cork stoppers, which were produced in Portugal, Spain, and Italy, used in wine bottles were examined. The domestic cork products, cork granules, and mucus used for cork products were also analyzed. The levels of mono- and dibutyltin compounds in corks were found in the range from <0.0024 to 3.3 and from <0.0029 to 6.7 mug of Sn/g, respectively. A low level of tributyltin contamination was also found in 2 of 31 tested samples. The presence of butyltin compounds in agglomerated cork stoppers was confirmed by GC-MS. Experimental results indicated that all overseas agglomerated cork stoppers studied contained mono- and/or dibutyltins. Butyltins were not detected in cork granules, mucus, most of the natural cork stoppers, and domestic agglomerated cork products. The concentrations of mono- and dibutyltins increased with the time in a 30-day experiment, showing that butyltin compounds can leach from agglomerated cork to the wine. When the butyltin concentrations in wine samples were compared with their levels in the corresponding agglomerated cork stoppers, a correlation was found. The potential harm of such food contamination was evaluated by the toxic research of butyltin compounds using Daphnia sp. as the experimental model
Synaptic vesicle dynamics in mouse rod bipolar cells.
To better understand synaptic signaling at the mammalian rod bipolar cell terminal and pave the way for applying genetic approaches to the study of visual information processing in the mammalian retina, synaptic vesicle dynamics and intraterminal calcium were monitored in terminals of acutely isolated mouse rod bipolar cells and the number of ribbon-style active zones quantified. We identified a releasable pool, corresponding to a maximum of 7 s. The presence of a smaller, rapidly releasing pool and a small, fast component of refilling was also suggested. Following calcium channel closure, membrane surface area was restored to baseline with a time constant that ranged from 2 to 21 s depending on the magnitude of the preceding Ca2+ transient. In addition, a brief, calcium-dependent delay often preceded the start of onset of membrane recovery. Thus, several aspects of synaptic vesicle dynamics appear to be conserved between rod-dominant bipolar cells of fish and mammalian rod bipolar cells. A major difference is that the number of vesicles available for release is significantly smaller in the mouse rod bipolar cell, both as a function of the total number per neuron and on a per active zone basis
Study on the Imprinting Status of Insulin-Like Growth Factor II (IGF-II) Gene in Villus during 6–10 Gestational Weeks
Objective. To compare the difference of imprinting status of insulin-like growth factor II (IGF-II) gene in villus between normal embryo development group and abnormal embryo development group and to investigate the relationship between karyotype and the imprinting status of IGF-II gene. Methods. A total of 85 pregnant women with singleton pregnancy were divided into two groups: one with abnormal embryo development (n = 38) and the other with normal embryo development (n = 47). Apa I polymorphism of IGF-II gene in chorionic villus was assayed with reverse transcriptase polymerase chain reaction (RT-PCR) and restriction fragment length polymorphism (RFLP). The relationship between chromosomal abnormal karyotype and IGF-II gene imprinting status was analyzed by primary cell culture and G-banding chromosomal karyotype analysis.
Results. IGF-II imprinting loss rate was higher in the abnormal embryo development group than the normal embryo development group (44.7% versus 31.6%), but without significant difference (P > .05). The percentage of abnormal chromosomes of chorionic villus in the abnormal embryo development group was 42.5%, in which IGF-II imprinting loss rate reached 64.7%. No abnormal karyotypes were found in the normal embryo development group. However, there was significant difference in IGF-II imprinting loss rate between two groups (P > .05).
Conclusion. During weeks 6–10 of gestation, abnormal embryonic development is correlated with chromosomal abnormalities. The imprinting status of IGF-II gene played important roles in embryonic development, and imprinting loss might be related to chromosomal abnormalities
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