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Anthropogenic land use within watersheds has substantial effects on aquatic habitats and biological communities. From September 2006 to December 2008, we investigated the effects of land use on benthic macroinvertebrate communities by comparing Song Stream and Odae Stream, two adjacent mountain streams in Korea whose watersheds have different land use patterns. Song Stream is significantly disturbed by agricultural activities in the watershed, whereas Odae Stream is relatively undisturbed and is surrounded by a well-conserved forest area. Song Stream had significantly higher levels of all nutrients and sediment-related factors due to the adjacent agricultural area. As a result, Song Stream had markedly lower species community indices, such as taxa richness and abundance. In Song Stream, macroinvertebrate scrapers and predators were most adversely affected, whereas collector-gatherers became a dominant group. Based on correlation and multivariate analyses, total dissolved solids had the strongest negative relationship with macroinvertebrate assemblages, followed by electrical conductivity, total nitrogen, and pH. The proportion of cobble in stream substrate was positively related to the richness and abundance of macroinvertebrates. Our results indicate that disturbances caused by agricultural land use, particularly sand deposition, had significant adverse effects on macroinvertebrate habitats and on the biotic integrity of benthic macroinvertebrate communities.
The morphological definition of atrial chambers, and the determination of atrial laterality, are based on analysis of the structure of the atrial appendages. The systemic and pulmonary venous connections to the heart, nonetheless, are important in the management of patients having isomeric appendages. In this study, therefore, we analysed the morphology of the postero-superior walls of the atrial chambers so as to provide evidence concerning the morphogenetic background of those hearts, and to improve operative management.
We reviewed 15 autopsied specimens with isomeric right appendages, and 10 with isomeric left appendages, paying particular attention to the morphology of the systemic and pulmonary venous connections. The postero-superior walls of the atrial chambers can be made up of the atrial body, the systemic venous components, or the pulmonary venous component. We analysed the contributions made by each of these components.
The postero-superior walls of the atrial chambers were markedly variable, but could be grouped into five patterns. Bilaterally well-developed systemic venous components and absence of the pulmonary venous component within the hypoplastic atrial body were present in 9 hearts with extracardiac pulmonary venous connections in the setting of right isomerism. Bilaterally well-developed systemic venous components, and a hypoplastic pulmonary venous component within the hypoplastic atrial body, were present in 5 hearts with intracardiac pulmonary venous connections in right isomerism. Bilaterally well-developed systemic venous components, and a hypoplastic pulmonary venous component within the sizable atrial body, were present in 1 heart with an intracardiac pulmonary venous connection in right isomerism. A well-developed pulmonary venous component within the atrial body, and hypoplasia of one systemic venous component, were present in 7 hearts with left isomerism. A well-developed pulmonary venous component within the atrial body, and hypoplasia of bilateral systemic venous components, were present in 3 hearts with left isomerism.
The postero-superior walls of the atrial chambers in hearts with isomeric atrial appendages can be analysed on the basis of a compound structure made of bilateral systemic venous components, a central pulmonary venous component, and the body of the atrium. Hearts with isomeric right appendages have absence or hypoplasia of the pulmonary venous component, while hearts with isomeric left appendages have hypoplastic systemic venous components.
Proper selection of an osteotome for nasal osteotomy is important for minimizing soft tissue trauma. Radiographic analysis of the facial bony lateral wall thickness was performed to suggest a guideline for an appropriate osteotome size for Asians. Facial bone computed tomography (CT) of 100 patients (50 male, 50 female) were studied. The thickness of the facial bony lateral wall at three points along the track of a lateral osteotomy, and two points along the track of a medial osteotomy and intermediate osteotomy were measured. The average bony thickness along the track of a lateral osteotomy was 2.61 ± 0.66 mm at the low level, 2.75 ± 0.76 mm at the middle level, and 2.72 ± 0.53 mm at the high level in subjects. The average bony thickness along the track of an intermediate osteotomy were 1.26 ± 0.34 mm at the low level, and 1.31 ± 0.32 mm at the high level in the subjects. The average bony thickness along the track of the medial osteotomy were 2.54 ± 0.31 mm at the lowlevel, and 2.77 ± 0.30 mm at the high level in subjects. These results may provide a guideline for choosing an osteotome of appropriate size for the Asian population.
A patient with an arteriovenous fistula that developed after a traffic accident was recently treated. The patient noticed pulsatile tinnitus in the right orbital region two months after the accident. On the first visit, the preliminary clinical impression of this case was a carotid-cavernous fistula, but angiography showed a fistula between the posterior auricular artery and the internal jugular vein. Although rare, this arteriovenous fistula should be included in the differential diagnosis of pusatile tinnitus in the orbit region. The fistula was controlled by embolization with a platinum coil. This is the first report of an arteriovenous fistula between the posterior auricular artery and internal jugular vein.
We have investigated the variables affecting passivation and resistivities of Cu alloy, which was sputter prepared from a Cu(6 at.%Mg) target. The results show that oxidation of Cu(Mg) alloy includes the surface segregation of Mg and its preferential oxidation. Sufficient surface segregation of Mg is necessary to form the high quality, protective MgO layer on the surface. The interfacial oxide layer produced from the reaction of Mg and SiO2 does not serve as a barrier against Mg diffusion, thereby the generation of free Si seems to continue until Mg is exhausted in copper. Therefore, lowering the contents of Mg in copper is required to reduce the resistivity of Cu(Mg) alloy. In-situ heating of substrate is very effective to reduce the Mg contents in copper alloy and to enhance the surface segregation of Mg, thereby facilitating the passivation of Cu(Mg) alloy with the low resistivity, especially during the low temperature oxidation.
One of the biggest problems in pneumatic system
design is over design. Thus, the results are excessive
in costs of the initial investment and it requires too
much energy. This article describes the development of
expert system based pneumatic design system, PNEUDES (PNEUmatic
Design Expert System), prototype that enables the user
the optimal design of pneumatic system. Once the design
requirements such as cylinder type and work load, etc.
are input to the system, optimal cylinder specifications
with standardized order-based size, valves types, and necessary
accessories are all determined. Also the configuration
information such as the connectivity among components and
cylinder image data are supplied to the user. It can also
help the novice of pneumatic design. The rule-based reasoning
approach is used as a reasoning strategy with Intelligent
Rule Element shell.
Uniform and reproducible silicon tip arrays were fabricated using the reactive ion etching followed by the re-oxidation sharpening. Molybdenum was then coated on the some of the silicon tip array. Current-voltage characteristics and current fluctuations were measured in the high vacuum environment. Field emission currents were proved by the Fowler-Nordheim plot studies.
Heterostructural properties of pseudomorphic (AlGaAs/GaAs), partially strained (GaInAs/GaAs), and highly strained (GaAs/Si) semiconductor systems have been studied using High Resolution Double-Crystal X-ray Diffraction (DXRD), Transmission Electron Microscopy (TEM), and Scanning Electron Microscopy (SEM). Using the high resolution DXRD with CuKα1 and two-reflection Si (220) monochromator, we obtained (004) symmetric and (115) or (224) asymmetric reflection rocking curves for samples grown by molecular beam epitaxy. With 0.5 μm thick samples, perpendicular and in-plane lattice mismatches were calculated using elastic theory and compared with each other. The different degree of relaxation for these samples was observed and correlated with the lattice mismatch, X-ray layer peak broadening (i.e., full width at half maximum), and SEM surface morphology. For a GaInAs/GaAs sample, the strain relaxation along one of the <110> directions was more than the other direction, that is, the strain relaxation is not isotrophic. Also we observed that the lines were mainly parallel in one direction, i.e., they did not form a cross-hatch pattern. TEM images from both cross-sectional and planar views of the samples will be presented.
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