582 research outputs found
Устойчивое водопотребление и геоэкологическая безопасность (на примере Западной Сибири)
Представлены результаты многолетних исследований факторов, определяющих состояние водных ресурсов, и тенденции изменения качества природных вод. Охарактеризованы элементы концепции обеспечения геоэкологической безопасности хозяйственно-питьевого водопотребления в Западной Сибири. Она учитывает естественно-природные (ландшафтно-климатические, гидрогеологические, экологические и др.), техногенные (эмиссия загрязняющих веществ, гидротехнические сооружения, добыча энергоресурсов и др.) и социально-экономические (уровень урбанизации, финансовое обеспечение и др.) факторы.The article deals with long-term studies of factors determining the state of water resources, and trends in the quality of natural water. The concept of providing geoecological safety of domestic and drinking water consumption in Western Siberia is described. It takes into account the natural (landscapeclimatic, hydro-geological, ecological, etc.), technogenic (emission of pollutants, hydraulic structures, extraction of energy resources, etc.) and socio-economic (level of urbanization, financial provision, etc.) factors
Structural Health Monitoring for Bridge Structures using Smart Sensors
Structural health monitoring (SHM) has drawn significant attention in recent decades because of its potential to reduce maintenance costs and increase the reliability of structures. An important class of structures that can potentially benefit from SHM are bridges, many of which are structurally deficient due to lack of adequate maintenance.
Through condition assessment of these bridges, an effective plan of maintenance can be determined, offering the possibility to prolong service life, as well as to prevent catastrophic disasters due to sudden collapse. To date, numerous damage detection algorithms have been proposed. Still, challenges remain in applying such algorithms to
monitor bridges in the field. In reality, the extent of an SHM system is limited by available budgets, which define the number of sensors that can be deployed.
A solution to include many sensors within a limited budget with increased efficiency
is to use a Wireless Smart Sensor Network (WSSN) because of the merits of low cost,
easy installation, and effective data management. An acceleration-based SHM algorithm for WSSN has been developed with a decentralized network topology. This approach has
been implemented into a modularized damage detection service. The SHM application is designed to leverage the on-board computation capability of the WSSN, reducing the transmitted data size by distributing the computation burden. The SHM application for WSSN has been validated in lab-scale experiments on a truss bridge model.
Nonetheless, the real challenge of SHM is in the deployment on full-scale bridges for continuous monitoring. The usability and stability of WSSN has been validated on an architectural staircase in the Siebel Center. Based on the usability investigation, the deployment of the world’s largest WSSN on the Jindo Bridge, a cable-stayed bridge has
been achieved in South Korea. The main purpose of the deployment was to validate the bridge monitoring system using WSSN and energy harvesting devices in a long-term manner.
The ultimate goal of this report is to deploy the developed on-board decentralized damage identification application using WSSN on a historic truss bridge. As a first step, a series of dynamic tests were conducted for modal analysis using both wired and wireless sensor systems. During the tests, the functionality of the wireless sensor system
with ISHMP Services Toolsuite was confirmed. For model-based damage identification approach developed herein, a finite element (FE) model was created. The initial FE model was updated based on a visual estimate of the corrosion. The updated model was used to generate baseline information for damage detection. Finally, the WSSN-based
autonomous SHM system using the decentralized damage detection application was deployed on the historic bridge. The permanent SHM system was installed on the bridge, and the damage detection application was successfully run on the bridge. The damage
detection results using the decentralized comprehensive application will be compared with those from the centralized approach using WSSN. The performance of WSSN and energy harvesting devices will be evaluated. In summary, this report provides a robust SHM system for bridge structures in use of WSSN.Financial support for this research was provided in part by a Samsung Scholarship, the National Science Foundation (NSF) under NSF grant CMS 06-00433 (Dr. S. C. Liu, Program Manager), and the Global Research Network program from the Natural Research Foundation in Korea (NRF-2008-220-D00117).Ope
Observation of two-dimensional Fermi surface and Dirac dispersion in YbMnSb
We present the crystal structure, electronic structure, and transport
properties of the material YbMnSb, a candidate system for the investigation
of Dirac physics in the presence of magnetic order. Our measurements reveal
that this system is a low-carrier-density semimetal with a 2D Fermi surface
arising from a Dirac dispersion, consistent with the predictions of density
functional theory calculations of the antiferromagnetic system. The low
temperature resistivity is very large, suggesting scattering in this system is
highly efficient at dissipating momentum despite its Dirac-like nature.Comment: 8 pages, 6 figure
PREVALENCE, PATHOLOGY, AND RISK FACTORS ASSOCIATED WITH STREPTOCOCCUS PHOCAE INFECTION IN SOUTHERN SEA OTTERS (ENHYDRA LUTRIS NEREIS), 2004-10
Generalized Pustular Psoriasis and Hepatic Dysfunction Associated with Oral Terbinafine Therapy
We report a case of 61-yr-old man with stable psoriasis who progressively developed generalized pustular eruption, erythroderma, fever, and hepatic dysfunction following oral terbinafine. Skin biopsy was compatible with pustular psoriasis. After discontinuation of terbinafine and initiating topical corticosteroid and calcipotriol combination with narrow band ultraviolet B therapy, patient'S condition slowly improved until complete remission was reached 2 weeks later. The diagnosis of generalized pustular psoriasis (GPP) induced by oral terbinafine was made. To our knowledge, this is the first report of GPP accompanied by hepatic dysfunction associated with oral terbinafine therapy
Salmonella and Campylobacter spp. in Northern Elephant Seals, California
Campylobacter and Salmonella spp. prevalence and antimicrobial drug sensitivity were determined in northern elephant seals that had not entered the water and seals that were stranded on the California coast. Stranded seals had a higher prevalence of pathogenic bacteria, possibly from terrestrial sources, which were more likely to be resistant
Dendrotoxin-κ suppresses tumor growth induced by human lung adenocarcinoma A549 cells in nude mice
Voltage-gated K+ (Kv) channels have been considered to be a regulator of membrane potential and neuronal excitability. Recently, accumulated evidence has indicated that several Kv channel subtypes contribute to the control of cell proliferation in various types of cells and are worth noting as potential emerging molecular targets of cancer therapy. In the present study, we investigated the effects of the Kv1.1-specific blocker, dendrotoxin-κ (DTX-κ), on tumor formation induced by the human lung adenocarcinoma cell line A549 in a xenograft model. Kv1.1 mRNA and protein was expressed in A549 cells and the blockade of Kv1.1 by DTX-κ, reduced tumor formation in nude mice. Furthermore, treatment with DTX-κ significantly increased protein expression of p21Waf1/Cip1, p27Kip1, and p15INK4B and significantly decreased protein expression of cyclin D3 in tumor tissues compared to the control. These results suggest that DTX-κ has anti-tumor effects in A549 cells through the pathway governing G1-S transition
Enteric bacterial pathogen detection in southern sea otters (Enhydra lutris nereis) is associated with coastal urbanization and freshwater runoff
Although protected for nearly a century, California’s sea otters have been slow to recover, in part due to exposure to fecally-associated protozoal pathogens like Toxoplasma gondii and Sarcocystis neurona. However, potential impacts from exposure to fecal bacteria have not been systematically explored. Using selective media, we examined feces from live and dead sea otters from California for specific enteric bacterial pathogens (Campylobacter, Salmonella, Clostridium perfringens, C. difficile and Escherichia coli O157:H7), and pathogens endemic to the marine environment (Vibrio cholerae, V. parahaemolyticus and Plesiomonas shigelloides). We evaluated statistical associations between detection of these pathogens in otter feces and demographic or environmental risk factors for otter exposure, and found that dead otters were more likely to test positive for C. perfringens, Campylobacter and V. parahaemolyticus than were live otters. Otters from more urbanized coastlines and areas with high freshwater runoff (near outflows of rivers or streams) were more likely to test positive for one or more of these bacterial pathogens. Other risk factors for bacterial detection in otters included male gender and fecal samples collected during the rainy season when surface runoff is maximal. Similar risk factors were reported in prior studies of pathogen exposure for California otters and their invertebrate prey, suggesting that land-sea transfer and/or facilitation of pathogen survival in degraded coastal marine habitat may be impacting sea otter recovery. Because otters and humans share many of the same foods, our findings may also have implications for human health
Serum TSH Level in Healthy Koreans and the Association of TSH with Serum Lipid Concentration and Metabolic Syndrome
- …