257 research outputs found
Consideration of apllicability of stochastic tropical cyclone model for probability assessment of storm surge
Storm surge risk is basic and important information for design of coastal structure, but its probability assessment is difficult because the frequency of devastating TC is not so high. Furthermore, storm surge damage is very sensitive to not only its intensity but also its track and translation speed. Therefore, the estimation of occurrence probability of devastating disaster from our limited observation data has uncertainty. Recently, we have developed Global Stochastic Tropical cyclone Model (GSTM). The comparison of observation data and simulation results of GSTM showed the reasonable reproducibility of macroscopic statistics of TC parameters such as central pressure, translation direction and speed. However, the verification area of previous study was too large to consider the applicability to risk assessment of local bay scale. Therefore, the microscopic and detailed verification of GSTM is necessary. In this study, we tried to evaluation of reproducibility of TC parameters which was calculated by GSTM at small region as a local bay scale. Furthermore, we improved GSTM by implementation of the cluster analysis of observation data to the process of estimation of the joint Probability Density Function (joint PDF) of temporal correlation of TC parameters. At last of this study, a case study approach by storm surge simulation was performed in order to explain the practical meaning of GSTM. Synthetic TC data based on historical TC track was generated and they were used for input to numerical model for estimating the water height of storm surge at regional scale. Then, the TC track of the worst-case scenario for Yatsushiro bay located in center of west Kyushu Island was decided. Finally, the occurrence probability of the worst-case scenario was calculated from GSTM results
Flood Risk Management: An Illustrative Approach
Widespread flooding with significant damage in many countries, such as the Philippines in 2013, highlights the ongoing need for effective flood risk management (FRM). This hinges on comprehensive access to and dissemination of information about the elements and the people at risk. Simulations, real-time graphs, and maps illustrate the spatial distribution of flood risks, spatial allocation and dissemination of flood effects, if flood risk reduction measures are not implemented, as well as the benefits to be derived from the effective implementation and maintenance of flood risk management measures not realized. Using precipitation, river water, and tide levels, a real-time monitoring site was set up for the Shirakawa River, Kumamoto, Japan. The data gathered from the July 2012 flood event is used as a demonstrator, illustrating a flood event as well as how to utilize the information provided on this site to determine the future time and possibility of flooding. Additionally, an electronically generated flood hazard map making process is being developed for distribution across Japan. These illustrative approaches can be utilized in cities and communities around the globe
Decreases in blood perfusion of the anterior cingulate gyri in Anorexia Nervosa Restricters assessed by SPECT image analysis
BACKGROUND: It is possible that psychopathological differences exist between the restricting and bulimic forms of anorexia nervosa. We investigated localized differences of brain blood flow of anorexia nervosa patients using SPECT image analysis with statistic parametric mapping (SPM) in an attempt to link brain blood flow patterns to neurophysiologic characteristics. METHODS: The subjects enrolled in this study included the following three groups: pure restrictor anorexics (AN-R), anorexic bulimics (AN-BP), and healthy volunteers (HV). All images were transformed into the standard anatomical space of the stereotactic brain atlas, then smoothed. After statistical analysis of each brain image, the relationships among images were evaluated. RESULTS: SPM analysis of the SPECT images revealed that the blood flow of frontal area mainly containing bilateral anterior cingulate gyri (ACC) was significantly decreased in the AN-R group compared to the AN-BP and HV groups. CONCLUSIONS: These findings suggest that some localized functions ofthe ACCare possibly relevant to the psychopathological aspects of AN-R
Hippocampal Deletion of BDNF Gene Attenuates Gamma Oscillations in Area CA1 by Up-Regulating 5-HT3 Receptor
Background: Pyramidal neurons in the hippocampal area CA3 express high levels of BDNF, but how this BDNF contributes to oscillatory properties of hippocampus is unknown. Methodology/Principal Findings: Here we examined carbachol-induced gamma oscillations in hippocampal slices lacking BDNF gene in the area CA3. The power of oscillations was reduced in the hippocampal area CA1, which coincided with increases in the expression and activity of 5-HT3 receptor. Pharmacological block of this receptor partially restored power of gamma oscillations in slices from KO mice, but had no effect in slices from WT mice. Conclusion/Significance: These data suggest that BDNF facilitates gamma oscillations in the hippocampus by attenuating signaling through 5-HT3 receptor. Thus, BDNF modulates hippocampal oscillations through serotonergic system
Kv7 Channels Can Function without Constitutive Calmodulin Tethering
M-channels are voltage-gated potassium channels composed of Kv7.2-7.5 subunits that serve as important regulators of neuronal excitability. Calmodulin binding is required for Kv7 channel function and mutations in Kv7.2 that disrupt calmodulin binding cause Benign Familial Neonatal Convulsions (BFNC), a dominantly inherited human epilepsy. On the basis that Kv7.2 mutants deficient in calmodulin binding are not functional, calmodulin has been defined as an auxiliary subunit of Kv7 channels. However, we have identified a presumably phosphomimetic mutation S511D that permits calmodulin-independent function. Thus, our data reveal that constitutive tethering of calmodulin is not required for Kv7 channel function
Prevalence of putative virulence factors and antimicrobial susceptibility of Enterococcus faecalis isolates from patients with dental Diseases
<p>Abstract</p> <p>Background</p> <p>This study investigated the prevalence of <it>Enterococcus faecalis</it>, its putative virulence factors and antimicrobial susceptibility in individuals with and without dental diseases. A total of 159 oral rinse specimens were collected from patients (n = 109) suffering from dental diseases and healthy controls (n = 50).</p> <p>Results</p> <p><it>E. faecalis </it>was detected using only culture in 8/109 (7.3%) of the patients with various types of dental diseases, whereas no <it>E. faecalis </it>was found in the healthy controls weather using both culture and PCR. Phenotype characterizations of the 8 <it>E. faecalis </it>isolates indicated that 25% of the isolates produced haemolysin and 37.5% produced gelatinase. Most important virulence genes; collagen binding protein (<it>ace</it>) and endocarditis antigen (<it>efaA</it>) were present in all 8 <it>E. faecalis </it>isolates, while haemolysin activator gene (<it>cylA</it>) was detected only in 25% of isolates, and all isolates were negative for <it>esp </it>gene. All <it>E. faecalis </it>isolates were 100% susceptible to ampicillin, chloramphenicol, ciprofloxacin, vancomycin, and teicoplanin, and to less extent to erythromycin (62.5%).</p> <p>Conclusion</p> <p>This study shows that all <it>E. faecalis </it>isolates were recovered only from patients with dental diseases especially necrotic pulps, and all isolates carried both collagen binding protein and endocarditis antigen genes and highly susceptible to frequently used antimicrobial drugs in Jordan.</p
Detection of sentinel and non-sentinel lymph node micrometastases by complete serial sectioning and immunohistochemical analysis for gastric cancer
<p>Abstract</p> <p>Background</p> <p>We investigated the presence and distribution of the sentinel and the non-sentinel node micrometastases using complete serial sectioning and immunohistochemical staining (IHC), to inspect whether lymph node micrometastases spread to the sentinel lymph nodes first.</p> <p>Methods</p> <p>A total of 35 patients, who underwent gastrectomy with a sentinel lymph node biopsy for gastric cancer, were enrolled in this study. Total of 1028 lymph nodes of 35 patients having gastric cancer without metastasis of lymph node by permanent section with hematoxylin and eosin staining (H&E) were selected. There were 252 sentinel nodes and the other 776 were non-sentinel nodes. All nodes were sectioned serially and stained alternately with H&E and IHC. Lymph node micrometastases was defined as proving to be positive first either the IHC or the complete serial sectioning.</p> <p>Results</p> <p>Micrometastases were detected in 4 (11%) of the 35 patients, 6 (0.58%) of 1028 nodes. Of these 4 patients, 3 had micrometastases exclusively in sentinel nodes, and the other had micrometastasis in both sentinel and non-sentinel nodes. There was no patient who had the micrometasitases only in non-sentinel nodes.</p> <p>Conclusion</p> <p>These results support the concept that lymph node micrometastasis of gastric cancer spreads first to sentinel nodes.</p
Discovery of a Novel Activator of KCNQ1-KCNE1 K+ Channel Complexes
KCNQ1 voltage-gated K+ channels (Kv7.1) associate with the family of five KCNE peptides to form complexes with diverse gating properties and pharmacological sensitivities. The varied gating properties of the different KCNQ1-KCNE complexes enables the same K+ channel to function in both excitable and non excitable tissues. Small molecule activators would be valuable tools for dissecting the gating mechanisms of KCNQ1-KCNE complexes; however, there are very few known activators of KCNQ1 channels and most are ineffective on the physiologically relevant KCNQ1-KCNE complexes. Here we show that a simple boronic acid, phenylboronic acid (PBA), activates KCNQ1/KCNE1 complexes co-expressed in Xenopus oocytes at millimolar concentrations. PBA shifts the voltage sensitivity of KCNQ1 channel complexes to favor the open state at negative potentials. Analysis of different-sized charge carriers revealed that PBA also targets the permeation pathway of KCNQ1 channels. Activation by the boronic acid moiety has some specificity for the Kv7 family members (KCNQ1, KCNQ2/3, and KCNQ4) since PBA does not activate Shaker or hERG channels. Furthermore, the commercial availability of numerous PBA derivatives provides a large class of compounds to investigate the gating mechanisms of KCNQ1-KCNE complexes
- …