WorldWideScience

Sample records for bacteria final progress

  1. Final Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Josef Michl

    2011-10-31

    In this project we have established guidelines for the design on organic chromophores suitable for producing high triplet yields via singlet fission. We have proven their utility by identifying a chromophore of a structural class that had never been examined for singlet fission before, 1,3-diphenylisobenzofuran, and demonstrating in two independent ways that a thin layer of this material produces a triplet yield of 200% within experimental error. We have also designed a second chromophore of a very different type, again of a structural class that had not been examined for singlet fission before, and found that in a thin layer it produces a 70% triplet yield. Finally, we have enhanced the theoretical understanding of the quantum mechanical nature of the singlet fission process.

  2. Final Performance Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Houldin, Joseph [Delaware Valley Industrial Resource Center, Philadelphia, PA (United States); Saboor, Veronica [Delaware Valley Industrial Resource Center, Philadelphia, PA (United States)

    2016-03-30

    about assessing a company’s technical assets, broadening our view of the business to go beyond what they make or what NAICS code they have…to better understand their capacity, capability, and expertise, and to learn more about THEIR customers. Knowing more about the markets they serve can often provide insight into their level of technical knowledge and sophistication. Finally, in the spirit of realizing the intent of the Accelerator we strove to align and integrate the work and activities supported by the five funding agencies to leverage each effort. To that end, we include in the Integrated Work Plan a graphic that illustrates that integration. What follows is our summary report of the project, aggregated from prior reports.

  3. IRIS Final Technical Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    M. D. Carelli

    2003-11-03

    OAK-B135 This NERI project, originally started as the Secure Transportable Autonomous Light Water Reactor (STAR-LW) and currently known as the International Reactor Innovative and Secure (IRIS) project, had the objective of investigating a novel type of water-cooled reactor to satisfy the Generation IV goals: fuel cycle sustainability, enhanced reliability and safety, and improved economics. The research objectives over the three-year (1999-2002) program were as follows: First year: Assess various design alternatives and establish main characteristics of a point design; Second year: Perform feasibility and engineering assessment of the selected design solutions; Third year: Complete reactor design and performance evaluation, including cost assessment These objectives were fully attained and actually they served to launch IRIS as a full fledged project for eventual commercial deployment. The program did not terminate in 2002 at the end of the NERI program, and has just entered in its fifth year. This has been made possible by the IRIS project participants which have grown from the original four member, two-countries team to the current twenty members, nine countries consortium. All the consortium members work under their own funding and it is estimated that the value of their in-kind contributions over the life of the project has been of the order of $30M. Currently, approximately 100 people worldwide are involved in the project. A very important constituency of the IRIS project is the academia: 7 universities from four countries are members of the consortium and five more US universities are associated via parallel NERI programs. To date, 97 students have worked or are working on IRIS; 59 IRIS-related graduate theses have been prepared or are in preparation, and 41 of these students have already graduated with M.S. (33) or Ph.D. (8) degrees. This ''final'' report (final only as far as the NERI program is concerned) summarizes the work performed

  4. Bacteria transport through porous material: Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Yen, T.F.

    1989-02-13

    The injection and penetration of bacteria into a reservoir is the most problematic and crucial of the steps in microbial enhanced recovery (MEOR). In the last phase of our work valuable information on bacterial transport in porous media was obtained. A great deal of progress was made to determine chemical bonding characteristics between adsorbed bacteria and the rock surfaces. In order to further enhance our knowledge of the effects of surface tensions on bacteria transport through porous media, a new approach was taken to illustrate the effect of liquid surface tension on bacterial transport through a sandpack column. Work in surface charge characterization of reservoir rock as a composite oxide system was also accomplished. In the last section of this report a mathematical model to simulate the simultaneous diffusion and growth of bacteria cells in a nutrient-enriched porous media is proposed.

  5. 1995 PVUSA progress report. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Photovoltaics for Utility Scale Applications (PVUSA) is a national public-private partnership that is assessing and demonstrating the viability of utility-scale (US) photovoltaic (PV) electric generation systems and recent developments in PV module technology. This report updates the project`s progress, reviews the status and performance of the various PV installations during 1995, summarizes key accomplishments and conclusions, and serves as the final report under Pacific Gas and Electric Company`s project management.

  6. Progress in Research of Bacteria Fertilizer Strengthening Resistance of Plants

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Bacteria fertilizer is used most widely among all kinds of microbial fertilizers. We summarize the research headway of bacteria fertilizer. It mainly focuses on bacteria fertilizer improving the stress resistance of plant. Then we can offer basis to research and exploit bacteria fertilizer. These bacteria include azotobacter, photosynthetic bacteria, Bacillus mucilaginosus siliceous, phosphorus bacteria, plant growth-promoting rhizobacteria(PGPR), effective microorganism(EM).

  7. Computational modeling of drug-resistant bacteria. Final report

    Energy Technology Data Exchange (ETDEWEB)

    MacDougall, Preston [Middle Tennessee State University

    2015-03-12

    Initial proposal summary: The evolution of antibiotic-resistant mutants among bacteria (superbugs) is a persistent and growing threat to public health. In many ways, we are engaged in a war with these microorganisms, where the corresponding arms race involves chemical weapons and biological targets. Just as advances in microelectronics, imaging technology and feature recognition software have turned conventional munitions into smart bombs, the long-term objectives of this proposal are to develop highly effective antibiotics using next-generation biomolecular modeling capabilities in tandem with novel subatomic feature detection software. Using model compounds and targets, our design methodology will be validated with correspondingly ultra-high resolution structure-determination methods at premier DOE facilities (single-crystal X-ray diffraction at Argonne National Laboratory, and neutron diffraction at Oak Ridge National Laboratory). The objectives and accomplishments are summarized.

  8. Stress responses of subsurface bacteria. Final report, June 1, 1995--February 1, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Chesbro, W.

    1998-07-01

    Five questions were investigated in this research: (1) can subsurface bacteria and phylogenetically related surface strains be cultured on a single carbon/energy substrate; (2) is the behavior of subsurface bacteria the same as phylogenetically related surface strains when both are subjected to progressive, chronic carbon/energy source starvation; (3) which phyllogenetic groups survive better; (4) do other factors affect survival in the degree that phyllogeny does (5) do dormant forms appear during starvation; (6) is ppGpp present in subsurface bacteria and what is its persistence in carbon/energy starvation?

  9. Bacteria inside semiconductors as potential sensor elements: biochip progress.

    Science.gov (United States)

    Sah, Vasu R; Baier, Robert E

    2014-01-01

    It was discovered at the beginning of this Century that living bacteria-and specifically the extremophile Pseudomonas syzgii-could be captured inside growing crystals of pure water-corroding semiconductors-specifically germanium-and thereby initiated pursuit of truly functional "biochip-based" biosensors. This observation was first made at the inside ultraviolet-illuminated walls of ultrapure water-flowing semiconductor fabrication facilities (fabs) and has since been, not as perfectly, replicated in simpler flow cell systems for chip manufacture, described here. Recognizing the potential importance of these adducts as optical switches, for example, or probes of metabolic events, the influences of the fabs and their components on the crystal nucleation and growth phenomena now identified are reviewed and discussed with regard to further research needs. For example, optical beams of current photonic circuits can be more easily modulated by integral embedded cells into electrical signals on semiconductors. Such research responds to a recently published Grand Challenge in ceramic science, designing and synthesizing oxide electronics, surfaces, interfaces and nanoscale structures that can be tuned by biological stimuli, to reveal phenomena not otherwise possible with conventional semiconductor electronics. This short review addresses only the fabrication facilities' features at the time of first production of these potential biochips.

  10. Marine microbiology. Final report. [Role of marine bacteria in the nitrogen cycle in oceans

    Energy Technology Data Exchange (ETDEWEB)

    Watson, S.W.

    1977-01-01

    Progress is reported on microbial investigations in the marine environment with emphasis on the role of bacteria in the nitrogen cycle, specifically concentrating on the organisms responsible for microbiological oxidation of ammonia to nitrite and nitrite to nitrate. The distribution rates of in situ reactions, fine structure and biochemical properties of these organisms were detailed. Rates of urea, acetate, and glucose decomposition in both inshore and offshore waters were determined using labelled compounds and the significance of these degradations in the hydrosphere was examined. A new test for the determination of bacterial biomass was developed and using this test in conjunction with more standard techniques it was demonstrated that bacteria comprised up to 50 percent of the total biomass in the oceans.

  11. Solid state NMR coal science. Final progress report

    Energy Technology Data Exchange (ETDEWEB)

    Zilm, K.W.

    1986-08-01

    This report covers the final work on this project and summarizes the accomplishments of the project. The dipolar shift correlated 2D NMR method described in previous reports has been applied to a whole coal successfully. The theory necessary for semi-quantitative interpretation of this data has also been worked out and implemented computationally. Several interesting structural features in coal seen by the 2D dipolar shift experiment not previously observed by other NMR methods are discussed. 4 figs.

  12. Final Progress Report for Ionospheric Dusty Plasma In the Laboratory [Smokey Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, Scott [Professor

    2010-09-28

    “Ionospheric Dusty Plasma in the Laboratory” is a research project with the purpose of finding and reproducing the characteristics of plasma in the polar mesosphere that is unusually cold (down to 140 K) and contains nanometer-sized dust particles. This final progress report summarizes results from four years of effort that include a final year with a no-cost extension.

  13. 1993 annual final progress report: July 1992 through June 1993

    Energy Technology Data Exchange (ETDEWEB)

    Rohatgi, A.; Crotty, G.; Chen, Z.; Sana, P.; Salami, J.; Doolittle, A.; Pang, A.; Pham, T. [Georgia Inst. of Tech., Atlanta, GA (United States). School of Electrical and Computer Engineering

    1994-11-01

    This is the first annual report since the Inauguration of the University Center of Excellence for Photovoltaics Research and Development (UCEP) at Georgia Tech. The essential objective of the Center is to improve the fundamental understanding of the science and technology of advanced PV devices and materials, to provide training and enrich the educational experience of students in the field, and to increase US competitiveness by providing guidelines to industry and DOE for achieving cost-effective and high efficiency PV devices. These objectives are to be accomplished through a combination of research and education. This report summarizes the technical accomplishments, including modeling, processing, and characterization of cast multicrystalline silicon solar cells; use of modeling and PCD measurements to develop a road map for progressing toward 20% multicrystalline and 25% single crystalline cells; the development of a novel PECVD SiN/SiO{sub 2} AR coating that also provides good surface passivation; PECVD deposited SiO{sub 2} films with record low S and D{sub it} at the SiO{sub 2}/Si interface; and educational activities and accomplishments.

  14. IRIS International Reactor Innovative and Secure Final Technical Progress Report

    International Nuclear Information System (INIS)

    OAK-B135 This NERI project, originally started as the Secure Transportable Autonomous Light Water Reactor (STAR-LW) and currently known as the International Reactor Innovative and Secure (IRIS) project, had the objective of investigating a novel type of water-cooled reactor to satisfy the Generation IV goals: fuel cycle sustainability, enhanced reliability and safety, and improved economics. The research objectives over the three-year (1999-2002) program were as follows: First year: Assess various design alternatives and establish main characteristics of a point design; Second year: Perform feasibility and engineering assessment of the selected design solutions; Third year: Complete reactor design and performance evaluation, including cost assessment These objectives were fully attained and actually they served to launch IRIS as a full fledged project for eventual commercial deployment. The program did not terminate in 2002 at the end of the NERI program, and has just entered in its fifth year. This has been made possible by the IRIS project participants which have grown from the original four member, two-countries team to the current twenty members, nine countries consortium. All the consortium members work under their own funding and it is estimated that the value of their in-kind contributions over the life of the project has been of the order of $30M. Currently, approximately 100 people worldwide are involved in the project. A very important constituency of the IRIS project is the academia: 7 universities from four countries are members of the consortium and five more US universities are associated via parallel NERI programs. To date, 97 students have worked or are working on IRIS; 59 IRIS-related graduate theses have been prepared or are in preparation, and 41 of these students have already graduated with M.S. (33) or Ph.D. (8) degrees. This ''final'' report (final only as far as the NERI program is concerned) summarizes the work performed in the first four

  15. Advanced Fuel Cycle Initiative University Fellowship Program. Final Progress Report

    International Nuclear Information System (INIS)

    2004-2011 Final Report for AFCI University Fellowship Program. The goal of this effort was to be supportive of university students and university programs - particularly those students and programs that will help to strengthen the development of nuclear-related fields. The program also supported the stability of the nuclear infrastructure and developed research partnerships that are helping to enlarge the national nuclear science technology base. In this fellowship program, the U.S. Department of Energy sought master's degree students in nuclear, mechanical, or chemical engineering, engineering/applied physics, physics, chemistry, radiochemistry, or fields of science and engineering applicable to the AFCI/Gen IV/GNEP missions in order to meet future U.S. nuclear program needs. The fellowship program identified candidates and selected full time students of high-caliber who were taking nuclear courses as part of their degree programs. The DOE Academic Program Managers encouraged fellows to pursue summer internships at national laboratories and supported the students with appropriate information so that both the fellows and the nation's nuclear energy objectives were successful.

  16. Verification of Steelmaking Slags Iron Content Final Technical Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    J.Y. Hwang

    2006-10-04

    The steel industry in the United States generates about 30 million tons of by-products each year, including 6 million tons of desulfurization and BOF/BOP slag. The recycling of BF (blast furnace) slag has made significant progress in past years with much of the material being utilized as construction aggregate and in cementitious applications. However, the recycling of desulfurization and BOF/BOP slags still faces many technical, economic, and environmental challenges. Previous efforts have focused on in-plant recycling of the by-products, achieving only limited success. As a result, large amounts of by-products of various qualities have been stockpiled at steel mills or disposed into landfills. After more than 50 years of stockpiling and landfilling, available mill site space has diminished and environmental constraints have increased. The prospect of conventionally landfilling of the material is a high cost option, a waste of true national resources, and an eternal material liability issue. The research effort has demonstrated that major inroads have been made in establishing the viability of recycling and reuse of the steelmaking slags. The research identified key components in the slags, developed technologies to separate the iron units and produce marketable products from the separation processes. Three products are generated from the technology developed in this research, including a high grade iron product containing about 90%Fe, a medium grade iron product containing about 60% Fe, and a low grade iron product containing less than 10% Fe. The high grade iron product contains primarily metallic iron and can be marketed as a replacement of pig iron or DRI (Direct Reduced Iron) for steel mills. The medium grade iron product contains both iron oxide and metallic iron and can be utilized as a substitute for the iron ore in the blast furnace. The low grade iron product is rich in calcium, magnesium and iron oxides and silicates. It has a sufficient lime value and

  17. Final Technical Progress Report Long term risk from actinides in the environment: Modes of mobility; FINAL

    International Nuclear Information System (INIS)

    in diameter and approximately 22 cm long. A thin ''marker layer'' of white soil was added to the top of each column followed by a thin layer of soil that had been spiked with 137Cs, cerium and lanthanum was applied to the surface. Approximately 900 cm of water (the equivalent of about 30 years of rainfall) was then applied at a rate of 3.2 L d-1. All of the activity contained in the soil core appeared to be in the top few mm of soil, i.e. there was virtually no movement of the 134Cs labeled particles. Finally, a library of object-oriented model components was created using Visual Basic to support the construction of contaminant transport models. These components greatly simplify the task of building 1- to 3- dimensional simulation models for risk assessment. The model components created under this funding were subsequently applied to help answer questions regarding risks from irrigation associated with potential releases from the Yucca Mountain waste repository

  18. Genetics of thermophilic bacteria. Final progress report, May 1, 1984--April 30, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Welker, N.E.

    1991-12-31

    Organisms adapted to high temperature have evolved a variety of unique solutions to the biochemical problems imposed by this environment. Adaptation is commonly used to describe the biochemical properties of organisms which have become adapted to their environment (genetic adaptation). It can also mean the direct response-at the cellular level-of an organism to changes in temperature (physiological adaptation). Thermophilic bacilli (strains of Bacillus stearothermophilus) can exhibit a variety of biochemical adaptations in response to changes in temperature. These include changes in the composition and stability of the membrane, metabolic potential, the transport of amino acids, regulatory mechanisms, ribose methylation of tRNA, protein thermostability, and nutritional requirements. The objectives of the research were to develop efficient and reliable genetic systems to analyze and manipulate B. Stearothermophilus, and to use these systems initiate a biochemical, molecular, and genetic investigations of genes that are required for growth at high temperature.

  19. A New Selectable Marker System for Genetic Studies of Bacteria: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Parsons, D; Tolmasky, M; Chain, P; Segelke, B W

    2011-03-18

    Genetic manipulations in bacteria currently rely on the introduction of antibiotic resistance genes into a bacterial strain; for those organisms that will be used for commercial or industrial applications, the genetic cassette encoding the antibiotic resistance is sometimes removed after selection. it is clear that if alternative technologies could obviate the need to introduce antibiotic resistance into bacteria, they would most certainly become a standard tool in molecular micriobiology for commercial, industrial as well as research applications. Here, they present the development of a novel genetic engineering technology based on toxin-antitoxin systems to modify bacterial genomes without the use of antibiotic resistance in the mutagenesis process. The primary goal is to develop antibiotic-free selection for genetically altered select agent pathogens. They are adapting the toxinc-antitoxin system to enable gene replacement in select agent pathogens since the NIH restrictions introducing antibiotic resistance into select agent pathogens have hindered research with select agent pathogens.

  20. Recent progress in understanding the molecular mechanisms of radioresistance in Deinococcus bacteria.

    Science.gov (United States)

    Munteanu, Alexandra- Cristina; Uivarosi, Valentina; Andries, Adrian

    2015-07-01

    The deleterious effects of ionizing radiation are a major concern of the modern world. In the last decades, outstanding interest has been given to developing new therapeutic tools designed for protection against the toxic effects of ionizing radiation. Deinococcus spp. are among the most radioresistant organisms on Earth, being able to survive extreme doses of radiation, 1000-fold higher than most vertebrates. The molecular mechanisms underlying DNA repair and biomolecular protection, which are responsible for the remarkable radioresistance of Deinococcus bacteria, have been a debatable subject for the last 60 years. This paper is focused on the most recent findings regarding the molecular background of radioresistance and on Deinococcus bacteria response to oxidative stress. Novel proteins and genes involved in the highly regulated DNA repair processes, and enzymatic and non- enzymatic antioxidant systems are presented. In addition, a recently proposed mechanism that may contribute to oxidative damage protection in Deinococcus bacteria is discussed. A better understanding of these molecular mechanisms may draw future perspectives for counteracting radiation-related toxicity.

  1. Flow-induced vibration for light water reactors. Final progress report, July 1981-September 1981

    International Nuclear Information System (INIS)

    Flow-Induced Vibration for Light Water Reactors (FIV for LWRs) is a program designed to improve the FIV performance of light water reactors through the development of design criteria, analytical models for predicting behavior of components, and general scaling laws to improve the accuracy of reduced-scale tests, and through the identification of high FIV risk areas. The program is managed by the General Electric Nuclear Power Systems Engineering Department and has three major contributors: General Electric Nuclear Power Systems Engineering Department (NPSED), General Electric Corporate Research and Development (CR and D) and Argonne National Laboratory (ANL). The program commenced December 1, 1976. This progress report summarizes the accomplishments achieved during the final period from July 1981 to September 1981. This is the last quarterly progress report to be issued for this program

  2. Relationship between the adhesive properties of bacteria and their transport and colonization in the subsurface environment. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Fletcher, M.

    1997-03-13

    The adhesion of bacteria to sediment particle or rock surfaces considerably effects their transport in subsurface environments. This research focuses on the macromolecular properties of bacteria that determine their adhesiveness and on the significance of adhesion in transport of subsurface bacteria. Specific objectives include (1) to obtain adhesion mutants of subsurface Pseudomonas species altered in surface adhesives; (2) to determine alterations in adhesives in selected mutants; (3) to evaluate the effect of adhesiveness on transport and long-term distribution and colonization of bacteria in porous media. Primary methods will be tranposon mutagenesis to generate adhesion mutants, biochemical analyses of cell surface polymers, and the use of laboratory columns containing subsurface materials to study the distribution and transport of bacteria along flow paths over time.

  3. Final Technical Progress Report: Development of Low-Cost Suspension Heliostat; December 7, 2011 - December 6, 2012

    Energy Technology Data Exchange (ETDEWEB)

    Bender, W.

    2013-01-01

    Final technical progress report of SunShot Incubator Solaflect Energy. The project succeeded in demonstrating that the Solaflect Suspension Heliostat design is viable for large-scale CSP installations. Canting accuracy is acceptable and is continually improving as Solaflect improves its understanding of this design. Cost reduction initiatives were successful, and there are still many opportunities for further development and further cost reduction.

  4. Improved methods for water shutoff. Final technical progress report, October 1, 1997--September 30, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Seright, R.S.; Liang, J.T.; Schrader, R.; Hagstrom, J. II; Liu, J.; Wavrik, K.

    1998-10-01

    In the United States, more than 20 billion barrels of salt water are produced each year during oilfield operations. A tremendous economic incentive exists to reduce water production if that can be accomplished without significantly sacrificing hydrocarbon production. This three-year research project had three objectives. The first objective was to identify chemical blocking agents that will (a) during placement, flow readily through fractures without penetrating significantly into porous rock and with screening out or developing excessive pressure gradients and (b) at a predictable and controllable time, become immobile and resistant breakdown upon exposure to moderate to high pressure gradients. The second objective was to identify schemes that optimize placement of the above blocking agents. The third objective was to explain why gels and other chemical blocking agents reduce permeability to one phase (e.g., water) more than that to another phase (e.g., oil or gas). The authors also wanted to identify conditions that maximize this phenomenon. This project consisted of three tasks, each of which addressed one of the above objectives. This report describes work performed during the third and final period of the project. During this three-year project, they: (1) Developed a procedure and software for sizing gelant treatments in hydraulically fractured production wells; (2) Developed a method (based on interwell tracer results) to determine the potential for applying gel treatments in naturally fractured reservoirs; (3) Characterized gel properties during extrusion through fractures; (4) Developed a method to predict gel placement in naturally fractured reservoirs; (5) Made progress in elucidating the mechanism for why some gels can reduce permeability to water more than that to oil; (6) Demonstrated the limitations of using water/oil ratio diagnostic plots to distinguish between channeling and coning; and (7) Proposed a philosophy for diagnosing and attacking water

  5. High-Efficiency Nitride-Based Solid-State Lighting. Final Technical Progress Report

    International Nuclear Information System (INIS)

    In this final technical progress report we summarize research accomplished during Department of Energy contract DE-FC26-01NT41203, entitled ''High-Efficiency Nitride-Based Solid-State Lighting''. Two teams, from the University of California at Santa Barbara (Principle Investigator: Dr. Shuji Nakamura) and the Lighting Research Center at Rensselaer Polytechnic Institute (led by Dr. N. Narendran), pursued the goals of this contract from thin film growth, characterization, and packaging/luminaire design standpoints. The UCSB team initially pursued the development of blue gallium nitride (GaN)-based vertical-cavity surface-emitting lasers, as well as ultraviolet GaN-based light emitting diodes (LEDs). In Year 2, the emphasis shifted to resonant-cavity light emitting diodes, also known as micro-cavity LEDs when extremely thin device cavities are fabricated. These devices have very directional emission and higher light extraction efficiency than conventional LEDs. Via the optimization of thin-film growth and refinement of device processing, we decreased the total cavity thickness to less than 1 (micro)m, such that micro-cavity effects were clearly observed and a light extraction efficiency of over 10% was reached. We also began the development of photonic crystals for increased light extraction, in particular for so-called ''guided modes'' which would otherwise propagate laterally in the device and be re-absorbed. Finally, we pursued the growth of smooth, high-quality nonpolar a-plane and m-plane GaN films, as well as blue light emitting diodes on these novel films. Initial nonpolar LEDs showed the expected behavior of negligible peak wavelength shift with increasing drive current. M-plane LEDs in particular show promise, as unpackaged devices had unsaturated optical output power of ∼ 3 mW at 200 mA drive current. The LRC's tasks were aimed at developing the subcomponents necessary for packaging UCSB's light emitting diodes, and packaging them to produce a white light

  6. 甲烷氧化菌分类及代谢途径研究进展%Progresses in the classification and mechanism of methane-oxidizing bacteria

    Institute of Scientific and Technical Information of China (English)

    蔡朝阳; 何崭飞; 胡宝兰

    2016-01-01

    Summary Methane (CH4) as a colorless,odorless organic gas,is one of the most simple hydrocarbons and is widely distributed in environment.As the second most important greenhouse gas,only following carbon dioxide, methane contributes a lot to the global warming. Methane-oxidizing bacteria are a kind of microorganisms which directly use methane as carbon and energy source.Because they can convert methane into carbon dioxide and mitigate the global greenhouse effect,methane-oxidizing bacteria are attracting more and more attention.Methane-oxidizing bacteria not only reduce methane emissions in the soil,but also uptake the methane in the gas phase of the unsaturated soil.They are important to mitigate the global greenhouse effect. According to whether can uptake oxygen in environment as the electron acceptor or not,methane-oxidizing bacteria can be divided into aerobic and anaerobic methane-oxidizing bacteria.Aerobic methane-oxidizing bacteria are gram-negative bacteria,which use methane as carbon and energy source,have been discovered as early as 1906. Because of the potential value of aerobic methane-oxidizing bacteria in practice production,scientists have made extensive research about them in the past 40 years.At the same time,aerobic methane-oxidizing bacteria can reduce soil methane emissions and uptake methane in the atmosphere,playing an important role in global carbon cycle. Because anaerobic methane-oxidizing bacteria”s doubling time is long,research progress about them is slow. Cellular components of different kinds of methane-oxidizing bacteria are different,and they have different enzymes and C1 metabolic pathways.The center metabolic mechanism of C1 component determines the competition ability of different bacteria in different environments.The main center metabolic mechanism can be divided into three categories:ribulose monophosphate cycle,serine cycle,and the Calvin-Benson-Bassham cycle.%甲烷作为仅次于二氧化碳的第2号温室气体,是

  7. Antimicrobial Activity of Cationic Antimicrobial Peptides against Gram-Positives: Current Progress Made in Understanding the Mode of Action and the Response of Bacteria

    Science.gov (United States)

    Omardien, Soraya; Brul, Stanley; Zaat, Sebastian A. J.

    2016-01-01

    Antimicrobial peptides (AMPs) have been proposed as a novel class of antimicrobials that could aid the fight against antibiotic resistant bacteria. The mode of action of AMPs as acting on the bacterial cytoplasmic membrane has often been presented as an enigma and there are doubts whether the membrane is the sole target of AMPs. Progress has been made in clarifying the possible targets of these peptides, which is reported in this review with as focus gram-positive vegetative cells and spores. Numerical estimates are discussed to evaluate the possibility that targets, other than the membrane, could play a role in susceptibility to AMPs. Concerns about possible resistance that bacteria might develop to AMPs are addressed. Proteomics, transcriptomics, and other molecular techniques are reviewed in the context of explaining the response of bacteria to the presence of AMPs and to predict what resistance strategies might be. Emergent mechanisms are cell envelope stress responses as well as enzymes able to degrade and/or specifically bind (and thus inactivate) AMPs. Further studies are needed to address the broadness of the AMP resistance and stress responses observed.

  8. CRISPR在细菌分型和进化中的研究进展%Progress in CRISPR Research on Bacteria Typing and Evolution

    Institute of Scientific and Technical Information of China (English)

    王建; 邱少富; 宋宏彬; 孙岩松

    2013-01-01

      Clustered regularly interspaced short palindromic repeats(CRSIPR) are recently discovered and wide⁃spread in the genomes of many bacteria and almost archaea, which provide acquired immunity against foreign DNA. The polymorphism of CRISPR makes it possible to be used as the ideal locus of bacteria typing and evolu⁃tion study. In this review, the basic structure of CRISPR as well as the research progress of CRISPR on bacteria typing and evolution were introduced.%  规律成簇的间隔的短回文重复序列(CRISPR)是近年发现的一类存在于古细菌和细菌基因组内的结构,该结构可以使细菌获得对外源DNA如质粒和噬菌体的免疫,同时由于其结构的多态性,也可作为细菌分型和进化研究的位点。简要综述了CRSIPR系统的基本结构,及其在分型和进化应用方面的研究进展。

  9. Study of private enterprise development on the Raft River KGRA. Final progress report

    Energy Technology Data Exchange (ETDEWEB)

    Green, S.J.; Brown, W.S.; Meldrum, P.D.

    1977-07-01

    Information, analysis, and conclusions based on the small for-profit venture business model are presented. The necessary tasks are described and progress is reviewed. Water availability and business analysis problems are described. Included in the appendix are materials on land availability, characterization of geothermal resources under Idaho law, and greenhouse analysis and geothermal applications. (MHR)

  10. Research progress in the relationship between childhood wheezing and bacteria%儿童喘息与细菌关系的研究进展

    Institute of Scientific and Technical Information of China (English)

    丁凤霞(综述); 罗健; 符州(审校)

    2015-01-01

    喘息是儿童时期最常见的呼吸系统疾病临床表现之一,主要与病毒感染有关。近年来有文献报道细菌在呼吸道的定植或感染也可能与儿童喘息,尤其是婴幼儿喘息相关。气道中发现这些菌群是一种正常的临床现象,还是其中部分细菌引起了儿童反复喘息,以及其在喘息性疾病发生发展中的作用与机制,目前尚不完全清楚。该文主要综述儿童喘息与细菌关系及细菌引起儿童喘息的可能机制的最新研究进展。%Wheezing is one of the most common clinical manifestations of childhood respiratory diseases, mainly associated with virus infection. Recent years, bacteria colonization and its infection are reported to involve in childhood wheezing, especially in infantile wheezing. However, the bacteria lfora in the airway is only a phenomenon or a reason to induce some childhood wheezing, and its roles, as well as the mechanism in the development of wheezing remain unknown. This article summarizes the research progress in the relationship between childhood wheezing and bacteria and in the possible mechanisms of childhood wheezing caused by bacteria.

  11. Processes of energy deposition by heavy-particle and electron impact. Final progress report

    International Nuclear Information System (INIS)

    Progress is reported in three areas of reasearch during the present period: K-shell ionization in high energy collisions of heavy ions with light target atoms using the sudden (Magnus) approximation, K-L level matching phenomena associated with K-shell vacancy production in heavy-ion collisions, and studies of low energy collisions of electrons with molecules using semi-classical perturbation theory. A brief discussion of each of these activities is given

  12. Biomedical Computing Technology Information Center (BCTIC): Final progress report, March 1, 1986-September 30, 1986

    International Nuclear Information System (INIS)

    During this time, BCTIC packaged and disseminated computing technology and honored all requests made before September 1, 1986. The final month of operation was devoted to completing code requests, returning submitted codes, and sending out notices of BCTIC's termination of services on September 30th. Final BCTIC library listings were distributed to members of the active mailing list. Also included in the library listing are names and addresses of program authors and contributors in order that users may have continued support of their programs. The BCTIC library list is attached

  13. Final Report on Models, Periodic Progress, Report No D1.3, Globeman21, ESPRIT 26509

    DEFF Research Database (Denmark)

    Pedersen, Jens Dahl; Tølle, Martin; Vesterager, Johan

    1999-01-01

    This deliverable D1.3 is the third and final deliverable of WP1 - Global Manufacturing Concept of the European part of the Globeman21 project. The report essentially presents the final models on generic Extended Enterprise Management (EEM) and generic Product Life Cycle Management (PLCM......), a collection of practical experiences, and requirements for enhanced methods and tools for modelling. First, the deliverable outlines the GM21 understanding regarding extended enterprises and virtual enterprises. This is done by extracting and synthesising the essence of key definitions and concepts...... Framework forms the common structure for the work and results of this deliverable. The deliverable furthermore discusses work preparation as an important activity in extended enterprise planning. In this relation different forms of work preparation are introduced and discussed leading to a specific...

  14. Experimental Program Final Technical Progress Report: 15 February 2007 to 30 September 2012

    Energy Technology Data Exchange (ETDEWEB)

    Kinney, Edward R. [University of Colorado, Boulder, CO

    2014-09-12

    This is the final technical report of the grant DE-FG02-04ER41301 to the University of Colorado at Boulder entitled "Intermediate Energy Nuclear Physics" and describes the results of our funded activities during the period 15 February 2007 to 30 September 2012. These activities were primarily carried out at Fermilab, RHIC, and the German lab DESY. Significant advances in these experiments were carried out by members of the Colorado group and are described in detail.

  15. Research progress on intracellular bacteria of the genus Wolbachia%细胞内共生菌Wolbachia研究进展

    Institute of Scientific and Technical Information of China (English)

    周丹; 朱颖; 李朋玲; 高琼; 朱昌亮

    2010-01-01

    Intracellular rickettsial bacteria of the genus Wolbachia are found in numerous invertebrates including insects and nematodes. In their insect hosts, Wolbachia often manipulate the reproductive mode of their hosts, causing cytoplasmic incompatibility(CI), parthenogenesis induction(PI), feminization of genetic,or male killing(MK). Many studies have determined that filarial pathogenesis were reliant on this endosymbiont for embryogenesis, growth and survival. Additional researches have also focused on determining the role of Wolbachia in horizontal gene transfer, antiviral responses, potential applications in pest and disease vector control,speciation and so on. This review summarized the significant advances in the study of Wolbachia. Future research directions of this interesting intracellular rickettsial bacteria are also discussed.%Wolbachia是一类广泛共生于节肢动物和线虫体内的立克次体,能够通过细胞质不亲和、孤雌生殖、雄性雌性化和杀雄等多种机制调控节肢动物的生殖行为,并在丝虫发育、生殖和致病过程中发挥重要作用.近年来的研究结果显示Wolbachia在水平基因转移、抗病毒作用、物种进化等方面亦具有重要价值.该文对Wolbachia近年研究成果进行综述,重点介绍其生物学特征、传播方式、对共生宿主的影响作用及其意义,初步探讨了其在媒介生物防治与相关疾病控制中的潜在价值.

  16. [Tampa Electric Company IGCC project]. Final public design report; Technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

    This final Public Design Report (PDR) provides completed design information about Tampa Electric Company`s Polk Power Station Unit No. 1, which will demonstrate in a commercial 250 MW unit the operating parameters and benefits of the integration of oxygen-blown, entrained-flow coal gasification with advanced combined cycle technology. Pending development of technically and commercially viable sorbent for the Hot Gas Cleanup System, the HGCU also is demonstrated. The report is organized under the following sections: design basis description; plant descriptions; plant systems; project costs and schedule; heat and material balances; general arrangement drawings; equipment list; and miscellaneous drawings.

  17. Comparative biochemistry and physiology of iron-respiring bacteria from acidic and neutral-pH environments: Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Magnuson, T S

    2009-04-07

    Acidophilic dissimilatory iron-reducing bacteria (DIRB) are now being detected in a variety of ‘extreme’ low-pH, radionuclide- and heavy-metal contaminated habitats where Fe(III) reduction is taking place, and may represent a significant proportion of metal-transforming organisms in these environments. Acidiphilium cryptum is our model organism, a facultative iron-respiring Alphaproteobacterium. Major findings of this project have been 1) Discovery of novel outer-membrane and periplasmic cytochromes c in acidophiles that are reactive with Fe and Cr, 2) Discovery of Cr(VI) reduction mechanisms in acidophiles, mediated by c-type cytochromes and other reductase activity, 3) Development of enzyme detection methods specific for Cr-reducing enzymes, 4) Characterization of biofilm formation in A. cryptum, and 5) Annotation of the Acidiphilium cryptum genome (Magnuson, Kusel, and Cummings, DOE-JGI 2005-2006). Two manuscripts and one book chapter have been published, and several more mauscripts are prepared for submission.

  18. Biologic considerations in anatomic imaging with radionuclides. Final progress report, July 1974--June 1975

    International Nuclear Information System (INIS)

    An important task relating to anatomic imaging with radionuclides is the determination of factors which effect the use of imaging procedures. This is important to reduce radiation exposure in the population, to improve the efficacy of diagnostic imaging procedures and finally to provide a basis for evaluating the potential effects of proposed regulation of use rates. In this report we describe a methodology for obtaining clinical data relating to the use of the brain scan in an inner city teaching hospital. The development of a questionnaire suitable for use in a clinical setting and providing both prospective and retrospective data is presented. The results of the use of the questionnaire at the Johns Hopkins Hospital during a three month period in 1974 are shown and discussed. Some preliminary results from these data are given and a method for further analysis is indicated

  19. Final Progress Report: Coupled Biogeochemical Process Evaluation for Conceptualizing Trichloroethylene Cometabolism

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, Ronald L; Paszczynski, Andrzej J

    2010-02-19

    Our goal within the overall project is to demonstrate the presence and abundance of methane monooxygenases (MMOs) enzymes and their genes within the microbial community of the Idaho National Laboratory (INL) Test Area North (TAN) site. MMOs are thought to be the primary catalysts of natural attenuation of trichloroethylene (TCE) in contaminated groundwater at this location. The actual presence of the proteins making up MMO complexes would provide direct evidence for its participation in TCE degradation. The quantitative estimation of MMO genes and their translation products (sMMO and pMMO proteins) and the knowledge about kinetics and substrate specificity of MMOs will be used to develop mathematical models of the natural attenuation process in the TAN aquifer. The model will be particularly useful in prediction of TCE degradation rate in TAN and possibly in the other DOE sites. Bacteria known as methanotrophs produce a set of proteins that assemble to form methane monooxygenase complexes (MMOs), enzymes that oxidize methane as their natural substrate, thereby providing a carbon and energy source for the organisms. MMOs are also capable of co-metabolically transforming chlorinated solvents like TCE into nontoxic end products such as carbon dioxide and chloride. There are two known forms of methane monooxygenase, a membrane-bound particulate form (pMMO) and a cytoplasmic soluble form (sMMO). pMMO consists of two components, pMMOH (a hydroxylase comprised of 47-, 27-, and 24-kDa subunits) and pMMOR (a reductase comprised of 63 and 8-kDa subunits). sMMO consists of three components: a hydroxylase (protein A-250 kDa), a dimer of three subunits (α2β2γ2), a regulatory protein (protein B-15.8 kDa), and a reductase (protein C-38.6 kDa). All methanotrophs will produce a methanol dehydrogenase to channel the product of methane oxidation (methanol) into the central metabolite formaldehyde. University of Idaho (UI) efforts focused on proteomic analyses using mass

  20. Advanced Coal Conversion Process Demonstration Project. Final technical progress report, January 1, 1995--December 31, 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    This report describes the technical progress made on the Advanced Coal Conversion Process (ACCP) Demonstration Project from January 1, 1995 through December 31, 1995. This project demonstrates an advanced, thermal, coal upgrading process, coupled with physical cleaning techniques, that is designed to upgrade high-moisture, low-rank coals to a high-quality, low-sulfur fuel, registered as the SynCoal Process. The coal is processed through three stages (two heating stages followed by an inert cooling stage) of vibrating fluidized bed reactors that remove chemically bound water, carboxyl groups, and volatile sulfur compounds. After thermal upgrading, the coal is put through a deep-bed stratifier cleaning process to separate the pyrite-rich ash from the coal. The SynCoal Process enhances low-rank, western coals, usually with a moisture content of 25 to 55 percent, sulfur content of 0.5 to 1.5 percent, and heating value of 5,5000 to 9,000 British thermal units per pound (Btu/lb), by producing a stable, upgraded, coal product with a moisture content as low as 1 percent, sulfur content as low as 0.3 percent, and heating value up to 12,000 Btu/lb. During this reporting period, the primary focus for the ACCP Demonstration Project team was to expand SynCoal market awareness and acceptability for both the products and the technology. The ACCP Project team continued to focus on improving the operation, developing commercial markets, and improving the SynCoal products as well as the product`s acceptance.

  1. Theoretical studies in nuclear structure. Final progress report, June 1, 1991--July 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Marshalek, E.R.

    1997-06-01

    The general purview of the project is the theory of collective motion in atomic nuclei. The chief aim is to elucidate the phenomena of (1) anharmonic multiphonon excitations, and (2) collective tilted rotation, both of which are topics of considerable current interest. In the primary stage of an investigation it is often necessary to develop appropriate mathematical tools, as was the case here. In the next stage, the formalism must be tested on simple soluble models. The work described here is mainly concerned with these two stages. The final stage of realistic applications will require more time, manpower and, of course, the necessary funding. Some planning for this last stage has been carried out and anticipated problems axe briefly discussed. As it turns out, both of the above topics can be approached within the unified framework of a theorem that I developed, called the Cranking Bifurcation Theorem (CBT) to be described below. The CBT can be regarded as an outgrowth of the boson expansion method, which provides a general, and, in principal, exact formalism for treating collective excitations. We begin with a brief discussion of the CBT and then continue on to the applications.

  2. Light scattering studies of lower dimensional colloidal particle and critical fluid systems. Final progress report

    International Nuclear Information System (INIS)

    We have completed a program of small angle scattering Rayleigh linewidth measurements on thin films of a 2,6-lutidine + water mixture. No statistically significant departures from three dimensional dynamic response were seen, although the conditions set by the theory of Calvo and Ferrell were met. We have applied digital image processing to evaluate fractal scale invariance in two dimensional particle aggregates arising from the induced coagulation of colloidal particle monolayer crystals. Our system gives us the capability of calculating the pair correlation function for both small and very large (2 x 104 particles) particle clusters. We find evidence of an apparent crossover between kinetic clustering aggregation at small distances (about 20 particle diameters) to percolation or gel/sol transition-behavior at large distances. This is evident in both isolated clusters and in final state ''giant'' aggregates. We are carrying through a parallel program of computer calculations whose motivation is to assess the sensitivity of experimental measures of self similarity to cluster size and image resolution, and to generate efficient algorithms which can be applied to calculate fractal ''critical exponents'' other than the Hausdorff dimension. We have succeeded in measuring the surface tension of a water surface covered by a colloidal particle monolayer crystal, in both its repulsive-dipole and close-packed van der Waals phases

  3. Novel catalysts for methane activation. Final progress report, September 30, 1992--April 30, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Hirschon, A.S.; Du, Y.; Wu, H.J.; Malhotra, R.; Wilson, R.B.

    1996-06-11

    This final report summarizes the results of our research under Contract No. DE-AC22-92PC92112, Novel Catalysts for Methane Activation. In this research we prepared and tested fullerene soots for converting methane into higher hydrocarbons. We conducted the methane conversions using dehydrocoupling conditions, primarily in the temperature regimes of 600{degrees}-1000{degrees}C and atmospheric pressures. The research was divided into three sections. The first section focused on comparing fullerene soots with other forms of carbon such as acetylene black and Norit-A. We found that the fullerene soot was indeed more reactive than the other forms of carbon. However, due to its high reactivity, it was not selective. The second section focused on the effect of metals on the reactivity of the soots, including both transition metals and alkali metals. We found that potassium could enhance the selectivities of fullerene soot to higher hydrocarbons, but the effect was unique to fullerene soot and did not improve the performance of other forms of carbon. The third part focused on the use of co-feeds for methane activation to enhance the selectivities and lower the temperature threshold of methane activation.

  4. Coal plasticity at high heating rates and temperatures. Final technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    Gerjarusak, S.; Peters, W.A.; Howard, J.B.

    1995-05-01

    Plastic coals are important feedstocks in coke manufacture, coal liquefaction, gasification, and combustion. During these processes, the thermoplastic behavior of these coals is also important since it may contribute to desirable or undesirable characteristics. For example, during liquefaction, the plastic behavior is desired since it leads to liquid-liquid reactions which are faster than solid-liquid reactions. During gasification, the elastic behavior is undesired since it leads to caking and agglomeration of coal particles which result in bed bogging in fixed or fluidized bed gasifiers. The plastic behavior of different coals was studied using a fast-response plastometer. A modified plastometer was used to measure the torque required to turn at constant angular speed a cone-shaped disk embedded in a thin layer of coal. The coal particles were packed between two metal plates which are heated electrically. Heating rates, final temperatures, pressures, and durations of experiment ranged from 200--800 K/s, 700--1300 K, vacuum-50 atm helium, and 0--40 s, respectively. The apparent viscosity of the molten coal was calculated from the measured torque using the governing equation of the cone-and-plate viscometer. Using a concentrated suspension model, the molten coal`s apparent viscosity was related to the quantity of the liquid metaplast present during pyrolysis. Seven coals from Argonne National Laboratory Premium Coal Sample Bank were studied. Five bituminous coals, from high-volatile to low-volatile bituminous, were found to have very good plastic behavior. Coal type strongly affects the magnitude and duration of plasticity. Hvb coals were most plastic. Mvb and lvb coals, though the maximum plasticity and plastic period were less. Low rank coals such as subbituminous and lignite did not exhibit any plasticity in the present studies. Coal plasticity is moderately well correlated with simple indices of coal type such as the elemental C,O, and H contents.

  5. Research Progress of Aromatic Polyketides in Bacteria%细菌芳香聚酮研究进展

    Institute of Scientific and Technical Information of China (English)

    黄连琴; 黄建忠

    2013-01-01

    鉴于芳香聚酮化合物在抗菌、抗肿瘤、抗病毒等方面具有重要的临床药用价值,该文综述了细菌芳香聚酮化合物及其生物合成研究的主要进展,重点讨论了四类芳香聚酮的生物活性和化学结构以及芳香聚酮生物合成机理研究的基础理论意义。在此基础上对组合生物合成新的具有一定生物活性化合物的研究前景进行了展望。%This article provides a research progress of aromatic polyketide and its biosynthetic logic in light of its significant application pharmaceutically and clinically as noteworthy anticancer,antibacterial,antifungal and antivi-ral substances,with the emphasis on the discussion of four classes of aromatic compounds in bioactivity and chemical structure as well as several fundamental insights on the biosynthetic mechanism.By means of a deeper understanding of the biosynthetic process,it is proposed that combinatorial biosynthesis affords a number of new avenues for creating novel molecular structures that will likely have new biological activity.

  6. Final Progress Report for the NASA Inductrack Model Rocket Launcher at the Lawrence Livermore National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Tung, L S; Post, R F; Martinez-Frias, J

    2001-06-27

    The Inductrack magnetic levitation system, developed at the Lawrence Livermore National Laboratory, was studied for its possible use for launching rockets. Under NASA sponsorship, a small model system was constructed at the Laboratory to pursue key technical aspects of this proposed application. The Inductrack is a passive magnetic levitation system employing special arrays of high-field permanent magnets (Halbach arrays) on the levitating cradle, moving above a ''track'' consisting of a close-packed array of shorted coils with which are interleaved with special drive coils. Halbach arrays produce a strong spatially periodic magnetic field on the front surface of the arrays, while canceling the field on their back surface. Relative motion between the Halbach arrays and the track coils induces currents in those coils. These currents levitate the cradle by interacting with the horizontal component of the magnetic field. Pulsed currents in the drive coils, synchronized with the motion of the carrier, interact with the vertical component of the magnetic field to provide acceleration forces. Motional stability, including resistance to both vertical and lateral aerodynamic forces, is provided by having Halbach arrays that interact with both the upper and the lower sides of the track coils. At present, a 7.8 meter track composed of drive and levitation coils has been built and the electronic drive circuitry performs as designed. A 9 kg cradle that carries the Halbach array of permanent magnets has been built. A mechanical launcher is nearly complete which will provide an initial cradle velocity of 9 m/s into the electronic drive section. We have found that the drag forces from the levitation coils were higher than in our original design. However, measurements of drag force at velocities less than 1 m/s are exactly as predicted by theory. Provided here are recommended design changes to improve the track's performance so that a final velocity of 40

  7. Final Technical Progress Report Long term risk from actinides in the environment: Modes of mobility

    International Nuclear Information System (INIS)

    in diameter and approximately 22 cm long. A thin ''marker layer'' of white soil was added to the top of each column followed by a thin layer of soil that had been spiked with 137Cs, cerium and lanthanum was applied to the surface. Approximately 900 cm of water (the equivalent of about 30 years of rainfall) was then applied at a rate of 3.2 L d-1. All of the activity contained in the soil core appeared to be in the top few mm of soil, i.e. there was virtually no movement of the 134Cs labeled particles. Finally, a library of object-oriented model components was created using Visual Basic to support the construction of contaminant transport models. These components greatly simplify the task of building 1- to 3- dimensional simulation models for risk assessment. The model components created under this funding were subsequently applied to help answer questions regarding risks from irrigation associated with potential releases from the Yucca Mountain waste repository

  8. Final Technical Progress Report Long term risk from actinides in the environment: Modes of mobility

    Energy Technology Data Exchange (ETDEWEB)

    Thomas B. Kirchner

    2002-03-22

    in diameter and approximately 22 cm long. A thin ''marker layer'' of white soil was added to the top of each column followed by a thin layer of soil that had been spiked with 137Cs, cerium and lanthanum was applied to the surface. Approximately 900 cm of water (the equivalent of about 30 years of rainfall) was then applied at a rate of 3.2 L d-1. All of the activity contained in the soil core appeared to be in the top few mm of soil, i.e. there was virtually no movement of the 134Cs labeled particles. Finally, a library of object-oriented model components was created using Visual Basic to support the construction of contaminant transport models. These components greatly simplify the task of building 1- to 3- dimensional simulation models for risk assessment. The model components created under this funding were subsequently applied to help answer questions regarding risks from irrigation associated with potential releases from the Yucca Mountain waste repository.

  9. Final Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, Herbert J

    2012-02-06

    The BIOMOL grant was for 'Local System Support for PDB Biological Unit Search and Display' to augment Rasmol's [Bernstein 2000] [Sayle, Milner-White 1995] existing macromolecular display functions with new capabilities by taking advantage of recent increases in local computing power in order to move functionality that is now scattered among various local and remote systems into one local package. Work included new algorithms for molecular surface display, an extended format for Protein Data Bank Entries, work on issues relating to the integration of multiple diffraction images formats.

  10. Final Technical Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    J.Y. Hwang; R.C. Greenlund

    2002-12-31

    Michigan Technological University has demonstrated major inroads in establishing the viability of utilizing aluminum smelting by-product waste materials in lightweight concrete product applications. The research identified key elements of producing various forms of lightweight concrete products through utilizing various procedures and mixture components with the by-product materials. A process was developed through pilot plant testing that results in additional aluminum recovery at finer sizes, a clean returnable salt product through spray drying technology, and a low-salt-content oxide product with enough aluminum metal content that it can be used to form lightweight cementitious mixtures. Having three distinct products aids in generating favorable process economics. Revenue projections from aluminum recovery and salt recovery are enough to cover processing costs and create a cost-free oxide product to market for lightweight concrete applications. This supply side commercialization strategy offers aluminum by-product recyclers a potentially no cost product, which has been demonstrated through this project to create desirable and marketable lightweight concrete products of various forms. Environmental benefits to the public are tremendous. At best, all dross and salt cake materials have the potential to be completely recycled and utilized. At worst, disposal sites would see a reduced amount of material: a post processed oxide product with little salt and no hydrogen sulfide or ammonia gas generating capability, which, if isolated from high alkali conditions, would pose no reactivity concerns. The US aluminum industry has historically, along with the steel industry, been a leader in recycling metal. The findings from this project, increased metal recovery, improved salt recycling, and demonstrated end uses for oxide residues, will go a long way in helping the aluminum industry obtain 100% material utilization and zero discharge.

  11. Final Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Kotov, Valeri [Univ. of Vermont, Burlington, VT (United States)

    2016-05-29

    The research in this program involves theoretical investigations of electronic, optical and mechanical properties of graphene and its derivatives, such as bi-layer graphene, graphene-based van der Waals heterostructures, strained graphene, as well as graphene on various surfaces. One line of research has been development of theoretical models that support graphene’s large array of possible technological applications. For example one of our goals has been the understanding of surface plasmons and spin relaxation mechanisms in graphene, related to novel optoelectronics and spintronics applications. Our current research focus is on understanding the role of correlations in graphene under mechanical deformations, such as strain. The main goal is to describe the mutual interplay between strain and electron-electron interactions which could lead to the formation of novel elec- tronic phases with strongly modified electronic, magnetic and optical properties. This direction of research contributes to deeper understanding of interactions in graphene and related atomically-thin materials - a subject at the forefront of research on graphene and its derivatives.

  12. Central receiver solar thermal power system, Phase 1. Quarterly progress report (final) for period ending March 31, 1976

    Energy Technology Data Exchange (ETDEWEB)

    None

    1976-10-01

    During this period (January 1976 through March 1976), the primary program effort was expended toward the completion of the detail design of the three major research experiments. Also, the Preliminary Pilot Plant Economic Cost Study was completed. In the Collector Subsystem, the designs for both the twenty-five mirror and the nine-mirror heliostats were completed and released. In the Receiver Subsystem, Foster Wheeler continued with the detail design of the 5 MW research experiment receiver. A preliminary draft of the detailed test plan for the receiver subsystem research experiment was prepared and is now undergoing a final review. The detailed design of the Thermal Storage Subsystem continued at Georgia Institute of Technology. Several incremental detail design reviews were held as the design progressed. During this period, Bechtel completed the preliminary environmental analysis for the Pilot Plant. The optimization studies of the electrical power generation subsystem were initiated. A major effort was the preparation of the preliminary cost analysis for the 10 MWe Central Receiver Solar Thermal Pilot Plant. This task required the development of a cost accounting structure and a definition of all of the costs associated with the design, construction, checkout, and two-year test of the Pilot Plant. (WDM)

  13. 乳酸菌细菌素应用研究进展%Progress of Application Research on Lactic Acid Bacteria Bacteriocin

    Institute of Scientific and Technical Information of China (English)

    徐炳政; 王颖; 梁小月; 张东杰; 张桂芳

    2015-01-01

    The inhibitory metabolites from fermentation process of lactic acid bacteria included organic acid and bacteriocin,and bacteriocins from LAB have been concerned as the biological bacteriostat in recent years. This article briefly expounded the general classifications of bacteriocins from LAB,and focused on summarizing application progress of bacteriocins from LAB in the food industry,biological medicine industry and animal husbandry,and discussed its application safety and the existing problems in the present research. The bacteriocins from LAB as a kind of natural food preservative would be very broadly applied in the future.%乳酸菌发酵过程中的抑菌代谢产物包括有机酸和细菌素,乳酸菌细菌素作为一类生物抑菌剂近年来得到了广泛关注。文章简述了乳酸菌细菌素通用分类方式,着重综述了乳酸菌细菌素在食品工业、生物医药及畜牧养殖领域的应用进展,同时探讨了其应用安全性及目前研究中所存在的问题。相信不久的将来乳酸菌细菌素作为一类理想的天然食品防腐剂,应用前景将十分广阔。

  14. Research progress on antagonistic bacteria against Phytophthora infestans%致病疫霉颉颃细菌研究进展

    Institute of Scientific and Technical Information of China (English)

    黄英菊; 蒋继志; 冯丽娜; 赵偲

    2013-01-01

    致病疫霉可引起马铃薯和番茄晚疫病,常造成巨大损失,生产中主要依靠抗病品种和化学农药防治。但因病菌生理分化明显、遗传变异迅速,已出现能克服现有全部抗病基因的菌株,且抗药性日益突出,致使该病难以完全有效地得到控制。发掘致病疫霉颉颃微生物,并研发安全、高效的微生物农药是当前的研究热点之一。结合笔者开展的研究工作,就近年来国内外对致病疫霉颉颃细菌的筛选、颉颃物质及其作用机制等进行了综述。同时,对该领域当前存在的一些问题和今后的研究重点进行了讨论,以期加快对致病疫霉颉颃细菌的利用。%Phytophthora infestans caused late blight of potato and tomato, often caused a great loss. Resistant varieties and pesticides were current main measures for controlling late blight of potato and tomato. Because of obvious physiological differentiation and quick hereditary variation of P. infestans, some new strains with strong chemicals resistance appeared in many potato production areas could overcome existing resistance genes. Research progress on screening of antagonistic bacteria, active substances and action mechanisms on P. infestans in recent years at home and abroad was reviewed, and some problems in this field and research highlight in future were discussed, which could contribute to its utilizations.

  15. 乳酸菌降低胆固醇作用及其机理的研究进展%Progress in the Effect of Lactic Acid Bacteria on Cholesterol-lowering and Its Mechanism

    Institute of Scientific and Technical Information of China (English)

    路四海; 赵瑞香; 牛生洋; 袁峥

    2012-01-01

    乳酸菌及其相关制品具有降低介质以及血清中胆固醇的能力,巳被体内及体外的大量实验所证实。就国内外关于乳酸菌在体内及体外降低胆固醇作用的研究进展进行了综述,在此基础上对其作用机理进行了探讨,并提出了目前研究中存在的一些问题,以期对乳酸菌资源的进一步开发和利用提供帮助。%Numerous evidences in vivo and vitro have showed that administration of lactic acid bacteria and relat- ed products were able to reduce medium and serum cholesterol. We reviewed the research progress in lactic acid bacteria which could reduce the cholesterol in vivo and vitro, and also discussed the mechanism of lactic acid bacteria in reducing cholesterol, proposed some issues existed in the current research, hoping this will be useful for the exploitation and utilization of lactic acid bacteria.

  16. The research and development progress of cholesterol-lowering Lactic acid bacteria%具有降胆固醇作用乳酸菌的研究和开发进展

    Institute of Scientific and Technical Information of China (English)

    杨晶; 杨庆

    2011-01-01

    This paper reviewed the research progress in lactic acid bacteria which can reduce the cholesterol in vivo and in vitro. It also approached the function and the mechanism of lactic acid bacteria in decreasing serum cholesterol, and summarized the application of cholesterol-lowering lactic acid bacteria in food fermentation and medical care and proposed the emphasis for future research. All these will be useful to the exploitation and utilization of lactic acid bacteria.%本文综述了国内外关于具有降胆固醇作用的乳酸菌的降胆固醇作用和作用机制的研究进展,同时总结了降胆固醇乳酸菌在食品发酵和医疗保健方面的应用,提出以后研究的重点,以期对乳酸菌的进一步开发和利用提供帮助.

  17. Low-dose fractionated radiotherapy and concomitant chemotherapy for recurrent or progressive glioblastoma. Final report of a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Balducci, M.; Diletto, B.; Chiesa, S.; D' Agostino, G.R.; Gambacorta, M.A.; Ferro, M.; Valentini, V. [Catholic University of the Sacred Heart, Department of Radiation Oncology, Rome (Italy); Colosimo, C. [Catholic University of the Sacred Heart, Department of Radiology, Rome (Italy); Maira, G.; Anile, C. [Catholic University of the Sacred Heart, Department of Neurosurgery, Rome (Italy)

    2014-04-15

    Evaluated in this study were the feasibility and the efficacy of concurrent low dose fractionated radiotherapy (LD-FRT) and chemotherapy as palliative treatment for recurrent/progressive glioblastoma multiforme (GBM). Eligible patients had recurrent or progressive GBM, Karnofsky performance status ≥70, prior surgery, and standard radiochemotherapy treatment. Recurrence/progression disease during temozolomide (TMZ) received cisplatin (CDDP; 30 mg/m{sup 2} on days 1, 8, 15), fotemustine (FTM; 40 mg/m{sup 2} on days 2, 9, 16), and concurrent LD-FRT (0.3 Gy twice daily); recurrence/progression after 4 months from the end of adjuvant TMZ were treated by TMZ (150/200 mg/m{sup 2} on days 1-5) concomitant with LD-FRT (0.4 Gy twice daily). Primary endpoints were safety and toxicity. A total of 32 patients were enrolled. Hematologic toxicity G1-2 was observed in 18.7% of patients and G3-4 in 9.4%. One patient (3.1%) had complete response, 3 (9.4%) had partial response, 8 (25%) had stable disease for at least 8 weeks, while 20 patients (62.5%) experienced progressive disease. The clinical benefit was 37.5%. Median progression-free survival (PFS) and overall survival (OS) were 5 and 8 months, respectively. Survival rate at 12 months was of 27.8%. LD-FRT and chemotherapy for recurrent/progressive GBM have a good toxicity profile and clinical outcomes, even though further investigation of this novel palliative treatment approach is warranted. (orig.)

  18. Some aspects of the mechanism of bacteriophage function. Final progress report. [Mechanisms of inactivation of bacteriophages by ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Freifelder, D.

    1977-06-12

    Data are summarized from a ten-year study on the radiobiology of phages. The results showed that: phages are inactivated principally by damage to DNA; DNA damage is of two types, base damage and double-strand breakage; double-strand breakage may be lethal because of interruption within a gene, however in phage systems the damage is more fundamental in that only a single DNA fragment is injected into the host; E. coli phage T4 is relatively resistant to inactivation by x-rays; and the rate of production of strand breaks and base damage is nearly the same in bacteriophage and bacteria.

  19. Final Technical Progress Report; Closeout Certifications; CSSV Newsletter Volume I; CSSV Newsletter Volume II; CSSV Activity Journal; CSSV Final Financial Report

    Energy Technology Data Exchange (ETDEWEB)

    Houston, Johnny L [PI; Geter, Kerry [Division of Business and Finance

    2013-08-23

    This Project?s third year of implementation in 2007-2008, the final year, as designated by Elizabeth City State University (ECSU), in cooperation with the National Association of Mathematicians (NAM) Inc., in an effort to promote research and research training programs in computational science ? scientific visualization (CSSV). A major goal of the Project was to attract the energetic and productive faculty, graduate and upper division undergraduate students of diverse ethnicities to a program that investigates science and computational science issues of long-term interest to the Department of Energy (DoE) and the nation. The breadth and depth of computational science?scientific visualization and the magnitude of resources available are enormous for permitting a variety of research activities. ECSU?s Computational Science-Science Visualization Center will serve as a conduit for directing users to these enormous resources.

  20. Research Progress of Lactic Acid Bacteria Application to Cider Brewing%乳酸菌在苹果酒中的应用研究进展

    Institute of Scientific and Technical Information of China (English)

    吕兆林; 姚永红; 林西; 任美玲; 张柏林

    2012-01-01

    通过添加乳酸茵,苹果酒在主发酵后能继续进行二次发酵,即苹果酸-乳酸发酵,该过程具有增加苹果酒风味多样性的作用.论述在苹果酒中添加乳酸茵的菌种要求、发酵条件对乳酸茵诱导苹果酸-乳酸发酵的影响,及乳酸茵与苹果酒感官和风味的关系.%The secondary fermentation, i. e. , malolactic fermentation (MLF) could take place in the cider after the primary fermentation if lactic acid bacteria were added, which could improve the flavor diversity of the cider , making the taste softer and weakening the influence of styphnic acid. The requirements for the lactic acid bacteria which could be added to cider, the influence of different fermentation conditions on induction of the lactic acid bacteria to motivate malolactic fermentation and the correlations between the lactic acid bacteria and the flavor and other properties of cider were discussed in the paper.

  1. Final Progress Report for Collaborative Research: Aging of Black Carbon during Atmospheric Transport: Understanding Results from the DOE’s 2010 CARES and 2012 ClearfLo Campaigns

    Energy Technology Data Exchange (ETDEWEB)

    Mazzoleni, Claudio [Michigan Technological Univ., Houghton, MI (United States); Subramanian, R. [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    2016-08-31

    Over the course of this project, we have analyzed data and samples from the Carbonaceous Aerosol and Radiative Effects Study (CARES) and the Clear air for London (ClearfLo) campaign, as well as conducted or participated in laboratory experiments designed to better understand black carbon mixing state and climate-relevant properties. The laboratory campaigns took place at the Pacific Northwest National Laboratory and Carnegie Mellon University to study various climate-relevant aerosol properties of different sources of soot mixing with secondary organic aerosol precursors. Results from some of these activities were summarized in the previous progress report. This final report presents the manuscripts that have been published (many in the period since the last progress report), lists presentations at different conferences based on grant-related activities, and presents some results that are likely to be submitted for publication in the near future.

  2. Methanotrophic bacteria.

    OpenAIRE

    Hanson, R S; Hanson, T. E.

    1996-01-01

    Methane-utilizing bacteria (methanotrophs) are a diverse group of gram-negative bacteria that are related to other members of the Proteobacteria. These bacteria are classified into three groups based on the pathways used for assimilation of formaldehyde, the major source of cell carbon, and other physiological and morphological features. The type I and type X methanotrophs are found within the gamma subdivision of the Proteobacteria and employ the ribulose monophosphate pathway for formaldehy...

  3. 生物膜内自养硝化菌与异养菌竞争关系的研究进展%Progress on Competition between Autotrophic Nitrifying Bacteria and Heterotrophic Bacteria in Biofilm

    Institute of Scientific and Technical Information of China (English)

    殷峻; 徐恒娟

    2013-01-01

    As one of efficient technologies in biological removal of organic matter and nitrogen,biofilm technology has been widely applied to the industrial and domestic wastewater treatment in the past decades.But during the practical wastewater treatment,insufficient and instable nitrogen removal often occurs.At present,many research mainly focused reactor performance,biofilm formation,hydrodynamics,mass transfer and reaction kinetics in the biofilm reactor.However,the competition between different microorganisms directly affects morphology,stability and conversion efficiency of biofilm.In this paper,the affecting factors were discussed,especially competition between autotrophic nitrifying bacteria and heterotrophic bacteria.Future issues were also proposed.%生物膜工艺作为一种高效的生物除碳脱氮技术,近20年来被广泛应用于工业废水和城市生活污水的生物处理.但在实际污水处理过程中,生物膜系统往往会出现脱氮效果不稳定的情况.目前大量的研究工作主要集中在系统的处理效率、生物膜形成、流体力学、传质以及反应动力学特性等方面.而生物膜内微生物之间的竞争关系直接影响到生物膜的形态、稳定性以及转化效率.本文针对生膜工艺及其影响因素对生物膜中自养硝化菌和异养菌竞争的研究进展进行了综述,并提出了值得进一步研究的内容.

  4. Fusion reactor systems studies. Progress report for the period November 1, 1996--October 31, 1997, and final report

    International Nuclear Information System (INIS)

    During FY97, the University of Wisconsin Fusion Technology Institute personnel have participated in the ARIES-RS and the ARIES-ST projects. The main areas of effort are: (1) neutronics analysis; (2) shielding of components and personnel; (3) neutron wall loading distribution; (4) radiation damage to in-vessel components; (5) components lifetimes; (6) embrittled materials designs issues; (7) stress and structural analysis; (8) activation, LOCA, and safety analysis; (9) support and fabrication of components; (10) vacuum system; and (11) maintenance. Progress made in these areas are summarized

  5. Fusion reactor systems studies. Progress report for the period November 1, 1996--October 31, 1997, and final report

    Energy Technology Data Exchange (ETDEWEB)

    El-Guebaly, L.A.; Blanchard, J.P.; Kulcinski, G.L.

    1997-08-01

    During FY97, the University of Wisconsin Fusion Technology Institute personnel have participated in the ARIES-RS and the ARIES-ST projects. The main areas of effort are: (1) neutronics analysis; (2) shielding of components and personnel; (3) neutron wall loading distribution; (4) radiation damage to in-vessel components; (5) components lifetimes; (6) embrittled materials designs issues; (7) stress and structural analysis; (8) activation, LOCA, and safety analysis; (9) support and fabrication of components; (10) vacuum system; and (11) maintenance. Progress made in these areas are summarized.

  6. Third annual progress report on the electrofluid dynamic wind generator. Final report, September 15, 1977-September 30, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Minardi, J.E.; Lawson, M.O.; Wattendorf, F.L.

    1979-05-01

    The objective of the program is to conduct research leading to the development of EFD wind driven generators. In such generators, the wind blows through suitably oriented arrays of electrodes, transports charged particles against an electrical potential gradient, and thereby generates electrical power directly without moving parts. Significant progress has been made in accomplishing major research objectives. During the past year, the effort was directed toward the achievement of three milestones, namely: development of a laboratory method for the production of an adequate supply of suitably low mobility charged droplets for the testing of generator performance; experimental verification of generator performance theory; and development of methods for practical production of charged droplets.

  7. 细菌碳代谢抑制作用的研究进展%Research Progress on Carbon Catabolite Repression Control in Bacteria

    Institute of Scientific and Technical Information of China (English)

    林文娜; 李亮; 王瑞; 韩云蕾; 代淑贤; 平淑珍; 金芜军; 燕永亮

    2011-01-01

    When exposed to a medium with multi-carbon sources, most bacteria can use one preferred carbon source and prevent the metabolism and utilization of other compounds through decreasing the expression of corresponding genes by repression protein of carbon metabolism. This is called as carbon catabolism repression and widespread in bacteria, which is one of the hotspot of microbe metabolizability research. Through selective utilization of the carbon sources, bacteria obtain high competition and adaptation ability in their living niches. The protein of catabolism repression could play a role through complicated regulation systems, including transcription of activation or repression and control translation of related genes. There are some differences between the class of acting proteins and mechanisms in different bacteria. This review summarized some kind of acting proteins and mechanisms of CRC,which contributed to convince the environment adaption and metabolic diversity and the molecular regulation of carbon metabolism in bacteria.%当生长介质中存在多种碳源时,细菌通常选择利用某一种优先碳源,同时在碳代谢抑制蛋白参与下抑制其他碳源的代谢和利用.这种碳代谢抑制现象广泛存在于细菌中,是当前微生物代谢研究的热点和前沿之一.通过对碳源的选择性优先利用,细菌可以在生存环境中保持高度的竞争力和环境适应能力.碳代谢抑制蛋白通过复杂的调控网络发挥作用,主要通过转录水平上的激活/抑制或者与RNA结合蛋白的翻译控制等方式进行.在不同微生物中,碳代谢抑制蛋白的种类及其作用机制存在一定的差异.综述了目前研究较为深入的几种细菌中的碳代谢抑制蛋白及其作用机制,将有助于深化微生物的环境适应性,代谢多样性和碳代谢分子调控的认识.

  8. IDENTIFICATION OF BACTERIA IN LATEX PAINTS

    Directory of Open Access Journals (Sweden)

    Rojas, J.

    2008-01-01

    Full Text Available The bacteria are prokaryote organisms with a high capacity to colonize many types of habits. This research was developed with the object to identify extremophiles bacteria presents in latex paint. The bacteria were cultivated in culture mediums TSA, Blood Agar, Mc Conkey and finally the biochemical proof API-NF® for bacteria's isolation and identification, respectively. Characterization showed bacterial profile of Pasteurella sp. Hypothesis that could be found extremophiles bacteria in latex paint were demonstrated.

  9. 真菌和细菌联合处理染料废水的研究进展%Research progress in the combined treatment of dye wastewater with fungi and bacteria

    Institute of Scientific and Technical Information of China (English)

    谭靓; 宁淑香

    2013-01-01

    Dyestuff-containing wastewater is a kind of typical refractory industrial wastewater,which is a challenge to traditional biological processes.The biological treatment process with the combination of fungi and bacteria is a novel technique combining the advantages of both fungi and bacteria in the decomposition course of organisms.The mechanisms of using fungi and bacteria for the combined treatment of organic pollutants are analyzed,according to the organic matter degradation mechanism by using fungi and its enzyme system.Based on the above explanation,the research progress in the combined treatment of dye wastewater by using fungi and bacteria is reviewed.The related research direction and its application prospect of this technique in the future are pointed out.%染料废水是一类典型的难降解工业废水,对传统生物处理技术提出了挑战.真菌和细菌联合处理技术是一项新兴的污水生物处理技术,结合了细菌和真菌各自在有机物分解过程中的优势.通过真菌对有机物的降解机理及其酶系,分析了利用真菌和细菌联合处理有机污染物的机理,在此基础上综述了利用真菌和细菌联合处理染料废水的研究进展,并指出了今后的相关研究方向及该项技术的应用前景.

  10. 冰核活性细菌的研究进展及其开发前景%Studies on the Progress of Ice Nucleation Active Bacteria and its Application Prospective

    Institute of Scientific and Technical Information of China (English)

    高秀芝; 陈庆森

    2001-01-01

    A new research field about ice nucleation active (INA) bacteria and INA protein has been studied in American,Japan,Canada and other countries. Since INA bacteria was first detected by L.R.Maki in 1974.Bacterial ice nucleation has been applied to agriculture, food, medicine,entertainment and many other fields. Studies of INA bacteria in our country began in 1986.Our studies were mainly concerned about the species and their distributions on pattern,insect pests control by accelerating their frozen point with INAbacteria. This paper reported the progress on the studies of INA bacteria and INA protein. Its prospective development and application were also discussed.%自1974年发现冰核活性细菌(ice nucleation active bacteria,简称INA细菌)以来,美国、日本等20多个国家分别对冰核活性细菌及冰核活性蛋白进行了多方面的研究,并且逐步将其应用于农业、娱乐业、食品行业等领域。我国自1986年起开始了对冰核细菌的研究,研究主要集中在种群分布、植物保护、人工降雪等方面。本文从冰核活性蛋白的分子生物学基础出发,对冰核活性细菌的研究进展及开发应用前景进行论述。

  11. The research progress in Wolbachia bacteria in the parasitic wasps%寄生蜂体内共生菌Wolbachia研究进展

    Institute of Scientific and Technical Information of China (English)

    刘淑平; 徐红星; 郑许松; 吕仲贤

    2011-01-01

    Wolbachia is a kind of cytoplasmically inherited bacteria and widely found in reproductive tissues of arthropods. Wolbachia have evolved various mechanisms on manipulating reproduction of their hosts, including induction of cytoplasmic incompatipility (CI), parthenogenesis inducing (PI), genetic male feminization and male killing. Wolbachia species distribution and differentiation, transmission ways in or between host parasitoids and their impact in the biological characteristics of infested parasitoids were summarized, meanwhile the effect of temperature on the performances of parasitic wasps through Wolbachia bacteria was expounded. The potential capacities of parasitoids in insect pest natural control enhanced by genetically manipulating Wolbachia bacteria in parasitic wasps were discussed also.%Wolbachia是广泛分布在节肢动物生殖组织中的细胞质遗传细菌,在寄生蜂中可以通过诱导胞质不亲和、孤雌生殖、雄性雌性化和杀雄等多种方式调节寄主的生殖.本文在综述了寄生蜂体内共生菌Wolbachia的类群和分化、传播方式及其对寄主生物学特性的影响、温度通过对Wolbachia的作用而影响寄生蜂的表现等基础上,讨论了如何利用寄生蜂体内Wolbachia提高寄生蜂自然控制害虫的能力.

  12. Final Progress Report: FRACTURE AND SUBCRITICAL DEBONDING IN THIN LAYERED STRUCTURES: EXPERIMENTS AND MULTI-SCALE MODELING

    Energy Technology Data Exchange (ETDEWEB)

    Reinhold H. Dauskardt

    2005-08-30

    Final technical report detailing unique experimental and multi-scale computational modeling capabilities developed to study fracture and subcritical cracking in thin-film structures. Our program to date at Stanford has studied the mechanisms of fracture and fatigue crack-growth in structural ceramics at high temperature, bulk and thin-film glasses in selected moist environments where we demonstrated the presence of a true mechanical fatigue effect in some glass compositions. We also reported on the effects of complex environments and fatigue loading on subcritical cracking that effects the reliability of MEMS and other micro-devices using novel micro-machined silicon specimens and nanomaterial layers.

  13. 乳酸菌分类鉴定方法的研究进展%Progress in research on lactic acid bacteria identification methods

    Institute of Scientific and Technical Information of China (English)

    庞会利; 谈重芳; 蔡义民; 秦广雍

    2009-01-01

    This paper provides an overview of phenotypic and genotype techniques that are currently used for identification of LAB, and the merit and shortcoming of all kinds of methods are summerized.The conventional phenotypes based on the physiological and biochemical characteristics of lactic acid bacteria identification not only time-consuming but also sometimes difficult to work out.With the development of molecular techniques and genetic database, using a combination of molecular markers, emerging identification technologies and conventional methods will enable the classification and identification of lactic acid bacteria more accurate and convenient.%对目前使用的乳酸菌表型特征鉴定和基因型特征鉴定方法的优缺点进行了综述.依据表型的常规生理生化特征进行乳酸菌的分类鉴定不仅费时,有时甚至难以完成.随着分子生物技术的发展和基因数据库的建立,将分子标记技术、新兴鉴定技术与常规方法结合使用,将使乳酸菌的分类、鉴定更为准确和便捷.

  14. Progresses in Application of Photosynthetic Bacteria in Environmental Remediation%光合细菌在环境修复中的研究进展

    Institute of Scientific and Technical Information of China (English)

    陈莎; 刘勇

    2012-01-01

    A photosynthetic bacterium is a class of special anaerobic microorganism which can carry on photosynthesis, and it has played a very important role in environmental remediation due to its unique physiological and biochemical characteristics. The applications of photosynthetic bacteria in the treatments for high-concentration of organic wastewater, soil heavy metal contamination, degradation of organophosphorus pesticide, etc. in recent years were reviewed. In the end, the application prospect and developmental direction of photosynthetic bacteria in environmental remediation are forecasted.%光合细菌是在自然界中能进行光合作用的一类特殊厌氧微生物,其独特的生理生化特性,使得其在环境修复中发挥着十分重要的作用.对近年来光合细菌在处理高浓度有机废水、土壤重金属污染治理、有机磷农药降解及养殖水体的净化等方面的应用进行了综述,最后对光合细菌在环境修复中的应用前景和发展方向进行了展望.

  15. Positron tomographic imaging of tumors using monoclonal antibodies. Final progress report, April 15, 1989--October 31, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Zalutsky, M.R.

    1997-02-01

    The overall objective of this research is to develop methods for utilizing positron emission tomography (PET) to increase the clinical potential of radiolabeled monoclonal antibodies (MAbs). Enhancement of MAb tumor localization by hyperthermia also was proposed. Studies were to have been performed with both {sup 18}F and {sup 124}I; however, the lack of its availability (until quite recently) prevented experiments with {sup 124}I. Instead, two additional lines of inquiry were initiated in which they utilized aspects of the radiofluorination chemistries originally developed for MAbs for labeling chemotactic peptides and meta-iodobenzylguanidine (MIBG) analogues with {sup 18}F. This final report summarizes the original specific aims and the main research accomplishments in studies of mouse, dog and human models.

  16. Positron tomographic imaging of tumors using monoclonal antibodies. Final progress report, April 15, 1989--October 31, 1995

    International Nuclear Information System (INIS)

    The overall objective of this research is to develop methods for utilizing positron emission tomography (PET) to increase the clinical potential of radiolabeled monoclonal antibodies (MAbs). Enhancement of MAb tumor localization by hyperthermia also was proposed. Studies were to have been performed with both 18F and 124I; however, the lack of its availability (until quite recently) prevented experiments with 124I. Instead, two additional lines of inquiry were initiated in which they utilized aspects of the radiofluorination chemistries originally developed for MAbs for labeling chemotactic peptides and meta-iodobenzylguanidine (MIBG) analogues with 18F. This final report summarizes the original specific aims and the main research accomplishments in studies of mouse, dog and human models

  17. Research Progress on Methanotrophic Bacteria in Landfills and the Reduction of Methane Emission%垃圾填埋场甲烷氧化菌及甲烷减排的研究进展

    Institute of Scientific and Technical Information of China (English)

    王晓琳; 曹爱新; 周传斌; 赵恺凝; 赵国柱

    2016-01-01

    As the main source of anthropogenic methane emission,landfills globally produce 35-69 Tg methane per year. The technology of reducing the methane emission in landfills has become a hot topic at present. Methanotrophic bacteria decomposing methane are the important biological collection to reduce atmospheric methane emissions,which is of significance in keeping the balance of the methane concentration in the atmosphere. Starting from the taxonomy and characteristics of methanotrophic bacteria,and the mechanism of its oxidizing methane, we summarized the latest research progress on the methods of studying diversity,factors affecting the activities of methanotrophic bacteria in landfills,and applications of them in the biological reduction of methane emission. Based on the prior researches,the issues in current studies of methanotrophic bacteria are also discussed. We propose comprehensive measures of utilizing the complex microbial agents of methanotrophic bacteria in landfills,providing a new thought in the research and application of reducing methane emission in landfills.%垃圾填埋场是全球最重要的人为甲烷排放源之一,其全球年甲烷释放量为35-69 Tg,垃圾填埋场甲烷减排是目前全球温室气体研究的热点。甲烷氧化菌能够氧化分解甲烷,作为减少大气甲烷排放的重要生物汇,对保持大气中甲烷浓度的平衡具有重要意义。从甲烷氧化菌的类型及其特征、甲烷氧化机理着手,介绍了多样性研究方法、填埋场中甲烷氧化菌的活性影响因素及甲烷生物减排应用等最新研究进展。在综述前人研究的基础上,探讨了目前研究的不足,提出了利用甲烷氧化菌复合微生物菌剂等综合处理措施,旨为垃圾填埋场甲烷减排的研究和应用提供新的思路。

  18. Measurement and apportionment of radon source terms for modeling indoor environments. Final progress report, March 1990--August 1992

    Energy Technology Data Exchange (ETDEWEB)

    Harley, N.H.

    1992-12-31

    During the present 2 1/2 year contract period, we have made significant Progress in modeling the source apportionment of indoor {sup 222}Rn and in {sup 222}Rn decay product dosimetry. Two additional areas were worked on which we believe are useful for the DOE Radon research Program. One involved an analysis of the research house data, grouping the hourly house {sup 222}Rn measurements into 2 day, 7 day and 90 day intervals to simulate the response of passive monitors. Another area requiring some attention resulted in a publication of 3 years of our indoor/outdoor measurements in a high-rise apartment. Little interest has been evinced in apartment measurements yet 20% of the US population lives in multiple-family dwellings, not in contact with the ground. These data together with a summary of all other published data on apartments showed that apartments have only about 50% greater {sup 222}Rn concentration than the measured outdoor {sup 222}Rn. Apartment dwellers generally represent a low risk group regarding {sup 222}Rn exposure. The following sections describe the main projects in some detail.

  19. Engineering support services for the DOE/GRI coal gasification research program. Final technical progress report, October 1978-November 1982

    Energy Technology Data Exchange (ETDEWEB)

    Bostwick, L.E.

    1982-01-01

    The agreement between the United States Government Department of Energy and the Gas Research Institute for the Joint Coal Gasification Research Program provided for one or more technical evaluation contractors. Pullman Kellogg (now the M.W. Kellogg Company) was selected as evaluation contractor to assess, and report to the DOE/GRI Operating Committee on, the relative merits of the active programs covered by the agreement. This report includes the period from 1 October 1978 to 30 November 1982. The objective was to provide engineering support for the DOE/GRI high Btu coal gasification program. This support generally consisted of assistance in developing or advancing each process to its maximum potential. Kellogg monitored and evaluated the startup and operational activities of all pilot plant projects within the combined DOE/GRI program. Kellogg evaluated proposals to determine their technical feasibility as potential processes or as viable processing operations for commercial-scale gasification of coal. Kellogg also recorded observations on the reliability, maintainability, and availability of the equipment used in the pilot plant or PDU facilities. Kellogg performed design reviews, data analyses, and engineering evaluations of proposals, cost estimates and monthly progress reports to provide information considered essential to the overall objectives of the combined DOE/GRI program.

  20. Relationship between the adhesive properties of bacteria and their transport and colonization in the subsurface environment. Final report for period September 15, 1996 - September 30, 1999

    Energy Technology Data Exchange (ETDEWEB)

    Madilyn Fletcher

    2000-04-06

    This research has focused on the attachment of bacteria to solid surfaces and the significance of their adhesion properties in their transport through porous media. Our work has focused on strains of Pseudomonas and a related species Burkholderia cepacia. Most of our experimental strains were isolated from subsurface environments at USDOE experimental field sites. The first portion of this project was conducted at the University of Maryland during 1994-1996, during which two graduates and one graduate student were supported by the award. The project was then continued under contract number DE-FG02-96ER62302 at the University of South Carolina, where one postdoctoral associate has been supported by the award.

  1. Progress of functional bacteria in printing and dyeing wastewater:Biological treatment%印染废水处理功能菌研究进展

    Institute of Scientific and Technical Information of China (English)

    谢学辉; 朱玲玉; 刘娜; 姜鸿; 杨芳; 柳建设

    2015-01-01

    利用微生物处理印染废水被认为是较为经济、有效的方法。本文将印染废水成分分类,分别介绍了印染废水中难降解污染物,如染料、助剂(表面活性剂)、浆料(聚乙烯醇)的分类,并进一步阐述其结构特征。另外,本文以印染废水的主要成分为基础,分别系统总结了功能菌对其降解机理、降解条件的优化调控及降解产物等方面的内容。目前,虽然功能菌在印染废水处理的实验室研究较为广泛,但是由于实验室多用传统的高营养型LB培养基进行筛选,导致其对工程无机环境适应性差、无法存活。本文提出在深入探讨微生物作用机理的基础上,筛选出以目标污染物作为唯一碳源、氮源及能量的高效功能菌群及菌株,从而极大地发挥功能菌在印染废水处理的实际工程中的作用。%The use of microorganisms for the degradation of textile wastewater is considered as a relatively economical and effective method. The paper was aimed to sketch the composition of printing and dyeing wastewater systematically,and to introduce the structure characteristics of refractory pollutants in printing and dyeing wastewater,such as dyes,auxiliaries,and PVA. In addition,the paper was also aimed to summarize the degradation mechanism,the optimal conditions and degradation products on the basis of main components in printing and dyeing wastewater. At present,although the functional bacteria are widely studied in laboratory,due to the high nutrient screening methods,the ability of functional bacteria to adapt the inorganic environment is poor. In this paper the target pollutants are considered as a sole carbon source,nitrogen source and energy to screen the functional bacteria for the study of microbial mechanism. And then the effect of functional bacteria in dyeing wastewater treatment may be maximized.

  2. Construction of a genome-wide human BAC-Unigene resource. Final progress report, 1989--1996

    Energy Technology Data Exchange (ETDEWEB)

    Lim, C.S.; Xu, R.X.; Wang, M. [and others

    1996-12-31

    Currently, over 30,000 mapped STSs and 27,000 mapped Unigenes (non-redundant, unigene sets of cDNA representing EST clusters) are available for human alone. A total of 44,000 Unigene cDNA clones have been supplied by Research Genetics. Unigenes, or cDNAs are excellent resource for map building for two reasons. Firstly, they exist in two alternative forms -- as both sequence information for PCR primer pairs, and cDNA clones -- thus making library screening by colony hybridization as well as pooled library PCR possible. The authors have developed an efficient and robust procedure to screen genomic libraries with large number of DNA probes. Secondly, the linkage and order of expressed sequences, or genes are highly conserved among human, mouse and other mammalian species. Therefore, mapping with cDNA markers rather than random anonymous STSs will greatly facilitate comparative, evolutionary studies as well as physical map building. They have currently deconvoluted over 10,000 Unigene probes against a 4X coverage human BAC clones from the approved library D by high density colony hybridization method. 10,000 batches of Unigenes are arrayed in an imaginary 100 X 100 matrix from which 100 row pools and 100 column pools are obtained. Library filters are hybridized with pooled probes, thus reducing the number of hybridization required for addressing the positives for each Unigene from 10,000 to 200. Details on the experimental scheme as well as daily progress report is posted on the Web site (http://www.tree.caltech.edu).

  3. Anaerobic bacteria

    Science.gov (United States)

    Brook I, Goldstein EJ. Diseases caused by non-spore forming anaerobic bacteria. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 297. Stedman's Online ...

  4. The oncogenic action of ionizing radiation on rat skin. Final progress report, May 1, 1990--April 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Burns, F.J.; Garte, S.J.

    1992-12-31

    The multistage theory of carcinogenesis specifies that cells progress to cancer through a series of discrete, irreversible genetic alterations, but data on radiation-induced cancer incidence in rat skin suggests that an intermediate repairable alteration may occur. Data are presented on cancer induction in rat skin exposed to an electron beam (LET=0.34 keV/{mu}), a neon ion beam (LET=45) or an argon ion beam (LET=125). The rats were observed for tumors at least 78 weeks with squamous and basal cell carcinomas observed. The total cancer yield was fitted by the quadratic equation, and the equation parameters were estimated by linear regression for each type of radiation. Analysis of the DNA from the electron-induced carcinomas indicated that K-ras and/or c-myc oncogenes were activated. In situ hybridization indicated that the cancers contain subpopulations of cells with differing amounts of c-myc and H-ras amplification. The results are consistent with the idea that ionizing radiation produces stable, carcinogenically relevant lesions via 2 repairable events at low LET and via a non-repairable linked event pathway at high LET; either pathway may advance the cell by 1 stage. The proliferative response of rat epidermis following exposure to ionizing radiation was quantified by injection of {sup 14}C-thymidine. The return of these cells to S-phase a second time was detected by a second label ({sup 3}H). When the labeled cells were in G1-phase, the dorsal skin was irradiated with X-rays. All labeling indices were determined. The {sup 14}C labeling index was constant and unaffected by the radiation. The proportion of all cells entering S-phase averaged 3.5% at 18 hr and increased after 44, 52 and 75 hr to average levels of 11.8%, 5. 3%, and 6.6% at 0, 10 and 25 Gy respectively. The proportion of S-phase cells labeled with {sup 14}C increased after 42 hr and remained relatively constant thereafter.

  5. Hybrid solar thermal-photovoltaic systems demonstration, Phase I and II. Final technical progress report, July 5, 1979-December 1982

    Energy Technology Data Exchange (ETDEWEB)

    Loferski, J.J. (ed.)

    1983-12-01

    The purpose of the project is to investigate a system based on combined photovoltaic/thermal (PV/T) panels to supply the energy needs of a small single family residence. The system finally selected and constructed uses PV/T panels which utilize air as the heat transfer medium. Optimization of thermal performance was accomplished by attaching metal fins to the back surface of each cell which significantly increased the heat transfer coefficient from the solar cells to the air stream. The other major components of the selected system are an air-to-air heat pump, a rock bin thermal energy storage bin, a synchronous dc-to-ac converter, a microprocessor to control the system, a heat exchanger for the domestic hot water system and of course the building itself which is a one story, well insulated structure having a floor area of 1200 ft/sup 2/. A prototype collector was constructed and tested. Based on this experience, twenty collectors, containing 2860 four inch diameter solar cells, were constructed and installed on the building. Performance of the system was simulated using a TRNSYS-derived program, modified to accommodate PV/T panels and to include the particular components included in the selected system. Simulation of the performance showed that about 65 percent of the total annual energy needs of the building would be provided by the PV/T system. Of this total, about one half is produced at a time when it can be used in the building and one half must be sold back to the utility.

  6. IDENTIFICATION OF BACTERIA IN LATEX PAINTS

    OpenAIRE

    Rojas, J

    2008-01-01

    The bacteria are prokaryote organisms with a high capacity to colonize many types of habits. This research was developed with the object to identify extremophiles bacteria presents in latex paint. The bacteria were cultivated in culture mediums TSA, Blood Agar, Mc Conkey and finally the biochemical proof API-NF® for bacteria's isolation and identification, respectively. Characterization showed bacterial profile of Pasteurella sp. Hypothesis that could be found extremophiles bac...

  7. Microbial reduction of SO{sub 2} and NO{sub x} as a means of by-product recovery/disposal from regenerable processes for the desulfurization of flue gas. Technical progress report, December 11, 1992--March 11, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Sublette, K.L.

    1993-12-31

    This report describes the potential of sulfate reducing bacteria to fix sulfur derived from flue gas desulfurization. The first section reviews the problem, the second section reviews progress of this study to use desulfovibrio desulfuricans for this purpose. The final section related progress during the current reporting period. This latter section describes studies to immobilize the bacteria in co-culture with floc-forming anaerobes, use of sewage sludges in the culture media, and sulfate production from sulfur dioxide.

  8. Big bacteria

    DEFF Research Database (Denmark)

    Schulz, HN; Jørgensen, BB

    2001-01-01

    , the 80 x 600 mum large Epulopiscium sp. from the gut of tropical fish, are presumably living in a very nutrient-rich medium. Many large bacteria contain numerous inclusions in the cells that reduce the volume of active cytoplasm. The most striking examples of competitive advantage from large cell size...

  9. Understanding the industrial application potential of lactic acid bacteria through genomics.

    Science.gov (United States)

    Zhu, Yan; Zhang, Yanping; Li, Yin

    2009-06-01

    Lactic acid bacteria (LAB) are a heterogeneous group of bacteria contributing to various industrial applications, ranging from food and beverage fermentation, bulk and fine chemicals production to pharmaceuticals manufacturing. Genome sequencing is booming; hitherto, 25 genomes of LAB have been published and many more are in progress. Based on genomic content of LAB, this review highlights some findings related to applications revealed by genomics and functional genomics analyses. Finally, this review summarizes mathematical modeling strategies of LAB in the context of genomics, to further our understanding of industrial related features.

  10. Shorebird Project Final Progress Report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This study documented the habitats, hydrology, vegetation communities and weather patterns that create or destroy shorebird habitat. This project examined shorebird...

  11. ROCK DEFORMATION. Final Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    None

    2002-05-24

    The Gordon Research Conference (GRC) on ROCK DEFORMATION was held at II Ciocco from 5/19/02 thru 5/24/02. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

  12. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Estep, Donald [Colorado State University

    2015-11-30

    This is the final report for the project titled "Enabling Predictive Simulation and UQ of complex Multiphysics PDE systems by the Development of Goal-Oriented Variational Sensitivity Analysis and a-Posteriori Error Estimation Methods" that ran from 9/1/2010 through 8/31/2015. The report describes the scientific progress, all manuscripts, and records project-related activities.

  13. 由乳酸菌制备维生素B类化合物的研究进展%Research Progress of B-Group Vitamins Produced by Lactic Acid Bacteria

    Institute of Scientific and Technical Information of China (English)

    夏亚穆; 杜康健; 夏军

    2012-01-01

    B-Group vitamins are a group of human essential substances that play important roles in cell metabolism. They can be externally obtained from food and medicine. Most lactic acid bacteria(LAB) can produce B-group vitamins which are natural,various and easy to be absorbed in human body. This review shows current research progress of B-group vitamins produced by LAB. It provides some references for the study of screening LAB strains and for the improvement of the metabolic engineering.%雄生素B类化合物是人体必需物质,主要通过外源性的食物或药物来补充.选育得到的乳酸菌能产生天然的人体易于吸收的不同类型维生素B.介绍了近年来通过乳酸菌生物合成维生素B类化合物的研究进展,为进一步研究产维生素B类化合物乳酸菌菌种选育和代谢工程改造提供参考.

  14. Rumen bacteria

    International Nuclear Information System (INIS)

    The rumen is the most extensively studied gut community and is characterized by its high population density, wide diversity and complexity of interactions. This complex, mixed microbial culture is comprised of prokaryote organisms including methane-producing archaebacteria, eukaryote organisms, such as ciliate and flagellate protozoa, anaerobic phycomycete fungi and bacteriophage. Bacteria are predominant (up to 1011 viable cells per g comprising 200 species) but a variety of ciliate protozoa occur widely (104-106/g distributed over 25 genera). The anaerobic fungi are also widely distributed (zoospore population densities of 102-104/g distributed over 5 genera). The occurrence of bacteriophage is well documented (107-109 particles/g). This section focuses primarily on the widely used methods for the cultivation and the enumeration of rumen microbes, especially bacteria, which grow under anaerobic conditions. Methods that can be used to measure hydrolytic enzymes (cellulases, xylanases, amylases and proteinases) are also described, along with cell harvesting and fractionation procedures. Brief reference is also made to fungi and protozoa, but detailed explanations for culturing and enumerating these microbes is presented in Chapters 2.4 and 2.5

  15. Nutritional Interdependence Among Rumen Bacteria During Cellulose Digestion In Vitro

    OpenAIRE

    Miura, Hideki; HORIGUCHI, Masaaki; Ogimoto, Keiji; MATSUMOTO, Tatsuro

    1983-01-01

    A study has been made of the promoting effect of starch on cellulose digestion by mixed rumen bacteria in a cellulose-urea medium. Starch supplementation of the medium promoted the growth of bacteria that required neither amino acids (AA) nor branched-chain fatty acids (BrFA). The growth of these bacteria was followed by the growth of AA-dependent bacteria, AA- or BrFA-dependent bacteria, BrFA-producing bacteria, and finally, BrFA-dependent cellulolytic bacteria. Population changes of these b...

  16. Experimental verification of a progressive damage model for composite laminates based on continuum damage mechanics. M.S. Thesis Final Report

    Science.gov (United States)

    Coats, Timothy William

    1994-01-01

    Progressive failure is a crucial concern when using laminated composites in structural design. Therefore the ability to model damage and predict the life of laminated composites is vital. The purpose of this research was to experimentally verify the application of the continuum damage model, a progressive failure theory utilizing continuum damage mechanics, to a toughened material system. Damage due to tension-tension fatigue was documented for the IM7/5260 composite laminates. Crack density and delamination surface area were used to calculate matrix cracking and delamination internal state variables, respectively, to predict stiffness loss. A damage dependent finite element code qualitatively predicted trends in transverse matrix cracking, axial splits and local stress-strain distributions for notched quasi-isotropic laminates. The predictions were similar to the experimental data and it was concluded that the continuum damage model provided a good prediction of stiffness loss while qualitatively predicting damage growth in notched laminates.

  17. Federal Assistance Program Quarterly Project Progress Report. Geothermal Energy Program: Information Dissemination, Public Outreach, and Technical Analysis Activities. Reporting Period: January 1 - March 31, 2001 [Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lund, John W.

    2002-03-22

    The final report of the accomplishments of the geothermal energy program: information dissemination, public outreach and technical analysis activities by the project team consisting of the Geo-Heat Center, Geothermal Resources Council, Geothermal Education Office, Geothermal Energy Association and the Washington State University Energy Program.

  18. Biodegradation of Complex Bacteria on Phenolic Derivatives in River Water

    Institute of Scientific and Technical Information of China (English)

    GUANG-HUA LU; CHAO WANG; ZHE SUN

    2009-01-01

    Objective To isolate, incubate, and identify 4-chlorophenol-degrading complex bacteria, determine the tolerance of these bacteria to phenolic derivatives and study their synergetic metabolism as well as the aboriginal microbes and co-metabolic degradation of mixed chlorophenols in river water. Methods Microbial community of complex bacteria was identified by plate culture observation techniques and Gram stain method. Bacterial growth inhibition test was used to determine the tolerance of complex bacteria to toxicants. Biodegradability of phenolic derivatives was determined by adding 4-chlorophenol-degrading bacteria in river water. Results The complex bacteria were identified as Mycopiana, Alcaligenes, Pseudvmonas, and Flavobacterium. The domesticated complex bacteria were more tolerant to phenolic derivatives than the aboriginal bacteria from Qinhuai River. The biodegradability of chlorophenols, dihydroxybenzenes and nitrophenols under various aquatic conditions was determined and compared. The complex bacteria exhibited a higher metabolic efficiency on chemicals than the aboriginal microbes, and the final removal rate of phenolic derivatives was increased at least by 55% when the complex bacteria were added into river water. The metabolic relationship between dominant mixed bacteria and river bacteria was studied. Conclusion The complex bacteria domesticated by 4-chlorophenol can grow and be metabolized to take other chlorophenols, dihydroxybenzenes and nitrophenols as the sole carbon and energy source. There is a synergetic metabolism of most compounds between the aboriginal microbes in river water and the domesticated complex bacteria. 4-chlorophenol-degrading bacteria can co-metabolize various chlorophenols in river water.

  19. Bacteria isolated from amoebae/bacteria consortium

    Science.gov (United States)

    Tyndall, Richard L.

    1995-01-01

    New protozoan derived microbial consortia and method for their isolation are provided. Consortia and bacteria isolated therefrom are useful for treating wastes such as trichloroethylene and trinitrotoluene. Consortia, bacteria isolated therefrom, and dispersants isolated therefrom are useful for dispersing hydrocarbons such as oil, creosote, wax, and grease.

  20. Research progress in proteolysis system of lactic acid bacteria and related gene expression%乳酸菌蛋白水解体系及相关基因表达的研究进展

    Institute of Scientific and Technical Information of China (English)

    杜越欧; 侯俊财

    2013-01-01

    乳酸菌的蛋白水解体系包括胞外酶、转运系统和多种胞内酶.它们将外源蛋白质逐步水解成能被乳酸菌直接利用的游离氨基酸,弥补了因乳酸菌自身不能直接利用外源无机氯和蛋白质的缺陷,对于乳酸菌的正常生长具有非常重要的意义.目前,国内外正在研究利用现代分子技术,从基因表达层面检测不同菌株之间或菌株经过不同处理前后关键蛋白水解酶的表达水平差异,筛选出蛋白酶高表达量的菌株,从而得到蛋白水解能力强的优质乳酸菌发酵剂菌株.本文将对乳酸菌的蛋白水解体系及近几年乳酸菌蛋白水解体系中相关基因表达情况的研究进展进行综述,以期为乳酸菌蛋白质代谢的进一步研究提供参考.%The proteolytic system of lactic acid bacteria which hydrolyzes exogenous protein into free amino acid were consists of extracellular peptidases,the peptide transport systems and a variety of intracellular peptidases. That makes up of the deficiency that lactic acid bacteria can not directly use inorganic nitrogen and protein. Therefore the proteolytic system has very important significance for the normal growth of lactic acid bacteria. Currently some scientists use the modern molecular techniques to study the gene expression levels of the key proteolytic enzymes of the different strains or the strains after different treatments in order to screen out the strains in which the genes of proteinases has high expression level and obtain the high-quality starter lactic acid bacteria strams.The proteolytic system of lactic acid bacteria and the advances in the expression level of genes related to the proteolytic system of lactic acid bacteria were reviewed in this paper with the hope of providing reference materials for the further study on protein metabolism of lactic acid bacteria.

  1. Progress on Technologies of Isolation and Identification of Lactic Acid Bacteria in Animal Intestines%动物肠道乳酸菌的分离鉴定技术研究进展

    Institute of Scientific and Technical Information of China (English)

    梁彦彦; 兰道亮; 林宝山; 黄偲; 陈亚冰; 李键

    2015-01-01

    乳酸菌是可发酵碳水化合物产生大量乳酸的细菌的统称,是对人和畜禽有益的益生菌。动物肠道中的乳酸菌耐受胃酸有更好的适应性,更易于在肠道中定植抵抗病原微生物的黏附,并且耐酸性好易于生存。论文综述了动物肠道乳酸菌分离培养的几种方法,总结出更适合分离乳酸菌的培养基。归纳了动物肠道乳酸菌的鉴定方法,包括形态鉴定、生化鉴定以及分子生物学的鉴定,重点介绍了16 S rDNA 的分子生物学鉴定方法。这对建立动物肠道中乳酸菌分离鉴定的方法,研究动物肠道中的微生物菌群组成有重要意义。%The bacteria which can ferment carbohydrates to produce large amounts of lactic acid are called as lactic acid bacteria.They are probiotics beneficial to people and livestock and poultry.Lactic acid bacteria of animal intestines have a better adaptability because it has resistance to the acid.It could survive easily in the gut to resist pathogenic microorganism adhesion.This paper reviewed several methods of isolation and cultivation of lactic acid bacteria of animal intestines and summarized the better media to isolate lactic acid bacteria.This report summarized the methods to identificate actic acid bacteria in the intestines of animals, including morphological identification,biochemical identification and molecular biological identification methods,and focused on the 16 S rDNA of molecular biological identification.It has important significance to establish the methods for isolation and identification of lactic acid bacteria in the animal intestines and study the composition of microbial flora in the intestines of animals.

  2. Bleach vs. Bacteria

    Science.gov (United States)

    ... Articles | Inside Life Science Home Page Bleach vs. Bacteria By Sharon Reynolds Posted April 2, 2014 Your ... hypochlorous acid to help kill invading microbes, including bacteria. Researchers funded by the National Institutes of Health ...

  3. Recovery of valuable chlorosilane intermediates by a novel waste conversion process. Technical report for phase IIIA (final) and phase IIIB (progress)

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, K.E.

    1998-10-01

    From July 1994 through May 1998, direct process residue (DPR) hydrogenolysis has been studied in the laboratory, at a small Pilot Plant, and finally at a larger Pilot Plant within Dow Corning`s Carrollton, Kentucky plant. The system reacts filtered DPR with monomer at high temperature and pressure. The process demonstrates DPR conversion up to 86%. The reaction product contains high concentrations of valuable monomers such as dimethyldichlorosilane and methyldichlorosilane. A larger DPR hydrogenolysis reactor based on these results is being designed for operation in Europe at Dow Corning`s Barry, Wales site.

  4. Analysis and control of the METC fluid bed gasifier. Final report (includes technical progress report for October 1994--January 1995), September 1994--September 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    This document presents a modeling and control study of the Fluid Bed Gasification (FBG) unit at the Morgantown Energy Technology Center (METC). The work is performed under contract no. DE-FG21-94MC31384. The purpose of this study is to generate a simple FBG model from process data, and then use the model to suggest an improved control scheme which will improve operation of the gasifier. The work first developes a simple linear model of the gasifier, then suggests an improved gasifier pressure and MGCR control configuration, and finally suggests the use of a multivariable control strategy for the gasifier.

  5. Bacteria and lignin degradation

    Institute of Scientific and Technical Information of China (English)

    Jing LI; Hongli YUAN; Jinshui YANG

    2009-01-01

    Lignin is both the most abundant aromatic (phenolic) polymer and the second most abundant raw material.It is degraded and modified by bacteria in the natural world,and bacteria seem to play a leading role in decomposing lignin in aquatic ecosystems.Lignin-degrading bacteria approach the polymer by mechanisms such as tunneling,erosion,and cavitation.With the advantages of immense environmental adaptability and biochemical versatility,bacteria deserve to be studied for their ligninolytic potential.

  6. Research progress of angiotensin converting enzyme inhibitory peptide and binding pathogen metabolites of lactic acid bacteria%乳酸菌抑制ACE及病原菌代谢产物研究进展

    Institute of Scientific and Technical Information of China (English)

    张国亮; 冀朵朵; 金苏; 王德纯; 孙爱东; 张柏林

    2009-01-01

    Milk products fermented by lactic acid bacteria can be used to reduce blood pressure and inhibit ACE. The functions of eliminating the pathogen metabolites were also studied in this paper.This showed that the lactic acid bacteria had great applications in the future.%主要对乳酸菌及其发酵乳产品产生降血压的血管紧张素转换酶(ACE)抑制肽及乳酸菌消除肠道微生物降解氨基酸产生致癌因子的作用进行了阐述,表明了乳酸菌在降血压及抗癌方面具有巨大的应用前案.

  7. Research Progress on the Mechanism of Lactic Acid Bacteria in Treatment of Dairy Mastitis%乳酸菌治疗奶牛乳房炎的机理与研究进展

    Institute of Scientific and Technical Information of China (English)

    马晨; 赵洁; 张和平

    2014-01-01

    Mastitis is a common disease in mammals, which occur widely in the farming, and bring huge economic losses to dairy industry. The main treatment of antibiotics have brought many problems, such as antibiotic resistance and the environment pollution caused by the resistance genes. So there need a safe and effective treatment to instead it. Taking probiotics is the most prominent in all antibiotic replacement therapy plan, and to the evaluation of the therapeutic effect of some strains of lactic acid bacteria. Lactic acid bacteria are essential for health and it has important physiological function, which widely exist in intestinal of animal body. Most of the lactic acid bacteria has a very close relationship with host’ health. Such probiotic bacteria can inhibit pathogenic bacteria colonization, and mutualism with animals also environment pollution-free. Most probiotic bacteria, especially lactobacillus, has a potential alternative antibiotic treatment of mastitis. The lactic acid bacteria which isolated from the milk as probiotics in the treatment of mastitis has its own advantages. We reviewed the researches about the mastitis detection and the application of lactic acid bacteria in the treatment of mastitis in recent years, aimed to provide certain guidance for prevention and control work of mastitis in practice.%乳房炎是奶牛养殖中常见的疾病之一,给乳业带来极大的经济损失。目前主要的治疗手段是抗生素,但抗生素治疗可导致细菌耐药性增加、抗生素残留、抗性基因污染和牛乳品质下降等诸多问题。寻求绿色、安全、高效的治疗方法迫在眉睫,目前喂饲乳酸菌是公认的替代抗生素疗法的最佳方案。乳酸菌是奶牛胃肠道中重要的菌群之一,能够对奶牛机体健康产生多种正面影响,诸如与致病菌产生拮抗、改善消化道菌群、减少对环境的污染等,与动物互利共生等。本文综述了近年来国内外乳酸菌在治

  8. Intracellular Bacteria in Protozoa

    Science.gov (United States)

    Görtz, Hans-Dieter; Brigge, Theo

    Intracellular bacteria in humans are typically detrimental, and such infections are regarded by the patients as accidental and abnormal. In protozoa it seems obvious that many bacteria have coevolved with their hosts and are well adapted to the intracellular way of life. Manifold interactions between hosts and intracellular bacteria are found, and examples of antibacterial resistance of unknown mechanisms are observed. The wide diversity of intracellular bacteria in protozoa has become particularly obvious since they have begun to be classified by molecular techniques. Some of the bacteria are closely related to pathogens; others are responsible for the production of toxins.

  9. Plasma Science Committee (PLSC) and the Panel on Opportunities in Plasma Science and Technology (OPST). Final technical progress report, 1 June 1993--31 May 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    The Plasma Science Committee (PLSC) of the National Research Council (NRC) is charged with monitoring the health of the field of plasma science in the United States. Accordingly, the Committee identifies and examines both broad and specific issues affecting the field. Regular meetings, teleconferences, briefings from agencies and the scientific community, the formation of study panels to prepare reports, and special symposia are among the mechanisms used by the PLSC to meet its charge. This progress report presents a review of PLSC activities from June 1, 1993 to May 31, 1994. The details of prior activities are discussed in earlier reports. This report also includes the status of activities associated with the PLSC study on opportunities in plasma science and technology. During the above period, the PLSC continued to track and participate in, when requested, discussions on the health of the field. Much of the perspective of the PLSC has been presented in its report Research Briefing on Contemporary Problems in Plasma Science. That report not only has served as the basis for briefings to representatives of the federal government and the community-at-large, but also served as the starting point for the Panel on Opportunities in Plasma Science and Technology (OPST) as it began an assessment of the field. The PLSC also continued its follow-up briefings and discussions on the results of the report Plasma Processing of Materials: Scientific and Technological Opportunities (PPPM). As a result of these activities, the Committee is now working with the NRC Committee on Atomic, Molecular, and Optical Sciences (CAMOS) to organize a symposium on database needs in plasma processing of materials.

  10. 硫酸盐还原菌处理重金属废水研究进展%Study Progress on Disposal of Waste Water Containing Heavy Metals by Sulfate Reducing Bacteria

    Institute of Scientific and Technical Information of China (English)

    汪爱河; 胡凯光; 廖建军; 熊日新

    2006-01-01

    介绍了硫酸盐还原菌(sulfate reducing bacteria,SRB)生长的影响因子,包括温度、碳源、培养体系中的含氧量等,探讨了硫酸盐还原菌处理重金属废水的机理,概括了国内外关于利用硫酸盐还原菌处理废水中的重金属离子的研究概况.

  11. Lack of inhibitory effects of Lactic acid bacteria on 1,2-dimethylhydrazine-induced colon tumors in rats

    Institute of Scientific and Technical Information of China (English)

    Wei Li; Chong-Bi Li

    2003-01-01

    AIM: A myriad of healthful effects has been attributed to the probiotic lactic acid bacteria, perhaps the most controversial issue remains that of anticancer activity. This study was aimed at investigating the putative anti-cancer effects of lactic acid bacteria strains on the progression of colon tumor in 1,2-dimethylhydrazine (DMH)-treated animals.METHODS: The strain of lactic acid bacteria used in this study was lactic acid bacteria NZ9000 that conformed to the characteristics of plasmid free. Sixty male Wistar rats were given subcutaneous injections of DMH at a dose of 40 mg/kg body wt or saline once a week for 10 weeks. The rats were divided into 6 experimental groups. After the last DMH injection,animals in groups 1 and 4 were gavaged with 1 mi of lactic acid bacteria at a dose of 5×109 per day or vehide until sacrifice at the end of week 22 or week 52. Animals in groups 1-3 were killed at the end of week 22 for histopathological examination.The whole period of experimental observation was 52 weeks.RESULTS: By the end of 22nd week, final average body weights of the rats treated with DMH alone and all animals receiving lactic acid bacteria were significantly decreased compared with the vehicle control (P<0.05). No differences in tumor inridence, multiplicity, dimensions and stage in the colonic mucosa were observed among the groups. At week 52, the survival rate of the rats administered lactic acid bacteria was lower than that of the rats treated with DMH that were fed on control fluids of non-lactococcus lactis. The mean survival time of lactic acid bacteria-treated animals was 39 weeks.CONCLUSION: These results indicate that lactic acid bacteria lacks inhibitory effects on the progression of colon tumor in DMH-treated animals, and does not support the hypothesis that alteration of colonic flora may exert an influence on the progression of colon tumor.

  12. The beneficial function of Lactic acid bacteria and research progress in its application%乳酸菌的益生作用及其应用研究进展

    Institute of Scientific and Technical Information of China (English)

    周晓莹; 陈晓琳

    2011-01-01

    Lactic acid bacteria as a major class of microorganisms are beneficial to human health. All the cells, non-cell extracts and extracellular secretion have beneficial effects which are mainly on scavenging of free radicals, anti-lip-id peroxidative effects, reducing of cholesterol content, put-off of aging bodies and elimination of diseases. Therefore, the probiotic products containing lactic acid bacteria have extensive range of application in feedstuff, food and medicine.%乳酸菌是一类有益于人类健康的重要微生物,它的菌体、无细胞提取物和胞外分泌物都有益生作用,其益生作用主要表现在清除自由基、抗脂质过氧化性、降低胆固醇含量、延缓机体老化和消除病变等方面.因而,含有乳酸菌的益生菌产品在饲料生产、食品和临床上都有着广泛的应用.

  13. Studies of transport pathways of Th, U, rare earths, Ra-228, and Ra-226 from soil to plants and farm animals: Final progress report, 1983-1988

    Energy Technology Data Exchange (ETDEWEB)

    Linsalata, P

    1988-07-01

    This report consists of three parts. Part 1 discusses a field study conducted in an area of enhanced, natural radioactivity to assess the soil to edible vegetable concentration ratios (CR = concentration in dry vegetable/concentration in dry soil) of Th-232, Th-230, Ra-226, Ra-228, and the light rare earth elements (REE's), La, Ce, and Nd. Twenty-eight soil, and approximately 42 vegetable samples consisting of relatively equal numbers of seven varieties, were obtained from 11 farms on the Pocos de Caldas Plateau in the state of Minas Gerais, Brazil. This region is the site of a major natural analogue study to assess the mobilization and retardation processes affecting thorium and the REE's at the Morro do Ferro ore body, and uranium series radionuclides at the Osamu Utsumi open pit uranium mine. Thorium (IV) serves as a chemical analogue for quadrivalent plutonium, the light REE's (III) as chemical analogues for trivalent americium and curium, and uranium (VI) as an analogue for transuranics with stable oxidation states above IV, e.g., Pu(VI). Part 2 includes our final measurement results for naturally occurring light rare earth elements (REE's include La, Ce, Nd, and SM), U-series and Th-series radionuclides in adult farm animal tissues, feeds and soils. Our findings on soil-to-tissue concentration ratios (CR's) and the comparative behavior of these elements in farm animals raised under natural conditions by local farmers are presented. Part 3 summarizes our findings to date on the distribution and mobilization of Th-232, light rare earth elements (LREE), U-238 and Ra-228 in the MF basin. Estimates of first order, present day, mobilization rate constants resulting from ground water solubilization and seepage/stream transport are calculated using revised inventory estimates for the occurrence of these elements in the ore body and annual flux estimates for the transport of these elements away from the ore body. 151 refs., 20 figs., 40 tabs.

  14. Characterization of superconducting and magnetic materials with muon spin rotation and neutron scattering. Progress report, March 1996--August 1997 and final report, June 1988--August 1997

    Energy Technology Data Exchange (ETDEWEB)

    Stronach, C.E.; Noakes, D.R.

    1997-09-01

    This report represents the culmination of over nine years of research activity in the study of superconducting and magnetically ordered materials using the muon spin rotation ({mu}SR) and neutron scattering techniques. Because all the activities that took place up until March 1996 have been covered in previous annual reports, this final report includes only a brief overview of activities prior to that date, and concentrates on the period from March 1996 through August 1997. The primary activity undertaken in this project has been studies of high-temperature superconductors and their close chemical relatives with the {mu}SR technique. These experiments extend from early work done with a relatively primitive muon beam at the AGS of Brookhaven National Laboratory and large polycrystalline samples of the earliest known high-{Tc} materials to studies of very small high-purity single crystals of the best high-{Tc} materials currently available using the highest quality surface muon beams and specially-designed low-background spectrometers at the Tri-University Meson Facility (TRIUMF) in the past three years. During the period since the last annual report five {mu}SR experiments were done at TRIUMF with DOE support. A study of single-crystal high-temperature superconductors was done in July 1996. A study of the quasicrystal materials Gd{sub 8}Mg{sub 42}Zn{sub 50} and Tb{sub 8}Mg{sub 42}Zn{sub 50} was done by D.R. Noakes in collaboration with G.M. Kalvius of the Technical University of Munich and R. Waeppling of Uppsala University during the first week of December 1996. During the second week of December 1996 a study of the cryocrystals CH{sub 4} and CF{sub 4} was done by D.R. Noakes in collaboration with S. Storchak of Moscow State University and J.H. Brewer of the University of British Columbia. A study of high-{Tc} superconductors was done at TRIUMF during the third week of December 1996 by C.E. Stronach and D.R. Noakes.

  15. Genomics of Probiotic Bacteria

    Science.gov (United States)

    O'Flaherty, Sarah; Goh, Yong Jun; Klaenhammer, Todd R.

    Probiotic bacteria from the Lactobacillus and Bifidobacterium species belong to the Firmicutes and the Actinobacteria phylum, respectively. Lactobacilli are members of the lactic acid bacteria (LAB) group, a broadly defined family of microorganisms that ferment various hexoses into primarily lactic acid. Lactobacilli are typically low G + C gram-positive species which are phylogenetically diverse, with over 100 species documented to date. Bifidobacteria are heterofermentative, high G + C content bacteria with about 30 species of bifidobacteria described to date.

  16. Learning Chemistry from Bacteria

    OpenAIRE

    Clardy, Jon

    2013-01-01

    Dr. Jon Clardy Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University All animals, including humans, originated and evolved on a planet already teeming with bacteria, and the two kingdoms of life have been competing and cooperating through their joint history. Although bacteria are most familiar as pathogens, some bacteria produce small molecules that are essential for the biology of animals and other eukaryotes. This lecture explores some of...

  17. 基于LuxS的群体感应系统在乳酸茵共培养中的研究%Resent Progresses on LuxS-Mediated Quorum Sensing System in Co-culture Among Latic Acid Bacteria

    Institute of Scientific and Technical Information of China (English)

    张腾; 贺银凤

    2012-01-01

    群体感应是微生物调控群体行为的重要方式,基于LuxS的群体感应系统广泛存在于各种属细菌中。AI一2作为LuxS系统的信号分子,在细胞交流中起到关键作用。LuxS系统在多种乳酸菌共同作用完成发酵任务以及某些乳酸菌行使益生功能中发挥了重要作用。文中综述了AI一2的合成途径、转导方式并重点阐述LuxS系统对乳酸菌共培养过程中蛋白表达和基因转录的影响。对LuxS系统进行深入研究,必将进一步揭示多种乳酸菌共同发酵以及其完成益生功能的机理,为从分子水平调控乳酸菌的发酵和益生行为提供了可能。%Quorum sensing is an important way for bacteria to control its group behaviors. LuxS-mediated quorum sensing widely exists in many species of bacteria. AI-2 used as autoinducer of LuxS-mediated system plays an impor- tant role in cell to cell communication. LuxS-mediated system makes a significant effect on fermentation process con- trolled by multiple latic acid bacteria (LAB). This paper reviews the way of AI-2 synthesis and transduction. We will also focus on the changes of protein expression and gene transcription regulated by LuxS-mediated system under the condition of co-culture among LABs. Researching in LuxS-mediated system will further reveal the mechanism of multiple LABs jointly working in fermentation and make it possible to control sourdough LABs' group behaviors in the mo- lecular level.

  18. 重症监护室耐药非发酵革兰阴性菌院内感染的危险因素及治疗进展研究%Progress on risk factors and treatment of nosocomial infection of resistant nonfermenting gram-negative bacteria in intensive care unit

    Institute of Scientific and Technical Information of China (English)

    祁春艳; 阎锡新

    2010-01-01

    多耐药非发酵革兰阴性菌已成为重症监护室院内感染的重要病原菌,近年来其检出率在全球有逐年上升的趋势,对其危险因素和治疗进展的探讨具有重要意义.入院前有抗生素使用史、反复插管、最初不恰当抗生素治疗即病原菌对所用抗菌药物不敏感、重症监护室住院时间延长等是耐药菌院内感染常见的危险因素.关于耐药菌院内感染的治疗,采用早期适当联合用药原则,控制感染.%Multidrug resistant nonfermenting gram-negative bacteria have become important nosocomial pathogens in intensive care unit. In recent years,the incidence in the world has increased year after year,it is significant to discuss the risk factors and progress of treatment. The common risk factors of nosocomial infection of drug-resistant bacteria are antibiotic usc before admission, repeated intubation,initial inappropriate antibiotic treatment (pathogens are not sensitive to antibiotics),and extended length of stay in intensive care unit. The principle of treatment about nosocomial infection of drug-resistant bacteria is early and appropriate drug combination to control infection.

  19. How honey kills bacteria

    NARCIS (Netherlands)

    P.H.S. Kwakman; A.A. te Velde; L. de Boer; D. Speijer; C.M.J.E. Vandenbroucke-Grauls; S.A.J. Zaat

    2010-01-01

    With the rise in prevalence of antibiotic-resistant bacteria, honey is increasingly valued for its antibacterial activity. To characterize all bactericidal factors in a medical-grade honey, we used a novel approach of successive neutralization of individual honey bactericidal factors. All bacteria t

  20. Metallization of bacteria cells

    Institute of Scientific and Technical Information of China (English)

    LI; Xiangfeng; (黎向锋); LI; Yaqin; (李雅芹); CAI; Jun; (蔡军); ZHANG; Deyuan; (张德远)

    2003-01-01

    Bacteria cells with different standard shapes are well suited for use as templates for the fabrication of magnetic and electrically conductive microstructures. In this paper, metallization of bacteria cells is demonstrated by an electroless deposition technique of nickel-phosphorus initiated by colloid palladium-tin catalyst on the surfaces of Citeromyces matritensis and Bacillus cereus. The activated and metallized bacteria cells have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction analysis (XRD). Results showed that both Citeromyces matritensis and Bacillus cereus had no deformation in shape after metallization; the metallized films deposited on the surfaces of bacteria cells are homogeneous in thickness and noncrystalline in phase structure. The kinetics of colloid palladium-tin solution and electroless plating on bacteria cells is discussed.

  1. Widespread distribution of archaeal reverse gyrase in thermophilic bacteria suggests a complex history of vertical inheritance and lateral gene transfers

    Directory of Open Access Journals (Sweden)

    Céline Brochier-Armanet

    2006-01-01

    Full Text Available Reverse gyrase, an enzyme of uncertain funtion, is present in all hyperthermophilic archaea and bacteria. Previous phylogenetic studies have suggested that the gene for reverse gyrase has an archaeal origin and was transferred laterally (LGT to the ancestors of the two bacterial hyperthermophilic phyla, Thermotogales and Aquificales. Here, we performed an in-depth analysis of the evolutionary history of reverse gyrase in light of genomic progress. We found genes coding for reverse gyrase in the genomes of several thermophilic bacteria that belong to phyla other than Aquificales and Thermotogales. Several of these bacteria are not, strictly speaking, hyperthermophiles because their reported optimal growth temperatures are below 80 °C. Furthermore, we detected a reverse gyrase gene in the sequence of the large plasmid of Thermus thermophilus strain HB8, suggesting a possible mechanism of transfer to the T. thermophilus strain HB8 involving plasmids and transposases. The archaeal part of the reverse gyrase tree is congruent with recent phylogenies of the archaeal domain based on ribosomal proteins or RNA polymerase subunits. Although poorly resolved, the complete reverse gyrase phylogeny suggests an ancient acquisition of the gene by bacteria via one or two LGT events, followed by its secondary distribution by LGT within bacteria. Finally, several genes of archaeal origin located in proximity to the reverse gyrase gene in bacterial genomes have bacterial homologues mostly in thermophiles or hyperthermophiles, raising the possibility that they were co-transferred with the reverse gyrase gene. Our new analysis of the reverse gyrase history strengthens the hypothesis that the acquisition of reverse gyrase may have been a crucial evolutionary step in the adaptation of bacteria to high-temperature environments. However, it also questions the role of this enzyme in thermophilic bacteria and the selective advantage its presence could provide.

  2. Innovative conservation housing. Final progress report

    Energy Technology Data Exchange (ETDEWEB)

    Nuttle, D.A.

    1983-01-01

    A new passive solar thermal storage brick was developed and tested. A new insulating curtain concept was developed to assist in passive solar heating and cooling. A steel truss was designed to replace the wood truss in solar attic applications where the wood truss typically suffers some 50% loss of structural strength. Improvements were made of the dry composting toilet and grey water recycling for homes. An algae cultivation system was created for production of food, feed, fertilizer, or biomass as needed for home, farm, or industry. New concepts were explored in the areas of economy shelter, solar hot water heating, home generation of electricity, edible landscapes and other home food production, growing of fiber crops for cottage industry, storage, insulation, solar cooking, and solar refrigeration. (LEW)

  3. ESG-CET Final Progress Title

    Energy Technology Data Exchange (ETDEWEB)

    Don Middleton

    2011-10-06

    Drawing to a close after five years of funding from DOE's ASCR and BER program offices, the SciDAC-2 project called the Earth System Grid (ESG) Center for Enabling Technologies has successfully established a new capability for serving data from distributed centers. The system enables users to access, analyze, and visualize data using a globally federated collection of networks, computers and software. The ESG software - now known as the Earth System Grid Federation (ESGF) - has attracted a broad developer base and has been widely adopted so that it is now being utilized in serving the most comprehensive multi-model climate data sets in the world. The system is used to support international climate model intercomparison activities as well as high profile U.S. DOE, NOAA, NASA, and NSF projects. It currently provides more than 25,000 users access to more than half a petabyte of climate data (from models and from observations) and has enabled over a 1,000 scientific publications.

  4. Electron Donor Acceptor Interactions. Final Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    None

    2002-08-16

    The Gordon Research Conference (GRC) on Electron Donor Acceptor Interactions was held at Salve Regina University, Newport, Rhode Island, 8/11-16/02. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

  5. Studies in genetic discrimination. Final progress report

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    We have screened 1006 respondents in a study of genetic discrimination. Analysis of these responses has produced evidence of the range of institutions engaged in genetic discrimination and demonstrates the impact of this discrimination on the respondents to the study. We have found that both ignorance and policy underlie genetic discrimination and that anti-discrimination laws are being violated.

  6. Chemical Reactions at Surfaces. Final Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    None

    2003-02-21

    The Gordon Research Conference (GRC) on Chemical Reactions at Surfaces was held at Holiday Inn, Ventura, California, 2/16-21/03. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

  7. Water & Aqueous Solutions. Final Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    None

    2002-08-09

    The Gordon Research Conference (GRC) on Water & Aqueous Solutions was held at Holderness School, New Hampshire, 8/4/02 thru 8/9/02. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

  8. 人和动物丝虫共生菌--沃尔巴克氏体研究进展%Progress onWolbachia ---Symbiotic Bacteria in Human and Animal Filariae

    Institute of Scientific and Technical Information of China (English)

    刘梅; 杨光友

    2015-01-01

    Wolbachia is a symbiotic bacteria found in filariae,which induces immune-pathology inflamma-tion and is one of the main reasons that cause diseases after filariae infection.This paper reviewed the clas-sification,structure and distribution,reproduction and route of transmission,genome of the Wolbadhia in filariae,and the interaction relationship between Wolbachia and filariae.It mainly described that the Wol-bachia with filarial pathogenicity and the role of the drugs in depletion ofWolbachia in treatment of human and animal filariasis,which provides references for research about controlling human and animal filariasis.%沃尔巴克氏体(Wolbachia ,Wb)是在丝虫体内发现的一类共生菌,它诱导的免疫病理引起的炎症反应是丝虫感染后致病的主要原因之一。论文论述了丝虫沃尔巴克氏体的分类、结构与分布、生殖及传播方式、基因组和沃尔巴克氏体与丝虫之间的相互作用关系,重点阐述了沃尔巴克氏体与丝虫致病性和清除沃尔巴克氏体药物在人和动物丝虫病治疗中的作用,为人和动物丝虫病的防治研究提供参考。

  9. Progress on reversal of activity of efflux pump in gram-negative resistance bacteria%逆转革兰阴性耐药菌外排泵活性的研究进展

    Institute of Scientific and Technical Information of China (English)

    徐艳玲; 王彤

    2013-01-01

    外排泵的过度表达是多重耐药菌的耐药机制之一,要对抗这种耐药机制,必须从基因、结构和功能多方面破译这个转运系统.通过了解外排泵如何工作,我们有可能发现一群新的抗菌分子,并可以统一叫做外排泵逆转剂,如膜通透性增高剂、外排泵抑制剂和外排泵竞争剂、特异性外排泵阻断剂、外排泵能量毒性剂等.目前已经发现一些化合物显示出有效阻断一些多重耐药革兰阴性菌的外排泵的作用,这一类家族代表了一个新的特异作用于细菌主动转运的抗菌素种类.%Over-expression of efflux pumps is one of the mechanisms causing multidrug resistant bacteria.It is necessary to clearly decipher this transport system from the genetic,structural,and functional aspects in order to combat this poly-selective mechanism.By understanding how efflux pumps work,we may be able to find a new group of antibacterial agents,termed efflux reversals,including membrane permeabilisers,efflux pump inhibitors and flux-competitive agents,specific blockers,energy poisons,etc.Several chemical families of efflux pump inhibitors have been described and characterized.This new family of molecules represents the first antibacterial class of compound specifically targeting active transport in the bacterial cell.

  10. Extracellular communication in bacteria

    DEFF Research Database (Denmark)

    Chhabra, S.R.; Philipp, B.; Eberl, L.;

    2005-01-01

    molecules, in different Gram-positive and Gram-negative bacteria they control pathogenicity, secondary metabolite production, biofilm differentiation, DNA transfer and bioluminescence. The development of biosensors for the detection of these signal molecules has greatly facilitated their subsequent chemical...

  11. Indicator For Pseudomonas Bacteria

    Science.gov (United States)

    Margalit, Ruth

    1990-01-01

    Characteristic protein extracted and detected. Natural protein marker found in Pseudomonas bacteria. Azurin, protein containing copper readily extracted, purified, and used to prepare antibodies. Possible to develop simple, fast, and accurate test for marker carried out in doctor's office.

  12. Progressive Finland sees progress with nuclear projects

    International Nuclear Information System (INIS)

    The Finnish Hanhikivi-1 reactor project is firmly on track and a licence has been granted for construction of a final disposal facility for spent nuclear fuel - the first final repository in the world to enter the construction phase. Significant progress has been made with plans for Finland to build its sixth nuclear reactor unit at Hanhikivi. Fennovoima's licensing manager Janne Liuko said the company expects to receive the construction licence for the Generation III+ Hanhikivi-1 plant in late 2017. The application was submitted to the Finnish Ministry of Employment and the Economy in June 2015.

  13. Progressive Finland sees progress with nuclear projects

    Energy Technology Data Exchange (ETDEWEB)

    Dalton, David [NucNet, Brussels (Belgium)

    2016-02-15

    The Finnish Hanhikivi-1 reactor project is firmly on track and a licence has been granted for construction of a final disposal facility for spent nuclear fuel - the first final repository in the world to enter the construction phase. Significant progress has been made with plans for Finland to build its sixth nuclear reactor unit at Hanhikivi. Fennovoima's licensing manager Janne Liuko said the company expects to receive the construction licence for the Generation III+ Hanhikivi-1 plant in late 2017. The application was submitted to the Finnish Ministry of Employment and the Economy in June 2015.

  14. Molecular identification and physiological characterization of yeasts, lactic acid bacteria and acetic acid bacteria isolated from heap and box cocoa bean fermentations in West Africa.

    Science.gov (United States)

    Visintin, Simonetta; Alessandria, Valentina; Valente, Antonio; Dolci, Paola; Cocolin, Luca

    2016-01-01

    Yeast, lactic acid bacteria (LAB) and acetic acid bacteria (AAB) populations, isolated from cocoa bean heap and box fermentations in West Africa, have been investigated. The fermentation dynamicswere determined by viable counts, and 106 yeasts, 105 LAB and 82 AAB isolateswere identified by means of rep-PCR grouping and sequencing of the rRNA genes. During the box fermentations, the most abundant species were Saccharomyces cerevisiae, Candida ethanolica, Lactobacillus fermentum, Lactobacillus plantarum, Acetobacter pasteurianus and Acetobacter syzygii, while S. cerevisiae, Schizosaccharomyces pombe, Hanseniaspora guilliermondii, Pichia manshurica, C. ethanolica, Hanseniaspora uvarum, Lb. fermentum, Lb. plantarum, A. pasteurianus and Acetobacter lovaniensis were identified in the heap fermentations. Furthermore, the most abundant species were molecularly characterized by analyzing the rep-PCR profiles. Strains grouped according to the type of fermentations and their progression during the transformation process were also highlighted. The yeast, LAB and AAB isolates were physiologically characterized to determine their ability to grow at different temperatures, as well as at different pH, and ethanol concentrations, tolerance to osmotic stress, and lactic acid and acetic acid inhibition. Temperatures of 45 °C, a pH of 2.5 to 3.5, 12% (v/v) ethanol and high concentrations of lactic and acetic acid have a significant influence on the growth of yeasts, LAB and AAB. Finally, the yeastswere screened for enzymatic activity, and the S. cerevisiae, H. guilliermondii, H. uvarumand C. ethanolica species were shown to possess several enzymes that may impact the quality of the final product.

  15. Quarterly Technical Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Ayman I. Hawari

    2002-12-30

    This report presents the progress made during the first quarter of phase 2 for the project entitled ''Development and Validation of Thermal Neutron Scattering Laws from Applications and Safety Implications in Generation IV Reactor Designs.'' (B204) THIS IS NOT A FINAL REPORT

  16. All ecosystems potentially host electrogenic bacteria.

    Science.gov (United States)

    Chabert, Nicolas; Amin Ali, Oulfat; Achouak, Wafa

    2015-12-01

    Instead of requiring metal catalysts, MFCs utilize bacteria that oxidize organic matter and either transfer electrons to the anode or take electrons from the cathode. These devices are thus based on a wide microbial diversity that can convert a large array of organic matter components into sustainable and renewable energy. A wide variety of explored environments were found to host electrogenic bacteria, including extreme environments. In the present review, we describe how different ecosystems host electrogenic bacteria, as well as the physicochemical, electrochemical and biological parameters that control the currents from MFCs. We also report how using new molecular techniques allowed characterization of electrochemical biofilms and identification of potentially new electrogenic species. Finally we discuss these findings in the context of future research directions. PMID:26298511

  17. The fecal bacteria

    Science.gov (United States)

    Sadowsky, Michael J.; Whitman, Richard L.

    2011-01-01

    The Fecal Bacteria offers a balanced, integrated discussion of fecal bacteria and their presence and ecology in the intestinal tract of mammals, in the environment, and in the food supply. This volume covers their use in examining and assessing water quality in order to offer protection from illnesses related to swimming in or ingesting contaminated water, in addition to discussing their use in engineering considerations of water quality, modeling, monitoring, and regulations. Fecal bacteria are additionally used as indicators of contamination of ready-to-eat foods and fresh produce. The intestinal environment, the microbial community structure of the gut microbiota, and the physiology and genomics of this broad group of microorganisms are explored in the book. With contributions from an internationally recognized group of experts, the book integrates medicine, public health, environmental, and microbiological topics in order to provide a unique, holistic understanding of fecal bacteria. Moreover, it shows how the latest basic science and applied research findings are helping to solve problems and develop effective management strategies. For example, readers will discover how the latest tools and molecular approaches have led to our current understanding of fecal bacteria and enabled us to improve human health and water quality. The Fecal Bacteria is recommended for microbiologists, clinicians, animal scientists, engineers, environmental scientists, food safety experts, water quality managers, and students. It will help them better understand fecal bacteria and use their knowledge to protect human and environmental health. They can also apply many of the techniques and molecular tools discussed in this book to the study of a broad range of microorganisms in a variety of habitats.

  18. Bacteria and microbial induced corrosion in district heating systems; Bakterier og mikrobiel betinget korrosion i fjernvarmesystemer

    Energy Technology Data Exchange (ETDEWEB)

    Froelund, B. [Dansk Teknologisk Inst., Miljoeteknik, Aarhus (Denmark); Smidt, H.D. [Dansk Teknologisk Inst., Energi, Aarhus (Denmark); Halkjaer Nielsen, P. [Aalborg Univ., Lab. for Miljoeteknik (Denmark)

    1998-09-01

    Bacteria has been found in district heating systems in a number that indicate the risk of technical problems of a microbial nature. Bacteria in district heating systems can cause problems like unpleasant smell, increased roughness on the inner side of the pipes, decreased performance of the heat exchangers etc. There is also found bio film containing bacteria on the surface of the pipes. In the bio film there are often other conditions than in water, e.g. a lower pH value that improves growth of bacteria. Finally there is found sulphate-reducing bacteria. These bacteria can cause corrosion; a corrosion form called microbial induced corrosion. The report gives recommendations on how to reduce these bacteria. The bacteria can be reduced by regulating the pH value or by minimising the organic material in the water and finally by biocides that are able to kill the microorganisms. (SM) EFP-95. 12 refs.

  19. Sterol synthesis in diverse bacteria

    Directory of Open Access Journals (Sweden)

    Jeremy H Wei

    2016-06-01

    Full Text Available Sterols are essential components of eukaryotic cells whose biosynthesis and function has been studied extensively. Sterols are also recognized as the diagenetic precursors of steranes preserved in sedimentary rocks where they can function as geological proxies for eukaryotic organisms and/or aerobic metabolisms and environments. However, production of these lipids is not restricted to the eukaryotic domain as a few bacterial species also synthesize sterols. Phylogenomic studies have identified genes encoding homologs of sterol biosynthesis proteins in the genomes of several additional species, indicating that sterol production may be more widespread in the bacterial domain than previously thought. Although the occurrence of sterol synthesis genes in a genome indicates the potential for sterol production, it provides neither conclusive evidence of sterol synthesis nor information about the composition and abundance of basic and modified sterols that are actually being produced. Here, we coupled bioinformatics with lipid analyses to investigate the scope of bacterial sterol production. We identified oxidosqualene cyclase (Osc, which catalyzes the initial cyclization of oxidosqualene to the basic sterol structure, in 34 bacterial genomes from 5 phyla (Bacteroidetes, Cyanobacteria, Planctomycetes, Proteobacteria and Verrucomicrobia and in 176 metagenomes. Our data indicate that bacterial sterol synthesis likely occurs in diverse organisms and environments and also provides evidence that there are as yet uncultured groups of bacterial sterol producers. Phylogenetic analysis of bacterial and eukaryotic Osc sequences confirmed a complex evolutionary history of sterol synthesis in this domain. Finally, we characterized the lipids produced by Osc-containing bacteria and found that we could generally predict the ability to synthesize sterols. However, predicting the final modified sterol based on our current knowledge of sterol synthesis was difficult

  20. Sterol Synthesis in Diverse Bacteria.

    Science.gov (United States)

    Wei, Jeremy H; Yin, Xinchi; Welander, Paula V

    2016-01-01

    Sterols are essential components of eukaryotic cells whose biosynthesis and function has been studied extensively. Sterols are also recognized as the diagenetic precursors of steranes preserved in sedimentary rocks where they can function as geological proxies for eukaryotic organisms and/or aerobic metabolisms and environments. However, production of these lipids is not restricted to the eukaryotic domain as a few bacterial species also synthesize sterols. Phylogenomic studies have identified genes encoding homologs of sterol biosynthesis proteins in the genomes of several additional species, indicating that sterol production may be more widespread in the bacterial domain than previously thought. Although the occurrence of sterol synthesis genes in a genome indicates the potential for sterol production, it provides neither conclusive evidence of sterol synthesis nor information about the composition and abundance of basic and modified sterols that are actually being produced. Here, we coupled bioinformatics with lipid analyses to investigate the scope of bacterial sterol production. We identified oxidosqualene cyclase (Osc), which catalyzes the initial cyclization of oxidosqualene to the basic sterol structure, in 34 bacterial genomes from five phyla (Bacteroidetes, Cyanobacteria, Planctomycetes, Proteobacteria, and Verrucomicrobia) and in 176 metagenomes. Our data indicate that bacterial sterol synthesis likely occurs in diverse organisms and environments and also provides evidence that there are as yet uncultured groups of bacterial sterol producers. Phylogenetic analysis of bacterial and eukaryotic Osc sequences confirmed a complex evolutionary history of sterol synthesis in this domain. Finally, we characterized the lipids produced by Osc-containing bacteria and found that we could generally predict the ability to synthesize sterols. However, predicting the final modified sterol based on our current knowledge of sterol synthesis was difficult. Some bacteria

  1. Sterol Synthesis in Diverse Bacteria.

    Science.gov (United States)

    Wei, Jeremy H; Yin, Xinchi; Welander, Paula V

    2016-01-01

    Sterols are essential components of eukaryotic cells whose biosynthesis and function has been studied extensively. Sterols are also recognized as the diagenetic precursors of steranes preserved in sedimentary rocks where they can function as geological proxies for eukaryotic organisms and/or aerobic metabolisms and environments. However, production of these lipids is not restricted to the eukaryotic domain as a few bacterial species also synthesize sterols. Phylogenomic studies have identified genes encoding homologs of sterol biosynthesis proteins in the genomes of several additional species, indicating that sterol production may be more widespread in the bacterial domain than previously thought. Although the occurrence of sterol synthesis genes in a genome indicates the potential for sterol production, it provides neither conclusive evidence of sterol synthesis nor information about the composition and abundance of basic and modified sterols that are actually being produced. Here, we coupled bioinformatics with lipid analyses to investigate the scope of bacterial sterol production. We identified oxidosqualene cyclase (Osc), which catalyzes the initial cyclization of oxidosqualene to the basic sterol structure, in 34 bacterial genomes from five phyla (Bacteroidetes, Cyanobacteria, Planctomycetes, Proteobacteria, and Verrucomicrobia) and in 176 metagenomes. Our data indicate that bacterial sterol synthesis likely occurs in diverse organisms and environments and also provides evidence that there are as yet uncultured groups of bacterial sterol producers. Phylogenetic analysis of bacterial and eukaryotic Osc sequences confirmed a complex evolutionary history of sterol synthesis in this domain. Finally, we characterized the lipids produced by Osc-containing bacteria and found that we could generally predict the ability to synthesize sterols. However, predicting the final modified sterol based on our current knowledge of sterol synthesis was difficult. Some bacteria

  2. Anaerobic bacteria in otitis media.

    Science.gov (United States)

    Fulghum, R S; Daniel, H J; Yarborough, J G

    1977-01-01

    Anaerobic bacteria, Peptostrepotococcus intermedius and Propionibacterium acnes, were found in mixed culture specimens from four to ten tested cases of chronic secretory otitis media. These anaerobic bacteria were in a mixed infection flora with aerobic bacteria most often Staphylococcus epidermidis and Cornybacterium sp. which do not fit any established species. The findings of anaerobic bacteria in otitis media is consistent with the sporadic report of the involvement of anaerobic bacteria in otitis media in the literature since 1898.

  3. Mycophagous soil bacteria

    NARCIS (Netherlands)

    Rudnick, M.B.

    2015-01-01

    Abstract

    Soil microorganisms evolved several strategies to compete for limited nutrients in soil. Bacteria of the genus Collimonas developed a way to exploit fungi as a source of organic nutrients. This strategy has been termed “mycophagy&r

  4. 1985. Annual progress report

    International Nuclear Information System (INIS)

    This annual progress report of the CEA Protection and Nuclear Safety Institut outlines a description of the progress made in each sections of the Institut Research activities of the different departments include: reactor safety analysis, fuel cycle facilities analysis; and associated safety research programs (criticality, sites, transport ...), radioecology and environmental radioprotection techniques; data acquisition on radioactive waste storage sites; radiation effects on man, studies on radioprotection techniques; nuclear material security including security of facilities, security of nuclear material transport, and monitoring of nuclear material management; nuclear facility decommissioning; and finally the public information

  5. Progress Report

    DEFF Research Database (Denmark)

    Duer, Karsten

    1999-01-01

    Progress report describing the work carried out by the Danish participant in the ALTSET project in the period January 1999 to July 1999.......Progress report describing the work carried out by the Danish participant in the ALTSET project in the period January 1999 to July 1999....

  6. Thermophilic, lignocellulolytic bacteria for ethanol production: current state and perspectives

    DEFF Research Database (Denmark)

    Chang, Tinghong; Yao, Shuo

    2011-01-01

    for efficient biomass hydrolysis. Secondly, thermophilic bacteria ferment a broad range of carbohydrates into ethanol, and some of them display potential for ethanologenic fermentation at high yield. Thirdly, the establishment of the genetic tools for thermophilic bacteria has allowed metabolic engineering...... of cellulolytic and saccharolytic thermophilic bacteria for lignocellulosic ethanol production because of their unique properties. First of all, thermophilic bacteria possess unique cellulolytic and hemicellulolytic systems and are considered as potential sources of highly active and thermostable enzymes......, in particular with emphasis on improving ethanol yield, and this facilitates their employment for ethanol production. Finally, different processes for second-generation ethanol production based on thermophilic bacteria have been proposed with the aim to achieve cost-competitive processes. However, thermophilic...

  7. Can bacteria save the planet?

    OpenAIRE

    Hunter, Philip

    2010-01-01

    Bacteria might just hold the key to preserving the environment for our great grandchildren. Philip Hunter explores some of the novel ways in which systems biology and biotechnology are harnessing bacteria to produce renewable energy and clean up pollution.

  8. Manufacture of Probiotic Bacteria

    Science.gov (United States)

    Muller, J. A.; Ross, R. P.; Fitzgerald, G. F.; Stanton, C.

    Lactic acid bacteria (LAB) have been used for many years as natural biopreservatives in fermented foods. A small group of LAB are also believed to have beneficial health effects on the host, so called probiotic bacteria. Probiotics have emerged from the niche industry from Asia into European and American markets. Functional foods are one of the fastest growing markets today, with estimated growth to 20 billion dollars worldwide by 2010 (GIA, 2008). The increasing demand for probiotics and the new food markets where probiotics are introduced, challenges the industry to produce high quantities of probiotic cultures in a viable and stable form. Dried concentrated probiotic cultures are the most convenient form for incorporation into functional foods, given the ease of storage, handling and transport, especially for shelf-stable functional products. This chapter will discuss various aspects of the challenges associated with the manufacturing of probiotic cultures.

  9. Lipoprotein sorting in bacteria.

    Science.gov (United States)

    Okuda, Suguru; Tokuda, Hajime

    2011-01-01

    Bacterial lipoproteins are synthesized as precursors in the cytoplasm and processed into mature forms on the cytoplasmic membrane. A lipid moiety attached to the N terminus anchors these proteins to the membrane surface. Many bacteria are predicted to express more than 100 lipoproteins, which play diverse functions on the cell surface. The Lol system, composed of five proteins, catalyzes the localization of Escherichia coli lipoproteins to the outer membrane. Some lipoproteins play vital roles in the sorting of other lipoproteins, lipopolysaccharides, and β-barrel proteins to the outer membrane. On the basis of results from biochemical, genetic, and structural studies, we discuss the biogenesis of lipoproteins in bacteria, their importance in cellular functions, and the molecular mechanisms underlying efficient sorting of hydrophobic lipoproteins to the outer membrane through the hydrophilic periplasm. PMID:21663440

  10. Exopolysaccharides from Marine Bacteria

    Institute of Scientific and Technical Information of China (English)

    CHI Zhenming; FANG Yan

    2005-01-01

    Microbial polysaccharides represent a class of important products of growing interest for many sectors of industry. In recent years, there has been a growing interest in isolating new exopolysaccharides (EPSs)-producing bacteria from marine environments, particularly from various extreme marine environments. Many new marine microbial EPSs with novel chemical compositions, properties and structures have been found to have potential applications in fields such as adhesives,textiles, pharmaceuticals and medicine for anti-cancer, food additives, oil recovery and metal removal in mining and industrial waste treatments, etc This paper gives a brief summary of the information about the EPSs produced by marine bacteria,including their chemical compositions, properties and structures, together with their potential applications in industry.

  11. Formation of a carcinogenic aromatic amine from an azo dye by human skin bacteria in vitro.

    Science.gov (United States)

    Platzek, T; Lang, C; Grohmann, G; Gi, U S; Baltes, W

    1999-09-01

    Azo dyes represent the major class of dyestuffs. They are metabolised to the corresponding amines by liver enzymes and the intestinal microflora following incorporation by both experimental animals and humans. For safety evaluation of the dermal exposure of consumers to azo dyes from wearing coloured textiles, a possible cleavage of azo dyes by the skin microflora should be considered since, in contrast to many dyes, aromatic amines are easily absorbed by the skin. A method for measuring the ability of human skin flora to reduce azo dyes was established. In a standard experiment, 3x10(11) cells of a culture of Staphylococcus aureus were incubated in synthetic sweat (pH 6.8, final volume 20 mL) at 28 degrees C for 24 h with Direct Blue 14 (C.I. 23850, DB 14). The reaction products were extracted and analysed using HPLC. The reduction product o-tolidine (3,3'-dimethylbenzidine, OT) could indeed be detected showing that the strain used was able to metabolise DB 14 to the corresponding aromatic amine. In addition to OT, two further metabolites of DB 14 were detected. Using mass spectrometry they were identified as 3,3'-dimethyl-4-amino-4'-hydroxybiphenyl and 3, 3'-dimethyl-4-aminobiphenyl. The ability to cleave azo dyes seems to be widely distributed among human skin bacteria, as, under these in vitro conditions, bacteria isolated from healthy human skin and human skin bacteria from strain collections also exhibited azo reductase activity. Further studies are in progress in order to include additional azo dyes and coloured textiles. At the moment, the meaning of the results with regard to consumer health cannot be finally assessed.

  12. Collective Sensing-Capacity of Bacteria Populations

    CERN Document Server

    Einolghozati, Arash; Fekri, Faramarz

    2012-01-01

    The design of biological networks using bacteria as the basic elements of the network is initially motivated by a phenomenon called quorum sensing. Through quorum sensing, each bacterium performs sensing the medium and communicating it to others via molecular communication. As a result, bacteria can orchestrate and act collectively and perform tasks impossible otherwise. In this paper, we consider a population of bacteria as a single node in a network. In our version of biological communication networks, such a node would communicate with one another via molecular signals. As a first step toward such networks, this paper focuses on the study of the transfer of information to the population (i.e., the node) by stimulating it with a concentration of special type of a molecules signal. These molecules trigger a chain of processes inside each bacteria that results in a final output in the form of light or fluorescence. Each stage in the process adds noise to the signal carried to the next stage. Our objective is ...

  13. Deoxyribonucleoside kinases activate nucleoside antibiotics in severely pathogenic bacteria

    DEFF Research Database (Denmark)

    Sandrini, Michael; Shannon, O.; Clausen, A.R.;

    2007-01-01

    Common bacterial pathogens are becoming progressively more resistant to traditional antibiotics, representing a major public-health crisis. Therefore, there is a need for a variety of antibiotics with alternative modes of action. In our study, several nucleoside analogs were tested against...... alternative for combating pathogenic bacteria....

  14. Early detection of emphysema progression

    DEFF Research Database (Denmark)

    Gorbunova, Vladlena; Jacobs, Sander S A M; Lo, Pechin;

    2010-01-01

    more sensitive estimates of emphysema progression. The standard CT densitometric score of emphysema is the relative area of voxels below a threshold (RA). The RA score is a global measurement and reflects the overall emphysema progression. In this work, we propose a framework for estimation of local...... emphysema progression from longitudinal chest CT scans. First, images are registered to a common system of coordinates and then local image dissimilarities are computed in corresponding anatomical locations. Finally, the obtained dissimilarity representation is converted into a single emphysema progression...... score. We applied the proposed algorithm on 27 patients with severe emphysema with CT scans acquired five time points, at baseline, after 3, after 12, after 21 and after 24 or 30 months. The results showed consistent emphysema progression with time and the overall progression score correlates...

  15. Pepsin homologues in bacteria

    Directory of Open Access Journals (Sweden)

    Bateman Alex

    2009-09-01

    Full Text Available Abstract Background Peptidase family A1, to which pepsin belongs, had been assumed to be restricted to eukaryotes. The tertiary structure of pepsin shows two lobes with similar folds and it has been suggested that the gene has arisen from an ancient duplication and fusion event. The only sequence similarity between the lobes is restricted to the motif around the active site aspartate and a hydrophobic-hydrophobic-Gly motif. Together, these contribute to an essential structural feature known as a psi-loop. There is one such psi-loop in each lobe, and so each lobe presents an active Asp. The human immunodeficiency virus peptidase, retropepsin, from peptidase family A2 also has a similar fold but consists of one lobe only and has to dimerize to be active. All known members of family A1 show the bilobed structure, but it is unclear if the ancestor of family A1 was similar to an A2 peptidase, or if the ancestral retropepsin was derived from a half-pepsin gene. The presence of a pepsin homologue in a prokaryote might give insights into the evolution of the pepsin family. Results Homologues of the aspartic peptidase pepsin have been found in the completed genomic sequences from seven species of bacteria. The bacterial homologues, unlike those from eukaryotes, do not possess signal peptides, and would therefore be intracellular acting at neutral pH. The bacterial homologues have Thr218 replaced by Asp, a change which in renin has been shown to confer activity at neutral pH. No pepsin homologues could be detected in any archaean genome. Conclusion The peptidase family A1 is found in some species of bacteria as well as eukaryotes. The bacterial homologues fall into two groups, one from oceanic bacteria and one from plant symbionts. The bacterial homologues are all predicted to be intracellular proteins, unlike the eukaryotic enzymes. The bacterial homologues are bilobed like pepsin, implying that if no horizontal gene transfer has occurred the duplication

  16. Role of periodontal pathogenic bacteria in RANKL-mediated bone destruction in periodontal disease

    OpenAIRE

    Kajiya, Mikihito; Giro, Gabriela; Taubman, Martin A.; Han, Xiaozhe; Marcia P.A. Mayer; Kawai, Toshihisa

    2010-01-01

    Accumulated lines of evidence suggest that hyperimmune responses to periodontal bacteria result in the destruction of periodontal connective tissue and alveolar bone. The etiological roles of periodontal bacteria in the onset and progression of periodontal disease (PD) are well documented. However, the mechanism underlying the engagement of periodontal bacteria in RANKL-mediated alveolar bone resorption remains unclear. Therefore, this review article addresses three critical subjects. First, ...

  17. Bacteria Inside Semiconductors as Potential Sensor Elements: Biochip Progress

    Directory of Open Access Journals (Sweden)

    Vasu R. Sah

    2014-06-01

    Full Text Available It was discovered at the beginning of this Century that living bacteria—and specifically the extremophile Pseudomonas syzgii—could be captured inside growing crystals of pure water-corroding semiconductors—specifically germanium—and thereby initiated pursuit of truly functional “biochip-based” biosensors. This observation was first made at the inside ultraviolet-illuminated walls of ultrapure water-flowing semiconductor fabrication facilities (fabs and has since been, not as perfectly, replicated in simpler flow cell systems for chip manufacture, described here. Recognizing the potential importance of these adducts as optical switches, for example, or probes of metabolic events, the influences of the fabs and their components on the crystal nucleation and growth phenomena now identified are reviewed and discussed with regard to further research needs. For example, optical beams of current photonic circuits can be more easily modulated by integral embedded cells into electrical signals on semiconductors. Such research responds to a recently published Grand Challenge in ceramic science, designing and synthesizing oxide electronics, surfaces, interfaces and nanoscale structures that can be tuned by biological stimuli, to reveal phenomena not otherwise possible with conventional semiconductor electronics. This short review addresses only the fabrication facilities’ features at the time of first production of these potential biochips.

  18. Progressive Business

    DEFF Research Database (Denmark)

    Christiansen, Christian O.

    2016-01-01

    Guest Post to the Society for U.S. Intellectual History Blog. Brief introduction to the book Progressive Business: An Intellectual History of the Role of Business in American Society, Oxford U.P., 2015.......Guest Post to the Society for U.S. Intellectual History Blog. Brief introduction to the book Progressive Business: An Intellectual History of the Role of Business in American Society, Oxford U.P., 2015....

  19. Beneficial uses program. Progress report ending December 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-06-01

    Progress is reported in research on uses of irradiated sewage sludge, particularly as a cattle feed supplement and commercial fertilizer additive, on potential sites for irradiator demonstration plants, and on the inactivation of enteric bacteria by radiation treatment. (LCL)

  20. Progress of Deep-sea Bacteria and its B ioactive Compounds on Prve ention of Plant Pathogenic Fungi%深海细菌及其活性物质防控植物病原真菌的研究进展

    Institute of Scientific and Technical Information of China (English)

    孙晓磊; 闫培生; 王凯; 王文威; 李梦瀛

    2015-01-01

    Abstrcat:In recent years,the development of biopesticides from natural products has been concerned by scholars .For the unique living environment, marine microorganisms producing many novel bioactive compounds that never been found in the terrestrial microorganisms,which provide bright prospects for developing novel biopesticides.The research progress of deeps-ea bacteria against phytopathogenic fungi was briefly summarized from three aspects of species diversity , kinds and structures of antifungal substances and antifungal mechanisms.Developing biological pesticide from marine microorganisms was prospected in this paper . This review might provide some insight for development and utilization of marine microorganisms in anti-phytopathogenic fungi.%近年来,从天然产物中开发生物农药成为了研究者关注的热点,海洋微生物因其独特的生存环境,产生了许多从陆地微生物中未曾发现的生物活性物质,为新型生物农药开发带来了佳音。从微生物多样性、抑菌物质的种类与结构和抑菌机理3个方面阐述深海细菌防控植物病原真菌的研究进展,并对其发展前景进行了展望,以期为抗植物病原真菌的海洋微生物的开发利用提供参考。

  1. Sulfur-oxidizing bacteria in environmental technology.

    Science.gov (United States)

    Pokorna, Dana; Zabranska, Jana

    2015-11-01

    Hydrogen sulfide is widely known as the most undesirable component of biogas that caused not only serious sensoric and toxic problems, but also corrosion of concrete and steel structures. Many agricultural and industrial waste used in biogas production, may contain a large amount of substances that serve as direct precursors to the formation of sulfide sulfur-sources of hydrogen sulfide in the biogas. Biological desulfurization methods are currently promoted to abiotic methods because they are less expensive and do not produce undesirable materials which must be disposed of. The final products of oxidation of sulfides are no longer hazardous. Biological removal of sulfide from a liquid or gaseous phase is based on the activity of sulfur-oxidizing bacteria. They need an oxidizing agent such as an acceptor of electrons released during the oxidation of sulfides-atmospheric oxygen or oxidized forms of nitrogen. Different genera of sulfur-oxidizing bacteria and their technological application are discussed.

  2. Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Michael Laub

    2008-12-29

    Our team of investigators from MIT (Michael Laub) and Stanford (Harley McAdams and Lucy Shapiro) conducted a multi-faceted, systematic experimental analysis of the 106 Caulobacter two-component signal transduction system proteins (62 histidine kinases and 44 response regulators) to understand how they coordinate cell cycle progression, metabolism, and response to environmental changes. These two-component signaling proteins were characterized at the genetic, biochemical, and genomic levels. The results generated by our laboratories have provided numerous insights into how Caulobacter cells sense and respond to a myriad of signals. As nearly all bacteria use two-component signaling for cell regulation, the results from this project help to deepen our general understanding of bacterial signal transduction. The tools and approaches developed can be applied to other bacteria. In particular, work from the Laub laboratory now enables the systematic, rational rewiring of two-component signaling proteins, a major advance that stands to impact synthetic biology and the development of biosensors and other designer molecular circuits. Results are summarized from our work. Each section lists publications and publicly-available resources which result from the work described.

  3. Nitrogen control in bacteria.

    Science.gov (United States)

    Merrick, M J; Edwards, R A

    1995-12-01

    Nitrogen metabolism in prokaryotes involves the coordinated expression of a large number of enzymes concerned with both utilization of extracellular nitrogen sources and intracellular biosynthesis of nitrogen-containing compounds. The control of this expression is determined by the availability of fixed nitrogen to the cell and is effected by complex regulatory networks involving regulation at both the transcriptional and posttranslational levels. While the most detailed studies to date have been carried out with enteric bacteria, there is a considerable body of evidence to show that the nitrogen regulation (ntr) systems described in the enterics extend to many other genera. Furthermore, as the range of bacteria in which the phenomenon of nitrogen control is examined is being extended, new regulatory mechanisms are also being discovered. In this review, we have attempted to summarize recent research in prokaryotic nitrogen control; to show the ubiquity of the ntr system, at least in gram-negative organisms; and to identify those areas and groups of organisms about which there is much still to learn. PMID:8531888

  4. Chemical communication in bacteria

    Science.gov (United States)

    Suravajhala, Srinivasa Sandeep; Saini, Deepak; Nott, Prabhu

    Luminescence in Vibrio fischeri is a model for quorum-sensing-gene-regulation in bacteria. We study luminescence response of V. fischeri to both internal and external cues at the single cell and population level. Experiments with ES114, a wild-type strain, and ainS mutant show that luminescence induction in cultures is not always proportional to cell-density and there is always a basal level of luminescence. At any given concentration of the exogenously added signals, C6-HSL and C8-HSL, luminescence per cell reaches a maximum during the exponential phase and decreases thereafter. We hypothesize that (1) C6-HSL production and LuxR activity are not proportional to cell-density, and (2) there is a shift in equilibrium from C6-HSL to C8-HSL during the later stages of growth of the culture. RT-PCR analysis of luxI and luxR shows that the expression of these genes is maximum corresponding to the highest level of luminescence. The shift in equilibrium is shown by studying competitive binding of C6-HSL and C8-HSL to LuxR. We argue that luminescence is a unicellular behaviour, and an intensive property like per cell luminescence is more important than gross luminescence of the population in understanding response of bacteria to chemical signalling. Funding from the Department of Science and Technology, India is acknowledged.

  5. Beneficial bacteria inhibit cachexia.

    Science.gov (United States)

    Varian, Bernard J; Goureshetti, Sravya; Poutahidis, Theofilos; Lakritz, Jessica R; Levkovich, Tatiana; Kwok, Caitlin; Teliousis, Konstantinos; Ibrahim, Yassin M; Mirabal, Sheyla; Erdman, Susan E

    2016-03-15

    Muscle wasting, known as cachexia, is a debilitating condition associated with chronic inflammation such as during cancer. Beneficial microbes have been shown to optimize systemic inflammatory tone during good health; however, interactions between microbes and host immunity in the context of cachexia are incompletely understood. Here we use mouse models to test roles for bacteria in muscle wasting syndromes. We find that feeding of a human commensal microbe, Lactobacillus reuteri, to mice is sufficient to lower systemic indices of inflammation and inhibit cachexia. Further, the microbial muscle-building phenomenon extends to normal aging as wild type animals exhibited increased growth hormone levels and up-regulation of transcription factor Forkhead Box N1 [FoxN1] associated with thymus gland retention and longevity. Interestingly, mice with a defective FoxN1 gene (athymic nude) fail to inhibit sarcopenia after L. reuteri therapy, indicating a FoxN1-mediated mechanism. In conclusion, symbiotic bacteria may serve to stimulate FoxN1 and thymic functions that regulate inflammation, offering possible alternatives for cachexia prevention and novel insights into roles for microbiota in mammalian ontogeny and phylogeny. PMID:26933816

  6. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Gurney, Kevin R

    2015-01-12

    This document constitutes the final report under DOE grant DE-FG-08ER64649. The organization of this document is as follows: first, I will review the original scope of the proposed research. Second, I will present the current draft of a paper nearing submission to Nature Climate Change on the initial results of this funded effort. Finally, I will present the last phase of the research under this grant which has supported a Ph.D. student. To that end, I will present the graduate student’s proposed research, a portion of which is completed and reflected in the paper nearing submission. This final work phase will be completed in the next 12 months. This final workphase will likely result in 1-2 additional publications and we consider the results (as exemplified by the current paper) high quality. The continuing results will acknowledge the funding provided by DOE grant DE-FG-08ER64649.

  7. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    DeTar, Carleton [P.I.

    2012-12-10

    This document constitutes the Final Report for award DE-FC02-06ER41446 as required by the Office of Science. It summarizes accomplishments and provides copies of scientific publications with significant contribution from this award.

  8. Immunomodulatory properties of probiotic bacteria

    DEFF Research Database (Denmark)

    Fink, Lisbeth Nielsen

    2007-01-01

    Certain lactic acid bacteria (LAB) are part of the commensal intestinal flora and considered beneficial for health, as they compete with pathogens for adhesion sites in the intestine and ferment otherwise indigestible compounds. Another important property of these so-called probiotic bacteria...... with bacteria, and the cytokine pattern induced by specific bacteria resembled the pattern induced in MoDC, except for TNF-alpha and IL-6, which were induced in response to different bacteria in blood DC/monocytes and monocyte-derived DC. Autologous NK cells produced IFN-gamma when cultured with blood DC......, monocytes and monocyte-derived DC and IL-12-inducing bacteria, whereas only DC induced IFN-gamma production in allogeneic T cells. In vitro-generated DC is a commonly used model of tissue DC, but they differ in certain aspects from intestinal DC, which are in direct contact with the intestinal microbiota...

  9. Cable Bacteria in Freshwater Sediments

    DEFF Research Database (Denmark)

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus;

    2015-01-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable...... bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures...... marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary...

  10. Radiation-resistant asporogenic bacteria

    International Nuclear Information System (INIS)

    This paper reports the biological and ecological examinations on the radiation-resistant asporogenic bacteria (mainly concerning Micrococcus radiodurans). Radiation-resistant asporogenic bacteria were isolated from the irradiated areas of the natural world as well as from the general areas and from the Rn waters in the Misasa hot spring. The acquiring of the tolerance to radiation in bacteria was also examined. In addition, the future problems of microbiological treatment with irradiation were mentioned. (Tsukamoto, Y.)

  11. Bacteriophages of methanotrophic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Tyutikow, F.M. (All-Union Research Inst. for Genetics and Selection of Industrial Microorganisms, Moscow, USSR); Bespalova, I.A.; Rebentish, B.A.; Aleksandrushkina, N.N.; Krivisky, A.S.

    1980-10-01

    Bacteriophages of methanotrophic bacteria have been found in 16 out of 88 studied samples (underground waters, pond water, soil, gas and oil installation waters, fermentor cultural fluids, bacterial paste, and rumen of cattle) taken in different geographic zones of the Soviet Union. Altogether, 23 phage strains were isolated. By fine structure, the phages were divided into two types (with very short or long noncontractile tails); by host range and serological properties, they fell into three types. All phages had guanine- and cytosine-rich double-stranded deoxyribonucleic acid consisting of common nitrogen bases. By all of the above-mentioned properties, all phages within each of the groups were completely identical to one another, but differed from phages of other groups.

  12. Bacteria, phages and septicemia.

    Directory of Open Access Journals (Sweden)

    Ausra Gaidelyte

    Full Text Available The use of phages is an attractive option to battle antibiotic resistant bacteria in certain bacterial infections, but the role of phage ecology in bacterial infections is obscure. Here we surveyed the phage ecology in septicemia, the most severe type of bacterial infection. We observed that the majority of the bacterial isolates from septicemia patients spontaneously secreted phages active against other isolates of the same bacterial strain, but not to the strain causing the disease. Such phages were also detected in the initial blood cultures, indicating that phages are circulating in the blood at the onset of sepsis. The fact that most of the septicemic bacterial isolates carry functional prophages suggests an active role of phages in bacterial infections. Apparently, prophages present in sepsis-causing bacterial clones play a role in clonal selection during bacterial invasion.

  13. Anhydrobiosis in bacteria: From physiology to applications

    Indian Academy of Sciences (India)

    Armando Hernández García

    2011-12-01

    Anhydrobiosis is a phenomenon related to the partial or total desiccation of living organisms, keeping their vital functions after rehydration. The desiccated state in prokaryotes has been widely studied, mainly due to the broad spectrum of the anhydrobiosis applications. In this review, we present the basic theoretical concepts related to anhydrobiosis, focusing on bacterial species. An update about desiccation tolerance in bacteria is given; and the general mechanisms of desiccation tolerance and desiccation damage are described. In addition, we show how the study of anhydrobiosis in prokaryotes has established the theoretical and practical basis for the development of the drying technologies. With regard to the desiccation tolerance in bacteria, although many mechanisms remain undiscovered at the molecular level, important research about the physiology of the anhydrobiotic state and its applications has been performed, and here we provide the most recent information about this subject. On the other hand, the most widely used drying technologies and their particular applications in several fields are described (e.g. medicine, agriculture and food industry). Finally, topics on the stability of desiccated bacterial cells are treated, concluding with the necessity of focusing the research on the mathematical modelling of the desiccated state in bacteria.

  14. 水生细菌对原生动物的反捕食对策%DEFENSE STRATEGIES OF AQUATIC BACTERIA TO PROTOZOA

    Institute of Scientific and Technical Information of China (English)

    周可新; 许木启; 曹宏; 仝恩丛; 李志杰; 马向民; 尹彦品; 刘伟

    2003-01-01

    The research progress in the defense strategies of aquatic bacteria to protozoa was reviewed in this paper, Aquatic bacteria can reduce or avoid grazing mortality from protozoa through changing size or shape, reducing cell surface hydrophobieity, reducing mobility or searching refuges. It is the main trends of the field in the future to study the coevolution mode of aquatic bacteria and protozoa. Ref 47

  15. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Baron, Edward [Univ. of Oklahoma

    2014-04-28

    The progress over the course of the grant period was excellent. We went from 3-D test codes to full 3-D production codes. We studied several SNe Ia. Most of the support has gone for the 3 years of support of OU graduate student Brian Friesen, who is now mature in his fourth year of research. It is unfortunate that there will be no further DOE support to see him through to the completion of his PhD.

  16. Effect of irradiation on detection of bacteria in dehydrated vegetables with ATP bioluminescence assay

    International Nuclear Information System (INIS)

    ATP bioluminescence intensity of 4 kinds of irradiated dehydrated vegetables was inconsistent with the bacteria number, the reasons were investigated in this paper. Results showed that irradiation had little effect on background luminescence, and there was no effect on luciferase-luminous system. When irradiation killed the bacteria, the ATPase activity also decreased. As a result, the ATP content in bacteria didn't decreased with the killed of bacteria, which contributed to the increase of free ATP in ATP extract and finally led to the disagreement between the bioluminescence intensity and the actual number of bacteria. When the free ATP in the dehydrated vegetable was removed, the bioluminescence intensity of ATP extract was consistent with the actual number of bacteria in irradiated dehydrated vegetable and ATP bioluminescence technology could be used in bacteria detection of irradiated samples. (authors)

  17. Neutron spectroscopy. Final report

    International Nuclear Information System (INIS)

    The researches carried by the Columbia University Department of Applied Physics and Nuclear Engineering, and its predecessors, in contract initially with the AEC, then with ERDA, and finally with DOE, had as its initial objective the measurement of fission cross sections and energy distributions of the fission fragments, as measured by pulse heights in detectors. These investigations sought to establish relations between the energy distributions and the quantum numbers of the resonances. In addition, some related, together with some unrelated, investigations were conducted. Progress is reported on measurements on the fissile isotopes, capture cross section measurements, theoretical developments, and the NEVIS synchrocyclotron pulsed neutron source

  18. Swimming bacteria in liquid crystal

    Science.gov (United States)

    Sokolov, Andrey; Zhou, Shuang; Aranson, Igor; Lavrentovich, Oleg

    2014-03-01

    Dynamics of swimming bacteria can be very complex due to the interaction between the bacteria and the fluid, especially when the suspending fluid is non-Newtonian. Placement of swimming bacteria in lyotropic liquid crystal produces a new class of active materials by combining features of two seemingly incompatible constituents: self-propelled live bacteria and ordered liquid crystals. Here we present fundamentally new phenomena caused by the coupling between direction of bacterial swimming, bacteria-triggered flows and director orientations. Locomotion of bacteria may locally reduce the degree of order in liquid crystal or even trigger nematic-isotropic phase transition. Microscopic flows generated by bacterial flagella disturb director orientation. Emerged birefringence patterns allow direct optical observation and quantitative characterization of flagella dynamics. At high concentration of bacteria we observed the emergence of self-organized periodic texture caused by bacteria swimming. Our work sheds new light on self-organization in hybrid bio-mechanical systems and can lead to valuable biomedical applications. Was supported by the US DOE, Office of Basic Energy Sciences, Division of Materials Science and Engineering, under the Contract No. DE AC02-06CH11357.

  19. Final Report

    DEFF Research Database (Denmark)

    Heiselberg, Per; Brohus, Henrik; Nielsen, Peter V.

    This final report for the Hybrid Ventilation Centre at Aalborg University describes the activities and research achievement in the project period from August 2001 to August 2006. The report summarises the work performed and the results achieved with reference to articles and reports published...

  20. Recent Progress in Nuclear Astrophysics

    OpenAIRE

    Langanke, K

    1999-01-01

    The manuscript reviews progress achieved in recent years in various aspects of nuclear astrophysics, including stellar nucleosynthesis, nuclear aspects of supernova collapse and explosion, neutrino-induced reactions and their possible role in the supernova mechanism and nucleosynthesis, explosive hydrogen burning in binary systems, and finally the observation of $\\gamma$-rays from supernova remnants.

  1. Antimicrobials Influence Bond Stiffness and Detachment of Oral Bacteria.

    Science.gov (United States)

    Song, L; Hou, J; van der Mei, H C; Veeregowda, D H; Busscher, H J; Sjollema, J

    2016-07-01

    Oral biofilm can never be fully removed by oral hygiene measures. Biofilm left behind after brushing is often left behind on the same sites and exposed multiple times to antimicrobials from toothpastes and mouthrinses, after which removal becomes increasingly difficult. On the basis of this observation, we hypothesize that oral bacteria adhering to salivary conditioning films become more difficult to remove after adsorption of antimicrobials due to stiffening of their adhesive bond. To verify this hypothesis, bacteria adhering to bare and saliva-coated glass were exposed to 3 different mouthrinses, containing chlorhexidine-digluconate, cetylpyridinium-chloride, or amine-fluoride, after which bacterial vibration spectroscopy was carried out or a liquid-air interface was passed over the adhering bacteria to stimulate their detachment. Brownian motion-induced nanoscopic vibration amplitudes of 4 oral streptococcal strains, reflecting their bond stiffness, decreased after exposure to mouthrinses. Concurrently, the percentage detachment of adhering bacteria upon the passage of a liquid-air interface decreased after exposure to mouthrinses. A buffer control left both vibration amplitudes and detachment percentages unaffected. Exposure to either of the selected mouthrinses yielded more positively charged bacteria by particulate microelectrophoresis, suggesting antimicrobial adsorption to bacterial cell surface components. To rule out that exposure of adhering bacteria to the mouthrinses stimulated polysaccharide production with an impact on their detachment, Fourier transform infrared spectroscopy was carried out on bacteria adhering to an internal reflection element, prior to and after exposure to the mouthrinses. Infrared absorption band areas indicated no significant change in amount of polysaccharides after exposure of adhering bacteria to mouthrinses, but wave number shifts demonstrated stiffening of polysaccharides in the bond, as a result of antimicrobial

  2. Sampling bacteria with a laser

    Science.gov (United States)

    Schwarzwälder, Kordula; Rutschmann, Peter

    2014-05-01

    Water quality is a topic of high interest and it's getting more and more important due to climate change and the implementation of European Water Framework Directive (WFD). One point of interest here is the inflow of bacteria into a river caused by combined sewer overflows which lead untreated wastewater including bacteria directly into a river. These bacteria remain in the river for a certain time, they settle down and can be remobilised again. In our study we want to investigate these processes of sedimentation and resuspension and use the results for the development of a software module coupled with the software Flow3D. Thereby we should be able to simulate and therefore predict the water quality influenced by combined sewer overflows. Hence we need to get information about the bacteria transport and fate. We need to know about the size of the bacteria or of the bacteria clumps and the size of the particles the bacteria are attached to. The agglomerates lead to different characteristics and velocities of settlement. The timespan during this bacteria can be detected in the bulk phase depends on many factors like the intensity of UV light, turbidity of the water, the temperature of the water, if there are grazers and a lot more. The size, density and composition of the agglomerates is just a part of all these influencing factors, but it is extremely difficult to differ between the other effects if we have no information about the simple sedimentation in default of these basic information. However we have a big problem getting the data. The chaining between bacteria or bacteria and particles is not too strong, so filtering the water to get a sieving curve may destroy these connections. We did some experiments similar to PIV (particle image velocimetry) measurements and evaluated the pictures with a macro written for the software ImageJ. Doing so we were able to get the concentration of bacteria in the water and collect information about the size of the bacteria. We

  3. Beer spoilage bacteria and hop resistance

    NARCIS (Netherlands)

    Sakamoto, K; Konings, WN

    2003-01-01

    For brewing industry, beer spoilage bacteria have been problematic for centuries. They include some lactic acid bacteria such as Lactobacillus brevis, Lactobacillus lindneri and Pediococcus damnosus, and some Gram-negative bacteria such as Pectinatus cerevisiiphilus, Pectinatus frisingensis and Mega

  4. Development of combinatorial bacteria for metal and radionuclide bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    A. C. Matin, Ph. D.

    2006-06-15

    The grant concerned chromate [Cr(VI)] bioremediation and it was our aim from the outset to construct individual bacterial strains capable of improved bioremediation of multiple pollutants and to identify the enzymes suited to this end. Bacteria with superior capacity to remediate multiple pollutants can be an asset for the cleanup of DOE sites as they contain mixed waste. I describe below the progress made during the period of the current grant, providing appropriate context.

  5. Development of combinatorial bacteria for metal and radionuclide bioremediation

    International Nuclear Information System (INIS)

    The grant concerned chromate [Cr(VI)] bioremediation and it was our aim from the outset to construct individual bacterial strains capable of improved bioremediation of multiple pollutants and to identify the enzymes suited to this end. Bacteria with superior capacity to remediate multiple pollutants can be an asset for the cleanup of DOE sites as they contain mixed waste. I describe below the progress made during the period of the current grant, providing appropriate context

  6. Antimicrobial Effect of Lactic Acid Bacteria against Common Pathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Mohammad Mohammaddoost Chakoosari ( Msc

    2016-01-01

    Full Text Available Background and Objective: Probiotics are living microorganisms that have beneficial effects on the health of digestive system. The aim of this study was to evaluate the antimicrobial ability of acidic and neutral supernatants (culture supernatant of lactic acid bacteria against common bacterial pathogens. Methods: Four species of lactic acid bacteria (Lactobacillus plantarum PTCC1745, Lactobacillus PTCC1608, Lactobacillus Saki PTCC1712 and Lactobacillus Lactis PTCC1336 were obtained from the microbial collection of Iranian Research Organization for Science and Technology in Lyophilized form. The antimicrobial activity of neutral and acidic supernatants against bacterial pathogens was investigated using the Disk and Well Diffusion Agar methods. Results: Lactic acid bacteria showed good antimicrobial ability against six pathogenic bacteria with the highest inhibitory effect observed in Lactococcus lactis against E. coli PTCC1399 through well method with an average diameter of 14 mm inhibition zone. In this study, the well diffusion method was far more sensitive compared to the disk method and acidic supernatants showed higher antimicrobial efficiency compared to neutral types. Conclusion: the Metabolites produced by lactic acid bacteria are able to inhibit the growth of pathogenic bacteria that can be an important and practical solution for the prevention and treatment of infections and ultimately improve human health. Keywords: Lactobacillus; Lactococcus; Probiotic; Antibacterial

  7. Screening of aspartate dehydrogenase of bacteria

    OpenAIRE

    Fukuda, Shoko; Okamura, Tokumitsu; Yasumasa, Izumi; Takeno, Tomomi; Ohsugi, Masahiro

    2001-01-01

    Fifty-two strains of bacteria cultured under aerobic conditions and 12 strains of bacteria cultured under anaerobic conditions demonstrated high activity staining of aspartate dehydrogenase with NAD^+. Four strains of bacteria cultured under aerobic conditions and 7 strains of bacteria cultured under anaerobic conditions demonstrated high activity staining of aspartate dehydrogenase with NADP^+. Seven strains of bacteria cultured under aerobic conditions and 4 strains of bacteria cultured und...

  8. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Yelton, John Martin [UF; Mitselmakher, Guenakh [UF; Korytov, Andrey [UF; Avery, Paul [UF; Furic, Ivan [UF; Acosta, Darin [UF; Konigsberg, Jacobo [UF; Field, Richard [UF; Matchev, Konstantin [UF; Ramond, Pierre [UF; Thorn, Richard [UF; Sikivie, Pierre [UF; Ray, Heather [UF; Tanner, David [UF

    2013-10-10

    We report on progress in a series of different directions within high energy physics research. 1. Neutrino research in hardware and software on the Minerva and MiniBooNE experiments 2. Experimental particle physics at the hadron colliders, with emphasis on research and development and data analysis on the CMS experiment operating at the CERN LHC. This includes research on the discovery and properties on the Higgs Boson. 3. Educational outreach through the Quarknet program, taking physics research into High School classrooms. 4. Theoretical and Phenomenological High Energy research, covering a broad range of activities ranging from fundamental theoretical issues to areas of immediate phenomenological importance. 5. Experiment searches for the Axion, as part of the ADMX experiment.

  9. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    R Paul Drake

    2004-01-12

    OAK-B135 This is the final report from the project Hydrodynamics by High-Energy-Density Plasma Flow and Hydrodynamics and Radiation Hydrodynamics with Astrophysical Applications. This project supported a group at the University of Michigan in the invention, design, performance, and analysis of experiments using high-energy-density research facilities. The experiments explored compressible nonlinear hydrodynamics, in particular at decelerating interfaces, and the radiation hydrodynamics of strong shock waves. It has application to supernovae, astrophysical jets, shock-cloud interactions, and radiative shock waves.

  10. Bacteria, fungi and protozoa paper

    Data.gov (United States)

    U.S. Environmental Protection Agency — Bacteria and fungi in source and treated drinking water This dataset is associated with the following publication: King , D., S. Pfaller , M. Donohue , S. Vesper ,...

  11. Measuring progress

    DEFF Research Database (Denmark)

    Wahlberg, Ayo

    2007-01-01

    . In this paper, I argue that a growing focus on frontier technologies in the life sciences in discussions about bio-power today has come at the cost of empirical investigations into how, for example, 'quality of life' came to be a crucial object of bio-power in the 20th century. Just as Foucault outlined......In recent years, sociological examinations of genetics, therapeutic cloning, neuroscience and tissue engineering have suggested that 'life itself' is currently being transformed through technique with profound implications for the ways in which we understand and govern ourselves and others...... in much the same way that mortality rates, life expectancy or morbidity rates can. By analysing the concrete ways in which human progress has been globally measured and taxonomised in the past two centuries or so, I will show how global stratifications of countries according to their states...

  12. Progress report

    International Nuclear Information System (INIS)

    Progress Report, covering the period up to the end of 1979 year, was sent to the IAEA according to the research agreement No. 1971 /CF. This work covered the following fields: preparation and dummy irradiation experiments with a new experimental capsule of ''CHOUCA-M'' type; measurement of temperature fields and design of specimen holders; measurement of neutron energy spectrum in the irradiation place in our experimental reactor of VVR-S type (Nuclear Research Institute) using a set of activation detectors; unification and calibration of the measurement of neutron fluence with the use of Fe, Cu, Mn-Mg and Co-Al monitors; development and improvement of the measuring apparatus and technique for the dynamic testing of pre-cracked specimens with determination of dynamic parameters of fracture mechanics; preparation and manufacture of testing specimens from the Japanese steels - forging, plate and weld metal; preparation of the irradiation capsule for assembling

  13. Adherention ability of intestinal bacteria

    OpenAIRE

    Morgensternová, Tereza

    2014-01-01

    Probiotics are live microorganisms that provide positive health benefits. Bacteria of the genus Bifidobacterium belong to this group. These bacteria have to meet a number of criteria so that they could be considered for probiotic. These include the ability to survive, grow, and be metabolically active in the gastrointestinal tract of the recipient. Probiotics protect the intestinal mucus from the adhesion of pathogenic organisms. The aim of this thesis was to test the ability of different ...

  14. Thymidine kinase diversity in bacteria

    DEFF Research Database (Denmark)

    Sandrini, Michael; Clausen, A.R.; Munch-Petersen, B.;

    2006-01-01

    Thymidine kinases (TKs) appear to be almost ubiquitous and are found in nearly all prokaryotes, eukaryotes, and several viruses. They are the key enzymes in thymidine salvage and activation of several anti-cancer and antiviral drugs. We show that bacterial TKs can be subdivided into 2 groups. The....... The TKs from Gram-positive bacteria are more closely related to the eukaryotic TK1 enzymes than are TKs from Gram-negative bacteria....

  15. A comparative effect of 3 disinfectants on heterotrophic bacteria, iron bacteria and sulfate-reducing bacteria

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The disinfection effect of chlorine dioxide, chlorine and their mixture on heterotrophic bacteria, iron bacteria and sulfate-reducing bacteria in circulating cooling water was studied. The results of the test indicated that high purity chlorine dioxide was the most effective biocide in the 3 disinfectants, and with a dosage of 0.5mg/L, chlorine dioxide could obtain perfect effect. High purity chloride dioxide could have the excellent effect with the pH value of 6 to 10, and could keep it within 72 h. Chlorine and their mixture couldn't reach the effect of chlorine dioxide.

  16. Bioreporter bacteria for landmine detection

    Energy Technology Data Exchange (ETDEWEB)

    Burlage, R.S. [Oak Ridge National Lab., TN (United States); Youngblood, T. [Frisby Technologies, Aiken, SC (United States); Lamothe, D. [American Technologies, Inc., Huntsville, AL (United States). Ordnance/Explosives Environmental Services Div.

    1998-04-01

    Landmines (and other UXO) gradually leak explosive chemicals into the soil at significant concentrations. Bacteria, which have adapted to scavenge low concentrations of nutrients, can detect these explosive chemicals. Uptake of these chemicals results in the triggering of specific bacterial genes. The authors have created genetically recombinant bioreporter bacteria that detect small concentrations of energetic chemicals. These bacteria are genetically engineered to produce a bioluminescent signal when they contact specific explosives. A gene for a brightly fluorescent compound can be substituted for increased sensitivity. By finding the fluorescent bacteria, you find the landmine. Detection might be accomplished using stand-off illumination of the minefield and GPS technology, which would result in greatly reduced risk to the deminers. Bioreporter technology has been proven at the laboratory scale, and will be tested under field conditions in the near future. They have created a bacterial strain that detects sub-micromolar concentrations of o- and p-nitrotoluene. Related bacterial strains were produced using standard laboratory protocols, and bioreporters of dinitrotoluene and trinitrotoluene were produced, screening for activity with the explosive compounds. Response time is dependent on the growth rate of the bacteria. Although frill signal production may require several hours, the bacteria can be applied over vast areas and scanned quickly, producing an equivalent detection speed that is very fast. This technology may be applicable to other needs, such as locating buried explosives at military and ordnance/explosive manufacturing facilities.

  17. Isolation and Identification of Concrete Environment Bacteria

    Science.gov (United States)

    Irwan, J. M.; Anneza, L. H.; Othman, N.; Husnul, T.; Alshalif, A. F.

    2016-07-01

    This paper presents the isolation and molecular method for bacteria identification through PCR and DNA sequencing. Identification of the bacteria species is required in order to fully utilize the bacterium capability for precipitation of calcium carbonate in concrete. This process is to enable the addition of suitable catalyst according to the bacterium enzymatic pathway that is known through the bacteria species used. The objective of this study is to isolate, enriched and identify the bacteria species. The bacteria in this study was isolated from fresh urine and acid mine drainage water, Kota Tinggi, Johor. Enrichment of the isolated bacteria was conducted to ensure the bacteria survivability in concrete. The identification of bacteria species was done through polymerase chain reaction (PCR) and rRDNA sequencing. The isolation and enrichment of the bacteria was done successfully. Whereas, the results for bacteria identification showed that the isolated bacteria strains are Bacillus sp and Enterococus faecalis.

  18. Recent progress in ion sources

    International Nuclear Information System (INIS)

    This paper is intended to survey recent developments in ion sources, particularly work reported at the ''Symposium on Ion Sources and the Formation of Ion Beams'' held in Berkeley in October 1974. The approach here will be to subdivide this topic into three main areas; briefly list and discuss notable progress in each; and finally add some additional detail through a few specific, selected examples. The major items of progress discussed include development of large-area plasma surfaces for multiple- aperture ion sources, a significant increase in available negative-ion current densities, and improved general agreement between extraction electrode design and performance. (U.S.)

  19. Early detection of emphysema progression

    DEFF Research Database (Denmark)

    Gorbunova, Vladlena; Jacobs, Sander S A M; Lo, Pechin;

    2010-01-01

    Emphysema is one of the most widespread diseases in subjects with smoking history. The gold standard method for estimating the severity of emphysema is a lung function test, such as forced expiratory volume in first second (FEV1). However, several clinical studies showed that chest CT scans offer...... emphysema progression from longitudinal chest CT scans. First, images are registered to a common system of coordinates and then local image dissimilarities are computed in corresponding anatomical locations. Finally, the obtained dissimilarity representation is converted into a single emphysema progression...

  20. Early Detection of Emphysema Progression

    DEFF Research Database (Denmark)

    Gorbunova, V.; Jacobs, S.S.A.M.; Lo, Pechin Chien Pau;

    2010-01-01

    Emphysema is one of the most widespread diseases in subjects with smoking history. The gold standard method for estimating the severity of emphysema is a lung function test, such as forced expiratory volume in first second (FEV1). However, several clinical studies showed that chest CT scans offer...... emphysema progression from longitudinal chest CT scans. First, images are registered to a common system of coordinates and then local image dissimilarities are computed in corresponding anatomical locations. Finally, the obtained dissimilarity representation is converted into a single emphysema progression...

  1. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    J. Toulouse

    2012-04-05

    The purpose of this project was to better understand the 'Multiscale Dynamics of Relaxor Ferroelectrics'. The output of the project is summarized in the narrative. The results of the work were presented at a number of different conferences and four papers were written, the references to which are also indicated in the report and which have also been uploaded on e-link. The multiscale dynamics of relaxors was clearly identified in the three characteristic temperatures that were identified. In particular, we were the first group to identify an intermediate temperature, T*, at which the correlations between off-center ions in relaxor cross-over from being dynamic to being static and giving rise to the characteristic relaxor behavior in the dielectric constant. Other groups have now confirmed the existence of such an intermediate temperature. We also made and reported two other observations: (1) a coherent interference phenomena (EIT-like effect) near the transition of several relaxors, which provides information on the nature and mechanism of the transition; and (2) in a similar way, inelastic neutron scattering results were interpreted as resonant scattering of acoustic phonons by localized modes in polar nanodomains. In parallel with the neutron scattering work, we also developed a theory of the scattering of phonons by the above localized modes. The theoretical development is very formal at this point and did not allow an easy comparison with the experimental results. This work is in progress.

  2. Productization and Manufacturing Scaling of High-Efficiency Solar Cell and Module Products Based on a Disruptive Low-Cost, Mono-Crystalline Technology: Final Technical Progress Report, April 1, 2009 - December 30, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Fatemi, H.

    2012-07-01

    Final report for PV incubator subcontract with Solexel, Inc. The purpose of this project was to develop Solexel's Unique IP, productize it, and transfer it to manufacturing. Silicon constitutes a significant fraction of the total solar cell cost, resulting in an industry-wide drive to lower silicon usage. Solexel's disruptive Solar cell structure got around these challenges and promised superior light trapping, efficiency and mechanical strength, despite being significantly thinner than commercially available cells. Solexel's successful participation in this incubator project became evident as the company is now moving into commercial production and position itself to be competitive for the next Technology Pathway Partnerships (TPP) funding opportunity.

  3. Implementing Program Integrity from an HBCU Perspective: Progress, Problems, and Prospects. An Analysis of Part H, Program Integrity - TRIAD of the Higher Education Act and the Final Rules and Related Interim Final Regulations Published in the "Federal Register" on April 29, 1994.

    Science.gov (United States)

    Blakely, William A.

    This paper examines the impact and implications for the nation's 104 historically black colleges and universities (HBCUs) of the final regulations published in the April 29, 1994 "Federal Register" and traces both the legislative and regulatory history of Part H of the Higher Education Act provisions. The analysis addresses specific issues,…

  4. Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Simon Silver

    2009-05-28

    The work done with DOE support during this 15 year period was extensive and successful. It is best summarized by the list of 58 publications (below) which reported progress made with DOE support. These are from the grant period and a few more recent reporting on grant research. Mostly these are primary research reports in reviewed journals. There are also, however, many summary reviews in review journals and in scientific monographs, as they also are key places for reporting research progress. What we did during this grant period (and much longer) was to characterize genetic determinants for bacterial resistances to additional toxic heavy metals of DOE concern, through starting with phenotypic properties of the resistant bacteria to DNA sequence determination and characterization of the genes involved. Over the years (and as shown in the list of publications), the toxic metal-forming elements we have studied included Ag, As, Cd, Cr, and Hg. In each case, we started with basically nothing (or very little) known, progressed through quite detailed understanding, until other laboratory groups also became strongly involved in related studies. More recently, with DOE support, we were the first laboratory group in the world to identify genes for bacterial resistance to silver salts (sil genes) and the closely related silver-and-copper resistance genes cus. This was initially reported in detail in Gupta et al. (1999; see publications list below). We also identified the first toxic metal 'gene island' (multiple transcripts and perhaps 25 genes each in need of detailed study) which encodes the subunits of arsenite oxidase (which we called aso; Silver and Phung, 2005; but most other researchers have subsequently settled on aox for the gene mnemonic). Both of these systems were firsts. Now a few years later, a search on GenBank shows that each is now represented by gene families with more than a dozen examples that have been identified and sequenced. Most of the

  5. Control of indigenous pathogenic bacteria in seafood

    DEFF Research Database (Denmark)

    Huss, Hans Henrik

    1997-01-01

    The pathogenic bacteria indigenous to the aquatic and general environment are listed. Their distribution in nature, prevalence in seafood and the possibilities for growth of these organisms in various types of products are outlined These data, combined with what is known regarding the epidemiology...... of disease, are used to place the various seafood products in risk categories and to identify areas of concern. It is concluded that the presence of pathogens in molluscs and the growth of Listeria monocytogenes in lightly preserved fish products are hazards which are presently not under control. In order...... to prevent growth and toxin production by Clostridium botulinum when products are stored at abuse temperature, it is recommended that additional barriers to growth are included in lightly preserved (e.g. cold smoked salmon) and low-heat treated (e.g REPFEDS) products. It is finally pointed out...

  6. Isolation and Identification of Nitrite- oxidizing Bacteria

    Institute of Scientific and Technical Information of China (English)

    Yulong; CHEN; Wenyong; TAN; Da; YANG

    2015-01-01

    In order to select the strain that can degrade nitrite,we use the screening plate with nitrite as the sole nitrogen source to select the strain with ability to degrade nitrite,and get a strain with nitrite degrading capacity from the silt of shrimp farming pond in Hepu City,Guangxi Zhuang Autonomous Region. By identifying the strain from colony morphology,physiological and biochemical characteristics and 16 S r RNA sequence,we finally get a bacteria strain that can degrade nitrite,and this strain can grow well on the culture medium with nitrite concentration of 2 g / L. Based on morphology,nitrogen source requirements and evolutionary tree analysis of the above 16 S r RNA sequence,it is found that this strain belongs to Pannonibacter phragmitetus. According to the screening location,it is named HPPP007 strain.

  7. [Genetic resources of nodule bacteria].

    Science.gov (United States)

    Rumiantseva, M L

    2009-09-01

    Nodule bacteria (rhizobia) form highly specific symbiosis with leguminous plants. The efficiency of accumulation of biological nitrogen depends on molecular-genetic interaction between the host plant and rhizobia. Genetic characteristics of microsymbiotic strains are crucial in developing highly productive and stress-resistant symbiotic pairs: rhizobium strain-host plant cultivar (species). The present review considers the issue of studying genetic resources of nodule bacteria to identify genes and their blocks, responsible for the ability of rhizobia to form highly effective symbiosis in various agroecological conditions. The main approaches to investigation of intraspecific and interspecific genetic and genomic diversity of nodule bacteria are considered, from MLEE analysis to the recent methods of genomic DNA analysis using biochips. The data are presented showing that gene centers of host plants are centers of genetic diversification of nodule bacteria, because the intraspecific polymorphism of genetic markers of the core and the accessory rhizobial genomes is extremely high in them. Genotypic features of trapped and nodule subpopulations of alfalfa nodule bacteria are discussed. A survey of literature showed that the genomes of natural strains in alfalfa gene centers exhibit significant differences in genes involved in control of metabolism, replication, recombination, and the formation of defense response (hsd genes). Natural populations of rhizobia are regarded as a huge gene pool serving as a source of evolutionary innovations.

  8. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Robert C. [Texas A& M University; Kamon, Teruki [Texas A& M University; Toback, David [Texas A& M University; Safonov, Alexei [Texas A& M University; Dutta, Bhaskar [Texas A& M University; Dimitri, Nanopoulos [Texas A& M University; Pope, Christopher [Texas A& M University; White, James [Texas A& M University

    2013-11-18

    Overview The High Energy Physics Group at Texas A&M University is submitting this final report for our grant number DE-FG02-95ER40917. This grant has supported our wide range of research activities for over a decade. The reports contained here summarize the latest work done by our research team. Task A (Collider Physics Program): CMS & CDF Profs. T. Kamon, A. Safonov, and D. Toback co-lead the Texas A&M (TAMU) collider program focusing on CDF and CMS experiments. Task D: Particle Physics Theory Our particle physics theory task is the combined effort of Profs. B. Dutta, D. Nanopoulos, and C. Pope. Task E (Underground Physics): LUX & NEXT Profs. R. Webb and J. White(deceased) lead the Xenon-based underground research program consisting of two main thrusts: the first, participation in the LUX two-phase xenon dark matter search experiment and the second, detector R&D primarily aimed at developing future detectors for underground physics (e.g. NEXT and LZ).

  9. Toxicity Evaluation of Pig Slurry Using Luminescent Bacteria and Zebrafish

    Directory of Open Access Journals (Sweden)

    Wenyan Chen

    2014-07-01

    Full Text Available Biogas slurry has become a serious pollution problem and anaerobic digestion is widely applied to pig manure treatment for environmental protection and energy recovery. To evaluate environmental risk of the emission of biogas slurry, luminescent bacteria (Vibrio fischeri, larvae and embryos of zebrafish (Danio rerio were used to detect the acute and development toxicity of digested and post-treated slurry. Then the ability of treatment process was evaluated. The results showed that digested slurry displayed strong toxicity to both zebrafish and luminescent bacteria, while the EC50 for luminescent bacteria and the LC50 for larvae were only 6.81% (v/v and 1.95% (v/v respectively, and embryonic development was inhibited at just 1% (v/v. Slurry still maintained a high level of toxicity although it had been treated by membrane bioreactor (MBR, while the LC50 of larvae was 75.23% (v/v and there was a little effect on the development of embryos and V. fischeri; the results also revealed that the zebrafish larvae are more sensitive than embryos and luminescent bacteria to pig slurry. Finally, we also found the toxicity removal rate was higher than 90% after the treatment of MBR according to toxicity tests. In conclusion, further treatment should be used in pig slurry disposal or reused of final effluent.

  10. Toxicity evaluation of pig slurry using luminescent bacteria and zebrafish.

    Science.gov (United States)

    Chen, Wenyan; Cai, Qiang; Zhao, Yuan; Zheng, Guojuan; Liang, Yuting

    2014-07-01

    Biogas slurry has become a serious pollution problem and anaerobic digestion is widely applied to pig manure treatment for environmental protection and energy recovery. To evaluate environmental risk of the emission of biogas slurry, luminescent bacteria (Vibrio fischeri), larvae and embryos of zebrafish (Danio rerio) were used to detect the acute and development toxicity of digested and post-treated slurry. Then the ability of treatment process was evaluated. The results showed that digested slurry displayed strong toxicity to both zebrafish and luminescent bacteria, while the EC50 for luminescent bacteria and the LC50 for larvae were only 6.81% (v/v) and 1.95% (v/v) respectively, and embryonic development was inhibited at just 1% (v/v). Slurry still maintained a high level of toxicity although it had been treated by membrane bioreactor (MBR), while the LC50 of larvae was 75.23% (v/v) and there was a little effect on the development of embryos and V. fischeri; the results also revealed that the zebrafish larvae are more sensitive than embryos and luminescent bacteria to pig slurry. Finally, we also found the toxicity removal rate was higher than 90% after the treatment of MBR according to toxicity tests. In conclusion, further treatment should be used in pig slurry disposal or reused of final effluent. PMID:24995598

  11. Enzymatic Digestion for Improved Bacteria Separation from Leafy Green Vegetables.

    Science.gov (United States)

    Wang, Danhui; Wang, Ziyuan; He, Fei; Kinchla, Amanda J; Nugen, Sam R

    2016-08-01

    An effective and rapid method for the separation of bacteria from food matrix remains a bottleneck for rapid bacteria detection for food safety. Bacteria can strongly attach to a food surface or internalize within the matrix, making their isolation extremely difficult. Traditional methods of separating bacteria from food routinely involve stomaching, blending, and shaking. However, these methods may not be efficient at removing all the bacteria from complex matrices. Here, we investigate the benefits of using enzyme digestion followed by immunomagnetic separation to isolate Salmonella from spinach and lettuce. Enzymatic digestion using pectinase and cellulase was able to break down the structure of the leafy green vegetables, resulting in the detachment and release of Salmonella from the leaves. Immunomagnetic separation of Salmonella from the liquefied sample allowed an additional separation step to achieve a more pure sample without leaf debris that may benefit additional downstream applications. We have investigated the optimal combination of pectinase and cellulase for the digestion of spinach and lettuce to improve sample detection yields. The concentrations of enzymes used to digest the leaves were confirmed to have no significant effect on the viability of the inoculated Salmonella. Results reported that the recovery of the Salmonella from the produce after enzyme digestion of the leaves was significantly higher (P < 0.05) than traditional sample preparation methods to separate bacteria (stomaching and manually shaking). The results demonstrate the potential for use of enzyme digestion prior to separation can improve the efficiency of bacteria separation and increase the likelihood of detecting pathogens in the final detection assay.

  12. Antibacterial Effect of Teucrium polium on the Bacteria Causing Urinary

    Directory of Open Access Journals (Sweden)

    Samira Shahba

    2014-03-01

    Full Text Available Background: The present investigation was conducted to study the antibacterial effect of aqueous, ethanolic and ethyl acetate extracts of Teucrium polium plant on the bacteria isolated from urine samples of those with UTI and to compare it with the effect of commonly used antibiotics in treating UTIs. Materials and Methods: The antibiotic resistance of 147 strains of bacteria causing UTIs to the antibiotics selected through Kirby-Bauer disk diffusion method was determined. In the meantime, the aqueous, ethanolic and ethyl acetate extracts of T. polium plant were prepared. The antibacterial activity of these extracts was examined using Disk Diffusion Method. Finally, Minimum Inhibitory Concentration (MIC and Minimum Bactericidal Concentration (MBC of antibacterial were determined using serial dilution method. Results: T. polium extracts were merely effective in enterococcus and pseudomonas bacteria. In general, the MIC rate of aqueous extract in enterococcus was 1.25-5 mg/ml. The MIC rate of ethanolic extract for enterococcus was calculated as 10 mg/ml. The MIC of aqueous and ethyl acetate extracts for pseudomonas bacteria were achieved as 5 and 20 mg/ml, respectively. The MBC contents of aqueous and ethyl acetate extracts of teucrium for pseudomonas bacteria was 10 mg/ml in aqueous and 20 mg/ml in ethyl acetate extracts. The MBC content of extracts for enterococcus bacteria were 10 mg/ml in aqueous extract and 20 mg/ml in ethanolic extract. Conclusion: T. polium extract can be effective in some bacteria causing urinary tract infection, especially enterococcus.

  13. Computational models of populations of bacteria and lytic phage.

    Science.gov (United States)

    Krysiak-Baltyn, Konrad; Martin, Gregory J O; Stickland, Anthony D; Scales, Peter J; Gras, Sally L

    2016-11-01

    The use of phages to control and reduce numbers of unwanted bacteria can be traced back to the early 1900s, when phages were explored as a tool to treat infections before the wide scale use of antibiotics. Recently, phage therapy has received renewed interest as a method to treat multiresistant bacteria. Phages are also widely used in the food industry to prevent the growth of certain bacteria in foods, and are currently being explored as a tool for use in bioremediation and wastewater treatment. Despite the large body of biological research on phages, relatively little attention has been given to computational modeling of the population dynamics of phage and bacterial interactions. The earliest model was described by Campbell in the 1960s. Subsequent modifications to this model include partial or complete resistance, multiple phage binding sites, and spatial heterogeneity. This review provides a general introduction to modeling of the population dynamics of bacteria and phage. The review introduces the basic model and relevant concepts and evaluates more complex variations of the basic model published to date, including a model of disease epidemics caused by infectious bacteria. Finally, the shortcomings and potential ways to improve the models are discussed. PMID:26828960

  14. Bacteria sensing mechanisms in Drosophila gut: Local and systemic consequences.

    Science.gov (United States)

    Capo, Florence; Charroux, Bernard; Royet, Julien

    2016-11-01

    All insects are colonized by microorganisms on their exoskeleton, their gut and even in some cases within their own somatic and germ line cells. This microbiota that can represent up to a few percent of the insect biomass may have a pervasive impact on many aspects of insect biology including physiology, nutrient acquisition, ageing, behaviour and resistance to infection. Mainly through ingestion of contaminated food, the mouth-gut axis represents the first and principal access of external bacteria to the host. Soon after ingestion, the feeding insect needs to rapidly and accurately identify the ingested microbes and decide whether to preserve them if beneficial or neutral, or to eliminate them if potentially harmful. We will review here the recent data acquired in Drosophila on the mechanisms that invertebrate enterocytes rely on to detect the presence of bacteria in the gut. We will compare these modes of bacteria sensing to those in other immune competent tissues and try to rationalize differences that may exist. We will also analyse the physiological consequences of bacteria detection not only locally for the gut itself but also for remote tissues. Finally, we will describe the physiological disorders that can occur due to inaccurate bacteria identification by the gut epithelium. PMID:26778296

  15. Algae-bacteria interactions: Evolution, ecology and emerging applications.

    Science.gov (United States)

    Ramanan, Rishiram; Kim, Byung-Hyuk; Cho, Dae-Hyun; Oh, Hee-Mock; Kim, Hee-Sik

    2016-01-01

    Algae and bacteria have coexisted ever since the early stages of evolution. This coevolution has revolutionized life on earth in many aspects. Algae and bacteria together influence ecosystems as varied as deep seas to lichens and represent all conceivable modes of interactions - from mutualism to parasitism. Several studies have shown that algae and bacteria synergistically affect each other's physiology and metabolism, a classic case being algae-roseobacter interaction. These interactions are ubiquitous and define the primary productivity in most ecosystems. In recent years, algae have received much attention for industrial exploitation but their interaction with bacteria is often considered a contamination during commercialization. A few recent studies have shown that bacteria not only enhance algal growth but also help in flocculation, both essential processes in algal biotechnology. Hence, there is a need to understand these interactions from an evolutionary and ecological standpoint, and integrate this understanding for industrial use. Here we reflect on the diversity of such relationships and their associated mechanisms, as well as the habitats that they mutually influence. This review also outlines the role of these interactions in key evolutionary events such as endosymbiosis, besides their ecological role in biogeochemical cycles. Finally, we focus on extending such studies on algal-bacterial interactions to various environmental and bio-technological applications. PMID:26657897

  16. FINAL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    PETER, GARY F. [UNIVERSITY OF FLORIDA

    2014-07-16

    Excellent progress was made in standardizing three complementary methods: Magnetic resonance imaging, x-ray micro CT, and MALDI imaging linear ion trap mass spectroscopy to image biomass and chemical, anatomical and functional changes that occur during pretreatment and hydrolysis. Magnetic resonance microscopy provides excellent images with as low as 5 uM resolution with hydrated biomass samples. We visualized dramatic changes in signal associated with the hydrolysis of the carbohydrates by strong acids. Quantitative diffusion approaches were used to probe more subtle structural changes in biomass. Diffusion tensor calculations reflect diffusion anisotropy and fractional anisotropy maps clearly show the longer range diffusion within the vessels compared to within the fiber cells. The diffusion is increased along the cell walls of the vessels. Suggesting that further research with NMR imaging should be pursued. X-ray CT provides excellent images at as low as 3.5 uM resolution from dried biomass. Small increases in surface area, and decreases in local density have been quantified in with wood after mild pretreatments; these changes are expected to be underestimates of the hydrated wood, due to the ~12% shrinkage that occurs upon drying untreated wood. MALDI-MS spectra show high ion intensities at most mass to charge ratios in untreated and pretreated woody material. MALDI-MSn is required to improve specificity and reduce background for imaging. MALDI-TOF is not specific enough for carbohydrate identification. Using MALDI-LIT/MSn we can readily identify oligomeric glucans and xylans and their fragmentation patterns as well as those of the glucuronic acid side chains of birch 4-O-methyl glucuronxylan. Imaging of glucan and xylan oligomers show that many contain isobaric ions with different distributions, indicating again that MSn is needed for accurate imaging of lignocellulosic materials. We are now starting to integrate the three imaging methods by using the same set

  17. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Gentile, Thomas R.

    2014-03-14

    We propose to extend the technique of polarized neutron scattering into new domains by continued development and application of polarized 3He spin-filters. These devices are particularly relevant to the Spallation Neutron Source, as the polarizing monochromators historically used at reactor sources will usually not be suitable polarizers, and wide-angle polarization analysis will be essential. With prior support from the Office of Science, we have developed neutron spin-filters based on the large spin dependence of the cross section for neutron capture by 3He, and applied these devices to a small angle neutron scattering spectrometer (SANS), polarized neutron reflectometers, a thermal energy single crystal diffractometer (SCD), and a thermal energy triple-axis instrument. Our developments have been adopted for application on the magnetism reflectometer at the SNS and for the NIST Center for Neutron Research (NCNR) 3He user capability. Results from both these programs are emerging. We have made significant progress in the past grant period on wide-angle polarization analysis. We have also performed several studies relevant to continuous optical pumping, including collaboration on experiments that have revealed neutron beam effects on spin filters that are continuously pumped by spin-exchange optical pumping. We contributed to an experiment on a neutron interferometer, in which the successful results obtained are directly related to both 3He cell technology and high accuracy 3He -based neutron polarimetry. Implementation of wide-angle polarization analysis will continue to be key thrust for our work in this new proposal. We will also focus on continuous optical pumping and the fundamental issues that determine the achievable 3He polarization. This project will be carried out by a collaboration involving scientists at NIST, Indiana University, Hamilton College, and the Univ. of Wisconsin who are experts in 3He polarization techniques, and materials scientists from the

  18. DEVELOPMENT OF TOFU PRODUCTION METHOD WITH PROBIOTIC BACTERIA ADDITION

    Directory of Open Access Journals (Sweden)

    Dorota Zielińska

    2015-06-01

    Full Text Available The aim of the study was to develop a production method for tofu with probiotic bacteria under laboratory conditions. The works included: selection of a strain and tofu production conditions, and a storage test of the manufactured product. It was concluded that the sensory quality of tofu with the addition of different probiotic cultures did not differ significantly (p>0.01, depending on used strains and their mixtures, and the sample quality was comparable to the commercial product. It was observed that the number of Lactobacillus bacteria in study samples was the factor determining the palatability of tofu (r= 0.75. On the other hand, the sensory quality of products was significantly affected by the production method of tofu with the addition of probiotic bacteria. It was concluded that the formation of curds from soy beverage by the addition of CaSO4, followed by inoculation with Lactobacillus casei ŁOCK 0900 at the amount of 9.26 log CFU/g and incubation at temp. of 37C for 2h as well as for 20h are methods recommended for production tofu with regard to sensory qualities of the final product among all tested methods. The number of lactic acid bacteria in studied tofu samples was maintained at the high level (109-1010 CFU/g, and the number of Bifidobacterium animalis ssp lactis BB-12 bacteria did not exceed 103 CFU/g, whereas the number of Lactobacillus bacteria was equal to 108-109 CFU/g. For the period of 15 days of storage of tofu with probiotic bacteria at the temperature of 4C the number of lactic acid bacteria was maintained at the constant level of approx. 109 CFU/g. It was concluded that it is possible to produce tofu with probiotic bacteria that has acceptable sensory characteristics and a high number of lactic acid bacteria, therefore the product could be considered as a functional one.

  19. Methylotrophic bacteria in sustainable agriculture.

    Science.gov (United States)

    Kumar, Manish; Tomar, Rajesh Singh; Lade, Harshad; Paul, Diby

    2016-07-01

    Excessive use of chemical fertilizers to increase production from available land has resulted in deterioration of soil quality. To prevent further soil deterioration, the use of methylotrophic bacteria that have the ability to colonize different habitats, including soil, sediment, water, and both epiphytes and endophytes as host plants, has been suggested for sustainable agriculture. Methylotrophic bacteria are known to play a significant role in the biogeochemical cycle in soil ecosystems, ultimately fortifying plants and sustaining agriculture. Methylotrophs also improve air quality by using volatile organic compounds such as dichloromethane, formaldehyde, methanol, and formic acid. Additionally, methylotrophs are involved in phosphorous, nitrogen, and carbon cycling and can help reduce global warming. In this review, different aspects of the interaction between methylotrophs and host plants are discussed, including the role of methylotrophs in phosphorus acquisition, nitrogen fixation, phytohormone production, iron chelation, and plant growth promotion, and co-inoculation of these bacteria as biofertilizers for viable agriculture practices. PMID:27263015

  20. Methylotrophic bacteria in sustainable agriculture.

    Science.gov (United States)

    Kumar, Manish; Tomar, Rajesh Singh; Lade, Harshad; Paul, Diby

    2016-07-01

    Excessive use of chemical fertilizers to increase production from available land has resulted in deterioration of soil quality. To prevent further soil deterioration, the use of methylotrophic bacteria that have the ability to colonize different habitats, including soil, sediment, water, and both epiphytes and endophytes as host plants, has been suggested for sustainable agriculture. Methylotrophic bacteria are known to play a significant role in the biogeochemical cycle in soil ecosystems, ultimately fortifying plants and sustaining agriculture. Methylotrophs also improve air quality by using volatile organic compounds such as dichloromethane, formaldehyde, methanol, and formic acid. Additionally, methylotrophs are involved in phosphorous, nitrogen, and carbon cycling and can help reduce global warming. In this review, different aspects of the interaction between methylotrophs and host plants are discussed, including the role of methylotrophs in phosphorus acquisition, nitrogen fixation, phytohormone production, iron chelation, and plant growth promotion, and co-inoculation of these bacteria as biofertilizers for viable agriculture practices.

  1. Chitin Degradation In Marine Bacteria

    DEFF Research Database (Denmark)

    Paulsen, Sara; Machado, Henrique; Gram, Lone

    2015-01-01

    Introduction: Chitin is the most abundant polymer in the marine environment and the second most abundant in nature. Chitin does not accumulate on the ocean floor, because of microbial breakdown. Chitin degrading bacteria could have potential in the utilization of chitin as a renewable carbon...... and nitrogen source in the fermentation industry.Methods: Here, whole genome sequenced marine bacteria were screened for chitin degradation using phenotypic and in silico analyses.Results: The in silico analyses revealed the presence of three to nine chitinases in each strain, however the number of chitinases...... chitin regulatory system.Conclusions: This study has provided insight into the ecology of chitin degradation in marine bacteria. It also served as a basis for choosing a more efficient chitin degrading production strain e.g. for the use of chitin waste for large-scale fermentations....

  2. Quantitative monitoring of the Chlamydia trachomatis developmental cycle using GFP-expressing bacteria, microscopy and flow cytometry.

    Directory of Open Access Journals (Sweden)

    François Vromman

    Full Text Available Chlamydiae are obligate intracellular bacteria. These pathogens develop inside host cells through a biphasic cycle alternating between two morphologically distinct forms, the infectious elementary body and the replicative reticulate body. Recently, C. trachomatis strains stably expressing fluorescent proteins were obtained. The fluorochromes are expressed during the intracellular growth of the microbe, allowing bacterial visualization by fluorescence microscopy. Whether they are also present in the infectious form, the elementary body, to a detectable level has not been studied. Here, we show that a C. trachomatis strain transformed with a plasmid expressing the green fluorescent protein (GFP accumulates sufficient quantities of the probe in elementary bodies for detection by microscopy and flow cytometry. Adhesion of single bacteria was detected. The precise kinetics of bacterial entry were determined by microscopy using automated procedures. We show that during the intracellular replication phase, GFP is a convenient read-out for bacterial growth with several advantages over current methods. In particular, infection rates within a non-homogenous cell population are easily quantified. Finally, in spite of their small size, individual elementary bodies are detected by flow cytometers, allowing for direct enumeration of a bacterial preparation. In conclusion, GFP-expressing chlamydiae are suitable to monitor, in a quantitative manner, progression throughout the developmental cycle. This will facilitate the identification of the developmental steps targeted by anti-chlamydial drugs or host factors.

  3. Adaptation, Bacteria and Maxwell's Demons

    Science.gov (United States)

    Galajda, Peter; Keymer, Juan E.; Austin, Robert H.

    2007-03-01

    We propose a method to study the adaptation of bacterial populations with an asymmetric wall of Maxwell Demon openings. A Maxwell Demon opening is a funnel which is easier to enter than to leave. The interaction of swimming cells with such a Maxwell Demon Wall results in a population density separation, in apparent (but not real) violation of the Second Law of Thermodynamics, as we will show. Bacteria can be exposed to spatial challenges in order to move to e. g. higher food levels. The question we address in these experiments is: do the bacteria adapt and overcome the Maxwell Demon Wall?

  4. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    David W. Mazyck; Angela Lindner; CY Wu, Rick Sheahan, Ashok Jain

    2007-06-30

    Nuchar granular activated carbon, perlite, Osmocote slow release ammonium nitrate pellets, and Agrasoke water crystals in a 4:2:1:1 ratio by volume. The biofilter was inoculated with a bacterial culture collected from a Florida pulp and paperboard plant. A non-inoculated biofilter column was also tested. Use of a biological inoculum enriched from biofilm in the pulp and paper process has the potential to enhance the performance of a GAC biofilter. During testing, packing material was removed from the inlet and oulet of the biofilters and analyzed for genetic diversity using molecular techniques. The biofilter inoculated with specifically-enhanced inoculum showed higher bacterial diversity for methylotrophs and all bacteria, as compared to a non-inoculated biofilter. Mixed methylotrophic cultures, selected as potential biofilter inocula, showed increased methanol removal with highest concentrations of nitrogen provided as nitrate.

  5. EDITORIAL: Catalysing progress Catalysing progress

    Science.gov (United States)

    Demming, Anna

    2010-01-01

    Examples of the merits of blue-sky research in the history of science are legion. The invention of the laser, celebrating its 50th anniversary this year, is an excellent example. When it was invented it was considered to be 'a solution waiting for a problem', and yet the level to which it has now infiltrated our day-to-day technological landscape speaks volumes. At the same time it is also true to say that the direction of research is also at times rightly influenced by the needs and concerns of the general public. Over recent years, growing concerns about the environment have had a noticeable effect on research in nanotechnology, motivating work on a range of topics from green nanomaterial synthesis [1] to high-efficiency solar cells [2] and hydrogen storage [3]. The impact of the world's energy consumption on the welfare of the planet is now an enduring and well founded concern. In the face of an instinctive reluctance to curtail habits of comfort and convenience and the appendages of culture and consumerism, research into renewable and more efficient energy sources seem an encouraging approach to alleviating an impending energy crisis. Fuel cells present one alternative to traditional combustion cells that have huge benefits in terms of the efficiency of energy conversion and the limited harmful emissions. In last week's issue of Nanotechnology, Chuan-Jian Zhong and colleagues at the State University of New York at Binghamton in the USA presented an overview of research on nanostructured catalysts in fuel cells [4]. The topical review includes insights into the interactions between nanoparticles and between nanoparticles and their substrate as well as control over the composition and nanostructure of catalysts. The review also serves to highlight how the flourishing of nanotechnology research has heralded great progress in the exploitation of catalysts with nanostructures ingeniously controlled to maximize surface area and optimize energetics for synthesis

  6. EDITORIAL: Catalysing progress Catalysing progress

    Science.gov (United States)

    Demming, Anna

    2010-01-01

    Examples of the merits of blue-sky research in the history of science are legion. The invention of the laser, celebrating its 50th anniversary this year, is an excellent example. When it was invented it was considered to be 'a solution waiting for a problem', and yet the level to which it has now infiltrated our day-to-day technological landscape speaks volumes. At the same time it is also true to say that the direction of research is also at times rightly influenced by the needs and concerns of the general public. Over recent years, growing concerns about the environment have had a noticeable effect on research in nanotechnology, motivating work on a range of topics from green nanomaterial synthesis [1] to high-efficiency solar cells [2] and hydrogen storage [3]. The impact of the world's energy consumption on the welfare of the planet is now an enduring and well founded concern. In the face of an instinctive reluctance to curtail habits of comfort and convenience and the appendages of culture and consumerism, research into renewable and more efficient energy sources seem an encouraging approach to alleviating an impending energy crisis. Fuel cells present one alternative to traditional combustion cells that have huge benefits in terms of the efficiency of energy conversion and the limited harmful emissions. In last week's issue of Nanotechnology, Chuan-Jian Zhong and colleagues at the State University of New York at Binghamton in the USA presented an overview of research on nanostructured catalysts in fuel cells [4]. The topical review includes insights into the interactions between nanoparticles and between nanoparticles and their substrate as well as control over the composition and nanostructure of catalysts. The review also serves to highlight how the flourishing of nanotechnology research has heralded great progress in the exploitation of catalysts with nanostructures ingeniously controlled to maximize surface area and optimize energetics for synthesis

  7. Search for a final repository. Final repository commission and the public. Questions concerning cooperation and progress of the process at half time of the commission; Endlagersuche. Endlager-Kommission und Oeffentlichkeit(en). Fragen nach Zusammenarbeit und Fortschritten im Prozess zur Halbzeit der Kommission

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Monika C.M. (ed.) [Evangelische Akademie Loccum (Germany). Arbeitsbereich Naturwissenschaften, Oekologie und Umweltpolitik

    2016-08-01

    The volume includes the following contributions: Presumptions and success of public participation. Refusal as legitimate and necessary mean. Experiences form the participation process in Switzerland. Cooperation of the final repository commission and the public. Regional participation: the view of a process attendant in the Swiss procedure. Synergies or friction losses? Who is coordinating the institutions/activities and is bringing them together? Players in the nuclear waste conflict - rights and duties in the frame of the search for waste storage as safe as possible. Transparency and Participation - what is the role of online media in the site search process?.

  8. Manipulating Genetic Material in Bacteria

    Science.gov (United States)

    1998-01-01

    Lisa Crawford, a graduate research assistant from the University of Toledo, works with Laurel Karr of Marshall Space Flight Center (MSFC) in the molecular biology laboratory. They are donducting genetic manipulation of bacteria and yeast for the production of large amount of desired protein. Photo credit: NASA/Marshall Space Flight Center (MSFC)

  9. Engineering robust lactic acid bacteria

    NARCIS (Netherlands)

    Bron, P.A.; Bokhorst-van de Veen, van H.; Wels, M.; Kleerebezem, M.

    2011-01-01

    For centuries, lactic acid bacteria (LAB) have been industrially exploited as starter cultures in the fermentation of foods and feeds for their spoilage-preventing and flavor-enhancing characteristics. More recently, the health-promoting effects of LAB on the consumer have been widely acknowledged,

  10. [Free-living amoebae as vehicles of pathogenic bacteria].

    Science.gov (United States)

    Derda, Monika; Sułek-Stankiewicz, Anna; Hadaś, Edward

    2006-01-01

    The free-living amoebae are ubiquitous organisms. They are found in humid soil and all water reservoirs, i.e. fresh, sea, freezing and hot water. They mainly feed on bacteria. Pathogenic properties of amoebae and the mechanisms underlying pathological changes induced during human infection have not yet been fully elucidated. They are the causative agents of primary amoebic meningo-encephalitis (PAM), granulomatous amebic encephalitis (GAE), a chronic progressive disease of the central nervous system, amebic keratitis (AK), a chronic eye infection; amebic pneumitis (AP), a chronic lung infection, and skin infection. Only a few isolates are strongly and permanently pathogenic to humans. Some isolates lose their pathogenic properties after one passage. It has been assumed that such "temporary", unstable pathogenic properties of the amoebae may be caused by internal factors carried by them. It is generally known that the free-living amoebae may be naturally infected with pathogenic bacteria, which have the ability to survive for a long time and to proliferate in the amoebae cells. The role of the amoeba in the process of maintaining, propagating and transmitting human pathogens has not been well recognized. It has been suggested that some infections can be acquired by inhaling aerosols containing amoebae cells filled with bacteria. The presence of bacteria inside the free-living amoebae possess a great challenge to organisations responsible for testing and inspecting the quality and cleanliness of surface waters, swimming pools and drinking water intakes.

  11. Fuzzy species among recombinogenic bacteria

    Directory of Open Access Journals (Sweden)

    Fraser Christophe

    2005-03-01

    Full Text Available Abstract Background It is a matter of ongoing debate whether a universal species concept is possible for bacteria. Indeed, it is not clear whether closely related isolates of bacteria typically form discrete genotypic clusters that can be assigned as species. The most challenging test of whether species can be clearly delineated is provided by analysis of large populations of closely-related, highly recombinogenic, bacteria that colonise the same body site. We have used concatenated sequences of seven house-keeping loci from 770 strains of 11 named Neisseria species, and phylogenetic trees, to investigate whether genotypic clusters can be resolved among these recombinogenic bacteria and, if so, the extent to which they correspond to named species. Results Alleles at individual loci were widely distributed among the named species but this distorting effect of recombination was largely buffered by using concatenated sequences, which resolved clusters corresponding to the three species most numerous in the sample, N. meningitidis, N. lactamica and N. gonorrhoeae. A few isolates arose from the branch that separated N. meningitidis from N. lactamica leading us to describe these species as 'fuzzy'. Conclusion A multilocus approach using large samples of closely related isolates delineates species even in the highly recombinogenic human Neisseria where individual loci are inadequate for the task. This approach should be applied by taxonomists to large samples of other groups of closely-related bacteria, and especially to those where species delineation has historically been difficult, to determine whether genotypic clusters can be delineated, and to guide the definition of species.

  12. Progression of Liver Disease

    Science.gov (United States)

    ... Browse Related Terms Progression of Liver Disease , Family History of Liver Disease , Liver Wellness , Liver Failure , Liver Biopsy Home > Your Liver > Liver Disease Information > The Progression ...

  13. Learning numerical progressions.

    Science.gov (United States)

    Vitz, P C; Hazan, D N

    1974-01-01

    Learning of simple numerical progressions and compound progressions formed by combining two or three simple progressions is investigated. In two experiments, time to solution was greater for compound vs simple progressions; greater the higher the progression's solution level; and greater if the progression consisted of large vs small numbers. A set of strategies is proposed to account for progression learning based on the assumption S computes differences between integers, differences between differences, etc., in a hierarchical fashion. Two measures of progression difficulty, each a summary of the strategies, are proposed; C1 is a count of the number of differences needed to solve a progression; C2 is the same count with higher level differences given more weight. The measures accurately predict in both experiments the mean time to solve 16 different progressions with C2 being somewhat superior. The measures also predict the learning difficulty of 10 other progressions reported by Bjork (1968).

  14. A Novel Lactic Acid Bacteria Growth-stimulating Peptide from Broad Bean (Vicia faba .) Protein Hydrolysates

    OpenAIRE

    Ping Xiao; Yuan Liu; Rizwan-ur-Rehman; Ran Kang; Yanping Wang

    2015-01-01

    In this study, broad bean protein hydrolysates (BPH) produced by alcalase with strong-stimulating activity for lactic acid bacteria (LAB) was first time reported. In order to obtain the key peptide that have growth-stimulating activity for lactic acid bacteria (LAB), gel filtration chromatography and Reverse Phase High Performance Liquid Chromatography (RP-HPLC) were applied to isolate and purify the peptides from BPH. Finally, F4-2 elicited the highest activity for LAB, corresponding to amin...

  15. Physico-chemical factors and bacteria in fish ponds

    OpenAIRE

    Jun, X.; Xiuzheng, F.; Tongbing, Y.

    2000-01-01

    Analyses of pond water and mud samples show that nitrifying bacteria (including ammonifying bacteria, nitrite bacteria, nitrobacteria and denitrifying bacteria) are in general closely correlated with various physico-chemical factors, ammonifying bacteria are mainly correlated with dissolved oxygen; denitrifying bacteria are inversely correlated with phosphorus; nitrite bacteria are closely correlated with nitrites, nitrobacteria are inversely correlated with ammoniac nitrogen. The nitrifying ...

  16. Smokeless Tobacco May Contain Potentially Harmful Bacteria

    Science.gov (United States)

    ... 160769.html Smokeless Tobacco May Contain Potentially Harmful Bacteria Infections, diarrhea and vomiting are possible consequences, FDA ... products can harbor several species of potentially harmful bacteria, researchers warn. Two types in particular -- Bacillus licheniformis ...

  17. Stress Physiology of Lactic Acid Bacteria.

    Science.gov (United States)

    Papadimitriou, Konstantinos; Alegría, Ángel; Bron, Peter A; de Angelis, Maria; Gobbetti, Marco; Kleerebezem, Michiel; Lemos, José A; Linares, Daniel M; Ross, Paul; Stanton, Catherine; Turroni, Francesca; van Sinderen, Douwe; Varmanen, Pekka; Ventura, Marco; Zúñiga, Manuel; Tsakalidou, Effie; Kok, Jan

    2016-09-01

    Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diverse as starter (e.g., Lactococcus lactis), probiotic (e.g., several Lactobacillus spp.), and pathogenic (e.g., Enterococcus and Streptococcus spp.) LAB. Here we present the state of the art for LAB stress behavior. We describe the multitude of stresses that LAB are confronted with, and we present the experimental context used to study the stress responses of LAB, focusing on adaptation, habituation, and cross-protection as well as on self-induced multistress resistance in stationary phase, biofilms, and dormancy. We also consider stress responses at the population and single-cell levels. Subsequently, we concentrate on the stress defense mechanisms that have been reported to date, grouping them according to their direct participation in preserving cell energy, defending macromolecules, and protecting the cell envelope. Stress-induced responses of probiotic LAB and commensal/pathogenic LAB are highlighted separately due to the complexity of the peculiar multistress conditions to which these bacteria are subjected in their hosts. Induction of prophages under environmental stresses is then discussed. Finally, we present systems-based strategies to characterize the "stressome" of LAB and to engineer new food-related and probiotic LAB with improved stress tolerance. PMID:27466284

  18. Stress Physiology of Lactic Acid Bacteria.

    Science.gov (United States)

    Papadimitriou, Konstantinos; Alegría, Ángel; Bron, Peter A; de Angelis, Maria; Gobbetti, Marco; Kleerebezem, Michiel; Lemos, José A; Linares, Daniel M; Ross, Paul; Stanton, Catherine; Turroni, Francesca; van Sinderen, Douwe; Varmanen, Pekka; Ventura, Marco; Zúñiga, Manuel; Tsakalidou, Effie; Kok, Jan

    2016-09-01

    Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diverse as starter (e.g., Lactococcus lactis), probiotic (e.g., several Lactobacillus spp.), and pathogenic (e.g., Enterococcus and Streptococcus spp.) LAB. Here we present the state of the art for LAB stress behavior. We describe the multitude of stresses that LAB are confronted with, and we present the experimental context used to study the stress responses of LAB, focusing on adaptation, habituation, and cross-protection as well as on self-induced multistress resistance in stationary phase, biofilms, and dormancy. We also consider stress responses at the population and single-cell levels. Subsequently, we concentrate on the stress defense mechanisms that have been reported to date, grouping them according to their direct participation in preserving cell energy, defending macromolecules, and protecting the cell envelope. Stress-induced responses of probiotic LAB and commensal/pathogenic LAB are highlighted separately due to the complexity of the peculiar multistress conditions to which these bacteria are subjected in their hosts. Induction of prophages under environmental stresses is then discussed. Finally, we present systems-based strategies to characterize the "stressome" of LAB and to engineer new food-related and probiotic LAB with improved stress tolerance.

  19. Genetics of Lactic Acid Bacteria

    Science.gov (United States)

    Zagorec, Monique; Anba-Mondoloni, Jamila; Coq, Anne-Marie Crutz-Le; Champomier-Vergès, Marie-Christine

    Many meat (or fish) products, obtained by the fermentation of meat originating from various animals by the flora that naturally contaminates it, are part of the human diet since millenaries. Historically, the use of bacteria as starters for the fermentation of meat, to produce dry sausages, was thus performed empirically through the endogenous micro-biota, then, by a volunteer addition of starters, often performed by back-slopping, without knowing precisely the microbial species involved. It is only since about 50 years that well defined bacterial cultures have been used as starters for the fermentation of dry sausages. Nowadays, the indigenous micro-biota of fermented meat products is well identified, and the literature is rich of reports on the identification of lactic acid bacteria (LAB) present in many traditional fermented products from various geographical origin, obtained without the addition of commercial starters (See Talon, Leroy, & Lebert, 2007, and references therein).

  20. Aggregation Patterns in Stressed Bacteria

    CERN Document Server

    Tsimring, L S; Aranson, I S; Ben-Jacob, E; Cohen, I; Shochet, O; Tsimring, Lev; Levine, Herbert; Aranson, Igor; Ben-Jacob, Eshel; Cohen, Inon; Shochet, Ofer

    1995-01-01

    We study the formation of spot patterns seen in a variety of bacterial species when the bacteria are subjected to oxidative stress due to hazardous byproducts of respiration. Our approach consists of coupling the cell density field to a chemoattractant concentration as well as to nutrient and waste fields. The latter serves as a triggering field for emission of chemoattractant. Important elements in the proposed model include the propagation of a front of motile bacteria radially outward form an initial site, a Turing instability of the uniformly dense state and a reduction of motility for cells sufficiently far behind the front. The wide variety of patterns seen in the experiments is explained as being due the variation of the details of the initiation of the chemoattractant emission as well as the transition to a non-motile phase.

  1. Dissipative Shocks behind Bacteria Gliding

    CERN Document Server

    Virga, Epifanio G

    2014-01-01

    Gliding is a means of locomotion on rigid substrates utilized by a number of bacteria includingmyxobacteria and cyanobacteria. One of the hypotheses advanced to explain this motility mechanism hinges on the role played by the slime filaments continuously extruded from gliding bacteria. This paper solves in full a non-linear mechanical theory that treats as dissipative shocks both the point where the extruded slime filament comes in contact with the substrate, called the filament's foot, and the pore on the bacterium outer surface from where the filament is ejected. We prove that kinematic compatibility for shock propagation requires that the bacterium uniform gliding velocity (relative to the substrate) and the slime ejecting velocity (relative to the bacterium) must be equal, a coincidence that seems to have already been observed.

  2. LACTIC ACID BACTERIA: PROBIOTIC APPLICATIONS

    Directory of Open Access Journals (Sweden)

    NEENA GARG

    2015-10-01

    Full Text Available Lactic acid bacteria (LAB is a heterotrophic Gram-positive bacteria which under goes lactic acid fermentations and leads to production of lactic acid as an end product. LAB includes Lactobacillus, Leuconostoc, Pediococcus, Lactococcus and Streptococcus which are grouped together in the family lactobacillaceae. LAB shows numerous antimicrobial activities due to production of antibacterial and antifungal compounds such as organic acids, bacteriocins, diacetyl, hydrogen peroxide and reutrin. LAB are used as starter culture, consortium members and bioprotective agents in food industry that improve food quality, safety and shelf life. A variety of probiotic LAB species are available including Lactobacillus acidophilus, L. bulgaricus, L. lactis, L. plantarum, L. rhamnosus, L. reuteri, L. fermentum, Bifidobacterium longum, B. breve, B. bifidum, B. esselnsis, B. lactis, B. infantis that are currently recommended for development of functional food products with health-promoting capacities.

  3. Re-engineering bacteria for ethanol production

    Science.gov (United States)

    Yomano, Lorraine P; York, Sean W; Zhou, Shengde; Shanmugam, Keelnatham; Ingram, Lonnie O

    2014-05-06

    The invention provides recombinant bacteria, which comprise a full complement of heterologous ethanol production genes. Expression of the full complement of heterologous ethanol production genes causes the recombinant bacteria to produce ethanol as the primary fermentation product when grown in mineral salts medium, without the addition of complex nutrients. Methods for producing the recombinant bacteria and methods for producing ethanol using the recombinant bacteria are also disclosed.

  4. Compartmentalization of bacteria in microcapsules.

    Science.gov (United States)

    van Wijk, Judith; Heunis, Tiaan; Harmzen, Elrika; Dicks, Leon M T; Meuldijk, Jan; Klumperman, Bert

    2014-12-18

    Lactobacillus plantarum strain 423 was encapsulated in hollow poly(organosiloxane) microcapsules by templating water-in-oil Pickering emulsion droplets via the interfacial reaction of alkylchlorosilanes. The bacteria were suspended in growth medium or buffer to protect the cells against pH changes during the interfacial reactions with alkylchlorosilanes. The results of this work open up novel avenues for the encapsulation of microbial cells.

  5. Folate Production by Probiotic Bacteria

    OpenAIRE

    Stefano Raimondi; Alberto Amaretti; Maddalena Rossi

    2011-01-01

    Probiotic bacteria, mostly belonging to the genera Lactobacillus and Bifidobacterium, confer a number of health benefits to the host, including vitamin production. With the aim to produce folate-enriched fermented products and/or develop probiotic supplements that accomplish folate biosynthesis in vivo within the colon, bifidobacteria and lactobacilli have been extensively studied for their capability to produce this vitamin. On the basis of physiological studies and genome analysis, wild-typ...

  6. Magnetotactic Bacteria from Extreme Environments

    OpenAIRE

    Lefèvre, Christopher T; Dennis A. Bazylinski

    2013-01-01

    Magnetotactic bacteria (MTB) represent a diverse collection of motile prokaryotes that biomineralize intracellular, membrane-bounded, tens-of-nanometer-sized crystals of a magnetic mineral called magnetosomes. Magnetosome minerals consist of either magnetite (Fe3O4) or greigite (Fe3S4) and cause cells to align along the Earth’s geomagnetic field lines as they swim, a trait called magnetotaxis. MTB are known to mainly inhabit the oxic–anoxic interface (OAI) in water columns or sediments of aqu...

  7. Characterization of Mediterranean Magnetotactic Bacteria

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Magnetotactic bacteria are a diverse group of motile prokaryotes that are ubiquitous in aquatic habitats and cosmopolitan in distribution. In this study, we collected magnetotactic bacteria from the Mediterranean Sea. A remarkable diversity of morphotypes was observed, including muiticellular types that seemed to differ from those previously found in North and South America. Another interesting organism was one with magnetosomes arranged in a six-stranded bundle which occupied one third of the cell width. The magnetosome bundle was evident even under optic microscopy. These cells were connected together and swam as a linear entire unit. Magnetosomes did not always align up to form a straight linear chain. A chain composed of rectangle magnetosomes bent at a position with an oval crystal. High resolution transmission electron microscopy analysis of the crystal at the pivotal position suggested uncompleted formation of the crystal. This is the first report of Mediterranean magnetotactic bacteria, which should be useful for studies of biogeochemical cycling and geohistory of the Mediterranean Sea.

  8. Laser-Based Identification of Pathogenic Bacteria

    Science.gov (United States)

    Rehse, Steven J.

    2009-01-01

    Bacteria are ubiquitous in our world. From our homes, to our work environment, to our own bodies, bacteria are the omnipresent although often unobserved companions to human life. Physicists are typically untroubled professionally by the presence of these bacteria, as their study usually falls safely outside the realm of our typical domain. In the…

  9. Nitrogen-fixing methane-utilizing bacteria

    NARCIS (Netherlands)

    Bont, de J.A.M.

    1976-01-01

    Methane occurs abundantly in nature. In the presence of oxygen this gas may be metabolized by bacteria that are able to use it as carbon and energy source. Several types of bacteria involved in the oxidation of methane have been described in literature. Methane-utilizing bacteria have in common that

  10. Drosophila lifespan enhancement by exogenous bacteria

    OpenAIRE

    Brummel, Ted; Ching, Alisa; Seroude, Laurent; Simon, Anne F.; Benzer, Seymour

    2004-01-01

    We researched the lifespan of Drosophila under axenic conditions compared with customary procedure. The experiments revealed that the presence of bacteria during the first week of adult life can enhance lifespan, despite unchanged food intake. Later in life, the presence of bacteria can reduce lifespan. Certain long-lived mutants react in different ways, indicating an interplay between bacteria and longevity-enhancing genes.

  11. Current strategies for improving food bacteria

    NARCIS (Netherlands)

    Kuipers, O P; Buist, Girbe; Kok, Jan

    2000-01-01

    Novel concepts and methodologies are emerging that hold great promise for the directed improvement of food-related bacteria, specifically lactic acid bacteria. Also, the battle against food spoilage and pathogenic bacteria can now be fought more effectively. Here we describe recent advances in micro

  12. Lactic acid bacteria: the bugs of the new millennium.

    Science.gov (United States)

    Konings, W N; Kok, J; Kuipers, O P; Poolman, B

    2000-06-01

    Lactic acid bacteria (LABs) are widely used in the manufacturing of fermented food and are among the best-studied microorganisms. Detailed knowledge of a number of physiological traits has opened new potential applications for these organisms in the food industry, while other traits might be beneficial for human health. Important new developments have been made in the research of LABs in the areas of multidrug resistance, bacteriocins and quorum sensing, osmoregulation, proteolysis, autolysins and bacteriophages. Recently, progress has been made in the construction of food-grade genetically modified LABs.

  13. Cellulose fermentation by nitrogen-fixing anaerobic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Canale-Parola, E.

    1992-12-13

    In anaerobic natural environments cellulose is degraded to methane, carbon dioxide and other products by the combined activities of many diverse microorganisms. We are simulating processes occurring in natural environments by constructing biologically-defined, stable, heterogeneous bacterial communities (consortia) that we use as in vitro systems for quantitative studies of cellulose degradation under conditions of combined nitrogen deprivation. These studies include the investigation of (i) metabolic interactions among members of cellulose-degrading microbial populations, and (ii) processes that regulate the activity or biosynthesis of cellulolytic enzymes. In addition, we are studying the sensory mechanisms that, in natural environments, may enable motile cellulolytic bacteria to migrate toward cellulose. This part of our work includes biochemical characterization of the cellobiose chemoreceptor of cellulolytic bacteria. Finally, an important aspect of our research is the investigation of the mechanisms by which multienzyme complexes of anaerobic bacteria catalyze the depolymerization of crystalline cellulose and of other plant cell wall polysacchaddes. The research will provide fundamental information on the physiology and ecology of cellulose-fermenting, N{sub 2}-fixing bacteria, and on the intricate processes involved in C and N cycling in anaerobic environments. Furthermore, the information will be valuable for the development of practical applications, such as the conversion of plant biomass (e.g., agricultural, forestry and municipal wastes) to automotive fuels such as ethanol.

  14. Development of luminescent bacteria as tracers for geological reservoir characterization

    Energy Technology Data Exchange (ETDEWEB)

    King, J.W.

    1991-10-01

    Bioluminescent cultures were acquired and tested for use as biological tracers for reservoir characterization by small independent oil companies. Initially these bacterial cultures were fastidious to work with, but when we finally determined their critical growth parameters simple test variations were developed that could be routinely accomplished. The intensity of their luminescence is easily distinguished by the human eye and requires no sophisticated technical knowledge or instrumentation. Cultures were received from culture banks and collected from marine environments. In our laboratory they were screened using the criteria of optimum growth and luminescence. Three stock cultures proved to grow profusely even when variations were made in nutrient additions, salts, and temperature. These three selected cultures were not inhibited when introduced to formations and formation waters and were not overgrown by other bacteria. Cultures isolated from the Gulf of Mexico were overgrown by indigenous bacteria and therefore, they were eliminated from further screening and adaption. Experiments were performed according to three major task descriptions: 1. Establish growth and luminescencing limitations of selected bacteria in various media, varying salt concentration and temperature. 2. Adapt cultures to formation waters. 3. Determine transport limitations of bioluminescent bacteria through representative reservoir cores. 19 refs., 5 figs., 7 tabs.

  15. Geothermal progress monitor. Progress report No. 1

    Energy Technology Data Exchange (ETDEWEB)

    1979-12-01

    Progress is reported on the following: electrical uses, direct-heat uses, drilling activities, leases, geothermal loan guarantee program, general activities, and legal, institutional, and regulatory activites. (MHR)

  16. Thermophilic fermentative bacteria from a deep borehole in granitic rock in Sweden

    Science.gov (United States)

    Szewzyk, Ulrich; Szewzyk, Regine; Stenstroem, Thor-Axel

    1997-07-01

    A borehole drilled to a final depth of 6779 m in granitic rock in Gravberg, Sweden, was sampled and examined for the presence and activity of anaerobic bacteria. The application of anaerobic enrichment and isolation techniques resulted in pure cultures of various fermenting bacteria. Growth in enrichment cultures was observed only in those cultures inoculated from water samples from a depth of 3500 m. Pure cultures of anaerobic, fermenting bacteria were obtained with the following substrates: glucose, starch, xylane, ethanol, and lactate. All isolated bacteria were so far undiscribed bacteria by means of their physiological properties. One strain of the glucose fermenting bacteria was further characterized concerning its phylogenetic position and was found to be closest related to Clostridium thermohydrosulfuricum. However, by means of its characteristic metabolism, it was clearly separated from C. thermohydrosulfuricum. No sulfate-reducing or methanogenic bacteria were found in any of the samples. Fermentative bacteria growing in the presence of hematite often reduced the iron and induced the formation and deposition of insoluble iron sulfides.

  17. Genetically modified lactic acid bacteria: applications to food or health and risk assessment.

    Science.gov (United States)

    Renault, Pierre

    2002-11-01

    Lactic acid bacteria have a long history of use in fermented food products. Progress in gene technology allows their modification by introducing new genes or by modifying their metabolic functions. These modifications may lead to improvements in food technology (bacteria better fitted to technological processes, leading to improved organoleptic properties em leader ), or to new applications including bacteria producing therapeutic molecules that could be delivered by mouth. Examples in these two fields will be discussed, at the same time evaluating their potential benefit to society and the possible risks associated with their use. Risk assessment and expected benefits will determine the future use of modified bacteria in the domains of food technology and health.

  18. Final Progress Report for FG02-89ER14030

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, Maureen R

    2011-10-26

    Intracellular Dynamics of Energy-Transducing Organelles. The location and interaction of intracellular organelles is important for exchange of substrate and product between compartments for optimum functioning of biochemical pathways and energy transduction. Plastids and stromules, tubular plastid extensions, are highly dynamic in many plant tissues. Stromules can connect two or more plastids and proteins and macromolecular complexes can be transferred between them. Stromules have been observed to form close contacts with other organelles, the plasma membrane, and can pass through channels in the nucleus. Chloroplasts move in response to light and mechanical stimulus. Especially in non-green cells, plastids change shape and position, and stromules extend and retract. Stromules appear to be involved in recycling of chloroplast proteins when photosynthesis is limited, through an autophagic process that results in degradation of portions of the stromal contents without complete destruction of the chloroplast. Mutations in several genes known to mediate chloroplast division result in altered stromule morphology in some cells. Plastid and stromule motility is mediated by the actin cytoskeleton. The possible role of myosins in chloroplast movement was investigated by labeling the cargo-binding tails of six Arabidopsis myosin XI proteins with yellow fluorescent protein (YFP). The fluorescent proteins were found to localize to vesicles and peroxisomes. The portion of the myosin tail domain fused to YFP affected whether specific or non-specific localization was observed. In contrast to experiments in animal cells, movement of labeled organelles was not entirely inhibited by expression of defective myosin in which the motor domain was replaced with a fluorescent protein. None of the six myosin proteins tested labeled plastids or chloroplasts. However, the Arabidopsis myosin XI gene family expresses an additional seven myosins that await further examination. These experiments have provided more information on stromule formation and function and the actin-myosin machinery that mediates the intracellular trafficking that is required for photosynthesis and metabolism to operate efficiently within the plant cell.

  19. Fourth international workshop on human chromosome 5. Final progress report

    Energy Technology Data Exchange (ETDEWEB)

    McPherson, J.D.

    1996-12-31

    The Fourth International Workshop on Human Chromosome 5 was held in Manchester, UK on November 9--10, 1996 and was hosted by the University of Manchester. The major goals of the workshop were: (1) to collate the various genetic, cytogenetic and physical maps of human chromosome 5; (2) to integrate these maps and identify/correct discrepancies between them wherever possible; (3) to catalogue the sequence-ready contigs of the chromosome; (4) to co-ordinate the various sequencing efforts to avoid future duplication; (5) to establish the first (to the author`s knowledge) web site for the human chromosome 5 community which contains the above information in a readily accessible form.

  20. Final Progress Report for the activity called AMO2010 committee

    Energy Technology Data Exchange (ETDEWEB)

    Donald Shapero; Michael Moloney

    2006-12-31

    The committee was charged to produce a comprehensive report on the status of AMO Science. The committee was charged to produce a report that: 1. Reviewed the field of AMO science, emphasize recent accomplishments, and identify new opportunities and compelling scientific questions; 2. Identified the impact of AMO science on other scientific fields, emerging technologies, and national needs; 3. Identified future workforce, societal and educational needs for AMO science; and 4. Made recommendations on how the US research enterprise might realize the full potential of AMO science. The committee also produced an intermediate report addressing key research issues and themes facing the research community.

  1. HARNESS: Heterogeneous Adaptable Reconfigurable Networked Systems. Final Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Fagg, G. E.

    2004-01-20

    HARNESS was proposed as a system that combined the best of emerging technologies found in current distributed computing research and commercial products into a very flexible, dynamically adaptable framework that could be used by applications to allow them to evolve and better handle their execution environment. The HARNESS system was designed using the considerable experience from previous projects such as PVM, MPI, IceT and Cumulvs. As such, the system was designed to avoid any of the common problems found with using these current systems, such as no single point of failure, ability to survive machine, node and software failures. Additional features included improved intercomponent connectivity, with full support for dynamic down loading of addition components at run-time thus reducing the stress on application developers to build in all the libraries they need in advance.

  2. Inventors Center of Michigan Technical Assessment Program. Final progress report

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-31

    The Technical Assessment Program at the Inventors Center of Michigan is designed to provide independent inventors with a reliable assessment of the technical merits of their proposed inventions. Using faculty from within Ferris State University`s College of Technology an assessment process examines the inventor`s assumptions, documentation, and prototypes, as well as, reviewing patent search results and technical literature to provide the inventor with a written report on the technical aspects of the proposed invention. The forms for applying for a technical assessment of an invention are included.

  3. Final Progress Report - Heavy Ion Accelerator Theory and Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Haber, Irving

    2009-10-31

    The use of a beam of heavy ions to heat a target for the study of warm dense matter physics, high energy density physics, and ultimately to ignite an inertial fusion pellet, requires the achievement of beam intensities somewhat greater than have traditionally been obtained using conventional accelerator technology. The research program described here has substantially contributed to understanding the basic nonlinear intense-beam physics that is central to the attainment of the requisite intensities. Since it is very difficult to reverse intensity dilution, avoiding excessive dilution over the entire beam lifetime is necessary for achieving the required beam intensities on target. The central emphasis in this research has therefore been on understanding the nonlinear mechanisms that are responsible for intensity dilution and which generally occur when intense space-charge-dominated beams are not in detailed equilibrium with the external forces used to confine them. This is an important area of study because such lack of detailed equilibrium can be an unavoidable consequence of the beam manipulations such as acceleration, bunching, and focusing necessary to attain sufficient intensity on target. The primary tool employed in this effort has been the use of simulation, particularly the WARP code, in concert with experiment, to identify the nonlinear dynamical characteristics that are important in practical high intensity accelerators. This research has gradually made a transition from the study of idealized systems and comparisons with theory, to study the fundamental scaling of intensity dilution in intense beams, and more recently to explicit identification of the mechanisms relevant to actual experiments. This work consists of two categories; work in direct support beam physics directly applicable to NDCX and a larger effort to further the general understanding of space-charge-dominated beam physics.

  4. Non-destructive determination of trace elements. Final progress report

    International Nuclear Information System (INIS)

    In the course of this project we have successfully designed, built, and tested the first neutron beam facility dedicated to routine multielement neutron capture prompt-γ activation analysis (PGAA). This technique is capable of accurately measuring concentrations of up to 20 elements in a number of sample types, and is an extremely valuable complement to instrumental neutron activation analysis (INAA) and other analytical methods. We have found PGAA to have some major advantages over INAA: (1) the sample is subjected to neutron fluxes about five orders of magnitude less than in PGAA, with essentially no radiation or heating damage; (2) as the data are taken during sample irradiation, analyses can be performed immediately instead of waiting up to four weeks as in INAA; (3) it is capable of measuring all major elements, except oxygen, in many samples, including H, C, N, and Si, which cannot be done by INAA; and (4) it is especially sensitive for the trace elements B, Cd, Sm and Gd. In addition, we have characterized the overall capabilities of PGAA and the corrections necessary to make it an extremely accurate technique. We have applied PGAA in a number of studies in which it has proved to be extremely valuable and, at times, even providing crucial information that other techniques were incapable of supplying. 1 fig., 6 tabs

  5. Rooftop PV system. Final technical progress report, Phase II

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-01

    Under this four-year PV:BONUS Program, ECD and United Solar are developing and demonstrating two new lightweight flexible building integrated Photovoltaic (BIPV) modules specifically designed as exact replacements for conventional asphalt shingles and standing seam metal roofing. These modules can be economically and aesthetically integrated into new residential and commercial buildings, and address the even larger roofing replacement market. The modules are designed to be installed by roofing contractors without special training which minimizes the installation and balance of system costs. The modules will be fabricated from high-efficiency, multiple-junction a-Si alloy solar cells developed by ECD and United Solar. Under the Phase I Program, which ended in March 1994, we developed two different concept designs for rooftop PV modules: (1) the United Solar overlapping (asphalt shingle replacement) shingle-type modules and (2) the ECD metal roof-type modules. We also developed a plan for fabricating, testing and demonstrating these modules. Candidate demonstration sites for our rooftop PV modules were identified and preliminary engineering designs for these demonstrations were developed; a marketing study plan was also developed. The major objectives of the Phase II Program, which started in June 1994 was (1) to develop, test, and qualify these new rooftop modules; (2) to develop mechanical and electrical engineering specifications for the demonstration projects; and (3) to develop a marketing/commercialization plan.

  6. Gene transcription and electromagnetic fields. Final progress report

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, A.S.

    1992-12-31

    Our overall aim is to obtain sufficient information to allow us to ultimately determine whether ELF EM field exposure is an initiating factor in neoplastic transformation and/or if exposure can mimic characteristics of the second-step counterpart in neoplastic disease. This aim is based on our previous findings that levels of some transcripts are increased in cells exposed to EM fields. While the research is basic in nature, the ramifications have bearing on the general safety of exposure to EM fields in industrial and everyday life. A large array of diverse biological effects are reported to occur as the result of exposure to elf EM fields, suggesting that the cell response to EM fields is at a basic level, presumably initiated by molecular and/or biophysical events at the cell membrane. The hypothesized route is a signal transduction pathway involving membrane calcium fluxes. Information flow resulting from signal transduction can mediate the induction of regulatory factors in the cell, and directly affect how transcription is regulated.

  7. Potential role of bacteria packaging by protozoa in the persistence and transmission of pathogenic bacteria

    OpenAIRE

    Alix M Denoncourt; Paquet, Valérie E.; Charette, Steve J.

    2014-01-01

    Many pathogenic bacteria live in close association with protozoa. These unicellular eukaryotic microorganisms are ubiquitous in various environments. A number of protozoa such as amoebae and ciliates ingest pathogenic bacteria, package them usually in membrane structures, and then release them into the environment. Packaged bacteria are more resistant to various stresses and are more apt to survive than free bacteria. New evidence indicates that protozoa and not bacteria control the packaging...

  8. Programmed survival of soil bacteria

    DEFF Research Database (Denmark)

    Jensen, Lars Bogø; Molin, Søren; Sternberg, Claus;

    Biological containment systems have been developed for Pseudomonas putida and related soil bacteria. The systems are based on combinations of lethal genes and regulated gene expression. Two types of killing function have been employed: 1) A membrane protein interfering with the membrane potential...... (geJ). and 2) a nuclease attacking nucleic acids intracellularly. The efficacy of these lethal genes has been assessed in model constructions with a synthetic lac promoter. By combination with the regulatory pathway of the TOL genes. a system was designed which allows bacterial growth in the presence...

  9. Bacteria and vampirism in cinema.

    Science.gov (United States)

    Castel, O; Bourry, A; Thévenot, S; Burucoa, C

    2013-09-01

    A vampire is a non-dead and non-alive chimerical creature, which, according to various folklores and popular superstitions, feeds on blood of the living to draw vital force. Vampires do not reproduce by copulation, but by bite. Vampirism is thus similar to a contagious disease contracted by intravascular inoculation with a suspected microbial origin. In several vampire films, two real bacteria were staged, better integrated than others in popular imagination: Yersinia pestis and Treponema pallidum. Bacillus vampiris was created for science-fiction. These films are attempts to better define humans through one of their greatest fears: infectious disease. PMID:23916557

  10. Sewage-pollution indicator bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.; Rodrigues, V.; Alwares, E.; Rodrigues, C.; Baksh, R.; Jayan, S.; Mohandass, C.

    ?8 September 2002), and post-monsoon (12?15 March 2003). The schedule of observations is given in table 11.1. At each location, water samples were collected every three hours for 24 hours. The eight samples collected over a 24-hour period allowed us to examine..., small (less than 2 mm June 13, 2007 20:6 RPS rpb001ch11 SEWAGE-POLLUTION INDICATOR BACTERIA 117 Table 11.1 Sampling schedule followed for enumeration of bacterial populations during this study. Estuary Sampling dates Sampling strategy Mandovi 28?29 April...

  11. Bacteria and vampirism in cinema.

    Science.gov (United States)

    Castel, O; Bourry, A; Thévenot, S; Burucoa, C

    2013-09-01

    A vampire is a non-dead and non-alive chimerical creature, which, according to various folklores and popular superstitions, feeds on blood of the living to draw vital force. Vampires do not reproduce by copulation, but by bite. Vampirism is thus similar to a contagious disease contracted by intravascular inoculation with a suspected microbial origin. In several vampire films, two real bacteria were staged, better integrated than others in popular imagination: Yersinia pestis and Treponema pallidum. Bacillus vampiris was created for science-fiction. These films are attempts to better define humans through one of their greatest fears: infectious disease.

  12. Technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    This report summarizes experimental and theoretical work in basic nuclear physics carried out between October 1, 1995, the closing of our last Progress Report, and September 30, 1996 at the Nuclear Physics Laboratory of the University of Colorado, Boulder, under contracts DE-FG03-93ER-40774 and DE-FG03-95ER-40913 with the United States Department of Energy. The experimental contract supports broadly-based experimental research in intermediate energy nuclear physics. This report includes results from studies of Elementary Systems involving the study of the structure of the nucleon via polarized high-energy positron scattering (the HERMES experiment) and lower energy pion scattering from both polarized and unpolarized nucleon targets. Results from pion- and kaon-induced reactions in a variety of nuclear systems are reported under the section heading Meson Reactions; the impact of these and other results on understanding the nucleus is presented in the Nuclear Structure section. In addition, new results from scattering of high-energy electrons (from CEBAF/TJNAF) and pions (from KEK) from a broad range of nuclei are reported in the section on Incoherent Reactions. Finally, the development and performance of detectors produced by the laboratory are described in the section titled Instrumentation.

  13. Technical progress report

    International Nuclear Information System (INIS)

    This report summarizes experimental and theoretical work in basic nuclear physics carried out between October 1, 1995, the closing of our last Progress Report, and September 30, 1996 at the Nuclear Physics Laboratory of the University of Colorado, Boulder, under contracts DE-FG03-93ER-40774 and DE-FG03-95ER-40913 with the United States Department of Energy. The experimental contract supports broadly-based experimental research in intermediate energy nuclear physics. This report includes results from studies of Elementary Systems involving the study of the structure of the nucleon via polarized high-energy positron scattering (the HERMES experiment) and lower energy pion scattering from both polarized and unpolarized nucleon targets. Results from pion- and kaon-induced reactions in a variety of nuclear systems are reported under the section heading Meson Reactions; the impact of these and other results on understanding the nucleus is presented in the Nuclear Structure section. In addition, new results from scattering of high-energy electrons (from CEBAF/TJNAF) and pions (from KEK) from a broad range of nuclei are reported in the section on Incoherent Reactions. Finally, the development and performance of detectors produced by the laboratory are described in the section titled Instrumentation

  14. Progress in ITER Construction

    International Nuclear Information System (INIS)

    Full text: Since the entry into force of the ITER Agreement in October 2007, the ITER Organization and the Domestic Agencies have made significant progress in the finalization of the ITER design and the establishment of the baseline. This paper will describe the main advances and achievements since the last IAEA conference. The Integrated Project Schedule has gone through a number of iterations following interactions with Domestic Agencies and their industries. With operating a First Plasma at the end of 2019 construction will be finished and the functionality of all major components will be demonstrated. Through a series of operation and installation campaigns in the following seven years full DT operation should be reached by 2026. The associated resource estimate for the cost of the ITER Organization has been reviewed by an independent panel and has been developed using common project management practices. Attention has been paid to the development of risk based assessments of the schedule giving confidence that this schedule can be achieved if no major unforeseen events happen. The ITER platform has been prepared by Agence ITER France and was finalized by the summer of 2009. The next stage will be the start of the excavation and construction of the anti-seismic support structure for the tokamak building. The road between the harbor of Marseille and the Cadarache site is ready to receive the first test convoys. Just under 90% of the components for ITER will provided in-kind by the Members through so-called Procurement Arrangements, which are bi-lateral agreements between the ITER Organization and the Domestic Agencies. Until now 34 Procurement Arrangements have been signed, representing almost half of the value of the total in-kind contributions. The first Procurement Arrangements concentrated on the long-lead items, such as the Magnet systems, Buildings and the Vacuum Vessel. Most of the Procurement Arrangements for these long-lead items have now been

  15. Effect of dielectrophoretic force on swimming bacteria.

    Science.gov (United States)

    Tran, Ngoc Phu; Marcos

    2015-07-01

    Dielectrophoresis (DEP) has been applied widely in bacterial manipulation such as separating, concentrating, and focusing. Previous studies primarily focused on the collective effects of DEP force on the bacterial population. However, the influence of DEP force on the swimming of a single bacterium had not been investigated. In this study, we present a model to analyze the effect of DEP force on a swimming helically flagellated bacterium, particularly on its swimming direction and velocity. We consider a simple DEP force that acts along the X-direction, and its strength as well as direction varies with the X- and Y-positions. Resistive force theory is employed to compute the hydrodynamic force on the bacterium's flagellar bundle, and the effects of both DEP force and rotational diffusion on the swimming of the bacterium are simultaneously taken into consideration using the Fokker-Planck equation. We show the mechanism of how DEP force alters the orientation and velocity of the bacterium. In most cases, the DEP force dominantly influences the orientation of the swimming bacterium; however, when the DEP force strongly varies along the Y-direction, the rotational diffusion is also responsible for determining the bacterium's reorientation. More interestingly, the variance of DEP force along the Y-direction causes the bacterium to experience a translational velocity perpendicular to its primary axis, and this phenomenon could be utilized to focus the bacteria. Finally, we show the feasibility of applying our findings to achieve bacterial focusing. PMID:25785901

  16. Cariogenic bacteria degrade dental resin composites and adhesives.

    Science.gov (United States)

    Bourbia, M; Ma, D; Cvitkovitch, D G; Santerre, J P; Finer, Y

    2013-11-01

    A major reason for dental resin composite restoration replacement is related to secondary caries promoted by acid production from bacteria including Streptococcus mutans (S. mutans). We hypothesized that S. mutans has esterase activities that degrade dental resin composites and adhesives. Standardized specimens of resin composite (Z250), total-etch (Scotchbond Multipurpose, SB), and self-etch (Easybond, EB) adhesives were incubated with S. mutans UA159 or uninoculated culture medium (control) for up to 30 days. Quantification of the BisGMA-derived biodegradation by-product, bishydroxy-propoxy-phenyl-propane (BisHPPP), was performed by high-performance liquid chromatography. Surface analysis of the specimens was performed by scanning electron microscopy (SEM). S. mutans was shown to have esterase activities in levels comparable with those found in human saliva. A trend of increasing BisHPPP release throughout the incubation period was observed for all materials and was more elevated in the presence of bacteria vs. control medium for EB and Z250, but not for SB (p < .05). SEM confirmed the increased degradation of all materials with S. mutans UA159 vs. control. S. mutans has esterase activities at levels that degrade resin composites and adhesives; degree of degradation was dependent on the material's chemical formulation. This finding suggests that the resin-dentin interface could be compromised by oral bacteria that contribute to the progression of secondary caries.

  17. High-Fat Diet: Bacteria Interactions Promote Intestinal Inflammation Which Precedes and Correlates with Obesity and Insulin Resistance in Mouse

    OpenAIRE

    Shengli Ding; Chi, Michael M.; Scull, Brooks P.; Rachael Rigby; Schwerbrock, Nicole M.J.; Scott Magness; Christian Jobin; Lund, Pauline K.

    2010-01-01

    BACKGROUND: Obesity induced by high fat (HF) diet is associated with inflammation which contributes to development of insulin resistance. Most prior studies have focused on adipose tissue as the source of obesity-associated inflammation. Increasing evidence links intestinal bacteria to development of diet-induced obesity (DIO). This study tested the hypothesis that HF western diet and gut bacteria interact to promote intestinal inflammation, which contributes to the progression of obesity and...

  18. GENETIC EXCHANGE BETWEEN BACILLUS THURINGIENSIS SUBSP. KURSTAKI AND INDIGENOUS BACTERIA IN SOILS OF SARDINIA. (R826107)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  19. TOXICITY OF CHLOROFORM BIOTRANSFORMATION TO METHANOGENIC BACTERIA. (R825549C053)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  20. Progress against Prostate Cancer

    Science.gov (United States)

    ... this page please turn Javascript on. Feature: Prostate Cancer Progress Against Prostate Cancer Past Issues / Winter 2010 Table of Contents ... Read More "Prostate Cancer" Articles Progress Against Prostate Cancer / Prostate Cancer Research Trial Helps John Spencer Treat His ...

  1. DMTB: the magnetotactic bacteria database

    Science.gov (United States)

    Pan, Y.; Lin, W.

    2012-12-01

    Magnetotactic bacteria (MTB) are of interest in biogeomagnetism, rock magnetism, microbiology, biomineralization, and advanced magnetic materials because of their ability to synthesize highly ordered intracellular nano-sized magnetic minerals, magnetite or greigite. Great strides for MTB studies have been made in the past few decades. More than 600 articles concerning MTB have been published. These rapidly growing data are stimulating cross disciplinary studies in such field as biogeomagnetism. We have compiled the first online database for MTB, i.e., Database of Magnestotactic Bacteria (DMTB, http://database.biomnsl.com). It contains useful information of 16S rRNA gene sequences, oligonucleotides, and magnetic properties of MTB, and corresponding ecological metadata of sampling sites. The 16S rRNA gene sequences are collected from the GenBank database, while all other data are collected from the scientific literature. Rock magnetic properties for both uncultivated and cultivated MTB species are also included. In the DMTB database, data are accessible through four main interfaces: Site Sort, Phylo Sort, Oligonucleotides, and Magnetic Properties. References in each entry serve as links to specific pages within public databases. The online comprehensive DMTB will provide a very useful data resource for researchers from various disciplines, e.g., microbiology, rock magnetism and paleomagnetism, biogeomagnetism, magnetic material sciences and others.

  2. 1984-85 ISN progress report

    International Nuclear Information System (INIS)

    This progress report ISN 1984-1985 deals with the following subjects: nuclear physics theory, peripheral and intermediate energy physics, characteristics of reaction mechanisms in heavy ion collisions, nuclear structure, fundamental interactions, experimental methods and new instrumentation, some interdisciplinary research activities and technical activities, the SARA cyclotron and finally, technology transfer and valorisation

  3. Activity Progress report 1982-1985

    International Nuclear Information System (INIS)

    This reports gives a summary of all activities of the Elementary Particle Physics Department at Saclay between the beginning of 1982 and the end of 1985. The experiments in progress or in preparation are presented by subject. The main technical studies and achievements are also described. Finally lists of publications and information concerning Department organization are given

  4. Acetic Acid Bacteria and the Affecting Factors on QuaI ity of Wine Vinegar%醋酸菌及其酒醋质量的影响因素

    Institute of Scientific and Technical Information of China (English)

    龚国利; 张甜

    2015-01-01

    醋的生产主要是依靠醋酸菌的氧化过程,酒醋作为副产品是生产醋的不完全发酵而产生的,由于其独特的风味使得近年来人们对它的生产工艺的优化有进一步的研究。醋酸菌种决定醋的质量,但是醋的最终质量是工艺方法、木材接触和熟化合并的结果。综述了近年来醋酸菌的研究进展以及酒醋的生产工艺、化学特性和感官品质的影响因素。%The production of vinegar depends on an oxidation process that is mainly performed by acetic acid bacteria.However,the characterization of wine vinegar as a byproduct means that its production is often inadequately performed.Its unique flavor makes further research in recent years to optimize its production process.The acetic acid bacteria determine the quality of vinegar,but the final quality of vinegar is combined result of technological process,wood contact,and aging.This paper reviews the recent research progress of acetic acid bacteria, the production process, chemical properties and sensory quality of wine vinegar.

  5. Endophytic bacteria in Coffea arabica L.

    Science.gov (United States)

    Vega, Fernando E; Pava-Ripoll, Monica; Posada, Francisco; Buyer, Jeffrey S

    2005-01-01

    Eighty-seven culturable endophytic bacterial isolates in 19 genera were obtained from coffee plants collected in Colombia (n = 67), Hawaii (n = 17), and Mexico (n = 3). Both Gram positive and Gram negative bacteria were isolated, with a greater percentage (68%) being Gram negative. Tissues yielding bacterial endophytes included adult plant leaves, various parts of the berry (e.g., crown, pulp, peduncle and seed), and leaves, stems, and roots of seedlings. Some of the bacteria also occurred as epiphytes. The highest number of bacteria among the berry tissues sampled was isolated from the seed, and includes Bacillus , Burkholderia , Clavibacter , Curtobacterium , Escherichia , Micrococcus , Pantoea , Pseudomonas , Serratia , and Stenotrophomonas . This is the first survey of the endophytic bacteria diversity in various coffee tissues, and the first study reporting endophytic bacteria in coffee seeds. The possible role for these bacteria in the biology of the coffee plant remains unknown.

  6. Sulfur metabolism in phototrophic sulfur bacteria

    DEFF Research Database (Denmark)

    Frigaard, Niels-Ulrik; Dahl, Christiane

    2008-01-01

    in other types of anoxygenic phototrophic bacteria. The biochemistry and genetics of sulfur compound oxidation in PSB and GSB are described in detail. A variety of enzymes catalyzing sulfur oxidation reactions have been isolated from GSB and PSB (especially Allochromatium vinosum, a representative......Phototrophic sulfur bacteria are characterized by oxidizing various inorganic sulfur compounds for use as electron donors in carbon dioxide fixation during anoxygenic photosynthetic growth. These bacteria are divided into the purple sulfur bacteria (PSB) and the green sulfur bacteria (GSB......). They utilize various combinations of sulfide, elemental sulfur, and thiosulfate and sometimes also ferrous iron and hydrogen as electron donors. This review focuses on the dissimilatory and assimilatory metabolism of inorganic sulfur compounds in these bacteria and also briefly discusses these metabolisms...

  7. Endophytic bacteria in Coffea arabica L.

    Science.gov (United States)

    Vega, Fernando E; Pava-Ripoll, Monica; Posada, Francisco; Buyer, Jeffrey S

    2005-01-01

    Eighty-seven culturable endophytic bacterial isolates in 19 genera were obtained from coffee plants collected in Colombia (n = 67), Hawaii (n = 17), and Mexico (n = 3). Both Gram positive and Gram negative bacteria were isolated, with a greater percentage (68%) being Gram negative. Tissues yielding bacterial endophytes included adult plant leaves, various parts of the berry (e.g., crown, pulp, peduncle and seed), and leaves, stems, and roots of seedlings. Some of the bacteria also occurred as epiphytes. The highest number of bacteria among the berry tissues sampled was isolated from the seed, and includes Bacillus , Burkholderia , Clavibacter , Curtobacterium , Escherichia , Micrococcus , Pantoea , Pseudomonas , Serratia , and Stenotrophomonas . This is the first survey of the endophytic bacteria diversity in various coffee tissues, and the first study reporting endophytic bacteria in coffee seeds. The possible role for these bacteria in the biology of the coffee plant remains unknown. PMID:16187260

  8. Transformation of gram positive bacteria by sonoporation

    Science.gov (United States)

    Yang, Yunfeng; Li, Yongchao

    2014-03-11

    The present invention provides a sonoporation-based method that can be universally applied for delivery of compounds into Gram positive bacteria. Gram positive bacteria which can be transformed by sonoporation include, for example, Bacillus, Streptococcus, Acetobacterium, and Clostridium. Compounds which can be delivered into Gram positive bacteria via sonoporation include nucleic acids (DNA or RNA), proteins, lipids, carbohydrates, viruses, small organic and inorganic molecules, and nano-particles.

  9. Mortality of fecal bacteria in seawater.

    OpenAIRE

    Garcia-Lara, J.; Menon, P.; Servais, P; Billen, G.

    1991-01-01

    We propose a method for determining the mortality rate for allochthonous bacteria released in aquatic environments without interference due to the loss of culturability in specific culture media. This method consists of following the disappearance of radioactivity from the trichloroacetic acid-insoluble fraction in water samples to which [3H]thymidine-prelabeled allochthonous bacteria have been added. In coastal seawater, we found that the actual rate of disappearance of fecal bacteria was 1 ...

  10. Exploitation of host lipids by bacteria

    OpenAIRE

    Vromman, François; Subtil, Agathe

    2014-01-01

    International audience; Bacteria that interact with eukaryotic cells have developed a variety of strategies to divert host lipids, or cellular processes driven by lipids, to their benefit. Host lipids serve as building blocks for bacterial membrane formation and as energy source. They promote the formation of specific microdomains, facilitating interactions with the host. Host lipids are also critical players in the entry of bacteria or toxins into cells, and, for bacteria growing inside para...

  11. Chemical Profiles of Microalgae with Emphasis on Lipids: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Benemann, J. R.; Tillett, D. M.; Suen, Y.; Hubbard, J.; Tornabene, T. G.

    1986-02-01

    This final report details progress during the third year of this subcontract. The overall objective of this subcontract was two fold: to provide the analytical capability required for selecting microalgae strains with high energy contents and to develop fundamental knowledge required for optimizing the energy yield from microalgae cultures. The progress made towards these objectives during this year is detailed in this report.

  12. Cell Size Regulation in Bacteria

    Science.gov (United States)

    Amir, Ariel

    2014-05-01

    Various bacteria such as the canonical gram negative Escherichia coli or the well-studied gram positive Bacillus subtilis divide symmetrically after they approximately double their volume. Their size at division is not constant, but is typically distributed over a narrow range. Here, we propose an analytically tractable model for cell size control, and calculate the cell size and interdivision time distributions, as well as the correlations between these variables. We suggest ways of extracting the model parameters from experimental data, and show that existing data for E. coli supports partial size control, and a particular explanation: a cell attempts to add a constant volume from the time of initiation of DNA replication to the next initiation event. This hypothesis accounts for the experimentally observed correlations between mother and daughter cells as well as the exponential dependence of size on growth rate.

  13. Single Bacteria as Turing Machines

    Science.gov (United States)

    Bos, Julia; Zang, Qiucen; Vyawahare, Saurabh; Austin, Robert

    2014-03-01

    In Allan Turing's famous 1950 paper on Computing Machinery and Intelligence, he started with the provocative statement: ``I propose to consider the question, `Can machines think?' This should begin with definitions of the meaning of the terms `machine' and `think'.'' In our own work on exploring the way that organisms respond to stress and evolve, it seems at times as if they come to remarkably fast solutions to problems, indicating some sort of very clever computational machinery. I'll discuss how it would appear that bacteria can indeed create a form of a Turing Machine, the first example of a computer, and how they might use this algorithm to do rapid evolution to solve a genomics problem.

  14. Mitochondria: a target for bacteria.

    Science.gov (United States)

    Lobet, Elodie; Letesson, Jean-Jacques; Arnould, Thierry

    2015-04-01

    Eukaryotic cells developed strategies to detect and eradicate infections. The innate immune system, which is the first line of defence against invading pathogens, relies on the recognition of molecular patterns conserved among pathogens. Pathogen associated molecular pattern binding to pattern recognition receptor triggers the activation of several signalling pathways leading to the establishment of a pro-inflammatory state required to control the infection. In addition, pathogens evolved to subvert those responses (with passive and active strategies) allowing their entry and persistence in the host cells and tissues. Indeed, several bacteria actively manipulate immune system or interfere with the cell fate for their own benefit. One can imagine that bacterial effectors can potentially manipulate every single organelle in the cell. However, the multiple functions fulfilled by mitochondria especially their involvement in the regulation of innate immune response, make mitochondria a target of choice for bacterial pathogens as they are not only a key component of the central metabolism through ATP production and synthesis of various biomolecules but they also take part to cell signalling through ROS production and control of calcium homeostasis as well as the control of cell survival/programmed cell death. Furthermore, considering that mitochondria derived from an ancestral bacterial endosymbiosis, it is not surprising that a special connection does exist between this organelle and bacteria. In this review, we will discuss different mitochondrial functions that are affected during bacterial infection as well as different strategies developed by bacterial pathogens to subvert functions related to calcium homeostasis, maintenance of redox status and mitochondrial morphology.

  15. SOS, the formidable strategy of bacteria against aggressions.

    Science.gov (United States)

    Baharoglu, Zeynep; Mazel, Didier

    2014-11-01

    The presence of an abnormal amount of single-stranded DNA in the bacterial cell constitutes a genotoxic alarm signal that induces the SOS response, a broad regulatory network found in most bacterial species to address DNA damage. The aim of this review was to point out that beyond being a repair process, SOS induction leads to a very strong but transient response to genotoxic stress, during which bacteria can rearrange and mutate their genome, induce several phenotypic changes through differential regulation of genes, and sometimes acquire characteristics that potentiate bacterial survival and adaptation to changing environments. We review here the causes and consequences of SOS induction, but also how this response can be modulated under various circumstances and how it is connected to the network of other important stress responses. In the first section, we review articles describing the induction of the SOS response at the molecular level. The second section discusses consequences of this induction in terms of DNA repair, changes in the genome and gene expression, and sharing of genomic information, with their effects on the bacteria's life and evolution. The third section is about the fine tuning of this response to fit with the bacteria's 'needs'. Finally, we discuss recent findings linking the SOS response to other stress responses. Under these perspectives, SOS can be perceived as a powerful bacterial strategy against aggressions.

  16. Protective role of lignan-converting bacteria on chemically-induced breast cancer in gnotobiotic rats

    OpenAIRE

    Mabrok, Hoda Hussein Bakr

    2013-01-01

    Enterolignans (enterodiol and enterolactone) exhibit structural similarity to estradiol and have therefore been hypothesized to modulate hormone related cancers such as breast cancer. The bioactivation of the plant lignan secoisolariciresinol diglucoside (SDG) requires the transformation by intestinal bacteria including the deglycosylation of SDG to secoisolariciresinol (SECO) followed by demethylation and dehydroxylation of SECO to enterodiol (ED). Finally, ED is dehydrogenated to enterolact...

  17. 西瓜枯萎病土壤拮抗菌的筛选%Screening of Soil Antagonistic Bacteria for Watermelon Fusarium Wilt

    Institute of Scientific and Technical Information of China (English)

    胡雪芹; 张洪斌; 苏晓飞

    2008-01-01

    [Objective] The aim of this study was to screen bacteria strains with stable antagonistic effect against watermelon fusarium wilt from soil and investigate the biological control of watermelon fusarium wilt by applying the antagonistic bacteria strains into soil. [Method] Actinomycete strains, fluorescent bacteria strains and bacillus strains were isolated from soil samples by the dilution-plate method, then its resistance was screened respectively by the improved confront culture method after colonies were purified. Finally, bacteria strains with better antagonistic effect were identified. [Result] 29 bacteria strains with stable antagonistic effect against watermelon fusarium wilt were screened from 39 soil samples, which contained 15 fluorescent bacteria strains, 5 bacillus strains and 9 actinomycete strains. Furthermore, three antagonistic bacteria strains of FM2, FM3 and FM4 with the strongest antagonism were identified primarily. [Conclusion] According to cultural characteristics, morphological observation, biochemical and physiological tests, FM2 belongs to bacillus subtilis, while FM3 and FM4 belong to micrococcus.

  18. 2004 Progress Report

    International Nuclear Information System (INIS)

    Fusion research is undertaken all over the world with the objective of realising an environmentally responsible source of energy with essentially unlimited and widely distributed fuel reserves. The results of the worldwide efforts made in recent years are now embodied in ITER, the International Thermonuclear Experimental Reactor, designed to produce at least 500 MW of fusion power with a power gain of ten. ITER will test for the first time the interaction of fusion plasma physics with power station technology. In this international framework, during 2004 Fusion Technical and Scientific Unit of ENEA obtained important results in several keys areas. At the Frascati Tokamak Upgrade the lower hybrid microwave system was fully exploited to study the generation and control of the plasma current, and the electron cyclotron heating system reached full power (1.5 MW). With the simultaneous injection of the two waves, good energy confinement regimes with internal transport barriers were obtained at the highest plasma densities ever achieved. Advanced scenario regimes were also addressed in the activities of ENEA at JET. The engineering design of the IGNITOR machine was finalised, and significant progress was made in understanding the plasma physics regimes. Among the technology activities, the qualification of the deposition process of a copper liner on carbon fibre composite (CFC) hollow tiles may be mentioned as the most important achievement. This innovative pre brazed casting process is a competitive candidate for the fabrication of the CFCbased ITER divertor components. ENEA participated in the European activity for the definition and production on an industrial scale of an advanced Nb3Sn strand for the ITER superconducting central solenoid and toroidal field coils. Contributions were also made to the design of the final conductor layout and the characterisation tests. Inertial fusion studies continued along the previous lines, namely, the study of the implosion

  19. 2004 Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Batistoni, Paola; De Marco, Francesco; Pieroni, Leonardo (ed.)

    2005-07-01

    Fusion research is undertaken all over the world with the objective of realising an environmentally responsible source of energy with essentially unlimited and widely distributed fuel reserves. The results of the worldwide efforts made in recent years are now embodied in ITER, the International Thermonuclear Experimental Reactor, designed to produce at least 500 MW of fusion power with a power gain of ten. ITER will test for the first time the interaction of fusion plasma physics with power station technology. In this international framework, during 2004 Fusion Technical and Scientific Unit of ENEA obtained important results in several keys areas. At the Frascati Tokamak Upgrade the lower hybrid microwave system was fully exploited to study the generation and control of the plasma current, and the electron cyclotron heating system reached full power (1.5 MW). With the simultaneous injection of the two waves, good energy confinement regimes with internal transport barriers were obtained at the highest plasma densities ever achieved. Advanced scenario regimes were also addressed in the activities of ENEA at JET. The engineering design of the IGNITOR machine was finalised, and significant progress was made in understanding the plasma physics regimes. Among the technology activities, the qualification of the deposition process of a copper liner on carbon fibre composite (CFC) hollow tiles may be mentioned as the most important achievement. This innovative pre brazed casting process is a competitive candidate for the fabrication of the CFCbased ITER divertor components. ENEA participated in the European activity for the definition and production on an industrial scale of an advanced Nb3Sn strand for the ITER superconducting central solenoid and toroidal field coils. Contributions were also made to the design of the final conductor layout and the characterisation tests. Inertial fusion studies continued along the previous lines, namely, the study of the implosion

  20. On disciplinary fragmentation and scientific progress.

    Directory of Open Access Journals (Sweden)

    Stefano Balietti

    Full Text Available Why are some scientific disciplines, such as sociology and psychology, more fragmented into conflicting schools of thought than other fields, such as physics and biology? Furthermore, why does high fragmentation tend to coincide with limited scientific progress? We analyzed a formal model where scientists seek to identify the correct answer to a research question. Each scientist is influenced by three forces: (i signals received from the correct answer to the question; (ii peer influence; and (iii noise. We observed the emergence of different macroscopic patterns of collective exploration, and studied how the three forces affect the degree to which disciplines fall apart into divergent fragments, or so-called "schools of thought". We conducted two simulation experiments where we tested (A whether the three forces foster or hamper progress, and (B whether disciplinary fragmentation causally affects scientific progress and vice versa. We found that fragmentation critically limits scientific progress. Strikingly, there is no effect in the opposite causal direction. What is more, our results shows that at the heart of the mechanisms driving scientific progress we find (i social interactions, and (ii peer disagreement. In fact, fragmentation is increased and progress limited if the simulated scientists are open to influence only by peers with very similar views, or when within-school diversity is lost. Finally, disciplines where the scientists received strong signals from the correct answer were less fragmented and experienced faster progress. We discuss model's implications for the design of social institutions fostering interdisciplinarity and participation in science.

  1. Site Characterization Progress Report Number 21

    Energy Technology Data Exchange (ETDEWEB)

    None

    1999-09-30

    This is the 21 st progress report issued by the U.S. Department of Energy. This report provides a summary-level discussion of Yucca Mountain Site Characterization Project progress. Accomplishments this period are presented in a format that identifies important progress achieved and conveys how that progress supports the near-term objectives in the U.S. Department of Energy's schedule. Greater detail is documented in the cited references and in deliverables listed in Appendix A to this report. This document provides a discussion of recently completed and ongoing activities conducted by the Yucca Mountain Site Characterization Project during the six-month reporting period from April 1, 1999, through September 30, 1999. Some information presented herein is by necessity preliminary, because some deliverables and reports that support the discussions have not been finalized. Projected future deliverables and reports are listed in Appendix B and are noted in the text as works in progress. Appendix C lists the status of milestone reports referenced in previous progress reports commencing with Progress Report 17. A glossary of Yucca Mountain Site Characterization Project-specific terms used in this report is given in Appendix D.

  2. Sabine Kacunko. Bacteria, Art and other Bagatelles

    DEFF Research Database (Denmark)

    Kacunko, Slavko

    This book appears on the occasion of the project INVINCIBLE – a Big Bacteria project for Colosseum, Rome (17.–19.09.2015), which is being granted UNESCO-patronage in the context of the International Year of Light and Light-Based Technologies 2015. With Sabine Kacunko’s bacteria art in mind, alleged...

  3. Rapid methods for detection of bacteria

    DEFF Research Database (Denmark)

    Corfitzen, Charlotte B.; Andersen, B.Ø.; Miller, M.;

    2006-01-01

    Traditional methods for detection of bacteria in drinking water e.g. Heterotrophic Plate Counts (HPC) or Most Probable Number (MNP) take 48-72 hours to give the result. New rapid methods for detection of bacteria are needed to protect the consumers against contaminations. Two rapid methods...

  4. Lactic Acid Bacteria in the Gut

    NARCIS (Netherlands)

    Stolaki, M.; Vos, de W.M.; Kleerebezem, M.; Zoetendal, E.G.

    2012-01-01

    From all bacterial groups, the lactic acid bacteria (LAB) are probably the group of bacteria that is most associated with human lifestyle. The term LAB mainly refers to the ability of these organisms to convert sugars to lactic acid. The LAB comprise non-sporing, aerotolerant, coccus or rod-shaped,

  5. Why do bacteria engage in homologous recombination?

    NARCIS (Netherlands)

    Vos, M.

    2009-01-01

    Microbiologists have long recognized that the uptake and incorporation of homologous DNA from outside the cell is a common feature of bacteria, with important implications for their evolution. However, the exact reasons why bacteria engage in homologous recombination remain elusive. This Opinion art

  6. Method of dispersing a hydrocarbon using bacteria

    Science.gov (United States)

    Tyndall, Richard L.

    1996-01-01

    New protozoan derived microbial consortia and method for their isolation are provided. Consortia and bacteria isolated therefrom are useful for treating wastes such as trichloroethylene and trinitrotoluene. Consortia, bacteria isolated therefrom, and dispersants isolated therefrom are useful for dispersing hydrocarbons such as oil, creosote, wax, and grease.

  7. Quorum sensing in gram-negative bacteria

    DEFF Research Database (Denmark)

    Wu, H.; Song, Z.J.; Høiby, N.;

    2004-01-01

    molecules. Among Gram-negative bacteria N-acyl-L-homoserine lactone (acyl-HSL)-dependent quorum sensing systems are particularly widespread. These systems are used to coordinate expression of phenotypes that are fundamental to the interaction of bacteria with each other and with their environment...

  8. Resuscitation effects of catalase on airborne bacteria.

    OpenAIRE

    Marthi, B; Shaffer, B. T.; Lighthart, B; Ganio, L

    1991-01-01

    Catalase incorporation into enumeration media caused a significant increase (greater than 63%) in the colony-forming abilities of airborne bacteria. Incubation for 30 to 60 min of airborne bacteria in collection fluid containing catalase caused a greater than 95% increase in colony-forming ability. However, catalase did not have any effects on enumeration at high relative humidities (80 to 90%).

  9. Research Advances in Bacteria-based Microrobot.

    Science.gov (United States)

    Liang, Yao-Jie; Sun, Jun-Zhong

    2016-08-01

    The concept of bacteria-based microrobot has been well recognized. It has shown great advantages and potentials for the early diagnosis and early treatment of malignant tumor and in reducing chemotherapy toxicities. In this article we review the concept,structure,and potential clinical applications of bacteria-based microrobot. PMID:27594160

  10. Improved sectioning and ultrastructure of bacteria and animal cells embedded in Lowicryl.

    Science.gov (United States)

    Bénichou, J C; Fréhel, C; Ryter, A

    1990-04-01

    Lowicryl K4M-embedded Gram-positive and Gram-negative bacteria have a tendency to separate between the cell surface and the resin. This often leads to distortion of bacteria and more especially of mycobacteria. We describe attempts made to overcome this technical problem. Different assays were made on Bacillus subtilis, Escherichia coli, and Mycobacterium avium: 1) Modification of the bacterial surface by coating of bacteria with proteinic compounds; 2) treatment of bacteria with metallic salts known to modify cell wall polysaccharides; and 3) comparison between Lowicryl K4M and HM20. Conditions have been found in which the separation of all bacterial species from the resin is abolished. The most important factor appeared to be the treatment of bacteria before dehydration, with 0.5% uranyl acetate for 30 min. The second most important factor, especially for M. avium and to a lower extent for Gram-negative bacteria, was the use of Lowicryl HM20. No differences were observed with Gram-positive bacteria between K4M and HM20. Pre-embedding in gelatin instead of agar improved sectioning of M. avium, but had no effects on the other bacterial species. These conditions applied to macrophages infected with Shigella dysenteriae or M. avium also gave excellent results. In addition to sectioning improvement of bacteria, uranyl acetate improved the ultrastructure of bacteria and macrophages. All organelles were more clearly delineated and, hence, more easily identified. Finally, it was shown that UA treatment did not affect immunogold labeling of a variety of antigens. PMID:2110246

  11. Final Technical Report

    International Nuclear Information System (INIS)

    The two main objectives of this project were: (1) to develop and test technologies to harvest, transport, store, and separate corn stover to supply a clean raw material to the bioproducts industry, and (2) engineer fermentation systems to meet performance targets for lactic acid and ethanol manufacturers. Significant progress was made in testing methods to harvest corn stover in a 'single pass' harvest mode (collect corn grain and stover at the same time). This is technically feasible on small scale, but additional equipment refinements will be needed to facilitate cost effective harvest on a larger scale. Transportation models were developed, which indicate that at a corn stover yield of 2.8 tons/acre and purchase price of $35/ton stover, it would be unprofitable to transport stover more than about 25 miles; thus suggesting the development of many regional collection centers. Therefore, collection centers should be located within about 30 miles of the farm, to keep transportation costs to an acceptable level. These collection centers could then potentially do some preprocessing (to fractionate or increase bulk density) and/or ship the biomass by rail or barge to the final customers. Wet storage of stover via ensilage was tested, but no clear economic advantages were evident. Wet storage eliminates fire risk, but increases the complexity of component separation and may result in a small loss of carbohydrate content (fermentation potential). A study of possible supplier-producer relationships, concluded that a 'quasi-vertical' integration model would be best suited for new bioproducts industries based on stover. In this model, the relationship would involve a multiyear supply contract (processor with purchase guarantees, producer group with supply guarantees). Price will likely be fixed or calculated based on some formula (possibly a cost plus). Initial quality requirements will be specified (but subject to refinement).Producers would invest in harvest

  12. Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Aristos Aristidou Natureworks); Robert Kean (NatureWorks); Tom Schechinger (IronHorse Farms, Mat); Stuart Birrell (Iowa State); Jill Euken (Wallace Foundation & Iowa State)

    2007-10-01

    The two main objectives of this project were: 1) to develop and test technologies to harvest, transport, store, and separate corn stover to supply a clean raw material to the bioproducts industry, and 2) engineer fermentation systems to meet performance targets for lactic acid and ethanol manufacturers. Significant progress was made in testing methods to harvest corn stover in a “single pass” harvest mode (collect corn grain and stover at the same time). This is technically feasible on small scale, but additional equipment refinements will be needed to facilitate cost effective harvest on a larger scale. Transportation models were developed, which indicate that at a corn stover yield of 2.8 tons/acre and purchase price of $35/ton stover, it would be unprofitable to transport stover more than about 25 miles; thus suggesting the development of many regional collection centers. Therefore, collection centers should be located within about 30 miles of the farm, to keep transportation costs to an acceptable level. These collection centers could then potentially do some preprocessing (to fractionate or increase bulk density) and/or ship the biomass by rail or barge to the final customers. Wet storage of stover via ensilage was tested, but no clear economic advantages were evident. Wet storage eliminates fire risk, but increases the complexity of component separation and may result in a small loss of carbohydrate content (fermentation potential). A study of possible supplier-producer relationships, concluded that a “quasi-vertical” integration model would be best suited for new bioproducts industries based on stover. In this model, the relationship would involve a multiyear supply contract (processor with purchase guarantees, producer group with supply guarantees). Price will likely be fixed or calculated based on some formula (possibly a cost plus). Initial quality requirements will be specified (but subject to refinement).Producers would invest in harvest

  13. Chemotactic selection of pollutant degrading soil bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Hazen, T.C.

    1991-03-04

    A method is described for identifying soil microbial strains which may be bacterial degraders of pollutants. This method includes: Placing a concentration of a pollutant in a substantially closed container; placing the container in a sample of soil for a period of time ranging from one minute to several hours; retrieving the container and collecting its contents; microscopically determining the identity of the bacteria present. Different concentrations of the pollutant can be used to determine which bacteria respond to each concentration. The method can be used for characterizing a polluted site or for looking for naturally occurring biological degraders of the pollutant. Then bacteria identified as degraders of the pollutant and as chemotactically attracted to the pollutant are used to innoculate contaminated soil. To enhance the effect of the bacteria on the pollutant, nutrients are cyclicly provided to the bacteria then withheld to alternately build up the size of the bacterial colony or community and then allow it to degrade the pollutant.

  14. Bacteria dispersal by hitchhiking on zooplankton

    DEFF Research Database (Denmark)

    Grossart, Hans-Peter; Dziallas, Claudia; Leunert, Franziska;

    2010-01-01

    and nonpathogenic bacteria has shown that direct association with zooplankton has significant influences on the bacteria's physiology and ecology. We used stratified migration columns to study vertical dispersal of hitchhiking bacteria through migrating zooplankton across a density gradient that was otherwise...... impenetrable for bacteria in both upward and downward directions (conveyor-belt hypothesis). The strength of our experiments is to permit quantitative estimation of transport and release of associated bacteria: vertical migration of Daphnia magna yielded an average dispersal rate of 1.3 x 10(5) x cells x...... Daphnia(-1) x migration cycle(-1) for the lake bacterium Brevundimonas sp. Bidirectional vertical dispersal by migrating D. magna was also shown for two other bacterial species, albeit at lower rates. The prediction that diurnally migrating zooplankton acquire different attached bacterial communities from...

  15. Coryneform bacteria associated with canine otitis externa

    DEFF Research Database (Denmark)

    Aalbæk, Bent; Bemis, David A.; Schjærff, Mette;

    2010-01-01

    This study aims to investigate the occurrence of coryneform bacteria in canine otitis externa. A combined case series and case-control study was carried out to improve the current knowledge on frequency and clinical significance of coryneform bacteria in samples from canine otitis externa. A total...... of 16 cases of otitis externa with involvement of coryneform bacteria were recorded at two referral veterinary hospitals in Denmark and the US, respectively. Coryneform bacteria were identified by partial 16S rRNA gene sequencing. Corynebacterium auriscanis was the most common coryneform species (10...... cases). Small colony variants of this species were also observed. Other coryneform isolates were identified as Corynebacterium amycolatum (3 cases), Corynebacterium freneyi (2 cases) and an Arcanobacterium-like species (1 case). The coryneform bacteria were in all cases isolated together with other...

  16. HYDROCARBON-DEGRADING BACTERIA AND SURFACTANT ACTIVITY

    Energy Technology Data Exchange (ETDEWEB)

    Brigmon, R; Topher Berry, T; Grazyna A. Plaza, G; jacek Wypych, j

    2006-08-15

    Fate of benzene ethylbenzene toluene xylenes (BTEX) compounds through biodegradation was investigated using two different bacteria, Ralstonia picketti (BP-20) and Alcaligenes piechaudii (CZOR L-1B). These bacteria were isolated from extremely polluted petroleum hydrocarbon contaminated soils. PCR and Fatty Acid Methyl Ester (FAME) were used to identify the isolates. Biodegradation was measured using each organism individually and in combination. Both bacteria were shown to degrade each of the BTEX compounds. Alcaligenes piechaudii biodegraded BTEXs more efficiently while mixed with BP-20 and individually. Biosurfactant production was observed by culture techniques. In addition 3-hydroxy fatty acids, important in biosurfactant production, was observed by FAME analysis. In the all experiments toluene and m+p- xylenes were better growth substrates for both bacteria than the other BTEX compounds. In addition, the test results indicate that the bacteria could contribute to bioremediation of aromatic hydrocarbons (BTEX) pollution increase biodegradation through the action by biosurfactants.

  17. Chryseobacterium indologenes, novel mannanase-producing bacteria

    Directory of Open Access Journals (Sweden)

    Surachai Rattanasuk

    2009-10-01

    Full Text Available Mannanase is a mannan degrading enzyme which is produced by microorganisms, including bacteria. This enzyme can be used in many industrial processes as well as for improving the quality of animal feeds. The aim of the present study was toscreen and characterize the mannanase-producing bacteria. Two genera of bacteria were isolated from Thai soil samples,fermented coconut, and fertilizer. Screening was carried out on agar plates containing mannan stained with iodine solution.The bacteria were identified by partial 16S rRNA gene sequence, biochemical test and morphology, respectively. The mannanase activity was determined by zymogram and DNS method. Two strains of bacteria with mannanase activity were identified as Bacillus and Chryseobacterium. This is the first report of mannanase-producing Chryseobacterium.

  18. Non-classical protein secretion in bacteria

    Directory of Open Access Journals (Sweden)

    Fausbøll Anders

    2005-10-01

    Full Text Available Abstract Background We present an overview of bacterial non-classical secretion and a prediction method for identification of proteins following signal peptide independent secretion pathways. We have compiled a list of proteins found extracellularly despite the absence of a signal peptide. Some of these proteins also have known roles in the cytoplasm, which means they could be so-called "moon-lightning" proteins having more than one function. Results A thorough literature search was conducted to compile a list of currently known bacterial non-classically secreted proteins. Pattern finding methods were applied to the sequences in order to identify putative signal sequences or motifs responsible for their secretion. We have found no signal or motif characteristic to any majority of the proteins in the compiled list of non-classically secreted proteins, and conclude that these proteins, indeed, seem to be secreted in a novel fashion. However, we also show that the apparently non-classically secreted proteins are still distinguished from cellular proteins by properties such as amino acid composition, secondary structure and disordered regions. Specifically, prediction of disorder reveals that bacterial secretory proteins are more structurally disordered than their cytoplasmic counterparts. Finally, artificial neural networks were used to construct protein feature based methods for identification of non-classically secreted proteins in both Gram-positive and Gram-negative bacteria. Conclusion We present a publicly available prediction method capable of discriminating between this group of proteins and other proteins, thus allowing for the identification of novel non-classically secreted proteins. We suggest candidates for non-classically secreted proteins in Escherichia coli and Bacillus subtilis. The prediction method is available online.

  19. Progressive fractal coding

    OpenAIRE

    Kopilovic, Ivan; Saupe, Dietmar; Hamzaoui, Raouf

    2001-01-01

    Progressive coding is an important feature of compression schemes. Wavelet coders are well suited for this purpose because the wavelet coefficients can be naturally ordered according to decreasing importance. Progressive fractal coding is feasible, but it was proposed only for hybrid fractal-wavelet schemes. We introduce a progressive fractal image coder in the spatial domain. A Lagrange optimization based on rate-distortion performance estimates determines an optimal ordering of the code bit...

  20. Comparative cytotoxicity of periodontal bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, R.H.; Hammond, B.F.

    1988-11-01

    The direct cytotoxicity of sonic extracts (SE) from nine periodontal bacteria for human gingival fibroblasts (HGF) was compared. Equivalent dosages (in terms of protein concentration) of SE were used to challenge HGF cultures. The cytotoxic potential of each SE was assessed by its ability to (1) inhibit HGF proliferation, as measured by direct cell counts; (2) inhibit 3H-thymidine incorporation in HGF cultures; or (3) cause morphological alterations of the cells in challenged cultures. The highest concentration (500 micrograms SE protein/ml) of any of the SEs used to challenge the cells was found to be markedly inhibitory to the HGFs by all three of the criteria of cytotoxicity. At the lowest dosage tested (50 micrograms SE protein/ml); only SE from Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, and Fusobacterium nucleatum caused a significant effect (greater than 90% inhibition or overt morphological abnormalities) in the HGFs as determined by any of the criteria employed. SE from Capnocytophaga sputigena, Eikenella corrodens, or Wolinella recta also inhibited cell proliferation and thymidine incorporation at this dosage; however, the degree of inhibition (5-50%) was consistently, clearly less than that of the first group of three organisms named above. The SE of the three other organisms tested (Actinomyces odontolyticus, Bacteroides intermedius, and Streptococcus sanguis) had little or no effect (0-10% inhibition) at this concentration. The data suggest that the outcome of the interaction between bacterial components and normal resident cells of the periodontium is, at least in part, a function of the bacterial species.

  1. Antibiotic resistance in probiotic bacteria

    Directory of Open Access Journals (Sweden)

    Miguel eGueimonde

    2013-07-01

    Full Text Available Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. The main probiotic bacteria are strains belonging to the genera Lactobacillus and Bifidobacterium, although other representatives, such as Bacillus or Escherichia coli strains, have also been used. Lactobacillus and Bifidobacterium are two common inhabitants of the human intestinal microbiota. Also, some species are used in food fermentation processes as starters, or as adjunct cultures in the food industry. With some exceptions, antibiotic resistance in these beneficial microbes does not constitute a safety concern in itself, when mutations or intrinsic resistance mechanisms are responsible for the resistance phenotype. In fact, some probiotic strains with intrinsic antibiotic resistance could be useful for restoring the gut microbiota after antibiotic treatment. However, specific antibiotic resistance determinants carried on mobile genetic elements, such as tetracycline resistance genes, are often detected in the typical probiotic genera, and constitute a reservoir of resistance for potential food or gut pathogens, thus representing a serious safety issue.

  2. Potential role of bacteria packaging by protozoa in the persistence and transmission of pathogenic bacteria.

    Science.gov (United States)

    Denoncourt, Alix M; Paquet, Valérie E; Charette, Steve J

    2014-01-01

    Many pathogenic bacteria live in close association with protozoa. These unicellular eukaryotic microorganisms are ubiquitous in various environments. A number of protozoa such as amoebae and ciliates ingest pathogenic bacteria, package them usually in membrane structures, and then release them into the environment. Packaged bacteria are more resistant to various stresses and are more apt to survive than free bacteria. New evidence indicates that protozoa and not bacteria control the packaging process. It is possible that packaging is more common than suspected and may play a major role in the persistence and transmission of pathogenic bacteria. To confirm the role of packaging in the propagation of infections, it is vital that the molecular mechanisms governing the packaging of bacteria by protozoa be identified as well as elements related to the ecology of this process in order to determine whether packaging acts as a Trojan Horse.

  3. Potential role of bacteria packaging by protozoa in the persistence and transmission of pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Alix M Denoncourt

    2014-05-01

    Full Text Available Many pathogenic bacteria live in close association with protozoa. These unicellular eukaryotic microorganisms are ubiquitous in various environments. A number of protozoa such as amoebae and ciliates ingest pathogenic bacteria, package them usually in membrane structures, and then release them into the environment. Packaged bacteria are more resistant to various stresses and are more apt to survive than free bacteria. New evidence indicates that protozoa and not bacteria control the packaging process. It is possible that packaging is more common than suspected and may play a major role in the persistence and transmission of pathogenic bacteria. To confirm the role of packaging in the propagation of infections, it is vital that the molecular mechanisms governing the packaging of bacteria by protozoa be identified as well as elements related to the ecology of this process in order to determine whether packaging acts as a Trojan Horse.

  4. Modeling of kinetics of the inducible protein complexes of the SOS system in bacteria E. coli which realize TLS process

    International Nuclear Information System (INIS)

    The mathematical model describing kinetics of the inducible genes of the protein complexes, formed during SOS response in bacteria Escherichia coli is developed. Within the bounds of developed approaches the auxiliary mathematical model describing changes in concentrations of the dimers, which are the components of final protein complexes, is developed. The solutions of both models are based on the experimental data concerning expression of the basic genes of the SOS system in bacteria Escherichia coli

  5. Thin bacteria/Layered Double Hydroxide films using a layer-by-layer approach.

    Science.gov (United States)

    Halma, Matilte; Khenifi, Aicha; Sancelme, Martine; Besse-Hoggan, Pascale; Bussière, Pierre-Olivier; Prévot, Vanessa; Mousty, Christine

    2016-07-15

    This paper reports the design of thin bacteria/Layered Double Hydroxides (LDH) films in which bacterial cells of Pseudomonas sp. strain ADP were assembled alternatively with Mg2Al-NO3 LDH nanosheets by a layer-by-layer deposition method. The UV-Vis spectroscopy was used to monitor the assembly process, showing a progressive increase in immobilized bacteria amount upon deposited cycles. The {ADP/LDH}n film was characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy and atomic force microscopy. The metabolic activity of immobilized bacteria was determined using chronoamperometry by measuring the biochemical oxygen demand in presence of glucose using an artificial electron acceptor (Fe(CN)6(3-)) at 0.5V/Ag-AgCl. A steady current of 0.250μAcm(-2) was reached in about 30s after the addition of 5mM glucose. PMID:27124809

  6. Making Progress: The Use of Multiple Progress Reports to Enhance Advertising Students' Media Plan Term Projects

    Science.gov (United States)

    Kritz, Gary H.; Lozada, Hector R.; Long, Mary M.

    2007-01-01

    Since the AACSB mandates that students demonstrate effective oral and written communication skills, it is imperative that business professors do what is necessary to improve such skills. The authors investigate whether the use of using multiple progress reports in an Advertising class project improves the final product. The data results show that…

  7. Progression i musikundervisningen

    DEFF Research Database (Denmark)

    Dahlbæk, Annelise

    Hvad er progression? ; Musikalitetsbegrebet ; Fælles mål for musik ; Modeller som redskab ; Stemmen : sang ; Sammenspil ; Dans og bevægelse ; Lytning......Hvad er progression? ; Musikalitetsbegrebet ; Fælles mål for musik ; Modeller som redskab ; Stemmen : sang ; Sammenspil ; Dans og bevægelse ; Lytning...

  8. Natalizumab in progressive MS

    DEFF Research Database (Denmark)

    Romme Christensen, Jeppe; Ratzer, Rikke; Börnsen, Lars;

    2014-01-01

    OBJECTIVE: Natalizumab inhibits the migration of systemic immune cells to the CNS and may be beneficial in progressive multiple sclerosis (MS). The objective of the study was to examine the effects of natalizumab in progressive MS. METHODS: In an open-label phase 2A study, 24 patients with progre...

  9. White matter lesion progression

    DEFF Research Database (Denmark)

    Hofer, Edith; Cavalieri, Margherita; Bis, Joshua C;

    2016-01-01

    BACKGROUND AND PURPOSE: White matter lesion (WML) progression on magnetic resonance imaging is related to cognitive decline and stroke, but its determinants besides baseline WML burden are largely unknown. Here, we estimated heritability of WML progression, and sought common genetic variants asso...

  10. Comparative quantification of human intestinal bacteria based on cPCR and LDR/LCR

    Institute of Scientific and Technical Information of China (English)

    Zhou-Rui Tang; Kai Li; Yu-Xun Zhou; Zhen-Xian Xiao; Jun-Hua Xiao; Rui Huang; Guo-Hao Gu

    2012-01-01

    AIM: To establish a multiple detection method based on comparative polymerase chain reaction (cPCR) and ligase detection reaction (LDR)/ligase chain reaction (LCR) to quantify the intestinal bacterial components.METHODS: Comparative quantification of 16S rDNAs from different intestinal bacterial components was used to quantify multiple intestinal bacteria. The 16S rDNAs of different bacteria were amplified simultaneously by cPCR. The LDR/LCR was examined to actualize the genotyping and quantification. Two beneficial (Bifidobacterium, Lactobacillus) and three conditionally pathogenic bacteria (Enterococcus, Enterobacterium and Eubacterium) were used in this detection. With cloned standard bacterial 16S rDNAs, standard curves were prepared to validate the quantitative relations between the ratio of original concentrations of two templates and the ratio of the fluorescence signals of their final ligation products. The internal controls were added to monitor the whole detection flow. The quantity ratio between two bacteria was tested.RESULTS: cPCR and LDR revealed obvious linear correlations with standard DNAs, but cPCR and LCR did not. In the sample test, the distributions of the quantity ratio between each two bacterial species were obtained. There were significant differences among these distributions in the total samples. But these distributions of quantity ratio of each two bacteria remained stable among groups divided by age or sex.CONCLUSION: The detection method in this study can be used to conduct multiple intestinal bacteria genotyping and quantification, and to monitor the human intestinal health status as well.

  11. Indicator bacteria and associated water quality constituents in stormwater and snowmelt from four urban catchments

    Science.gov (United States)

    Galfi, H.; Österlund, H.; Marsalek, J.; Viklander, M.

    2016-08-01

    Four indicator bacteria were measured in association with physico-chemical constituents and selected inorganics during rainfall, baseflow and snowmelt periods in storm sewers of four urban catchments in a northern Swedish city. The variation patterns of coliforms, Escherichia coli, enterococci and Clostridium perfringens concentrations were assessed in manually collected grab samples together with those of phosphorus, nitrogen, solids, and readings of pH, turbidity, water conductivity, temperature and flow rates to examine whether these constituents could serve as potential indicators of bacteria sources. A similar analysis was applied to variation patterns of eight selected inorganics typical for baseflow and stormwater runoff to test the feasibility of using these inorganics to distinguish between natural and anthropogenic sources of inflow into storm sewers. The monitored catchments varied in size, the degree of development, and land use. Catchment and season (i.e., rainy or snowmelt periods) specific variations were investigated for sets of individual stormwater samples by the principal component analysis (PCA) to identify the constituents with variation patterns similar to those of indicator bacteria, and to exclude the constituents with less similarity. In the reduced data set, the similarities were quantified by the clustering correlation analysis. Finally, the positive/negative relationships found between indicator bacteria and the identified associated constituent groups were described by multilinear regressions. In the order of decreasing concentrations, coliforms, E. coli and enterococci were found in the highest mean concentrations during both rainfall and snowmelt generated runoff. Compared to dry weather baseflow, concentrations of these three indicators in stormwater were 10 (snowmelt runoff) to 102 (rain runoff) times higher. C. perfringens mean concentrations were practically constant regardless of the season and catchment. The type and number of

  12. Magnetotactic Bacteria from Extreme Environments

    Science.gov (United States)

    Bazylinski, Dennis A.; Lefère, Christopher T.

    2013-03-01

    Magnetotactic bacteria (MTB) represent a diverse collection of motile prokaryotes that biomineralize intracellular, membrane-bounded, tens-of-nanometer-sized crystals of a magnetic mineral called magnetosomes. Magnetosome minerals consist of either magnetite (Fe3O4) or greigite (Fe3S4) and cause cells to align along the Earth's geomagnetic field lines as they swim, a trait called magnetotaxis. MTB are known to mainly inhabit the oxic-anoxic interface (OAI) in water columns or sediments of aquatic habitats and it is currently thought that magnetosomes function as a means of making chemotaxis more efficient in locating and maintaining an optimal position for growth and survival at the OAI. Known cultured and uncultured MTB are phylogenetically associated with the Alpha-, Gamma- and Deltaproteobacteria classes of the phylum Proteobacteria, the Nitrospirae phylum and the candidate division OP3, part of the Planctomycetes-Verrucomicrobia-Chlamydiae (PVC) bacterial superphylum. MTB are generally thought to be ubiquitous in aquatic environments as they are cosmopolitan in distribution and have been found in every continent although for years MTB were thought to be restricted to habitats with pH values near neutral and at ambient temperature. Recently, however, moderate thermophilic and alkaliphilic MTB have been described including: an uncultured, moderately thermophilic magnetotactic bacterium present in hot springs in northern Nevada with a probable upper growth limit of about 63 °C; and several strains of obligately alkaliphilic MTB isolated in pure culture from different aquatic habitats in California, including the hypersaline, extremely alkaline Mono Lake, with an optimal growth pH of >9.0.

  13. Magnetotactic Bacteria from Extreme Environments

    Directory of Open Access Journals (Sweden)

    Christopher T. Lefèvre

    2013-03-01

    Full Text Available Magnetotactic bacteria (MTB represent a diverse collection of motile prokaryotes that biomineralize intracellular, membrane-bounded, tens-of-nanometer-sized crystals of a magnetic mineral called magnetosomes. Magnetosome minerals consist of either magnetite (Fe3O4 or greigite (Fe3S4 and cause cells to align along the Earth’s geomagnetic field lines as they swim, a trait called magnetotaxis. MTB are known to mainly inhabit the oxic–anoxic interface (OAI in water columns or sediments of aquatic habitats and it is currently thought that magnetosomes function as a means of making chemotaxis more efficient in locating and maintaining an optimal position for growth and survival at the OAI. Known cultured and uncultured MTB are phylogenetically associated with the Alpha-, Gamma- and Deltaproteobacteria classes of the phylum Proteobacteria, the Nitrospirae phylum and the candidate division OP3, part of the Planctomycetes-Verrucomicrobia-Chlamydiae (PVC bacterial superphylum. MTB are generally thought to be ubiquitous in aquatic environments as they are cosmopolitan in distribution and have been found in every continent although for years MTB were thought to be restricted to habitats with pH values near neutral and at ambient temperature. Recently, however, moderate thermophilic and alkaliphilic MTB have been described including: an uncultured, moderately thermophilic magnetotactic bacterium present in hot springs in northern Nevada with a probable upper growth limit of about 63 °C; and several strains of obligately alkaliphilic MTB isolated in pure culture from different aquatic habitats in California, including the hypersaline, extremely alkaline Mono Lake, with an optimal growth pH of >9.0.

  14. R-body-producing bacteria.

    Science.gov (United States)

    Pond, F R; Gibson, I; Lalucat, J; Quackenbush, R L

    1989-03-01

    Until 10 years ago, R bodies were known only as diagnostic features by which endosymbionts of paramecia were identified as kappa particles. They were thought to be limited to the cytoplasm of two species in the Paramecium aurelia species complex. Now, R bodies have been found in free-living bacteria and other Paramecium species. The organisms now known to form R bodies include the cytoplasmic kappa endosymbionts of P. biaurelia and P. tetraurelia, the macronuclear kappa endosymbionts of P. caudatum, Pseudomonas avenae (a free-living plant pathogen), Pseudomonas taeniospiralis (a hydrogen-oxidizing soil microorganism), Rhodospirillum centenum (a photosynthetic bacterium), and a soil bacterium, EPS-5028, which is probably a pseudomonad. R bodies themselves fall into five distinct groups, distinguished by size, the morphology of the R-body ribbons, and the unrolling behavior of wound R bodies. In recent years, the inherent difficulties in studying the organization and assembly of R bodies by the obligate endosymbiont kappa, have been alleviated by cloning and expressing genetic determinants for these R bodies (type 51) in Escherichia coli. Type 51 R-body synthesis requires three low-molecular-mass polypeptides. One of these is modified posttranslationally, giving rise to 12 polypeptide species, which are the major structural subunits of the R body. R bodies are encoded in kappa species by extrachromosomal elements. Type 51 R bodies, produced in Caedibacter taeniospiralis, are encoded by a plasmid, whereas bacteriophage genomes probably control R-body synthesis in other kappa species. However, there is no evidence that either bacteriophages or plasmids are present in P. avenae or P. taeniospiralis. No sequence homology was detected between type 51 R-body-encoding DNA and DNA from any R-body-producing species, except C. varicaedens 1038. The evolutionary relatedness of different types of R bodies remains unknown. PMID:2651865

  15. Folate Production by Probiotic Bacteria

    Directory of Open Access Journals (Sweden)

    Stefano Raimondi

    2011-01-01

    Full Text Available Probiotic bacteria, mostly belonging to the genera Lactobacillus and Bifidobacterium, confer a number of health benefits to the host, including vitamin production. With the aim to produce folate-enriched fermented products and/or develop probiotic supplements that accomplish folate biosynthesis in vivo within the colon, bifidobacteria and lactobacilli have been extensively studied for their capability to produce this vitamin. On the basis of physiological studies and genome analysis, wild-type lactobacilli cannot synthesize folate, generally require it for growth, and provide a negative contribution to folate levels in fermented dairy products. Lactobacillus plantarum constitutes an exception among lactobacilli, since it is capable of folate production in presence of para-aminobenzoic acid (pABA and deserves to be used in animal trials to validate its ability to produce the vitamin in vivo. On the other hand, several folate-producing strains have been selected within the genus Bifidobacterium, with a great variability in the extent of vitamin released in the medium. Most of them belong to the species B. adolescentis and B. pseudocatenulatum, but few folate producing strains are found in the other species as well. Rats fed a probiotic formulation of folate-producing bifidobacteria exhibited increased plasma folate level, confirming that the vitamin is produced in vivo and absorbed. In a human trial, the same supplement raised folate concentration in feces. The use of folate-producing probiotic strains can be regarded as a new perspective in the specific use of probiotics. They could more efficiently confer protection against inflammation and cancer, both exerting the beneficial effects of probiotics and preventing the folate deficiency that is associated with premalignant changes in the colonic epithelia.

  16. Folate production by probiotic bacteria.

    Science.gov (United States)

    Rossi, Maddalena; Amaretti, Alberto; Raimondi, Stefano

    2011-01-01

    Probiotic bacteria, mostly belonging to the genera Lactobacillus and Bifidobacterium, confer a number of health benefits to the host, including vitamin production. With the aim to produce folate-enriched fermented products and/or develop probiotic supplements that accomplish folate biosynthesis in vivo within the colon, bifidobacteria and lactobacilli have been extensively studied for their capability to produce this vitamin. On the basis of physiological studies and genome analysis, wild-type lactobacilli cannot synthesize folate, generally require it for growth, and provide a negative contribution to folate levels in fermented dairy products. Lactobacillus plantarum constitutes an exception among lactobacilli, since it is capable of folate production in presence of para-aminobenzoic acid (pABA) and deserves to be used in animal trials to validate its ability to produce the vitamin in vivo. On the other hand, several folate-producing strains have been selected within the genus Bifidobacterium, with a great variability in the extent of vitamin released in the medium. Most of them belong to the species B. adolescentis and B. pseudocatenulatum, but few folate producing strains are found in the other species as well. Rats fed a probiotic formulation of folate-producing bifidobacteria exhibited increased plasma folate level, confirming that the vitamin is produced in vivo and absorbed. In a human trial, the same supplement raised folate concentration in feces. The use of folate-producing probiotic strains can be regarded as a new perspective in the specific use of probiotics. They could more efficiently confer protection against inflammation and cancer, both exerting the beneficial effects of probiotics and preventing the folate deficiency that is associated with premalignant changes in the colonic epithelia. PMID:22254078

  17. Immune regulation of a chronic bacteria infection and consequences for pathogen transmission

    Directory of Open Access Journals (Sweden)

    Pathak Ashutosh K

    2010-08-01

    Full Text Available Abstract Background The role of host immunity has been recognized as not only playing a fundamental role in the interaction between the host and pathogen but also in influencing host infectiousness and the ability to shed pathogens. Despite the interest in this area of study, and the development of theoretical work on the immuno-epidemiology of infections, little is known about the immunological processes that influence pathogen shedding patterns. Results We used the respiratory bacterium Bordetella bronchiseptica and its common natural host, the rabbit, to examine the intensity and duration of oro-nasal bacteria shedding in relation to changes in the level of serum antibodies, blood cells, cytokine expression and number of bacteria colonies in the respiratory tract. Findings show that infected rabbits shed B. bronchiseptica by contact up to 4.5 months post infection. Shedding was positively affected by number of bacteria in the nasal cavity (CFU/g but negatively influenced by serum IgG, which also contributed to the initial reduction of bacteria in the nasal cavity. Three main patterns of shedding were identified: i- bacteria were shed intermittently (46% of individuals, ii- bacteria shedding fell with the progression of the infection (31% and iii- individuals never shed bacteria despite being infected (23%. Differences in the initial number of bacteria shed between the first two groups were associated with differences in the level of serum antibodies and white blood cells. These results suggest that the immunological conditions at the early stage of the infection may play a role in modulating the long term dynamics of B. bronchiseptica shedding. Conclusions We propose that IgG influences the threshold of bacteria in the oro-nasal cavity which then affects the intensity and duration of individual shedding. In addition, we suggest that a threshold level of infection is required for shedding, below this value individuals never shed bacteria

  18. The Microworld of Marine-Bacteria

    DEFF Research Database (Denmark)

    JØRGENSEN, BB

    1995-01-01

    Microsensor studies show that the marine environment in the size scale of bacteria is physically and chemically very different from the macroenvironment. The microbial world of the sediment-water interface is thus dominated by water viscosity and steep diffusion gradients. Because of the diverse...... metabolism types, bacteria in the mostly anoxic sea floor play an important role in the major element cycles of the ocean. The communities of giant, filamentous sulfur bacteria that live in the deep-sea hydrothermal vents or along the Pacific coast of South America are presented here as examples....

  19. The role of intestinal microflora and probiotic bacteria in prophylactic and development of colorectal cancer

    Directory of Open Access Journals (Sweden)

    Ewa Wasilewska

    2013-08-01

    Full Text Available The gut microbiota comprises a large and diverse range of microorganisms whose activities have a significant impact on health. It interacts with its host at both the local and systemic level, resulting in a broad range of beneficial or detrimental outcomes for nutrition, infections, xenobiotic metabolism, and cancer. The current paper reviews research on the role of intestinal microflora in colorectal cancer development. Especially a protective effect of beneficial bacteria and probiotics on the risk of cancer development is highly discussed. There is substantial experimental evidence that the beneficial gut bacteria and their metabolism have the potential to inhibit the development and progression of neoplasia in the large intestine. Most of the data derive, however, from experimental and animal trials. Over a dozen well-documented animal studies have been published, wherein it has been clearly revealed that some lactic acid bacteria, especially lactobacilli and bifidobacteria, inhibit initiation and progression of colorectal cancer. Studies on cancer suppression in humans as a result of the consumption of probiotics are still sparse. Nevertheless, some epidemiological and interventional studies seem to confirm the bacterial anticancerogenic activity also in human gut. The mechanism by which probiotics may inhibit cancer development is unknown. Probiotics increase the amount of beneficial bacteria and decrease the pathogen level in the gut, consequently altering metabolic, enzymatic and carcinogenic activity in the intestine, decreasing inflammation and enhancing immune function, which may contribute to cancer defense.

  20. Stop the Spread of Superbugs: Help Fight Drug Resistant Bacteria

    Science.gov (United States)

    ... the Spread of Superbugs Help Fight Drug-Resistant Bacteria For nearly a century, bacteria-fighting drugs known as antibiotics have helped to control and destroy many of the harmful bacteria that can make us sick. But in recent ...

  1. Birefringence Determination of Magnetic Moments of Magnetotactic Bacteria

    OpenAIRE

    Rosenblatt, Charles; de Araujo, F. Flavio Torres; Frankel, Richard B.

    1982-01-01

    A birefringence technique is used to determine the average magnetic moments of magnetotactic bacteria in culture. Differences in are noted between live and dead bacteria, as well as between normal density and high density samples of live bacteria.

  2. Bacteria engineered for fuel ethanol production: current status

    Energy Technology Data Exchange (ETDEWEB)

    Dien, B.S.; Cotta, M.A. [National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, Peoria, IL (United States); Jeffries, T.W. [Inst. for Microbial and Biochemical Technology, Forest Service, Forest Products Lab., USDA, Madison, WI (United States)

    2004-07-01

    The lack of industrially suitable microorganisms for converting biomass into fuel ethanol has traditionally been cited as a major technical roadblock to developing a bioethanol industry. In the last two decades, numerous microorganisms have been engineered to selectively produce ethanol. Lignocellulosic biomass contains complex carbohydrates that necessitate utilizing microorganisms capable of fermenting sugars not fermentable by brewers' yeast. The most significant of these is xylose. The greatest successes have been in the engineering of gram-negative bacteria: Escherichia coli, Klebsiella oxytoca, and Zymomonas mobilis. E. coli and K. oxytoca are naturally able to use a wide spectrum of sugars, and work has concentrated on engineering these strains to selectively produce ethanol. Z. mobilis produces ethanol at high yields, but ferments only glucose and fructose. Work on this organism has concentrated on introducing pathways for the fermentation of arabinose and xylose. The history of constructing these strains and current progress in refining them are detailed in this review. (orig.)

  3. Life with compass: diversity and biogeography of magnetotactic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Wei [Institute of Geology and Geophysics; Bazylinski, Dennis A [Ames Laboratory; Xiao, Tian [Chinese Academy of Sciences; Wu, Long-Fei [v; Pan, Yongxin [Institute of Geology and Geophysics

    2013-11-12

    Magnetotactic bacteria (MTB) are unique in their ability to synthesize intracellular nano-sized minerals of magnetite and/or greigite magnetosomes for magnetic orientation. Thus, they provide an excellent model system to investigate mechanisms of biomineralization. MTB play important roles in bulk sedimentary magnetism and have numerous versatile applications in paleoenvironmental reconstructions, and biotechnological and biomedical fields. Significant progress has been made in recent years in describing the composition of MTB communities and distribution through innovative cultivation-dependent and -independent techniques. In this review, the most recent contributions to the field of diversity and biogeography of MTB are summarized and reviewed. Emphasis is on the novel insights into various factors/processes potentially affecting MTB community distribution. An understanding of the present-day biogeography of MTB, and the ruling parameters of their spatial distribution, will eventually help us predict MTB community shifts with environmental changes and assess their roles in global iron cycling.

  4. Life with compass: diversity and biogeography of magnetotactic bacteria.

    Science.gov (United States)

    Lin, Wei; Bazylinski, Dennis A; Xiao, Tian; Wu, Long-Fei; Pan, Yongxin

    2014-09-01

    Magnetotactic bacteria (MTB) are unique in their ability to synthesize intracellular nano-sized minerals of magnetite and/or greigite magnetosomes for magnetic orientation. Thus, they provide an excellent model system to investigate mechanisms of biomineralization. MTB play important roles in bulk sedimentary magnetism and have numerous versatile applications in paleoenvironmental reconstructions, and biotechnological and biomedical fields. Significant progress has been made in recent years in describing the composition of MTB communities and distribution through innovative cultivation-dependent and -independent techniques. In this review, the most recent contributions to the field of diversity and biogeography of MTB are summarized and reviewed. Emphasis is on the novel insights into various factors/processes potentially affecting MTB community distribution. An understanding of the present-day biogeography of MTB, and the ruling parameters of their spatial distribution, will eventually help us predict MTB community shifts with environmental changes and assess their roles in global iron cycling. PMID:24148107

  5. [Anaerobic bacteria 150 years after their discovery by Pasteur].

    Science.gov (United States)

    García-Sánchez, José Elías; García-Sánchez, Enrique; Martín-Del-Rey, Ángel; García-Merino, Enrique

    2015-02-01

    In 2011 we celebrated the 150th anniversary of the discovery of anaerobic bacteria by Louis Pasteur. The interest of the biomedical community on such bacteria is still maintained, and is particularly focused on Clostridium difficile. In the past few years important advances in taxonomy have been made due to the genetic, technological and computing developments. Thus, a significant number of new species related to human infections have been characterised, and some already known have been reclassified. At pathogenic level some specimens of anaerobic microflora, that had not been isolated from human infections, have been now isolated in some clinical conditions. There was emergence (or re-emergence) of some species and clinical conditions. Certain anaerobic bacteria have been associated with established infectious syndromes. The virulence of certain strains has increased, and some hypotheses on their participation in certain diseases have been given. In terms of diagnosis, the routine use of MALDI-TOF has led to a shortening of time and a cost reduction in the identification, with an improvement directly related to the improvement of data bases. The application of real-time PCR has been another major progress, and the sequencing of 16srRNA gene and others is currently a reality for several laboratories. Anaerobes have increased their resistance to antimicrobial agents, and the emergence of resistance to carbapenems and metronidazole, and multi-resistance is a current reality. In this situation, linezolid could be an effective alternative for Bacteroides. Fidaxomicin is the only anti-anaerobic agent introduced in the recent years, specifically for the diarrhoea caused by C.difficile. Moreover, some mathematical models have also been proposed in relation with this species.

  6. Development of radiation sterilized dip slides for enumerating lactic acid bacteria and total count in foodstuffs

    Science.gov (United States)

    Eisenberg, E.; Padova, R.; Kirsch, E.; Weissman, Sh.; Hirshfeld, T.; Shenfeld, A.

    APT agar (APT) used for enumeration of lactic acid bacteria and Plate Count agar (PCA) applied for total count were sterilized by gamma radiation using radiation dose of 10-15 kGy. Radiosterilized PCA and APT modified by adding catalase prior to irradiation, or APT with increased content of yeast extract performed, as well as, the heat sterilized commercial media. Growth performance was evaluated on several strains of microorganisms, as well as, by enumeration of bacteria in food products. Radiosterilization of culture media in final packaging, can be applied to produce dip slide kits containing PCA or APT.

  7. Acetic Acid Bacteria and the Production and Quality of Wine Vinegar

    Directory of Open Access Journals (Sweden)

    Albert Mas

    2014-01-01

    Full Text Available The production of vinegar depends on an oxidation process that is mainly performed by acetic acid bacteria. Despite the different methods of vinegar production (more or less designated as either “fast” or “traditional”, the use of pure starter cultures remains far from being a reality. Uncontrolled mixed cultures are normally used, but this review proposes the use of controlled mixed cultures. The acetic acid bacteria species determine the quality of vinegar, although the final quality is a combined result of technological process, wood contact, and aging. This discussion centers on wine vinegar and evaluates the effects of these different processes on its chemical and sensory properties.

  8. The in Vitro Antimicrobial Efficacy of PDT against Periodontopathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Philippe A. Haag

    2015-11-01

    Full Text Available Periodontitis, an inflammatory disease, is caused by biofilms with a mixed microbial etiology and involves the progressive destruction of the tooth-supporting tissues. A rising number of studies investigate the clinical potential of photodynamic therapy (PDT as an adjunct during active therapy. The aim of the present review was to evaluate the available literature for the in vitro antimicrobial efficacy of photodynamic therapy focusing on the periodontopathogenic bacteria Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Fusobacterium nucleatum. The focused question was: “Is it possible to decrease (at least 3 log steps or 99.9% or even eliminate bacterial growth by photodynamic therapy in vitro when compared to untreated control groups or control groups treated by placebo?” In general, PDT resulted in a substantial reduction of surviving bacteria. However, not all studies showed the desired reduction or elimination. The ranges of log10-reduction were 0.38 (58% to a complete eradication (100% for P. gingivalis, 0.21 (39% to 100% for A. actinomycetemcomitans and 0.3 (50% to 100% for F. nucleatum. In conclusion, further and particularly more comparable studies are needed to evaluate if PDT can be clinically successful as an adjuvant in periodontal therapy.

  9. Treatment of antimony mine drainage: challenges and opportunities with special emphasis on mineral adsorption and sulfate reducing bacteria.

    Science.gov (United States)

    Li, Yongchao; Hu, Xiaoxian; Ren, Bozhi

    2016-01-01

    The present article summarizes antimony mine distribution, antimony mine drainage generation and environmental impacts, and critically analyses the remediation approach with special emphasis on iron oxidizing bacteria and sulfate reducing bacteria. Most recent research focuses on readily available low-cost adsorbents, such as minerals, wastes, and biosorbents. It is found that iron oxides prepared by chemical methods present superior adsorption ability for Sb(III) and Sb(V). However, this process is more costly and iron oxide activity can be inhibited by plenty of sulfate in antimony mine drainage. In the presence of sulfate reducing bacteria, sulfate can be reduced to sulfide and form Sb(2)S(3) precipitates. However, dissolved oxygen and lack of nutrient source in antimony mine drainage inhibit sulfate reducing bacteria activity. Biogenetic iron oxide minerals from iron corrosion by iron-oxidizing bacteria may prove promising for antimony adsorption, while the micro-environment generated from iron corrosion by iron oxidizing bacteria may provide better growth conditions for symbiotic sulfate reducing bacteria. Finally, based on biogenetic iron oxide adsorption and sulfate reducing bacteria followed by precipitation, the paper suggests an alternative treatment for antimony mine drainage that deserves exploration.

  10. Viewing marine bacteria, their activity and response to environmental drivers from orbit: satellite remote sensing of bacteria.

    Science.gov (United States)

    Grimes, D Jay; Ford, Tim E; Colwell, Rita R; Baker-Austin, Craig; Martinez-Urtaza, Jaime; Subramaniam, Ajit; Capone, Douglas G

    2014-04-01

    Satellite-based remote sensing of marine microorganisms has become a useful tool in predicting human health risks associated with these microscopic targets. Early applications were focused on harmful algal blooms, but more recently methods have been developed to interrogate the ocean for bacteria. As satellite-based sensors have become more sophisticated and our ability to interpret information derived from these sensors has advanced, we have progressed from merely making fascinating pictures from space to developing process models with predictive capability. Our understanding of the role of marine microorganisms in primary production and global elemental cycles has been vastly improved as has our ability to use the combination of remote sensing data and models to provide early warning systems for disease outbreaks. This manuscript will discuss current approaches to monitoring cyanobacteria and vibrios, their activity and response to environmental drivers, and will also suggest future directions.

  11. Abundance, viability and culturability of Antarctic bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; DeSouza, M.J.B.D.; Nair, S.; Chandramohan, D.

    The viability of total number of bacteria decide the mineralisation rate in any ecosystem and ultimately the fertility of the region. This study aims at establishing the extent of viability in the standing stock of the Antarctic bacterial population...

  12. Distribution of phytopathogenic bacteria in infested seeds

    Science.gov (United States)

    Populations of phytopathogenic bacteria representing five host-pathogen combinations were assessed to determine if there was a mathematical relationship common across seedborne bacterial diseases. Bacterial populations were estimated from naturally-infested seeds of cowpea (Vigna unguiculata), peppe...

  13. Protection of probiotic bacteria in synbiotic matrices

    Science.gov (United States)

    Probiotics, like Lactobacillus acidophilus, Lactobacillus reuteri, Bifidobacterium breve, Bifidobacterium longum, when encapsulated with prebiotic fibers such as fructo-oligosaccharides (FOS), inulin (I) and pectic-oligosaccharides (POS), formed a synbiotic matrix system that protected the bacteria ...

  14. Quorum sensing in Gram-negative bacteria

    Institute of Scientific and Technical Information of China (English)

    WU Hong; SONG Zhijun; Niels HФIBY; Michael GIVSKOV

    2004-01-01

    Bacteria can communicate with each other by means of signal molecules to coordinate the behavior of the entire community,and the mechanism is referred to as quorum sensing (QS).Signal systems enable bacteria to sense the size of their densities by monitoring the concentration of the signal molecules.Among Gram-negative bacteria N-acyl-L-homoserine lactone (acyl-HSL)-dependent quorum sensing systems are particularly widespread.These systems are used to coordinate expression of phenotypes that are fundamental to the interaction of bacteria with each other and with their environment and particularly higher organisms,covering a variety of functions ranging from pathogenic to symbiotic interactions.The detailed knowledge of these bacterial communication systems has opened completely new perspectives for controlling undesired microbial activities.

  15. Ecology: Electrical Cable Bacteria Save Marine Life.

    Science.gov (United States)

    Nielsen, Lars Peter

    2016-01-11

    Animals at the bottom of the sea survive oxygen depletion surprisingly often, and a new study identifies cable bacteria in the sediment as the saviors. The bacterial electrical activity creates an iron 'carpet', trapping toxic hydrogen sulfide.

  16. Comparative genomics of the lactic acid bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Makarova, K.; Slesarev, A.; Wolf, Y.; Sorokin, A.; Mirkin, B.; Koonin, E.; Pavlov, A.; Pavlova, N.; Karamychev, V.; Polouchine, N.; Shakhova, V.; Grigoriev, I.; Lou, Y.; Rokhsar, D.; Lucas, S.; Huang, K.; Goodstein, D. M.; Hawkins, T.; Plengvidhya, V.; Welker, D.; Hughes, J.; Goh, Y.; Benson, A.; Baldwin, K.; Lee, J. -H.; Diaz-Muniz, I.; Dosti, B.; Smeianov, V; Wechter, W.; Barabote, R.; Lorca, G.; Altermann, E.; Barrangou, R.; Ganesan, B.; Xie, Y.; Rawsthorne, H.; Tamir, D.; Parker, C.; Breidt, F.; Broadbent, J.; Hutkins, R.; O' Sullivan, D.; Steele, J.; Unlu, G.; Saier, M.; Klaenhammer, T.; Richardson, P.; Kozyavkin, S.; Weimer, B.; Mills, D.

    2006-06-01

    Lactic acid-producing bacteria are associated with various plant and animal niches and play a key role in the production of fermented foods and beverages. We report nine genome sequences representing the phylogenetic and functional diversity of these bacteria. The small genomes of lactic acid bacteria encode a broad repertoire of transporters for efficient carbon and nitrogen acquisition from the nutritionally rich environments they inhabit and reflect a limited range of biosynthetic capabilities that indicate both prototrophic and auxotrophic strains. Phylogenetic analyses, comparison of gene content across the group, and reconstruction of ancestral gene sets indicate a combination of extensive gene loss and key gene acquisitions via horizontal gene transfer during the coevolution of lactic acid bacteria with their habitats.

  17. Comparative Genomics of Green Sulfur Bacteria

    DEFF Research Database (Denmark)

    Ussery, David; Davenport, C; Tümmler, B

    2010-01-01

    Eleven completely sequenced Chlorobi genomes were compared in oligonucleotide usage, gene contents, and synteny. The green sulfur bacteria (GSB) are equipped with a core genome that sustains their anoxygenic phototrophic lifestyle by photosynthesis, sulfur oxidation, and CO(2) fixation. Whole...

  18. Progress of ITER vacuum vessel

    International Nuclear Information System (INIS)

    Highlights: ► This covers the overall status and progress of the ITER vacuum vessel activities. ► It includes design, R and D, manufacturing and approval process of the regulators. ► The baseline design was completed and now manufacturing designs are on-going. ► R and D includes ISI, dynamic test of keys and lip-seal welding/cutting technology. ► The VV suppliers produced full-scale mock-ups and started VV manufacturing. -- Abstract: Design modifications were implemented in the vacuum vessel (VV) baseline design in 2011–2012 for finalization. The modifications are mostly due to interface components, such as support rails and feedthroughs for the in-vessel coils (IVC). Manufacturing designs are being developed at the domestic agencies (DAs) based on the baseline design. The VV support design was also finalized and tests on scale mock-ups are under preparation. Design of the in-wall shielding (IWS) has progressed, considering the assembly methods and the required tolerances. Further modifications are required to be consistent with the DAs’ manufacturing designs. Dynamic tests on the inter-modular and stub keys to support the blanket modules are being performed to measure the dynamic amplification factor (DAF). An in-service inspection (ISI) plan has been developed and R and D was launched for ISI. Conceptual design of the VV instrumentation has been developed. The VV baseline design was approved by the agreed notified body (ANB) in accordance with the French Nuclear Pressure Equipment Order procedure

  19. Microgravity effects on pathogenicity of bacteria

    OpenAIRE

    Wang, Ya-Juan; Liu, Chang-Ting

    2013-01-01

    Microgravity is one of the important environmental conditions during spaceflight. A series of studies have shown that many kinds of bacteria could be detected in space station and space shuttle. Space environment or simulated microgravity may throw a certain influence on those opportunistic pathogens and lead to some changes on their virulence, biofilm formation and drug tolerance. The mechanism of bacteria response to space environment or simulated microgravity has not been defined. However,...

  20. Keratinolytic activity of cutaneous and oral bacteria.

    OpenAIRE

    Mikx, F H; De Jong, M H

    1987-01-01

    A test was developed to measure the keratinolytic activity of cutaneous and oral bacteria. Keratin, labeled with fluorescein isothiocyanate, was used in a phosphate buffer (pH 7.2) with 1 mM dithiothreitol. The degradation of keratin was estimated by measuring the fluorescence of the degradation products in the supernatant of the reaction mixtures in a luminescence spectrometer. Several oral and cutaneous bacteria were investigated: Bacteroides gingivalis, Bacteroides intermedius, Treponema d...

  1. Interactions between ectomycorrhizal associations and bacteria

    OpenAIRE

    Marupakula, Srisailam

    2016-01-01

    Boreal forest podzol soils have vertically stratified horizons with different physico-chemical characteristics and high microbial diversity. Ectomycorrhizal fungi play key roles in accessing nutrients from both organic and mineral substrates. The role of associated bacteria in these processes is still poorly understood. The aim of the studies described in this thesis was to improve understanding of the distribution, diversity and community structure of fungi and bacteria on roots and in soil ...

  2. How Bacteria Turn Fiber into Food

    OpenAIRE

    Martens, Eric C.; Lowe, Elisabeth C.; Chiang, Herbert; Nicholas A Pudlo; Wu, Meng; McNulty, Nathan P.; Abbott, D Wade; Henrissat, Bernard; Gilbert, Harry J.; Bolam, David N.; Jeffrey I Gordon

    2011-01-01

    Symbiotic bacteria inhabiting the human gut have evolved under intense pressure to utilize complex carbohydrates, primarily plant cell wall glycans in our diets. These polysaccharides are not digested by human enzymes, but are processed to absorbable short chain fatty acids by gut bacteria. The Bacteroidetes, one of two dominant bacterial phyla in the adult gut, possess broad glycan-degrading abilities. These species use a series of membrane protein complexes, termed Sus-like systems, for cat...

  3. Bacteria in goat meat: Biological danger

    OpenAIRE

    Ivanović S.; Pavlović I.; Žujović M.; Tomić Z.; Memiši N.

    2011-01-01

    In the world, especially in China, India, Pаkistаn and Nigeria goat meat represents an important foodstuff in nutrition of people. Goat meat is being increasingly consumed in Serbia owing to its distinctive taste and desirable chemical composition. As many other types of meat, goat meat can be the source of pathogenic bacteria. Bacteria can find their way into meat of healthy goats or goats with no clinical symptoms premortally (infection) or postmortally (...

  4. Study of Lactobacillus as Probiotic Bacteria

    OpenAIRE

    J. Nowroozi; Mirzaii, M; M. Norouzi

    2004-01-01

    Because of inhibitory effect, selected probiotic lactobacilli may be used as biological preservative, so, the aim of this study was to present some data on lactobacillus as probiotic bacteria. Lactic acid bacteria were isolated from sausage. Each isolate of lactobacillus species was identified by biochemical tests and comparing their sugar fermentation pattern. Antibacterial activities were done by an agar spot, well diffusion and blank disk method. Enzyme sensitivity of supernatant fluid and...

  5. Ecology: Electrical Cable Bacteria Save Marine Life

    DEFF Research Database (Denmark)

    Nielsen, Lars Peter

    2016-01-01

    Animals at the bottom of the sea survive oxygen depletion surprisingly often, and a new study identifies cable bacteria in the sediment as the saviors. The bacterial electrical activity creates an iron 'carpet', trapping toxic hydrogen sulfide.......Animals at the bottom of the sea survive oxygen depletion surprisingly often, and a new study identifies cable bacteria in the sediment as the saviors. The bacterial electrical activity creates an iron 'carpet', trapping toxic hydrogen sulfide....

  6. Manganese Oxidation by Bacteria: Biogeochemical Aspects

    Digital Repository Service at National Institute of Oceanography (India)

    Sujith, P.P.; LokaBharathi, P.A.

    and protection against oxidative stress in bacteria (Christianson 1997 and Spiro et al. 2010). It is important for general metabolism, carbohydrate metabolism and for both anabolic and catabolic functions in anaerobiosis and aerobiosis (Crowley et al. 2000... in biochemical processes in rivers must be great but require further investigations to know about their nutritional needs, metabolism and enzymatic systems. Knowing the importance of Mn 2+ oxidation by bacteria Johnson and Stokes (1966) readily stated...

  7. Molecular genetic studies on obligate anaerobic bacteria

    International Nuclear Information System (INIS)

    Molecular genetic studies on obligate anaerobic bacteria have lagged behind similar studies in aerobes. However, the current interest in biotechnology, the involvement of anaerobes in disease and the emergence of antibioticresistant strains have focused attention on the genetics of anaerobes. This article reviews molecular genetic studies in Bacteroides spp., Clostridium spp. and methanogens. Certain genetic systems in some anaerobes differ from those in aerobes and illustrate the genetic diversity among bacteria

  8. Quorum sensing mechanism in lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Hatice Yılmaz - Yıldıran

    2015-04-01

    and detection occurs as a consecution it is hard to understand their QS mechanism. In this review, connection between QS mechanism and some characteristics of lactic acid bacteria are evaluated such as concordance with its host, inhibition of pathogen development and colonization in gastrointestinal system, bacteriocin production, acid and bile resistance, adhesion to epithelium cells. Understanding QS mechanism of lactic acid bacteria will be useful to design metabiotics which is defined as novel probiotics.

  9. New Trends in Impedimetric Biosensors for the Detection of Foodborne Pathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Yixian Wang

    2012-03-01

    Full Text Available The development of a rapid, sensitive, specific method for the foodborne pathogenic bacteria detection is of great importance to ensure food safety and security. In recent years impedimetric biosensors which integrate biological recognition technology and impedance have gained widespread application in the field of bacteria detection. This paper presents an overview on the progress and application of impedimetric biosensors for detection of foodborne pathogenic bacteria, particularly the new trends in the past few years, including the new specific bio-recognition elements such as bacteriophage and lectin, the use of nanomaterials and microfluidics techniques. The applications of these new materials or techniques have provided unprecedented opportunities for the development of high-performance impedance bacteria biosensors. The significant developments of impedimetric biosensors for bacteria detection in the last five years have been reviewed according to the classification of with or without specific bio-recognition element. In addition, some microfluidics systems, which were used in the construction of impedimetric biosensors to improve analytical performance, are introduced in this review.

  10. Progress in plant protoplast research.

    Science.gov (United States)

    Eeckhaut, Tom; Lakshmanan, Prabhu Shankar; Deryckere, Dieter; Van Bockstaele, Erik; Van Huylenbroeck, Johan

    2013-12-01

    In this review we focus on recent progress in protoplast regeneration, symmetric and asymmetric hybridization and novel technology developments. Regeneration of new species and improved culture techniques opened new horizons for practical breeding in a number of crops. The importance of protoplast sources and embedding systems is discussed. The study of reactive oxygen species effects and DNA (de)condensation, along with thorough phytohormone monitoring, are in our opinion the most promising research topics in the further strive for rationalization of protoplast regeneration. Following, fusion and fragmentation progress is summarized. Genomic, transcriptomic and proteomic studies have led to better insights in fundamental processes such as cell wall formation, cell development and chromosome rearrangements in fusion products, whether or not obtained after irradiation. Advanced molecular screening methods of both genome and cytoplasmome facilitate efficient screening of both symmetric and asymmetric fusion products. We expect that emerging technologies as GISH, high resolution melting and next generation sequencing will pay major contributions to our insights of genome creation and stabilization, mainly after asymmetric hybridization. Finally, we demonstrate agricultural valorization of somatic hybridization through enumerating recent introgression of diverse traits in a number of commercial crops. PMID:23955146

  11. Cassini's Grand Finale: The Final Orbits

    Science.gov (United States)

    Spilker, Linda; Edgington, Scott

    2016-04-01

    The Cassini-Huygens mission, a joint collaboration between NASA, ESA and the Italian Space Agency, is approaching its last year of operations after nearly 12 years in orbit around Saturn. Cassini will send back its final bits of unique data on September 15th, 2017 as it plunges into Saturn's atmosphere, vaporizing and satisfying planetary protection requirements. Before that time Cassini will continue its legacy of exploration and discovery with 12 close flybys of Titan in 2016 and 2017 that will return new science data as well as sculpt the inclinations and periods of the final orbits. Even though all of our close icy satellite flybys, including those of Enceladus, are now completed, numerous Voyager-class flybys (summer solstice approaches. In November 2016 Cassini will transition to a series of orbits with peripases just outside Saturn's F ring. These 20 orbits will include close flybys of some tiny ring moons and excellent views of the F ring and outer A ring. The 126th and final close flyby of Titan will propel Cassini across Saturn's main rings and into its final orbits. Cassini's Grand Finale, starting in April 2017, is comprised of 22 orbits at an inclination of 63 degrees. Cassini will repeatedly dive between the innermost rings and the upper atmosphere of the planet providing insights into fundamental questions unattainable during the rest of the mission. Cassini will be the first spacecraft to explore this region. These close orbits provide the highest resolution observations of both the rings and Saturn, and direct in situ sampling of the ring particles, composition, plasma, Saturn's exosphere and the innermost radiation belts. Saturn's gravitational field will be measured to unprecedented accuracy, providing information on the interior structure of the planet, winds in the outer layers of Saturn's atmosphere, and the mass distribution in the rings. Probing the magnetic field will give insight into the nature of the magnetic dynamo, telling us: why the

  12. Study of Lactobacillus as Probiotic Bacteria

    Directory of Open Access Journals (Sweden)

    J Nowroozi

    2004-07-01

    Full Text Available Because of inhibitory effect, selected probiotic lactobacilli may be used as biological preservative, so, the aim of this study was to present some data on lactobacillus as probiotic bacteria. Lactic acid bacteria were isolated from sausage. Each isolate of lactobacillus species was identified by biochemical tests and comparing their sugar fermentation pattern. Antibacterial activities were done by an agar spot, well diffusion and blank disk method. Enzyme sensitivity of supernatant fluid and concentrated cell free culture after treatment with α-amylase, lysozyme and trypsin was determined. The isolated bacteria were Lacto. plantarum, Lacto delbruekii, Lacto. acidophilus, Lacto. brevis. The isolated bacteria had strong activity against indicator strains. The antibacterial activity was stable at 100ºC for 10 min and at 56ºC for 30 min, but activity was lost after autoclaving. The maximum production of plantaricin was obtained at 25 - 30ºC at pH 6.5. Because, lactobacilli that used to process sausage fermentation are producing antimicrobial activity with heat stability bacteriocin, so, these bacteria may be considered to be a healthy probiotic diet. Lactobacilli originally isolated from meat products are the best condidates as probiotic bacteria to improve the microbiological safety of these foods.

  13. Mimicking Seawater For Culturing Marine Bacteria

    DEFF Research Database (Denmark)

    Rygaard, Anita Mac; Sonnenschein, Eva; Gram, Lone;

    2015-01-01

    Only about 1% of marine bacteria have been brought into culture using traditional techniques. The purpose of this study was to investigate if mimicking the natural bacterial environment can increase culturability.We used marine substrates containing defined algal polymers or gellan gum as solidif......Only about 1% of marine bacteria have been brought into culture using traditional techniques. The purpose of this study was to investigate if mimicking the natural bacterial environment can increase culturability.We used marine substrates containing defined algal polymers or gellan gum...... as solidifying agents, and enumerated bacteria from seawater and algal exudates. We tested if culturability could be influenced by addition of quorum sensing signals (AHLs). All plates were incubated at 15°C. Bacterial counts (CFU/g) from algal exudates from brown algae were highest on media containing algal...... polymers. In general, bacteria isolated from algal exudates preferred more rich media than bacteria isolated from seawater. Overall, culturability ranged from 0.01 to 0.8% as compared to total cell count. Substitution of agar with gellan gum increased the culturability of seawater bacteria approximately...

  14. Competition for hydrogen by human faecal bacteria: evidence for the predominance of methane producing bacteria.

    OpenAIRE

    Strocchi, A; Furne, J K; Ellis, C J; Levitt, M D

    1991-01-01

    Studies of sludge have shown that some species of sulphate reducing bacteria outcompete methane producing bacteria for the common substrate H2. A similar competition may exist in human faeces where the methane (CH4) producing status of an individual depends on the faecal concentration of sulphate reducing bacteria. To determine if non-methanogenic faeces outcompete CH4 producing faeces for H2, aliquots of each type of faeces were incubated alone or mixed together, with or without addition of ...

  15. Progressive Supranuclear Palsy

    Science.gov (United States)

    Progressive supranuclear palsy (PSP) is a rare brain disease. It affects brain cells that control the movement of your eyes. This leads to ... speech, vision and swallowing problems. Doctors sometimes confuse PSP with Parkinson's disease or Alzheimer's disease. PSP has ...

  16. Physicians’ Progress Notes

    DEFF Research Database (Denmark)

    Bansler, Jørgen; Havn, Erling C.; Mønsted, Troels;

    2013-01-01

    This paper examines physicians’ progress notes, an artifact that, in spite of its obvious importance in the coordination of cooperative work in clinical settings, has not been subjected to systematic study under CSCW auspices. While several studies have addressed the role of the medical record...... in patient care, they have not dealt specifically with the role, structure, and content of the progress notes. As a consequence, CSCW research has not yet taken fully into account the fact that progress notes are coordinative artifacts of a rather special kind, an open-ended chain of prose texts, written...... sequentially by cooperating physicians for their own use as well as for that of their colleagues. We argue that progress notes are the core of the medical record, in that they marshal and summarize the overwhelming amount of data that is available in the modern hospital environment, and that their narrative...

  17. Progress for the Paralyzed

    Science.gov (United States)

    ... this page please turn Javascript on. Feature: NIBIB Robotics Progress for the Paralyzed Past Issues / Spring 2013 ... Paralyzed —The expanding options for paralyzed individuals include: robotic arms spinal cord stimulation improved prosthetic limbs restored ...

  18. Progress report for '89

    International Nuclear Information System (INIS)

    The 1989 Progress Report presents the most important scientific and technical achievements of the Nuclear Research Institute's research work. Some specialized products prepared at or fabricated by the NRI are mentioned as well. (author). 24 figs., 8 tabs., 101 refs

  19. Progress report, Physics Division

    International Nuclear Information System (INIS)

    This report reviews events and progress in the following areas: development of the TASCC facility; experimental and theoretical nuclear physics research; radionuclide standardization; condensed matter research; applied mathematics; and computer facility operation

  20. Progress report 1985

    International Nuclear Information System (INIS)

    This progress report of the nuclear physics institute includes five basic subjects: theoretical physics, high energy and intermediate energy physics, nuclear physics, combined research physics and instrumentation (microelectronics, imaging, multidetectors, scintillators,...)

  1. Comparison of spectacle classical progressive and office progressive lenses.

    Science.gov (United States)

    Kozlík, Marek; Knollová, Libuse Nováková

    2013-04-01

    This paper elaborates on analysis of progressive spectacle lenses, to correct presbyopia, which are nowadays offered at the market. The paper describes different types of progressive lenses, their parameters, length and width of their progressive segments. It also describes degressive spectacles lenses--progressive lenses on middle and near distance. The main part of the paper is a comparison of functional differences among different types of progressive spectacles lenses. The paper also addresses correctness of choice of progressive lenses for different works and professions. Lastly, it elaborates on differences of centration of different types of progressive lenses and parameters for correct choice of glasses frame for progressive spectacles lenses. PMID:23837232

  2. Antioxidant activity of Sphaerococcus coronopifolius associated bacteria

    Directory of Open Access Journals (Sweden)

    Nádia Fino

    2014-06-01

    Full Text Available Associated bacteria living on macroalgae surfaces are an interesting source of new secondary metabolites with biological activities. The aim of this study was the isolation and identification of epiphytic bacteria from the marine algae Sphaerococcus coronopifolius and the evaluation of the antioxidant activity of the bacteria extracts. The identification of epiphytic bacteria was determined by 16S rRNA gene sequencing. Bacteria extracts were obtained with methanol and dichloromethane (1:1 extraction. Antioxidant activity was evaluated by quantification of total phenolic content (TPC, 2,2-diphenyl-1-picrylhydrazyl (DPPH radical scavenging activity and oxygen radical absorbent capacity (ORAC. The extracts with higher antioxidant activity were tested on MCF-7 and HepG-2 cell lines in oxidative stress conditions induced by H2O2 at 0.2 mM and 0.5 mM, respectively. In total were isolated 21 Sphaerococcus coronopifolius associated bacteria and identified as Vibrio sp. (28.57%, Shewanella sp. (23.81%, Pseudoalteromonas sp. (19.05%, Bacillus sp. (9.52% and Halomonas sp. (9.52%. Two (9.52% of them presented less than 90% Basic Local Alignment Search Tool (BLAST match. The epiphytic bacteria with the most antioxidant potential evaluated by ORAC and DPPH methods were Sp2, Sp12, Sp23, Sp25 and Sp27. The strain Sp4 show high antioxidant activity in all antioxidant methods (ORAC, DPPH and TPC. In oxidative stress conditions on MCF-7 cell line, the extracts of bacteria (1mg.ml-1: 24hours Sp4 (16.15%, Sp25 (17.95% and Sp27 (10.65% prevented the cell death induced by H2O2. In the HepG-2 cell line was the extracts of Sp2 (9.01%, Sp4 (11.21%, Sp12 (7.20% and Sp23 (8.81% bacteria that high prevented the oxidative stress condition induced by H2O2. In conclusion, the Sphaerococcus coronopifolius associated bacteria can be an interesting and excellent source of marine natural compounds with antioxidant activity.

  3. [Progressive visual agnosia].

    Science.gov (United States)

    Sugimoto, Azusa; Futamura, Akinori; Kawamura, Mitsuru

    2011-10-01

    Progressive visual agnosia was discovered in the 20th century following the discovery of classical non-progressive visual agnosia. In contrast to the classical type, which is caused by cerebral vascular disease or traumatic injury, progressive visual agnosia is a symptom of neurological degeneration. The condition of progressive visual loss, including visual agnosia, and posterior cerebral atrophy was named posterior cortical atrophy (PCA) by Benson et al. (1988). Progressive visual agnosia is also observed in semantic dementia (SD) and other degenerative diseases, but there is a difference in the subtype of visual agnosia associated with these diseases. Lissauer (1890) classified visual agnosia into apperceptive and associative types, and it in most cases, PCA is associated with the apperceptive type. However, SD patients exhibit symptoms of associative visual agnosia before changing to those of semantic memory disorder. Insights into progressive visual agnosia have helped us understand the visual system and discover how we "perceive" the outer world neuronally, with regard to consciousness. Although PCA is a type of atypical dementia, its diagnosis is important to enable patients to live better lives with appropriate functional support.

  4. Flagellated ectosymbiotic bacteria propel a eucaryotic cell.

    Science.gov (United States)

    Tamm, S L

    1982-09-01

    A devescovinid flagellate from termites exhibits rapid gliding movements only when in close contact with other cells or with a substrate. Locomotion is powered not by the cell's own flagella nor by its remarkable rotary axostyle, but by the flagella of thousands of rod bacteria which live on its surface. That the ectosymbiotic bacteria actually propel the protozoan was shown by the following: (a) the bacteria, which lie in specialized pockets of the host membrane, bear typical procaryotic flagella on their exposed surface; (b) gliding continues when the devescovinid's own flagella and rotary axostyle are inactivated; (c) agents which inhibit bacterial flagellar motility, but not the protozoan's motile systems, stop gliding movements; (d) isolated vesicles derived from the surface of the devescovinid rotate at speeds dependent on the number of rod bacteria still attached; (e) individual rod bacteria can move independently over the surface of compressed cells; and (f) wave propagation by the flagellar bundles of the ectosymbiotic bacteria is visualized directly by video-enhanced polarization microscopy. Proximity to solid boundaries may be required to align the flagellar bundles of adjacent bacteria in the same direction, and/or to increase their propulsive efficiency (wall effect). This motility-linked symbiosis resembles the association of locomotory spirochetes with the Australian termite flagellate Mixotricha (Cleveland, L. R., and A. V. Grimstone, 1964, Proc. R. Soc. Lond. B Biol. Sci., 159:668-686), except that in our case propulsion is provided by bacterial flagella themselves. Since bacterial flagella rotate, an additional novelty of this system is that the surface bearing the procaryotic rotary motors is turned by the eucaryotic rotary motor within.

  5. COMETABOLISM OF CHLORINATED SOLVENTS BY NITRIFYING BACTERIA: KINETICS, SUBSTRATE INTERACTIONS, TOXICITY EFFECTS, AND BACTERIAL RESPONSE. (R825689C013)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  6. Effect of metalloporphyrins on red autofluorescence from oral bacteria.

    Science.gov (United States)

    Volgenant, Catherine M C; van der Veen, Monique H; de Soet, Johannes J; ten Cate, Jacob M

    2013-06-01

    The aim of this study was to assess the red autofluorescence from bacterial species related to dental caries and periodontitis in the presence of different nutrients in the growth medium. Bacteria were grown anaerobically on tryptic soy agar (TSA) supplemented with nutrients, including magnesium-porphyrins from spinach and iron-porphyrins from heme. The autofluorescence was then assessed at 405 nm excitation. On the TSA without additives, no autofluorescence was observed from any of the species tested. On the TSA containing sheep blood, red autofluorescence was observed only from Parvimonas micra. When the TSA was supplemented with blood, hemin, and vitamin K, red autofluorescence was observed from Actinomyces naeslundii, Bifidobacterium dentium, and Streptococcus mutans. Finally, on the TSA supplemented with spinach extract, red autofluorescence was observed from Aggregatibacter actinomycetemcomitans, A. naeslundii, Enterococcus faecalis, Fusobacterium nucleatum, Lactobacillus salivarius, S. mutans, and Veillonella parvula. We conclude that the bacteria related to dental caries and periodontal disease exhibit red autofluorescence. The autofluorescence characteristics of the tested strains depended on the nutrients present, such as metalloporphyrins, suggesting that the metabolic products of the oral biofilm could be responsible for red autofluorescence. PMID:23659237

  7. Plasmid copy number noise in monoclonal populations of bacteria

    Science.gov (United States)

    Wong Ng, Jérôme; Chatenay, Didier; Robert, Jérôme; Poirier, Michael Guy

    2010-01-01

    Plasmids are extra chromosomal DNA that can confer to their hosts’ supplementary characteristics such as antibiotic resistance. Plasmids code for their copy number through their own replication frequency. Even though the biochemical networks underlying the plasmid copy number (PCN) regulation processes have been studied and modeled, no measurement of the heterogeneity in PCN within a whole population has been done. We have developed a fluorescent-based measurement system, which enables determination of the mean and noise in PCN within a monoclonal population of bacteria. Two different fluorescent protein reporters were inserted: one on the chromosome and the other on the plasmid. The fluorescence of these bacteria was measured with a microfluidic flow cytometry device. We show that our measurements are consistent with known plasmid characteristics. We find that the partitioning system lowers the PCN mean and standard deviation. Finally, bacterial populations were allowed to grow without selective pressure. In this case, we were able to determine the plasmid loss rate and growth inhibition effect.

  8. Effects of Lactic Acid Bacteria Inoculated Fermentation on Pickled Cucumbers

    Directory of Open Access Journals (Sweden)

    Xiaoyi Ji

    2013-12-01

    Full Text Available The aim of this study was to determine the effects of Lactic Acid Bacteria (LAB fermentation on the texture and organic acid of pickled cucumbers. Texture and sensory evaluation as well as a microscopic observation were performed to study the textural differences among fresh cucumber, Spontaneous fermentation (SF cucumber and LAB Inoculating Fermentation (LABIF cucumber. Accumulation of seven organic acids i.e., oxalic, tartaric, malic, lactic, acetic, citric and succinic acid during cucumber pickling were also studied. The disruption extent of the middle lamella in SF cucumber displayed more obviously than that in LABIF cucumber, implying that LABIF contributed to keep the cucumber original structure intact. Based on the organic acid accumulation pattern, in SF LAB and Acetic Acid Bacteria (AAB fermented simultaneously, while in LABIF LAB fermented beforehand thus being in dominant position, then AAB fermented vigorously in a acidic condition created by LAB. The acetic acid accumulaton pattern could be regarded as the distinctive feature between SF and LABIF. The orgnic acids produced in LABIF were higher than that in SF. The final score of sensory evaluation combining texture analysis demonstrated that LABIF overmatched SF. It was concluded that LABIF could obviously enhance the quality of pickled cucumber and overwhelming SF, due to LABIF more beneficial to keep the cucumber original structure intact and organic acids accumulation.

  9. Genetic tools for the investigation of Roseobacter clade bacteria

    Directory of Open Access Journals (Sweden)

    Tielen Petra

    2009-12-01

    Full Text Available Abstract Background The Roseobacter clade represents one of the most abundant, metabolically versatile and ecologically important bacterial groups found in marine habitats. A detailed molecular investigation of the regulatory and metabolic networks of these organisms is currently limited for many strains by missing suitable genetic tools. Results Conjugation and electroporation methods for the efficient and stable genetic transformation of selected Roseobacter clade bacteria including Dinoroseobacter shibae, Oceanibulbus indolifex, Phaeobacter gallaeciensis, Phaeobacter inhibens, Roseobacter denitrificans and Roseobacter litoralis were tested. For this purpose an antibiotic resistance screening was performed and suitable genetic markers were selected. Based on these transformation protocols stably maintained plasmids were identified. A plasmid encoded oxygen-independent fluorescent system was established using the flavin mononucleotide-based fluorescent protein FbFP. Finally, a chromosomal gene knockout strategy was successfully employed for the inactivation of the anaerobic metabolism regulatory gene dnr from D. shibae DFL12T. Conclusion A genetic toolbox for members of the Roseobacter clade was established. This provides a solid methodical basis for the detailed elucidation of gene regulatory and metabolic networks underlying the ecological success of this group of marine bacteria.

  10. Straw bio-degradation by acidogenic bacteria and composite fungi

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ke-qiang; CHEN Xiu-wei; JI Min; NING An-rong; FAN Huan; ZHOU Ke

    2004-01-01

    A composite microbial system, including a strain of Candida tropicalis ( W3 ), a strain of Lactobacillus plantarm(WY3) and three strains of basidiomycete pL104, pL113 and C33, was chosen to degrade corn straw.The final pH was acid owing to the inoculation of acidogenic bacteria, and under this condition the composite fungi system could produce complex enzyme to destroy the compact structure of corn straw. The experimental results showed that the biomass of composite fungi could reach up to maximum when the pH value was 4.5. Through the bio-degradation by combining acidogenic bacteria with the composite fungi system, the cellulose, hemi-cellulose and lignin degradation rates of corn straw powder were 26.36%, 43.30% and 26.96%, respectively. And the gross crude protein content increased 60.41%. This study provided the evidence for the feasibility of developing a composite microbial system with high capability of degrading straw lignocelluloses in order to make reasonable use of straw resource and protect rural eco-environment.

  11. The Effect of Bacteria Penetration on Chalk Permeability

    DEFF Research Database (Denmark)

    Halim, Amalia Yunita; Shapiro, Alexander; Nielsen, Sidsel Marie;

    into reservoirs, however, a complete understanding of the penetration behavior of bacteria is lacking, especially in chalk formations where the pore throat sizes are almost comparable with the sizes of bacteria vegetative cells. This study investigates the penetration of bacteria into chalk. Two bacteria types...

  12. Reduction of nitrate and uranium by indigenous bacteria

    International Nuclear Information System (INIS)

    A bio-remediation concept has been developed to clean up ground water contaminated with nitrate (1200 mg.L-1) and uranium (0.25 mg.L-1). We studied the Tuba City mill tailings site, Arizona, USA. Indigenous bacteria capable of catalyzing the reduction of NO3- and U(VI) were identified in the ground water and in the host rock, the Navajo sandstone. After complete reduction of O2 and NO3- within one week, U(VI) was reduced and precipitated as uraninite. Final uranium concentrations -1 were reached after a few weeks at 24 deg C. Iron sulfide also precipitated as a result of reduction of Fe(III) on the sand surface and sulfate in the ground water. U(VI) was not reduced by sulfide. It was found that enzymatic reduction of U(VI) is faster than abiotic reduction under the conditions given by the composition of the ground water. (authors)

  13. Morphological plasticity of bacteria-Open questions.

    Science.gov (United States)

    Shen, Jie-Pan; Chou, Chia-Fu

    2016-05-01

    Morphological plasticity of bacteria is a cryptic phenomenon, by which bacteria acquire adaptive benefits for coping with changing environments. Some environmental cues were identified to induce morphological plasticity, but the underlying molecular mechanisms remain largely unknown. Physical and chemical factors causing morphological changes in bacteria have been investigated and mostly associated with potential pathways linked to the cell wall synthetic machinery. These include starvation, oxidative stresses, predation effectors, antimicrobial agents, temperature stresses, osmotic shock, and mechanical constraints. In an extreme scenario of morphological plasticity, bacteria can be induced to be shapeshifters when the cell walls are defective or deficient. They follow distinct developmental pathways and transform into assorted morphological variants, and most of them would eventually revert to typical cell morphology. It is suggested that phenotypic heterogeneity might play a functional role in the development of morphological diversity and/or plasticity within an isogenic population. Accordingly, phenotypic heterogeneity and inherited morphological plasticity are found to be survival strategies adopted by bacteria in response to environmental stresses. Here, microfluidic and nanofabrication technology is considered to provide versatile solutions to induce morphological plasticity, sort and isolate morphological variants, and perform single-cell analysis including transcriptional and epigenetic profiling. Questions such as how morphogenesis network is modulated or rewired (if epigenetic controls of cell morphogenesis apply) to induce bacterial morphological plasticity could be resolved with the aid of micro-nanofluidic platforms and optimization algorithms, such as feedback system control. PMID:27375812

  14. Molecular analysis of deep subsurface bacteria

    International Nuclear Information System (INIS)

    Deep sediments samples from site C10a, in Appleton, and sites, P24, P28, and P29, at the Savannah River Site (SRS), near Aiken, South Carolina were studied to determine their microbial community composition, DNA homology and mol %G+C. Different geological formations with great variability in hydrogeological parameters were found across the depth profile. Phenotypic identification of deep subsurface bacteria underestimated the bacterial diversity at the three SRS sites, since bacteria with the same phenotype have different DNA composition and less than 70% DNA homology. Total DNA hybridization and mol %G+C analysis of deep sediment bacterial isolates suggested that each formation is comprised of different microbial communities. Depositional environment was more important than site and geological formation on the DNA relatedness between deep subsurface bacteria, since more 70% of bacteria with 20% or more of DNA homology came from the same depositional environments. Based on phenotypic and genotypic tests Pseudomonas spp. and Acinetobacter spp.-like bacteria were identified in 85 million years old sediments. This suggests that these microbial communities might have been adapted during a long period of time to the environmental conditions of the deep subsurface

  15. COMPETITION BETWEEN ANOXYGENIC PHOTOTROPHIC BACTERIA AND COLORLESS SULFUR BACTERIA IN A MICROBIAL MAT

    NARCIS (Netherlands)

    VISSCHER, PT; VANDENENDE, FP; SCHAUB, BEM; VANGEMERDEN, H

    1992-01-01

    The populations of chemolithoautotrophic (colorless) sulfur bacteria and anoxygenic phototrophic bacteria were enumerated in a marine microbial mat. The highest population densities were found in the 0-5 mm layer of the mat: 2.0 X 10(9) cells CM-3 sediment, and 4.0 X 10(7) cells cm-3 sediment for th

  16. Method of Detecting Coliform Bacteria and Escherichia Coli Bacteria from Reflected Light

    Science.gov (United States)

    Vincent, Robert (Inventor)

    2013-01-01

    The present invention relates to a method of detecting coliform bacteria in water from reflected light and a method of detecting Eschericha Coli bacteria in water from reflected light, and also includes devices for the measurement, calculation and transmission of data relating to that method.

  17. [Domestic violence: any progress?].

    Science.gov (United States)

    Henrion, Roger

    2014-01-01

    Since the publication of the French national survey of violence against women in 2000, the fight against domestic violence has made steady progress. Knowledge of the phenomenon has significantly improved. A nationwide study of murders and manslaughters perpetrated by one partner of a couple against the other has been published annually since 2006. In 2012, domestic violence resulted in the deaths of 314 persons: 166 women, 31 men, 25 children, 9 collateral victims, 14 rivals, and two former spouses killed by their ex-fathers in law. In addition, 67 perpetrators committed suicide (51 men and3 women). The number of victims fluctuates from year to year but has remained fairly stable since 2006 (n=168). Legislation has improved significantly: eight new laws have been passed since 2004, all designed to protect women and to ensure that violent men are restrained and treated. New measures to inform and protect women have been implemented and others have been improved, such as the anonymous helpline (phone no 3919, "domestic violence information"). An inter-ministerial committee on the protection of women from violence and the prevention of human trafficking (MIPROF) was created on 3 January 2013. A website entitled "Stop violence against women " (Stop violences faites aux femmes) is now available. The "Imminent Danger" mobile phone system, designed to alert police if a suspected or known perpetrator breaches restraint conditions, will be extended to the entire country from January 2014. Referees charged with coordinating comprehensive long-tern care of women victims have been deployed at the county level. Information centers on the rights of women and families (CIDFF) now form a local nationwide network. Routine interviews with a midwife during the fourth month of pregnancy, focusing on the woman's emotional, economic and social conditions, have been implemented in 21 % of maternity units and should gradually be generalized. The authorities who have enforced the law have

  18. [Domestic violence: any progress?].

    Science.gov (United States)

    Henrion, Roger

    2014-01-01

    Since the publication of the French national survey of violence against women in 2000, the fight against domestic violence has made steady progress. Knowledge of the phenomenon has significantly improved. A nationwide study of murders and manslaughters perpetrated by one partner of a couple against the other has been published annually since 2006. In 2012, domestic violence resulted in the deaths of 314 persons: 166 women, 31 men, 25 children, 9 collateral victims, 14 rivals, and two former spouses killed by their ex-fathers in law. In addition, 67 perpetrators committed suicide (51 men and3 women). The number of victims fluctuates from year to year but has remained fairly stable since 2006 (n=168). Legislation has improved significantly: eight new laws have been passed since 2004, all designed to protect women and to ensure that violent men are restrained and treated. New measures to inform and protect women have been implemented and others have been improved, such as the anonymous helpline (phone no 3919, "domestic violence information"). An inter-ministerial committee on the protection of women from violence and the prevention of human trafficking (MIPROF) was created on 3 January 2013. A website entitled "Stop violence against women " (Stop violences faites aux femmes) is now available. The "Imminent Danger" mobile phone system, designed to alert police if a suspected or known perpetrator breaches restraint conditions, will be extended to the entire country from January 2014. Referees charged with coordinating comprehensive long-tern care of women victims have been deployed at the county level. Information centers on the rights of women and families (CIDFF) now form a local nationwide network. Routine interviews with a midwife during the fourth month of pregnancy, focusing on the woman's emotional, economic and social conditions, have been implemented in 21 % of maternity units and should gradually be generalized. The authorities who have enforced the law have

  19. Fossil bacteria in Xuanlong iron ore deposits of Hebei Province

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Discovered in Early Proterozoic Xuanlong iron ore deposits are six genera of fossil iron bacteria, i. e. sphere (coenobium of) rod-shaped (monomer) Naumanniella, ellipsoid elliptical Ochrobium, sphere spherical Siderocapsa and chain spherical Siderococcus, chain rod-shaped Leptothrix and Lieskeella, and six genera of fossil blue bacteria, namely sphere spherical Gloeocapsa, Synechocystis and Globobacter, chain spherical Anabaena and Nostoc, and constrictive septate tubular Nodularia. The biomineralized monomers and coenobia of the two categories of bacteria, together with hematite plates made up the bacteria pelletal, bacteria silky,bacteria fibrous and clasty bacteria pelletal textural lamina. The bacteria pelletal laminae combined with other bacteria laminae to make up oncolite, stromatolite and laminate. The precipitation of iron oxide was accelerated due to iron and blue bacteria cohabiting on microbial film or mat. The Xuanlong iron ore deposits are microbial binding ore deposits of ocean source.

  20. Studies on ultrasmall bacteria in relation to the presence of bacteria in the stratosphere

    Science.gov (United States)

    Alshammari, Fawaz; Wainwright, Milton; Alabri, Khalid; Alharbi, Sulamain A.

    2011-04-01

    Recent studies confirm that bacteria exist in the stratosphere. It is generally assumed that these bacteria are exiting from Earth, although it is possible that some are incoming from space. Most stratospheric bacterial isolates belong to the spore-forming genus Bacillus, although non-spore formers have also been isolated. Theoretically, the smaller a bacterium is, the more likely it is to be carried from Earth to the stratosphere. Ultrasmall bacteria have been frequently isolated from Earth environments, but not yet from the stratosphere. This is an anomalous situation, since we would expect such small bacteria to be over represented in the stratosphere-microflora. Here, we show that ultrasmall bacteria are present in the environment on Earth (i.e. in seawater and rainwater) and discuss the paradox of why they have not been isolated from the stratosphere.

  1. Effect of fermented broth from lactic acid bacteria on pathogenic bacteria proliferation.

    Science.gov (United States)

    Gutiérrez, S; Martínez-Blanco, H; Rodríguez-Aparicio, L B; Ferrero, M A

    2016-04-01

    In this study, the effect that 5 fermented broths of lactic acid bacteria (LAB) strains have on the viability or proliferation and adhesion of 7 potentially pathogenic microorganisms was tested. The fermented broth from Lactococcus lactis C660 had a growth inhibitory effect on Escherichia coli K92 that reached of 31%, 19% to Pseudomonas fluorescens, and 76% to Staphylococcus epidermidis. The growth of Staph. epidermidis was negatively affected to 90% by Lc. lactis 11454 broth, whereas the growth of P. fluorescens (25%) and both species of Staphylococcus (35% to Staphylococcus aureus and 76% to Staph. epidermidis) were inhibited when they were incubated in the presence of Lactobacillus casei 393 broth. Finally, the fermented broth of Lactobacillus rhamnosus showed an inhibitory effect on growth of E. coli K92, Listeria innocua, and Staph. epidermidis reached values of 12, 28, and 76%, respectively. Staphylococcus epidermidis was the most affected strain because the effect was detected from the early stages of growth and it was completely abolished. The results of bacterial adhesion revealed that broths from Lc. lactis strains, Lactobacillus paracasei, and Lb. rhamnosus caused a loss of E. coli K92 adhesion. Bacillus cereus showed a decreased of adhesion in the presence of the broths of Lc. lactis strains and Lb. paracasei. Listeria innocua adhesion inhibition was observed in the presence of Lb. paracasei broth, and the greatest inhibitory effect was registered when this pathogenic bacterium was incubated in presence of Lc. lactis 11454 broth. With respect to the 2 Pseudomonas, we observed a slight adhesion inhibition showed by Lactobacillus rhamnosus broth against Pseudomonas putida. These results confirm that the effect caused by the different LAB assayed is also broth- and species-specific and reveal that the broth from LAB tested can be used as functional bioactive compounds to regulate the adhesion and biofilm synthesis and ultimately lead to preventing food and

  2. Acetic acid bacteria in traditional balsamic vinegar: phenotypic traits relevant for starter cultures selection.

    Science.gov (United States)

    Gullo, Maria; Giudici, Paolo

    2008-06-30

    This review focuses on acetic acid bacteria in traditional balsamic vinegar process. Although several studies are available on acetic acid bacteria ecology, metabolism and nutritional requirements, their activity as well as their technological traits in homemade vinegars as traditional balsamic vinegar is not well known. The basic technology to oxidise cooked grape must to produce traditional balsamic vinegar is performed by the so called "seed-vinegar" that is a microbiologically undefined starter culture obtained from spontaneous acetification of previous raw material. Selected starter cultures are the main technological improvement in order to innovate traditional balsamic vinegar production but until now they are rarely applied. To develop acetic acid bacteria starter cultures, selection criteria have to take in account composition of raw material, acetic acid bacteria metabolic activities, applied technology and desired characteristics of the final product. For traditional balsamic vinegar, significative phenotypical traits of acetic acid bacteria have been highlighted. Basic traits are: ethanol preferred and efficient oxidation, fast rate of acetic acid production, tolerance to high concentration of acetic acid, no overoxidation and low pH resistance. Specific traits are tolerance to high sugar concentration and to a wide temperature range. Gluconacetobacter europaeus and Acetobacter malorum strains can be evaluated to develop selected starter cultures since they show one or more suitable characters. PMID:18177968

  3. Engineering Bacteria to Search for Specific Concentrations of Molecules by a Systematic Synthetic Biology Design Method

    Science.gov (United States)

    Chen, Bor-Sen

    2016-01-01

    Bacteria navigate environments full of various chemicals to seek favorable places for survival by controlling the flagella’s rotation using a complicated signal transduction pathway. By influencing the pathway, bacteria can be engineered to search for specific molecules, which has great potential for application to biomedicine and bioremediation. In this study, genetic circuits were constructed to make bacteria search for a specific molecule at particular concentrations in their environment through a synthetic biology method. In addition, by replacing the “brake component” in the synthetic circuit with some specific sensitivities, the bacteria can be engineered to locate areas containing specific concentrations of the molecule. Measured by the swarm assay qualitatively and microfluidic techniques quantitatively, the characteristics of each “brake component” were identified and represented by a mathematical model. Furthermore, we established another mathematical model to anticipate the characteristics of the “brake component”. Based on this model, an abundant component library can be established to provide adequate component selection for different searching conditions without identifying all components individually. Finally, a systematic design procedure was proposed. Following this systematic procedure, one can design a genetic circuit for bacteria to rapidly search for and locate different concentrations of particular molecules by selecting the most adequate “brake component” in the library. Moreover, following simple procedures, one can also establish an exclusive component library suitable for other cultivated environments, promoter systems, or bacterial strains. PMID:27096615

  4. Using Fluorescent Viruses for Detecting Bacteria in Water

    Science.gov (United States)

    Tabacco, Mary Beth; Qian, Xiaohua; Russo, Jaimie A.

    2009-01-01

    A method of detecting water-borne pathogenic bacteria is based partly on established molecular-recognition and fluorescent-labeling concepts, according to which bacteria of a species of interest are labeled with fluorescent reporter molecules and the bacteria can then be detected by fluorescence spectroscopy. The novelty of the present method lies in the use of bacteriophages (viruses that infect bacteria) to deliver the fluorescent reporter molecules to the bacteria of the species of interest.

  5. Bacteriocins From Lactic Acid Bacteria: Interest For Food Products Biopreservation

    OpenAIRE

    Dortu, C.; Thonart, Philippe

    2009-01-01

    Bacteriocins from lactic acid bacteria: interest for food products biopreservation. Bacteriocins from lactic acid bacteria are low molecular weight antimicrobial peptides. They have inhibitory activity against the bacteria that are closed related to the producer strains and a narrow inhibitory spectrum. Nevertheless, most of them have activity against some food-born pathogenic bacteria as Listeria monocytogenes. The application of bacteriocins or bacteriocin producing lactic acid bacteria in ...

  6. Inorganic nanoparticles engineered to attack bacteria.

    Science.gov (United States)

    Miller, Kristen P; Wang, Lei; Benicewicz, Brian C; Decho, Alan W

    2015-11-01

    Antibiotics were once the golden bullet to constrain infectious bacteria. However, the rapid and continuing emergence of antibiotic resistance (AR) among infectious microbial pathogens has questioned the future utility of antibiotics. This dilemma has recently fueled the marriage of the disparate fields of nanochemistry and antibiotics. Nanoparticles and other types of nanomaterials have been extensively developed for drug delivery to eukaryotic cells. However, bacteria have very different cellular architectures than eukaryotic cells. This review addresses the chemistry of nanoparticle-based antibiotic carriers, and how their technical capabilities are now being re-engineered to attack, kill, but also non-lethally manipulate the physiologies of bacteria. This review also discusses the surface functionalization of inorganic nanoparticles with small ligand molecules, polymers, and charged moieties to achieve drug loading and controllable release.

  7. Urban ants and transportation of nosocomial bacteria.

    Science.gov (United States)

    Rodovalho, Cynara M; Santos, Ana L; Marcolino, Marcus T; Bonetti, Ana M; Brandeburgo, Malcon A M

    2007-01-01

    Many ant species displaying synanthropic behavior that have successfully dispersed in urban areas can cause problems in hospitals by acting as bacterial vectors. In this study, we encountered bacteria on ants collected at the Universidade Federal de Uberlândia hospital, in the campus and at households nearby. The ants were identified as Tapinoma melanocephalum (Fabricius) and Camponotus vittatus (Forel) (Hymenoptera: Formicidae) and the bacterial strains found here belong to the group of the coagulase-positive staphylococcus, coagulase-negative staphylococcus and gram negative bacilli, including antimicrobial drug-resistant strains. An investigation of the bacteria found in the ants and in the environment revealed that some ants carried non-isolated bacteria from the same environment and with high levels of resistance, evidencing the transmission potential of these insects. PMID:17710329

  8. Lethal photosensitization of biofilm-grown bacteria

    Science.gov (United States)

    Wilson, Michael

    1997-12-01

    Antibacterial agents are increasingly being used for the prophylaxis and treatment of oral diseases. As these agents can be rendered ineffective by resistance development in the target organisms there is a need to develop alternative antimicrobial approaches. Light-activated antimicrobial agents release singlet oxygen and free radicals which can kill adjacent bacteria and a wide range of cariogenic and periodontopathogenic bacteria has been shown to be susceptible to such agents. In the oral cavity these organisms are present as biofilms (dental plaques) which are less susceptible to traditional antimicrobial agents than bacterial suspensions. The results of these studies have shown that biofilm-grown oral bacteria are also susceptible to lethal photosensitization although the light energy doses required are grater than those needed to kill the organisms when they are grown as aqueous suspensions.

  9. Copper tolerance and virulence in bacteria

    Science.gov (United States)

    Ladomersky, Erik; Petris, Michael J.

    2015-01-01

    Copper (Cu) is an essential trace element for all aerobic organisms. It functions as a cofactor in enzymes that catalyze a wide variety of redox reactions due to its ability to cycle between two oxidation states, Cu(I) and Cu(II). This same redox property of copper has the potential to cause toxicity if copper homeostasis is not maintained. Studies suggest that the toxic properties of copper are harnessed by the innate immune system of the host to kill bacteria. To counter such defenses, bacteria rely on copper tolerance genes for virulence within the host. These discoveries suggest bacterial copper intoxication is a component of host nutritional immunity, thus expanding our knowledge of the roles of copper in biology. This review summarizes our current understanding of copper tolerance in bacteria, and the extent to which these pathways contribute to bacterial virulence within the host. PMID:25652326

  10. Comparison of Spectacle Classical Progressive and Office Progressive Lenses

    OpenAIRE

    Kozlík, Marek; Nováková Knollová, Libuše

    2013-01-01

    This paper elaborates on analysis of progressive spectacle lenses, to correct presbyopia, which are nowadays offered at the market. The paper describes different types of progressive lenses, their parameters, length and width of their progressive segments. It also describes degressive spectacles lenses – progressive lenses on middle and near distance. The main part of the paper is a comparison of functional differences among different types of progressive spectacles lenses. The paper also add...

  11. Chronic progressive multiple sclerosis

    International Nuclear Information System (INIS)

    A long-lasting immunological suppression action seems to be produced by total lymphoid irradiation; some authors emphasize the favorable effect of this treatment on chronic progressive multiple sclerosis. In order to evaluate the actual role of TLI, 6 patients affected with chronic progressive multiple sclerosis were submitted to TLI with shaped and personalized fields at the Istituto del Radio, University of Brescia, Italy. The total dose delivered was 19.8 Gy in 4 weeks, 1.8 Gy/day, 5d/w; a week elapsed between the first and the second irradiation course. Disability according to Kurtzke scale was evaluated, together with blood lymphocyte count and irradiation side-effects, over a mean follow-up period of 20.8 months (range: 13-24). Our findings indicate that: a) disease progression was not markedly reduced by TLI; b) steroid hormones responsivity was restored after irradiation, and c) side-effects were mild and tolerable

  12. Applicability of photodynamic antimicrobial chemotherapy as an alternative to inactivate fish pathogenic bacteria in aquaculture systems.

    Science.gov (United States)

    Arrojado, Cátia; Pereira, Carla; Tomé, João P C; Faustino, Maria A F; Neves, Maria G P M S; Tomé, Augusto C; Cavaleiro, José A S; Cunha, Angela; Calado, Ricardo; Gomes, Newton C M; Almeida, Adelaide

    2011-10-01

    Aquaculture activities are increasing worldwide, stimulated by the progressive reduction of natural fish stocks in the oceans. However, these activities also suffer heavy production and financial losses resulting from fish infections caused by microbial pathogens, including multidrug resistant bacteria. Therefore, strategies to control fish infections are urgently needed, in order to make aquaculture industry more sustainable. Antimicrobial photodynamic therapy (aPDT) has emerged as an alternative to treat diseases and prevent the development of antibiotic resistance by pathogenic bacteria. The aim of this work was to evaluate the applicability of aPDT to inactivate pathogenic fish bacteria. To reach this objective a cationic porphyrin Tri-Py(+)-Me-PF was tested against nine pathogenic bacteria isolated from a semi-intensive aquaculture system and against the cultivable bacteria of the aquaculture system. The ecological impact of aPDT in the aquatic environment was also tested on the natural bacterial community, using the overall bacterial community structure and the cultivable bacteria as indicators. Photodynamic inactivation of bacterial isolates and of cultivable bacteria was assessed counting the number of colonies. The impact of aPDT in the overall bacterial community structure of the aquaculture water was evaluated by denaturing gel gradient electrophoresis (DGGE). The results showed that, in the presence of Tri-Py(+)-Me-PF, the growth of bacterial isolates was inhibited, resulting in a decrease of ≈7-8 log after 60-270 min of irradiation. Cultivable bacteria were also considerably affected, showing decreases up to the detection limit (≈2 log decrease on cell survival), but the inactivation rate varied significantly with the sampling period. The DGGE fingerprint analyses revealed changes in the bacterial community structure caused by the combination of aPDT and light. The results indicate that aPDT can be regarded as a new approach to control fish

  13. Progress in physical chemistry

    CERN Document Server

    Hempelmann, Rolf

    2008-01-01

    Progress in Physical Chemistry is a collection of recent ""Review Articles"" published in the ""Zeitschrift für Physikalische Chemie"". The second volume of Progress in Physical Chemistry is a collection of thematically closely related minireview articles written by the members of the Collaborative Research Centre (SFB) 277 of the German Research Foundation (DFG). These articles are based on twelve years of intense coordinated research efforts. Central topics are the synthesis and the characterization of interface-dominated, i.e. nanostructured materials, mainly in the solid state but also as

  14. Annual progress report 1981

    International Nuclear Information System (INIS)

    This annual progress report of the CEA Protection and Nuclear Safety Institut outlines a brief description of the progress made in each section of the Institut. Research activities of the Protection department include, radiation effects on man, radioecology and environment radioprotection techniques. Research activities of the Nuclear Safety department include, reactor safety analysis, fuel cycle facilities safety analysis, safety research programs. The third section deals with nuclear material security including security of facilities, security of nuclear material transport and monitoring of nuclear material management

  15. Progress report 1982

    International Nuclear Information System (INIS)

    The progress report describes the scientific work and research results of the institute for radium research and nuclear physics of the Austrian Academy of Sciences for the period of 1982. The progress report covers the subject areas of nuclear theory, nuclear model calculations, experimental nuclear physics and neutron involved reactions, medium energy physics, instrumentation and detectors, evaluation of nuclear data and numerical data processing, dating, applications in medicine, dosimetry and environmental studies. A list of publications of this institute is given. (A.N.)

  16. Der Progress Test Medizin

    OpenAIRE

    Osterberg, K.; Kölbel, S; Brauns, K

    2006-01-01

    In 1999 a interdiciplinary, formative progress test for medical students has been established at the Charité - Universitätsmedizin Berlin. It contents of 200 MC-questions on a graduate level and is performed at the beginning of each semester since then.The ascertained test data is evaluated and reported back in a detailed written feedback to each participant.After initial problems in recruiting new item authors and an efficient administration of test items the progress test now is a well est...

  17. Progressive symmetric erythrokeratoderma

    Directory of Open Access Journals (Sweden)

    Gharpuray Mohan

    1990-01-01

    Full Text Available Four patients had symmetrically distributed hyperkeratotic plaques on the trunk and extremities; The lesions in all of them had appeared during infancy, and after a brief period of progression, had remained static, All of them had no family history of similar skin lesions. They responded well to topical applications of 6% salicylic acid in 50% propylene glycol. Unusual features in these cases of progressive symmetric erythrokeratoderma were the sparing of palms and soles, involvement of the trunk and absence of erythema.

  18. Bacteriophage biosensors for antibiotic-resistant bacteria.

    Science.gov (United States)

    Sorokulova, Irina; Olsen, Eric; Vodyanoy, Vitaly

    2014-03-01

    An increasing number of disease-causing bacteria are resistant to one or more anti-bacterial drugs utilized for therapy. Early and speedy detection of these pathogens is therefore very important. Traditional pathogen detection techniques, that include microbiological and biochemical assays are long and labor-intensive, while antibody or DNA-based methods require substantial sample preparation and purification. Biosensors based on bacteriophages have demonstrated remarkable potential to surmount these restrictions and to offer rapid, efficient and sensitive detection technique for antibiotic-resistant bacteria.

  19. Bacteria-Triggered Release of Antimicrobial Agents

    DEFF Research Database (Denmark)

    Komnatnyy, Vitaly V.; Chiang, Wen-Chi; Tolker-Nielsen, Tim;

    2014-01-01

    Medical devices employed in healthcare practice are often susceptible to microbial contamination. Pathogenic bacteria may attach themselves to device surfaces of catheters or implants by formation of chemically complex biofilms, which may be the direct cause of device failure. Extracellular...... material is demonstrated by the bacteria‐triggered release of antibiotics to control bacterial populations and signaling molecules to modulate quorum sensing. The self‐regulating system provides the basis for the development of device‐relevant polymeric materials, which only release antibiotics...... in dependency of the titer of bacteria surrounding the medical device....

  20. Bacteria Provide Cleanup of Oil Spills, Wastewater

    Science.gov (United States)

    2010-01-01

    Through Small Business Innovation Research (SBIR) contracts with Marshall Space Flight Center, Micro-Bac International Inc., of Round Rock, Texas, developed a phototrophic cell for water purification in space. Inside the cell: millions of photosynthetic bacteria. Micro-Bac proceeded to commercialize the bacterial formulation it developed for the SBIR project. The formulation is now used for the remediation of wastewater systems and waste from livestock farms and food manufacturers. Strains of the SBIR-derived bacteria also feature in microbial solutions that treat environmentally damaging oil spills, such as that resulting from the catastrophic 2010 Deepwater Horizon oil rig explosion in the Gulf of Mexico.

  1. Functional Encyclopedia of Bacteria and Archaea

    Energy Technology Data Exchange (ETDEWEB)

    Blow, M. J.; Deutschbauer, A. M.; Hoover, C. A.; Lamson, J.; Lamson, J.; Price, M. N.; Waters, J.; Wetmore, K. M.; Bristow, J.; Arkin, A. P.

    2013-03-20

    Bacteria and Archaea exhibit a huge diversity of metabolic capabilities with fundamental importance in the environment, and potential applications in biotechnology. However, the genetic bases of these capabilities remain unclear due largely to an absence of technologies that link DNA sequence to molecular function. To address this challenge, we are developing a pipeline for high throughput annotation of gene function using mutagenesis, growth assays and DNA sequencing. By applying this pipeline to annotate gene function in 50 diverse microbes we hope to discover thousands of new gene functions and produce a proof of principle `Functional Encyclopedia of Bacteria and Archaea?.

  2. DNA Barcoding on Bacteria: A Review

    Directory of Open Access Journals (Sweden)

    D. E. Lebonah

    2014-01-01

    Full Text Available Bacteria are omnipotent and they can be found everywhere. The study of bacterial pathogens has been happening from olden days to prevent epidemics, food spoilage, losses in agricultural production, and loss of lives. Modern techniques in DNA based species identification are considered. So, there is a need to acquire simple and quick identification technique. Hence, this review article covers the efficacy of DNA barcoding of bacteria. Routine DNA barcoding involves the production of PCR amplicons from particular regions to sequence them and these sequence data are used to identify or “barcode” that organism to make a distinction from other species.

  3. Pervasive transcription: detecting functional RNAs in bacteria.

    Science.gov (United States)

    Lybecker, Meghan; Bilusic, Ivana; Raghavan, Rahul

    2014-01-01

    Pervasive, or genome-wide, transcription has been reported in all domains of life. In bacteria, most pervasive transcription occurs antisense to protein-coding transcripts, although recently a new class of pervasive RNAs was identified that originates from within annotated genes. Initially considered to be non-functional transcriptional noise, pervasive transcription is increasingly being recognized as important in regulating gene expression. The function of pervasive transcription is an extensively debated question in the field of transcriptomics and regulatory RNA biology. Here, we highlight the most recent contributions addressing the purpose of pervasive transcription in bacteria and discuss their implications.

  4. Recent Progress in Lectin-Based Biosensors

    Directory of Open Access Journals (Sweden)

    Baozhen Wang

    2015-12-01

    Full Text Available This article reviews recent progress in the development of lectin-based biosensors used for the determination of glucose, pathogenic bacteria and toxins, cancer cells, and lectins. Lectin proteins have been widely used for the construction of optical and electrochemical biosensors by exploiting the specific binding affinity to carbohydrates. Among lectin proteins, concanavalin A (Con A is most frequently used for this purpose as glucose- and mannose-selective lectin. Con A is useful for immobilizing enzymes including glucose oxidase (GOx and horseradish peroxidase (HRP on the surface of a solid support to construct glucose and hydrogen peroxide sensors, because these enzymes are covered with intrinsic hydrocarbon chains. Con A-modified electrodes can be used as biosensors sensitive to glucose, cancer cells, and pathogenic bacteria covered with hydrocarbon chains. The target substrates are selectively adsorbed to the surface of Con A-modified electrodes through strong affinity of Con A to hydrocarbon chains. A recent topic in the development of lectin-based biosensors is a successful use of nanomaterials, such as metal nanoparticles and carbon nanotubes, for amplifying output signals of the sensors. In addition, lectin-based biosensors are useful for studying glycan expression on living cells.

  5. Protein transport across the cell wall of monoderm Gram-positive bacteria

    OpenAIRE

    Forster, Brian M.; Marquis, Hélène

    2012-01-01

    In monoderm (single membrane) Gram-positive bacteria, the majority of secreted proteins are first translocated across the cytoplasmic membrane into the inner wall zone. For a subset of these proteins, final destination is within the cell envelope either as membrane-anchored or cell wall-anchored proteins, whereas another subset of proteins is destined to be transported across the cell wall into the extracellular milieu. Although the cell wall is a porous structure, there is evidence that, for...

  6. Antioxidant properties of caroot juices and their impact on intestinal and probiotic bacteria

    OpenAIRE

    Aleksandra Duda-Chodak; Tomasz Tarko; Łukasz Wajda; Bożena Kręcioch

    2015-01-01

    There is a growing interest in non-dairy probiotic products. The main aim of the study was to evaluate the impact of juice prepared from 15 various cultivars of carrot on the growth of representatives of human intestinal microbiota (Bifidobacterium catenulatum, Escherichia coli) and probiotic strains (Lactobacillus acidophilus LA-5, Lactobacillus casei 01). Carrot juice was added to liquid medium at a final concentration of 5.0% and their impact on the bacteria number was assess...

  7. [Application of immunologic methods to the analysis of bio-leaching bacteria].

    Science.gov (United States)

    Coto, O; Fernández, A I; León, T; Rodríguez, D

    1994-09-01

    Pure cultures of Thiobacillus ferrooxidans and mixed cultures of Thiobacillus ferrooxidans and Leptospirillum ferrooxidans isolated from the Matahambre mine (Cuba) were used to fit immunodiffusion and immunoelectron microscopy to the study of iron oxidizing bacteria. The possibilities, advantages and limits of those techniques have been studied from both the identification and the serological characterization points of view. Finally, the efficiency of these methods was tested by applying them to the identification of microorganisms from acidic waters from the mine.

  8. Theory of hydrokinetic clearance of bacteria from the urinary bladder. I. Effect of variations in bacterial growth rate.

    Science.gov (United States)

    Mackintosh, I P; Hammond, B J; Watson, B W; O'Grady, F

    1975-05-01

    If the bladder is regularly emptied in appropriate circumstances the concentration of bacteria in successively voided samples progressively falls. By making a number of assumptions about conditions of bacterial growth in the bladder the way in which this washout of bacteria will occur can be predicted. Such predictions give a form of washout curve which differs significantly from that commonly encountered in patients. The shape of the predicted washout curve is affected by the form of the bacterial growth curve but this influence is not sufficient to account for the observed difference between patients and predictions. PMID:1120639

  9. WMO Marine Final Reports

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Final reports of the World Meteorological Organization (WMO) Commission for Marine Meteorology, Commission for Synoptic Meteorology, and Commission for Basic...

  10. Aurora final report

    Energy Technology Data Exchange (ETDEWEB)

    Robert, Dross; Amedeo, Conti

    2013-12-06

    Final Technical report detailing the work done by Nuvera and its partners to fulfill the goals of the program "Transport Studies Enabling Efficiency Optimization of Cost-Competitive Fuel Cell Stacks" (a.k.a. AURORA)

  11. Final focus nomenclature

    Energy Technology Data Exchange (ETDEWEB)

    Erickson, R.

    1986-08-08

    The formal names and common names for all devices in the final focus system of the SLC are listed. The formal names consist of a device type designator, microprocessor designator, and a four-digit unit number. (LEW)

  12. Transacsys PLC - Final Results

    CERN Multimedia

    2002-01-01

    Final results from Transacsys PLC. A subsidary of this company was set up to develop the CERN EDH system into a commercial product but incurred too much financial loss so the project was cancelled (1/2 page).

  13. Cassini's Grand Finale

    Science.gov (United States)

    Edgington, Scott G.; Spilker, Linda J.

    2016-07-01

    After more than a decade exploring Saturn and its moons, the Cassini mission is in its closing act. Cassini's last year is an encore performance stuffed with science, including a final plunge into Saturn's atmosphere.

  14. Progress report 1979

    International Nuclear Information System (INIS)

    This progress report deals with service oriented work performed at the AAEC Research Establishment in the twelve month period ending September 30, 1979. Services provided by the Engineering Services Division, the Safety Department, Site Information Services Department and Commercial Applications are described

  15. MCNP Progress & Performance Improvements

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Forrest B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bull, Jeffrey S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rising, Michael Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-04-14

    Twenty-eight slides give information about the work of the US DOE/NNSA Nuclear Criticality Safety Program on MCNP6 under the following headings: MCNP6.1.1 Release, with ENDF/B-VII.1; Verification/Validation; User Support & Training; Performance Improvements; and Work in Progress. Whisper methodology will be incorporated into the code, and run speed should be increased.

  16. Progress in inertial fusion

    International Nuclear Information System (INIS)

    The requirements for high gain in inertial confinement are given in terms of target implosion requirements. Results of experimental studies of the laser/target interaction and of the dynamics of laser implosion. A report of the progress of advanced laser development is also presented. 3 refs., 8 figs., 1 tab

  17. Stellarator theory: Progress report

    International Nuclear Information System (INIS)

    This paper discusses progress in the following areas: The propagator method; ripple transport in tokamaks; self-consistent bounce-averaged numerical transport; computations: The bootstrap current; comparisons of stellarator ripple transport calculations; and plasma transport in IMS using a 1D fluid transport code

  18. Learning Progressions & Climate Change

    Science.gov (United States)

    Parker, Joyce M.; de los Santos, Elizabeth X.; Anderson, Charles W.

    2015-01-01

    Our society is currently having serious debates about sources of energy and global climate change. But do students (and the public) have the requisite knowledge to engage these issues as informed citizenry? The learning-progression research summarized here indicates that only 10% of high school students typically have a level of understanding…

  19. Managing Progressive MS

    Science.gov (United States)

    ... area of assistive devices for personal hygiene and bathroom adjustments that make toilet functions more effective and safe. They have extensive practical information on devices and techniques. 27 | Managing Progressive MS If you need help with basic activities, get advice and inform ...

  20. Research progress of RNAi

    Institute of Scientific and Technical Information of China (English)

    邹建

    2014-01-01

    the double stranded RNA into cell could cause homologous gene silencing, a phenomenon called RNA interference (RNA interference, RNAi). Research progress of RNA interference characteristics, in this paper, the mechanism of RNA interference technology, RNA interference and existing problems are summarized.

  1. Progress on Display

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    An exhibition in Beijing highlights achievements in China’s autonomous regions An exhibition on social progress in China’s five autonomous re-gions, including Inner Mongolia,Xinjiang, Guangxi, Ningxia and Tibet, opened at the Cultural Palace of Nationalities in Beijing on August 25. It runs until September 17.

  2. Progress in optics

    CERN Document Server

    Wolf, Emil

    2015-01-01

    The Progress in Optics series contains more than 300 review articles by distinguished research workers, which have become permanent records for many important developments, helping optical scientists and optical engineers stay abreast of their fields. Comprehensive, in-depth reviewsEdited by the leading authority in the field

  3. Recent progress in Biophysics

    International Nuclear Information System (INIS)

    Recent progress in biophysics is reviewed, and three examples of the use of physical techniques and ideas in biological research are given. The first one deals with the oxygen transporting protein-hemoglobin, the second one with photosynthesis, and the third one with image formation, using nuclear magnetic resonance. (Author)

  4. Has Macro Progressed?

    OpenAIRE

    Fair, Ray C.

    2009-01-01

    There have been a number of recent papers arguing that there has been considerable convergence in macro research and to the good. This paper considers the question whether what has been converged to is good. Has progress been made in understanding how the macro economy works?

  5. Progressive Retirement Programme

    CERN Multimedia

    HR Department

    2007-01-01

    Following discussion at the Standing Concertation Committee at its meeting on 30 January 2007, the Director-General has approved the extension of the Progressive Retirement Programme with effect from 1 April 2007 until 31 March 2008. Human Resources Department Tel. 74484/74128

  6. Progress report of CJD

    International Nuclear Information System (INIS)

    This paper is the progress report of the Russian Nuclear Data Center at F.E.I., Obninsk. Evaluations have been made for dosimetry reactions and neutron reactions. Analysis of the spectra and the production cross sections were made. (a.n.)

  7. BARC progress report - 1998

    International Nuclear Information System (INIS)

    This report is a compilation of the progress in various major activities and Research and Development programmes of the different Divisions of the Bhabha Atomic Research Centre, Mumbai. The list of publications and papers presented at the various conferences, symposia, workshops and papers published in journal by the staff members of the Divisions are also given. (author)

  8. Progress report 1979

    International Nuclear Information System (INIS)

    This progress report deals with technical and research work done at the AAEC Research Establishment in the twelve month period ending September 30, 1979. Work done in the following research divisions is reported: Applied Maths and Computing, Chemical Technology, Engineering Research, Environmental Science, Instrumentation and Control, Isotope, Materials and Physics

  9. BARC progress report - 1997

    International Nuclear Information System (INIS)

    This report is a compilation of the progress in various major activities and Research and Development programmes of the different Divisions of the Bhabha Atomic Research Centre, Mumbai. The list of publications and papers presented at the various conferences, symposia, workshops and papers published in journal by the staff members of the Divisions are also given. (author)

  10. Progressive taxation and the subjective well-being of nations.

    Science.gov (United States)

    Oishi, Shigehiro; Schimmack, Ulrich; Diener, Ed

    2012-01-01

    Using data from the Gallup World Poll, we examined whether progressive taxation is associated with increased levels of subjective well-being. Consistent with Rawls's theory of justice, our results showed that progressive taxation was positively associated with the subjective well-being of nations. However, the overall tax rate and government spending were not associated with the subjective well-being of nations. Furthermore, controlling for the wealth of nations and income inequality, we found that respondents living in a nation with more-progressive taxation evaluated their lives as closer to the best possible life and reported having more positive and less negative daily experiences than did respondents living in a nation with less-progressive taxation. Finally, we found that the association between more-progressive taxation and higher levels of subjective well-being was mediated by citizens' satisfaction with public goods, such as education and public transportation.

  11. Bacteria in crude oil survived autoclaving and stimulated differentially by exogenous bacteria.

    Science.gov (United States)

    Gong, Xiao-Cui; Liu, Ze-Shen; Guo, Peng; Chi, Chang-Qiao; Chen, Jian; Wang, Xing-Biao; Tang, Yue-Qin; Wu, Xiao-Lei; Liu, Chun-Zhong

    2012-01-01

    Autoclaving of crude oil is often used to evaluate the hydrocarbon-degrading abilities of bacteria. This may be potentially useful for bioaugmentation and microbial enhanced oil recovery (MEOR). However, it is not entirely clear if "endogenous" bacteria (e.g., spores) in/on crude oil survive the autoclaving process, or influence subsequent evaluation of the hydrocarbon-degradation abilities of the "exogenous" bacterial strains. To test this, we inoculated autoclaved crude oil medium with six exogenous bacterial strains (three Dietzia strains, two Acinetobacter strains, and one Pseudomonas strain). The survival of the spore-forming Bacillus and Paenibacillus and the non-spore-forming mesophilic Pseudomonas, Dietzia, Alcaligenes, and Microbacterium was detected using a 16S rRNA gene clone library and terminal restriction fragment length polymorphism (T-RFLP) analysis. However, neither bacteria nor bacterial activity was detected in three controls consisting of non-inoculated autoclaved crude oil medium. These results suggest that detection of endogenous bacteria was stimulated by the six inoculated strains. In addition, inoculation with Acinetobacter spp. stimulated detection of Bacillus, while inoculation with Dietzia spp. and Pseudomonas sp. stimulated the detection of more Pseudomonas. In contrast, similar exogenous bacteria stimulated similar endogenous bacteria at the genus level. Based on these results, special emphasis should be applied to evaluate the influence of bacteria capable of surviving autoclaving on the hydrocarbon-degrading abilities of exogenous bacteria, in particular, with regard to bioaugmentation and MEOR. Bioaugmentation and MEOR technologies could then be developed to more accurately direct the growth of specific endogenous bacteria that may then improve the efficiency of treatment or recovery of crude oil. PMID:23028421

  12. Bacteria in crude oil survived autoclaving and stimulated differentially by exogenous bacteria.

    Directory of Open Access Journals (Sweden)

    Xiao-Cui Gong

    Full Text Available Autoclaving of crude oil is often used to evaluate the hydrocarbon-degrading abilities of bacteria. This may be potentially useful for bioaugmentation and microbial enhanced oil recovery (MEOR. However, it is not entirely clear if "endogenous" bacteria (e.g., spores in/on crude oil survive the autoclaving process, or influence subsequent evaluation of the hydrocarbon-degradation abilities of the "exogenous" bacterial strains. To test this, we inoculated autoclaved crude oil medium with six exogenous bacterial strains (three Dietzia strains, two Acinetobacter strains, and one Pseudomonas strain. The survival of the spore-forming Bacillus and Paenibacillus and the non-spore-forming mesophilic Pseudomonas, Dietzia, Alcaligenes, and Microbacterium was detected using a 16S rRNA gene clone library and terminal restriction fragment length polymorphism (T-RFLP analysis. However, neither bacteria nor bacterial activity was detected in three controls consisting of non-inoculated autoclaved crude oil medium. These results suggest that detection of endogenous bacteria was stimulated by the six inoculated strains. In addition, inoculation with Acinetobacter spp. stimulated detection of Bacillus, while inoculation with Dietzia spp. and Pseudomonas sp. stimulated the detection of more Pseudomonas. In contrast, similar exogenous bacteria stimulated similar endogenous bacteria at the genus level. Based on these results, special emphasis should be applied to evaluate the influence of bacteria capable of surviving autoclaving on the hydrocarbon-degrading abilities of exogenous bacteria, in particular, with regard to bioaugmentation and MEOR. Bioaugmentation and MEOR technologies could then be developed to more accurately direct the growth of specific endogenous bacteria that may then improve the efficiency of treatment or recovery of crude oil.

  13. Progression og underviserkompetencer

    Directory of Open Access Journals (Sweden)

    Lene Tortzen Bager

    2014-03-01

    Full Text Available På baggrund af en kvalitativ interviewundersøgelse af undervisere ved Aarhus Universitet lavet i 2012, tematiserer artiklen, hvordan undervisere udvikler deres faglige og pædagogiske kompetencer i forhold til at kunne skabe progression inden for innovation og entreprenørskab forstået enten som didaktik, arbejdsformer i faglige forløb eller som fag på universitetet. I arbejdet med progression er det en udfordring at integrere de nye faglige dimensioner i det kernefaglige felt. Den seneste model for progression inden for innovation og entreprenør-skab siger, at det er den lærendes generelle erfaringsniveau, der er den afgørende progressionsskabende faktor (Progressionsmodellen, Fonden for Entreprenørskab, 2013b. Samtidig skelner international forskning inden for studiekompetenceområdet mellem niveauer, hvor indlejret viden er det mest avancerede kompetenceniveau (Barrie, 2002.Ifølge progressionsmodellen og den nævnte kompetenceforskning er erfaring og dybt integreret læring altså centrale dimensioner i progression. Men hvad er underviserens rolle heri? Underviserens professionelle udviklingsarbejde forekommer at være underbelyst i forhold til, at underviseren er den legitime garant for integrationen af nye faglige dimensioner og for den studerendes kompetenceniveau. Interviewundersøgelsen forholder sig til spørgsmålet om progression gennem de deltagende underviseres beskrivelse af betydningslag i entreprenørskabsbegrebet koblet til de praksisformer i undervisningen, der knytter sig hertil samt et indblik i undervisernes refleksioner over deres kompetenceudviklingsprocesser. Artiklens bidrag til progression er at se underviserens motivation og kompetenceudvikling som forudsætninger herfor.  Based on a qualitative study of five teachers in the Faculty of Arts at Aarhus University that took place during 2012, the article thematizes how teachers develop their professional and educational qualifications in innovation and

  14. Genetics of thermophilic bacteria: Progress report, May 1, 1986--June 30, 1988

    Energy Technology Data Exchange (ETDEWEB)

    Welker, N.E.

    1988-01-01

    Efficient and reliable protoplasting, regeneration and fusion techniques have been established for a prototrophic strain of Bacillus stearothermophilus. A variety of auxotrophic mutants and a restriction-deficient mutant were isolated and protoplast fusion was used to construct isogenic strains and for chromosomal mapping. Two linkage groups (hom thr and his gly pur-1) were established using this system. The order of the markers is similar to analagous markers on the Bacillus subtilis chromosome. We have evidence that this genetic exchange system can be used for linear chromosomal DNA transformation of protoplasts. Investigations have recently been initiated to develop a transducing system in this strain. Attempts to introduce a thermophile plasmid into strain NUB36 by transformation of protoplasts or protoplast fusion were unsuccessful. We think that the lack of success encountered in these studies is because this plasmid is not stably maintained at high temperature and/or is incompatible with the cryptic plasmids contained in this strain. This is the first report of a reliable genetic exchange system in B. stearothermophilus. This system can be used for the genetic analysis of this organism and for molecular cloning. The development of a host-vector system for cloning in B. stearothermophilus will make it possible to clone genes encoding cellulose hydrolysis, alcohol formation, or methane production. In addition, information gained from the genetic analysis of thermophilic bacilli may be of value in developing genetic systems in thermophilic eubacteria and archaebacteria. 3 tabs.

  15. Taxonomy progress of acetic acid bacteria%醋酸菌的分类进展

    Institute of Scientific and Technical Information of China (English)

    王斌; 陈福生

    2014-01-01

    醋酸菌是好氧型革兰氏阴性菌,能以氧气为终端电子受体,氧化糖类、糖醇类和醇类生成相应的糖醇、酮和有机酸.从1898年Beijerinck定义第一个醋酸菌属-醋酸杆菌属(Acetobacter)以来,截止2014年初,已报道的醋酸菌共16个属,共84个种.该文总结了醋酸菌的分离、分类、鉴定与保藏方法,并对醋酸菌命名原则、种属名称演变以及醋酸菌的种属特征进行了归纳.

  16. Distribution of Gram Negative Bacteria and Evaluation of Resistance Profiles

    Directory of Open Access Journals (Sweden)

    Serap Pamukcuoglu

    2014-03-01

    Full Text Available Aim: In this study, we aimed to examine the distributon of Gram negative bacteria isolated from urine cultures of out-patients in Afyonkarahisar State Hospital and evaluate the antimicrobial resistance rates of these pathogens. Material and Method: Urine samples of out-patients which were sent to microbiology laboratory between 2012-2013 were retrospectively evaluated. The isolates were identified using conventional methods and/or automated Vitec 2.0 system. Antibiogram sensitivities were determined by Kirby-Bauer disc diffusion method or automated system and interpreted on the basis of Clinical and Laboratory Standards Institute (CSI criteria. Double disc sinergy test (DDST or Vitec 2.0 system was used to detect extended spectrum beta-lactamase (ESBL.When conventional methods could%u2019t be clarified according to their colony morphologies, gram staining patterns, biochemical test; automated system has been used. Results: A total of 671 isolates acquired from urine samples were studied. 427 Escherichia coli (63.6 %, 165 Klebsiella spp. (24.6 %, 22 Pseudomonas spp. (3.3 %, nine Acinetobacter spp. (1.3 %, 41 Proteus spp. (6.1 % and seven Serratia (1.0 % strains were identified among isolates. 97 E.coli (22.8 % and 41 Klebsiella (24.8 % isolates were ESBL positive. Most common bacteria were E.coli, 31.1 % of which were resistant to trimethoprim-sulfamethoxazole, 16 % to ciprofloxacin and 3.6 % to nitrofurantoin. Among Enterobacteriaceae, no resistance aganist carbapenems were detected. Moreover, aminoglicoside sensitivity rate was significantly high in this group. Discussion: Microorganisms that have progressively increasing antimicrobial resistance should be considered in the treatment of urinary tract infections. It is also important to use the most appropriate antibiotics to avoid unnecessary usage of these drugs in order to decrease drug resistance rates and ESBL production which may effect the success of the treatment.

  17. A resistant starch fiber diet ameliorates oxidative stress, inflammation, and progression of chronic kidney disease (CKD)

    Science.gov (United States)

    Inflammation is a constant feature and a major mediator of CKD progression. It is, in part, driven by altered gut microbiome and disruption of intestinal epithelial barrier, events which are primarily caused by: 1- urea influx in the intestine resulting in dominance of urease-possessing bacteria; 2-...

  18. High amylose resistant starch diet ameliorates oxidative stress, inflammation, and progression of chronic kidney disease

    Science.gov (United States)

    Inflammation is a major mediator of CKD progression and is partly driven by altered gut microbiome and intestinal barrier disruption, events which are caused by: urea influx in the intestine resulting in dominance of urease-possessing bacteria; disruption of epithelial barrier by urea-derived ammoni...

  19. Physiology of Haloalkaliphilic Sulfur-oxidizing Bacteria

    NARCIS (Netherlands)

    Banciu, H.L.

    2004-01-01

    The inorganic sulfur oxidation by obligate haloalkaliphilic chemolithoautotrophs was only recently discovered and investigated. These autotrophic sulfur oxidizing bacteria (SOB), capable of oxidation of inorganic sulfur compounds at moderate to high salt concentration and at high pH, can be divided

  20. Flow cytometry, fluorescent probes, and flashing bacteria

    NARCIS (Netherlands)

    Bunthof, C.J.

    2002-01-01

     


    Key words: fluorescent probes, flow cytometry, CSLM, viability, survival, microbial physiology, lactic acid bacteria, Lactococcus lactis , Lactobacillus plantarum , cheese, milk, probiotic In food industry there is a perceived need for rapid methods for detection and viability a

  1. Genetics of proteinases of lactic acid bacteria

    NARCIS (Netherlands)

    Kok, Jan; Venema, Gerhardus

    1988-01-01

    Because it is essential for good growth with concomitant rapid acid production, and for the production of flavorous peptides and amino acids, the proteolytic ability of lactic acid bacteria is of crucial importance for reliable dairy product quality. In view of this importance, considerable research

  2. Freeze-drying of lactic acid bacteria.

    Science.gov (United States)

    Fonseca, Fernanda; Cenard, Stéphanie; Passot, Stéphanie

    2015-01-01

    Lactic acid bacteria are of great importance for the food and biotechnology industry. They are widely used as starters for manufacturing food (e.g., yogurt, cheese, fermented meats, and vegetables) and probiotic products, as well as for green chemistry applications. Freeze-drying or lyophilization is a convenient method for preservation of bacteria. By reducing water activity to values below 0.2, it allows long-term storage and low-cost distribution at suprazero temperatures, while minimizing losses in viability and functionality. Stabilization of bacteria via freeze-drying starts with the addition of a protectant solution to the bacterial suspension. Freeze-drying includes three steps, namely, (1) freezing of the concentrated and protected cell suspension, (2) primary drying to remove ice by sublimation, and (3) secondary drying to remove unfrozen water by desorption. In this chapter we describe a method for freeze-drying of lactic acid bacteria at a pilot scale, thus allowing control of the process parameters for maximal survival and functionality recovery.

  3. Exopolysaccharides produced by lactic acid bacteria

    NARCIS (Netherlands)

    Caggianiello, Graziano; Kleerebezem, Michiel; Spano, Giuseppe

    2016-01-01

    A wide range of lactic acid bacteria (LAB) is able to produce capsular or extracellular polysaccharides, with various chemical compositions and properties. Polysaccharides produced by LAB alter the rheological properties of the matrix in which they are dispersed, leading to typically viscous and

  4. Discovering lactic acid bacteria by genomics

    NARCIS (Netherlands)

    Klaenhammer, T; Altermann, E; Arigoni, F; Bolotin, A; Breidt, F; Broadbent, J; Cano, R; Chaillou, S; Deutscher, J; Gasson, M; van de Guchte, M; Guzzo, J; Hartke, A; Hawkins, T; Hols, P; Hutkins, R; Kleerebezem, M; Kok, J; Kuipers, O; Maguin, E; McKay, L; Mills, D; Nauta, A; Overbeek, R; Pel, H; Pridmore, D; Saier, M; van Sinderen, D; Sorokin, A; Steele, J; O'Sullivan, D; de Vos, W; Weimer, B; Zagorec, M; Siezen, R

    2002-01-01

    This review summarizes a collection of lactic acid bacteria that are now undergoing genomic sequencing and analysis. Summaries are presented on twenty different species, with each overview discussing the organisms fundamental and practical significance, environmental habitat, and its role in ferment

  5. NSAID enteropathy and bacteria: a complicated relationship.

    Science.gov (United States)

    Syer, Stephanie D; Blackler, Rory W; Martin, Rebeca; de Palma, Giada; Rossi, Laura; Verdu, Elena; Bercik, Premek; Surette, Michael G; Aucouturier, Anne; Langella, Philippe; Wallace, John L

    2015-04-01

    The clinical significance of small intestinal damage caused by nonsteroidal anti-inflammatory drugs (NSAIDs) remains under-appreciated. It occurs with greater frequency than the damage caused by these drugs in the upper gastrointestinal tract, but is much more difficult to diagnose and treat. Although the pathogenesis of NSAID enteropathy remains incompletely understood, it is clear that bacteria, bile, and the enterohepatic circulation of NSAIDs are all important factors. However, they are also interrelated with one another. Bacterial enzymes can affect the cytotoxicity of bile and are essential for enterohepatic circulation of NSAIDs. Gram-negative bacteria appear to be particularly important in the pathogenesis of NSAID enteropathy, possibly through release of endotoxin. Inhibitors of gastric acid secretion significantly aggravate NSAID enteropathy, and this effect is due to significant changes in the intestinal microbiome. Treatment with antibiotics can, in some circumstances, reduce the severity of NSAID enteropathy, but published results are inconsistent. Specific antibiotic-induced changes in the microbiota have not been causally linked to prevention of intestinal damage. Treatment with probiotics, particularly Bifidobacterium, Lactobacillus, and Faecalibacteriaum prausnitzii, has shown promising effects in animal models. Our studies suggest that these beneficial effects are due to colonization by the bacteria, rather than to products released by the bacteria.

  6. Antimicrobial resistant bacteria in the food chain

    DEFF Research Database (Denmark)

    Wegener, Henrik Caspar

    2003-01-01

    Antimicrobials are used for treatment and prevention of disease in food animals and as feed additives for growth promotion. All uses lead to the development of resistant bacteria, some of which are pathogenic to humans. Current main concerns are with resistance in Salmonella and Campylobacter...

  7. Bioluminescent bacteria: lux genes as environmental biosensors

    OpenAIRE

    Nunes-Halldorson Vânia da Silva; Duran Norma Letícia

    2003-01-01

    Bioluminescent bacteria are widespread in natural environments. Over the years, many researchers have been studying the physiology, biochemistry and genetic control of bacterial bioluminescence. These discoveries have revolutionized the area of Environmental Microbiology through the use of luminescent genes as biosensors for environmental studies. This paper will review the chronology of scientific discoveries on bacterial bioluminescence and the current applications of bioluminescence in env...

  8. Comparative activity of ciprofloxacin against anaerobic bacteria.

    OpenAIRE

    Sutter, V L; Kwok, Y Y; Bulkacz, J

    1985-01-01

    The in vitro activity of ciprofloxacin was assessed against 362 strains of anaerobic bacteria and compared with that of cefoxitin, clindamycin, metronidazole, and mezlocillin. Only 31% of the strains tested were susceptible to ciprofloxacin. The other agents were active against most of the strains tested.

  9. Bacteria in ice may record climate change

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ To many people, bacteria and climate change are like chalk and cheese: the srnallest creature versus one of the biggest phenomena on Earth. Not really.Scientists with the CAS Institute of Tibetan Plateau Research (ITP) and coworkers recently reported that small bugs deposited in ice and snow might tell how our climate has been changing.

  10. Platinum electrodes for electrochemical detection of bacteria

    Science.gov (United States)

    Wilkins, J. R.

    1979-01-01

    Bacteria is detected electro-chemically by measuring evolution of hydrogen in test system with platinum and reference electrode. Using system, electrodes of platinum are used to detect and enumerate varieties of gram-positive and gram-negative organisms compared in different media.

  11. [Innovative treatments for multidrug-resistant bacteria].

    Science.gov (United States)

    Pierre, Tattevin; Aurélien, Lorleac'h; Matthieu, Revest

    2014-03-01

    The spread of multidrug-resistant bacteria has accelerated sharply in the last decade. According to the World Health Organization they are responsible for an estimated 25 000 deaths in Europe each year. In addition, few new antibiotics are under development, raising the spectrum of a return to the "pre-antibiotic era". Non antibiotic antibacterial agents have recently attracted renewed interest. The most promising candidates are: i) phages (bacteria-infecting viruses) have been widely used in Eastern European countries since the 1930s but come up against logistic and regulatory obstacles due to the evolutionary nature of these biologic agents, while convincing clinical data are lacking; ii) bacteriocines are smallantibacterialpeptidesproducedby numerous bacteria; some have a rapid bactericidal effect, good tolerability, and a limited impact on the commensal flora; however, clinical use of bacteriocines is complicated by their fragility, poor penetration, and substantial risk of resistance selection ; iii) antisense oligonucleo tides act by inactivating genes through specific interaction with a complementary DNA or RNA fragment, potentially allowing specific inhibition of selected bacterial virulence factors. However, this therapeutic class may be more suitable for viral or genetic diseases than for multidrug-resistant bacterial infections, owing to the difficulty of delivering them inside bacteria. PMID:26427289

  12. Magnetotactic bacteria and microjets: A comparative study

    NARCIS (Netherlands)

    Khalil, Islam S.M.; Magdanz, Veronika; Sanchez, Samuel; Schmidt, Oliver G.; Misra, Sarthak

    2013-01-01

    We provide a comparative study between two self-propelled microrobots, i.e., magnetotactic bacteria and microjets. This study includes characterization of their fluidic properties (linear and rotational drag coefficients) based on their morphologies and characterization of their magnetic properties

  13. Drug efflux proteins in multidrug resistant bacteria

    NARCIS (Netherlands)

    vanVeen, HW; Konings, WN

    1997-01-01

    Bacteria contain an array of transport proteins in their cytoplasmic membrane. Many of these proteins play an important role in conferring resistance to toxic compounds. The multidrug efflux systems encountered in prokaryotic cells are very similar to those observed in eukaryotic cells. Therefore, a

  14. Anchoring of proteins to lactic acid bacteria

    NARCIS (Netherlands)

    Leenhouts, K; Buist, Girbe; Kok, Jan

    1999-01-01

    The anchoring of proteins to the cell surface of lactic acid bacteria (LAB) using genetic techniques is an exciting and emerging research area that holds great promise for a wide variety of biotechnological applications. This paper reviews five different types of anchoring domains that have been exp

  15. Radiographic markers - A reservoir for bacteria?

    Energy Technology Data Exchange (ETDEWEB)

    Tugwell, Jenna, E-mail: jenna.tugwell@googlemail.co [Department of Radiology, Ysbyty Gwynedd Hospital, Bangor, North Wales (United Kingdom); Maddison, Adele [Nuffield Health, Shrewsbury Hospital (United Kingdom)

    2011-05-15

    Introduction: Amongst the most frequently handled objects in the radiology department are radiographic markers. They are personal accessories used with every patient, and are kept in the radiographers pockets when not utilised. Upon enquiry it was discovered that many radiographers disregarded the potential of these accessories to become a vector for cross-contamination thus never or rarely clean them. The aims of this study were therefore to identify if radiographic markers are a reservoir for bacteria and to establish an effective cleaning method for decontaminating them. Methodology: 25 radiographers/student radiographers were selected for this study. Swabbing of their markers prior and post cleaning took place. The microbiology laboratory subsequently analyzed the results by quantifying and identifying the bacteria present. The participants also completed a closed questionnaire regarding their markers (e.g. frequency of cleaning and type of marker) to help specify the results gained from the swabbing procedure. Results: From the sample swabbed, 92% were contaminated with various organisms including Staphylococcus and Bacillus species, the amount of bacteria present ranged from 0 to >50 CFU. There were no significant differences between disinfectant wipes and alcohol gel in decontaminating the markers. Both successfully reduced their bacterial load, with 80% of the markers post cleaning having 0 CFU. Conclusion: The results indicated that radiographic markers can become highly contaminated with various organisms thus serve as a reservoir for bacteria. In addition, the markers need to be cleaned on a regular basis, with either disinfectant wipes or alcohol gel to reduce their bacterial load.

  16. Emerging Plant Pathogenic Bacteria and Global Warming

    Science.gov (United States)

    Several bacteria, previously classified as non-fluorescent, oxidase positive pseudomonads, Ralstonia, Acidovorax, and Burkholdria have emerged as serious problems world-wide. Perhaps the most destructive is R. solanacearum (RS), a soilborne pathogen with a very wide host range. RS race 3, biovar 2...

  17. Multidrug transporters in lactic acid bacteria

    NARCIS (Netherlands)

    Mazurkiewicz, P; Sakamoto, K; Poelarends, GJ; Konings, WN

    2005-01-01

    Gram-positive lactic acid bacteria possess several Multi-Drug Resistance systems (MDRs) that excrete out of the cell a wide variety of mainly cationic lipophilic cytotoxic compounds as well as many clinically relevant antibiotics. These MDRs are either proton/drug antiporters belonging to the major

  18. DETOXIFICATION BY MAGNETOTACTIC BACTERIA IN SEDIMENTS

    Science.gov (United States)

    The ability of certain bacteria to take up iron in the environment and biosynthesis magnetic materials such as magnetite (Fe3O4) and greigite (Fe3S4) has been recognized (Blakemore, 1982; Bazylinski and Frankel, 2000). Two different mechanisms, biologically induced mineralizat...

  19. Filamentous bacteria transport electrons over centimetre distances

    DEFF Research Database (Denmark)

    Pfeffer, Christian; Larsen, Steffen; Song, Jie;

    2012-01-01

    across centimetre-wide zones. Here we present evidence that the native conductors are long, filamentous bacteria. They abounded in sediment zones with electric currents and along their length they contained strings with distinct properties in accordance with a function as electron transporters. Living...

  20. The interaction of bacteria and metal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Mansfeld, Florian [Corrosion and Environmental Effects Laboratory (CEEL), The Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089-0241 (United States)

    2007-10-10

    This review discusses different examples for the interaction of bacteria and metal surfaces based on work reported previously by various authors and work performed by the author with colleagues at other institutions and with his graduate students at CEEL. Traditionally it has been assumed that the interaction of bacteria with metal surfaces always causes increased corrosion rates ('microbiologically influenced corrosion' (MIC)). However, more recently it has been observed that many bacteria can reduce corrosion rates of different metals and alloys in many corrosive environments. For example, it has been found that certain strains of Shewanella can prevent pitting of Al 2024 in artificial seawater, tarnishing of brass and rusting of mild steel. It has been observed that corrosion started again when the biofilm was killed by adding antibiotics. The mechanism of corrosion protection seems to be different for different bacteria since it has been found that the corrosion potential E{sub corr} became more negative in the presence of Shewanella ana and algae, but more positive in the presence of Bacillus subtilis. These findings have been used in an initial study of the bacterial battery in which Shewanella oneidensis MR-1 was added to a cell containing Al 2024 and Cu in a growth medium. It was found that the power output of this cell continuously increased with time. In the microbial fuel cell (MFC) bacteria oxidize the fuel and transfer electrons directly to the anode. In initial studies EIS has been used to characterize the anode, cathode and membrane properties for different operating conditions of a MFC that contained Shewanella oneidensis MR-1. Cell voltage (V) - current density (i) curves were obtained using potentiodynamic sweeps. The current output of a MFC has been monitored for different experimental conditions. (author)

  1. The interaction of bacteria and metal surfaces

    International Nuclear Information System (INIS)

    This review discusses different examples for the interaction of bacteria and metal surfaces based on work reported previously by various authors and work performed by the author with colleagues at other institutions and with his graduate students at CEEL. Traditionally it has been assumed that the interaction of bacteria with metal surfaces always causes increased corrosion rates ('microbiologically influenced corrosion' (MIC)). However, more recently it has been observed that many bacteria can reduce corrosion rates of different metals and alloys in many corrosive environments. For example, it has been found that certain strains of Shewanella can prevent pitting of Al 2024 in artificial seawater, tarnishing of brass and rusting of mild steel. It has been observed that corrosion started again when the biofilm was killed by adding antibiotics. The mechanism of corrosion protection seems to be different for different bacteria since it has been found that the corrosion potential Ecorr became more negative in the presence of Shewanella ana and algae, but more positive in the presence of Bacillus subtilis. These findings have been used in an initial study of the bacterial battery in which Shewanella oneidensis MR-1 was added to a cell containing Al 2024 and Cu in a growth medium. It was found that the power output of this cell continuously increased with time. In the microbial fuel cell (MFC) bacteria oxidize the fuel and transfer electrons directly to the anode. In initial studies EIS has been used to characterize the anode, cathode and membrane properties for different operating conditions of a MFC that contained Shewanella oneidensis MR-1. Cell voltage (V)-current density (i) curves were obtained using potentiodynamic sweeps. The current output of a MFC has been monitored for different experimental conditions

  2. Invasion of dentinal tubules by oral bacteria.

    Science.gov (United States)

    Love, R M; Jenkinson, H F

    2002-01-01

    Bacterial invasion of dentinal tubules commonly occurs when dentin is exposed following a breach in the integrity of the overlying enamel or cementum. Bacterial products diffuse through the dentinal tubule toward the pulp and evoke inflammatory changes in the pulpo-dentin complex. These may eliminate the bacterial insult and block the route of infection. Unchecked, invasion results in pulpitis and pulp necrosis, infection of the root canal system, and periapical disease. While several hundred bacterial species are known to inhabit the oral cavity, a relatively small and select group of bacteria is involved in the invasion of dentinal tubules and subsequent infection of the root canal space. Gram-positive organisms dominate the tubule microflora in both carious and non-carious dentin. The relatively high numbers of obligate anaerobes present-such as Eubacterium spp., Propionibacterium spp., Bifidobacterium spp., Peptostreptococcus micros, and Veillonella spp.-suggest that the environment favors growth of these bacteria. Gram-negative obligate anaerobic rods, e.g., Porphyromonas spp., are less frequently recovered. Streptococci are among the most commonly identified bacteria that invade dentin. Recent evidence suggests that streptococci may recognize components present within dentinal tubules, such as collagen type I, which stimulate bacterial adhesion and intra-tubular growth. Specific interactions of other oral bacteria with invading streptococci may then facilitate the invasion of dentin by select bacterial groupings. An understanding the mechanisms involved in dentinal tubule invasion by bacteria should allow for the development of new control strategies, such as inhibitory compounds incorporated into oral health care products or dental materials, which would assist in the practice of endodontics.

  3. MAPK Usage in Periodontal Disease Progression

    Directory of Open Access Journals (Sweden)

    Qiyan Li

    2012-01-01

    Full Text Available In periodontal disease, host recognition of bacterial constituents, including lipopolysaccharide (LPS, induces p38 MAPK activation and subsequent inflammatory cytokine expression, favoring osteoclastogenesis and increased net bone resorption in the local periodontal environment. In this paper, we discuss evidence that the p38/MAPK-activated protein kinase-2 (MK2 signaling axis is needed for periodontal disease progression: an orally administered p38α inhibitor reduced the progression of experimental periodontal bone loss by reducing inflammation and cytokine expression. Subsequently, the significance of p38 signaling was confirmed with RNA interference to attenuate MK2-reduced cytokine expression and LPS-induced alveolar bone loss. MAPK phosphatase-1 (MKP-1, a negative regulator of MAPK activation, was also critical for periodontal disease progression. In MPK-1-deficient mice, p38-sustained activation increased osteoclast formation and bone loss, whereas MKP-1 overexpression dampened p38 signaling and subsequent cytokine expression. Finally, overexpression of the p38/MK2 target RNA-binding tristetraprolin (TTP decreased mRNA stability of key inflammatory cytokines at the posttranscriptional level, thereby protecting against periodontal inflammation. Collectively, these studies highlight the importance of p38 MAPK signaling in immune cytokine production and periodontal disease progression.

  4. Segmentation of Bacteria Image Based on Level Set Method

    Institute of Scientific and Technical Information of China (English)

    WANG Hua; CHEN Chun-xiao; HU Yong-hong; YANG Wen-ge

    2008-01-01

    In biology ferment engineering, accurate statistics of the quantity of bacte-ria is one of the most important subjects. In this paper, the quantity of bacteria which was observed traditionally manuauy can be detected automatically. Image acquisition and pro-cessing system is designed to accomplish image preprocessing, image segmentation and statistics of the quantity of bacteria. Segmentation of bacteria images is successfully real-ized by means of a region-based level set method and then the quantity of bacteria is com-puted precisely, which plays an important role in optimizing the growth conditions of bac-teria.

  5. Antibacterial activity of silver-killed bacteria: the "zombies" effect

    Science.gov (United States)

    Wakshlak, Racheli Ben-Knaz; Pedahzur, Rami; Avnir, David

    2015-04-01

    We report a previously unrecognized mechanism for the prolonged action of biocidal agents, which we denote as the zombies effect: biocidally-killed bacteria are capable of killing living bacteria. The concept is demonstrated by first killing Pseudomonas aeruginosa PAO1 with silver nitrate and then challenging, with the dead bacteria, a viable culture of the same bacterium: Efficient antibacterial activity of the killed bacteria is observed. A mechanism is suggested in terms of the action of the dead bacteria as a reservoir of silver, which, due to Le-Chatelier's principle, is re-targeted to the living bacteria. Langmuirian behavior, as well as deviations from it, support the proposed mechanism.

  6. Label-Free Applications of SERS for Bacteria Analysis

    OpenAIRE

    Zhou, Haibo

    2014-01-01

    In the first part, we report on surface-enhanced Raman scattering (SERS) for living bacteria detection in drinking water by employing a synthesis of silver nanoparticles coating the cell wall of bacteria (Bacteria@AgNPs). In the second part of this thesis, we present a label-free SERS detection of bacteria on microarray at single cell level. In the third part of this thesis, we successfully counted live and dead bacteria with Bacteria@AgNPs method by SERS mapping technique.

  7. Lactic acid bacteria in the quality improvement and depreciation of wine.

    Science.gov (United States)

    Lonvaud-Funel, A

    1999-01-01

    The winemaking process includes two main steps: lactic acid bacteria are responsible for the malolactic fermentation which follows the alcoholic fermentation by yeasts. Both types of microorganisms are present on grapes and on cellar equipment. Yeasts are better adapted to growth in grape must than lactic acid bacteria, so the alcoholic fermentation starts quickly. In must, up to ten lactic acid bacteria species can be identified. They belong to the Lactobacillus, Pediococcus, Leuconostoc and Oenococcus genera. Throughout alcoholic fermentation, a natural selection occurs and finally the dominant species is O. oeni, due to interactions between yeasts and bacteria and between bacteria themselves. After bacterial growth, when the population is over 10(6) CFU/ml, malolactic transformation is the obvious change in wine composition. However, many other substrates can be metabolized. Some like remaining sugars and citric acid are always assimilated by lactic acid bacteria, thus providing them with energy and carbon. Other substrates such as some amino acids may be used following pathways restricted to strains carrying the adequate enzymes. Some strains can also produce exopolysaccharides. All these transformations greatly influence the sensory and hygienic quality of wine. Malic acid transformation is encouraged because it induces deacidification. Diacetyl produced from citric acid is also helpful to some extent. Sensory analyses show that many other reactions change the aromas and make malolactic fermentation beneficial, but they are as yet unknown. On the contrary, an excess of acetic acid, the synthesis of glucane, biogenic amines and precursors of ethylcarbamate are undesirable. Fortunately, lactic acid bacteria normally multiply in dry wines; moreover some of these activities are not widespread. Moreover, the most striking trait of wine lactic acid bacteria is their capacity to adapt to a hostile environment. The mechanisms for this are not yet completely elucidated

  8. Internationalisering og progression

    Directory of Open Access Journals (Sweden)

    Lisanne Wilken

    2014-09-01

    Full Text Available I Danmark har vi traditionelt tænkt universiteternes femårige kandidatuddannelser som sammenhængende forløb, hvor den studerende gradvist opbygger en stadig mere specialiseret viden inden for et givet fagområde. Denne idé om progression er i de senere år blevet udfordret fra flere sider. Især er progressionsidéen blevet diskuteret i forhold til tværfaglige uddannelsesforløb, men også de mange internationale uddannelser, der etableres, udfordrer den måde, hvorpå vi traditionelt har forstået progression i det danske uddannelsessystem. På internationale kandidatuddannelser finder vi nemlig typisk både studerende, for hvem kandidatuddannelsen er en forlængelse af en grunduddannelse, og studerende, der har taget deres grunduddannelse et andet sted og muligvis endda i et andet fag. I denne artikel undersøger vi, hvordan undervisere på kandidatuddannelser som både er tværfaglige og internationale forholder sig til progression. Artiklen er skrevet på baggrund af semistrukturerede interviews med undervisere fra tværfaglige, internationale uddannelser ved Aarhus Universitet.University programs in Denmark have traditionally been perceived as a continuous education consisting of three years of basic education followed by two years of specialization within the same discipline. This idea is now being challenged on several fronts. For instance, it is becoming more common for Danish universities to offer interdisciplinary master programs. Also, the trend for greater internationalization in higher education means that programs can attract students from outside Denmark, and these students often come from different academic backgrounds. To investigate how these changes are affecting the way professors who teach on interdisciplinary international masters programs conceive student progress, we carried out semi-structured interviews with teachers on international programs at Aarhus University, the second largest university in Denmark. The

  9. Inhibition of Complement Retards Ankylosing Spondylitis Progression

    Science.gov (United States)

    Yang, Chaoqun; Ding, Peipei; Wang, Qingkai; Zhang, Long; Zhang, Xin; Zhao, Jianquan; Xu, Enjie; Wang, Na; Chen, Jianfeng; Yang, Guang; Hu, Weiguo; Zhou, Xuhui

    2016-01-01

    Ankylosing spondylitis (AS) is a chronic axial spondyloarthritis (SpA) resulting in back pain and progressive spinal ankyloses. Currently, there are no effective therapeutics targeting AS largely due to elusive pathogenesis mechanisms, even as potential candidates such as HLA-B27 autoantigen have been identified. Herein, we employed a proteoglycan (PG)-induced AS mouse model together with clinical specimens, and found that the complement system was substantially activated in the spinal bone marrow, accompanied by a remarkable proportion alteration of neutrophils and macrophage in bone marrow and spleen, and by the significant increase of TGF-β1 in serum. The combined treatment with a bacteria-derived complement inhibitor Efb-C (C-terminal of extracellular fibrinogen-binding protein of Staphylococcus aureus) remarkably retarded the progression of mouse AS by reducing osteoblast differentiation. Furthermore, we demonstrated that two important modulators involved in AS disease, TGF-β1 and RANKL, were elevated upon in vitro complement attack in osteoblast and/or osteoclast cells. These findings further unravel that complement activation is closely related with the pathogenesis of AS, and suggest that complement inhibition may hold great potential for AS therapy. PMID:27698377

  10. Isolation and life-cycle characterization of lytic viruses infecting heterotrophic bacteria and cyanobacteria

    DEFF Research Database (Denmark)

    Middelboe, Mathias; Chan, Amy; Bertelsen, Sif Koldborg

    2010-01-01

    Basic knowledge on viruses infecting heterotrophic bacteria and cyanobacteria is key to future progress in understanding the role of viruses in aquatic systems and the influence of virus–host interactions on microbial mortality, biogeochemical cycles, and genetic exchange. Such studies require...... the isolation, propagation, and purification of host–virus systems. This contribution presents some of the most widely used methodological approaches for isolation and purification of bacteriophages and cyanophages, the first step in detailed studies of virus–host interactions and viral genetic composition......, and discusses the applications and limitations of different isolation procedures. Most work on phage isolation has been carried out with aerobic heterotrophic bacteria and cyanobacteria, culturable both on agar plates and in enriched liquid cultures. The procedures presented here are limited to lytic viruses...

  11. Lactic acid bacteria from fresh fruit and vegetables as biocontrol agents of phytopathogenic bacteria and fungi

    OpenAIRE

    Trias Mansilla, Rosalia; Bañeras Vives, Lluís; Montesinos Seguí, Emilio; Badosa Romañó, Esther

    2008-01-01

    This study evaluated the efficacy of lactic acid bacteria (LAB) isolated from fresh fruits and vegetables as biocontrol agents against the phytopathogenic and spoilage bacteria and fungi, Xanthomonas campestris, Erwinia carotovora, Penicillium expansum, Monilinia laxa, and Botrytis cinerea. The antagonistic activity of 496 LAB strains was tested in vitro and all tested microorganisms except P. expansum were inhibited by at least one isolate. The 496 isolates were also analyzed for the inhibit...

  12. Spray drying of dairy bacteria: New opportunities to improve the viability of bacteria powders

    OpenAIRE

    Dolivet, Anne; Mejean, Serge; Hervé, C.; Jeantet, Romain

    2013-01-01

    The most frequently used technique for dehydration of dairy bacteria is freeze drying. Of the other possible preservation techniques used in the dairy industry to produce large amounts of dairy ingredients at commercially viable processing costs, spray drying is one of the main processing tools and the cost is 10 times lower than that of freeze drying. In this work, some examples are presented for different species of dairy bacteria with respect to spray-drying processes (as an alternative ap...

  13. Final disposal of nuclear waste

    International Nuclear Information System (INIS)

    The nuclear industry argues that high level radioactive waste can be safely disposed of in deep underground repositories. As yet, however, no such repositories are in use and the amount of spent nuclear fuel in ponds and dry storage is steadily increasing. Although the nuclear industry further argues that storage is a safe option for up to 50 years and has the merit of allowing the radioactivity of the fuel to decay to a more manageable level, the situation seems to be far from ideal. The real reasons for procrastination over deep disposal seem to have as much to do with politics as safe technology. The progress of different countries in finding a solution to the final disposal of high level waste is examined. In some, notably the countries of the former Soviet Union, cost is a barrier; in others, the problem has not yet been faced. In these countries undertaking serious research into deep disposal there has been a tendency, in the face of opposition from environmental groups, to retreat to sites close to existing nuclear installations and to set up rock laboratories to characterize them. These sites are not necessarily the best geologically, but the laboratories may end up being converted into actual repositories because of the considerable financial investment they represent. (UK)

  14. Final disposal of nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1995-10-01

    The nuclear industry argues that high level radioactive waste can be safely disposed of in deep underground repositories. As yet, however, no such repositories are in use and the amount of spent nuclear fuel in ponds and dry storage is steadily increasing. Although the nuclear industry further argues that storage is a safe option for up to 50 years and has the merit of allowing the radioactivity of the fuel to decay to a more manageable level, the situation seems to be far from ideal. The real reasons for procrastination over deep disposal seem to have as much to do with politics as safe technology. The progress of different countries in finding a solution to the final disposal of high level waste is examined. In some, notably the countries of the former Soviet Union, cost is a barrier; in others, the problem has not yet been faced. In these countries undertaking serious research into deep disposal there has been a tendency, in the face of opposition from environmental groups, to retreat to sites close to existing nuclear installations and to set up rock laboratories to characterize them. These sites are not necessarily the best geologically, but the laboratories may end up being converted into actual repositories because of the considerable financial investment they represent. (UK).

  15. Progressive familial intrahepatic cholestasis

    Institute of Scientific and Technical Information of China (English)

    Tomohide Hori; Justin H. Nguyen; Shinji Uemoto

    2010-01-01

    BACKGROUND: Three types of progressive familial intrahepatic cholestasis (PFIC) have been identiifed, but their etiologies include unknown mechanisms. DATA SOURCES: A PubMed search on "progressive familial intrahepatic cholestasis" and "PFIC" was performed on the topic, and the relevant articles were reviewed. RESULTS: The etiologies of the three PFIC types still include unknown mechanisms. Especially in PFIC type 1, enterohepatic circulation of bile acid should be considered. Ursodeoxycholic acid, partial external biliary diversion and liver transplantation have been used for the treatment of PFIC patients according to disease course. CONCLUSIONS: Since the etiologies and disease mechanisms of PFIC are still unclear, detailed studies are urgently required. Strategies for more advanced therapies are also needed. These developments in the future are indispensable, especially for PFIC type 1 patients.

  16. A hybrid actuated microrobot using an electromagnetic field and flagellated bacteria for tumor-targeting therapy.

    Science.gov (United States)

    Li, Donghai; Choi, Hyunchul; Cho, Sunghoon; Jeong, Semi; Jin, Zhen; Lee, Cheong; Ko, Seong Young; Park, Jong-Oh; Park, Sukho

    2015-08-01

    In this paper, we propose a new concept for a hybrid actuated microrobot for tumor-targeting therapy. For drug delivery in tumor therapy, various electromagnetic actuated microrobot systems have been studied. In addition, bacteria-based microrobot (so-called bacteriobot), which use tumor targeting and the therapeutic function of the bacteria, has also been proposed for solid tumor therapy. Compared with bacteriobot, electromagnetic actuated microrobot has larger driving force and locomotive controllability due to their position recognition and magnetic field control. However, because electromagnetic actuated microrobot does not have self-tumor targeting, they need to be controlled by an external magnetic field. In contrast, the bacteriobot uses tumor targeting and the bacteria's own motility, and can exhibit self-targeting performance at solid tumors. However, because the propulsion forces of the bacteria are too small, it is very difficult for bacteriobot to track a tumor in a vessel with a large bloodstream. Therefore, we propose a hybrid actuated microrobot combined with electromagnetic actuation in large blood vessels with a macro range and bacterial actuation in small vessels with a micro range. In addition, the proposed microrobot consists of biodegradable and biocompatible microbeads in which the drugs and magnetic particles can be encapsulated; the bacteria can be attached to the surface of the microbeads and propel the microrobot. We carried out macro-manipulation of the hybrid actuated microrobot along a desired path through electromagnetic field control and the micro-manipulation of the hybrid actuated microrobot toward a chemical attractant through the chemotaxis of the bacteria. For the validation of the hybrid actuation of the microrobot, we fabricated a hydrogel microfluidic channel that can generate a chemical gradient. Finally, we evaluated the motility performance of the hybrid actuated microrobot in the hydrogel microfluidic channel. We expect

  17. [Selective detection of viable pathogenic bacteria in water using reverse transcription quantitative PCR].

    Science.gov (United States)

    Lin, Yi-Wen; Li, Dan; Wu, Shu-Xu; He, Miao; Yang, Tian

    2012-11-01

    A reverse transcription q quantitative PCR (RT-qPCR) assay method was established, which can quantify the copy numbers of RNA in pathogenic bacteria of E. coli and Enterococcus faecium. The results showed that cDNA was generated with the RT-PCR reagents, target gene was quantified with the qPCR, the copy numbers of RNA were stable at about 1 copies x CFU(-1) for E. coli and 7.98 x 10(2) copies x CFU(-1) for Enterococcus faecium respectively during the stationary grow phase for the both indicator bacteria [E. coli (6-18 h) and Enterococcus faecium (10-38 h)]. The established RT-qPCR method can quantify the numbers of viable bacteria through detecting bacterial RNA targets. Through detecting the heat-treated E. coli and Enterococcus faecium by three methods (culture method, qPCR, RT-qPCR), we found that the qPCR and RT-qPCR can distinguish 1.43 lg copy non-viable E. coli and 2.5 lg copy non-viable Enterococcus faecium. These results indicated that the established methods could effectively distinguish viable bacteria from non-viable bacteria. Finally we used this method to evaluate the real effluents of the secondary sedimentation of wastewater treatment plant (WWTP), the results showed that the correlation coefficients (R2) between RT-qPCR and culture method were 0.930 (E. coli) and 0.948 (Enterococcus faecium), and this established RT-PCR method can rapidly detect viable pathogenic bacteria in genuine waters. PMID:23323443

  18. A hybrid actuated microrobot using an electromagnetic field and flagellated bacteria for tumor-targeting therapy.

    Science.gov (United States)

    Li, Donghai; Choi, Hyunchul; Cho, Sunghoon; Jeong, Semi; Jin, Zhen; Lee, Cheong; Ko, Seong Young; Park, Jong-Oh; Park, Sukho

    2015-08-01

    In this paper, we propose a new concept for a hybrid actuated microrobot for tumor-targeting therapy. For drug delivery in tumor therapy, various electromagnetic actuated microrobot systems have been studied. In addition, bacteria-based microrobot (so-called bacteriobot), which use tumor targeting and the therapeutic function of the bacteria, has also been proposed for solid tumor therapy. Compared with bacteriobot, electromagnetic actuated microrobot has larger driving force and locomotive controllability due to their position recognition and magnetic field control. However, because electromagnetic actuated microrobot does not have self-tumor targeting, they need to be controlled by an external magnetic field. In contrast, the bacteriobot uses tumor targeting and the bacteria's own motility, and can exhibit self-targeting performance at solid tumors. However, because the propulsion forces of the bacteria are too small, it is very difficult for bacteriobot to track a tumor in a vessel with a large bloodstream. Therefore, we propose a hybrid actuated microrobot combined with electromagnetic actuation in large blood vessels with a macro range and bacterial actuation in small vessels with a micro range. In addition, the proposed microrobot consists of biodegradable and biocompatible microbeads in which the drugs and magnetic particles can be encapsulated; the bacteria can be attached to the surface of the microbeads and propel the microrobot. We carried out macro-manipulation of the hybrid actuated microrobot along a desired path through electromagnetic field control and the micro-manipulation of the hybrid actuated microrobot toward a chemical attractant through the chemotaxis of the bacteria. For the validation of the hybrid actuation of the microrobot, we fabricated a hydrogel microfluidic channel that can generate a chemical gradient. Finally, we evaluated the motility performance of the hybrid actuated microrobot in the hydrogel microfluidic channel. We expect

  19. Progress in Helias reactor studies

    International Nuclear Information System (INIS)

    The Helias reactor is an upgraded version of the Wendelstein 7-X experiment, which is under construction in the city of Greifswald. The modular coil system comprises 50 coils, which are constructed using NbTi-superconducting cables. The basic dimensions are: major radius 22 m, average plasma radius 1.8 m, magnetic field on axis 5 T, maximum field on coils 10 T. Over the past year progress toward better understanding of the fusion plasma has been made. In particular, the following issues have been addressed: Plasma equilibrium and MHD-stability; Neoclassical transport in the Helias configuration; Start-up scenarios and steady state burn; Alpha-particle orbits and alpha-particle losses; Drift waves in Helias configurations; Modelling the fusion plasma using empirical scaling laws Technical studies have been focussed on the optimization of the coil system with respect to magnetic field distribution, forces and stresses. In this context the ANSYS-code has been found useful for optimising the support system. In a first survey several blanket concepts, developed for the DEMO tokamak, have been adapted to the Helias geometry. Presently a water-cooled LiPb-blanket is favored in comparison with ceramic breeders, since safety properties and maintenance procedure seem to be more advantageous within this concept. Maintenance and replacement of blanket segments through portholes have also been studied with respect to their geometric compatibility. Finally parameter studies of low aspect ratio Helias reactors will be discussed. (orig.)

  20. Silicon spintronics: Progress and challenges

    Energy Technology Data Exchange (ETDEWEB)

    Sverdlov, Viktor; Selberherr, Siegfried, E-mail: Selberherr@TUWien.ac.at

    2015-07-14

    Electron spin attracts much attention as an alternative to the electron charge degree of freedom for low-power reprogrammable logic and non-volatile memory applications. Silicon appears to be the perfect material for spin-driven applications. Recent progress and challenges regarding spin-based devices are reviewed. An order of magnitude enhancement of the electron spin lifetime in silicon thin films by shear strain is predicted and its impact on spin transport in SpinFETs is discussed. A relatively weak coupling between spin and effective electric field in silicon allows magnetoresistance modulation at room temperature, however, for long channel lengths. Due to tunneling magnetoresistance and spin transfer torque effects, a much stronger coupling between the spin (magnetization) orientation and charge current is achieved in magnetic tunnel junctions. Magnetic random access memory (MRAM) built on magnetic tunnel junctions is CMOS compatible and possesses all properties needed for future universal memory. Designs of spin-based non-volatile MRAM cells are presented. By means of micromagnetic simulations it is demonstrated that a substantial reduction of the switching time can be achieved. Finally, it is shown that any two arbitrary memory cells from an MRAM array can be used to perform a logic operation. Thus, an intrinsic non-volatile logic-in-memory architecture can be realized.