4,073 research outputs found
Shrinking population and the urban hierarchy
This paper examines whether population shrinkage leads to changes in urban hierarchy in terms of their relative size and function from the standpoint of the new economic geography. We find some salient patterns in which small cities in the agglomeration shadow become relatively bigger as medium industries spill over on them. This appears to be quite robust against a variation in the rate of natural change among cities. Thus, rank-size relationship and the urban hierarchy are partly disrupted as population shrinks. Regarding the welfare of the residents, a lower demand for land initially causes rent to go down, which boosts the utility. However, the illusion is short-lived because markets soon begin to shrink and suppress wages. We also find that it is better to maintain a slow pace of overall population decline in the long-term perspective. More importantly, it is crucial to sustain the relative livability of smaller cities to minimize the overall loss of utility
Transient receptor potential canonical type 3 channels control the vascular contractility of mouse mesenteric arteries
Transient receptor potential canonical type 3 (TRPC3) channels are non-selective cation channels and regulate intracellular Ca2+ concentration. We examined the role of TRPC3 channels in agonist-, membrane depolarization (high K+)-, and mechanical (pressure)-induced vasoconstriction and vasorelaxation in mouse mesenteric arteries. Vasoconstriction and vasorelaxation of endothelial cells intact mesenteric arteries were measured in TRPC3 wild-type (WT) and knockout (KO) mice. Calcium concentration ([Ca2+]) was measured in isolated arteries from TRPC3 WT and KO mice as well as in the mouse endothelial cell line bEnd.3. Nitric oxide (NO) production and nitrate/nitrite concentrations were also measured in TRPC3 WT and KO mice. Phenylephrine-induced vasoconstriction was reduced in TRPC3 KO mice when compared to that of WT mice, but neither high K+- nor pressure-induced vasoconstriction was altered in TRPC3 KO mice. Acetylcholine-induced vasorelaxation was inhibited in TRPC3 KO mice and by the selective TRPC3 blocker pyrazole-3. Acetylcholine blocked the phenylephrine-induced increase in Ca2+ ratio and then relaxation in TRPC3 WT mice but had little effect on those outcomes in KO mice. Acetylcholine evoked a Ca2+ increase in endothelial cells, which was inhibited by pyrazole-3. Acetylcholine induced increased NO release in TRPC3 WT mice, but not in KO mice. Acetylcholine also increased the nitrate/nitrite concentration in TRPC3 WT mice, but not in KO mice. The present study directly demonstrated that the TRPC3 channel is involved in agonist-induced vasoconstriction and plays important role in NO-mediated vasorelaxation of intact mesenteric arteries.Fil: Yeon, Soo-In. Yonsei University College of Medicine; Corea del SurFil: Kim, Joo Young. Yonsei University College Of Medicine; . Yonsei University College of Medicine; Corea del SurFil: Yeon, Dong-Soo. Kwandong University College of Medicine; Corea del SurFil: Abramowitz, Joel. National Institute of Environmental Health Sciences; Estados UnidosFil: Birnbaumer, Lutz. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. National Institute of Environmental Health Sciences; Estados UnidosFil: Muallem, Shmuel. National Institutes of Health; Estados UnidosFil: Lee, Young-Ho. Yonsei University College of Medicine; Corea del Su
Nucleon cosmological constant term and flavor structure of the gravitational form factors
The gravitational form factors furnish information on the mechanics of the
nucleon. It is essential to compute the generalized isovector-vector form
factors to examine the flavor structure of the gravitational form factors. The
flavor-decomposed form factors reveal the internal structure of the nucleon.
The up quark dominates over the down quark for the mass and spin of the
nucleon, whereas the down quark takes over the up quark for the -term form
factor. We investigate for the first time the isovector cosmological constant
term of the nucleon and its physical implications. The flavor-decomposed
cosmological constant terms of the nucleon unveil how the up-quark contribution
is exactly canceled by the down-quark contribution inside a nucleon within the
framework of the pion mean-field approach. While the nucleon cosmological
constant term does not contribute to the nucleon mass, its flavor structure
sheds light on how the strong force fields due to the cosmological constant
term characterize the stability of the nucleon.Comment: 7 pages and 4 figures. The text was improved and extende
Gravitational form factors of the baryon octet with flavor SU(3) symmetry breaking
We investigate the gravitational form factors of the baryon octet within the
framework of the SU(3) chiral quark-soliton model, considering the effects of
flavor SU(3) symmetry breaking, and the corresponding energy-momentum tensor
distributions. We examine the effects of flavor SU(3) symmetry breaking to the
mass, angular momentum, pressure, and shear force distributions of the baryon
octet. We first find that a heavier baryon is energetically more compact than a
lighter one. For the spin distributions of the baryon octet, they are properly
normalized to their spins and are decomposed into the flavor-singlet axial
charge and the orbital angular momentum even when the flavor SU(3) symmetry is
broken. While the effects of the flavor SU(3) symmetry breaking differently
contribute to the angular momentum distributions for the octet baryons, they
are found to be rather small. The spin and orbital angular momentum almost
equally contribute to the angular momentum distributions for the octet baryons.
We also estimate the effects of the flavor SU(3) symmetry breaking to the
pressure and shear force distributions. Interestingly, even if we include the
effects of the SU(3) flavor symmetry breaking, the shear force distributions
are kept to be positive over . It indicates that the Polyakov & Schweitzer
local stability condition is kept to be intact with the flavor SU(3) symmetry
broken. Lastly, we discuss how much the gravitational form factors vary with
the effects of flavor SU(3) symmetry breaking considered.Comment: 27 pages, 8 figure
Structural Optimization of a Knuckle with Consideration of Stiffness and Durability Requirements
The automobile’s knuckle is connected to the parts of the steering system and the suspension system and it is used for adjusting the direction of a rotation through its attachment to the wheel. This study changes the existing material made of GCD45 to Al6082M and recommends the lightweight design of the knuckle as the optimal design technique to be installed in small cars. Six shape design variables were selected for the optimization of the knuckle and the criteria relevant to stiffness and durability were considered as the design requirements during the optimization process. The metamodel-based optimization method that uses the kriging interpolation method as the optimization technique was applied. The result shows that all constraints for stiffness and durability are satisfied using A16082M, while reducing the weight of the knuckle by 60% compared to that of the existing GCD450
GBParsy: A GenBank flatfile parser library with high speed
<p>Abstract</p> <p>Background</p> <p>GenBank flatfile (GBF) format is one of the most popular sequence file formats because of its detailed sequence features and ease of readability. To use the data in the file by a computer, a parsing process is required and is performed according to a given grammar for the sequence and the description in a GBF. Currently, several parser libraries for the GBF have been developed. However, with the accumulation of DNA sequence information from eukaryotic chromosomes, parsing a eukaryotic genome sequence with these libraries inevitably takes a long time, due to the large GBF file and its correspondingly large genomic nucleotide sequence and related feature information. Thus, there is significant need to develop a parsing program with high speed and efficient use of system memory.</p> <p>Results</p> <p>We developed a library, GBParsy, which was C language-based and parses GBF files. The parsing speed was maximized by using content-specified functions in place of regular expressions that are flexible but slow. In addition, we optimized an algorithm related to memory usage so that it also increased parsing performance and efficiency of memory usage. GBParsy is at least 5 - 100Ă— faster than current parsers in benchmark tests.</p> <p>Conclusion</p> <p>GBParsy is estimated to extract annotated information from almost 100 Mb of a GenBank flatfile for chromosomal sequence information within a second. Thus, it should be used for a variety of applications such as on-time visualization of a genome at a web site.</p
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
Evaluation of the high temperature solid Oxide cells using La0.1Sr0.9Co0.8Fe0.2O3-δ
The performance of the SOCs using La0.1Sr0.9Co0.8Fe0.2O3-δ (LSCF1982) was characterized by I-V measurement and electrochemical impedance spectroscopy (EIS). The distribution function of relaxation times of EIS was used to analyze the polarization resistance of the cells. The fitting was performed using the appropriate equivalent circuit through DRT analysis. Furthermore, we co-electrolyzed CO2 and H2O to obtain H2 / CO syngas as well as water splitting. The composition of syngas was investigated by gas chromatography and controlled by varying in-let gas composition
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