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Sample records for monitoring bacterial transport

  1. BACTERIAL TRANSPORT THROUGH HOMOGENEOUS SOIL

    Science.gov (United States)

    The transport of microorganisms in soils is of major importance for bioremediation of subsurface polluted zones and for pollution of groundwater with pathogens. A procedure for evaluating the relative mobility and recovery of bacteria in the soil matrix was developed. In the meth...

  2. Bacterial ferrous iron transport: the Feo system.

    Science.gov (United States)

    Lau, Cheryl K Y; Krewulak, Karla D; Vogel, Hans J

    2016-03-01

    To maintain iron homeostasis within the cell, bacteria have evolved various types of iron acquisition systems. Ferric iron (Fe(3+)) is the dominant species in an oxygenated environment, while ferrous iron (Fe(2+)) is more abundant under anaerobic conditions or at low pH. For organisms that must combat oxygen limitation for their everyday survival, pathways for the uptake of ferrous iron are essential. Several bacterial ferrous iron transport systems have been described; however, only the Feo system appears to be widely distributed and is exclusively dedicated to the transport of iron. In recent years, many studies have explored the role of the FeoB and FeoA proteins in ferrous iron transport and their contribution toward bacterial virulence. The three-dimensional structures for the Feo proteins have recently been determined and provide insight into the molecular details of the transport system. A highly select group of bacteria also express the FeoC protein from the same operon. This review will provide a comprehensive look at the structural and functional aspects of the Feo system. In addition, bioinformatics analyses of the feo operon and the Feo proteins have been performed to complement our understanding of this ubiquitous bacterial uptake system, providing a new outlook for future studies. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Transport equation for growing bacterial populations (II

    Directory of Open Access Journals (Sweden)

    Mohamed Boulanouar

    2012-12-01

    Full Text Available This article studies the growing bacterial population. Each bacterium is distinguished by its degree of maturity and its maturation velocity. To complete the study in [3], we describe the bacterial profile of this population by proving that the generated semigroup possesses an asynchronous exponential growth property.

  4. Monitoring Alpine Transportation Infrastructures Using Space Techniues

    Science.gov (United States)

    Strozzi, Tazio; Caduff, Rafael; Wegmuller, Urs; Brandstaetter, Michael; Kuhtreiber, Norbert

    2013-12-01

    Integration of satellite SAR interferometry, terrestrial radar interferometry and GPS is considered for the monitoring of ground motion along Alpine transportation infrastructures. We present results related to large-scale surveys in Switzerland along the Gotthard railway with satellite SAR interferometry and to a local monitoring of an active rockfall above the Pyhrn motorway in Austria using terrestrial radar interferometry and GPS.

  5. Bacterial transport suppressed by fluid shear

    Science.gov (United States)

    Rusconi, Roberto; Guasto, Jeffrey S.; Stocker, Roman

    2014-03-01

    Bacteria often live in dynamic fluid environments and flow can affect fundamental microbial processes such as nutrient uptake and infection. However, little is known about the consequences of the forces and torques associated with fluid flow on bacteria. Through microfluidic experiments, we show that fluid shear produces strong spatial heterogeneity in suspensions of motile bacteria, characterized by up to 70% cell depletion from low-shear regions due to `trapping’ in high-shear regions. Two mathematical models and a scaling analysis accurately capture these observations, including the maximal depletion at mean shear rates of 2.5-10 s-1, and reveal that trapping by shear originates from the competition between the cell alignment with the flow and the stochasticity in the swimming orientation. We show that this shear-induced trapping directly impacts widespread bacterial behaviours, by hampering chemotaxis and promoting surface attachment. These results suggest that the hydrodynamic environment may directly affect bacterial fitness and should be carefully considered in the study of microbial processes.

  6. Molecular properties of bacterial multidrug transporters

    NARCIS (Netherlands)

    Putman, M; van Veen, HW; Konings, WN

    2000-01-01

    One of the mechanisms that bacteria utilize to evade the toxic effects of antibiotics is the active extrusion of structurally unrelated drugs from the cell. Both intrinsic and acquired multidrug transporters play an important role in antibiotic resistance of several pathogens, including Neisseria go

  7. Bacterial degradation and corrosion of naphtha in transporting pipeline.

    Science.gov (United States)

    Rajasekar, A; Ponmariappan, S; Maruthamuthu, S; Palaniswamy, N

    2007-11-01

    Five naphtha hydrocarbon-degrading bacteria including representative strains of the two classified species (Serratia marcescensAR1, Bacillus pumilusAR2, Bacillus carboniphilus AR3, Bacillus megaterium AR4, and Bacillus cereus AR5) were identified by 16S rDNA gene sequence in a naphtha-transporting pipeline. The naphtha-degrading strains were able to be involved in the corrosion process of API 5LX steel and also utilized the naphtha as the sole carbon source. The biodegradation of naphtha by the bacterial isolates was characterized by gas chromatography-mass spectrometry. Weight-loss measurement on the corrosion of API 5LX steel in the presence/absence of consortia grown in naphtha-water aqueous media was performed. The scanning electron microscope observation showed that the consortia were able to attack the steel API 5LX surface, creating localized corrosion (pit). The biodegradation of naphtha by the strains AR1, AR2, AR3, AR4, and AR5 showed biodegradation efficiency of about 76.21, 67.20, 68.78, 68.78, and 68.15, respectively. The role of degradation on corrosion has been discussed. This basic study will be useful for the development of new approaches for the detection, monitoring, and control of microbial corrosion in a petroleum product pipeline.

  8. Extensive Identification of Bacterial Riboflavin Transporters and Their Distribution across Bacterial Species.

    Directory of Open Access Journals (Sweden)

    Ana Gutiérrez-Preciado

    Full Text Available Riboflavin, the precursor for the cofactors flavin mononucleotide (FMN and flavin adenine dinucleotide, is an essential metabolite in all organisms. While the functions for de novo riboflavin biosynthesis and riboflavin import may coexist in bacteria, the extent of this co-occurrence is undetermined. The RibM, RibN, RfuABCD and the energy-coupling factor-RibU bacterial riboflavin transporters have been experimentally characterized. In addition, ImpX, RfnT and RibXY are proposed as riboflavin transporters based on positional clustering with riboflavin biosynthetic pathway (RBP genes or conservation of the FMN riboswitch regulatory element. Here, we searched for the FMN riboswitch in bacterial genomes to identify genes encoding riboflavin transporters and assessed their distribution among bacteria. Two new putative riboflavin transporters were identified: RibZ in Clostridium and RibV in Mesoplasma florum. Trans-complementation of an Escherichia coli riboflavin auxotroph strain confirmed the riboflavin transport activity of RibZ from Clostridium difficile, RibXY from Chloroflexus aurantiacus, ImpX from Fusobacterium nucleatum and RfnT from Ochrobactrum anthropi. The analysis of the genomic distribution of all known bacterial riboflavin transporters revealed that most occur in species possessing the RBP and that some bacteria may even encode functional riboflavin transporters from two different families. Our results indicate that some species possess ancestral riboflavin transporters, while others possess transporters that appear to have evolved recently. Moreover, our data suggest that unidentified riboflavin transporters also exist. The present study doubles the number of experimentally characterized riboflavin transporters and suggests a specific, non-accessory role for these proteins in riboflavin-prototrophic bacteria.

  9. Bacterial transport of sulfate, molybdate, and related oxyanions.

    Science.gov (United States)

    Aguilar-Barajas, Esther; Díaz-Pérez, César; Ramírez-Díaz, Martha I; Riveros-Rosas, Héctor; Cervantes, Carlos

    2011-08-01

    Sulfur is an essential element for microorganisms and it can be obtained from varied compounds, sulfate being the preferred source. The first step for sulfate assimilation, sulfate uptake, has been studied in several bacterial species. This article reviews the properties of different bacterial (and archaeal) transporters for sulfate, molybdate, and related oxyanions. Sulfate uptake is carried out by sulfate permeases that belong to the SulT (CysPTWA), SulP, CysP/(PiT), and CysZ families. The oxyanions molybdate, tungstate, selenate and chromate are structurally related to sulfate. Molybdate is transported mainly by the high-affinity ModABC system and tungstate by the TupABC and WtpABC systems. CysPTWA, ModABC, TupABC, and WtpABC are homologous ATP-binding cassette (ABC)-type transporters with similar organization and properties. Uptake of selenate and chromate oxyanions occurs mainly through sulfate permeases.

  10. Transport of magnesium by a bacterial Nramp-related gene.

    Directory of Open Access Journals (Sweden)

    Jung-Ho Shin

    2014-06-01

    Full Text Available Magnesium is an essential divalent metal that serves many cellular functions. While most divalent cations are maintained at relatively low intracellular concentrations, magnesium is maintained at a higher level (∼0.5-2.0 mM. Three families of transport proteins were previously identified for magnesium import: CorA, MgtE, and MgtA/MgtB P-type ATPases. In the current study, we find that expression of a bacterial protein unrelated to these transporters can fully restore growth to a bacterial mutant that lacks known magnesium transporters, suggesting it is a new importer for magnesium. We demonstrate that this transport activity is likely to be specific rather than resulting from substrate promiscuity because the proteins are incapable of manganese import. This magnesium transport protein is distantly related to the Nramp family of proteins, which have been shown to transport divalent cations but have never been shown to recognize magnesium. We also find gene expression of the new magnesium transporter to be controlled by a magnesium-sensing riboswitch. Importantly, we find additional examples of riboswitch-regulated homologues, suggesting that they are a frequent occurrence in bacteria. Therefore, our aggregate data discover a new and perhaps broadly important path for magnesium import and highlight how identification of riboswitch RNAs can help shed light on new, and sometimes unexpected, functions of their downstream genes.

  11. Bound to be different: neurotransmitter transporters meet their bacterial cousins.

    Science.gov (United States)

    Henry, L Keith; Meiler, Jens; Blakely, Randy D

    2007-12-01

    The neurotransmitter transporters belonging to the solute carrier 6 (SLC6) family, including the gamma-aminobutyric acid (GAT), norepinephrine (NET), serotonin (SERT) and dopamine (DAT) transporters are extremely important drug targets of great clinical relevance. These Na+, Cl(-)-dependent transporters primarily function following neurotransmission to reset neuronal signaling by transporting neurotransmitter out of the synapse and back into the pre-synaptic neuron. Recent studies have tracked down an elusive binding site for Cl(-) that facilitates neurotransmitter transport using structural differences evident with bacterial family members (e.g., the Aquifex aeolicus leucine transporter LeuT Aa) that lack Cl(-) dependence. Additionally, the crystal structures of antidepressant-bound LeuT Aa reveals a surprising mode of drug interaction that may have relevance for medication development. The study of sequence and structural divergence between LeuT Aa and human SLC6 family transporters can thus inform us as to how and why neurotransmitter transporters evolved a reliance on extracellular Cl(-) to propel the transport cycle; what residue changes and helical rearrangements give rise to recognition of different substrates; and how drugs such as antidepressants, cocaine, and amphetamines halt (or reverse) the transport process.

  12. Bacterial monitoring with adhesive sheet in the international space station-"Kibo", the Japanese experiment module.

    Science.gov (United States)

    Ichijo, Tomoaki; Hieda, Hatsuki; Ishihara, Rie; Yamaguchi, Nobuyasu; Nasu, Masao

    2013-01-01

    Microbiological monitoring is important to assure microbiological safety, especially in long-duration space habitation. We have been continuously monitoring the abundance and diversity of bacteria in the International Space Station (ISS)-"Kibo" module to accumulate knowledge on microbes in the ISS. In this study, we used a new sampling device, a microbe-collecting adhesive sheet developed in our laboratory. This adhesive sheet has high operability, needs no water for sampling, and is easy to transport and store. We first validated the adhesive sheet as a sampling device to be used in a space habitat with regard to the stability of the bacterial number on the sheet during prolonged storage of up to 12 months. Bacterial abundance on the surfaces in Kibo was then determined and was lower than on the surfaces in our laboratory (10(5) cells [cm(2)](-1)), except for the return air grill, and the bacteria detected in Kibo were human skin microflora. From these aspects of microbial abundance and their phylogenetic affiliation, we concluded that Kibo has been microbiologically well maintained; however, microbial abundance may increase with the prolonged stay of astronauts. To ensure crew safety and understand bacterial dynamics in space habitation environments, continuous bacterial monitoring in Kibo is required.

  13. Use of intracranial pressure monitoring in bacterial meningitis

    DEFF Research Database (Denmark)

    Larsen, Lykke; Rom Poulsen, Frantz; Nielsen, Troels H

    2017-01-01

    BACKGROUND: The aim of this study was to evaluate the clinical outcome of patients with severe bacterial meningitis where intracranial pressure (ICP) monitoring has been performed. METHODS: A retrospective observational study including patients admitted 1st(.) January 2005 to 31st(.) December 2014...... = 0.034). Lower mean-cerebral perfusion pressure (CPP) was found to correlate with adverse outcome (p = 0.005). Cerebrospinal fluid (CSF) was drained in fourteen patients. Increased ICP (>20 mmHg) was observed in twenty four patients. No significant correlation was found between measured ICP and head...

  14. Rapid microbiological testing: monitoring the development of bacterial stress.

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    Boris Zavizion

    Full Text Available The ability to respond to adverse environments effectively along with the ability to reproduce are sine qua non conditions for all sustainable cellular forms of life. Given the availability of an appropriate sensing modality, the ubiquity and immediacy of the stress response could form the basis for a new approach for rapid biological testing. We have found that measuring the dielectric permittivity of a cellular suspension, an easily measurable electronic property, is an effective way to monitor the response of bacterial cells to adverse conditions continuously. The dielectric permittivity of susceptible and resistant strains of Escherichia coli and Staphylococcus aureus, treated with gentamicin and vancomycin, were measured directly using differential impedance sensing methods and expressed as the Normalized Impedance Response (NIR. These same strains were also heat-shocked and chemically stressed with Triton X-100 or H(2O(2. The NIR profiles obtained for antibiotic-treated susceptible organisms showed a strong and continuous decrease in value. In addition, the intensity of the NIR value decrease for susceptible cells varied in proportion to the amount of antibiotic added. Qualitatively similar profiles were found for the chemically treated and heat-shocked bacteria. In contrast, antibiotic-resistant cells showed no change in the NIR values in the presence of the drug to which it is resistant. The data presented here show that changes in the dielectric permittivity of a cell suspension are directly correlated with the development of a stress response as well as bacterial recovery from stressful conditions. The availability of a practical sensing modality capable of monitoring changes in the dielectric properties of stressed cells could have wide applications in areas ranging from the detection of bacterial infections in clinical specimens to antibiotic susceptibility testing and drug discovery.

  15. Monitoring Transport Across Modified Nanoporous Alumina Membranes

    Directory of Open Access Journals (Sweden)

    Erich D. Steinle

    2007-11-01

    Full Text Available This paper describes the use of several characterization methods to examinealumina nanotubule membranes that have been modified with specific silanes. The functionof these silanes is to alter the transport properties through the membrane by changing thelocal environment inside the alumina nanotube. The presence of alkyl groups, either long(C18 or short and branched (isopropyl hydrocarbon chains, on these silanes significantlydecreases the rate of transport of permeant molecules through membranes containingalumina nanotubes as monitored via absorbance spectroscopy. The presence of an ionicsurfactant can alter the polarity of these modified nanotubes, which correlates to anincreased transport of ions. Fluorescent spectroscopy is also utilized to enhance thesensitivity of detecting these permeant molecules. Confirmation of the alkylsilaneattachment to the alumina membrane is achieved with traditional infrared spectroscopy,which can also examine the lifetime of the modified membrane. The physical parameters ofthese silane-modified porous alumina membranes are studied via scanning electronmicroscopy. The alumina nanotubes are not physically closed off or capped by the silanesthat are attached to the alumina surfaces.

  16. Ternary Complexation on Bacterial Surfaces: Implications for Subsurface Anion Transport

    Science.gov (United States)

    Maclean, L. C.; Higginbottom, C. M.; Fowle, D. A.

    2002-12-01

    The physical, chemical, and biological controls on contaminant mobilities in aquatic ecosystems must be determined to establish the threat that contamination poses to the environment. Quantitative models of contaminant mobilities are required as a prerequisite to guide remediation efforts and to prioritize the potential hazard to the ecosystem of each contaminated site. It is well established that mineral surface adsorption is an important control on contaminant mobilities, and many studies have utilized thermodynamics to quantify metal/organic adsorption in order to yield predictive models of contaminant transport. However, these models of contaminant transport may not be representative of the reactions which control contaminant mobilities as most mineral surfaces are coated with organic acids, bacteria, and extracellular polymers. Numerous laboratory studies have demonstrated that bacterial cell walls have a high affinity for binding metal cations, and field studies indicate that a significant proportion of bacteria cells and associated extracellular matrices are coated with small scale hydrous metal oxides. The small size of bacteria, and in many cases the nanoscale of their associated mineral phases, suggests these bacteria-mineral composites may represent a large proportion of surface area exposed to fluid flow. Therefore, due to the affinity of bacterial cell walls for cations and biominerals, bacteria may also have a significant impact on anionic contaminant mobility in many natural systems. The extent of metal-bacteria adsorption reactions varies drastically as a function of pH and solution chemistry. Current adsorption models have focused on the interactions of positively charged metal cations with bacterial surfaces, however in many oxidizing environments metals such as Cr exist as anions or anionic complexes. We have studied the ability of non-metabolizing cells of the bacterial species Bacillus subtilis and Shewanella putrifaciens to adsorb aqueous Cr

  17. Sediment transport monitoring for sustainable hydropower development

    Science.gov (United States)

    Rüther, Nils; Guerrero, Massimo; Stokseth, Siri

    2015-04-01

    Due to the increasing demand of CO2 neutral energy not only in Europe but also in World, a relatively large amount of new hydro power plants (HPP) are built. In addition, will existing ones refurbished and renewed in order to run them more cost effective. A huge thread to HPPs is incoming sediments in suspension from the rivers upstream. The sediments settle in the reservoir and reduce the effective head and volume and reduce consequently the life time of the reservoir. In addition are the fine sediments causing severe damages to turbines and infrastructure of a HPP. For estimating the amount of incoming sediments in suspension and therefore planning efficient counter measures, it is essential to monitor the rivers within the catchment of the HPP for suspended sediments. This work is considerably time consuming and requires highly educated personnel and is therefore expensive. Consequently will this study present a method to measure suspended sediment concentrations and their grain size distribution with a dual frequency acoustic Doppler current profiler (ADCP). This method is more cost effective and reliable in comparison to traditional measurement methods. Having more detailed information about the sediments being transported in a river, the hydro power plant can be planned, built, and operated much more efficiently and sustainable. The two horizontal ADCPs are installed at a measurement cross section in the Devoll river in Albania. To verify the new method, the suspended load concentrations will be monitored also in the traditional ways at the same cross sections. It is planned to install turbidity measurement devices included with an automatic sampling devices. It is also planned to use an optical in situ measurement device (LISST SL by Sequoia Inc.) to have detailed information of sediment concentration and grain sizes over the depth.

  18. Rolling vibes : continuous transport infrastructure monitoring

    NARCIS (Netherlands)

    Seraj, Fatjon

    2017-01-01

    Transport infrastructure is a people to people technology, in the sense that is build by people to serve people, by facilitating transportation, connection and communication. People improved infrastructure by applying simple methods derived from their sensing and thinking. Since the early ages,

  19. Impact of fluorochrome stains used to study bacterial transport in shallow aquifers on motility and chemotaxis of Pseudomonas species.

    Science.gov (United States)

    Toepfer, J Amanda; Ford, Roseanne M; Metge, David; Harvey, Ronald W

    2012-07-01

    One of the most common methods of tracking movement of bacteria in groundwater environments involves a priori fluorescent staining. A major concern in using these stains to label bacteria in subsurface injection-and-recovery studies is the effect they may have on the bacterium's transport properties. Previous studies investigated the impact of fluorophores on bacterial surface properties (e.g. zeta potential). However, no previous study has looked at the impact of fluorescent staining on swimming speed and chemotaxis. It was found that DAPI lowered the mean population swimming speed of Pseudomonas putida F1 by 46% and Pseudomonas stutzeri by 55%. DAPI also inhibited the chemotaxis in both strains. The swimming speeds of P. putida F1 and P. stutzeri were diminished slightly by CFDA/SE, but not to a statistically significant extent. CFDA/SE had no effect on chemotaxis of either strain to acetate. SYBR(®) Gold had no effect on swimming speed or the chemotactic response to acetate for either strain. This research indicates that although DAPI may not affect sorption to grain surfaces, it adversely affects other potentially important transport properties such as swimming and chemotaxis. Consequently, bacterial transport studies conducted using DAPI are biased to nonchemotactic conditions and do not appear to be suitable for monitoring the effect of chemotaxis on bacterial transport in shallow aquifers.

  20. 40 CFR 52.140 - Monitoring transportation trends.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Monitoring transportation trends. 52.140 Section 52.140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Arizona § 52.140 Monitoring...

  1. ABC transporters : Lessons from a bacterial oligopeptide uptake system

    NARCIS (Netherlands)

    Doeven, Mark Koop

    2006-01-01

    ABC transporters are proteins that are involved in the uptake of nutrients and excretion of harmful substances in biological cells. Defects in human ABC transporters can result in severe diseases. Too high ABC transporter activity can lead to non-responsiveness of cancercells to chemotherapy, and

  2. Impact of lux gene insertion on bacterial surface properties and transport.

    Science.gov (United States)

    Chen, Gang; Srinivasa Ranga, Vijay Penagonda; Mao, Yongjun; Chen, Kevin; Qiao, Hanzi

    2008-03-01

    Genetic markers have been in popular use for tracing microbial movement in the environment. However, the impact of genetic marker insertion on microbial surface properties and consequent transport is often ignored. For this research, we investigated the impact of luminescence-based genetic marker insertion on bacterial surface properties and transport. Typical Gram-positive bacterial strains of Lactobacillus casei, Streptococcus mitis and Micrococcus luteus were used as model bacterial strains in this research. We manipulated gene transfer to observe the impact of lux gene insertion on bacterial surface properties based on contact angle measurements, and we conducted column experiments to evaluate the impact of lux gene insertion on bacterial transport. After lux gene insertion, bacterial interactions with the porous media increased, demonstrating stronger deposition potential in the porous media. Accordingly, retention of the daughter strains increased. Lux gene insertion also resulted in an increase in bacterial dispersion and equilibrium adsorption in the porous media. The bacterial deposition coefficient was found to correlate with the free energy of interactions between bacteria and the porous media.

  3. Bacterial multidrug resistance mediated by a homologue of the human multidrug transporter P-glycoprotein

    NARCIS (Netherlands)

    Konings, WN; Poelarends, GJ

    2002-01-01

    Most ATP-binding cassette (ABC) multidrug transporters known to date are of eukaryotic origin, such as the P-glycoproteins (Pgps) and multidrug resistance-associated proteins (MRPs). Only one well-characterized ABC multidrug transporter, LmrA, is of bacterial origin. On the basis of its structural a

  4. What is an antidepressant binding site doing in a bacterial transporter?

    Science.gov (United States)

    Rudnick, Gary

    2007-09-21

    LeuT is a bacterial amino acid transporter belonging to a large family of membrane proteins, including the neurotransmitter transporters that are targets for antidepressant drugs. The high-resolution structure of LeuT has provided an important model for understanding structure and function in this family. Two recent papers found that LeuT can bind tricyclic antidepressants, raising the possibility that it may also serve as a model for the pharmacological properties of neurotransmitter transporters.

  5. Effect of cell physicochemical characteristics and motility on bacterial transport in groundwater

    Science.gov (United States)

    Becker, M.W.; Collins, S.A.; Metge, D.W.; Harvey, R.W.; Shapiro, A.M.

    2004-01-01

    The influence of physicochemical characteristics and motility on bacterial transport in groundwater were examined in flow-through columns. Four strains of bacteria isolated from a crystalline rock groundwater system were investigated, with carboxylate-modified and amidine-modified latex microspheres and bromide as reference tracers. The bacterial isolates included a gram-positive rod (ML1), a gram-negative motile rod (ML2), a nonmotile mutant of ML2 (ML2m), and a gram-positive coccoid (ML3). Experiments were repeated at two flow velocities, in a glass column packed with glass beads, and in another packed with iron-oxyhydroxide coated glass beads. Bacteria breakthrough curves were interpreted using a transport equation that incorporates a sorption model from microscopic observation of bacterial deposition in flow-cell experiments. The model predicts that bacterial desorption rate will decrease exponentially with the amount of time the cell is attached to the solid surface. Desorption kinetics appeared to influence transport at the lower flow rate, but were not discernable at the higher flow rate. Iron-oxyhydroxide coatings had a lower-than-expected effect on bacterial breakthrough and no effect on the microsphere recovery in the column experiments. Cell wall type and shape also had minor effects on breakthrough. Motility tended to increase the adsorption rate, and decrease the desorption rate. The transport model predicts that at field scale, desorption rate kinetics may be important to the prediction of bacteria transport rates. ?? 2003 Elsevier B.V. All rights reserved.

  6. GPS technology to monitoring auto transport in Latvia

    Directory of Open Access Journals (Sweden)

    Victor Boicov

    2014-01-01

    Full Text Available This paper is the result of authors’ activities in the field of research and implementation of global positioning system (GPS technologies in the Latvian car industry. The subject of study is the characteristics of Latvian auto transport management. Topicality and importance of this issue are related with new GPS applications to auto transport monitoring. Principal practical application of this paper is reflected in the methodology developed by the authors in order to design, elaborate and introduce GPS systems.

  7. Development of monitoring applications for refrigerated perishable goods transportation

    OpenAIRE

    Ruiz García, Luis

    2011-01-01

    Perishable food products are at risk of suffering various damages along the cold chain. The parties involved should control and monitor the conditions of goods in order to ensure their quality for consumers and to comply with all legal requirements. Among environmental parameters during transport, temperature is the most important in prolonging the shelf life of the products. The aim of this PhD thesis is to improve the control during transport, storage and distribution through the developmen...

  8. Lessons learned from bacterial transport research at the South Oyster Site

    Energy Technology Data Exchange (ETDEWEB)

    Scheibe, T.; Hubbard, S.S.; Onstott, T.C.; DeFlaun, M.F.

    2011-04-01

    This paper provides a review of bacterial transport experiments conducted by a multi-investigator, multi-institution, multi-disciplinary team of researchers under the auspices of the U. S. Department of Energy (DOE). The experiments were conducted during the time period 1999-2001 at a field site near the town of Oyster, Virginia known as the South Oyster Site, and included four major experimental campaigns aimed at understanding and quantifying bacterial transport in the subsurface environment. Several key elements of the research are discussed here: (1) quantification of bacterial transport in physically, chemically and biologically heterogeneous aquifers, (2) evaluation of the efficacy of conventional colloid filtration theory, (3) scale effects in bacterial transport, (4) development of new methods for microbial enumeration and screening for low adhesion strains, (5) application of novel hydrogeophysical techniques for aquifer characterization, and (6) experiences regarding management of a large field research effort. Lessons learned are summarized in each of these areas. The body of literature resulting from South Oyster Site research has been widely cited and continues to influence research into the controls exerted by aquifer heterogeneity on reactive transport (including microbial transport). It also served as a model (and provided valuable experience) for subsequent and ongoing highly-instrumented field research efforts conducted by DOE-sponsored investigators.

  9. Guidelines for monitoring bulk tank milk somatic cell and bacterial counts.

    Science.gov (United States)

    Jayarao, B M; Pillai, S R; Sawant, A A; Wolfgang, D R; Hegde, N V

    2004-10-01

    This study was conducted to establish guidelines for monitoring bulk tank milk somatic cell count and bacterial counts, and to understand the relationship between different bacterial groups that occur in bulk tank milk. One hundred twenty-six dairy farms in 14 counties of Pennsylvania participated, each providing one bulk tank milk sample every 15 d for 2 mo. The 4 bulk tank milk samples from each farm were examined for bulk tank somatic cell count and bacterial counts including standard plate count, preliminary incubation count, laboratory pasteurization count, coagulase-negative staphylococcal count, environmental streptococcal count, coliform count, and gram-negative noncoliform count. The milk samples were also examined for presence of Staphylococcus aureus, Streptococcus agalactiae, and Mycoplasma. The bacterial counts of 4 bulk tank milk samples examined over an 8-wk period were averaged and expressed as mean bacterial count per milliliter. The study revealed that an increase in the frequency of isolation of Staphylococcus aureus and Streptococcus agalactiae was significantly associated with an increased bulk tank somatic cell count. Paired correlation analysis showed that there was low correlation between different bacterial counts. Bulk tank milk with low (standard plate count also had a significantly low level of mean bulk tank somatic cell count (count (count (counts (count (count was less likely to be associated with somatic cell or other bacterial counts. Herd size and farm management practices had considerable influence on somatic cell and bacterial counts in bulk tank milk. Dairy herds that used automatic milking detachers, sand as bedding material, dip cups for teat dipping instead of spraying, and practiced pre-and postdipping had significantly lower bulk tank somatic cell and/or bacterial counts. In conclusion, categorized bulk tank somatic cell and bacterial counts could serve as indicators and facilitate monitoring of herd udder health and milk

  10. Effects of starvation on bacterial transport through porous media

    Science.gov (United States)

    Cunningham, Alfred B.; Sharp, Robert R.; Caccavo, Frank; Gerlach, Robin

    2007-06-01

    A major problem preventing widespread implementation of microbial injection strategies for bioremediation and/or microbially enhanced oil recovery is the tendency of bacteria to strongly adhere to surfaces in the immediate vicinity of the injection point. Long term (weeks to months) nutrient starvation of bacteria prior to injection can decrease attachment and enhance transport through porous media. This paper summarizes results of starvation-enhanced transport experiments in sand columns of 30 cm, 3 m, and 16 m in length. The 16 m column experiments compared transport, breakthrough and distribution of adhered cells for starved and vegetative cultures of Klebsiella oxytoca, a copious biofilm producer. Results from these experiments were subsequently used to design and construct a field-scale biofilm barrier using starved Pseudomonas fluorescens. The 30 cm and 3 m sand columns experiments investigated starvation-enhanced transport of Shewanella algae BrY, a dissimilatory metal-reducing bacterium. In both cases the vegetative cells adsorbed onto the sand in higher numbers than the starved cells, especially near the entrance of the column. These results, taken together with studies cited in the literature, indicate that starved cells penetrate farther (i.e. higher breakthrough concentration) and adsorb more uniformly along the flow path than vegetative cells.

  11. The Use of Advanced Transportation Monitoring Data for Official Statistics

    NARCIS (Netherlands)

    Y. Ma (Yinyi)

    2016-01-01

    markdownabstractTraffic and transportation statistics are mainly published as aggregated information, and are traditionally based on surveys or secondary data sources, like public registers and companies’ administrations. Nowadays, advanced monitoring systems are installed in the road network, offering

  12. Antidepressant Binding Site in a Bacterial Homologue of Neurotransmitter Transporters

    Energy Technology Data Exchange (ETDEWEB)

    Singh,S.; Yamashita, A.; Gouaux, E.

    2007-01-01

    Sodium-coupled transporters are ubiquitous pumps that harness pre-existing sodium gradients to catalyse the thermodynamically unfavourable uptake of essential nutrients, neurotransmitters and inorganic ions across the lipid bilayer. Dysfunction of these integral membrane proteins has been implicated in glucose/galactose malabsorption, congenital hypothyroidism, Bartter's syndrome, epilepsy, depression, autism and obsessive-compulsive disorder. Sodium-coupled transporters are blocked by a number of therapeutically important compounds, including diuretics, anticonvulsants and antidepressants, many of which have also become indispensable tools in biochemical experiments designed to probe antagonist binding sites and to elucidate transport mechanisms. Steady-state kinetic data have revealed that both competitive and noncompetitive modes of inhibition exist. Antagonist dissociation experiments on the serotonin transporter (SERT) have also unveiled the existence of a low-affinity allosteric site that slows the dissociation of inhibitors from a separate high-affinity site. Despite these strides, atomic-level insights into inhibitor action have remained elusive. Here we screen a panel of molecules for their ability to inhibit LeuT, a prokaryotic homologue of mammalian neurotransmitter sodium symporters, and show that the tricyclic antidepressant (TCA) clomipramine noncompetitively inhibits substrate uptake. Cocrystal structures show that clomipramine, along with two other TCAs, binds in an extracellular-facing vestibule about 11 {angstrom} above the substrate and two sodium ions, apparently stabilizing the extracellular gate in a closed conformation. Off-rate assays establish that clomipramine reduces the rate at which leucine dissociates from LeuT and reinforce our contention that this TCA inhibits LeuT by slowing substrate release. Our results represent a molecular view into noncompetitive inhibition of a sodium-coupled transporter and define principles for the

  13. Impact of Bacterial NO3- Transport on Sediment Biogeochemistry

    DEFF Research Database (Denmark)

    Nielsen, Lars Peter

    2005-01-01

    Experiments demonstrated that Beggiatoa could induce a H2S-depleted suboxic zone of more than 10 mm in marine sediments and cause a divergence in sediment NO3- reduction from denitrification to dissimilatory NO3- reduction to ammonium. pH, O2, and H2S profiles indicated that the bacteria oxidized......2S with NO3- and transported S0 to the sediment surface for aerobic oxidation....

  14. Impact of bacterial NO3- transport on sediment biogeochemistry

    DEFF Research Database (Denmark)

    Sayama, Mikio; Risgaard-Petersen, Nils; Nielsen, Lars Peter

    2005-01-01

    Experiments demonstrated that Beggiatoa could induce a H2S-depleted suboxic zone of more than 10 mm in marine sediments and cause a divergence in sediment NO3– reduction from denitrification to dissimilatory NO3– reduction to ammonium. pH, O2, and H2S profiles indicated that the bacteria oxidized H......2S with NO3– and transported S0 to the sediment surface for aerobic oxidation....

  15. Flow cytometric bacterial cell counts challenge conventional heterotrophic plate counts for routine microbiological drinking water monitoring.

    Science.gov (United States)

    Van Nevel, S; Koetzsch, S; Proctor, C R; Besmer, M D; Prest, E I; Vrouwenvelder, J S; Knezev, A; Boon, N; Hammes, F

    2017-04-15

    Drinking water utilities and researchers continue to rely on the century-old heterotrophic plate counts (HPC) method for routine assessment of general microbiological water quality. Bacterial cell counting with flow cytometry (FCM) is one of a number of alternative methods that challenge this status quo and provide an opportunity for improved water quality monitoring. After more than a decade of application in drinking water research, FCM methodology is optimised and established for routine application, supported by a considerable amount of data from multiple full-scale studies. Bacterial cell concentrations obtained by FCM enable quantification of the entire bacterial community instead of the minute fraction of cultivable bacteria detected with HPC (typically water samples per day, depending on the laboratory and selected staining procedure(s). Moreover, many studies have shown FCM total (TCC) and intact (ICC) cell concentrations to be reliable and robust process variables, responsive to changes in the bacterial abundance and relevant for characterising and monitoring drinking water treatment and distribution systems. The purpose of this critical review is to initiate a constructive discussion on whether FCM could replace HPC in routine water quality monitoring. We argue that FCM provides a faster, more descriptive and more representative quantification of bacterial abundance in drinking water.

  16. Assessment of Two Alternative Sample Transport and Fixation Methods in the Microbiological Diagnosis of Bacterial Vaginosis

    Directory of Open Access Journals (Sweden)

    Erica Eason

    2003-01-01

    Full Text Available BACKGROUND: The standard method for specimen collection and transport for microbiological diagnosis of bacterial vaginosis is an air-dried smear of vaginal secretions, promptly heat- or alcohol-fixed, Gram-stained and scored by Nugent's criteria.

  17. Animal welfare monitoring and livestock traceability during transport

    Directory of Open Access Journals (Sweden)

    Adriano Di Pasquale

    2009-12-01

    Full Text Available The authors present an experimental project that aims to establish an effective navigation system in accordance with European Council Regulation 1/2005 concerning animal welfare during transport. The prototype created during the project consists of both hardware and software components. An onboard unit is installed at truck level. It collects and transmits real-time information of the animal transport to a remote receiver database. A Web/geographic information system (GIS application is used to analyse and monitor the information received. The architecture of the hardware and software of the project is presented, focusing on the features of the Web-GIS application.

  18. Facilitated transport of heavy metals by bacterial colloids in sand columns

    Science.gov (United States)

    Guiné, V.; Martins, J.; Gaudet, J. P.

    2003-05-01

    The aim of this work is to evaluate the ability of biotic collois (e.g. bacterial cells) to facilitate the transport of heavy metals in soils. and to identify the main factors influencing colloid transport in order to detelmine the geo-chemical conditions where this secondary transport process may become dominant. The model colloids studied here are living cells of Escherichia coli and Ralstonia metallidurans. We studied the transport of mercury zinc, and cadmium in columns of Fontainebleau sand. The properties (i.e. optical and morphological properties, charge (zeta potential, zeta) and hydrophobia (water/hexadecane distribution parameter, K_{hw})) of the bacterial cells surface were characterised, as well as their potential for heavy metals sorption (kinetic and isotherm). Both surface charge (zeta=-54 and -14 mV) and hydrophobia (K_{hw} = 0.25 and 0.05) differ strongly for the two bacteria. Column studies were conducted with bacteria and heavy metals separately or simultaneously. The cell surface differences led to different transport behaviour of the two bacteria, although the retardation factor is close to 1 for both. We observed that colloid mobility increases when increasing bacterial cells concentration and when decreasing the ionic strength. We also observed that bacterial colloids appeared as excellent vectors for Hg, Zn and Cd. Indeed, heavy metals adsorbed on the Fontainebleau sand when injected alone in columns (retardation factors of 1.4 ; 2.9 and 3.8 for Hg, Zn and Cd, respectively); whereas no retardation (R≈1) is observed when injected in the presence of both bacteria. Moreover, transport of bio-sorbed metal appears to be 4 to 6 times higher than dissolved heavy-metal.

  19. Active Transport of Phosphorylated Carbohydrates Promotes Intestinal Colonization and Transmission of a Bacterial Pathogen.

    Directory of Open Access Journals (Sweden)

    Brandon Sit

    2015-08-01

    Full Text Available Efficient acquisition of extracellular nutrients is essential for bacterial pathogenesis, however the identities and mechanisms for transport of many of these substrates remain unclear. Here, we investigate the predicted iron-binding transporter AfuABC and its role in bacterial pathogenesis in vivo. By crystallographic, biophysical and in vivo approaches, we show that AfuABC is in fact a cyclic hexose/heptose-phosphate transporter with high selectivity and specificity for a set of ubiquitous metabolites (glucose-6-phosphate, fructose-6-phosphate and sedoheptulose-7-phosphate. AfuABC is conserved across a wide range of bacterial genera, including the enteric pathogens EHEC O157:H7 and its murine-specific relative Citrobacter rodentium, where it lies adjacent to genes implicated in sugar sensing and acquisition. C. rodentium ΔafuA was significantly impaired in an in vivo murine competitive assay as well as its ability to transmit infection from an afflicted to a naïve murine host. Sugar-phosphates were present in normal and infected intestinal mucus and stool samples, indicating that these metabolites are available within the intestinal lumen for enteric bacteria to import during infection. Our study shows that AfuABC-dependent uptake of sugar-phosphates plays a critical role during enteric bacterial infection and uncovers previously unrecognized roles for these metabolites as important contributors to successful pathogenesis.

  20. Active Transport of Phosphorylated Carbohydrates Promotes Intestinal Colonization and Transmission of a Bacterial Pathogen

    Science.gov (United States)

    Sit, Brandon; Crowley, Shauna M.; Bhullar, Kirandeep; Lai, Christine Chieh-Lin; Tang, Calvin; Hooda, Yogesh; Calmettes, Charles; Khambati, Husain; Ma, Caixia; Brumell, John H.; Schryvers, Anthony B.; Vallance, Bruce A.; Moraes, Trevor F.

    2015-01-01

    Efficient acquisition of extracellular nutrients is essential for bacterial pathogenesis, however the identities and mechanisms for transport of many of these substrates remain unclear. Here, we investigate the predicted iron-binding transporter AfuABC and its role in bacterial pathogenesis in vivo. By crystallographic, biophysical and in vivo approaches, we show that AfuABC is in fact a cyclic hexose/heptose-phosphate transporter with high selectivity and specificity for a set of ubiquitous metabolites (glucose-6-phosphate, fructose-6-phosphate and sedoheptulose-7-phosphate). AfuABC is conserved across a wide range of bacterial genera, including the enteric pathogens EHEC O157:H7 and its murine-specific relative Citrobacter rodentium, where it lies adjacent to genes implicated in sugar sensing and acquisition. C. rodentium ΔafuA was significantly impaired in an in vivo murine competitive assay as well as its ability to transmit infection from an afflicted to a naïve murine host. Sugar-phosphates were present in normal and infected intestinal mucus and stool samples, indicating that these metabolites are available within the intestinal lumen for enteric bacteria to import during infection. Our study shows that AfuABC-dependent uptake of sugar-phosphates plays a critical role during enteric bacterial infection and uncovers previously unrecognized roles for these metabolites as important contributors to successful pathogenesis. PMID:26295949

  1. Fast and Inexpensive Detection of Bacterial Viability and Drug Effectiveness through Metabolic Monitoring

    Directory of Open Access Journals (Sweden)

    Sondos Ayyash

    2016-11-01

    Full Text Available Conventional methods for the detection of bacterial infection such as DNA or immunoassays are expensive, time consuming, or not definitive and thus may not provide all the information sought by medical professionals. In particular, it is difficult to obtain information about viability or drug effectiveness, which is crucial to formulate a treatment. Bacterial culture tests are the “gold standard” because they are inexpensive and do not require extensive sample preparation, and most importantly, provide all the necessary information sought by healthcare professionals, such as bacterial presence, viability and drug effectiveness. These conventional culture methods, however, have a long turnaround time, anywhere between 1 day and 4 weeks. Here, we solve this problem by monitoring the growth of bacteria in thousands of nanowells simultaneously to more quickly identify their presence in the sample and their viability. The segmentation of a sample with low bacterial concentration into thousands of nanoliter wells digitizes the samples and increases the effective concentration in those wells that contain bacteria. We monitor the metabolism of aerobic bacteria by using an oxygen-sensitive fluorophore, ruthenium tris (2,2’-diprydl dichloride hexahydrate (RTDP, which allows us to monitor the dissolved oxygen concentration in the nanowells. Using E. coli K12 as a model pathogen, we demonstrate that the detection time of E. coli can be as fast as 35–60 min with sample concentrations varying from 104 (62 min for detection, 106 (42 min and 108 cells/mL (38 min. More importantly, we also demonstrate that reducing the well size can reduce the detection time. Finally we show that drug effectiveness information can be obtained in this format by loading the wells with the drug and monitoring the metabolism of the bacteria. The method that we have developed is low cost, simple, requires minimal sample preparation and can potentially be used with a wide

  2. [Use of transport medium in sputum bacterial culture examination of lower airway infection].

    Science.gov (United States)

    Muraki, Masato; Kitaguchi, Sayako; Ichihashi, Hideo; Tsuji, Fumio; Ohmori, Takashi; Haraguchi, Ryuta; Tohda, Yuji

    2006-06-01

    Our medical institution does not have a bacterial culture facility, requiring outsourcing of bacterial culture tests. Due to the time elapsed from the time of specimen collection to culturing, the identification of causative bacteria in respiratory tract infections tends to be difficult. We therefore used transport medium for sputum bacteria examinations. Expectorated purulent or purulent-mucous sputum specimens were collected from 32 patients with lower respiratory tract infection. We divided each of the sputum specimens into the two treatment groups: transport medium (Seedswab gamma2) ndar and stad disinfection container. Paired samples prepared from each patient were sent out for bacterial culture together. The time elapsed from collection to delivery to the lab were as follows: day 0 (same day, n = 14 patients), day 1 (n = 15), day 2 (n = 2), and day 3 (n = 1). The identified causative bacteria were Streptococcus pneumoniae (n = 6 patients), Haemophilus influenzae (n =5), Pseudomonas aeruginosa (n = 4), Staphylococcus aureus (n = 2), Moraxella catarrhalis (n = 2), Klebsiella pneumoniae (n = 1), and Streptococcus agalactiae (n = 1). Samples prepared by each of the two methods gave similar results. The utility of transport medium for examination of general bacteria for lower airway infection from sputum samples was not demonstrated. The rate of detection of bacteria decreased, when the transport of samples was delayed. Therefore, we need to send the sputum specimens as quickly as possible.

  3. Low Resolution Structure of a Bacterial SLC26 Transporter Reveals Dimeric Stoichiometry and Mobile Intracellular Domains*

    Science.gov (United States)

    Compton, Emma L. R.; Karinou, Eleni; Naismith, James H.; Gabel, Frank; Javelle, Arnaud

    2011-01-01

    The SLC26/SulP (solute carrier/sulfate transporter) proteins are a superfamily of anion transporters conserved from bacteria to man, of which four have been identified in human diseases. Proteins within the SLC26/SulP family exhibit a wide variety of functions, transporting anions from halides to carboxylic acids. The proteins comprise a transmembrane domain containing between 10–12 transmembrane helices followed a by C-terminal cytoplasmic sulfate transporter and anti-sigma factor antagonist (STAS) domain. These proteins are expected to undergo conformational changes during the transport cycle; however, structural information for this family remains sparse, particularly for the full-length proteins. To address this issue, we conducted an expression and detergent screen on bacterial Slc26 proteins. The screen identified a Yersinia enterocolitica Slc26A protein as the ideal candidate for further structural studies as it can be purified to homogeneity. Partial proteolysis, co-purification, and analytical size exclusion chromatography demonstrate that the protein purifies as stable oligomers. Using small angle neutron scattering combined with contrast variation, we have determined the first low resolution structure of a bacterial Slc26 protein without spectral contribution from the detergent. The structure confirms that the protein forms a dimer stabilized via its transmembrane core; the cytoplasmic STAS domain projects away from the transmembrane domain and is not involved in dimerization. Supported by additional biochemical data, the structure suggests that large movements of the STAS domain underlie the conformational changes that occur during transport. PMID:21659513

  4. Hydrogeological characterization of the South Oyster bacterial transport site using geophysical data

    Science.gov (United States)

    Hubbard, Susan S.; Chen, Jinsong; Peterson, John; Majer, Ernest L.; Williams, Kenneth H.; Swift, Donald J.; Mailloux, Brian; Rubin, Yoram

    2001-10-01

    A multidisciplinary research team has conducted a field-scale bacterial transport study within an uncontaminated sandy Pleistocene aquifer near Oyster, Virginia. The overall goal of the project was to evaluate the importance of heterogeneities in controlling the field-scale transport of bacteria that are injected into the ground for remediation purposes. Geochemical, hydrological, geological, and geophysical data were collected to characterize the site prior to conducting chemical and bacterial injection experiments. In this paper we focus on results of a hydrogeological characterization effort using geophysical data collected across a range of spatial scales. The geophysical data employed include surface ground-penetrating radar, radar cross-hole tomography, seismic cross-hole tomography, cone penetrometer, and borehole electromagnetic flowmeter. These data were used to interpret the subregional and local stratigraphy, to provide high-resolution hydraulic conductivity estimates, and to provide information about the log conductivity spatial correlation function. The information from geophysical data was used to guide and assist the field operations and to constrain the numerical bacterial transport model. Although more field work of this nature is necessary to validate the usefulness and cost-effectiveness of including geophysical data in the characterization effort, qualitative and quantitative comparisons between tomographically obtained flow and transport parameter estimates with hydraulic well bore and bromide breakthrough measurements suggest that geophysical data can provide valuable, high-resolution information. This information, traditionally only partially obtainable by performing extensive and intrusive well bore sampling, may help to reduce the ambiguity associated with hydrogeological heterogeneity that is often encountered when interpreting field-scale bacterial transport data.

  5. Discovery of an archetypal protein transport system in bacterial outer membranes.

    Science.gov (United States)

    Selkrig, Joel; Mosbahi, Khedidja; Webb, Chaille T; Belousoff, Matthew J; Perry, Andrew J; Wells, Timothy J; Morris, Faye; Leyton, Denisse L; Totsika, Makrina; Phan, Minh-Duy; Celik, Nermin; Kelly, Michelle; Oates, Clare; Hartland, Elizabeth L; Robins-Browne, Roy M; Ramarathinam, Sri Harsha; Purcell, Anthony W; Schembri, Mark A; Strugnell, Richard A; Henderson, Ian R; Walker, Daniel; Lithgow, Trevor

    2012-04-01

    Bacteria have mechanisms to export proteins for diverse purposes, including colonization of hosts and pathogenesis. A small number of archetypal bacterial secretion machines have been found in several groups of bacteria and mediate a fundamentally distinct secretion process. Perhaps erroneously, proteins called 'autotransporters' have long been thought to be one of these protein secretion systems. Mounting evidence suggests that autotransporters might be substrates to be secreted, not an autonomous transporter system. We have discovered a new translocation and assembly module (TAM) that promotes efficient secretion of autotransporters in proteobacteria. Functional analysis of the TAM in Citrobacter rodentium, Salmonella enterica and Escherichia coli showed that it consists of an Omp85-family protein, TamA, in the outer membrane and TamB in the inner membrane of diverse bacterial species. The discovery of the TAM provides a new target for the development of therapies to inhibit colonization by bacterial pathogens.

  6. An integrated suspended sediment transport monitoring and analysis concept

    Institute of Scientific and Technical Information of China (English)

    Marlene HAIMANN; Marcel LIEDERMANN; Petra LALK; Helmut HABERSACK

    2014-01-01

    A new integrated suspended sediment monitoring strategy applying direct and indirect technologies is presented. Optical sensors continuously record the turbidity at one point in the channel cross section close to the river bank and are calibrated by water samples taken close to the sensor. Additionally measurements are performed to establish the distribution of suspended sediment in a cross section (bottle samples combined with acoustic devices). Using correction factors (probe and cross-sectional factor) these monitoring methods are combined and it is, thus, possible to fully document the temporal and spatial variability of the suspended sediment transport and to estimate the suspended sediment load for certain time periods. This monitoring strategy was implemented at various measurement sites in Austria as well as at the Hainburg Road Bridge site on the Danube River. It has already been successfully applied for three years at this measurement site and suspended sediment loads during high discharges up to a 15 year flood event have been monitored. To evaluate the new monitoring methods the results were compared with load estimation methods found in the literature including averaging and ratio estimators as well as rating curves. The results prove that with the new methodology, the temporal variability of the suspended sediment transport can be detected more accurately compared with the other methods. They also demonstrate that the additional consideration of the spatial distribution of the suspended sediment concentration in the cross section is crucial as the mean concentration in the cross section can significantly exceed the concentration near the banks, especially at large rivers like the Danube River.

  7. Flow cytometric bacterial cell counts challenge conventional heterotrophic plate counts for routine microbiological drinking water monitoring

    KAUST Repository

    Van Nevel, S.

    2017-02-08

    Drinking water utilities and researchers continue to rely on the century-old heterotrophic plate counts (HPC) method for routine assessment of general microbiological water quality. Bacterial cell counting with flow cytometry (FCM) is one of a number of alternative methods that challenge this status quo and provide an opportunity for improved water quality monitoring. After more than a decade of application in drinking water research, FCM methodology is optimised and established for routine application, supported by a considerable amount of data from multiple full-scale studies. Bacterial cell concentrations obtained by FCM enable quantification of the entire bacterial community instead of the minute fraction of cultivable bacteria detected with HPC (typically < 1% of all bacteria). FCM measurements are reproducible with relative standard deviations below 3% and can be available within 15 min of samples arriving in the laboratory. High throughput sample processing and complete automation are feasible and FCM analysis is arguably less expensive than HPC when measuring more than 15 water samples per day, depending on the laboratory and selected staining procedure(s). Moreover, many studies have shown FCM total (TCC) and intact (ICC) cell concentrations to be reliable and robust process variables, responsive to changes in the bacterial abundance and relevant for characterising and monitoring drinking water treatment and distribution systems. The purpose of this critical review is to initiate a constructive discussion on whether FCM could replace HPC in routine water quality monitoring. We argue that FCM provides a faster, more descriptive and more representative quantification of bacterial abundance in drinking water.

  8. Biofilm bacterial communities in urban drinking water distribution systems transporting waters with different purification strategies.

    Science.gov (United States)

    Wu, Huiting; Zhang, Jingxu; Mi, Zilong; Xie, Shuguang; Chen, Chao; Zhang, Xiaojian

    2015-02-01

    Biofilm formation in drinking water distribution systems (DWDS) has many adverse consequences. Knowledge of microbial community structure of DWDS biofilm can aid in the design of an effective control strategy. However, biofilm bacterial community in real DWDS and the impact of drinking water purification strategy remain unclear. The present study investigated the composition and diversity of biofilm bacterial community in real DWDSs transporting waters with different purification strategies (conventional treatment and integrated treatment). High-throughput Illumina MiSeq sequencing analysis illustrated a large shift in the diversity and structure of biofilm bacterial community in real DWDS. Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Nitrospirae, and Cyanobacteria were the major components of biofilm bacterial community. Proteobacteria (mainly Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria) predominated in each DWDS biofilm, but the compositions of the dominant proteobacterial classes and genera and their proportions varied among biofilm samples. Drinking water purification strategy could shape DWDS biofilm bacterial community. Moreover, Pearson's correlation analysis indicated that Actinobacteria was positively correlated with the levels of total alkalinity and dissolved organic carbon in tap water, while Firmicutes had a significant positive correlation with nitrite nitrogen.

  9. Continuous monitoring of bacterial biofilm growth using uncoated Thickness-Shear Mode resonators

    Science.gov (United States)

    Castro, P.; Resa, P.; Durán, C.; Maestre, J. R.; Mateo, M.; Elvira, L.

    2012-12-01

    Quartz Crystal Microbalances (QCM) were used to nondestructively monitor in real time the microbial growth of the bacteria Staphylococcus epidermidis (S. epidermidis) in a liquid broth. QCM, sometimes referred to as Thickness-Shear Mode (TSM) resonators, are highly sensitive sensors not only able to measure very small mass, but also non-gravimetric contributions of viscoelastic media. These devices can be used as biosensors for bacterial detection and are employed in many applications including their use in the food industry, water and environment monitoring, pharmaceutical sciences and clinical diagnosis. In this work, three strains of S. epidermidis (which differ in the ability to produce biofilm) have been continuously monitored using an array of piezoelectric TSM resonators, at 37 °C in a selective culturing media. Microbial growth was followed by measuring the changes in the crystal resonant frequency and bandwidth at several harmonics. It was shown that microbial growth can be monitored in real time using multichannel and multiparametric QCM sensors.

  10. Infrared thermography applied to transport infrastructures monitoring: outcomes and perspectives

    Science.gov (United States)

    Dumoulin, J.; Crinière, A.

    2017-05-01

    Long term monitoring of transport infrastructures by infrared thermography has been studied and tested on different structures. A first standalone infrared system architecture developed is presented and discussed. Results obtained with such system on different Civil Engineering structures are presented. Some data processing approaches and inverse thermal model for data analysis are introduced and discussed. Lessons learned from experiments carried out in outdoor with such system are listed and analyzed. Then, a new generation of infrared system architecture is proposed. Finally, conclusions and perspectives are addressed.

  11. Bacterial interactions and transport in geological formation of alumino-silica clays.

    Science.gov (United States)

    Vu, Kien; Yang, Guang; Wang, Boya; Tawfiq, Kamal; Chen, Gang

    2015-01-01

    Bacterial transport in the subsurface is controlled by their interactions with the surrounding environment, which are determined by the surface properties of the geological formation and bacterial surfaces. In this research, surface thermodynamic properties of Escherichia coli and the geological formation of alumino-silica clays were characterized based on contact angle measurements, which were utilized to quantify the distance-dependent interactions between E. coli and the geological formation according to the traditional and extended Derjaguin, Landau, Verwey and Overbeek (DLVO) theory. E. coli attachment to alumino-silica clays was evaluated in laboratory columns under saturated and steady-state flow conditions. E. coli deposition coefficient and desorption coefficient were simulated using convection-dispersion transport models against E. coli breakthrough curves, which were then linked to interactions between E. coli and the geological formation. It was discovered that E. coli deposition was controlled by the long-ranged electrostatic interaction and E. coli desorption was attributed to the short-ranged Lifshitz-van der Waals and Lewis acid-base interactions. E. coli transport in three layers of different alumino-silica clays was further examined and the breakthrough curve was simulated using E. coli deposition coefficient and desorption coefficient obtained from their individual column experiments. The well-fitted simulation confirmed that E. coli transport observations were interaction-dependent phenomena between E. coli and the geological formation.

  12. Directed transport of bacteria-based drug delivery vehicles: bacterial chemotaxis dominates particle shape.

    Science.gov (United States)

    Sahari, Ali; Traore, Mahama A; Scharf, Birgit E; Behkam, Bahareh

    2014-10-01

    Several attenuated and non-pathogenic bacterial species have been demonstrated to actively target diseased sites and successfully deliver plasmid DNA, proteins and other therapeutic agents into mammalian cells. These disease-targeting bacteria can be employed for targeted delivery of therapeutic and imaging cargos in the form of a bio-hybrid system. The bio-hybrid drug delivery system constructed here is comprised of motile Escherichia coli MG1655 bacteria and elliptical disk-shaped polymeric microparticles. The transport direction for these vehicles can be controlled through biased random walk of the attached bacteria in presence of chemoattractant gradients in a process known as chemotaxis. In this work, we utilize a diffusion-based microfluidic platform to establish steady linear concentration gradients of a chemoattractant and investigate the roles of chemotaxis and geometry in transport of bio-hybrid drug delivery vehicles. Our experimental results demonstrate for the first time that bacterial chemotactic response dominates the effect of body shape in extravascular transport; thus, the non-spherical system could be more favorable for drug delivery applications owing to the known benefits of using non-spherical particles for vascular transport (e.g. relatively long circulation time).

  13. Biomimetic Bacterial Identification Platform Based on Thermal Wave Transport Analysis (TWTA) through Surface-Imprinted Polymers.

    Science.gov (United States)

    Steen Redeker, Erik; Eersels, Kasper; Akkermans, Onno; Royakkers, Jeroen; Dyson, Simba; Nurekeyeva, Kunya; Ferrando, Beniamino; Cornelis, Peter; Peeters, Marloes; Wagner, Patrick; Diliën, Hanne; van Grinsven, Bart; Cleij, Thomas Jan

    2017-05-12

    This paper introduces a novel bacterial identification assay based on thermal wave analysis through surface-imprinted polymers (SIPs). Aluminum chips are coated with SIPs, serving as synthetic cell receptors that have been combined previously with the heat-transfer method (HTM) for the selective detection of bacteria. In this work, the concept of bacterial identification is extended toward the detection of nine different bacterial species. In addition, a novel sensing approach, thermal wave transport analysis (TWTA), is introduced, which analyzes the propagation of a thermal wave through a functional interface. The results presented here demonstrate that bacterial rebinding to the SIP layer resulted in a measurable phase shift in the propagated wave, which is most pronounced at a frequency of 0.03 Hz. In this way, the sensor is able to selectively distinguish between the different bacterial species used in this study. Furthermore, a dose-response curve was constructed to determine a limit of detection of 1 × 10(4) CFU mL(-1), indicating that TWTA is advantageous over HTM in terms of sensitivity and response time. Additionally, the limit of selectivity of the sensor was tested in a mixed bacterial solution, containing the target species in the presence of a 99-fold excess of competitor species. Finally, a first application for the sensor in terms of infection diagnosis is presented, revealing that the platform is able to detect bacteria in clinically relevant concentrations as low as 3 × 10(4) CFU mL(-1) in spiked urine samples.

  14. 16S rRNA beacons for bacterial monitoring during human space missions.

    Science.gov (United States)

    Larios-Sanz, Maia; Kourentzi, Katerina D; Warmflash, David; Jones, Jeffrey; Pierson, Duane L; Willson, Richard C; Fox, George E

    2007-04-01

    Microorganisms are unavoidable in space environments and their presence has, at times, been a source of problems. Concerns about disease during human space missions are particularly important considering the significant changes the immune system incurs during spaceflight and the history of microbial contamination aboard the Mir space station. Additionally, these contaminants may have adverse effects on instrumentation and life-support systems. A sensitive, highly specific system to detect, characterize, and monitor these microbial populations is essential. Herein we describe a monitoring approach that uses 16S rRNA targeted molecular beacons to successfully detect several specific bacterial groupings. This methodology will greatly simplify in-flight monitoring by minimizing sample handling and processing. We also address and provide solutions to target accessibility problems encountered in hybridizations that target 16S rRNA.

  15. Monitoring of bacterial contamination of dental unit water lines using adenosine triphosphate bioluminescence.

    Science.gov (United States)

    Watanabe, A; Tamaki, N; Yokota, K; Matsuyama, M; Kokeguchi, S

    2016-12-01

    Bacterial contamination of dental unit waterlines (DUWLs) was evaluated using ATP bioluminescence analysis and a conventional culture method. Water samples (N=44) from DUWLs were investigated for heterotrophic bacteria by culture on R2A agar, which gave counts ranging from 1.4×10(3) to 2.7×10(5) cfu/mL. The ATP bioluminescence results for DUWL samples ranged from 6 to 1189 relative light units and could be obtained within 1min; these correlated well with the culture results (r=0.727-0.855). We conclude that the results of the ATP bioluminescence assay accurately reflect the results of conventional culture-based testing. This method is potentially useful for rapid and simple monitoring of DUWL bacterial contamination.

  16. Progress towards Acoustic Suspended Sediment Transport Monitoring: Fraser River, BC

    Science.gov (United States)

    Attard, M. E.; Venditti, J. G.; Church, M. A.; Kostaschuk, R. A.

    2011-12-01

    Our ability to predict the timing and quantity of suspended sediment transport is limited because fine sand, silt and clay delivery are supply limited, requiring empirical modeling approaches of limited temporal stability. A solution is the development of continuous monitoring techniques capable of tracking sediment concentrations and grain-size. Here we examine sediment delivery from upstream sources to the lower Fraser River. The sediment budget of the lower Fraser River provides a long-term perspective of the net changes in the channels and in sediment delivery to Fraser Delta. The budget is based on historical sediment rating curves developed from data collected from 1965-1986 by the Water Survey of Canada. We explore the possibility of re-establishing the sediment-monitoring program using hydro-acoustics by evaluating the use of a 300 kHz side-looking acoustic Doppler current profiler (aDcp), mounted just downstream of the sand-gravel transition at Mission, for continuous measurement of suspended sediment transport. Complementary field observations include conventional bottle sampling with a P-63 sampler, vertical profiles with a downward-looking 600 kHz aDcp, and 1200 kHz aDcp discharge measurements. We have successfully completed calibration of the downward-looking aDcp with the P-63 samples; the side-looking aDcp signals remain under investigation. A comparison of several methods for obtaining total sediment flux indicates that suspended sediment concentration (SSC) closely follows discharge through the freshet and peaks in total SSC and sand SSC coincide with peak measurements of discharge. Low flows are dominated by fine sediment and grain size increases with higher flows. This research assesses several techniques for obtaining sediment flux and contributes to the understanding of sediment delivery to sand-bedded portions of the river.

  17. Monitoring bacterial resistance to chloramphenicol and other antibiotics by liquid chromatography electrospray ionization tandem mass spectrometry using selected reaction monitoring.

    Science.gov (United States)

    Haag, Anthony M; Medina, Audrie M; Royall, Ariel E; Herzog, Norbert K; Niesel, David W

    2013-06-01

    Antibiotic resistance is a growing problem worldwide. For this reason, clinical laboratories often determine the susceptibility of the bacterial isolate to a number of different antibiotics in order to establish the most effective antibiotic for treatment. Unfortunately, current susceptibility assays are time consuming. Antibiotic resistance often involves the chemical modification of an antibiotic to an inactive form by an enzyme expressed by the bacterium. Selected reaction monitoring (SRM) has the ability to quickly monitor and identify these chemical changes in an unprecedented time scale. In this work, we used SRM as a technique to determine the susceptibility of several different antibiotics to the chemically modifying enzymes β-lactamase and chloramphenicol acetyltransferase, enzymes used by bacteria to confer resistance to major classes of commonly used antibiotics. We also used this technique to directly monitor the effects of resistant bacteria grown in a broth containing a specific antibiotic. Because SRM is highly selective and can also identify chemical changes in a multitude of antibiotics in a single assay, SRM has the ability to detect organisms that are resistant to multiple antibiotics in a single assay. For these reasons, the use of SRM greatly reduces the time it takes to determine the susceptibility or resistance of an organism to a multitude of antibiotics by eliminating the time-consuming process found in other currently used methods.

  18. Application of a microcomputer-based system to control and monitor bacterial growth.

    Science.gov (United States)

    Titus, J A; Luli, G W; Dekleva, M L; Strohl, W R

    1984-02-01

    A modular microcomputer-based system was developed to control and monitor various modes of bacterial growth. The control system was composed of an Apple II Plus microcomputer with 64-kilobyte random-access memory; a Cyborg ISAAC model 91A multichannel analog-to-digital and digital-to-analog converter; paired MRR-1 pH, pO(2), and foam control units; and in-house-designed relay, servo control, and turbidimetry systems. To demonstrate the flexibility of the system, we grew bacteria under various computer-controlled and monitored modes of growth, including batch, turbidostat, and chemostat systems. The Apple-ISAAC system was programmed in Labsoft BASIC (extended Applesoft) with an average control program using ca. 6 to 8 kilobytes of memory and up to 30 kilobytes for datum arrays. This modular microcomputer-based control system was easily coupled to laboratory scale fermentors for a variety of fermentations.

  19. Characterization of corrosive bacterial consortia isolated from petroleum-product-transporting pipelines.

    Science.gov (United States)

    Rajasekar, Aruliah; Anandkumar, Balakrishnan; Maruthamuthu, Sundaram; Ting, Yen-Peng; Rahman, Pattanathu K S M

    2010-01-01

    Microbiologically influenced corrosion is a problem commonly encountered in facilities in the oil and gas industries. The present study describes bacterial enumeration and identification in diesel and naphtha pipelines located in the northwest and southwest region in India, using traditional cultivation technique and 16S rDNA gene sequencing. Phylogenetic analysis of 16S rRNA sequences of the isolates was carried out, and the samples obtained from the diesel and naphtha-transporting pipelines showed the occurrence of 11 bacterial species namely Serratia marcescens ACE2, Bacillus subtilis AR12, Bacillus cereus ACE4, Pseudomonas aeruginosa AI1, Klebsiella oxytoca ACP, Pseudomonas stutzeri AP2, Bacillus litoralis AN1, Bacillus sp., Bacillus pumilus AR2, Bacillus carboniphilus AR3, and Bacillus megaterium AR4. Sulfate-reducing bacteria were not detected in samples from both pipelines. The dominant bacterial species identified in the petroleum pipeline samples were B. cereus and S. marcescens in the diesel and naphtha pipelines, respectively. Therefore, several types of bacteria may be involved in biocorrosion arising from natural biofilms that develop in industrial facilities. In addition, localized (pitting) corrosion of the pipeline steel in the presence of the consortia was observed by scanning electron microscopy analysis. The potential role of each species in biofilm formation and steel corrosion is discussed.

  20. Characterization of corrosive bacterial consortia isolated from petroleum-product-transporting pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Rajasekar, Aruliah; Ting, Yen-Peng [National Univ. of Singapore (Singapore). Dept. of Chemical and Biomolecular Engineering; Anandkumar, Balakrishnan [Sourashtra Coll., Madurai (India). Dept. of Biotechnology; Maruthamuthu, Sundaram [Central Electrochemical Research Inst., Karaikudi (India). Biocorrosion Group; Rahman, Pattanathu K.S.M. [Teesside Univ., Tees Valley (United Kingdom). Chemical and Bioprocess Engineering Group

    2010-01-15

    Microbiologically influenced corrosion is a problem commonly encountered in facilities in the oil and gas industries. The present study describes bacterial enumeration and identification in diesel and naphtha pipelines located in the northwest and southwest region in India, using traditional cultivation technique and 16S rDNA gene sequencing. Phylogenetic analysis of 16S rRNA sequences of the isolates was carried out, and the samples obtained from the diesel and naphtha-transporting pipelines showed the occurrence of 11 bacterial species namely Serratia marcescens ACE2, Bacillus subtilis AR12, Bacillus cereus ACE4, Pseudomonas aeruginosa AI1, Klebsiella oxytoca ACP, Pseudomonas stutzeri AP2, Bacillus litoralis AN1, Bacillus sp., Bacillus pumilus AR2, Bacillus carboniphilus AR3, and Bacillus megaterium AR4. Sulfate-reducing bacteria were not detected in samples from both pipelines. The dominant bacterial species identified in the petroleum pipeline samples were B. cereus and S. marcescens in the diesel and naphtha pipelines, respectively. Therefore, several types of bacteria may be involved in biocorrosion arising from natural biofilms that develop in industrial facilities. In addition, localized (pitting) corrosion of the pipeline steel in the presence of the consortia was observed by scanning electron microscopy analysis. The potential role of each species in biofilm formation and steel corrosion is discussed. (orig.)

  1. Structure, biosynthesis, and function of bacterial capsular polysaccharides synthesized by ABC transporter-dependent pathways.

    Science.gov (United States)

    Willis, Lisa M; Whitfield, Chris

    2013-08-30

    Bacterial capsules are formed primarily from long-chain polysaccharides with repeat-unit structures. A given bacterial species can produce a range of capsular polysaccharides (CPSs) with different structures and these help distinguish isolates by serotyping, as is the case with Escherichia coli K antigens. Capsules are important virulence factors for many pathogens and this review focuses on CPSs synthesized via ATP-binding cassette (ABC) transporter-dependent processes in Gram-negative bacteria. Bacteria utilizing this pathway are often associated with urinary tract infections, septicemia, and meningitis, and E. coli and Neisseria meningitidis provide well-studied examples. CPSs from ABC transporter-dependent pathways are synthesized at the cytoplasmic face of the inner membrane through the concerted action of glycosyltransferases before being exported across the inner membrane and translocated to the cell surface. A hallmark of these CPSs is a conserved reducing terminal glycolipid composed of phosphatidylglycerol and a poly-3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) linker. Recent discovery of the structure of this conserved lipid terminus provides new insights into the early steps in CPS biosynthesis.

  2. Bacterial glyphosate resistance conferred by overexpression of an E. coli membrane efflux transporter.

    Science.gov (United States)

    Staub, Jeffrey M; Brand, Leslie; Tran, Minhtien; Kong, Yifei; Rogers, Stephen G

    2012-04-01

    Glyphosate herbicide-resistant crop plants, introduced commercially in 1994, now represent approximately 85% of the land area devoted to transgenic crops. Herbicide resistance in commercial glyphosate-resistant crops is due to expression of a variant form of a bacterial 5-enolpyruvylshikimate-3-phosphate synthase with a significantly decreased binding affinity for glyphosate at the target site of the enzyme. As a result of widespread and recurrent glyphosate use, often as the only herbicide used for weed management, increasing numbers of weedy species have evolved resistance to glyphosate. Weed resistance is most often due to changes in herbicide translocation patterns, presumed to be through the activity of an as yet unidentified membrane transporter in plants. To provide insight into glyphosate resistance mechanisms and identify a potential glyphosate transporter, we screened Escherichia coli genomic DNA for alternate sources of glyphosate resistance genes. Our search identified a single non-target gene that, when overexpressed in E. coli and Pseudomonas, confers high-level glyphosate resistance. The gene, yhhS, encodes a predicted membrane transporter of the major facilitator superfamily involved in drug efflux. We report here that an alternative mode of glyphosate resistance in E. coli is due to reduced accumulation of glyphosate in cells that overexpress this membrane transporter and discuss the implications for potential alternative resistance mechanisms in other organisms such as plants.

  3. Fast 2D NMR Spectroscopy for In vivo Monitoring of Bacterial Metabolism in Complex Mixtures

    Directory of Open Access Journals (Sweden)

    Rupashree Dass

    2017-07-01

    Full Text Available The biological toolbox is full of techniques developed originally for analytical chemistry. Among them, spectroscopic experiments are very important source of atomic-level structural information. Nuclear magnetic resonance (NMR spectroscopy, although very advanced in chemical and biophysical applications, has been used in microbiology only in a limited manner. So far, mostly one-dimensional 1H experiments have been reported in studies of bacterial metabolism monitored in situ. However, low spectral resolution and limited information on molecular topology limits the usability of these methods. These problems are particularly evident in the case of complex mixtures, where spectral peaks originating from many compounds overlap and make the interpretation of changes in a spectrum difficult or even impossible. Often a suite of two-dimensional (2D NMR experiments is used to improve resolution and extract structural information from internuclear correlations. However, for dynamically changing sample, like bacterial culture, the time-consuming sampling of so-called indirect time dimensions in 2D experiments is inefficient. Here, we propose the technique known from analytical chemistry and structural biology of proteins, i.e., time-resolved non-uniform sampling. The method allows application of 2D (and multi-D experiments in the case of quickly varying samples. The indirect dimension here is sparsely sampled resulting in significant reduction of experimental time. Compared to conventional approach based on a series of 1D measurements, this method provides extraordinary resolution and is a real-time approach to process monitoring. In this study, we demonstrate the usability of the method on a sample of Escherichia coli culture affected by ampicillin and on a sample of Propionibacterium acnes, an acne causing bacterium, mixed with a dose of face tonic, which is a complicated, multi-component mixture providing complex NMR spectrum. Through our experiments

  4. Monitoring bacterial biofilms with a microfluidic flow chip designed for imaging with white-light interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Brann, Michelle; Suter, Jonathan D.; Addleman, R. Shane; Larimer, Curtis

    2017-07-01

    There is a need for imaging and sensing instrumentation that can monitor transitions in biofilm structure in order to better understand biofilm development and emergent properties such as anti-microbial resistance. Herein, we expanded on our previously reported technique for measuring and monitoring the thickness and topology of live biofilms using white-light interferometry (WLI). A flow cell designed for WLI enabled the use of this non-disruptive imaging method for the capture of high resolution three-dimensional profile images of biofilm growth over time. The fine axial resolution (3 nm) and wide field of view (>1 mm by 1 mm) enabled detection of biofilm formation as early as three hours after inoculation of the flow cell with a live bacterial culture (Pseudomonas fluorescens). WLI imaging facilitated monitoring the early stages of biofilm development and subtle variations in the structure of mature biofilms. Minimally-invasive imaging enabled monitoring of biofilm structure with surface metrology metrics (e.g., surface roughness). The system was used to observe a transition in biofilm structure that occurred in response to expsoure to a common antiseptic. In the future, WLI and the biofilm imaging cell described herein may be used to test the effectiveness of biofilm-specific therapies to combat common diseases associated with biofilm formation such as cystic fibrosis and periodontitis.

  5. Continuous monitoring of water flow and solute transport using vadose zone monitoring technology

    Science.gov (United States)

    Dahan, O.

    2009-04-01

    Groundwater contamination is usually attributed to pollution events that initiate on land surface. These may be related to various sources such as industrial, urban or agricultural, and may appear as point or non point sources, through a single accidental event or a continuous pollution process. In all cases, groundwater pollution is a consequence of pollutant transport processes that take place in the vadose zone above the water table. Attempts to control pollution events and prevent groundwater contamination usually involve groundwater monitoring programs. This, however, can not provide any protection against contamination since pollution identification in groundwater is clear evidence that the groundwater is already polluted and contaminants have already traversed the entire vadose zone. Accordingly, an efficient monitoring program that aims at providing information that may prevent groundwater pollution has to include vadose-zone monitoring systems. Such system should provide real-time information on the hydrological and chemical properties of the percolating water and serve as an early warning system capable of detecting pollution events in their early stages before arrival of contaminants to groundwater. Recently, a vadose-zone monitoring system (VMS) was developed to allow continuous monitoring of the hydrological and chemical properties of percolating water in the deep vadose zone. The VMS includes flexible time-domain reflectometry (FTDR) probes for continuous tracking of water content profiles, and vadose-zone sampling ports (VSPs) for frequent sampling of the deep vadose pore water at multiple depths. The monitoring probes and sampling ports are installed through uncased slanted boreholes using a flexible sleeve that allows attachment of the monitoring devices to the borehole walls while achieving good contact between the sensors and the undisturbed sediment column. The system has been successfully implemented in several studies on water flow and

  6. Monitoring Large-Scale Sediment Transport Dynamics with Multibeam Sonar

    Science.gov (United States)

    Parsons, D. R.; Simmons, S. M.; Best, J. L.; Keevil, G. M.; Oberg, K.; Czuba, J. A.

    2009-05-01

    Multibeam Echo-Sounder systems have developed rapidly over recent decades and are routinely deployed to provide high-resolution bathymetric information in and range of environments. Modern data handling and storage technologies now facilitate the logging of the raw acoustic back-scatter information that was previously discarded by these systems. This paper describes methodologies that exploit this logging capability to quantify both the concentration and dynamics of suspended sediment within the water column. This development provides a multi-purpose tool for the holistic surveying of sediment transport dynamics by imaging suspended sediment concentration, the associated flows and providing concurrent high-resolution bathymetry. Results obtained a RESON 7125 MBES are presented from both well constrained dock-side testing and full field deployment over dune bedforms in the Mississippi. The capacity of the system to image suspended sediment structures is demonstrated and a novel methodology for estimating 2D flow velocities, based on frame cross-correlation methods, is introduced. The results demonstrate the capability of MBES systems to successfully map spatial and temporal variations in suspended sediment concentration throughout a 2D swath and application of the velocity estimation algorithms allow real-time holistic monitoring of turbulent flow processes and suspended sediment fluxes at a scale previously unrealisable. Turbulent flow over a natural dune bedform on the Mississippi is used to highlight the process information provided and the insights that can be gleaned for this technical development.

  7. Validation of Global Ozone Monitoring Experiment zone profiles and evaluation of stratospheric transport in a global chemistry transport model

    NARCIS (Netherlands)

    Laat, A.T.J.de; Landgraf, J.; Aben, I.; Hasekamp, O.; Bregman, B.

    2007-01-01

    This paper presents a validation of Global Ozone Monitoring Experiment (GOME) ozone (O3) profiles which are used to evaluate stratospheric transport in the chemistry transport model (CTM) Tracer Model version 5 (TM5) using a linearized stratospheric O3 chemistry scheme. A comparison of GOME O3 profi

  8. Induction of cystine/glutamate transporter in bacterial lipopolysaccharide induced endotoxemia in mice

    Directory of Open Access Journals (Sweden)

    Bannai Shiro

    2007-09-01

    Full Text Available Abstract Background Cystine/glutamate transporter, system xc-, contributes to the maintenance of intracellular glutathione levels and the redox balance in the extracellular space. The main component of the transporter, xCT, is known to be strongly induced by various stimuli like oxidative stress in mammalian cultured cells. We examined the expression of xCT mRNA in vivo in the experimental endotoxemia. Methods Northern blot analysis and in situ hybridization were used to investigate the expression of xCT mRNA in the tissues of the mice exposed to bacterial lipopolysaccharide (LPS. Results Northern blot analysis revealed that xCT mRNA was constitutively expressed in the brain, thymus, and spleen, and that the expression of xCT mRNA was strongly up-regulated in thymus and spleen by the administration of a sublethal dose of LPS. In addition to brain, thymus, and spleen, xCT mRNA was detected also in the bronchiolar epithelium of the lung by the administration of the lethal dose of LPS. Conclusion xCT is induced in some specific tissues by the administration of LPS. The results suggest that cystine/glutamate transporter plays an important role under the inflammatory conditions.

  9. Monitoring bacterial and archaeal community shifts in a mesophilic anaerobic batch reactor treating a high-strength organic wastewater.

    Science.gov (United States)

    Lee, Changsoo; Kim, Jaai; Shin, Seung Gu; Hwang, Seokhwan

    2008-09-01

    Shifts in bacterial and archaeal communities, associated with changes in chemical profiles, were investigated in an anaerobic batch reactor treating dairy-processing wastewater prepared with whey permeate powder. The dynamics of bacterial and archaeal populations were monitored by quantitative real-time PCR and showed good agreement with the process data. A rapid increase in bacterial populations and a high rate of substrate fermentation were observed during the initial period. Growth and regrowth of archaeal populations occurred with biphasic production of methane, corresponding to the diauxic consumption of acetate and propionate. Bacterial community structure was examined by denaturing gel gradient electrophoresis (DGGE) targeting 16S rRNA genes. An Aeromonas-like organism was suggested to be mainly responsible for the rapid fermentation of carbohydrate during the initial period. Several band sequences closely related to the Clostridium species, capable of carbohydrate fermentation, lactate or ethanol fermentation, and/or homoacetogenesis, were also detected. Statistical analyses of the DGGE profiles showed that the bacterial community structure, as well as the process performance, varied with the incubation time. Our results demonstrated that the bacterial community shifted, reflecting the performance changes and, particularly, that a significant community shift corresponded to a considerable process event. This suggested that the diagnosis of an anaerobic digestion process could be possible by monitoring bacterial community shifts.

  10. Modeling of microfluidic microbial fuel cells using quantitative bacterial transport parameters

    Science.gov (United States)

    Mardanpour, Mohammad Mahdi; Yaghmaei, Soheila; Kalantar, Mohammad

    2017-02-01

    The objective of present study is to analyze the dynamic modeling of bioelectrochemical processes and improvement of the performance of previous models using quantitative data of bacterial transport parameters. The main deficiency of previous MFC models concerning spatial distribution of biocatalysts is an assumption of initial distribution of attached/suspended bacteria on electrode or in anolyte bulk which is the foundation for biofilm formation. In order to modify this imperfection, the quantification of chemotactic motility to understand the mechanisms of the suspended microorganisms' distribution in anolyte and/or their attachment to anode surface to extend the biofilm is implemented numerically. The spatial and temporal distributions of the bacteria, as well as the dynamic behavior of the anolyte and biofilm are simulated. The performance of the microfluidic MFC as a chemotaxis assay is assessed by analyzing the bacteria activity, substrate variation, bioelectricity production rate and the influences of external resistance on the biofilm and anolyte's features.

  11. Time-course monitoring of urban bioaerosol bacterial communities and its use in microbial hazard identification during Asian Dust events in Seoul, Korea

    Science.gov (United States)

    Park, J.

    2015-12-01

    The microbial communities transported by Asian dust events have attracted much attention as bioaerosols because the transported airborne microbes may strongly influence the downwind ecosystems and potentially human health in East Asia. Bioaerosol study has received relatively little attention and their characterization and risk assessments remain poorly developed. We used high throughput 16S rRNA gene targeted pyrosequencing and real-time quantitative PCR (qPCR) to monitor airborne bacterial communities and assess their potential risk. We monitored microbial communities in bioaerosol in Seoul between 2011 and 2013 using high volume air samplers. Six samples were collected during Asian dust (AD) events and the other 34 samples were urban air collected during non-Asian dust (non-AD) events. According to the qPCR result, the gene copy numbers of 16S rRNA genes were significantly higher during the AD events (P bioaerosol episodes using Poisson regression and calculated relative risk. The findings are useful in building a database for bacterial pathogens in AD events.

  12. Using Bacterial Surrogates to Assess Pathogen Transport in the Subsurface: Laboratory and Field Indications of Co-Transport Considerations

    Science.gov (United States)

    Emelko, M.; Stimson, J. R.; McLellan, N. L.; Mesquita, M.

    2009-12-01

    Prediction of the transport and fate of colloids and nanoparticles in porous media environments remains challenging because factors such as experimental scale, subsurface heterogeneity, and variable flow paths and fluxes have made it difficult to relate laboratory outcomes to field performance. Moreover, field studies have been plagued with inadequate consideration of ground water flow, reliance on unproven “surrogate” parameters, non-detects at the extraction well, and limited sampling. Riverbank filtration (RBF) is an example of an application for which some predictive capacity regarding colloid transport is desirable. RBF is a relatively low-cost, natural water treatment technology in which surface water contaminants are removed or degraded as the infiltrating water flows from a surface source to abstraction wells. RBF has been used for water treatment for at least 200 years and its potential to provide a significant barrier to microorganisms has been demonstrated. Assignment of microbial treatment credits for RBF remains a regulatory challenge because strategies for demonstrating effective subsurface filtration of organisms are not standardized. The potential passage of Giardia lamblia and Cryptosporidium parvum through RBF systems is of particular regulatory concern because these pathogens are known to be resistant to conventional disinfection processes. The transport or relatively small, pathogenic viruses through RBF systems is also a common concern. To comply with the U.S. Long Term 2 Enhanced Surface Water Treatment Rule, utilities with sufficiently high levels of Cryptosporidium oocysts in their source water must amend existing treatment by choosing from a ‘‘toolbox’’ of technologies, including RBF. Aerobic bacterial spores have been evaluated and proposed by some as surrogates for evaluating drinking water treatment plant performance; they also have been proposed as potential surrogates for Cryptosporidium removal during subsurface filtration

  13. The bacterial flagellar protein export apparatus processively transports flagellar proteins even with extremely infrequent ATP hydrolysis.

    Science.gov (United States)

    Minamino, Tohru; Morimoto, Yusuke V; Kinoshita, Miki; Aldridge, Phillip D; Namba, Keiichi

    2014-12-22

    For self-assembly of the bacterial flagellum, a specific protein export apparatus utilizes ATP and proton motive force (PMF) as the energy source to transport component proteins to the distal growing end. The export apparatus consists of a transmembrane PMF-driven export gate and a cytoplasmic ATPase complex composed of FliH, FliI and FliJ. The FliI(6)FliJ complex is structurally similar to the α(3)β(3)γ complex of F(O)F(1)-ATPase. FliJ allows the gate to efficiently utilize PMF to drive flagellar protein export but it remains unknown how. Here, we report the role of ATP hydrolysis by the FliI(6)FliJ complex. The export apparatus processively transported flagellar proteins to grow flagella even with extremely infrequent or no ATP hydrolysis by FliI mutation (E211D and E211Q, respectively). This indicates that the rate of ATP hydrolysis is not at all coupled with the export rate. Deletion of FliI residues 401 to 410 resulted in no flagellar formation although this FliI deletion mutant retained 40% of the ATPase activity, suggesting uncoupling between ATP hydrolysis and activation of the gate. We propose that infrequent ATP hydrolysis by the FliI6FliJ ring is sufficient for gate activation, allowing processive translocation of export substrates for efficient flagellar assembly.

  14. Investigation of the faecal microbiota of kittens: monitoring bacterial succession and effect of diet.

    Science.gov (United States)

    Jia, Jie; Frantz, Nolan; Khoo, Christina; Gibson, Glenn R; Rastall, Robert A; McCartney, Anne L

    2011-11-01

    Weaning is a stressful process for kittens and is often associated with diarrhoea and the onset of infectious diseases. The gastrointestinal (GI) microbiota plays an essential role in host well-being, including improving homoeostasis. Composition of the GI microbiota of young cats is poorly understood and the impact of diet on the kitten microbiota unknown. The aims of this study were to monitor the faecal microbiota of kittens and determine the effect(s) of diet on its composition. Bacterial succession was monitored in two groups of kittens (at 4 and 6 weeks, and 4 and 9 months of age) fed different foods. Age-related microbial changes revealed significantly different counts of total bacteria, lactic acid bacteria, Desulfovibrionales, Clostridium cluster IX and Bacteroidetes between 4-week- and 9-month-old kittens. Diet-associated differences in the faecal microbiota of the two feeding groups were evident. In general, fluorescence in situ hybridization analysis demonstrated bifidobacteria, Atopobium group, Clostridium cluster XIV and lactic acid bacteria were dominant in kittens. Denaturing gradient gel electrophoresis profiling showed highly complex and diverse faecal microbiotas for kittens, with age- and/or food-related changes seen in relation to species richness and similarity indices. Four-week-old kittens harboured more diverse and variable profiles than those of weaned kittens.

  15. Monitoring the Amazon plume northwestward transport along Lagrangian pathways

    Science.gov (United States)

    Fournier, Severine; Gaultier, Lucile; Vandemark, Douglas; Lee, Tong; Gierach, Michelle

    2016-04-01

    Large rivers are important to marine air-sea interactions and local biogeochemistry. By modifying the local and regional sea surface salinity (SSS), the freshwater inputs associated with major river plumes cause the formation of a layer near the surface with salinity stratification but near-uniform temperature, known as the barrier layer (BL). The BL prevent exchanges between the warm mixed layer and the cold ocean interior, and thus affect the vertical mixing of heat between the mixed layer and the thermocline. This can have an important impact on air-sea interactions such as hurricanes intensification. Our study focuses on the Amazon and Orinoco rivers, respectively the first and fourth world's largest rivers in terms of discharge. Amazon-Orinoco waters are carried northwestward by the North Brazilian Current (NBC) during the first part of the year and then eastward along the North Equatorial Counter Current. The hurricane season in the tropical Atlantic extends from June through November, the period of Amazon-Orinoco plume maximum northwestward extension, on a hurricane route. Being able to monitor the spatial and temporal dispersal of the Amazon and Orinoco river plumes is therefore important to better understand their impact on barrier layer thickness and SST variation at seasonal to interannual time scales. Variations from year to year in spatial extent of the plume may result from several processes including changes in Amazon discharge, ocean advection, turbulent mixing, and wind field. Satellite remote sensing data provide several means to visualize the surface dispersal of the Amazon plume, with ocean color data being the first to track it in the tropical Atlantic ocean further than 1000 km from shore. With the launches of the ESA Soil Moisture and Ocean Salinity (SMOS) and the NASA Aquarius/SAC-D missions, we are now able to use the SSS observations in combination with ocean color, altimetry and sea surface temperature observations to track surface plume

  16. Real time monitoring of population dynamics in concurrent bacterial growth using SIFT-MS quantification of volatile metabolites.

    Science.gov (United States)

    Sovová, Kristýna; Čepl, Jaroslav; Markoš, Anton; Španěl, Patrik

    2013-09-07

    Population dynamics of three different bacterial species, Serratia rubidaea (R), Serratia marcescens (F) and Escherichia coli (Ec), growing in single or mixed populations in liquid media, was monitored by real time headspace quantification of volatile compounds using selected ion flow tube mass spectrometry, SIFT-MS. The three bacterial species interact with each other in a competitive fashion in a way similar to the game "rock-paper-scissors" (R-Ec-F). The concentrations of volatile metabolites (ammonia, ethanol, acetaldehyde, propanol, acetoin, acetone and acetic acid) were measured in the headspace of the individual species and of their mixtures continuously for 24 hour periods. The results demonstrate that dynamics in bacterial cultures can be monitored using SIFT-MS in real time.

  17. Reactive Transport Modeling and Geophysical Monitoring of Bioclogging at Reservoir Scale

    Science.gov (United States)

    Surasani, V.; Commer, M.; Ajo Franklin, J. B.; Li, L.; Hubbard, S. S.

    2012-12-01

    In Microbial-Enhanced-Hydrocarbon-Recovery (MEHR), preferential bioclogging targets the growth of the biofilms (def. immobilized biopolymers with active cells embodied in it) in highly permeable thief zones to enhance sweep efficiency in oil reservoirs. During MEHR, understanding and controlling bioclogging is hindered by the lack of advanced modeling and monitoring tools; these deficiencies contribute to suboptimal performance. Our focus in this study was on developing a systematic approach to understand and monitor bioclogging at the reservoir scale using a combination of reactive transport modeling and geophysical imaging tools (EM & seismic). In this study, we created a realistic reservoir model from a heterogeneous gas reservoir in the Southern Sacramento basin, California; the model well (Citizen Green #1) was characterized using sonic, electrical, nuclear, and NMR logs for hydrologic and geophysical properties. From the simplified 2D log data model, a strip of size 150m x75m with several high permeability streaks is identified for bioclogging simulation experiments. From the NMR log data it is observed that a good linear correlation exist between logarithmic permeability (0.55- 3.34 log (mD)) versus porosity (0.041-0.28). L. mesenteroides was chosen as the model bacteria. In the presence of sucrose, it enzymatically catalyzes the production of dextran, a useful bioclogging agent. Using microbial kinetics from our laboratory experiment and reservoir heterogeneity, a reactive transport model (RTM) is established for two kinds of bioclogging treatments based on whether microbes are present in situ or are supplied externally. In both cases, sucrose media (1.5 M) is injected at the rate of 1 liter/s for 20 days into the center of high permeable strip to stimulate microbes. Simulations show that the high dextran production was deep into the formation from the injection well. This phenomenon can be explained precisely with bacterial kinetics and injection rate. In

  18. Monitoring PfMDR1 transport in Plasmodium falciparum.

    Science.gov (United States)

    Reiling, Sarah J; Rohrbach, Petra

    2015-07-15

    The Plasmodium falciparum multidrug resistance 1 transporter, PfMDR1, contains five amino acid polymorphisms that are suggested to be involved in altered drug transport from the parasite's cytosol into the digestive vacuole (DV). Transport of a substrate into another intracellular compartment influences drug availability at its site of action, therefore making the parasite more susceptible or resistant to a drug. Fluo-4 is a known fluorescent substrate that can be used as a molecular tool to investigate transport dynamics of PfMDR1 in many parasite strains. Six P. falciparum strains with varying PfMDR1 mutations were loaded with Fluo-4 AM. Accumulation of the fluorophore in the DV was measured using confocal microscopy. The role of a key amino acid mutation was verified using selected parasite clones with point mutations at PfMDR1 amino acid position 1042. Equal expression of PfMDR1 was confirmed by Western blot. Fluo-4 was transported by PfMDR1 into the DV of most drug-sensitive and -resistant parasites. Asparagine at PfMDR1 amino acid position 1042 was crucial for Fluo-4 transport, while the N1042D substitution abolished Fluo-4 transport. Competition studies of Fluo-4 with chloroquine, quinine and mefloquine were performed on parasites harbouring asparagine at position 1042. A distinct Fluo-4 transport inhibition pattern for each tested anti-malarial drug was observed in parasite strains of different genetic background. This study demonstrates that Fluo-4 can be used to investigate PfMDR1 transport dynamics in both drug-sensitive and -resistant parasites. Furthermore, direct evidence of altered Fluo-4 transport in PfMDR1 is linked to a single amino acid mutation in the substrate binding pocket. This system offers a great tool to investigate the role of substrate transport by PfMDR1 and the mutations necessary to support transport, which would lead to new insights for the development of novel anti-malarial drugs.

  19. Microbiological quality and bacterial diversity of the tropical oyster Crassostrea rhizophorae in a monitored farming system and from natural stocks.

    Science.gov (United States)

    Silva Neta, M T; Maciel, B M; Lopes, A T S; Marques, E L S; Rezende, R P; Boehs, G

    2015-12-02

    Microbiological evaluation is one of the most important parameters for analyzing the viability of an oyster farming system, which addresses public health and ecological concerns. Here, the microbiological quality of the oyster Crassostrea rhizophorae cultivated in a monitored environment and from natural beds in Bahia, northeastern Brazil, was determined. Bacterial diversity in oysters was measured by polymerase chain reaction-denaturing gradient gel electrophoresis. Sequence analysis revealed that most bacterial species showed similarity with uncultured or unidentified bacteria from environmental samples, and were clustered into the phylum Proteobacteria. Diverse bacteria from cultivated (monitored) oyster samples were grouped in the same cluster with a high similarity index (above 79%). Microbiological analyses revealed that these oysters did not contain pathogens. These results reflect the natural balance of the microbial communities essential to the maintenance of health and in inhibiting pathogen colonization in the oyster. On the other hand, bacterial diversity of samples from native stocks in extractive areas displayed a similarity index varying between 55 and 77%, and all samples were clustered separately from each other and from the cluster of samples derived from the cultivation area. Microbiological analyses showed that oysters from the extractive area were not fit for human consumption. This reflected a different composition of the microbial community in this area, probably resulting from anthropic impact. Our study also demonstrated that low temperatures and high rainfall limits the bacterial concentration in tropical oysters. This is the first study analyzing the total bacterial community profiles of the oyster C. rhizophorae.

  20. Effect of transportation on fecal bacterial communities and fermentative activities in horses: impact of Saccharomyces cerevisiae CNCM I-1077 supplementation.

    Science.gov (United States)

    Faubladier, C; Chaucheyras-Durand, F; da Veiga, L; Julliand, V

    2013-04-01

    This study evaluated the effect of transportation on fecal bacterial communities and activities in horses with or without supplementation of live yeast and attempted to link those effects with changes in blood stress markers. Four mature horses were assigned to a crossover design and fed a basal diet (60:40 forage to concentrate; 1.45% BW on a DM basis), with or without supplementation, of 2 × 10(10) cfu/d of Saccharomyces cerevisiae CNCM I-1077. After a 14-d adaptation to dietary treatments, the 5-d experiment started 1 d before transportation (d -1). At d 0, horses were simultaneously transported in a truck for 2 h. Feces were sampled 4 h after the morning meal of concentrate at d -1, 0 (immediately after transportation), and 3 for enumeration of the main functional bacterial groups and determination of fermentative variables. Within each dietary treatment, feces were pooled before DNA extraction and molecular analysis of the bacterial communities, using temporal temperature gradient electrophoreses (TTGE). Blood samples were collected at the same time for determination of white blood cells (WBC) counts and glucose and total protein concentrations. Regardless of dietary treatment, the neutrophil to lymphocyte ratio increased during transportation (P horses were stressed. In both treatments, TTGE profiles were clearly different before and 3 d after transportation, and the percentage of similarity between profiles at d -1 and 3 was greater in supplemented horses compared with the controls. From d 0 to 3, the molar percentage of propionate increased and total concentration of VFA and the acetate + butyrate to propionate ratio decreased, regardless of dietary treatment (P horses (P = 0.03). Regardless of day of sampling, fecal concentrations of lactate-utilizing bacteria and cellulolytic bacteria were greater in supplemented horses than in control horses (P = 0.04 and 0.08, respectively). Our results indicate that transportation for 2 h disturbed the fecal bacterial

  1. Evaluation of transgenic tobacco plants expressing a bacterial Co-Ni transporter for acquisition of cobalt.

    Science.gov (United States)

    Nair, Smitha; Joshi-Saha, Archana; Singh, Sudhir; Ramachandran, V; Singh, Surya; Thorat, Vidya; Kaushik, C P; Eapen, Susan; D'Souza, S F

    2012-11-15

    Phytoremediation is a viable strategy for management of toxic wastes in a large area/volume with low concentrations of toxic elemental pollutants. With increased industrial use of cobalt and its alloys, it has become a major metal contaminant in soils and water bodies surrounding these industries and mining sites with adverse effects on the biota. A bacterial Co-Ni permease was cloned from Rhodopseudomonas palustris and introduced into Nicotiana tabacum to explore its potential for phytoremediation and was found to be specific for cobalt and nickel. The transgenic plants accumulated more cobalt and nickel as compared to control, whereas no significant difference in accumulation of other divalent ions was observed. The transgenic plants were evaluated for cobalt content and showed increased acquisition of cobalt (up to 5 times) as compared to control. The plants were also assessed for accumulation of nickel and found to accumulate up to 2 times more nickel than control. At the same initial concentration of cobalt and nickel, transgenic plant preferentially accumulated cobalt as compared to nickel. The present study is perhaps the first attempt to develop transgenic plants expressing heterologous Co transporter with an improved capacity to uptake cobalt. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Monitoring the lactic acid bacterial diversity during shochu fermentation by PCR-denaturing gradient gel electrophoresis.

    Science.gov (United States)

    Endo, Akihito; Okada, Sanae

    2005-03-01

    The presence of lactic acid bacteria (LAB) during shochu fermentation was monitored by PCR-denaturing gradient gel electrophoresis (DGGE) and by bacteriological culturing. No LAB were detected from fermented mashes by PCR-DGGE using a universal bacterial PCR primer set. However, PCR-DGGE using a new primer specific for the 16S rDNA of Lactococcus, Streptococcus, Tetragenococcus, Enterococcus, and Vagococcus and two primers specific for the 16S rDNA of Lactobacillus, Pediococcus, Leuconostoc, and Weissella revealed that Enterococcus faecium, Lactobacillus casei, Lactobacillus fermentum, Lactobacillus nagelii, Lactobacillus plantarum, Lactococcus lactis, Leuconostoc citreum, Leuconostoc mesenteroides, and Weissella cibaria inhabited in shochu mashes. It was also found that the LAB community composition during shochu fermentation changed after the main ingredient and water were added during the fermentation process. Therefore, we confirmed that PCR-DGGE using all three primers specific for groups of LAB together was well suited to the study of the LAB diversity in shochu mashes. The results of DGGE profiles were similar to the results of bacteriological culturing. In conclusion, LAB are present during shochu fermentation but not dominant.

  3. Ascitic fluid analysis for diagnosis and monitoring of spontaneous bacterial peritonitis

    Institute of Scientific and Technical Information of China (English)

    Oliviero Riggio; Stefania Angeloni

    2009-01-01

    Polymorphonuclear (PMN) cell count in the ascitic fluid is essential for the diagnosis and management of spontaneous bacterial peritonitis (SBP). To date, PMN cell count is routinely performed by traditional manual counting. However, this method is time-consuming, costly, and not always timely available. Therefore, considerable efforts have been made in recent years to develop an alternative test for a more rapid diagnosis and monitoring of SBP. The use of urinary reagent strips was proposed to achieve an "instant" bedside diagnosis of SBP. A series of reports evaluated the urine strip test for SBP diagnosis and reported promising results. However, a recent large multicenter study revealed a surprising lack of diagnostic efficacy of the urine screening test for SBP diagnosis. Another method, more recently proposed as an alternative to the manual PMN count, is the measurement of lactoferrin in ascitic fluid, but the data available on the diagnostic value of this test are limited to a single study. However,both urinary reagent strips and ascitic lactoferrin tests are qualitative methods and need, therefore, to be further confirmed by standard cytology of the ascitic fluid.To date, the only quantitative method proposed as a valid alternative to manual PMN counting is automated blood cell counters, commonly used in all laboratories for blood cell counting. Data available in the literature on the diagnostic performance of this method are limited but very promising, and this tool seems to have the potential to replace the manual counting method.

  4. Space Geodesy Monitoring Mass Transport in Global Geophysical Fluids

    Science.gov (United States)

    Chao, Benjamin F.

    2004-01-01

    Mass transports occurring in the atmosphere-hydrosphere-cryosphere-solid Earth-core system (the 'global geophysical fluids') are important geophysical phenomena. They occur on all temporal and spatial scales. Examples include air mass and ocean circulations, oceanic and solid tides, hydrological water and idsnow redistribution, mantle processes such as post-glacial rebound, earthquakes and tectonic motions, and core geodynamo activities. The temporal history and spatial pattern of such mass transport are often not amenable to direct observations. Space geodesy techniques, however, have proven to be an effective tool in monitorihg certain direct consequences of the mass transport, including Earth's rotation variations, gravitational field variations, and the geocenter motion. Considerable advances have been made in recent years in observing and understanding of these geodynamic effects. This paper will use several prominent examples to illustrate the triumphs in research over the past years under a 'Moore's law' in space geodesy. New space missions and projects promise to further advance our knowledge about the global mass transports. The latter contributes to our understanding of the geophysical processes that produce and regulate the mass transports, as well as of the solid Earth's response to such changes in terms of Earth's mechanical properties.

  5. Bacterial mobilization and transport through manure enriched soils: Experiment and modeling.

    Science.gov (United States)

    Sepehrnia, N; Memarianfard, L; Moosavi, A A; Bachmann, J; Guggenberger, G; Rezanezhad, F

    2017-10-01

    A precise evaluation of bacteria transport and mathematical investigations are useful for best management practices in agroecosystems. In this study, using laboratory experiments and modeling approaches, we assess the transport of bacteria released from three types of manure (cow, sheep, and poultry) to find the importance of the common manures in agricultural activities in soil and water pollution. Thirty six intact soil columns with different textures (sandy, loamy, and silty clay loam) were sampled. Fecal coliform leaching from layers of the manures on the soil surface was conducted under steady-state saturated flow conditions at 20 °C for up to four Pore Volumes (PVs). Separate leaching experiments were conducted to obtain the initial concentrations of bacteria released from the manures (Co). Influent (Co) and effluent (C) bacteria concentrations were measured by the plate-count method and the normalized concentrations (C/C0) were plotted versus PV representing the breakthrough curves (BTCs). Transport parameters were predicted using the attachment/detachment model (two-kinetic site) in HYDRUS-1D. Simulations fitted well the experimental data (R(2) = 0.50-0.96). The attachment, detachment, and straining coefficients of bacteria were more influenced by the soils treated with cow manure compared to the sheep and poultry manures. Influent curves of fecal coliforms from the manures (leached without soil) illustrated that the poultry manure had the highest potential to pollute the effluent water from the soils in term of concentration, but the BTCs and simulated data related to the treated soils illustrated that the physical shape of cow manure was more important to both straining and detachment of bacteria back into the soil solution. Detachment trends of bacteria were observed through loam and silty clay loam soils treated with cow manure compared to the cow manure enriched sandy soil. We conclude that management strategies must specifically minimize the

  6. Applications of ZigBee Technology in the Safety Monitoring System of Low Gas Pipeline Transportation

    Directory of Open Access Journals (Sweden)

    Wei Deyu

    2015-01-01

    Full Text Available The existing safety monitoring system of low gas pipeline transportation establishes a wired communication network monitoring system mainly on the basis of industrial bus. It has problems such as large transmission signal attenuation, complex wiring, high-labor intensity, inconvenient installation and maintenance, high maintenance cost, and so on. Featuring low cost, power-saving, reliability, stability and flexibility, the wireless sensor network established by ZigBee wireless communication technology can realize the real-time all-dimensional dynamic monitoring on parameters of low gas pipeline transportation system and overcome the shortcomings and deficiencies of wired network system.

  7. Structural and functional studies of multiheme cytochromes C involved in extracellular electron transport in bacterial dissimilatory metal reduction.

    Science.gov (United States)

    Tikhonova, T V; Popov, V O

    2014-12-01

    Bacteria utilizing insoluble mineral forms of metal oxides as electron acceptors in respiratory processes are widespread in the nature. The electron transfer from a pool of reduced quinones in the cytoplasmic membrane across the periplasm to the bacterial outer membrane and then to an extracellular acceptor is a key step in bacterial dissimilatory metal reduction. Multiheme cytochromes c play a crucial role in the extracellular electron transfer. The bacterium Shewanella oneidensis MR-1 was used as a model organism to study the mechanism of extracellular electron transport. In this review, we discuss recent data on the composition, structures, and functions of multiheme cytochromes c and their functional complexes responsible for extracellular electron transport in Shewanella oneidensis.

  8. Lagrangian tools to monitor transport and mixing in the ocean

    CERN Document Server

    Prants, S V; Uleysky, M Yu

    2012-01-01

    We apply the Lagrangian approach to study surface transport and mixing in the ocean. New tools have been developed to track the motion of water masses, their origin and fate and to quantify transport and mixing. To illustrate the methods used we compute the Lagrangian synoptic maps a comparatively small marine bay, the Peter the Great Bay in the Japan Sea near Vladivostok city (Russia), and in a comparatively large region in the North Pacific, the Kuroshio Extension system. In the first case we use velocity data from a Japan Sea circulation numerical model and in the second one the velocity data are derived from satellite altimeter measurements of anomalies of the sea height distributed by AVISO.

  9. Monitoring bacterial processes by Fourier transform infrared spectroscopy : Helicobacter pylori drug inactivation and plasmid bioproduction in recombinant Escherichia coli cultures

    OpenAIRE

    Scholz, Teresa; Lopes, Vitor V.; Calado, Cecília R. C.

    2011-01-01

    Fourier transform infrared (FTIR) spectroscopy is evaluated as a tool to monitor two bacterial processes: strain discrimination and drug inactivation studies with the gastric pathogen Helicobacter pylori and the plasmid production process based on high-density cultures of recombinant Escherichia coli. Results show, that after evaluation of different incubation conditions of H.pylori with the drug model, the application of principal component analysis to the FTIR spectra assembles the samples ...

  10. Uptake of biotin by Chlamydia Spp. through the use of a bacterial transporter (BioY and a host-cell transporter (SMVT.

    Directory of Open Access Journals (Sweden)

    Derek J Fisher

    Full Text Available Chlamydia spp. are obligate intracellular Gram-negative bacterial pathogens that cause disease in humans and animals. Minor variations in metabolic capacity between species have been causally linked to host and tissue tropisms. Analysis of the highly conserved genomes of Chlamydia spp. reveals divergence in the metabolism of the essential vitamin biotin with genes for either synthesis (bioF_2ADB and/or transport (bioY. Streptavidin blotting confirmed the presence of a single biotinylated protein in Chlamydia. As a first step in unraveling the need for divergent biotin acquisition strategies, we examined BioY (CTL0613 from C. trachomatis 434/Bu which is annotated as an S component of the type II energy coupling-factor transporters (ECF. Type II ECFs are typically composed of a transport specific component (S and a chromosomally unlinked energy module (AT. Intriguingly, Chlamydia lack recognizable AT modules. Using (3H-biotin and recombinant E. coli expressing CTL0613, we demonstrated that biotin was transported with high affinity (a property of Type II ECFs previously shown to require an AT module and capacity (apparent K(m of 3.35 nM and V(max of 55.1 pmol×min(-1×mg(-1. Since Chlamydia reside in a host derived membrane vacuole, termed an inclusion, we also sought a mechanism for transport of biotin from the cell cytoplasm into the inclusion vacuole. Immunofluorescence microscopy revealed that the mammalian sodium multivitamin transporter (SMVT, which transports lipoic acid, biotin, and pantothenic acid into cells, localizes to the inclusion. Since Chlamydia also are auxotrophic for lipoic and pantothenic acids, SMVT may be subverted by Chlamydia to move multiple essential compounds into the inclusion where BioY and another transporter(s would be present to facilitate transport into the bacterium. Collectively, our data validates the first BioY from a pathogenic organism and describes a two-step mechanism by which Chlamydia transport biotin

  11. CAP-D3 Promotes Bacterial Clearance in Human Intestinal Epithelial Cells by Repressing Expression of Amino Acid Transporters

    Science.gov (United States)

    Kemp, Jacqueline R.; Nickerson, Kourtney P.; Deutschman, Emily; Kim, Yeojung; West, Gail; Sadler, Tammy; Stylianou, Eleni; Krokowski, Dawid; Hatzoglou, Maria; de la Motte, Carol; Rubin, Brian P.; Fiocchi, Claudio

    2015-01-01

    BACKGROUND & AIMS Defects in colonic epithelial barrier defenses are associated with ulcerative colitis (UC). The proteins that regulate bacterial clearance in the colonic epithelium have not been completely identified. The chromosome-associated protein D3 (dCAP-D3), regulates responses to bacterial infection. We examined whether CAP-D3 promotes bacterial clearance in human colonic epithelium. METHODS Clearance of Salmonella or adherent-invasive Escherichia coli LF82 was assessed by gentamycin protection assays in HT-29 and Caco-2 cells expressing small hairpin RNAs against CAP-D3. We used immunoblot assays to measure levels of CAP-D3 in colonic epithelial cells from patients with UC and healthy individuals (controls). RNA sequencing identified genes activated by CAP-D3. We analyzed the roles of CAP-D3 target genes in bacterial clearance using gentamycin protection and immunofluorescence assays and studies with pharmacologic inhibitors. RESULTS CAP-D3 expression was reduced in colonic epithelial cells from patients with active UC. Reduced CAP-D3 expression decreased autophagy and impaired intracellular bacterial clearance by HT-29 and Caco-2 colonic epithelial cells. Lower levels of CAP-D3 increased transcription of genes encoding SLC7A5 and SLC3A2, whose products heterodimerize to form an amino acid transporter in HT-29 cells following bacterial infection; levels of SLC7A5–SLC3A2 were increased in tissues from patients with UC, compared with controls. Reduced CAP-D3 in HT-29 cells resulted in earlier recruitment of SLC7A5 to Salmonella-containing vacuoles, increased activity of mTORC1, and increased survival of bacteria. Inhibition of SLC7A5–SLC3A2 or mTORC1 activity rescued the bacterial clearance defects of CAP-D3– deficient cells. CONCLUSIONS CAP-D3 downregulates transcription of genes that encode amino acid transporters (SLC7A5 and SLC3A2) to promote bacterial autophagy by colon epithelial cells. Levels of CAP-D3 protein are reduced in patients with

  12. Monitoring Potential Transport of Radioactive Contaminants in Shallow Ephemeral Channels

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Julianne J.; Mizell, Steve A.; Nikolich, George; Campbell, Scott A.

    2012-02-01

    The U.S. Department of Energy (DOE) National Nuclear Security Administration (NNSA), Nevada Site Office (NSO), Environmental Restoration Soils Activity has authorized the Desert Research Institute (DRI) to conduct field assessments of potential sediment transport of contaminated soil from Corrective Action Unit (CAU) 550, Area 8 Smoky Contamination Area (CA), during precipitation runoff events. CAU 550 includes Corrective Action Sites (CASs) 08-23-03, 08-23-04, 08-23-06, and 08-23-07; these CASs are associated with tests designated Ceres, Smoky, Oberon, and Titania, respectively.

  13. Transport, monitoring, and successful brain MR imaging in unsedated neonates

    Energy Technology Data Exchange (ETDEWEB)

    Mathur, Amit M. [St. Louis Children' s Hospital at the Washington University School of Medicine, Department of Pediatrics and Newborn Medicine, St. Louis, MO (United States); St. Louis Children' s Hospital, Division of Newborn Medicine, St. Louis, MO (United States); Neil, Jeffrey J. [St. Louis Children' s Hospital at the Washington University School of Medicine, Department of Neurology, St. Louis, MO (United States); Mallinckrodt Institute of Radiology, St. Louis, MO (United States); McKinstry, Robert C. [Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Inder, Terrie E. [St. Louis Children' s Hospital at the Washington University School of Medicine, Department of Pediatrics and Newborn Medicine, St. Louis, MO (United States); St. Louis Children' s Hospital at the Washington University School of Medicine, Department of Neurology, St. Louis, MO (United States); Mallinckrodt Institute of Radiology, St. Louis, MO (United States)

    2008-03-15

    Neonatal cerebral MR imaging is a sensitive technique for evaluating brain injury in the term and preterm infant. In term encephalopathic infants, MR imaging reliably detects not only the pattern of brain injury but might also provide clues about the timing of injury. In premature infants, MR imaging has surpassed US in the detection of white matter injury, a common lesion in this population. Concerns remain about the safety and transport of sedated neonates for MR examination to radiology suites, which are usually located at a distance from neonatal intensive care units. We present our own institutional experience and guidelines used to optimize the performance of cerebral MR examinations in neonates without sedation or anesthesia. (orig.)

  14. The Siderocalin/Enterobactin Interaction: A Link between Mammalian Immunity and Bacterial Iron Transport

    Energy Technology Data Exchange (ETDEWEB)

    Meux, Susan C.

    2008-05-12

    The siderophore enterobactin (Ent) is produced by enteric bacteria to mediate iron uptake. Ent scavenges iron and is taken up by the bacteria as the highly stable ferric complex [Fe{sup III}(Ent)]{sup 3-}. This complex is also a specific target of the mammalian innate immune system protein, Siderocalin (Scn), which acts as an anti-bacterial agent by specifically sequestering siderophores and their ferric complexes during infection. Recent literature suggesting that Scn may also be involved in cellular iron transport has increased the importance of understanding the mechanism of siderophore interception and clearance by Scn; Scn is observed to release iron in acidic endosomes and [Fe{sup III}(Ent)]{sup 3-} is known to undergo a change from catecholate to salicylate coordination in acidic conditions, which is predicted to be sterically incompatible with the Scn binding pocket (also referred to as the calyx). To investigate the interactions between the ferric Ent complex and Scn at different pH values, two recombinant forms of Scn with mutations in three residues lining the calyx were prepared: Scn-W79A/R81A and Scn-Y106F. Binding studies and crystal structures of the Scn-W79A/R81A:[Fe{sup III}(Ent)]{sup 3-} and Scn-Y106F:[Fe{sup III}(Ent)]{sup 3-} complexes confirm that such mutations do not affect the overall conformation of the protein but do weaken significantly its affinity for [Fe{sup III}(Ent)]{sup 3-}. Fluorescence, UV-Vis and EXAFS spectroscopies were used to determine Scn/siderophore dissociation constants and to characterize the coordination mode of iron over a wide pH range, in the presence of both mutant proteins and synthetic salicylate analogs of Ent. While Scn binding hinders salicylate coordination transformation, strong acidification results in the release of iron and degraded siderophore. Iron release may therefore result from a combination of Ent degradation and coordination change.

  15. Chlamydia trachomatis intercepts Golgi-derived sphingolipids through a Rab14-mediated transport required for bacterial development and replication.

    Directory of Open Access Journals (Sweden)

    Anahí Capmany

    Full Text Available Chlamydia trachomatis are obligate intracellular bacteria that survive and replicate in a bacterial-modified phagosome called inclusion. As other intracellular parasites, these bacteria subvert the phagocytic pathway to avoid degradation in phagolysosomes and exploit trafficking pathways to acquire both energy and nutrients essential for their survival. Rabs are host proteins that control intracellular vesicular trafficking. Rab14, a Golgi-related Rab, controls Golgi to endosomes transport. Since Chlamydia establish a close relationship with the Golgi apparatus, the recruitment and participation of Rab14 on inclusion development and bacteria growth were analyzed. Time course analysis revealed that Rab14 associated with inclusions by 10 h post infection and was maintained throughout the entire developmental cycle. The recruitment was bacterial protein synthesis-dependent but independent of microtubules and Golgi integrity. Overexpression of Rab14 dominant negative mutants delayed inclusion enlargement, and impaired bacteria replication as determined by IFU. Silencing of Rab14 by siRNA also decreased bacteria multiplication and infectivity. By electron microscopy, aberrant bacteria were observed in cells overexpressing the cytosolic negative Rab14 mutant. Our results showed that Rab14 facilitates the delivery of sphingolipids required for bacterial development and replication from the Golgi to chlamydial inclusions. Novel anti-chlamydial therapies could be developed based on the knowledge of how bacteria subvert host vesicular transport events through Rabs manipulation.

  16. Monitoring Potential Transport of Radioactive Contaminants in Shallow Ephemeral Channels: FY2013 and FY2014 (revised)

    Energy Technology Data Exchange (ETDEWEB)

    Mizell, Steve A. [Desert Research Inst. (DRI), Las Vegas, NV (United States); Miller, Julianne J. [Desert Research Inst. (DRI), Las Vegas, NV (United States); McCurdy, Greg D. [Desert Research Inst. (DRI), Reno, NV (United States); Campbell, Scott A. [Desert Research Inst. (DRI), Las Vegas, NV (United States)

    2017-06-01

    The Desert Research Institute (DRI) is conducting a field assessment of the potential for contaminated soil to be transported from the Smoky Contamination Area (CA) as a result of storm runoff, which supports National Nuclear Security Administration (NNSA) efforts to complete regulatory closure of the Soils Corrective Action Unit (CAU) contamination areas. The work is intended to confirm the likely mechanism of transport and determine the meteorological conditions that might cause movement of contaminated soils, as well as determine the particle size fraction that is most closely associated with transported radionuclide-contaminated soils. These data will facilitate the appropriate closure design and post-closure monitoring program.

  17. Monitoring water supplies for weaponized bacteria and bacterial toxins using rapid fluorescence-based viability and affinity assays

    Science.gov (United States)

    Van Tassell, Roger L.; Evans, Mishell

    2004-03-01

    The rapid detection of weaponized bacteria and toxins is a major problem during a biological attack. Although sensitive detection formats exist for many biowarfare agents, they often require advanced training and complex procedures. Luna has developed simple, rapid means for determining the presence of pathogens and bacterial toxins in water supplies using fluorescence-based assays that can be adapted for field use. The batteries of rapid assays are designed for i) determining cell viability and bacterial loads by exploiting metabolic markers (e.g., acid-production, redox potentials, etc) and ii) detecting bacterial toxins using fluorescent, polymerized affinity liposomes (fluorosomes). The viability assays were characterized using E. coli, S. aureus and the anthrax simulant, B. globigii. The viability assays detected bacterial loads of ~ 104 CFU/ml and with simple filtration ~ 100CFU/ml could be detected. The affinity fluorosomes were characterized using cholera toxin (CT). Affinity liposomes displaying GM1 and anti-CT antibodies could detect CT at <μg/ml levels. Stability studies showed that affinity vesicles could be stored for weeks at 4°C or freeze-dried with no significant loss of binding capacity. Using an in-house fiber optic fluorescence system, Luna characterized the binding of affinity fluorosomes to respective targets and determined the responses of bacterial loads in the fluorescent viability assays. Using this two-tiered approach, Luna demonstrated that water susceptible to sabotage could be easily monitored and confirmed for specific agents using simple, general and specific fluorescence-based detection schemes based on metabolism and ligand-target interactions.

  18. [Monitoring of water and salt transport in silt and sandy soil during the leaching process].

    Science.gov (United States)

    Fu, Teng-Fei; Jia, Yong-Gang; Guo, Lei; Liu, Xiao-Lei

    2012-11-01

    Water and salt transport in soil and its mechanism is the key point of the saline soil research. The dynamic rule of water and transport in soil during the leaching process is the theoretical basis of formation, flush, drainage and improvement of saline soil. In this study, a vertical infiltration experiment was conducted to monitor the variation in the resistivity of silt and sandy soil during the leaching process by the self-designed automatic monitoring device. The experimental results showed that the peaks in the resistivity of the two soils went down and faded away in the course of leaching. It took about 30 minutes for sandy soil to reach the water-salt balance, whereas the silt took about 70 minutes. With the increasing leaching times, the desalination depth remained basically the same, being 35 cm for sandy soil and 10 cm for the silt from the top to bottom of soil column. Therefore, 3 and 7 leaching processes were required respectively for the complete desalination of the soil column. The temporal and spatial resolution of this monitoring device can be adjusted according to the practical demand. This device can not only achieve the remote, in situ and dynamic monitoring data of water and salt transport, but also provide an effective method in monitoring, assessment and early warning of salinization.

  19. Development and application of the active surveillance of pathogens microarray to monitor bacterial gene flux

    Directory of Open Access Journals (Sweden)

    Hinds Jason

    2008-10-01

    Full Text Available Abstract Background Human and animal health is constantly under threat by emerging pathogens that have recently acquired genetic determinants that enhance their survival, transmissibility and virulence. We describe the construction and development of an Active Surveillance of Pathogens (ASP oligonucleotide microarray, designed to 'actively survey' the genome of a given bacterial pathogen for virulence-associated genes. Results The microarray consists of 4958 reporters from 151 bacterial species and include genes for the identification of individual bacterial species as well as mobile genetic elements (transposons, plasmid and phage, virulence genes and antibiotic resistance genes. The ASP microarray was validated with nineteen bacterial pathogens species, including Francisella tularensis, Clostridium difficile, Staphylococcus aureus, Enterococcus faecium and Stenotrophomonas maltophilia. The ASP microarray identified these bacteria, and provided information on potential antibiotic resistance (eg sufamethoxazole resistance and sulfonamide resistance and virulence determinants including genes likely to be acquired by horizontal gene transfer (e.g. an alpha-haemolysin. Conclusion The ASP microarray has potential in the clinic as a diagnostic tool, as a research tool for both known and emerging pathogens, and as an early warning system for pathogenic bacteria that have been recently modified either naturally or deliberately.

  20. Drosophila embryos as model systems for monitoring bacterial infection in real time.

    Directory of Open Access Journals (Sweden)

    Isabella Vlisidou

    2009-07-01

    Full Text Available Drosophila embryos are well studied developmental microcosms that have been used extensively as models for early development and more recently wound repair. Here we extend this work by looking at embryos as model systems for following bacterial infection in real time. We examine the behaviour of injected pathogenic (Photorhabdus asymbiotica and non-pathogenic (Escherichia coli bacteria and their interaction with embryonic hemocytes using time-lapse confocal microscopy. We find that embryonic hemocytes both recognise and phagocytose injected wild type, non-pathogenic E. coli in a Dscam independent manner, proving that embryonic hemocytes are phagocytically competent. In contrast, injection of bacterial cells of the insect pathogen Photorhabdus leads to a rapid 'freezing' phenotype of the hemocytes associated with significant rearrangement of the actin cytoskeleton. This freezing phenotype can be phenocopied by either injection of the purified insecticidal toxin Makes Caterpillars Floppy 1 (Mcf1 or by recombinant E. coli expressing the mcf1 gene. Mcf1 mediated hemocyte freezing is shibire dependent, suggesting that endocytosis is required for Mcf1 toxicity and can be modulated by dominant negative or constitutively active Rac expression, suggesting early and unexpected effects of Mcf1 on the actin cytoskeleton. Together these data show how Drosophila embryos can be used to track bacterial infection in real time and how mutant analysis can be used to genetically dissect the effects of specific bacterial virulence factors.

  1. Quantitative spectral light scattering polarimetry for monitoring fractal growth pattern of Bacillus thuringiensis bacterial colonies

    Science.gov (United States)

    Banerjee, Paromita; Soni, Jalpa; Ghosh, Nirmalya; Sengupta, Tapas K.

    2013-02-01

    It is of considerable current interest to develop various methods which help to understand and quantify the cellular association in growing bacterial colonies and is also important in terms of detection and identification of a bacterial species. A novel approach is used here to probe the morphological structural changes occurring during the growth of the bacterial colony of Bacillus thuringiensis under different environmental conditions (in normal nutrient agar, in presence of glucose - acting as additional nutrient and additional 3mM arsenate as additional toxic material). This approach combines the quantitative Mueller matrix polarimetry to extract intrinsic polarization properties and inverse analysis of the polarization preserving part of the light scattering spectra to determine the fractal parameter H (Hurst exponent) using Born approximation. Interesting differences are observed in the intrinsic polarization parameters and also in the Hurst exponent, which is a measurement of the fractality of a pattern formed by bacteria while growing as a colony. These findings are further confirmed with optical microscopic studies of the same sample and the results indicate a very strong and distinct dependence on the environmental conditions during growth, which can be exploited to quantify different bacterial species and their growth patterns.

  2. Aphid amino acid transporter regulates glutamine supply to intracellular bacterial symbionts.

    Science.gov (United States)

    Price, Daniel R G; Feng, Honglin; Baker, James D; Bavan, Selvan; Luetje, Charles W; Wilson, Alex C C

    2014-01-01

    Endosymbiotic associations have played a major role in evolution. However, the molecular basis for the biochemical interdependence of these associations remains poorly understood. The aphid-Buchnera endosymbiosis provides a powerful system to elucidate how these symbioses are regulated. In aphids, the supply of essential amino acids depends on an ancient nutritional symbiotic association with the gamma-proteobacterium Buchnera aphidicola. Buchnera cells are densely packed in specialized aphid bacteriocyte cells. Here we confirm that five putative amino acid transporters are highly expressed and/or highly enriched in Acyrthosiphon pisum bacteriocyte tissues. When expressed in Xenopus laevis oocytes, two bacteriocyte amino acid transporters displayed significant levels of glutamine uptake, with transporter ACYPI001018, LOC100159667 (named here as Acyrthosiphon pisum glutamine transporter 1, ApGLNT1) functioning as the most active glutamine transporter. Transporter ApGLNT1 has narrow substrate selectivity, with high glutamine and low arginine transport capacity. Notably, ApGLNT1 has high binding affinity for arginine, and arginine acts as a competitive inhibitor for glutamine transport. Using immunocytochemistry, we show that ApGLNT1 is localized predominantly to the bacteriocyte plasma membrane, a location consistent with the transport of glutamine from A. pisum hemolymph to the bacteriocyte cytoplasm. On the basis of functional transport data and localization, we propose a substrate feedback inhibition model in which the accumulation of the essential amino acid arginine in A. pisum hemolymph reduces the transport of the precursor glutamine into bacteriocytes, thereby regulating amino acid biosynthesis in the bacteriocyte. Structural similarities in the arrangement of hosts and symbionts across endosymbiotic systems suggest that substrate feedback inhibition may be mechanistically important in other endosymbioses.

  3. Real-time activity monitoring of New Delhi metallo-β-lactamase-1 in living bacterial cells by UV-Vis spectroscopy.

    Science.gov (United States)

    Yang, Ke-Wu; Zhou, Yajun; Ge, Ying; Zhang, Yuejuan

    2017-07-13

    We report an UV-Vis method for monitoring the hydrolysis of the β-lactam antibiotics inside living bacterial cells. Cell-based studies demonstrated that the hydrolysis of cefazolin was inhibited by three known NDM-1 inhibitors. This approach can be applied to the monitoring of reactions in a complex biological system, for instance in medical testing.

  4. Using Amplicon Sequencing To Characterize and Monitor Bacterial Diversity in Drinking Water Distribution Systems

    Science.gov (United States)

    Shaw, Jennifer L. A.; Weyrich, Laura S.; Sawade, Emma; Drikas, Mary; Cooper, Alan J.

    2015-01-01

    Drinking water assessments use a variety of microbial, physical, and chemical indicators to evaluate water treatment efficiency and product water quality. However, these indicators do not allow the complex biological communities, which can adversely impact the performance of drinking water distribution systems (DWDSs), to be characterized. Entire bacterial communities can be studied quickly and inexpensively using targeted metagenomic amplicon sequencing. Here, amplicon sequencing of the 16S rRNA gene region was performed alongside traditional water quality measures to assess the health, quality, and efficiency of two distinct, full-scale DWDSs: (i) a linear DWDS supplied with unfiltered water subjected to basic disinfection before distribution and (ii) a complex, branching DWDS treated by a four-stage water treatment plant (WTP) prior to disinfection and distribution. In both DWDSs bacterial communities differed significantly after disinfection, demonstrating the effectiveness of both treatment regimes. However, bacterial repopulation occurred further along in the DWDSs, and some end-user samples were more similar to the source water than to the postdisinfection water. Three sample locations appeared to be nitrified, displaying elevated nitrate levels and decreased ammonia levels, and nitrifying bacterial species, such as Nitrospira, were detected. Burkholderiales were abundant in samples containing large amounts of monochloramine, indicating resistance to disinfection. Genera known to contain pathogenic and fecal-associated species were also identified in several locations. From this study, we conclude that metagenomic amplicon sequencing is an informative method to support current compliance-based methods and can be used to reveal bacterial community interactions with the chemical and physical properties of DWDSs. PMID:26162884

  5. Using Amplicon Sequencing To Characterize and Monitor Bacterial Diversity in Drinking Water Distribution Systems.

    Science.gov (United States)

    Shaw, Jennifer L A; Monis, Paul; Weyrich, Laura S; Sawade, Emma; Drikas, Mary; Cooper, Alan J

    2015-09-01

    Drinking water assessments use a variety of microbial, physical, and chemical indicators to evaluate water treatment efficiency and product water quality. However, these indicators do not allow the complex biological communities, which can adversely impact the performance of drinking water distribution systems (DWDSs), to be characterized. Entire bacterial communities can be studied quickly and inexpensively using targeted metagenomic amplicon sequencing. Here, amplicon sequencing of the 16S rRNA gene region was performed alongside traditional water quality measures to assess the health, quality, and efficiency of two distinct, full-scale DWDSs: (i) a linear DWDS supplied with unfiltered water subjected to basic disinfection before distribution and (ii) a complex, branching DWDS treated by a four-stage water treatment plant (WTP) prior to disinfection and distribution. In both DWDSs bacterial communities differed significantly after disinfection, demonstrating the effectiveness of both treatment regimes. However, bacterial repopulation occurred further along in the DWDSs, and some end-user samples were more similar to the source water than to the postdisinfection water. Three sample locations appeared to be nitrified, displaying elevated nitrate levels and decreased ammonia levels, and nitrifying bacterial species, such as Nitrospira, were detected. Burkholderiales were abundant in samples containing large amounts of monochloramine, indicating resistance to disinfection. Genera known to contain pathogenic and fecal-associated species were also identified in several locations. From this study, we conclude that metagenomic amplicon sequencing is an informative method to support current compliance-based methods and can be used to reveal bacterial community interactions with the chemical and physical properties of DWDSs. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  6. Structure and Mechanism of the S Component of a Bacterial ECF Transporter

    Energy Technology Data Exchange (ETDEWEB)

    P Zhang; J Wang; Y Shi

    2011-12-31

    The energy-coupling factor (ECF) transporters, responsible for vitamin uptake in prokaryotes, are a unique family of membrane transporters. Each ECF transporter contains a membrane-embedded, substrate-binding protein (known as the S component), an energy-coupling module that comprises two ATP-binding proteins (known as the A and A' components) and a transmembrane protein (known as the T component). The structure and transport mechanism of the ECF family remain unknown. Here we report the crystal structure of RibU, the S component of the ECF-type riboflavin transporter from Staphylococcus aureus at 3.6-{angstrom} resolution. RibU contains six transmembrane segments, adopts a previously unreported transporter fold and contains a riboflavin molecule bound to the L1 loop and the periplasmic portion of transmembrane segments 4-6. Structural analysis reveals the essential ligand-binding residues, identifies the putative transport path and, with sequence alignment, uncovers conserved structural features and suggests potential mechanisms of action among the ECF transporters.

  7. 2D and 3D crystallization of a bacterial homologue of human vitamin C membrane transport proteins.

    Science.gov (United States)

    Jeckelmann, Jean-Marc; Harder, Daniel; Ucurum, Zöhre; Fotiadis, Dimitrios

    2014-10-01

    Most organisms are able to synthesize vitamin C whereas humans are not. In order to contribute to the elucidation of the molecular working mechanism of vitamin C transport through biological membranes, we cloned, overexpressed, purified, functionally characterized, and 2D- and 3D-crystallized a bacterial protein (UraDp) with 29% of amino acid sequence identity to the human sodium-dependent vitamin C transporter 1 (SVCT1). Ligand-binding experiments by scintillation proximity assay revealed that uracil is a substrate preferably bound to UraDp. For structural analysis, we report on the production of tubular 2D crystals and present a first projection structure of UraDp from negatively stained tubes. On the other hand the successful growth of UraDp 3D crystals and their crystallographic analysis is described. These 3D crystals, which diffract X-rays to 4.2Å resolution, pave the way towards the high-resolution crystal structure of a bacterial homologue with high amino acid sequence identity to human SVCT1.

  8. Effects of temperature on bacterial transport and destruction in bioretention media: field and laboratory evaluations.

    Science.gov (United States)

    Zhang, Lan; Seagren, Eric A; Davis, Allen P; Karns, Jeffrey S

    2012-06-01

    Microbial activities are significantly influenced by temperature. This study investigated the effects of temperature on the capture and destruction of bacteria from urban stormwater runoff in bioretention media using 2-year field evaluations coupled with controlled laboratory column studies. Field data from two bioretention cells show that the concentration of indicator bacteria (fecal coliforms and Escherichia coli) was reduced during most storm events, and that the probability of meeting specific water quality criteria in the discharge was increased. Indicator bacteria concentration in the input flow typically increased with higher daily temperature. Although bacterial removal efficiency was independent of temperature in the field and laboratory, column tests showed that bacterial decay coefficients in conventional bioretention media (CBM) increase exponentially with elevated temperature. Increases in levels of protozoa and heterotrophic bacteria associated with increasing temperature appear to contribute to faster die-off of trapped E. coli in CBM via predation and competition.

  9. Sensing Models and Sensor Network Architectures for Transport Infrastructure Monitoring in Smart Cities

    Science.gov (United States)

    Simonis, Ingo

    2015-04-01

    Transport infrastructure monitoring and analysis is one of the focus areas in the context of smart cities. With the growing number of people moving into densely populated urban metro areas, precise tracking of moving people and goods is the basis for profound decision-making and future planning. With the goal of defining optimal extensions and modifications to existing transport infrastructures, multi-modal transport has to be monitored and analysed. This process is performed on the basis of sensor networks that combine a variety of sensor models, types, and deployments within the area of interest. Multi-generation networks, consisting of a number of sensor types and versions, are causing further challenges for the integration and processing of sensor observations. These challenges are not getting any smaller with the development of the Internet of Things, which brings promising opportunities, but is currently stuck in a type of protocol war between big industry players from both the hardware and network infrastructure domain. In this paper, we will highlight how the OGC suite of standards, with the Sensor Web standards developed by the Sensor Web Enablement Initiative together with the latest developments by the Sensor Web for Internet of Things community can be applied to the monitoring and improvement of transport infrastructures. Sensor Web standards have been applied in the past to pure technical domains, but need to be broadened now in order to meet new challenges. Only cross domain approaches will allow to develop satisfying transport infrastructure approaches that take into account requirements coming form a variety of sectors such as tourism, administration, transport industry, emergency services, or private people. The goal is the development of interoperable components that can be easily integrated within data infrastructures and follow well defined information models to allow robust processing.

  10. The bacterial dicarboxylate transporter VcINDY uses a two-domain elevator-type mechanism.

    Science.gov (United States)

    Mulligan, Christopher; Fenollar-Ferrer, Cristina; Fitzgerald, Gabriel A; Vergara-Jaque, Ariela; Kaufmann, Desirée; Li, Yan; Forrest, Lucy R; Mindell, Joseph A

    2016-03-01

    Secondary transporters use alternating-access mechanisms to couple uphill substrate movement to downhill ion flux. Most known transporters use a 'rocking bundle' motion, wherein the protein moves around an immobile substrate-binding site. However, the glutamate-transporter homolog GltPh translocates its substrate-binding site vertically across the membrane, through an 'elevator' mechanism. Here, we used the 'repeat swap' approach to computationally predict the outward-facing state of the Na(+)/succinate transporter VcINDY, from Vibrio cholerae. Our model predicts a substantial elevator-like movement of VcINDY's substrate-binding site, with a vertical translation of ~15 Å and a rotation of ~43°. Our observation that multiple disulfide cross-links completely inhibit transport provides experimental confirmation of the model and demonstrates that such movement is essential. In contrast, cross-links across the VcINDY dimer interface preserve transport, thus revealing an absence of large-scale coupling between protomers.

  11. Characteristic monitoring of groundwater-salt transportation and input-output in inland arid irrigation area.

    Science.gov (United States)

    Xu, Cundong; Zhang, Hongyang; Han, Liwei; Zhai, Luxin

    2014-11-01

    The rules of microscopic water-salt transportation can be revealed and the impact on the macroscopic water and soil resources can be further predicted by selecting a typical study area and carrying out continuous monitoring. In this paper, Jingtaichuan Electrical Lifting Irrigation District in Gansu Province (hereinafter called as JingDian irrigation district (JID)) located at the inland desert region of northwest China was selected as study area. Based on the groundwater-salt transportation data of representative groundwater monitoring wells in different hydrogeological units, the groundwater-salt evolution and transportation tendency in both closed and unclosed hydrogeological units were analyzed and the quantity relative ratio relationship of regional water-salt input-excretion was calculated. The results showed that the salt brought in by artificial irrigation accounts for the highest proportion of about 63.99% and the salt carried off by the discharge of irrigation water accounts for 66.42%, namely, the water-salt evolution and transportation were mainly controlled by artificial irrigation. As the general features of regional water-salt transportation, groundwater salinity and soil salt content variation were mainly decided by the transportation of soil soluble salt which showed an obvious symbiosis gathering regularity, but the differentiation with insoluble salt components was significant in the transportation process. Besides, groundwater salinity of the unclosed hydrogeological unit presented a periodically fluctuating trend, while the groundwater salinity and soil salt content in water and salt accumulation zone of the closed hydrogeological unit showed an increasing tendency, which formed the main occurrence area of soil secondary salinization.

  12. Functional role of oligomerization for bacterial and plant SWEET sugar transporter family.

    Science.gov (United States)

    Xuan, Yuan Hu; Hu, Yi Bing; Chen, Li-Qing; Sosso, Davide; Ducat, Daniel C; Hou, Bi-Huei; Frommer, Wolf B

    2013-09-24

    Eukaryotic sugar transporters of the MFS and SWEET superfamilies consist of 12 and 7 α-helical transmembrane domains (TMs), respectively. Structural analyses indicate that MFS transporters evolved from a series of tandem duplications of an ancestral 3-TM unit. SWEETs are heptahelical proteins carrying a tandem repeat of 3-TM separated by a single TM. Here, we show that prokaryotes have ancestral SWEET homologs with only 3-TM and that the Bradyrhizobium japonicum SemiSWEET1, like Arabidopsis SWEET11, mediates sucrose transport. Eukaryotic SWEETs most likely evolved by internal duplication of the 3-TM, suggesting that SemiSWEETs form oligomers to create a functional pore. However, it remains elusive whether the 7-TM SWEETs are the functional unit or require oligomerization to form a pore sufficiently large to allow for sucrose passage. Split ubiquitin yeast two-hybrid and split GFP assays indicate that Arabidopsis SWEETs homo- and heterooligomerize. We examined mutant SWEET variants for negative dominance to test if oligomerization is necessary for function. Mutation of the conserved Y57 or G58 in SWEET1 led to loss of activity. Coexpression of the defective mutants with functional A. thaliana SWEET1 inhibited glucose transport, indicating that homooligomerization is necessary for function. Collectively, these data imply that the basic unit of SWEETs, similar to MFS sugar transporters, is a 3-TM unit and that a functional transporter contains at least four such domains. We hypothesize that the functional unit of the SWEET family of transporters possesses a structure resembling the 12-TM MFS structure, however, with a parallel orientation of the 3-TM unit.

  13. Electrical resistivity tomography as monitoring tool for unsaturated zone transport: an example of preferential transport of deicing chemicals.

    Science.gov (United States)

    Wehrer, Markus; Lissner, Heidi; Bloem, Esther; French, Helen; Totsche, Kai Uwe

    2014-01-01

    Non-invasive spatially resolved monitoring techniques may hold the key to observe heterogeneous flow and transport behavior of contaminants in soils. In this study, time-lapse electrical resistivity tomography (ERT) was employed during an infiltration experiment with deicing chemical in a small field lysimeter. Deicing chemicals like potassium formate, which frequently impact soils on airport sites, were infiltrated during snow melt. Chemical composition of seepage water and the electrical response was recorded over the spring period 2010. Time-lapse electrical resistivity tomographs are able to show the infiltration of the melt water loaded with ionic constituents of deicing chemicals and their degradation product hydrogen carbonate. The tomographs indicate early breakthrough behavior in parts of the profile. Groundtruthing with pore fluid conductivity and water content variations shows disagreement between expected and observed bulk conductivity. This was attributed to the different sampling volume of traditional methods and ERT due to a considerable fraction of immobile water in the soil. The results show that ERT can be used as a soil monitoring tool on airport sites if assisted by common soil monitoring techniques.

  14. Sensor Networks Hierarchical Optimization Model for Security Monitoring in High-Speed Railway Transport Hub

    Directory of Open Access Journals (Sweden)

    Zhengyu Xie

    2015-01-01

    Full Text Available We consider the sensor networks hierarchical optimization problem in high-speed railway transport hub (HRTH. The sensor networks are optimized from three hierarchies which are key area sensors optimization, passenger line sensors optimization, and whole area sensors optimization. Case study on a specific HRTH in China showed that the hierarchical optimization method is effective to optimize the sensor networks for security monitoring in HRTH.

  15. Monitoring of probiotic bacterial cells Lactobacillus casei in dry fermented sausages

    Directory of Open Access Journals (Sweden)

    Radka Burdychová

    2008-01-01

    Full Text Available Combination of microbiology cultivation methods and methods of molecular biology is the best way how to achieve correct qualitative and quantitative probiotic analysis. The aim of this study was mo­ni­to­ring of amounts of different starter bacteria supplemented with probiotic bacterial cells Lactobacillus casei (Chr. Hansen during fermentation and ripening of fermented sausages. Two starter cultures, one consisted of Pediococcus pentosaceus and Staphylococcus xylosus, the second of Pediococcus pentosaceus and Staphylococcus carnosus, were used for the production of sausages. As a detection method of starter and probiotic cell counts, the cultivation on MRS –IM – sorbitol agar was used. Furthermore, the confirmation of L. casei was carried out using species specific PCR. The counts of probiotic L. casei in both probiotic sausages were 106/g and stayed at this level during the whole ripening period (100 days. The counts of starter bacteria were 107/g after the 7 days of fermentation and stayed at this level during the whole fermentation period. PCR from one bacterial colony confirmed the identity of L. casei in 80% of analysed colonies.

  16. Label-free interdigitated microelectrode based biosensors for bacterial biofilm growth monitoring using Petri dishes.

    Science.gov (United States)

    Paredes, Jacobo; Becerro, Sheila; Arana, Sergio

    2014-05-01

    Impedance microbiology (IM) is a known technique that has been applied during the last decades to detect the presence of microorganisms in real samples in different fields: food industry, healthcare, environment, etc. Bacterial biofilms however have not been so far studied despite the fact that they are the most common microbiological formation and that they present resistance to antimicrobial agents. In situ early detection of bacterial biofilm is still a challenge nowadays that causes huge impact in many different scenarios. The ability to detect biofilm generation early will allow better and more efficient treatments preventing high costs and important problems. In this work a new performance of this technique with interdigitated microelectrode sensors (IDE) is proposed. A specific culturing setup where the sensors have been integrated in Petri Dishes has been developed. From the results it can be highlighted that low frequencies are more sensitive for detection than higher ones. The results achieved record variations of approximately 40% in the equivalent serial resistance after 10h of culture. Electrical models have been successfully simulated to find the electrical behavior of the development of biofilms. Variations in both the capacitance and resistance were recorded during the growth of the microbes.

  17. Application of column tests and electrical resistivity methods for leachate transport monitoring

    Directory of Open Access Journals (Sweden)

    Wychowaniak Dorota

    2015-09-01

    Full Text Available Development of the human civilization leads to the pollution of environment. One of the contamination which are a real threat to soil and groundwater are leachates from landfills. In this paper the solute transport through soil was considered. For this purpose, the laboratory column tests of chlorides tracer and leachates transport on two soil samples have been carried out. Furthermore, the electrical resistivity method was applied as auxiliary tool to follow the movements of solute through the soil column what allowed to compare between the results obtained with column test method and electrical resistivity measurements. Breakthrough curves obtained by conductivity and resistivity methods represents similar trends which leads to the conclusion about the suitability of electrical resistivity methods for contamination transport monitoring in soil-water systems.

  18. Structure, function, evolution, and application of bacterial Pnu-type vitamin transporters

    NARCIS (Netherlands)

    Jähme, Michael; Slotboom, Dirk Jan

    2015-01-01

    Many bacteria can take up vitamins from the environment via specific transport machineries. Uptake is essential for organisms that lack complete vitamin biosynthesis pathways, but even in the presence of biosynthesis routes uptake is likely preferred, because it is energetically less costly. Pnu tra

  19. TIPEX (Tropical Indo-Pacific water transport and ecosystem monitoring EXperiment Program

    Directory of Open Access Journals (Sweden)

    Dongchull Jeon

    2013-09-01

    Full Text Available One of the factors influencing the climate around Korea is the oceanic-atmospheric variability in the tropical region between the eastern Indian and the western Pacific Oceans. Lack of knowledge about the air-sea interaction in the tropical Indo-Pacific region continues to make it problematic forecasting the ocean climate in the East Asia. The ‘Tropical Indo-Pacific water transport and ecosystem monitoring EXperiment (TIPEX’ is a program for monitoring the ocean circulation variability between Pacific and Indian Oceans and for improving the accuracy of future climate forecasting. The main goal of the TIPEX program is to quantify the climate and ocean circulation change between the Indian and the Pacific Oceans. The contents of the program are 1 to observe the mixing process of different water masses and water transport in the eastern Indian and the western Pacific, 2 to understand the large-scale oceanic-climatic variation including El Niño-Southern Oscillation (ENSO/Warm Pool/Pacific Decadal Oscillation (PDO/Indian Ocean Dipole (IOD, and 3 to monitor the biogeochemical processes, material flux, and biological changes due to the climate change. In order to effectively carry out the monitoring program, close international cooperation and the proper co-work sharing of tasks between China, Japan, Indonesia, and India as well as USA is required.

  20. Objectification of the school-related transport monitoring of the adolescents

    Directory of Open Access Journals (Sweden)

    Michal Kudláček

    2013-03-01

    Full Text Available BACKGROUND: School and school-related physical activity (PA are important for the total PA of children and youth. The total amount of PA is higher within school days compare to weekends. Children and youth, who use active transportation (to/from the school, confirm the higher PA per week compared to those without active transportation (using car, train, bus. There is a lack of available data in the Czech Republic about active transportation of children and adolescents. AIM: The main aim of the study is the objectification of the school-related transport monitoring of the adolescents. One of the additional outcomes is to enrich this relatively new scientific area in the Czech Republic. METHODS: There was one high school chosen for this project - Gymnázium Nový Jičín. Data were collected by using ActiGraph GT1M, pedometer YAMAX SW-700, NQLS questionnaire and internet system INDARES. RESULTS: By using the newly developer map module "tracker", within the system INDARES, we could compare the participants which active transport (AT was lower than 1000 m, with participants with the AT values higher than 1000 m. We found out significant differences between school days and weekends in the intensity of 1 to 3 MET. The statistical significance was supported by the coefficient effect size (d = 0.83. The participants recording AT values lower than 1000 m showing significantly higher level of PA in school days then during weekends (p = .003; F = 26.149; ω2 = 0.456. Similar results were found in participants recording AT values higher than 1000 m; the differences between school days and weekends are highly significant (p = .0004; F = 26.149; ω 2 = 0.456. CONCLUSIONS: We have contributed to the objectification of the school-related transport monitoring of the adolescents by the creation of the map module within the INDARES system. The usage of a triangulation approach (objective methods - subjective methods - system INDARES into the PA monitoring in

  1. The ISTIMES project: a new integrated system for monitoring critical transport infrastructures interested by natural hazards

    Science.gov (United States)

    Proto, Monica; Massimo, Bavusi; Francesco, Soldovieri

    2010-05-01

    The research project "Integrated System for Transport Infrastructure surveillance and Monitoring by Electromagnetic Sensing" (ISTIMES), was approved in the 7th Framework Programme, in the Joint Call ICT and Security and started on 1st July 2009. The purpose of ISTIMES project is to design, assess and promote an ICT-based system, exploiting distributed and local sensors, for non-destructive electromagnetic monitoring in order to achieve the critical transport infrastructures more reliable and safe. The transportation sector's components are susceptible to the consequences of natural disasters and can also be attractive as terrorist targets. The sector's size, its physically dispersed and decentralized nature, the many public and private entities involved in its operations, the critical importance of cost considerations, and the inherent requirement of convenient accessibility to its services by all users - make the transportation particularly vulnerable to security and safety threats. As well known, the surface transportation system consists of interconnected infrastructures including highways, transit systems, railroads, airports, waterways, pipelines and ports, and the vehicles, aircraft, and vessels that operate along these networks. Thus, interdependencies exist between transportation and nearly every other sector of the economy and the effective operation of this system is essential to the European economic productivity; therefore, transportation sector protection is of paramount importance since threats to it may impact other industries that rely on it. The system exploits an open network architecture that can accommodate a wide range of sensors, static and mobile, and can be easily scaled up to allow the integration of additional sensors and interfacing with other networks. It relies on heterogeneous state-of-the-art electromagnetic sensors, enabling a self-organizing, self-healing, ad-hoc networking of terrestrial sensors, supported by specific satellite

  2. Recent trends in non-invasive in situ techniques to monitor bacterial colonies in solid (model food

    Directory of Open Access Journals (Sweden)

    Maria eMartinez Lobete

    2015-03-01

    Full Text Available Planktonic cells typically found in liquid systems, are routinely used for building predictive models or assessing the efficacy of food preserving technologies. However, freely suspended cells often show different susceptibility to environmental hurdles than colony cells in solid matrices. Limited oxygen, water and nutrient availability, metabolite accumulation and physical constraints due to cell immobilization in the matrix, are main factors affecting cell growth. Moreover, intra- and inter-colony interactions, as a consequence of the initial microbial load in solid systems, may affect microbial physiology. Predictive food microbiology approaches are moving towards a more realistic resemblance to food products, performing studies in structured solid systems instead of liquids. Since structured systems promote microbial cells to become immobilized and grow as colonies, it is essential to study the colony behaviour, not only for food safety assurance systems, but also for understanding cell physiology and optimizing food production processes in solid matrices. Traditionally, microbial dynamics in solid systems have been assessed with a macroscopic approach by applying invasive analytical techniques; for instance, viable plate counting, which yield information about overall population. In the last years, this approach is being substituted by more mechanistically-inspired ones at mesoscopic (colony and microscopic (cell levels. Therefore, non-invasive and in-situ monitoring is mandatory for a deeper insight into bacterial colony dynamics. Several methodologies that enable high-throughput data collection have been developed, such as microscopy-based techniques coupled with image analysis and OD–based measurements in microplate readers. This research paper provides an overview of non-invasive in-situ techniques to monitor bacterial colonies in solid (model food and emphasizes their advantages and inconveniences in terms of accuracy, performance

  3. Molecular mechanism of substrate specificity in the bacterial neutral amino acid transporter LeuT.

    Science.gov (United States)

    Noskov, Sergei Y

    2008-12-01

    The recently published X-ray structure of LeuT, a Na(+)/Cl(-)-dependent neurotransmitter transporter, has provided fresh impetus to efforts directed at understanding the molecular principles governing specific neurotransmitter transport. The combination of the LeuT crystal structure with the results of molecular simulations enables the functional data on specific binding and transport to be related to molecular structure. All-atom FEP and molecular dynamics (MD) simulations of LeuT embedded in an explicit membrane were performed alongside a decomposition analysis to dissect the molecular determinants of the substrate specificity of LeuT. It was found that the ligand must be in a zwitterionic (ZW) form to bind tightly to the transporter. The theoretical results on the absolute binding-free energies for leucine, alanine, and glycine show that alanine can be a potent substrate for LeuT, although leucine is preferred, which is consistent with the recent experimental data (Singh et al., Nature 2007;448:952-956). Furthermore, LeuT displays robust specificity for leucine over glycine. Interestingly, the ability of LeuT to discriminate between substrates relies on the dynamics of residues that form its binding pocket (e.g., F253 and Q250) and the charged side chains (R30-D404) from a second coordination shell. The water-mediated R30-D404 salt bridge is thought to be part of the extracellular (EC) gate of LeuT. The introduction of a polar ligand such as glycine to the water-depleted binding pocket of LeuT gives rise to structural rearrangements of the R30-D404-Q250 hydrogen-bonding network and leads to increased hydration of the binding pocket. Conformational changes associated with the broken hydrogen bond between Q250 and R30 are shown to be important for tight and selective ligand binding to LeuT.

  4. Impact of Bacterial NO3- Transport on Sediment Biogeochemistry

    DEFF Research Database (Denmark)

    Nielsen, Lars Peter

    2005-01-01

    Experiments demonstrated that Beggiatoa could induce a H2S-depleted suboxic zone of more than 10 mm in marine sediments and cause a divergence in sediment NO3- reduction from denitrification to dissimilatory NO3- reduction to ammonium. pH, O2, and H2S profiles indicated that the bacteria oxidized H......2S with NO3- and transported S0 to the sediment surface for aerobic oxidation....

  5. Watershed Scale Monitoring and Modeling of Natural Organic Matter (NOM) Generation and Transport

    Science.gov (United States)

    Adams, R.; Rees, P. L.; Reckhow, D. A.; Castellon, C. M.

    2006-05-01

    This study describes a coupled watershed scale monitoring campaign, laboratory study, and hydrological modeling study which has been focused on determining the sources and transport mechanisms for Natural Organic Matter (NOM), in a small, mostly forested New England watershed. For some time, the state conservation authorities and a large metropolitan water authority have been concerned that the level of naturally-occurring disinfection byproducts in drinking water supplied by a large surface water reservoir (Watchusett Reservoir, MA) have been increasing over time. The resulting study has attempted to investigate how these compounds, which are mostly formed by the chlorination process at the water treatment plant, are related to NOM precursor compounds which are generated from organic matter and transported by runoff processes in the watershed of the Watchusett Reservoir. The laboratory study measures disinfection byproduct formation potential (DBPFP) through chlorination of raw water samples obtained through field monitoring. Samples are analysed for trihalomethanes (THMs), and haloacetic acids (HAAs). Samples are also analysed for dissolved organic carbon (DOC) and ultraviolet absorbance at 254 nm (UV254). The samples have been collected from as many components of the hydrological cycle as possible in one of the subcatchments of Watchusett Reservoir (Stillwater River). To date the samples include, stream runoff, water impounded naturally in small ponds by beaver dams, rainfall, snow, throughfall (drainage from tree canopies) and samples pumped from shallow suction lysimeters which were installed to monitor soil water in the riparian zone. The current monitoring program began in late-Summer 2005, however infrequent stream samples are available dating back to 2000 from an earlier research project and water quality monitoring by various regulatory authorities. The monitoring program has been designed to capture as much seasonal variation in water chemistry as

  6. Crystal Structure and Conformational Change Mechanism of a Bacterial Nramp-Family Divalent Metal Transporter.

    Science.gov (United States)

    Bozzi, Aaron T; Bane, Lukas B; Weihofen, Wilhelm A; Singharoy, Abhishek; Guillen, Eduardo R; Ploegh, Hidde L; Schulten, Klaus; Gaudet, Rachelle

    2016-12-06

    The widely conserved natural resistance-associated macrophage protein (Nramp) family of divalent metal transporters enables manganese import in bacteria and dietary iron uptake in mammals. We determined the crystal structure of the Deinococcus radiodurans Nramp homolog (DraNramp) in an inward-facing apo state, including the complete transmembrane (TM) segment 1a (absent from a previous Nramp structure). Mapping our cysteine accessibility scanning results onto this structure, we identified the metal-permeation pathway in the alternate outward-open conformation. We investigated the functional impact of two natural anemia-causing glycine-to-arginine mutations that impaired transition metal transport in both human Nramp2 and DraNramp. The TM4 G153R mutation perturbs the closing of the outward metal-permeation pathway and alters the selectivity of the conserved metal-binding site. In contrast, the TM1a G45R mutation prevents conformational change by sterically blocking the essential movement of that helix, thus locking the transporter in an inward-facing state.

  7. Unscented Kalman filter assimilation of time-lapse self-potential data for monitoring solute transport

    Science.gov (United States)

    Cui, Yi-an; Liu, Lanbo; Zhu, Xiaoxiong

    2017-08-01

    Monitoring the extent and evolution of contaminant plumes in local and regional groundwater systems from existing landfills is critical in contamination control and remediation. The self-potential survey is an efficient and economical nondestructive geophysical technique that can be used to investigate underground contaminant plumes. Based on the unscented transform, we have built a Kalman filtering cycle to conduct time-lapse data assimilation for monitoring the transport of solute based on the solute transport experiment using a bench-scale physical model. The data assimilation was formed by modeling the evolution based on the random walk model and observation correcting based on the self-potential forward. Thus, monitoring self-potential data can be inverted by the data assimilation technique. As a result, we can reconstruct the dynamic process of the contaminant plume instead of using traditional frame-to-frame static inversion, which may cause inversion artifacts. The data assimilation inversion algorithm was evaluated through noise-added synthetic time-lapse self-potential data. The result of the numerical experiment shows validity, accuracy and tolerance to the noise of the dynamic inversion. To validate the proposed algorithm, we conducted a scaled-down sandbox self-potential observation experiment to generate time-lapse data that closely mimics the real-world contaminant monitoring setup. The results of physical experiments support the idea that the data assimilation method is a potentially useful approach for characterizing the transport of contamination plumes using the unscented Kalman filter (UKF) data assimilation technique applied to field time-lapse self-potential data.

  8. Regulated bioluminescence as a tool for bioremediation process monitoring and control of bacterial cultures

    Science.gov (United States)

    Burlage, Robert S.; Heitzer, Armin; Digrazia, Philip M.

    1991-01-01

    An effective on-line monitoring technique for toxic waste bioremediation using bioluminescent microorganisms has shown great potential for the description and optimization of biological processes. The lux genes of the bacterium Vibrio fischeri are used by this species to produce visible light. The lux genes can be genetically fused to the control region of a catabolic gene, with the result that bioluminescence is produced whenever the catabolic gene is induced. Thus the detection of light from a sample indicates that genetic expression from a specific gene is occurring. This technique was used to monitor biodegradation of specific contaminants from waste sites. For these studies, fusions between the lux genes and the operons for naphthalene and toluene/xylene degradation were constructed. Strains carrying one of these fusions respond sensitively and specifically to target substrates. Bioluminescence from these cultures can be rapidly measured in a nondestructive and noninvasive manner. The potential for this technique in this and other biological systems is discussed.

  9. Bedload transport monitoring with acoustic sensors in the Swiss Albula mountain river

    Science.gov (United States)

    Rickenmann, Dieter; Antoniazza, Gilles; Wyss, Carlos R.; Fritschi, Bruno; Boss, Stefan

    2017-03-01

    Bedload transport measurements with acoustic sensors were obtained during summer 2015 in the Albula River in Switzerland. An impact plate measuring system was used with geophone and accelerometer sensors. This system provides indirect estimations of bedload transport in water courses. In April 2015, 30 impact sensors were installed in a new permanent measuring station to monitor continuously bedload transport in a mountain river with a large annual rate of sediment transport (around 90 000 m3 yr-1). Records of the first year of measurement showed that (i) the signal response in terms of geophone and accelerometer impulses is comparable for both types of sensors; (ii) there is a good correlation between discharge data and impulses recorded by both types of sensors; (iii) the critical discharge at the start of bedload transport is around 5 m3 s-1; (iv) a mean calibration factor for the geophone impulses can be estimated which is in a similar range as values determined from other sites with field calibration measurements.

  10. Flume and field-based calibration of surrogate sensors for monitoring bedload transport

    Science.gov (United States)

    Mao, L.; Carrillo, R.; Escauriaza, C.; Iroume, A.

    2016-01-01

    Bedload transport assessment is important for geomorphological, engineering, and ecological studies of gravel-bed rivers. Bedload can be monitored at experimental stations that require expensive maintenance or by using portable traps, which allows measuring instantaneous transport rates but at a single point and at high costs and operational risks. The need for continuously measuring bedload intensity and dynamics has therefore increased the use and enhancement of surrogate methods. This paper reports on a set of flume experiments in which a Japanese acoustic pipe and an impact plate have been tested using four well-sorted and three poorly sorted sediment mixtures. Additional data were collected in a glacierized high-gradient Andean stream (Estero Morales) using a portable Bunte-type bedload sampler. Results show that the data provided by the acoustic pipe (which is amplified on 6 channels having different gains) can be calibrated for the grain size and for the intensity of transported sediments coarser than 9 mm (R2 = 0.93 and 0.88, respectively). Even if the flume-based calibration is very robust, upscaling the calibration to field applications is more challenging, and the bedload intensity could be predicted better than the grain size of transported sediments (R2 = 0.61 and 0.43, respectively). The inexpensive impact plate equipped with accelerometer could be calibrated for bedload intensity quite well in the flume but only poorly in the field (R2 = 0.16) and could not provide information on the size of transported sediments.

  11. Monitoring bedload entrainment and transport in snowmelt-dominated forest streams of the Columbia Mountains, Canada

    Science.gov (United States)

    Green, Kim; Brardinoni, Francesco; Alila, Younes

    2014-05-01

    We monitor bedload transport and water discharge at six stations in two forested headwater streams of the Columbia Mountains, Canada. The monitoring network of sediment traps is designed to examine the effects of channel bed texture, and the influence of alluvial (i.e., step pools, and riffle pools) and semi-alluvial morphologies (i.e., boulder cascades and forced step pools) on bedload entrainment and transport. Results suggest that patterns of bedload entrainment are influenced by flow resistance while the value of the critical dimensionless shear stress for mobilization of the surface D50 varies due to channel gradient, grain sheltering effects and, to a less extent, flow resistance. Regardless of channel morphology we observe: (i) equal-threshold entrainment for all mobile grains in channels with high grain and/or form resistance; and (ii) initial equal-threshold entrainment of calibers ≤ 22mm, and subsequent size-selective entrainment of coarser material in channels with low form resistance (e.g. riffle pool). Scaled fractional analysis reveals that in reaches with high flow resistance most bedload transport occurs in partial mobility fashion relative to the available bed material and that only material finer than 16mm attains full mobility during over-bank flows. Equal mobility transport for a wider range of grain sizes is achieved in reaches with reduced flow resistance. Evaluation of bedload rating curves across sites identifies that grain effects predominate with respect to bedload flux whereas morphological effects (i.e. form resistance) play a secondary role. Application of selected empirical formulae developed in steep alpine channels present variable success in predicting transport rates in the study reaches.

  12. Bradyrhizobium BclA Is a Peptide Transporter Required for Bacterial Differentiation in Symbiosis with Aeschynomene Legumes.

    Science.gov (United States)

    Guefrachi, Ibtissem; Pierre, Olivier; Timchenko, Tatiana; Alunni, Benoît; Barrière, Quentin; Czernic, Pierre; Villaécija-Aguilar, José-Antonio; Verly, Camille; Bourge, Mickaël; Fardoux, Joël; Mars, Mohamed; Kondorosi, Eva; Giraud, Eric; Mergaert, Peter

    2015-11-01

    Nodules of legume plants are highly integrated symbiotic systems shaped by millions of years of evolution. They harbor nitrogen-fixing rhizobium bacteria called bacteroids. Several legume species produce peptides called nodule-specific cysteine-rich (NCR) peptides in the symbiotic nodule cells which house the bacteroids. NCR peptides are related to antimicrobial peptides of innate immunity. They induce the endosymbionts into a differentiated, enlarged, and polyploid state. The bacterial symbionts, on their side, evolved functions for the response to the NCR peptides. Here, we identified the bclA gene of Bradyrhizobium sp. strains ORS278 and ORS285, which is required for the formation of differentiated and functional bacteroids in the nodules of the NCR peptide-producing Aeschynomene legumes. The BclA ABC transporter promotes the import of NCR peptides and provides protection against the antimicrobial activity of these peptides. Moreover, BclA can complement the role of the related BacA transporter of Sinorhizobium meliloti, which has a similar symbiotic function in the interaction with Medicago legumes.

  13. Testing ZigBee Motes for Monitoring Refrigerated Vegetable Transportation under Real Conditions

    Directory of Open Access Journals (Sweden)

    Luis Ruiz-Garcia

    2010-05-01

    Full Text Available Quality control and monitoring of perishable goods during transportation and delivery services is an increasing concern for producers, suppliers, transport decision makers and consumers. The major challenge is to ensure a continuous ‘cold chain’ from producer to consumer in order to guaranty prime condition of goods. In this framework, the suitability of ZigBee protocol for monitoring refrigerated transportation has been proposed by several authors. However, up to date there was not any experimental work performed under real conditions. Thus, the main objective of our experiment was to test wireless sensor motes based in the ZigBee/IEEE 802.15.4 protocol during a real shipment. The experiment was conducted in a refrigerated truck traveling through two countries (Spain and France which means a journey of 1,051 kilometers. The paper illustrates the great potential of this type of motes, providing information about several parameters such as temperature, relative humidity, door openings and truck stops. Psychrometric charts have also been developed for improving the knowledge about water loss and condensation on the product during shipments.

  14. Toward Optimized Bioclogging and Biocementation Through Combining Advanced Geophysical Monitoring and Reactive Transport Modeling Approaches

    Science.gov (United States)

    Hubbard, C. G.; Hubbard, S. S.; Wu, Y.; Surasani, V.; Ajo Franklin, J. B.; Commer, M.; Dou, S.; Kwon, T.; Li, L.; Fouke, B. W.; Coates, J. D.

    2012-12-01

    Bioclogging and biocementation offer exciting opportunities for solutions to diverse problems ranging from soil stabilization to microbially enhanced hydrocarbon recovery. The effectiveness of bioclogging and biocementation strategies is governed by processes and properties ranging from microbial metabolism at the submicron scale, to changes in pore geometry at the pore scale, to geological heterogeneities at the field scale. Optimization of these strategies requires advances in mechanistic reactive transport modeling and geophysical monitoring methodologies. Our research focuses on (i) performing laboratory experiments to refine understanding of reaction networks and to quantify changes in hydrological properties (e.g. permeability), the evolution of biominerals and geophysical responses (focusing on seismic and electrical techniques); (ii) developing and using a reactive transport simulator capable of predicting the induced metabolic processes to numerically explore how to optimize the desired effect; and (iii) using loosely coupled reactive transport and geophysical simulators to explore detectability and resolvability of induced bioclogging and biocementation processes at the field scale using time-lapse geophysical methods. Here we present examples of our research focused on three different microbially-mediated methods to enhance hydrocarbon recovery through selective clogging of reservior thief zones, including: (a) biopolymer clogging through dextran production; (b) biomineral clogging through iron oxide precipitation; and (c) biomineral clogging through carbonate precipitation. We will compare the utility of these approaches for enhancing hydrocarbon recovery and will describe the utility of geophysical methods to remotely monitor associated field treatments.

  15. Testing ZigBee motes for monitoring refrigerated vegetable transportation under real conditions.

    Science.gov (United States)

    Ruiz-Garcia, Luis; Barreiro, Pilar; Robla, Jose Ignacio; Lunadei, Loredana

    2010-01-01

    Quality control and monitoring of perishable goods during transportation and delivery services is an increasing concern for producers, suppliers, transport decision makers and consumers. The major challenge is to ensure a continuous 'cold chain' from producer to consumer in order to guaranty prime condition of goods. In this framework, the suitability of ZigBee protocol for monitoring refrigerated transportation has been proposed by several authors. However, up to date there was not any experimental work performed under real conditions. Thus, the main objective of our experiment was to test wireless sensor motes based in the ZigBee/IEEE 802.15.4 protocol during a real shipment. The experiment was conducted in a refrigerated truck traveling through two countries (Spain and France) which means a journey of 1,051 kilometers. The paper illustrates the great potential of this type of motes, providing information about several parameters such as temperature, relative humidity, door openings and truck stops. Psychrometric charts have also been developed for improving the knowledge about water loss and condensation on the product during shipments.

  16. Transport infrastructure surveillance and monitoring by electromagnetic sensing: the ISTIMES project.

    Science.gov (United States)

    Proto, Monica; Bavusi, Massimo; Bernini, Romeo; Bigagli, Lorenzo; Bost, Marie; Bourquin, Frédrèric; Cottineau, Louis-Marie; Cuomo, Vincenzo; Della Vecchia, Pietro; Dolce, Mauro; Dumoulin, Jean; Eppelbaum, Lev; Fornaro, Gianfranco; Gustafsson, Mats; Hugenschmidt, Johannes; Kaspersen, Peter; Kim, Hyunwook; Lapenna, Vincenzo; Leggio, Mario; Loperte, Antonio; Mazzetti, Paolo; Moroni, Claudio; Nativi, Stefano; Nordebo, Sven; Pacini, Fabrizio; Palombo, Angelo; Pascucci, Simone; Perrone, Angela; Pignatti, Stefano; Ponzo, Felice Carlo; Rizzo, Enzo; Soldovieri, Francesco; Taillade, Fédrèric

    2010-01-01

    The ISTIMES project, funded by the European Commission in the frame of a joint Call "ICT and Security" of the Seventh Framework Programme, is presented and preliminary research results are discussed. The main objective of the ISTIMES project is to design, assess and promote an Information and Communication Technologies (ICT)-based system, exploiting distributed and local sensors, for non-destructive electromagnetic monitoring of critical transport infrastructures. The integration of electromagnetic technologies with new ICT information and telecommunications systems enables remotely controlled monitoring and surveillance and real time data imaging of the critical transport infrastructures. The project exploits different non-invasive imaging technologies based on electromagnetic sensing (optic fiber sensors, Synthetic Aperture Radar satellite platform based, hyperspectral spectroscopy, Infrared thermography, Ground Penetrating Radar-, low-frequency geophysical techniques, Ground based systems for displacement monitoring). In this paper, we show the preliminary results arising from the GPR and infrared thermographic measurements carried out on the Musmeci bridge in Potenza, located in a highly seismic area of the Apennine chain (Southern Italy) and representing one of the test beds of the project.

  17. Transport Infrastructure Surveillance and Monitoring by Electromagnetic Sensing: The ISTIMES Project

    Directory of Open Access Journals (Sweden)

    Marie Bost

    2010-11-01

    Full Text Available The ISTIMES project, funded by the European Commission in the frame of a joint Call “ICT and Security” of the Seventh Framework Programme, is presented and preliminary research results are discussed. The main objective of the ISTIMES project is to design, assess and promote an Information and Communication Technologies (ICT-based system, exploiting distributed and local sensors, for non-destructive electromagnetic monitoring of critical transport infrastructures. The integration of electromagnetic technologies with new ICT information and telecommunications systems enables remotely controlled monitoring and surveillance and real time data imaging of the critical transport infrastructures. The project exploits different non-invasive imaging technologies based on electromagnetic sensing (optic fiber sensors, Synthetic Aperture Radar satellite platform based, hyperspectral spectroscopy, Infrared thermography, Ground Penetrating Radar-, low-frequency geophysical techniques, Ground based systems for displacement monitoring. In this paper, we show the preliminary results arising from the GPR and infrared thermographic measurements carried out on the Musmeci bridge in Potenza, located in a highly seismic area of the Apennine chain (Southern Italy and representing one of the test beds of the project.

  18. Comparison of culture-dependent and -independent methods for bacterial community monitoring during Montasio cheese manufacturing.

    Science.gov (United States)

    Carraro, Lisa; Maifreni, Michela; Bartolomeoli, Ingrid; Martino, Maria Elena; Novelli, Enrico; Frigo, Francesca; Marino, Marilena; Cardazzo, Barbara

    2011-04-01

    The microbial community in milk is of great importance in the manufacture of traditional cheeses produced using raw milk and natural cultures. During milk curdling and cheese ripening, complex interactions occur in the microbial community, and accurate identification of the microorganisms involved provides essential information for understanding their role in these processes and in flavor production. Recent improvements in molecular biological methods have led to their application to food matrices, and thereby opened new perspectives for the study of microbial communities in fermented foods. In this study, a description of microbial community composition during the manufacture and ripening of Montasio cheese was provided. A combined approach using culture-dependent and -independent methods was applied. Culture-dependent identification was compared with 16S clone libraries sequencing data obtained from both DNA and reverse-transcribed RNA (cDNA) amplification and real-time quantitative PCR (qPCR) assays developed to detect and quantify specific bacterial species/genera (Streptococcus thermophilus, Lactobacillus casei, Pediococcus pentosaceus, Enterococcus spp., Pseudomonas spp.). S. thermophilus was the predominant LAB species throughout the entire ripening period of Montasio cheese. The culture-independent method demonstrates the relevant presence of Pseudomonas spp. and Lactococcus piscium at the beginning of ripening. The culture-dependent approach and the two culture-independent approaches produced complementary information, together generating a general view of cheese microbial ecology.

  19. Long range excitonic transport in a biomimetic system inspired by the bacterial light-harvesting apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Harel, Elad [Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208 (United States)

    2012-05-07

    Photosynthesis, the process by which energy from sunlight drives cellular metabolism, relies on a unique organization of light-harvesting and reaction center complexes. Recently, the organization of light-harvesting LH2 complexes and dimeric reaction center-light-harvesting I-PufX core complexes in membranes of purple non-sulfur bacteria was revealed by atomic force microscopy [S. Bahatyrova et al., Nature (London) 430, 1058 (2004)]. Here, we discuss optimal exciton transfer in a biomimetic system closely modeled on the structure of LH2 and its organization within the membrane using a Markovian quantum model with dissipation and trapping added phenomenologically. In a deliberate manner, we neglect the high level detail of the bacterial light-harvesting complex and its interaction with the phonon bath in order to elucidate a set of design principles that may be incorporated in artificial pigment-scaffold constructs in a supramolecular assembly. We show that our scheme reproduces many of the most salient features found in their natural counterpart and may be largely explained by simple electrostatic considerations. Most importantly, we show that quantum effects act primarily to enforce robustness with respect to spatial and spectral disorder between and within complexes. The implications of such an arrangement are discussed in the context of biomimetic photosynthetic analogs capable of transferring energy efficiently across tens to hundreds of nanometers.

  20. Long range excitonic transport in a biomimetic system inspired by the bacterial light-harvesting apparatus

    Science.gov (United States)

    Harel, Elad

    2012-05-01

    Photosynthesis, the process by which energy from sunlight drives cellular metabolism, relies on a unique organization of light-harvesting and reaction center complexes. Recently, the organization of light-harvesting LH2 complexes and dimeric reaction center-light-harvesting I-PufX core complexes in membranes of purple non-sulfur bacteria was revealed by atomic force microscopy [S. Bahatyrova et al., Nature (London) 430, 1058 (2004)]. Here, we discuss optimal exciton transfer in a biomimetic system closely modeled on the structure of LH2 and its organization within the membrane using a Markovian quantum model with dissipation and trapping added phenomenologically. In a deliberate manner, we neglect the high level detail of the bacterial light-harvesting complex and its interaction with the phonon bath in order to elucidate a set of design principles that may be incorporated in artificial pigment-scaffold constructs in a supramolecular assembly. We show that our scheme reproduces many of the most salient features found in their natural counterpart and may be largely explained by simple electrostatic considerations. Most importantly, we show that quantum effects act primarily to enforce robustness with respect to spatial and spectral disorder between and within complexes. The implications of such an arrangement are discussed in the context of biomimetic photosynthetic analogs capable of transferring energy efficiently across tens to hundreds of nanometers.

  1. Single-molecule interrogation of a bacterial sugar transporter allows the discovery of an extracellular inhibitor

    Science.gov (United States)

    Kong, Lingbing; Harrington, Leon; Li, Qiuhong; Cheley, Stephen; Davis, Benjamin G.; Bayley, Hagan

    2013-08-01

    Capsular polysaccharides form the outermost protective layer around many Gram-negative bacteria. Antibiotics aimed directly at weakening this layer are not yet available. In pathogenic Escherichia coli E69, a protein, Wza, forms a pore in the outer membrane that transports K30 capsular polysaccharide from its site of synthesis to the outside of the cell. This therefore represents a prospective antibiotic target. Here we test a variety of grommet-like mimics of K30 capsular polysaccharide on wild-type Wza and on mutant open forms of the pore by electrical recording in planar lipid bilayers. The most effective glycomimetic was the unnatural cyclic octasaccharide octakis(6-deoxy-6-amino)cyclomaltooctaose (am8γCD), which blocks the α-helix barrel of Wza, a site that is directly accessible from the external medium. This glycomimetic inhibited K30 polysaccharide transport in live E. coli E69. With the protective outer membrane disrupted, the bacteria can be recognized and killed by the human immune system.

  2. Efflux Transporter of Siderophore Staphyloferrin A in Staphylococcus aureus Contributes to Bacterial Fitness in Abscesses and Epithelial Cells.

    Science.gov (United States)

    Nakaminami, Hidemasa; Chen, Chunhui; Truong-Bolduc, Que Chi; Kim, Eu Suk; Wang, Yin; Hooper, David C

    2017-08-01

    The siderophores staphyloferrin A (SA) and staphyloferrin B (SB) of Staphylococcus aureus are essential for iron acquisition in the iron-restricted environment of the host, such as in subcutaneous abscesses. SA and SB are secreted by SfaA and SbnD transporters, respectively. To assess the further function of SfaA and SbnD in S. aureus fitness, we tested its effect on murine abscess models and intracellular replication in epithelial cells. Bacterial fitness in abscesses and in epithelial cells was studied, by comparing the parental strains RN6390 and MW2 and their ΔsfaA and ΔsbnD mutants using competition assays in a murine abscess model and invasion and replication assays with human lung adenocarcinoma cell line A549. In the murine abscess model using equal inocula of a ΔsfaA or ΔsbnD mutant and the wild-type RN6390 strain, the ΔsfaA mutant exhibited growth defects of 2.2-fold. Additionally, replication of the ΔsfaA mutant within A549 cells was decreased 3.0-fold. In complementation experiments, the ΔsfaA mutant carrying plasmid-borne sfaA restored the growth fitness in abscesses and epithelial cells. The ΔsbnD mutant, in contrast, showed no growth defect in either abscesses or epithelial cells. Our findings demonstrate that the efflux transporter of the siderophore SA contributes to the ability of S. aureus to replicate in abscesses and epithelial cells. Furthermore, fitness of S. aureus in these sites of replication is not compromised by the absence of transporter SbnD. Copyright © 2017 American Society for Microbiology.

  3. Monitoring Dynamic Protein Expression in Single Living E. Coli. Bacterial Cells by Laser Tweezers Raman Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Chan, J W; Winhold, H; Corzett, M H; Ulloa, J M; Cosman, M; Balhorn, R; Huser, T

    2007-01-09

    Laser tweezers Raman spectroscopy (LTRS) is a novel, nondestructive, and label-free method that can be used to quantitatively measure changes in cellular activity in single living cells. Here, we demonstrate its use to monitor changes in a population of E. coli cells that occur during overexpression of a protein, the extracellular domain of myelin oligodendrocyte glycoprotein (MOG(1-120)) Raman spectra were acquired of individual E. coli cells suspended in solution and trapped by a single tightly focused laser beam. Overexpression of MOG(1-120) in transformed E. coli Rosetta-Gami (DE3)pLysS cells was induced by addition of isopropyl thiogalactoside (IPTG). Changes in the peak intensities of the Raman spectra from a population of cells were monitored and analyzed over a total duration of three hours. Data was also collected for concentrated purified MOG(1-120) protein in solution, and the spectra compared with that obtained for the MOG(1-120) expressing cells. Raman spectra of individual, living E. coli cells exhibit signatures due to DNA and protein molecular vibrations. Characteristic Raman markers associated with protein vibrations, such as 1257 cm{sup -1}, 1340 cm{sup -1}, 1453 cm{sup -1} and 1660 cm{sup -1}, are shown to increase as a function of time following the addition of IPTG. Comparison of these spectra and the spectra of purified MOG protein indicates that the changes are predominantly due to the induction of MOG protein expression. Protein expression was found to occur mostly within the second hour, with a 470% increase relative to the protein expressed in the first hour. A 230% relative increase between the second and third hour indicates that protein expression begins to level off within the third hour. It is demonstrated that LTRS has sufficient sensitivity for real-time, nondestructive, and quantitative monitoring of biological processes, such as protein expression, in single living cells. Such capabilities, which are not currently available in

  4. Vertical wicking tester for monitoring water transportation behavior in fibrous assembly

    Science.gov (United States)

    Singh, Pratibha; Chatterjee, Arobindo; Ghosh, Subrata

    2016-10-01

    An instrument based on the principle of change of resistance of fibrous assembly on wetting has been developed for precise monitoring of the water transportation behaviour in the fibrous assemblies. The conducting probes sense the change in resistance of a dry fibrous assembly on wetting. This change in resistance generates analog signals which trigger an amplifying circuit. This circuit produces an enlarged copy of the received signals which are further converted to digital signals by a Darlington pair and are encoded to measurable quantity with the help of a microcontroller. The data thus obtained are displayed on a suitable display device. Comparison between conventional strip test and experimental results obtained by the developed instrument shows its reliability. The developed instrument measures the initial rate of water transport with increased precision and hence could be used for detailed study of fluid flow in the fibrous structure.

  5. Prototyping of beam position monitor for medium energy beam transport section of RAON heavy ion accelerator

    Science.gov (United States)

    Jang, Hyojae; Jin, Hyunchang; Jang, Ji-Ho; Hong, In-Seok

    2016-02-01

    A heavy ion accelerator, RAON is going to be built by Rare Isotope Science Project in Korea. Its target is to accelerate various stable ions such as uranium, proton, and xenon from electron cyclotron resonance ion source and some rare isotopes from isotope separation on-line. The beam shaping, charge selection, and modulation should be applied to the ions from these ion sources because RAON adopts a superconducting linear accelerator structure for beam acceleration. For such treatment, low energy beam transport, radio frequency quadrupole, and medium energy beam transport (MEBT) will be installed in injector part of RAON accelerator. Recently, development of a prototype of stripline beam position monitor (BPM) to measure the position of ion beams in MEBT section is under way. In this presentation, design of stripline, electromagnetic (EM) simulation results, and RF measurement test results obtained from the prototyped BPM will be described.

  6. Prototyping of beam position monitor for medium energy beam transport section of RAON heavy ion accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Hyojae, E-mail: lkcom@ibs.re.kr; Jin, Hyunchang; Jang, Ji-Ho; Hong, In-Seok [Rare Isotope Science Project, Institute for Basic Science, Daejeon (Korea, Republic of)

    2016-02-15

    A heavy ion accelerator, RAON is going to be built by Rare Isotope Science Project in Korea. Its target is to accelerate various stable ions such as uranium, proton, and xenon from electron cyclotron resonance ion source and some rare isotopes from isotope separation on-line. The beam shaping, charge selection, and modulation should be applied to the ions from these ion sources because RAON adopts a superconducting linear accelerator structure for beam acceleration. For such treatment, low energy beam transport, radio frequency quadrupole, and medium energy beam transport (MEBT) will be installed in injector part of RAON accelerator. Recently, development of a prototype of stripline beam position monitor (BPM) to measure the position of ion beams in MEBT section is under way. In this presentation, design of stripline, electromagnetic (EM) simulation results, and RF measurement test results obtained from the prototyped BPM will be described.

  7. Comparing Methods of Separating Bacterial Biofilms on the Surface of Water Transportation Pipes and Equipment of Milking in the Farms

    Directory of Open Access Journals (Sweden)

    setareh nabizadeh

    2016-08-01

    Full Text Available Introduction Bacterial biofilms can be both useful and harmful based on their combination and locations. Biofilm formation occurs as a stepwise process. Their formation in liquid transportation pipes used for milking system and drinking water in animal farms may create some problems and is a potential source of pollution. Speed of biofilm formation depends on many factors including: construction and functional characteristics of bacteria, the composition and culture conditions such as temperature and substratum. In this research the Bacillus subtillis bacteria with special characteristics was selected due to its capability for biofilm creation. Bacillus subtillis bacteria is mobility and a stronger connection than other bacteria levels are created. In the research conducted in the biofilm there are many resources on biofilm formation by Bacillus subtillis bacteria. Bacillus subtillis is saprophytic in the soil, water and air. There is also the ability to form spores of Bacillus subtillis. Materials and Methods Firstly the possibility of creating biofilms on different Plastic (polyvinilchlorid, polypropylene, polyethylengelycole, alluminum and glass surfaces in three temperatures of 4°C, 30°C and 37°C were studied. Two different methods of biofilms separation including separating swap and vortex were tested and their efficienceies were calculated. After biofilm formation on parts of the vortex separation method after washing parts in sterile conditions in a tube containing normal saline for 4 minutes was vortex. The bacterial suspension decreasing dilution series was created. Pour plate in medium using agar plate count agar and was cultured at 30°C for 24-48 hours. Numbers of colonies were counted. The numbers of biofilm cells were calculated. In swap method after biofilm formation on parts using a cotton swap was isolated biofilms. The swap was transferred to tube containing normal saline and the bacterial suspension decreasing dilution

  8. Development of a Computer Aided Transport Monitoring System (CATRAMS for Manufacturing Organizations

    Directory of Open Access Journals (Sweden)

    DIPO THEOPHILUS AKOMOLAFE

    2011-09-01

    Full Text Available Presently, there are different types of monitoring systems and devices being used to monitor vehicles, products, processes and activities in manufacturing organizations. Each of these devices has their unique strengths and weaknesses but one problem that is common to them is that there is no knitted relationship between the devices and parameters necessary for effective and efficient monitoring system. Therefore, there is the need to develop a system that will address this shortcoming.CATRAMS is an integration of computer and communication facilities to monitor and control movement of vehicles and goods. Its objectives are to provide detail information on movement of vehicles and reduce likely operational delays associated with movement of vehicles and goods. The development of the system was carried out by studying some existing devices to know their limitations, designing of road transport database, specifying hardware requirements and integrating the hardware and software resources to make a complete system. The system was tested using data collected from some manufacturing industries and it was found out that detail information about movement of vehicles and goods could be provided by the system.

  9. Understanding transport pathways in a river system - Monitoring sediments contaminated by an incident

    Science.gov (United States)

    Dietrich, S.; Kleisinger, C.; Hillebrand, G.; Claus, E.; Schwartz, R.; Carls, I.; Winterscheid, A.; Schubert, B.

    2016-12-01

    Experiments to trace transport of sediments and suspended particulate matter on a river scale are an expensive and difficult venture, since it causes a lot of official requirements. In spring 2015, polychlorinated biphenyls (PCB) were released during restoration works at a bridge in the upper part of the Elbe River, near the Czech-German border. In this study, the particle-bound PCB-transport is applied as a tracer for monitoring transport pathways of suspended solids (SS) along a whole river stretch over 700 km length. The incident was monitored by concentration measurements of seven indicator PCB congeners along the inland part of the Elbe River as well as in the Elbe estuary. Data from 15 monitoring stations (settling tanks) as well as from two longitudinal campaigns (grab samples) along the river in July and August 2015 are considered. The total PCB load is calculated for all stations on the basis of monthly contaminant concentrations and daily suspended sediment concentrations. Monte-Carlo simulations assess the uncertainties of the calculated load. 1D water levels and GIS analysis were used to locate temporal storage areas for the SS. It is shown that the ratio of high versus low chlorinated PCB congeners is a suitable tracer to distinguish the PCB load of the incident from the long-term background signal. Furthermore, the reduction of total PCB load within the upper Elbe indicates that roughly 24% of the SS were transported with the water by wash load. Approximately 600 km downstream of the incident site, the PCB-marked wash load was first identified in July 2015. PCB load transported intermittently in suspension was detected roughly 400 km downstream of the incident site by August 2015. In the Elbe Estuary, PCB-marked SS were only found upstream of the steep slope of water depth (approx. 4 to 15 m) within Hamburg harbor that acts as a major sediment sink. Here, SS from the inland Elbe are mixed with lowly contaminated marine material, which may mask the

  10. Basic problems and new potentials in monitoring sediment transport using Japanese pipe type geophone

    Science.gov (United States)

    Sakajo, Saiichi

    2016-04-01

    The authors have conducted a lot of series of monitoring of sediment transport by pipe type geophone in a model hydrological channel with various gradients and water discharge, using the various size of particles from 2 to 21 mm in the diameter. In the case of casting soils particle by particle into the water channel, 1,000 test cases were conducted. In the case of casting all soils at a breath into the water channel, 100 test cases were conducted. The all test results were totally analyzed by the conventional method, with visible judgement by video pictures. Then several important basic problems were found in estimating the volume and particle distributions by the conventional method, which was not found in the past similar studies. It was because the past studies did not consider the types of collisions between sediment particle and pipe. Based on these experiments, the authors have firstly implemented this idea into the old formula to estimate the amount of sediment transport. In the formula, two factors of 1) the rate of sensing in a single collision and 2) the rate of collided particles to a cast all soil particles were concretely considered. The parameters of these factors could be determined from the experimental results and it was found that the obtained formula could estimate grain size distribution. In this paper, they explain the prototype formula to estimate a set of volume and distribution of sediment transport. Another finding in this study is to propose a single collision as a river index to recognize its characteristics of sediment transport. This result could characterize the risk ranking of sediment transport in the rivers and mudflow in the mountainous rivers. Furthermore, in this paper the authors explain how the preciseness of the pipe geophone to sense the smaller sediment particles shall be improved, which has never been able to be sensed.

  11. Results of the MITRA project: Monitoring and intervention for the transportation of dangerous goods

    Energy Technology Data Exchange (ETDEWEB)

    Planas, E. [Centre d' Estudis del Risc Tecnologic (CERTEC), Departament d' Enginyeria Quimica, Universitat Politecnica de Catalunya, Diagonal 647, 08028-Barcelona, Catalonia (Spain)], E-mail: eulalia.planas@upc.edu; Pastor, E. [Centre d' Estudis del Risc Tecnologic (CERTEC), Departament d' Enginyeria Quimica, Universitat Politecnica de Catalunya, Diagonal 647, 08028-Barcelona, Catalonia (Spain); Presutto, F. [M3 Systems, 1 Rue des Oiseaux, 31410 Lavernose (France); Tixier, J. [Ecole des Mines d' Ales, Ales (France)

    2008-04-01

    The objective of the MITRA (monitoring and intervention for the transportation of dangerous goods) project was to prototype a new operational system for monitoring the transportation of dangerous goods in Europe based on regional responsibilities. This concept, based on systems used in air traffic control, aims to provide civil security centres with real-time knowledge of the position and contents of dangerous vehicles circulating in their area of responsibility, and, in the event of a dangerous situation, to issue warnings, alerts and crisis management information, thereby allowing intervention teams to react immediately with maximum safety. The project was funded by the European Commission under the 6th Framework Programme (STREP - specific targeted research project - under the Information Society Technologies priority). It started on 1 September 2004 and ended on 31 October 2006. This paper presents the results of this project and the conclusions derived from the field tests carried out in Germany and in the French/Spanish border region in order to test the proposed operational system.

  12. Monitoring suspended sediment transport in an ice-affected river using acoustic Doppler current profilers

    Science.gov (United States)

    Moore, S. A.; Ghareh Aghaji Zare, S.; Rennie, C. D.; Ahmari, H.; Seidou, O.

    2013-12-01

    Quantifying sediment budgets and understanding the processes which control fluvial sediment transport is paramount to monitoring river geomorphology and ecological habitat. In regions that are subject to freezing there is the added complexity of ice. River ice processes impact flow distribution, water stage and sediment transport. Ice processes typically have the largest impact on sediment transport and channel morphodynamics when ice jams occur during ice cover formation and breakup. Ice jams may restrict flow and cause local acceleration when released. Additionally, ice can mechanically scour river bed and banks. Under-ice sediment transport measurements are lacking due to obvious safety and logistical reasons, in addition to a lack of adequate measurement techniques. Since some rivers can be covered in ice during six months of the year, the lack of data in winter months leads to large uncertainty in annual sediment load calculations. To address this problem, acoustic profilers are being used to monitor flow velocity, suspended sediment and ice processes in the Lower Nelson River, Manitoba, Canada. Acoustic profilers are ideal for under-ice sediment flux measurements since they can be operated autonomously and continuously, they do not disturb the flow in the zone of measurement and acoustic backscatter can be related to sediment size and concentration. In March 2012 two upward-facing profilers (1200 kHz acoustic Doppler current profiler, 546 KHz acoustic backscatter profiler) were installed through a hole in the ice on the Nelson River, 50 km downstream of the Limestone Generating Station. Data were recorded for four months, including both stable cover and breakup periods. This paper presents suspended sediment fluxes calculated from the acoustic measurements. Velocity data were used to infer the vertical distribution of sediment sizes and concentrations; this information was then used in the interpretation of the backscattered intensity data. It was found that

  13. Development of a structural health monitoring system for the life assessment of critical transportation infrastructure.

    Energy Technology Data Exchange (ETDEWEB)

    Roach, Dennis Patrick; Jauregui, David Villegas (New Mexico State University, Las Cruces, NM); Daumueller, Andrew Nicholas (New Mexico State University, Las Cruces, NM)

    2012-02-01

    Recent structural failures such as the I-35W Mississippi River Bridge in Minnesota have underscored the urgent need for improved methods and procedures for evaluating our aging transportation infrastructure. This research seeks to develop a basis for a Structural Health Monitoring (SHM) system to provide quantitative information related to the structural integrity of metallic structures to make appropriate management decisions and ensuring public safety. This research employs advanced structural analysis and nondestructive testing (NDT) methods for an accurate fatigue analysis. Metal railroad bridges in New Mexico will be the focus since many of these structures are over 100 years old and classified as fracture-critical. The term fracture-critical indicates that failure of a single component may result in complete collapse of the structure such as the one experienced by the I-35W Bridge. Failure may originate from sources such as loss of section due to corrosion or cracking caused by fatigue loading. Because standard inspection practice is primarily visual, these types of defects can go undetected due to oversight, lack of access to critical areas, or, in riveted members, hidden defects that are beneath fasteners or connection angles. Another issue is that it is difficult to determine the fatigue damage that a structure has experienced and the rate at which damage is accumulating due to uncertain history and load distribution in supporting members. A SHM system has several advantages that can overcome these limitations. SHM allows critical areas of the structure to be monitored more quantitatively under actual loading. The research needed to apply SHM to metallic structures was performed and a case study was carried out to show the potential of SHM-driven fatigue evaluation to assess the condition of critical transportation infrastructure and to guide inspectors to potential problem areas. This project combines the expertise in transportation infrastructure at New

  14. Novel nickel transport mechanism across the bacterial outer membrane energized by the TonB/ExbB/ExbD machinery.

    Science.gov (United States)

    Schauer, Kristine; Gouget, Barbara; Carrière, Marie; Labigne, Agnès; de Reuse, Hilde

    2007-02-01

    Nickel is a cofactor for various microbial enzymes, yet as a trace element, its scavenging is challenging. In the case of the pathogen Helicobacter pylori, nickel is essential for the survival in the human stomach, because it is the cofactor of the important virulence factor urease. While nickel transport across the cytoplasmic membrane is accomplished by the nickel permease NixA, the mechanism by which nickel traverses the outer membrane (OM) of this Gram-negative bacterium is unknown. Import of iron-siderophores and cobalamin through the bacterial OM is carried out by specific receptors energized by the TonB/ExbB/ExbD machinery. In this study, we show for the first time that H. pylori utilizes TonB/ExbB/ExbD for nickel uptake in addition to iron acquisition. We have identified the nickel-regulated protein FrpB4, homologous to TonB-dependent proteins, as an OM receptor involved in nickel uptake. We demonstrate that ExbB/ExbD/TonB and FrpB4 deficient bacteria are unable to efficiently scavenge nickel at low pH. This condition mimics those encountered by H. pylori during stomach colonization, under which nickel supply and full urease activity are essential to combat acidity. We anticipate that this nickel scavenging system is not restricted to H. pylori, but will be represented more largely among Gram-negative bacteria.

  15. Bayesian model selection in hydrogeophysics: Application to conceptual subsurface models of the South Oyster Bacterial Transport Site, Virginia, USA

    Science.gov (United States)

    Brunetti, Carlotta; Linde, Niklas; Vrugt, Jasper A.

    2017-04-01

    Geophysical data can help to discriminate among multiple competing subsurface hypotheses (conceptual models). Here, we explore the merits of Bayesian model selection in hydrogeophysics using crosshole ground-penetrating radar data from the South Oyster Bacterial Transport Site in Virginia, USA. Implementation of Bayesian model selection requires computation of the marginal likelihood of the measured data, or evidence, for each conceptual model being used. In this paper, we compare three different evidence estimators, including (1) the brute force Monte Carlo method, (2) the Laplace-Metropolis method, and (3) the numerical integration method proposed by Volpi et al. (2016). The three types of subsurface models that we consider differ in their treatment of the porosity distribution and use (a) horizontal layering with fixed layer thicknesses, (b) vertical layering with fixed layer thicknesses and (c) a multi-Gaussian field. Our results demonstrate that all three estimators provide equivalent results in low parameter dimensions, yet in higher dimensions the brute force Monte Carlo method is inefficient. The isotropic multi-Gaussian model is most supported by the travel time data with Bayes factors that are larger than 10100 compared to conceptual models that assume horizontal or vertical layering of the porosity field.

  16. Monitoring of fluvial transport in small upland catchments - methods and preliminary results

    Science.gov (United States)

    Janicki, Grzegorz; Rodzik, Jan; Chabudziński, Łukasz; Franczak, Łukasz; Siłuch, Marcin; Stępniewski, Krzysztof; Dyer, Jamie L.; Kołodziej, Grzegorz; Maciejewska, Ewa

    2014-06-01

    In April 2011 a study was initiated, financed from resources of the Polish National Science Centre, entitled: ‘Rainstorm prediction and mathematic modelling of their environmental and social-economical effects’ (No. NN/306571640). The study, implemented by a Polish-American team, covers meteorological research, including: (1) monitoring of single cell storms developing in various synoptic situations, (2) detection of their movement courses, and (3) estimation of parameters of their rain field. Empirical studies, including hydrological and geomorphological measurements, are conducted in objects researched thoroughly in physiographic terms (experimental catchments) in the Lublin region (SE Poland), distinguished by high frequency of occurrence of the events described. For comparative purposes, studies are also carried out on selected model areas in the lower course of the Mississippi River valley (USA), in a region with high frequency of summer rainstorms. For detailed studies on sediment transport processes during rainstorm events, catchments of low hydrological rank and their sub-catchments in a cascade system were selected. For the basic, relatively uniform geomorpho logical units distinguished this way, erosion and deposition balance of material transported was determined. The aim of work was to determine influence of weather condition on fluvial transport rate in small catchment with low hydrological order

  17. In-situ strain monitoring in liquid containers of LNG transporting carriers

    Science.gov (United States)

    Oh, Min-Cheol; Seo, Jun-Kyu; Kim, Kyung-Jo; Lee, Sang-Min; Kim, Myung-Hyun

    2008-08-01

    Liquefied natural gas (LNG) transport carriers are exposed to a risk by the repeated bump in the LNG container during the vessel traveling over the wave in ocean. The liquid inside the container, especially when it was not fully contained, make a strong bump onto the insulation panel of the tank wall. The insulation panel consists of several layers of thick polyurethane foam (PUF) to maintain the LNG below the cryogenic temperature, -162°C. Due to the repeated shock on the PUF, a crack could be developed on the tank wall causing a tremendous disaster for LNG carriers. To prevent the accidental crack on the tank, a continuous monitoring of the strain imposed on the PUF is recommended. In this work, a fiber-optic Bragg grating was imbedded inside the PUF for monitoring the strain parallel to the impact direction. The optical fiber sensor with a small diameter of 125 μm was suitable to be inserted in the PUF through a small hole drilled after the PUF was cured. In-situ monitoring of the strain producing the change of Bragg reflection wavelength, a high speed wavelength interrogation method was employed by using an arrayed waveguide grating. By dropping a heavy mass on the PUF, we measured the strain imposed on the insulation panel.

  18. Geophysical monitoring and reactive transport modeling of ureolytically-driven calcium carbonate precipitation

    Directory of Open Access Journals (Sweden)

    Taylor Joanna

    2011-09-01

    Full Text Available Abstract Ureolytically-driven calcium carbonate precipitation is the basis for a promising in-situ remediation method for sequestration of divalent radionuclide and trace metal ions. It has also been proposed for use in geotechnical engineering for soil strengthening applications. Monitoring the occurrence, spatial distribution, and temporal evolution of calcium carbonate precipitation in the subsurface is critical for evaluating the performance of this technology and for developing the predictive models needed for engineering application. In this study, we conducted laboratory column experiments using natural sediment and groundwater to evaluate the utility of geophysical (complex resistivity and seismic sensing methods, dynamic synchrotron x-ray computed tomography (micro-CT, and reactive transport modeling for tracking ureolytically-driven calcium carbonate precipitation processes under site relevant conditions. Reactive transport modeling with TOUGHREACT successfully simulated the changes of the major chemical components during urea hydrolysis. Even at the relatively low level of urea hydrolysis observed in the experiments, the simulations predicted an enhanced calcium carbonate precipitation rate that was 3-4 times greater than the baseline level. Reactive transport modeling results, geophysical monitoring data and micro-CT imaging correlated well with reaction processes validated by geochemical data. In particular, increases in ionic strength of the pore fluid during urea hydrolysis predicted by geochemical modeling were successfully captured by electrical conductivity measurements and confirmed by geochemical data. The low level of urea hydrolysis and calcium carbonate precipitation suggested by the model and geochemical data was corroborated by minor changes in seismic P-wave velocity measurements and micro-CT imaging; the latter provided direct evidence of sparsely distributed calcium carbonate precipitation. Ion exchange processes

  19. Geophysical monitoring and reactive transport modeling of ureolytically-driven calcium carbonate precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Y.; Ajo-Franklin, J.B.; Spycher, N.; Hubbard, S.S.; Zhang, G.; Williams, K.H.; Taylor, J.; Fujita, Y.; Smith, R.

    2011-07-15

    Ureolytically-driven calcium carbonate precipitation is the basis for a promising in-situ remediation method for sequestration of divalent radionuclide and trace metal ions. It has also been proposed for use in geotechnical engineering for soil strengthening applications. Monitoring the occurrence, spatial distribution, and temporal evolution of calcium carbonate precipitation in the subsurface is critical for evaluating the performance of this technology and for developing the predictive models needed for engineering application. In this study, we conducted laboratory column experiments using natural sediment and groundwater to evaluate the utility of geophysical (complex resistivity and seismic) sensing methods, dynamic synchrotron x-ray computed tomography (micro-CT), and reactive transport modeling for tracking ureolytically-driven calcium carbonate precipitation processes under site relevant conditions. Reactive transport modeling with TOUGHREACT successfully simulated the changes of the major chemical components during urea hydrolysis. Even at the relatively low level of urea hydrolysis observed in the experiments, the simulations predicted an enhanced calcium carbonate precipitation rate that was 3-4 times greater than the baseline level. Reactive transport modeling results, geophysical monitoring data and micro-CT imaging correlated well with reaction processes validated by geochemical data. In particular, increases in ionic strength of the pore fluid during urea hydrolysis predicted by geochemical modeling were successfully captured by electrical conductivity measurements and confirmed by geochemical data. The low level of urea hydrolysis and calcium carbonate precipitation suggested by the model and geochemical data was corroborated by minor changes in seismic P-wave velocity measurements and micro-CT imaging; the latter provided direct evidence of sparsely distributed calcium carbonate precipitation. Ion exchange processes promoted through NH{sub 4}{sup

  20. Geophysical monitoring and reactive transport modeling of ureolytically-driven calcium carbonate precipitation.

    Science.gov (United States)

    Wu, Yuxin; Ajo-Franklin, Jonathan B; Spycher, Nicolas; Hubbard, Susan S; Zhang, Guoxiang; Williams, Kenneth H; Taylor, Joanna; Fujita, Yoshiko; Smith, Robert

    2011-09-23

    Ureolytically-driven calcium carbonate precipitation is the basis for a promising in-situ remediation method for sequestration of divalent radionuclide and trace metal ions. It has also been proposed for use in geotechnical engineering for soil strengthening applications. Monitoring the occurrence, spatial distribution, and temporal evolution of calcium carbonate precipitation in the subsurface is critical for evaluating the performance of this technology and for developing the predictive models needed for engineering application. In this study, we conducted laboratory column experiments using natural sediment and groundwater to evaluate the utility of geophysical (complex resistivity and seismic) sensing methods, dynamic synchrotron x-ray computed tomography (micro-CT), and reactive transport modeling for tracking ureolytically-driven calcium carbonate precipitation processes under site relevant conditions. Reactive transport modeling with TOUGHREACT successfully simulated the changes of the major chemical components during urea hydrolysis. Even at the relatively low level of urea hydrolysis observed in the experiments, the simulations predicted an enhanced calcium carbonate precipitation rate that was 3-4 times greater than the baseline level. Reactive transport modeling results, geophysical monitoring data and micro-CT imaging correlated well with reaction processes validated by geochemical data. In particular, increases in ionic strength of the pore fluid during urea hydrolysis predicted by geochemical modeling were successfully captured by electrical conductivity measurements and confirmed by geochemical data. The low level of urea hydrolysis and calcium carbonate precipitation suggested by the model and geochemical data was corroborated by minor changes in seismic P-wave velocity measurements and micro-CT imaging; the latter provided direct evidence of sparsely distributed calcium carbonate precipitation. Ion exchange processes promoted through NH4

  1. Atmospheric effects on infrared measurements at ground level: Application to monitoring of transport infrastructures

    Science.gov (United States)

    Boucher, Vincent; Dumoulin, Jean

    2014-05-01

    Being able to perform easily non-invasive diagnostics for surveillance and monitoring of critical transport infrastructures is a major preoccupation of many technical offices. Among all the existing electromagnetic methods [1], long term thermal monitoring by uncooled infrared camera [2] is a promising technique due to its dissemination potential according to its low cost on the market. Nevertheless, Knowledge of environmental parameters during measurement in outdoor applications is required to carry out accurate measurement corrections induced by atmospheric effects at ground level. Particularly considering atmospheric effects and measurements in foggy conditions close as possible to those that can be encountered around transport infrastructures, both in visible and infrared spectra. In the present study, atmospheric effects are first addressed by using data base available in literature and modelling. Atmospheric attenuation by particles depends greatly of aerosols density, but when relative humidity increases, water vapor condenses onto the particulates suspended in the atmosphere. This condensed water increases the size of the aerosols and changes their composition and their effective refractive index. The resulting effect of the aerosols on the absorption and scattering of radiation will correspondingly be modified. In a first approach, we used aerosols size distributions derived from Shettle and Fenn [3] for urban area which could match some of experimental conditions encountered during trials on transport infrastructures opened to traffic. In order to calculate the influence of relative humidity on refractive index, the Hänel's model [4] could be used. The change in the particulate size is first related to relative humidity through dry particle radius, particle density and water activity. Once the wet aerosol particle size is found, the effective complex refractive index is the volume weighted average of the refractive indexes of the dry aerosol substance

  2. Corrosion in systems for storage and transportation of petroleum products and biofuels identification, monitoring and solutions

    CERN Document Server

    Groysman, Alec

    2014-01-01

    This book treats corrosion as it occurs and affects processes in real-world situations, and thus points the way to practical solutions. Topics described include the conditions in which petroleum products are corrosive to metals; corrosion mechanisms of petroleum products; which parts of storage tanks containing crude oils and petroleum products undergo corrosion; dependence of corrosion in tanks on type of petroleum products; aggressiveness of petroleum products to polymeric material; how microorganisms take part in corrosion of tanks and pipes containing petroleum products; which corrosion monitoring methods are used in systems for storage and transportation of petroleum products; what corrosion control measures should be chosen; how to choose coatings for inner and outer surfaces of tanks containing petroleum products; and how different additives (oxygenates, aromatic solvents) to petroleum products and biofuels influence metallic and polymeric materials. The book is of interest to corrosion engineers, mat...

  3. Monitoring the FLASH Cryomodule Transportation from DESY Hamburg to CEA Saclay: Coupler Contact, Vacuum, Acceleration and Vibration Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Barbanotti, S.; Bosotti, A.; Fusetti, M.; Michelato, P.; /INFN, Milan /LASA, Segrate; Bertolini, A.; /Hannover, Max Planck Inst. Grav.; Berry, S.; Dorlot, M.; Madec, C.; Napoly, O.; /Saclay; Amirikas, R.; Boehnert, M.; /DESY /Fermilab

    2009-05-01

    With a view to the series production of one hundred, 12 m long XFEL 1.3 GHz cryomodules and their transportation from the assembly site at CEA Saclay (F) to the installation site at DESY Hamburg (D) a test transportation of a FLASH cryomodule has been performed, in the condition foreseen for the mass transportation. The present study examines the stresses induced on the module and verifies the damping capabilities of the transport frame in order to minimize risk of damage to the most critical components. During the transportation, acceleration and vibration have been monitored as well as coupler antenna contacts and vacuum performances. This paper describes the analysis performed and compares those results to the data of a similar transportation study at Fermilab for the CM1 cryomodule.

  4. Advances toward a transportable antineutrino detector system for reactor monitoring and safeguards

    Energy Technology Data Exchange (ETDEWEB)

    Reyna, D. [Sandia National Laboratories, Livermore, CA 94550 (United States); Bernstein, A. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Lund, J.; Kiff, S.; Cabrera-Palmer, B. [Sandia National Laboratories, Livermore, CA 94550 (United States); Bowden, N. S.; Dazeley, S.; Keefer, G. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)

    2011-07-01

    Nuclear reactors have served as the neutrino source for many fundamental physics experiments. The techniques developed by these experiments make it possible to use these very weakly interacting particles for a practical purpose. The large flux of antineutrinos that leaves a reactor carries information about two quantities of interest for safeguards: the reactor power and fissile inventory. Our SNL/LLNL collaboration has demonstrated that such antineutrino based monitoring is feasible using a relatively small cubic meter scale liquid scintillator detector at tens of meters standoff from a commercial Pressurized Water Reactor (PWR). With little or no burden on the plant operator we have been able to remotely and automatically monitor the reactor operational status (on/off), power level, and fuel burnup. The initial detector was deployed in an underground gallery that lies directly under the containment dome of an operating PWR. The gallery is 25 meters from the reactor core center, is rarely accessed by plant personnel, and provides a muon-screening effect of some 20-30 meters of water equivalent earth and concrete overburden. Unfortunately, many reactor facilities do not contain an equivalent underground location. We have therefore attempted to construct a complete detector system which would be capable of operating in an aboveground location and could be transported to a reactor facility with relative ease. A standard 6-meter shipping container was used as our transportable laboratory - containing active and passive shielding components, the antineutrino detector and all electronics, as well as climate control systems. This aboveground system was deployed and tested at the San Onofre Nuclear Generating Station (SONGS) in southern California in 2010 and early 2011. We will first present an overview of the initial demonstrations of our below ground detector. Then we will describe the aboveground system and the technological developments of the two antineutrino

  5. Preliminary investigation on monitoring transportation effects by full field methods: a digital holographic speckle pattern interferometry study on canvas paintings

    Science.gov (United States)

    Tsiranidou, Elsa; Bernikola, Eirini; Tornari, Vivi; Fankhauser, Thomas; Läuchli, Matthias; Palmbach, Cornelius; Bäschlin, Nathalie

    2011-06-01

    A preliminary investigation has taken place employing Digital Holographic Speckle Pattern Interferometry (DHSPI) in order to assess the effect of handling and transportation on canvas paintings. Canvas dummies were used on a series of measurements on a transport simulator which allows reproducible simulation of any transport logs in the laboratory. A number of cycles of controlled vibrations were applied on the samples and after each cycle a measurement with DHSPI was taken to monitor the behavior of the samples while increasing the vibration loading and also to record the conditions under which the first crack appears. The transport simulations in combination with DHSPI monitoring revealed the amplitude of oscillation where the first cracks appear on new canvas paintings and also the way these cracks grow. During the tests it was also feasible to locate areas at risk of future deterioration.

  6. Drug transport mechanism of P-glycoprotein monitored by single molecule fluorescence resonance energy transfer

    Science.gov (United States)

    Ernst, S.; Verhalen, B.; Zarrabi, N.; Wilkens, S.; Börsch, M.

    2011-03-01

    In this work we monitor the catalytic mechanism of P-glycoprotein (Pgp) using single-molecule fluorescence resonance energy transfer (FRET). Pgp, a member of the ATP binding cassette family of transport proteins, is found in the plasma membrane of animal cells where it is involved in the ATP hydrolysis driven export of hydrophobic molecules. When expressed in the plasma membrane of cancer cells, the transport activity of Pgp can lead to the failure of chemotherapy by excluding the mostly hydrophobic drugs from the interior of the cell. Despite ongoing effort, the catalytic mechanism by which Pgp couples MgATP binding and hydrolysis to translocation of drug molecules across the lipid bilayer is poorly understood. Using site directed mutagenesis, we have introduced cysteine residues for fluorescence labeling into different regions of the nucleotide binding domains (NBDs) of Pgp. Double-labeled single Pgp molecules showed fluctuating FRET efficiencies during drug stimulated ATP hydrolysis suggesting that the NBDs undergo significant movements during catalysis. Duty cycle-optimized alternating laser excitation (DCO-ALEX) is applied to minimize FRET artifacts and to select the appropriate molecules. The data show that Pgp is a highly dynamic enzyme that appears to fluctuate between at least two major conformations during steady state turnover.

  7. Monitoring of Fluvial Transport in the Mountain River Bed Using Terrestrial Laser Scanning

    Science.gov (United States)

    Jozkow, G.; Borkowski, A.; Kasprzak, M.

    2016-06-01

    The fluvial transport is the surface process that has a strong impact on the topography changes, especially in mountain areas. Traditional hydrological measurements usually give a good understanding of the river flow, however, the information of the bedload movement in the rivers is still insufficient. In particular, there is limited knowledge about the movement of the largest clasts, i.e. boulders. This investigation addresses mentioned issues by employing Terrestrial Laser Scanning (TLS) to monitor annual changes of the mountain river bed. The vertical changes were estimated based on the Digital Elevation Model (DEM) of difference (DoD) while transported boulders were identified based on the distances between point clouds and RGB-coloured points. Combined RGB point clouds allowed also to measure 3D displacements of boulders. The results showed that the highest dynamic of the fluvial process occurred between years 2012-2013. Obtained DoD clearly indicated alternating zones of erosion and deposition of the sediment finer fractions in the local sedimentary traps. The horizontal displacement of the rock material in the river bed showed high complexity resulting in the displacement of large boulders (major axis about 0.8 m) for the distance up to 2.3 m.

  8. MONITORING OF FLUVIAL TRANSPORT IN THE MOUNTAIN RIVER BED USING TERRESTRIAL LASER SCANNING

    Directory of Open Access Journals (Sweden)

    G. Jozkow

    2016-06-01

    Full Text Available The fluvial transport is the surface process that has a strong impact on the topography changes, especially in mountain areas. Traditional hydrological measurements usually give a good understanding of the river flow, however, the information of the bedload movement in the rivers is still insufficient. In particular, there is limited knowledge about the movement of the largest clasts, i.e. boulders. This investigation addresses mentioned issues by employing Terrestrial Laser Scanning (TLS to monitor annual changes of the mountain river bed. The vertical changes were estimated based on the Digital Elevation Model (DEM of difference (DoD while transported boulders were identified based on the distances between point clouds and RGB-coloured points. Combined RGB point clouds allowed also to measure 3D displacements of boulders. The results showed that the highest dynamic of the fluvial process occurred between years 2012-2013. Obtained DoD clearly indicated alternating zones of erosion and deposition of the sediment finer fractions in the local sedimentary traps. The horizontal displacement of the rock material in the river bed showed high complexity resulting in the displacement of large boulders (major axis about 0.8 m for the distance up to 2.3 m.

  9. Engineering monitoring of rockfall hazards along transportation corridors: using mobile terrestrial LiDAR

    Directory of Open Access Journals (Sweden)

    M. Lato

    2009-06-01

    Full Text Available Geotechnical hazards along linear transportation corridors are challenging to identify and often require constant monitoring. Inspecting corridors using traditional, manual methods requires the engineer to be unnecessarily exposed to the hazard. It also requires closure of the corridor to ensure safety of the worker from passing vehicles. This paper identifies the use of mobile terrestrial LiDAR data as a compliment to traditional field methods. Mobile terrestrial LiDAR is an emerging remote data collection technique capable of generating accurate fully three-dimensional virtual models while driving at speeds up to 100 km/h. Data is collected from a truck that causes no delays to active traffic nor does it impede corridor use. These resultant georeferenced data can be used for geomechanical structural feature identification and kinematic analysis, rockfall path identification and differential monitoring of rock movement or failure over time. Comparisons between mobile terrestrial and static LiDAR data collection and analysis are presented. As well, detailed discussions on workflow procedures for possible implementation are discussed. Future use of mobile terrestrial LiDAR data for corridor analysis will focus on repeated surveys and developing dynamic four-dimensional models, higher resolution data collection. As well, computationally advanced, spatially accurate, geomechanically controlled three-dimensional rockfall simulations should be investigated.

  10. Serotonin Transporter Genotype and Action Monitoring Dysfunction: A Possible Substrate Underlying Increased Vulnerability to Depression

    Science.gov (United States)

    Holmes, Avram J; Bogdan, Ryan; Pizzagalli, Diego A

    2010-01-01

    A variable number of tandem repeats (short (S) vs long (L)) in the promoter region of the serotonin transporter gene (5-HTTLPR) and a functional variant of a single-nucleotide polymorphism (rs25531) in 5-HTTLPR have been recently associated with increased risk for major depressive disorder (MDD). In particular, relative to L/L or LA homozygotes (hereafter referred to as L′ participants), S carriers or Lg-allele carriers (S′ participants) have been found to have a higher probability of developing depression after stressful life events, although inconsistencies abound. Previous research indicates that patients with MDD are characterized by executive dysfunction and abnormal activation within the anterior cingulate cortex (ACC), particularly in situations requiring adaptive behavioral adjustments following errors and response conflict (action monitoring). The goal of this study was to test whether psychiatrically healthy S′ participants would show abnormalities similar to those of MDD subjects. To this end, 19 S′ and 14 L′ participants performed a modified Flanker task known to induce errors, response conflict, and activations in various ACC subdivisions during functional magnetic resonance imaging. As hypothesized, relative to L′ participants, S′ participants showed (1) impaired post-error and post-conflict behavioral adjustments; (2) larger error-related rostral ACC activation; and (3) lower conflict-related dorsal ACC activation. As similar behavioral and neural dysfunctions have been recently described in MDD patient samples, the current results raise the possibility that impaired action monitoring and associated ACC dysregulation may represent risk factors increased vulnerability to depression. PMID:20090673

  11. Transport infrastructure monitoring: Testing of the NIODIM optical displacement monitoring system at the Sihlhochstrasse bridge in Zürich, Switzerland.

    Science.gov (United States)

    Hagene, J. K.

    2012-04-01

    A gound based optical displacement monitoring system, "NIODIM", is being developed by Norsk Elektro Optikk in the framework of the activities of the European project "Integrated System for Transport Infrastructure surveillance and Monitoring by Electromagnetic Sensing" (ISTIMES), funded in the 7th Framework Programme (FP7/2007-2013). The optical displacement monitoring system has now participated in two real life field campaigns one in Switzerland and one in Italy. The test campaign in Switzerland during a week in May 2011 will be presented below. The NIODIM system is based on a camera part mounted on firm ground and this camera is imaging a reference point, normally a light emitting diode (LED) which is supposed to be mounted on an object susceptible to move or oscillate. A microprocessor based unit is processing the acquired images and is calculating the displacement. The Sihlhochstrasse bridge is placed on concrete pillars in the river Sihl in Zürich and the motorway is one of the entrance routes to the city. A site visit had been performed in advance and it had been decided to mount the camera part as well as the processing unit at the lower part of the pillar above the relatively dry riverbed. The reference point in form of a light emitting diode was to be mounted below the bridge deck. However, due to practical access limitations it was not possible to place the reference LED in the middle between pillar pairs, but the LED had to be placed closer to next pair of the pillars downstream the river thus increasing the distance and possibly reducing the potential displacement. A lower signal due to reduced sensitivity (length) and due to lower deflection (better support from the pillar) had to be expected. The system would be powered by a generator placed on the riverbed. Arriving at the river front the fist day of the field trials was a surprise to most the campaign members. Due to heavy rain the week before, and in particular up in the mountains, the water

  12. Nitrate Transport Modeling in Deep Aquifers. Comparison between Model Results and Data from the Groundwater Monitoring Network

    NARCIS (Netherlands)

    Uffink GJM; Romkens PFAM; LBG

    2001-01-01

    Nitrate measurements from the Netherlands Groundwater Monitoring Network and model simulations were compared for deep aquifers in the eastern part of the Netherlands. The area studied measured 40 x 30 km2. The model describes advective-dispersive solute transport in groundwater and utilizes a first-

  13. Monitoring of oil pollution at Gemsa Bay and bioremediation capacity of bacterial isolates with biosurfactants and nanoparticles.

    Science.gov (United States)

    El-Sheshtawy, H S; Khalil, N M; Ahmed, W; Abdallah, R I

    2014-10-15

    Fifteen crude oil-degrading bacterial isolates were isolated from an oil-polluted area in Gemsa Bay, Red Sea, Egypt. Two bacterial species showed the highest growth rate on crude oil hydrocarbons. From an analysis of 16S rRNA sequences, these isolates were identified as Pseudomonas xanthomarina KMM 1447 and Pseudomonas stutzeri ATCC 17588. Gas Chromatographic (GC) analysis of the crude oil remaining in the culture medium after one week at 30°C showed that the optimum biodegradation of crude petroleum oil was demonstrated at 50% in medium containing biosurfactant with two types of nanoparticles separately and two bacterial species. The complete degradation of some different members of polyaromatics and the percentage biodegradation of other polyaromatics increased in microcosm containing two different types of nanoparticles with biosurfactant after 7 days. In conclusion, these bacterial strains may be useful for the bioremediation process in the Gemsa Bay, Red Sea decreasing oil pollution in this marine ecosystem.

  14. Monitoring and analysis of nonlinear dynamic damage of transport roadway supported by composite hard rock materials in Linglong Gold Mine

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The study concentrates mainly on the development of failure process in composite rock mass. By use of acoustic emission(AE), convergence inspection, pressure monitoring, level measurement techniques and the modem signal analysis technology, as wellas scan electron microscopy (SEM) experiment, various aspects of nonlinear dynamic damage of composite rock mass surroundingthe transport roadway in Linglong gold mine are discussed. According to the monitoring results, the stability of the rock mass can besynthetically evaluated, and the intrinsic relation between the damage and the characteristic parameters of acoustic emission can bedetermined. The location of the damage of rock mass can also be detected based on the acoustic emission couple monitoring signals.Finally, the key factors which influence the stability of the transport roadway supported by composite hard rock materials are foundout.

  15. Co-monitoring bacterial and dinoflagellates communities by denaturing gradient gel electrophoresis (DGGE) and SSU rRNA sequencing during a dinoflagellates bloom

    Institute of Scientific and Technical Information of China (English)

    KANJinjun; CHENFeng

    2004-01-01

    Dinoflagellates are unicellular eukaryotic protists that dominate in all coastal waters, and are also present in oceanic waters. Despite the central importance of dinoflagellates in global primary production, the relationship between dinoflagellates and bacteria are still poorly understood. In order to understand the ecological interaction between bacterial and dinoflageUates communities, denaturing gradient gel electrophoresis (DGGE) and SSU rRNA sequencing were applied to monitoring the population dynamics of bacteria and dinoflagellates from the onset to disappearance of a dinoflagellates bloom occurred in Baltimore Inner Harbor, from April 15 to 24, 2002. Although Prorocentrum minimum was the major bloom forming species under the light microscopy, DGGE method with dinoflagellate specific primers demonstrated that Prorocentrum micans, Gymnodinium galatheanum and Gyrodinium uncatenum were also present during the bloom. Population shifts among the minor dinoflagellate groups were observed. DGGE of PCR-amplified 16S rRNA gene fragments indicated that cyanobacteria, α, β, γ-proteobacteria, FlavobacteriumBacteroides-Cytophaga (FBC), and Planctomcetes were the major components of bacterial assemblages during the bloom. DGGE analysis showed that Cytophagales and α-proteobacteria played important roles at different stages of dinoflagellates bloom. DGGE can be used as a rapid tool to simultaneously monitor population dynamics of both bacterial and dinoflagellates communities in aquatic environments, which is demonstrated here.

  16. Inversion of Source and Transport Parameters of Relativistic SEPs from Neutron Monitor Data

    Science.gov (United States)

    Agueda, Neus; Bütikofer, Rolf; Vainio, Rami; Heber, Bernd; Afanasiev, Alexander; Malandraki, Olga E.

    2016-04-01

    We present a new methodology to study the release processes of relativistic solar energetic particles (SEPs) based on the direct inversion of Ground Level Enhancements (GLEs) observed by the worldwide network of neutron monitors (NMs). The new approach makes use of several models, including: the propagation of relativistic SEPs from the Sun to the Earth, their transport in the Earth's magnetosphere and atmosphere, as well as the detection of the nucleon component of the secondary cosmic rays by ground based NMs. The combination of these models allows us to compute the expected ground-level NM counting rates for a series of instantaneous releases from the Sun. The amplitudes of the source components are then inferred by fitting the NM observations with the modeled NM counting rate increases. Within the HESPERIA project, we will develop the first software package for the direct inversion of GLEs and we will make it freely available for the solar and heliospheric communities. Acknowledgement: This work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 637324.

  17. Evaluation of a transportable capnometer for monitoring end-tidal carbon dioxide

    DEFF Research Database (Denmark)

    Hildebrandt, T; Tobiasen, Malene Espelund; Olsen, K S

    2010-01-01

    We compared a small and transportable Capnometer (EMMA™) with a reference capnometer, the Siesta i TS Anaesthesia. During air-breathing through a facemask, both the EMMA (nine modules) and reference capnometer sampled expired gas simultaneously. A wide range of end-tidal carbon dioxide values were...... obtained during inhalation of carbon dioxide and voluntary hyperventilation. The median IQR [range] difference between all sets of carbon dioxide values (EMMA - reference) was -0.3 (-0.6 to 0.0 [-1.7 to 1.6] kPa; n = 297) using new batteries, which was statistically significant (p = 0.04) and located...... to two of the nine EMMAs tested. Using batteries with reduced voltage did not influence the measurements. The 95% CI of the medians of the differences were -0.4 to -0.2. We conclude that the EMMA can slightly under-read the end-tidal carbon dioxide but is generally comparable with a free-standing monitor...

  18. Evaluation of a transportable capnometer for monitoring end-tidal carbon dioxide

    DEFF Research Database (Denmark)

    Hildebrandt, T; Tobiasen, Malene Espelund; Olsen, K S

    2010-01-01

    We compared a small and transportable Capnometer (EMMA™) with a reference capnometer, the Siesta i TS Anaesthesia. During air-breathing through a facemask, both the EMMA (nine modules) and reference capnometer sampled expired gas simultaneously. A wide range of end-tidal carbon dioxide values were...... obtained during inhalation of carbon dioxide and voluntary hyperventilation. The median IQR [range] difference between all sets of carbon dioxide values (EMMA - reference) was -0.3 (-0.6 to 0.0 [-1.7 to 1.6] kPa; n = 297) using new batteries, which was statistically significant (p = 0.04) and located...... to two of the nine EMMAs tested. Using batteries with reduced voltage did not influence the measurements. The 95% CI of the medians of the differences were -0.4 to -0.2. We conclude that the EMMA can slightly under-read the end-tidal carbon dioxide but is generally comparable with a free-standing monitor...

  19. Effects of altered groundwater chemistry upon the pH-dependency and magnitude of bacterial attachment during transport within an organically contaminated sandy aquifer

    Science.gov (United States)

    Harvey, Ronald W.; Metge, David W.; Barber, Larry B.; Aiken, George R.

    2010-01-01

    The effects of a dilute (ionic strength = 5 ?? 10-3 M) plume of treated sewage, with elevated levels (3.9 mg/L) of dissolved organic carbon (DOC), upon the pH-dependency and magnitude of bacterial transport through an iron-laden, quartz sand aquifer (Cape Cod, MA) were evaluated using sets of replicate, static minicolumns. Compared with uncontaminated groundwater, the plume chemistry diminished bacterial attachment under mildly acidic (pH 5.0-6.5) in-situ conditions, in spite of the 5-fold increase in ionic strength and substantively enhanced attachment under more alkaline conditions. The effects of the hydrophobic neutral and total fractions of the plume DOC; modest concentrations of fulvic and humic acids (1.5 mg/L); linear alkyl benzene sulfonate (LAS) (25 mg/L); Imbentin (200 ??g/L), a model nonionic surfactant; sulfate (28 mg/L); and calcium (20 mg/L) varied sharply in response to relatively small changes in pH, although the plume constituents collectively decreased the pH-dependency of bacterial attachment. LAS and other hydrophobic neutrals (collectively representing only ???3% of the plume DOC) had a disproportionately large effect upon bacterial attachment, as did the elevated concentrations of sulfate within the plume. The findings further suggest that the roles of organic plume constituents in transport or bacteria through acidic aquifer sediments can be very different than would be predicted from column studies performed at circumneutral pH and that the inorganic constituents within the plume cannot be ignored.

  20. Effects of altered groundwater chemistry upon the pH-dependency and magnitude of bacterial attachment during transport within an organically contaminated sandy aquifer.

    Science.gov (United States)

    Harvey, Ronald W; Metge, David W; Barber, L B; Aiken, George R

    2010-02-01

    The effects of a dilute (ionic strength=5x10(-3)M) plume of treated sewage, with elevated levels (3.9 mg/L) of dissolved organic carbon (DOC), upon the pH-dependency and magnitude of bacterial transport through an iron-laden, quartz sand aquifer (Cape Cod, MA) were evaluated using sets of replicate, static minicolumns. Compared with uncontaminated groundwater, the plume chemistry diminished bacterial attachment under mildly acidic (pH 5.0-6.5) in-situ conditions, in spite of the 5-fold increase in ionic strength and substantively enhanced attachment under more alkaline conditions. The effects of the hydrophobic neutral and total fractions of the plume DOC; modest concentrations of fulvic and humic acids (1.5 mg/L); linear alkyl benzene sulfonate (LAS) (25 mg/L); Imbentin (200 microg/L), a model nonionic surfactant; sulfate (28 mg/L); and calcium (20 mg/L) varied sharply in response to relatively small changes in pH, although the plume constituents collectively decreased the pH-dependency of bacterial attachment. LAS and other hydrophobic neutrals (collectively representing only approximately 3% of the plume DOC) had a disproportionately large effect upon bacterial attachment, as did the elevated concentrations of sulfate within the plume. The findings further suggest that the roles of organic plume constituents in transport or bacteria through acidic aquifer sediments can be very different than would be predicted from column studies performed at circumneutral pH and that the inorganic constituents within the plume cannot be ignored.

  1. Solid transport in mountain rivers: monitoring techniques and long term assessment as flood prevention tools

    Science.gov (United States)

    Longoni, Laura; Brambilla, Davide; Ivanov, Vladislav; Messa, Giacomo; Veronelli, Andrea; Radice, Alessio; Papini, Monica

    2017-04-01

    Floods are calamitous phenomena with an ever-increasing frequency around the globe, that often result in socio-economic damage and casualties. The role of the solid fraction in the river dynamic has been widely debated in the last decade and its importance is recognized as critical and not negligible in flood simulations as it has been evidenced that the severity of an event is often the result of the coupling of a flood wave with elevated solid transport rates. Nevertheless, assessing the quantity of sediment mobilized in a particular event is not feasible without a long term analysis of the river's dynamics and its morphological evolution since it is defined by past events. This work is focused on the techniques to improve knowledge about sediment production and transport through hydrological networks as a necessary component of a wise flood prevention planning. In particular, a multidisciplinary approach that combines hydraulic and geological knowledge is required in order to understand the evolution of the river sediment and how it will influence the following critical event. The methods are presented through a case study in Italy where a series of different approaches have been integrated to gain a comprehensive understanding of the problem: the sediment movement has been studied by a Eulerian as well as a Lagrangian approaches while hydraulic properties of the stream have been measured. The research started with an attempt to monitor sediment movements: in June 2016 300 sample pebbles, equipped with RFID (Radio Frequency IDentification) transponders, have been deployed in the river and tracked after every major rainfall event. The obtained data-set has been combined with a morphological analysis and a river flow discharge computed through PIV (Particle Image Velocimetry) method in order to identify the relation between a given rainfall event and sediment transport. Moreover, critical sediment size has been estimated from field data using three approaches: two

  2. Establishing Bedding Requirements during Transport and Monitoring Skin Temperature during Cold and Mild Seasons after Transport for Finishing Pigs

    Directory of Open Access Journals (Sweden)

    John McGlone

    2014-05-01

    Full Text Available The broad aim of this study was to determine whether bedding level in the transport trailer influenced pig performance and welfare. Specifically, the objective was to define the bedding requirements of pigs during transportation in commercial settings during cold and mild weather. Animals (n = 112,078 pigs on 572 trailers used were raised in commercial finishing sites and transported in trailers to commercial processing plants. Dead on arrival (DOA, non-ambulatory (NA, and total dead and down (D&D data were collected and skin surface temperatures of the pigs were measured by infrared thermography. Data were collected during winter (Experiment 1 and fall/spring (Experiment 2. Total D&D percent showed no interaction between bedding level and outside air temperature in any experiments. Average skin surface temperature during unloading increased with outside air temperature linearly in both experiments (P < 0.01. In conclusion, over-use of bedding may be economically inefficient. Pig skin surface temperature could be a useful measure of pig welfare during or after transport.

  3. Monitoring the fate and transport of deicing chemicals in lysimeter experiments

    Science.gov (United States)

    Lißner, H.; Wehrer, M.; Totsche, K. U.

    2012-04-01

    Large amounts of the deicing chemicals (DIC) propylene glycol (PG) and formate are spread for removal of snow and ice on the aircrafts and airfields every winter. A considerable amount of these chemicals are carried into surrounding areas, where they mix with snow and infiltrate in the soil during snowmelt. Even though DIC are easily degradable, the high mobility and the high biological oxygen demand of PG in particular can influence the hydrogeochemistry of the unsaturated and saturated zone. The aims of the study were to evaluate and quantify transport of deicing chemicals during snowmelt under field conditions, and to study effects of DIC degradation on the hydrogeochemistry of the unsaturated zone. Eight undisturbed soil cores (0.3 m x 1 m, 0.071 m3) were retrieved at the Gardermoen Airport, Norway, and installed as non-weighable small scale lysimeters at a nearby field site. Before snowmelt in March 2010, a mix of snow containing 350 g/m2 PG, 71 g/m2 formate, and 17 g/m2 of bromide were added to the lysimeters. To determine the fate and transport of PG we monitored PG and its metabolites, bromide, manganese, and iron in the seepage water. High cumulative infiltration and marginal degradation of PG during the snowmelt period allowed up to 50 % of the PG to leave the upper, microbially most active, region of the soil. Only marginal concentrations of formate were analysed in all lysimeters, indicating fast degradation and favoured metabolism by soil bacteria compared to PG. Low contents of metabolites and the concurrent breakthrough of PG and Br in the seepage water even imply that PG was not significantly degraded before June. Redox values down to 200 mV in April, the detection of propionate and manganese, as well as a rise in pH, suggest partially anearobic localities in the soil, not only during high soil water saturation in April and May but also during summer when PG degradation was very efficient. In the longterm, the intense depletion of electron acceptors

  4. Optimized Field Sampling and Monitoring of Airborne Hazardous Transport Plumes; A Geostatistical Simulation Approach

    Energy Technology Data Exchange (ETDEWEB)

    Chen, DI-WEN

    2001-11-21

    Airborne hazardous plumes inadvertently released during nuclear/chemical/biological incidents are mostly of unknown composition and concentration until measurements are taken of post-accident ground concentrations from plume-ground deposition of constituents. Unfortunately, measurements often are days post-incident and rely on hazardous manned air-vehicle measurements. Before this happens, computational plume migration models are the only source of information on the plume characteristics, constituents, concentrations, directions of travel, ground deposition, etc. A mobile ''lighter than air'' (LTA) system is being developed at Oak Ridge National Laboratory that will be part of the first response in emergency conditions. These interactive and remote unmanned air vehicles will carry light-weight detectors and weather instrumentation to measure the conditions during and after plume release. This requires a cooperative computationally organized, GPS-controlled set of LTA's that self-coordinate around the objectives in an emergency situation in restricted time frames. A critical step before an optimum and cost-effective field sampling and monitoring program proceeds is the collection of data that provides statistically significant information, collected in a reliable and expeditious manner. Efficient aerial arrangements of the detectors taking the data (for active airborne release conditions) are necessary for plume identification, computational 3-dimensional reconstruction, and source distribution functions. This report describes the application of stochastic or geostatistical simulations to delineate the plume for guiding subsequent sampling and monitoring designs. A case study is presented of building digital plume images, based on existing ''hard'' experimental data and ''soft'' preliminary transport modeling results of Prairie Grass Trials Site. Markov Bayes Simulation, a coupled Bayesian

  5. Dynamic Monitoring on the Bacterial Endotoxin Concentration in Whole Blood and Blood Component%全血及成分血内毒素动态监测

    Institute of Scientific and Technical Information of China (English)

    鲍自谦; 刘怡; 王飞; 陈云龙

    2012-01-01

    目的 通过监测全血及成分血的内毒素含量动态变化,探讨内毒素监控的意义,为评估血液安全提供依据,保证安全输血.方法 选择2009年3月至4月本血液中心献血者中,符合国家《献血者健康检查要求》的自愿献血者血液样品300份为研究对象.按血液成分分为3组:全血组(n=50)、悬浮RBC成分血组(n=150)及PLT成分血组(n=100).采用动态浊度法内毒素定量检测技术分别于各组血液保存前期、中期及后期检测各个血液样品内毒素含量,并采用方差分析比较各个检测时间点血样内毒素变化情况.结果 全血保存期前中后期中,内毒素含量在部分时段差异有统计学意义(W=0.860,P<0.05);而PLT悬液、悬浮RBC在3个时间段的内毒素含量差异无统计学意义(P>0.05).结论 对全血及成分血的内毒素含量监测,结果显示血液保存期的内毒素含量稳定与其细菌培养阴性相吻合,表明现行的采供血流程的质量控制是有效的,可有效保障血液的安全.%Objective To explore the importance of dynamic monitoring on the bacterial endotoxin and assess the blood safety to guarantee the safety of blood transfusion,through dynamically monitoring the bacterial endotoxin concentration in whole blood and blood component. Methods From March to April 2009,300 donors' samples,which had met the requirements of donors' health check,were included in this study.According to the blood component,all these samples were performed into three groups:whole blood group (n=50),red blood cells (RBC) suspension group (n=150),platelet (PLT) components group (n=100).Dynamic turbidity in blood which were respectively stored at early stage,metaphase and later stage,were used as the detection quantitative method of bacterial endotoxin.And the results were further analyzed by variance of repeated measurement data. Results There was no difference of the bacterial endotoxin concentration during the preservation in

  6. Geodetic monitoring (TLS of a steel transport trestle bridge located in an active mining exploitation site

    Directory of Open Access Journals (Sweden)

    Skoczylas Arkadiusz

    2016-09-01

    Full Text Available Underground mining exploitation causes, in general, irregular vertical and horizontal shifts in the superficial layer of the rock mass. In the case of construction objects seated on this layer, a deformation of the object’s foundation can be observed. This leads to additional loads and deformations. Identification of surface geometry changes in construction objects located within the premises of underground mining exploitation areas is an important task as far as safety of mining sites is concerned. Surveys targeting shifts and deformations in engineering objects preformed with the use of classic methods are of a selective nature and do not provide the full image of the phenomenon being the subject of the observation. This paper presents possibilities of terrestrial laser scanning technology application in the monitoring of engineering objects that allows for a complete spatial documentation of an object subjected to the influence of an active mining exploitation. This paper describes an observation of a 100 m section of a steel transport trestle bridge located on the premises of hard coal mine Lubelski Węgiel “Bogdanka” S.A. carried out in 2015. Measurements were carried out using a Z+F Imager 5010C scanner at an interval of 3.5 months. Changes in the structure’s geometry were determined by comparing the point clouds recorded during the two measurement periods. The results of the analyses showed shifts in the trestle bridge towards the exploited coal wall accompanied by object deformation. The obtained results indicate the possibility of of terrestrial laser scanning application in studying the aftereffects of underground mining exploitation on surface engineering objects.

  7. ISTIMES Integrated System for Transport Infrastructures Surveillance and Monitoring by Electromagnetic Sensing

    Science.gov (United States)

    Argenti, M.; Giannini, V.; Averty, R.; Bigagli, L.; Dumoulin, J.

    2012-04-01

    The EC FP7 ISTIMES project has the goal of realizing an ICT-based system exploiting distributed and local sensors for non destructive electromagnetic monitoring in order to make critical transport infrastructures more reliable and safe. Higher situation awareness thanks to real time and detailed information and images of the controlled infrastructure status allows improving decision capabilities for emergency management stakeholders. Web-enabled sensors and a service-oriented approach are used as core of the architecture providing a sys-tem that adopts open standards (e.g. OGC SWE, OGC CSW etc.) and makes efforts to achieve full interoperability with other GMES and European Spatial Data Infrastructure initiatives as well as compliance with INSPIRE. The system exploits an open easily scalable network architecture to accommodate a wide range of sensors integrated with a set of tools for handling, analyzing and processing large data volumes from different organizations with different data models. Situation Awareness tools are also integrated in the system. Definition of sensor observations and services follows a metadata model based on the ISO 19115 Core set of metadata elements and the O&M model of OGC SWE. The ISTIMES infrastructure is based on an e-Infrastructure for geospatial data sharing, with a Data Cata-log that implements the discovery services for sensor data retrieval, acting as a broker through static connections based on standard SOS and WNS interfaces; a Decision Support component which helps decision makers providing support for data fusion and inference and generation of situation indexes; a Presentation component which implements system-users interaction services for information publication and rendering, by means of a WEB Portal using SOA design principles; A security framework using Shibboleth open source middleware based on the Security Assertion Markup Language supporting Single Sign On (SSO). ACKNOWLEDGEMENT - The research leading to these

  8. Real-time monitoring of bacterial and organic pollution in a water stream by fluorescence depletion spectroscopy

    Science.gov (United States)

    Gaulier, Geoffrey; Staedler, Davide; Sousa, Gustavo; Bonacina, Luigi; Wolf, Jean-Pierre

    2017-02-01

    We demonstrate an approach for a real-time, consumable-free optical system operating on a liquid jet which can be easily derived from the water distribution infrastructure. We apply a pump-probe scheme based on the acquisition and nanosecond manipulation of UV-excited fluorescence to increase the selective identification of bacterial against organic pollutants in water.

  9. Bedload transport rates in a gravel bedded-river derived from high-resolution monitoring using seismic impact plates

    Science.gov (United States)

    Downs, Peter; Soar, Philip

    2015-04-01

    Accurate characterisation of bedload transport rates is critical for a better understanding of geomorphological process dynamics, aquatic habitats, sediment budgets and strategies for catchment-scale initiatives in sediment management under conditions of climate change. However, rate estimation is challenging in practice: direct measurements are costly and logistically difficult to achieve with acceptable accuracy over geomorphologically-relevant time periods, and the uncertainty in transport rates predicted from empirical formulae and numerical simulation is rarely below 50 per cent. Partly reflecting these issues, passive technologies for continuous bedload monitoring are becoming increasingly popular. Sensors such as seismic impact plates offer the opportunity to characterise bedload activity at exceptionally high resolution - monitoring from the River Avon, (Devon, UK) indicated that despite significant intra-event and between-plate differences in apparent bedload transport aggregated over 5-minute periods, the magnitude-frequency product of discharge and impact frequency result in a highly plausible effective discharge, supporting the potential value of impact plates as indicators of relative sediment transport loads over annual timescales. Whereas the focus in bedload rate estimation to date has been on developing satisfactory sediment rating curves from detection signals, we instead develop a method for directly estimating bedload transport rates from impact plate data as a function of intensity of transport (count, n, per second), bed material mass (kg) and cross-stream transport variability. Bulk sediment samples are converted to a mass in transit for each instantaneous discharge according to the intensity of transport and a Monte Carlo simulation of the load in transit determined at random from the bed material particle size distribution. The lower detection threshold is determined using experimental calibration and the upper size limit is determined from

  10. Bacterial and fungal growth for monitoring the impact of wildfire combined or not with different soil stabilization treatments

    Science.gov (United States)

    Barreiro, Ana; Baath, Erland; Díaz-Raviña, Montserrat

    2015-04-01

    Soil stabilization techniques are rapidly gaining acceptance as efficient tool for reducing post-fire erosion. However, despite its interest, information concerning their impact on soil biota is scarce. We examined, under field conditions, the bacterial and fungal medium-term responses in a hillslope area located in Laza (NW Spain) affected by a high severity wildfire with the following treatments established by triplicate (4 x 20 m plots): unburnt control soil, burnt control soil, burnt soil with rye seeding and burnt soil with straw mulch. The bacterial and fungal growth, as well as respiration, were measured 4 years after fire and application of treatments using leucine incorporation for bacterial growth and acetate-in-ergosterol incorporation for fungal growth. The results showed that soil respiration and fungal biomass were negatively affected by fire, in the top layer (0-5 cm), while bacterial and fungal growth was stimulated. These microbial changes induced by fire were associated with modifications in organic matter (50% reduction in C content) and soil pH (increase of 0.5-0.9 units). Thus, the results suggested that under acid environment (pH in water 3.5) post-fire conditions might have favoured both microbial groups, which is supported by the fact that estimated bacterial and fungal growth were positive and significant correlated with soil pH (range of 3.5-4.5). This contrast with the well-known reported investigations showing that bacteria rather than fungi proliferation occurred after prescribed fire or wildfire; it should be noticed, however, that soils with a higher pH than that in the present study were used. Our data also indicated that bacterial and fungal communities were not significantly affected by seeding and mulching treatments. The results highlighted the importance of pre-fire soil pH as key factor in determining the microbial response after fire. Acknowledgements. A. Barreiro is recipient of FPU grant from Spanish Ministry of Education

  11. Spray washing, absorbent cornstarch powder, and dry time to reduce bacterial numbers on soiled transport cage flooring

    Science.gov (United States)

    Broiler transport cages are often used repeatedly without washing and fecal matter deposited on the floor surface can transfer Campylobacter from one flock to another. Allowing feces to dry is an effective but slow and logistically impractical means to kill Campylobacter in soiled transport cages. ...

  12. Bacterial community shift for monitoring the co-composting of oil palm empty fruit bunch and palm oil mill effluent anaerobic sludge.

    Science.gov (United States)

    Zainudin, Mohd Huzairi Mohd; Ramli, Norhayati; Hassan, Mohd Ali; Shirai, Yoshihito; Tashiro, Kosuke; Sakai, Kenji; Tashiro, Yukihiro

    2017-02-14

    A recently developed rapid co-composting of oil palm empty fruit bunch (OPEFB) and palm oil mill effluent (POME) anaerobic sludge is beginning to attract attention from the palm oil industry in managing the disposal of these wastes. However, a deeper understanding of microbial diversity is required for the sustainable practice of the co-compositing process. In this study, an in-depth assessment of bacterial community succession at different stages of the pilot scale co-composting of OPEFB-POME anaerobic sludge was performed using 454-pyrosequencing, which was then correlated with the changes of physicochemical properties including temperature, oxygen level and moisture content. Approximately 58,122 of 16S rRNA gene amplicons with more than 500 operational taxonomy units (OTUs) were obtained. Alpha diversity and principal component analysis (PCoA) indicated that bacterial diversity and distributions were most influenced by the physicochemical properties of the co-composting stages, which showed remarkable shifts of dominant species throughout the process. Species related to Devosia yakushimensis and Desemzia incerta are shown to emerge as dominant bacteria in the thermophilic stage, while Planococcus rifietoensis correlated best with the later stage of co-composting. This study proved the bacterial community shifts in the co-composting stages corresponded with the changes of the physicochemical properties, and may, therefore, be useful in monitoring the progress of co-composting and compost maturity.

  13. Two-colour fluorescence fluorimetric analysis for direct quantification of bacteria and its application in monitoring bacterial growth in cellulose degradation systems.

    Science.gov (United States)

    Duedu, Kwabena O; French, Christopher E

    2017-04-01

    Monitoring bacterial growth is an important technique required for many applications such as testing bacteria against compounds (e.g. drugs), evaluating bacterial composition in the environment (e.g. sewage and wastewater or food suspensions) and testing engineered bacteria for various functions (e.g. cellulose degradation). T?=1,^FigItem(1) ^ReloadFigure=Yesraditionally, rapid estimation of bacterial growth is performed using spectrophotometric measurement at 600nm (OD600) but this estimation does not differentiate live and dead cells or other debris. Colony counting enumerates live cells but the process is laborious and not suitable for large numbers of samples. Enumeration of live bacteria by flow cytometry is a more suitable rapid method with the use of dual staining with SYBR I Green nucleic acid gel stain and Propidium Iodide (SYBR-I/PI). Flow cytometry equipment and maintenance costs however are relatively high and this technique is unavailable in many laboratories that may require a rapid method for evaluating bacteria growth. We therefore sought to adapt and evaluate the SYBR-I/PI technique of enumerating live bacterial cells for a cheaper platform, a fluorimeter. The fluorimetry adapted SYBR-I/PI enumeration of bacteria in turbid growth media had direct correlations with OD600 (p>0.001). To enable comparison of fluorescence results across labs and instruments, a fluorescence intensity standard unit, the equivalent fluorescent DNA (EFD) was proposed, evaluated and found useful. The technique was further evaluated for its usefulness in enumerating bacteria in turbid media containing insoluble particles. Reproducible results were obtained which OD600 could not give. An alternative method based on the assessment of total protein using the Pierce Coomassie Plus (Bradford) Assay was also evaluated and compared. In all, the SYBR-I/PI method was found to be the quickest and most reliable. The protocol is potentially useful for high-throughput applications such as

  14. A microfluidic device for real-time monitoring of Bacillus subtilis bacterial spores during germination based on non-specific physicochemical interactions on the nanoscale level.

    Science.gov (United States)

    Zabrocka, L; Langer, K; Michalski, A; Kocik, J; Langer, J J

    2015-01-07

    A microfluidic device for studies on the germination of bacterial spores (e.g. Bacillus subtilis) based on non-specific interactions on the nanoscale is presented. A decrease in the population of spores during germination followed by the appearance of transition forms and an increase in the number of vegetative cells can be registered directly and simultaneously by using the microfluidic device, which is equipped with a conductive polymer layer (polyaniline) in the form of a nano-network. The lab-on-a-chip-type device, operating in a continuous flow regime, allows monitoring of germination of bacterial spores and analysis of the process in detail. The procedure is fast and accurate enough for quantitative real-time monitoring of the main steps of germination, including final transformation of the spores into vegetative cells. All of this is done without the use of biomarkers or any bio-specific materials, such as enzymes, antibodies and aptamers, and is simply based on an analysis of physicochemical interactions on the nanoscale level.

  15. The Staphylococcus aureus ABC-Type Manganese Transporter MntABC Is Critical for Reinitiation of Bacterial Replication Following Exposure to Phagocytic Oxidative Burst.

    Directory of Open Access Journals (Sweden)

    Alison Coady

    Full Text Available Manganese plays a central role in cellular detoxification of reactive oxygen species (ROS. Therefore, manganese acquisition is considered to be important for bacterial pathogenesis by counteracting the oxidative burst of phagocytic cells during host infection. However, detailed analysis of the interplay between bacterial manganese acquisition and phagocytic cells and its impact on bacterial pathogenesis has remained elusive for Staphylococcus aureus, a major human pathogen. Here, we show that a mntC mutant, which lacks the functional manganese transporter MntABC, was more sensitive to killing by human neutrophils but not murine macrophages, unless the mntC mutant was pre-exposed to oxidative stress. Notably, the mntC mutant formed strikingly small colonies when recovered from both type of phagocytic cells. We show that this phenotype is a direct consequence of the inability of the mntC mutant to reinitiate growth after exposure to phagocytic oxidative burst. Transcript and quantitative proteomics analyses revealed that the manganese-dependent ribonucleotide reductase complex NrdEF, which is essential for DNA synthesis and repair, was highly induced in the mntC mutant under oxidative stress conditions including after phagocytosis. Since NrdEF proteins are essential for S. aureus viability we hypothesize that cells lacking MntABC might attempt to compensate for the impaired function of NrdEF by increasing their expression. Our data suggest that besides ROS detoxification, functional manganese acquisition is likely crucial for S. aureus pathogenesis by repairing oxidative damages, thereby ensuring efficient bacterial growth after phagocytic oxidative burst, which is an attribute critical for disseminating and establishing infection in the host.

  16. The Staphylococcus aureus ABC-Type Manganese Transporter MntABC Is Critical for Reinitiation of Bacterial Replication Following Exposure to Phagocytic Oxidative Burst.

    Science.gov (United States)

    Coady, Alison; Xu, Min; Phung, Qui; Cheung, Tommy K; Bakalarski, Corey; Alexander, Mary Kate; Lehar, Sophie M; Kim, Janice; Park, Summer; Tan, Man-Wah; Nishiyama, Mireille

    2015-01-01

    Manganese plays a central role in cellular detoxification of reactive oxygen species (ROS). Therefore, manganese acquisition is considered to be important for bacterial pathogenesis by counteracting the oxidative burst of phagocytic cells during host infection. However, detailed analysis of the interplay between bacterial manganese acquisition and phagocytic cells and its impact on bacterial pathogenesis has remained elusive for Staphylococcus aureus, a major human pathogen. Here, we show that a mntC mutant, which lacks the functional manganese transporter MntABC, was more sensitive to killing by human neutrophils but not murine macrophages, unless the mntC mutant was pre-exposed to oxidative stress. Notably, the mntC mutant formed strikingly small colonies when recovered from both type of phagocytic cells. We show that this phenotype is a direct consequence of the inability of the mntC mutant to reinitiate growth after exposure to phagocytic oxidative burst. Transcript and quantitative proteomics analyses revealed that the manganese-dependent ribonucleotide reductase complex NrdEF, which is essential for DNA synthesis and repair, was highly induced in the mntC mutant under oxidative stress conditions including after phagocytosis. Since NrdEF proteins are essential for S. aureus viability we hypothesize that cells lacking MntABC might attempt to compensate for the impaired function of NrdEF by increasing their expression. Our data suggest that besides ROS detoxification, functional manganese acquisition is likely crucial for S. aureus pathogenesis by repairing oxidative damages, thereby ensuring efficient bacterial growth after phagocytic oxidative burst, which is an attribute critical for disseminating and establishing infection in the host.

  17. A Versatile Strategy for Production of Membrane Proteins with Diverse Topologies: Application to Investigation of Bacterial Homologues of Human Divalent Metal Ion and Nucleoside Transporters.

    Directory of Open Access Journals (Sweden)

    Cheng Ma

    Full Text Available Membrane proteins play key roles in many biological processes, from acquisition of nutrients to neurotransmission, and are targets for more than 50% of current therapeutic drugs. However, their investigation is hampered by difficulties in their production and purification on a scale suitable for structural studies. In particular, the nature and location of affinity tags introduced for the purification of recombinant membrane proteins can greatly influence their expression levels by affecting their membrane insertion. The extent of such effects typically depends on the transmembrane topologies of the proteins, which for proteins of unknown structure are usually uncertain. For example, attachment of oligohistidine tags to the periplasmic termini of membrane proteins often interferes with folding and drastically impairs expression in Escherichia coli. To circumvent this problem we have employed a novel strategy to enable the rapid production of constructs bearing a range of different affinity tags compatible with either cytoplasmic or periplasmic attachment. Tags include conventional oligohistidine tags compatible with cytoplasmic attachment and, for attachment to proteins with a periplasmic terminus, either tandem Strep-tag II sequences or oligohistidine tags fused to maltose binding protein and a signal sequence. Inclusion of cleavage sites for TEV or HRV-3C protease enables tag removal prior to crystallisation trials or a second step of purification. Together with the use of bioinformatic approaches to identify members of membrane protein families with topologies favourable to cytoplasmic tagging, this has enabled us to express and purify multiple bacterial membrane transporters. To illustrate this strategy, we describe here its use to purify bacterial homologues of human membrane proteins from the Nramp and ZIP families of divalent metal cation transporters and from the concentrative nucleoside transporter family. The proteins are expressed in

  18. Monitoring biochemical changes in bacterial spore during thermal and pressure-assisted thermal processing using FT-IR spectroscopy.

    Science.gov (United States)

    Subramanian, Anand; Ahn, Juhee; Balasubramaniam, V M; Rodriguez-Saona, Luis

    2007-10-31

    Pressure-assisted thermal processing (PATP) is being widely investigated for processing low acid foods. However, its microbial safety has not been well established and the mechanism of inactivation of pathogens and spores is not well understood. Fourier transform infrared (FT-IR) spectroscopy was used to study some of the biochemical changes in bacterial spores occurring during PATP and thermal processing (TP). Spore suspensions (approximately 10(9) CFU/mL of water) of Clostridium tyrobutyricum, Bacillus sphaericus, and three strains of Bacillus amyloliquefaciens were treated by PATP (121 degrees C and 700 MPa) for 0, 10, 20, and 30 s and TP (121 degrees C) for 0, 10, 20, and 30 s. Treated and untreated spore suspensions were analyzed using FT-IR in the mid-infrared region (4000-800 cm(-1)). Multivariate classification models based on soft independent modeling of class analogy (SIMCA) were developed using second derivative-transformed spectra. The spores could be differentiated up to the strain level due to differences in their biochemical composition, especially dipicolinic acid (DPA) and secondary structure of proteins. During PATP changes in alpha-helix and beta-sheets of secondary protein were evident in the spectral regions 1655 and 1626 cm(-1), respectively. Infrared absorption bands from DPA (1281, 1378, 1440, and 1568 cm(-1)) decreased significantly during the initial stages of PATP, indicating release of DPA. During TP changes were evident in the bands associated with secondary proteins. DPA bands showed little or no change during TP. A correlation was found between the spore's Ca-DPA content and its resistance to PATP. FT-IR spectroscopy could classify different strains of bacterial spores and determine some of the changes occurring during spore inactivation by PATP and TP. Furthermore, this technique shows great promise for rapid screening PATP-resistant bacterial spores.

  19. Modelling and monitoring of the transport of dissolved substances in tidal water. Modellierung und Ueberwachung des Transportes geloester Stoffe in Tidegewaessern

    Energy Technology Data Exchange (ETDEWEB)

    Kappenberg, J.

    1987-12-18

    It was tried with simple model attempts to simulate the mechanisms of pollutant transportation in tide rivers (Elbe) and to control the water quality by means of monitoring systems. In particular, there were developed explicit models for the hydrodynamics in a channel-like river section in explicit (EXKA and ERKA) and implicit (IMKA) forms. The refined model MKMO was developed, in which the river is simulated by a number of parallel channels, as well as the model HAFEN, representing a network of channels and arms of rivers as it is typical for the Hamburg harbour. The physical transport was simulated partially in fixed (Euler-)coordinates (model EUTR) partially in a grid, which was transported by the current (Lagrangian coordinates, model LATR). The biochemical oxygen degradation was first simulated by combining all oxygen consumers in the BOD (biological oxygen demand) with a simple nonlinear Streeter-Phelps model. Then, a more accurate model was made of the oxygen depletion by organic nitrogen oxidation (nitrification), which is of special importance in the Elbe.

  20. Monitoring urban transport air pollution and energy demand in Rawalpindi and Islamabad using leap model

    Energy Technology Data Exchange (ETDEWEB)

    Shabbir, Rabia; Ahmad, Sheikh Saeed [Department of Environmental Sciences, Fatima Jinnah Women University, Rawalpindi (Pakistan)

    2010-05-15

    A research associated with urban transportation was carried out in Rawalpindi and Islamabad to analyze the status of emission of air pollutants and energy demands. The study included a discussion of past trends and future scenarios in order to reduce the future emissions. A simple model of passenger transport has been developed using computer based software called Long-Range Energy Alternatives Planning System (LEAP). The LEAP model was used to estimate total energy demand and the vehicular emissions for the base year 2000 and extrapolated till 2030 for the future predictions. Transport database in Rawalpindi and Islamabad, together with fuel consumption values for the vehicle types and emission factors of NO{sub x}, SO{sub 2} and PM{sub 10} corresponding to the actual vehicle types, formed the basis of the transport demand, energy consumption and total emission calculations. Apart from base scenario, the model was run under three alternative scenarios to study the impact of different urban transport policy initiatives that would reduce energy demand and emissions in transport sector of Rawalpindi and Islamabad. The prime objective was to arrive at an optimal transport policy, which limits the future growth of fuel consumption as well as air pollution. (author)

  1. Spray washing, absorbent corn starch powder and dry time to reduce bacterial numbers on soiled boiler transport cage flooring

    Science.gov (United States)

    Most broilers in the U.S. are transported live to slaughter facilities in cages with fiberglass floors. Cages are often used repeatedly without washing and fecal matter deposited on the floor surface can transfer Campylobacter from one flock to another. Drying feces out between uses is an effectiv...

  2. Photoacoustic monitoring of water transport process in calcareous stone coated with biopolymers

    Science.gov (United States)

    May-Crespo, J.; Ortega-Morales, B. O.; Camacho-Chab, J. C.; Quintana, P.; Alvarado-Gil, J. J.; Gonzalez-García, G.; Reyes-Estebanez, M.; Chan-Bacab, M. J.

    2016-12-01

    Moisture is a critical control of chemical and physical processes leading to stone deterioration. These processes can be enhanced by microbial biofilms and associated exopolymers (EPS). There is limited current understanding of the water transport process across rocks covered by EPS. In the present work, we employed the photoacoustic technique to study the influence of three biopolymers (xanthan, microbactan and arabic gum) in the water transport process of two types of limestone rock of similar mineralogy but contrasting porosity. Both controls of RL (low porosity) and RP (high porosity) presented the higher values of water diffusion coefficient ( D) than biopolymer-coated samples, indicating that biopolymer layers slowed down the transport of water. This trend was steeper for RP samples as water was transported seven times faster than in the more porous rock. Important differences of D values were observed among samples coated by different biopolymers. Scanning electron microscopy and optical microscopy showed that surface topography was different between both types of rocks; adherence of coatings was seen predominantly in the less porous rocks samples. FTIR and NMR analysis showed the presence of pyruvate and acetate in microbactan and xanthan gum, suggesting their participation on adherence to the calcareous surfaces, sealing surface pores. These results indicate that water transport at rock interfaces is dependent on the chemistry of biopolymer and surface porosity. The implications for reduced water transport in stone conservation under the influence of biopolymers include both enhanced and lower deterioration rates along with altered efficiency of biocide treatment of epilithic biofilms.

  3. Analysis for the presence of determinants involved in the transport of mercury across bacterial membrane from polluted water bodies of India

    Directory of Open Access Journals (Sweden)

    Arif Tasleem Jan

    2016-03-01

    Full Text Available Abstract Mercury, which is ubiquitous and recalcitrant to biodegradation processes, threatens human health by escaping to the environment via various natural and anthropogenic activities. Non-biodegradability of mercury pollutants has necessitated the development and implementation of economic alternatives with promising potential to remove metals from the environment. Enhancement of microbial based remediation strategies through genetic engineering approaches provides one such alternative with a promising future. In this study, bacterial isolates inhabiting polluted sites were screened for tolerance to varying concentrations of mercuric chloride. Following identification, several Pseudomonas and Klebsiella species were found to exhibit the highest tolerance to both organic and inorganic mercury. Screened bacterial isolates were examined for their genetic make-up in terms of the presence of genes (merP and merT involved in the transport of mercury across the membrane either alone or in combination to deal with the toxic mercury. Gene sequence analysis revealed that the merP gene showed 86–99% homology, while the merT gene showed >98% homology with previously reported sequences. By exploring the genes involved in imparting metal resistance to bacteria, this study will serve to highlight the credentials that are particularly advantageous for their practical application to remediation of mercury from the environment.

  4. Assessing quality of Medicago sativa silage by monitoring bacterial composition with single molecule, real-time sequencing technology and various physiological parameters

    Science.gov (United States)

    Bao, Weichen; Mi, Zhihui; Xu, Haiyan; Zheng, Yi; Kwok, Lai Yu; Zhang, Heping; Zhang, Wenyi

    2016-01-01

    The present study applied the PacBio single molecule, real-time sequencing technology (SMRT) in evaluating the quality of silage production. Specifically, we produced four types of Medicago sativa silages by using four different lactic acid bacteria-based additives (AD-I, AD-II, AD-III and AD-IV). We monitored the changes in pH, organic acids (including butyric acid, the ratio of acetic acid/lactic acid, γ-aminobutyric acid, 4-hyroxy benzoic acid and phenyl lactic acid), mycotoxins, and bacterial microbiota during silage fermentation. Our results showed that the use of the additives was beneficial to the silage fermentation by enhancing a general pH and mycotoxin reduction, while increasing the organic acids content. By SMRT analysis of the microbial composition in eight silage samples, we found that the bacterial species number and relative abundances shifted apparently after fermentation. Such changes were specific to the LAB species in the additives. Particularly, Bacillus megaterium was the initial dominant species in the raw materials; and after the fermentation process, Pediococcus acidilactici and Lactobacillus plantarum became the most prevalent species, both of which were intrinsically present in the LAB additives. Our data have demonstrated that the SMRT sequencing platform is applicable in assessing the quality of silage. PMID:27340760

  5. Assessing quality of Medicago sativa silage by monitoring bacterial composition with single molecule, real-time sequencing technology and various physiological parameters.

    Science.gov (United States)

    Bao, Weichen; Mi, Zhihui; Xu, Haiyan; Zheng, Yi; Kwok, Lai Yu; Zhang, Heping; Zhang, Wenyi

    2016-06-24

    The present study applied the PacBio single molecule, real-time sequencing technology (SMRT) in evaluating the quality of silage production. Specifically, we produced four types of Medicago sativa silages by using four different lactic acid bacteria-based additives (AD-I, AD-II, AD-III and AD-IV). We monitored the changes in pH, organic acids (including butyric acid, the ratio of acetic acid/lactic acid, γ-aminobutyric acid, 4-hyroxy benzoic acid and phenyl lactic acid), mycotoxins, and bacterial microbiota during silage fermentation. Our results showed that the use of the additives was beneficial to the silage fermentation by enhancing a general pH and mycotoxin reduction, while increasing the organic acids content. By SMRT analysis of the microbial composition in eight silage samples, we found that the bacterial species number and relative abundances shifted apparently after fermentation. Such changes were specific to the LAB species in the additives. Particularly, Bacillus megaterium was the initial dominant species in the raw materials; and after the fermentation process, Pediococcus acidilactici and Lactobacillus plantarum became the most prevalent species, both of which were intrinsically present in the LAB additives. Our data have demonstrated that the SMRT sequencing platform is applicable in assessing the quality of silage.

  6. Zero-tension lysimeters: An improved design to monitor colloid-facilitated contaminant transport in the vadose zone

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, M.L.; Scharf, R.L.; Shang, C.

    1995-04-24

    There is increasing evidence that mobile colloids facilitate the long-distance transport of contaminants. The mobility of fine particles and macromolecules has been linked to the movement of actinides, organic contaminants, and heavy metals through soil. Direct evidence for colloid mobility includes the presence of humic materials in deep aquifers as well as coatings of accumulated clay, organic matter, or sesquioxides on particle or aggregate surfaces in subsoil horizons of many soils. The potential for colloid-facilitated transport of contaminants from hazardous-waste sites requires adequate monitoring before, during, and after in-situ remediation treatments. Zero-tension lysimeters (ZTLs) are especially appropriate for sampling water as it moves through saturated soil, although some unsaturated flow events may be sampled as well. Because no ceramic barrier or fiberglass wick is involved to maintain tension on the water (as is the case with other lysimeters), particles suspended in the water as well as dissolved species may be sampled with ZTLs. In this report, a ZTL design is proposed that is more suitable for monitoring colloid-facilitated contaminant migration. The improved design consists of a cylinder made of polycarbonate or polytetrafluoroethylene (PTFE) that is placed below undisturbed soil material. In many soils, a hydraulically powered tube may be used to extract an undisturbed core of soil before placement of the lysimeter. In those cases, the design has significant advantages over conventional designs with respect to simplicity and speed of installation. Therefore, it will allow colloid-facilitated transport of contaminants to be monitored at more locations at a given site.

  7. Functional characterization of SbmA, a bacterial inner membrane transporter required for importing the antimicrobial peptide Bac7(1-35).

    Science.gov (United States)

    Runti, Giulia; Lopez Ruiz, Maria del Carmen; Stoilova, Tatiana; Hussain, Rohanah; Jennions, Matthew; Choudhury, Hassanul G; Benincasa, Monica; Gennaro, Renato; Beis, Konstantinos; Scocchi, Marco

    2013-12-01

    SbmA is an inner membrane protein of Gram-negative bacteria that is involved in the internalization of glycopeptides and prokaryotic and eukaryotic antimicrobial peptides, as well as of peptide nucleic acid (PNA) oligomers. The SbmA homolog BacA is required for the development of Sinorhizobium meliloti bacteroids within plant cells and favors chronic infections with Brucella abortus and Mycobacterium tuberculosis in mice. Here, we investigated functional features of SbmA/BacA using the proline-rich antimicrobial peptide Bac7(1-35) as a substrate. Circular dichroism and affinity chromatography studies were used to investigate the ability of SbmA to bind the peptide, and a whole-cell transport assay with fluorescently labeled peptide allowed the determination of transport kinetic parameters with a calculated Km value of 6.95 ± 0.89 μM peptide and a Vmax of 53.91 ± 3.17 nmol/min/mg SbmA. Use of a bacterial two-hybrid system coupled to SEC-MALLS (size exclusion chromatography coupled with multiangle laser light scattering) analyses established that SbmA is a homodimer in the membrane, and treatment of the cells with arsenate or ionophores indicated that the peptide transport mediated by SbmA is driven by the electrochemical gradient. Overall, these results shed light on the SbmA-mediated internalization of peptide substrates and suggest that the transport of an unknown substrate(s) represents the function of this protein.

  8. Monitoring near-shore shingle transport under waves using a passive acoustic technique.

    Science.gov (United States)

    Mason, T; Priestley, D; Reeve, D E

    2007-08-01

    Passive acoustic techniques have been used to measure shingle (gravel) sediment transport in very shallow water, near the wave breaking zone on a beach. The experiments were conducted at 1:1 scale in the Large Wave Flume, Grosse Wellen Kanal (GWK) at Hannover, Germany. The frequency spectrum induced by shingle mobilized under breaking waves can be distinguished from other ambient noise, and is found to be independent of water depth and wave conditions. The inverse relationship between centroid frequency and representative grain size is shown to remain valid in shallow water wave conditions. Individual phases of onshore and offshore transport can be identified. Analysis of the acoustic frequency spectrum provides insight into the mechanics of phase-resolved shingle transport.

  9. Assessing Watershed Transport of Atrazine and Nitrate to Evaluate Conservation Practice Effects and Advise Future Monitoring Strategies

    Science.gov (United States)

    O'Donnell, T. Kevin

    2012-01-01

    Continued public support for U.S. taxpayer funded programs aimed at reducing agricultural pollutants depends on clear demonstrations of water quality improvements. The objective of this research was to determine if implementation of agricultural best management practices (BMPs) in the Goodwater Creek Experimental Watershed (GCEW) resulted in changes to atrazine and nitrate (NO3-N) loads during storm events. An additional objective was to estimate future monitoring periods necessary to detect a 5, 10, 20, and 25% reduction in atrazine and NO3-N event load. The GCEW is a 73 km2 watershed located in northcentral Missouri, USA. Linear regressions and Akaike Information Criteria were used to determine if reductions in atrazine and NO3-N event loads occurred as BMPs were implemented. No effects due to any BMP type were indicated for the period of record. Further investigation of event sampling from the long-term GCEW monitoring program indicated errors in atrazine load calculations may be possible due to pre-existing minimum threshold levels used to trigger autosampling and sample compositing. Variation of event loads was better explained by linear regressions for NO3-N than for atrazine. Decommissioning of upstream monitoring stations during the study period represented a missed opportunity to further explain variation of event loads at the watershed outlet. Atrazine requires approximately twice the monitoring period relative to NO3-N to detect future reductions in event load. Appropriate matching of pollutant transport mechanisms with autosampling protocols remains a critical information need when setting up or adapting watershed monitoring networks aimed at detecting watershed-scale BMP effects.

  10. Multiple-reaction monitoring for multiplex detection of three bacterial toxins using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Alam, S I; Uppal, A; Gupta, P; Kamboj, D V

    2017-03-01

    Clostridium perfringens epsilon toxin, staphylococcal enterotoxin B and shiga toxin are implicated in a number of diseases and food-borne intoxications and are considered potential agents for bioterrorism and warfare. Artificially generated aerosol is the likely mode of delivery of these for nefarious uses, potentially capable of causing mass destruction to human and animal health by inhalation of toxic bioaerosol. Multiplex and unambiguous detection of these agents is of paramount importance for emergency response in a biothreat scenario and for food safety. Multiple-reaction monitoring (MRM) assay for simultaneous monitoring of the three toxins is reported here using reverse-phase high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry. Three different peptides with two fragment ions each were considered for quantification and confirmation. One of the three MRM transitions from each toxin, which exhibited the best sensitivity, was selected for multiplexing of the assay. Simulating a biothreat scenario wherein the bioaerosol is collected in 10 ml of buffer, the multiplex assay was tested with blind samples with one or more of the three toxins even in the presence of interfering Escherichia coli lysate proteins. © 2016 The Society for Applied Microbiology.

  11. Assessing the thermal dissipation sap flux density method for monitoring cold season water transport in seasonally snow-covered forests.

    Science.gov (United States)

    Chan, Allison M; Bowling, David R; Phillips, Nathan

    2017-07-01

    Productivity of conifers in seasonally snow-covered forests is high before and during snowmelt when environmental conditions are optimal for photosynthesis. Climate change is altering the timing of spring in many locations, and changes in the date of transition from winter dormancy can have large impacts on annual productivity. Sap flow methods provide a promising approach to monitor tree activity during the cold season and the winter-spring and fall-winter transitions. Although sap flow techniques have been widely used, cold season results are generally not reported. Here we examine the feasibility of using the Granier thermal dissipation (TD) sap flux density method to monitor transpiration and dormancy of evergreen conifers during the cold season. We conducted a laboratory experiment which demonstrated that the TD method reliably detects xylem water transport (when it occurs) both at near freezing temperature and at low flow rate, and that the sensors can withstand repeated freeze-thaw events. However, the dependence between sensor output and water transport rate in these experiments differed from the established TD relation. In field experiments, sensors installed in two Abies forests lasted through two winters and a summer with low failure. The baseline (no-flow) sensor output varied considerably with temperature during the cold season, and a new baseline algorithm was developed to accommodate this variation. The Abies forests differed in elevation (2070 and 2620 m), and there was a clear difference in timing of initiation and cessation of transpiration between them. We conclude that the TD method can be reliably used to examine water transport during cold periods with associated low flow conditions. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Real-time monitoring of mass-transport-related enzymatic reaction kinetics in a nanochannel-array reactor.

    Science.gov (United States)

    Li, Su-Juan; Wang, Chen; Wu, Zeng-Qiang; Xu, Jing-Juan; Xia, Xing-Hua; Chen, Hong-Yuan

    2010-09-01

    To understand the fundamentals of enzymatic reactions confined in micro-/nanosystems, the construction of a small enzyme reactor coupled with an integrated real-time detection system for monitoring the kinetic information is a significant challenge. Nano-enzyme array reactors were fabricated by covalently linking enzymes to the inner channels of a porous anodic alumina (PAA) membrane. The mechanical stability of this nanodevice enables us to integrate an electrochemical detector for the real-time monitoring of the formation of the enzyme reaction product by sputtering a thin Pt film on one side of the PAA membrane. Because the enzymatic reaction is confined in a limited nanospace, the mass transport of the substrate would influence the reaction kinetics considerably. Therefore, the oxidation of glucose by dissolved oxygen catalyzed by immobilized glucose oxidase was used as a model to investigate the mass-transport-related enzymatic reaction kinetics in confined nanospaces. The activity and stability of the enzyme immobilized in the nanochannels was enhanced. In this nano-enzyme reactor, the enzymatic reaction was controlled by mass transport if the flux was low. With an increase in the flux (e.g., >50 microL min(-1)), the enzymatic reaction kinetics became the rate-determining step. This change resulted in the decrease in the conversion efficiency of the nano-enzyme reactor and the apparent Michaelis-Menten constant with an increase in substrate flux. This nanodevice integrated with an electrochemical detector could help to understand the fundamentals of enzymatic reactions confined in nanospaces and provide a platform for the design of highly efficient enzyme reactors. In addition, we believe that such nanodevices will find widespread applications in biosensing, drug screening, and biochemical synthesis.

  13. Impacts on particles and ozone by transport processes recorded at urban and high-altitude monitoring stations.

    Science.gov (United States)

    Nicolás, J F; Crespo, J; Yubero, E; Soler, R; Carratalá, A; Mantilla, E

    2014-01-01

    In order to evaluate the influence of particle transport episodes on particle number concentration temporal trends at both urban and high-altitude (Aitana peak-1558 m a.s.l.) stations, a simultaneous sampling campaign from October 2011 to September 2012 was performed. The monitoring stations are located in southeastern Spain, close to the Mediterranean coast. The annual average value of particle concentration obtained in the larger accumulation mode (size range 0.25-1 μm) at the mountain site, 55.0 ± 3.0 cm(-3), was practically half that of the value obtained at the urban station (112.0 ± 4.0 cm(-3)). The largest difference between both stations was recorded during December 2011 and January 2012, when particles at the mountain station registered the lowest values. It was observed that during urban stagnant episodes, particle transport from urban sites to the mountain station could take place under specific atmospheric conditions. During these transports, the major particle transfer is produced in the 0.5-2 μm size range. The minimum difference between stations was recorded in summer, particularly in July 2012, which is most likely due to several particle transport events that affected only the mountain station. The particle concentration in the coarse mode was very similar at both monitoring sites, with the biggest difference being recorded during the summer months, 0.4 ± 0.1cm(-3) at the urban site and 0.9 ± 0.1cm(-3) at the Aitana peak in August 2012. Saharan dust outbreaks were the main factor responsible for these values during summer time. The regional station was affected more by these outbreaks, recording values of >4.0 cm(-3), than the urban site. This long-range particle transport from the Sahara desert also had an effect upon O3 levels measured at the mountain station. During periods affected by Saharan dust outbreaks, ozone levels underwent a significant decrease (3-17%) with respect to its mean value.

  14. Impacts on particles and ozone by transport processes recorded at urban and high-altitude monitoring stations

    Energy Technology Data Exchange (ETDEWEB)

    Nicolás, J.F., E-mail: j.nicolas@umh.es [Laboratory of Atmospheric Pollution (LCA), Miguel Hernández University, Av. de la Universidad s/n, Edif. Alcudia, 03202 Elche (Spain); Crespo, J.; Yubero, E.; Soler, R. [Laboratory of Atmospheric Pollution (LCA), Miguel Hernández University, Av. de la Universidad s/n, Edif. Alcudia, 03202 Elche (Spain); Carratalá, A. [Department of Chemical Engineering, University of Alicante, P.O. Box 99, 03080 Alicante (Spain); Mantilla, E. [Instituto Universitario CEAM-UMH, Parque Tecnológico, C/Charles R. Darwin 14, E-46980 Paterna (Spain)

    2014-01-01

    In order to evaluate the influence of particle transport episodes on particle number concentration temporal trends at both urban and high-altitude (Aitana peak-1558 m a.s.l.) stations, a simultaneous sampling campaign from October 2011 to September 2012 was performed. The monitoring stations are located in southeastern Spain, close to the Mediterranean coast. The annual average value of particle concentration obtained in the larger accumulation mode (size range 0.25–1 μm) at the mountain site, 55.0 ± 3.0 cm{sup − 3}, was practically half that of the value obtained at the urban station (112.0 ± 4.0 cm{sup − 3}). The largest difference between both stations was recorded during December 2011 and January 2012, when particles at the mountain station registered the lowest values. It was observed that during urban stagnant episodes, particle transport from urban sites to the mountain station could take place under specific atmospheric conditions. During these transports, the major particle transfer is produced in the 0.5–2 μm size range. The minimum difference between stations was recorded in summer, particularly in July 2012, which is most likely due to several particle transport events that affected only the mountain station. The particle concentration in the coarse mode was very similar at both monitoring sites, with the biggest difference being recorded during the summer months, 0.4 ± 0.1 cm{sup − 3} at the urban site and 0.9 ± 0.1 cm{sup − 3} at the Aitana peak in August 2012. Saharan dust outbreaks were the main factor responsible for these values during summer time. The regional station was affected more by these outbreaks, recording values of > 4.0 cm{sup − 3}, than the urban site. This long-range particle transport from the Sahara desert also had an effect upon O{sub 3} levels measured at the mountain station. During periods affected by Saharan dust outbreaks, ozone levels underwent a significant decrease (3–17%) with respect to its mean

  15. Joint monitoring of hydrosedimentological events and transport of caesium 137 in a small basin

    Energy Technology Data Exchange (ETDEWEB)

    Preti, F.; Lubello, C.; Becchi, I. (Florence Univ. (Italy). Dept. of Civil Engineering)

    1993-01-01

    Research was carried out to analyse the transport of Caesium 137 in a small calcareous watershed (3.6 Km[sup 2]) of the Tuscan Appennines (Central Italy). The presence of the radionuclide 137 Cs, adsorbed by the soil, is due to the nuclear tests in the 1960s-70s and to the Chernobyl disaster in 1986. For representation of the transport dynamics of 137 Cs a distributed parameters model has been developed, in order to consider the variability of the physical characteristics of the area. The results of the simulation, compared with the concentrations of Caesium measured by a devised experimental method in the lake-sediments of a hill catchment placed in the closing section of the basin, showed an excellent agreement. (author).

  16. Estimation of Recharge from Long-Term Monitoring of Saline Tracer Transport Using Electrical Resistivity Tomography

    DEFF Research Database (Denmark)

    Haarder, Eline Bojsen; Jensen, Karsten Høgh; Binley, Andrew;

    2015-01-01

    The movement of a saline tracer added to the soil surface was monitored in the unsaturated zone using cross-borehole electrical resistivity tomography (ERT) and subjected to natural rainfall conditions. The ERT data were inverted and corrected for subsurface temperature changes, and spatial moment...... methods. In September 2011, a saline tracer was added across a 142-m2 area at the surface at an application rate mimicking natural infiltration. The movement of the saline tracer front was monitored using cross-borehole electrical resistivity tomography (ERT); data were collected on a daily to weekly...... basis and continued for 1 yr after tracer application. The ERT data were inverted and corrected for temperature changes in the subsurface, and spatial moment analysis was used to calculate the tracer mass, position of the center of mass, and thereby the downwardly recharging flux. The recovered mass...

  17. A cost-effective and field-ready potentiostat that poises subsurface electrodes to monitor bacterial respiration.

    Science.gov (United States)

    Friedman, Elliot S; Rosenbaum, Miriam A; Lee, Alexander W; Lipson, David A; Land, Bruce R; Angenent, Largus T

    2012-02-15

    Here, we present the proof-of-concept for a subsurface bioelectrochemical system (BES)-based biosensor capable of monitoring microbial respiration that occurs through exocellular electron transfer. This system includes our open-source design of a three-channel microcontroller-unit (MCU)-based potentiostat that is capable of chronoamperometry, which laboratory tests showed to be accurate within 0.95 ± 0.58% (95% Confidence Limit) of a commercial potentiostat. The potentiostat design is freely available online: http://angenent.bee.cornell.edu/potentiostat.html. This robust and field-ready potentiostat, which can withstand temperatures of -30°C, can be manufactured at relatively low cost ($600), thus, allowing for en-masse deployment at field sites. The MCU-based potentiostat was integrated with electrodes and a solar panel-based power system, and deployed as a biosensor to monitor microbial respiration in drained thaw lake basins outside Barrow, AK. At three different depths, the working electrode of a microbial three-electrode system (M3C) was maintained at potentials corresponding to the microbial reduction of iron(III) compounds and humic acids. Thereby, the working electrode mimics these compounds and is used by certain microbes as an electron acceptor. The sensors revealed daily cycles in microbial respiration. In the medium- and deep-depth electrodes the onset of these cycles followed a considerable increase in overall activity that corresponded to those soils reaching temperatures conducive to microbial activity as the summer thaw progressed. The BES biosensor is a valuable tool for studying microbial activity in situ in remote environments, and the cost-efficient design of the potentiostat allows for wide-scale use in remote areas. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Monitoring and tracking the trans-Pacific transport of aerosols using multi-satellite aerosol optical depth composites

    Science.gov (United States)

    Naeger, Aaron R.; Gupta, Pawan; Zavodsky, Bradley T.; McGrath, Kevin M.

    2016-06-01

    The primary goal of this study was to generate a near-real time (NRT) aerosol optical depth (AOD) product capable of providing a comprehensive understanding of the aerosol spatial distribution over the Pacific Ocean, in order to better monitor and track the trans-Pacific transport of aerosols. Therefore, we developed a NRT product that takes advantage of observations from both low-earth orbiting and geostationary satellites. In particular, we utilize AOD products from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Suomi National Polar-orbiting Partnership (NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) satellites. Then, we combine these AOD products with our own retrieval algorithms developed for the NOAA Geostationary Operational Environmental Satellite (GOES-15) and Japan Meteorological Agency (JMA) Multi-functional Transport Satellite (MTSAT-2) to generate a NRT daily AOD composite product. We present examples of the daily AOD composite product for a case study of trans-Pacific transport of Asian pollution and dust aerosols in mid-March 2014. Overall, the new product successfully tracks this aerosol plume during its trans-Pacific transport to the west coast of North America as the frequent geostationary observations lead to a greater coverage of cloud-free AOD retrievals equatorward of about 35° N, while the polar-orbiting satellites provide a greater coverage of AOD poleward of 35° N. However, we note several areas across the domain of interest from Asia to North America where the GOES-15 and MTSAT-2 retrieval algorithms can introduce significant uncertainties into the new product.

  19. Monitoring and tracking the trans-Pacific transport of aerosols using multi-satellite aerosol optical depth retrievals

    Directory of Open Access Journals (Sweden)

    A. R. Naeger

    2015-10-01

    Full Text Available The primary goal of this study was to generate a near-real time (NRT aerosol optical depth (AOD product capable of providing a comprehensive understanding of the aerosol spatial distribution over the Pacific Ocean in order to better monitor and track the trans-Pacific transport of aerosols. Therefore, we developed a NRT product that takes advantage of observations from both low-earth orbiting and geostationary satellites. In particular, we utilize AOD products from the Moderate Resolution Imaging Spectroradiometer (MODIS and Suomi National Polar-orbiting Partnership (NPP Visible Infrared Imaging Radiometer Suite (VIIRS satellites. Then, we combine these AOD products with our own retrieval algorithms developed for the NOAA Geostationary Operational Environmental Satellite (GOES-15 and Japan Meteorological Agency (JMA Multi-functional Transport Satellite (MTSAT-2 to generate a NRT daily AOD composite product. We present examples of the daily AOD composite product for a case study of trans-Pacific transport of Asian pollution and dust aerosols in mid-March 2014. Overall, the new product successfully tracks this aerosol plume during its trans-Pacific transport to the west coast of North America. However, we identify several areas across the domain of interest from Asia to North America where the new product can encounter significant uncertainties due to the inclusion of the geostationary AOD retrievals. The uncertainties associated with geostationary AOD retrievals are expected to be minimized after the successful launch of the next-generation advanced NOAA GOES-R and recently launched JMA Himawari satellites. Observations from these advanced satellites will ultimately provide an enhanced understanding of the spatial and temporal distribution of aerosols over the Pacific.

  20. Monitoring the bacterial population dynamics in sourdough fermentation processes by using PCR-denaturing gradient gel electrophoresis.

    Science.gov (United States)

    Meroth, Christiane B; Walter, Jens; Hertel, Christian; Brandt, Markus J; Hammes, Walter P

    2003-01-01

    Four sourdoughs (A to D) were produced under practical conditions by using a starter mixture of three commercially available sourdough starters and a baker's yeast constitutively containing various species of lactic acid bacteria (LAB). The sourdoughs were continuously propagated until the composition of the LAB flora remained stable. Two LAB-specific PCR-denaturing gradient gel electrophoresis (DGGE) systems were established and used to monitor the development of the microflora. Depending on the prevailing ecological conditions in the different sourdough fermentations, only a few Lactobacillus species were found to be competitive and became dominant. In sourdough A (traditional process with rye flour), Lactobacillus sanfranciscensis and a new species, L. mindensis, were detected. In rye flour sourdoughs B and C, which differed in the process temperature, exclusively L. crispatus and L. pontis became the predominant species in sourdough B and L. crispatus, L. panis, and L. frumenti became the predominant species in sourdough C. On the other hand, in sourdough D (corresponding to sourdough C but produced with rye bran), L. johnsonii and L. reuteri were found. The results of PCR-DGGE were consistent with those obtained by culturing, except for sourdough B, in which L. fermentum was also detected. Isolates of the species L. sanfranciscensis and L. fermentum were shown by randomly amplified polymorphic DNA-PCR analysis to originate from the commercial starters and the baker's yeast, respectively.

  1. Review of Bioassays for Monitoring Fate and Transport ofEstrogenic Endocrine Disrupting Compounds in Water

    Energy Technology Data Exchange (ETDEWEB)

    CGCampbell@lbl.gov

    2004-01-30

    Endocrine disrupting compounds (EDCs) are recognizedcontaminants threatening water quality. Despite efforts in sourceidentification, few strategies exist for characterization or treatment ofthis environmental pollution. Given that there are numerous EDCs that cannegatively affect humans and wildlife, general screening techniques likebioassays and biosensors provide an essential rapid and intensiveanalysis capacity. Commonly applied bioassays include the ELISA and YESassays, but promising technologies include ER-CALUXa, ELRA, Endotecta,RIANA, and IR-bioamplification. Two biosensors, Endotecta and RIANA, arefield portable using non-cellular biological detection strategies.Environmental management of EDCs in water requires integration ofbiosensors and bioassays for monitoring and assessment.

  2. RESIDUAL GAS IONIZATION BEAM PROFILE MONITOR ON 40MeV H— BEAM TRANSPORT LINE

    Institute of Scientific and Technical Information of China (English)

    徐伟鹏; E.Takasaki

    1995-01-01

    The monitor is composed of a pair of electrodes,a single stage of microchannel plate,a phosphor screen,a CCD camera and a PC computer,To obtain a good uniform collecting field,forming electrodes system is used instead of that with a resistive divider,The readout system is performed by the phosphor screen and the CCD camera because the spatial resolution is not limited by the mechanical structure like the anode strip type and such video display system is very useful for beam studies and operation of the 40MeV linac,Besides,the design and test results are described in detail.

  3. Can riverside seismic monitoring constrain temporal and spatial variations in bedload transport during a controlled flood of the Trinity River?

    Science.gov (United States)

    Glasgow, M. E.; Schmandt, B.; Gaeuman, D.

    2015-12-01

    To evaluate the utility of riverside seismic monitoring for constraining temporal and spatial variations in coarse bedload transport in gravel-bed rivers we collected seismic data during a dam-controlled flood of the Trinity River in northern California in May 2015. This field area was chosen because the Trinity River Restoration Project conducts extensive monitoring of water and sediment transport, and riverbed morphology to guide management of the river with the goal of improving salmon habitat. Four three component broadband seismometers were collocated with water discharge and bedload physical sampling sites along a ~30 km reach of the Trinity River downstream of the Lewiston Dam. Arrays with 10-80 cable-free vertical component geophones were also deployed at each of the four sites in order to constrain spatial variability and amplitude decay of seismic signals emanating from the river. Nominal inter-station spacing within the geophone arrays was ~30 m. The largest geophone array consisted of 83 nodes along a 700 m reach of the Trinity River with a gravel augmentation site at its upstream end. Initial analyses of the seismic data show that ground velocity power from averaged from ~7 - 90 Hz is correlated with discharge at all sites. The array at the gravel injection site shows greater high frequency (>30 Hz) power at the upstream end where gravel was injected during the release compared to ~300 m downstream, consistent with bedload transport providing a significant source of seismic energy in addition to water discharge. Declining seismic power during a ~3 day plateau at peak discharge when physical sampler data shows decreasing bedload flux provides a further indication that the seismic data are sensitive to bedload transport. We will use the array data to back-project the seismic signals in multiple frequency bands into the channel to create maps of the time-varying spatial intensity of seismic energy production. We hypothesize that the greatest seismic

  4. Conceptual design and development of GEM based detecting system for tomographic tungsten focused transport monitoring

    Science.gov (United States)

    Chernyshova, M.; Czarski, T.; Malinowski, K.; Kowalska-Strzęciwilk, E.; Poźniak, K.; Kasprowicz, G.; Zabołotny, W.; Wojeński, A.; Kolasiński, P.; Mazon, D.; Malard, P.

    2015-10-01

    Implementing tungsten as a plasma facing material in ITER and future fusion reactors will require effective monitoring of not just its level in the plasma but also its distribution. That can be successfully achieved using detectors based on Gas Electron Multiplier (GEM) technology. This work presents the conceptual design of the detecting unit for poloidal tomography to be tested at the WEST project tokamak. The current stage of the development is discussed covering aspects which include detector's spatial dimensions, gas mixtures, window materials and arrangements inside and outside the tokamak ports, details of detector's structure itself and details of the detecting module electronics. It is expected that the detecting unit under development, when implemented, will add to the safe operation of tokamak bringing the creation of sustainable nuclear fusion reactors a step closer. A shorter version of this contribution is due to be published in PoS at: 1st EPS conference on Plasma Diagnostics

  5. Modeling atmospheric transport of CO2 at High Resolution to estimate the potentialities of spaceborne observation to monitor anthropogenic emissions

    Science.gov (United States)

    Ciais, P.; Chimot, J.; Klonecki, A.; Prunet, P.; Vinuessa, J.; Nussli, C.; Breon, F.

    2010-12-01

    There is a crucial and urgent need to quantify and monitor anthropogenic fossil fuel emissions of CO2. Spaceborne measurements, such as those from GOSAT or the forthcoming OCO-2, or other space missions in preparation, could provide the necessary information, in particular over regions with few in-situ measurements of atmospheric concentration are too scarce. Contrarily to biogenic flux, anthropogenic emissions are highly heterogeneous in space with typical values that vary by several orders of magnitudes. A proper analysis of the impact of anthropogenic emissions on the atmospheric concentration of CO2 therefore requires a high spatial resolution, typically of a few km. Simulations of the transport of fossil CO2 plumes were performed with a resolution of 1 km over the main industrialized regions of France, and using other models of lower resolution to account for the influence of distant sources advected into the area of interest. The results clearly show the plumes from intense yet localized sources, such as urban areas or power plants, and how their structures vary with the meteorology (wind speed and direction). They also show that the plume from distant sources, such as the large emission from Northern Europe, may sometime mask the local plume, even from large cities like Paris or Lyon. These atmospheric transport simulations are then sampled according to cloud cover, spaceborne instrument sampling and typical errors, to analyze the information content of the remote sensing data and how they can improve the current knowledge on anthropogenic emissions.

  6. 不同类型公共场所环境空气细菌总数的监测结果分析%Analysis of monitoring results of different types of public environmental air-total bacterial count

    Institute of Scientific and Technical Information of China (English)

    李晓莉

    2014-01-01

    Objective To investigate the monitoring results of different types of public environmental air total bacterial count. Methods 254 samples were selected in our hospital in 2012 January -2013 year in December from different public places to col-lect, the total number of bacteria in the air of the environment. Results Shopping malls, public transport waiting room, waiting room of hospital air bacterial count qualified rate reached 100%, cultural entertainment and qualified rate was 85.5%, the hair-dressing industry 97.6%, hotel of 65.8%. Different types of public environmental air bacteria are statistically significant difference (P<0.05). Conclusion Understanding the different types of public environmental air bacteria, strengthen the management, to im-prove the public plays an important role in environmental treatment.%目的:探讨不同类型公共场所环境空气细菌总数的监测结果。方法选取我中心2012年1月-2013年12月自不同公共场所所采集到的254份样品,对其环境空气细菌总数进行分析。结果商场、公共交通等候室、医院候诊室环境空气细菌总数合格率达到100%,文化娱乐场所合格率85.5%,理发美容业97.6%,旅店业65.8%。不同类型公共场所环境空气细菌总数存在明显统计学差异性(P<0.05)。结论了解不同类型公共场所环境空气细菌总数,加强其管理,对于提高公共场所环境治疗具有重要作用。

  7. A sensor network based virtual beam-like structure method for fault diagnosis and monitoring of complex structures with Improved Bacterial Optimization

    Science.gov (United States)

    Wang, H.; Jing, X. J.

    2017-02-01

    This paper proposes a novel method for the fault diagnosis of complex structures based on an optimized virtual beam-like structure approach. A complex structure can be regarded as a combination of numerous virtual beam-like structures considering the vibration transmission path from vibration sources to each sensor. The structural 'virtual beam' consists of a sensor chain automatically obtained by an Improved Bacterial Optimization Algorithm (IBOA). The biologically inspired optimization method (i.e. IBOA) is proposed for solving the discrete optimization problem associated with the selection of the optimal virtual beam for fault diagnosis. This novel virtual beam-like-structure approach needs less or little prior knowledge. Neither does it require stationary response data, nor is it confined to a specific structure design. It is easy to implement within a sensor network attached to the monitored structure. The proposed fault diagnosis method has been tested on the detection of loosening screws located at varying positions in a real satellite-like model. Compared with empirical methods, the proposed virtual beam-like structure method has proved to be very effective and more reliable for fault localization.

  8. Phylogenetic evidence for a fusion of archaeal and bacterial SemiSWEETs to form eukaryotic SWEETs and identification of SWEET hexose transporters in the amphibian chytrid pathogen Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Hu, Yi-Bing; Sosso, Davide; Qu, Xiao-Qing; Chen, Li-Qing; Ma, Lai; Chermak, Diane; Zhang, De-Chun; Frommer, Wolf B

    2016-10-01

    SWEETs represent a new class of sugar transporters first described in plants, animals, and humans and later in prokaryotes. Plant SWEETs play key roles in phloem loading, seed filling, and nectar secretion, whereas the role of archaeal, bacterial, and animal transporters remains elusive. Structural analyses show that eukaryotic SWEETs are composed of 2 triple-helix bundles (THBs) fused via an inversion linker helix, whereas prokaryotic SemiSWEETs contain only a single THB and require homodimerization to form transport pores. This study indicates that SWEETs retained sugar transport activity in all kingdoms of life, and that SemiSWEETs are likely their ancestral units. Fusion of oligomeric subunits into single polypeptides during evolution of eukaryotes is commonly found for transporters. Phylogenetic analyses indicate that THBs of eukaryotic SWEETs may not have evolved by tandem duplication of an open reading frame, but rather originated by fusion between an archaeal and a bacterial SemiSWEET, which potentially explains the asymmetry of eukaryotic SWEETs. Moreover, despite the ancient ancestry, SWEETs had not been identified in fungi or oomycetes. Here, we report the identification of SWEETs in oomycetes as well as SWEETs and a potential SemiSWEET in primitive fungi. BdSWEET1 and BdSWEET2 from Batrachochytrium dendrobatidis, a nonhyphal zoosporic fungus that causes global decline in amphibians, showed glucose and fructose transport activities.-Hu, Y.-B., Sosso, D., Qu, X.-Q., Chen, L.-Q., Ma, L., Chermak, D., Zhang, D.-C., Frommer, W. B. Phylogenetic evidence for a fusion of archaeal and bacterial SemiSWEETs to form eukaryotic SWEETs and identification of SWEET hexose transporters in the amphibian chytrid pathogen Batrachochytrium dendrobatidis. © FASEB.

  9. Satellite Monitoring of Long-Range Transport of Asian Dust Storms from Sources to Sinks

    Science.gov (United States)

    Hsu, N.; Tsay, S.; Jeong, M.; King, M.; Holben, B.

    2007-05-01

    Among the many components that contribute to air pollution, airborne mineral dust plays an important role due to its biogeochemical impact on the ecosystem and its radiative-forcing effect on the climate system. In East Asia, dust storms frequently accompany the cold and dry air masses that occur as part of spring-time cold front systems. China's capital, Beijing, and other large cities are on the primary pathway of these dust storm plumes, and their passage over such popu-lation centers causes flight delays, pushes grit through windows and doors, and forces people indoors. Furthermore, during the spring these anthropogenic and natural air pollutants, once generated over the source regions, can be transported out of the boundary layer into the free troposphere and can travel thousands of kilometers across the Pacific into the United States and beyond. In this paper, we will demonstrate the capability of a new satellite algorithm to retrieve aerosol optical thickness and single scattering albedo over bright-reflecting surfaces such as urban areas and deserts. Such retrievals have been dif-ficult to perform using previously available algorithms that use wavelengths from the mid-visible to the near IR because they have trouble separating the aerosol signal from the contribution due to the bright surface reflectance. The new algorithm, called Deep Blue, utilizes blue-wavelength measurements from instruments such as SeaWiFS and MODIS to infer the properties of aerosols, since the surface reflectance over land in the blue part of the spectrum is much lower than for longer wavelength channels. Deep Blue algorithm has recently been integrated into the MODIS processing stream and began to provide aerosol products over land as part of the opera-tional MYD04 products. In this talk, we will show the comparisons of the MODIS Deep Blue products with data from AERONET sunphotometers on a global ba-sis. The results indicate reasonable agreements between these two. These new

  10. Strategy for monitoring and ensuring safe operation of Russian gas transportation systems

    Directory of Open Access Journals (Sweden)

    Dudin Sergey

    2017-01-01

    Full Text Available The authors examined the legislative framework of the Russian Federation operating in the field of industrial safety, and described how to obtain a license to operate hazardous production facilities. The paper demonstrates that the importance should be given to the quality and completeness of the background information, as well as the choice of inspection strategy in evaluating the technical condition of the line section of main gas pipelines. As a part of a package of measures to ensure industrial safety and technical reliability of existing gas pipelines it is proposed to carry out conditioning of their line sections. The paper describes general requirements for pipeline inspection, which include: detection efficiency of dangerous damages and major leaks, maximum accuracy of detection of the defect location, continuity of monitoring throughout the entire range of operation modes of the pipeline, cost recovery at the stages of development and operation of control systems, forecasting the state of the pipeline and the effects of accidents. In practice, these parameters have the prevailing significance.

  11. Noninvasive technique for monitoring drug transport through the murine cochlea using micro-computed tomography.

    Science.gov (United States)

    Haghpanahi, Masoumeh; Gladstone, Miriam B; Zhu, Xiaoxia; Frisina, Robert D; Borkholder, David A

    2013-10-01

    Local delivery of drugs to the inner ear has the potential to treat inner ear disorders including permanent hearing loss or deafness. Current mathematical models describing the pharmacokinetics of drug delivery to the inner ear have been based on large rodent studies with invasive measurements of concentration at few locations within the cochlea. Hence, estimates of clearance and diffusion parameters are based on fitting measured data with limited spatial resolution to a model. To overcome these limitations, we developed a noninvasive imaging technique to monitor and characterize drug delivery inside the mouse cochlea using micro-computed tomography (μCT). To increase the measurement accuracy, we performed a subject-atlas image registration to exploit the information readily available in the atlas image of the mouse cochlea and pass segmentation or labeling information from the atlas to our μCT scans. The approach presented here has the potential to quantify concentrations at any point along fluid-filled scalae of the inner ear. This may permit determination of spatially dependent diffusion and clearance parameters for enhanced models.

  12. Quantitative Evaluation of an Air-monitoring Network Using Atmospheric Transport Modeling and Frequency of Detection Methods.

    Science.gov (United States)

    Rood, Arthur S; Sondrup, A Jeffrey; Ritter, Paul D

    2016-04-01

    A methodology has been developed to quantify the performance of an air-monitoring network in terms of frequency of detection. Frequency of detection is defined as the fraction of "events" that result in a detection at either a single sampler or network of samplers. An "event" is defined as a release to the atmosphere of a specified amount of activity over a finite duration that begins on a given day and hour of the year. The methodology uses an atmospheric transport model to predict air concentrations of radionuclides at the samplers for a given release time and duration. Another metric of interest determined by the methodology is called the network intensity, which is defined as the fraction of samplers in the network that have a positive detection for a given event. The frequency of detection methodology allows for evaluation of short-term releases that include effects of short-term variability in meteorological conditions. The methodology was tested using the U.S. Department of Energy Idaho National Laboratory Site ambient air-monitoring network consisting of 37 low-volume air samplers in 31 different locations covering a 17,630 km region. Releases from six major facilities distributed over an area of 1,435 km were modeled and included three stack sources and eight ground-level sources. A Lagrangian Puff air dispersion model (CALPUFF) was used to model atmospheric transport. The model was validated using historical Sb releases and measurements. Relevant 1-wk release quantities from each emission source were calculated based on a dose of 1.9×10 mSv at a public receptor (0.01 mSv assuming release persists over a year). Important radionuclides were Am, Cs, Pu, Pu, Sr, and tritium. Results show the detection frequency was over 97.5% for the entire network considering all sources and radionuclides. Network intensity results ranged from 3.75% to 62.7%. Evaluation of individual samplers indicated some samplers were poorly located and added little to the overall

  13. Lane Detection in Video-Based Intelligent Transportation Monitoring via Fast Extracting and Clustering of Vehicle Motion Trajectories

    Directory of Open Access Journals (Sweden)

    Jianqiang Ren

    2014-01-01

    Full Text Available Lane detection is a crucial process in video-based transportation monitoring system. This paper proposes a novel method to detect the lane center via rapid extraction and high accuracy clustering of vehicle motion trajectories. First, we use the activity map to realize automatically the extraction of road region, the calibration of dynamic camera, and the setting of three virtual detecting lines. Secondly, the three virtual detecting lines and a local background model with traffic flow feedback are used to extract and group vehicle feature points in unit of vehicle. Then, the feature point groups are described accurately by edge weighted dynamic graph and modified by a motion-similarity Kalman filter during the sparse feature point tracking. After obtaining the vehicle trajectories, a rough k-means incremental clustering with Hausdorff distance is designed to realize the rapid online extraction of lane center with high accuracy. The use of rough set reduces effectively the accuracy decrease, which results from the trajectories that run irregularly. Experimental results prove that the proposed method can detect lane center position efficiently, the affected time of subsequent tasks can be reduced obviously, and the safety of traffic surveillance systems can be enhanced significantly.

  14. Bacterial Vaginosis

    Science.gov (United States)

    ... Form Controls Cancel Submit Search the CDC Bacterial Vaginosis (BV) Note: Javascript is disabled or is not ... STD on Facebook Sexually Transmitted Diseases (STDs) Bacterial Vaginosis – CDC Fact Sheet Language: English (US) Españ ...

  15. Development of Information Support of the Automated System for Monitoring the State of the Gas Transportation System’s Industrial Safety

    Directory of Open Access Journals (Sweden)

    Ruslan Skrynkovskyy

    2017-08-01

    Full Text Available The purpose of the article is to developing the information security of the automated system for monitoring the state of industrial safety of the gas transportation system within the framework of the safety management system, which will enable timely and objective detection of adverse accident hazards (hazardous events and taking the necessary specific measures to eliminate them and operate the gas transport system safely. It is proved that the basis of the information provision of the automated system for monitoring the state of the industrial safety of the gas transmission system is a methodology that includes the following basic procedures: identifying hazards; qualitative and quantitative assessment of emergencies; establishing of unacceptable (unallowable risks and their introduction to the information base (register of unacceptable risks of objects of the gas transportation system; comprehensive assessment and certification of the state of industrial safety of objects of the gas transportation system; identification of effective, productive (efficient risk management measures. The prospect of further research in this area is the development and implementation of an automated system for monitoring the state of industrial safety of the objects of the gas transmission system based on the results of the research (of the submitted information provision.

  16. Simple and Versatile Turbidimetric Monitoring of Bacterial Growth in Liquid Cultures Using a Customized 3D Printed Culture Tube Holder and a Miniaturized Spectrophotometer: Application to Facultative and Strictly Anaerobic Bacteria

    Science.gov (United States)

    Maia, Margarida R. G.; Marques, Sara; Cabrita, Ana R. J.; Wallace, R. John; Thompson, Gertrude; Fonseca, António J. M.; Oliveira, Hugo M.

    2016-01-01

    Here we introduce a novel strategy for turbidimetric monitoring of bacterial growth in liquid culture. The instrumentation comprises a light source, a customized 3D printed culture tube holder and a miniaturized spectrophotometer, connected through optical cables. Due to its small footprint and the possibility to operate with external light, bacterial growth was directly monitored from culture tubes in a simple and versatile fashion. This new portable measurement technique was used to monitor the growth of facultative (Escherichia coli ATCC/25922, and Staphylococcus aureus ATCC/29213) and strictly (Butyrivibrio fibrisolvens JW11, Butyrivibrio proteoclasticus P18, and Propionibacterium acnes DSMZ 1897) anaerobic bacteria. For E. coli and S. aureus, the growth rates calculated from normalized optical density values were compared with those ones obtained using a benchtop spectrophotometer without significant differences (P = 0.256). For the strictly anaerobic species, a high precision (relative standard deviation < 3.5%) was observed between replicates up to 48 h. Regarding its potential for customization, this manifold could accommodate further developments for customized turbidimetric monitoring, such as the use of light-emitting diodes as a light source or flow cells. PMID:27630632

  17. Simple and versatile turbidimetric monitoring of bacterial growth in liquid cultures using a customized 3D printed culture tube holder and a miniaturized spectrophotometer: application to facultative and strictly anaerobic bacteria

    Directory of Open Access Journals (Sweden)

    Margarida R. G. Maia

    2016-08-01

    Full Text Available Here we introduce a novel strategy for turbidimetric monitoring of bacterial growth in liquid culture. The instrumentation comprises a light source, a customized 3D printed culture tube holder and a miniaturized spectrophotometer, connected through optical cables. Due to its small footprint and the possibility to operate with external light, bacterial growth was directly monitored from culture tubes in a simple and versatile fashion. This new portable measurement technique was used to monitor the growth of facultative (Escherichia coli ATCC/25922, and Staphylococcus aureus ATCC/29213 and strictly (Butyrivibrio fibrisolvens JW11, Butyrivibrio proteoclasticus P18, and Propionibacterium acnes DSMZ 1897 anaerobic bacteria. For E. coli and S. aureus, the growth rates calculated from normalized optical density values were compared with those ones obtained using a benchtop spectrophotometer without significant differences (P = 0.256. For the strictly anaerobic species, a high precision (RSD < 3.5% was observed between replicates up to 48 h. Regarding its potential for customization, this manifold could accommodate further developments for customized turbidimetric monitoring, such as the use of light-emitting diodes as a light source or flow cells.

  18. Simple and Versatile Turbidimetric Monitoring of Bacterial Growth in Liquid Cultures Using a Customized 3D Printed Culture Tube Holder and a Miniaturized Spectrophotometer: Application to Facultative and Strictly Anaerobic Bacteria.

    Science.gov (United States)

    Maia, Margarida R G; Marques, Sara; Cabrita, Ana R J; Wallace, R John; Thompson, Gertrude; Fonseca, António J M; Oliveira, Hugo M

    2016-01-01

    Here we introduce a novel strategy for turbidimetric monitoring of bacterial growth in liquid culture. The instrumentation comprises a light source, a customized 3D printed culture tube holder and a miniaturized spectrophotometer, connected through optical cables. Due to its small footprint and the possibility to operate with external light, bacterial growth was directly monitored from culture tubes in a simple and versatile fashion. This new portable measurement technique was used to monitor the growth of facultative (Escherichia coli ATCC/25922, and Staphylococcus aureus ATCC/29213) and strictly (Butyrivibrio fibrisolvens JW11, Butyrivibrio proteoclasticus P18, and Propionibacterium acnes DSMZ 1897) anaerobic bacteria. For E. coli and S. aureus, the growth rates calculated from normalized optical density values were compared with those ones obtained using a benchtop spectrophotometer without significant differences (P = 0.256). For the strictly anaerobic species, a high precision (relative standard deviation < 3.5%) was observed between replicates up to 48 h. Regarding its potential for customization, this manifold could accommodate further developments for customized turbidimetric monitoring, such as the use of light-emitting diodes as a light source or flow cells.

  19. Bacterial Vaginosis

    Science.gov (United States)

    ... Issues > Conditions > Sexually Transmitted > Bacterial Vaginosis Health Issues Listen Español Text Size Email Print Share Bacterial Vaginosis Page Content Bacterial vaginosis (BV) is the most common vaginal infection in sexually active teenaged girls . It appears to be caused by ...

  20. Assessment of potential long-range transport of particulate air pollution using trajectory modeling and monitoring data

    Science.gov (United States)

    Pongkiatkul, Prapat; Kim Oanh, Nguyen Thi

    2007-07-01

    Quantification of the long-range transport (LRT) contribution to ambient air pollution levels at a location is a challenging task and is normally done with a high uncertainty. In the lack of accurate emission data over the large regional domain for dispersion modeling, this study attempts to use both trajectory analysis and monitoring data to assess the potential contribution of LRT to particulate air pollution (PM) in the Bangkok Metropolitan Region (BMR). The 10-day backward trajectories of air masses arriving at BMR from January 2002 to December 2004 were determined using Hybrid Single-Particle Langrangian Integrated Trajectory model version 4 (HYSPLIT4) and were categorized by k-means clustering into 6 clusters. Subsequently, PM levels in the BMR associated with each air mass cluster during this period were analyzed. Clusters 1 and 6 were observed with the highest and 2nd highest average PM 10 and PM 2.5 levels in the BMR, respectively, which commonly have a longer air mass pathway over populated South East Asia (SEA). The third highest PM levels were associated with air masses from the east (clusters 2 and 5), which enter the BMR via the Gulf of Thailand without passing the SEA regions. The other two clusters (3 and 4) are characterized with a long pathway of air masses over the Indian Ocean and the lowest PM levels. High PM days, which are defined based on the spatial coverage of high PM levels in the BMR, were identified and analyzed for the possibility of long-range transport contribution of PM. The potential source contribution function (PSCF) and air mass trajectories show that on high PM day, the air masses commonly originated and passed over populated regions before arriving at the BMR, which suggests a possible LRT contribution. Considerations are made for surface ozone, SO 42-/SO 2 and average SO 2, PM 2.5/PM 10, and weekday-weekend traffic emission within each air mass trajectory cluster to reveal the possible LRT contribution.

  1. High-frequency monitoring reveals nutrient sources and transport processes in an agriculture-dominated lowland water system

    Science.gov (United States)

    van der Grift, Bas; Broers, Hans Peter; Berendrecht, Wilbert; Rozemeijer, Joachim; Osté, Leonard; Griffioen, Jasper

    2016-05-01

    Many agriculture-dominated lowland water systems worldwide suffer from eutrophication caused by high nutrient loads. Insight in the hydrochemical functioning of embanked polder catchments is highly relevant for improving the water quality in such areas or for reducing export loads to downstream water bodies. This paper introduces new insights in nutrient sources and transport processes in a polder in the Netherlands situated below sea level using high-frequency monitoring technology at the outlet, where the water is pumped into a higher situated lake, combined with a low-frequency water quality monitoring programme at six locations within the drainage area. Seasonal trends and short-scale temporal dynamics in concentrations indicated that the NO3 concentration at the pumping station originated from N loss from agricultural lands. The NO3 loads appear as losses via tube drains after intensive rainfall events during the winter months due to preferential flow through the cracked clay soil. Transfer function-noise modelling of hourly NO3 concentrations reveals that a large part of the dynamics in NO3 concentrations during the winter months can be related to rainfall. The total phosphorus (TP) concentration and turbidity almost doubled during operation of the pumping station, which points to resuspension of particulate P from channel bed sediments induced by changes in water flow due to pumping. Rainfall events that caused peaks in NO3 concentrations did not results in TP concentration peaks. The rainfall induced and NO3 enriched quick interflow, may also be enriched in TP but retention of TP due to sedimentation of particulate P then results in the absence of rainfall induced TP concentration peaks. Increased TP concentrations associated with run-off events is only observed during a rainfall event at the end of a freeze-thaw cycle. All these observations suggest that the P retention potential of polder water systems is primarily due to the artificial pumping regime

  2. Bacterial Sialidase

    Science.gov (United States)

    2004-01-01

    Data shows that elevated sialidase in bacterial vaginosis patients correlates to premature births in women. Bacterial sialidase also plays a significant role in the unusual colonization of Pseudomonas aeruginosa in cystic fibrosis patients. Crystals of Salmonella sialidase have been reproduced and are used for studying the inhibitor-enzyme complexes. These inhibitors may also be used to inhibit a trans-sialidase of Trypanosome cruzi, a very similar enzyme to bacterial sialidase, therefore preventing T. cruzi infection, the causitive agent of Chagas' disease. The Center for Macromolecular Crystallography suggests that inhibitors of bacterial sialidases can be used as prophylactic drugs to prevent bacterial infections in these critical cases.

  3. Design of an eMonitor system to transport electronic patient care report (ePCR) information in unstable MobileIP wireless environment.

    Science.gov (United States)

    Giovanni, Mazza G; Shenvi, Rohit; Battles, Marcie; Orthner, Helmuth F

    2008-11-06

    The eMonitor is a component of the ePatient system; a prototype system used by emergency medical services (EMS) personnel in the field to record and transmits electronic patient care report (ePCR) information interactively. The eMonitor component allows each Mobile Data Terminal (MDT) on an unreliable Cisco MobileIP wireless network to securely send and received XML messages used to update patient information to and from the MDT before, during and after the transport of a patient.

  4. Neurotransmitter transporters

    DEFF Research Database (Denmark)

    Gether, Ulrik; Andersen, Peter H; Larsson, Orla M

    2006-01-01

    The concentration of neurotransmitters in the extracellular space is tightly controlled by distinct classes of membrane transport proteins. This review focuses on the molecular function of two major classes of neurotransmitter transporter that are present in the cell membrane of neurons and....../or glial cells: the solute carrier (SLC)1 transporter family, which includes the transporters that mediate the Na(+)-dependent uptake of glutamate, and the SLC6 transporter family, which includes the transporters that mediate the Na(+)-dependent uptake of dopamine, 5-HT, norepinephrine, glycine and GABA....... Recent research has provided substantial insight into the structure and function of these transporters. In particular, the recent crystallizations of bacterial homologs are of the utmost importance, enabling the first reliable structural models of the mammalian neurotransmitter transporters...

  5. Real-time monitoring of nitrate transport in the deep vadose zone under a crop field - implications for groundwater protection

    Science.gov (United States)

    Turkeltaub, Tuvia; Kurtzman, Daniel; Dahan, Ofer

    2016-08-01

    Nitrate is considered the most common non-point pollutant in groundwater. It is often attributed to agricultural management, when excess application of nitrogen fertilizer leaches below the root zone and is eventually transported as nitrate through the unsaturated zone to the water table. A lag time of years to decades between processes occurring in the root zone and their final imprint on groundwater quality prevents proper decision-making on land use and groundwater-resource management. This study implemented the vadose-zone monitoring system (VMS) under a commercial crop field. Data obtained by the VMS for 6 years allowed, for the first time known to us, a unique detailed tracking of water percolation and nitrate migration from the surface through the entire vadose zone to the water table at 18.5 m depth. A nitrate concentration time series, which varied with time and depth, revealed - in real time - a major pulse of nitrate mass propagating down through the vadose zone from the root zone toward the water table. Analysis of stable nitrate isotopes indicated that manure is the prevalent source of nitrate in the deep vadose zone and that nitrogen transformation processes have little effect on nitrate isotopic signature. The total nitrogen mass calculations emphasized the nitrate mass migration towards the water table. Furthermore, the simulated pore-water velocity through analytical solution of the convection-dispersion equation shows that nitrate migration time from land surface to groundwater is relatively rapid, approximately 5.9 years. Ultimately, agricultural land uses, which are constrained to high nitrogen application rates and coarse soil texture, are prone to inducing substantial nitrate leaching.

  6. Natural Radioactivity Accumulated in the Arctic from Long-range Atmospheric Transport - Observations in Canadian Monitoring Stations

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jing; Zhang, Weihua [Radiation Protection Bureau, Health Canada, 775 Brookfield Road, Ottawa K1A 1C1 (Canada)

    2014-07-01

    In the environment, the main sources of naturally occurring radionuclides come from radionuclides in the uranium decay series. Activity concentrations of uranium decay series radionuclides may vary considerably from place to place depending on the geological characteristics at the location. Their releases to the atmosphere are mainly through radon ({sup 222}Rn), a radioactive noble gas occurring naturally as an indirect decay product of uranium in soils and rocks. Due to the abundance of uranium, radon continuously emanates from continental land masses. With radon as the main source of naturally occurring radioactivity in the environment, one would think that the Arctic should be an area of low background radiation, because a considerable area of the Arctic is covered by glaciers and permafrost, and radon emanation rate has been reported to be negligible from those glacier and permafrost areas. However, available data have shown the opposite. The elevated level of naturally occurring radioactivity in the Arctic is due to natural sources outside of the Arctic, mainly through long-range atmospheric transport of radon and radon progeny. In some cases, natural radioactivity can accumulate to relatively high levels and become a health concern or a limiting factor of country food consumption. By definition, contaminants are undesirable substances which can cause harm to the environment, the biota, and humans. We can call these naturally accumulating radiological burdens to the Arctic 'natural contaminants' to distinguish them from the traditional meaning of contamination, the 'artificial contaminants' which are attributable to industrial or man-made sources. This paper reviews information available in the literature, analyses long-term atmospheric monitoring data in the Canadian high Arctic, sub-Arctic and mid-latitude sites, and provides discussion on research needed to address questions, such as how heavily the Arctic has been impacted by the

  7. Monitoring transport conditions of key comparison travelling standards using a data logger. Experiences from key comparison CCAUV.U-K3.1

    Science.gov (United States)

    Haller, Julian; Koch, Christian

    2015-12-01

    In the framework of the international key comparison CCAUV.U-K3.1, a data logger was used to monitor temperature, pressure, humidity, and acceleration during transportation of an artefact travelling between participating laboratories. From the recorded data, environmental conditions of different kinds of transportation have been investigated and corresponding recommendations for the safe and proper transfer of artefacts between laboratories could be deduced. Transportation by courier services bears the risk of strong mechanical shocks and exposure to comparably high or low temperatures due to inappropriate handling or storage and is thus only suitable for insensitive or well-packed artefacts. Quite low temperatures (T  ≈  5 °C) have been observed in the cargo area during flights, so that hand-carrying of an artefact with transportation in the passenger cabin during flights is recommended, particularly for temperature-sensitive artefacts. Significant decreases of the pressure (p  ≈  750 mbar) have been recorded both for transportation in the passenger cabin and in the cargo area. Air-tight packing is thus recommended for pressure-sensitive devices. In general, the suitability of a data logger to provide evidence of the transport conditions during a key comparison has been demonstrated and the use of such a device is recommended for all key comparisons. The data logger has also been successfully employed to validate the protection properties of the passively insulating packaging of the artefact against pressure and temperature changes.

  8. Intramolecular cross-linking in a bacterial homolog of mammalian SLC6 neurotransmitter transporters suggests an evolutionary conserved role of transmembrane segments 7 and 8

    DEFF Research Database (Denmark)

    Kniazeff, Julie; Loland, Claus Juul; Goldberg, Naomi

    2005-01-01

    The extracellular concentration of the neurotransmitters dopamine, serotonin, norepinephrine, GABA and glycine is tightly controlled by plasma membrane transporters belonging to the SLC6 gene family. A very large number of putative transport proteins with a remarkable homology to the SLC6...... transporters has recently been identified in prokaryotes. Here we have probed structural relationships in a 'microdoman' corresponding to the extracellular ends of transmembrane segments (TM) 7 and 8 in one of these homologs, the tryptophan transporter TnaT from Symbiobacterium thermophilum. We found...

  9. Non-invasive, in-vivo monitoring of neuronal transport impairment in a mouse model of tauopathy using MEMRI

    Science.gov (United States)

    Bertrand, Anne; Khan, Umer; Hoang, Dung M.; Novikov, Dmitry S.; Krishnamurthy, Pavan; Rajamohamed Sait, Hameetha B.; Little, Benjamin W.; Sigurdsson, Einar M.; Wadghiri, Youssef Z.

    2012-01-01

    The impairment of axonal transport by overexpression or hyperphosphorylation of tau is well documented for in vitro conditions; however, only a few studies on this phenomenon have been conducted in vivo, using invasive procedures, and with contradictory results. Here we used the non-invasive, Manganese-Enhanced Magnetic Resonance Imaging technique (MEMRI), to study for the first time a pure model of tauopathy, the JNPL3 transgenic mouse line, which overexpresses a mutated (P301L) form of the human tau protein. We show progressive impairment in neuronal transport as tauopathy advances. These findings are further supported by a significant correlation between the severity of the impairment in neuronal transport assessed by MEMRI, and the degree of abnormal tau assessed by histology. Unlike conventional techniques that focus on axonal transport measurement, MEMRI can provide a global analysis of neuronal transport, i.e. from dendrites to axons and at the macroscopic scale of fiber tracts. Neuronal transport impairment has been shown to be a key pathogenic process in Alzheimer’s disease and numerous other neurodegenerative disorders. Hence, MEMRI provides a promising set of functional biomarkers to be used during preclinical trials to facilitate the selection of new drugs aimed at restoring neuronal transport in neurodegenerative diseases. PMID:22960250

  10. Bacterial gastroenteritis

    Science.gov (United States)

    ... most common types of bacterial gastroenteritis in a couple of days. The goal is to make you feel better and avoid dehydration. Drinking enough fluids and learning what to eat will help ease symptoms. You ...

  11. Bacterial vaginosis

    National Research Council Canada - National Science Library

    Islam, Aliya; Safdar, Anjum; Malik, Ayesha

    2009-01-01

    To estimate the frequency of bacterial vaginosis in women with preterm labour. Descriptive cross sectional study carried out in department of Obstetrics and Gynaecology, Military Hospital and Army Medical College Laboratory, Rawalpindi...

  12. Analysis of the contribution of sedimentation to bacterial mass transport in a parallel plate flow chamber Part II : Use of fluorescence imaging

    NARCIS (Netherlands)

    Li, Jiuyi; Busscher, Henk J.; van der Mei, Henny C.; Norde, Willem; Krom, Bastiaan P.; Sjollema, Jelmer

    2011-01-01

    Using a new phase-contrast microscopy-based method of analysis, sedimentation has recently been demonstrated to be the major mass transport mechanism of bacteria towards substratum surfaces in a parallel plate flow chamber (J. Li, H.J. Busscher, W. Norde, J. Sjollema, Colloid Surf. B. 84 (2011)76).

  13. Analysis of the contribution of sedimentation to bacterial mass transport in a parallel plate flow chamber Part II: Use of fluorescence imaging

    NARCIS (Netherlands)

    Li, J.Y.; Busscher, H.J.; Mei, van der H.C.; Norde, W.; Krom, B.P.; Sjollema, J.

    2011-01-01

    Using a new phase-contrast microscopy-based method of analysis, sedimentation has recently been demonstrated to be the major mass transport mechanism of bacteria towards substratum surfaces in a parallel plate flow chamber (J. Li, H.J. Busscher, W. Norde, J. Sjollema, Colloid Surf. B. 84 (2011)76).

  14. Down-regulation of monocarboxylate transporter 1 (MCT1) gene expression in the colon of piglets is linked to bacterial protein fermentation and pro-inflammatory cytokine-mediated signalling.

    Science.gov (United States)

    Villodre Tudela, Carmen; Boudry, Christelle; Stumpff, Friederike; Aschenbach, Jörg R; Vahjen, Wilfried; Zentek, Jürgen; Pieper, Robert

    2015-02-28

    The present study investigated the influence of bacterial metabolites on monocarboxylate transporter 1 (MCT1) expression in pigs using in vivo, ex vivo and in vitro approaches. Piglets (n 24) were fed high-protein (26 %) or low-protein (18 %) diets with or without fermentable carbohydrates. Colonic digesta samples were analysed for a broad range of bacterial metabolites. The expression of MCT1, TNF-α, interferon γ (IFN-γ) and IL-8 was determined in colonic tissue. The expression of MCT1 was lower and of TNF-α and IL-8 was higher with high-protein diets (P< 0·05). MCT1 expression was positively correlated with l-lactate, whereas negatively correlated with NH₃ and putrescine (P< 0·05). The expression of IL-8 and TNF-α was negatively correlated with l-lactate and positively correlated with NH₃ and putrescine, whereas the expression of IFN-γ was positively correlated with histamine and 4-ethylphenol (P< 0·05). Subsequently, porcine colonic tissue and Caco-2 cells were incubated with Na-butyrate, NH₄Cl or TNF-α as selected bacterial metabolites or mediators of inflammation. Colonic MCT1 expression was higher after incubation with Na-butyrate (P< 0·05) and lower after incubation with NH₄Cl or TNF-α (P< 0·05). Incubation of Caco-2 cells with increasing concentrations of these metabolites confirmed the up-regulation of MCT1 expression by Na-butyrate (linear, P< 0·05) and down-regulation by TNF-α and NH₄Cl (linear, P< 0·05). The high-protein diet decreased the expression of MCT1 in the colon of pigs, which appears to be linked to NH₃- and TNF-α-mediated signalling.

  15. Quality assurance monitoring of a citywide transportation protocol improves clinical indicators of intravenous tissue plasminogen activator therapy: a community-based, longitudinal study.

    Science.gov (United States)

    Atsumi, Chihiro; Hasegawa, Yasuhiro; Tsumura, Kohtaro; Ueda, Toshihiro; Suzuki, Kazunari; Sugiyama, Makoto; Nozaki, Hiroyuki; Suzuki, Shinichi; Nakane, Makoto; Nagashima, Goro; Kitamura, Takayuki; Nikaido, Hirofumi; Sasanuma, Jinichi

    2015-01-01

    Stroke-bypass transportation to the stroke center by paramedics is important to maximize the efficiency of intravenous tissue plasminogen activator (iv-tPA) therapy. To improve access to stroke thrombolysis, a citywide protocol was launched on January 2007 in Kawasaki City (population 1.4 million) using the Maria Prehospital Stroke Scale (MPSS), and quality assurance monitoring has been performed every 6 months. The aim was to identify whether the citywide quality assurance monitoring improves the process and outcome of iv-tPA therapy. All of the MPSS-based transportation data prospectively recorded by the Kawasaki City Fire Department and the associated clinical data in the 11 hospitals that accept stroke-bypass transfers were merged every 6 months for the quality assurance monitoring. Clinical indicators such as ambulance call-to-door time, onset-to-needle time, door-to-needle time, frequency of thrombolytic use, and outcome of thrombolytic therapy were analyzed. These clinical indicators were also compared between patients transferred on weekdays and on weekends. A total of 2049 patients was registered from April 2009 to March 2013. Their mean age was 70.4 ± 13.2 (range, 24-98) years, and 64.3% were male. Ambulance call-to-door time decreased gradually from 37.5 ± 12.5 minutes to 33.9 ± 11.7 minutes over 4 years (P = .000, analysis of variance with the post hoc Dunnett test). Onset-to-needle time and door-to-needle time were similar over the 4 years. Good outcome (modified Rankin Scale score protocol significantly decreased the delay in the ambulance call-to-door time. The implementation of standardized cross-institutional quality assurance programs for acute stroke therapy may improve the process and outcome of iv-tPA therapy in the community. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  16. Non-invasive, in vivo monitoring of neuronal transport impairment in a mouse model of tauopathy using MEMRI

    OpenAIRE

    Bertrand, Anne; Khan, Umer; Hoang, Dung M.; Novikov, Dmitry S.; Krishnamurthy, Pavan; Rajamohamed Sait, Hameetha B.; Little, Benjamin W.; Sigurdsson, Einar M.; Wadghiri, Youssef Z.

    2013-01-01

    International audience; The impairment of axonal transport by overexpression or hyperphosphorylation of tau is well documented for in vitro conditions; however, only a few studies on this phenomenon have been conducted in vivo, using invasive procedures, and with contradictory results. Here we used the non-invasive, Manganese-Enhanced Magnetic Resonance Imaging technique (MEMRI), to study for the first time a pure model of tauopathy, the JNPL3 transgenic mouse line, which overexpresses a muta...

  17. Non-invasive, in-vivo monitoring of neuronal transport impairment in a mouse model of tauopathy using MEMRI

    OpenAIRE

    Bertrand, Anne; Khan, Umer; Hoang, Dung M.; Novikov, Dmitry S.; Krishnamurthy, Pavan; Rajamohamed Sait, Hameetha B.; Little, Benjamin W.; Sigurdsson, Einar M.; Wadghiri, Youssef Z.

    2012-01-01

    The impairment of axonal transport by overexpression or hyperphosphorylation of tau is well documented for in vitro conditions; however, only a few studies on this phenomenon have been conducted in vivo, using invasive procedures, and with contradictory results. Here we used the non-invasive, Manganese-Enhanced Magnetic Resonance Imaging technique (MEMRI), to study for the first time a pure model of tauopathy, the JNPL3 transgenic mouse line, which overexpresses a mutated (P301L) form of the ...

  18. Development of a web application for recording bacterial etiologic agents and their antimicrobial susceptibility to improve the treatment of urinary tract infections and monitor resistance to antibiotics.

    Science.gov (United States)

    Gómez-Palomo, Francisco; Sorlózano-Puerto, Antonio; Miranda-Casas, Consuelo; Rodríguez-Rodríguez, José María; Navarro-Marí, José María; Gutiérrez-Fernández, José

    2016-04-01

    We describe the development of a web platform that provides an updated record of the etiology and antimicrobial susceptibility of the different microorganisms responsible for urinary tract infections. The MicrobDinamyc system (Francisco Soria Melguizo, SA, Madrid, Spain) is employed for the management of information derived from the urine culture results. The web application database automatically gathers the results of urine cultures conducted in the laboratory. Results. The user can consult the distribution of bacterial etiologies and antimicrobial susceptibilities in the different clinical settings during a specific time window. Using susceptibility data obtained in previous studies and stored on the web platform, it is possible to deduce the clinical activity of a given antibiotic in a specific setting.

  19. A virtual high-throughput screening approach to the discovery of novel inhibitors of the bacterial leucine transporter, LeuT.

    Science.gov (United States)

    Simmons, Katie J; Gotfryd, Kamil; Billesbølle, Christian B; Loland, Claus J; Gether, Ulrik; Fishwick, Colin W G; Johnson, A Peter

    2013-03-01

    Membrane proteins are intrinsically involved in both human and pathogen physiology, and are the target of 60% of all marketed drugs. During the past decade, advances in the studies of membrane proteins using X-ray crystallography, electron microscopy and NMR-based techniques led to the elucidation of over 250 unique membrane protein crystal structures. The aim of the European Drug Initiative for Channels and Transporter (EDICT) project is to use the structures of clinically significant membrane proteins for the development of lead molecules. One of the approaches used to achieve this is a virtual high-throughput screening (vHTS) technique initially developed for soluble proteins. This paper describes application of this technique to the discovery of inhibitors of the leucine transporter (LeuT), a member of the neurotransmitter:sodium symporter (NSS) family.

  20. A virtual high-throughput screening approach to the discovery of novel inhibitors of the bacterial leucine transporter, LeuT

    DEFF Research Database (Denmark)

    Simmons, Katie J; Gotfryd, Kamil; Billesbølle, Christian B

    2013-01-01

    this is a virtual high-throughput screening (vHTS) technique initially developed for soluble proteins. This paper describes application of this technique to the discovery of inhibitors of the leucine transporter (LeuT), a member of the neurotransmitter:sodium symporter (NSS) family.......Abstract Membrane proteins are intrinsically involved in both human and pathogen physiology, and are the target of 60% of all marketed drugs. During the past decade, advances in the studies of membrane proteins using X-ray crystallography, electron microscopy and NMR-based techniques led...... to the elucidation of over 250 unique membrane protein crystal structures. The aim of the European Drug Initiative for Channels and Transporter (EDICT) project is to use the structures of clinically significant membrane proteins for the development of lead molecules. One of the approaches used to achieve...

  1. EPR spectroscopy of MolB2C2-a reveals mechanism of transport for a bacterial type II molybdate importer.

    Science.gov (United States)

    Rice, Austin J; Alvarez, Frances J D; Schultz, Kathryn M; Klug, Candice S; Davidson, Amy L; Pinkett, Heather W

    2013-07-19

    In bacteria, ATP-binding cassette (ABC) transporters are vital for the uptake of nutrients and cofactors. Based on differences in structure and activity, ABC importers are divided into two types. Type I transporters have been well studied and employ a tightly regulated alternating access mechanism. Less is known about Type II importers, but much of what we do know has been observed in studies of the vitamin B12 importer BtuC2D2. MolB2C2 (formally known as HI1470/71) is also a Type II importer, but its substrate, molybdate, is ∼10-fold smaller than vitamin B12. To understand mechanistic differences among Type II importers, we focused our studies on MolBC, for which alternative conformations may be required to transport its relatively small substrate. To investigate the mechanism of MolBC, we employed disulfide cross-linking and EPR spectroscopy. From these studies, we found that nucleotide binding is coupled to a conformational shift at the periplasmic gate. Unlike the larger conformational changes in BtuCD-F, this shift in MolBC-A is akin to unlocking a swinging door: allowing just enough space for molybdate to slip into the cell. The lower cytoplasmic gate, identified in BtuCD-F as "gate I," remains open throughout the MolBC-A mechanism, and cytoplasmic gate II closes in the presence of nucleotide. Combining our results, we propose a peristaltic mechanism for MolBC-A, which gives new insight in the transport of small substrates by a Type II importer.

  2. Bacterial Ecology

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2011-01-01

    Bacterial ecology is concerned with the interactions between bacteria and their biological and nonbiological environments and with the role of bacteria in biogeochemical element cycling. Many fundamental properties of bacteria are consequences of their small size. Thus, they can efficiently exploit...

  3. Bacterial lipases

    NARCIS (Netherlands)

    Jaeger, Karl-Erich; Ransac, Stéphane; Dijkstra, Bauke W.; Colson, Charles; Heuvel, Margreet van; Misset, Onno

    1994-01-01

    Many different bacterial species produce lipases which hydrolyze esters of glycerol with preferably long-chain fatty acids. They act at the interface generated by a hydrophobic lipid substrate in a hydrophilic aqueous medium. A characteristic property of lipases is called interfacial activation, mea

  4. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

    tract to the microbial flocs in waste water treatment facilities. Microbial biofilms may however also cause a wide range of industrial and medical problems, and have been implicated in a wide range of persistent infectious diseases, including implantassociated microbial infections. Bacterial adhesion...... is the first committing step in biofilm formation, and has therefore been intensely scrutinized. Much however, still remains elusive. Bacterial adhesion is a highly complex process, which is influenced by a variety of factors. In this thesis, a range of physico-chemical, molecular and environmental parameters......, which influence the transition from a planktonic lifestyle to a sessile lifestyle, have been studied. Protein conditioning film formation was found to influence bacterial adhesion and subsequent biofilm formation considerable, and an aqueous extract of fish muscle tissue was shown to significantly...

  5. Monitoring and Predicting the Long Distance Transport of Fusarium graminearum, Causal Agent of Fusarium Head Blight in Wheat and Barley

    Science.gov (United States)

    Prussin, Aaron Justin, II

    Fusarium head blight (FHB), caused by Fusarium graminearum , is a serious disease of wheat and barley that has caused several billion dollars in crop losses over the last decade in the United States. Spores of F. graminearum are released from corn and small grain residues left-over from the previous growing season and are transported long distances in the atmosphere before being deposited. Current risk assessment tools consider environmental conditions favorable for disease development, but do not include spore transport. Long distance transport models have been proposed for a number of plant pathogens, but many of these models have not been experimentally validated. In order to predict the atmospheric transport of F. graminearum, the potential source strength ( Qpot) of inoculum must be known. We conducted a series of laboratory and field experiments to estimate Qpot from a field-scale source of inoculum of F. graminearum. Perithecia were generated on artificial (carrot agar) and natural (corn stalk) substrates. Artificial substrate (carrot agar) produced 15+/-0.4 perithecia cm-2, and natural substrate (corn stalk) produced 44+/-2 perithecia cm-2. Individual perithecia were excised from both substrate types and allowed to release ascospores every 24 hours. Perithecia generated from artificial (carrot agar) and natural (corn stalk) substrates released a mean of 104+/-5 and 276+/-16 ascospores, respectively. A volumetric spore trap was placed inside a 3,716 m2 clonal source of inoculum in 2011 and 2012. Results indicated that ascospores were released under field conditions predominantly (>90%) during the night (1900 to 0700 hours). Estimates of Qpot for our field-scale sources of inoculum were approximately 4 billion ascospores per 3,716 m 2. Release-recapture studies were conducted from a clonal field-scale source of F. graminearum in 2011 and 2012. Microsatellites were used to identify the released clone of F. graminearum at distances up to 1 km from the source

  6. Compact mobile-reader system for two-way wireless communication, tracking and status monitoring for transport safety and security

    Science.gov (United States)

    Tsai, Han-Chung; Liu, Yung Y.; Lee, Hok L.; Craig, Brian; Byrne, Kevin; Mittal, Ketan; Scherer, Justin C.

    2016-12-06

    A system for monitoring a plurality radio frequency identification tags is described. The system uses at least one set of radio frequency identification tags. Each tag is attached to a container and includes several sensors for detecting physical conditions of said container. The system includes at least one autonomous intermediate reader in wireless communication with the frequency identification tags. The intermediate reader includes external wireless communication system, intermediate reader logic controller, and a self-contained rechargeable power supply. The system uses a central status reporting system in communication the intermediate reader.

  7. Evolução do comportamento auditivo após meningite bacteriana: relato de caso Auditory behaviour monitoring after bacterial meningitis: case report

    Directory of Open Access Journals (Sweden)

    Ida Lichtig

    1997-06-01

    Full Text Available A deficiência auditiva adquirida tem nas meningites bacterianas a sua principal etiologia e pouco tem-se dito a respeito da evolução para melhora ou piora do comportamento auditivo após a alta hospitalar. O presente estudo descreve o caso de um menino que teve meningite por Haemophilus influenzae aos 5 meses de vida e que entre outras complicações apresentou diminuição da acuidade auditiva detectada na evolução imediata, com melhora significativa posteriormente, confirmada por testes qualitativos e quantitativos. Discute-se a importância e a necessidade do seguimento fonoaudiológico de tais indivíduos para estabelecer orientação adequada.Bacterial meningitis is the main cause for acquired hearing loss. Nevertheless very little has been written about the development of the auditory behaviour either for improvement or for deterioration, after hospital release. The present study describes the case of a five month old boy with Haemophilus influenzae meningitis. Amongst various complications, a decrement in the auditory acuity was detected in the immediate evolution, with significant improvement later on by qualitative and quantitative tests.

  8. An observational study to monitor the efficacy and tolerability of levofloxacin 500 mg once daily for treatment of chronic bacterial prostatitis in Saudi Arabia

    Science.gov (United States)

    El Meliegy, Amr Ismail; Torky, Mohammed

    2015-01-01

    Introduction: Chronic prostatitis is a common urological problem in men <50-year-old. Untypical uropathogens and an intact blood prostate barrier cause difficulty in using antibiotics to treat the infection. Patients and Methods: In this open-label, observational study, levofloxacin 500 mg was given once daily for 28 days for treatment of chronic prostatitis. The primary efficacy measurement was the disappearance of all pre-treatment symptoms. Efficacy analysis is based on the per protocol population (PPP), all other analyses use the intent to treat (ITT) population. Results: The ITT included 154 men and the PPP included 151 (results are for the ITT unless otherwise indicated). Mean age was 42 ± 9 years, common concomitant conditions were diabetes mellitus (7%) and hypertension (5%). All symptoms decreased at day 28. Notably, the rate of dysuria decreased from 86.1% to 10.6%, painful ejaculation from 71% to 2.6% and perineal discomfort from 60.3% to 7.3%. A cure of condition was identified in 58.9%. No treatment failures were reported. Physician-reported adherence to study medication was 96.8%. Conclusion: Levofloxacin appears to be an effective antibiotic for treating symptoms of chronic bacterial prostatitis. Levofloxacin was well-tolerated in this population. PMID:25657549

  9. Multiphase, multicomponent flow and transport models for Nuclear Test-Ban Treaty monitoring and nuclear waste disposal applications

    Science.gov (United States)

    Jordan, Amy

    Open challenges remain in using numerical models of subsurface flow and transport systems to make useful predictions related to nuclear waste storage and nonproliferation. The work presented here addresses the sensitivity of model results to unknown parameters, states, and processes, particularly uncertainties related to incorporating previously unrepresented processes (e.g., explosion-induced fracturing, hydrous mineral dehydration) into a subsurface flow and transport numerical simulator. The Finite Element Heat and Mass (FEHM) transfer code is used for all numerical models in this research. An experimental campaign intended to validate the predictive capability of numerical models that include the strongly coupled thermal, hydrological, and chemical processes in bedded salt is also presented. Underground nuclear explosions (UNEs) produce radionuclide gases that may seep to the surface over weeks to months. The estimated timing of gas arrival at the surface may be used to deploy personnel and equipment to the site of a suspected UNE, if allowed under the terms of the Comprehensive Nuclear Test-Ban Treaty. A model was developed using FEHM that considers barometrically pumped gas transport through a simplified fractured medium and was used to quantify the impact of uncertainties in hydrologic parameters (fracture aperture, matrix permeability, porosity, and saturation) and season of detonation on the timing of gas breakthrough. Numerical sensitivity analyses were performed for the case of a 1 kt UNE at a 400 m burial depth. Gas arrival time was found to be most affected by matrix permeability and fracture aperture. Gases having higher diffusivity were more sensitive to uncertainty in the rock properties. The effect of seasonality in the barometric pressure forcing was found to be important, with detonations in March the least likely to be detectable based on barometric data for Rainier Mesa, Nevada. Monte Carlo modeling was also used to predict the window of

  10. Evaluation of bacterial profile and biodegradation potential of ...

    African Journals Online (AJOL)

    ADEBAYO1

    3Department of Animal and Environmental Biology, Faculty of Life Sciences, ... Abattoir wastewater treatments were monitored using physicochemical parameters, bacterial profile ... industry produces large volumes of slaughterhouse.

  11. Antimicrobial Susceptibility Monitoring of Bacterial Pathogens Isolated from Urinary Tract Infections in Dogs and Cats Across Europe: ComPath Results.

    Science.gov (United States)

    Moyaert, Hilde; Morrissey, Ian; de Jong, Anno; El Garch, Farid; Klein, Ulrich; Ludwig, Carolin; Thiry, Julien; Youala, Myriam

    2017-04-01

    ComPath is a pan-European antimicrobial surveillance program collecting bacterial pathogens from dogs and cats not recently exposed to antimicrobials. We present minimum inhibitory concentration data obtained using Clinical and Laboratory Standards Institute methodology for 616 urinary tract infection (UTI) isolates collected between 2008 and 2010. In both dogs and cats, the most common pathogen was Escherichia coli (59.8% and 46.7%, respectively). Antimicrobial activity against E. coli in dogs and cats was similar with fluoroquinolone and trimethoprim/sulfamethoxazole susceptibility >90%. Ampicillin susceptibility was ∼80%. Staphylococcus intermedius Group isolates from dogs (67/437, 15.3%) had high antimicrobial susceptibility (>90%) toward beta-lactams, fluoroquinolones, and trimethoprim/sulfamethoxazole. Four canine isolates (6%) were oxacillin resistant, and harbored mecA. Proteus mirabilis from dogs (48/437, 11.0%) had high antimicrobial susceptibility (∼90%) to amoxicillin/clavulanic acid, enrofloxacin, and marbofloxacin and slightly lower susceptibility (∼80-85%) to ampicillin and orbifloxacin. Streptococcus canis isolates (35/437, 8.0%) from dogs were all susceptible to ampicillin and amoxicillin/clavulanic acid and >90% susceptible to marbofloxacin. Although resistance was not observed, high intermediate susceptibility was seen for both enrofloxacin (28.6%) and orbifloxacin (85.7%). Overall, antimicrobial in vitro activity appears to be high in UTI pathogens from dogs and cats with low multidrug resistance, although a lack of specific dog and cat breakpoints for important antimicrobials such as cefovecin, cephalexin, and ibafloxacin prevents analysis of susceptibility for these agents.

  12. [Bacterial vaginosis].

    Science.gov (United States)

    Romero Herrero, Daniel; Andreu Domingo, Antonia

    2016-07-01

    Bacterial vaginosis (BV) is the main cause of vaginal dysbacteriosis in the women during the reproductive age. It is an entity in which many studies have focused for years and which is still open for discussion topics. This is due to the diversity of microorganisms that cause it and therefore, its difficult treatment. Bacterial vaginosis is probably the result of vaginal colonization by complex bacterial communities, many of them non-cultivable and with interdependent metabolism where anaerobic populations most likely play an important role in its pathogenesis. The main symptoms are an increase of vaginal discharge and the unpleasant smell of it. It can lead to serious consequences for women, such as an increased risk of contracting sexually transmitted infections including human immunodeficiency virus and upper genital tract and pregnancy complications. Gram stain is the gold standard for microbiological diagnosis of BV, but can also be diagnosed using the Amsel clinical criteria. It should not be considered a sexually transmitted disease but it is highly related to sex. Recurrence is the main problem of medical treatment. Apart from BV, there are other dysbacteriosis less characterized like aerobic vaginitis of which further studies are coming slowly but are achieving more attention and consensus among specialists.

  13. Radar observations of the 2009 eruption of Redoubt Volcano, Alaska: Initial deployment of a transportable Doppler radar system for volcano-monitoring

    Science.gov (United States)

    Hoblitt, R. P.; Schneider, D. J.

    2009-12-01

    The rapid detection of explosive volcanic eruptions and accurate determination of eruption-column altitude and ash-cloud movement are critical factors in the mitigation of volcanic risks to aviation and in the forecasting of ash fall on nearby communities. The U.S. Geological Survey (USGS) deployed a transportable Doppler radar during the precursory stage of the 2009 eruption of Redoubt Volcano, Alaska, and it provided valuable information during subsequent explosive events. We describe the capabilities of this new monitoring tool and present data that it captured during the Redoubt eruption. The volcano-monitoring Doppler radar operates in the C-band (5.36 cm) and has a 2.4-m parabolic antenna with a beam width of 1.6 degrees, a transmitter power of 330 watts, and a maximum effective range of 240 km. The entire disassembled system, including a radome, fits inside a 6-m-long steel shipping container that has been modified to serve as base for the antenna/radome, and as a field station for observers and other monitoring equipment. The radar was installed at the Kenai Municipal Airport, 82 km east of Redoubt and about 100 km southwest of Anchorage. In addition to an unobstructed view of the volcano, this secure site offered the support of the airport staff and the City of Kenai. A further advantage was the proximity of a NEXRAD Doppler radar operated by the Federal Aviation Administration. This permitted comparisons with an established weather-monitoring radar system. The new radar system first became functional on March 20, roughly a day before the first of nineteen explosive ash-producing events of Redoubt between March 21 and April 4. Despite inevitable start-up problems, nearly all of the events were observed by the radar, which was remotely operated from the Alaska Volcano Observatory office in Anchorage. The USGS and NEXRAD radars both detected the eruption columns and tracked the directions of drifting ash clouds. The USGS radar scanned a 45-degree sector

  14. Monitoring and modeling of water flow and solute transport in the soil-plant-atmosphere system of poplar trees to evaluate the effectiveness of phytoremediation techniques.

    Science.gov (United States)

    Palladino, Mario; Di Fiore, Paola; Speranza, Giuseppe; Sica, Benedetto; Romano, Nunzio

    2015-04-01

    This work is part of a series of studies being carried out within the EU-Life+ project ECOREMED (Implementation of eco-compatible protocols for agricultural soil remediation in Litorale Domizio-Agro Aversano NIPS). The project refers to Litorale Domitio-Agro Aversano that has been identified as National Interest Priority Site (NIPS) and includes some polluted agricultural land belonging to more than 61 municipalities in the Naples and Caserta provinces of the Campania Region. The major aim of the project is to define an operating protocol for agriculture-based bioremediation of contaminated agricultural soils, also including the use of plant extracting pollutants to be used as biomasses for renewable energy production. This contribution specifically address the question of evaluating the effectiveness of phytoremediation actions selected by the project in the pilot area of Trentola-Ducenta and will provide some preliminary results of monitoring and modeling activities. A physical and hydraulic characterization has been carried out in this area where poplar trees were planted. Monitoring of water flow, root water uptake and solute transport in the soil-plant-atmosphere is under way with reference to two trees using capacitance soil moisture and matric potential sensors located at three different soil depths, whereas plant water status and evapotranspiration fluxes are indirectly estimated using fast-responding stem dendrometers.

  15. Radiological and Environmental Monitoring at the Clean Slate I and III Sites, Tonopah Test Range, Nevada, With Emphasis on the Implications for Off-site Transport

    Energy Technology Data Exchange (ETDEWEB)

    Mizell, Steve A [Desert Research Inst. (DRI), Las Vegas, NV (United States); Etyemezian, Vic [Desert Research Inst. (DRI), Las Vegas, NV (United States); McCurdy, Greg [Desert Research Inst. (DRI), Las Vegas, NV (United States); Nikolich, George [Desert Research Inst. (DRI), Las Vegas, NV (United States); Shadel, Craig [Desert Research Inst. (DRI), Las Vegas, NV (United States); Miller, Julianne J [Desert Research Inst. (DRI), Las Vegas, NV (United States)

    2014-09-01

    In 1963, the U.S. Department of Energy (DOE) (formerly the Atomic Energy Commission [AEC]) implemented Operation Roller Coaster on the Tonopah Test Range (TTR) and an adjacent area of the Nevada Test and Training Range (NTTR) (formerly the Nellis Air Force Range [NAFR]). Operation Roller Coaster consisted of four tests in which chemical explosions were detonated in the presence of nuclear devices to assess the dispersal of radionuclides and evaluate the effectiveness of storage structures to contain the ejected radionuclides. These tests resulted in the dispersal of plutonium over the ground surface downwind of the test ground zero (GZ). Three tests—Clean Slate I, II, and III—were conducted on the TTR in Cactus Flat. The fourth, Double Tracks, was conducted in Stonewall Flat on the NTTR. The Desert Research Institute (DRI) installed two monitoring stations in 2008, Station 400 at the Sandia National Laboratories (SNL) Range Operations Center (ROC) and Station 401 at Clean Slate III. Station 402 was installed at Clean Slate I in 2011 to measure radiological, meteorological, and dust conditions. The monitoring activity was implemented to determine if radionuclide contamination in the soil at the Clean Slate sites was being transported beyond the contamination area boundaries. Some of the data collected also permits comparison of radiological exposure at the TTR monitoring stations to conditions observed at Community Environmental Monitoring Program (CEMP) stations around the NTTR. Annual average gross alpha values from the TTR monitoring stations are higher than values from the surrounding CEMP stations. Annual average gross beta values from the TTR monitoring stations are generally lower than values observed for the surrounding CEMP stations. This may be due to use of sample filters with larger pore space because when glass-fiber filters began to be used at TTR Station 400, gross beta values increased. Gamma spectroscopy typically identified only naturally

  16. Continuous water-quality and suspended-sediment transport monitoring in the San Francisco Bay, California, water years 2011-13

    Science.gov (United States)

    Buchanan, Paul A.; Downing-Kunz, Maureen A.; Schoellhamer, David H.; Shellenbarger, Gregory; Weidich, Kurt W.

    2014-01-01

    The U.S. Geological Survey (USGS) monitors water quality and suspended-sediment transport in the San Francisco Bay. The San Francisco Bay area is home to millions of people, and the bay teems with both resident and migratory wildlife, plants, and fish. Fresh water mixes with salt water in the bay, which is subject both to riverine and marine (tides, waves, influx of salt water) influences. To understand this environment, the USGS, along with its partners, has been monitoring the bay’s waters continuously since 1988. Several water-quality variables are of particular importance to State and Federal resource managers and are monitored at key locations throughout the bay. Salinity, which indicates the relative mixing of fresh and ocean waters in the bay, is derived from specific conductance measurements. Water temperature, along with salinity, affects the density of water, which causes gravity driven circulation patterns and stratification in the water column. Turbidity is measured using light-scattering from suspended solids in water, and is used as a surrogate for suspended-sediment concentration (SSC). Suspended sediment often carries adsorbed contaminants; attenuates sunlight in the water column; deposits on tidal marsh and intertidal mudflats, which can help sustain these habitats as sea level rises; and deposits in ports and shipping channels, which can necessitate dredging. Dissolved oxygen, which is essential to a healthy ecosystem, is a fundamental indicator of water quality, and its concentration is affected by water temperature, salinity, ecosystem metabolism, tidal currents, and wind. Tidal currents in the bay reverse four times a day, and wind direction and intensity typically change on a daily cycle: consequently, salinity, water temperature, suspendedsediment concentration, and dissolvedoxygen concentration vary spatially and temporally throughout the bay, and continuous measurements are needed to observe these changes. The purpose of this fact sheet

  17. Towards monitoring transport of single cargos across individual nuclear pore complexes by time-lapse atomic force microscopy.

    Science.gov (United States)

    Huang, Ning-Ping; Stubenrauch, Mike; Köser, Joachim; Taschner, Nicole; Aebi, Ueli; Stolz, Martin

    2010-08-01

    A new preparation procedure was developed for the stable adsorption of either the cytoplasmic or the nuclear face of native (i.e. in physiological buffer without detergent extraction and in the absence of chemical fixatives) Xenopus oocyte nuclear envelopes (NEs) onto silicon (Si) surfaces. This yields optimal structural preservation of the nuclear pore complexes (NPCs) without compromising their functional properties. The functional viability of thus prepared NPCs was documented by time-lapse atomic force microscopy (AFM) of the reversible calcium-mediated opening (i.e. +Ca(2+)) and closing (i.e. -Ca(2+)) of the iris diaphragm-like distal ring topping the NPCs' nuclear baskets. Moreover, site-specific single colloidal gold particle detection was documented by AFM imaging one and the same NPC before and after immuno-gold labeling the sample with a nucleoporin-specific antibody. With this new preparation protocol at hand, we should eventually be able to follow by time-lapse AFM transport of single gold-conjugated cargos across individual NPCs.

  18. Monitoring cholinergic activity during attentional performance in mice heterozygous for the choline transporter: a model of cholinergic capacity limits.

    Science.gov (United States)

    Paolone, Giovanna; Mallory, Caitlin S; Koshy Cherian, Ajeesh; Miller, Thomas R; Blakely, Randy D; Sarter, Martin

    2013-12-01

    Reductions in the capacity of the human choline transporter (SLC5A7, CHT) have been hypothesized to diminish cortical cholinergic neurotransmission, leading to risk for cognitive and mood disorders. To determine the acetylcholine (ACh) release capacity of cortical cholinergic projections in a mouse model of cholinergic hypofunction, the CHT+/- mouse, we assessed extracellular ACh levels while mice performed an operant sustained attention task (SAT). We found that whereas SAT-performance-associated increases in extracellular ACh levels of CHT+/- mice were significantly attenuated relative to wildtype littermates, performance on the SAT was normal. Tetrodotoxin-induced blockade of neuronal excitability reduced both dialysate ACh levels and SAT performance similarly in both genotypes. Likewise, lesions of cholinergic neurons abolished SAT performance in both genotypes. However, cholinergic activation remained more vulnerable to the reverse-dialyzed muscarinic antagonist atropine in CHT+/- mice. Additionally, CHT+/- mice displayed greater SAT-disrupting effects of reverse dialysis of the nAChR antagonist mecamylamine. Receptor binding assays revealed a higher density of α4β2* nAChRs in the cortex of CHT+/- mice compared to controls. These findings reveal compensatory mechanisms that, in the context of moderate cognitive challenges, can overcome the performance deficits expected from the significantly reduced ACh capacity of CHT+/- cholinergic terminals. Further analyses of molecular and functional compensations in the CHT+/- model may provide insights into both risk and resiliency factors involved in cognitive and mood disorders.

  19. Remote Maintenance Monitoring System -

    Data.gov (United States)

    Department of Transportation — The Remote Maintenance and Monitoring System (RMMS) is a collection of subsystems that includes telecommunication components, hardware, and software, which serve to...

  20. A self-referencing biosensor for real-time monitoring of physiological ATP transport in plant systems.

    Science.gov (United States)

    Vanegas, Diana C; Clark, Greg; Cannon, Ashley E; Roux, Stanley; Chaturvedi, Prachee; McLamore, Eric S

    2015-12-15

    The objective of this study was to develop a self-referencing electrochemical biosensor for the direct measurement of ATP flux into the extracellular matrix by living cells/organisms. The working mechanism of the developed biosensor is based on the activity of glycerol kinase and glycerol-3-phosphate oxidase. A stratified bi-enzyme nanocomposite was created using a protein-templated silica sol gel encapsulation technique on top of graphene-modified platinum electrodes. The biosensor exhibited excellent electrochemical performance with a sensitivity of 2.4±1.8 nA/µM, a response time of 20±13 s and a lower detection limit of 1.3±0.7 nM. The self-referencing biosensor was used to measure exogenous ATP efflux by (i) germinating Ceratopteris spores and (ii) growing Zea mays L. roots. This manuscript demonstrates the first development of a non-invasive ATP micro-biosensor for the direct measurement of eATP transport in living tissues. Before this work, assays of eATP have not been able to record the temporally transient movement of ATP at physiological levels (nM and sub-nM). The method demonstrated here accurately measured [eATP] flux in the immediate vicinity of plant cells. Although these proof of concept experiments focus on plant tissues, the technique developed herein is applicable to any living tissue, where nanomolar concentrations of ATP play a critical role in signaling and development. This tool will be invaluable for conducting hypothesis-driven life science research aimed at understanding the role of ATP in the extracellular environment.

  1. Site S-7 VOC Transport modeling for the Vadose Zone Monitoring System (VZMS), McClellan AFB - 1999 Semi-Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Doughty, Christine; Oldenburg, Curtis M.; James, April L.

    1999-06-15

    Enhanced data analysis is continuing for the Vadose Zone Monitoring System (VZMS) installed at site S-7 in IC 34 at McClellan AFB. Air temperatures along with data from the four highest levels of thermistors in VZMS-A and B are used with an analytical solution for the heat conduction equation to show that heat transfer in the shallow vadose zone at S-7 is conduction-dominated. This analysis is extended to reveal that stiace temperature, i.e., the temperature of the concrete slab at S-7, is significantly higher in summer than the surrounding air temperature. These high temperatures in the shallow vadose zone can lead to increased volatilization of VOCS. Seasonal temperature reversals can cause upward buoyant gas flow in the uppermost 30 feet of the vadose zone in the winter. Data on gas-phase VOC concentrations in VZMS-A and B show highest concentrations in the shallow subsurface, low concentrations between depths of 30-70 feet, and slightly higher concentrations near the water table. Modeling VOC flow and transport subject to the constraints of data collected by the VZMS requires extension of the one-dimensional site-representative model used previously. Conceptual models broadly consistent with these data include (1) a diffusion-only model; (2) a preferential flow model; or (3) two- and three-dimensional flow models where the VOC plume undergoes lateral migration. Simulations of VOC transport suggest that there are VOCS at depths shallower than 6 feet, that significant NAPL is unlikely to be present, and that a source of VOCS may be provided by lateral flow in the gravel layer between two concrete layers present at the site. The conceptual models upon which VOC transport modeling is based require further development and testing. Prior Vapour-T modeling results for the S-7 site based on cis-1,2-DCE concentrations in well SS7SB08 are not substantiated by VZMS data, but these data are localized whereas VapourT results are generalized for the S-7 site as a whole

  2. 基于物联网技术的高速公路交通流监控研究%Study on Monitoring of Highway Traffic Transportation Flow on Internet of Things

    Institute of Scientific and Technical Information of China (English)

    陈军

    2012-01-01

    In order to improve the monitoring efficient of the highway traffic transportation flow effectively, and prevent the traffic accidents, and the application of internet of things on it is studied in depth, first, the character of the highway transportation flow is analyzed, and then the basic theory of the application of the internet of thing on the detection of the highway traffic transportation flow is studied, and then model of the highway transportation flow is discussed. Next the hardware and software of the monitoring system of the highway transportation flow is designed. Finally, the simulation analysis of real-time monitoring of a highway transportation flow is carried out, and results show that the internet of things has broad prospects for development on the monitoring of the highway traffic transportation flow.%为了能够有效地提高高速公路交通流监控的效率,防止交通事故的发生,深入地研究了物联网技术在其中的应用.首先,分析了高速公路交通流的特点.其次,研究了物联网在高速公路交通流监控中应用的基本原理.接着,讨论了高速公路交通流的模型.接下来,设计了高速公路交通流监控制系统的软件和硬件.最后,进行了高速公路交通流实时监控仿真研究.仿真结果表明物联网技术在高速公路交通流监控中具有较广阔的发展前景.

  3. Influence of heterogeneous ammonium availability on bacterial community structure and the expression of nitrogen fixation and ammonium transporter genes during in situ bioremediation of uranium-contaminated groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Mouser, P.J.; N' Guessan, A.L.; Elifantz, H.; Holmes, D.E.; Williams, K.H.; Wilkins, M.J.; Long, P.E.; Lovley, D.R.

    2009-04-01

    The impact of ammonium availability on microbial community structure and the physiological status and activity of Geobacter species during in situ bioremediation of uranium-contaminated groundwater was evaluated. Ammonium concentrations varied by as much as two orders of magnitude (<4 to 400 {micro}M) across the study site. Analysis of 16S rRNA gene sequences suggested that ammonium influenced the composition of the microbial community prior to acetate addition with Rhodoferax species predominating over Geobacter species at the site with the highest ammonium, and Dechloromonas species dominating at sites with lowest ammonium. However, once acetate was added, and dissimilatory metal reduction was stimulated, Geobacter species became the predominant organisms at all locations. Rates of U(VI) reduction appeared to be more related to the concentration of acetate that was delivered to each location rather than the amount of ammonium available in the groundwater. In situ mRNA transcript abundance of the nitrogen fixation gene, nifD, and the ammonium importer gene, amtB, in Geobacter species indicated that ammonium was the primary source of nitrogen during in situ uranium reduction, and that the abundance of amtB transcripts was inversely correlated to ammonium levels across all sites examined. These results suggest that nifD and amtB expression by subsurface Geobacter species are closely regulated in response to ammonium availability to ensure an adequate supply of nitrogen while conserving cell resources. Thus, quantifying nifD and amtB expression appears to be a useful approach for monitoring the nitrogen-related physiological status of Geobacter species in subsurface environments during bioremediation. This study also emphasizes the need for more detailed analysis of geochemical/physiological interactions at the field scale, in order to adequately model subsurface microbial processes.

  4. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

    tract to the microbial flocs in waste water treatment facilities. Microbial biofilms may however also cause a wide range of industrial and medical problems, and have been implicated in a wide range of persistent infectious diseases, including implantassociated microbial infections. Bacterial adhesion...... in the formation of highly complex sessile communities, referred to as biofilms. Such microbial communities are often highly dynamic and heterogeneous in nature. Microbial biofilms are of great importance in a wide range of natural processes and industrial settings, from the commensal flora of the gastrointestinal...

  5. Monte Carlo transport simulation for a long counter neutron detector employed as a cosmic rays induced neutron monitor at ground level

    Energy Technology Data Exchange (ETDEWEB)

    Pazianotto, Mauricio Tizziani; Carlson, Brett Vern [Instituto Tecnologico de Aeronautica (ITA), Sao Jose dos Campos, SP (Brazil); Federico, Claudio Antonio; Goncalez, Odair Lelis [Centro Tecnico Aeroespacial (CTA), Sao Jose dos Campos, SP (Brazil). Instituto de Estudos Avancados

    2011-07-01

    Full text: Great effort is required to understand better the cosmic radiation (CR) dose received by sensitive equipment, on-board computers and aircraft crew members at Brazil airspace, because there is a large area of South America and Brazil subject to the South Atlantic Anomaly (SAA). High energy neutrons are produced by interactions between primary cosmic ray and atmospheric atoms, and also undergo moderation resulting in a wider spectrum of energy ranging from thermal energies (0:025eV ) to energies of several hundreds of MeV. Measurements of the cosmic radiation dose on-board aircrafts need to be followed with an integral flow monitor on the ground level in order to register CR intensity variations during the measurements. The Long Counter (LC) neutron detector was designed as a directional neutron flux meter standard because it presents fairly constant response for energy under 10MeV. However we would like to use it as a ground based neutron monitor for cosmic ray induced neutron spectrum (CRINS) that presents an isotropic fluency and a wider spectrum of energy. The LC was modeled and tested using a Monte Carlo transport simulation for irradiations with known neutron sources ({sup 241}Am-Be and {sup 251}Cf) as a benchmark. Using this geometric model its efficiency was calculated to CRINS isotropic flux, introducing high energy neutron interactions models. The objective of this work is to present the model for simulation of the isotropic neutron source employing the MCNPX code (Monte Carlo N-Particle eXtended) and then access the LC efficiency to compare it with experimental results for cosmic ray neutrons measures on ground level. (author)

  6. Monitoring of long range transported pollutants. Annual report for 1997; Overvaaking av langtransportert forurenset luft og nedboer. Atmosfaerisk tilfoersel, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Luekewille, A.; Manoe, S.; Toerseth, K

    1998-05-01

    The report includes the 1997 monitoring results from the rural air and precipitation chemistry network in Norway. In 1997, main components in precipitation were measured at 33 sites. Trace elements were determined at 14 sites, air concentrations of sulphur and nitrogen compounds at 13 sites and ozone concentrations at 14 sites. An overview of the measurement programme is given in appendix B2. The highest mean volume weighted concentrations of sulphate, nitrate, ammonium and strong acid in precipitation were found along the southern Norwegian coast. The lowest values were measured in the central and northern parts of Norway. In almost all parts of the country the mean pollutant concentrations in precipitation were generally lower in 1997 compared to 1996. At most places in Norway pollutant deposition was generally the lowest measured so far. The annual mean concentrations of sulphate and strong acid in precipitation have been decreasing since the end of the 1970's. Since 1980 the content of sulphate has decreased by about 40-55% in southern Norway and by about 50-60% in northern Norway. The observed reductions in concentration levels are in agreement with reported downwards trends in pollutant emissions in Europe. There is no significant decrease in nitrogen compounds in precipitation. Sea salts deposited along the western coast was measured. The highest content of particulate sulphate and of nitrogen components in air and precipitation were measured in southern Norway. Due to emissions from nickel smelters in Russia the mean concentrations of sulphur dioxide were highest in Finnmark. The annual mean air concentrations of particulate sulphate have generally decreased by 45 to 60% compared to those measured in 1980. At Ny-Aalesund, annual mean concentrations of sulphur dioxide and sulphate have decreased by 58% and 54%, respectively. Since the late 1970's, the mean concentrations have shown similar developments in all parts of Norway. Due to emission

  7. Monitoring of long range transported pollutants. Annual report for 1997; Overvaaking av langtransportert forurenset luft og nedboer. Atmosfaerisk tilfoersel, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Luekewille, A.; Manoe, S.; Toerseth, K

    1998-05-01

    The report includes the 1997 monitoring results from the rural air and precipitation chemistry network in Norway. In 1997, main components in precipitation were measured at 33 sites. Trace elements were determined at 14 sites, air concentrations of sulphur and nitrogen compounds at 13 sites and ozone concentrations at 14 sites. An overview of the measurement programme is given in appendix B2. The highest mean volume weighted concentrations of sulphate, nitrate, ammonium and strong acid in precipitation were found along the southern Norwegian coast. The lowest values were measured in the central and northern parts of Norway. In almost all parts of the country the mean pollutant concentrations in precipitation were generally lower in 1997 compared to 1996. At most places in Norway pollutant deposition was generally the lowest measured so far. The annual mean concentrations of sulphate and strong acid in precipitation have been decreasing since the end of the 1970's. Since 1980 the content of sulphate has decreased by about 40-55% in southern Norway and by about 50-60% in northern Norway. The observed reductions in concentration levels are in agreement with reported downwards trends in pollutant emissions in Europe. There is no significant decrease in nitrogen compounds in precipitation. Sea salts deposited along the western coast was measured. The highest content of particulate sulphate and of nitrogen components in air and precipitation were measured in southern Norway. Due to emissions from nickel smelters in Russia the mean concentrations of sulphur dioxide were highest in Finnmark. The annual mean air concentrations of particulate sulphate have generally decreased by 45 to 60% compared to those measured in 1980. At Ny-Aalesund, annual mean concentrations of sulphur dioxide and sulphate have decreased by 58% and 54%, respectively. Since the late 1970's, the mean concentrations have shown similar developments in all parts of Norway. Due to emission

  8. Bacterial hydrodynamics

    CERN Document Server

    Lauga, Eric

    2015-01-01

    Bacteria predate plants and animals by billions of years. Today, they are the world's smallest cells yet they represent the bulk of the world's biomass, and the main reservoir of nutrients for higher organisms. Most bacteria can move on their own, and the majority of motile bacteria are able to swim in viscous fluids using slender helical appendages called flagella. Low-Reynolds-number hydrodynamics is at the heart of the ability of flagella to generate propulsion at the micron scale. In fact, fluid dynamic forces impact many aspects of bacteriology, ranging from the ability of cells to reorient and search their surroundings to their interactions within mechanically and chemically-complex environments. Using hydrodynamics as an organizing framework, we review the biomechanics of bacterial motility and look ahead to future challenges.

  9. THE CONTROL MEASURES AND MONITORING FOR BACTERIAL CONTAMINATION OF MEDICALLY USED WATER IN DENTAL DEPARTMENTS%口腔科医疗用水细菌污染控制与监测

    Institute of Scientific and Technical Information of China (English)

    邵卫东; 李艳娟; 郑岗; 魏慧

    2013-01-01

    Objective To understand the hygiene quality of medically used water in dental department and to discuss control measures for bacterial contamination. Methods Water sampling and bacterial detection tests were used to monitor the hygiene quality of medically used water in dental department of this hospital and to compare effects of different control measures. Results During January 2008 to December 2009, in the medically used water in dental department of this hospital, the qualified rate of hygiene quality of dental handpiece water was 23. 1% , that was 42. 0% for the three ways syringe. From March 2010 to September 2010, after filters were equipped, the qualified rate of hygiene quality of dental hand-piece water was 24. 7% , that was 36. 1% for the three ways syringe,50. 0% for the water source and 100% for the washing water. Conclusion The hygiene quality of medically used water in dental department of this hospital is poor and the water quality is associated with municipal water supply. The water quality improvements are not distinct simply plusing filters so comprehensive management measures should be taken.%目的 了解口腔科医疗用水卫生质量状况,探讨其细菌污染控制措施.方法 通过收集水样和细菌检验方法,对本医院口腔科医疗用水卫生质量进行了监测,比较不同控制措施的效果.结果 在2008年1月-2009年12月期间,本医院口腔科医疗用水中,手机喷水卫生质量合格率为23.1%,三用枪喷水卫生质量合格率为42.0%.2010年3-9月,口腔科医疗用水加过滤装置后,手机喷水卫生质量合格率为24.7%,三用枪喷水合格率为36.1%,水源水质量合格率为50.0%,洗涤用水合格率为100%.结论 医院口腔科医疗用水卫生质量堪忧,其水质直接受市政供水水质影响,简单加过滤器效果改善不明显,需要综合管理措施.

  10. Analysis of the use of antimicrobial agents and the monitoring of bacterial resistance%2011-2013年我院抗菌药物使用与细菌耐药性监测的分析

    Institute of Scientific and Technical Information of China (English)

    宋桂芳; 王韵

    2015-01-01

    Objective:To analyze relevance between the DDDs of antimicrobial agents and the drug resistance of common clinical pathogens in our hospital during 2011-2013 so as to provide a basis for guiding rational drug use. Methods:The number of consumption of antimicrobial agents and the incidence of major drug resistant pathogens were statistically analyzed and the related data were compared. Results:The DDDs of the third generation of cephalosporins, cephamycins, carbapenems and macrolides showed an upward trend, and the rates of drug resistance of main bacteria such as Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa Bowman/hemolytic Acinetobacter, Staphylococcus aureus and so on also showed an increasing trend. Conclusion:The DDDs of antimicrobial agents and bacterial resistance are closely related and therefore the management of antimicrobial agents should be further strengthened and improved and great attention should be paid to the monitoring of bacterial resistance.%目的:分析我院抗菌药物用药频度及与临床常见致病菌耐药情况的关联性,为指导合理用药提供依据。方法:对本院2011-2013年抗菌药物消耗数量进行统计分析,并对主要致病菌的耐药率进行统计,分析比较相关数据。结果:三代头孢菌素、头霉素类、碳青霉烯类和大环内酯类的DDDs呈上升趋势,主要致病菌大肠埃希氏菌、肺炎克雷伯氏菌、铜绿假单胞菌、鲍曼/溶血不动杆菌、金黄色葡萄球菌等的耐药率也呈逐年上升的趋势。结论:抗菌药物的DDDs对细菌耐药率关联性高,医院需要进一步加强和完善抗菌药物的管理,对细菌耐药率监测应高度重视。

  11. Pregnancy Complications: Bacterial Vaginosis

    Science.gov (United States)

    ... Complications & Loss > Pregnancy complications > Bacterial vaginosis and pregnancy Bacterial vaginosis and pregnancy E-mail to a friend Please ... this page It's been added to your dashboard . Bacterial vaginosis (also called BV or vaginitis) is an infection ...

  12. Pregnancy Complications: Bacterial Vaginosis

    Science.gov (United States)

    ... Loss > Pregnancy complications > Bacterial vaginosis and pregnancy Bacterial vaginosis and pregnancy E-mail to a friend Please ... page It's been added to your dashboard . Bacterial vaginosis (also called BV or vaginitis) is an infection ...

  13. Bacterial vaginosis -- aftercare

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000687.htm Bacterial vaginosis - aftercare To use the sharing features on this ... back after you use the bathroom. Preventing Bacterial Vaginosis You can help prevent bacterial vaginosis by: Not ...

  14. Bacterial pericarditis (image)

    Science.gov (United States)

    Bacterial pericarditis is an inflammation of the pericardium, the sac-like covering of the heart, caused by a bacterial infection. The bacterial infection causes inflammation and swelling of the pericardium. Pain ...

  15. Bacterial oligopeptide-binding proteins.

    Science.gov (United States)

    Monnet, V

    2003-10-01

    This review focuses on bacterial oligopeptide-binding proteins, which form part of the oligopeptide transport system belonging to the ATP-binding cassette family of transporters. Depending on the bacterial species, these binding proteins (OppA) capture peptides ranging in size from 2 to 18 amino acids from the environment and pass them on to the other components of the oligopeptide transport system for internalisation. Bacteria have developed several strategies to produce these binding proteins, which are periplasmic in Gram- bacteria and membrane-anchored in Gram+, with a higher stoichiometry (probably necessary for efficient transport) than the other components in the transport system. The expression of OppA-encoding genes is clearly modulated by external factors, especially nitrogen compounds, but the mechanisms of regulation are not always clear. The best-understood roles played by OppAs are internalisation of peptides for nutrition and recycling of muropeptides. It has, however, recently become clear that OppAs are also involved in sensing the external medium via specific or non-specific peptides.

  16. Monitoring of Emerging and Legacy Contaminants in Groundwater and Tap Water of the Karst Region in Northern Puerto Rico for Assessment of Sources and Fate and Transport Processes

    Science.gov (United States)

    Padilla, I. Y.; Cotto, I.; Torres, P. M.

    2014-12-01

    The karst aquifer region of northern Puerto Rico is the area with the highest groundwater extraction in the island. Urban and industrial development has led to extensive contamination of the groundwater in the region. Of particular concern, is the presence of emerging and legacy organic contaminants, such as phthalates and chlorinated organic compounds (CVOCs), because there high risk for exposure and adverse health impact. Variable sources and the heterogeneous and dynamic conditions of karst groundwater systems, limits the ability to properly assess and manage the water quality of these precious water resources. This work develops a monitoring and water analysis scheme to assess spatial-temporal exposure of hazardous contaminants trough karst water in northern Puerto Rico. Groundwater and tap water are sampled in the region and analyzed for phthalates, CVOCs, and common ions. Detections and concentrations of phthalates and CVOCs are determined by using modified EPA methods, which rely on liquid-liquid extractions and gas chromatography techniques. The modified methods have reduced the volume of samples and solvent waste, decreased the time of analysis, increased analysis outcomes, and lower potential for hazardous exposure. Results show intermittent presence of di-ethyl, di-butyl and di (2-ethyl hexyl) phthalates in 36% of the groundwater and 53% of tap water samples, with detected concentrations ranging between 0.1-88.7 μg/L. These results indicate that karst groundwater can serve as a route of exposure for phthalates, but there are additional disperse sources in the water system. CVOCs are detected in groundwater at much higher frequencies (50%) than phthalates, and include trichloromethane (TCM), carbon tetrachloride (CT), trichloroethylene (TCE), and tetrachloroethylene (TCE). CVOCs, except for TCM, are found at lower frequencies on tap water (5.8%) than groundwater (27%). TCM is detected more frequently and at higher concentrations in tap water (56.8%) than

  17. Design of an intelligent monitoring microsystem for dangerous/fragile cargo transportation%危险/易损货物运输监测智能微系统设计

    Institute of Scientific and Technical Information of China (English)

    娄文忠; 郭明儒; 祖绍鹏

    2012-01-01

    针对当前物流行业发展需求及现有监测系统的不足,提出了一种新的危险/易损货物运输监测智能微系统.该系统采用信息管理分系统、数据交换分系统和状态监测分系统3层构架,分别实现信息管理、数据传输和状态监测等功能,形成了全程、多态、实时的货物监测网络.系统采用模块化设计,通过独立的微型模块执行感知、处理、传输和存储等功能,并可根据需求进行模块裁剪.系统充分采用MEMS技术成果,实现了小型化、低功耗.试运行结果表明,该系统可以对危险/易损货物的运输实施有效监控,有助于提高物流的安全性和信息化.%An intelligent micro-system system is designed to monitor the transportation of dangerous/ fragile goods. It is necessary to monitor the transportation of special goods such as toxic substances or fireworks, but the correlation systems or devices have some deficiencies in the functional integrity and application scope. A novel monitoring system is designed to solve this problem. The new system consists of information management subsystem, communication subsystem and monitoring subsystem. The information management subsystem includes a server and several clients. It manages the data of the system and provides query functions. The communication subsystem is mainly used to convert the communication protocols. The monitoring subsystem is the key of the whole system which performs the functions of monitoring, data processing and safety assessing. The three parts work together to form a powerful net that could realize real-time monitoring. The monitoring subsystem, which adapts modularization design, can be divided into several function modules such as controlling module, detecting module, communicating module, etc. These modules are connected by internal bus, so the monitoring subsystem is scalable to meet the requirements of different customers. The MEMS technology and achievements

  18. Hygiene monitoring in a hospital immunohaematological laboratory.

    Science.gov (United States)

    Strobel, E; Gleich, P

    2015-01-01

    Not only in blood donation services, but also in the immunohaematological laboratory of a hospital including the depository for blood products a hygiene plan must be drawn up and its realization has to be documented. From 2011 to 2014, some equipment in the depository and in the immunohematological laboratory was microbiologically monitored once a year. The examinations were done by direct contact cultures taken from several places of each device. Most of the devices showed inconspicuous numbers of environmental microorganisms. Sometimes the refrigerators for fresh frozen plasma and a transport container for blood products revealed moderately, the incubator in the laboratory and a transport container for patient blood samples inadequately increased bacterial contamination. Microbiological examinations can detect critical points in the immunohaematological laboratory of a hospital. By communicating these results, the staff can be motivated to observe the regulations of the hygiene plan. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  19. Water-quality variability and constituent transport and processes in streams of Johnson County, Kansas, using continuous monitoring and regression models, 2003-11

    Science.gov (United States)

    Rasmussen, Teresa; Gatotho, Jackline

    2014-01-01

    The population of Johnson County, Kansas increased by about 24 percent between 2000 and 2012, making it one of the most rapidly developing areas of Kansas. The U.S. Geological Survey, in cooperation with the Johnson County Stormwater Management Program, began a comprehensive study of Johnson County streams in 2002 to evaluate and monitor changes in stream quality. The purpose of this report is to describe water-quality variability and constituent transport for streams representing the five largest watersheds in Johnson County, Kansas during 2003 through 2011. The watersheds ranged in urban development from 98.3 percent urban (Indian Creek) to 16.7 percent urban (Kill Creek). Water-quality conditions are quantified among the watersheds of similar size (50.1 square miles to 65.7 square miles) using continuous, in-stream measurements, and using regression models developed from continuous and discrete data. These data are used to quantify variability in concentrations and loads during changing streamflow and seasonal conditions, describe differences among sites, and assess water quality relative to water-quality standards and stream management goals. Water quality varied relative to streamflow conditions, urbanization in the upstream watershed, and contributions from wastewater treatment facilities and storm runoff. Generally, as percent impervious surface (a measure of urbanization) increased, streamflow yield increased. Water temperature of Indian Creek, the most urban site which is also downstream from wastewater facility discharges, was higher than the other sites about 50 percent of the time, particularly during winter months. Dissolved oxygen concentrations were less than the Kansas Department of Health and Environment minimum criterion of 5 milligrams per liter about 15 percent of the time at the Indian Creek site. Dissolved oxygen concentrations were less than the criterion about 10 percent of the time at the rural Blue River and Kill Creek sites, and less than

  20. The structure of glutamate transporters shows channel-like features

    NARCIS (Netherlands)

    Slotboom, DJ; Konings, WN; Lolkema, JS

    2001-01-01

    Neuronal and glial glutamate transporters remove the excitatory neurotransmitter glutamate from the synaptic cleft and thus prevent neurotoxicity, The proteins belong to a large family of secondary transporters, which includes transporters from a variety of bacterial, archaeal and eukaryotic organis

  1. Study on Environmental Monitoring Network Information Management System of Transportation Industry on GIS%基于GIS的交通运输行业环境监测网络信息管理系统研究

    Institute of Scientific and Technical Information of China (English)

    赵兵

    2012-01-01

    In this paper, study on environmental monitoring network information management system of transportation industry were analyzed by using GIS. The technical characters of the environmental monitoring network information management system of transportation industry were analyzed . Some problems relevant to the establishment of the environmental monitoring network information management system of transportation industry were discussed. The paper provided scientifical support for traffic environment construction.%利用地理信息系统(GIS)技术在交通运输行业研究中开展了环境监测网络信息管理系统方面的应用研究,分析了交通运输行业环境监测网络信息管理系统的技术特征,并对建立交通运输行业环境监测网络信息管理系统的一些问题进行了探讨,为交通环境建设提供科学支持。

  2. Application of Load Sense and GPS Positioning Technologies in Monitoring of Nightsoil Collection and Transportation%车载负重感应与GPS定位技术在粪渣收运监管中的应用

    Institute of Scientific and Technical Information of China (English)

    周超; 王芙蓉

    2011-01-01

    以深圳市为例,总结了现有粪便收运方式存在的问题.通过在粪渣收运车上安装压力传感器和GPS定位系统,并通过对测量数据的无线远传,实现了对粪渣收运车行走路线和质量变化情况的实时监控.%Taking Shenzhen city as an example, existing problems in the present nightsoil collection and transportation mode were summarized. By equipped with pressure sensor and GPS positioning system on vehicle for nightsoil rollpction and transportation, and through wireless remote transmission of measurement data, real-time monitoring of transportation route and nightsoil weight can be come true.

  3. IrLaW an OGC compliant infrared thermography measurement system developed on mini PC with real time computing capabilities for long term monitoring of transport infrastructures

    Science.gov (United States)

    Dumoulin, J.; Averty, R.

    2012-04-01

    One of the objectives of ISTIMES project is to evaluate the potentialities offered by the integration of different electromagnetic techniques able to perform non-invasive diagnostics for surveillance and monitoring of transport infrastructures. Among the EM methods investigated, uncooled infrared camera is a promising technique due to its dissemination potential according to its relative low cost on the market. Infrared thermography, when it is used in quantitative mode (not in laboratory conditions) and not in qualitative mode (vision applied to survey), requires to process in real time thermal radiative corrections on raw data acquired to take into account influences of natural environment evolution with time. But, camera sensor has to be enough smart to apply in real time calibration law and radiometric corrections in a varying atmosphere. So, a complete measurement system was studied and developed with low cost infrared cameras available on the market. In the system developed, infrared camera is coupled with other sensors to feed simplified radiative models running, in real time, on GPU available on small PC. The system studied and developed uses a fast Ethernet camera FLIR A320 [1] coupled with a VAISALA WXT520 [2] weather station and a light GPS unit [3] for positioning and dating. It can be used with other Ethernet infrared cameras (i.e. visible ones) but requires to be able to access measured data at raw level. In the present study, it has been made possible thanks to a specific agreement signed with FLIR Company. The prototype system studied and developed is implemented on low cost small computer that integrates a GPU card to allow real time parallel computing [4] of simplified radiometric [5] heat balance using information measured with the weather station. An HMI was developed under Linux using OpenSource and complementary pieces of software developed at IFSTTAR. This new HMI called "IrLaW" has various functionalities that let it compliant to be use in

  4. Bacterial toxins and Multiple Sclerosis.

    Science.gov (United States)

    Gay, Frederick

    2007-11-15

    The primary pathogenetic mechanism responsible for the distinctive demyelinating lesions in the Central Nervous System (CNS) in Multiple Sclerosis (MS), first described in remarkable detail by Charcot more than 170 years ago, remains one of the most baffling conundrums in medicine. A possible role for bacterial cell molecules and transportable proteins in the pathogenesis of MS is reviewed. The ability of bacterial toxins to distort immunity and to cause distinctive toxic damage in the nervous system is discussed in the light of largely forgotten data linking bacterial nasopharyngeal infections with optic neuritis, optochiasmatic arachnoiditis and MS. While the blood-brain barrier substantially protects the CNS from hematogenous toxins, there is a route by which the barrier may be by-passed. Data is reviewed which shows that the CSF and extra-cellular fluid circulation is bi-directionally linked to the lymphatic drainage channels of the nasopharyngeal mucosa. While this provides a facility by which the CNS may mount immunological responses to antigenic challenges from within, it is also a route by which products of nasopharyngeal infection may drain into the CNS and be processed by the immune cells of the meninges and Virchow-Robin perivascular spaces. If potentially toxic bacterial products are identified in early MS tissues at these sites, this would provide an entirely new insight into the pathogenetic mechanisms of this frustratingly enigmatic disease.

  5. Binding and entry of DNA in bacterial transformation

    Energy Technology Data Exchange (ETDEWEB)

    Lacks, S.A.

    1976-01-01

    Bacterial transformation in relation to DNA transport and competence in Streptococcus pneumoniae (also called Diplococcus pneumoniae) is discussed. This species will serve as a model with which to compare transformation in other bacterial species, particularly Bacillus subtilis and Haemophilus influenzae, with emphasis on the many similarities as well as differences.

  6. Bacterial toxins and small molecules elucidate endosomal trafficking.

    Science.gov (United States)

    Slater, Louise H; Clatworthy, Anne E; Hung, Deborah T

    2014-02-01

    Bacterial toxins and small molecules are useful tools for studying eukaryotic cell biology. In a recent issue of PNAS, Gillespie and colleagues describe a novel small molecule inhibitor of bacterial toxins and virus trafficking through the endocytic pathway, 4-bromobenzaldehyde N-(2,6-dimethylphenyl)semicarbazone (EGA), that prevents transport from early to late endosomes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Virtual reality transfer protocol (VRTP): implementing a monitor application for the Real-time Transport Protocol (RTP) using the Java Media Framework (JMF)

    OpenAIRE

    Afonso, Francisco Carlos

    1999-01-01

    Approved for public release; distribution is unlimited The Real-time Transport Protocol (RTP) supports the transmission of time-based media, such as audio and video, over wide-area networks (WANs), by adding synchronization and quality-of-service (QoS) feedback capabilities to the existing transport protocol. RTP has been widely used in the Multicast Backbone (MBone), a virtual network that has become a shared worldwide medium for Internet multicast communications. This work presents the d...

  8. Anti-bacterial compounds from the sponge Haliclona sp.

    Digital Repository Service at National Institute of Oceanography (India)

    Parameswaran, P.S.; Kamat, S.Y.; Chandramohan, D.; Nair, S.; Das, B.

    The crude methanolic extract of the sponge Haliclona sp., collected off Gujarat coast exhibited promising anti-viral (in vitro, 75%) and anti-bacterial properties Partitioning of the extract between various organic solvents, monitored by bioassay...

  9. UF-1000i尿沉渣分析仪细菌计数在院感卫生学监测中的应用%Application Value of Bacterial Counts with UF-1000i Urinalysis Analyzer in Health Monitoring of Hospital Infection

    Institute of Scientific and Technical Information of China (English)

    李朝金; 古小琼; 李靖; 伍玉容

    2011-01-01

    Objective To discussion the value of bacterial counts with UF-1000i urinalysis analyzer (next called the UF-1000i) in health monitoring of hospital infection. Methods Direct sampling of sterile/sterile saline and broth samples corresponding to the 160. Use the UF 1000i for bacterial counts in the former and the latter were cultured. To determine the degree of agreement of UF-1000i bacterial count compared with the culture of monitoring results. Results UF-1000i bacterial counts and culture on the coincidence of the monitoring results were determined:determination of qualified, 100%and judgement on failure:the latter than the former. Iodine and alcohol could not be determined. Conclusion UF-1000i bacteria count could be used for health monitoring of hospital infection of surface ,the hands of medical staff and the using glutaraldehyde, sodium hypochlorite,etc. It could play the role of screening and rapid detection,and save a lot of manpower and material resources ,and also identify problems in time and benefit to a better hospital infection control.%目的 探讨UF-1000i尿沉渣分析仪(下称UF-1000i)的细菌计数在医院感染卫生学监测中的应用价值.方法 同时用无菌管直接采样/无菌生理盐水和中和试剂对应采样各160份,前者用UF-1000i进行细菌计数,后者进行培养,比较UF-1000i细菌计数与培养法对监测结果判定的吻合程度.结果 UF-1000i细菌计数与培养法对监测结果判定的吻合程度分别为:对合格的判定,100%;对不合格的判定,前者多于后者.碘酒和酒精UF-1000i无法判定.结论 UF-1000i细菌计数可用于物体表面、医护人员手以及使用中的戊二醛、次氯酸钠等消毒液的院感卫生学监测,可起到过筛、快速检测的作用,节省大量人力物力的同时还可及时发现问题,有利于更好的院感控制.

  10. Electromagnetism of Bacterial Growth

    Science.gov (United States)

    Ainiwaer, Ailiyasi

    2011-10-01

    There has been increasing concern from the public about personal health due to the significant rise in the daily use of electrical devices such as cell phones, radios, computers, GPS, video games and television. All of these devices create electromagnetic (EM) fields, which are simply magnetic and electric fields surrounding the appliances that simultaneously affect the human bio-system. Although these can affect the human system, obstacles can easily shield or weaken the electrical fields; however, magnetic fields cannot be weakened and can pass through walls, human bodies and most other objects. The present study was conducted to examine the possible effects of bacteria when exposed to magnetic fields. The results indicate that a strong causal relationship is not clear, since different magnetic fields affect the bacteria differently, with some causing an increase in bacterial cells, and others causing a decrease in the same cells. This phenomenon has yet to be explained, but the current study attempts to offer a mathematical explanation for this occurrence. The researchers added cultures to the magnetic fields to examine any effects to ion transportation. Researchers discovered ions such as potassium and sodium are affected by the magnetic field. A formula is presented in the analysis section to explain this effect.

  11. Design of monitoring system for locomotive transportation in mines based on ARM9 and ZigBee%基于ARM9和ZigBee的矿井机车运输监控系统的设计

    Institute of Scientific and Technical Information of China (English)

    刘广亚; 姚善化

    2012-01-01

    In order to further enhance the security and effectiveness of locomotive transportation in underground collieries,the paper designed a monitoring system for locomotive transportation based on embedded and ZigBee technology,and described the design scheme and the operation principle of the monitoring system as well as the structure of the structure,the basic structure of the nodes,node communication and software design and so on.With the combination of ZigBee wireless network and all-optical network,the intelligent monitor of locomotive transportation conditions was realized.It will be of great reality significance for improving the safe production and management in mines.%为了进一步提高煤矿井下机车运输管理的安全性和有效性,设计了基于嵌入式和ZigBee技术的机车运输监控系统,介绍了系统的设计方案和工作原理,包括系统结构,节点基本结构,节点通信以及软件设计等。通过ZigBee无线网络和全光网络等技术的结合,实现了地面控制中心对井下机车运输状况的智能监控,对改善煤矿的安全生产和管理有着重要的现实意义。

  12. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach...... that imposes selection pressure for resistant bacteria. New approaches are urgently needed. Targeting bacterial virulence functions directly is an attractive alternative. An obvious target is bacterial adhesion. Bacterial adhesion to surfaces is the first step in colonization, invasion, and biofilm formation....... As such, adhesion represents the Achilles heel of crucial pathogenic functions. It follows that interference with adhesion can reduce bacterial virulence. Here, we illustrate this important topic with examples of techniques being developed that can inhibit bacterial adhesion. Some of these will become...

  13. 基于加速度传感器的物品运输监测系统设计%Design of Goods Transportation Monitoring System Based on Acceleration Sensor

    Institute of Scientific and Technical Information of China (English)

    赵俊涛

    2013-01-01

    本文设计了一种新型的可以对物品在运输过程中的状态和周围温湿度环境进行实时监测的系统。该系统以MMA8451加速度传感器模块和HT46RU232中央处理单元为核心,集成了GPS实时定位模块,自动评估危险程度并进行报警提示,利用上位机软件可以实现对物品状态信息的实时记录和储存,便于用户和司机对物品运输过程进行分析。经过模拟运输实验验证,该系统工作稳定可靠。%This paper puts forward a new kind of goods transportation monitoring system,which can monitor the the transport process the surrounding temperature and humidity environment of the goods in real time. The system works with MMA8451 acceleration sensor module and HT46RU232 central processing unit as the core, integrated with GPS positioning module, real-time automatic assessment of risk and alarm prompt, and using the PC software can realize real-time recording and storage of goods status information,which is convenient for the user and the driver analysis of the goods transport process. Through simulating transportation experiment, it proved that the system works stably and reliably.

  14. Resuspension and transport of suspended solids in Eurajoensalmi Bay. Final report of monitoring activities in 2009-2011; Resuspensio ja kiintoaineen kulkeutuminen Eurajoensalmessa. Vesistoemittausten loppuraportti

    Energy Technology Data Exchange (ETDEWEB)

    Mykkanen, J.; Kiirikki, M.; Lindfors, A. [Luode Consulting Oy, Espoo (Finland)

    2012-11-15

    The goal of monitoring activities carried out in Eurajoensalmi Bay was to indentify factors affecting dispersal of river waters and suspended solid matter in the estuary area. In addition to suspended solids load and dispersal of river water, also release of sedimented particles from the sea bed in resuspension was studied. River water quality and discharge as well as resuspension in Eurajoensalmi estuary area were monitored with Luode automatic monitoring stations equipped with water quality, water level, wave height and weather sensors. Dynamics of Eurajoensalmi estuary area was studied by installing profiling current meters (ADCP) and water quality sensors to the sea floor at the mouth of Eurajoensalmi. Spatial variation of surface water quality was monitored with a flow-through method from a moving vessel and manual profiling several times during the monitoring period. Collected data was processed and used in determining suspended solids balance of Eurajoensalmi Bay. The balance was determined by creating a regression model for water exchange and sediment flux over the cross section at the mouth of Eurajoensalmi. Regression model was created also to determine resuspension in Eurajoensalmi area. Sediment flux and resuspension were modeled using long term wind data from Kylmaepihlaja meteorological station as a variable to determine overall sediment balance of Eurajoensalmi.

  15. Monitoring and Evaluation of Smolt Migration in the Columbia Basin : Volume XVI : Survival and Transportation Effects for Migrating Snake River Hatchery Chinook Salmon and Steelhead: Historical Estimates from 1996-2003.

    Energy Technology Data Exchange (ETDEWEB)

    Buchanan, Rebecca A.; Skalski, John R.

    2007-12-07

    Snake River Basin averaged 0.45% (SE=0.11%), including age-1-ocean returns, for release years 1996 through 2003. For release years when the ocean return probability from Bonneville back to Bonneville could be estimated (i.e., 1999 through 2003), it was estimated that on average approximately 86% of the total integrated mortality for nontransported, tagged hatchery spring and summer Chinook, and 74% for steelhead, occurred during the ocean life stage (i.e., from Bonneville to Bonneville). This suggests that additional monitoring and research efforts should include the ocean and estuary environment. Annual estimates of the systemwide T/I are weighted averages of the dam-specific T/I ratios for each transport dam (with {ge} 5,000 tagged fish transported), weighted by the probabilities of being transported at each dam. The systemwide T/I compares the observed SAR under the existing transportation system with the expected SAR if the transportation system had not been operated. Estimates of 1.0 indicate that the systemwide transportation program has no effect on SAR, while estimates > 1.0 indicate that the transportation program increases SAR. Excluding the 2001 release group, the geometric mean of the systemwide T/I estimates for hatchery spring Chinook salmon from the Snake River Basin was 1.15 (SE=0.03) for release years 1997 through 2003. The geometric mean of the systemwide T/I estimates for hatchery summer Chinook salmon from the Snake River Basin was 1.28 (SE=0.13) for release years 1997 through 2000 and 2003. Estimates were much higher for the 2001 release groups. These estimates reflect transportation from Lower Granite and/or Little Goose for most release years, depending on the number of tagged smolts actually transported at each dam during each release year. Differential post-Bonneville mortality (D) is the ratio of post-Bonneville survival to Lower Granite Dam of transported fish to that of nontransported ('inriver') fish. Excluding the 2001 release

  16. Total on-line monitoring system of Tokyo gas transmission pipelines; Systeme global de controle et de surveillance des canalisations de transport du gaz developpe par Tokyo gas

    Energy Technology Data Exchange (ETDEWEB)

    Shibata, M. [Tokyo Gas Co., Ltd (Japan)

    2000-07-01

    As Tokyo Gas transmission pipeline is located in residential areas of Metropolitan Tokyo, more precise and advanced maintenance and inspection methods become necessary. A more efficient maintenance and inspection management system is being sought in line with the extension of gas transmission pipelines. Research and development is underway for various types of maintenance /monitoring systems that predict or detect pipeline damage or failure. Some systems have already been put to practical use. Tokyo Gas has developed a total online monitoring system featuring upgraded performance and centralized data processing. This system carries out 24-hour monitoring for damage and failure, and sends warnings to operators at the Pipeline Regional Network Office. This paper introduces the functions of the system, as well as the functions which are currently in the R and D stage. (author)

  17. Monitoring of long-range transported air pollutants, Annual report for 2011; Overvaaking av langtransportert forurenset luft og nedboer. Atmosfaeriske tilfoersler, 2011

    Energy Technology Data Exchange (ETDEWEB)

    Aas, Wenche; Solberg, Sverre; Manoe, Stein; Yttri, Karl Espen

    2012-07-01

    This report presents the 2011 monitoring results from the rural air- and precipitation chemistry monitoring network in Norway. In 2011, main components in precipitation were measured at 15 sites. Trace elements were determined at four sites. Air concentrations of sulphur and nitrogen compounds were measured at six sites, and ozone concentrations at eight sites. Persistent organic pollutants and heavy metals in air are determined at three sites. Measurements of PM10 and PM2.5 mass are also determined at three sites, including measurements of organic and elemental carbon (OC and EC). An overview of the measurement programme is given in Appendix B2. (Author)

  18. Monitoring of long-range transported air pollutants. Annual report for 1995; Overvaaking av langtransportert forurenset luft og nedboer. Atmosfaerisk tilfoersel, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Toerseth, K.

    1996-06-01

    Air and precipitation chemistry is determined though various monitoring programmes at several sites located in the rural areas of Norway. This report describes the results for 1995, and these are compared to the previous years. 52 refs., 32 figs., 80 tabs.

  19. Biogeographic Congruency among Bacterial Communities from Terrestrial Sulfidic Springs

    Directory of Open Access Journals (Sweden)

    Brendan eHeadd

    2014-09-01

    Full Text Available Terrestrial sulfidic springs support diverse microbial communities by serving as stable conduits for geochemically diverse and nutrient-rich subsurface waters. Microorganisms that colonize terrestrial springs likely originate from groundwater, but may also be sourced from the surface. As such, the biogeographic distribution of microbial communities inhabiting sulfidic springs should be controlled by a combination of spring geochemistry and surface and subsurface transport mechanisms, and not necessarily geographic proximity to other springs. We examined the bacterial diversity of seven springs to test the hypothesis that occurrence of taxonomically similar microbes, important to the sulfur cycle, at each spring is controlled by geochemistry. Complementary Sanger sequencing and 454 pyrosequencing of 16S rRNA genes retrieved five proteobacterial classes, and Bacteroidetes, Chlorobi, Chloroflexi, and Firmicutes phyla from all springs, which suggested the potential for a core sulfidic spring microbiome. Among the putative sulfide-oxidizing groups (Epsilonproteobacteria and Gammaproteobacteria, up to 83% of the sequences from geochemically similar springs clustered together. Abundant populations of Hydrogenimonas-like or Sulfurovum-like spp. (Epsilonproteobacteria occurred with abundant Thiothrix and Thiofaba spp. (Gammaproteobacteria, but Arcobacter-like and Sulfurimonas spp. (Epsilonproteobacteria occurred with less abundant gammaproteobacterial populations. These distribution patterns confirmed that geochemistry rather than biogeography regulates bacterial dominance at each spring. Potential biogeographic controls were related to paleogeologic sedimentation patterns that could control long-term microbial transport mechanisms that link surface and subsurface environments. Knowing the composition of a core sulfidic spring microbial community could provide a way to monitor diversity changes if a system is threatened by anthropogenic processes or

  20. Peritonitis - spontaneous bacterial

    Science.gov (United States)

    Spontaneous bacterial peritonitis (SBP); Ascites - peritonitis; Cirrhosis - peritonitis ... who are on peritoneal dialysis for kidney failure. Peritonitis may have other causes . These include infection from ...

  1. ELISA detection of multixenobiotic resistance transporter induction in indigenous freshwater Chironomidae larvae (Diptera): A biomarker calibration step for in situ monitoring of xenobiotic exposure

    Energy Technology Data Exchange (ETDEWEB)

    Moreau, X.; Saez, G.; Thiery, A. [Equipe ' Biomarqueurs and Bioindicateurs Environnementaux' , UMR-CNRS 6116 IMEP, Universite de Provence, 3 Place Victor Hugo, 13331 Marseille cedex 3 (France); Clot-Faybesse, O.; Guiraudie-Capraz, G. [' Neurobiologie Integrative et Adaptative' -UMR 6149, Universite de Provence, 3 Place Victor Hugo, 13331 Marseille cedex 3 (France); Bienboire-Frosini, C. [' Neurobiologie Integrative et Adaptative' -UMR 6149, Universite de Provence, 3 Place Victor Hugo, 13331 Marseille cedex 3 (France); Pherosynthese, Le Rieu Neuf, 84490 St Saturnin d' Apt (France); Martin, C. [Equipe ' Biomarqueurs and Bioindicateurs Environnementaux' , UMR-CNRS 6116 IMEP, UAPV, 33 rue Louis Pasteur, 84000 Avignon (France); De Jong, L. [Equipe ' Biomarqueurs and Bioindicateurs Environnementaux' , UMR-CNRS 6116 IMEP, Universite de Provence, 3 Place Victor Hugo, 13331 Marseille cedex 3 (France)], E-mail: laetitia.moreau@univ-provence.fr

    2008-06-15

    A new simple and sensitive method to distinguish chemically polluted from unpolluted situations in freshwater ecosystems is reported. For this purpose, Chironomus gr thumni larvae were collected from a polluted urban river downstream a sewage treatment plant. For the first time, ELISA assay was used to semi-quantify the multixenobiotic resistance transporters (MXR) in these small pertinent bioindicators. The use of samples immediately fixed in the field gives a delay to isolate larvae and allows multi-sampling along a longitudinal transect in a river at a given time. Results exhibit an induction of MXR proteins in larvae from the polluted river and a deinduction in larvae maintained 11 days in unpolluted water. They show new evidences to use midge larvae in biomonitoring environmental programs. They answer to first biomarker calibration steps for the ongoing development of MXR transporters as a detection tool of xenobiotic impacts on bioindicator invertebrates in their freshwater habitats. - Semi-quantification of midge larval MXR transporters by ELISA is a simple and sensitive method to detect chemically polluted situations in running freshwaters.

  2. Monitoring and Evaluation of Smolt Migration in the Columbia Basin : Volume XVI : Survival and Transportation Effects for Migrating Snake River Hatchery Chinook Salmon and Steelhead: Historical Estimates from 1996-2003.

    Energy Technology Data Exchange (ETDEWEB)

    Buchanan, Rebecca A.; Skalski, John R.

    2007-12-07

    Snake River Basin averaged 0.45% (SE=0.11%), including age-1-ocean returns, for release years 1996 through 2003. For release years when the ocean return probability from Bonneville back to Bonneville could be estimated (i.e., 1999 through 2003), it was estimated that on average approximately 86% of the total integrated mortality for nontransported, tagged hatchery spring and summer Chinook, and 74% for steelhead, occurred during the ocean life stage (i.e., from Bonneville to Bonneville). This suggests that additional monitoring and research efforts should include the ocean and estuary environment. Annual estimates of the systemwide T/I are weighted averages of the dam-specific T/I ratios for each transport dam (with {ge} 5,000 tagged fish transported), weighted by the probabilities of being transported at each dam. The systemwide T/I compares the observed SAR under the existing transportation system with the expected SAR if the transportation system had not been operated. Estimates of 1.0 indicate that the systemwide transportation program has no effect on SAR, while estimates > 1.0 indicate that the transportation program increases SAR. Excluding the 2001 release group, the geometric mean of the systemwide T/I estimates for hatchery spring Chinook salmon from the Snake River Basin was 1.15 (SE=0.03) for release years 1997 through 2003. The geometric mean of the systemwide T/I estimates for hatchery summer Chinook salmon from the Snake River Basin was 1.28 (SE=0.13) for release years 1997 through 2000 and 2003. Estimates were much higher for the 2001 release groups. These estimates reflect transportation from Lower Granite and/or Little Goose for most release years, depending on the number of tagged smolts actually transported at each dam during each release year. Differential post-Bonneville mortality (D) is the ratio of post-Bonneville survival to Lower Granite Dam of transported fish to that of nontransported ('inriver') fish. Excluding the 2001 release

  3. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach that ...... valuable weapons for preventing pathogen contamination and fighting infectious diseases in the future....

  4. Bacterial diseases affecting apple

    Science.gov (United States)

    Bacterial diseases of plants are usually difficult to control and often require a combination of control measures to successfully manage the disease. There are often stark differences between the means available to control bacterial diseases in annual crops versus a woody tree crop, such as apple. ...

  5. Jellyfish modulate bacterial dynamic and community structure.

    Science.gov (United States)

    Tinta, Tinkara; Kogovšek, Tjaša; Malej, Alenka; Turk, Valentina

    2012-01-01

    Jellyfish blooms have increased in coastal areas around the world and the outbreaks have become longer and more frequent over the past few decades. The Mediterranean Sea is among the heavily affected regions and the common bloom-forming taxa are scyphozoans Aurelia aurita s.l., Pelagia noctiluca, and Rhizostoma pulmo. Jellyfish have few natural predators, therefore their carcasses at the termination of a bloom represent an organic-rich substrate that supports rapid bacterial growth, and may have a large impact on the surrounding environment. The focus of this study was to explore whether jellyfish substrate have an impact on bacterial community phylotype selection. We conducted in situ jellyfish-enrichment experiment with three different jellyfish species. Bacterial dynamic together with nutrients were monitored to assess decaying jellyfish-bacteria dynamics. Our results show that jellyfish biomass is characterized by protein rich organic matter, which is highly bioavailable to 'jellyfish-associated' and 'free-living' bacteria, and triggers rapid shifts in bacterial population dynamics and composition. Based on 16S rRNA clone libraries and denaturing gradient gel electrophoresis (DGGE) analysis, we observed a rapid shift in community composition from unculturable Alphaproteobacteria to culturable species of Gammaproteobacteria and Flavobacteria. The results of sequence analyses of bacterial isolates and of total bacterial community determined by culture independent genetic analysis showed the dominance of the Pseudoalteromonadaceae and the Vibrionaceae families. Elevated levels of dissolved proteins, dissolved organic and inorganic nutrient release, bacterial abundance and carbon production as well as ammonium concentrations characterized the degradation process. The biochemical composition of jellyfish species may influence changes in the amount of accumulated dissolved organic and inorganic nutrients. Our results can contribute insights into possible changes in

  6. Jellyfish modulate bacterial dynamic and community structure.

    Directory of Open Access Journals (Sweden)

    Tinkara Tinta

    Full Text Available Jellyfish blooms have increased in coastal areas around the world and the outbreaks have become longer and more frequent over the past few decades. The Mediterranean Sea is among the heavily affected regions and the common bloom-forming taxa are scyphozoans Aurelia aurita s.l., Pelagia noctiluca, and Rhizostoma pulmo. Jellyfish have few natural predators, therefore their carcasses at the termination of a bloom represent an organic-rich substrate that supports rapid bacterial growth, and may have a large impact on the surrounding environment. The focus of this study was to explore whether jellyfish substrate have an impact on bacterial community phylotype selection. We conducted in situ jellyfish-enrichment experiment with three different jellyfish species. Bacterial dynamic together with nutrients were monitored to assess decaying jellyfish-bacteria dynamics. Our results show that jellyfish biomass is characterized by protein rich organic matter, which is highly bioavailable to 'jellyfish-associated' and 'free-living' bacteria, and triggers rapid shifts in bacterial population dynamics and composition. Based on 16S rRNA clone libraries and denaturing gradient gel electrophoresis (DGGE analysis, we observed a rapid shift in community composition from unculturable Alphaproteobacteria to culturable species of Gammaproteobacteria and Flavobacteria. The results of sequence analyses of bacterial isolates and of total bacterial community determined by culture independent genetic analysis showed the dominance of the Pseudoalteromonadaceae and the Vibrionaceae families. Elevated levels of dissolved proteins, dissolved organic and inorganic nutrient release, bacterial abundance and carbon production as well as ammonium concentrations characterized the degradation process. The biochemical composition of jellyfish species may influence changes in the amount of accumulated dissolved organic and inorganic nutrients. Our results can contribute insights into

  7. Vimentin in Bacterial Infections

    DEFF Research Database (Denmark)

    Mak, Tim N; Brüggemann, Holger

    2016-01-01

    Despite well-studied bacterial strategies to target actin to subvert the host cell cytoskeleton, thus promoting bacterial survival, replication, and dissemination, relatively little is known about the bacterial interaction with other components of the host cell cytoskeleton, including intermediate...... filaments (IFs). IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge...... about the role of IFs in bacterial infections, focusing on the type III IF protein vimentin. Recent studies have revealed the involvement of vimentin in host cell defenses, acting as ligand for several pattern recognition receptors of the innate immune system. Two main aspects of bacteria...

  8. Evaluation of 16S rRNA Gene Primer Pairs for Monitoring Microbial Community Structures Showed High Reproducibility within and Low Comparability between Datasets Generated with Multiple Archaeal and Bacterial Primer Pairs.

    Science.gov (United States)

    Fischer, Martin A; Güllert, Simon; Neulinger, Sven C; Streit, Wolfgang R; Schmitz, Ruth A

    2016-01-01

    The application of next-generation sequencing technology in microbial community analysis increased our knowledge and understanding of the complexity and diversity of a variety of ecosystems. In contrast to Bacteria, the archaeal domain was often not particularly addressed in the analysis of microbial communities. Consequently, established primers specifically amplifying the archaeal 16S ribosomal gene region are scarce compared to the variety of primers targeting bacterial sequences. In this study, we aimed to validate archaeal primers suitable for high throughput next generation sequencing. Three archaeal 16S primer pairs as well as two bacterial and one general microbial 16S primer pairs were comprehensively tested by in-silico evaluation and performing an experimental analysis of a complex microbial community of a biogas reactor. The results obtained clearly demonstrate that comparability of community profiles established using different primer pairs is difficult. 16S rRNA gene data derived from a shotgun metagenome of the same reactor sample added an additional perspective on the community structure. Furthermore, in-silico evaluation of primers, especially those for amplification of archaeal 16S rRNA gene regions, does not necessarily reflect the results obtained in experimental approaches. In the latter, archaeal primer pair ArchV34 showed the highest similarity to the archaeal community structure compared to observed by the metagenomic approach and thus appears to be the appropriate for analyzing archaeal communities in biogas reactors. However, a disadvantage of this primer pair was its low specificity for the archaeal domain in the experimental application leading to high amounts of bacterial sequences within the dataset. Overall our results indicate a rather limited comparability between community structures investigated and determined using different primer pairs as well as between metagenome and 16S rRNA gene amplicon based community structure analysis

  9. A cytosolic relay of heat shock proteins HSP70-1A and HSP90β monitors the folding trajectory of the serotonin transporter.

    Science.gov (United States)

    El-Kasaby, Ali; Koban, Florian; Sitte, Harald H; Freissmuth, Michael; Sucic, Sonja

    2014-10-17

    Mutations in the C terminus of the serotonin transporter (SERT) disrupt folding and export from the endoplasmic reticulum. Here we examined the hypothesis that a cytosolic heat shock protein relay was recruited to the C terminus to assist folding of SERT. This conjecture was verified by the following observations. (i) The proximal portion of the SERT C terminus conforms to a canonical binding site for DnaK/heat shock protein of 70 kDa (HSP70). A peptide covering this segment stimulated ATPase activity of purified HSP70-1A. (ii) A GST fusion protein comprising the C terminus of SERT pulled down HSP70-1A. The interaction between HSP70-1A and SERT was visualized in live cells by Förster resonance energy transfer: it was restricted to endoplasmic reticulum-resident transporters and enhanced by an inhibitor that traps HSP70-1A in its closed state. (iv) Co-immunoprecipitation confirmed complex formation of SERT with HSP70-1A and HSP90β. Consistent with an HSP relay, co-chaperones (e.g. HSC70-HSP90-organizing protein) were co-immunoprecipitated with the stalled mutants SERT-R607A/I608A and SERT-P601A/G602A. (v) Depletion of HSP90β by siRNA or its inhibition increased the cell surface expression of wild type SERT and SERT-F604Q. In contrast, SERT-R607A/I608A and SERT-P601A/G602A were only rendered susceptible to inhibition of HSP70 and HSP90 by concomitant pharmacochaperoning with noribogaine. (vi) In JAR cells, inhibition of HSP90 also increased the levels of SERT, indicating that endogenously expressed transporter was also susceptible to control by HSP90β. These findings support the concept that the folding trajectory of SERT is sampled by a cytoplasmic chaperone relay.

  10. A Cytosolic Relay of Heat Shock Proteins HSP70-1A and HSP90β Monitors the Folding Trajectory of the Serotonin Transporter*

    OpenAIRE

    2014-01-01

    Mutations in the C terminus of the serotonin transporter (SERT) disrupt folding and export from the endoplasmic reticulum. Here we examined the hypothesis that a cytosolic heat shock protein relay was recruited to the C terminus to assist folding of SERT. This conjecture was verified by the following observations. (i) The proximal portion of the SERT C terminus conforms to a canonical binding site for DnaK/heat shock protein of 70 kDa (HSP70). A peptide covering this segment stimulated ATPase...

  11. Monitoring and prediction of geotechnical and environmental risks for security in natural gas transportation; Monitoramento e previsao de riscos geotecnicos e ambientais para seguranca no transporte do gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Chamecki, Paulo R.; Ligocki, Laryssa P.; Andrade, Heber A.C.; Manzolli, Andre; Horbatiuk, Borys W.D. [LACTEC - Instituto de Tecnologia para o Desenvolvimento, Curitiba, PR (Brazil); Strieder, Adelir J.; Quadros, Telmo F.P.; Buffon, Sergio A.; Stupf, Leonardo; Bressani, Luiz A.; Bica, Adriano V. Damiani [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil); Schiafino, Antonio V.; Bastos, Cesar B. [Fundacao Universidade Federal do Rio Grande (FURG), RS (Brazil); Radu, Marcos S.; Nascimento Filho, Lenart P. [PETROBRAS, Rio de Janeiro, RJ (Brazil); Santoro, Alcides [Centro de Tecnologias do Gas (CTGAS), Natal, RN (Brazil); Vasconcellos, Carlos R.A.; Oliveira, Hudson R. [TBG - Transportadora Brasileira Gasoduto Bolivia-Brasil S.A., Rio de Janeiro, RJ (Brazil)

    2004-07-01

    In order to take care of the consumption issues, often the bands of pipelines have to cross regions that do not present ideal conditions in terms of geotechnical and geologic characteristics. The present work describes a research in progress, involving a partnership between LACTEC, UFRGS, RedeGasEnergia and FINEP, that aims the development of a methodology for instrumentation and remote monitoring of places which present risks to the infrastructure of the gas-lines and the environment, due to geological and geotechnical conditions, as well as the definition of these places. The methodology is practically concluded and will be applied in the place defined for the case study in natural gas Bolivia-Brazil gas-line. Satellite images are being used, along whit computational modeling, geophysical methods, exploratory boreholes and field and laboratory tests, for the definition of points of risk. In the remote monitoring, besides a data communication system, residual stress test of the pipelines, strain gauges and automatic instruments, inclinometers, piezometer and pluviometers are being used. (author)

  12. Rigidity of the subunit interfaces of the trimeric glutamate transporter GItT during translocation

    NARCIS (Netherlands)

    Groeneveld, Maarten; Slotboom, Dirk-Jan

    2007-01-01

    Glutamate transporters are trimeric membrane proteins in which each protomer contains a separate translocation path. To determine whether structural rearrangements take place at the subunit interfaces during transport, intersubunit disulfide bridges were introduced in the bacterial transporter GltT.

  13. Using GOCI Retrieval Data to Initialize and Validate a Sediment Transport Model for Monitoring Diurnal Variation of SSC in Hangzhou Bay, China

    Directory of Open Access Journals (Sweden)

    Xuefei Yang

    2016-03-01

    Full Text Available The diurnal variation of the suspended sediment concentration (SSC in Hangzhou Bay, China has been investigated using remotely-sensed SSC derived from the Geostationary Ocean Color Imager (GOCI in combination with a coupled hydrodynamic-ecological model for regional and shelf seas (COHERENS. The SSC maps were inferred through a UV-AC atmospheric correction algorithm and an empirical inversion algorithm from the GOCI Level-1B data. The sediment transport model was initialized from maps of the GOCI-derived SSC and the model results were validated through a comparison with remotely-sensed data. The comparison demonstrated that the model results agreed well with the observations. The relationship between SSC distribution and hydrodynamic conditions was analyzed to investigate the sediment transport dynamics. The model’s results indicate that the action of tidal currents dominate the sediment deposition and re-suspension in the coastal waters of the East China Sea. This is especially the case in Hangzhou Bay where the tidal currents are strongest. The satellite-derived sediment data product can not only dramatically improve the specification of the initial conditions for the sediment model, but can also provide valuable information for the model validation, thereby improving the model’s overall performance.

  14. Citrobacter rodentium mouse model of bacterial infection.

    Science.gov (United States)

    Crepin, Valerie F; Collins, James W; Habibzay, Maryam; Frankel, Gad

    2016-10-01

    Infection of mice with Citrobacter rodentium is a robust model to study bacterial pathogenesis, mucosal immunology, the health benefits of probiotics and the role of the microbiota during infection. C. rodentium was first isolated by Barthold from an outbreak of mouse diarrhea in Yale University in 1972 and was 'rediscovered' by Falkow and Schauer in 1993. Since then the use of the model has proliferated, and it is now the gold standard for studying virulence of the closely related human pathogens enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC, respectively). Here we provide a detailed protocol for various applications of the model, including bacterial growth, site-directed mutagenesis, mouse inoculation (from cultured cells and after cohabitation), monitoring of bacterial colonization, tissue extraction and analysis, immune responses, probiotic treatment and microbiota analysis. The main protocol, from mouse infection to clearance and analysis of tissues and host responses, takes ∼5 weeks to complete.

  15. A Cytosolic Relay of Heat Shock Proteins HSP70-1A and HSP90β Monitors the Folding Trajectory of the Serotonin Transporter*

    Science.gov (United States)

    El-Kasaby, Ali; Koban, Florian; Sitte, Harald H.; Freissmuth, Michael; Sucic, Sonja

    2014-01-01

    Mutations in the C terminus of the serotonin transporter (SERT) disrupt folding and export from the endoplasmic reticulum. Here we examined the hypothesis that a cytosolic heat shock protein relay was recruited to the C terminus to assist folding of SERT. This conjecture was verified by the following observations. (i) The proximal portion of the SERT C terminus conforms to a canonical binding site for DnaK/heat shock protein of 70 kDa (HSP70). A peptide covering this segment stimulated ATPase activity of purified HSP70-1A. (ii) A GST fusion protein comprising the C terminus of SERT pulled down HSP70-1A. The interaction between HSP70-1A and SERT was visualized in live cells by Förster resonance energy transfer: it was restricted to endoplasmic reticulum-resident transporters and enhanced by an inhibitor that traps HSP70-1A in its closed state. (iv) Co-immunoprecipitation confirmed complex formation of SERT with HSP70-1A and HSP90β. Consistent with an HSP relay, co-chaperones (e.g. HSC70-HSP90-organizing protein) were co-immunoprecipitated with the stalled mutants SERT-R607A/I608A and SERT-P601A/G602A. (v) Depletion of HSP90β by siRNA or its inhibition increased the cell surface expression of wild type SERT and SERT-F604Q. In contrast, SERT-R607A/I608A and SERT-P601A/G602A were only rendered susceptible to inhibition of HSP70 and HSP90 by concomitant pharmacochaperoning with noribogaine. (vi) In JAR cells, inhibition of HSP90 also increased the levels of SERT, indicating that endogenously expressed transporter was also susceptible to control by HSP90β. These findings support the concept that the folding trajectory of SERT is sampled by a cytoplasmic chaperone relay. PMID:25202009

  16. Research on Geographical Urban Conditions Monitoring

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    by LUO A1inghai Abstract Geographical national conditions monitoring has become an important task of surveying and geographical information industry, and will make a profound influence on the development of surveying and ge- ographical information. This paper introduced the basic concept of ge- ographical national conditions monitoring, and discussed its main tasks including complete surveying, dynamic monitoring, statistical analysis and regular release, and expounded the main content of geographical urban conditions monitoring including urbanization monitoring, social- economic development monitoring, transportation foundation monitor- ing and natural ecological environment monitoring, and put forwards the framework system of geographical urban conditions monitoring. Key words surveying and mapping ,geographical national conditions, monitoring ( Page:l )

  17. In operando x-ray tomography for next-generation batteries: a systematic approach to monitor reaction product distribution and transport processes

    Science.gov (United States)

    Schröder, D.; Bender, C. L.; Arlt, T.; Osenberg, M.; Hilger, A.; Risse, S.; Ballauff, M.; Manke, I.; Janek, J.

    2016-10-01

    Computed tomography with x-rays is a powerful tool to analyze the complex reaction and transport processes that occur inside electrochemical storage devices. To this day, a better insight into the occurring processes is needed and will yield improvements in energy density and cycling stability of next-generation batteries. Herein we present general considerations for the use of x-ray tomography of batteries to gain a detailed insight during operation. Furthermore, we present examples for the tomography of zinc-oxygen batteries, sodium-oxygen batteries and metal-sulfur batteries, elucidating performance limiting degradation processes such as dendrite formation and loss of liquid electrolyte. With the method applied, we aim to establish an effective link between the battery and x-ray community by offering a guideline on how to apply x-ray tomography to propel research on battery materials and entire batteries.

  18. Interfering with bacterial gossip

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Tolker-Nielsen, Tim; Givskov, Michael

    2011-01-01

    defense. Antibiotics exhibit a rather limited effect on biofilms. Furthermore, antibiotics have an ‘inherent obsolescence’ because they select for development of resistance. Bacterial infections with origin in bacterial biofilms have become a serious threat in developed countries. Pseudomonas aeruginosa...... that appropriately target bacteria in their relevant habitat with the aim of mitigating their destructive impact on patients. In this review we describe molecular mechanisms involved in “bacterial gossip” (more scientifically referred to as quorum sensing (QS) and c-di-GMP signaling), virulence, biofilm formation......, resistance and QS inhibition as future antimicrobial targets, in particular those that would work to minimize selection pressures for the development of resistant bacteria....

  19. Diagnosis and therapeutic monitoring of inborn errors of creatine metabolism and transport using liquid chromatography-tandem mass spectrometry in urine, plasma and CSF.

    Science.gov (United States)

    Haas, Dorothea; Gan-Schreier, Hongying; Langhans, Claus-Dieter; Anninos, Alexandros; Haege, Gisela; Burgard, Peter; Schulze, Andreas; Hoffmann, Georg F; Okun, Jürgen G

    2014-03-15

    Biochemical detection of inborn errors of creatine metabolism or transport relies on the analysis of three main metabolites in biological fluids: guanidinoacetate (GAA), creatine (CT) and creatinine (CTN). Unspecific clinical presentation of the diseases might be the cause that only few patients have been diagnosed so far. We describe a LC-MS/MS method allowing fast and reliable diagnosis by simultaneous quantification of GAA, CT and CTN in urine, plasma and cerebrospinal fluid (CSF) and established reference values for each material. For quantification deuterated stable isotopes of each analyte were used as internal standards. GAA, CT and CTN were separated by reversed-phase HPLC. The characterization was carried out by scanning the ions of each compound by negative ion tandem mass spectrometry. Butylation is needed to achieve sufficient signal intensity for GAA and CT but it is not useful for analyzing CTN. The assay is linear in a broad range of analyte concentrations usually found in urine, plasma and CSF. Comparison of the "traditional" cation-exchange chromatography and LC-MS/MS showed proportional differences but linear relationships between the two methods. The described method is characterized by high speed and linearity over large concentration ranges comparable to other published LC-MS methods but with higher sensitivity for GAA and CT. In addition, we present the largest reference group ever published for guanidino compounds in all relevant body fluids. Therefore this method is applicable for high-throughput approaches for diagnosis and follow-up of inborn errors of creatine metabolism and transport.

  20. Monitoring and Evaluation of Smolt Migration in the Columbia Basin : Volume XVIII: Survival and Transportation Effects of Migrating Snake River Wild Chinook Salmon and Steelhead: Historical Estimates From 1996-2004 and Comparison to Hatchery Results. Draft.

    Energy Technology Data Exchange (ETDEWEB)

    Buchanan, Rebecca A.; Skalski, John R.; Broms, Kristin

    2008-12-03

    release groups were pooled across the entire Snake River Basin upstream of Lower Granite Dam for this report. Annual estimates of SAR from Lower Granite back to Lower Granite averaged 0.92% with an estimated standard error (dSE) of 0.25% for wild spring and summer Chinook salmon for tagged groups released from 1996 through 2004, omitting age-1-ocean (jack) returns. Only for the 1999 and 2000 release years did the wild Chinook SAR approach the target value of 2%, identified by the NPCC as the minimum SAR necessary for recovery. Annual estimates of SAR for wild steelhead from the Snake River Basin averaged 0.63% (dSE = 0.15%), including age-1-ocean returns, for release years 1996 through 2004. For release years when the ocean return probability from Bonneville back to Bonneville could be estimated (i.e., 1999 through 2004), it was estimated that on average approximately 83% of the total integrated mortality for nontransported, tagged wild spring and summer Chinook, and 78% for steelhead (omitting the 2001 release year), occurred during the ocean life stage (i.e., from Bonneville to Bonneville). This suggests that additional monitoring and research efforts should include the ocean and estuary environment. Annual estimates of the dam-specific T/I for Lower Granite Dam were available for the 2003 and 2004 release years for both wild Chinook salmon and wild steelhead. The estimated T/I for Lower Granite was significantly > 1.0 for Chinook in 2004 (P < 0.0001) and for steelhead in both 2003 (P < 0.0001) and 2004 (P < 0.0001), indicating that for these release years, wild fish transported at Lower Granite returned there in higher proportions than fish that were returned to the river at Lower Granite, or that passed Lower Granite without detection as juveniles. Annual estimates of the dam-specific T/I for Little Goose Dam were available for wild Chinook salmon for both 2003 and 2004. The estimated T/I for Little Goose was significantly > 1.0 for wild Chinook in 2004 (P = 0

  1. Bacterial Culture of Neonatal Sepsis

    Directory of Open Access Journals (Sweden)

    AH Movahedian

    2006-08-01

    Full Text Available Neonatal bacterial sepsis is one of the major cause of morbidity and mortality in neonates. This retrospective study was performed to determine the incidence of bacterial sepsis with focus on Gram negative organisms in neonates admitted at Beheshti Hospital in Kashan, during a 3-yr period, from September 2002 to September 2005. Blood culture was performed on all neonates with risk factors or signs of suggestive sepsis. Blood samples were cultured using brain heart infusion (BHI broth according to standard method. From the 1680 neonates 36% had positive blood culture for Pseudomans aeruginosa, 20.7% for Coagulase negative Staphylococci, and 17% for Klebsiella spp. Gram-negative organisms accounted for 72.1% of all positive cultures. The overall mortality rate was 19.8% (22 /111 of whom 63.6% (14 /22 were preterm. Pseudomona aeruginosa and Klebsiella spp. showed a high degree of resistance to commonly used antibiotics (ampicillin, gentamicin as well as third generation cephalosporins. Continued local surveillance studies are urged to monitor emerging antimicrobial resistance and to guide interventions to minimize its occurrence.

  2. 胶轮车监控系统在煤矿井下车辆运输管理中的应用%Application of Monitoring and Control System of Rubber-tyred Vehicle in Underground Vehicle Transportation Management

    Institute of Scientific and Technical Information of China (English)

    王瑞峰

    2012-01-01

    介绍了胶轮车监控系统的组成及工作原理;以车辆通过两个避车硐室之间的单向区间为例说明了系统的调度控制方式;结合系统在高河煤矿的应用情况,提出了实际应用中需注意的几个问题.该系统以调度控制分站为控制核心,实现了对井下胶轮车的实时监控和自动调度功能,提高了车辆运输管理效率.%The paper introduced composition and working principle of monitoring and control system of rubber-tyred vehicle, described scheduling control mode of the system by example of a vehicle passing an one-way interval between two refuge chambers, and proposed several issues needing paying attention to in actual application combining with the application in Gaohe Coal Mine. The system takes scheduling control sub-station as control core, and realizes functions of real-time monitoring and automatic schedulling of underground rubble-tyred vehicle, so as to improve efficiency of vehicle transportation management.

  3. Bacterial Meningitis in Infants

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2004-04-01

    Full Text Available A retrospective study of 80 infantile patients (ages 30-365 days; 47 male, 33 female with culture-proven bacterial meningitis seen over a 16 year period (1986-2001 is reported from Taiwan.

  4. Bacterial surface adaptation

    Science.gov (United States)

    Utada, Andrew

    2014-03-01

    Biofilms are structured multi-cellular communities that are fundamental to the biology and ecology of bacteria. Parasitic bacterial biofilms can cause lethal infections and biofouling, but commensal bacterial biofilms, such as those found in the gut, can break down otherwise indigestible plant polysaccharides and allow us to enjoy vegetables. The first step in biofilm formation, adaptation to life on a surface, requires a working knowledge of low Reynolds number fluid physics, and the coordination of biochemical signaling, polysaccharide production, and molecular motility motors. These crucial early stages of biofilm formation are at present poorly understood. By adapting methods from soft matter physics, we dissect bacterial social behavior at the single cell level for several prototypical bacterial species, including Pseudomonas aeruginosa and Vibrio cholerae.

  5. Bacterial intermediate filaments

    DEFF Research Database (Denmark)

    Charbon, Godefroid; Cabeen, M.; Jacobs-Wagner, C.

    2009-01-01

    Crescentin, which is the founding member of a rapidly growing family of bacterial cytoskeletal proteins, was previously proposed to resemble eukaryotic intermediate filament (IF) proteins based on structural prediction and in vitro polymerization properties. Here, we demonstrate that crescentin...

  6. Bacterial toxins as immunomodulators.

    Science.gov (United States)

    Donaldson, David S; Williams, Neil A

    2009-01-01

    Bacterial toxins are the causative agent at pathology in a variety of diseases. Although not always the primary target of these toxins, many have been shown to have potent immunomodulatory effects, for example, inducing immune responses to co-administered antigens and suppressing activation of immune cells. These abilities of bacterial toxins can be harnessed and used in a therapeutic manner, such as in vaccination or the treatment of autoimmune diseases. Furthermore, the ability of toxins to gain entry to cells can be used in novel bacterial toxin based immuno-therapies in order to deliver antigens into MHC Class I processing pathways. Whether the immunomodulatory properties of these toxins arose in order to enhance bacterial survival within hosts, to aid spread within the population or is pure serendipity, it is interesting to think that these same toxins potentially hold the key to preventing or treating human disease.

  7. Bacterial Wound Culture

    Science.gov (United States)

    ... and services. Advertising & Sponsorship: Policy | Opportunities Bacterial Wound Culture Share this page: Was this page helpful? Also known as: Aerobic Wound Culture; Anaerobic Wound Culture Formal name: Culture, wound Related ...

  8. Dequalinium for bacterial vaginosis.

    Science.gov (United States)

    2017-05-01

    Bacterial vaginosis is an infection characterised by overgrowth of anaerobic bacteria in the vagina with an accompanying loss of lactobacilli, and is thought to be the most common cause of abnormal vaginal discharge in women of child-bearing age.(1) Standard treatment for symptomatic bacterial vaginosis consists of a short course of an oral or topical antibiotic.(2) Dequalinium, a topical antiseptic agent, has been available for many years as a treatment for oral infections.(3) A new formulation, dequalinium 10mg vaginal tablets (Fluomizin-Kora Healthcare), was licensed in the UK in June 2015 for the treatment of bacterial vaginosis.(4) Here, we review evidence for the effectiveness and safety of dequalinium vaginal tablets in the management of bacterial vaginosis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  9. Bacterial proteases and virulence

    DEFF Research Database (Denmark)

    Frees, Dorte; Brøndsted, Lone; Ingmer, Hanne

    2013-01-01

    Bacterial pathogens rely on proteolysis for variety of purposes during the infection process. In the cytosol, the main proteolytic players are the conserved Clp and Lon proteases that directly contribute to virulence through the timely degradation of virulence regulators and indirectly by providing....... These extracellular proteases are activated in complex cascades involving auto-processing and proteolytic maturation. Thus, proteolysis has been adopted by bacterial pathogens at multiple levels to ensure the success of the pathogen in contact with the human host....

  10. Meteorological Monitoring Program

    Energy Technology Data Exchange (ETDEWEB)

    Hancock, H.A. Jr. [ed.; Parker, M.J.; Addis, R.P.

    1994-09-01

    The purpose of this technical report is to provide a comprehensive, detailed overview of the meteorological monitoring program at the Savannah River Site (SRS) near Aiken, South Carolina. The principle function of the program is to provide current, accurate meteorological data as input for calculating the transport and diffusion of any unplanned release of an atmospheric pollutant. The report is recommended for meteorologists, technicians, or any personnel who require an in-depth understanding of the meteorological monitoring program.

  11. [Diagnosis of bacterial vaginosis].

    Science.gov (United States)

    Djukić, Slobodanka; Ćirković, Ivana; Arsić, Biljana; Garalejić, Eliana

    2013-01-01

    Bacterial vaginosis is a common, complex clinical syndrome characterized by alterations in the normal vaginal flora. When symptomatic, it is associated with a malodorous vaginal discharge and on occasion vaginal burning or itching. Under normal conditions, lactobacilli constitute 95% of the bacteria in the vagina. Bacterial vaginosis is associated with severe reduction or absence of the normal H2O2-producing lactobacilli and overgrowth of anaerobic bacteria and Gardnerella vaginalis, Atopobium vaginae, Mycoplasma hominis and Mobiluncus species. Most types of infectious disease are diagnosed by culture, by isolating an antigen or RNA/DNA from the microbe, or by serodiagnosis to determine the presence of antibodies to the microbe. Therefore, demonstration of the presence of an infectious agent is often a necessary criterion for the diagnosis of the disease. This is not the case for bacterial vaginosis, since the ultimate cause of the disease is not yet known. There are a variety of methods for the diagnosis of bacterial vaginosis but no method can at present be regarded as the best. Diagnosing bacterial vaginosis has long been based on the clinical criteria of Amsel, whereby three of four defined criteria must be satisfied. Nugent's scoring system has been further developed and includes validation of the categories of observable bacteria structures. Up-to-date molecular tests are introduced, and better understanding of vaginal microbiome, a clear definition for bacterial vaginosis, and short-term and long-term fluctuations in vaginal microflora will help to better define molecular tests within the broader clinical context.

  12. Extracellular heme uptake and the challenges of bacterial cell membranes.

    Science.gov (United States)

    Smith, Aaron D; Wilks, Angela

    2012-01-01

    In bacteria, the fine balance of maintaining adequate iron levels while preventing the deleterious effects of excess iron has led to the evolution of sophisticated cellular mechanisms to obtain, store, and regulate iron. Iron uptake provides a significant challenge given its limited bioavailability and need to be transported across the bacterial cell wall and membranes. Pathogenic bacteria have circumvented the iron-availability issue by utilizing the hosts' heme-containing proteins as a source of iron. Once internalized, iron is liberated from the porphyrin enzymatically for cellular processes within the bacterial cell. Heme, a lipophilic and toxic molecule, poses a significant challenge in terms of transport given its chemical reactivity. As such, pathogenic bacteria have evolved sophisticated membrane transporters to coordinate, sequester, and transport heme. Recent advances in the biochemical and structural characterization of the membrane-bound heme transport proteins are discussed in the context of ligand coordination, protein-protein interaction, and heme transfer.

  13. 49 CFR 193.2507 - Monitoring operations.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Monitoring operations. 193.2507 Section 193.2507 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY LIQUEFIED NATURAL GAS FACILITIES...

  14. Airborne mercury species at the Råö background monitoring site in Sweden: distribution of mercury as an effect of long-range transport

    Science.gov (United States)

    Wängberg, Ingvar; Nerentorp Mastromonaco, Michelle G.; Munthe, John; Gårdfeldt, Katarina

    2016-10-01

    Within the EU-funded project, Global Mercury Observation System (GMOS) airborne mercury has been monitored at the background Råö measurement site on the western coast of Sweden from mid-May 2012 to the beginning of July 2013 and from the beginning of February 2014 to the end of May 2015. The following mercury species/fractions were measured: gaseous elemental mercury (GEM), particulate bound mercury (PBM) and gaseous oxidised mercury (GOM) using the Tekran measurement system. The mercury concentrations measured at the Råö site were found to be low in comparison to other, comparable, European measurement sites. A back-trajectory analysis to study the origin of air masses reaching the Råö site was performed. Due to the remote location of the Råö measurement station it receives background air about 60 % of the time. However, elevated mercury concentrations arriving with air masses coming from the south-east are noticeable. GEM and PBM concentrations show a clear annual variation with the highest values occurring during winter, whereas the highest concentrations of GOM were obtained in spring and summer. An evaluation of the diurnal pattern of GOM, with peak concentrations at midday or in the early afternoon, which often is observed at remote places, shows that it is likely to be driven by local meteorology in a similar way to ozone. Evidence that a significant part of the GOM measured at the Råö site has been formed in free tropospheric air is presented.

  15. Meningitis bacteriana Bacterial meningitis

    Directory of Open Access Journals (Sweden)

    Ana Teresa Alvarado Guevara

    2006-03-01

    causales son virales lo cual conlleva a las diferentes sub-clasificaciones. También en ciertos casos puede ser ocasionada por hongos, bacterias atípicas, micobacterias y parásitos.In Costa Rica the bacterial meningitis had turn into a high-priority subject in which to monitoring epidemiologist. It had been talked about in the last months, to dice an increase in the attention is published of this subject, due to this phenomenon it becomes necessary to make a revision of topic. Meningitis is an inflammation of leptomeninges and colonization of the subarachnoid cerebrospinal fluid (LCR due to different agents, which produces meningeal symptoms (ex. migraine, neck rigidity, and photophobia and pleocytosis in LCR. De pending on the variables to take into account is possible to group it in different classifications, taking into account the time of evolution are possible to be divided in acute or chronic, to first with few hours or days of beginning of the symptoms, whereas the chronicle also presents a silence course but of the disease of approximately 4 weeks of instauration. There is a difference according to its etiologic agent; they can be infectious and non-infectious. Examples of common non-infectious causes include medications (ex, nonsteroidal anti-inflammatory drugs, and antibiotics and carcinomatosis. A classification exists as well according to the causal agent. The acute bacterial meningitis remarks a bacterial origin of the syndrome, which characterizes by the by an acute onset of meningeal symptoms and neutrophilic pleocytosis. Each one of the bacteriological agents, parasitic or fungus finishes by characterizing the different presentations of the clinical features (ex, meningocóccica meningitis, Cryptococcus meningitis. Finally, there is also the aseptic meningitis, denominated in this form because it’s nonpyogenic cellular response caused by many types of agents. The patients show an acute beginning of symptoms, fever and lymphocytic pleocytosis. After

  16. Mathematical model of optimizing the arrival of fire units with the use of information systems for monitoring transport logistics of Voronezh city

    Directory of Open Access Journals (Sweden)

    A. V. Kochegarov

    2016-01-01

    Full Text Available In recent years, the strong pace of construction is increasing in big cities. With their growth becomes a question of the deployment of firefighters and the number of fire stations. The most effective solution is the problem of finding the optimum route of fire departments, taking into account the information transport logistics systems within the city that will allow us to arrive at the scene at any time, regardless of the degree of congestion of city roads. Prompt arrival of fire units provides the most successful fire fighting. The main objective of the study is to develop a preliminary route and the route in case of unforeseen factors affecting the time fire engine arrived. To construct the routes used to develop actively in the current methods of machine learning artificial neural networks. To construct the optimal route requires a correct prediction of the future behavior of a complex system of urban traffic based on its past behavior. Within the framework of statistical machine learning theory considered the problem of classification and regression. The learning process is to select a classification or a regression function of a predetermined broad class of such functions. After determining the prediction scheme, it is necessary to evaluate the quality of its forecasts, which are measured not on the basis of observations, and on the basis of an improved stochastic process, the result of the construction of the prediction rules. The model is verified on the basis of data collected in real departures real fire brigades, which made it possible to obtain a minimum time of arrival of fire units.

  17. The bacterial lipocalins.

    Science.gov (United States)

    Bishop, R E

    2000-10-18

    The lipocalins were once regarded as a eukaryotic protein family, but new members have been recently discovered in bacteria. The first bacterial lipocalin (Blc) was identified in Escherichia coli as an outer membrane lipoprotein expressed under conditions of environmental stress. Blc is distinguished from most lipocalins by the absence of intramolecular disulfide bonds, but the presence of a membrane anchor is shared with two of its closest homologues, apolipoprotein D and lazarillo. Several common features of the membrane-anchored lipocalins suggest that each may play an important role in membrane biogenesis and repair. Additionally, Blc proteins are implicated in the dissemination of antibiotic resistance genes and in the activation of immunity. Recent genome sequencing efforts reveal the existence of at least 20 bacterial lipocalins. The lipocalins appear to have originated in Gram-negative bacteria and were probably transferred horizontally to eukaryotes from the endosymbiotic alpha-proteobacterial ancestor of the mitochondrion. The genome sequences also reveal that some bacterial lipocalins exhibit disulfide bonds and alternative modes of subcellular localization, which include targeting to the periplasmic space, the cytoplasmic membrane, and the cytosol. The relationships between bacterial lipocalin structure and function further illuminate the common biochemistry of bacterial and eukaryotic cells.

  18. Radiation Transport

    Energy Technology Data Exchange (ETDEWEB)

    Urbatsch, Todd James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-15

    We present an overview of radiation transport, covering terminology, blackbody raditation, opacities, Boltzmann transport theory, approximations to the transport equation. Next we introduce several transport methods. We present a section on Caseology, observing transport boundary layers. We briefly broach topics of software development, including verification and validation, and we close with a section on high energy-density experiments that highlight and support radiation transport.

  19. Lipoproteins of Bacterial Pathogens▿

    Science.gov (United States)

    Kovacs-Simon, A.; Titball, R. W.; Michell, S. L.

    2011-01-01

    Bacterial lipoproteins are a set of membrane proteins with many different functions. Due to this broad-ranging functionality, these proteins have a considerable significance in many phenomena, from cellular physiology through cell division and virulence. Here we give a general overview of lipoprotein biogenesis and highlight examples of the roles of lipoproteins in bacterial disease caused by a selection of medically relevant Gram-negative and Gram-positive pathogens: Mycobacterium tuberculosis, Streptococcus pneumoniae, Borrelia burgdorferi, and Neisseria meningitidis. Lipoproteins have been shown to play key roles in adhesion to host cells, modulation of inflammatory processes, and translocation of virulence factors into host cells. As such, a number of lipoproteins have been shown to be potential vaccines. This review provides a summary of some of the reported roles of lipoproteins and of how this knowledge has been exploited in some cases for the generation of novel countermeasures to bacterial diseases. PMID:20974828

  20. Advanced Technologies for Monitoring CO2 Saturation and Pore Pressure in Geologic Formations: Linking the Chemical and Physical Effects to Elastic and Transport Properties

    Energy Technology Data Exchange (ETDEWEB)

    Mavko, G.; Vanorio, T.; Vialle, S.; Saxena, N.

    2014-03-31

    Ultrasonic P- and S-wave velocities were measured over a range of confining pressures while injecting CO2 and brine into the samples. Pore fluid pressure was also varied and monitored together with porosity during injection. Effective medium models were developed to understand the mechanisms and impact of observed changes and to provide the means for implementation of the interpretation methodologies in the field. Ultrasonic P- and S-wave velocities in carbonate rocks show as much as 20-50% decrease after injection of the reactive CO2-brine mixture; the changes were caused by permanent changes to the rock elastic frame associated with dissolution of mineral. Velocity decreases were observed under both dry and fluid-saturated conditions, and the amount of change was correlated with the initial pore fabrics. Scanning Electron Microscope images of carbonate rock microstructures were taken before and after injection of CO2-rich water. The images reveal enlargement of the pores, dissolution of micrite (micron-scale calcite crystals), and pitting of grain surfaces caused by the fluid- solid chemical reactivity. The magnitude of the changes correlates with the rock microtexture – tight, high surface area samples showed the largest changes in permeability and smallest changes in porosity and elastic stiffness compared to those in rocks with looser texture and larger intergranular pore space. Changes to the pore space also occurred from flow of fine particles with the injected fluid. Carbonates with grain-coating materials, such as residual oil, experienced very little permanent change during injection. In the tight micrite/spar cement component, dissolution is controlled by diffusion: the mass transfer of products and reactants is thus slow and the fluid is expected to be close to thermodynamical equilibrium with the calcite, leading to very little dissolution, or even precipitation. In the microporous rounded micrite and macropores, dissolution is controlled by

  1. Use of matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry for bacterial monitoring in routine analysis at a drinking water treatment plant.

    Science.gov (United States)

    Sala-Comorera, Laura; Vilaró, Carles; Galofré, Belén; Blanch, Anicet R; García-Aljaro, Cristina

    2016-10-01

    The study of bacterial communities throughout a drinking water treatment plant could provide a basic understanding of the effects of water processing that could then be used to improve the management of such plants. However, it is necessary to develop new analytical techniques that are sufficiently efficient, robust and fast for their effective and useful application in routine analysis. The aim of this study is therefore to assess the performance of matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS), as compared to the PhenePlate™ system, for routine analysis in a drinking water treatment plant. To this end we studied a total of 277 colonies isolated in different seasons and from different points throughout the water treatment process, including: raw water, sand filtration, ultrafiltration, reverse osmosis and chlorination. The colonies were analysed using MALDI-TOF MS by direct deposition of the cells on the plate. The colonies were also biochemically fingerprinted using the PhenePlate™ system, clustered according to their similarity and a representative strain was selected for 16S rRNA gene sequencing and API(®) gallery-based identification. The use of MALDI-TOF MS was reliable compared to the PhenePlate™ system and has the advantage of being faster and relatively cheap. Bacteria typing by MALDI-TOF MS is therefore a promising method to replace conventional routine phenotypic methods for the identification of bacteria in drinking water laboratories, thanks to its robustness. The major limiting factor for MALDI-TOF MS is the lack of a suitable mass spectra database; although each laboratory can develop its own library. This methodology will provide a tracking tool for companies to use in risk management and the detection of possible failures in both the water treatment processes and the distribution network, as well as offering characterization of the intrinsic microbial populations.

  2. Diagnosis of bacterial vaginosis

    Directory of Open Access Journals (Sweden)

    Đukić Slobodanka

    2013-01-01

    Full Text Available Bacterial vaginosis is a common, complex clinical syndrome characterized by alterations in the normal vaginal flora. When symptomatic, it is associated with a malodorous vaginal discharge and on occasion vaginal burning or itching. Under normal conditions, lactobacilli constitute 95% of the bacteria in the vagina. Bacterial vaginosis is associated with severe reduction or absence of the normal H2O2­producing lactobacilli and overgrowth of anaerobic bacteria and Gardnerella vaginalis, Atopobium vaginae, Mycoplasma hominis and Mobiluncus species. Most types of infectious disease are diagnosed by culture, by isolating an antigen or RNA/DNA from the microbe, or by serodiagnosis to determine the presence of antibodies to the microbe. Therefore, demonstration of the presence of an infectious agent is often a necessary criterion for the diagnosis of the disease. This is not the case for bacterial vaginosis, since the ultimate cause of the disease is not yet known. There are a variety of methods for the diagnosis of bacterial vaginosis but no method can at present be regarded as the best. Diagnosing bacterial vaginosis has long been based on the clinical criteria of Amsel, whereby three of four defined criteria must be satisfied. Nugent’s scoring system has been further developed and includes validation of the categories of observable bacteria structures. Up­to­date molecular tests are introduced, and better understanding of vaginal microbiome, a clear definition for bacterial vaginosis, and short­term and long­term fluctuations in vaginal microflora will help to better define molecular tests within the broader clinical context.

  3. Bacterial blight of cotton

    Directory of Open Access Journals (Sweden)

    Aïda JALLOUL

    2015-04-01

    Full Text Available Bacterial blight of cotton (Gossypium ssp., caused by Xanthomonas citri pathovar malvacearum, is a severe disease occurring in all cotton-growing areas. The interactions between host plants and the bacteria are based on the gene-for-gene concept, representing a complex resistance gene/avr gene system. In light of the recent data, this review focuses on the understanding of these interactions with emphasis on (1 the genetic basis for plant resistance and bacterial virulence, (2 physiological mechanisms involved in the hypersensitive response to the pathogen, including hormonal signaling, the oxylipin pathway, synthesis of antimicrobial molecules and alteration of host cell structures, and (3 control of the disease.

  4. Bacterial glycosyltransferase toxins.

    Science.gov (United States)

    Jank, Thomas; Belyi, Yury; Aktories, Klaus

    2015-12-01

    Mono-glycosylation of host proteins is a common mechanism by which bacterial protein toxins manipulate cellular functions of eukaryotic target host cells. Prototypic for this group of glycosyltransferase toxins are Clostridium difficile toxins A and B, which modify guanine nucleotide-binding proteins of the Rho family. However, toxin-induced glycosylation is not restricted to the Clostridia. Various types of bacterial pathogens including Escherichia coli, Yersinia, Photorhabdus and Legionella species produce glycosyltransferase toxins. Recent studies discovered novel unexpected variations in host protein targets and amino acid acceptors of toxin-catalysed glycosylation. These findings open new perspectives in toxin as well as in carbohydrate research.

  5. Bacterial survey of well water--Tehran, Iran.

    Science.gov (United States)

    Shariatpanahi, M; Anderson, A C

    1987-08-01

    One hundred twenty-one wells throughout the city of Tehran were monitored during the four seasons of the year for the presence of bacterial indicators of fecal pollution. None of the sites monitored was connected to Tehran's main water distribution system but represented drinking water sources for small communities, individual factories, hospitals, etc. Only 17 samples showed no indication of fecal bacterial contamination throughout the study. The remaining sites were positive for at least one of the following at some season of the year: Escherichia coli, Shigella sp., Citrobacter sp., Klebsiella-Enterobacter group, Clostridium perfringens, or Streptococcus faecalis.

  6. A Long-distance γ Monitoring Method Using Plastic Fiber Transportation%采用塑料光纤传输实现γ辐射远距离测量

    Institute of Scientific and Technical Information of China (English)

    雷世雄; 陈少杰; 余方伟

    2013-01-01

    研究了一种采用闪烁探测器探测γ射线、塑料光纤传输闪烁光进行γ辐射远距离测量的方法.由于单个γ光子在闪烁体中发出的闪烁光子数量十分有限,通过增大闪烁体的尺寸提高γ射线激发光子的产额,采用大芯径的塑料光纤和光子收集过渡转接头提高光导对闪烁光的传输效率,再利用电流积分法读取光电转换单元的信号以有效提高电子学的信噪比,实现了γ辐射的远距离测量.%A method using scintillator detect γ-ray and plastic fiber transport scintillated light for radioactive signal long-distance monitoring was studied.Since the amounts of scintillation photon excited by a single γ-ray were limited,way of augmenting the size of scintillator was adopted for improving the accepted γ-ray numbers.The large core plastic fiber and transmission connector were also used to improve the transport efficiency of scintillated light.Current integrate circuit was used to read out signal of photoelectric convert unit to enhance the electrical SNR.The remote measurement of γ-radiation was realized.

  7. 基于GPS与地图匹配的铁路运输安全监控技术研究%Study on Railway Transportation Safety Monitoring Based on GPS and Map Matching Technology

    Institute of Scientific and Technical Information of China (English)

    张冰; 孙长国

    2013-01-01

    列车运行途中环境复杂,监控与定位难度较大,由于单一的GPS车载定位会因为地理环境等原因在一定范围和时间内失效或定位不连续,针对这一局限性,采用GPS/DR与电子地图匹配的定位算法不仅克服了GPS信号在盲区间断或失效的缺点,也避免了DR定位误差随时间的不断积累,提高了定位精度和系统的可靠性。可应用于铁路运输安全,为物资押运列车提供优质的监控。%Monitoring and positioning is difficult when Trains is running on the way with complex environment,A single GPS positioning will be discontinuous even disabled because of geographical environment in certain scope, Against the limitations, Using GPS/DR and the positioning of the electronic map matching algorithm, which overcome the faults of interruption or failure for GPS signal in the blind area, also avoid the DR position error accumulated over time, Improves the location accuracy and the reliability of the system. The method Can be applied to the safety of railway transportation, to provide quality monitoring under escort goods train.

  8. Chamber transport

    Energy Technology Data Exchange (ETDEWEB)

    OLSON,CRAIG L.

    2000-05-17

    Heavy ion beam transport through the containment chamber plays a crucial role in all heavy ion fusion (HIF) scenarios. Here, several parameters are used to characterize the operating space for HIF beams; transport modes are assessed in relation to evolving target/accelerator requirements; results of recent relevant experiments and simulations of HIF transport are summarized; and relevant instabilities are reviewed. All transport options still exist, including (1) vacuum ballistic transport, (2) neutralized ballistic transport, and (3) channel-like transport. Presently, the European HIF program favors vacuum ballistic transport, while the US HIF program favors neutralized ballistic transport with channel-like transport as an alternate approach. Further transport research is needed to clearly guide selection of the most attractive, integrated HIF system.

  9. A general method for determining secondary active transporter substrate stoichiometry.

    Science.gov (United States)

    Fitzgerald, Gabriel A; Mulligan, Christopher; Mindell, Joseph A

    2017-01-25

    The number of ions required to drive substrate transport through a secondary active transporter determines the protein's ability to create a substrate gradient, a feature essential to its physiological function, and places fundamental constraints on the transporter's mechanism. Stoichiometry is known for a wide array of mammalian transporters, but, due to a lack of readily available tools, not for most of the prokaryotic transporters for which high-resolution structures are available. Here, we describe a general method for using radiolabeled substrate flux assays to determine coupling stoichiometries of electrogenic secondary active transporters reconstituted in proteoliposomes by measuring transporter equilibrium potentials. We demonstrate the utility of this method by determining the coupling stoichiometry of VcINDY, a bacterial Na(+)-coupled succinate transporter, and further validate it by confirming the coupling stoichiometry of vSGLT, a bacterial sugar transporter. This robust thermodynamic method should be especially useful in probing the mechanisms of transporters with available structures.

  10. [Spontaneous bacterial peritonitis].

    Science.gov (United States)

    Velkey, Bálint; Vitális, Eszter; Vitális, Zsuzsanna

    2017-01-01

    Spontaneous bacterial peritonitis occurs most commonly in cirrhotic patients with ascites. Pathogens get into the circulation by intestinal translocation and colonize in peritoneal fluid. Diagnosis of spontaneous bacterial peritonitis is based on elevated polymorphonuclear leukocyte count in the ascites (>0,25 G/L). Ascites culture is often negative but aids to get information about antibiotic sensitivity in positive cases. Treatment in stable patient can be intravenous then orally administrated ciprofloxacin or amoxicillin/clavulanic acid, while in severe cases intravenous III. generation cephalosporin. Nosocomial spontaneous bacterial peritonitis often caused by Gram-positive bacteria and multi-resistant pathogens can also be expected thus carbapenem should be the choice of the empiric treatment. Antibiotic prophylaxis should be considered. Norfloxacin is used most commonly, but changes are expected due to increase in quinolone resistance. As a primary prophylaxis, a short-term antibiotic treatment is recommended after gastrointestinal bleeding for 5 days, while long-term prophylaxis is for patients with low ascites protein, and advanced disease (400 mg/day). Secondary prophylaxis is recommended for all patients recovered from spontaneous bacterial peritonitis. Due to increasing antibiotic use of antibiotics prophylaxis is debated to some degree. Orv. Hetil., 2017, 158(2), 50-57.

  11. Seizures Complicating Bacterial Meningitis

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2004-09-01

    Full Text Available The clinical data of 116 patients, 1 month to <5 years of age, admitted for bacterial meningitis, and grouped according to those with and without seizures during hospitalization, were compared in a study at Buddhist Dalin Tzu Chi General Hospital, Chang Gung Memorial Hospital and other centers in Taiwan.

  12. Bacterial fingerprints across Europe

    NARCIS (Netherlands)

    Glasner, Corinna

    2014-01-01

    Bacterial pathogens, such as Staphylococcus aureus and carbapenemase-producing Enterobacteriaceae (CPE), impose major threats to human health worldwide. Both have a ‘Jekyll & Hyde’ character, since they can be present as human commensals, but can also become harmful invasive pathogens especially

  13. Bacterial cell factoriest

    NARCIS (Netherlands)

    Kranenburg, van Richard

    2017-01-01

    The research of Bacterial Cell Factories aims to apply bacteria for production of biobased chemicals from renewable resources. The focus lies on thermophilic Gram-positives. This group of relatively unexplored thermophiles has many relevant characteristics that make them attractive as production

  14. Structure and operation of bacterial tripartite pumps.

    Science.gov (United States)

    Hinchliffe, Philip; Symmons, Martyn F; Hughes, Colin; Koronakis, Vassilis

    2013-01-01

    In bacteria such as Pseudomonas aeruginosa and Escherichia coli, tripartite membrane machineries, or pumps, determine the efflux of small noxious molecules, such as detergents, heavy metals, and antibiotics, and the export of large proteins including toxins. They are therefore influential in bacterial survival, particularly during infections caused by multidrug-resistant pathogens. In these tripartite pumps an inner membrane transporter, typically an ATPase or proton antiporter, binds and translocates export or efflux substrates. In cooperation with a periplasmic adaptor protein it recruits and opens a TolC family cell exit duct, which is anchored in the outer membrane and projects across the periplasmic space between inner and outer membranes. Assembled tripartite pumps thus span the entire bacterial cell envelope. We review the atomic structures of each of the three pump components and discuss how these have allowed high-resolution views of tripartite pump assembly, operation, and possible inhibition.

  15. Transformation of serum-susceptible Escherichia coli O111 with p16Slux plasmid to allow for real-time monitoring of complement-based inactivation of bacterial growth in bovine milk.

    Science.gov (United States)

    Maye, S; Stanton, C; Fitzgerald, G F; Kelly, P M

    2016-01-01

    Complement activity has only recently been characterized in raw bovine milk. However, the activity of this component of the innate immune system was found to diminish as milk was subjected to heat or partitioning during cream separation. Detection of complement in milk relies on a bactericidal assay. This assay exploits the specific growth susceptibility of Escherichia coli O111 to the presence of complement. Practical application of the assay was demonstrated when a reduction in complement activity was recorded in the case of pasteurized and reduced-fat milks. This presented an opportunity to improve the functionality of the bactericidal assay by incorporating bioluminescence capability into the target organism. Following some adaptation, the strain was transformed by correctly integrating the p16Slux plasmid. Growth properties of the transformed strain of E. coli O111 were unaffected by the modification. The efficacy of the strain adaptation was correlated using the LINEST function analysis [r=0.966; standard error of prediction (SEy)=0.957] bioluminescence with that of bactericidal assay total plate counts within the range of 7.5 to 9.2 log cfu/mL using a combination of raw and processed milk samples. Importantly, the transformed E. coli O111 p16Slux strain could be identified in milk and broth samples using bioluminescence measurement, thus enabling the bactericidal assay-viability test to be monitored in real time throughout incubation.

  16. Bacterial Trapping in Porous Media Flows

    Science.gov (United States)

    Dehkharghani, Amin; Waisbord, Nicolas; Dunkel, Jörn; Guasto, Jeffrey

    2016-11-01

    Swimming bacteria inhabit heterogeneous, microstructured environments that are often characterized by complex, ambient flows. Understanding the physical mechanisms underlying cell transport in these systems is key to controlling important processes such as bioremediation in porous soils and infections in human tissues. We study the transport of swimming bacteria (Bacillus subtilis) in quasi-two-dimensional porous microfluidic channels with a range of periodic microstructures and flow strengths. Measured cell trajectories and the local cell number density reveal the formation of filamentous cell concentration patterns within the porous structures. The local cell densification is maximized at shear rates in the range 1-10 s-1, but widely varies with pore geometry and flow topology. Experimental observations are complemented by Langevin simulations to demonstrate that the filamentous patterns result from a coupling of bacterial motility to the complex flow fields via Jeffery orbits, which effectively 'trap' the bacteria on streamlines. The resulting microscopic heterogeneity observed here suppresses bacterial transport and likely has implications for both mixing and cell nutrient uptake in porous media flows. NSF CBET-1511340.

  17. Mechanisms of bacterial resistance to chromium compounds.

    Science.gov (United States)

    Ramírez-Díaz, Martha I; Díaz-Pérez, César; Vargas, Eréndira; Riveros-Rosas, Héctor; Campos-García, Jesús; Cervantes, Carlos

    2008-06-01

    Chromium is a non-essential and well-known toxic metal for microorganisms and plants. The widespread industrial use of this heavy metal has caused it to be considered as a serious environmental pollutant. Chromium exists in nature as two main species, the trivalent form, Cr(III), which is relatively innocuous, and the hexavalent form, Cr(VI), considered a more toxic species. At the intracellular level, however, Cr(III) seems to be responsible for most toxic effects of chromium. Cr(VI) is usually present as the oxyanion chromate. Inhibition of sulfate membrane transport and oxidative damage to biomolecules are associated with the toxic effects of chromate in bacteria. Several bacterial mechanisms of resistance to chromate have been reported. The best characterized mechanisms comprise efflux of chromate ions from the cell cytoplasm and reduction of Cr(VI) to Cr(III). Chromate efflux by the ChrA transporter has been established in Pseudomonas aeruginosa and Cupriavidus metallidurans (formerly Alcaligenes eutrophus) and consists of an energy-dependent process driven by the membrane potential. The CHR protein family, which includes putative ChrA orthologs, currently contains about 135 sequences from all three domains of life. Chromate reduction is carried out by chromate reductases from diverse bacterial species generating Cr(III) that may be detoxified by other mechanisms. Most characterized enzymes belong to the widespread NAD(P)H-dependent flavoprotein family of reductases. Several examples of bacterial systems protecting from the oxidative stress caused by chromate have been described. Other mechanisms of bacterial resistance to chromate involve the expression of components of the machinery for repair of DNA damage, and systems related to the homeostasis of iron and sulfur.

  18. Computational Studies of Glutamate Transporters

    Directory of Open Access Journals (Sweden)

    Jeffry Setiadi

    2015-11-01

    Full Text Available Glutamate is the major excitatory neurotransmitter in the human brain whose binding to receptors on neurons excites them while excess glutamate are removed from synapses via transporter proteins. Determination of the crystal structures of bacterial aspartate transporters has paved the way for computational investigation of their function and dynamics at the molecular level. Here, we review molecular dynamics and free energy calculation methods used in these computational studies and discuss the recent applications to glutamate transporters. The focus of the review is on the insights gained on the transport mechanism through computational methods, which otherwise is not directly accessible by experimental probes. Recent efforts to model the mammalian glutamate and other amino acid transporters, whose crystal structures have not been solved yet, are included in the review.

  19. Cd adsorption onto bacterial surfaces: A universal adsorption edge?

    Science.gov (United States)

    Yee, Nathan; Fein, Jeremy

    2001-07-01

    In this study, we measure the thermodynamic stability constants for proton and Cd binding onto the Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa, and the Gram-positive bacteria Bacillus megaturium, Streptococcus faecalis, Staphylococcus aureus, Sporosarcina ureae, and Bacillus cereus. Potentiometric titrations and Cd-bacteria adsorption experiments yield average values for the carboxyl site pK a, site concentration, and log stability constant for the bacterial surface Cd-carboxyl complex of 5.0, 2.0 × 10 -3 mol/g and 4.0 respectively. Our results indicate that a wide range of bacterial species exhibit nearly identical Cd adsorption behavior as a function of pH. We propose that metal-bacteria adsorption is not dependent on the bacterial species involved, and we develop a generalized adsorption model which may greatly simplify the task of quantifying the effects of bacterial adsorption on dissolved mass transport in realistic geologic systems.

  20. Formation of bacterial nanocells

    Science.gov (United States)

    Vainshtein, Mikhail; Kudryashova, Ekaterina; Suzina, Natalia; Ariskina, Elena; Voronkov, Vadim

    1998-07-01

    Existence of nanobacteria received increasing attention both in environmental microbiology/geomicro-biology and in medical microbiology. In order to study a production of nanoforms by typical bacterial cells. Effects of different physical factors were investigated. Treatment of bacterial cultures with microwave radiation, or culturing in field of electric current resulted in formation a few types of nanocells. The number and type of nanoforms were determined with type and dose of the treatment. The produced nanoforms were: i) globules, ii) clusters of the globules--probably produced by liaison, iii) nanocells coated with membrane. The viability of the globules is an object opened for doubts. The nanocells discovered multiplication and growth on solidified nutrient media. The authors suggest that formation of nanocells is a common response of bacteria to stress-actions produced by different agents.

  1. Cooperative Bacterial Foraging Optimization

    Directory of Open Access Journals (Sweden)

    Hanning Chen

    2009-01-01

    Full Text Available Bacterial Foraging Optimization (BFO is a novel optimization algorithm based on the social foraging behavior of E. coli bacteria. This paper presents a variation on the original BFO algorithm, namely, the Cooperative Bacterial Foraging Optimization (CBFO, which significantly improve the original BFO in solving complex optimization problems. This significant improvement is achieved by applying two cooperative approaches to the original BFO, namely, the serial heterogeneous cooperation on the implicit space decomposition level and the serial heterogeneous cooperation on the hybrid space decomposition level. The experiments compare the performance of two CBFO variants with the original BFO, the standard PSO and a real-coded GA on four widely used benchmark functions. The new method shows a marked improvement in performance over the original BFO and appears to be comparable with the PSO and GA.

  2. Bacterial Colony Optimization

    Directory of Open Access Journals (Sweden)

    Ben Niu

    2012-01-01

    Full Text Available This paper investigates the behaviors at different developmental stages in Escherichia coli (E. coli lifecycle and developing a new biologically inspired optimization algorithm named bacterial colony optimization (BCO. BCO is based on a lifecycle model that simulates some typical behaviors of E. coli bacteria during their whole lifecycle, including chemotaxis, communication, elimination, reproduction, and migration. A newly created chemotaxis strategy combined with communication mechanism is developed to simplify the bacterial optimization, which is spread over the whole optimization process. However, the other behaviors such as elimination, reproduction, and migration are implemented only when the given conditions are satisfied. Two types of interactive communication schemas: individuals exchange schema and group exchange schema are designed to improve the optimization efficiency. In the simulation studies, a set of 12 benchmark functions belonging to three classes (unimodal, multimodal, and rotated problems are performed, and the performances of the proposed algorithms are compared with five recent evolutionary algorithms to demonstrate the superiority of BCO.

  3. Targeting bacterial toxins.

    Science.gov (United States)

    Ivarsson, Mattias E; Leroux, Jean-Christophe; Castagner, Bastien

    2012-04-23

    Protein toxins constitute the main virulence factors of several species of bacteria and have proven to be attractive targets for drug development. Lead candidates that target bacterial toxins range from small molecules to polymeric binders, and act at each of the multiple steps in the process of toxin-mediated pathogenicity. Despite recent and significant advances in the field, a rationally designed drug that targets toxins has yet to reach the market. This Review presents the state of the art in bacterial toxin targeted drug development with a critical consideration of achieved breakthroughs and withstanding challenges. The discussion focuses on A-B-type protein toxins secreted by four species of bacteria, namely Clostridium difficile (toxins A and B), Vibrio cholerae (cholera toxin), enterohemorrhagic Escherichia coli (Shiga toxin), and Bacillus anthracis (anthrax toxin), which are the causative agents of diseases for which treatments need to be improved. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Bacterial assays for recombinagens.

    Science.gov (United States)

    Hoffmann, G R

    1992-12-01

    Two principal strategies have been used for studying recombinagenic effects of chemicals and radiation in bacteria: (1) measurement of homologous recombination involving defined alleles in a partially diploid strain, and (2) measurement of the formation and loss of genetic duplications in the bacterial chromosome. In the former category, most methods involve one allele in the bacterial chromosome and another in a plasmid, but it is also possible to detect recombination between two chromosomal alleles or between two extrachromosomal alleles. This review summarizes methods that use each of these approaches for detecting recombination and tabulates data on agents that have been found to be recombinagenic in bacteria. The assays are discussed with respect to their effectiveness in testing for recombinagens and their potential for elucidating mechanisms underlying recombinagenic effects.

  5. Novel receptors for bacterial protein toxins.

    Science.gov (United States)

    Schmidt, Gudula; Papatheodorou, Panagiotis; Aktories, Klaus

    2015-02-01

    While bacterial effectors are often directly introduced into eukaryotic target cells by various types of injection machines, toxins enter the cytosol of host cells from endosomal compartments or after retrograde transport via Golgi from the ER. A first crucial step of toxin-host interaction is receptor binding. Using optimized protocols and new methods novel toxin receptors have been identified, including metalloprotease ADAM 10 for Staphylococcus aureus α-toxin, laminin receptor Lu/BCAM for Escherichia coli cytotoxic necrotizing factor CNF1, lipolysis stimulated lipoprotein receptor (LSR) for Clostridium difficile transferase CDT and low-density lipoprotein receptor-related protein (LRP) 1 for Clostridium perfringens TpeL toxin.

  6. Functional characterisation and Mutational analysis of a bacterial dynamin-like protein, DynA

    OpenAIRE

    2015-01-01

    Membrane remodeling is a dynamic process that occurs in bacterial cells to facilitate substrate transport and to provide protection to bacteria during environmental stress. In eukaryotic cells, membrane remodeling is carried out by dynamin-like proteins (DLPs). These proteins are involved in diverse membrane-associated functions such as cargo transport via vesicles, cytokinesis, division of cell organelles and resistance to pathogens. DLPs are also conserved in bacterial species; howeve...

  7. Bacterial transformation of terpenoids

    Science.gov (United States)

    Grishko, V. V.; Nogovitsina, Y. M.; Ivshina, I. B.

    2014-04-01

    Data on the bacterial transformation of terpenoids published in the literature in the past decade are analyzed. Possible pathways for chemo-, regio- and stereoselective modifications of terpenoids are discussed. Considerable attention is given to new technological approaches to the synthesis of terpenoid derivatives suitable for the use in the perfume and food industry and promising as drugs and chiral intermediates for fine organic synthesis. The bibliography includes 246 references.

  8. Spontaneous bacterial peritonitis

    OpenAIRE

    Al Amri Saleh

    1995-01-01

    Spontaneous bacterial peritonitis (SBP) is an infection of the ascitic fluid without obvious intra-abdominal source of sepsis; usually complicates advanced liver disease. The pathogenesis of the disease is multifactorial: low ascitic protein-content, which reflects defi-cient ascitic fluid complement and hence, reduced opsonic activity is thought to be the most important pathogenic factor. Frequent and prolonged bacteremia has been considered as another pertinent cause of SBP. This disease is...

  9. Modelling bacterial speciation

    OpenAIRE

    2006-01-01

    A central problem in understanding bacterial speciation is how clusters of closely related strains emerge and persist in the face of recombination. We use a neutral Fisher–Wright model in which genotypes, defined by the alleles at 140 house-keeping loci, change in each generation by mutation or recombination, and examine conditions in which an initially uniform population gives rise to resolved clusters. Where recombination occurs at equal frequency between all members of the population, we o...

  10. Monitoring of bacterial drug resistance and their analysis of antimicrobial susceptibility in our hospital%我院细菌耐药性监测与抗菌药物敏感性分析

    Institute of Scientific and Technical Information of China (English)

    廖俊艳

    2014-01-01

    Objective To understand the antimicrobial susceptibility of the bacteria in our hospital, and guide the application of antibiotics.Methods In the Luozhuang center hospital of Linyi in 2012, the drug resistance of clinically isolated strains was monitored, and their antimicrobial susceptibility were analyzed by disc diffusion method recommended by CLSI, using WHONET5.3 software to analyze the results.Results According to the moni-toring programme, the result of susceptibility test of 780 strains of bacteria to antimicrobial agents were obtained, in-cluding 239 strains of gram-positive bacteria, accounting for 30.6%;541 strains of gram-negative bacteria, account-ing for 69.4%.Except for pseudomonas aeruginosa, drug sensitive rate of all gram-negative bacillus to carbapenems were over 85.7%, those of piperacillin-tazobactam were more than 79.6%;those of all the staphylococcus aureus to vancomycin were 100.0%.Methicillin-resistant staphylococcus aureus(MRSA)detection rate was 51.1%, sensitive rate of MRSA to chloromycetin was 80.0%, with resistance to other antibiotics;the sensitive rate of faecium and fae-calis to vancomycin and linezolid were the highest (96.6%,100.0%;100.0%,100.0%).Conclusion The sensi-tive rates of klebsiella pneumoniae, escherichia coli, acinetobacter and enterobacter to carbapenems were higher, but the drug resistence rate of pseudomonas aeruginosa to it was higher.The sensitive rates of staphylococcus aureus to vancomycin, linezolid and teicoplanin were higher.%目的:了解该院细菌对抗菌药物的敏感性,指导临床抗菌药物合理应用。方法监测该院2012年临床分离菌株的耐药性,以美国临床和实验室标准协会( CLSI)推荐的纸片扩散法测定其抗菌药物敏感性,用WHONET5.3软件分析结果。结果按照监测方案,共获得780株细菌对抗菌药物敏感性结果,其中革兰阳性菌239株,占30.6%;革兰阴性菌541株,占69.4%。除绿脓杆菌外,所有革兰阴

  11. Neglected bacterial zoonoses.

    Science.gov (United States)

    Chikeka, I; Dumler, J S

    2015-05-01

    Bacterial zoonoses comprise a group of diseases in humans or animals acquired by direct contact with or by oral consumption of contaminated animal materials, or via arthropod vectors. Among neglected infections, bacterial zoonoses are among the most neglected given emerging data on incidence and prevalence as causes of acute febrile illness, even in areas where recognized neglected tropical diseases occur frequently. Although many other bacterial infections could also be considered in this neglected category, five distinct infections stand out because they are globally distributed, are acute febrile diseases, have high rates of morbidity and case fatality, and are reported as commonly as malaria, typhoid or dengue virus infections in carefully designed studies in which broad-spectrum diagnoses are actively sought. This review will focus attention on leptospirosis, relapsing fever borreliosis and rickettsioses, including scrub typhus, murine typhus and spotted fever group rickettsiosis. Of greatest interest is the lack of distinguishing clinical features among these infections when in humans, which confounds diagnosis where laboratory confirmation is lacking, and in regions where clinical diagnosis is often attributed to one of several perceived more common threats. As diseases such as malaria come under improved control, the real impact of these common and under-recognized infections will become evident, as will the requirement for the strategies and allocation of resources for their control.

  12. Adaptive Bacterial Foraging Optimization

    Directory of Open Access Journals (Sweden)

    Hanning Chen

    2011-01-01

    Full Text Available Bacterial Foraging Optimization (BFO is a recently developed nature-inspired optimization algorithm, which is based on the foraging behavior of E. coli bacteria. Up to now, BFO has been applied successfully to some engineering problems due to its simplicity and ease of implementation. However, BFO possesses a poor convergence behavior over complex optimization problems as compared to other nature-inspired optimization techniques. This paper first analyzes how the run-length unit parameter of BFO controls the exploration of the whole search space and the exploitation of the promising areas. Then it presents a variation on the original BFO, called the adaptive bacterial foraging optimization (ABFO, employing the adaptive foraging strategies to improve the performance of the original BFO. This improvement is achieved by enabling the bacterial foraging algorithm to adjust the run-length unit parameter dynamically during algorithm execution in order to balance the exploration/exploitation tradeoff. The experiments compare the performance of two versions of ABFO with the original BFO, the standard particle swarm optimization (PSO and a real-coded genetic algorithm (GA on four widely-used benchmark functions. The proposed ABFO shows a marked improvement in performance over the original BFO and appears to be comparable with the PSO and GA.

  13. A study on bacterial softrot in witloof chicory.

    NARCIS (Netherlands)

    Schober, B.M.

    1998-01-01

    The production process of witloof chicory, which consists of the root production stage, the storage of the roots and the forcing of the chicory heads, was monitored for the presence of softrot bacteria. In the Netherlands, bacterial softrot in chicory is caused by Erwinia carotovora subsp . carotovo

  14. In situ real-time measurement of physical characteristics of airborne bacterial particles

    Science.gov (United States)

    Jung, Jae Hee; Lee, Jung Eun

    2013-12-01

    Bioaerosols, including aerosolized bacteria, viruses, and fungi, are associated with public health and environmental problems. One promising control method to reduce the harmful effects of bioaerosols is thermal inactivation via a continuous-flow high-temperature short-time (HTST) system. However, variations in bioaerosol physical characteristics - for example, the particle size and shape - during the continuous-flow inactivation process can change the transport properties in the air, which can affect particle deposition in the human respiratory system or the filtration efficiency of ventilation systems. Real-time particle monitoring techniques are a desirable alternative to the time-consuming process of microscopic analysis that is conventionally used in sampling and particle characterization. Here, we report in situ real-time optical scattering measurements of the physical characteristics of airborne bacteria particles following an HTST process in a continuous-flow system. Our results demonstrate that the aerodynamic diameter of bacterial aerosols decreases when exposed to a high-temperature environment, and that the shape of the bacterial cells is significantly altered. These variations in physical characteristics using optical scattering measurements were found to be in agreement with the results of scanning electron microscopy analysis.

  15. Transport of the LHC cryodipoles

    CERN Document Server

    Buenaventura, A

    2000-01-01

    The LHC cryodipoles will be assembled at ground level and then transported and handled by various means until their final positioning in the tunnel. The dynamic behaviour of the cryodipole is different for each means of transport and has been studied using finite elements. The effect of the transport restraints on the dynamic behaviour of the cryodipole was assessed and a layout of transport restraints for the LHC cryodipoles is proposed. Furthermore, the maximum admissible accelerations during transport are presented. Accelerations should be monitored from the assembly operation until the cryodipoles are in their final position in the tunnel. For this purpose, a system based on self-contained tri-axial shock and vibrometer monitors is proposed.

  16. School Transportation.

    Science.gov (United States)

    Executive Educator, 1990

    1990-01-01

    This special section on student transportation offers a case study of a school system that recycles buses for safety drills; articles on fuel-saving strategies, the pros and cons of contracting for transportation services or operating a publicly owned bus fleet, and advice on full cost accounting for transportation costs; and a transportation…

  17. High-Throughput Screening Assay for Inhibitors of TonB-Dependent Iron Transport.

    Science.gov (United States)

    Hanson, Mathew; Jordan, Lorne D; Shipelskiy, Yan; Newton, Salete M; Klebba, Phillip E

    2016-03-01

    The TonB-dependent Gram-negative bacterial outer membrane protein FepA actively transports the siderophore ferric enterobactin (FeEnt) into the periplasm. We developed a high-throughput screening (HTS) assay that observes FeEnt uptake through FepA in living Escherichia coli, by monitoring fluorescence quenching that occurs upon binding of FeEnt, and then unquenching as the bacteria deplete it from solution by transport. We optimized the labeling and spectroscopic methods to screen for inhibitors of TonB-dependent iron uptake through the outer membrane. The assay works like a molecular switch that is on in the presence of TonB activity and off in its absence. It functions in 96-well microtiter plates, in a variety of conditions, with Z factors of 0.8-1.0. TonB-dependent iron transport is energy dependent, and the inhibitory effects of the metabolic inhibitors carbonyl cyanide m-chlorophenylhydrazone, 2,4-dinitrophenol, azide, cyanide, and arsenate on FeEnt uptake were readily detected by the assay. Because iron acquisition is a determinant of bacterial pathogenesis, HTS with this method may identify inhibitors that block TonB function and constitute novel therapeutics against infectious disease caused by Gram-negative bacteria. © 2015 Society for Laboratory Automation and Screening.

  18. Cysteine transport through excitatory amino acid transporter 3 (EAAT3).

    Science.gov (United States)

    Watts, Spencer D; Torres-Salazar, Delany; Divito, Christopher B; Amara, Susan G

    2014-01-01

    Excitatory amino acid transporters (EAATs) limit glutamatergic signaling and maintain extracellular glutamate concentrations below neurotoxic levels. Of the five known EAAT isoforms (EAATs 1-5), only the neuronal isoform, EAAT3 (EAAC1), can efficiently transport the uncharged amino acid L-cysteine. EAAT3-mediated cysteine transport has been proposed to be a primary mechanism used by neurons to obtain cysteine for the synthesis of glutathione, a key molecule in preventing oxidative stress and neuronal toxicity. The molecular mechanisms underlying the selective transport of cysteine by EAAT3 have not been elucidated. Here we propose that the transport of cysteine through EAAT3 requires formation of the thiolate form of cysteine in the binding site. Using Xenopus oocytes and HEK293 cells expressing EAAT2 and EAAT3, we assessed the transport kinetics of different substrates and measured transporter-associated currents electrophysiologically. Our results show that L-selenocysteine, a cysteine analog that forms a negatively-charged selenolate ion at physiological pH, is efficiently transported by EAATs 1-3 and has a much higher apparent affinity for transport when compared to cysteine. Using a membrane tethered GFP variant to monitor intracellular pH changes associated with transport activity, we observed that transport of either L-glutamate or L-selenocysteine by EAAT3 decreased intracellular pH, whereas transport of cysteine resulted in cytoplasmic alkalinization. No change in pH was observed when cysteine was applied to cells expressing EAAT2, which displays negligible transport of cysteine. Under conditions that favor release of intracellular substrates through EAAT3 we observed release of labeled intracellular glutamate but did not detect cysteine release. Our results support a model whereby cysteine transport through EAAT3 is facilitated through cysteine de-protonation and that once inside, the thiolate is rapidly re-protonated. Moreover, these findings suggest

  19. Nano Particles: Emerging Warheads Against Bacterial Superbugs.

    Science.gov (United States)

    Dwivedi, Gaurav Raj; Sanchita; Singh, D P; Sharma, Ashok; Darokar, Mahendra P; Srivastava, Santosh K

    2016-01-01

    Infectious diseases are one of the major causes of morbidity and mortality in children in developing and underdeveloped countries. Limited knowledge of targets (cell wall synthesis, replication, transcription, protein synthesis) for antibiotics and lack of novel antibiotics have lead to an emergence of different level of resistance in bacterial pathogens. Multidrug resistance is the phenomenon by which the bacteria exerts resistance against the two or more structurally unrelated drugs/antibiotics. A common goal in the post-genomic era is to identify novel targets/drugs for various life threatening bacterial pathogens. Nanoparticles are broadly defined as submicron colloidal particles of size less than 1μm. Nanoparticles of size less than 100nm are the most promising warheads to overcome microbial drug resistance because they can act as antibacterial/antibiotic modulating agents at the site of infection and may have more than one mode of action. These nanoparticles will be of immense help in transporting drugs directly at the infected sites. Thus prevent drug resistance development to a great extent. In this review, the key mechanisms of resistance in bacterial superbugs have been discussed as well as how nanoparticles can overcome them. It is hypothesized that the nanoparticles can overcome the drug resistance via a novel mechanism of action. Additionaly, nanopaticles may also work synergistically with antibiotics via increased uptake, decreased efflux and inhibition of biofilm formation. The degradation by metallo beta lactamases and synthesis of porins may also be facilitated through these nanoparticles.

  20. Sustainable Transportation

    DEFF Research Database (Denmark)

    Hall, Ralph P.; Gudmundsson, Henrik; Marsden, Greg

    2014-01-01

    The transportation system is the backbone of economic and social progress and the means by which humans access goods and services and connect with one another. Yet, as the scale of transportation activities has grown worldwide, so too have the negative environmental, social, and economic impacts...... that relate to the construction and maintenance of transportation infrastructure and the operation or use of the different transportation modes. The concept of sustainable transportation emerged in response to these concerns as part of the broader notion of sustainable development. Given the transportation...... sector’s significant contribution to global challenges such as climate change, it is often said that sustainable development cannot be achieved without sustainable transportation....

  1. Modulation of Bacterial Multidrug Resistance Efflux Pumps of the Major Facilitator Superfamily

    Directory of Open Access Journals (Sweden)

    Sanath Kumar

    2013-01-01

    Full Text Available Bacterial infections pose a serious public health concern, especially when an infectious disease has a multidrug resistant causative agent. Such multidrug resistant bacteria can compromise the clinical utility of major chemotherapeutic antimicrobial agents. Drug and multidrug resistant bacteria harbor several distinct molecular mechanisms for resistance. Bacterial antimicrobial agent efflux pumps represent a major mechanism of clinical resistance. The major facilitator superfamily (MFS is one of the largest groups of solute transporters to date and includes a significant number of bacterial drug and multidrug efflux pumps. We review recent work on the modulation of multidrug efflux pumps, paying special attention to those transporters belonging primarily to the MFS.

  2. Radiology of bacterial pneumonia

    Energy Technology Data Exchange (ETDEWEB)

    Vilar, Jose E-mail: vilar_jlu@gva.es; Domingo, Maria Luisa; Soto, Cristina; Cogollos, Jonathan

    2004-08-01

    Bacterial pneumonia is commonly encountered in clinical practice. Radiology plays a prominent role in the evaluation of pneumonia. Chest radiography is the most commonly used imaging tool in pneumonias due to its availability and excellent cost benefit ratio. CT should be used in unresolved cases or when complications of pneumonia are suspected. The main applications of radiology in pneumonia are oriented to detection, characterisation and follow-up, especially regarding complications. The classical classification of pneumonias into lobar and bronchial pneumonia has been abandoned for a more clinical classification. Thus, bacterial pneumonias are typified into three main groups: Community acquired pneumonia (CAD), Aspiration pneumonia and Nosocomial pneumonia (NP).The usual pattern of CAD is that of the previously called lobar pneumonia; an air-space consolidation limited to one lobe or segment. Nevertheless, the radiographic patterns of CAD may be variable and are often related to the causative agent. Aspiration pneumonia generally involves the lower lobes with bilateral multicentric opacities. Nosocomial Pneumonia (NP) occurs in hospitalised patients. The importance of NP is related to its high mortality and, thus, the need to obtain a prompt diagnosis. The role of imaging in NP is limited but decisive. The most valuable information is when the chest radiographs are negative and rule out pneumonia. The radiographic patterns of NP are very variable, most commonly showing diffuse multifocal involvement and pleural effusion. Imaging plays also an important role in the detection and evaluation of complications of bacterial pneumonias. In many of these cases, especially in hospitalised patients, chest CT must be obtained in order to better depict these associate findings.

  3. 49 CFR 192.477 - Internal corrosion control: Monitoring.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Internal corrosion control: Monitoring. 192.477... Control § 192.477 Internal corrosion control: Monitoring. If corrosive gas is being transported, coupons... internal corrosion. Each coupon or other means of monitoring internal corrosion must be checked two...

  4. Bacterial ligands generated in a phagosome are targets of the cytosolic innate immune system.

    Directory of Open Access Journals (Sweden)

    Anat A Herskovits

    2007-03-01

    Full Text Available Macrophages are permissive hosts to intracellular pathogens, but upon activation become microbiocidal effectors of innate and cell-mediated immunity. How the fate of internalized microorganisms is monitored by macrophages, and how that information is integrated to stimulate specific immune responses is not understood. Activation of macrophages with interferon (IFN-gamma leads to rapid killing and degradation of Listeria monocytogenes in a phagosome, thus preventing escape of bacteria to the cytosol. Here, we show that activated macrophages induce a specific gene expression program to L. monocytogenes degraded in the phago-lysosome. In addition to activation of Toll-like receptor (TLR signaling pathways, degraded bacteria also activated a TLR-independent transcriptional response that was similar to the response induced by cytosolic L. monocytogenes. More specifically, degraded bacteria induced a TLR-independent IFN-beta response that was previously shown to be specific to cytosolic bacteria and not to intact bacteria localized to the phagosome. This response required the generation of bacterial ligands in the phago-lysosome and was largely dependent on nucleotide-binding oligomerization domain 2 (NOD2, a cytosolic receptor known to respond to bacterial peptidoglycan fragments. The NOD2-dependent response to degraded bacteria required the phagosomal membrane potential and the activity of lysosomal proteases. The NOD2-dependent IFN-beta production resulted from synergism with other cytosolic microbial sensors. This study supports the hypothesis that in activated macrophages, cytosolic innate immune receptors are activated by bacterial ligands generated in the phagosome and transported to the cytosol.

  5. Bacterial mitotic machineries

    DEFF Research Database (Denmark)

    Gerdes, Kenn; Møller-Jensen, Jakob; Ebersbach, Gitte;

    2004-01-01

    Here, we review recent progress that yields fundamental new insight into the molecular mechanisms behind plasmid and chromosome segregation in prokaryotic cells. In particular, we describe how prokaryotic actin homologs form mitotic machineries that segregate DNA before cell division. Thus, the Par......M protein of plasmid R1 forms F actin-like filaments that separate and move plasmid DNA from mid-cell to the cell poles. Evidence from three different laboratories indicate that the morphogenetic MreB protein may be involved in segregation of the bacterial chromosome....

  6. Bacterial chromosome segregation.

    Science.gov (United States)

    Possoz, Christophe; Junier, Ivan; Espeli, Olivier

    2012-01-01

    Dividing cells have mechanisms to ensure that their genomes are faithfully segregated into daughter cells. In bacteria, the description of these mechanisms has been considerably improved in the recent years. This review focuses on the different aspects of bacterial chromosome segregation that can be understood thanks to the studies performed with model organisms: Escherichia coli, Bacillus subtilis, Caulobacter crescentus and Vibrio cholerae. We describe the global positionning of the nucleoid in the cell and the specific localization and dynamics of different chromosomal loci, kinetic and biophysic aspects of chromosome segregation are presented. Finally, a presentation of the key proteins involved in the chromosome segregation is made.

  7. Spontaneous bacterial peritonitis

    Directory of Open Access Journals (Sweden)

    Al Amri Saleh

    1995-01-01

    Full Text Available Spontaneous bacterial peritonitis (SBP is an infection of the ascitic fluid without obvious intra-abdominal source of sepsis; usually complicates advanced liver disease. The pathogenesis of the disease is multifactorial: low ascitic protein-content, which reflects defi-cient ascitic fluid complement and hence, reduced opsonic activity is thought to be the most important pathogenic factor. Frequent and prolonged bacteremia has been considered as another pertinent cause of SBP. This disease is associated with high mortality and recurrence. Therefore, orompt recognition and institution of therapy and plan of prophylaxis is vital.

  8. Nitrogen starvation affects bacterial adhesion to soil

    Science.gov (United States)

    Borges, Maria Tereza; Nascimento, Antônio Galvão; Rocha, Ulisses Nunes; Tótola, Marcos Rogério

    2008-01-01

    One of the main factors limiting the bioremediation of subsoil environments based on bioaugmentation is the transport of selected microorganisms to the contaminated zones. The characterization of the physiological responses of the inoculated microorganisms to starvation, especially the evaluation of characteristics that affect the adhesion of the cells to soil particles, is fundamental to anticipate the success or failure of bioaugmentation. The objective of this study was to investigate the effect of nitrogen starvation on cell surface hydrophobicity and cell adhesion to soil particles by bacterial strains previously characterized as able to use benzene, toluene or xilenes as carbon and energy sources. The strains LBBMA 18-T (non-identified), Arthrobacter aurescens LBBMA 98, Arthrobacter oxydans LBBMA 201, and Klebsiella sp. LBBMA 204–1 were used in the experiments. Cultivation of the cells in nitrogen-deficient medium caused a significant reduction of the adhesion to soil particles by all the four strains. Nitrogen starvation also reduced significantly the strength of cell adhesion to the soil particles, except for Klebsiella sp. LBBMA 204–1. Two of the four strains showed significant reduction in cell surface hydrophobicity. It is inferred that the efficiency of bacterial transport through soils might be potentially increased by nitrogen starvation. PMID:24031246

  9. Channel-Forming Bacterial Toxins in Biosensing and Macromolecule Delivery

    Directory of Open Access Journals (Sweden)

    Philip A. Gurnev

    2014-08-01

    Full Text Available To intoxicate cells, pore-forming bacterial toxins are evolved to allow for the transmembrane traffic of different substrates, ranging from small inorganic ions to cell-specific polypeptides. Recent developments in single-channel electrical recordings, X-ray crystallography, protein engineering, and computational methods have generated a large body of knowledge about the basic principles of channel-mediated molecular transport. These discoveries provide a robust framework for expansion of the described principles and methods toward use of biological nanopores in the growing field of nanobiotechnology. This article, written for a special volume on “Intracellular Traffic and Transport of Bacterial Protein Toxins”, reviews the current state of applications of pore-forming bacterial toxins in small- and macromolecule-sensing, targeted cancer therapy, and drug delivery. We discuss the electrophysiological studies that explore molecular details of channel-facilitated protein and polymer transport across cellular membranes using both natural and foreign substrates. The review focuses on the structurally and functionally different bacterial toxins: gramicidin A of Bacillus brevis, α-hemolysin of Staphylococcus aureus, and binary toxin of Bacillus anthracis, which have found their “second life” in a variety of developing medical and technological applications.

  10. Channel-forming bacterial toxins in biosensing and macromolecule delivery.

    Science.gov (United States)

    Gurnev, Philip A; Nestorovich, Ekaterina M

    2014-08-21

    To intoxicate cells, pore-forming bacterial toxins are evolved to allow for the transmembrane traffic of different substrates, ranging from small inorganic ions to cell-specific polypeptides. Recent developments in single-channel electrical recordings, X-ray crystallography, protein engineering, and computational methods have generated a large body of knowledge about the basic principles of channel-mediated molecular transport. These discoveries provide a robust framework for expansion of the described principles and methods toward use of biological nanopores in the growing field of nanobiotechnology. This article, written for a special volume on "Intracellular Traffic and Transport of Bacterial Protein Toxins", reviews the current state of applications of pore-forming bacterial toxins in small- and macromolecule-sensing, targeted cancer therapy, and drug delivery. We discuss the electrophysiological studies that explore molecular details of channel-facilitated protein and polymer transport across cellular membranes using both natural and foreign substrates. The review focuses on the structurally and functionally different bacterial toxins: gramicidin A of Bacillus brevis, α-hemolysin of Staphylococcus aureus, and binary toxin of Bacillus anthracis, which have found their "second life" in a variety of developing medical and technological applications.

  11. Spontaneous bacterial peritonitis

    Institute of Scientific and Technical Information of China (English)

    Anastasios Koulaouzidis; Shivaram Bhat; Athar A Saeed

    2009-01-01

    Since its initial description in 1964, research has transformed spontaneous bacterial peritonitis (SBP) from a feared disease (with reported mortality of 90%) to a treatable complication of decompensated cirrhosis,albeit with steady prevalence and a high recurrence rate. Bacterial translocation, the key mechanism in the pathogenesis of SBP, is only possible because of the concurrent failure of defensive mechanisms in cirrhosis.Variants of SBP should be treated. Leucocyte esterase reagent strips have managed to shorten the 'tap-toshot' time, while future studies should look into their combined use with ascitic fluid pH. Third generation cephalosporins are the antibiotic of choice because they have a number of advantages. Renal dysfunction has been shown to be an independent predictor of mortality in patients with SBP. Albumin is felt to reduce the risk of renal impairment by improving effective intravascular volume, and by helping to bind proinflammatory molecules. Following a single episode of SBP, patients should have long-term antibiotic prophylaxis and be considered for liver transplantation.

  12. Characterization of the DNA-Mediated Oxidation of Dps, A Bacterial Ferritin.

    Science.gov (United States)

    Arnold, Anna R; Zhou, Andy; Barton, Jacqueline K

    2016-09-07

    Dps proteins are bacterial ferritins that protect DNA from oxidative stress and have been implicated in bacterial survival and virulence. In addition to direct oxidation of the Dps iron sites by diffusing oxidants, oxidation from a distance via DNA charge transport (CT), where electrons and electron holes are rapidly transported through the base-pair π-stack, could represent an efficient DNA protection mechanism utilized by Dps. Here, we spectroscopically characterize the DNA-mediated oxidation of ferrous iron-loaded Dps. X-band EPR was used to monitor the oxidation of DNA-bound Dps after DNA photooxidation using an intercalating ruthenium photooxidant and the flash-quench technique. Upon irradiation with poly(dGdC)2, a signal arises with g = 4.3, consistent with the formation of mononuclear high-spin Fe(III) sites of low symmetry, the expected oxidation product of Dps with one iron bound at each ferroxidase site. When poly(dGdC)2 is substituted with poly(dAdT)2, the yield of Dps oxidation is decreased significantly, consistent with guanine radical intermediates facilitating Dps oxidation. We have also explored possible protein electron transfer (ET) intermediates in the DNA-mediated oxidation of ferrous iron-loaded Dps. Dps proteins contain a conserved tryptophan residue in close proximity to the iron-binding ferroxidase site (W52 in E. coli Dps). In EPR studies of the oxidation of ferrous iron-loaded Dps following DNA photooxidation, a W52A Dps mutant was significantly deficient compared to WT Dps in forming the characteristic EPR signal at g = 4.3, consistent with W52 acting as an ET hopping intermediate. This effect is mirrored in vivo in E. coli survival in response to hydrogen peroxide, where mutation of W52 leads to decreased survival under oxidative stress.

  13. Antimicrobials for bacterial bioterrorism agents.

    Science.gov (United States)

    Sarkar-Tyson, Mitali; Atkins, Helen S

    2011-06-01

    The limitations of current antimicrobials for highly virulent pathogens considered as potential bioterrorism agents drives the requirement for new antimicrobials that are suitable for use in populations in the event of a deliberate release. Strategies targeting bacterial virulence offer the potential for new countermeasures to combat bacterial bioterrorism agents, including those active against a broad spectrum of pathogens. Although early in the development of antivirulence approaches, inhibitors of bacterial type III secretion systems and cell division mechanisms show promise for the future.

  14. Sustainable Transportation

    DEFF Research Database (Denmark)

    Hall, Ralph P.; Gudmundsson, Henrik; Marsden, Greg

    2014-01-01

    The transportation system is the backbone of economic and social progress and the means by which humans access goods and services and connect with one another. Yet, as the scale of transportation activities has grown worldwide, so too have the negative environmental, social, and economic impacts ...... sector’s significant contribution to global challenges such as climate change, it is often said that sustainable development cannot be achieved without sustainable transportation....

  15. Positively regulated bacterial expression systems.

    Science.gov (United States)

    Brautaset, Trygve; Lale, Rahmi; Valla, Svein

    2009-01-01

    Regulated promoters are useful tools for many aspects related to recombinant gene expression in bacteria, including for high-level expression of heterologous proteins and for expression at physiological levels in metabolic engineering applications. In general, it is common to express the genes of interest from an inducible promoter controlled either by a positive regulator or by a repressor protein. In this review, we discuss established and potentially useful positively regulated bacterial promoter systems, with a particular emphasis on those that are controlled by the AraC-XylS family of transcriptional activators. The systems function in a wide range of microorganisms, including enterobacteria, soil bacteria, lactic bacteria and streptomycetes. The available systems that have been applied to express heterologous genes are regulated either by sugars (L-arabinose, L-rhamnose, xylose and sucrose), substituted benzenes, cyclohexanone-related compounds, ε-caprolactam, propionate, thiostrepton, alkanes or peptides. It is of applied interest that some of the inducers require the presence of transport systems, some are more prone than others to become metabolized by the host and some have been applied mainly in one or a limited number of species. Based on bioinformatics analyses, the AraC-XylS family of regulators contains a large number of different members (currently over 300), but only a small fraction of these, the XylS/Pm, AraC/P(BAD), RhaR-RhaS/rhaBAD, NitR/PnitA and ChnR/Pb regulator/promoter systems, have so far been explored for biotechnological applications.

  16. 全面建设安徽省交通运输环境监测网络的必要性探讨%Discussion on the necessity of building a comprehensive network of traffic and transportation environmental monitoring in Anhui Province

    Institute of Scientific and Technical Information of China (English)

    康启兵

    2016-01-01

    随着我国交通基础设施建设全面推进,交通运输网络日趋完善,国家对交通运输行业环境保护要求也越来越高,有必要建立系统的交通运输环境监测网络,及时、全面掌握交通运输环境保护状况,为交通环保政策和规划制定、监管与科研等提供科学依据。本文就安徽省交通运输环境监测网络建设的必要性进行简要探讨。%Highway and waterway transportation environment monitoring is an important technical means of environmental regula⁃tion, and it is the important foundation of the long term management of traffic environmental protection. The development of environment monitoring in industry can effectively grasp environmental quality and pollution sources emission status and change trend of, strengthen environmental supervision, promote pollution treatment facilities operation, reduce the occurrence of environmental pollution accidents, protecting the ecological environment along the line of the traffic facilities; it can provide data support for coding of the transportation de⁃velopment planning, transportation and environmental protection laws and regulations and standard setting, to carry out transportation en⁃vironmental protection science research, fill in the environment of transportation statistics such as; can provide the basis for the effective⁃ness of industry management departments at all levels to evaluate the environmental protection work effectiveness and traffic environmen⁃tal protection facilities. Therefore, the construction of scientific layout, reasonable levels of energy-saving environmental protection in⁃dustry monitoring network ", and gradually improve the traffic system of environmental monitoring in China, improve the comprehensive ability of monitoring, has become one of the focus of environmental protection work in traffic.

  17. Structural and mechanistic insights into prokaryotic energy-coupling factor transporters

    NARCIS (Netherlands)

    Slotboom, Dirk J.

    2014-01-01

    Energy-coupling factor (ECF) transporters belong to the ATP-binding cassette (ABC)-transporter family and mediate the uptake of essential micronutrients in many prokaryotic species. Two crystal structures of bacterial ECF transporters have recently been obtained and suggest that transport involves

  18. Functional characterization and Me2+ ion specificity of a Ca2+-citrate transporter from Enterococcus faecalis

    NARCIS (Netherlands)

    Blancato, Victor S.; Magni, Christian; Lolkema, Juke S.

    2006-01-01

    Secondary transporters of the bacterial CitMHS family transport citrate in complex with a metal ion. Different members of the family are specific for the metal ion in the complex and have been shown to transport Mg2+-citrate, Ca2+-citrate or Fe3+-citrate. The Fe3+-citrate transporter of Streptococcu

  19. Bacterial polyhydroxyalkanoates: Still fabulous?

    Science.gov (United States)

    Możejko-Ciesielska, Justyna; Kiewisz, Robert

    2016-11-01

    Bacterial polyhydroxyalkanoates (PHA) are polyesters accumulated as carbon and energy storage materials under limited growth conditions in the presence of excess carbon sources. They have been developed as biomaterials with unique properties for the past many years being considered as a potential substitute for conventional non-degradable plastics. Due to the increasing concern towards global climate change, depleting petroleum resource and problems with an utilization of a growing number of synthetic plastics, PHAs have gained much more attention from industry and research. These environmentally friendly microbial polymers have great potential in biomedical, agricultural, and industrial applications. However, their production on a large scale is still limited. This paper describes the backgrounds of PHAs and discussed the current state of knowledge on the polyhydroxyalkanoates. Ability of bacteria to convert different carbon sources to PHAs, the opportunities and challenges of their introduction to global market as valuable renewable products have been also discussed.

  20. Epigenetics and bacterial infections.

    Science.gov (United States)

    Bierne, Hélène; Hamon, Mélanie; Cossart, Pascale

    2012-12-01

    Epigenetic mechanisms regulate expression of the genome to generate various cell types during development or orchestrate cellular responses to external stimuli. Recent studies highlight that bacteria can affect the chromatin structure and transcriptional program of host cells by influencing diverse epigenetic factors (i.e., histone modifications, DNA methylation, chromatin-associated complexes, noncoding RNAs, and RNA splicing factors). In this article, we first review the molecular bases of the epigenetic language and then describe the current state of research regarding how bacteria can alter epigenetic marks and machineries. Bacterial-induced epigenetic deregulations may affect host cell function either to promote host defense or to allow pathogen persistence. Thus, pathogenic bacteria can be considered as potential epimutagens able to reshape the epigenome. Their effects might generate specific, long-lasting imprints on host cells, leading to a memory of infection that influences immunity and might be at the origin of unexplained diseases.

  1. Transport Phenomena.

    Science.gov (United States)

    McCready, Mark J.; Leighton, David T.

    1987-01-01

    Discusses the problems created in graduate chemical engineering programs when students enter with a wide diversity of understandings of transport phenomena. Describes a two-semester graduate transport course sequence at the University of Notre Dame which focuses on fluid mechanics and heat and mass transfer. (TW)

  2. Bacterial sepsis in the neonate.

    Science.gov (United States)

    Rubarth, Lori Baas; Christensen, Carla M; Riley, Cheryl

    2017-09-21

    Neonatal bacterial infections leading to sepsis occur frequently in the first few days or weeks of life. NPs must be able to recognize the early signs of sepsis and understand the need for rapid evaluation and treatment. This article discusses antibiotic treatments for various types and locations of bacterial infections and sepsis in the neonate.

  3. Evaluation of microbial transport during aerobic bioaugmentation of an RDX-contaminated aquifer.

    Science.gov (United States)

    Crocker, Fiona H; Indest, Karl J; Jung, Carina M; Hancock, Dawn E; Fuller, Mark E; Hatzinger, Paul B; Vainberg, Simon; Istok, Jonathan D; Wilson, Edward; Michalsen, Mandy M

    2015-11-01

    In situ bioaugmentation with aerobic hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)-degrading bacteria is being considered for treatment of explosives-contaminated groundwater at Umatilla Chemical Depot, Oregon (UMCD). Two forced-gradient bacterial transport tests of site groundwater containing chloride or bromide tracer and either a mixed culture of Gordonia sp. KTR9 (xplA (+)Km(R)), Rhodococcus jostii RHA1 (pGKT2 transconjugant; xplA (+)Km(R)) and Pseudomonas fluorescens I-C (xenB (+)), or a single culture of Gordonia sp. KTR9 (xplA (+); i.e. wild-type) were conducted at UMCD. Groundwater monitoring evaluated cell viability and migration in the injection well and downgradient monitoring wells. Enhanced degradation of RDX was not evaluated in these demonstrations. Quantitative PCR analysis of xplA, the kanamycin resistance gene (aph), and xenB indicated that the mixed culture was transported at least 3 m within 2 h of injection. During a subsequent field injection of bioaugmented groundwater, strain KTR9 (wild-type) migrated up to 23-m downgradient of the injection well within 3 days. Thus, the three RDX-degrading strains were effectively introduced and transported within the UMCD aquifer. This demonstration represents an innovative application of bioaugmentation to potentially enhance RDX biodegradation in aerobic aquifers.

  4. Impairment of the Bacterial Biofilm Stability by Triclosan

    Science.gov (United States)

    Hubas, Cédric; Behrens, Sebastian; Ricciardi, Francesco; Paterson, David M.

    2012-01-01

    The accumulation of the widely-used antibacterial and antifungal compound triclosan (TCS) in freshwaters raises concerns about the impact of this harmful chemical on the biofilms that are the dominant life style of microorganisms in aquatic systems. However, investigations to-date rarely go beyond effects at the cellular, physiological or morphological level. The present paper focuses on bacterial biofilms addressing the possible chemical impairment of their functionality, while also examining their substratum stabilization potential as one example of an important ecosystem service. The development of a bacterial assemblage of natural composition – isolated from sediments of the Eden Estuary (Scotland, UK) – on non-cohesive glass beads (<63 µm) and exposed to a range of triclosan concentrations (control, 2 – 100 µg L−1) was monitored over time by Magnetic Particle Induction (MagPI). In parallel, bacterial cell numbers, division rate, community composition (DGGE) and EPS (extracellular polymeric substances: carbohydrates and proteins) secretion were determined. While the triclosan exposure did not prevent bacterial settlement, biofilm development was increasingly inhibited by increasing TCS levels. The surface binding capacity (MagPI) of the assemblages was positively correlated to the microbial secreted EPS matrix. The EPS concentrations and composition (quantity and quality) were closely linked to bacterial growth, which was affected by enhanced TCS exposure. Furthermore, TCS induced significant changes in bacterial community composition as well as a significant decrease in bacterial diversity. The impairment of the stabilization potential of bacterial biofilm under even low, environmentally relevant TCS levels is of concern since the resistance of sediments to erosive forces has large implications for the dynamics of sediments and associated pollutant dispersal. In addition, the surface adhesive capacity of the biofilm acts as a sensitive measure of

  5. Impairment of the bacterial biofilm stability by triclosan.

    Directory of Open Access Journals (Sweden)

    Helen V Lubarsky

    Full Text Available The accumulation of the widely-used antibacterial and antifungal compound triclosan (TCS in freshwaters raises concerns about the impact of this harmful chemical on the biofilms that are the dominant life style of microorganisms in aquatic systems. However, investigations to-date rarely go beyond effects at the cellular, physiological or morphological level. The present paper focuses on bacterial biofilms addressing the possible chemical impairment of their functionality, while also examining their substratum stabilization potential as one example of an important ecosystem service. The development of a bacterial assemblage of natural composition--isolated from sediments of the Eden Estuary (Scotland, UK--on non-cohesive glass beads (<63 µm and exposed to a range of triclosan concentrations (control, 2-100 µg L(-1 was monitored over time by Magnetic Particle Induction (MagPI. In parallel, bacterial cell numbers, division rate, community composition (DGGE and EPS (extracellular polymeric substances: carbohydrates and proteins secretion were determined. While the triclosan exposure did not prevent bacterial settlement, biofilm development was increasingly inhibited by increasing TCS levels. The surface binding capacity (MagPI of the assemblages was positively correlated to the microbial secreted EPS matrix. The EPS concentrations and composition (quantity and quality were closely linked to bacterial growth, which was affected by enhanced TCS exposure. Furthermore, TCS induced significant changes in bacterial community composition as well as a significant decrease in bacterial diversity. The impairment of the stabilization potential of bacterial biofilm under even low, environmentally relevant TCS levels is of concern since the resistance of sediments to erosive forces has large implications for the dynamics of sediments and associated pollutant dispersal. In addition, the surface adhesive capacity of the biofilm acts as a sensitive measure of

  6. Revegetation rewilds the soil bacterial microbiome of an old field.

    Science.gov (United States)

    Gellie, Nicholas J C; Mills, Jacob G; Breed, Martin F; Lowe, Andrew J

    2017-03-05

    Ecological restoration is a globally important and well-financed management intervention used to combat biodiversity declines and land degradation. Most restoration aims to increase biodiversity towards a reference state, but there are concerns that intended outcomes are not reached due to unsuccessful interventions and land use legacy issues. Monitoring biodiversity recovery is essential to measure success, however most projects remain insufficiently monitored. Current field-based methods are hard to standardise and are limited in their ability to assess important components of ecosystems, such as bacteria. High-throughput amplicon sequencing of environmental DNA (metabarcoding of eDNA) has been proposed as a cost-effective, scalable and uniform ecological monitoring solution, but its application in restoration remains largely untested. Here we show that metabarcoding of soil eDNA is effective at demonstrating the return of the native bacterial community in an old field following native plant revegetation. Bacterial composition shifted significantly after 8 years of revegetation, where younger sites were more similar to cleared sites and older sites were more similar to remnant stands. Revegetation of the native plant community strongly impacted on the belowground bacterial community, despite the revegetated sites having a long and dramatically altered land use history (i.e. >100 years grazing). We demonstrate that metabarcoding of eDNA provides an effective way of monitoring changes in bacterial communities that would otherwise go unchecked with conventional monitoring of restoration projects. With further development, awareness of microbial diversity in restoration has significant scope for improving the efficacy of restoration interventions more broadly. This article is protected by copyright. All rights reserved.

  7. MECHANISMS OF BACTERIAL POLYHOSTALITY

    Directory of Open Access Journals (Sweden)

    Markova Yu.A.

    2007-12-01

    Full Text Available In the review data about factors of pathogenicity of the bacteria, capable to amaze both animals, and a plant are collected. Such properties of microorganisms as adhesion, secretion of some enzymes, mobility, a phenomenon of cooperative sensitivity - play an essential role at defeat of different organisms. They are used for many universal offensive strategy overcoming protection of an organism, irrespective of its evolutionary origin. Studying of these mechanisms, will allow to provide new approaches to monitoring illnesses.

  8. Monitoring madness

    Energy Technology Data Exchange (ETDEWEB)

    Blankinship, S.

    2006-01-15

    High quality continuous emission monitoring capability can be as essential as high quality emission control equipment. Future mercury monitoring and control requirements add to the justification for better CEMS. The article discusses two prominent mercury measurement methods - the cold vapour atomic absorptive spectrometer (CVAAs) and the atomic absorptive spectrometer (AFS). It stresses the importance of maintaining a CEMS. 1 photo.

  9. Mobility Monitor

    DEFF Research Database (Denmark)

    Schæbel, Anne-Lise; Dybbro, Karina Løvendahl; Andersen, Lisbeth Støvring;

    2015-01-01

    Undersøgelse af digital monitorering af plejehjemsbeboeres vendinger under søvn på Fremtidens Plejehjem, Nørresundby......Undersøgelse af digital monitorering af plejehjemsbeboeres vendinger under søvn på Fremtidens Plejehjem, Nørresundby...

  10. Implementing, monitoring, evaluating, and updating a road safety programme : contribution to the Best in Europe 2003 Conference of the European Transport Safety Council: Targeted Road Safety Programmes in the EU, Brussels, June 10, 2003.

    NARCIS (Netherlands)

    Wegman, F.C.M.

    2004-01-01

    In all EU countries, attempts are being made to promote road safety, and each country has its own approach. This contribution examines the implementation of road safety programmes, their monitoring and evaluation, and their updating. For analyzing policy implementation, monitoring and evaluation, a

  11. Implementing, monitoring, evaluating, and updating a road safety programme : contribution to the Best in Europe 2003 Conference of the European Transport Safety Council: Targeted Road Safety Programmes in the EU, Brussels, June 10, 2003.

    NARCIS (Netherlands)

    Wegman, F.C.M.

    2004-01-01

    In all EU countries, attempts are being made to promote road safety, and each country has its own approach. This contribution examines the implementation of road safety programmes, their monitoring and evaluation, and their updating. For analyzing policy implementation, monitoring and evaluation, a

  12. Hopanoids as functional analogues of cholesterol in bacterial membranes.

    Science.gov (United States)

    Sáenz, James P; Grosser, Daniel; Bradley, Alexander S; Lagny, Thibaut J; Lavrynenko, Oksana; Broda, Martyna; Simons, Kai

    2015-09-22

    The functionality of cellular membranes relies on the molecular order imparted by lipids. In eukaryotes, sterols such as cholesterol modulate membrane order, yet they are not typically found in prokaryotes. The structurally similar bacterial hopanoids exhibit similar ordering properties as sterols in vitro, but their exact physiological role in living bacteria is relatively uncharted. We present evidence that hopanoids interact with glycolipids in bacterial outer membranes to form a highly ordered bilayer in a manner analogous to the interaction of sterols with sphingolipids in eukaryotic plasma membranes. Furthermore, multidrug transport is impaired in a hopanoid-deficient mutant of the gram-negative Methylobacterium extorquens, which introduces a link between membrane order and an energy-dependent, membrane-associated function in prokaryotes. Thus, we reveal a convergence in the architecture of bacterial and eukaryotic membranes and implicate the biosynthetic pathways of hopanoids and other order-modulating lipids as potential targets to fight pathogenic multidrug resistance.

  13. Bacterial floc mediated rapid streamer formation in creeping flows

    CERN Document Server

    Hassanpourfard, Mahtab; Ghosh, Ranajay; Das, Siddhartha; Thundat, Thomas; Liu, Yang; Kumar, Aloke

    2015-01-01

    One of the central puzzles concerning the interaction of low Reynolds number (Re<<1) fluid transport with bacterial biomass is the formation of filamentous structures called streamers. In this manuscript, we report our discovery of a new kind of low Re bacterial streamers, which appear from pre-formed bacterial flocs. In sharp contrast to the biofilm-mediated streamers, these streamers form over extremely small timescales (less than a second). Our experiments, carried out in a microchannel with micropillars rely on fluorescence microscopy techniques to illustrate that floc-mediated streamers form when a freely-moving floc adheres to the micropillar wall and gets rapidly sheared by the background flow. We also show that at their inception the deformation of the flocs is dominated by recoverable large strains indicating significant elasticity. These strains subsequently increase tremendously to produce filamentous streamers. Interestingly, we find that these fully formed streamers are not static structure...

  14. Animal Transports

    Directory of Open Access Journals (Sweden)

    Diana Ludrovcová

    2016-08-01

    Full Text Available Purpose and Originality: The research is aimed to the animal transports issue, from two points of view – first is the animal cruelty and second is the policy and economic consideration. The goal is to acquaint the readers with the transports risks and its cruelty and evaluation of the economic, political aspects for he involved countries. The study is oriented on more points of view, what is rare in works with a similar theme. Method: This paper examines many issues and examinations from different authors and subsequently summarized the findings with authors own knowledge to one expanded unit. Results: Results proves, that livestock transports have negative impact on animal´s health, environment. Number of transported animals is rising every year. Society: Research familiarize the society with the animal transports, cruelty against animals during them, and influence of transports on some countries, their economy, policy. People get better informed and can form their own opinion on this topic. They may start acting, undertaking some steps to improve the present situation, what could help a lot to animals and environment. Limitations / further research: Future research could show progress and improvement of transports, quality of food supply and economics.

  15. SUSTAINABLE TRANSPORTATION

    Directory of Open Access Journals (Sweden)

    Linda STEG

    2007-01-01

    Full Text Available This paper discusses possible contributions of psychologists to sustainable transportation. It is argued that in order to reach sustainable transportation, among others, behaviour changes of individual car users are needed. As transport policies will be more effective if they target important antecedents of travel behaviour, first, factors influencing such behaviour are discussed. It is argued that car use is very attractive and sometimes even necessary for many different reasons. This implies that a combination of policies is called for, each targeting different factors that support car use and hinder the use of more sustainable modes of transport. Next, the paper elaborates on policy strategies that may be employed to achieve sustainable transportation by changing car use. Increasing the attractiveness of sustainable transport modes by means of pull measures seems not sufficient to reduce the level of car use. Besides, car use should be made less attractive by means of push measures to force drivers to reconsider their travel behaviour. The acceptability of such policies may be increased by clearly communicating the aim of these policies, and the expected positive consequences (e.g., less congestion, improved environmental quality. Moreover, possible negative effects for individual freedom may be compensated by implementing additional policies aimed at facilitating the use of sustainable transport modes.

  16. Geo-Chip analysis reveals reduced functional diversity of the bacterial community at a dumping site for dredged Elbe sediment.

    Science.gov (United States)

    Störmer, Rebecca; Wichels, Antje; Gerdts, Gunnar

    2013-12-15

    The dumping of dredged sediments represents a major stressor for coastal ecosystems. The impact on the ecosystem function is determined by its complexity not easy to assess. In the present study, we evaluated the potential of bacterial community analyses to act as ecological indicators in environmental monitoring programmes. We investigated the functional structure of bacterial communities, applying functional gene arrays (GeoChip4.2). The relationship between functional genes and environmental factors was analysed using distance-based multivariate multiple regression. Apparently, both the function and structure of the bacterial communities are impacted by dumping activities. The bacterial community at the dumping centre displayed a significant reduction of its entire functional diversity compared with that found at a reference site. DDX compounds separated bacterial communities of the dumping site from those of un-impacted sites. Thus, bacterial community analyses show great potential as ecological indicators in environmental monitoring.

  17. Luminescent Bacterial Sensors Made from Immobilized Films of Photobacterium Phosphoreum

    Institute of Scientific and Technical Information of China (English)

    YIN Ji-qiu; LI Xiao-zhou; ZHOU Chi; ZHANG Yi-hua

    2005-01-01

    A kind of luminous bacterial sensors that can quickly detect the acute toxicity of environmental pollutants were developed. The method is based on the detection of the cellular light of bright luminous bacillus by means of fixing cells so as to detect acute toxicity of luminous bacillus. The bacterial sensor is composed of immobilized film of photobacterium phosphoreum. These bacterial films are sensitive to detecting the toxicoids, which are difficult or even impossible to be measured by traditional analytical chemistry methods. The films should be stored at 4 ℃ and the stability of the sensors exceeds 1 month with no measurable deterioration of the signal. These results demonstrate that the immobilized film of P.phosphreum can be used to develop the on-line environmental contamination monitor.

  18. Chronic Ocular Hypertension after Treated Multifocal Bacterial Keratitis

    Directory of Open Access Journals (Sweden)

    Theodoros Athanassios Papadopoulos

    2013-02-01

    Full Text Available Purpose: To report an unusual case of multifocal bacterial keratitis that despite success-ful treatment caused chronic ocular hypertension. Methods: A 67-year-old woman with unilateral multifocal keratitis and no previous ocular pathology was admitted to our hospital. Corneal scrapings and conjunctival samples were obtained for culture and the patient received intensive therapy with fortified vancomycin and tobramycin eye drops. Results: The cultures demonstrated two strains of Staphylococcus epidermidis, one resistant to ciprofloxacin and both sensitive to vancomycin. Treatment was effective and gradually discontinued after total cessation of the inflammatory activity. During the follow-up period, the patient developed late and persistent ocular hypertension of unknown etiology, in absence of any detectable inflammation or complication, and received permanent antiglaucoma therapy. Conclusion: Differential diagnosis between fungal and bacterial infection is critical in cases of multifocal keratitis. Patients with multifocal bacterial keratitis may need intraocular pressure monitoring, even after complete infection healing.

  19. Kinetic theory and transport phenomena

    CERN Document Server

    Soto, Rodrigo

    2016-01-01

    This textbook presents kinetic theory, which is a systematic approach to describing nonequilibrium systems. The text is balanced between the fundamental concepts of kinetic theory (irreversibility, transport processes, separation of time scales, conservations, coarse graining, distribution functions, etc.) and the results and predictions of the theory, where the relevant properties of different systems are computed. The book is organised in thematic chapters where different paradigmatic systems are studied. The specific features of these systems are described, building and analysing the appropriate kinetic equations. Specifically, the book considers the classical transport of charges, the dynamics of classical gases, Brownian motion, plasmas, and self-gravitating systems, quantum gases, the electronic transport in solids and, finally, semiconductors. Besides these systems that are studied in detail, concepts are applied to some modern examples including the quark–gluon plasma, the motion of bacterial suspen...

  20. Evolution of Bacterial Suicide

    Science.gov (United States)

    Tchernookov, Martin; Nemenman, Ilya

    2013-03-01

    While active, controlled cellular suicide (autolysis) in bacteria is commonly observed, it has been hard to argue that autolysis can be beneficial to an individual who commits it. We propose a theoretical model that predicts that bacterial autolysis is evolutionarily advantageous to an individualand would fixate in physically structured environments for stationary phase colonies. We perform spatially resolved agent-based simulations of the model, which predict that lower mixing in the environment results in fixation of a higher autolysis rate from a single mutated cell, regardless of the colony's genetic diversity. We argue that quorum sensing will fixate as well, even if initially rare, if it is coupled to controlling the autolysis rate. The model does not predict a strong additional competitive advantage for cells where autolysis is controlled by quorum sensing systems that distinguish self from nonself. These predictions are broadly supported by recent experimental results in B. subtilisand S. pneumoniae. Research partially supported by the James S McDonnell Foundation grant No. 220020321 and by HFSP grant No. RGY0084/2011.

  1. Bacterial degradation of aminopyrine.

    Science.gov (United States)

    Blecher, H; Blecher, R; Wegst, W; Eberspaecher, J; Lingens, F

    1981-11-01

    1. Four strains of bacteria growing with aminopyrine as sole source of carbon were isolated from soil and were identified as strains of Phenylobacterium immobilis. 2. Strain M13 and strain E, the type species of Phenylobacterium immobilis (DSM 1986), which had been isolated by enrichment with chloridazon (5-amino-4-chloro-2-phenyl-2H-pyridazin-3-one) were used to investigate the bacterial degradation of aminopyrine. 3. Three metabolites were isolated and identified as: 4-(dimethylamino)-1,2-dihydro-1,5-dimethyl-2-(2,3-dihydro-2,3-dihydroxy-4,6-cyc lohexadien-1-yl)-3H-pyrazol-3-one, 4-(dimethylamino)-1,2-dihydro-1,5-dimethyl-2-(2,3-dihydroxyphenyl)-3H-pyrazol-3 -one and 4-(dimethylamino)-1,2-dihydro-1,5-dimethyl-3H-pyrazol-3-one. 4. An enzyme extract from cells of strain m13 was shown to further metabolize the catechol derivative of aminopyrine, with the formation of 2-pyrone-6-carboxylic acid. 5. Results indicate that the benzene ring of aminopyrine is the principal site of microbial metabolism.

  2. Bacterial endocarditis prophylaxis.

    Science.gov (United States)

    Blanco-Carrión, Andrés

    2004-01-01

    Bacterial endocarditis (BE) is a disease resulting from the association of morphological alterations of the heart and bacteraemia originating from different sources that at times can be indiscernible (infectious endocarditis). It is classified on the basis of the morphological alteration involved, depending on the clinical manifestations and course of illness, which varies according to the causative microorganism and host conditions (for example, it is characteristic in I.V. drug users). The most common microorganisms involved are: Streptococcus viridans (55%), Staphylococcus aureus (30%), Enterococcus (6%) and HACEK bacteria (corresponding to the initials: Haemophilus, Actinobacillus, Cardiobacterium, Eikenella and Kingella), although on occasions it can also be caused by fungi. The oral microbiological flora plays a very important role in the aetiopathogenesis of BE, given that the condition may be of oral or dental origin. This paper will deal with the prevention of said bacteraemia. Prophylaxis will be undertaken using amoxicillin or clindamycin according to action protocols, with special emphasis placed on oral hygiene in patients with structural defects of the heart.

  3. Bacterial invasion reconstructed molecule by molecule

    Energy Technology Data Exchange (ETDEWEB)

    Werner, James H [Los Alamos National Laboratory

    2009-01-01

    point of bacterial attachment to a human cell. Goal 2--Determine if the transport method of host cell receptors to the site of Salmonella infection depends upon their initial spatial location. We hypothesize that host receptors originally near the infection site will diffuse in the host membrane till 'caught' by the bacteria, while receptors further away from the bacteria will be driven by actin to the infection site in a highly directed fashion. Goal 3--Measure the 3D path taken by a bacterial effector to find its host counterpart. We hypothesize that bacterial effectors, after passing into the host via the TTSS, fmd their host target proteins through an un-biased diffusion process (e.g. a random walk, rather than active transport). This hypothesis will be tested on the bacterial effector SopE as it searches for its host partner, Racl.

  4. Quantifying bacterial attachment and detachment using leaching solutions of various ionic strengths after bacterial pulse.

    Science.gov (United States)

    Choi, Nag-Choul; Choi, Jae-Woo; Kwon, Kyu-Sang; Lee, Sang-Gil; Lee, Soonjae

    2017-12-01

    In this study, we quantified the attachment and detachment of bacteria during transport in order to elucidate the contributions of reversible attachment on bacterial breakthrough curves. The first set of breakthrough experiment was performed for a laboratory sand column using leaching solutions of deionized water and mineral salt medium (MSM) of 200 mM with reference to KCl solution by employing Pseudomonas putida as a model bacterium. In the second set of experiment, the ionic strengths of leaching solutions immediately after bacterial pulse were lowered to tenfold and 100-fold diluted system (2 and 20 mM MSM) to focus on the influence of physicochemical factor. Results have shown that bacterial retention occurred in the sand column due to the physical deposition and physicochemical attachment. The physicochemical attachment was attributed to the high ionic strength (200 mM MSM) of leaching solution and the formation of primary energy minimum. Replacing the 200 mM leaching solution with the lower ionic strengths after pulse resulted in the increased tailing of breakthrough curve due to the detachment from the attached bacteria. The detachment could be well explained by DLVO theory, which showed the formation of energy barrier and disappearance of the secondary minimum as the ionic strength gradually decreased. Analysis of mass recovery revealed that 12-20% of the attachment was due to physical and physicochemical attachment, respectively, where the latter consisted of 25-75% of irreversible and reversible attachment respectively.

  5. Sediment Transport

    DEFF Research Database (Denmark)

    Liu, Zhou

    Flow and sediment transport are important in relation to several engineering topics, e.g. erosion around structures, backfilling of dredged channels and nearshore morphological change. The purpose of the present book is to describe both the basic hydrodynamics and the basic sediment transport...... mechanics. Chapter 1 deals with fundamentals in fluid mechanics with emphasis on bed shear stress by currents, while chapter 3 discusses wave boundary layer theory. They are both written with a view to sediment transport. Sediment transport in rivers, cross-shore and longshore are dealt with in chapters 2......, 4 and 5, respectively. It is not the intention of the book to give a broad review of the literature on this very wide topic. The book tries to pick up information which is of engineering importance. An obstacle to the study of sedimentation is the scale effect in model tests. Whenever small...

  6. Transport Phenomena.

    Science.gov (United States)

    Shah, D. B.

    1984-01-01

    Describes a course designed to achieve a balance between exposing students to (1) advanced topics in transport phenomena, pointing out similarities and differences between three transfer processes and (2) common methods of solving differential equations. (JN)

  7. Nicaragua - Transportation

    Data.gov (United States)

    Millennium Challenge Corporation — The evaluation examines impacts of the Transportation Project in three ways. First, we calculate economic rates of return associated with reduced user costs for each...

  8. Amino acid sequences of bacterial cytochromes c' and c-556.

    OpenAIRE

    Ambler, R. P.; Bartsch, R. G.; Daniel, M.; Kamen, M. D.; McLellan, L; Meyer, T. E.; Van Beeumen, J

    1981-01-01

    The cytochrome c' are electron transport proteins widely distributed in photosynthetic and aerobic bacteria. We report the amino acid sequences of the proteins from 12 different bacterial species, and we show by sequences that the cytochromes c-556 from 2 different bacteria are structurally related to the cytochromes c'. Unlike the mitochondrial cytochromes c, the heme binding site in the cytochromes c' and c-556 is near the COOH terminus. The cytochromes c-556 probably have a methionine sixt...

  9. Transport service

    CERN Document Server

    C. Cerruti / FI

    2006-01-01

    A large number of pallet-crates (panières grillagées), which are used for transporting equipment and for removals, have been dispatched to various locations around the CERN site. We kindly request all users who may have such crates in their possession and no longer need them to make the necessary arrangements (EDH request to the Transport Group) to return them to Building 133, as we currently have no more in stock. Claude CERRUTI / FI-PI

  10. Monarch Monitoring

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The US Fish and Wildlife Service has engaged in a multi-partnered, integrated strategy for monitoring conservation of the monarch butterfly (Danaus plexippus...

  11. Monitoring Hadoop

    CERN Document Server

    Singh, Gurmukh

    2015-01-01

    This book is useful for Hadoop administrators who need to learn how to monitor and diagnose their clusters. Also, the book will prove useful for new users of the technology, as the language used is simple and easy to grasp.

  12. Recombination monitor

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S. Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-02-03

    This is a brief report on LEReC recombination monitor design considerations. The recombination produced Au78+ ion rate is reviewed. Based on this two designs are discussed. One is to use the large dispersion lattice. It is shown that even with the large separation of the Au78+ beam from the Au79+ beam, the continued monitoring of the recombination is not possible. Accumulation of Au78+ ions is needed, plus collimation of the Au79+ beam. In another design, it is shown that the recombination monitor can be built based on the proposed scheme with the nominal lattice. From machine operation point of view, this design is preferable. Finally, possible studies and the alternative strategies with the basic goal of the monitor are discussed.

  13. Bayesian Monitoring.

    OpenAIRE

    Kirstein, Roland

    2005-01-01

    This paper presents a modification of the inspection game: The ?Bayesian Monitoring? model rests on the assumption that judges are interested in enforcing compliant behavior and making correct decisions. They may base their judgements on an informative but imperfect signal which can be generated costlessly. In the original inspection game, monitoring is costly and generates a perfectly informative signal. While the inspection game has only one mixed strategy equilibrium, three Perfect Bayesia...

  14. Bacterial contribution to dissolved organic matter in eutrophic Lake Kasumigaura, Japan.

    Science.gov (United States)

    Kawasaki, Nobuyuki; Komatsu, Kazuhiro; Kohzu, Ayato; Tomioka, Noriko; Shinohara, Ryuichiro; Satou, Takayuki; Watanabe, Fumiko Nara; Tada, Yuya; Hamasaki, Koji; Kushairi, M R M; Imai, Akio

    2013-12-01

    Incubation experiments using filtered waters from Lake Kasumigaura were conducted to examine bacterial contribution to a dissolved organic carbon (DOC) pool. Bacterial abundance, bacterial production, concentrations of DOC, total dissolved amino acids (TDAA), and total dissolved neutral sugars (TDNS) were monitored during the experiments. Bacterial production during the first few days was very high (20 to 35 μg C liter(-1) day(-1)), accounting for 40 to 70% of primary production. The total bacterial production accounted for 34 to 55% of the DOC loss during the experiment, indicating high bacterial activities in Lake Kasumigaura. The DOC degradation was only 12 to 15%, whereas the degradation of TDAA and TDNS ranged from 30 to 50%, suggesting the preferential usage of TDAA and TDNS. The contribution of bacterially derived carbon to a DOC pool in Lake Kasumigaura was estimated using d-amino acids as bacterial biomarkers and accounted for 30 to 50% of the lake DOC. These values were much higher than those estimated for the open ocean (20 to 30%). The ratio of bacterially derived carbon to bulk carbon increased slightly with time, suggesting that the bacterially derived carbon is more resistant to microbial degradation than bulk carbon. This is the first study to estimate the bacterial contribution to a DOC pool in freshwater environments. These results indicate that bacteria play even more important roles in carbon cycles in freshwater environments than in open oceans and also suggests that recent increases in recalcitrant DOC in various lakes could be attributed to bacterially derived carbon. The potential differences in bacterial contributions to dissolved organic matter (DOM) between freshwater and marine environments are discussed.

  15. Field determination of bacterial disappearance in seawater

    DEFF Research Database (Denmark)

    Harremoës, Poul

    1970-01-01

    The article presents two approaches to field determination of disappearance of viable, fecal bacteria after discharge with sewage into a marine environment. The first approach is based on simultaneous sampling for bacterial counting and monitoring of dilution using a conservative tracer, which...... is released continuously with the sewage. The second approach uses an abrupt release of tracer for determination of both dilution and residence time in the sewage field. In both cases, the disappearance rate is best determined by comparison of fluxes of two bacteria and of tracer through cross......-sections of the field. The approaches are exemplified with two case reports, which show that the disappearance rate can be determined to less than 10 per cent inaccuracy....

  16. Transforming clinical microbiology with bacterial genome sequencing.

    Science.gov (United States)

    Didelot, Xavier; Bowden, Rory; Wilson, Daniel J; Peto, Tim E A; Crook, Derrick W

    2012-09-01

    Whole-genome sequencing of bacteria has recently emerged as a cost-effective and convenient approach for addressing many microbiological questions. Here, we review the current status of clinical microbiology and how it has already begun to be transformed by using next-generation sequencing. We focus on three essential tasks: identifying the species of an isolate, testing its properties, such as resistance to antibiotics and virulence, and monitoring the emergence and spread of bacterial pathogens. We predict that the application of next-generation sequencing will soon be sufficiently fast, accurate and cheap to be used in routine clinical microbiology practice, where it could replace many complex current techniques with a single, more efficient workflow.

  17. Measurement of bacterial ingestion and killing by macrophages.

    Science.gov (United States)

    Campbell, P A; Canono, B P; Drevets, D A

    2001-05-01

    This unit presents fairly simple assays for measuring the binding of bacteria to macrophages, internalization of bacteria (also called ingestion or phagocytosis), and bacterial killing by macrophages. The first basic protocol describes how to measure the ability of macrophages to ingest bacteria. Because it is critical to remove residual extracellular organisms, the protocol presents two alternative steps to accomplish this: a washing procedure and a more stringent method in which cells are sedimented through sucrose. In addition, it is important to distinguish those bacteria truly ingested by a macrophage from those that are bound to, but not internalized by, the cell. A simple but effective way to do this is described in an alternate protocol. The unit also presents two ways to measure the ability of a macrophage to kill bacteria it has internalized. The first is a straightforward assay in which bacterial colonies are enumerated before and after a killing period; a subsequent colony count will indicate whether the bacteria grew within or were killed by the macrophage. The second protocol describes a way to measure bacterial viability based on bacterial metabolism, in which the ability of bacterial dehydrogenases to mediate the reduction of a tetrazolium salt to purple formazan is monitored by measuring absorbance spectrophotometrically.

  18. Bacterial Communities: Interactions to Scale

    Directory of Open Access Journals (Sweden)

    Reed M. Stubbendieck

    2016-08-01

    Full Text Available In the environment, bacteria live in complex multispecies communities. These communities span in scale from small, multicellular aggregates to billions or trillions of cells within the gastrointestinal tract of animals. The dynamics of bacterial communities are determined by pairwise interactions that occur between different species in the community. Though interactions occur between a few cells at a time, the outcomes of these interchanges have ramifications that ripple through many orders of magnitude, and ultimately affect the macroscopic world including the health of host organisms. In this review we cover how bacterial competition influences the structures of bacterial communities. We also emphasize methods and insights garnered from culture-dependent pairwise interaction studies, metagenomic analyses, and modeling experiments. Finally, we argue that the integration of multiple approaches will be instrumental to future understanding of the underlying dynamics of bacterial communities.

  19. Transport of subsurface bacteria in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Bales, R.C.; Arnold, R.G.; Gerba, C.P.

    1995-02-01

    The primary objective of this study was to develop tools with which to measure the advective transport of microorganisms through porous media. These tools were then applied to investigate the sorptive properties of representative microorganisms that were selected at random from the DOE`s deep subsurface collection of bacterial, maintained at Florida State University. The transport screening procedure that arose from this study was also used to investigate biological factors that affect the transport/sorption of biocolloids during their movement through porous media with the bulk advective flow.

  20. Surface micropattern limits bacterial contamination

    OpenAIRE

    Mann, Ethan E.; Manna, Dipankar; Mettetal, Michael R; May, Rhea M.; Dannemiller, Elisa M; Chung, Kenneth K.; Brennan, Anthony B; Reddy, Shravanthi T

    2014-01-01

    Background Bacterial surface contamination contributes to transmission of nosocomial infections. Chemical cleansers used to control surface contamination are often toxic and incorrectly implemented. Additional non-toxic strategies should be combined with regular cleanings to mitigate risks of human error and further decrease rates of nosocomial infections. The Sharklet micropattern (MP), inspired by shark skin, is an effective tool for reducing bacterial load on surfaces without toxic additiv...

  1. Bacterial cellulose/boehmite composites

    Energy Technology Data Exchange (ETDEWEB)

    Salvi, Denise T.B. de; Barud, Hernane S.; Messaddeq, Younes; Ribeiro, Sidney J.L. [Universidade Estadual Paulista Julio de Mesquita Filho. UNESP. Instituto de Quimica de Araraquara, SP (Brazil); Caiut, Jose Mauricio A. [Universidade de Sao Paulo. Departamento de Quimica - FFCLRP/USP, Ribeirao Preto, SP (Brazil)

    2011-07-01

    Composites based on bacterial cellulose membranes and boehmite were obtained. SEM results indicate that the bacterial cellulose (BC) membranes are totally covered by boehmite and obtained XRD patterns suggest structural changes due to this boehmite addition. Thermal stability is accessed through TG curves and is dependent on boehmite content. Transparency is high comparing to pure BC as can be seen through UV-vis absorption spectroscopy. (author)

  2. Bacterial toxins: friends or foes?

    OpenAIRE

    Schmitt, C K; Meysick, K. C.; O'Brien, A D

    1999-01-01

    Many emerging and reemerging bacterial pathogens synthesize toxins that serve as primary virulence factors. We highlight seven bacterial toxins produced by well-established or newly emergent pathogenic microbes. These toxins, which affect eukaryotic cells by a variety of means, include Staphylococcus aureus alpha-toxin, Shiga toxin, cytotoxic necrotizing factor type 1, Escherichia coli heat-stable toxin, botulinum and tetanus neurotoxins, and S. aureus toxic-shock syndrome toxin. For each, we...

  3. Bacterial Chromosome Organization and Segregation

    OpenAIRE

    Toro, Esteban; Shapiro, Lucy

    2010-01-01

    Bacterial chromosomes are generally ∼1000 times longer than the cells in which they reside, and concurrent replication, segregation, and transcription/translation of this crowded mass of DNA poses a challenging organizational problem. Recent advances in cell-imaging technology with subdiffraction resolution have revealed that the bacterial nucleoid is reliably oriented and highly organized within the cell. Such organization is transmitted from one generation to the next by progressive segrega...

  4. [Current knowledge of bacterial vaginosis].

    Science.gov (United States)

    Djukić, Slobodanka; Opavski, Nataša; Mijač, Vera; Ranin, Lazar

    2011-01-01

    Bacterial vaginosis, earlier termed nonspecific vaginitis (anaerobic vaginosis) because of the absence of recognized pathogens, is most common vaginal syndrome of women of childbearing age affecting 15-30%. This syndrome, whose aetiology and pathogenesis remains unknown, is characterized by significant changes in the vaginal ecosystem. These changes consist of a decrease in the number of lactobacilli and a large increase in the number of anaerobic organisms. The bacteria adhere to desquamated epithelial cells with a distinctive appearance of clue cells The main complaints of women with symptomatic bacterial vaginosis include vaginal discharge and odour. However, a significant number of all women who have bacterial vaginosis deny symptoms. Bacterial vaginosis is associated with a number of gynaecologic and obstetric complications including cervicitis, cervical neoplasia, pelvic inflammatory disease, postoperative infections, and preterm labour.The diagnosis is most frequently made based on vaginal smear stained according to Gram (Nugent scoring method). Metronidazole and clindamycin are the drugs of choice for treatment of women with bacterial vaginosis. Which women should undergo treatment? According to the prevailing attitude, it should include women with symptoms. Symptomatic women with frequent relapses of bacterial vaginosisas, as a rule, have poor response to the applied therapy. To achieve better efficiency in the treatment of such women, it is necessary to have more extensive understanding of all factors in the pathogenesis of the syndrome.

  5. Current knowledge of bacterial vaginosis

    Directory of Open Access Journals (Sweden)

    Đukić Slobodanka

    2011-01-01

    Full Text Available Bacterial vaginosis, earlier termed nonspecific vaginitis (anaerobic vaginosis because of the absence of recognized pathogens, is most common vaginal syndrome of women of childbearing age affecting 15-30%. This syndrome, whose aetiology and pathogenesis remains unknown, is characterized by significant changes in the vaginal ecosystem. These changes consist of a decrease in the number of lactobacilli and a large increase in the number of anaerobic organisms. The bacteria adhere to desquamated epithelial cells with a distinctive appearance of clue cells The main complaints of women with symptomatic bacterial vaginosis include vaginal discharge and odour. However, a significant number of all women who have bacterial vaginosis deny symptoms. Bacterial vaginosis is associated with a number of gynaecologic and obstetric complications including cervicitis, cervical neoplasia, pelvic inflammatory disease, postoperative infections, and preterm labour. The diagnosis is most frequently made based on vaginal smear stained according to Gram (Nugent scoring method. Metronidazole and clindamycin are the drugs of choice for treatment of women with bacterial vaginosis. Which women should undergo treatment? According to the prevailing attitude, it should include women with symptoms. Symptomatic women with frequent relapses of bacterial vaginosisas, as a rule, have poor response to the applied therapy. To achieve better efficiency in the treatment of such women, it is necessary to have more extensive understanding of all factors in the pathogenesis of the syndrome.

  6. SUBSURFACE EMPLACEMENT TRANSPORTATION SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    T. Wilson; R. Novotny

    1999-11-22

    The objective of this analysis is to identify issues and criteria that apply to the design of the Subsurface Emplacement Transportation System (SET). The SET consists of the track used by the waste package handling equipment, the conductors and related equipment used to supply electrical power to that equipment, and the instrumentation and controls used to monitor and operate those track and power supply systems. Major considerations of this analysis include: (1) Operational life of the SET; (2) Geometric constraints on the track layout; (3) Operating loads on the track; (4) Environmentally induced loads on the track; (5) Power supply (electrification) requirements; and (6) Instrumentation and control requirements. This analysis will provide the basis for development of the system description document (SDD) for the SET. This analysis also defines the interfaces that need to be considered in the design of the SET. These interfaces include, but are not limited to, the following: (1) Waste handling building; (2) Monitored Geologic Repository (MGR) surface site layout; (3) Waste Emplacement System (WES); (4) Waste Retrieval System (WRS); (5) Ground Control System (GCS); (6) Ex-Container System (XCS); (7) Subsurface Electrical Distribution System (SED); (8) MGR Operations Monitoring and Control System (OMC); (9) Subsurface Facility System (SFS); (10) Subsurface Fire Protection System (SFR); (11) Performance Confirmation Emplacement Drift Monitoring System (PCM); and (12) Backfill Emplacement System (BES).

  7. Resource niche overlap promotes stability of bacterial community metabolism in experimental microcosms

    Directory of Open Access Journals (Sweden)

    Ellard Roy Hunting

    2015-02-01

    Full Text Available Decomposition of organic matter is an important ecosystem process governed in part by bacteria. The process of decomposition is expected to benefit from interspecific bacterial interactions such as resource partitioning and facilitation. However, the relative importance of resource niche breadth (metabolic diversity and resource niche overlap (functional redundancy on decomposition and the temporal stability of ecosystem processes received little scientific attention. Therefore, this study aims to evaluate the effect of an increase in bacterial community resemblance on both decomposition and the stability of bacterial metabolism in aquatic sediments. To this end, we performed laboratory microcosm experiments in which we examined the influence of bacterial consortia differing in number and composition of species on bacterial activity (Electron Transport System Activity, ETSA, dissolved organic carbon production and wavelet transformed measurements of redox potential (Eh. Single substrate affinities of the individual bacterial species in order to calculate the metabolic diversity of the microbial community. Results presented here indicate that bacterial activity and organic matter decomposition increase with widening of the resource niche breadth, and that metabolic stability increases with increasing overlap in bacterial resource niches, hinting that resource niche overlap can promote the stability of bacterial community metabolism.

  8. Genetic and computational identification of a conserved bacterial metabolic module.

    Directory of Open Access Journals (Sweden)

    Cara C Boutte

    2008-12-01

    Full Text Available We have experimentally and computationally defined a set of genes that form a conserved metabolic module in the alpha-proteobacterium Caulobacter crescentus and used this module to illustrate a schema for the propagation of pathway-level annotation across bacterial genera. Applying comprehensive forward and reverse genetic methods and genome-wide transcriptional analysis, we (1 confirmed the presence of genes involved in catabolism of the abundant environmental sugar myo-inositol, (2 defined an operon encoding an ABC-family myo-inositol transmembrane transporter, and (3 identified a novel myo-inositol regulator protein and cis-acting regulatory motif that control expression of genes in this metabolic module. Despite being encoded from non-contiguous loci on the C. crescentus chromosome, these myo-inositol catabolic enzymes and transporter proteins form a tightly linked functional group in a computationally inferred network of protein associations. Primary sequence comparison was not sufficient to confidently extend annotation of all components of this novel metabolic module to related bacterial genera. Consequently, we implemented the Graemlin multiple-network alignment algorithm to generate cross-species predictions of genes involved in myo-inositol transport and catabolism in other alpha-proteobacteria. Although the chromosomal organization of genes in this functional module varied between species, the upstream regions of genes in this aligned network were enriched for the same palindromic cis-regulatory motif identified experimentally in C. crescentus. Transposon disruption of the operon encoding the computationally predicted ABC myo-inositol transporter of Sinorhizobium meliloti abolished growth on myo-inositol as the sole carbon source, confirming our cross-genera functional prediction. Thus, we have defined regulatory, transport, and catabolic genes and a cis-acting regulatory sequence that form a conserved module required for myo

  9. Pulmonary bacterial pathogens in cystic fibrosis patients and antibiotic therapy: a tool for the health workers

    OpenAIRE

    Coutinho, Henrique Douglas M.; Falcão-Silva,Vivyanne S.; Gonçalves, Gregório Fernandes

    2008-01-01

    Cystic fibrosis is the most common and best known genetic disease involving a defect in transepithelial Cl- transport by mutations in the CF gene on chromosome 7, which codes for the cystic fibrosis transmembrane conductance regulator protein (CFTR). The most serious symptoms are observed in the lungs, augmenting the risk of bacterial infection. The objective of this review was to describe the bacterial pathogens colonizing patients with cystic fibrosis. A systematic search was conducted usin...

  10. Bacterial pathogens in rainbow trout, Oncorhynchus mykiss (Walbaum), reared at Danish freshwater farms

    DEFF Research Database (Denmark)

    Dalsgaard, Inger; Madsen, Lone

    2000-01-01

    During a 2-year period, bacterial fish pathogens were monitored on five rainbow trout, Oncorhynchus mykirs (Walbaum), freshwater farms in Denmark. A total of 1206 fish were examined and 361 bacterial isolates were identified phenotypically. Enteric redmouth disease, furunculosis and rainbow trout....... psychrophilum isolates showed resistance to oxolinic acid and oxytetracycline. No antibiotic resistant isolates were found among Y. ruckeri and A. salmonicida.......During a 2-year period, bacterial fish pathogens were monitored on five rainbow trout, Oncorhynchus mykirs (Walbaum), freshwater farms in Denmark. A total of 1206 fish were examined and 361 bacterial isolates were identified phenotypically. Enteric redmouth disease, furunculosis and rainbow trout...... of fry and larger fish. All isolates of F. psychrophilum showed proteolytic activities; however, a few isolates, belonging to serotype Fp(T) did not degrade elastin and were not associated with mortality. Increasing resistance problems to oxytetracycline were demonstrated. More than half of the F...

  11. Cysteine transport through excitatory amino acid transporter 3 (EAAT3.

    Directory of Open Access Journals (Sweden)

    Spencer D Watts

    Full Text Available Excitatory amino acid transporters (EAATs limit glutamatergic signaling and maintain extracellular glutamate concentrations below neurotoxic levels. Of the five known EAAT isoforms (EAATs 1-5, only the neuronal isoform, EAAT3 (EAAC1, can efficiently transport the uncharged amino acid L-cysteine. EAAT3-mediated cysteine transport has been proposed to be a primary mechanism used by neurons to obtain cysteine for the synthesis of glutathione, a key molecule in preventing oxidative stress and neuronal toxicity. The molecular mechanisms underlying the selective transport of cysteine by EAAT3 have not been elucidated. Here we propose that the transport of cysteine through EAAT3 requires formation of the thiolate form of cysteine in the binding site. Using Xenopus oocytes and HEK293 cells expressing EAAT2 and EAAT3, we assessed the transport kinetics of different substrates and measured transporter-associated currents electrophysiologically. Our results show that L-selenocysteine, a cysteine analog that forms a negatively-charged selenolate ion at physiological pH, is efficiently transported by EAATs 1-3 and has a much higher apparent affinity for transport when compared to cysteine. Using a membrane tethered GFP variant to monitor intracellular pH changes associated with transport activity, we observed that transport of either L-glutamate or L-selenocysteine by EAAT3 decreased intracellular pH, whereas transport of cysteine resulted in cytoplasmic alkalinization. No change in pH was observed when cysteine was applied to cells expressing EAAT2, which displays negligible transport of cysteine. Under conditions that favor release of intracellular substrates through EAAT3 we observed release of labeled intracellular glutamate but did not detect cysteine release. Our results support a model whereby cysteine transport through EAAT3 is facilitated through cysteine de-protonation and that once inside, the thiolate is rapidly re-protonated. Moreover, these

  12. A conserved serine-rich stretch in the glutamate transporter family forms a substrate-sensitive reentrant loop

    NARCIS (Netherlands)

    Slotboom, Dirk Jan; Sobczak, Iwona; Konings, Wil N.; Lolkema, Juke S.

    1999-01-01

    Neuronal and glial glutamate transporters remove the excitatory neurotransmitter glutamate from the synaptic cleft. The proteins belong to a large family of secondary transporters, which includes bacterial glutamate transporters. The C-terminal half of the glutamate transporters is well conserved an

  13. Towards innovative roadside monitoring

    Science.gov (United States)

    Ojha, G.; Appel, E.; Magiera, T.

    2012-04-01

    Soil contamination along roadsides is an important factor of anthropogenic point source pollution. Climatic and traffic-specific factors influence the amount and characteristics of pollution emitted and deposited in the roadside soil. In our present study we focus on monitoring typical traffic pollutants (heavy metals HM, platinum group elements, polycyclic hydrocarbons PAH), and investigate the use of magnetic parameters, especially magnetic susceptibility (MS) as proxy. Monitoring plots were installed along roadside in areas with different climatic conditions and different traffic-specific activities (traffic density and speed, vehicle types, abrasion of tires, brake linings, petrol/diesel compounds and road maintenance). For monitoring we removed 10-15 cm of top soil at 1 m distance from the roadside edge and placed 30 plastic boxes there filled with clean quartz sand, to be sampled after regular intervals within two years. Preliminary data from the first year of monitoring are presented. Magnetic results revealed that a coarse grained magnetite-like phase is responsible for the enhancement of magnetic concentration. The mass-specific MS and concentration of pollutants (HM, PAH) all show a significant increase with time, however, there are obviously also seasonal and site-dependent effects which lead to more stable values over several months or even some decrease in the upper few cm due to migration into depth. Source identification indicates that the accumulated PAHs are primarily emissions from traffic. In order to be able to discriminate in between different kinds of transport and deposition (surface run off from the road and neighbouring soil material, splash water, air transport), we additionally established pillars at the roadside with clean quartz sampling boxes at different heights (surface, 0.5 m, 2 m). As a first surprising result we observed that the increase in the boxes at surface is not necessarily higher than at 0.5 m height. The results from our

  14. Travel and transport

    DEFF Research Database (Denmark)

    Bill, Jan; Roesdahl, Else

    2007-01-01

    On the interrelationship between travel, transport and society; on land transport, sea and river transport, and on winter transport;  on the related technologies and their developments......On the interrelationship between travel, transport and society; on land transport, sea and river transport, and on winter transport;  on the related technologies and their developments...

  15. The Human Vaginal Bacterial Biota and Bacterial Vaginosis

    Directory of Open Access Journals (Sweden)

    Sujatha Srinivasan

    2008-01-01

    Full Text Available The bacterial biota of the human vagina can have a profound impact on the health of women and their neonates. Changes in the vaginal microbiota have been associated with several adverse health outcomes including premature birth, pelvic inflammatory disease, and acquisition of HIV infection. Cultivation-independent molecular methods have provided new insights regarding bacterial diversity in this important niche, particularly in women with the common condition bacterial vaginosis (BV. PCR methods have shown that women with BV have complex communities of vaginal bacteria that include many fastidious species, particularly from the phyla Bacteroidetes and Actinobacteria. Healthy women are mostly colonized with lactobacilli such as Lactobacillus crispatus, Lactobacillus jensenii, and Lactobacillus iners, though a variety of other bacteria may be present. The microbiology of BV is heterogeneous. The presence of Gardnerella vaginalis and Atopobium vaginae coating the vaginal epithelium in some subjects with BV suggests that biofilms may contribute to this condition.

  16. Optimal transport

    CERN Document Server

    Eckmann, B

    2008-01-01

    At the close of the 1980s, the independent contributions of Yann Brenier, Mike Cullen and John Mather launched a revolution in the venerable field of optimal transport founded by G Monge in the 18th century, which has made breathtaking forays into various other domains of mathematics ever since. The author presents a broad overview of this area.

  17. Transport modeling

    Institute of Scientific and Technical Information of China (English)

    R.E. Waltz

    2007-01-01

    @@ There has been remarkable progress during the past decade in understanding and modeling turbulent transport in tokamaks. With some exceptions the progress is derived from the huge increases in computational power and the ability to simulate tokamak turbulence with ever more fundamental and physically realistic dynamical equations, e.g.

  18. Transport fuel

    DEFF Research Database (Denmark)

    Ronsse, Frederik; Jørgensen, Henning; Schüßler, Ingmar

    2014-01-01

    Worldwide, the use of transport fuel derived from biomass increased four-fold between 2003 and 2012. Mainly based on food resources, these conventional biofuels did not achieve the expected emission savings and contributed to higher prices for food commod - ities, especially maize and oilseeds...

  19. Anomalous transport

    Science.gov (United States)

    Cheverry, Christophe

    2017-02-01

    This article is concerned with the relativistic Vlasov equation, for collisionless axisymmetric plasmas immersed in a strong magnetic field, like in tokamaks. It provides a consistent kinetic treatment of the microscopic particle phase-space dynamics. It shows that the turbulent transport can be completely described through WKB expansions.

  20. Transport system

    NARCIS (Netherlands)

    Drenth, K.F.

    1999-01-01

    The transport system comprises at least one road surface (2) and at least one vehicle (4) on wheels (6). The road surface (2) has a substantially bowl-shaped cross section and the vehicle (4) is designed so that the wheels (6) run directly on the road surface (2) while the road surface (2) acts as a

  1. Monoamine transporters: Insights from molecular dynamics simulations

    Directory of Open Access Journals (Sweden)

    Julie eGrouleff

    2015-10-01

    Full Text Available The human monoamine transporters facilitate the reuptake of the neurotransmitters serotonin, dopamine, and norepinephrine from the synaptic cleft. Imbalance in monoaminergic neurotransmission is linked to various diseases including major depression, attention deficit hyperactivity disorder, schizophrenia and Parkinson’s disease. Inhibition of the monoamine transporters is thus an important strategy for treatment of such diseases. The monoamine transporters are sodium-coupled transport proteins belonging to the neurotransmitter/Na+ symporter (NSS family, and the publication of the first high-resolution structure of a NSS family member, the bacterial leucine transporter LeuT, in 2005, proved to be a major stepping stone for understanding this family of transporters. Structural data allows for the use of computational methods to study the monoamine transporters, which in turn has led to a number of important discoveries. The process of substrate translocation across the membrane is an intrinsically dynamic process. Molecular dynamics simulations, which can provide atomistic details of molecular motion on ns to ms timescales, are therefore well-suited for studying transport processes. In this review, we outline how molecular dynamics simulations have provided insight into the large scale motions associated with transport of the neurotransmitters, as well as the presence of external and internal gates, the coupling between ion and substrate transport, and differences in the conformational changes induced by substrates and inhibitors.

  2. Electrical response of culture media during bacterial growth on a paper-based device

    Science.gov (United States)

    Srimongkon, Tithimanan; Buerkle, Marius; Nakamura, Akira; Enomae, Toshiharu; Ushijima, Hirobumi; Fukuda, Nobuko

    2017-05-01

    In this work, we evaluated the feasibility of a paper-based bacterial detection system. The paper served as a substrate for the measurement electrodes and the culture medium. Using a printing technique, we patterned gold electrodes onto the paper substrate and applied Luria broth (LB) agar gel as a culture medium on top of the electrodes. As the first step towards the development of a bacterial detection system, we determined changes in the surface potential during bacterial growth and monitored these changes over 24 h. This allowed us to correlate changes in the surface potential with the different growth phases of the bacteria.

  3. New Treatments for Bacterial Keratitis

    Directory of Open Access Journals (Sweden)

    Raymond L. M. Wong

    2012-01-01

    Full Text Available Purpose. To review the newer treatments for bacterial keratitis. Data Sources. PubMed literature search up to April 2012. Study Selection. Key words used for literature search: “infectious keratitis”, “microbial keratitis”, “infective keratitis”, “new treatments for infectious keratitis”, “fourth generation fluoroquinolones”, “moxifloxacin”, “gatifloxacin”, “collagen cross-linking”, and “photodynamic therapy”. Data Extraction. Over 2400 articles were retrieved. Large scale studies or publications at more recent dates were selected. Data Synthesis. Broad spectrum antibiotics have been the main stay of treatment for bacterial keratitis but with the emergence of bacterial resistance; there is a need for newer antimicrobial agents and treatment methods. Fourth-generation fluoroquinolones and corneal collagen cross-linking are amongst the new treatments. In vitro studies and prospective clinical trials have shown that fourth-generation fluoroquinolones are better than the older generation fluoroquinolones and are as potent as combined fortified antibiotics against common pathogens that cause bacterial keratitis. Collagen cross-linking was shown to improve healing of infectious corneal ulcer in treatment-resistant cases or as an adjunct to antibiotics treatment. Conclusion. Fourth-generation fluoroquinolones are good alternatives to standard treatment of bacterial keratitis using combined fortified topical antibiotics. Collagen cross-linking may be considered in treatment-resistant infectious keratitis or as an adjunct to antibiotics therapy.

  4. Bacterial carbonatogenesis; La carbonatogenese bacterienne

    Energy Technology Data Exchange (ETDEWEB)

    Castanier, S. [Angers Univ., 49 (France). Faculte des Sciences; Le Metayer-Levrel, G.; Perthuisot, J.P. [Nantes Univ., 44 (France). Laboratoire de Biogeologie, Faculte des Sciences et des Techniques

    1998-12-31

    Several series of experiments in the laboratory as well as in natural conditions teach that the production of carbonate particles by heterotrophic bacteria follows different ways. The `passive` carbonatogenesis is generated by modifications of the medium that lead to the accumulation of carbonate and bicarbonate ions and to the precipitation of solid particles. The `active` carbonatogenesis is independent of the metabolic pathways. The carbonate particles are produced by ionic exchanges through the cell membrane following still poorly known mechanisms. Carbonatogenesis appears to be the response of heterotrophic bacterial communities to an enrichment of the milieu in organic matter. The active carbonatogenesis seems to start first. It is followed by the passive one which induces the growth of initially produced particles. The yield of heterotrophic bacterial carbonatogenesis and the amounts of solid carbonates production by bacteria are potentially very high as compared to autotrophic or chemical sedimentation from marine, paralic or continental waters. Furthermore, the bacterial processes are environmentally very ubiquitous; they just require organic matter enrichment. Thus, apart from purely evaporite and autotrophic ones, all Ca and/or Mg carbonates must be considered as from heterotrophic bacterial origin. By the way, the carbon of carbonates comes from primary organic matter. Such considerations ask questions about some interpretations from isotopic data on carbonates. Finally, bacterial heterotrophic carbonatogenesis appears as a fundamental phase in the relationships between atmosphere and lithosphere and in the geo-biological evolution of Earth. (author) 43 refs.

  5. Development of guidelines for monitoring routine enforcement. The "Escape" Project, Working Paper 12. Project funded by the European Commission under the Transport RTD Programme of the 4th Framework Programme.

    NARCIS (Netherlands)

    Gelau, C. Gitelman, V. Jayet, M.-C. & Heidstra, J.

    2010-01-01

    The aim of this study was to provide the background for the development of guidelines for monitoring routine police enforcement based on practical measures of non-compliance in driver behaviour and other available data, and to sum up the findings in the form of a reasonable set of instructions for a

  6. Bacterial diversity assessed by cultivation-based techniques shows predominance of Staphylococccus species on coins collected in Lisbon and Casablanca.

    Science.gov (United States)

    de Carvalho, Carla C C R; Caramujo, Maria José

    2014-04-01

    Money is usually considered a source of infections, yet survival of bacteria on dry metal surfaces is limited. The aim of this work was to assess the bacterial numbers and diversity on coins collected in Casablanca and Lisbon as these two cities, on different continents and only 585 km apart, have diverse cultural habitats, but have similar climate. A cultivation-based characterisation of the bacterial community showed that a relatively low number of cells per area of coin were found on both Moroccan Dirhams and Euros (0.014 and 0.125 colony-forming units (CFU) mm(-2) , respectively). Most of the bacterial isolates were located near the rim of the coins, and coins collected in Europe contained more CFU/area of coin. Coins collected in Europe and transported in pockets presented a higher number of bacterial isolates (maximum 0.125 CFU mm(-2) ) than coins transported in wallets (maximum 0.042 CFU mm(-2) ), regardless of the gender of the person transporting them, suggesting that temperature and moisture might be key parameters for bacterial survival on metallic coins. Bacterial diversity was higher for coins collected in Casablanca relative to coins collected in Lisbon, and there was no evidence that it was dependent on the gender of the person transporting the coins or the place of transport (pockets or wallets). Curiously, the percentage of Staphylococcus strains was 44% of the total isolates on both currencies.

  7. Structural and mechanistic insights into ABC-type ECF transporters for vitamin uptake

    NARCIS (Netherlands)

    Dosz-Majsnerowska, Maria

    2014-01-01

    Dit proefschrift gaat over de relatie tussen de structuur en het mechanisme van ABC-type ECF transporters voor vitamines, uit de bacterie Lactococcus lactis. Energy-Coupling Factor (ECF) transporters vormen een subgroep van de ATP-binding cassette (ABC) transporters en zijn betrokken bij de opname v

  8. Structural and mechanistic insights into ABC-type ECF transporters for vitamin uptake

    NARCIS (Netherlands)

    Dosz-Majsnerowska, Maria

    2014-01-01

    Dit proefschrift gaat over de relatie tussen de structuur en het mechanisme van ABC-type ECF transporters voor vitamines, uit de bacterie Lactococcus lactis. Energy-Coupling Factor (ECF) transporters vormen een subgroep van de ATP-binding cassette (ABC) transporters en zijn betrokken bij de opname

  9. Recent advances in the understanding of the interaction of antidepressant drugs with serotonin and norepinephrine transporters

    DEFF Research Database (Denmark)

    Andersen, Jacob; Kristensen, Anders Skov; Bang-Andersen, Benny;

    2009-01-01

    and amphetamine. Seminal advances in the understanding of the structure and function of this transporter family have recently been accomplished by structural studies of a bacterial transporter, as well as medicinal chemistry and pharmacological studies of mammalian transporters. This feature article focuses...

  10. Gram-Negative Bacterial Sensors for Eukaryotic Signal Molecules

    Directory of Open Access Journals (Sweden)

    Olivier Lesouhaitier

    2009-09-01

    Full Text Available Ample evidence exists showing that eukaryotic signal molecules synthesized and released by the host can activate the virulence of opportunistic pathogens. The sensitivity of prokaryotes to host signal molecules requires the presence of bacterial sensors. These prokaryotic sensors, or receptors, have a double function: stereospecific recognition in a complex environment and transduction of the message in order to initiate bacterial physiological modifications. As messengers are generally unable to freely cross the bacterial membrane, they require either the presence of sensors anchored in the membrane or transporters allowing direct recognition inside the bacterial cytoplasm. Since the discovery of quorum sensing, it was established that the production of virulence factors by bacteria is tightly growth-phase regulated. It is now obvious that expression of bacterial virulence is also controlled by detection of the eukaryotic messengers released in the micro-environment as endocrine or neuro-endocrine modulators. In the presence of host physiological stress many eukaryotic factors are released and detected by Gram-negative bacteria which in return rapidly adapt their physiology. For instance, Pseudomonas aeruginosa can bind elements of the host immune system such as interferon-γ and dynorphin and then through quorum sensing circuitry enhance its virulence. Escherichia coli sensitivity to the neurohormones of the catecholamines family appears relayed by a recently identified bacterial adrenergic receptor. In the present review, we will describe the mechanisms by which various eukaryotic signal molecules produced by host may activate Gram-negative bacteria virulence. Particular attention will be paid to Pseudomonas, a genus whose representative species, P. aeruginosa, is a common opportunistic pathogen. The discussion will be particularly focused on the pivotal role played by these new types of pathogen sensors from the sensing to the transduction

  11. Bacterial Degradation of Aromatic Compounds

    Directory of Open Access Journals (Sweden)

    Qing X. Li

    2009-01-01

    Full Text Available Aromatic compounds are among the most prevalent and persistent pollutants in the environment. Petroleum-contaminated soil and sediment commonly contain a mixture of polycyclic aromatic hydrocarbons (PAHs and heterocyclic aromatics. Aromatics derived from industrial activities often have functional groups such as alkyls, halogens and nitro groups. Biodegradation is a major mechanism of removal of organic pollutants from a contaminated site. This review focuses on bacterial degradation pathways of selected aromatic compounds. Catabolic pathways of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene are described in detail. Bacterial catabolism of the heterocycles dibenzofuran, carbazole, dibenzothiophene, and dibenzodioxin is discussed. Bacterial catabolism of alkylated PAHs is summarized, followed by a brief discussion of proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms.

  12. Acute bacterial and viral meningitis.

    Science.gov (United States)

    Bartt, Russell

    2012-12-01

    Most cases of acute meningitis are infectious and result from a potentially wide range of bacterial and viral pathogens. The organized approach to the patient with suspected meningitis enables the prompt administration of antibiotics, possibly corticosteroids, and diagnostic testing with neuroimaging and spinal fluid analysis. Acute meningitis is infectious in most cases and caused by a potentially wide range of bacterial and viral pathogens. Shifts in the epidemiology of bacterial pathogens have been influenced by changes in vaccines and their implementation. Seasonal and environmental changes influence the likely viral and rickettsial pathogens. The organized approach to the patient with suspected meningitis enables the prompt administration of antibiotics, possibly corticosteroids, and diagnostic testing with neuroimaging and spinal fluid analysis. Pertinent testing and treatment can vary with the clinical presentation, season, and possible exposures. This article reviews the epidemiology, clinical presentation, diagnosis, and treatment of acute meningitis.

  13. Bacterial vaginosis and preterm birth.

    Science.gov (United States)

    Manns-James, Laura

    2011-01-01

    Although it has been clear for more than 2 decades that bacterial vaginosis increases the risk for preterm birth in some women, it is not yet fully understood why this association exists or how best to modify the risk. Incomplete understanding of this polymicrobial condition and difficulties in classification contribute to the challenge. The relationship between altered vaginal microflora and preterm birth is likely mediated by host immune responses. Because treatment of bacterial vaginosis during pregnancy does not improve preterm birth rates, and may in fact increase them, screening and treatment of asymptomatic pregnant women is discouraged. Symptomatic women should be treated for symptom relief. This article reviews the pathophysiology of bacterial vaginosis and controversy surrounding management during pregnancy. Agents currently recommended for treatment of this condition are reviewed. © 2011 by the American College of Nurse-Midwives.

  14. Bacterial attraction and quorum sensing inhibition in Caenorhabditis elegans exudates.

    Science.gov (United States)

    Kaplan, Fatma; Badri, Dayakar V; Zachariah, Cherian; Ajredini, Ramadan; Sandoval, Francisco J; Roje, Sanja; Levine, Lanfang H; Zhang, Fengli; Robinette, Steven L; Alborn, Hans T; Zhao, Wei; Stadler, Michael; Nimalendran, Rathika; Dossey, Aaron T; Brüschweiler, Rafael; Vivanco, Jorge M; Edison, Arthur S

    2009-08-01

    Caenorhabditis elegans, a bacterivorous nematode, lives in complex rotting fruit, soil, and compost environments, and chemical interactions are required for mating, monitoring population density, recognition of food, avoidance of pathogenic microbes, and other essential ecological functions. Despite being one of the best-studied model organisms in biology, relatively little is known about the signals that C. elegans uses to interact chemically with its environment or as defense. C. elegans exudates were analyzed by using several analytical methods and found to contain 36 common metabolites that include organic acids, amino acids, and sugars, all in relatively high abundance. Furthermore, the concentrations of amino acids in the exudates were dependent on developmental stage. The C. elegans exudates were tested for bacterial chemotaxis using Pseudomonas putida (KT2440), a plant growth promoting rhizobacterium, Pseudomonas aeruginosa (PAO1), a soil bacterium pathogenic to C. elegans, and Escherichia coli (OP50), a non-motile bacterium tested as a control. The C. elegans exudates attracted the two Pseudomonas species, but had no detectable antibacterial activity against P. aeruginosa. To our surprise, the exudates of young adult and adult life stages of C. elegans exudates inhibited quorum sensing in the reporter system based on the LuxR bacterial quorum sensing (QS) system, which regulates bacterial virulence and other factors in Vibrio fischeri. We were able to fractionate the QS inhibition and bacterial chemotaxis activities, thus demonstrating that these activities are chemically distinct. Our results demonstrate that C. elegans can attract its bacterial food and has the potential of partially regulating the virulence of bacterial pathogens by inhibiting specific QS systems.

  15. Molecular mechanisms underlying bacterial persisters

    DEFF Research Database (Denmark)

    Maisonneuve, Etienne; Gerdes, Kenn

    2014-01-01

    All bacteria form persisters, cells that are multidrug tolerant and therefore able to survive antibiotic treatment. Due to the low frequencies of persisters in growing bacterial cultures and the complex underlying molecular mechanisms, the phenomenon has been challenging to study. However, recent...... technological advances in microfluidics and reporter genes have improved this scenario. Here, we summarize recent progress in the field, revealing the ubiquitous bacterial stress alarmone ppGpp as an emerging central regulator of multidrug tolerance and persistence, both in stochastically and environmentally...... induced persistence. In several different organisms, toxin-antitoxin modules function as effectors of ppGpp-induced persistence....

  16. Food-Borne Bacterial Toxins

    Science.gov (United States)

    Thatcher, F. S.

    1966-01-01

    Food poisoning caused by the ingestion of preformed bacterial toxins is considered in relation to comparative symptoms, procedures for extraction and purification of the causal toxins, their chemistry, serology, assay procedures and pharmacology, in so far as these are known. The bacteria discussed in this context are Clostridium botulinum, C. perfringens, Staphylococcus aureus, Bacillus cereus, and Vibrio parahemolyticus. The possible roles of the enterococci, Proteus, E. coli and of unknown species, in relation to production of non-antigenic toxic substances, are discussed briefly. Requirements for prevention of the various forms of bacterial food poisoning are outlined. PMID:5905949

  17. Bacterial pathogens in rainbow trout, Oncorhynchus mykiss (Walbaum), reared at Danish freshwater farms

    DEFF Research Database (Denmark)

    Dalsgaard, Inger; Madsen, Lone

    2000-01-01

    During a 2-year period, bacterial fish pathogens were monitored on five rainbow trout, Oncorhynchus mykirs (Walbaum), freshwater farms in Denmark. A total of 1206 fish were examined and 361 bacterial isolates were identified phenotypically. Enteric redmouth disease, furunculosis and rainbow trout....... psychrophilum isolates showed resistance to oxolinic acid and oxytetracycline. No antibiotic resistant isolates were found among Y. ruckeri and A. salmonicida....... fry syndrome/coldwater disease were recorded. Infections caused by Flavobacterium