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Sample records for achieve economically viable

  1. An economically viable space power relay system

    NASA Astrophysics Data System (ADS)

    Bekey, Ivan; Boudreault, Richard

    1999-09-01

    This paper describes and analyzes the economics of a power relay system that takes advantage of recent technological advances to implement a system that is economically viable. A series of power relay systems are described and analyzed which transport power ranging from 1,250 megawatts to 5,000 megawatts, and distribute it to receiving sites at transcontinental distances. Two classes of systems are discussed—those with a single reflector and delivering all the power to a single rectenna, and a second type which has multiple reflectors and distributes it to 10 rectenna sites, sharing power among them. It is shown that when offering electricity at prices competitive to those prevalent in developed cities in the US that a low IRR is inevitable, and economic feasibility of a business is unlikely. However, when the target market is Japan where the prevalent electricity prices are much greater, that an IRR exceeding 65% is readily attainable. This is extremely attractive to potential investors, making capitalization of a venture likely. The paper shows that the capital investment required for the system can be less than 1 per installed watt, contributing less than 0.02 /KW-hr to the cost of energy provision. Since selling prices in feasible regions range from 0.18 to over 030 $/kW-hr, these costs are but a small fraction of the operating expenses. Thus a very large IRR is possible for such a business.

  2. Catalytic pyrolysis of plastic wastes - Towards an economically viable process

    SciTech Connect

    McIntosh, M.J.; Arzoumanidis, G.G.; Brockmeier, F.E.

    1996-07-01

    The ultimate goal of our project is an economically viable pyrolysis process to recover useful fuels and/or chemicals from plastics- containing wastes. This paper reports the effects of various promoted and unpromoted binary oxide catalysts on yields and compositions of liquid organic products, as measured in a small laboratory pyrolysis reactor. On the basis of these results, a commercial scale catalytic pyrolysis reactor was simulated by the Aspen software and rough costs were estimated. The results suggest that such a process has potential economic viability.

  3. Dye Sensitized Solar Cells for Economically Viable Photovoltaic Systems.

    PubMed

    Jung, Hyun Suk; Lee, Jung-Kun

    2013-05-16

    TiO2 nanoparticle-based dye sensitized solar cells (DSSCs) have attracted a significant level of scientific and technological interest for their potential as economically viable photovoltaic devices. While DSSCs have multiple benefits such as material abundance, a short energy payback period, constant power output, and compatibility with flexible applications, there are still several challenges that hold back large scale commercialization. Critical factors determining the future of DSSCs involve energy conversion efficiency, long-term stability, and production cost. Continuous advancement of their long-term stability suggests that state-of-the-art DSSCs will operate for over 20 years without a significant decrease in performance. Nevertheless, key questions remain in regards to energy conversion efficiency improvements and material cost reduction. In this Perspective, the present state of the field and the ongoing efforts to address the requirements of DSSCs are summarized with views on the future of DSSCs.

  4. The Most Economic, Socially Viable, and Environmentally Sustainable Alternative Energy

    ERIC Educational Resources Information Center

    Vanderburg, Willem H.

    2008-01-01

    The strengths and weaknesses of current energy planning can be attributed to the limited economic, social, and environmental contexts taken into account as a result of the current intellectual and professional division of labor. A preventive approach is developed by which the ratio of desired to undesired effects can be substantially improved. It…

  5. Entrepreneurship: A Viable Addition to Home Economics Curriculum.

    ERIC Educational Resources Information Center

    Fortenberry, Sally L.

    1988-01-01

    Argues that information relating to entrepreneurship should be part of every curriculum within the field of home economics. Discusses characteristics of successful entrepreneurs and discusses how the curriculum can be modified to develop these characteristics. Reviews sources of entrepreneurship materials. (CH)

  6. Economically viable biochemical processes for the advanced rural biorefinery and downstream recovery operations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rural biorefineries offer an alternative to traditional ethanol production by providing the opportunity to produce fuel on site to reduce costs associated with biomass transportation thus making the fuel economically viable. Widespread installation of rural biorefineries could lead to increased upt...

  7. Achieving Proficiencies in Economics Capstone Courses

    ERIC Educational Resources Information Center

    Seeborg, Michael C.

    2008-01-01

    This paper argues that capstone courses in economics should be integrative experiences that require students to demonstrate six core proficiencies. The capstone economics senior seminar at Illinois Wesleyan University is used as an example of how a capstone course that requires completion of an original research paper might achieve these…

  8. Student Achievement and National Economic Growth

    ERIC Educational Resources Information Center

    Ramirez, Francisco O.; Luo, Xiaowei; Schofer, Evan; Meyer, John W.

    2006-01-01

    Educational policy around the world has increasingly focused on improving aggregate student achievement as a means to increase economic growth. In the last two decades, attention has focused especially on the importance of achievement in science and mathematics. Yet, the policy commitments involved have not been based on research evidence. The…

  9. Is biomass fractionation by Organosolv-like processes economically viable? A conceptual design study.

    PubMed

    Viell, Jörn; Harwardt, Andreas; Seiler, Jan; Marquardt, Wolfgang

    2013-12-01

    In this work, the conceptual designs of the established Organosolv process and a novel biphasic, so-called Organocat process are developed and analyzed. Solvent recycling and energy integration are emphasized to properly assess economic viability. Both processes show a similar energy consumption (approximately 5 MJ/kg(dry biomass)). However, they still show a lack of economic attractiveness even at larger scale. The Organocat process is more favorable due to more efficient lignin separation. The analysis uncovers the remaining challenges toward an economically viable design. They largely originate from by-products formation, product isolation, and solvent recycling. Necessary improvements in process chemistry, equipment design, energy efficiency and process design are discussed to establish economically attractive Organosolv-like processes of moderate capacity as a building block of a future biorefinery. PMID:24157680

  10. Is biomass fractionation by Organosolv-like processes economically viable? A conceptual design study.

    PubMed

    Viell, Jörn; Harwardt, Andreas; Seiler, Jan; Marquardt, Wolfgang

    2013-12-01

    In this work, the conceptual designs of the established Organosolv process and a novel biphasic, so-called Organocat process are developed and analyzed. Solvent recycling and energy integration are emphasized to properly assess economic viability. Both processes show a similar energy consumption (approximately 5 MJ/kg(dry biomass)). However, they still show a lack of economic attractiveness even at larger scale. The Organocat process is more favorable due to more efficient lignin separation. The analysis uncovers the remaining challenges toward an economically viable design. They largely originate from by-products formation, product isolation, and solvent recycling. Necessary improvements in process chemistry, equipment design, energy efficiency and process design are discussed to establish economically attractive Organosolv-like processes of moderate capacity as a building block of a future biorefinery.

  11. Parental Economic Hardship and Children's Achievement Orientations*

    PubMed Central

    Zhang, Frank Lei; Hussemann, Jeanette; Wu, Chen-Yu

    2015-01-01

    While children’s orientations to achievement are strong predictors of attainments, little is known about how parental economic hardship during recessionary times influences children’s orientations to their futures. The Youth Development Study has followed a community sample of young people in St Paul, Minnesota from mid-adolescence through their mid-thirties with near-annual surveys, and has recently begun surveying the children of this cohort. Using linked parent and child data, the present study examines the relationship between parental economic hardship and children's achievement orientations in the aftermath of the recent “Great Recession.” Initial OLS analyses draw on 345 parent-child pairs, with data collected from parents during their adolescence, during the decade prior to the recession, and in 2011, and from their children (age 11 and older) in 2011. Then, first difference models are estimated, based on a smaller sample (N=186) of parents and children who completed surveys in both 2009 and 2011. Our findings indicate that when families are more vulnerable, as a result of low parental education and prior parental unemployment experience, children’s achievement orientations are more strongly threatened by the family’s economic circumstances. For example, as parental financial problems increased, economic expectations declined only among children of the least well-educated parents. Low household incomes diminished educational aspirations only when parents experienced unemployment during the ten years prior to the recent recession. Parental achievement orientations, as adolescents, were also found to moderate the impacts of shifts in the family’s economic circumstances. Finally, boys reacted more strongly to their parents’ hardship than girls. PMID:25774223

  12. Economically Viable Components from Jerusalem Artichoke (Helianthus tuberosus L.) in a Biorefinery Concept

    PubMed Central

    Johansson, Eva; Prade, Thomas; Angelidaki, Irini; Svensson, Sven-Erik; Newson, William R.; Gunnarsson, Ingólfur Bragi; Persson Hovmalm, Helena

    2015-01-01

    Biorefinery applications are receiving growing interest due to climatic and waste disposal issues and lack of petroleum resources. Jerusalem artichoke (Helianthus tuberosus L.) is suitable for biorefinery applications due to high biomass production and limited cultivation requirements. This paper focuses on the potential of Jerusalem artichoke as a biorefinery crop and the most viable products in such a case. The carbohydrates in the tubers were found to have potential for production of platform chemicals, e.g., succinic acid. However, economic analysis showed that production of platform chemicals as a single product was too expensive to be competitive with petrochemically produced sugars. Therefore, production of several products from the same crop is a must. Additional products are protein based ones from tubers and leaves and biogas from residues, although both are of low value and amount. High bioactive activity was found in the young leaves of the crop, and the sesquiterpene lactones are of specific interest, as other compounds from this group have shown inhibitory effects on several human diseases. Thus, future focus should be on understanding the usefulness of small molecules, to develop methods for their extraction and purification and to further develop sustainable and viable methods for the production of platform chemicals. PMID:25913379

  13. Economically viable components from Jerusalem artichoke (Helianthus tuberosus L.) in a biorefinery concept.

    PubMed

    Johansson, Eva; Prade, Thomas; Angelidaki, Irini; Svensson, Sven-Erik; Newson, William R; Gunnarsson, Ingólfur Bragi; Hovmalm, Helena Persson

    2015-04-22

    Biorefinery applications are receiving growing interest due to climatic and waste disposal issues and lack of petroleum resources. Jerusalem artichoke (Helianthus tuberosus L.) is suitable for biorefinery applications due to high biomass production and limited cultivation requirements. This paper focuses on the potential of Jerusalem artichoke as a biorefinery crop and the most viable products in such a case. The carbohydrates in the tubers were found to have potential for production of platform chemicals, e.g., succinic acid. However, economic analysis showed that production of platform chemicals as a single product was too expensive to be competitive with petrochemically produced sugars. Therefore, production of several products from the same crop is a must. Additional products are protein based ones from tubers and leaves and biogas from residues, although both are of low value and amount. High bioactive activity was found in the young leaves of the crop, and the sesquiterpene lactones are of specific interest, as other compounds from this group have shown inhibitory effects on several human diseases. Thus, future focus should be on understanding the usefulness of small molecules, to develop methods for their extraction and purification and to further develop sustainable and viable methods for the production of platform chemicals.

  14. Economically viable components from Jerusalem artichoke (Helianthus tuberosus L.) in a biorefinery concept.

    PubMed

    Johansson, Eva; Prade, Thomas; Angelidaki, Irini; Svensson, Sven-Erik; Newson, William R; Gunnarsson, Ingólfur Bragi; Hovmalm, Helena Persson

    2015-01-01

    Biorefinery applications are receiving growing interest due to climatic and waste disposal issues and lack of petroleum resources. Jerusalem artichoke (Helianthus tuberosus L.) is suitable for biorefinery applications due to high biomass production and limited cultivation requirements. This paper focuses on the potential of Jerusalem artichoke as a biorefinery crop and the most viable products in such a case. The carbohydrates in the tubers were found to have potential for production of platform chemicals, e.g., succinic acid. However, economic analysis showed that production of platform chemicals as a single product was too expensive to be competitive with petrochemically produced sugars. Therefore, production of several products from the same crop is a must. Additional products are protein based ones from tubers and leaves and biogas from residues, although both are of low value and amount. High bioactive activity was found in the young leaves of the crop, and the sesquiterpene lactones are of specific interest, as other compounds from this group have shown inhibitory effects on several human diseases. Thus, future focus should be on understanding the usefulness of small molecules, to develop methods for their extraction and purification and to further develop sustainable and viable methods for the production of platform chemicals. PMID:25913379

  15. How Close We Are to Achieving Commercially Viable Large-Scale Photobiological Hydrogen Production by Cyanobacteria: A Review of the Biological Aspects

    PubMed Central

    Sakurai, Hidehiro; Masukawa, Hajime; Kitashima, Masaharu; Inoue, Kazuhito

    2015-01-01

    Photobiological production of H2 by cyanobacteria is considered to be an ideal source of renewable energy because the inputs, water and sunlight, are abundant. The products of photobiological systems are H2 and O2; the H2 can be used as the energy source of fuel cells, etc., which generate electricity at high efficiencies and minimal pollution, as the waste product is H2O. Overall, production of commercially viable algal fuels in any form, including biomass and biodiesel, is challenging, and the very few systems that are operational have yet to be evaluated. In this paper we will: briefly review some of the necessary conditions for economical production, summarize the reports of photobiological H2 production by cyanobacteria, present our schemes for future production, and discuss the necessity for further progress in the research needed to achieve commercially viable large-scale H2 production. PMID:25793279

  16. Can CO-tolerant Anodes be Economically Viable for PEMFC Applications with Reformates?

    DOE PAGES

    He, P.; Zhang, Y.; Ye., S.; Wang, J. X.

    2014-10-05

    Several years ago, the answer to this question was negative based on the criteria for an anode with <0.1 mg cm-2 of platinum group metals to perform similarly without and with 50 ppm CO in hydrogen proton exchange membrane fuel cells (PEMFCs). Now, with the amount of CO impurities reduced to 10 ppm in reformates, a <1% performance loss with a 1.5% air-bleed has become a reasonable target. The CO-tolerant catalyst also needs to be dissolution resistant up to 0.93 V, viz., the potential experienced at the anode during startup and shutdown of the fuel cells. We recently demonstrated ourmore » ability to simultaneously enhance activity and stability by using single crystalline Ru@Pt core-shell nanocatalysts. Here, we report that the performance target with reformates was met using bilayer-thick Ru@Pt core-shell nanocatalysts with 0.047 mg cm-2 Pt and 0.024 mg cm-2 Ru loading, supporting a positive prognosis for the economically viable use of reformates in PEMFC applications.« less

  17. Can CO-tolerant Anodes be Economically Viable for PEMFC Applications with Reformates?

    SciTech Connect

    He, P.; Zhang, Y.; Ye., S.; Wang, J. X.

    2014-10-05

    Several years ago, the answer to this question was negative based on the criteria for an anode with <0.1 mg cm-2 of platinum group metals to perform similarly without and with 50 ppm CO in hydrogen proton exchange membrane fuel cells (PEMFCs). Now, with the amount of CO impurities reduced to 10 ppm in reformates, a <1% performance loss with a 1.5% air-bleed has become a reasonable target. The CO-tolerant catalyst also needs to be dissolution resistant up to 0.93 V, viz., the potential experienced at the anode during startup and shutdown of the fuel cells. We recently demonstrated our ability to simultaneously enhance activity and stability by using single crystalline Ru@Pt core-shell nanocatalysts. Here, we report that the performance target with reformates was met using bilayer-thick Ru@Pt core-shell nanocatalysts with 0.047 mg cm-2 Pt and 0.024 mg cm-2 Ru loading, supporting a positive prognosis for the economically viable use of reformates in PEMFC applications.

  18. Conceptualizing an economically, legally, and politically viable active debris removal option

    NASA Astrophysics Data System (ADS)

    Emanuelli, M.; Federico, G.; Loughman, J.; Prasad, D.; Chow, T.; Rathnasabapathy, M.

    2014-11-01

    challenges and propose an economically, politically, and legally viable ADR option. Much like waste management on Earth, cleaning up space junk will likely lie somewhere between a public good and a private sector service. An international, cooperative, public-private partnership concept can address many of these issues and be economically sustainable, while also driving the creation of a proper set of regulations, standards and best practices.

  19. Measuring Student Achievement in Home Economics.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of Home Economics Education.

    Many home economics teachers have experienced difficulty in developing good classroom tests and have expressed a need for help. This publication was prepared to provide guidance in the construction and use of a variety of measurement devices. Section 1 discusses the role of measurement in the instructional process including why measure, what to…

  20. Social Capital: A Neglected Resource to Create Viable and Sustainable Youth Economic Groups in Urban Tanzania

    ERIC Educational Resources Information Center

    Manyerere, David J.

    2015-01-01

    There has been an alarming increase in the rate of unemployment among active urban population in Tanzania whereby the youth are severely affected. In this regard Youth Economic Groups (YEGs) program was formed as one among the best alternative strategies to address this perennial problem. Membership in YEGs act as a means to complement youth…

  1. Renewal of Collaborative Research: Economically Viable Forest Harvesting Practices That Increase Carbon Sequestration

    SciTech Connect

    Davidson, E.A.; Dail, D.B., Hollinger, D.; Scott, N.; Richardson, A.

    2012-08-02

    Forests provide wildlife habitat, water and air purification, climate moderation, and timber and nontimber products. Concern about climate change has put forests in the limelight as sinks of atmospheric carbon. The C stored in the global vegetation, mostly in forests, is nearly equivalent to the amount present in atmospheric CO{sub 2}. Both voluntary and government-mandated carbon trading markets are being developed and debated, some of which include C sequestration resulting from forest management as a possible tradeable commodity. However, uncertainties regarding sources of variation in sequestration rates, validation, and leakage remain significant challenges for devising strategies to include forest management in C markets. Hence, the need for scientifically-based information on C sequestration by forest management has never been greater. The consequences of forest management on the US carbon budget are large, because about two-thirds of the {approx}300 million hectare US forest resource is classified as 'commercial forest.' In most C accounting budgets, forest harvesting is usually considered to cause a net release of C from the terrestrial biosphere to the atmosphere. However, forest management practices could be designed to meet the multiple goals of providing wood and paper products, creating economic returns from natural resources, while sequestering C from the atmosphere. The shelterwood harvest strategy, which removes about 30% of the basal area of the overstory trees in each of three successive harvests spread out over thirty years as part of a stand rotation of 60-100 years, may improve net C sequestration compared to clear-cutting because: (1) the average C stored on the land surface over a rotation increases, (2) harvesting only overstory trees means that a larger fraction of the harvested logs can be used for long-lived sawtimber products, compared to more pulp resulting from clearcutting, (3) the shelterwood cut encourages growth of subcanopy trees

  2. Propulsion challenges for a 21st century economically viable, environmentally compatible High-Speed Civil Transport

    NASA Technical Reports Server (NTRS)

    Shaw, Robert J.

    1991-01-01

    Recent NASA funded studies suggest an opportunity exists for a 21st Century High Speed Civil Transport (HSCT) to become part of the international air transportation system. However, before this opportunity for high speed travel can be realized, certain environmental and economic barrier issues must be overcome. These challenges are outlined. Research activities which NASA has planned to address these barrier issues and provide a technology base to allow the U.S. manufacturers to make an informed go/no go decision on developing an HSCT are discussed.

  3. Freedom space for rivers: An economically viable river management concept in a changing climate

    NASA Astrophysics Data System (ADS)

    Buffin-Bélanger, Thomas; Biron, Pascale M.; Larocque, Marie; Demers, Sylvio; Olsen, Taylor; Choné, Guénolé; Ouellet, Marie-Audray; Cloutier, Claude-André; Desjarlais, Claude; Eyquem, Joanna

    2015-12-01

    The freedom space concept applies hydrogeomorphic principles to delineate zones that are either frequently flooded or actively eroding, or that include riparian wetlands. Freedom space limits mapped for three rivers in southern Quebec (Canada) were assessed to determine whether they would still be valid under a future climate using a sensitivity analysis approach with numerical models predicting mobility of meanders (RVRMeander) and flood stage (HEC-RAS). The freedom space limits were also used in a cost-benefit analysis over a 50-year period where costs consist of loss or limitations to the right of farming and construction in this zone, whereas benefits are avoided costs for existing or future bank stabilization structures and avoided costs of flooding in agricultural areas. The economic value of ecosystem services provided by riparian wetlands and increased buffer zones within the freedom space were also included in the analysis. Results show that freedom space limits would be robust in future climate, and show net present values ranging from CDN0.7 to 3.7 million for the three rivers, with ratios of benefits over costs ranging between 1.5:1 and 4.8:1. River management based on freedom space is thus beneficial for society over a 50-year period.

  4. Bovine meat and bone meal is an economically viable alternative in quail feeding in the initial phase.

    PubMed

    Pizzolante, Carla C; Kakimoto, Sérgio K; Moraes, José E; Saccomani, Ana Paula O; Soares, Daniela F; Paschoalin, Gustavo C; Budiño, Fábio E L

    2016-05-31

    Quail egg production has experienced a steep rise in the last decade. Nutrition is the main factor affecting productive potential in the poultry industry, as appropriate nutritional management is necessary to ensure the maintenance of optimal physical conditions, growth and the production of high quality products. Meat and bone meal (MBM) has often been used in the poultry industry as an alternative and cost-effective source of protein in partial replacement of corn and soybean meal. However, there have been no studies to date that have investigated the effect of dietary MBM on the performance of quail or on the costs of production in the starter phase. This is particularly important considering that this phase is characterized by large investments by producers, without immediate economic return. In this study, we investigated whether partial replacement of soybean meal (SBM) by meat and bone meal (MBM) in the diet of Japanese quail during the starter phase is a viable alternative that would maintain or improve their productive and economic performance. Our results show that the inclusion of MBM in the diet of quail reduces feeding costs by up to 6% without impairing productive performance. PMID:27254452

  5. Do Peers Influence Achievement in High School Economics? Evidence from Georgia's Economics End of Course Test

    ERIC Educational Resources Information Center

    Clark, Christopher; Scafidi, Benjamin; Swinton, John R.

    2011-01-01

    The authors provide the first estimates of the impact of peers on achievement in high school economics. The estimates are obtained by analyzing three years of data on all high school students who take Georgia's required economics course and its accompanying high-stakes End of Course Test (Georgia Department of Education). They use an instrumental…

  6. Can mass trapping reduce thrips damage and is it economically viable? Management of the Western flower thrips in strawberry.

    PubMed

    Sampson, Clare; Kirk, William D J

    2013-01-01

    The western flower thrips Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) is a cosmopolitan, polyphagous insect pest that causes bronzing to fruit of strawberry (Fragaria x ananassa). The main aim of this study was to test whether mass trapping could reduce damage and to predict whether this approach would be economically viable. In semi-protected strawberry crops, mass trapping of F. occidentalis using blue sticky roller traps reduced adult thrips numbers per flower by 61% and fruit bronzing by 55%. The addition of the F. occidentalis aggregation pheromone, neryl (S)-2-methylbutanoate, to the traps doubled the trap catch, reduced adult thrips numbers per flower by 73% and fruit bronzing by 68%. The factors affecting trapping efficiency through the season are discussed. Damage that would result in downgrading of fruit to a cheaper price occurred when bronzing affected about 10% of the red fruit surface. Cost-benefit analysis using this threshold showed that mass trapping of thrips using blue sticky roller traps can be cost-effective in high-value crops. The addition of blue sticky roller traps to an integrated pest management programme maintained thrips numbers below the damage threshold and increased grower returns by a conservative estimate of £2.2k per hectare. Further work is required to develop the F. occidentalis aggregation pheromone for mass trapping and to determine the best timing for trap deployment. Mass trapping of thrips is likely to be cost-effective in other countries and other high-value crops affected by F. occidentalis damage, such as cucumber and cut flowers. PMID:24282554

  7. Can Mass Trapping Reduce Thrips Damage and Is It Economically Viable? Management of the Western Flower Thrips in Strawberry

    PubMed Central

    Sampson, Clare; Kirk, William D. J.

    2013-01-01

    The western flower thrips Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) is a cosmopolitan, polyphagous insect pest that causes bronzing to fruit of strawberry (Fragaria x ananassa). The main aim of this study was to test whether mass trapping could reduce damage and to predict whether this approach would be economically viable. In semi-protected strawberry crops, mass trapping of F. occidentalis using blue sticky roller traps reduced adult thrips numbers per flower by 61% and fruit bronzing by 55%. The addition of the F. occidentalis aggregation pheromone, neryl (S)-2-methylbutanoate, to the traps doubled the trap catch, reduced adult thrips numbers per flower by 73% and fruit bronzing by 68%. The factors affecting trapping efficiency through the season are discussed. Damage that would result in downgrading of fruit to a cheaper price occurred when bronzing affected about 10% of the red fruit surface. Cost-benefit analysis using this threshold showed that mass trapping of thrips using blue sticky roller traps can be cost-effective in high-value crops. The addition of blue sticky roller traps to an integrated pest management programme maintained thrips numbers below the damage threshold and increased grower returns by a conservative estimate of £2.2k per hectare. Further work is required to develop the F. occidentalis aggregation pheromone for mass trapping and to determine the best timing for trap deployment. Mass trapping of thrips is likely to be cost-effective in other countries and other high-value crops affected by F. occidentalis damage, such as cucumber and cut flowers. PMID:24282554

  8. Can mass trapping reduce thrips damage and is it economically viable? Management of the Western flower thrips in strawberry.

    PubMed

    Sampson, Clare; Kirk, William D J

    2013-01-01

    The western flower thrips Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) is a cosmopolitan, polyphagous insect pest that causes bronzing to fruit of strawberry (Fragaria x ananassa). The main aim of this study was to test whether mass trapping could reduce damage and to predict whether this approach would be economically viable. In semi-protected strawberry crops, mass trapping of F. occidentalis using blue sticky roller traps reduced adult thrips numbers per flower by 61% and fruit bronzing by 55%. The addition of the F. occidentalis aggregation pheromone, neryl (S)-2-methylbutanoate, to the traps doubled the trap catch, reduced adult thrips numbers per flower by 73% and fruit bronzing by 68%. The factors affecting trapping efficiency through the season are discussed. Damage that would result in downgrading of fruit to a cheaper price occurred when bronzing affected about 10% of the red fruit surface. Cost-benefit analysis using this threshold showed that mass trapping of thrips using blue sticky roller traps can be cost-effective in high-value crops. The addition of blue sticky roller traps to an integrated pest management programme maintained thrips numbers below the damage threshold and increased grower returns by a conservative estimate of £2.2k per hectare. Further work is required to develop the F. occidentalis aggregation pheromone for mass trapping and to determine the best timing for trap deployment. Mass trapping of thrips is likely to be cost-effective in other countries and other high-value crops affected by F. occidentalis damage, such as cucumber and cut flowers.

  9. Review: Balancing Limiting Factors and Economic Drivers to Achieve Sustainable Midwestern US Agricultural Residue Feedstock Supplies

    SciTech Connect

    Wally W. Wilhelm; J. Richard Hess; Douglas L. Karlen; David J. Muth; Jane M. F. Johnson; John M. Baker; Hero T. Gollany; Jeff M. Novak; Diane E. Stott; Gary E. Varvel

    2010-10-01

    Advanced biofuels will be developed using cellulosic feedstock rather than grain or oilseed crops that can also be used for food and feed. To be sustainable, these new agronomic production systems must be economically viable without degrading soil resources. This review examines six agronomic factors that collectively define many of the limits and opportunities for harvesting crop residue for biofuel feedstock. These six “limiting factors” are discussed in relationship to economic drivers associated with harvesting corn (Zea mays L.) stover as a potential cellulosic feedstock. The limiting factors include soil organic carbon, wind and water erosion, plant nutrient balance, soil water and temperature dynamics, soil compaction, and off-site environmental impacts. Initial evaluations using the Revised Universal Soil Loss Equation 2.0 (RUSLE2) show that a single factor analysis based on simply meeting tolerable soil loss might indicate stover could be harvested sustainably, but the same analysis based on maintaining soil organic carbon shows the practice to be non-sustainable. Modifying agricultural management to include either annual or perennial cover crops is shown to meet both soil erosion and soil carbon requirements. The importance of achieving high yields and planning in a holistic manner at the landscape scale are also shown to be crucial for balancing limitations and drivers associated with renewable bioenergy production.

  10. Determinants of Achievement of Economics Concepts by Elementary School Students.

    ERIC Educational Resources Information Center

    Sosin, Kim; And Others

    1997-01-01

    Uses test questions from the Basic Economics Test (BET) to reveal that elementary students are capable of understanding economics concepts. Maintains that neither ethnic background nor parental income makes a difference in economic learning. The most statistically significant determinant of improved scores was the extent to which a concept was…

  11. Are State-Sponsored New Radiation Therapy Facilities Economically Viable in Low- and Middle-Income Countries?

    SciTech Connect

    Datta, Niloy R.; Samiei, Massoud; Bodis, Stephan

    2015-10-01

    Purpose: The economic viability of establishing a state-funded radiation therapy (RT) infrastructure in low- and middle-income countries (LMICs) in accordance with the World Bank definition has been assessed through computation of a return on investment (ROI). Methods and Materials: Of the 139 LMICs, 100 were evaluated according to their RT facilities, gross national income (GNI) per capita, and employment/population ratio. The assumption was an investment of US$5 million for a basic RT center able to treat 1000 patients annually. The national breakeven points and percentage of ROI (%ROI) were calculated according to the GNI per capita and patient survival rates of 10% to 50% at 2 years. It was assumed that 50% of these patients would be of working age and that, if employed and able to work after treatment, they would contribute to the country's GNI for at least 2 years. The cumulative GNI after attaining the breakeven point until the end of the 15-year lifespan of the teletherapy unit was calculated to estimate the %ROI. The recurring and overhead costs were assumed to vary from 5.5% to 15% of the capital investment. Results: The %ROI was dependent on the GNI per capita, employment/population ratio and 2-year patient survival (all P<.001). Accordingly, none of the low-income countries would attain an ROI. If 50% of the patients survived for 2 years, the %ROI in the lower-middle and upper-middle income countries could range from 0% to 159.9% and 11.2% to 844.7%, respectively. Patient user fees to offset recurring and overhead costs could vary from “nil” to US$750, depending on state subsidies. Conclusions: Countries with a greater GNI per capita, higher employment/population ratio, and better survival could achieve a faster breakeven point, resulting in a higher %ROI. Additional factors such as user fees have also been considered. These can be tailored to the patient's ability to pay to cover the recurring costs. Certain pragmatic steps that could be

  12. 40 CFR 450.22 - Effluent limitations reflecting the best available technology economically achievable (BAT).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... best available technology economically achievable (BAT). 450.22 Section 450.22 Protection of... Effluent limitations reflecting the best available technology economically achievable (BAT). Except as provided in 40 CFR 125.30 through 125.32, any point source subject to this subpart must achieve, at...

  13. 40 CFR 450.22 - Effluent limitations reflecting the best available technology economically achievable (BAT).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... best available technology economically achievable (BAT). 450.22 Section 450.22 Protection of... limitations reflecting the best available technology economically achievable (BAT). Except as provided in 40 CFR 125.30 through 125.32, any point source subject to this subpart must achieve, at a minimum,...

  14. 40 CFR 450.22 - Effluent limitations reflecting the best available technology economically achievable (BAT).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... best available technology economically achievable (BAT). 450.22 Section 450.22 Protection of... Effluent limitations reflecting the best available technology economically achievable (BAT). Except as provided in 40 CFR 125.30 through 125.32, any point source subject to this subpart must achieve, at...

  15. 40 CFR 450.22 - Effluent limitations reflecting the best available technology economically achievable (BAT).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... best available technology economically achievable (BAT). 450.22 Section 450.22 Protection of... limitations reflecting the best available technology economically achievable (BAT). Except as provided in 40 CFR 125.30 through 125.32, any point source subject to this subpart must achieve, at a minimum,...

  16. 40 CFR 450.22 - Effluent limitations reflecting the best available technology economically achievable (BAT).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... best available technology economically achievable (BAT). 450.22 Section 450.22 Protection of... Effluent limitations reflecting the best available technology economically achievable (BAT). Except as provided in 40 CFR 125.30 through 125.32, any point source subject to this subpart must achieve, at...

  17. Crownhill Elementary Case Study: Closing the Economic Achievement Gap

    ERIC Educational Resources Information Center

    Washington State Board of Education, 2010

    2010-01-01

    To spotlight effective practices, the Washington State Board of Education (SBE) is highlighting schools that are closing achievement gaps and performing at high levels. In 2009, SBE partnered with the Office of Superintendent of Public Instruction (OSPI) to create the Washington Accountability Index. The Index is a new way to measure schools'…

  18. Extracts from Field Margin Weeds Provide Economically Viable and Environmentally Benign Pest Control Compared to Synthetic Pesticides.

    PubMed

    Mkenda, Prisila; Mwanauta, Regina; Stevenson, Philip C; Ndakidemi, Patrick; Mtei, Kelvin; Belmain, Steven R

    2015-01-01

    Plants with pesticidal properties have been investigated for decades as alternatives to synthetics, but most progress has been shown in the laboratory. Consequently, research on pesticidal plants is failing to address gaps in our knowledge that constrain their uptake. Some of these gaps are their evaluation of their efficacy under field conditions, their economic viability and impact on beneficial organisms. Extracts made from four abundant weed species found in northern Tanzania, Tithonia diversifolia, Tephrosia vogelii, Vernonia amygdalina and Lippia javanica offered effective control of key pest species on common bean plants (Phaseolus vulgaris) that was comparable to the pyrethroid synthetic, Karate. The plant pesticide treatments had significantly lower effects on natural enemies (lady beetles and spiders). Plant pesticide treatments were more cost effective to use than the synthetic pesticide where the marginal rate of return for the synthetic was no different from the untreated control, around 4USD/ha, compared to a rate of return of around 5.50USD/ha for plant pesticide treatments. Chemical analysis confirmed the presence of known insecticidal compounds in water extracts of T. vogelii (the rotenoid deguelin) and T. diversifolia (the sesquiterpene lactone tagitinin A). Sesquiterpene lactones and the saponin vernonioside C were also identified in organic extracts of V. amygdalina but only the saponin was recorded in water extracts which are similar to those used in the field trial. Pesticidal plants were better able to facilitate ecosystem services whilst effectively managing pests. The labour costs of collecting and processing abundant plants near farm land were less than the cost of purchasing synthetic pesticides. PMID:26599609

  19. Extracts from Field Margin Weeds Provide Economically Viable and Environmentally Benign Pest Control Compared to Synthetic Pesticides

    PubMed Central

    Mkenda, Prisila; Mwanauta, Regina; Stevenson, Philip C.; Ndakidemi, Patrick; Mtei, Kelvin; Belmain, Steven R.

    2015-01-01

    Plants with pesticidal properties have been investigated for decades as alternatives to synthetics, but most progress has been shown in the laboratory. Consequently, research on pesticidal plants is failing to address gaps in our knowledge that constrain their uptake. Some of these gaps are their evaluation of their efficacy under field conditions, their economic viability and impact on beneficial organisms. Extracts made from four abundant weed species found in northern Tanzania, Tithonia diversifolia, Tephrosia vogelii, Vernonia amygdalina and Lippia javanica offered effective control of key pest species on common bean plants (Phaseolus vulgaris) that was comparable to the pyrethroid synthetic, Karate. The plant pesticide treatments had significantly lower effects on natural enemies (lady beetles and spiders). Plant pesticide treatments were more cost effective to use than the synthetic pesticide where the marginal rate of return for the synthetic was no different from the untreated control, around 4USD/ha, compared to a rate of return of around 5.50USD/ha for plant pesticide treatments. Chemical analysis confirmed the presence of known insecticidal compounds in water extracts of T. vogelii (the rotenoid deguelin) and T. diversifolia (the sesquiterpene lactone tagitinin A). Sesquiterpene lactones and the saponin vernonioside C were also identified in organic extracts of V. amygdalina but only the saponin was recorded in water extracts which are similar to those used in the field trial. Pesticidal plants were better able to facilitate ecosystem services whilst effectively managing pests. The labour costs of collecting and processing abundant plants near farm land were less than the cost of purchasing synthetic pesticides. PMID:26599609

  20. Is CAPD a viable option among ADPKD with end stage renal disease population in India? Its outcomes and economics.

    PubMed

    Kaul, Anupma; Dharshan, R; Bhadhuaria, Dharmendra; Prasad, Narayan; Gupta, Amit; Sharma, R K

    2015-09-01

    Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited renal disease, with 50-75% of these patients requiring renal replacement therapy (RRT). The outcome of peritoneal dialysis (PD) in ADPKD with end-disease renal disease (ESRD) is not clearly defined, more so in developing countries. We conducted a retrospective analysis of the outcomes and economics of PD in these ESRD patients and compared them with other causes of ESRD on PD. Data were reviewed of all the PD patients who were followed-up at our institute from January 2007 to December 2011. The inclusion criteria were ADPKD patients who chose PD as the dialysis modality (Group 1), while age and gender-matched ESRD (other than ADPKD) patients who were started on PD during the same period were considered as the other group (Group 2). A total of 26 ADPKD patients underwent PD with an average size of kidneys among ADPKD ESRD patients of 15.2 + 2.1 cm. The overall peritonitis rates were similar among the compared groups. The median survival for the first peritonitis episodes were 1.2 and 1.8 years (95% confidence interval 0.82-1.91) for the control and ADPKD groups, respectively. The overall patient survival was 22 among PKD while five patients died among the control group. Among PKD, one patient died due to intra-cerebral bleed while one patient had severe cyst hemorrhage and infection, while three others had peritonitis and sepsis. Hernia was observed in four ADPKD patients, once on PD that was surgically corrected and PD was resumed in all. Two patients lost the catheter due to peritonitis while one patient had membrane failure while one underwent surgical exploration due to diverticulosis. PD treatment was not prevented by voluminous kidneys in any of these patients and no patient ceased PD treatment due to insufficient peritoneal space. Besides this, the cost on PD was much less as compared with that on hemodialysis (HD). PD is a reasonable mode of RRT among ADPKD, where HD is not

  1. 40 CFR 449.10 - Effluent limitations representing the best available technology economically achievable (BAT).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... available technology economically achievable (BAT). Except as provided in 40 CFR 125.30 through 125.32, any... best available technology economically achievable (BAT). 449.10 Section 449.10 Protection of... following requirements representing the degree of effluent reduction attainable by the application of...

  2. 40 CFR 449.10 - Effluent limitations representing the best available technology economically achievable (BAT).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... available technology economically achievable (BAT). Except as provided in 40 CFR 125.30 through 125.32, any... best available technology economically achievable (BAT). 449.10 Section 449.10 Protection of... following requirements representing the degree of effluent reduction attainable by the application of...

  3. 40 CFR 449.10 - Effluent limitations representing the best available technology economically achievable (BAT).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... available technology economically achievable (BAT). Except as provided in 40 CFR 125.30 through 125.32, any... best available technology economically achievable (BAT). 449.10 Section 449.10 Protection of... following requirements representing the degree of effluent reduction attainable by the application of...

  4. Cleaner cooking solutions to achieve health, climate, and economic cobenefits.

    PubMed

    Anenberg, Susan C; Balakrishnan, Kalpana; Jetter, James; Masera, Omar; Mehta, Sumi; Moss, Jacob; Ramanathan, Veerabhadran

    2013-05-01

    Nearly half the world's population must rely on solid fuels such as biomass (wood, charcoal, agricultural residues, and animal dung) and coal for household energy, burning them in inefficient open fires and stoves with inadequate ventilation. Household solid fuel combustion is associated with four million premature deaths annually; contributes to forest degradation, loss of habitat and biodiversity, and climate change; and hinders social and economic progress as women and children spend hours every day collecting fuel. Several recent studies, as well as key emerging national and international efforts, are making progress toward enabling wide-scale household adoption of cleaner and more efficient stoves and fuels. While significant challenges remain, these efforts offer considerable promise to save lives, improve forest sustainability, slow climate change, and empower women around the world.

  5. Seinfeld and Economics: How to Achieve the Revised Bloom's Taxonomy in an Introductory Economics Class

    ERIC Educational Resources Information Center

    Deal, John; Hegde, S. Aaron

    2013-01-01

    This paper presents an innovative teaching technique, the utilization of a popular sitcom to teach an introductory economics course. Using clips from the television show "Seinfeld," instructors can present the oft-perceived difficult, yet basic, economic concepts in an amenable manner, which also enables the achieving of higher levels of…

  6. The Bangladesh paradox: exceptional health achievement despite economic poverty.

    PubMed

    Chowdhury, A Mushtaque R; Bhuiya, Abbas; Chowdhury, Mahbub Elahi; Rasheed, Sabrina; Hussain, Zakir; Chen, Lincoln C

    2013-11-23

    Bangladesh, the eighth most populous country in the world with about 153 million people, has recently been applauded as an exceptional health performer. In the first paper in this Series, we present evidence to show that Bangladesh has achieved substantial health advances, but the country's success cannot be captured simplistically because health in Bangladesh has the paradox of steep and sustained reductions in birth rate and mortality alongside continued burdens of morbidity. Exceptional performance might be attributed to a pluralistic health system that has many stakeholders pursuing women-centred, gender-equity-oriented, highly focused health programmes in family planning, immunisation, oral rehydration therapy, maternal and child health, tuberculosis, vitamin A supplementation, and other activities, through the work of widely deployed community health workers reaching all households. Government and non-governmental organisations have pioneered many innovations that have been scaled up nationally. However, these remarkable achievements in equity and coverage are counterbalanced by the persistence of child and maternal malnutrition and the low use of maternity-related services. The Bangladesh paradox shows the net outcome of successful direct health action in both positive and negative social determinants of health--ie, positives such as women's empowerment, widespread education, and mitigation of the effect of natural disasters; and negatives such as low gross domestic product, pervasive poverty, and the persistence of income inequality. Bangladesh offers lessons such as how gender equity can improve health outcomes, how health innovations can be scaled up, and how direct health interventions can partly overcome socioeconomic constraints. PMID:24268002

  7. The Bangladesh paradox: exceptional health achievement despite economic poverty.

    PubMed

    Chowdhury, A Mushtaque R; Bhuiya, Abbas; Chowdhury, Mahbub Elahi; Rasheed, Sabrina; Hussain, Zakir; Chen, Lincoln C

    2013-11-23

    Bangladesh, the eighth most populous country in the world with about 153 million people, has recently been applauded as an exceptional health performer. In the first paper in this Series, we present evidence to show that Bangladesh has achieved substantial health advances, but the country's success cannot be captured simplistically because health in Bangladesh has the paradox of steep and sustained reductions in birth rate and mortality alongside continued burdens of morbidity. Exceptional performance might be attributed to a pluralistic health system that has many stakeholders pursuing women-centred, gender-equity-oriented, highly focused health programmes in family planning, immunisation, oral rehydration therapy, maternal and child health, tuberculosis, vitamin A supplementation, and other activities, through the work of widely deployed community health workers reaching all households. Government and non-governmental organisations have pioneered many innovations that have been scaled up nationally. However, these remarkable achievements in equity and coverage are counterbalanced by the persistence of child and maternal malnutrition and the low use of maternity-related services. The Bangladesh paradox shows the net outcome of successful direct health action in both positive and negative social determinants of health--ie, positives such as women's empowerment, widespread education, and mitigation of the effect of natural disasters; and negatives such as low gross domestic product, pervasive poverty, and the persistence of income inequality. Bangladesh offers lessons such as how gender equity can improve health outcomes, how health innovations can be scaled up, and how direct health interventions can partly overcome socioeconomic constraints.

  8. The Relationship between Teachers' Collective Efficacy and Student Achievement at Economically Disadvantaged Middle School Campuses

    ERIC Educational Resources Information Center

    Sandoval, Juan Manuel; Challoo, Linda B.; Kupczynski, Lori

    2011-01-01

    The purpose of this study was to examine the relationship between the collective efficacy of teachers and student achievement at economically disadvantaged middle school campuses. The population of the study consisted of Texas campuses that served economically disadvantaged students and received a campus rating of Exemplary or Academically…

  9. The Achievement of Economically Disadvantaged Fifth Graders in Summer Enrichment Camp

    ERIC Educational Resources Information Center

    Boulden, Laurie

    2013-01-01

    The achievement gap between economically disadvantaged students and their traditional counterparts has continued to be a problem in education. Based on cognitive constructivist theory and enrichment theory, the purpose of this study was to investigate the relationship between scores on a high-stakes achievement test and participation in a summer…

  10. The Economics of International Differences in Educational Achievement. NBER Working Paper No. 15949

    ERIC Educational Resources Information Center

    Hanushek, Eric A.; Woessmann, Ludger

    2010-01-01

    An emerging economic literature over the past decade has made use of international tests of educational achievement to analyze the determinants and impacts of cognitive skills. The cross-country comparative approach provides a number of unique advantages over national studies: It can exploit institutional variation that does not exist within…

  11. The Effect of Time Spent Online on Student Achievement in Online Economics and Finance Courses

    ERIC Educational Resources Information Center

    Calafiore, Pablo; Damianov, Damian S.

    2011-01-01

    This article studies the determinants of academic achievement in online courses in economics and finance. The authors use the online tracking feature in Blackboard (Campus Edition) to retrieve the real time that each student spent in the course for the entire semester and to analyze the impact of time spent online, prior grade point average (GPA),…

  12. Altruistic punishment as an explanation of hunter-gatherer cooperation: how much has experimental economics achieved?

    PubMed

    Sugden, Robert

    2012-02-01

    The discovery of the altruistic punishment mechanism as a replicable experimental result is a genuine achievement of behavioural economics. The hypothesis that cooperation in hunter-gatherer societies is sustained by altruistic punishment is a scientifically legitimate conjecture, but it must be tested against real-world observations. Guala's doubts about the evidential support for this hypothesis are well founded.

  13. Socio-Economic Background and Access to Internet as Correlates of Students' Achievement in Agricultural Science

    ERIC Educational Resources Information Center

    Adegoke, Sunday Paul; Osokoya, Modupe M.

    2015-01-01

    This study investigated access to internet and socio-economic background as correlates of students' achievement in Agricultural Science among selected Senior Secondary Schools Two Students in Ogbomoso South and North Local Government Areas. The study adopted multi-stage sampling technique. Simple random sampling was used to select 30 students from…

  14. School Effects and Ethnic, Gender and Socio-Economic Gaps in Educational Achievement at Age 11

    ERIC Educational Resources Information Center

    Strand, Steve

    2014-01-01

    There are long-standing achievement gaps in England associated with socio-economic status (SES), ethnicity and gender, but relatively little research has evaluated interactions between these variables or explored school effects on such gaps. This paper analyses the national test results at age 7 and age 11 of 2,836 pupils attending 68 mainstream…

  15. Containing Cost without Sacrificing Achievement: Some Evidence from College-Level Economics Classes.

    ERIC Educational Resources Information Center

    Zietz, Joachim; Cochran, Howard H., Jr.

    1997-01-01

    Summarizes a study that used a large database on the teaching of college economics (TUCE III) to identify and rank by cost-per-unit of student achievement various key controllable inputs into the educational process at the classroom level. Comprehensive final exams and regular homework assignments are highly effective inputs for raising student…

  16. The Economic Impact of Achievement Gaps in Pennsylvania's Public Schools. Research Report

    ERIC Educational Resources Information Center

    Karoly, Lynn A.

    2015-01-01

    This study documents the magnitude of the gaps in student performance for public school students in Pennsylvania and estimates the economic consequences of those education performance gaps. Although Pennsylvania is one of the top-scoring states on the 2013 National Assessment of Educational Progress (NAEP) on average, the achievement gaps between…

  17. Identifying Options for Achieving a Viable Campus.

    ERIC Educational Resources Information Center

    College of Marin, Kentfield, CA.

    This report presents the conclusions and recommendations of the Indian Valley campus (California) community task force to the Marin Community College District trustees. The trustees appointed the Indian Valley campus task force in 2000 to study options for the educational vitality, fiscal sustainability, and community benefit of the campus. This…

  18. How to achieve an economic and reliable CP design using DnV RP B401

    SciTech Connect

    Thomason, W.H.; Rippon, I.; Foong, J.

    1995-11-01

    The 1993 Revision of Det Norske Veritas Industri Norge AS`s Recommended Practice RP B401 Cathodic Protection Design offers the operator the opportunity to use his own experience and data to justify more or less conservative designs. Examples of the use of this option to achieve an economic Southern North Sea CP design are presented. These examples include cost comparisons of actual bids received for CP/coating systems using different coating types. Some comparisons with NACE`s RP-0176-94 Corrosion. Control of Steel Fixed Offshore Platforms Associated with Petroleum Production are also made.

  19. Growth in Literacy and Numeracy Achievement: Evidence and Explanations of a Summer Slowdown in Low Socio-Economic Schools

    ERIC Educational Resources Information Center

    Vale, Colleen; Weaven, Mary; Davies, Anne; Hooley, Neil; Davidson, Kristy; Loton, Daniel

    2013-01-01

    The phenomenon of summer slide or setback has gained a great deal of attention in the USA. It is understood to account for as much as 80% of the difference in achievement for students between low and high socio-economic families over their elementary schooling. In a mixed method longitudinal study of reforms in low socio-economic school…

  20. Measuring the Socio-Economic Background of Students and Its Effect on Achievement on PISA 2000 and PISA 2003

    ERIC Educational Resources Information Center

    Schulz, Wolfram

    2005-01-01

    One of the consistent findings of educational research studies is the effect of the students' family socio-economic background on their learning achievement. Consequently, international comparative studies emphasis the role of socio-economic background for determining learning outcomes. In particular, PISA results have been used to describe how…

  1. The Relationship between Teachers' Collective Efficacy and Student Achievement at Economically Disadvantaged Middle School Campuses in Texas

    ERIC Educational Resources Information Center

    Sandoval, Juan Manuel

    2010-01-01

    The purpose of this study was to examine the relationship between the collective efficacy of teachers and student achievement at economically disadvantaged middle school campuses. Schools of today are expected to show continuous improvement in student achievement from year to year, regardless of the students' family background, ethnicity, or…

  2. Economic costs of achieving current conservation goals in the future as climate changes.

    PubMed

    Shaw, M Rebecca; Klausmeyer, Kirk; Cameron, D Richard; Mackenzie, Jason; Roehrdanz, Patrick

    2012-06-01

    Conservation of biologically diverse regions has thus far been accomplished largely through the establishment and maintenance of protected areas. Climate change is expected to shift climate space of many species outside existing reserve boundaries. We used climate-envelope models to examine shifts in climate space of 11 species that are representative of the Mount Hamilton Project area (MHPA) (California, U.S.A.), which includes areas within Alameda, Santa Clara, San Joaquin, Stanislaus, Merced, and San Benito counties and is in the state's Central Coast ecoregion. We used Marxan site-selection software to determine the minimum area required as climate changes to achieve a baseline conservation goal equal to 80% of existing climate space for all species in the MHPA through 2050 and 2100. Additionally, we assessed the costs associated with use of existing conservation strategies (land acquisition and management actions such as species translocation, monitoring, and captive breeding) necessary to meet current species-conservation goals as climate changes. Meeting conservation goals as climate changes through 2050 required an additional 256,000 ha (332%) of protected area, primarily to the south and west of the MHPA. Through 2050 the total cost of land acquisition and management was estimated at US$1.67-1.79 billion, or 139-149% of the cost of achieving the same conservation goals with no climate change. To maintain 80% of climate space through 2100 required nearly 380,000 additional hectares that would cost $2.46-2.62 billion, or 209-219% of the cost of achieving the same conservation goals with no climate change. Furthermore, maintaining 80% of existing climate space within California for 27% of the focal species was not possible by 2100 because climate space for these species did not exist in the state. The high costs of conserving species as the climate changes-that we found in an assessment of one conservation project-highlights the need for tools that will aid

  3. Rankings of International Achievement Test Performance and Economic Strength: Correlation or Conjecture?

    ERIC Educational Resources Information Center

    Tienken, Christopher H.

    2008-01-01

    Examining a popular political notion, this article presents results from a series of Spearman Rho calculations conducted to investigate relationships between countries' rankings on international tests of mathematics and science and future economic competitiveness as measured by the 2006 World Economic Forum's Growth Competitiveness Index (GCI).…

  4. Pod Learning: Student Groups Create Podcasts to Achieve Economics Learning Goals

    ERIC Educational Resources Information Center

    Moryl, Rebecca L.

    2016-01-01

    In this article, the author describes a group project to create student-generated podcasts on economics topics. This project provides an innovative opportunity for students to demonstrate proficiency in skills required for the undergraduate economics major and valued in the professional marketplace. Results of a student self-assessment survey on…

  5. Closing the Achievement Gap: A Summer School Program to Accelerate the Academic Performance of Economically Disadvantaged Students

    ERIC Educational Resources Information Center

    Gonzalez, Ramon Michael

    2013-01-01

    With the increasing disparity in educational outcomes among economically and racially different groups of students, summer school has received attention from school reformers as a means to close the achievement gap. Given the interest in this topic by educators, researchers, and policymakers, there is little research on the impact of summer school…

  6. Teachers' Teaching Practice and Student Achievement in Basic Economics--A Comparison in Two Types of Schools in Malaysia

    ERIC Educational Resources Information Center

    Singh, Termit Kaur Ranjit; Krishnan, Sashi Kala

    2014-01-01

    The purpose of this study is to compare teachers' teaching practice based on students' perception towards achievement in the subject of Basic Economics between two different types of secondary schools in Malaysia, the National Secondary Schools (SMK) and Chinese National Type Secondary Schools (SMJK) in the state of Penang, Malaysia. The…

  7. The Influence of Gender, School Location and Socio-Economic Status on Students' Academic Achievement in Mathematics

    ERIC Educational Resources Information Center

    Alordiah, Caroline Ochuko; Akpadaka, Grace; Oviogbodu, Christy Oritseweyimi

    2015-01-01

    The study investigated the influence of gender, school location, and socio-economic status (SES) on students' academic achievement in mathematics. The study was an ex-post factor design in which the variables were not manipulated nor controlled. Four research questions and three hypotheses were formulated to guide the study. The stratified random…

  8. Improving Education Achievement and Attainment in Luxembourg. OECD Economics Department Working Papers, No. 508

    ERIC Educational Resources Information Center

    Carey, David; Ernst, Ekkehard

    2006-01-01

    Improving education achievement in Luxembourg is a priority for strengthening productivity growth and enhancing residents' employment prospects in the private sector, where employers mainly hire cross-border workers. Student achievement in Luxembourg is below the OECD average according to the 2003 OECD PISA study, with the performance gap between…

  9. Literacy Achievement and Economic Health: A Correlative Review of National and International Data

    ERIC Educational Resources Information Center

    Stephens, Monica Fadel

    2012-01-01

    In the face of global economic recession, the competition and collaboration for innovation and future growth among nations has led to discussions of how young people are being prepared to become the next generation of workers and leaders. Although the U.S. has enjoyed a strong presence among the international community since the turn of the…

  10. Apprenticeships and Regeneration: The Civic Struggle to Achieve Social and Economic Goals

    ERIC Educational Resources Information Center

    Fuller, Alison; Rizvi, Sadaf; Unwin, Lorna

    2013-01-01

    Apprenticeship has always played both a social and economic role. Today, it forms part of the regeneration strategies of cities in the United Kingdom. This involves the creation and management of complex institutional relationships across the public and private domains of the civic landscape. This paper argues that it is through closely observed…

  11. Linking Inputs and Outcomes: Achievement among Economically Disadvantaged Appalachian Middle Grades Students.

    ERIC Educational Resources Information Center

    Henry, Kenneth J.; And Others

    This paper examines school, family, and community factors related to the academic success of economically disadvantaged Appalachian students. In two middle schools in Appalachian Kentucky and Tennessee, 245 students who received free or reduced-price school lunches completed the Rural School Success Inventory (RSSI) and a writing sample about…

  12. Schooling Achievement among Rural Zimbabwean Children during a Period of Economic Turmoil

    ERIC Educational Resources Information Center

    Larochelle, Catherine; Alwang, Jeffrey; Taruvinga, Nelson

    2016-01-01

    Zimbabwe suffered severe economic crisis in the decade before 2009, and anecdotal evidence indicates that public education suffered due to uncertainty about salary payments and inflation. As the country recovers, it is important to understand how this crisis affected schooling participation before and during the crisis. This study focuses on the…

  13. The Viable Violinist.

    PubMed

    Hawking, Michael

    2016-06-01

    In the aftermath of the Kermit Gosnell trial and Giubilini and Minerva's article 'After-birth abortion', abortion-rights advocates have been pressured to provide an account of the moral difference between abortion, particularly late-term abortion, and infanticide. In response, some scholars have defended a moral distinction by appealing to an argument developed by Judith Jarvis Thomson in A defense of abortion. However, once Thomson's analogy is refined to account for the morally relevant features of late-term pregnancy, rather than distinguishing between late-term abortion and infanticide, it reinforces their moral similarity. This is because late-term abortion requires more than detachment - it requires an act of feticide to ensure the death of the viable fetus. As such, a Thomsonian account cannot be deployed successfully as a response to Giubilini and Minerva. Those wishing to defend late-term abortion while rejecting the permissibility of infanticide will need to provide an alternative account of the difference, or else accept Giubilini and Minerva's conclusion. PMID:26423668

  14. The Viable Violinist.

    PubMed

    Hawking, Michael

    2016-06-01

    In the aftermath of the Kermit Gosnell trial and Giubilini and Minerva's article 'After-birth abortion', abortion-rights advocates have been pressured to provide an account of the moral difference between abortion, particularly late-term abortion, and infanticide. In response, some scholars have defended a moral distinction by appealing to an argument developed by Judith Jarvis Thomson in A defense of abortion. However, once Thomson's analogy is refined to account for the morally relevant features of late-term pregnancy, rather than distinguishing between late-term abortion and infanticide, it reinforces their moral similarity. This is because late-term abortion requires more than detachment - it requires an act of feticide to ensure the death of the viable fetus. As such, a Thomsonian account cannot be deployed successfully as a response to Giubilini and Minerva. Those wishing to defend late-term abortion while rejecting the permissibility of infanticide will need to provide an alternative account of the difference, or else accept Giubilini and Minerva's conclusion.

  15. DC-9/JT8D refan, Phase 1. [technical and economic feasibility of retrofitting DC-9 aircraft with refan engine to achieve desired acoustic levels

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Analyses and design studies were conducted on the technical and economic feasibility of installing the JT8D-109 refan engine on the DC-9 aircraft. Design criteria included minimum change to the airframe to achieve desired acoustic levels. Several acoustic configurations were studied with two selected for detailed investigations. The minimum selected acoustic treatment configuration results in an estimated aircraft weight increase of 608 kg (1,342 lb) and the maximum selected acoustic treatment configuration results in an estimated aircraft weight increase of 809 kg (1,784 lb). The range loss for the minimum and maximum selected acoustic treatment configurations based on long range cruise at 10 668 m (35,000 ft) altitude with a typical payload of 6 804 kg (15,000 lb) amounts to 54 km (86 n. mi.) respectively. Estimated reduction in EPNL's for minimum selected treatment show 8 EPNdB at approach, 12 EPNdB for takeoff with power cutback, 15 EPNdB for takeoff without power cutback and 12 EPNdB for sideline using FAR Part 36. Little difference was estimated in EPNL between minimum and maximum treatments due to reduced performance of maximum treatment. No major technical problems were encountered in the study. The refan concept for the DC-9 appears technically feasible and economically viable at approximately $1,000,000 per airplane. An additional study of the installation of JT3D-9 refan engine on the DC-8-50/61 and DC-8-62/63 aircraft is included. Three levels of acoustic treatment were suggested for DC-8-50/61 and two levels for DC-8-62/63. Results indicate the DC-8 technically can be retrofitted with refan engines for approximately $2,500,000 per airplane.

  16. Interaction Effects of Socio-economic Status, Intelligence and Reading Program on Beginning Reading Achievement.

    ERIC Educational Resources Information Center

    Ho, Wai-Ching; Eiszler, Charles F.

    An investigation is being made of the effects of the interaction between differing socioeconomic backgrounds and two beginning reading programs on the reading achievement of pupils at three ability levels. This report gives the results of data that have been collected for grades 1 and 2 only. Participating were 754 pupils in a small city school…

  17. School Socio-Economic Status and Student Socio-Academic Achievement Goals in Upper Secondary Contexts

    ERIC Educational Resources Information Center

    Berger, Nathan; Archer, Jennifer

    2016-01-01

    In recent years motivational researchers have spent considerable time examining race/ethnicity and gender differences in academic and social achievement goals, but little time examining the influence of socioeconomic status (SES). This lack of attention is surprising given that both student motivation and SES have been shown to predict academic…

  18. Integrating Economic and Social Policy: Good Practices from High-Achieving Countries. Innocenti Working Papers.

    ERIC Educational Resources Information Center

    Mehrotra, Santosh

    This paper examines the successes of 10 "high achievers," countries with social indicators far higher than might be expected, given their national wealth, pulling together the lessons learned for social policy in the developing world. The 10 countries identified are Costa Rica, Cuba, Barbados, Botswana, Zimbabwe, Mauritius, Kerala, Sri Lanka,…

  19. Impact of Preschool Education on the Academic Achievement of Low Socio-Economic Status Elementary Students

    ERIC Educational Resources Information Center

    Dawson, Gary L.

    2014-01-01

    The purpose of this study was to determine if attending a four-year-old preschool program had an impact on the academic achievement of elementary age students. With limited funding and the demands of No Child Left Behind legislation, schools are constantly evaluating the effectiveness and cost of ongoing programming. In addition, educational…

  20. Racial identity, academic achievement, and the psychological well-being of economically disadvantaged adolescents.

    PubMed

    Arroyo, C G; Zigler, E

    1995-11-01

    The relation between racial identity and personal psychological functioning was examined within the framework of the "racelessness" construct proposed by Fordham and Ogbu (S. Fordham, 1988; S. Fordham & J. U. Ogbu, 1986). These researchers have proposed that academically successful African American students achieve their success by adopting behaviors and attitudes that distance them from their culture of origin, resulting in increased feelings of depression, anxiety, and identity confusion. Studies 1 and 2 describe the development of the Racelessness Scale (RS) designed to test these assumptions. Study 2 also investigated Race X Achievement level differences in students' responses to the RS. In Study 3, correlations between the RS and measures of depression, self-efficacy, anxiety, alienation, and collective self-esteem were assessed. The pattern of results in Study 2 suggest that the behaviors and attitudes described by Fordham and Ogbu are common to high-achieving adolescents and not specific to African Americans. However, racial differences in the pattern of associations between the RS and measures of depression suggest that racelessness may have important psychological consequences for African American adolescents.

  1. Nutritional and socio-economic determinants of cognitive function and educational achievement of Aboriginal schoolchildren in rural Malaysia.

    PubMed

    Al-Mekhlafi, Hesham M; Mahdy, Mohammed A; Sallam, Atiya A; Ariffin, W A; Al-Mekhlafi, Abdulsalam M; Amran, Adel A; Surin, Johari

    2011-10-01

    A community-based cross-sectional study was carried out among Aboriginal schoolchildren aged 7-12 years living in remote areas in Pos Betau, Pahang, Malaysia to investigate the potential determinants influencing the cognitive function and educational achievement of these children. Cognitive function was measured by intelligence quotient (IQ), while examination scores of selected school subjects were used in assessing educational achievement. Blood samples were collected to assess serum Fe status. All children were screened for soil-transmitted helminthes. Demographic and socio-economic data were collected using pre-tested questionnaires. Almost two-thirds (67·6 %) of the subjects had poor IQ and most of them (72·6 %) had insufficient educational achievement. Output of the stepwise multiple regression model showed that poor IQ was significantly associated with low household income which contributed the most to the regression variance (r2 0·059; P = 0·020). Low maternal education was also identified as a significant predictor of low IQ scores (r2 0·042; P = 0·043). With educational achievement, Fe-deficiency anaemia (IDA) was the only variable to show significant association (r2 0·025; P = 0·015). In conclusion, the cognitive function and educational achievement of Aboriginal schoolchildren are poor and influenced by household income, maternal education and IDA. Thus, effective and integrated measures to improve the nutritional and socio-economic status of rural children would have a pronounced positive effect on their education.

  2. Regulation of Viable and Optimal Cohorts

    SciTech Connect

    Aubin, Jean-Pierre

    2015-10-15

    This study deals with the evolution of (scalar) attributes (resources or income in evolutionary demography or economics, position in traffic management, etc.) of a population of “mobiles” (economic agents, vehicles, etc.). The set of mobiles sharing the same attributes is regarded as an instantaneous cohort described by the number of its elements. The union of instantaneous cohorts during a mobile window between two attributes is a cohort. Given a measure defining the number of instantaneous cohorts, the accumulation of the mobile attributes on a evolving mobile window is the measure of the cohort on this temporal mobile window. Imposing accumulation constraints and departure conditions, this study is devoted to the regulation of the evolutions of the attributes which are1.viable in the sense that the accumulations constraints are satisfied at each instant;2.and, among them, optimal, in the sense that both the duration of the temporal mobile window is maximum and that the accumulation on this temporal mobile window is the largest viable one. This value is the “accumulation valuation” function. Viable and optimal evolutions under accumulation constraints are regulated by an “implicit Volterra integro-differential inclusion” built from the accumulation valuation function, solution to an Hamilton–Jacobi–Bellman partial differential equation under constraints which is constructed for this purpose.

  3. Economics Understanding of Albanian High School Students: Factors Related to Achievement as Measured by Test Scores on the Test of Economic Literacy

    ERIC Educational Resources Information Center

    Bushati, Dolore

    2010-01-01

    This study examined the level of economics knowledge, overall and on specific economic concepts after Albanian 11th grade and 12th grade students completed their required economics course and investigated how economics knowledge differed by student and teacher characteristics. There were 1,509 students who participated in this research from 12…

  4. The Ability to Conserve Quantity of Liquid and Its Relationship to Socio-Economic Background, Intelligence, and Achievement Among Selected Fourth Grade Pupils.

    ERIC Educational Resources Information Center

    Bozarth, James Oliver

    Studied were the relationships between children's attainment of the concept of conservation of liquid and certain student characteristics. Student factors investigated were socio-economic background (high and low), status levels (conservers and non-conservers), verbal and non-verbal achievement, and science achievement. Classification of subjects…

  5. Towards a viable and just global nursing ethics.

    PubMed

    Crigger, Nancy J

    2008-01-01

    Globalization, an outgrowth of technology, while informing us about people throughout the world, also raises our awareness of the extreme economic and social disparities that exist among nations. As part of a global discipline, nurses are vitally interested in reducing and eliminating disparities so that better health is achieved for all people. Recent literature in nursing encourages our discipline to engage more actively with social justice issues. Justice in health care is a major commitment of nursing; thus questions in the larger sphere of globalization, justice and ethics, are our discipline's questions also. Global justice, or fairness, is not an issue for some groups or institutions, but a deeper human rights issue that is a responsibility for everyone. What can we do to help reduce or eliminate the social and economic disparities that are so evident? What kind of ethical milieu is needed to address the threat that globalization imposes on justice and fairness? This article enriches the conceptualization of globalization by investigating recent work by Schweiker and Twiss. In addition, I discuss five qualities or characteristics that will facilitate the development of a viable and just global ethic. A global ethic guides all people in their response to human rights and poverty. Technology and business, two major forces in globalization that are generally considered beneficial, are critiqued as barriers to social justice and the common good.

  6. Progress toward achieving a commercially viable solar reflective material

    SciTech Connect

    Kennedy, C.E.; Smilgys, R.V. |

    1998-06-01

    Solar thermal technologies use large mirrors to concentrate sunlight for renewable power generation. The development of advanced reflector materials is important to the viability of electricity production by solar thermal energy systems. The reflector materials must be low in cost and maintain high specular reflectance for extended lifetimes under severe outdoor environments. Production processes associated with candidate materials must be scalable to mass production techniques. A promising low-cost construction uses a stainless steel foil substrate with a silver reflective layer protected by an optically transparent oxide topcoat. Thick (2 to 4 micron), dense alumina coatings provide durable protective layers. The excellent performance of alumina-coated reflector materials in outdoor and accelerated testing suggests that a larger field trial of the material is warranted. The key to producing a greater quantity of material for field deployment and testing without incurring substantial capital is the use of a chilled drum coater. An existing chamber is being modified, and the deposition rate will be increased prior to the installation of a drum coater to produce 1-ft wide by 10-ft long strips of solar reflector material. The production and performance of these materials are discussed.

  7. Economics.

    ERIC Educational Resources Information Center

    Online-Offline, 1998

    1998-01-01

    This issue focuses on the theme of economics, and presents educational resources for teaching basics to children. Web sites, CD-ROMs and software, videos, books, and additional resources, as well as activities which focus on economics are described. Includes short features on related topics, and the subtopics of trade, money and banking, and…

  8. Economics.

    PubMed

    Palley, Paul D; Parcero, Miriam E

    2016-10-01

    A review of literature in the calendar year 2015 dedicated to environmental policies and sustainable development, and economic policies. This review is divided into these sections: sustainable development, irrigation, ecosystems and water management, climate change and disaster risk management, economic growth, water supply policies, water consumption, water price regulation, and water price valuation.

  9. Economics.

    PubMed

    Palley, Paul D; Parcero, Miriam E

    2016-10-01

    A review of literature in the calendar year 2015 dedicated to environmental policies and sustainable development, and economic policies. This review is divided into these sections: sustainable development, irrigation, ecosystems and water management, climate change and disaster risk management, economic growth, water supply policies, water consumption, water price regulation, and water price valuation. PMID:27620113

  10. Economics.

    ERIC Educational Resources Information Center

    James, L. D.

    1978-01-01

    Presents a literature review of the economic aspects of water pollution control covering publications of 1976-77. This review also includes the policy issues of water management. A list of 77 references is presented. (HM)

  11. The Economic Benefits of Closing Educational Achievement Gaps: Promoting Growth and Strengthening the Nation by Improving the Educational Outcomes of Children of Color

    ERIC Educational Resources Information Center

    Lynch, Robert G.; Oakford, Patrick

    2014-01-01

    Our nation is currently experiencing growing levels of income and wealth inequality, which are contributing to longstanding racial and ethnic gaps in education outcomes and other areas. This report quantifies the economic benefits of closing one of the most harmful racial and ethnic gaps: the educational achievement gap that exists between black…

  12. Associations between Students' Perceptions of Teacher-Student Relationship Quality, Academic Achievement, and Classroom Behavior: Are They Moderated by Ethnicity, Gender, or Socio Economic Status?

    ERIC Educational Resources Information Center

    Gill, Khushwinder Kaur

    2012-01-01

    The primary purpose of this study was to explore the correlations between students' perceptions of their relationships with teachers, students' academic achievement and students' classroom behavior. A secondary purpose of the study was to investigate if students' ethnicity, gender and socio-economic status moderate the…

  13. Socio-Economic Achievements of Individuals Born Very Preterm at the Age of 27 to 29 Years: A Nationwide Cohort Study

    ERIC Educational Resources Information Center

    Mathiasen, Rene; Hansen, Bo M.; Anderson, Anne-Marie Nybo; Greisen, Gorm

    2009-01-01

    Aim: To describe the socio economic achievement of individuals born very preterm (VPT) at the age of 27 to 29 years. Method: Demographic and social data were extracted from national registers for all individuals born between 1974 and 1976 in Denmark (n = 208 656). Of these, 203 283 individuals were alive in 2006. We compared VPT individuals…

  14. The Interaction of Logical Reasoning Ability and Socio-Economic Status on Achievement in Genetics among Secondary School Students in Nigeria

    ERIC Educational Resources Information Center

    Okoye, Nnamdi S.; Okecha, Rita Ebele

    2008-01-01

    The study examined the interaction of logical reasoning ability (cognitive development) and socio-economic status on achievement in genetics amongst secondary school students in Nigeria. Factorial Analysis of variance design with one dependent variable and two independent variables at two levels together with the t-test was used in the analysis of…

  15. Teacher Self-Efficacy Enhancement and School Location: Implication for Students' Achievement in Economics in Senior Secondary School in Ibadan, Oyo State, Nigeria

    ERIC Educational Resources Information Center

    Durowoju, Esther O.; Onuka, Adams O. U.

    2015-01-01

    The paper investigated the effect of teacher self-efficacy enhancement and school location on students' achievement in Economics in Senior Secondary School in Ibadan Metropolis of Oyo State, Nigeria. Three hypotheses were tested at 0.05 level of significance. Multi-stage sampling technique was adopted in the study. Four Local Government Areas (two…

  16. The Relations of a School's Capacity for Institutional Diversity to Student Achievement in Socio-Economically, Ethnically, and Linguistically Diverse Schools

    ERIC Educational Resources Information Center

    Min, Sookweon; Goff, Peter T.

    2016-01-01

    This study examines how a school's capacity for institutional diversity relates to student achievement in socio-economically, ethnically, and linguistically diverse schools. It also investigates whether various student groups benefit differently from a school's level of student diversity and its institutional capacity for diversity. Using data…

  17. Achieving Sustainability in a Semi-Arid Basin in Northwest Mexico through an Integrated Hydrologic-Economic-Institutional Model

    NASA Astrophysics Data System (ADS)

    Munoz-Hernandez, A.; Mayer, A. S.

    2008-12-01

    The hydrologic systems in Northwest Mexico are at risk of over exploitation due to poor management of the water resources and adverse climatic conditions. The purpose of this work is to create and Integrated Hydrologic-Economic-Institutional Model to support future development in the Yaqui River basin, well known by its agricultural productivity, by directing the water management practices toward sustainability. The Yaqui River basin is a semi-arid basin with an area of 72,000 square kilometers and an average precipitation of 527 mm per year. The primary user of water is agriculture followed by domestic use and industry. The water to meet user demands comes from three reservoirs constructed, in series, along the river. The main objective of the integrated simulation-optimization model is to maximize the economic benefit within the basin, subject to physical and environmental constraints. Decision variables include the water allocation to major users and reservoirs as well as aquifer releases. Economic and hydrologic (including the interaction of the surface water and groundwater) simulation models were both included in the integrated model. The surface water model refers to a rainfall-runoff model created, calibrated, and incorporated into a MATLAB code that estimates the monthly storage in the main reservoirs by solving a water balance. The rainfall-runoff model was coupled with a groundwater model of the Yaqui Valley which was previously developed (Addams, 2004). This model includes flow in the main canals and infiltration to the aquifer. The economic benefit of water for some activities such as agricultural use, domestic use, hydropower generation, and environmental value was determined. Sensitivity analysis was explored for those parameters that are not certain such as price elasticities or population growth. Different water allocation schemes were created based on climate change, climate variability, and socio-economic scenarios. Addams L. 2004. Water resource

  18. Cognitive capitalism: the effect of cognitive ability on wealth, as mediated through scientific achievement and economic freedom.

    PubMed

    Rindermann, Heiner; Thompson, James

    2011-06-01

    Traditional economic theories stress the relevance of political, institutional, geographic, and historical factors for economic growth. In contrast, human-capital theories suggest that peoples' competences, mediated by technological progress, are the deciding factor in a nation's wealth. Using three large-scale assessments, we calculated cognitive-competence sums for the mean and for upper- and lower-level groups for 90 countries and compared the influence of each group's intellectual ability on gross domestic product. In our cross-national analyses, we applied different statistical methods (path analyses, bootstrapping) and measures developed by different research groups to various country samples and historical periods. Our results underscore the decisive relevance of cognitive ability--particularly of an intellectual class with high cognitive ability and accomplishments in science, technology, engineering, and math--for national wealth. Furthermore, this group's cognitive ability predicts the quality of economic and political institutions, which further determines the economic affluence of the nation. Cognitive resources enable the evolution of capitalism and the rise of wealth.

  19. Do early life cognitive ability and self-regulation skills explain socio-economic inequalities in academic achievement? An effect decomposition analysis in UK and Australian cohorts.

    PubMed

    Pearce, Anna; Sawyer, Alyssa C P; Chittleborough, Catherine R; Mittinty, Murthy N; Law, Catherine; Lynch, John W

    2016-09-01

    Socio-economic inequalities in academic achievement emerge early in life and are observed across the globe. Cognitive ability and "non-cognitive" attributes (such as self-regulation) are the focus of many early years' interventions. Despite this, little research has compared the contributions of early cognitive and self-regulation abilities as separate pathways to inequalities in academic achievement. We examined this in two nationally representative cohorts in the UK (Millennium Cohort Study, n = 11,168; 61% original cohort) and Australia (LSAC, n = 3028; 59% original cohort). An effect decomposition method was used to examine the pathways from socio-economic disadvantage (in infancy) to two academic outcomes: 'low' maths and literacy scores (based on bottom quintile) at age 7-9 years. Risk ratios (RRs, and bootstrap 95% confidence intervals) were estimated with binary regression for each pathway of interest: the 'direct effect' of socio-economic disadvantage on academic achievement (not acting through self-regulation and cognitive ability in early childhood), and the 'indirect effects' of socio-economic disadvantage acting via self-regulation and cognitive ability (separately). Analyses were adjusted for baseline and intermediate confounding. Children from less advantaged families were up to twice as likely to be in the lowest quintile of maths and literacy scores. Around two-thirds of this elevated risk was 'direct' and the majority of the remainder was mediated by early cognitive ability and not self-regulation. For example in LSAC: the RR for the direct pathway from socio-economic disadvantage to poor maths scores was 1.46 (95% CI: 1.17-1.79). The indirect effect of socio-economic disadvantage through cognitive ability (RR = 1.13 [1.06-1.22]) was larger than the indirect effect through self-regulation (1.05 [1.01-1.11]). Similar patterns were observed for both outcomes and in both cohorts. Policies to alleviate social inequality (e.g. child poverty

  20. Update of Project to Introduce Technology in Urban Schools Which Have Low Achievement and Economically Poor Student Populations

    ERIC Educational Resources Information Center

    Smith, Gary R.

    2009-01-01

    This document provides new insights into events which occurred in a project funded by a Technology Literacy Challenge Fund grant awarded by Michigan Department of Education(MDE) in 2000. One purpose of this document is to update the formal report of the project which introduced new technology for use by low achieving students who are studying in…

  1. Developing Viable Financing Models for Space Tourism

    NASA Astrophysics Data System (ADS)

    Eilingsfeld, F.; Schaetzler, D.

    2002-01-01

    Increasing commercialization of space services and the impending release of government's control of space access promise to make space ventures more attractive. Still, many investors shy away from going into the space tourism market as long as they do not feel secure that their return expectations will be met. First and foremost, attracting investors from the capital markets requires qualifying financing models. Based on earlier research on the cost of capital for space tourism, this paper gives a brief run-through of commercial, technical and financial due diligence aspects. After that, a closer look is taken at different valuation techniques as well as alternative ways of streamlining financials. Experience from earlier ventures has shown that the high cost of capital represents a significant challenge. Thus, the sophistication and professionalism of business plans and financial models needs to be very high. Special emphasis is given to the optimization of the debt-to-equity ratio over time. The different roles of equity and debt over a venture's life cycle are explained. Based on the latter, guidelines for the design of an optimized loan structure are given. These are then applied to simulating the financial performance of a typical space tourism venture over time, including the calculation of Weighted Average Cost of Capital (WACC) and Net Present Value (NPV). Based on a concluding sensitivity analysis, the lessons learned are presented. If applied properly, these will help to make space tourism economically viable.

  2. Maintaining economic value of ecosystem services whilst reducing environmental cost: a way to achieve freshwater restoration in China.

    PubMed

    Lin, Mingli; Li, Zhongjie; Liu, Jiashou; Gozlan, Rodolphe E; Lek, Sovan; Zhang, Tanglin; Ye, Shaowen; Li, Wei; Yuan, Jing

    2015-01-01

    Freshwater fisheries are central to food security in China and this remains one of the most important priorities for the growing human population. Thus, combining ecosystem restoration with economics is pivotal in setting successful conservation in China. Here, we have developed a practical management model that combines fishery improvement with conservation. For six years, a ban on fertilizer and a reduction of planktivorous fish stocking along with the introduction of both mandarin fish Siniperca chuatsi and Chinese mitten crab Eriocheir sinensis was apparent in Wuhu Lake, a highly eutrophic lake located in the middle reaches of the Yangtze River. Annual fish yield decreased slightly after the change in management, whereas fisheries income increased 2.6 times. Mandarin fish and Chinese mitten crab accounted for only 16% of total fisheries production but for 48% of total fisheries income. During this six year period, water clarity increased significantly from 61 cm to 111 cm. Total nitrogen, total phosphorus and chlorophyll decreased significantly from 1.14 to 0.84 mg/L, 0.077 to 0.045 mg/L, and 21.45 to 11.59 μg/L respectively, and macrophyte coverage increased by about 30%. Our results showed that the ecological status of shallow lakes could be rapidly reversed from eutrophic to oligotrophic using simple biomanipulation, whilst maintaining fisheries economic value. It also offers a better approach to shallow fisheries lake management in Asia where traditionally the stocking of Chinese carp and use of fertilizers is still popular.

  3. Achieving the triple bottom line in the face of inherent trade-offs among social equity, economic return, and conservation.

    PubMed

    Halpern, Benjamin S; Klein, Carissa J; Brown, Christopher J; Beger, Maria; Grantham, Hedley S; Mangubhai, Sangeeta; Ruckelshaus, Mary; Tulloch, Vivitskaia J; Watts, Matt; White, Crow; Possingham, Hugh P

    2013-04-01

    Triple-bottom-line outcomes from resource management and conservation, where conservation goals and equity in social outcomes are maximized while overall costs are minimized, remain a highly sought-after ideal. However, despite widespread recognition of the importance that equitable distribution of benefits or costs across society can play in conservation success, little formal theory exists for how to explicitly incorporate equity into conservation planning and prioritization. Here, we develop that theory and implement it for three very different case studies in California (United States), Raja Ampat (Indonesia), and the wider Coral Triangle region (Southeast Asia). We show that equity tends to trade off nonlinearly with the potential to achieve conservation objectives, such that similar conservation outcomes can be possible with greater equity, to a point. However, these case studies also produce a range of trade-off typologies between equity and conservation, depending on how one defines and measures social equity, including direct (linear) and no trade-off. Important gaps remain in our understanding, most notably how equity influences probability of conservation success, in turn affecting the actual ability to achieve conservation objectives. Results here provide an important foundation for moving the science and practice of conservation planning-and broader spatial planning in general-toward more consistently achieving efficient, equitable, and effective outcomes. PMID:23530207

  4. Achieving the triple bottom line in the face of inherent trade-offs among social equity, economic return, and conservation.

    PubMed

    Halpern, Benjamin S; Klein, Carissa J; Brown, Christopher J; Beger, Maria; Grantham, Hedley S; Mangubhai, Sangeeta; Ruckelshaus, Mary; Tulloch, Vivitskaia J; Watts, Matt; White, Crow; Possingham, Hugh P

    2013-04-01

    Triple-bottom-line outcomes from resource management and conservation, where conservation goals and equity in social outcomes are maximized while overall costs are minimized, remain a highly sought-after ideal. However, despite widespread recognition of the importance that equitable distribution of benefits or costs across society can play in conservation success, little formal theory exists for how to explicitly incorporate equity into conservation planning and prioritization. Here, we develop that theory and implement it for three very different case studies in California (United States), Raja Ampat (Indonesia), and the wider Coral Triangle region (Southeast Asia). We show that equity tends to trade off nonlinearly with the potential to achieve conservation objectives, such that similar conservation outcomes can be possible with greater equity, to a point. However, these case studies also produce a range of trade-off typologies between equity and conservation, depending on how one defines and measures social equity, including direct (linear) and no trade-off. Important gaps remain in our understanding, most notably how equity influences probability of conservation success, in turn affecting the actual ability to achieve conservation objectives. Results here provide an important foundation for moving the science and practice of conservation planning-and broader spatial planning in general-toward more consistently achieving efficient, equitable, and effective outcomes.

  5. Maintaining economic value of ecosystem services whilst reducing environmental cost: a way to achieve freshwater restoration in China.

    PubMed

    Lin, Mingli; Li, Zhongjie; Liu, Jiashou; Gozlan, Rodolphe E; Lek, Sovan; Zhang, Tanglin; Ye, Shaowen; Li, Wei; Yuan, Jing

    2015-01-01

    Freshwater fisheries are central to food security in China and this remains one of the most important priorities for the growing human population. Thus, combining ecosystem restoration with economics is pivotal in setting successful conservation in China. Here, we have developed a practical management model that combines fishery improvement with conservation. For six years, a ban on fertilizer and a reduction of planktivorous fish stocking along with the introduction of both mandarin fish Siniperca chuatsi and Chinese mitten crab Eriocheir sinensis was apparent in Wuhu Lake, a highly eutrophic lake located in the middle reaches of the Yangtze River. Annual fish yield decreased slightly after the change in management, whereas fisheries income increased 2.6 times. Mandarin fish and Chinese mitten crab accounted for only 16% of total fisheries production but for 48% of total fisheries income. During this six year period, water clarity increased significantly from 61 cm to 111 cm. Total nitrogen, total phosphorus and chlorophyll decreased significantly from 1.14 to 0.84 mg/L, 0.077 to 0.045 mg/L, and 21.45 to 11.59 μg/L respectively, and macrophyte coverage increased by about 30%. Our results showed that the ecological status of shallow lakes could be rapidly reversed from eutrophic to oligotrophic using simple biomanipulation, whilst maintaining fisheries economic value. It also offers a better approach to shallow fisheries lake management in Asia where traditionally the stocking of Chinese carp and use of fertilizers is still popular. PMID:25803696

  6. Maintaining Economic Value of Ecosystem Services Whilst Reducing Environmental Cost: A Way to Achieve Freshwater Restoration in China

    PubMed Central

    Lin, Mingli; Li, Zhongjie; Liu, Jiashou; Gozlan, Rodolphe E.; Lek, Sovan; Zhang, Tanglin; Ye, Shaowen; Li, Wei; Yuan, Jing

    2015-01-01

    Freshwater fisheries are central to food security in China and this remains one of the most important priorities for the growing human population. Thus, combining ecosystem restoration with economics is pivotal in setting successful conservation in China. Here, we have developed a practical management model that combines fishery improvement with conservation. For six years, a ban on fertilizer and a reduction of planktivorous fish stocking along with the introduction of both mandarin fish Siniperca chuatsi and Chinese mitten crab Eriocheir sinensis was apparent in Wuhu Lake, a highly eutrophic lake located in the middle reaches of the Yangtze River. Annual fish yield decreased slightly after the change in management, whereas fisheries income increased 2.6 times. Mandarin fish and Chinese mitten crab accounted for only 16% of total fisheries production but for 48% of total fisheries income. During this six year period, water clarity increased significantly from 61 cm to 111 cm. Total nitrogen, total phosphorus and chlorophyll decreased significantly from 1.14 to 0.84 mg/L, 0.077 to 0.045 mg/L, and 21.45 to 11.59 μg/L respectively, and macrophyte coverage increased by about 30%. Our results showed that the ecological status of shallow lakes could be rapidly reversed from eutrophic to oligotrophic using simple biomanipulation, whilst maintaining fisheries economic value. It also offers a better approach to shallow fisheries lake management in Asia where traditionally the stocking of Chinese carp and use of fertilizers is still popular. PMID:25803696

  7. Neuroscience: viable applications in education?

    PubMed

    Devonshire, Ian M; Dommett, Eleanor J

    2010-08-01

    As a relatively young science, neuroscience is still finding its feet in potential collaborations with other disciplines. One such discipline is education, with the field of neuroeducation being on the horizon since the 1960s. However, although its achievements are now growing, the partnership has not been as successful as first hopes suggested it should be. Here the authors discuss the theoretical barriers and potential solutions to this, which have been suggested previously, with particular focus on levels of research in neuroscience and their applicability to education. Moreover, they propose that these theoretical barriers are driven and maintained by practical barriers surrounding common language and research literacy. They propose that by overcoming these practical barriers through appropriate training and shared experience, neuroeducation can reach its full potential.

  8. FEL powering of satellites: a technically and economically viable program

    NASA Astrophysics Data System (ADS)

    Bennett, Harold E.

    1999-07-01

    Beaming of laser energy through the atmosphere is a means of supplying electrical power to orbiting satellites. By using a new ground based free electron laser developed by Lawrence Berkeley National Laboratory many times the amount of electrical power can be generated by the satellite from the same area of array now used for solar power. There is currently a shortage of power in space, and the demand is rising exponentially. Satellites which appear from earth to remain fixed at one point in the sky are said to be in geosynchronous orbit (GEO). They are used to relay long distance telephone communications, television, e-mail, credit card checks from the local gas pump and a myriad of other applications. In addition to the shortage in power there is also a shortage of available bandwidth. In response to that problem a higher frequency band, the Ka band, is being opened for satellites and fifty companies in the United States are planning to launch satellites which use it. Unfortunately rainfade is a serious problem at this frequency and ten times the usual power is sometimes needed to overcome the effects of rain. Laser power beaming is an answer to this problem. Key elements are a powerful 200 kW free electron laser and a fully compensated 11-meter diameter adaptive optics projection telescope. Remarkable progress has been made on both these ambitious objectives in the last two years.

  9. Development of economically viable, highly integrated, highly modular SEGIS architecture.

    SciTech Connect

    Enslin, Johan; Hamaoui, Ronald; Gonzalez, Sigifredo; Haddad, Ghaith; Rustom, Khalid; Stuby, Rick; Kuran, Mohammad; Mark, Evlyn; Amarin, Ruba; Alatrash, Hussam; Bower, Ward Isaac; Kuszmaul, Scott S.; Sena-Henderson, Lisa; David, Carolyn; Akhil, Abbas Ali

    2012-03-01

    Initiated in 2008, the SEGIS initiative is a partnership involving the U.S. DOE, Sandia National Laboratories, private sector companies, electric utilities, and universities. Projects supported under the initiative have focused on the complete-system development of solar technologies, with the dual goal of expanding renewable PV applications and addressing new challenges of connecting large-scale solar installations in higher penetrations to the electric grid. Petra Solar, Inc., a New Jersey-based company, received SEGIS funds to develop solutions to two of these key challenges: integrating increasing quantities of solar resources into the grid without compromising (and likely improving) power quality and reliability, and moving the design from a concept of intelligent system controls to successful commercialization. The resulting state-of-the art technology now includes a distributed photovoltaic (PV) architecture comprising AC modules that not only feed directly into the electrical grid at distribution levels but are equipped with new functions that improve voltage stability and thus enhance overall grid stability. This integrated PV system technology, known as SunWave, has applications for 'Power on a Pole,' and comes with a suite of technical capabilities, including advanced inverter and system controls, micro-inverters (capable of operating at both the 120V and 240V levels), communication system, network management system, and semiconductor integration. Collectively, these components are poised to reduce total system cost, increase the system's overall value and help mitigate the challenges of solar intermittency. Designed to be strategically located near point of load, the new SunWave technology is suitable for integration directly into the electrical grid but is also suitable for emerging microgrid applications. SunWave was showcased as part of a SEGIS Demonstration Conference at Pepco Holdings, Inc., on September 29, 2011, and is presently undergoing further field testing as a prelude to improved and expanded commercialization.

  10. Waste-heat steam generation is economically viable in ceramics

    SciTech Connect

    McMann, F.C.; Marshall, R.W.

    1984-03-01

    Generation of electric power by turbine-driven generators serviced by waste heat boilers is not a blue sky dream. It is time-proven technology, employing time-proven equipment-equipment that is expected to run uninterrupted in fouryear cycles. This equipment and its control are made right here in the U.S. The equipment is very simple to operate and maintain. This article describes the applications of ceramics in this industry.

  11. On-Chip Dielectrophoretic Separation and Concentration of Viable, Non-Viable and Viable but Not Culturable (VBNC) Escherichia coli

    SciTech Connect

    Packard, M M; Shusteff, M; Alocilja, E C

    2012-04-12

    Although bacterial culture remains the gold standard for detection of viable bacteria in environmental specimens, the typical time requirement of twenty-four hours can delay and even jeopardize appropriate public health intervention. In addition, culture is incapable of detecting viable but not culturable (VBNC) species. Conversely, nucleic acid and antibody-based methods greatly decrease time to detection but rarely characterize viability of the bacteria detected. Through selection by membrane permeability, the method described in this work employs positive dielectrophoresis (pDEP) for separation and purification of viable and VBNC species from water and allows concentration of bacteria for downstream applications.

  12. Viable cosmological solutions in massive bimetric gravity

    SciTech Connect

    Koennig, Frank; Amendola, Luca; Patil, Aashay E-mail: aashay@students.iiserpune.ac.in

    2014-03-01

    We find the general conditions for viable cosmological solution at the background level in bigravity models. Furthermore, we constrain the parameters by comparing to the Union 2.1 supernovae catalog and identify, in some cases analytically, the best fit parameter or the degeneracy curve among pairs of parameters. We point out that a bimetric model with a single free parameter predicts a simple relation between the equation of state and the density parameter, fits well the supernovae data and is a valid and testable alternative to ΛCDM. Additionally, we identify the conditions for a phantom behavior and show that viable bimetric cosmologies cannot cross the phantom divide.

  13. Autofluorescence of viable cultured mammalian cells.

    PubMed

    Aubin, J E

    1979-01-01

    The autofluorescence other than intrinsic protein emission of viable cultured mammalian cells has been investigated. The fluorescence was found to originate in discrete cytoplasmic vesicle-like regions and to be absent from the nucleus. Excitation and emission spectra of viable cells revealed at least two distinct fluorescent species. Comparison of cell spectra with spectra of known cellular metabolites suggested that most, if not all, of the fluorescence arises from intracellular nicotinamide adenine dinucleotide (NADH) and riboflavin and flavin coenzymes. Various changes in culture conditions did not affect the observed autofluorescence intensity. A multiparameter flow system (MACCS) was used to compare the fluorescence intensities of numerous cultured mammalian cells.

  14. Propidium monoazide combined with real-time quantitative PCR to quantify viable Alternaria spp. contamination in tomato products.

    PubMed

    Crespo-Sempere, Ana; Estiarte, Núria; Marín, Sonia; Sanchis, Vicente; Ramos, Antonio J

    2013-08-01

    Alternaria is a common contaminating genus of fungi in fruits, grains, and vegetables that causes severe economic losses to farmers and the food industry. Furthermore, it is claimed that Alternaria spp. are able to produce phytotoxic metabolites, and mycotoxins that are unsafe for human and animal health. DNA amplification techniques are being increasingly applied to detect, identify, and quantify mycotoxigenic fungi in foodstuffs, but the inability of these methods to distinguish between viable and nonviable cells might lead to an overestimation of mycotoxin-producing living cells. A promising technique to overcome this problem is the pre-treatment of samples with nucleic acid intercalating dyes, such as propidium monoazide (PMA), prior to quantitative PCR (qPCR). PMA selectively penetrates cells with a damaged membrane inhibiting DNA amplification during qPCRs. In our study, a primer pair (Alt4-Alt5) to specifically amplify and quantify Alternaria spp. by qPCR was designed. Quantification data of qPCR achieved a detection limit of 10(2)conidia/g of tomato. Here, we have optimized for the first time a DNA amplification-based PMA sample pre-treatment protocol for detecting viable Alternaria spp. cells. Artificially inoculated tomato samples treated with 65μM of PMA, showed a reduction in the signal by almost 7cycles in qPCR between live and heat-killed Alternaria spp. conidia. The tomato matrix had a protective effect on the cells against PMA toxicity, reducing the efficiency to distinguish between viable and nonviable cells. The results reported here indicate that the PMA-qPCR method is a suitable tool for quantifying viable Alternaria cells, which could be useful for estimating potential risks of mycotoxin contamination.

  15. Dead or alive? Autofluorescence distinguishes heat-fixed from viable cells

    PubMed Central

    HENNINGS, LEAH; KAUFMANN, YIHONG; GRIFFIN, ROBERT; SIEGEL, ERIC; NOVAK, PETR; CORRY, PETER; MOROS, EDUARDO G.; SHAFIRSTEIN, GAL

    2010-01-01

    Purpose A proof-of-concept study to evaluate a new autofluorescence method to differentiate necrotic thermally fixed cells from viable tissue following thermal ablation. Methods A conductive interstitial thermal therapy (CITT) device was used to ablate swine mammary tissue and rabbit VX-2 carcinomas in vivo. The ablated regions and 10-mm margins were resected 24 h following treatment, embedded in HistOmer® and sectioned at 3 mm. The fresh sections were evaluated for gross viability with triphenyl tetrazolium chloride, 1 h post-resection. Representative non-viable and viable areas were then processed and embedded into paraffin, and sectioned at 5 μm. Standard H&E staining and proliferating cell nuclear antigen (PCNA) immunohistochemistry were compared against autofluorescence intensity, at 488-nm wavelength, for cellular viability. Results Heat-fixed cells in non-viable regions exhibit increased autofluorescence intensity compared to viable tissue (area under receiver operating characteristics (ROC) curve =0.96; Mann-Whitney P <0.0001). An autofluorescence intensity-based classification rule achieved 92% sensitivity with 100% specificity for distinguishing non-viable from viable samples. In contrast, PCNA staining did not reliably distinguish heat-fixed, dead cells from viable cells. Conclusions Examination of H&E-stained sections using autofluorescence intensity-based classification is a reliable and readily available method to accurately identify heat-fixed cells in ablated surgical margins. PMID:19533483

  16. Monotone viable trajectories for functional differential inclusions

    NASA Astrophysics Data System (ADS)

    Haddad, Georges

    This paper is a study on functional differential inclusions with memory which represent the multivalued version of retarded functional differential equations. The main result gives a necessary and sufficient equations. The main result gives a necessary and sufficient condition ensuring the existence of viable trajectories; that means trajectories remaining in a given nonempty closed convex set defined by given constraints the system must satisfy to be viable. Some motivations for this paper can be found in control theory where F( t, φ) = { f( t, φ, u)} uɛU is the set of possible velocities of the system at time t, depending on the past history represented by the function φ and on a control u ranging over a set U of controls. Other motivations can be found in planning procedures in microeconomics and in biological evolutions where problems with memory do effectively appear in a multivalued version. All these models require viability constraints represented by a closed convex set.

  17. The transfer of viable microorganisms between planets.

    PubMed

    Davies, P C

    1996-01-01

    There is increasing acceptance that catastrophic cosmic impacts have played an important role in shaping the history of terrestrial life. Large asteroid and cometary impacts are also capable of displacing substantial quantities of planetary surface material into space. The discovery of Martian rocks on Earth suggests that viable microorganisms within such ejecta could be exchanged between planets. If this conjecture is correct, it will have profound implications for the origin and evolution of life in the solar system.

  18. Process to Selectively Distinguish Viable from Non-Viable Bacterial Cells

    NASA Technical Reports Server (NTRS)

    LaDuc, Myron T.; Bernardini, Jame N.; Stam, Christina N.

    2010-01-01

    The combination of ethidium monoazide (EMA) and post-fragmentation, randomly primed DNA amplification technologies will enhance the analytical capability to discern viable from non-viable bacterial cells in spacecraft-related samples. Intercalating agents have been widely used since the inception of molecular biology to stain and visualize nucleic acids. Only recently, intercalating agents such as EMA have been exploited to selectively distinguish viable from dead bacterial cells. Intercalating dyes can only penetrate the membranes of dead cells. Once through the membrane and actually inside the cell, they intercalate DNA and, upon photolysis with visible light, produce stable DNA monoadducts. Once the DNA is crosslinked, it becomes insoluble and unable to be fragmented for post-fragmentation, randomly primed DNA library formation. Viable organisms DNA remains unaffected by the intercalating agents, allowing for amplification via post-fragmentation, randomly primed technologies. This results in the ability to carry out downstream nucleic acid-based analyses on viable microbes to the exclusion of all non-viable cells.

  19. Air-spore in Cartagena, Spain: viable and non-viable sampling methods.

    PubMed

    Elvira-Rendueles, Belen; Moreno, Jose; Garcia-Sanchez, Antonio; Vergara, Nuria; Martinez-Garcia, Maria Jose; Moreno-Grau, Stella

    2013-01-01

    In the presented study the airborne fungal spores of the semiarid city of Cartagena, Spain, are identified and quantified by means of viable or non-viable sampling methods. Airborne fungal samples were collected simultaneously using a filtration method and a pollen and particle sampler based on the Hirst methodology. This information is very useful for elucidating geographical patterns of hay fever and asthma. The qualitative results showed that when the non-viable methodology was employed, Cladosporium, Ustilago, and Alternaria were the most abundant spores identified in the atmosphere of Cartagena, while the viable methodology showed that the most abundant taxa were: Cladosporium, Penicillium, Aspergillus and Alternaria. The quantitative results of airborne fungal spores identified by the Hirst-type air sampler (non-viable method), showed that Deuteromycetes represented 74% of total annual spore counts, Cladosporium being the major component of the fungal spectrum (62.2%), followed by Alternaria (5.3%), and Stemphylium (1.3%). The Basidiomycetes group represented 18.9% of total annual spore counts, Ustilago (7.1%) being the most representative taxon of this group and the second most abundant spore type. Ascomycetes accounted for 6.9%, Nectria (2.3%) being the principal taxon. Oomycetes (0.2%) and Zygomycestes and Myxomycestes (0.06%) were scarce. The prevailing species define our bioaerosol as typical of dry air. The viable methodology was better at identifying small hyaline spores and allowed for the discrimination of the genus of some spore types. However, non-viable methods revealed the richness of fungal types present in the bioaerosol. Thus, the use of both methodologies provides a more comprehensive characterization of the spore profile.

  20. Natural transfer of viable microbes in space

    NASA Technical Reports Server (NTRS)

    Mileikowsky, C.; Cucinotta, F. A.; Wilson, J. W.; Gladman, B.; Horneck, G.; Lindegren, L.; Melosh, J.; Rickman, H.; Valtonen, M.; Zheng, J. Q.

    2000-01-01

    The possibility and probability of natural transfer of viable microbes from Mars to Earth and Earth to Mars traveling in meteoroids during the first 0.5 Ga and the following 4 Ga are investigated, including: --radiation protection against the galactic cosmic ray nuclei and the solar rays, dose rates as a function of the meteorite's radial column mass (radius x density), combined with dose rates generated by natural radioactivity within the meteorite; and survival curves for some bacterial species using NASA's HZETRN transport code --other factors affecting microbe survival: vacuum; central meteorite temperatures at launch, orbiting, and arrival; pressure and acceleration at launch; spontaneous DNA decay; metal ion migration --mean sizes and numbers of unshocked meteorites ejected and percentage falling on Earth, using current semiempirical results --viable flight times for the microbe species Bacillus subtilis and Deinococcus radiodurans R1 --the approximate fraction of microbes (with properties like the two species studied) viably arriving on Earth out of those ejected from Mars during the period 4 Ga BP to the present time, and during the 700 Ma from 4.5 to 3.8 Ga. Similarly, from Earth to Mars. The conclusion is that if microbes existed or exist on Mars, viable transfer to Earth is not only possible but also highly probable, due to microbes' impressive resistance to the dangers of space transfer and to the dense traffic of billions of martian meteorites which have fallen on Earth since the dawn of our planetary system. Earth-to-Mars transfer is also possible but at a much lower frequency.

  1. Inkjet printing of viable mammalian cells.

    PubMed

    Xu, Tao; Jin, Joyce; Gregory, Cassie; Hickman, J J James J; Boland, Thomas

    2005-01-01

    The purpose of this study was to explore the use of a commercial thermal printer to deposit Chinese Hamster Ovary (CHO) and embryonic motoneuron cells into pre-defined patterns. These experiments were undertaken to verify the biocompatibility of thermal inkjet printing of mammalian cells and the ability to assemble them into viable constructs. Using a modified Hewlett Packard (HP) 550C computer printer and an HP 51626a ink cartridge, CHO cells and rat embryonic motoneurons were suspended separately in a concentrated phosphate buffered saline solution (3 x). The cells were subsequently printed as a kind of "ink" onto several "bio-papers" made from soy agar and collagen gel. The appearance of the CHO cells and motoneurons on the bio-papers indicated an healthy cell morphology. Furthermore, the analyses of the CHO cell viability showed that less than 8% of the cells were lysed during printing. These data indicate that mammalian cells can be effectively delivered by a modified thermal inkjet printer onto biological substrates and that they retain their ability to function. The computer-aided inkjet printing of viable mammalian cells holds potential for creating living tissue analogs, and may eventually lead to the construction of engineered human organs.

  2. Recalled Test Anxiety in Relation to Achievement, in the Context of General Academic Self-Concept, Study Habits, Parental Involvement and Socio-Economic Status among Grade 6 Ethiopian Students

    ERIC Educational Resources Information Center

    Raju, P. Mohan; Asfaw, Abebech

    2009-01-01

    The study investigated the predictive nature of test anxiety on achievement in the presence of perceived general academic self-concept, study habits, parental involvement in children's learning and socio-economic status. From a population of 2482 Grade 6 students from seven government primary schools of a sub-city in Addis Ababa, 497 participants…

  3. The Relationship between Out-of-School-Suspension and English Language Arts Achievement of Students from Low Socio-Economic Settings

    ERIC Educational Resources Information Center

    Lobban, Carol Janet

    2012-01-01

    Out-of-school suspension (OSS) links low academic achievement to at risk students. Middle school students in one low socioeconomic urban setting experience lower academic achievement and higher rates of OSS. The purpose of this study was to determine the relationship between students' English Language Arts (ELA) achievement and OSS. Glasser's…

  4. Closing the Achievement Gap for Economically Disadvantaged Students? Analyzing Change since No Child Left Behind Using State Assessments and the National Assessment of Educational Progress

    ERIC Educational Resources Information Center

    Blank, Rolf K.

    2011-01-01

    A critical state-level indicator of progress in public education is student achievement annual performance and change over time. The Council of Chief State School Officers (CCSSO) has been very active in tracking and reporting on student achievement results and using state assessment scores and other data to analyze achievement trends. A central…

  5. [PAH Cations as Viable Carriers of DIBs

    NASA Technical Reports Server (NTRS)

    Snow, Ted

    1998-01-01

    This report is intended to fill in the blanks in NASA's file system for our lab astro study of molecular ions of astrophysical interest. In order to give NASA what it needs for its files, I attach below the text of the section from our recent proposal to continue this work, in which we describe progress to date, including a large number of publications. Our initial studies were focused on PAH cations, which appear to be viable candidates as the carriers of the DIBs, an idea that has been supported by laboratory spectroscopy of PAH cations in inert matrices. Beginning with the simplest aromatic (benzene; C6H6) and moving progressively to larger species (naphthalene, C10OH8; pyrene, C16H10; and most recently chrysene, C18H12), we have been able to derive rate coefficients for reactions with neutral spices that are abundant in the diffuse interstellar medium.

  6. Comparison of epifluorescent viable bacterial count methods

    NASA Technical Reports Server (NTRS)

    Rodgers, E. B.; Huff, T. L.

    1992-01-01

    Two methods, the 2-(4-Iodophenyl) 3-(4-nitrophenyl) 5-phenyltetrazolium chloride (INT) method and the direct viable count (DVC), were tested and compared for their efficiency for the determination of the viability of bacterial populations. Use of the INT method results in the formation of a dark spot within each respiring cell. The DVC method results in elongation or swelling of growing cells that are rendered incapable of cell division. Although both methods are subjective and can result in false positive results, the DVC method is best suited to analysis of waters in which the number of different types of organisms present in the same sample is assumed to be small, such as processed waters. The advantages and disadvantages of each method are discussed.

  7. Enumeration of viable and non-viable larvated Ascaris eggs with quantitative PCR

    EPA Science Inventory

    Aims: The goal of the study was to further develop an incubation-qPCR method for quantifying viable Ascaris eggs. The specific objectives were to characterize the detection limit and number of template copies per egg, determine the specificity of the method, and test the method w...

  8. The Effects of On-Time, Delayed and Early Kindergarten Enrollment on Children's Mathematics Achievement: Differences by Gender, Race, and Family Socio-Economic Status

    ERIC Educational Resources Information Center

    Yesil Dagli, Ummuhan; Jones, Ithel

    2012-01-01

    This study was an examination of the effect of delayed, early, and on-time kindergarten enrollment on children's kindergarten mathematics achievement. Central for this study was to explore if the relationship between the kindergarten enrollment status and mathematics achievement varies by children's gender, race, and family SES status. It used a…

  9. The Relationship of Teachers' Assigned Marks to Tested Achievement among Elementary Grade, Racially Divergent Lower Socio-Economic Status Boys and Girls.

    ERIC Educational Resources Information Center

    Fish, Enrica

    An investigation was made of the relationship of achievement marks assigned by teachers to elementary grade, lower socioeconomic status boys and girls to pupils' (1) racial background, (2) sex, (3) intelligence quotient, and (4) tested achievement. Teacher marking procedures were studied. The rationale was to inquire whether or not characteristics…

  10. Do the Factors Affecting Academic Achievement Differ by the Socio-Economic Status or Sex of the Student? A Puerto Rican Secondary School Sample. Final Report.

    ERIC Educational Resources Information Center

    Nuttall, Ronald L.

    Variables expected to be associated with academic achievement were examined in a sample (generally exceeding 2500) from eight secondary schools in Baymon Norte, Puerto Rico. Concern was whether variables associated with academic achievement differed by sex or by socioeconomic status (SES). Multivariate analyses of variance with three factors of…

  11. 43 CFR 9266.4 - Viable coral communities.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Viable coral communities. 9266.4 Section... § 9266.4 Viable coral communities. (a) Requirement for a permit. No person shall engage in any operation which directly causes damage or injury to a viable coral community that is located on the...

  12. 43 CFR 9266.4 - Viable coral communities.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Viable coral communities. 9266.4 Section... § 9266.4 Viable coral communities. (a) Requirement for a permit. No person shall engage in any operation which directly causes damage or injury to a viable coral community that is located on the...

  13. 43 CFR 9266.4 - Viable coral communities.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Viable coral communities. 9266.4 Section... § 9266.4 Viable coral communities. (a) Requirement for a permit. No person shall engage in any operation which directly causes damage or injury to a viable coral community that is located on the...

  14. 43 CFR 9266.4 - Viable coral communities.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Viable coral communities. 9266.4 Section... § 9266.4 Viable coral communities. (a) Requirement for a permit. No person shall engage in any operation which directly causes damage or injury to a viable coral community that is located on the...

  15. The Conceptual Mechanism for Viable Organizational Learning Based on Complex System Theory and the Viable System Model

    ERIC Educational Resources Information Center

    Sung, Dia; You, Yeongmahn; Song, Ji Hoon

    2008-01-01

    The purpose of this research is to explore the possibility of viable learning organizations based on identifying viable organizational learning mechanisms. Two theoretical foundations, complex system theory and viable system theory, have been integrated to provide the rationale for building the sustainable organizational learning mechanism. The…

  16. Predicting Student Achievement in University-Level Business and Economics Classes: Peer Observation of Classroom Instruction and Student Ratings of Teaching Effectiveness

    ERIC Educational Resources Information Center

    Galbraith, Craig S.; Merrill, Gregory B.

    2012-01-01

    We examine the validity of peer observation of classroom instruction for purposes of faculty evaluation. Using both a multi-section course sample and a sample of different courses across a university's School of Business and Economics we find that the results of annual classroom observations of faculty teaching are significantly and positively…

  17. Identifying Research-Based Teaching Strategies in Reading to Close the Achievement Gap for Low Socio-Economic Children in Texas

    ERIC Educational Resources Information Center

    Brownlee, Steven Albert

    2013-01-01

    This study examined the effects of scientifically research based (SRB) teaching strategies on the learning of students living in poverty in a Educational Service Center (ESC) Region VI of East Texas. By interviewing teachers within academically successful campuses with high economically disadvantaged student populations, an accurate assessment was…

  18. Effects of Learning Approaches, Locus of Control, Socio-Economic Status and Self-Efficacy on Academic Achievement: A Turkish Perspective

    ERIC Educational Resources Information Center

    Suphi, Nilgun; Yaratan, Huseyin

    2012-01-01

    In this study the effects of learning approaches, locus of control (LOC), socio-economic status and self-efficacy on undergraduate students in North Cyprus was investigated. Four questionnaires were administered on 99 students in order to collect data regarding the learning approaches, LOC, self-efficacy and demographic factors. High cumulative…

  19. Deletion of ultraconserved elements yields viable mice

    SciTech Connect

    Ahituv, Nadav; Zhu, Yiwen; Visel, Axel; Holt, Amy; Afzal, Veena; Pennacchio, Len A.; Rubin, Edward M.

    2007-07-15

    Ultraconserved elements have been suggested to retainextended perfect sequence identity between the human, mouse, and ratgenomes due to essential functional properties. To investigate thenecessities of these elements in vivo, we removed four non-codingultraconserved elements (ranging in length from 222 to 731 base pairs)from the mouse genome. To maximize the likelihood of observing aphenotype, we chose to delete elements that function as enhancers in amouse transgenic assay and that are near genes that exhibit markedphenotypes both when completely inactivated in the mouse as well as whentheir expression is altered due to other genomic modifications.Remarkably, all four resulting lines of mice lacking these ultraconservedelements were viable and fertile, and failed to reveal any criticalabnormalities when assayed for a variety of phenotypes including growth,longevity, pathology and metabolism. In addition more targeted screens,informed by the abnormalities observed in mice where genes in proximityto the investigated elements had been altered, also failed to revealnotable abnormalities. These results, while not inclusive of all thepossible phenotypic impact of the deleted sequences, indicate thatextreme sequence constraint does not necessarily reflect crucialfunctions required for viability.

  20. Economic Incentives for Cybersecurity: Using Economics to Design Technologies Ready for Deployment

    SciTech Connect

    Vishik, Claire; Sheldon, Frederick T; Ott, David

    2013-01-01

    Cybersecurity practice lags behind cyber technology achievements. Solutions designed to address many problems may and do exist but frequently cannot be broadly deployed due to economic constraints. Whereas security economics focuses on the cost/benefit analysis and supply/demand, we believe that more sophisticated theoretical approaches, such as economic modeling, rarely utilized, would derive greater societal benefits. Unfortunately, today technologists pursuing interesting and elegant solutions have little knowledge of the feasibility for broad deployment of their results and cannot anticipate the influences of other technologies, existing infrastructure, and technology evolution, nor bring the solutions lifecycle into the equation. Additionally, potentially viable solutions are not adopted because the risk perceptions by potential providers and users far outweighs the economic incentives to support introduction/adoption of new best practices and technologies that are not well enough defined. In some cases, there is no alignment with redominant and future business models as well as regulatory and policy requirements. This paper provides an overview of the economics of security, reviewing work that helped to define economic models for the Internet economy from the 1990s. We bring forward examples of potential use of theoretical economics in defining metrics for emerging technology areas, positioning infrastructure investment, and building real-time response capability as part of software development. These diverse examples help us understand the gaps in current research. Filling these gaps will be instrumental for defining viable economic incentives, economic policies, regulations as well as early-stage technology development approaches, that can speed up commercialization and deployment of new technologies in cybersecurity.

  1. The Effects of a School-Family-Community Partnership on the Academic Achievement, High School Graduation, and College Enrollment Rate of Economically Disadvantaged Youth

    ERIC Educational Resources Information Center

    Morgan, Yvette

    2012-01-01

    A school-family-community partnership to improve student achievement was examined at a comprehensive high school located in a low income urban community in Long Island City, New York. In this causal comparative analyses study, the researcher examines the effect of a school-family-community partnership on the educational outcomes of economically…

  2. Schooling and Achievement: A Discussion on African American Students from Low Socio-Economic Households and Their Over-Diagnoses of Learning Disabilities

    ERIC Educational Resources Information Center

    Hankerson, Pamela S.

    2011-01-01

    The following is a discussion on student level of academic achievement, specifically that of African American learners. The misdiagnosis of Black students having learning disabilities and other disabilities will be examined, and the factors as to why this misdiagnosis occurs so often. Research will be provided as evidence to support this claim, as…

  3. Trace detection of specific viable bacteria using tetracysteine-tagged bacteriophages.

    PubMed

    Wu, Lina; Luan, Tian; Yang, Xiaoting; Wang, Shuo; Zheng, Yan; Huang, Tianxun; Zhu, Shaobin; Yan, Xiaomei

    2014-01-01

    Advanced methods are urgently needed to determine the identity and viability of trace amounts of pathogenic bacteria in a short time. Existing approaches either fall short in the accurate assessment of microbial viability or lack specificity in bacterial identification. Bacteriophages (or phages for short) are viruses that exclusively infect bacterial host cells with high specificity. As phages infect and replicate only in living bacterial hosts, here we exploit the strategy of using tetracysteine (TC)-tagged phage in combination with biarsenical dye to the discriminative detection of viable target bacteria from dead target cells and other viable but nontarget bacterial cells. Using recombinant M13KE-TC phage and Escherichia coli ER2738 as a model system, distinct differentiation between individual viable target cells from dead target cells was demonstrated by flow cytometry and fluorescence microscopy. As few as 1% viable E. coli ER2738 can be accurately quantified in a mix with dead E. coli ER2738 by flow cytometry. With fluorescence microscopic measurement, specific detection of as rare as 1 cfu/mL original viable target bacteria was achieved in the presence of a large excess of dead target cells and other viable but nontarget bacterial cells in 40 mL artificially contaminated drinking water sample in less than 3 h. This TC-phage-FlAsH approach is sensitive, specific, rapid, and simple, and thus shows great potential in water safety monitoring, health surveillance, and clinical diagnosis of which trace detection and identification of viable bacterial pathogens is highly demanded.

  4. Rapid enumeration of viable bacteria by image analysis

    NASA Technical Reports Server (NTRS)

    Singh, A.; Pyle, B. H.; McFeters, G. A.

    1989-01-01

    A direct viable counting method for enumerating viable bacteria was modified and made compatible with image analysis. A comparison was made between viable cell counts determined by the spread plate method and direct viable counts obtained using epifluorescence microscopy either manually or by automatic image analysis. Cultures of Escherichia coli, Salmonella typhimurium, Vibrio cholerae, Yersinia enterocolitica and Pseudomonas aeruginosa were incubated at 35 degrees C in a dilute nutrient medium containing nalidixic acid. Filtered samples were stained for epifluorescence microscopy and analysed manually as well as by image analysis. Cells enlarged after incubation were considered viable. The viable cell counts determined using image analysis were higher than those obtained by either the direct manual count of viable cells or spread plate methods. The volume of sample filtered or the number of cells in the original sample did not influence the efficiency of the method. However, the optimal concentration of nalidixic acid (2.5-20 micrograms ml-1) and length of incubation (4-8 h) varied with the culture tested. The results of this study showed that under optimal conditions, the modification of the direct viable count method in combination with image analysis microscopy provided an efficient and quantitative technique for counting viable bacteria in a short time.

  5. BARTMAP: a viable structure for biclustering.

    PubMed

    Xu, Rui; Wunsch Ii, Donald C

    2011-09-01

    Clustering has been used extensively in the analysis of high-throughput messenger RNA (mRNA) expression profiling with microarrays. Furthermore, clustering has proven elemental in microRNA expression profiling, which demonstrates enormous promise in the areas of cancer diagnosis and treatment, gene function identification, therapy development and drug testing, and genetic regulatory network inference. However, such a practice is inherently limited due to the existence of many uncorrelated genes with respect to sample or condition clustering, or many unrelated samples or conditions with respect to gene clustering. Biclustering offers a solution to such problems by performing simultaneous clustering on both dimensions, or automatically integrating feature selection to clustering without any prior information, so that the relations of clusters of genes (generally, features) and clusters of samples or conditions (data objects) are established. However, the NP-complete computational complexity raises a great challenge to computational methods for identifying such local relations. Here, we propose and demonstrate that a neural-based classifier, ARTMAP, can be modified to perform biclustering in an efficient way, leading to a biclustering algorithm called Biclustering ARTMAP (BARTMAP). Experimental results on multiple human cancer data sets show that BARTMAP can achieve clustering structures with higher qualities than those achieved with other commonly used biclustering or clustering algorithms, and with fast run times. PMID:21493039

  6. 2011 and 2012 Early Careers Achievement Awards: improving the production, environmental, and economic efficiency of the stocker cattle industry in the southeastern United States.

    PubMed

    Beck, P A; Anders, M; Watkins, B; Gunter, S A; Hubbell, D; Gadberry, M S

    2013-06-01

    Grazing forages on small-grain fields can be a profitable "second crop" for grain producers and an opportunity for cow-calf producers to retain ownership of weaned calves. The increasing costs of conventional tillage and movement of soil nutrients into surface water creates a need for more sustainable production practices to be incorporated by producers into wheat pasture production systems. Research at the Livestock and Forestry Research Station near Batesville, AR, and the Southwest Research and Extension Center near Hope, AR, has been conducted over a 9-yr span to characterize the impacts of pasture systems on forage production, animal performance, soil quality, water runoff, and the economics associated with the stocker cattle enterprises. Gains of growing cattle grazing nontoxic endophyte-infected tall fescue and small-grain forages can be increased by 80 and 150%, respectively, compared with grazing Bermuda grass or toxic endophyte-infected tall fescue. Producers grazing spring-calving cowherds can use these improved forages to accelerate stocker performance when retaining calves in the fall and improve net returns by 99% with winter annual or nontoxic tall fescue production systems compared with Bermuda grass or toxic tall fescue. Rainfall simulation of small grain pastures indicates that runoff volume and nutrient load does not differ between conventionally tilled fields and no-till fields in the spring before tillage when soil surface cover is similar. In the fall after tillage, however, conventionally tilled fields had 4 times greater runoff; hence, there was 1.9 times greater N runoff and 3.2 times greater P runoff in conventionally tilled fields compared with no-till. Total natural rainfall runoff from conventionally tilled wheat fields were 2 times greater than from no-till fields with 25 mm rainfall events yet were 4 times greater with 62-mm rainfall events. Soil analysis shows that soil aggregate content was greater in no-till compared with

  7. Viable supersymmetric model with UV insensitive anomaly mediation

    SciTech Connect

    Ibe, Masahiro; Kitano, Ryuichiro; Murayama, Hitoshi

    2005-04-01

    We propose an electroweak model which is compatible with the UV insensitive anomaly-mediated supersymmetry breaking. The model is an extension of the next to minimal supersymmetric standard model (NMSSM) by adding vectorlike matter fields which can drive the soft scalar masses of the singlet Higgs field negative and the successful electroweak symmetry breaking is achieved. Viable parameter regions are found to preserve perturbativity of all the coupling constants up to the Planck scale. With this success, the model becomes a perfect candidate of physics beyond the standard model without the flavor changing neutral current and CP problem. The cosmology is also quite interesting. The lightest neutralino is the wino which is a perfect cold dark matter candidate assuming the nonthermal production from the gravitino decay. There is no gravitino problem because it decays before the big-bang nucleosynthesis era, and thus the thermal leptogenesis works. The cosmological domain wall problem inherent in the NMSSM is absent since the Z{sub 3} symmetry is broken by the QCD instanton effect in the presence of the vectorlike quarks. We also briefly comment on a possible solution to the strong CP problem a la the Nelson-Barr mechanism.

  8. A viable supersymmetric model with UV insensitive anomaly mediation

    SciTech Connect

    Ibe, Masahiro; Kitano, Ryuichiro; Murayama, Hitoshi

    2004-12-14

    We propose an electroweak model which is compatible with the UV insensitive anomaly mediated supersymmetry breaking. The model is an extension of the NMSSM by adding vector-like matter fields which can drive the soft scalar masses of the singlet Higgs field negative and the successful electroweak symmetry breaking is achieved. Viable parameter regions are found to preserve perturbativity of all the coupling constants up to the Planck scale. With this success, the model becomes a perfect candidate of physics beyond the standard model without the FCNC and CP problem. The cosmology is also quite interesting. The lightest neutralino is the wino which is a perfect cold dark matter candidate assuming the non-thermal production from the gravitino decay. There is no gravitino problem because it decays before the BBN era, and thus the thermal leptogenesis works. The cosmological domain wall problem inherent in the NMSSM is absent since the Z_3 symmetry is broken by the QCD instanton effect in the presence of the vector-like quarks. We also briefly comment on a possible solution to the strong CP problem a la the Nelson-Barr mechanism.

  9. The New European Economics.

    ERIC Educational Resources Information Center

    Bressand, Albert

    1979-01-01

    Discusses economic achievement, economic constraints, and economic policy issues relevant to Western Europe. Constraints include decreases in resources and energy, a slow-down in the baby boom, and public resistance to pollution-causing technology. Achievements include high standards of living, positive trade balances, and international…

  10. A search for viable organisms in a lunar sample.

    PubMed

    Oyama, V I; Merek, E L; Silverman, M P

    1970-01-30

    The hypothesis that the moon could harbor viable life forms was not verified on analysis of the first samnples from the Apollo 11 mission. Biological examnination of 50 grainis of the butlk fines confirmn the negative results obtained by the Manned Spacecraft Center quarantine teamyz. No viable life forms, including terrestrial contaminants, were found when the sample was tested in 300 separate environmtenits. Only colored illorganiic artifacts, resembling mnicrobial clonies, appeared aroun1cd some particles. Manned Spacecraft Center, Houston.

  11. Achieving All Our Ambitions

    ERIC Educational Resources Information Center

    Hartley, Tricia

    2009-01-01

    National learning and skills policy aims both to build economic prosperity and to achieve social justice. Participation in higher education (HE) has the potential to contribute substantially to both aims. That is why the Campaign for Learning has supported the ambition to increase the proportion of the working-age population with a Level 4…

  12. Economic Blues

    ERIC Educational Resources Information Center

    Stuart, Reginald

    2009-01-01

    Today, a national economy gone bust has derailed Black Americans' plans across the country. Gone are many of the economic gains, small as they were, achieved in the post-segregation era by millions of 1960s generation children and their children. Black America today is beset by job losses, business closures, pay cuts, furloughs, investment and…

  13. Hoechst fluorescence intensity can be used to separate viable bromodeoxyuridine-labeled cells from viable non-bromodeoxyuridine-labeled cells

    NASA Technical Reports Server (NTRS)

    Mozdziak, P. E.; Pulvermacher, P. M.; Schultz, E.; Schell, K.

    2000-01-01

    BACKGROUND: 5-Bromo-2'-deoxyuridine (BrdU) is a powerful compound to study the mitotic activity of a cell. Most techniques that identify BrdU-labeled cells require conditions that kill the cells. However, the fluorescence intensity of the membrane-permeable Hoechst dyes is reduced by the incorporation of BrdU into DNA, allowing the separation of viable BrdU positive (BrdU+) cells from viable BrdU negative (BrdU-) cells. METHODS: Cultures of proliferating cells were supplemented with BrdU for 48 h and other cultures of proliferating cells were maintained without BrdU. Mixtures of viable BrdU+ and viable BrdU- cells from the two proliferating cultures were stained with Hoechst 33342. The viable BrdU+ and BrdU- cells were sorted into different fractions from a mixture of BrdU+ and BrdU- cells based on Hoechst fluorescence intensity and the ability to exclude the vital dye, propidium iodide. Subsequently, samples from the original mixture, the sorted BrdU+ cell population, and the sorted BrdU- cell population were immunostained using an anti-BrdU monoclonal antibody and evaluated using flow cytometry. RESULTS: Two mixtures consisting of approximately 55% and 69% BrdU+ cells were sorted into fractions consisting of greater than 93% BrdU+ cells and 92% BrdU- cells. The separated cell populations were maintained in vitro after sorting to demonstrate their viability. CONCLUSIONS: Hoechst fluorescence intensity in combination with cell sorting is an effective tool to separate viable BrdU+ from viable BrdU- cells for further study. The separated cell populations were maintained in vitro after sorting to demonstrate their viability. Copyright 2000 Wiley-Liss, Inc.

  14. Quantification of viable helminth eggs in samples of sewage sludge.

    PubMed

    Rocha, Maria Carolina Vieira da; Barés, Monica Eboly; Braga, Maria Cristina Borba

    2016-10-15

    For the application of sewage sludge as fertilizer, it is of fundamental importance the absence of pathogenic organisms, such as viable helminth eggs. Thus, the quantification of these organisms has to be carried out by means of the application of reliable and accurate methodologies. Nevertheless, until the present date, there is no consensus with regard to the adoption of a universal methodology for the detection and quantification of viable helminth eggs. It is therefore necessary to instigate a debate on the different protocols currently in use, as well as to assemble relevant information in order to assist in the development of a more comprehensive and accurate method to quantify viable helminth eggs in samples of sewage sludge and its derivatives. PMID:27470467

  15. Fluorogenic Substrate Detection of Viable Intracellular and Extracellular Pathogenic Protozoa

    NASA Astrophysics Data System (ADS)

    Jackson, Peter R.; Pappas, Michael G.; Hansen, Brian D.

    1985-01-01

    Viable Leishmania promastigotes and amastigotes were detected by epifluorescence microscopy with fluorescein diacetate being used to mark living parasites and the nucleic acid-binding compound ethidium bromide to stain dead cells. This procedure is superior to other assays because it is faster and detects viable intracellular as well as extracellular Leishmania. Furthermore, destruction of intracellular pathogens by macrophages is more accurately determined with fluorescein diacetate than with other stains. The procedure may have applications in programs to develop drugs and vaccines against protozoa responsible for human and animal disease.

  16. Coscheduling in Clusters: Is It a Viable Alternative?

    SciTech Connect

    Choi, G S; Kim, J H; Ersoz, D; Yoo, A B; Das, C R

    2003-11-10

    As clusters are widely accepted as cost-effective infrastructures for many scientific and commercial applications, improving the deliverable performance and reducing the energy consumption of such systems has become a pressing issue. In this paper, we exploit the feasibility of achieving these objectives through efficiently scheduling the communicating processes of parallel applications. In this context, we conduct an in-depth evaluation of a broad spectrum of scheduling alternatives for clusters. These include the widely used batch scheduling, local scheduling, gang scheduling, all prior communication-driven coscheduling algorithms, and a newly proposed HYBRID coscheduling algorithm. In order to provide ease of implementation and portability across many cluster platforms, we propose a generic framework for deploying any coscheduling algorithm. We have implemented four prior coscheduling algorithms (Dynamic Coscheduling (DCS), Spin Block (SB), Periodic Boost (PB), and Co-ordinated Coscheduling (CC)) and the HYBRID coscheduling using this framework on a 16-node, Myrinet connected Linux cluster that uses GM as the communication layer. In addition, we use PBS as the batch scheduler and a previously proposed gang scheduler (SCore) to analyze all classes of scheduling techniques. Performance and energy measurements using several NAS and LLNL benchmarks on the Linux cluster provide several interesting conclusions. First, although batch scheduling is currently used in most clusters, all blocking-based coscheduling techniques such as SB, CC and HYBRID and the gang scheduling can provide much better performance even in a dedicated cluster platform. Under high system load, these coscheduling schemes can provide orders of magnitude reduction in average response time and much better performance-energy behavior compared to the PBS scheme. Second, in contrast to some of the prior studies, we observe that blocking-based schemes like SB and HYBRID can provide better performance

  17. Characteristics of Viable and Sustainable Workers for the Year 2015.

    ERIC Educational Resources Information Center

    Dean, Brenda Pennington; West, Russell

    A two-round Delphi study was conducted to identify the characteristics of viable and sustainable employees in northeastern Tennessee in 2015. The Delphi panel selected for the study consisted of 25 experts who represented a cross-section of the businesses and communities in the 10-county area of northeastern Tennessee served by Walters State…

  18. Lease/Purchase: A Viable Alternative for Financing Schools.

    ERIC Educational Resources Information Center

    Demers, Denise

    1989-01-01

    Lease-purchase finance is a viable alternative for school districts that cannot or do not want to employ traditional financing techniques. Outlines the advantages and disadvantages of lease-purchase financing compared to outright purchase; operating leasing, which is taxable; and traditional tax-exempt bond financing. (MLF)

  19. EXPERIMENTAL VIABLE VACCINE AGAINST PULMONARY COCCIDIOIDOMYCOSIS IN MONKEYS1

    PubMed Central

    Converse, John L.; Castleberry, Merida W.; Snyder, Ernest M.

    1963-01-01

    Converse, John L. (U.S. Army Biological Laboratories, Fort Detrick, Frederick, Md.), Merida W. Castleberry, and Ernest M. Snyder. Experimental viable vaccine against pulmonary coccidioidomycosis in monkeys. J. Bacteriol. 86:1041–1051. 1963.—Monkeys (Macaca mulatta) vaccinated by subcutaneous injection in the forearm with from 10 to 108 viable Coccidioides immitis arthrospores were protected against respiratory challenge with approximately 7000 viable arthrospores administered 6 months after vaccination. Protection was evident from: the healthy appearance throughout 4 months after respiratory challenge; negative chest X rays at 15, 30, 60, and 120 days; and only very minor histopathological pulmonary changes on autopsy at 120 days, with negative lung cultures in 80% of the animals. This was in striking contrast to the outward clinical appearance of control monkeys that were unvaccinated or had received nonviable arthrospore vaccines. These monkeys showed severe disease (loss of weight, accelerated respiration, severe coughing, general debilitation), positive X rays, massive pulmonary destruction, positive lung cultures, and death of five of nine animals. The appearance of spherules (very few in number, accompanied by very minor pathological changes) in the lungs of some of the “dissemination controls” (subcutaneous viable vaccination without respiratory challenge) indicated possible dissemination from the primary cutaneous infection, although oral transmission from the cutaneous lesions could not be ruled out. Images PMID:14080770

  20. Hybrid fiber coax networks: a viable option for telemedicine.

    PubMed

    Mueller, D

    1998-11-01

    Cable companies have improved their networks to the degree that they are viable alternatives to currently deployed networks. A detailed look at these cable networks shows them to be superior in bandwidth (capacity), speed, flexibility, and ubiquity. The services that can be provided by these networks are ideal to numerous advanced applications, including telemedicine. PMID:9848059

  1. High speed flow cytometric separation of viable cells

    DOEpatents

    Sasaki, D.T.; Van den Engh, G.J.; Buckie, A.M.

    1995-11-14

    Hematopoietic cell populations are separated to provide cell sets and subsets as viable cells with high purity and high yields, based on the number of original cells present in the mixture. High-speed flow cytometry is employed using light characteristics of the cells to separate the cells, where high flow speeds are used to reduce the sorting time.

  2. High speed flow cytometric separation of viable cells

    DOEpatents

    Sasaki, Dennis T.; Van den Engh, Gerrit J.; Buckie, Anne-Marie

    1995-01-01

    Hematopoietic cell populations are separated to provide cell sets and subsets as viable cells with high purity and high yields, based on the number of original cells present in the mixture. High-speed flow cytometry is employed using light characteristics of the cells to separate the cells, where high flow speeds are used to reduce the sorting time.

  3. A METHOD TO DETECT VIABLE HELICOBACTER PYLORI BACTERIA IN GROUNDWATER

    EPA Science Inventory

    The inability to detect the presence of viable Helicobacter pylori bacteria in environmental waters has hindered the public health community in assessing the role water may playin the transmission of this pathogen. This work describes a cultural enrichment method coupled with an...

  4. Viable viral efficiency of N95 and P100 respirator filters at constant and cyclic flow.

    PubMed

    Gardner, Paul D; Eshbaugh, Jonathan P; Harpest, Shannon D; Richardson, Aaron W; Hofacre, Kent C

    2013-01-01

    The growing threat of an influenza pandemic presents a unique challenge to healthcare workers, emergency responders, and the civilian population. The Occupational Safety and Health Administration (OSHA) recommends National Institute for Occupational Safety and Health (NIOSH)-approved respirators to provide protection against infectious airborne viruses in various workplace settings. The filtration efficiency of selected NIOSH-approved particulate N95 and P100 filtering facepiece respirators (FFRs) and filter cartridges was investigated against the viable MS2 virus, a non-pathogenic bacteriophage, aerosolized from a liquid suspension. Tests were performed under two cyclic flow conditions (minute volumes of 85 and 135 L/min) and two constant flow rates (85 and 270 L/min). The mean penetrations of viable MS2 through the N95 and P100 FFRs/cartridges were typically less than 2 and 0.03%, respectively, under all flow conditions. All N95 and P100 FFR and cartridge models assessed in this study, therefore, met or exceeded their respective efficiency ratings of 95 and 99.97% against the viable MS2 test aerosol, even under the very high flow conditions. These NIOSH-approved FFRs and particulate respirators equipped with these cartridges can be anticipated to achieve expected levels of protection (consistent with their assigned protection factor) against airborne viral agents, provided that they are properly selected, fitted, worn, and maintained. PMID:24011377

  5. Toward integrated strategies for achieving environmental quality

    SciTech Connect

    Kuusinen, T.; Lesperance, A.; Bilyard, G. )

    1994-03-01

    In the United States, environmentalists are constantly jumping from one environmental crisis of the day'' to another without any sense of what is important and what is trivial. Moreover, when designing fixes to the environmental problems one tries to resolve, one often comes up short. This country urgently needs a national environmental strategy that will approach environmental issues proactively and logically. Without such a strategy, the authors believe that long-term, sustainable economic growth cannot be achieved in the United States. This paper outlines a participatory process by which the framework for a national environmental strategy might be developed. It also proposes that such a strategy will likely include two fundamental components: (1) consensus principles for conducting risk assessments to decide what environmental problems are most important, and (2) a generalized, market-oriented model for resolving these problems. A viable national consensus will be required for such a strategy to succeed and will need to include industry, labor, legislators, regulators, national environmental advocacy groups, local grass roots organizations, and other interested parties.

  6. Renewal of Collaborative Research: Economically viable Forest Harvesting Practices that Increase Carbon Sequestration

    SciTech Connect

    Dail, David Bryan

    2012-08-02

    This technical report covers a 3-year cooperative agreement between the University of Maine and the Northeastern Forest Experiment Station that focused on the characterization of forest stands and the assessment of forest carbon storage (see attached for detailed description of the project). The goal of this work was to compare estimates of forest C storage made via remeasurement of FIA-type plots with eddy flux measurements. In addition to relating whole ecosystem estimates of carbon storage to changes in aboveground biomass, we explored methodologies by partitioning growth estimates from periodic inventory measurements into annual estimates. In the final year, we remeasured plots that were subject to a shelterwood harvest over the winter of 2001-02 to assess the production of coarse woody debris by this harvest, to remeasure trees in a long-term stand first established by NASA, to carry out other field activities at Howland, and, to assess the importance of downed and decaying wood as well as standing dead trees to the C inputs to harvested and non harvested plots.

  7. Evidence for viable, non-clonal but fatherless Boa constrictors.

    PubMed

    Booth, Warren; Johnson, Daniel H; Moore, Sharon; Schal, Coby; Vargo, Edward L

    2011-04-23

    Parthenogenesis in vertebrates is considered an evolutionary novelty. In snakes, all of which exhibit genetic sex determination with ZZ : ZW sex chromosomes, this rare form of asexual reproduction has failed to yield viable female WW offspring. Only through complex experimental manipulations have WW females been produced, and only in fish and amphibians. Through microsatellite DNA fingerprinting, we provide the first evidence of facultative parthenogenesis in a Boa constrictor, identifying multiple, viable, non-experimentally induced females for the first time in any vertebrate lineage. Although the elevated homozygosity of the offspring in relation to the mother suggests that the mechanism responsible may be terminal fusion automixis, no males were produced, potentially indicating maternal sex chromosome hemizygosity (WO). These findings provide the first evidence of parthenogenesis in the family Boidae (Boas), and suggest that WW females may be more common within basal reptilian lineages than previously assumed.

  8. Differentiation between Viable and Dead Cryptosporidium Oocysts Using Fluorochrome Staining.

    PubMed

    Tomonaga, Tatsuya; Rai, Shiba Kumar; Uga, Shoji

    2016-01-01

    The use of nucleic acid staining with a fluorochrome dye to differentiate viable and dead (heat-killed) Cryptosporidium oocysts was assessed. The specificities (percentage of unstained viable oocysts) and sensitivities (percentage of stained dead oocysts) of the seven tested dyes (SYTO-17® and SYTO-59® to 64®) ranged from 65 to 76% (average 71%) and 83 to 95% (average 91%), respectively. SYTO-59 and SYTO-17 imparted greater color (4+) intensity than the other dyes (2+ or less). Of these two dyes, SYTO-17 exhibited more brightness and slower discoloration and was selected for use in further experiments. The optimum staining time for SYTO-17 at 37℃ was one hour or more (sensitivity of 96%). Dye concentrations of 20 and 30 µM resulted in maximal color intensity, and no further improvement was observed with further increases in dye concentration. Staining a mixture of viable and dead oocysts (1:1 ratio) with 20 µM dye at 37℃ for one hour yielded the expected results (approximately 50%), but no remarkable increase in the percent staining with time (up to 8 hours) was observed. In this study, no ghost oocysts were observed. The present study indicated that the fluorogenic nucleic acid dye SYTO-17 could be used to discriminate between live and dead Cryptosporidium oocysts. PMID:27363397

  9. Gravitational waves in viable f(R) models

    SciTech Connect

    Yang, Louis; Lee, Chung-Chi; Geng, Chao-Qiang E-mail: geng@phys.nthu.edu.tw

    2011-08-01

    We study gravitational waves in viable f(R) theories under a non-zero background curvature. In general, an f(R) theory contains an extra scalar degree of freedom corresponding to a massive scalar mode of gravitational wave. For viable f(R) models, since there always exits a de-Sitter point where the background curvature in vacuum is non-zero, the mass squared of the scalar mode of gravitational wave is about the de-Sitter point curvature R{sub d} ∼ 10{sup −66}eV{sup 2}. We illustrate our results in two types of viable f(R) models: the exponential gravity and Starobinsky models. In both cases, the mass will be in the order of 10{sup −33}eV when it propagates in vacuum. However, in the presence of matter density in galaxy, the scalar mode can be heavy. Explicitly, in the exponential gravity model, the mass becomes almost infinity, implying the disappearance of the scalar mode of gravitational wave, while the Starobinsky model gives the lowest mass around 10{sup −24}eV, corresponding to the lowest frequency of 10{sup −9} Hz, which may be detected by the current and future gravitational wave probes, such as LISA and ASTROD-GW.

  10. Carbon dioxide-based copolymers: environmental benefits of PPC, an industrially viable catalyst.

    PubMed

    Qin, Yusheng; Wang, Xianhong

    2010-11-01

    Carbon dioxide-based copolymers utilize the green house gas CO(2) and can be applied in research and industry. Here we focus on industrially viable CO(2)-based catalysts in China and beyond. Poly(propylene carbonate) (PPC), an alternating copolymer of CO(2) and propylene oxide, is one of the emerging low-cost biodegradable plastics. We describe the thermal and mechanical performances of as-polymerized PPC, where amorphous state, low glass transition temperature, and biodegradability are the three main properties. We also describe modification of the PPC, the so-called toughening and strengthening at high temperature, and plasticizing at low temperature, including incorporation of a third monomer unit by chemical terpolymerization, and introduction of special intermolecular interactions or crystallizable components by physical blending. The fast development in catalyst design and performance improvement for PPC has created new chances for industry. In particular, high molecular weight PPC from rare earth ternary catalyst is becoming an economically viable biodegradable plastic with tens of thousands of tons produced per year, providing a new solution to overcome the problem of high cost in biodegradable plastics.

  11. Genetic algorithms and the search for viable string vacua

    NASA Astrophysics Data System (ADS)

    Abel, Steven; Rizos, John

    2014-08-01

    Genetic Algorithms are introduced as a search method for finding string vacua with viable phenomenological properties. It is shown, by testing them against a class of Free Fermionic models, that they are orders of magnitude more efficient than a randomised search. As an example, three generation, exophobic, Pati-Salam models with a top Yukawa occur once in every 1010 models, and yet a Genetic Algorithm can find them after constructing only 105 examples. Such non-deterministic search methods may be the only means to search for Standard Model string vacua with detailed phenomenological requirements.

  12. Detection of viable myocardium using coronary angiography and ventriculography.

    PubMed

    Conti, C Richard

    2002-08-01

    In 2002, coronary angiography is the only way to assess precisely the combination of proximal stenoses, distal target vessels, collaterals, microcirculation, and TIMI antegrade flow. At the time of coronary angiography, global LV function is best determined using biplane ventriculography in order to correlate wall motion with coronary stenoses, distal target vessels, microcirculation, collaterals, and antegrade TIMI flow. This can be done under resting conditions after nitrates or after postextrasystolic potentiation. The absolute diagnosis of viability can only be made retrospectively. Large areas of ischemic viable myocardium should improve contraction after revascularization, decrease symptoms, and prolong survival.

  13. Isolation of viable sperm cells from tobacco (Nicotiana tabacum).

    PubMed

    Cao, Y; Reece, A; Russell, S D

    1996-05-01

    Viable sperm cells of Nicotiana tabacum were isolated by the semi-vivo technique. After pollination, excised styles were floated, cut end immersed, in a solution of 15% sucrose with 0.01% boric acid and 0.03% Ca(NO3)2 at 27 degrees C in a growth chamber until pollen tubes emerged. After sperm cells were formed (at least 8 h after pollination) tubes were immersed in a 9% mannitol solution. In this solution, sperm cells are nearly ellipsoidal and retain viability for over 6 h.

  14. Purification Methodology for Viable and Infective Plasmodium vivax Gametocytes That Is Compatible with Transmission-Blocking Assays

    PubMed Central

    Vera, Omaira; Brelas de Brito, Paula; Albrecht, Letusa; Martins-Campos, Keillen Monick; Pimenta, Paulo F. P.; Monteiro, Wuelton M.; Lacerda, Marcus V. G.

    2015-01-01

    Significant progress toward the control of malaria has been achieved, especially regarding Plasmodium falciparum infections. However, the unique biology of Plasmodium vivax hampers current control strategies. The early appearance of P. vivax gametocytes in the peripheral blood and the impossibility of culturing this parasite are major drawbacks. Using blood samples from 40 P. vivax-infected patients, we describe here a methodology to purify viable gametocytes and further infect anophelines. This method opens new avenues to validate transmission-blocking strategies. PMID:26239989

  15. Viable infectious cell sorting in a BSL-3 facility.

    PubMed

    Perfetto, Stephen P; Ambrozak, David R; Roederer, Mario; Koup, Richard A

    2004-01-01

    With the increase in demand for high-speed cell sorting of viable infectious and now therapeutic cell samples, safety concerns for the protection of flow cytometer operators have increased. This chapter describes a quick, sensitive, and reproducible procedure to assure sample containment before sorting these samples. This procedure includes aerosol containment, physical barriers, environmental controls, and personal protection. An aerosol management system produces a negative pressure within the sort chamber where aerosols are vacuumed directly into a HEPA filter. Physical barriers include the manufacturer's standard plastic shield and panels. The flow cytometer is contained in a BSL-3 laboratory for maximum environmental control and the operator is protected using a respiratory system. Containment is measured using highly fluorescent Glo-Germ particles under the same conditions as the cell sort but with the sorter adjusted to produce large amounts of aerosols. These aerosols are collected by a vacuum air sampling system for 10 min in three locations onto a glass slide and examined microscopically. With this system in place, aerosol containment can be measured quickly and efficiently, therefore reducing the risk to the operator when sorting viable infectious cells. PMID:14976381

  16. Production of viable cultures of Flavobacterium psychrophilum: approach and control.

    PubMed

    Michel, C; Antonio, D; Hedrick, R P

    1999-06-01

    Although the fish pathogen Flavobacterium psychrophilum is a major source of concern in salmonid hatcheries, few studies have been conducted on its pathogenicity. Difficulties are often experienced when trying to control or quantify standard procedures for in vitro culture of the bacterium. Plate enumeration and counting chamber enumeration combined with epifluorescent microscopy with fluorescent dyes determined that no more than 25% of the bacterial cells present in the cultures were able to produce colonies on agar media. This was strongly dependent upon different medium components. Tryptone-enriched Anacker and Ordal medium proved more suitable than tryptone-yeast extract-salts with skimmed milk. Adding horse serum and trace elements in controlled proportions offered the most reproducible results. Viable but nonculturable forms were apparently not responsible for the difficulties in production of F. psychrophilum, but the cells were highly susceptible to osmotic conditions. Improvements in the media and careful handling of the bacteria in isotonic suspension media resulted in predictable production of viable bacteria and allowed an absorbance/colony-forming-units relation curve to be established.

  17. Microglia engulf viable newborn cells in the epileptic dentate gyrus.

    PubMed

    Luo, Cong; Koyama, Ryuta; Ikegaya, Yuji

    2016-09-01

    Microglia, which are the brain's resident immune cells, engulf dead neural progenitor cells during adult neurogenesis in the subgranular zone (SGZ) of the dentate gyrus (DG). The number of newborn cells in the SGZ increases significantly after status epilepticus (SE), but whether and how microglia regulate the number of newborn cells after SE remain unclear. Here, we show that microglia rapidly eliminate newborn cells after SE by primary phagocytosis, a process by which viable cells are engulfed, thereby regulating the number of newborn cells that are incorporated into the DG. The number of newborn cells in the DG was increased at 5 days after SE in the adult mouse brain but rapidly decreased to the control levels within a week. During this period, microglia in the DG were highly active and engulfed newborn cells. We found that the majority of engulfed newborn cells were caspase-negative viable cells. Finally, inactivation of microglia with minocycline maintained the increase in the number of newborn cells after SE. Furthermore, minocycline treatment after SE induced the emergence of hilar ectopic granule cells. Thus, our findings suggest that microglia may contribute to homeostasis of the dentate neurogenic niche by eliminating excess newborn cells after SE via primary phagocytosis. GLIA 2016;64:1508-1517.

  18. Measuring Intelligence and Achievement Motivation in Surveys. Appendices 3-6. Describing Research Findings Supplementary to the Final Report to U.S. Department of Health, Education and Welfare, Office of Economic Opportunity.

    ERIC Educational Resources Information Center

    Veroff, Joseph; And Others

    Appendix 3 to the report, Measuring Intelligence and Achievement Motivation in Surveys, describes a series of factor analyses of the achievement orientation measures, and a further analysis of strategies used in trying to interpret them. Also a tentative model for the components of achievement orientation is presented. Appendix 4 describes a…

  19. Specific and rapid enumeration of viable but nonculturable and viable-culturable gram-negative bacteria by using flow cytometry.

    PubMed

    Khan, Mohiuddin M Taimur; Pyle, Barry H; Camper, Anne K

    2010-08-01

    An issue of critical concern in microbiology is the ability to detect viable but nonculturable (VBNC) and viable-culturable (VC) cells by methods other than existing approaches. Culture methods are selective and underestimate the real population, and other options (direct viable count and the double-staining method using epifluorescence microscopy and inhibitory substance-influenced molecular methods) are also biased and time-consuming. A rapid approach that reduces selectivity, decreases bias from sample storage and incubation, and reduces assay time is needed. Flow cytometry is a sensitive analytical technique that can rapidly monitor physiological states of bacteria. This report outlines a method to optimize staining protocols and the flow cytometer (FCM) instrument settings for the enumeration of VBNC and VC bacterial cells within 70 min. Experiments were performed using the FCM to quantify VBNC and VC Escherichia coli O157:H7, Pseudomonas aeruginosa, Pseudomonas syringae, and Salmonella enterica serovar Typhimurium cells after staining with different fluorescent probes: SYTO 9, SYTO 13, SYTO 17, SYTO 40, and propidium iodide (PI). The FCM data were compared with those for specific standard nutrient agar to enumerate the number of cells in different states. By comparing results from cultures at late log phase, 1 to 64% of cells were nonculturable, 40 to 98% were culturable, and 0.7 to 4.5% had damaged cell membranes and were therefore theoretically dead. Data obtained using four different gram-negative bacteria exposed to heat and stained with PI also illustrate the usefulness of the approach for the rapid and unbiased detection of dead versus live organisms.

  20. Intracellular delivery of fluorescent protein into viable wheat microspores using cationic peptides

    PubMed Central

    Bilichak, Andriy; Luu, Justin; Eudes, François

    2015-01-01

    Microspores are specialized generative cells with haploid genome that demonstrate the amenability toward embryogenesis under certain conditions. The induced microspore culture technique is largely exploited by the breeding programs of wheat and other crops due to its high efficiency for generation of the large number of haploid plants in the relatively short period of time. The ability to produce mature double haploid plant from a single cell has also attracted attention of the plant biotechnologists in the past few years. More importantly, the possibility to deliver proteins for improvement of embryogenesis and the genome modification purposes holds great potential for transgene-free wheat biotechnology. In the present study, we examined the ability of cationic and amphipathic cell penetrating peptides (CPPs) to convey a covalently-linked mCherry protein inside the viable microspores. We demonstrate that the affinity of CPPs to the microspore cells dependents on their charge with the highest efficiency of CPP-mCherry binding to the cells achieved by cationic CPPs (penetratin and R9). Additionally, due to overall negative charge of the microspore cell wall, the successful uptake of the protein cargo by live microspore cells is attained by utilization of a reversible disulfide bond between the R9 CPP and mCherry protein. Overall, the approach proposed herein can be applied by the other biotechnology groups for the fast and efficient screening of the different CPP candidates for their ability to deliver proteins inside the viable plant cells. PMID:26379691

  1. Economic analysis

    SciTech Connect

    1980-06-01

    The Energy Policy and Conservation Act (EPCA) mandated that minimum energy efficiency standards be established for classes of refrigerators and refrigerator-freezers, freezers, clothes dryers, water heaters, room air conditioners, home heating equipment, kitchen ranges and ovens, central air conditioners, and furnaces. EPCA requires that standards be designed to achieve the maximum improvement in energy efficiency that is technologically feasible and economically justified. Following the introductory chapter, Chapter Two describes the methodology used in the economic analysis and its relationship to legislative criteria for consumer product efficiency assessment; details how the CPES Value Model systematically compared and evaluated the economic impacts of regulation on the consumer, manufacturer and Nation. Chapter Three briefly displays the results of the analysis and lists the proposed performance standards by product class. Chapter Four describes the reasons for developing a baseline forecast, characterizes the baseline scenario from which regulatory impacts were calculated and summarizes the primary models, data sources and assumptions used in the baseline formulations. Chapter Five summarizes the methodology used to calculate regulatory impacts; describes the impacts of energy performance standards relative to the baseline discussed in Chapter Four. Also discussed are regional standards and other program alternatives to performance standards. Chapter Six describes the procedure for balancing consumer, manufacturer, and national impacts to select standard levels. Details of models and data bases used in the analysis are included in Appendices A through K.

  2. Viable Compositional Analysis of an Eleven Species Oral Polymicrobial Biofilm

    PubMed Central

    Sherry, Leighann; Lappin, Gillian; O'Donnell, Lindsay E.; Millhouse, Emma; Millington, Owain R.; Bradshaw, David J.; Axe, Alyson S.; Williams, Craig; Nile, Christopher J.; Ramage, Gordon

    2016-01-01

    Purpose: Polymicrobial biofilms are abundant in clinical disease, particularly within the oral cavity. Creating complex biofilm models that recapitulate the polymicrobiality of oral disease are important in the development of new chemotherapeutic agents. In order to do this accurately we require the ability to undertake compositional analysis, in addition to determine individual cell viability, which is difficult using conventional microbiology. The aim of this study was to develop a defined multispecies denture biofilm model in vitro, and to assess viable compositional analysis following defined oral hygiene regimens. Methods: An in vitro multispecies denture biofilm containing various oral commensal and pathogenic bacteria and yeast was created on poly (methyl methacrylate) (PMMA). Denture hygiene regimens tested against the biofilm model included brushing only, denture cleansing only and combinational brushing and denture cleansing. Biofilm composition and viability were assessed by culture (CFU) and molecular (qPCR) methodologies. Scanning electron microscopy and confocal laser scanning microscopy were also employed to visualize changes in denture biofilms following treatment. Results: Combinational treatment of brushing and denture cleansing had the greatest impact on multispecies denture biofilms, reducing the number of live cells by more than 2 logs, and altering the overall composition in favor of streptococci. This was even more evident during the sequential testing, whereby daily sequential treatment reduced the total and live number of bacteria and yeast more than those treated intermittently. Bacteria and yeast remaining following treatment tended to aggregate in the pores of the PMMA, proving more difficult to fully eradicate the biofilm. Conclusions: Overall, we are the first to develop a method to enable viable compositional analysis of an 11 species denture biofilm following chemotherapeutic challenge. We were able to demonstrate viable cell

  3. Evaluations of lunar samples for the presence of viable organisms

    NASA Technical Reports Server (NTRS)

    Taylor, G. R.; Wooley, B. C.

    1973-01-01

    Samples from the six successful Apollo lunar exploration missions were examined for the presence of biological formed elements and were used to inoculate a variety of culture media designed to promote growth of a broad spectrum of microorganisms. No evidence of viable organisms was obtained from any of these analyses. Following incubation of the lunar material-culture medium complexes, microbial growth dynamics studies were conducted with known test species to evaluate the possible presence of toxic factors. Only extracts of culture media which had been in contact with a mixture of lunar material from both Apollo 11 core tubes proved to be toxic to all species tested. Attempts to reproduce this toxic effect with individual Apollo 11 core samples obtained at other parts of the core and analyzed under somewhat different conditions were unsuccessful. In all, 48 different lunar samples were examined. These samples were collected at the lunar surface, in trenches, and in core samples to a depth of 297 cm.

  4. A viable logarithmic f(R) model for inflation

    NASA Astrophysics Data System (ADS)

    Amin, M.; Khalil, S.; Salah, M.

    2016-08-01

    Inflation in the framework of f(R) modified gravity is revisited. We study the conditions that f(R) should satisfy in order to lead to a viable inflationary model in the original form and in the Einstein frame. Based on these criteria we propose a new logarithmic model as a potential candidate for f(R) theories aiming to describe inflation consistent with observations from Planck satellite (2015). The model predicts scalar spectral index 0.9615 < ns < 0.9693 in agreement with observation and tensor-to-scalar ratio r of order 10‑3. Furthermore, we show that for a class of models, a natural coupling between inflation and a scalar boson is generated through the minimal coupling between gravity and matter fields and a reheating temperature less that 109 GeV is obtained.

  5. Social Networking and Smart Technology: Viable Environmental Communication Tools…?

    NASA Astrophysics Data System (ADS)

    Montain, J.; Byrne, J. M.

    2010-12-01

    To what extent do popular social networking channels represent a viable means for disseminating information regarding environmental change to the general public? Are new forms of communication such as YouTube™, Facebook™, MySpace™ and Twitter™ and smart devices such as iPhone™ and BlackBerry™ useful and effective in terms motivating people into social action and behavioural modification; or do they simply pay ‘lip service’ to these pressing environmental issues? This project will explore the background connections between social networking and environmental communication and education; and outline why such tools might be an appropriate way to connect to a broad audience in an efficient and unconventional manner. Further, research will survey the current prevalence of reliable environmental change information on social networking Internet-based media; and finally, suggestions for improved strategies and new directions will be provided.

  6. Assessing minimum viable population size: Demography meets population genetics.

    PubMed

    Nunney, L; Campbell, K A

    1993-07-01

    The discussion of a population's minimum viable size provides a focus for the study of ecological and genetic factors that influence the persistence of a threatened population. There are many causes of extinction and the fate of a specific population cannot generally be predicted. This uncertainty has been dealt with in two ways: through stochastic demographic models to determine how to minimize extinction probabilities; and through population genetic theory to determine how best to maintain genetic variation, in the belief that the ability to evolve helps buffer a population against the unknown. Recent work suggests that these two very different approaches lead to very similar conclusions, at least under panmictic conditions. However, defining the ideal spatial distribution for an endangered species remains an important challenge.

  7. Minimum viable population sizes and global extinction risk are unrelated.

    PubMed

    Brook, Barry W; Traill, Lochran W; Bradshaw, Corey J A

    2006-04-01

    Theoretical and empirical work has shown that once reduced in size and geographical range, species face a considerably elevated risk of extinction. We predict minimum viable population sizes (MVP) for 1198 species based on long-term time-series data and model-averaged population dynamics simulations. The median MVP estimate was 1377 individuals (90% probability of persistence over 100 years) but the overall distribution was wide and strongly positively skewed. Factors commonly cited as correlating with extinction risk failed to predict MVP but were able to predict successfully the probability of World Conservation Union Listing. MVPs were most strongly related to local environmental variation rather than a species' intrinsic ecological and life history attributes. Further, the large variation in MVP across species is unrelated to (or at least dwarfed by) the anthropogenic threats that drive the global biodiversity crisis by causing once-abundant species to decline.

  8. Comparison of two viable variants of simian virus 40.

    PubMed Central

    Kay, A C; Rao, G R; Singer, M F

    1978-01-01

    The DNAs of two viable strains of simian virus 40, 776 and 777, have been compared by using restriction endonucleases. Differences between the two strains were detected at five separate points on the simian virus 40 genome. One of these differences, in the region of DNA coding for the major viral coat protein, was confirmed by tryptic peptide analysis of coat proteins from the two strains. Some physiological differences between the two strains were examined and can, in general, be explained by differences observed between the DNAs of the two strains. In addition, defective variants derived from strain 777 interfere more efficiently with the replication of strain 777 than with the replication of strain 776. Images PMID:202746

  9. Generation of viable male and female mice from two fathers.

    PubMed

    Deng, Jian Min; Satoh, Kei; Wang, Hongran; Chang, Hao; Zhang, Zhaoping; Stewart, M David; Cooney, Austin J; Behringer, Richard R

    2011-03-01

    In sexual species, fertilization of oocytes produces individuals with alleles derived from both parents. Here we use pluripotent stem cells derived from somatic cells to combine the haploid genomes from two males to produce viable sons and daughters. Male (XY) mouse induced pluripotent stem cells (Father #1) were used to isolate subclones that had spontaneously lost the Y chromosome to become genetically female (XO). These male-derived XO stem cells were used to generate female chimeras that were bred with genetically distinct males (Father #2), yielding progeny possessing genetic information that was equally derived from both fathers. Thus, functional oocytes can be generated from male somatic cells after reprogramming and spontaneous sex reversal. These findings have novel implications for mammalian reproduction and assisted reproductive technology.

  10. Simultaneous pyometra and viable puppies’ gestation in a bitch

    PubMed Central

    Risso, A.; Pellegrino, F.J.; Corrada, Y.

    2014-01-01

    Here we describe a case of pyometra coexisting with gestation in a 4.5 year-old miniature short-haired Dachshund. The dog exhibited depression, vaginal discharge, polydipsia and dehydration. Ultrasound examination revealed the presence of low to moderate anechoic fluid collection in the left uterine horn. Blood analysis revealed mild neutrophilia with a left shift. Based on these findings a presumptive diagnosis of pyometra was made and the bitch was treated using amoxicillin-clavulanate with dopaminergic agonist (cabergoline). A second ultrasound scan revealed the presence of two gestational vesicles in the right uterine horn that were successfully carried to term. Unusually, while pyometra persisted in the left uterine horn, two viable puppies were delivered by caesarean section from the right uterine horn. PMID:26623344

  11. Production of viable trout offspring derived from frozen whole fish

    PubMed Central

    Lee, Seungki; Seki, Shinsuke; Katayama, Naoto; Yoshizaki, Goro

    2015-01-01

    Long-term preservation of fish fertility is essential for the conservation of endangered fishes. However, cryopreservation techniques for fish oocytes and embryos have not yet been developed. In the present study, functional eggs and sperm were derived from whole rainbow trout that had been frozen in a freezer and stored without the aid of exogenous cryoprotectants. Type A spermatogonia retrieved from frozen-thawed whole trout remained viable after freezing duration up to 1,113 days. Long-term-frozen trout spermatogonia that were intraperitoneally transplanted into triploid salmon hatchlings migrated toward the recipient gonads, where they were incorporated, and proliferated rapidly. Although all triploid recipients that did not undergo transplantation were functionally sterile, 2 of 12 female recipients and 4 of 13 male recipients reached sexual maturity. Eggs and sperm obtained from the salmon recipients were capable of producing donor-derived trout offspring. This methodology is thus a convenient emergency tool for the preservation of endangered fishes. PMID:26522018

  12. Onshore ballast water treatment: a viable option for major ports.

    PubMed

    Pereira, Newton Narciso; Brinati, Hernani Luiz

    2012-11-01

    Ballast water treatment consists of the elimination of exotic species. Currently, the development of alternative methods for this process is directed toward treatment onboard ships. However, we present onshore treatment as a viable alternative for ballast water treatment. We investigated onshore treatment in two iron ore ports with movement capacities of 25 and 90 million tons annually (Mta) that receive 7.5 and 25 million cubic meters annually (Mm(3)) of ballast water, respectively. Discrete event simulation was used as the method of analysis, considering the processes of arrival, berthing, ship loading and capture and treatment of ballast water. We analyzed data from 71 ships operating in these ports to validate our simulation model. We were able to demonstrate that onshore treatment does not impact the cargo capacity, occupation rate or average queuing time of ships at these ports. We concluded that implementation of onshore ballast water treatment may be practicable in ports that receive high volumes of ballast water.

  13. Viable spore counts in biological controls pre-sterilization.

    PubMed

    Brusca, María I; Bernat, María I; Turcot, Liliana; Nastri, Natalia; Nastri, Maria; Rosa, Alcira

    2005-01-01

    The aim of the present study was to evaluate the total count of viable spores in standardized inoculated carriers pre-sterilization. Samples of "Bacterial Spore Sterilization Strip" (R Biological Laboratories) (well before their expiry date) were divided into Group A (B. subtilis) and Group B (B. stearothermophylus). Twenty-four strips were tested per group. The strips were minced in groups of three, placed in chilled sterile water and vortexed for 5 minutes to obtain a homogenous suspension. Ten ml of the homogenous suspension were transferred to two sterile jars, i.e. one jar per group. The samples were then heated in a water bath at 95 degrees C (Group A) or 80 degrees C (Group B) for 15 minutes and cooled rapidly in an ice bath at 0- 4 degrees C during 15 minutes. Successive dilutions were performed until a final aliquot of 30 to 300 colony-forming units (CFU) was obtained. The inoculums were placed in Petri dishes with culture medium (soy extract, casein agar adapted for spores, melted and cooled to 45-50 degrees C) and incubated at 55 degrees C or 37 degrees C. Statistical analysis of the data was performed. A larger number of spores were found at 48 hours than at 24 hours. However, this finding did not hold true for all the groups. The present results show that monitoring viable spores pre-sterilization would guarantee the accuracy of the data. Total spore counts must be within 50 and 300% of the number of spores indicated in the biological control. The procedure is essential to guarantee the efficacy of the biological control. PMID:16673791

  14. A quasi-economic role for lunar science

    SciTech Connect

    Jones, E.M.

    1989-01-01

    In broad economic terms, the development of lunar products will begin with a sequence of technology, production, and delivery demonstrations which will have to precede the emergence of markets. Economically viable products will tend to be those for which the sum of production and transport costs are lower for lunar suppliers than for terrestrial suppliers. As long as lunar production costs exceed terrestrial production costs -- as will be the case for most lunar products until such time as lunar development has reached a mature stage -- the most viable industries will be those producing low-tech products for lunar markets. The scale of initial lunar markets will depend on the size of a lunar base and/or its rate of growth. For a given level of public support, maximum base size can be achieved through the conduct, at the base, of a vigorous program of scientific and engineering research making use of as much local production and as many permanently-resident support staff as feasible. 5 refs.

  15. A fusion-driven subcritical system concept based on viable technologies

    NASA Astrophysics Data System (ADS)

    Wu, Y.; Jiang, J.; Wang, M.; Jin, M.; FDS Team

    2011-10-01

    A fusion-driven hybrid subcritical system (FDS) concept has been designed and proposed as spent fuel burner based on viable technologies. The plasma fusion driver can be designed based on relatively easily achieved plasma parameters extrapolated from the successful operation of existing fusion experimental devices such as the EAST tokamak in China and other tokamaks in the world, and the subcritical fission blanket can be designed based on the well-developed technologies of fission power plants. The simulation calculations and performance analyses of plasma physics, neutronics, thermal-hydraulics, thermomechanics and safety have shown that the proposed concept can meet the requirements of tritium self-sufficiency and sufficient energy gain as well as effective burning of nuclear waste from fission power plants and efficient breeding of nuclear fuel to feed fission power plants.

  16. Arthroscopic fenestration of the distal humerus: a viable option for painful elbow impingement in sportsmen.

    PubMed

    Degreef, Ilse

    2009-10-01

    Open ulnohumeral arthroplasty, also known as the Outerbridge-Kashiwaghi procedure, is performed in elbow arthritis to relieve pain and improve the range of motion. A similar technique of distal humeral fenestration is applied in elbow arthroscopy to achieve pain relief in degenerative elbow arthritis. We report a possible new indication in young sportsmen with recurrent posterior elbow impingement. A professional javelin thrower and a basketball player with recurrent loose bodies, posterior impingement and a minimal extension lack were free of complaints and resumed all sports activities within 6 weeks after an arthroscopic fenestration of the distal humerus. Their elbow function remained perfect within a 2 year follow-up period. We suggest that arthroscopic ulnohumeral arthroplasty is a viable option in sportsmen with recurrent loose bodies and elbow locking due to ongoing elbow arthritis.

  17. Final Report on Head Start Evaluation and Research: 1967-68 to the Office of Economic Opportunity. Section II: Achievement Motivation and Patterns of Reinforcement in Head Start Children.

    ERIC Educational Resources Information Center

    Espinosa, Renato

    Eighty-six Negro and Mexican-American children were divided into experimental and control groups in a study designed to learn the effects of an 8-week summer Head Start program on the achievement motive of these children. The study was based on McClelland's theory of achievement motive and the models of Atkinson and Aronson. Children were…

  18. Towards viable cosmological models of disformal theories of gravity

    NASA Astrophysics Data System (ADS)

    Sakstein, Jeremy

    2015-01-01

    The late-time cosmological dynamics of disformal gravity are investigated using dynamical systems methods. It is shown that in the general case there are no stable attractors that screen fifth forces locally and simultaneously describe a dark energy dominated universe. Viable scenarios have late-time properties that are independent of the disformal parameters and are identical to the equivalent conformal quintessence model. Our analysis reveals that configurations where the Jordan frame metric becomes singular are only reached in the infinite future, thus explaining the natural pathology resistance observed numerically by several previous works. The viability of models where this can happen is discussed in terms of both the cosmological dynamics and local phenomena. We identify a special parameter tuning such that there is a new fixed point that can match the presently observed dark energy density and equation of state. This model is unviable when the scalar couples to the visible sector but may provide a good candidate model for theories where only dark matter is disformally coupled.

  19. Keeping checkpoint/restart viable for exascale systems.

    SciTech Connect

    Riesen, Rolf E.; Bridges, Patrick G.; Stearley, Jon R.; Laros, James H., III; Oldfield, Ron A.; Arnold, Dorian; Pedretti, Kevin Thomas Tauke; Ferreira, Kurt Brian; Brightwell, Ronald Brian

    2011-09-01

    Next-generation exascale systems, those capable of performing a quintillion (10{sup 18}) operations per second, are expected to be delivered in the next 8-10 years. These systems, which will be 1,000 times faster than current systems, will be of unprecedented scale. As these systems continue to grow in size, faults will become increasingly common, even over the course of small calculations. Therefore, issues such as fault tolerance and reliability will limit application scalability. Current techniques to ensure progress across faults like checkpoint/restart, the dominant fault tolerance mechanism for the last 25 years, are increasingly problematic at the scales of future systems due to their excessive overheads. In this work, we evaluate a number of techniques to decrease the overhead of checkpoint/restart and keep this method viable for future exascale systems. More specifically, this work evaluates state-machine replication to dramatically increase the checkpoint interval (the time between successive checkpoint) and hash-based, probabilistic incremental checkpointing using graphics processing units to decrease the checkpoint commit time (the time to save one checkpoint). Using a combination of empirical analysis, modeling, and simulation, we study the costs and benefits of these approaches on a wide range of parameters. These results, which cover of number of high-performance computing capability workloads, different failure distributions, hardware mean time to failures, and I/O bandwidths, show the potential benefits of these techniques for meeting the reliability demands of future exascale platforms.

  20. A Microscopic Multiphase Diffusion Model of Viable Epidermis Permeability

    PubMed Central

    Nitsche, Johannes M.; Kasting, Gerald B.

    2013-01-01

    A microscopic model of passive transverse mass transport of small solutes in the viable epidermal layer of human skin is formulated on the basis of a hexagonal array of cells (i.e., keratinocytes) bounded by 4-nm-thick, anisotropic lipid bilayers and separated by 1-μm layers of extracellular fluid. Gap junctions and tight junctions with adjustable permeabilities are included to modulate the transport of solutes with low membrane permeabilities. Two keratinocyte aspect ratios are considered to represent basal and spinous cells (longer) and granular cells (more flattened). The diffusion problem is solved in a unit cell using a coordinate system conforming to the hexagonal cross section, and an efficient two-dimensional treatment is applied to describe transport in both the cell membranes and intercellular spaces, given their thinness. Results are presented in terms of an effective diffusion coefficient, D¯epi, and partition coefficient, K¯epi/w, for a homogenized representation of the microtransport problem. Representative calculations are carried out for three small solutes—water, L-glucose, and hydrocortisone—covering a wide range of membrane permeability. The effective transport parameters and their microscopic interpretation can be employed within the context of existing three-layer models of skin transport to provide more realistic estimates of the epidermal concentrations of topically applied solutes. PMID:23708370

  1. Rapid isolation of intact, viable fetal cartilage models

    SciTech Connect

    Schmidt, R.R.; Chepenik, K.P.; Paynton, B.V.; Cotler, J.M.

    1982-04-01

    A rapid procedure is described for the isolation of viable, intact, femoral cartilage models (humeri and femora) obtained from pregnant rats on the 18th day of gestation. Viability of these models is demonstrated in an in vitro system where the incorporation of /sup 35/S-sulfate was linear with time of incubation and with numbers of cartilage models utilized. Treatment of cartilage models with ice-cold trichloroacetic acid and a boiling water bath prior to incubation with radiolabel, reduced the amount of radioactivity incorporated to 1.3% of that observed for models incubated by routine procedures. Furthermore, digestion of cartilage model homogenates with protease yielded a supernatant from which 51% to 57% of the radioactivity was precipitated as GAG. This method may also be used to isolate fetal cartilage models as early as the 16th day of gestation. with this system, specific biochemical parameters of mammalian fetal chondrogenesis may be surveyed in normally and abnormally developing fetal cartilage free of surrounding soft tissue.

  2. The elusive minimum viable population size for white sturgeon

    SciTech Connect

    Jager, Yetta; Lepla, Ken B.; Van Winkle, Webb; James, Mr Brad; McAdam, Dr Steve

    2010-01-01

    Biological conservation of sturgeon populations is a concern for many species. Those responsible for managing the white sturgeon (Acipenser transmontanus) and similar species are interested in identifying extinction thresholds to avoid. Two thresholds that exist in theory are the minimum viable population size (MVP) and minimum amount of suitable habitat. In this paper, we present both model and empirical estimates of these thresholds. We modified a population viability analysis (PVA) model for white sturgeon to include two new Allee mechanisms. Despite this, PVA-based MVP estimates were unrealistically low compared with empirical estimates unless opportunities for spawning were assumed to be less frequent. PVA results revealed a trade-off between MVP and habitat thresholds; smaller populations persisted in longer river segments and vice versa. Our empirical analyses suggested (1) a MVP range based on population trends from 1,194 to 27,700 individuals, and (2) a MVP estimate of 4,000 individuals based on recruitment. Long-term historical population surveys are needed for more populations to pinpoint an MVP based on trends, whereas the available data were sufficient to estimate MVP based on recruitment. Beyond the MVP, we developed a hierarchical model for population status based on empirical data. Metapopulation support was the most important predictor of population health, followed by the length of free-flowing habitat, with habitat thresholds at 26 and 150 km. Together, these results suggest that habitat and connectivity are important determinants of population status that likely influence the site-specific MVP thresholds.

  3. Generation of Viable Cell and Biomaterial Patterns by Laser Transfer

    NASA Astrophysics Data System (ADS)

    Ringeisen, Bradley

    2001-03-01

    In order to fabricate and interface biological systems for next generation applications such as biosensors, protein recognition microarrays, and engineered tissues, it is imperative to have a method of accurately and rapidly depositing different active biomaterials in patterns or layered structures. Ideally, the biomaterial structures would also be compatible with many different substrates including technologically relevant platforms such as electronic circuits or various detection devices. We have developed a novel laser-based technique, termed matrix assisted pulsed laser evaporation direct write (MAPLE DW), that is able to direct write patterns and three-dimensional structures of numerous biologically active species ranging from proteins and antibodies to living cells. Specifically, we have shown that MAPLE DW is capable of forming mesoscopic patterns of living prokaryotic cells (E. coli bacteria), living mammalian cells (Chinese hamster ovaries), active proteins (biotinylated bovine serum albumin, horse radish peroxidase), and antibodies specific to a variety of classes of cancer related proteins including intracellular and extracellular matrix proteins, signaling proteins, cell cycle proteins, growth factors, and growth factor receptors. In addition, patterns of viable cells and active biomolecules were deposited on different substrates including metals, semiconductors, nutrient agar, and functionalized glass slides. We will present an explanation of the laser-based transfer mechanism as well as results from our recent efforts to fabricate protein recognition microarrays and tissue-based microfluidic networks.

  4. Megabase deletions of gene deserts result in viable mice

    SciTech Connect

    Nobrega, Marcelo A.; Zhu, Yiwen; Plajzer-Frick, Ingrid; Afzal,Veena; Rubin, Edward M.

    2004-05-01

    The functional importance of the approximately 98 percent of mammalian genomes not corresponding to protein coding sequences remain largely un-scrutinized 1. To test experimentally whether some extensive regions of non-coding DNA, referred to as gene deserts 2-4, contain critical functions essential for the viability of the organism, we deleted two large non-coding intervals, 1,511 kb and 845 kb in length, from the mouse genome. Viable mice homozygous for the deletions were generated and were indistinguishable from wild-type litter mates with regards to morphology, reproductive fitness, growth, longevity and a variety of parameters assaying general homeostasis. Further in-depth analysis of the expression of genes bracketing the deletions revealed similar expression characteristics in homozygous deletion and wild-type mice. Together, the two deleted segments harbour 1,243 non-coding sequences conserved between humans and rodents (>100bp, 70 percent identity). These studies demonstrate that some large-scale deletions of non-coding DNA can be well tolerated by an organism, bringing into question the role of many human-mouse conserved sequences 5,6, and further supports the existence of potentially ''disposable DNAi'' in the genomes of mammals.

  5. Oral vitamin D, still a viable treatment option for psoriasis.

    PubMed

    Kamangar, Faranak; Koo, John; Heller, Misha; Lee, Eric; Bhutani, Tina

    2013-08-01

    Vitamin D as a topical treatment has become one of the mainstays for treatment of psoriasis vulgaris. Oral vitamin D on the other hand has for the most part become a forgotten option. But a review of the literature on oral vitamin D as a treatment for psoriasis reveals that this treatment is efficacious. The main side effect of this therapy is hypercalcemia, which appears to be easily monitored and avoidable with proper dosing and monitoring. The literature also suggests a correlation between low levels of serum vitamin D in this patient population associated with increased severity of disease involvement. In addition, oral vitamin D improves psoriatic arthropathy. Moreover, vitamin D has been proven to have many health benefits such as prevention of cancer, improved cardiovascular health among many others. Psoriatic patients as a population are at increased risk of developing adverse health complications such as cardiovascular disease, and oral vitamin D may prove to be of benefit in this population. Oral vitamin D is inexpensive and easily available. It is still a viable option and should not be forgotten as a possible treatment for psoriasis.

  6. A microscopic multiphase diffusion model of viable epidermis permeability.

    PubMed

    Nitsche, Johannes M; Kasting, Gerald B

    2013-05-21

    A microscopic model of passive transverse mass transport of small solutes in the viable epidermal layer of human skin is formulated on the basis of a hexagonal array of cells (i.e., keratinocytes) bounded by 4-nm-thick, anisotropic lipid bilayers and separated by 1-μm layers of extracellular fluid. Gap junctions and tight junctions with adjustable permeabilities are included to modulate the transport of solutes with low membrane permeabilities. Two keratinocyte aspect ratios are considered to represent basal and spinous cells (longer) and granular cells (more flattened). The diffusion problem is solved in a unit cell using a coordinate system conforming to the hexagonal cross section, and an efficient two-dimensional treatment is applied to describe transport in both the cell membranes and intercellular spaces, given their thinness. Results are presented in terms of an effective diffusion coefficient, D¯(epi), and partition coefficient, K¯(epi/w), for a homogenized representation of the microtransport problem. Representative calculations are carried out for three small solutes-water, L-glucose, and hydrocortisone-covering a wide range of membrane permeability. The effective transport parameters and their microscopic interpretation can be employed within the context of existing three-layer models of skin transport to provide more realistic estimates of the epidermal concentrations of topically applied solutes.

  7. Strategies for promoting a viable rural health care system.

    PubMed

    Moscovice, I

    1989-07-01

    Strategies for promoting a viable rural health care system in the context of the rapidly changing rural health care environment are presented. Also included is a series of guiding principles that support rural health care. They focus on the need for cooperation rather than competition among rural communities and health providers; the need for leadership and empowerment in rural communities; the dependence of rural health on generalists; the need to transform the reimbursement system to reward rural health services; the importance of quality of care for rural providers; the challenge of providing health and social services to the aged; and the instability caused by uncertain government attention to rural concerns. Examples of current activities that exemplify the effective use of these principles with respect to rural hospitals are discussed. These include the proposed demonstration of a new health care institution called the Medical Assistance Facility, the development of rural hospital consortia, the establishment of a rural health care transition grants program, and the activities of the New York State Legislative Commission on Rural Resources.

  8. Al adjuvants can be tracked in viable cells by lumogallion staining.

    PubMed

    Mile, Irene; Svensson, Andreas; Darabi, Anna; Mold, Matthew; Siesjö, Peter; Eriksson, Håkan

    2015-07-01

    The mechanism behind the adjuvant effect of aluminum salts is poorly understood notwithstanding that aluminum salts have been used for decades in clinical vaccines. In an aqueous environment and at a nearly neutral pH, the aluminum salts form particulate aggregates, and one plausible explanation of the lack of information regarding the mechanisms could be the absence of an efficient method of tracking phagocytosed aluminum adjuvants and thereby the intracellular location of the adjuvant. In this paper, we want to report upon the use of lumogallion staining enabling the detection of phagocytosed aluminum adjuvants inside viable cells. Including micromolar concentrations of lumogallion in the culture medium resulted in a strong fluorescence signal from cells that had phagocytosed the aluminum adjuvant. The fluorescence appeared as spots in the cytoplasm and by confocal microscopy and co-staining with probes presenting fluorescence in the far-red region of the spectrum, aluminum adjuvants could to a certain extent be identified as localized in acidic vesicles, i.e., lysosomes. Staining and detection of intracellular aluminum adjuvants was achieved not only by diffusion of lumogallion into the cytoplasm, thereby highlighting the presence of the adjuvant, but also by pre-staining the aluminum adjuvant prior to incubation with cells. Pre-staining of aluminum adjuvants resulted in bright fluorescent particulate aggregates that remained fluorescent for weeks and with only a minor reduction of fluorescence upon extensive washing or incubation with cells. Both aluminum oxyhydroxide and aluminum hydroxyphosphate, two of the most commonly used aluminum adjuvants in clinical vaccines, could be pre-stained with lumogallion and were easily tracked intracellularly after incubation with phagocytosing cells. Staining of viable cells using lumogallion will be a useful method in investigations of the mechanisms behind aluminum adjuvants' differentiation of antigen-presenting cells

  9. Optimized heterologous transfection of viable adult organotypic brain slices using an enhanced gene gun

    PubMed Central

    2013-01-01

    Background Organotypic brain slices (OTBS) are an excellent experimental compromise between the facility of working with cell cultures and the biological relevance of using animal models where anatomical, morphological, and cellular function of specific brain regions can be maintained. The biological characteristics of OTBS can subsequently be examined under well-defined conditions. They do, however, have a number of limitations; most brain slices are derived from neonatal animals, as it is difficult to properly prepare and maintain adult OTBS. There are ample problems with tissue integrity as OTBS are delicate and frequently become damaged during the preparative stages. Notwithstanding these obstacles, the introduced exogenous proteins into both neuronal cells, and cells imbedded within tissues, have been consistently difficult to achieve. Results Following the ex vivo extraction of adult mouse brains, mounted inside a medium-agarose matrix, we have exploited a precise slicing procedure using a custom built vibroslicer. To transfect these slices we used an improved biolistic transfection method using a custom made low-pressure barrel and novel DNA-coated nanoparticles (40 nm), which are drastically smaller than traditional microparticles. These nanoparticles also minimize tissue damage as seen by a significant reduction in lactate dehydrogenase activity as well as propidium iodide (PI) and dUTP labelling compared to larger traditional gold particles used on these OTBS. Furthermore, following EYFP exogene delivery by gene gun, the 40 nm treated OTBS displayed a significantly larger number of viable NeuN and EYFP positive cells. These OTBS expressed the exogenous proteins for many weeks. Conclusions Our described methodology of producing OTBS, which results in better reproducibility with less tissue damage, permits the exploitation of mature fully formed adult brains for advanced neurobiological studies. The novel 40 nm particles are ideal for the viable

  10. Regeneration of viable oil palm plants from protoplasts by optimizing media components, growth regulators and cultivation procedures.

    PubMed

    Masani, Mat Yunus Abdul; Noll, Gundula; Parveez, Ghulam Kadir Ahmad; Sambanthamurthi, Ravigadevi; Prüfer, Dirk

    2013-09-01

    Oil palm protoplasts are suitable as a starting material for the production of oil palm plants with new traits using approaches such as somatic hybridization, but attempts to regenerate viable plants from protoplasts have failed thus far. Here we demonstrate, for the first time, the regeneration of viable plants from protoplasts isolated from cell suspension cultures. We achieved a protoplast yield of 1.14×10(6) per gram fresh weight with a viability of 82% by incubating the callus in a digestion solution comprising 2% cellulase, 1% pectinase, 0.5% cellulase onuzuka R10, 0.1% pectolyase Y23, 3% KCl, 0.5% CaCl2 and 3.6% mannitol. The regeneration of protoplasts into viable plants required media optimization, the inclusion of plant growth regulators and the correct culture technique. Microcalli derived from protoplasts were obtained by establishing agarose bead cultures using Y3A medium supplemented with 10μM naphthalene acetic acid, 2μM 2,4-dichlorophenoxyacetic acid, 2μM indole-3-butyric acid, 2μM gibberellic acid and 2μM 2-γ-dimethylallylaminopurine. Small plantlets were regenerated from microcalli by somatic embryogenesis after successive subculturing steps in medium with limiting amounts of growth regulators supplemented with 200mg/l ascorbic acid.

  11. The detection of viable vegetative cells of Bacillus sporothermodurans using propidium monoazide with semi-nested PCR.

    PubMed

    Cattani, F; Ferreira, C A S; Oliveira, S D

    2013-05-01

    Bacillus sporothermodurans produces highly heat-resistant spores that can survive ultra-high temperature (UHT) treatment in milk. Therefore, we developed a rapid, specific and sensitive semi-nested touchdown PCR assay combined with propidium monoazide (PMA) treatment for the detection of viable B. sporothermodurans vegetative cells. The semi-nested touchdown PCR alone proved to be specific for B. sporothermodurans, and the achieved detection limit was 4 CFU/mL from bacterial culture and artificially contaminated UHT milk. This method combined with PMA treatment was shown to amplify DNA specifically from viable cells and presented a detection limit of 10(2) CFU/mL in UHT milk. The developed PMA-PCR assay shows applicability for the specific detection of viable cells of B. sporothermodurans from UHT milk. This method is of special significance for applications in the food industry by reducing the time required for the analysis of milk and dairy products for the presence of this microorganism.

  12. Gender Disparities and Socio-Economic Factors on Learning Achievements in Agricultural Science in Rural and Urban Secondary Schools of Ogbomoso North Local Government Area of Oyo State, Nigeria

    ERIC Educational Resources Information Center

    Amao, S. R.; Gbadamosi, J.

    2015-01-01

    To contribute to the realization of the Millennium Development Goal (MDG) by the United Nations on the promotion of gender equity, the researchers sought to empirically verify the existence or otherwise of gender inequality in the agricultural and science achievement of urban and rural, male and female students in Ogbomoso North Local Government…

  13. Behavioral economics.

    PubMed

    Camerer, Colin F

    2014-09-22

    Behavioral economics uses evidence from psychology and other social sciences to create a precise and fruitful alternative to traditional economic theories, which are based on optimization. Behavioral economics may interest some biologists, as it shifts the basis for theories of economic choice away from logical calculation and maximization and toward biologically plausible mechanisms.

  14. Graded Achievement, Tested Achievement, and Validity

    ERIC Educational Resources Information Center

    Brookhart, Susan M.

    2015-01-01

    Twenty-eight studies of grades, over a century, were reviewed using the argument-based approach to validity suggested by Kane as a theoretical framework. The review draws conclusions about the meaning of graded achievement, its relation to tested achievement, and changes in the construct of graded achievement over time. "Graded…

  15. Nitrogen fixation at passivated Fe nanoclusters supported by an oxide surface: Identification of viable reaction routes using density functional calculations

    NASA Astrophysics Data System (ADS)

    Šljivančanin, Željko; Brune, Harald; Pasquarello, Alfredo

    2009-08-01

    Using density-functional calculations, we investigate the possibility of ammonia synthesis at supported Fe nanoclusters along catalytic routes closely resembling those in biological nitrogen fixation. To achieve similar catalytic conditions as at the active site of the enzyme nitrogenase, the clusters are passivated with either S or N atoms. From calculated potential-energy profiles for the N2 hydrogenation, we find that low-temperature synthesis of ammonia is viable at the clusters passivated by N atoms due to the strong binding energy of the N2 molecule in the initial adsorption step.

  16. A viable process for producing hydrogen synfuel using nuclear fusion heat

    NASA Astrophysics Data System (ADS)

    Galloway, T. R.; Brown, L. C.

    Analytical and costing analyses of a thermochemical water splitting plant powered by a tandem mirror fusion reactor are presented. Design criteria indicated directing high quality steam to the chemical plant, where no liquid metal coolants would be used. Minimal pumping distances for high pressure He, multiple barriers between the neutron-activated blanket and the hydrogen product, and modular construction where possible are necessary. A He-Brayton topping cycle, coupled to a steam-Rankine bottoming cycle are selected. Slightly over 1111 MWt and about 720 MWe could be produced by the plant if all low grade waste heat is directed to the Rankine cycle. SO3 is used with water for the splitting process, then recombined. H2 is siphoned off as a fuel and O2 is delivered to a coal reforming plant. A 30 yr plant life is projected, operating at a 70% thermal efficiency for the splitting process and producing H2 at $10-12/GJ. The plant is expected to become economically viable in the year 2030 if debt financing is available at 12.25% per year.

  17. n-butanol: challenges and solutions for shifting natural metabolic pathways into a viable microbial production.

    PubMed

    Branduardi, Paola; Porro, Danilo

    2016-04-01

    The economic upturn of the past 200 years would not have been conceivable without fossil resources such as coal and oil. However, the fossil-based economy increasingly reaches its limits and displays contradictions. Bioeconomy, strategically combining economy and ecology willing to make biobased and sustainable growth possible, is promising to make a significant contribution towards solving these issues. In this context, microbial bioconversions are promising to support partially the increasing need for materials and fuels starting from fresh, preferably waste, biomass. Butanol is a very attractive molecule finding applications both as a chemical platform and as a fuel. Today it principally derives from petroleum, but it also represents the final product of microbial catabolic pathways. Because of the need to maximize yield, titer and productivity to make the production competitive and viable, the challenge is to transform a robustly regulated metabolic network into the principal cellular activity. However, this goal can only be accomplished by a profound understanding of the cellular physiology, survival strategy and sensing/signalling cascades. Here, we shortly review on the natural cellular pathways and circumstances that lead to n-butanol accumulation, its physiological consequences that might not match industrial needs and on possible solutions for circumventing these natural constraints. PMID:27020412

  18. Making decentralised systems viable: a guide to managing decentralised assets and risks.

    PubMed

    Willetts, J; Fane, S; Mitchell, C

    2007-01-01

    Decentralised systems have the potential to provide a viable option for long term sustainable management of household wastewater. Yet, at present, such systems hold an uncertain status and are frequently omitted from consideration. Their potential can only be realised with improved approaches to their management, and improved methods to decision-making in planning of wastewater systems. The aim of this paper is to demonstrate the value of a novel framework to guide the planning of decentralised systems so that asset management and risk management are explicitly considered. The framework was developed through a detailed synthesis of literature and practice in the area of asset management of centralised water and wastewater systems, and risk management in the context of decentralised systems. Key aspects of the framework are attention to socio-economic risks as well as engineering, public health and ecological risks, the central place of communication with multiple stakeholders and establishing a shared asset information system. A case study is used to demonstrate how the framework can guide a different approach and lead to different, more sustainable outcomes, by explicitly considering the needs and perspectives of homeowners, water authorities, relevant government agencies and society as a whole.

  19. Making decentralised systems viable: a guide to managing decentralised assets and risks.

    PubMed

    Willetts, J; Fane, S; Mitchell, C

    2007-01-01

    Decentralised systems have the potential to provide a viable option for long term sustainable management of household wastewater. Yet, at present, such systems hold an uncertain status and are frequently omitted from consideration. Their potential can only be realised with improved approaches to their management, and improved methods to decision-making in planning of wastewater systems. The aim of this paper is to demonstrate the value of a novel framework to guide the planning of decentralised systems so that asset management and risk management are explicitly considered. The framework was developed through a detailed synthesis of literature and practice in the area of asset management of centralised water and wastewater systems, and risk management in the context of decentralised systems. Key aspects of the framework are attention to socio-economic risks as well as engineering, public health and ecological risks, the central place of communication with multiple stakeholders and establishing a shared asset information system. A case study is used to demonstrate how the framework can guide a different approach and lead to different, more sustainable outcomes, by explicitly considering the needs and perspectives of homeowners, water authorities, relevant government agencies and society as a whole. PMID:17881850

  20. Combustion aspects of the reapplication of energetic materials as fuels as a viable demil technology

    SciTech Connect

    Baxter, L.; Davis, K.; Sinquefield, S.; Huey, S.; Lipkin, J.; Shah, D.; Ross, J.; Sclippa, G.

    1996-05-01

    This investigation addresses the combustion-related aspects of the reapplication of energetic materials as fuels in boilers as an economically viable and environmentally acceptable use of excess energetic materials. The economics of this approach indicate that the revenues from power generation and chemical recovery approximately equal the costs of boiler modification and changes in operation. The primary tradeoff is the cost of desensitizing the fuels against the cost of open burn/open detonation (OB/OD) or other disposal techniques. Two principal combustion-related obstacles to the use of energetic-material-derived fuels are NO{sub x} generation and the behavior of metals. NO{sub x} measurements obtained in this investigation indicate that the nitrated components (nitrocellulose, nitroglycerin, etc.) of energetic materials decompose with NO{sub x} as the primary product. This can lead to high uncontrolled NO{sub x} levels (as high as 2,600 ppm on a 3% O{sub 2} basis for a 5% blend of energetic material in the fuel). NO{sub x} levels are sensitive to local stoichiometry and temperature. The observed trends resemble those common during the combustion of other nitrogen-containing fuels. Implications for NO{sub x} control strategies are discussed. The behavior of inorganic components in energetic materials tested in this investigation could lead to boiler maintenance problems such as deposition, grate failure, and bed agglomeration. The root cause of the problem is the potentially extreme temperature generated during metal combustion. Implications for furnace selection and operation are discussed.

  1. Supplementary steam - A viable hydrogen power generation concept

    NASA Technical Reports Server (NTRS)

    Wright, D. E.; Lee, J. C.

    1979-01-01

    Technical and economic aspects of a supplementary steam generation for peaking power applications are discussed. Preliminary designs of the hydrogen/oxygen combustors to be used for such applications are described. The integration of the hydrogen/oxygen steam-generating equipment into a typical coal-fired steam station is studied. The basic steam generation system was designed as a 20 MW supplementary system to be added to the existing 160 MW system. An analysis of the operating and design requirements of the supplementary system is conducted. Estimates were made for additional steam and fuel supply lines and for additional control required to operate the combustors and to integrate the combustor system into the facility.

  2. A technique for determining viable military logistics support alternatives

    NASA Astrophysics Data System (ADS)

    Hester, Jesse Stuart

    A look at today's US military will see them operating much beyond the scope of protecting and defending the United States. These operations now consist of, but are not limited to humanitarian aid, disaster relief, peace keeping, and conflict resolution. This broad spectrum of operational environments has necessitated a transformation of the individual military services to a hybrid force that is attempting to leverage the inherent and emerging capabilities and strengths of all those under the umbrella of the Department of Defense (DOD), this concept has been coined Joint Operations. Supporting Joint Operations requires a new approach to determining a viable military logistics support system. The logistics architecture for these operations has to accommodate scale, time, varied mission objectives, and imperfect information. Compounding the problem is the human in the loop (HITL) decision maker (DM) who is a necessary component for quickly assessing and planning logistics support activities. Past outcomes are not necessarily good indicators of future results, but they can provide a reasonable starting point for planning and prediction of specific needs for future requirements. Adequately forecasting the necessary logistical support structure and commodities needed for any resource intensive environment has progressed well beyond stable demand assumptions to one in which dynamic and nonlinear environments can be captured with some degree of fidelity and accuracy. While these advances are important, a holistic approach that allows exploration of the operational environment or design space does not exist to guide the military logistician in a methodical way to support military forecasting activities. To bridge this capability gap, a method called Adaptive Technique for Logistics Architecture Solutions (ATLAS) has been developed. This method provides a process that facilitates the use of techniques and tools that filter and provide relevant information to the DM. By doing

  3. (+)-Sorangicin A: evolution of a viable synthetic strategy

    PubMed Central

    Smith, Amos B.; Dong, Shuzhi; Fox, Richard J; Brenneman, Jehrod B.; Vanecko, John A.; Maegawa, Tomohiro

    2011-01-01

    An effective, asymmetric total synthesis of the antibiotic (+)-sorangicin A (1) has been achieved. Central to this venture was the development of first and second generation syntheses of the signature dioxabicyclo[3.2.1]octane core, the first featuring chemo- and stereoselective epoxide ring openings facilitated by a Co2(CO)6-alkyne complex, the second involving a KHMDS-promoted epoxide ring formation/opening cascade. Additional highlights include effective construction of the dihydro- and tetrahydropyran ring systems, respectively via a stereoselective conjugate addition/α-oxygenation protocol and a thioketalization/hydrostannane reduction sequence. Late-stage achievements entailed two Julia–Kociénski olefinations to unite three advanced fragments with high E-stereoselectivity, followed by a modified Stille protocol to introduce the Z,Z,E trienoate moiety, thereby completing the carbon skeleton. Mukaiyama macrolactonization, followed by carefully orchestrated Lewis and protic acid-promoted deprotections that suppressed isomerization and/or destruction of the sensitive (Z,Z,E)-trienoate linkage completed the first, and to date only, total synthesis of (+)-sorangicin A (1) PMID:22247573

  4. Free space optics: a viable last-mile alternative

    NASA Astrophysics Data System (ADS)

    Willebrand, Heinz A.; Clark, Gerald R.

    2001-10-01

    This paper explores Free Space Optics (FSO) as an access technology in the last mile of metropolitan area networks (MANs). These networks are based in part on fiber-optic telecommunications infrastructure, including network architectures of Synchronous Optical Network (commonly referred to as SONET), the North American standard for synchronous data transmission; and Synchronous Digital Hierarchy (commonly referred to as SDH), the international standard and equivalent of SONET. Several converging forces have moved FSO beyond a niche technology for use only in local area networks (LANs) as a bridge connecting two facilities. FSO now allows service providers to cost effectively provide optical bandwidth for access networks and accelerate the extension of metro optical networks bridging what has been termed by industry experts as the optical dead zone. The optical dead zone refers to both the slowdown in capital investment in the short-term future and the actual connectivity gap that exists today between core metro optical networks and the access optical networks. Service providers have built extensive core and minimal metro networks but have not yet provided optical bandwidth to the access market largely due to the non-compelling economics to bridge the dead zone with fiber. Historically, such infrastructure build-out slowdowns have been blamed on a combination of economics, time-to-market constraints and limited technology options. However, new technology developments and market acceptance of FSO give service providers a new cost-effective alternative to provide high-bandwidth services with optical bandwidth in the access networks. Merrill Lynch predicts FSO will grow into a $2 billion market by 2005. The drivers for this market are a mere 5%- 6% penetration of fiber to business buildings; cost effective solution versus RF or fiber; and significant capacity which can only be matched by a physical fiber link, Merrill Lynch reports. This paper will describe FSO

  5. Total viable bacterial count using a real time all-fibre spectroscopic system.

    PubMed

    Bogomolny, E; Swift, S; Vanholsbeeck, F

    2013-07-21

    Rapid, accurate and sensitive enumeration of bacterial populations in the natural environment is an essential task for many research fields. Widely used standard methods for counting bacteria such as heterotrophic plate count require 1 to 8 days of incubation time for limited accuracy, while more accurate and rapid techniques are often expensive and may require bulky equipment. In the present study, we have developed a computerized optical prototype for bacterial detection. The goal of this research was to estimate the potential of this optical system for Total Viable Bacterial Count in water. For this purpose, we tested water batches with different microbiological content. Bacterial detection was based on fluorescence enhanced by nucleic acid staining. High sensitivity was achieved by a stable diode pumped solid state laser, sensitive CCD spectrometer and in situ excitation and signal collection. The results have shown that the bacterial count from different water origins using our optical setup along with multivariate analysis presents a higher accuracy and a shorter detection time compared to standard methods. For example, in a case where the fluorescence signal is calibrated to the water batch regression line, the relative standard deviation of the optical system enumeration varies between 21 and 36%, while that of the heterotropic plate count counterpart varies between 41 and 59%. In summary, we conclude that the all-fibre optical system may offer the following advantages over conventional methods: near real time examinations, portability, sensitivity, accuracy and ability to detect 10(2) to 10(8) CFU per ml bacterial concentrations.

  6. Cost Savings from Palliative Care Teams and Guidance for a Financially Viable Palliative Care Program

    PubMed Central

    McCarthy, Ian M; Robinson, Chessie; Huq, Sakib; Philastre, Martha; Fine, Robert L

    2015-01-01

    Objectives To quantify the cost savings of palliative care (PC) and identify differences in savings according to team structure, patient diagnosis, and timing of consult. Data Sources Hospital administrative records on all inpatient stays at five hospital campuses from January 2009 through June 2012. Study Design The analysis matched PC patients to non-PC patients (separately by discharge status) using propensity score methods. Weighted generalized linear model regressions of hospital costs were estimated for the matched groups. Data Collection Data were restricted to patients at least 18 years old with inpatient stays of between 7 and 30 days. Variables available included patient demographics, primary and secondary diagnoses, hospital costs incurred for the inpatient stay, and when/if the patient had a PC consult. Principal Findings We found overall cost savings from PC of $3,426 per patient for those dying in the hospital. No significant cost savings were found for patients discharged alive; however, significant cost savings for patients discharged alive could be achieved for certain diagnoses, PC team structures, or if consults occurred within 10 days of admission. Conclusions Appropriately selected and timed PC consults with physician and RN involvement can help ensure a financially viable PC program via cost savings to the hospital. PMID:25040226

  7. Clinically viable magnetic poly(lactide-co-glycolide) (PLGA) particles for MRI-based cell tracking

    PubMed Central

    Granot, Dorit; Nkansah, Michael K.; Bennewitz, Margaret F.; Tang, Kevin S.; Markakis, Eleni A.; Shapiro, Erik M.

    2013-01-01

    Purpose To design, fabricate, characterize and in vivo assay clinically viable magnetic particles for MRI-based cell tracking. Methods PLGA encapsulated magnetic nano- and microparticles were fabricated. Multiple biologically relevant experiments were performed to assess cell viability, cellular performance and stem cell differentiation. In vivo MRI experiments were performed to separately test cell transplantation and cell migration paradigms, as well as in vivo biodegradation. Results Highly magnetic nano- (~100 nm) and microparticles (~1–2 μm) were fabricated. Magnetic cell labeling in culture occurred rapidly achieving 3–50 pg Fe/cell at 3 hrs for different particles types, and >100 pg Fe/cell after 10 hours, without the requirement of a transfection agent, and with no effect on cell viability. The capability of magnetically labeled mesenchymal or neural stem cells to differentiate down multiple lineages, or for magnetically labeled immune cells to release cytokines following stimulation, was uncompromised. An in vivo biodegradation study revealed that NPs degraded ~80% over the course of 12 weeks. MRI detected as few as 10 magnetically labeled cells, transplanted into the brains of rats. Also, these particles enabled the in vivo monitoring of endogenous neural progenitor cell migration in rat brains over 2 weeks. Conclusion The robust MRI properties and benign safety profile of these particles make them promising candidates for clinical translation for MRI-based cell tracking. PMID:23568825

  8. Improving prediction of total viable counts in pork based on hyperspectral scattering technique

    NASA Astrophysics Data System (ADS)

    Tao, Feifei; Peng, Yankun; Song, Yulin; Guo, Hui; Chao, Kuanglin

    2012-05-01

    A hyperspectral scattering technique was investigated for predicting the total viable counts (TVC) of pork in the article. Fresh pork was purchased from a local market and stored at 4°C for 1-15 days. Totally 35 samples were used in the experiment and 2-4 samples were taken out randomly each day for collecting hyperspectral images and reference microbiological tests. Gompertz function was applied to fit the scattering profiles of pork and Teflon, and the fitting results were pretty good in the spectral range of 470-1010 nm. Both individual parameters and integrated parameters were explored to develop the multi-linear regression models for predicting pork TVC, and the results indicated that individual Gompertz parameter α was superior to other individual parameters, while the integrated parameters can perform better. The best result for predicting pork TVC was achieved by the form of (α, β, ɛ), with the RCV of 0.963. The study demonstrated that hyperspectral scattering technique combined with Gompertz function was potential for rapid determination of pork TVC, and would be a valid tool for monitoring the quality and safety attributes of meat in the future.

  9. Status and economics of SRC-I coal liquefaction development

    SciTech Connect

    Tao, J.C.; Jones, J.P. III

    1982-11-01

    The results of commercial plant economic analysis indicate that the SRC-I technology is economically viable in the long-term. To achieve commercialization by the mid-1990s, it is necessary to proceed with the design, construction, and operation of the demonstration plant to prove the technical feasibility, economic viability, and environmental acceptability of the SRC-I technology. Today, synthetic fuels development no longer holds the urgency that elevated it to a position of national prominence a few years ago. However, most analysts agree that the underlying circumstances that will determine the U.S. energy future are unchanged. World oil supplies are dwindling, and the largest source of U.S. petroleum supplies remains one of the most politically volatile regions. In fact, the oil glut proclaimed only a few months ago shows signs of evaporating. Already, spot shortages of crucial energy products have been reported-most notably transportation fuels. The U.S. still has within its borders the largest coal reserves in the free world.

  10. Stimulating Economics

    ERIC Educational Resources Information Center

    Banaian, King

    2009-01-01

    With the current economic slump possibly the deepest since the Great Depression, interest in the subject of macroeconomics has reignited, and the number of students majoring in economics has increased during the last two years. While this would appear to be good news for educators in the economics field, the profession is nervous about more than…

  11. Television Economics.

    ERIC Educational Resources Information Center

    Owen, Bruce M.; And Others

    Intended as an introduction to the economics of commercial television for the general reader, this volume considers the theory and analytical basis of television and the policy implications of those economics. Part I considers the economics of television markets with particular attention of the determinants of viewer markets; the supply of…

  12. Developmental Spelling and Other Language Predictors of Reading Achievement.

    ERIC Educational Resources Information Center

    Robinson, Susan Smith

    A longitudinal study determined if children's invented spelling served as a viable predictor of reading achievement and compared the predictive value of assessing children's invented spelling relative to other notable predictors, such as letter names, letter sounds, a concept of a word, and phonemic awareness. Subjects, 52 kindergarten children…

  13. The economics of dairy production.

    PubMed

    Wolf, Christopher A

    2003-07-01

    structure and regional pattern of dairy farm size and production. For the most part, however, the policy effects have been of indirect nature. The Pacific region has grown (despite having the lowest average price) by taking advantage of economies of size by specializing in milking cows. The United States dairy industry is a technologically advanced, well-managed, and economically important sector of United States agriculture. Future challenges include the ability to remain viable economically while dealing with environmental and social sustainability issues in the form of new constraints from formal policies and from consumer perceptions.

  14. Lipogenic metabolism: a viable target for prostate cancer treatment?

    PubMed

    Liang, Mengmeng; Mulholland, David J

    2014-01-01

    Cancer cells often depend on altered metabolism compared with their normal counterparts. As observed in 1924 by Otto Warburg, cancer cells show preferential glucose consumption by way of aerobic glycolysis while normal cells generally assume mitochondrial oxidative phosphorylation. Another metabolic hallmark of carcinogenesis is altered lipid metabolism, whereby cancer cells may adopt enhanced de novo lipid production (lipogenesis). Enhanced lipid metabolism is also observed in individuals with metabolic syndromes potentially a consequence of increasing popularity of the Standard American Diet, composed of high levels of saturated fats and carbohydrates. A growing body of epidemiological data indicates a positive correlation between the occurrence of metabolic syndromes, such as cardiovascular disease, obesity, type-2 diabetes and associated hyperinsulemia, with the aggressiveness of cancer. Remarkably, it is estimated that for every 1% reduction in saturated fats, replaced by polyunsaturated, there would be a 2%-3% reduction in cardiovascular disease. Thus, it is conceivable that an equally remarkable attenuation in cancer progression might be achieved with such a reduction in lipid accumulation. PMID:24969061

  15. Telestroke a viable option to improve stroke care in India.

    PubMed

    Srivastava, Padma V; Sudhan, Paulin; Khurana, Dheeraj; Bhatia, Rohit; Kaul, Subash; Sylaja, P N; Moonis, Majaz; Pandian, Jeyaraj Durai

    2014-10-01

    In India, stroke care services are not well developed. There is a need to explore alternative options to tackle the rising burden of stroke. Telemedicine has been used by the Indian Space Research Organization (ISRO) to meet the needs of remote hospitals in India. The telemedicine network implemented by ISRO in 2001 presently stretches to around 100 hospitals all over the country, with 78 remote/rural/district health centers connected to 22 specialty hospitals in major cities, thus providing treatment to more than 25 000 patients, which includes stroke patients. Telemedicine is currently used in India for diagnosing stroke patients, subtyping stroke as ischemic or hemorrhagic, and treating accordingly. However, a dedicated telestroke system for providing acute stroke care is needed. Keeping in mind India's flourishing technology sector and leading communication networks, the hub-and-spoke model could work out really well in the upcoming years. Until then, simpler alternatives like smartphones, online data transfer, and new mobile applications like WhatsApp could be used. Telestroke facilities could increase the pool of patients eligible for thrombolysis. But this primary aim of telestroke can be achieved in India only if thrombolysis and imaging techniques are made available at all levels of health care.

  16. Nature's Way of Making Audacious Space Projects Viable

    NASA Technical Reports Server (NTRS)

    Metzger, Philip T.

    2011-01-01

    Building a starship within the next 100 years is an audacious goal. To be successful, we need sustained funding that may be difficult to maintain in the face of economic challenges that are poised to arise during these next 100 years. Our species' civilization has only recently reached the classification as (approximately) Type-I on the Kardashev scale; that is, we have spread out from one small locality to become a global species mastering the energy and resources of an entire planet. In the process we discovered the profound truth that the two-dimensional surface of our world is not flat, but has positive curvature and is closed so that its area and resources are finite. It should come as no surprise to a Type I civilization when its planet's resources dWindle; how could they not? Yet we have gone year by year, government by government, making little investment for the time when civilization becomes violent in the unwelcome contractions that must follow, when we are forced too late into the inevitable choice: to remain and diminish on an unhappy world; or to expand into the only dimension remaining perpendicularly outward from the surface into space. Then some day we may become a Type-II civilization, mastering the resources of an entire solar system. Our species cannot continue as we have on this planet for another 100 years. Doubtless it falls on us today, the very time we intended to start building a starship, to make the late choice. We wished this century to be filled with enlightenment and adventure; it could be an age of desperation and war. What a time to begin an audacious project in space! How will we maintain consistent funding for the next 100 years? Fortunately, saving a civilization, mastering a solar system, and doing other great things like building starships amount to mostly the same set of tasks. Recognizing what we must be about during the next 100 years will make it possible to do them all.

  17. Two-dimensional strain combined with adenosine stress echocardiography assessment of viable myocardium.

    PubMed

    Fang, Ling-Ling; Zhang, Ping-Yang; Wang, Chong; Wang, Li-Ming; Ma, Xiao-Wu; Shi, Hong-Wei; Feng, Xue-Hong

    2011-03-01

    The objective of this study was to explore a new method for the identification of viable myocardium by means of two-dimensional (2D) strain imaging combined with adenosine stress echocardiography. A total of 15 anesthetized open-chest healthy mongrel dogs underwent left anterior descending coronary artery occlusion for 90 min followed by 120-min reperfusion. Adenosine was infused at 140 μg kg(-1) min(-1) over a period of 6 min. Images were acquired at baseline (when pericardial cradle was made), after reperfusion (when reperfusion finished) and after adenosine administration (while administration stopped). Measurements of the regional peak-systolic strain in radial, circumferential, and longitudinal motion on anterior wall and anterior septum were, respectively, performed under different conditions. The dogs were killed after the echocardiographic studies finished and then the area of infracted myocardium was defined by triphenyltetrazolium chloride histology. A segment with equal or less than 50% area of infracted myocardium was considered to be viable. As a result, 37 regions were viable whereas 53 were non-viable among 90 regions in 15 dogs. At baseline, there was no significant difference in peak-systolic radial strain (Rs), circumferential strain (Cs), and longitudinal strain (Ls) between the viable and non-viable groups. After reperfusion, Rs, Cs, and Ls in absolute value decreased compared to those at baseline in both groups, although there was no significant difference between these groups. Rs and Ls increased after adenosine administration compared to reperfusion (p < 0.01; p < 0.05) in viable group while there were no changes in non-viable group. Compared with non-viable group Rs, Cs and Ls in viable group increased significantly (p < 0.01; 0.05) after adenosine administration. There was a negative correlation between Rs and infarct size (r = -0.72). Cs and Ls correlated well with infarct size, respectively (r = 0.40; 0.67). A change of Rs more than 13

  18. Signaling through Rho GTPase pathway as viable drug target.

    PubMed

    Lu, Qun; Longo, Frank M; Zhou, Huchen; Massa, Stephen M; Chen, Yan-Hua

    2009-01-01

    Signaling through the Rho family of small GTPases has been increasingly investigated for their involvement in a wide variety of diseases such as cardiovascular, pulmonary, and neurological disorders as well as cancer. Rho GTPases are a subfamily of the Ras superfamily proteins which play essential roles in a number of biological processes, especially in the regulation of cell shape change, cytokinesis, cell adhesion, and cell migration. Many of these processes demonstrate a common theme: the rapid and dynamic reorganization of actin cytoskeleton of which Rho signaling has now emerged as a major switch control. The involvement of dynamic changes of Rho GTPases in disease states underscores the need to produce effective inhibitors for their therapeutic applications. Fasudil and Y-27632, with many newer additions, are two classes of widely used chemical compounds that inhibit Rho kinase (ROCK), an important downstream effector of RhoA subfamily GTPases. These inhibitors have been successful in many preclinical studies, indicating the potential benefit of clinical Rho pathway inhibition. On the other hand, except for Rac1 inhibitor NSC23766, there are few effective inhibitors directly targeting Rho GTPases, likely due to the lack of optimal structural information on individual Rho-RhoGEF, Rho-RhoGAP, or Rho-RhoGDI interaction to achieve specificity. Recently, LM11A-31 and other derivatives of peptide mimetic ligands for p75 neurotrophin receptor (p75(NTR)) show promising effects upstream of Rho GTPase signaling in neuronal regeneration. CCG-1423, a chemical compound showing profiles of inhibiting downstream of RhoA, is a further attempt for the development of novel pharmacological tools to disrupt Rho signaling pathway in cancer. Because of a rapidly growing number of studies deciphering the role of the Rho proteins in many diseases, specific and potent pharmaceutical modulators of various steps of Rho GTPase signaling pathway are critically needed to target for

  19. Education and Economic Equality

    ERIC Educational Resources Information Center

    Thurow, Lester C.

    1972-01-01

    Argues that the present reliance on education as the ultimate policy for curing all problems, economic and social, is unwarranted at best and in all probability, ineffective. Suggests that any time a consensus emerges on the need for more equality, it can be at least partly achieved by making a frontal attack on wage differentials. (RJ)

  20. Advanced Economic Analysis

    NASA Technical Reports Server (NTRS)

    Greenberg, Marc W.; Laing, William

    2013-01-01

    An Economic Analysis (EA) is a systematic approach to the problem of choosing the best method of allocating scarce resources to achieve a given objective. An EA helps guide decisions on the "worth" of pursuing an action that departs from status quo ... an EA is the crux of decision-support.

  1. Vaccination with hatched but non-activated, non-viable oncospheres of Taenia taeniaeformis in rats.

    PubMed

    Ito, A; Hashimoto, A

    1993-06-01

    The usefulness of hatched but non-activated oncospheres as a candidate vaccine was evaluated using a Taenia taeniaeformis/rat system, since preparation of these oncospheres in vitro is known to be very simple. The findings were: (1) rats vaccinated with non-viable oncospheres became completely resistant to challenge infection; (2) intra-venous injection was the most effective to induce complete resistance; (3) a single oncosphere was sufficient to induce complete resistance in infected rats, whereas approximately 50 and 500 non-viable oncospheres were required to evoke strong and complete resistance, respectively, in vaccinated rats. The usefulness of non-viable oncospheres without adjuvant is discussed.

  2. Estimation of bacterial growth rates from turbidimetric and viable count data.

    PubMed

    Dalgaard, P; Ross, T; Kamperman, L; Neumeyer, K; McMeekin, T A

    1994-11-01

    The relationship between maximum specific growth rates (mu max) determined from viable counts and turbidimetric measurements for a range of bacterial species is examined in order to assess the potential of turbidimetric methods in predictive microbiology. Two methods for the estimation of mu max from turbidimetric data are presented. One is based on absorbance and the other on transmittance measurements. Both are compared to estimates obtained by viable count methods. Calibration factors, a function to correct the non-linearity of absorbance measurements, and variance stabilising transformations for corrected absorbance measurements and for viable count data, are determined. It is concluded that turbidimetric measurements may be used reliably for estimation of mu max.

  3. Sensitive and Specific Biomimetic Lipid Coated Microfluidics to Isolate Viable Circulating Tumor Cells and Microemboli for Cancer Detection

    PubMed Central

    Chen, Jia-Yang; Tsai, Wen-Sy; Shao, Hung-Jen; Wu, Jen-Chia; Lai, Jr-Ming; Lu, Si-Hong; Hung, Tsung-Fu; Yang, Chih-Tsung; Wu, Liang-Chun; Chen, Jinn-Shiun; Lee, Wen-Hwa; Chang, Ying-Chih

    2016-01-01

    Here we presented a simple and effective membrane mimetic microfluidic device with antibody conjugated supported lipid bilayer (SLB) “smart coating” to capture viable circulating tumor cells (CTCs) and circulating tumor microemboli (CTM) directly from whole blood of all stage clinical cancer patients. The non-covalently bound SLB was able to promote dynamic clustering of lipid-tethered antibodies to CTC antigens and minimized non-specific blood cells retention through its non-fouling nature. A gentle flow further flushed away loosely-bound blood cells to achieve high purity of CTCs, and a stream of air foam injected disintegrate the SLB assemblies to release intact and viable CTCs from the chip. Human blood spiked cancer cell line test showed the ~95% overall efficiency to recover both CTCs and CTMs. Live/dead assay showed that at least 86% of recovered cells maintain viability. By using 2 mL of peripheral blood, the CTCs and CTMs counts of 63 healthy and colorectal cancer donors were positively correlated with the cancer progression. In summary, a simple and effective strategy utilizing biomimetic principle was developed to retrieve viable CTCs for enumeration, molecular analysis, as well as ex vivo culture over weeks. Due to the high sensitivity and specificity, it is the first time to show the high detection rates and quantity of CTCs in non-metastatic cancer patients. This work offers the values in both early cancer detection and prognosis of CTC and provides an accurate non-invasive strategy for routine clinical investigation on CTCs. PMID:26938471

  4. Behavioral Economics

    PubMed Central

    Reed, Derek D.; Niileksela, Christopher R.; Kaplan, Brent A.

    2013-01-01

    In recent years, behavioral economics has gained much attention in psychology and public policy. Despite increased interest and continued basic experimental studies, the application of behavioral economics to therapeutic settings remains relatively sparse. Using examples from both basic and applied studies, we provide an overview of the principles comprising behavioral economic perspectives and discuss implications for behavior analysts in practice. A call for further translational research is provided. PMID:25729506

  5. Establishment of a Viable Population of Red-Cockaded Woodpeckers at the Savannah River Site

    SciTech Connect

    Johnston, P.A.

    2002-01-14

    Report on program's objective to restore viable population of Red-cockaded woodpecker at SRS. Several management strategies were used to promote population expansion of Red-cockaded woodpecker and reduction of interspecific competition with Red-Cockaded woodpecker.

  6. Near Real-Time Quantitation of Viable Microorganisms for Planetary Protection and Crew Health

    NASA Astrophysics Data System (ADS)

    Wainwright, N. R.

    2015-03-01

    For planetary protection and crew health, the knowledge of when minimal acceptable levels of microbial contamination are exceeded is critical. We have developed an instrument and procedures to detect as few as one viable organism under 1 hour.

  7. Exploring the Space of Viable Configurations in a Model of Metabolism-Boundary Co-construction.

    PubMed

    Agmon, Eran; Gates, Alexander J; Churavy, Valentin; Beer, Randall D

    2016-01-01

    We introduce a spatial model of concentration dynamics that supports the emergence of spatiotemporal inhomogeneities that engage in metabolism-boundary co-construction. These configurations exhibit disintegration following some perturbations, and self-repair in response to others. We define robustness as a viable configuration's tendency to return to its prior configuration in response to perturbations, and plasticity as a viable configuration's tendency to change to other viable configurations. These properties are demonstrated and quantified in the model, allowing us to map a space of viable configurations and their possible transitions. Combining robustness and plasticity provides a measure of viability as the average expected survival time under ongoing perturbation, and allows us to measure how viability is affected as the configuration undergoes transitions. The framework introduced here is independent of the specific model we used, and is applicable for quantifying robustness, plasticity, and viability in any computational model of artificial life that demonstrates the conditions for viability that we promote. PMID:26934090

  8. 30 CFR 203.67 - What economic criteria must I meet to get royalty relief on an authorized field or project?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... and Expansion Projects § 203.67 What economic criteria must I meet to get royalty relief on an... the field, development project, or expansion project economically viable. Your field or project...

  9. Comparing Science Achievement Constructs: Targeted and Achieved

    ERIC Educational Resources Information Center

    Ferrara, Steve; Duncan, Teresa

    2011-01-01

    This article illustrates how test specifications based solely on academic content standards, without attention to other cognitive skills and item response demands, can fall short of their targeted constructs. First, the authors inductively describe the science achievement construct represented by a statewide sixth-grade science proficiency test.…

  10. Economic Realities.

    ERIC Educational Resources Information Center

    Van Alstyne, Carol

    Concerns relating to the economics of higher education, including inflation, are considered. It is suggested that future sources of rising costs are energy, equipment, books, and federal requirements, and that another major economic concern involves trends in enrollments and in tuition revenues. Projections of declining enrollments should be…

  11. Re-engineering NASA's space communications to remain viable in a constrained fiscal environment

    NASA Technical Reports Server (NTRS)

    Hornstein, Rhoda Shaller; Hei, Donald J., Jr.; Kelly, Angelita C.; Lightfoot, Patricia C.; Bell, Holland T.; Cureton-Snead, Izeller E.; Hurd, William J.; Scales, Charles H.

    1994-01-01

    Along with the Red and Blue Teams commissioned by the NASA Administrator in 1992, NASA's Associate Administrator for Space Communications commissioned a Blue Team to review the Office of Space Communications (Code O) Core Program and determine how the program could be conducted faster, better, and cheaper. Since there was no corresponding Red Team for the Code O Blue Team, the Blue Team assumed a Red Team independent attitude and challenged the status quo, including current work processes, functional distinctions, interfaces, and information flow, as well as traditional management and system development practices. The Blue Team's unconstrained, non-parochial, and imaginative look at NASA's space communications program produced a simplified representation of the space communications infrastructure that transcends organizational and functional boundaries, in addition to existing systems and facilities. Further, the Blue Team adapted the 'faster, better, cheaper' charter to be relevant to the multi-mission, continuous nature of the space communications program and to serve as a gauge for improving customer services concurrent with achieving more efficient operations and infrastructure life cycle economies. This simplified representation, together with the adapted metrics, offers a future view and process model for reengineering NASA's space communications to remain viable in a constrained fiscal environment. Code O remains firm in its commitment to improve productivity, effectiveness, and efficiency. In October 1992, the Associate Administrator reconstituted the Blue Team as the Code O Success Team (COST) to serve as a catalyst for change. In this paper, the COST presents the chronicle and significance of the simplified representation and adapted metrics, and their application during the FY 1993-1994 activities.

  12. Re-engineering NASA's space communications to remain viable in a constrained fiscal environment

    NASA Astrophysics Data System (ADS)

    Hornstein, Rhoda Shaller; Hei, Donald J., Jr.; Kelly, Angelita C.; Lightfoot, Patricia C.; Bell, Holland T.; Cureton-Snead, Izeller E.; Hurd, William J.; Scales, Charles H.

    1994-11-01

    Along with the Red and Blue Teams commissioned by the NASA Administrator in 1992, NASA's Associate Administrator for Space Communications commissioned a Blue Team to review the Office of Space Communications (Code O) Core Program and determine how the program could be conducted faster, better, and cheaper. Since there was no corresponding Red Team for the Code O Blue Team, the Blue Team assumed a Red Team independent attitude and challenged the status quo, including current work processes, functional distinctions, interfaces, and information flow, as well as traditional management and system development practices. The Blue Team's unconstrained, non-parochial, and imaginative look at NASA's space communications program produced a simplified representation of the space communications infrastructure that transcends organizational and functional boundaries, in addition to existing systems and facilities. Further, the Blue Team adapted the 'faster, better, cheaper' charter to be relevant to the multi-mission, continuous nature of the space communications program and to serve as a gauge for improving customer services concurrent with achieving more efficient operations and infrastructure life cycle economies. This simplified representation, together with the adapted metrics, offers a future view and process model for reengineering NASA's space communications to remain viable in a constrained fiscal environment. Code O remains firm in its commitment to improve productivity, effectiveness, and efficiency. In October 1992, the Associate Administrator reconstituted the Blue Team as the Code O Success Team (COST) to serve as a catalyst for change. In this paper, the COST presents the chronicle and significance of the simplified representation and adapted metrics, and their application during the FY 1993-1994 activities.

  13. Koranic Education Centres: A viable educational alternative for the disadvantaged learner in Sahel Africa?

    NASA Astrophysics Data System (ADS)

    Bah-Lalya, Ibrahima

    2015-08-01

    Within the international momentum for achieving Education for All (EFA) and the Millennium Development Goals (MDGs), many African countries have made considerable progress during the last decade in terms of access to basic education. However, a significant number of children enrolled in the early grades of primary schools either repeat classes or drop out and never graduate. Moreover, there are currently about 30 million school-age children in sub-Saharan Africa who have never attended any form of schooling. In view of this situation, sub-Saharan African countries have been looking for alternative options to educate those who have not been accounted for in the formal school system. This note considers informal Koranic Education Centres (KECs) which are trying to fill the gap of schooling in the Sahel-Saharan strip. The author looks at the challenges this form of schooling faces and at how to meet them efficiently. He sounds out the possibility of using KECs to cater for those who have been left aside by formal schooling. Based on existing studies, data compiled by educational systems and a study conducted by the Working Group on Non-Formal Education (WGNFE) of the Association for the Development of Education in Africa (ADEA) in four West African countries (Burkina Faso, Mali, Mauritania and Senegal) in 2013, the author of this research note came to the conclusion that a holistic approach, where the two systems (the Koranic and the formal) collaborate and support one another, could effectively contribute to alleviating the dropout predicament and to reducing the number of unschooled children. It could offer a second-chance opportunity to dropout and unschooled children in the Sahel and Saharan zone. However, before this can become a viable alternative, a number of major challenges need to be addressed. Through its WGNFE, ADEA intends to further investigate the holistic approach of combining formal "modern" and informal "Koranic" schooling to come up with tangible

  14. Mobility and Reading Achievement.

    ERIC Educational Resources Information Center

    Waters, Theresa Z.

    A study examined the effect of geographic mobility on elementary school students' achievement. Although such mobility, which requires students to make multiple moves among schools, can have a negative impact on academic achievement, the hypothesis for the study was that it was not a determining factor in reading achievement test scores. Subjects…

  15. 7 CFR 4280.15 - Ultimate Recipient Projects eligible for Rural Economic Development Loan funding.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... AGRICULTURE LOANS AND GRANTS Rural Economic Development Loan and Grant Programs § 4280.15 Ultimate Recipient Projects eligible for Rural Economic Development Loan funding. An Intermediary may receive REDL funds only... Recipient to finance financially viable economic development or job creation Projects in a Rural Area....

  16. 7 CFR 4280.15 - Ultimate Recipient Projects eligible for Rural Economic Development Loan funding.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AGRICULTURE LOANS AND GRANTS Rural Economic Development Loan and Grant Programs § 4280.15 Ultimate Recipient Projects eligible for Rural Economic Development Loan funding. An Intermediary may receive REDL funds only... Recipient to finance financially viable economic development or job creation Projects in a Rural Area....

  17. 7 CFR 4280.15 - Ultimate Recipient Projects eligible for Rural Economic Development Loan funding.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AGRICULTURE LOANS AND GRANTS Rural Economic Development Loan and Grant Programs § 4280.15 Ultimate Recipient Projects eligible for Rural Economic Development Loan funding. An Intermediary may receive REDL funds only... Recipient to finance financially viable economic development or job creation Projects in a Rural Area....

  18. 7 CFR 4280.15 - Ultimate Recipient Projects eligible for Rural Economic Development Loan funding.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AGRICULTURE LOANS AND GRANTS Rural Economic Development Loan and Grant Programs § 4280.15 Ultimate Recipient Projects eligible for Rural Economic Development Loan funding. An Intermediary may receive REDL funds only... Recipient to finance financially viable economic development or job creation Projects in a Rural Area....

  19. 7 CFR 4280.15 - Ultimate Recipient Projects eligible for Rural Economic Development Loan funding.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AGRICULTURE LOANS AND GRANTS Rural Economic Development Loan and Grant Programs § 4280.15 Ultimate Recipient Projects eligible for Rural Economic Development Loan funding. An Intermediary may receive REDL funds only... Recipient to finance financially viable economic development or job creation Projects in a Rural Area....

  20. Recovery of Viable Bacteria from Probiotic Products that Target Oral Health

    PubMed Central

    Banas, Jeffrey A.; Popp, Eric T.

    2013-01-01

    Probiotic therapy has predominantly been directed toward promoting and maintaining intestinal health. In recent years, however, probiotic regimens that target oral health have appeared on the market. These regimens are often delivered in the form of lozenges. Despite the oral health claims made by the manufacturers of these products, there is little independent evidence in the literature to support such claims. In theory, probiotic organisms can be beneficial by several different means including direct inhibition of pathogens and boosting of the host immune response, with the underlying assumption that these mechanisms require a critical number of viable organisms. In this study, five brands of probiotics marketed for oral health were tested for the recovery of viable bacteria. For only one brand could viable bacteria be recovered within one log of the manufacturer’s stated starting amount of bacteria. Nearly a billion viable bacteria could be recovered from a lozenge of this brand. The other brands claimed similar starting amounts of bacteria at the time of manufacture but at least a three-log drop off was observed in the amount of viable bacteria recovered from those products. Refrigeration of the probiotics significantly improved the recovery for one brand, but recoveries for all but one brand remained below the recommended daily dosage for probiotic regimens. It is concluded that probiotic brands differ significantly in the quantities of bacteria that remain viable with most failing to meet recommended dosage targets. PMID:24015157

  1. Recovery of Viable Bacteria from Probiotic Products that Target Oral Health.

    PubMed

    Banas, Jeffrey A; Popp, Eric T

    2013-09-01

    Probiotic therapy has predominantly been directed toward promoting and maintaining intestinal health. In recent years, however, probiotic regimens that target oral health have appeared on the market. These regimens are often delivered in the form of lozenges. Despite the oral health claims made by the manufacturers of these products, there is little independent evidence in the literature to support such claims. In theory, probiotic organisms can be beneficial by several different means including direct inhibition of pathogens and boosting of the host immune response, with the underlying assumption that these mechanisms require a critical number of viable organisms. In this study, five brands of probiotics marketed for oral health were tested for the recovery of viable bacteria. For only one brand could viable bacteria be recovered within one log of the manufacturer's stated starting amount of bacteria. Nearly a billion viable bacteria could be recovered from a lozenge of this brand. The other brands claimed similar starting amounts of bacteria at the time of manufacture but at least a three-log drop off was observed in the amount of viable bacteria recovered from those products. Refrigeration of the probiotics significantly improved the recovery for one brand, but recoveries for all but one brand remained below the recommended daily dosage for probiotic regimens. It is concluded that probiotic brands differ significantly in the quantities of bacteria that remain viable with most failing to meet recommended dosage targets. PMID:24015157

  2. Correlation of direct viable counts with heterotrophic activity for marine bacteria.

    PubMed

    Kogure, K; Simidu, U; Taga, N; Colwell, R R

    1987-10-01

    Viable-bacteria counts, heterotrophic activity, and substrate responsiveness of viable bacteria have been used to measure microbial activity. However, the relationship between these parameters is not clear. Thus, the direct viable count (DVC) method was used to analyze seawater samples collected from several different geographical locations. Samples collected from offshore waters of the South China Sea and western Pacific Ocean yielded DVC that indicated the presence of surface and subsurface peaks of viable, substrate-responsive bacteria which could be correlated with turnover rates of amino acids obtained by using uniformly C-labeled amino acids. DVC were always less than total viable counts (acridine orange direct counts), and the DVC subsurface peak occurred close to and within the chlorophyll a zone, suggesting algal-bacterial interactions within the layer. For comparison with the open-ocean samples, selected substrates were used to determine the response of viable bacteria present in seawater samples collected near an ocean outfall of the Barceloneta Regional Waste Treatment Plant, Barceloneta, Puerto Rico. The number of specific substrate-responsive bacteria at the outfall stations varied depending on the substrate used and the sampling location. Changes in the population size or physiological condition of the bacteria were detected and found to be associated with the presence of pharmaceutical waste.

  3. Is a computer-assisted design and computer-assisted manufacturing method for mandibular reconstruction economically viable?

    PubMed

    Tarsitano, Achille; Battaglia, Salvatore; Crimi, Salvatore; Ciocca, Leonardo; Scotti, Roberto; Marchetti, Claudio

    2016-07-01

    The design and manufacture of patient-specific mandibular reconstruction plates, particularly in combination with cutting guides, has created many new opportunities for the planning and implementation of mandibular reconstruction. Although this surgical method is being used more widely and the outcomes appear to be improved, the question of the additional cost has to be discussed. To evaluate the cost generated by the management of this technology, we studied a cohort of patients treated for mandibular neoplasms. The population was divided into two groups of 20 patients each who were undergoing a 'traditional' freehand mandibular reconstruction or a computer-aided design/computer-aided manufacturing (CAD-CAM) mandibular reconstruction. Data concerning operation time, complications, and days of hospitalisation were used to evaluate costs related to the management of these patients. The mean operating time for the CAD-CAM group was 435 min, whereas that for the freehand group was 550.5 min. The total difference in terms of average time gain was 115.5 min. No microvascular complication occurred in the CAD-CAM group; two complications (10%) were observed in patients undergoing freehand reconstructions. The mean overall lengths of hospital stay were 13.8 days for the CAD-CAM group and 17 days for the freehand group. Finally, considering that the institutional cost per minute of theatre time is €30, the money saved as a result of the time gained was €3,450. This cost corresponds approximately to the total price of the CAD-CAM surgery. In conclusion, we believe that CAD-CAM technology for mandibular reconstruction will become a widely used reconstructive method and that its cost will be covered by gains in terms of surgical time, quality of reconstruction, and reduced complications.

  4. Ecological economics and economic growth.

    PubMed

    Victor, Peter A

    2010-01-01

    Boulding's 1966 paper on the economics of spaceship Earth established the framework for ecological economics and an understanding of economic growth. In ecological economics, economies are conceptualized as open subsystems of the closed biosphere and are subject to biophysical laws and constraints. Economic growth measured as an increase in real gross domestic product (GDP) has generally been associated with increases in the use of energy and materials and the generation of wastes. Scale, composition, and technology are the proximate determinants of environmental impacts. They are often reduced to two: scale (GDP) and intensity (impact per unit GDP). New work described in this paper defines "green" growth as intensity that declines faster than scale increases. Similarly, "brown" growth occurs when intensity declines more slowly than increases in scale, and "black" growth happens when both scale and intensity increase. These concepts are then related to the environmental Kuznets curve, which can be understood as a transition from brown to green growth. Ecological economics provides a macroperspective on economic growth. It offers broad policy principles, and it challenges the primacy of economic growth as a policy objective, but many important questions remain.

  5. Resource Economics

    NASA Astrophysics Data System (ADS)

    Conrad, Jon M.

    1999-10-01

    Resource Economics is a text for students with a background in calculus, intermediate microeconomics, and a familiarity with the spreadsheet software Excel. The book covers basic concepts, shows how to set up spreadsheets to solve dynamic allocation problems, and presents economic models for fisheries, forestry, nonrenewable resources, stock pollutants, option value, and sustainable development. Within the text, numerical examples are posed and solved using Excel's Solver. Through these examples and additional exercises at the end of each chapter, students can make dynamic models operational, develop their economic intuition, and learn how to set up spreadsheets for the simulation of optimization of resource and environmental systems.

  6. North Sea report. Economics crucial in UK projects

    SciTech Connect

    Not Available

    1983-09-01

    In developing the large discoveries that turned the North Sea into an oil province, it was enough of a problem to find technical solutions to the problems posed by the environment without worrying whether they might be the most inexpensive. Now that fields are smaller, and proportionally up to 10 times more expensive to develop, the pressure is to find technical solutions which can be applied economically. With an oil price that seems likely to remain no more than static in real terms, the oil industry can no longer rely on a rising price for its product to convert marginal prospects into viable development projects. The recent UK government tax measures to encourage new development have resulted in the reassessment of numerous projects. However, it is clear that before many of these become economic, significant savings must be made in development costs. This need is highlighted in a discussion of the potential Shell/Esso development of a cluster of small fields in the central North Sea. With the help of the new package and improved technology, such a project could be possible now, but it requires improvements in costs over even second generation developments such as North Cormorant and Fulmar. Further cost reductions of 15% are considered realistic and achievable.

  7. Spatially dynamic forest management to sustain biodiversity and economic returns.

    PubMed

    Mönkkönen, Mikko; Juutinen, Artti; Mazziotta, Adriano; Miettinen, Kaisa; Podkopaev, Dmitry; Reunanen, Pasi; Salminen, Hannu; Tikkanen, Olli-Pekka

    2014-02-15

    Production of marketed commodities and protection of biodiversity in natural systems often conflict and thus the continuously expanding human needs for more goods and benefits from global ecosystems urgently calls for strategies to resolve this conflict. In this paper, we addressed what is the potential of a forest landscape to simultaneously produce habitats for species and economic returns, and how the conflict between habitat availability and timber production varies among taxa. Secondly, we aimed at revealing an optimal combination of management regimes that maximizes habitat availability for given levels of economic returns. We used multi-objective optimization tools to analyze data from a boreal forest landscape consisting of about 30,000 forest stands simulated 50 years into future. We included seven alternative management regimes, spanning from the recommended intensive forest management regime to complete set-aside of stands (protection), and ten different taxa representing a wide variety of habitat associations and social values. Our results demonstrate it is possible to achieve large improvements in habitat availability with little loss in economic returns. In general, providing dead-wood associated species with more habitats tended to be more expensive than providing requirements for other species. No management regime alone maximized habitat availability for the species, and systematic use of any single management regime resulted in considerable reductions in economic returns. Compared with an optimal combination of management regimes, a consistent application of the recommended management regime would result in 5% reduction in economic returns and up to 270% reduction in habitat availability. Thus, for all taxa a combination of management regimes was required to achieve the optimum. Refraining from silvicultural thinnings on a proportion of stands should be considered as a cost-effective management in commercial forests to reconcile the conflict

  8. Barometers of Black Economic Achievement: the Reality and the Myth.

    ERIC Educational Resources Information Center

    Hurst, Beverly

    A comprehensive report on black employment in Chicago over the last decade is described. Employment, income, occupation, and industry are the four barometers analyzed. One finding of this analysis is that the proportion of unemployed blacks is twice that of whites. Both in Chicago and in the rest of the country, the dollar gap between median white…

  9. Cleaner Cooking Solutions to Achieve Health, Climate, and Economic Cobenefits

    EPA Science Inventory

    Nearly half the world’s population has to rely on solid fuels such as biomass (wood, charcoal, agricultural residues, and animal dung) and coal for household energy, burning them in inefficient open fires and stoves with inadequate ventilation. Household solid fuel combustion is...

  10. An Analysis of How Multicultural Adult Orphans Achieve Economic Success

    ERIC Educational Resources Information Center

    Simonee, Saundra W.

    2014-01-01

    Successful multicultural adult orphans who were not adopted pose an interesting challenge in their history, their physical, psychological, social emotional and personal identity development. One must understand their journey from orphanhood to adulthood and their current prominent status in life to build a contextualized personal story (Banks,…

  11. Ecological Economics

    NASA Astrophysics Data System (ADS)

    Common, Michael; Stagl, Sigrid

    2005-10-01

    Taking as its starting point the interdependence of the economy and the natural environment, this book provides a comprehensive introduction to the emerging field of ecological economics. The authors, who have written extensively on the economics of sustainability, build on insights from both mainstream economics and ecological sciences. Part I explores the interdependence of the modern economy and its environment, while Part II focuses mainly on the economy and on economics. Part III looks at how national governments set policy targets and the instruments used to pursue those targets. Part IV examines international trade and institutions, and two major global threats to sustainability - climate change and biodiversity loss. Assuming no prior knowledge of economics, this textbook is well suited for use on interdisciplinary environmental science and management courses. It has extensive student-friendly features including discussion questions and exercises, keyword highlighting, real-world illustrations, further reading and website addresses. A comprehensive introduction to a developing field which will interest students from science, economics and management backgrounds A global approach to the problems of sustainability and sustainable development, issues which are increasingly prominent in political debate and policy making Filled with student-friendly features including focus areas for each chapter, keyword highlighting, real-world illustrations, discussion questions and exercises, further reading and website addresses

  12. Behavioral economics.

    PubMed

    Hursh, S R

    1984-11-01

    Economics, like behavioral psychology, is a science of behavior, albeit highly organized human behavior. The value of economic concepts for behavioral psychology rests on (1) their empirical validity when tested in the laboratory with individual subjects and (2) their uniqueness when compared to established behavioral concepts. Several fundamental concepts are introduced and illustrated by reference to experimental data: open and closed economies, elastic and inelastic demand, and substitution versus complementarity. Changes in absolute response rate are analyzed in relation to elasticity and intensity of demand. The economic concepts of substitution and complementarity are related to traditional behavioral studies of choice and to the matching relation. The economic approach has many implications for the future of behavioral research and theory. In general, economic concepts are grounded on a dynamic view of reinforcement. The closed-economy methodology extends the generality of behavioral principles to situations in which response rate and obtained rate of reinforcement are interdependent. Analysis of results in terms of elasticity and intensity of demand promises to provide a more direct method for characterizing the effects of "motivational" variables. Future studies of choice should arrange heterogeneous reinforcers with varying elasticities, use closed economies, and modulate scarcity or income. The economic analysis can be extended to the study of performances that involve subtle discriminations or skilled movements that vary in accuracy or quality as opposed to rate or quantity, and thus permit examination of time/accuracy trade-offs.

  13. Economic targeting in modern warfare

    SciTech Connect

    Lambeth, B.S.; Lewis, K.N.

    1982-07-01

    Nuclear weapons and strategies for their use play a variety of roles in the defense and foreign policies of the United States and Soviet Union. Accordingly, both nations buy forces and prepare war plans for many purposes. Although it is perhaps the least likely contingency for which either country prepares, the scenario in which both sides launch more or less all-out attacks against their opponent's economic or urban-industrial target system often dominates public consideration of strategic policy issues. These kinds of strikes, generically termed countervalue attacks, are usually assumed to throw many thousands of nuclear weapons against cities and isolated facilities in order to destroy the adversary nation as an organized, functioning, and economically viable entity.

  14. PMA-Linked Fluorescence for Rapid Detection of Viable Bacterial Endospores

    NASA Technical Reports Server (NTRS)

    LaDuc, Myron T.; Venkateswaran, Kasthuri; Mohapatra, Bidyut

    2012-01-01

    The most common approach for assessing the abundance of viable bacterial endospores is the culture-based plating method. However, culture-based approaches are heavily biased and oftentimes incompatible with upstream sample processing strategies, which make viable cells/spores uncultivable. This shortcoming highlights the need for rapid molecular diagnostic tools to assess more accurately the abundance of viable spacecraft-associated microbiota, perhaps most importantly bacterial endospores. Propidium monoazide (PMA) has received a great deal of attention due to its ability to differentiate live, viable bacterial cells from dead ones. PMA gains access to the DNA of dead cells through compromised membranes. Once inside the cell, it intercalates and eventually covalently bonds with the double-helix structures upon photoactivation with visible light. The covalently bound DNA is significantly altered, and unavailable to downstream molecular-based manipulations and analyses. Microbiological samples can be treated with appropriate concentrations of PMA and exposed to visible light prior to undergoing total genomic DNA extraction, resulting in an extract comprised solely of DNA arising from viable cells. This ability to extract DNA selectively from living cells is extremely powerful, and bears great relevance to many microbiological arenas.

  15. Airborne viable fungi in school environments in different climatic regions - A review

    NASA Astrophysics Data System (ADS)

    Salonen, Heidi; Duchaine, Caroline; Mazaheri, Mandana; Clifford, Sam; Lappalainen, Sanna; Reijula, Kari; Morawska, Lidia

    2015-03-01

    Elevated levels of fungi in indoor environments have been linked with mould/moisture damage in building structures. However, there is a lack of information about "normal" concentrations and flora as well as guidelines of viable fungi in the school environment in different climatic conditions. We have reviewed existing guidelines for indoor fungi and the current knowledge of the concentrations and flora of viable fungi in different climatic areas, the impact of the local factors on concentrations and flora of viable fungi in school environments. Meta-regression was performed to estimate the average behaviour for each analysis of interest, showing wide variation in the mean concentrations in outdoor and indoor school environments (range: 101-103 cfu/m3). These concentrations were significantly higher for both outdoors and indoors in the moderate than in the continental climatic area, showing that the climatic condition was a determinant for the concentrations of airborne viable fungi. The most common fungal species both in the moderate and continental area were Cladosporium spp. and Penicillium spp. The suggested few quantitative guidelines for indoor air viable fungi for school buildings are much lower than for residential areas. This review provides a synthesis, which can be used to guide the interpretation of the fungi measurements results and help to find indications of mould/moisture in school building structures.

  16. Nitrogen and cobalt co-doped zinc oxide nanowires - Viable photoanodes for hydrogen generation via photoelectrochemical water splitting

    NASA Astrophysics Data System (ADS)

    Patel, Prasad Prakash; Hanumantha, Prashanth Jampani; Velikokhatnyi, Oleg I.; Datta, Moni Kanchan; Hong, Daeho; Gattu, Bharat; Poston, James A.; Manivannan, Ayyakkannu; Kumta, Prashant N.

    2015-12-01

    Photoelectrochemical (PEC) water splitting has been considered as a promising and environmentally benign approach for efficient and economic hydrogen generation by utilization of solar energy. Development of semiconductor materials with low band gap, high photoelectrochemical activity and stability has been of particular interest for a viable PEC water splitting system. In this study, Co doped ZnO, .i.e., (Zn0.95Co0.05)O nanowires (NWs) was selected as the composition for further co-doping with nitrogen by comparing solar to hydrogen efficiency (SHE) of ZnO NWs with that of various compositions of (Zn1-xCox)O NWs (x = 0, 0.05, 0.1). Furthermore, nanostructured vertically aligned Co and N-doped ZnO, .i.e., (Zn1-xCox)O:N NWs (x = 0.05) have been studied as photoanodes for PEC water splitting. An optimal SHE of 1.39% the highest reported so far to the best of our knowledge for ZnO based photoanodes was obtained for the co-doped NWs, (Zn0.95Co0.05)O:N - 600 NWs generated at 600 °C in ammonia atmosphere. Further, (Zn0.95Co0.05)O:N-600 NWs exhibited excellent photoelectrochemical stability under illumination compared to pure ZnO NWs. These promising results suggest the potential of (Zn0.95Co0.05)O:N-600 NWs as a viable photoanode in PEC water splitting cell. Additionally, theoretical first principles study conducted explains the beneficial effects of Co and N co-doping on both, the electronic structure and the band gap of ZnO.

  17. Assets and Educational Achievement: Theory and Evidence

    ERIC Educational Resources Information Center

    Elliott, William; Sherraden, Michael

    2013-01-01

    This special issue of Economics of Education Review explores the role of savings and asset holding in post-secondary educational achievement. Most college success research has focused on income rather than assets as a predictor, and most college financing policy has focused on tuition support and educational debt, rather than asset accumulation.…

  18. Closing the Achievement Gap: Four States' Efforts

    ERIC Educational Resources Information Center

    Wixom, Micah Ann

    2015-01-01

    The achievement gap separating economically disadvantaged students from their more advantaged peers disproportionately affects students of color and has been the focus of discussion, research and controversy for more than 40 years. While the gap between black and white students narrowed considerably from the 1950s to the 1980s, that gap has…

  19. General Achievement Trends: Oklahoma

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  20. General Achievement Trends: Georgia

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  1. General Achievement Trends: Nebraska

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  2. General Achievement Trends: Arkansas

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  3. General Achievement Trends: Maryland

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  4. General Achievement Trends: Maine

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  5. General Achievement Trends: Iowa

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  6. General Achievement Trends: Texas

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  7. General Achievement Trends: Hawaii

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  8. General Achievement Trends: Kansas

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  9. General Achievement Trends: Florida

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  10. General Achievement Trends: Massachusetts

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  11. General Achievement Trends: Tennessee

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  12. General Achievement Trends: Alabama

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  13. General Achievement Trends: Virginia

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  14. General Achievement Trends: Michigan

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  15. General Achievement Trends: Colorado

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  16. Inverting the Achievement Pyramid

    ERIC Educational Resources Information Center

    White-Hood, Marian; Shindel, Melissa

    2006-01-01

    Attempting to invert the pyramid to improve student achievement and increase all students' chances for success is not a new endeavor. For decades, educators have strategized, formed think tanks, and developed school improvement teams to find better ways to improve the achievement of all students. Currently, the No Child Left Behind Act (NCLB) is…

  17. Achievement Test Program.

    ERIC Educational Resources Information Center

    Ohio State Dept. of Education, Columbus. Trade and Industrial Education Service.

    The Ohio Trade and Industrial Education Achievement Test battery is comprised of seven basic achievement tests: Machine Trades, Automotive Mechanics, Basic Electricity, Basic Electronics, Mechanical Drafting, Printing, and Sheet Metal. The tests were developed by subject matter committees and specialists in testing and research. The Ohio Trade and…

  18. School Effects on Achievement.

    ERIC Educational Resources Information Center

    Nichols, Robert C.

    The New York State Education Department conducts a Pupil Evaluation Program (PEP) in which each year all third, sixth, and ninth grade students in the state are given a series of achievement tests in reading and mathematics. The data accumulated by the department includes achievement test scores, teacher characteristics, building and curriculum…

  19. Heritability of Creative Achievement

    ERIC Educational Resources Information Center

    Piffer, Davide; Hur, Yoon-Mi

    2014-01-01

    Although creative achievement is a subject of much attention to lay people, the origin of individual differences in creative accomplishments remain poorly understood. This study examined genetic and environmental influences on creative achievement in an adult sample of 338 twins (mean age = 26.3 years; SD = 6.6 years). Twins completed the Creative…

  20. Confronting the Achievement Gap

    ERIC Educational Resources Information Center

    Gardner, David

    2007-01-01

    This article talks about the large achievement gap between children of color and their white peers. The reasons for the achievement gap are varied. First, many urban minorities come from a background of poverty. One of the detrimental effects of growing up in poverty is receiving inadequate nourishment at a time when bodies and brains are rapidly…

  1. Achieving Public Schools

    ERIC Educational Resources Information Center

    Abowitz, Kathleen Knight

    2011-01-01

    Public schools are functionally provided through structural arrangements such as government funding, but public schools are achieved in substance, in part, through local governance. In this essay, Kathleen Knight Abowitz explains the bifocal nature of achieving public schools; that is, that schools are both subject to the unitary Public compact of…

  2. The Economic Value of Higher Teacher Quality

    ERIC Educational Resources Information Center

    Hanushek, Eric A.

    2011-01-01

    Most analyses of teacher quality end without any assessment of the economic value of altered teacher quality. This paper combines information about teacher effectiveness with the economic impact of higher achievement. It begins with an overview of what is known about the relationship between teacher quality and student achievement. This provides…

  3. Issues of organizational cybernetics and viability beyond Beer's viable systems model

    NASA Astrophysics Data System (ADS)

    Nechansky, Helmut

    2013-11-01

    The paper starts summarizing the claims of Beer's viable systems model to identify five issues any viable organizations has to deal with in an unequivocal hierarchical structure of five interrelated systems. Then the evidence is introduced for additional issues and related viable structures of organizations, which deviate from Beer's model. These issues are: (1) the establishment and (2) evolution of an organization; (3) systems for independent top-down control (like "Six Sigma"); (4) systems for independent bottom-up correction of performance problems (like "Kaizen"), both working outside a hierarchical structure; (5) pull production systems ("Just in Time") and (6) systems for checks and balances of top-level power (like boards and shareholder meetings). Based on that an evolutionary approach to organizational cybernetics is outlined, addressing the establishment of organizations and possible courses of developments, including recent developments in quality and production engineering, as well as problems of setting and changing goal values determining organizational policies.

  4. [Advances and challenges in health economics].

    PubMed

    Pena, P H; Arredondo, A; Ortiz, C; Rosenthal, G

    1995-08-01

    Health economics is a specialized field of economic science that applies the economic perspective to the fields of health, the medical-industrial complex and health services. A brief review of the evolution of this speciality by subject, as well as the level achieved assessed in terms of generation, diffusion, reproduction and application of its specialized knowledge, is presented.

  5. Composting, anaerobic digestion and biochar production in Ghana. Environmental–economic assessment in the context of voluntary carbon markets

    SciTech Connect

    Galgani, Pietro; Voet, Ester van der; Korevaar, Gijsbert

    2014-12-15

    Highlights: • Economic–environmental assessment of combining composting with biogas and biochar in Ghana. • These technologies can save greenhouse gas emissions for up to 0.57 t CO{sub 2} eq/t of waste treated. • Labor intensive, small-scale organic waste management is not viable without financial support. • Carbon markets would make these technologies viable with carbon prices in the range of 30–84 EUR/t. - Abstract: In some areas of Sub-Saharan Africa appropriate organic waste management technology could address development issues such as soil degradation, unemployment and energy scarcity, while at the same time reducing emissions of greenhouse gases. This paper investigates the role that carbon markets could have in facilitating the implementation of composting, anaerobic digestion and biochar production, in the city of Tamale, in the North of Ghana. Through a life cycle assessment of implementation scenarios for low-tech, small scale variants of the above mentioned three technologies, the potential contribution they could give to climate change mitigation was assessed. Furthermore an economic assessment was carried out to study their viability and the impact thereon of accessing carbon markets. It was found that substantial climate benefits can be achieved by avoiding landfilling of organic waste, producing electricity and substituting the use of chemical fertilizer. Biochar production could result in a net carbon sequestration. These technologies were however found not to be economically viable without external subsidies, and access to carbon markets at the considered carbon price of 7 EUR/ton of carbon would not change the situation significantly. Carbon markets could help the realization of the considered composting and anaerobic digestion systems only if the carbon price will rise above 75–84 EUR/t of carbon (respectively for anaerobic digestion and composting). Biochar production could achieve large climate benefits and, if approved as a land

  6. [Selective detection of viable pathogenic bacteria in water using reverse transcription quantitative PCR].

    PubMed

    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.

  7. Viable capture and release of cancer cells in human whole blood

    NASA Astrophysics Data System (ADS)

    Doh, Il; Yoo, Hwan-il; Cho, Young-Ho; Lee, Jinseon; Kwan Kim, Hong; Kim, Jhingook

    2012-07-01

    We present viable cancer cell isolation devices utilizing the physical properties of cells. The tapered slit structure is proposed to isolate cancer cells from blood cells and collect them by reversed flow. From the experimental study using the spiked cancer cells in human whole blood, we verified the capability of the present cancer cell isolation chip in terms of capture efficiency, viability, and release rate. The viable cancer cells obtained from the present chip can be used for the further applications of cancer diagnosis, treatment monitoring, and new target drug development for cancer stem cells.

  8. Modeling the effect of light and salinity on viable but non-culturable (VBNC) Enterococcus.

    PubMed

    Gin, Karina Yew-Hoong; Goh, Shin Giek

    2013-06-15

    Enterococci have been recommended as suitable bacteria indicators for assessing the microbial quality of recreational waters. However, recent studies have shown that bacteria, including enterococci, are able to enter a viable but non-culturable (VBNC) state under environmentally stressed conditions, where they may remain undetected if culture-based methods are employed. To appreciate the extent of transformation of these cells in surface waters, a model Enterococcus organism, E. faecalis, was examined in laboratory controlled microcosms under different light and salinity conditions. Cells were detected by both standard culture-based and PMA-qPCR (propidium monoazide quantitative PCR) methods so that the VBNC cells could be enumerated. The decay rates from the culture based method (kc) and PMA-qPCR method (kp) were established for the different conditions. In general, the kC values (ranging from 0.0088 hr(-1) to 0.9755 hr(-1)) were always higher than the kP values (0.0019 hr(-1) to 0.2373 hr(-1)), implying that cells were able to retain their viability for much longer periods than what is shown by the culture-based method. In both cases, the k values generally showed an increasing trend with an increase in light irradiation, implying greater die-off with light. For freshwater microcosms, the kp values were 3-6 times lower than the kc values for different irradiation conditions, whereas for seawater the difference was up to 12 times, showing that E. faecalis adapts well to seawater. The kinetic data were used to develop models to describe the dynamics of VBNC formation in natural waters. At low light intensities (less than about 20 Wm(-2)), the proportion of VBNC cells was found to steadily increase to as high as 50%, even after 4 days. However, at higher light levels, this proportion was achieved more quickly (less than 5 h) but also diminished more rapidly. Hence, at high light levels, the percentage of VBNC cells is expected to be significant only for a few hours

  9. Airship economics

    NASA Technical Reports Server (NTRS)

    Neumann, R. D.; Hackney, L. R. M.

    1975-01-01

    Projected operating and manufacturing costs of a large airship design which are considered practical with today's technology and environment are discussed. Data and information developed during an 18-month study on the question of feasibility, engineering, economics and production problems related to a large metalclad type airship are considered. An overview of other classic airship designs are provided, and why metalclad was selected as the most prudent and most economic design to be considered in the 1970-80 era is explained. Crew operation, ATC and enroute requirements are covered along with the question of handling, maintenance and application of systems to the large airship.

  10. Student Achievement and Motivation

    ERIC Educational Resources Information Center

    Flammer, Gordon H.; Mecham, Robert C.

    1974-01-01

    Compares the lecture and self-paced methods of instruction on the basis of student motivation and achieveme nt, comparing motivating and demotivating factors in each, and their potential for motivation and achievement. (Authors/JR)

  11. Economic Imperative

    ERIC Educational Resources Information Center

    Sack, Joetta L.

    2005-01-01

    The signals had been there for years. Task force reports and researchers all predicted it. Then, in the late 1990s, the economic collapse in this blue-collar region of central Maine began. First, the Cascade Co. closed its textile mill. Then the C.F. Hathaway Co. shut down, and Dumont Industries followed suit soon after. Several stores and other…

  12. Home Economics.

    ERIC Educational Resources Information Center

    Ontario Dept. of Education, Toronto. School Planning and Building Research Section.

    This presentation of suggested layouts and specifications for home economics facilities has been prepared to be of service to school boards, architects, teachers, and administrators who are planning new schools or making renovations to existing structures. Room layouts are shown for a foods and nutrition room, or the foods and nutrition area of a…

  13. Cable Economics.

    ERIC Educational Resources Information Center

    Cable Television Information Center, Washington, DC.

    A guide to the economic factors that influence cable television systems is presented. Designed for local officials who must have some familiarity with cable operations in order to make optimum decisions, the guide analyzes the financial framework of a cable system, not only from the operators viewpoint, but also from the perspective of the…

  14. Economic impact

    SciTech Connect

    Technology Transfer Department

    2001-06-01

    In federal fiscal year 2000 (FY00), Berkeley Lab had 4,347 full- and part-time employees. In addition, at any given time of the year, there were more than 1,000 Laboratory guests. These guests, who also reside locally, have an important economic impact on the nine-county Bay Area. However, Berkeley Lab's total economic impact transcends the direct effects of payroll and purchasing. The direct dollars paid to the Lab's employees in the form of wages, salaries, and benefits, and payments made to contractors for goods and services, are respent by employees and contractors again and again in the local and greater economy. Further, while Berkeley Lab has a strong reputation for basic scientific research, many of the Lab's scientific discoveries and inventions have had direct application in industry, spawning new businesses and creating new opportunities for existing firms. This analysis updates the Economic Impact Analysis done in 1996, and its purpose is to describe the economic and geographic impact of Laboratory expenditures and to provide a qualitative understanding of how Berkeley Lab impacts and supports the local community. It is intended as a guide for state, local, and national policy makers as well as local community members. Unless otherwise noted, this analysis uses data from FY00, the most recent year for which full data are available.

  15. Resource Economics

    NASA Astrophysics Data System (ADS)

    Conrad, Jon M.

    2000-01-01

    Resource Economics is a text for students with a background in calculus, intermediate microeconomics, and a familiarity with the spreadsheet software Excel. The book covers basic concepts, shows how to set up spreadsheets to solve dynamic allocation problems, and presents economic models for fisheries, forestry, nonrenewable resources, stock pollutants, option value, and sustainable development. Within the text, numerical examples are posed and solved using Excel's Solver. These problems help make concepts operational, develop economic intuition, and serve as a bridge to the study of real-world problems of resource management. Through these examples and additional exercises at the end of Chapters 1 to 8, students can make dynamic models operational, develop their economic intuition, and learn how to set up spreadsheets for the simulation of optimization of resource and environmental systems. Book is unique in its use of spreadsheet software (Excel) to solve dynamic allocation problems Conrad is co-author of a previous book for the Press on the subject for graduate students Approach is extremely student-friendly; gives students the tools to apply research results to actual environmental issues

  16. Economic Growth.

    ERIC Educational Resources Information Center

    O'Neill, James B.; And Others

    1986-01-01

    A conceptual introduction for teachers explains economic growth and how it is measured. Four instructional units follow, beginning with a preschool and kindergarten unit which offers young students an opportunity to interview puppet workers, set up a classroom corner store, and learn the importance of capital resources for increasing productivity…

  17. Quantitative study of viable Vibrio parahaemolyticus cells in raw seafood using propidium monoazide in combination with quantitative PCR.

    PubMed

    Zhu, Ru-Gang; Li, Tuo-Ping; Jia, You-Feng; Song, Li-Feng

    2012-09-01

    In this study we developed a specific and sensitive quantitative PCR (qPCR) method combined with a propidium monoazide (PMA) sample treatment to quantify tdh-positive viable cells of V. parahaemolyticus in raw seafood (PMA-qPCR). The high selectivity of primers and probes were demonstrated by using purified DNA from 57 strains belonging to 18 species. Using these primers and probes for qPCR and in artificial contamination samples, a good correlation was obtained between Ct values and log CFU/reaction in the range of 12-1.2×10(6)CFU/reaction both from qPCR and PMA-qPCR with R(2) values of 0.9973 and 0.9919, respectively. The optimization of PMA concentration showed that 8 μg/mL was considered optimal to achieve a compromise between minimal impact on intact cells and maximal signal reduction in compromised cells. However, turbidity and cell concentration experiments showed that PMA treatment was not effective in samples where turbidities were ≥10 NTU and OD(600 nm) values were ≥0.8. PMA-qPCR was compared with culture isolation and traditional qPCR in environmental samples (including oyster, scallop, shrimp, and crab). The PMA-qPCR resulted in lower numbers of log CFUg(-1) than qPCR, with values having better agreement with numbers determined by culture isolation. In conclusion, this method is an effective tool for producing reliable quantitative data on viable V. parahaemolyticus in raw seafood. PMID:22677606

  18. Induction of Viable but Nonculturable Escherichia coli O157:H7 by High Pressure CO2 and Its Characteristics

    PubMed Central

    Zhao, Feng; Bi, Xiufang; Hao, Yanling; Liao, Xiaojun

    2013-01-01

    The viable but nonculturable (VBNC) state is a survival strategy adopted by many pathogens when exposed to harsh environmental stresses. In this study, we investigated for the first time that whether high pressure CO2 (HPCD), one of the nonthermal pasteurization techniques, can induce Escherichia coli O157:H7 into the VBNC state. By measuring plate counts, viable cell counts and total cell counts, E. coli O157:H7 in 0.85% NaCl solution (pH 7.0) was able to enter the VBNC state by HPCD treatment at 5 MPa and four temperatures (25°C, 31°C, 34°C and 37°C). Meanwhile, with the improvement of treatment temperature, the time required for E. coli O157:H7 to enter VBNC state would shorten. Enzymatic activities in these VBNC cells were lower than those in the exponential-phase cells by using API ZYM kit, which were also reduced with increasing the treatment temperature, but the mechanical resistance of the VBNC cells to sonication was enhanced. These results further confirmed VBNC state was a self-protection mechanism for some bacteria, which minimized cellular energetic requirements and increased the cell resistance. When incubated in tryptic soy broth at 37°C, the VBNC cells induced by HPCD treatment at 25°C, 31°C and 34°C achieved resuscitation, but their resuscitation capabilities decreased with increasing the treatment temperature. Furthermore, electron microscopy revealed changes in the morphology and interior structure of the VBNC cells and the resuscitated cells. These results demonstrated that HPCD could induce E. coli O157:H7 into the VBNC state. Therefore, it is necessary to detect if there exist VBNC microorganisms in HPCD-treated products by molecular-based methods for food safety. PMID:23626816

  19. Toward a zero-carbon energy policy in Europe: defining a viable solution

    SciTech Connect

    Jones, Christopher; Glachant, Jean-Michel

    2010-04-15

    The present pace of carbon emission is not sustainable. Human societies need to react and to change. A rational responsive policy to deliver the required carbon emission reduction can be delineated if the key objective parameters are identified and addressed. This article attempts to lay the groundwork for a viable carbon energy policy for Europe. (author)

  20. COMPARISON OF ANALYTICAL METHODS FOR THE MEASUREMENT OF NON-VIABLE BIOLOGICAL PM

    EPA Science Inventory

    The paper describes a preliminary research effort to develop a methodology for the measurement of non-viable biologically based particulate matter (PM), analyzing for mold, dust mite, and ragweed antigens and endotoxins. Using a comparison of analytical methods, the research obj...

  1. Separable Bilayer Microfiltration Device for Viable Label-free Enrichment of Circulating Tumour Cells

    NASA Astrophysics Data System (ADS)

    Zhou, Ming-Da; Hao, Sijie; Williams, Anthony J.; Harouaka, Ramdane A.; Schrand, Brett; Rawal, Siddarth; Ao, Zheng; Brennaman, Randall; Gilboa, Eli; Lu, Bo; Wang, Shuwen; Zhu, Jiyue; Datar, Ram; Cote, Richard; Tai, Yu-Chong; Zheng, Si-Yang

    2014-12-01

    The analysis of circulating tumour cells (CTCs) in cancer patients could provide important information for therapeutic management. Enrichment of viable CTCs could permit performance of functional analyses on CTCs to broaden understanding of metastatic disease. However, this has not been widely accomplished. Addressing this challenge, we present a separable bilayer (SB) microfilter for viable size-based CTC capture. Unlike other single-layer CTC microfilters, the precise gap between the two layers and the architecture of pore alignment result in drastic reduction in mechanical stress on CTCs, capturing them viably. Using multiple cancer cell lines spiked in healthy donor blood, the SB microfilter demonstrated high capture efficiency (78-83%), high retention of cell viability (71-74%), high tumour cell enrichment against leukocytes (1.7-2 × 103), and widespread ability to establish cultures post-capture (100% of cell lines tested). In a metastatic mouse model, SB microfilters successfully enriched viable mouse CTCs from 0.4-0.6 mL whole mouse blood samples and established in vitro cultures for further genetic and functional analysis. Our preliminary studies reflect the efficacy of the SB microfilter device to efficiently and reliably enrich viable CTCs in animal model studies, constituting an exciting technology for new insights in cancer research.

  2. ATP as a biomarker of viable microorganisms in clean-room facilities

    NASA Technical Reports Server (NTRS)

    Venkateswaran, Kasthuri; Hattori, Noriaki; La Duc, Myron T.; Kern, Roger

    2003-01-01

    A new firefly luciferase bioluminescence assay method that differentiates free extracellular ATP (dead cells, etc.) from intracellular ATP (viable microbes) was used to determine the viable microbial cleanliness of various clean-room facilities. For comparison, samples were taken from both clean-rooms, where the air was filtered to remove particles >0.5 microm, and ordinary rooms with unfiltered air. The intracellular ATP was determined after enzymatically degrading the sample's free ATP. Also for comparison, cultivable microbial populations were counted on nutrient-rich trypticase soy agar (TSA) plates. Both the cultivable and ATP-based determinations indicate that the microbial burden was lower in clean-room facilities than in ordinary rooms. However, there was no direct correlation between the two sets of measurements because the two assays measured very different populations. A large fraction of the samples yielded no colony formers on TSA, but were positive for intracellular ATP. Subsequently, genomic DNA was isolated directly from selected samples and 16S rDNA fragments were cloned and sequenced, identifying nearest neighbors, many of which are known to be noncultivable in the media employed. It was concluded that viable microbial contamination can be reliably monitored by measurement of intracellular ATP, and that this method may be considered superior to cultivable colony counts due to its speed and its ability to report the presence of viable but noncultivable organisms. When the detection of nonviable microbes is of interest, the ATP assay can be supplemented with DNA analysis.

  3. 40 CFR 180.1011 - Viable spores of the microorganism Bacillus thuringiensis Berliner; exemption from the...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1011 Viable spores of the... fly larvae toxicity test (“Microbial Control of Insects and Mites,” R.P.M. Bond et al., p. 280...

  4. 40 CFR 180.1011 - Viable spores of the microorganism Bacillus thuringiensis Berliner; exemption from the...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1011 Viable spores of the... fly larvae toxicity test (“Microbial Control of Insects and Mites,” R.P.M. Bond et al., p. 280...

  5. 40 CFR 180.1011 - Viable spores of the microorganism Bacillus thuringiensis Berliner; exemption from the...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1011 Viable spores of the... fly larvae toxicity test (“Microbial Control of Insects and Mites,” R.P.M. Bond et al., p. 280...

  6. Retention of virulence in a viable but nonculturable Edwardsiella tarda isolate.

    PubMed

    Du, Meng; Chen, Jixiang; Zhang, Xiaohua; Li, Aijuan; Li, Yun; Wang, Yingeng

    2007-02-01

    Edwardsiella tarda is pathogen of fish and other animals. The aim of this study was to investigate the viable but nonculturable (VBNC) state and virulence retention of this bacterium. Edwardsiella tarda CW7 was cultured in sterilized aged seawater at 4 degrees C. Total cell counts remained constant throughout the 28-day period by acridine orange direct counting, while plate counts declined to undetectable levels (<0.1 CFU/ml) within 28 days by plate counting. The direct viable counts, on the other hand, declined to ca. 10(9) CFU/ml active cells and remained fairly constant at this level by direct viable counting. These results indicated that a large population of cells existed in a viable but nonculturable state. VBNC E. tarda CW7 could resuscitate in experimental chick embryos and in the presence of nutrition with a temperature upshift. The resuscitative times were 6 days and 8 days, respectively. The morphological changes of VBNC, normal, and resuscitative E. tarda CW7 cells were studied with a scanning electron microscope. The results showed that when the cells entered into the VBNC state, they gradually changed in shape from short rods to coccoid and decreased in size, but the resuscitative cells did not show any obvious differences from the normal cells. The VBNC and the resuscitative E. tarda CW7 cells were intraperitoneally inoculated into turbot separately, and the fish inoculated with the resuscitative cells died within 7 days, which suggested that VBNC E. tarda CW7 might retain pathogenicity. PMID:17189433

  7. Retention of Virulence in a Viable but Nonculturable Edwardsiella tarda Isolate▿

    PubMed Central

    Du, Meng; Chen, Jixiang; Zhang, Xiaohua; Li, Aijuan; Li, Yun; Wang, Yingeng

    2007-01-01

    Edwardsiella tarda is pathogen of fish and other animals. The aim of this study was to investigate the viable but nonculturable (VBNC) state and virulence retention of this bacterium. Edwardsiella tarda CW7 was cultured in sterilized aged seawater at 4°C. Total cell counts remained constant throughout the 28-day period by acridine orange direct counting, while plate counts declined to undetectable levels (<0.1 CFU/ml) within 28 days by plate counting. The direct viable counts, on the other hand, declined to ca. 109 CFU/ml active cells and remained fairly constant at this level by direct viable counting. These results indicated that a large population of cells existed in a viable but nonculturable state. VBNC E. tarda CW7 could resuscitate in experimental chick embryos and in the presence of nutrition with a temperature upshift. The resuscitative times were 6 days and 8 days, respectively. The morphological changes of VBNC, normal, and resuscitative E. tarda CW7 cells were studied with a scanning electron microscope. The results showed that when the cells entered into the VBNC state, they gradually changed in shape from short rods to coccoid and decreased in size, but the resuscitative cells did not show any obvious differences from the normal cells. The VBNC and the resuscitative E. tarda CW7 cells were intraperitoneally inoculated into turbot separately, and the fish inoculated with the resuscitative cells died within 7 days, which suggested that VBNC E. tarda CW7 might retain pathogenicity. PMID:17189433

  8. 9 CFR 113.26 - Detection of viable bacteria and fungi except in live vaccine.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Detection of viable bacteria and fungi except in live vaccine. 113.26 Section 113.26 Animals and Animal Products ANIMAL AND PLANT HEALTH... in live vaccine. Each serial and subserial of biological product except live vaccines shall be...

  9. 9 CFR 113.26 - Detection of viable bacteria and fungi except in live vaccine.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Detection of viable bacteria and fungi except in live vaccine. 113.26 Section 113.26 Animals and Animal Products ANIMAL AND PLANT HEALTH... in live vaccine. Each serial and subserial of biological product except live vaccines shall be...

  10. 9 CFR 113.26 - Detection of viable bacteria and fungi except in live vaccine.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Detection of viable bacteria and fungi except in live vaccine. 113.26 Section 113.26 Animals and Animal Products ANIMAL AND PLANT HEALTH... in live vaccine. Each serial and subserial of biological product except live vaccines shall be...

  11. 9 CFR 113.26 - Detection of viable bacteria and fungi except in live vaccine.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Detection of viable bacteria and fungi except in live vaccine. 113.26 Section 113.26 Animals and Animal Products ANIMAL AND PLANT HEALTH... in live vaccine. Each serial and subserial of biological product except live vaccines shall be...

  12. 9 CFR 113.26 - Detection of viable bacteria and fungi except in live vaccine.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Detection of viable bacteria and fungi except in live vaccine. 113.26 Section 113.26 Animals and Animal Products ANIMAL AND PLANT HEALTH... in live vaccine. Each serial and subserial of biological product except live vaccines shall be...

  13. Selective enumeration of viable Enterobacteriaceae and Pseudomonas spp. in milk within 7 h by multicolor fluorescence in situ hybridization following microcolony formation.

    PubMed

    Yamaguchi, Nobuyasu; Kitaguchi, Akiko; Nasu, Masao

    2012-06-01

    Rapid and simultaneous enumeration of viable Enterobacteriaceae and viable Pseudomonas spp. in milk was achieved by using multicolor fluorescence in situ hybridization (FISH) with oligonucleotide probes based on 16S ribosomal RNA (rRNA) sequences in combination with a microcolony growth method (multicolor microcolony-FISH; MMC-FISH). The procedure of MMC-FISH method is rather simple; that is milk clearing, filtration of cells, incubation, hybridization and enumeration. Enumeration of targeted bacteria in logarithmic growth phase, stationary phase, or in a starved state in milk by MMC-FISH required 5-7 h, while it took 1-3 days to test for Escherichia coli and Pseudomonas putida by the conventional culture method. The numbers of E. coli and P. putida in each phase or in a starved state in milk determined by MMC-FISH were almost the same or greater than the number of colony forming units determined by the plate counting method. The MMC-FISH allows rapid examination of contamination in milk by viable Enterobacteriaceae and Pseudomonas spp. with growth potential.

  14. Efficient long-term survival of cell grafts after myocardial infarction with thick viable cardiac tissue entirely from pluripotent stem cells

    PubMed Central

    Matsuo, Takehiko; Masumoto, Hidetoshi; Tajima, Shuhei; Ikuno, Takeshi; Katayama, Shiori; Minakata, Kenji; Ikeda, Tadashi; Yamamizu, Kohei; Tabata, Yasuhiko; Sakata, Ryuzo; Yamashita, Jun K.

    2015-01-01

    Poor engraftment of cells after transplantation to the heart is a common and unresolved problem in the cardiac cell therapies. We previously generated cardiovascular cell sheets entirely from pluripotent stem cells with cardiomyocytes, endothelial cells and vascular mural cells. Though sheet transplantation showed a better engraftment and improved cardiac function after myocardial infarction, stacking limitation (up to 3 sheets) by hypoxia hampered larger structure formation and long-term survival of the grafts. Here we report an efficient method to overcome the stacking limitation. Insertion of gelatin hydrogel microspheres (GHMs) between each cardiovascular cell sheet broke the viable limitation via appropriate spacing and fluid impregnation with GHMs. Fifteen sheets with GHMs (15-GHM construct; >1 mm thickness) were stacked within several hours and viable after 1 week in vitro. Transplantation of 5-GHM constructs (≈2 × 106 of total cells) to a rat myocardial infarction model showed rapid and sustained functional improvements. The grafts were efficiently engrafted as multiple layered cardiovascular cells accompanied by functional capillary networks. Large engrafted cardiac tissues (0.8 mm thickness with 40 cell layers) successfully survived 3 months after TX. We developed an efficient method to generate thicker viable tissue structures and achieve long-term survival of the cell graft to the heart. PMID:26585309

  15. Efficient long-term survival of cell grafts after myocardial infarction with thick viable cardiac tissue entirely from pluripotent stem cells.

    PubMed

    Matsuo, Takehiko; Masumoto, Hidetoshi; Tajima, Shuhei; Ikuno, Takeshi; Katayama, Shiori; Minakata, Kenji; Ikeda, Tadashi; Yamamizu, Kohei; Tabata, Yasuhiko; Sakata, Ryuzo; Yamashita, Jun K

    2015-11-20

    Poor engraftment of cells after transplantation to the heart is a common and unresolved problem in the cardiac cell therapies. We previously generated cardiovascular cell sheets entirely from pluripotent stem cells with cardiomyocytes, endothelial cells and vascular mural cells. Though sheet transplantation showed a better engraftment and improved cardiac function after myocardial infarction, stacking limitation (up to 3 sheets) by hypoxia hampered larger structure formation and long-term survival of the grafts. Here we report an efficient method to overcome the stacking limitation. Insertion of gelatin hydrogel microspheres (GHMs) between each cardiovascular cell sheet broke the viable limitation via appropriate spacing and fluid impregnation with GHMs. Fifteen sheets with GHMs (15-GHM construct; >1 mm thickness) were stacked within several hours and viable after 1 week in vitro. Transplantation of 5-GHM constructs (≈2 × 10(6) of total cells) to a rat myocardial infarction model showed rapid and sustained functional improvements. The grafts were efficiently engrafted as multiple layered cardiovascular cells accompanied by functional capillary networks. Large engrafted cardiac tissues (0.8 mm thickness with 40 cell layers) successfully survived 3 months after TX. We developed an efficient method to generate thicker viable tissue structures and achieve long-term survival of the cell graft to the heart.

  16. Retention of Endogenous Viable Cells Enhances the Anti-Inflammatory Activity of Cryopreserved Amnion

    PubMed Central

    Duan-Arnold, Yi; Gyurdieva, Alexandra; Johnson, Amy; Uveges, Thomas E.; Jacobstein, Douglas A.; Danilkovitch, Alla

    2015-01-01

    Objective: Human amniotic membrane (hAM) has been used to treat wounds for more than 100 years. However, widespread use of fresh hAM has been limited due to its short shelf life and safety concerns. To overcome these concerns, different preservation methods have been introduced. The majority of these methods result in devitalized hAM (dev-hAM). Recently, we developed a cryopreservation method that retains all hAM components intact (int-hAM), including viable endogenous cells. To understand the advantages of retaining viable cells in preserved hAM, we compared the anti-inflammatory properties of int-hAM and dev-hAM. Approach: The tissue composition of int-hAM and dev-hAM was compared with fresh hAM through histology and cell viability analysis. We also evaluated the ability of int-hAM and dev-hAM to regulate tumor necrosis factor-α (TNF-α), interleukin-1α (IL-1α), and IL-10 release when co-cultured with immune cells; to produce prostaglandin E2 (PGE2) on TNF-α stimulation; and to inhibit proteases. Results: Int-hAM maintained the structural and cellular integrity of fresh hAM. Int-hAM had >80% cell viability post-thaw and remained viable for at least a week in culture. Viable cells were not detected in dev-hAM. Compared with dev-hAM, int-hAM showed significantly greater downregulation of TNF-α and IL-1α, upregulation of PGE2 and IL-10, and stronger inhibition of collagenase. Innovation and Conclusion: A new cryopreservation method has been developed to retain all native components of hAM. For the first time, we show that viable endogenous cells significantly augment the anti-inflammatory activity of cryopreserved hAM. PMID:26401419

  17. The Economics of Concern and Compassion: Applications to Rural Justice.

    ERIC Educational Resources Information Center

    Brown, David W.

    The urgent need to correct inequities and shortsighted rural justice practices, i.e., juvenile delinquency problems, makes it crucial that available resources be used wisely and that careful choices be made among the viable alternatives. Twelve basic economic concepts can be helpful in providing a framework or diagnostic perspective that can be…

  18. Engendering economics.

    PubMed

    1995-08-01

    Gender has become a major issue in discussions of economic development, with international organizations having generated studies which demonstrate that investments in women yield high returns in productivity, child health, and family welfare. Discussions of gender usually have been compartmentalized, with little impact upon broader studies of development. Examining the role that gender plays in economic life, however, could lead to a better understanding of the role which social institutions play in development. The author discusses reexamining gender bias and collective action by men and women with respect to property rights, family law, and the labor market. It is noted in closing that individual preferences are partially shaped by social norms which are strongly influenced by the coalitions which hold power in a society. As women gain collective power, they are likely to challenge the social norms which are costly to them.

  19. Resolution of Viable and Membrane-Compromised Bacteria in Freshwater and Marine Waters Based on Analytical Flow Cytometry and Nucleic Acid Double Staining

    PubMed Central

    Grégori, Gérald; Citterio, Sandra; Ghiani, Alessandra; Labra, Massimo; Sgorbati, Sergio; Brown, Spencer; Denis, Michel

    2001-01-01

    The membrane integrity of a cell is a well-accepted criterion for characterizing viable (active or inactive) cells and distinguishing them from damaged and membrane-compromised cells. This information is of major importance in studies of the function of microbial assemblages in natural environments, in order to assign bulk activities measured by various methods to the very active cells that are effectively responsible for the observations. To achieve this task for bacteria in freshwater and marine waters, we propose a nucleic acid double-staining assay based on analytical flow cytometry, which allows us to distinguish viable from damaged and membrane-compromised bacteria and to sort out noise and detritus. This method is derived from the work of S. Barbesti et al. (Cytometry 40:214–218, 2000) which was conducted on cultured bacteria. The principle of this approach is to use simultaneously a permeant (SYBR Green; Molecular Probes) and an impermeant (propidium iodide) probe and to take advantage of the energy transfer which occurs between them when both probes are staining nucleic acids. A full quenching of the permeant probe fluorescence by the impermeant probe will point to cells with a compromised membrane, a partial quenching will indicate cells with a slightly damaged membrane, and a lack of quenching will characterize intact membrane cells identified as viable. In the present study, this approach has been adapted to bacteria in freshwater and marine waters of the Mediterranean region. It is fast and easy to use and shows that a large fraction of bacteria with low DNA content can be composed of viable cells. Admittedly, limitations stem from the unknown behavior of unidentified species present in natural environments which may depart from the established permeability properties with respect to the fluorescing dyes. PMID:11571170

  20. Economic Analysis of Photovoltaics Versus Traditional Energy Sources: Where Are We Now and Where Might We Be in the Near Future?; Preprint

    SciTech Connect

    Woodhouse, M.; James, T.; Margolis, R.; Feldman, D.; Merkel, T.; Goodrich, A.

    2011-07-01

    A precipitous drop in the price of the crystalline silicon solar photovoltaic (PV) modules typically employed for residential applications has recently been observed: The typical sales price for modules was around $4/WP DC in 2008 but could easily approach $1.50/W WP DC by the end of this year. As module price declines continue, and as gains are also realized in balance-of-system costs, the economics of PV systems for power generation become increasingly competitive. In this presentation, we will examine whether solar will reach grid parity in the United States if monocrystalline silicon modules achieve an optimistic-case scenario in efficiency and cost. The analysis suggests that PV systems are already economically viable in select markets, but further cost reductions and efficiency improvements above and beyond the monocrystalline optimistic-case scenarios are necessary in order to be competitive against incumbent electricity production in most markets across the United States.

  1. Iowa Women of Achievement.

    ERIC Educational Resources Information Center

    Ohrn, Deborah Gore, Ed.

    1993-01-01

    This issue of the Goldfinch highlights some of Iowa's 20th century women of achievement. These women have devoted their lives to working for human rights, education, equality, and individual rights. They come from the worlds of politics, art, music, education, sports, business, entertainment, and social work. They represent Native Americans,…

  2. Achieving Peace through Education.

    ERIC Educational Resources Information Center

    Clarken, Rodney H.

    While it is generally agreed that peace is desirable, there are barriers to achieving a peaceful world. These barriers are classified into three major areas: (1) an erroneous view of human nature; (2) injustice; and (3) fear of world unity. In a discussion of these barriers, it is noted that although the consciousness and conscience of the world…

  3. Increasing Male Academic Achievement

    ERIC Educational Resources Information Center

    Jackson, Barbara Talbert

    2008-01-01

    The No Child Left Behind legislation has brought greater attention to the academic performance of American youth. Its emphasis on student achievement requires a closer analysis of assessment data by school districts. To address the findings, educators must seek strategies to remedy failing results. In a mid-Atlantic district of the Unites States,…

  4. Leadership Issues: Raising Achievement.

    ERIC Educational Resources Information Center

    Horsfall, Chris, Ed.

    This document contains five papers examining the meaning and operation of leadership as a variable affecting student achievement in further education colleges in the United Kingdom. "Introduction" (Chris Horsfall) discusses school effectiveness studies' findings regarding the relationship between leadership and effective schools, distinguishes…

  5. Achievements or Disasters?

    ERIC Educational Resources Information Center

    Goodwin, MacArthur

    2000-01-01

    Focuses on policy issues that have affected arts education in the twentieth century, such as: interest in discipline-based arts education, influence of national arts associations, and national standards and coordinated assessment. States that whether the policy decisions are viewed as achievements or disasters are for future determination. (CMK)

  6. Achieving True Consensus.

    ERIC Educational Resources Information Center

    Napier, Rod; Sanaghan, Patrick

    2002-01-01

    Uses the example of Vermont's Middlebury College to explore the challenges and possibilities of achieving consensus about institutional change. Discusses why, unlike in this example, consensus usually fails, and presents four demands of an effective consensus process. Includes a list of "test" questions on successful collaboration. (EV)

  7. School Students' Science Achievement

    ERIC Educational Resources Information Center

    Shymansky, James; Wang, Tzu-Ling; Annetta, Leonard; Everett, Susan; Yore, Larry D.

    2013-01-01

    This paper is a report of the impact of an externally funded, multiyear systemic reform project on students' science achievement on a modified version of the Third International Mathematics and Science Study (TIMSS) test in 33 small, rural school districts in two Midwest states. The systemic reform effort utilized a cascading leadership strategy…

  8. Essays on Educational Achievement

    ERIC Educational Resources Information Center

    Ampaabeng, Samuel Kofi

    2013-01-01

    This dissertation examines the determinants of student outcomes--achievement, attainment, occupational choices and earnings--in three different contexts. The first two chapters focus on Ghana while the final chapter focuses on the US state of Massachusetts. In the first chapter, I exploit the incidence of famine and malnutrition that resulted to…

  9. Assessing Handwriting Achievement.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    Teachers in the school setting need to emphasize quality handwriting across the curriculum. Quality handwriting means that the written content is easy to read in either manuscript or cursive form. Handwriting achievement can be assessed, but not compared to the precision of assessing basic addition, subtraction, multiplication, and division facts.…

  10. Intelligence and Educational Achievement

    ERIC Educational Resources Information Center

    Deary, Ian J.; Strand, Steve; Smith, Pauline; Fernandes, Cres

    2007-01-01

    This 5-year prospective longitudinal study of 70,000+ English children examined the association between psychometric intelligence at age 11 years and educational achievement in national examinations in 25 academic subjects at age 16. The correlation between a latent intelligence trait (Spearman's "g"from CAT2E) and a latent trait of educational…

  11. Explorations in achievement motivation

    NASA Technical Reports Server (NTRS)

    Helmreich, Robert L.

    1982-01-01

    Recent research on the nature of achievement motivation is reviewed. A three-factor model of intrinsic motives is presented and related to various criteria of performance, job satisfaction and leisure activities. The relationships between intrinsic and extrinsic motives are discussed. Needed areas for future research are described.

  12. NCLB: Achievement Robin Hood?

    ERIC Educational Resources Information Center

    Bracey, Gerald W.

    2008-01-01

    In his "Wall Street Journal" op-ed on the 25th of anniversary of "A Nation At Risk", former assistant secretary of education Chester E. Finn Jr. applauded the report for turning U.S. education away from equality and toward achievement. It was not surprising, then, that in mid-2008, Finn arranged a conference to examine the potential "Robin Hood…

  13. INTELLIGENCE, PERSONALITY AND ACHIEVEMENT.

    ERIC Educational Resources Information Center

    MUIR, R.C.; AND OTHERS

    A LONGITUDINAL DEVELOPMENTAL STUDY OF A GROUP OF MIDDLE CLASS CHILDREN IS DESCRIBED, WITH EMPHASIS ON A SEGMENT OF THE RESEARCH INVESTIGATING THE RELATIONSHIP OF ACHIEVEMENT, INTELLIGENCE, AND EMOTIONAL DISTURBANCE. THE SUBJECTS WERE 105 CHILDREN AGED FIVE TO 6.3 ATTENDING TWO SCHOOLS IN MONTREAL. EACH CHILD WAS ASSESSED IN THE AREAS OF…

  14. SALT and Spelling Achievement.

    ERIC Educational Resources Information Center

    Nelson, Joan

    A study investigated the effects of suggestopedic accelerative learning and teaching (SALT) on the spelling achievement, attitudes toward school, and memory skills of fourth-grade students. Subjects were 20 male and 28 female students from two self-contained classrooms at Kennedy Elementary School in Rexburg, Idaho. The control classroom and the…

  15. Appraising Reading Achievement.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    To determine quality sequence in pupil progress, evaluation approaches need to be used which guide the teacher to assist learners to attain optimally. Teachers must use a variety of procedures to appraise student achievement in reading, because no one approach is adequate. Appraisal approaches might include: (1) observation and subsequent…

  16. [A method for assessing the total viable count of fresh meat based on hyperspectral scattering technique].

    PubMed

    Song, Yu-Lin; Peng, Yan-Kun; Guo, Hui; Zhang, Lei-Lei; Zhao, Juan

    2014-03-01

    The objective of this study is to develop a hyperspectral imaging system to predict the bacteria total viable count in fresh pork. The hyperspectral scattering data were curvefitted by different fitting methods, and correlation differences of models were compared based on the bacteria total viable count of fresh pork, thus providing modeling basis of device for future study. Total 63 fresh pork samples which was used in the experiment were stored at 4 degrees C in the refrigerator of constant temperature. Experiment was performed everyday for 15 days. 4 or 5 random samples were used each day for the experiment. Hyperspectral scattering images and spectral scattering optical data in the wavelength region of 400 to 1 100 nm were acquired from the surface of all of the pork samples. Lorentz and Gompertz function and the modified function was applied to fit the scattering profiles of pork samples. Different parameters could be obtained by Lorentz and Gompertz fitting and the modified function fitting. The different parameters could represent the optical characteristic of the scattering profiles. The standard values of the bacteria total viable count of pork were obtained by classical microbiological plating methods. Because the standard value of the bacteria total viable count was big, log10 of the bacteria total viable count obtained by classical microbiological plating was used to simplify the calculation. Both individual parameters and integrated parameters were explored to develop the models. The multi-linear regression statistical approach was used to establish the models for predicting pork the bacteria total viable count. Both Lorentz and Gompertz function and the modified function included three and four parameters formula. The results showed that correlation coefficient of the models is higher with Lorentz three parameters combination, Lorentz four parameters combination and Gompertz four parameters combination than the individual parameters and other two or

  17. [A method for assessing the total viable count of fresh meat based on hyperspectral scattering technique].

    PubMed

    Song, Yu-Lin; Peng, Yan-Kun; Guo, Hui; Zhang, Lei-Lei; Zhao, Juan

    2014-03-01

    The objective of this study is to develop a hyperspectral imaging system to predict the bacteria total viable count in fresh pork. The hyperspectral scattering data were curvefitted by different fitting methods, and correlation differences of models were compared based on the bacteria total viable count of fresh pork, thus providing modeling basis of device for future study. Total 63 fresh pork samples which was used in the experiment were stored at 4 degrees C in the refrigerator of constant temperature. Experiment was performed everyday for 15 days. 4 or 5 random samples were used each day for the experiment. Hyperspectral scattering images and spectral scattering optical data in the wavelength region of 400 to 1 100 nm were acquired from the surface of all of the pork samples. Lorentz and Gompertz function and the modified function was applied to fit the scattering profiles of pork samples. Different parameters could be obtained by Lorentz and Gompertz fitting and the modified function fitting. The different parameters could represent the optical characteristic of the scattering profiles. The standard values of the bacteria total viable count of pork were obtained by classical microbiological plating methods. Because the standard value of the bacteria total viable count was big, log10 of the bacteria total viable count obtained by classical microbiological plating was used to simplify the calculation. Both individual parameters and integrated parameters were explored to develop the models. The multi-linear regression statistical approach was used to establish the models for predicting pork the bacteria total viable count. Both Lorentz and Gompertz function and the modified function included three and four parameters formula. The results showed that correlation coefficient of the models is higher with Lorentz three parameters combination, Lorentz four parameters combination and Gompertz four parameters combination than the individual parameters and other two or

  18. Economic analysis of the unified heliostat array

    NASA Astrophysics Data System (ADS)

    1981-01-01

    Two heliostats, the Veda Industrial Heliostat (VIH) and the Repowering Heliostat were investigated in conjunction with the UHA. The UHA was found to be a viable candidate for solar thermal central receiver applications. The UHA-VIH combination was shown to provide very high flux densities and to be suitable for high temperature applications in the 10000 K to 20000 K range. These temperatures were shown to be achievable even with very small (1 MWt) collector fields.

  19. Solar energy system economic evaluation: IBM System 2, Togus, Maine

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The economic analysis of the solar energy system, is developed for Torgus and four other sites typical of a wide range of environmental and economic conditions in the continental United States. This analysis is accomplished based on the technical and economic models in the f-chart design procedure with inputs taken on the characteristics of the installed system and local conditions. The results are expressed in terms of the economic parameters of present worth of system cost over a projected twenty year life, life cycle savings, year of positive savings and year of payback for the optimized solar energy system at each of the analysis sites. The sensitivity of the economic evaluation to uncertainties in constituent system and economic variables is also investigated. Results demonstrate that the solar energy system is economically viable at all of the five sites for which the analysis was conducted.

  20. A new analytical platform based on field-flow fractionation and olfactory sensor to improve the detection of viable and non-viable bacteria in food.

    PubMed

    Roda, Barbara; Mirasoli, Mara; Zattoni, Andrea; Casale, Monica; Oliveri, Paolo; Bigi, Alessandro; Reschiglian, Pierluigi; Simoni, Patrizia; Roda, Aldo

    2016-10-01

    An integrated sensing system is presented for the first time, where a metal oxide semiconductor sensor-based electronic olfactory system (MOS array), employed for pathogen bacteria identification based on their volatile organic compound (VOC) characterisation, is assisted by a preliminary separative technique based on gravitational field-flow fractionation (GrFFF). In the integrated system, a preliminary step using GrFFF fractionation of a complex sample provided bacteria-enriched fractions readily available for subsequent MOS array analysis. The MOS array signals were then analysed employing a chemometric approach using principal components analysis (PCA) for a first-data exploration, followed by linear discriminant analysis (LDA) as a classification tool, using the PCA scores as input variables. The ability of the GrFFF-MOS system to distinguish between viable and non-viable cells of the same strain was demonstrated for the first time, yielding 100 % ability of correct prediction. The integrated system was also applied as a proof of concept for multianalyte purposes, for the detection of two bacterial strains (Escherichia coli O157:H7 and Yersinia enterocolitica) simultaneously present in artificially contaminated milk samples, obtaining a 100 % ability of correct prediction. Acquired results show that GrFFF band slicing before MOS array analysis can significantly increase reliability and reproducibility of pathogen bacteria identification based on their VOC production, simplifying the analytical procedure and largely eliminating sample matrix effects. The developed GrFFF-MOS integrated system can be considered a simple straightforward approach for pathogen bacteria identification directly from their food matrix. Graphical abstract An integrated sensing system is presented for pathogen bacteria identification in food, in which field-flow fractionation is exploited to prepare enriched cell fractions prior to their analysis by electronic olfactory system

  1. From Whitlam to Economic Rationalism and Beyond: A Conceptual Framework for Political Activism in Children's Services

    ERIC Educational Resources Information Center

    Sumsion, Jennifer

    2006-01-01

    Thirty years after the dismissal of the Whitlam Government, the Australian political, economic and social landscape is dominated by discourses of economic rationalism. The reification of market forces presents challenges for early childhood professionals seeking to establish a viable future trajectory for children's services that includes…

  2. Viable Intrauterine Pregnancy and Coexisting Molar Pregnancy in a Bicornuate Uterus: A Rare Presentation

    PubMed Central

    Krishnamoorthy, Kavitha; Gerkowicz, Sabrina; Verma, Usha

    2016-01-01

    A complete hydatidiform mole with a viable coexisting fetus (CMCF) is a rare occurrence. Similarly, Mullerian anomalies such as a bicornuate uterus are uncommon variants of normal anatomy. We report a case of a 40-year-old female with a known bicornuate uterus presenting at 13 weeks gestation with vaginal bleeding. Ultrasound findings showed a healthy viable pregnancy in the right horn with complete molar pregnancy in the left horn. After extensive counseling, the patient desired conservative management, however, was unable to continue due to profuse vaginal bleeding. The patient underwent suction dilation and curettage under general anesthesia and evacuation of the uterine horns. Postoperatively, the patient was followed until serum beta-human chorionic gonadotropin (β-hCG) level dropped to <5 mU. This is the first case of a CMCF reported in a bicornuate uterus, diagnosed with the use of ultrasound imaging. PMID:27403404

  3. PMA-PhyloChip DNA Microarray to Elucidate Viable Microbial Community Structure

    NASA Technical Reports Server (NTRS)

    Venkateswaran, Kasthuri J.; Stam, Christina N.; Andersen, Gary L.; DeSantis, Todd

    2011-01-01

    Since the Viking missions in the mid-1970s, traditional culture-based methods have been used for microbial enumeration by various NASA programs. Viable microbes are of particular concern for spacecraft cleanliness, for forward contamination of extraterrestrial bodies (proliferation of microbes), and for crew health/safety (viable pathogenic microbes). However, a "true" estimation of viable microbial population and differentiation from their dead cells using the most sensitive molecular methods is a challenge, because of the stability of DNA from dead cells. The goal of this research is to evaluate a rapid and sensitive microbial detection concept that will selectively estimate viable microbes. Nucleic acid amplification approaches such as the polymerase chain reaction (PCR) have shown promise for reducing time to detection for a wide range of applications. The proposed method is based on the use of a fluorescent DNA intercalating agent, propidium monoazide (PMA), which can only penetrate the membrane of dead cells. The PMA-quenched reaction mixtures can be screened, where only the DNA from live cells will be available for subsequent PCR reaction and microarray detection, and be identified as part of the viable microbial community. An additional advantage of the proposed rapid method is that it will detect viable microbes and differentiate from dead cells in only a few hours, as opposed to less comprehensive culture-based assays, which take days to complete. This novel combination approach is called the PMA-Microarray method. DNA intercalating agents such as PMA have previously been used to selectively distinguish between viable and dead bacterial cells. Once in the cell, the dye intercalates with the DNA and, upon photolysis under visible light, produces stable DNA adducts. DNA cross-linked in this way is unavailable for PCR. Environmental samples suspected of containing a mixture of live and dead microbial cells/spores will be treated with PMA, and then incubated

  4. Viable inflationary models ending with a first-order phase transition

    SciTech Connect

    Cortes, Marina; Liddle, Andrew R.

    2009-10-15

    We investigate the parameter space of two-field inflation models where inflation terminates via a first-order phase transition causing nucleation of bubbles. Such models experience a tension from the need to ensure nearly scale-invariant density perturbations, while avoiding a near scale-invariant bubble size distribution which would conflict observations. We perform an exact analysis of the different regimes of the models, where the energy density of the inflaton field ranges from being negligible as compared to the vacuum energy to providing most of the energy for inflation. Despite recent microwave anisotropy results favoring a spectral index less than 1, we find that there are still viable models that end with bubble production and can match all available observations. As a by-product of our analysis, we also provide an up-to-date assessment of the viable parameter space of Linde's original second-order hybrid model across its full parameter range.

  5. Isolation of viable Neospora caninum from brains of wild gray wolves (Canis lupus).

    PubMed

    Dubey, J P; Jenkins, M C; Ferreira, L R; Choudhary, S; Verma, S K; Kwok, O C H; Fetterer, R; Butler, E; Carstensen, M

    2014-03-17

    Neospora caninum is a common cause of abortion in cattle worldwide. Canids, including the dog and the dingo (Canis familiaris), the coyote (Canis latrans), and the gray wolf (Canis lupus) are its definitive hosts that can excrete environmentally resistant oocysts in the environment, but also can act as intermediate hosts, harboring tissue stages of the parasite. In an attempt to isolate viable N. caninum from tissues of naturally infected wolves, brain and heart tissue from 109 wolves from Minnesota were bioassayed in mice. Viable N. caninum (NcWolfMn1, NcWolfMn2) was isolated from the brains of two wolves by bioassays in interferon gamma gene knockout mice. DNA obtained from culture-derived N. caninum tachyzoites of the two isolates were analyzed by N. caninum-specific Nc5 polymerase chain reaction and confirmed diagnosis. This is the first report of isolation of N. caninum from tissues of any wild canid host. PMID:24522164

  6. Project ACHIEVE final report

    SciTech Connect

    1997-06-13

    Project ACHIEVE was a math/science academic enhancement program aimed at first year high school Hispanic American students. Four high schools -- two in El Paso, Texas and two in Bakersfield, California -- participated in this Department of Energy-funded program during the spring and summer of 1996. Over 50 students, many of whom felt they were facing a nightmare future, were given the opportunity to work closely with personal computers and software, sophisticated calculators, and computer-based laboratories -- an experience which their regular academic curriculum did not provide. Math and science projects, exercises, and experiments were completed that emphasized independent and creative applications of scientific and mathematical theories to real world problems. The most important outcome was the exposure Project ACHIEVE provided to students concerning the college and technical-field career possibilities available to them.

  7. Concurrent detection of other respiratory viruses in children shedding viable human respiratory syncytial virus.

    PubMed

    Gagliardi, T B; Paula, F E; Iwamoto, M A; Proença-Modena, J L; Santos, A E; Camara, A A; Cervi, M C; Cintra, O A L; Arruda, E

    2013-10-01

    Human respiratory syncytial virus (HRSV) is an important cause of respiratory disease. The majority of studies addressing the importance of virus co-infections to the HRSV-disease have been based on the detection of HRSV by RT-PCR, which may not distinguish current replication from prolonged shedding of remnant RNA from previous HRSV infections. To assess whether co-detections of other common respiratory viruses are associated with increased severity of HRSV illnesses from patients who were shedding viable-HRSV, nasopharyngeal aspirates from children younger than 5 years who sought medical care for respiratory infections in Ribeirão Preto (Brazil) were tested for HRSV by immunofluorescence, RT-PCR and virus isolation in cell culture. All samples with viable-HRSV were tested further by PCR for other respiratory viruses. HRSV-disease severity was assessed by a clinical score scale. A total of 266 samples from 247 children were collected and 111 (42%) were HRSV-positive. HRSV was isolated from 70 (63%), and 52 (74%) of them were positive for at least one additional virus. HRSV-positive diseases were more severe than HRSV-negative ones, but there was no difference in disease severity between patients with viable-HRSV and those HRSV-positives by RT-PCR. Co-detection of other viruses did not correlate with increased disease severity. HRSV isolation in cell culture does not seem to be superior to RT-PCR to distinguish infections associated with HRSV replication in studies of clinical impact of HRSV. A high rate of co-detection of other respiratory viruses was found in samples with viable-HRSV, but this was not associated with more severe HRSV infection.

  8. Challenge of N95 Filtering Facepiece Respirators with Viable H1N1 Influenza Aerosols

    PubMed Central

    Harnish, Delbert A.; Heimbuch, Brian K.; Husband, Michael; Lumley, April E.; Kinney, Kimberly; Shaffer, Ronald E.; Wander, Joseph D.

    2015-01-01

    OBJECTIVE Specification of appropriate personal protective equipment for respiratory protection against influenza is somewhat controversial. In a clinical environment, N95 filtering facepiece respirators (FFRs) are often recommended for respiratory protection against infectious aerosols. This study evaluates the ability of N95 FFRs to capture viable H1N1 influenza aerosols. METHODS Five N95 FFR models were challenged with aerosolized viable H1N1 influenza and inert polystyrene latex particles at continuous flow rates of 85 and 170 liters per minute. Virus was assayed using Madin-Darby canine kidney cells to determine the median tissue culture infective dose (TCID50). Aerosols were generated using a Collison nebulizer containing H1N1 influenza virus at 1 × 108 TCID50/mL. To determine filtration efficiency, viable sampling was performed upstream and downstream of the FFR. RESULTS N95 FFRs filtered 0.8-µm particles of both H1N1 influenza and inert origins with more than 95% efficiency. With the exception of 1 model, no statistically significant difference in filtration performance was observed between influenza and inert particles of similar size. Although statistically significant differences were observed for 2 models when comparing the 2 flow rates, the differences have no significance to protection. CONCLUSIONS This study empirically demonstrates that a National Institute for Occupational Safety and Health–approved N95 FFR captures viable H1N1 influenza aerosols as well as or better than its N95 rating, suggesting that a properly fitted FFR reduces inhalation exposure to airborne influenza virus. This study also provides evidence that filtration efficiency is based primarily on particle size rather than the nature of the particle’s origin. PMID:23571366

  9. An advanced PCR method for the specific detection of viable total coliform bacteria in pasteurized milk.

    PubMed

    Soejima, Takashi; Minami, Jun-ichi; Yaeshima, Tomoko; Iwatsuki, Keiji

    2012-07-01

    Pasteurized milk is a complex food that contains various inhibitors of polymerase chain reaction (PCR) and may contain a large number of dead bacteria, depending on the milking conditions and environment. Ethidium monoazide bromide (EMA)-PCR is occasionally used to distinguish between viable and dead bacteria in foods other than pasteurized milk. EMA is a DNA-intercalating dye that selectively permeates the compromised cell membranes of dead bacteria and cleaves DNA. Usually, EMA-PCR techniques reduce the detection of dead bacteria by up to 3.5 logs compared with techniques that do not use EMA. However, this difference may still be insufficient to suppress the amplification of DNA from dead Gram-negative bacteria (e.g., total coliform bacteria) if they are present in pasteurized milk in large numbers. Thus, false positives may result. We developed a new method that uses real-time PCR targeting of a long DNA template (16S-23S rRNA gene, principally 2,451 bp) following EMA treatment to completely suppress the amplification of DNA of up to 7 logs (10(7) cells) of dead total coliforms. Furthermore, we found that a low dose of proteinase K (25 U/ml) removed PCR inhibitors and simultaneously increased the signal from viable coliform bacteria. In conclusion, our simple protocol specifically detects viable total coliforms in pasteurized milk at an initial count of ≥1 colony forming unit (CFU)/2.22 ml within 7.5 h of total testing time. This detection limit for viable cells complies with the requirements for the analysis of total coliforms in pasteurized milk set by the Japanese Sanitation Act (which specifies <1 CFU/2.22 ml). PMID:22644523

  10. Fully-customized lingual appliances: how lingual orthodontics became a viable treatment option.

    PubMed

    George, Richard D; Hirani, Sunil

    2013-09-01

    Despite being available for over 30 years, it is perhaps only over the past decade or so that lingual therapy has entered into the mainstream and become a viable treatment option. This paper outlines the problems encountered with traditional lingual techniques and describes how fully-customized lingual appliances have been designed to overcome many of the issues that had risked confining lingual orthodontics to the margins of clinical practice.

  11. The importance of the viable but non-culturable state in human bacterial pathogens

    PubMed Central

    Li, Laam; Mendis, Nilmini; Trigui, Hana; Oliver, James D.; Faucher, Sebastien P.

    2014-01-01

    Many bacterial species have been found to exist in a viable but non-culturable (VBNC) state since its discovery in 1982. VBNC cells are characterized by a loss of culturability on routine agar, which impairs their detection by conventional plate count techniques. This leads to an underestimation of total viable cells in environmental or clinical samples, and thus poses a risk to public health. In this review, we present recent findings on the VBNC state of human bacterial pathogens. The characteristics of VBNC cells, including the similarities and differences to viable, culturable cells and dead cells, and different detection methods are discussed. Exposure to various stresses can induce the VBNC state, and VBNC cells may be resuscitated back to culturable cells under suitable stimuli. The conditions that trigger the induction of the VBNC state and resuscitation from it are summarized and the mechanisms underlying these two processes are discussed. Last but not least, the significance of VBNC cells and their potential influence on human health are also reviewed. PMID:24917854

  12. Diclofenac metabolic profile following in vitro percutaneous absorption through viable human skin.

    PubMed

    Tanojo, H; Wester, R C; Shainhouse, J Z; Maibach, H I

    1999-01-01

    The extent of metabolism of diclofenac sodium in excised viable human skin was investigated using combination HPLC and radioactivity assay. In an earlier diffusion experiment using an in vitro flow-through diffusion system, radiolabelled diclofenac sodium in either lotion (Pennsaid) or aqueous solution was applied to viable human skin, either as single dose or multiple dose (8 times over 2 days). In this study, the receptor fluid samples from the diffusion experiment were subjected to extraction and the aliquot was analysed using HPLC to separate diclofenac and authentic metabolites. Based on the radioactivity of each HPLC fraction, the collection time of the fractions was compared with the retention time of diclofenac and metabolites in standard solutions. The samples from a single or multiple dose application of lotion showed radioactivity in mainly one fraction, whose retention time corresponded with diclofenac. Other HPLC fractions showed none or only small amounts of radioactivity within the error range of the assay. The same results were obtained with the pooled samples from the application of the lotion or of aqueous solution. The results suggest that diclofenac sodium does not undergo metabolism in viable human epidermis during percutaneous absorption in vitro. Hence, with topical application to human skin in vivo, diclofenac will be delivered with minimal, if any, metabolism.

  13. Use of propidium monoazide for selective profiling of viable microbial cells during Gouda cheese ripening.

    PubMed

    Erkus, Oylum; de Jager, Victor C L; Geene, Renske T C M; van Alen-Boerrigter, Ingrid; Hazelwood, Lucie; van Hijum, Sacha A F T; Kleerebezem, Michiel; Smid, Eddy J

    2016-07-01

    DNA based microbial community profiling of food samples is confounded by the presence of DNA derived from membrane compromised (dead or injured) cells. Selective amplification of DNA from viable (intact) fraction of the community by propidium monoazide (PMA) treatment could circumvent this problem. Gouda cheese manufacturing is a proper model to evaluate the use of PMA for selective detection of intact cells since large fraction of membrane compromised cells emerges as a background in the cheese matrix during ripening. In this study, the effect of PMA on cheese community profiles was evaluated throughout manufacturing and ripening using quantitative PCR (qPCR). PMA effectively inhibited the amplification of DNA derived from membrane compromised cells and enhanced the analysis of the intact fraction residing in the cheese samples. Furthermore, a two-step protocol, which involves whole genome amplification (WGA) to enrich the DNA not modified with PMA and subsequent sequencing, was developed for the selective metagenome sequencing of viable fraction in the Gouda cheese microbial community. The metagenome profile of PMA treated cheese sample reflected the viable community profile at that time point in the cheese manufacturing. PMID:27077825

  14. Viable Biomass Sensor integration in the MELiSSA CI and CIII compartments

    NASA Astrophysics Data System (ADS)

    Duatis Juarez, Jordi; Peiro, Enrique; Bragos, Ramon

    Traditionally, the biomass quantity and quality in complex substrate reactor (e.g. activated sludge, high density, fixed bed,..) is determined off-line in laboratories. Within this study, the VIAMASS Sensor System, which uses Electrical Impedance Spectroscopy (EIS) techniques, has been tested for MELiSSA compartment CI and C III, the liquefying and the nitrifying compartment respectively. This sensor is able to measure viable cells on basis of an impedance spectroscopy measurement. The fact that viable biomass can be detected, distinguishes the sensor from classical biomass sensors used in wastewater treatment plants. Detection of viable biomass and composition of the biomass can be very useful for calibration and validation of biological models. The sensor can be used to detect toxicity in system leading to die-off of organisms. The technology developed initially for space applications has been adapted and will be also able to give overall information on the population distribution of cells, distinguishing what type of biomass is dominant (for example, bacteria or protozoa).

  15. Fluorescence particle detector for real-time quantification of viable organisms in air

    NASA Astrophysics Data System (ADS)

    Luoma, Greg; Cherrier, Pierre P.; Piccioni, Marc; Tanton, Carol; Herz, Steve; DeFreez, Richard K.; Potter, Michael; Girvin, Kenneth L.; Whitney, Ronald

    2002-02-01

    The ability to detect viable organisms in air in real time is important in a number of applications. Detecting high levels of airborne organisms in hospitals can prevent post-operative infections and the spread of diseases. Monitoring levels of airborne viable organisms in pharmaceutical facilities can ensure safe production of drugs or vaccines. Monitoring airborne bacterial levels in meat processing plants can help to prevent contamination of food products. Monitoring the level of airborne organisms in bio-containment facilities can ensure that proper procedures are being followed. Finally, detecting viable organisms in real time is a key to defending against biological agent attacks. This presentation describes the development and performance of a detector, based on fluorescence particle counting technology, where an ultraviolet laser is used to count particles by light scattering and elicit fluorescence from specific biomolecules found only in living organisms. The resulting detector can specifically detect airborne particles containing living organisms from among the large majority of other particles normally present in air. Efforts to develop the core sensor technology, focusing on integrating an UV laser with a specially designed particle-counting cell will be highlighted. The hardware/software used to capture the information from the sensor, provide an alarm in the presence of an unusual biological aerosol content will also be described. Finally, results from experiments to test the performance of the detector will be presented.

  16. Real-time quantification of viable bacteria in liquid medium using infrared thermography

    NASA Astrophysics Data System (ADS)

    Salaimeh, Ahmad A.; Campion, Jeffrey J.; Gharaibeh, Belal Y.; Evans, Martin E.; Saito, Kozo

    2011-11-01

    Quantifying viable bacteria in liquids is important in environmental, food processing, manufacturing, and medical applications. Since vegetative bacteria generate heat as a result of biochemical reactions associated with cellular functions, thermal sensing techniques, including infrared thermography (IRT), have been used to detect viable cells in biologic samples. We developed a novel method that extends the dynamic range and improves the sensitivity of bacterial quantification by IRT. The approach uses IRT video, thermodynamics laws, and heat transfer mechanisms to directly measure, in real-time, the amount of energy lost as heat from the surface of a liquid sample containing bacteria when the specimen cools to a lower temperature over 2 min. We show that the Energy Content ( EC) of liquid media containing as few as 120 colony-forming units (CFU) of Escherichia coli per ml was significantly higher than that of sterile media ( P < 0.0001), and that EC and viable counts were strongly positively correlated ( r = 0.986) over a range of 120 to approximately 5 × 10 8 CFU/ml. Our IRT approach is a unique non-contact method that provides real-time bacterial enumeration over a wide dynamic range without the need for sample concentration, modification, or destruction. The approach could be adapted to quantify other living cells in a liquid milieu and has the potential for automation and high throughput.

  17. Use of propidium monoazide for selective profiling of viable microbial cells during Gouda cheese ripening.

    PubMed

    Erkus, Oylum; de Jager, Victor C L; Geene, Renske T C M; van Alen-Boerrigter, Ingrid; Hazelwood, Lucie; van Hijum, Sacha A F T; Kleerebezem, Michiel; Smid, Eddy J

    2016-07-01

    DNA based microbial community profiling of food samples is confounded by the presence of DNA derived from membrane compromised (dead or injured) cells. Selective amplification of DNA from viable (intact) fraction of the community by propidium monoazide (PMA) treatment could circumvent this problem. Gouda cheese manufacturing is a proper model to evaluate the use of PMA for selective detection of intact cells since large fraction of membrane compromised cells emerges as a background in the cheese matrix during ripening. In this study, the effect of PMA on cheese community profiles was evaluated throughout manufacturing and ripening using quantitative PCR (qPCR). PMA effectively inhibited the amplification of DNA derived from membrane compromised cells and enhanced the analysis of the intact fraction residing in the cheese samples. Furthermore, a two-step protocol, which involves whole genome amplification (WGA) to enrich the DNA not modified with PMA and subsequent sequencing, was developed for the selective metagenome sequencing of viable fraction in the Gouda cheese microbial community. The metagenome profile of PMA treated cheese sample reflected the viable community profile at that time point in the cheese manufacturing.

  18. Desiccation induces viable but Non-Culturable cells in Sinorhizobium meliloti 1021

    PubMed Central

    2012-01-01

    Sinorhizobium meliloti is a microorganism commercially used in the production of e.g. Medicago sativa seed inocula. Many inocula are powder-based and production includes a drying step. Although S. meliloti survives drying well, the quality of the inocula is reduced during this process. In this study we determined survival during desiccation of the commercial strains 102F84 and 102F85 as well as the model strain USDA1021. The survival of S. meliloti 1021 was estimated during nine weeks at 22% relative humidity. We found that after an initial rapid decline of colony forming units, the decline slowed to a steady 10-fold reduction in colony forming units every 22 days. In spite of the reduction in colony forming units, the fraction of the population identified as viable (42-54%) based on the Baclight live/dead stain did not change significantly over time. This change in the ability of viable cells to form colonies shows (i) an underestimation of the survival of rhizobial cells using plating methods, and that (ii) in a part of the population desiccation induces a Viable But Non Culturable (VBNC)-like state, which has not been reported before. Resuscitation attempts did not lead to a higher recovery of colony forming units indicating the VBNC state is stable under the conditions tested. This observation has important consequences for the use of rhizobia. Finding methods to resuscitate this fraction may increase the quality of powder-based seed inocula. PMID:22260437

  19. Mice carrying a complete deletion of the talin2 coding sequence are viable and fertile

    SciTech Connect

    Debrand, Emmanuel; Conti, Francesco J.; Bate, Neil; Spence, Lorraine; Mazzeo, Daniela; Pritchard, Catrin A.; Monkley, Susan J.; Critchley, David R.

    2012-09-21

    Highlights: Black-Right-Pointing-Pointer Mice lacking talin2 are viable and fertile with only a mildly dystrophic phenotype. Black-Right-Pointing-Pointer Talin2 null fibroblasts show no major defects in proliferation, adhesion or migration. Black-Right-Pointing-Pointer Maintaining a colony of talin2 null mice is difficult indicating an underlying defect. -- Abstract: Mice homozygous for several Tln2 gene targeted alleles are viable and fertile. Here we show that although the expression of talin2 protein is drastically reduced in muscle from these mice, other tissues continue to express talin2 albeit at reduced levels. We therefore generated a Tln2 allele lacking the entire coding sequence (Tln2{sup cd}). Tln2{sup cd/cd} mice were viable and fertile, and the genotypes of Tln2{sup cd/+} intercrosses were at the expected Mendelian ratio. Tln2{sup cd/cd} mice showed no major difference in body mass or the weight of the major organs compared to wild-type, although they displayed a mildly dystrophic phenotype. Moreover, Tln2{sup cd/cd} mouse embryo fibroblasts showed no obvious defects in cell adhesion, migration or proliferation. However, the number of Tln2{sup cd/cd} pups surviving to adulthood was variable suggesting that such mice have an underlying defect.

  20. Elimination of harmonic induced viable bifurcations with TCSC for ac-fed electric arc furnaces

    NASA Astrophysics Data System (ADS)

    Varan, Metin; Uyarog˜lu, Yılmaz

    2012-11-01

    AC-fed electric arc furnaces (EAFs) are known with their unbalanced, excessively nonlinear and time varying load characteristics. The nonlinear oscillations produced by EAF operation cause several problems to interconnected feed system. Injection of harmonics/interharmonics and rising flicker effects on the feed system are two of major problems produced by EAF. These nonlinear effects result into quasistatic changes in the feed system parameters (L - R) . In last decade many studies have been reported that such quasistatic changes in the feed system parameters result in viable bifurcation formations which strictly cause sudden and drastic changes on system behaviors. This paper presents an analytical control procedure to eliminate viable bifurcation points on L - I and R - I curves that cause sudden resonant peak arc currents. After control procedure, stability margins of EAF are extended into larger levels and viable bifurcation points on the feed system parameter have been eliminated. During study, possible roles of small parameter changes of uncontrolled EAF around bifurcation points and controlled EAF have been traced over time series analysis, phase plane analysis and bifurcation diagrams. A wide collection of useful dynamic analysis procedures for the exploration of studied arc furnace dynamics have been handled through the AUTO open-source algorithms.

  1. Fate of Viable but Non-culturable Listeria monocytogenes in Pig Manure Microcosms

    PubMed Central

    Desneux, Jérémy; Biscuit, Audrey; Picard, Sylvie; Pourcher, Anne-Marie

    2016-01-01

    The fate of two strains of Listeria monocytogenes and their ability to become viable but non-culturable (VBNC) was investigated in microcosms containing piggery effluents (two raw manures and two biologically treated manures) stored for 2 months at 8 and 20°C. Levels of L. monocytogenes were estimated using the culture method, qPCR, and propidium monoazide treatment combined with qPCR (qPCRPMA). The chemical composition and the microbial community structure of the manures were also analyzed. The strains showed similar decline rates and persisted up to 63 days. At day zero, the percentage of VBNC cells among viable cells was higher in raw manures (81.5–94.8%) than in treated manures (67.8–79.2%). The changes in their proportion over time depended on the temperature and on the type of effluent: the biggest increase was observed in treated manures at 20°C and the smallest increase in raw manures at 8°C. The chemical parameters had no influence on the behavior of the strains, but decrease of the persistence of viable cells was associated with an increase in the microbial richness of the manures. This study demonstrated that storing manure altered the culturability of L. monocytogenes, which rapidly entered the VBNC state, and underlines the importance of including VBNC cells when estimating the persistence of the pathogens in farm effluents. PMID:26973623

  2. Economic Knowledge, Economic Education and Public Opinion on Economic Issues.

    ERIC Educational Resources Information Center

    Walstad, William B.

    This research study was based upon a national survey in March 1992, conducted to assess the economic literacy of the U.S. public. The survey data were used to measure the economic knowledge of the public, to identify factors that affect economic knowledge, and to evaluate the influence of economic knowledge on public opinion about current economic…

  3. Does achievement motivation mediate the semantic achievement priming effect?

    PubMed

    Engeser, Stefan; Baumann, Nicola

    2014-10-01

    The aim of our research was to understand the processes of the prime-to-behavior effects with semantic achievement primes. We extended existing models with a perspective from achievement motivation theory and additionally used achievement primes embedded in the running text of excerpts of school textbooks to simulate a more natural priming condition. Specifically, we proposed that achievement primes affect implicit achievement motivation and conducted pilot experiments and 3 main experiments to explore this proposition. We found no reliable positive effect of achievement primes on implicit achievement motivation. In light of these findings, we tested whether explicit (instead of implicit) achievement motivation is affected by achievement primes and found this to be the case. In the final experiment, we found support for the assumption that higher explicit achievement motivation implies that achievement priming affects the outcome expectations. The implications of the results are discussed, and we conclude that primes affect achievement behavior by heightening explicit achievement motivation and outcome expectancies. PMID:24820250

  4. Use of diesel engine and surface-piercing propeller to achieve fuel savings for inshore fishing boats

    NASA Astrophysics Data System (ADS)

    Zainol, Ismail; Yaakob, Omar

    2016-06-01

    Fishing is a major local industry in Malaysia, particularly in rural areas. However, the rapidly increasing price of fuel is seriously affecting the industry's viability. At present, outboard petrol engines are the preferred choice for use in small-scale fishing boats because they deliver the advantages of high speed and low weight, they are easy to install, and they use minimal space. Petrol outboard engines are known to consume a greater amount of fuel than inboard diesel engines, but installing diesel engines with conventional submerged propellers in existing small-scale fishing boats is not economically viable because major hullform modifications and extra expenditure are required to achieve this. This study describes a proposal to enable reductions in fuel consumption by introducing the combined use of a diesel engine and surface-piercing propeller (SPP). An analysis of fuel consumption reduction is presented, together with an economic feasibility study. Resulting data reveal that the use of the proposed modifications would save 23.31 liters of fuel per trip (40.75 %) compared to outboard motors, equaling annual savings of RM 3962 per year.

  5. Charter school education in Texas: Student achievement on the exit level assessment in math and science

    NASA Astrophysics Data System (ADS)

    Turner, Jeffery E.

    Public schools in the state of Texas are held accountable for performance and quality of education. Accountability is important to all schools, but it is critical to open-enrollment charter schools to remain in good standing. The current economic situation in Texas public education has brought attention as well as the need for alternative education programs such as charter schools. It is of the utmost importance for charter schools to illustrate that they are meeting the academic needs of the target market. This study addressed student achievement, as well as expenditure per student in both charter schools and traditional schools in the Region 10 educational service center. The datum for the study were obtained from the Texas Education Agency (TEA) website, specifically the Academic Excellence Indicator System Data (AEIS) files for the 2011-2012. The study sample included 30 open-enrollment charters schools and 30 traditional high schools within the Region 10 educational service center during the school year of 2011-2012. The research study determined significant statistical differences between open-enrollment charter schools and traditional high schools. The potential for the study was to gain additional knowledge and insight along with additional data for the open-enrollment charter schools and traditional schools in the Region 10 Educational Service Center. The study has potentially increased the information for researchers and practitioners in education. In addition this study has proved charter schools are a viable and an effective educational tool for the future.

  6. Localisation of threat substances in urban society - LOTUS: a viable tool for finding illegal bomb factories in cities

    NASA Astrophysics Data System (ADS)

    Önnerud, Hans; Wallin, Sara; Östmark, Henric; Menning, Dennis; Ek, Stefan; Ellis, Hanna; Kölhed, Malin

    2011-06-01

    Results of dispersion experiments and dispersion modelling of explosives, drugs, and their precursors will be presented. The dispersion of chemicals evolving during preparation of home made explosives and a drug produced in an improvised manner in an ordinary kitchen has been measured. Experiments with concentration of hydrogen peroxide have been performed during spring and summer of 2009 and 2010 and further experiments with concentration of hydrogen peroxide, synthesis and drying of TATP and Methamphetamine are planned for the spring and summer of 2011. Results from the experiments are compared to dispersion modelling to achieve a better understanding of the dispersion processes and the resulting substances and amounts available for detection outside the kitchen at distances of 10-30 m and longer. Typical concentration levels have been determined as a function of environmental conditions. The experiments and modelling are made as a part of the LOTUS project aimed at detecting and locating the illicit production of explosives and drugs in an urban environment. It can be concluded that the proposed LOTUS system concept, using mobile automatic sensors, data transfer, location via GSM/GPS for on-line detection of illicit production of explosive or precursors to explosives and drugs is a viable approach and is in accordance with historical and today's illicit bomb manufacturing. The overall objective and approach of the LOTUS project will also be presented together with two more projects called PREVAIL and EMPHASIS both aiming at hindering or finding illicit production of home made explosives.

  7. Lesson Plans in Urban Economics.

    ERIC Educational Resources Information Center

    Alexander, Albert

    1990-01-01

    Traces history of urbanization and problems created by growth of cities. Describes process of homogenization achieved by land-use regulations, income and education differentiation, and racial/ethnic characteristics. Focuses on the sociopolitical-economic challenges of the 1990s. Includes format for three lessons with a case study project and…

  8. Economic impact of stimulated technological activity. Part 1: Overall economic impact of technological progress: Its measurement

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Investigations were performed at the national economic level to explore the aggregate effects of technological progress on economic growth. Inadequacies in existing marco-economic yardsticks forced the study to focus on the cost savings effects achieved through technological progress. The central questions discussed in this report cover: (1) role of technological progress in economic growth, (2) factors determining the rate of economic growth due to technological progress; (3) quantitative measurements of relationships between technological progress, its determinants, and subsequent economic growth; and (4) effects of research and development activities of the space program. For Part 2, see N72-32174.

  9. Construction of luciferase reporter bacteriophage A511::luxAB for rapid and sensitive detection of viable Listeria cells.

    PubMed Central

    Loessner, M J; Rees, C E; Stewart, G S; Scherer, S

    1996-01-01

    Specific transfer and expression of bacterial luciferase genes via bacteriophages provides an efficient way to detect and assay viable host cells. Listeria bacteriophage A511 is a genus-specific, virulent myovirus which infects 95% of Listeria monocytogenes serovar 1/2 and 4 cells. We constructed recombinant derivative A511::luxAB, which carries the gene for a fused Vibrio harveyi LuxAB protein inserted immediately downstream of the major capsid protein gene (cps). Efficient transcription is initiated by the powerful cps promoter at 15 to 20 min postinfection. Site-specific introduction of the luciferase gene into the phage genome was achieved by homologous recombination in infected cells between a plasmid carrying A511 DNA flanking luxAB and phage DNA. Recombinants occurred in the lysate at a frequency of 5 x 10(-4) and were readily identified by the bioluminescent phenotype conferred on newly infected host cells. A511::luxAB can be used to directly detect Listeria cells. Following infection and a 2-h incubation period, numbers as low as 5 x 10(2) to 10(3) cells per ml were detected by using a single-tube luminometer. Extreme sensitivity was achieved by including an enrichment step prior to the lux phage assay; under these conditions less than 1 cell of L. monocytogenes Scott A per g of artificially contaminated salad was clearly identified. The assay is simple, rapid, inexpensive, and easy to perform. Our findings indicate that A511::luxAB is useful for routine screening of foods and environmental samples for Listeria cells. PMID:8919773

  10. Perspectives of High-Achieving Women on Teaching

    ERIC Educational Resources Information Center

    Snodgrass, Helen

    2010-01-01

    High-achieving women are significantly less likely to enter the teaching profession than they were just 40 years ago. Why? While the social and economic reasons for this decline have been well documented in the literature, what is lacking is a discussion with high-achieving women, as they make their first career decisions, about their perceptions…

  11. Educational Achievement and Black-White Inequality. Statistical Analysis Report.

    ERIC Educational Resources Information Center

    Jacobson, Jonathan; Olsen, Cara; Rice, Jennifer King; Sweetland, Stephen

    This study explored relationships between black-white differences in educational achievement and black-white differences in various educational and economic outcomes. Three data sets examined the extent to which black-white differences in labor market outcomes, in educational attainment, and in mathematics and reading achievement were present for…

  12. Urban School Reform, Family Support, and Student Achievement

    ERIC Educational Resources Information Center

    Greene, Kiersten; Anyon, Jean

    2010-01-01

    Teachers and other education professionals find themselves in schools and districts bombarded by reforms--each one purporting to improve student achievement, particularly in reading and mathematics. This article lays the political economic groundwork of student achievement in urban areas in an attempt to contextualize the studies of literacy in…

  13. Relationships among Projective and Direct Verbal Measures of Achievement Motivation.

    ERIC Educational Resources Information Center

    Singh, Satvir

    1979-01-01

    The ways in which projective and nonprojective verbal measures of achievement motivation elicit comparable and dissimilar responses in a "Third World" sample of entrepreneurs and farmers were explored as a test of McClelland's theory of economic growth. Results were generally consistent with the theory of achievement motivation. (Author/JKS)

  14. Growth Phase, Oxygen, Temperature, and Starvation Affect the Development of Viable but Non-culturable State of Vibrio cholerae.

    PubMed

    Wu, Bin; Liang, Weili; Kan, Biao

    2016-01-01

    Vibrio cholerae can enter into a viable but non-culturable (VBNC) state in order to survive in unfavorable environments. In this study, we studied the roles of five physicochemical and microbiological factors or states, namely, different strains, growth phases, oxygen, temperature, and starvation, on the development of VBNC of V. cholerae in artificial sea water (ASW). Different strains of the organism, the growth phase, and oxygen levels affected the progress of VBNC development. It was found that the VBNC state was induced faster in V. cholerae serogroup O1 classical biotype strain O395 than in O1 El Tor biotype strains C6706 and N16961. When cells in different growth phases were used for VBNC induction, stationary-phase cells lost their culturability more quickly than exponential-phase cells, while induction of a totally non-culturable state took longer to achieve for stationary-phase cells in all three strains, suggesting that heterogeneity of cells should be considered. Aeration strongly accelerated the loss of culturability. During the development of the VBNC state, the culturable cell count under aeration conditions was almost 10(6)-fold lower than under oxygen-limited conditions for all three strains. The other two factors, temperature and nutrients-rich environment, may prevent the induction of VBNC cells. At 22 or 37°C in ASW, most of the cells rapidly died and the culturable cell count reduced from about 10(8) to 10(6)-10(5) CFU/mL. The total cell counts showed that cells that lost viability were decomposed, and the viable cell counts were the same as culturable cell counts, indicating that the cells did not reach the VBNC state. VBNC state development was blocked when ASW was supplied with Luria-Bertani broth (LB), but it was not affected in ASW with M9, suggesting that specific nutrients in LB may prevent the development of VBNC state. These results revealed that the five factors evaluated in this study had different roles during the progress of VBNC

  15. Growth Phase, Oxygen, Temperature, and Starvation Affect the Development of Viable but Non-culturable State of Vibrio cholerae.

    PubMed

    Wu, Bin; Liang, Weili; Kan, Biao

    2016-01-01

    Vibrio cholerae can enter into a viable but non-culturable (VBNC) state in order to survive in unfavorable environments. In this study, we studied the roles of five physicochemical and microbiological factors or states, namely, different strains, growth phases, oxygen, temperature, and starvation, on the development of VBNC of V. cholerae in artificial sea water (ASW). Different strains of the organism, the growth phase, and oxygen levels affected the progress of VBNC development. It was found that the VBNC state was induced faster in V. cholerae serogroup O1 classical biotype strain O395 than in O1 El Tor biotype strains C6706 and N16961. When cells in different growth phases were used for VBNC induction, stationary-phase cells lost their culturability more quickly than exponential-phase cells, while induction of a totally non-culturable state took longer to achieve for stationary-phase cells in all three strains, suggesting that heterogeneity of cells should be considered. Aeration strongly accelerated the loss of culturability. During the development of the VBNC state, the culturable cell count under aeration conditions was almost 10(6)-fold lower than under oxygen-limited conditions for all three strains. The other two factors, temperature and nutrients-rich environment, may prevent the induction of VBNC cells. At 22 or 37°C in ASW, most of the cells rapidly died and the culturable cell count reduced from about 10(8) to 10(6)-10(5) CFU/mL. The total cell counts showed that cells that lost viability were decomposed, and the viable cell counts were the same as culturable cell counts, indicating that the cells did not reach the VBNC state. VBNC state development was blocked when ASW was supplied with Luria-Bertani broth (LB), but it was not affected in ASW with M9, suggesting that specific nutrients in LB may prevent the development of VBNC state. These results revealed that the five factors evaluated in this study had different roles during the progress of VBNC

  16. Assessment and economic analysis of the MOD III Stirling-engine driven chiller system. Final report, October 1989-July 1990

    SciTech Connect

    Moryl, J.

    1990-07-01

    The Stirling engine is an inherently clean and efficient engine. With the requirements for environmentally benign emissions and high energy efficiency, the Stirling engine is an attractive alternative to both internal combustion (IC) engines and electric motors. The study evaluated a Stirling-engine-driven chiller package. Technically, the Stirling engine is a good selection as a compressor drive, with inherently low vibrations, quiet operation, long life, and low maintenance. Exhaust emissions are below the projected 1995 stringent California standards. Economically, the Stirling-engine-driven chiller is a viable alternative to both IV-engine and electric-driven chillers, trading off slightly higher installed cost against lower total operating expenses. The penetration of a small portion of the projected near-term stationary engine market opportunity will provide the volume production basis to achieve competitively priced engines.

  17. Economic contribution and viability of dairy goats: implications for a breeding programme.

    PubMed

    Ogola, T D O; Nguyo, W K; Kosgey, I S

    2010-06-01

    To augment the incomes of smallholder farmers in Kenya and consequently improve their nutrition and income, many development organisations and policy makers are increasingly promoting dairy goat farming. Among the key organisations supporting the initiative is Heifer Project International-Kenya (HPIK). However, the economic contribution and viability of dairy goats under the HPIK project have not been studied so far. The aim of the present study was to determine the contribution of dairy goats to household income and the performance of the dairy goat enterprise using gross and net margins from dairy goat farming as an indicator of economic viability. A survey covering 71 farmers was carried out in the Coast, Nyanza, and the Rift Valley provinces of Kenya using a set of pre-tested structured and semi-structured questionnaires. Results showed that, on average, the dairy goat enterprise contributed, correspondingly, about 15.2% and 4.8% to the total livestock and overall household income and was viable. Differences in gross and net margins across agroecological zones were attributed to milk prices. Despite the existence of non-viable enterprises in two of the provinces, the few present suggest the possibility of obtaining reliable incomes from the enterprise. Redoubling of effort or re-orientation of production to match the local and external requirements would, however, be necessary. Costs and revenues were similar across the agroecological zones. Farmers with positive gross margins had better milk and stock sales and vice versa. The success of a dairy goat enterprise is attributed to location and good management. Besides, farmers' awareness of the market demands within and outside the community is important in establishing production goals and may be crucial to achieving a positive gross margin.

  18. Technical Note: Ethical Economics

    NASA Astrophysics Data System (ADS)

    Blodgett, J.

    Ethical economics is inspirational, expanding our vision beyond the narrow self-interest of the theoretical economic man. Ethical economics sees more value in space settlement than conventional economic calculations that can inappropriately discount the value of the future.

  19. Achieving closure at Fernald

    SciTech Connect

    Bradburne, John; Patton, Tisha C.

    2001-02-25

    When Fluor Fernald took over the management of the Fernald Environmental Management Project in 1992, the estimated closure date of the site was more than 25 years into the future. Fluor Fernald, in conjunction with DOE-Fernald, introduced the Accelerated Cleanup Plan, which was designed to substantially shorten that schedule and save taxpayers more than $3 billion. The management of Fluor Fernald believes there are three fundamental concerns that must be addressed by any contractor hoping to achieve closure of a site within the DOE complex. They are relationship management, resource management and contract management. Relationship management refers to the interaction between the site and local residents, regulators, union leadership, the workforce at large, the media, and any other interested stakeholder groups. Resource management is of course related to the effective administration of the site knowledge base and the skills of the workforce, the attraction and retention of qualified a nd competent technical personnel, and the best recognition and use of appropriate new technologies. Perhaps most importantly, resource management must also include a plan for survival in a flat-funding environment. Lastly, creative and disciplined contract management will be essential to effecting the closure of any DOE site. Fluor Fernald, together with DOE-Fernald, is breaking new ground in the closure arena, and ''business as usual'' has become a thing of the past. How Fluor Fernald has managed its work at the site over the last eight years, and how it will manage the new site closure contract in the future, will be an integral part of achieving successful closure at Fernald.

  20. Sorption and precipitation of Mn2+ by viable and autoclaved Shewanella putrefaciens: Effect of contact time

    NASA Astrophysics Data System (ADS)

    Chubar, Natalia; Visser, Tom; Avramut, Cristina; de Waard, Helen

    2013-01-01

    The sorption of Mn(II) by viable and inactivated cells of Shewanella putrefaciens, a non-pathogenic, facultative anaerobic, gram-negative bacterium characterised as a Mn(IV) and Fe(III) reducer, was studied under aerobic conditions, as a function of pH, bacterial density and metal loading. During a short contact time (3-24 h), the adsorptive behaviour of live and dead bacteria toward Mn(II) was sufficiently similar, an observation that was reflected in the studies on adsorption kinetics at various metal loadings, effects of pH, bacteria density, isotherms and drifting of pH during adsorption. Continuing the experiment for an additional 2-30 days demonstrated that the Mn(II) sorption by suspensions of viable and autoclaved cells differed significantly from one another. The sorption to dead cells was characterised by a rapid equilibration and was described by an isotherm. In contrast, the sorption (uptake) to live bacteria exhibited a complex time-dependent uptake. This uptake began as adsorption and ion exchange processes followed by bioprecipitation, and it was accompanied by the formation of polymeric sugars (EPS) and the release of dissolved organic substances. FTIR, EXAFS/XANES and XPS demonstrated that manganese(II) phosphate was the main precipitate formed in 125 ml batches, which is the first evidence of the ability of microbes to synthesise manganese phosphates. XPS and XANES spectra did not detect Mn(II) oxidation. Although the release of protein-like compounds by the viable bacteria increased in the presence of Mn2+ (and, by contrast, the release of carbohydrates did not change), electrochemical analyses did not indicate any aqueous complexation of Mn(II) by the organic ligands.

  1. A direct viable count method for the enumeration of attached bacteria and assessment of biofilm disinfection

    NASA Technical Reports Server (NTRS)

    Yu, F. P.; Pyle, B. H.; McFeters, G. A.

    1993-01-01

    This report describes the adaptation of an in situ direct viable count (in situ DVC) method in biofilm disinfection studies. The results obtained with this technique were compared to two other enumeration methods, the plate count (PC) and conventional direct viable count (c-DVC). An environmental isolate (Klebsiella pneumoniae Kp1) was used to form biofilms on stainless steel coupons in a stirred batch reactor. The in situ DVC method was applied to directly assess the viability of bacteria in biofilms without disturbing the integrity of the interfacial community. As additional advantages, the results were observed after 4 h instead of the 24 h incubation time required for colony formation and total cell numbers that remained on the substratum were enumerated. Chlorine and monochloramine were used to determine the susceptibilities of attached and planktonic bacteria to disinfection treatment using this novel analytical approach. The planktonic cells in the reactor showed no significant change in susceptibility to disinfectants during the period of biofilm formation. In addition, the attached cells did not reveal any more resistance to disinfection than planktonic cells. The disinfection studies of young biofilms indicated that 0.25 mg/l free chlorine (at pH 7.2) and 1 mg/l monochloramine (at pH 9.0) have comparable disinfection efficiencies at 25 degrees C. Although being a weaker disinfectant, monochloramine was more effective in removing attached bacteria from the substratum than free chlorine. The in situ DVC method always showed at least one log higher viable cell densities than the PC method, suggesting that the in situ DVC method is more efficient in the enumeration of biofilm bacteria. The results also indicated that the in situ DVC method can provide more accurate information regarding the cell numbers and viability of bacteria within biofilms following disinfection.

  2. Detection of viable Salmonella in lettuce by propidium monoazide real-time PCR.

    PubMed

    Liang, Ningjian; Dong, Jin; Luo, Laixin; Li, Yong

    2011-05-01

    Contamination of lettuce by Salmonella has caused serious public health problems. Polymerase chain reaction (PCR) allows rapid detection of pathogenic bacteria in food, but it is inaccurate as it might amplify DNA from dead target cells as well. This study aimed to investigate the stability of DNA of dead Salmonella cells in lettuce and to develop an approach to detecting viable Salmonella in lettuce. Salmonella-free lettuce was inoculated with heat-killed Salmonella Typhimurium cells and stored at 4 °C. Bacterial DNA extracted from the sample was amplified by real-time PCR targeting the invA gene. Our results indicate that DNA from the dead cells remained stable in lettuce for at least 8 d. To overcome this limitation, propidium monoazide (PMA), a dye that can selectively penetrate dead bacterial cells and cross-link their DNA upon light exposure, was combined with real-time PCR. Lettuce samples inoculated with different levels of dead or viable S. Typhimurium cells were treated or untreated with PMA before DNA extraction. Real-time PCR suggests that PMA treatment effectively prevented PCR amplification from as high as 10(8) CFU/g dead S. Typhimurium cells in lettuce. The PMA real-time PCR assay could detect viable Salmonella at as low as 10(2) CFU/mL in pure culture and 10(3) CFU/g in lettuce. With 12-h enrichment, S. Typhimurium of 10(1) CFU/g in lettuce was detectable. In conclusion, the PMA real-time PCR assay provides an alternative to real-time PCR assay for accurate detection of Salmonella in food.

  3. Immune responses to viable and degenerative metacestodes of Taenia solium in naturally infected swine.

    PubMed

    Singh, Aloukick K; Prasad, Kashi N; Prasad, Amit; Tripathi, Mukesh; Gupta, Rakesh K; Husain, Nuzhat

    2013-12-01

    Neurocysticercosis, caused by the larvae of the pork tapeworm Taenia solium, is the most common helminth infection of the CNS in humans worldwide. There is no existing animal model of neurocysticercosis that resembles human infection. To overcome this limitation, swine (the natural intermediate host of the parasite) may be a suitable model. The immune response associated with different stages of the parasite larva (metacestode) has not yet been explored. Therefore, we investigated the immune response to various stages of the metacestode (cyst) in the brain and muscles of naturally infected swine. Swine with neurocysticercosis (n = 10) and healthy controls (n = 10), as confirmed by magnetic resonance imaging, were included in this study. The animals were sacrificed, and the tissues containing viable or degenerative metacestods in the brain and infected muscles were collected and subjected to reverse transcriptase-PCR and ELISA to determine the expression of different cytokines (IFN-γ, TNF-α, IL-1β, IL-2, IL-4 IL-6, IL-8 and IL-10). Higher expression of IL-10 was found to be associated with viable cysts. Degenerating cysts displayed significantly increased levels of IFN-γ, TNF-α, IL-1β, IL-2, IL-6 and IL-8, whereas calcified cysts had elevated levels of IL-4, IL-10, TNF-α and IL-6. The present study indicated a strong regulatory (IL-10) and Th1 cytokine response in viable and degenerating cysts, respectively, whereas calcified cysts had a mixed anti-inflammatory (IL-4), regulatory (IL-10) and pro-inflammatory (TNF-α and IL-6) response. Thus, Th1 and Th2 immune response operate in the vicinity of metacestodes and the type of immune response may be responsible for disease severity.

  4. Natural Transfer of Viable Microbes in Space. 1. From Mars to Earth and Earth to Mars

    NASA Astrophysics Data System (ADS)

    Mileikowsky, Curt; Cucinotta, Francis A.; Wilson, John W.; Gladman, Brett; Horneck, Gerda; Lindegren, Lennart; Melosh, Jay; Rickman, Hans; Valtonen, Mauri; Zheng, J. Q.

    2000-06-01

    The possibility and probability of natural transfer of viable microbes from Mars to Earth and Earth to Mars traveling in meteoroids during the first 0.5 Ga and the following 4 Ga are investigated, including: —radiation protection against the galactic cosmic ray nuclei and the solar rays; dose rates as a function of the meteorite's radial column mass (radius×density), combined with dose rates generated by natural radioactivity within the meteorite; and survival curves for some bacterial species using NASA's HZETRN transport code —other factors affecting microbe survival: vacuum; central meteorite temperatures at launch, orbiting, and arrival; pressure and acceleration at launch; spontaneous DNA decay; metal ion migration —mean sizes and numbers of unshocked meteorites ejected and percentage falling on Earth, using current semiempirical results —viable flight times for the microbe species Bacillus subtilis and Deinococcus radiodurans R1 —the approximate fraction of microbes (with properties like the two species studied) viably arriving on Earth out of those ejected from Mars during the period 4 Ga BP to the present time, and during the 700 Ma from 4.5 to 3.8 Ga. Similarly, from Earth to Mars. The conclusion is that if microbes existed or exist on Mars, viable transfer to Earth is not only possible but also highly probable, due to microbes' impressive resistance to the dangers of space transfer and to the dense traffic of billions of martian meteorites which have fallen on Earth since the dawn of our planetary system. Earth-to-Mars transfer is also possible but at a much lower frequency.

  5. Behavioral economics.

    PubMed

    Chambers, David W

    2009-01-01

    It is human nature to overestimate how rational we are, both in general and even when we are trying to be. Such irrationality is not random, and the search for and explanation of patterns of fuzzy thinking is the basis for a new academic discipline known as behavioral economics. Examples are given of some of the best understood of our foibles, including prospect theory, framing, anchoring, salience, confirmation bias, superstition, and ownership. Humans have two cognitive systems: one conscious, deliberate, slow, and rational; the other fast, pattern-based, emotionally tinged, and intuitive. Each is subject to its own kind of error. In the case of rational thought, we tend to exaggerate our capacity; for intuition, we fail to train it or recognize contexts where it is inappropriate. Humans are especially poor at estimating probabilities, or even understanding what they are. It is a common human failing to reason backwards from random outcomes that are favorable to beliefs about our power to predict the future. Five suggestions are offered for thinking within our means.

  6. Stopping Oxytocin in Active Labor Rather Than Continuing it until Delivery: A Viable Option for the Induction of Labor

    PubMed Central

    Chopra, Seema; SenGupta, Sandip K.; Jain, Vanita; Kumar, Parveen

    2015-01-01

    Objective Induction of labor (IOL), using intravenous oxytocin, is the artificial initiation of labor before its spontaneous onset for the purpose of delivery of the fetoplacental unit. Although there are various studies looking at dosages of oxytocin, only a few have addressed the issue of discontinuation of oxytocin in the active stage of labor. Thus, our study was conducted to evaluate the need for continuation versus discontinuation of oxytocin during active labor. Methods This prospective, randomized controlled trial included 106 women who needed IOL. Oxytocin infusion was initiated at a rate of 3mIU/min and was incremental until 4–6cm cervical dilation. At this point the patients were randomly assigned into one of two groups. In group one, oxytocin was discontinued, and infusion was continued with 0.9% sodium chloride solution. In group two, oxytocin was continued at the same dose until delivery. Results The duration of oxytocin infusion was 5.5 hours in the oxytocin discontinuation group and 11.0 hours in oxytocin continuation group (p<0.001). The total dose of oxytocin was significantly higher in group two (6.1 units vs. 16.5 units; p=<0.001). The induction-delivery interval was significantly less in group one (9.1 and 11.2 hours in group one and group two, respectively; p=0.023). Conclusion Oxytocin discontinuation in the active stage of labor did not prolong the active stage. The total duration of labor and total oxytocin dose were significantly less in the oxytocin discontinuation group. Our results suggest that oxytocin discontinuation is an alternative and viable option particularly in resource poor and economically challenged settings. It not only reduces the need for intense monitoring and prolonged oxytocin use-associated dangers but reduces the total cost of labor management. PMID:26421111

  7. Viable singularity-free f(R) gravity without a cosmological constant.

    PubMed

    Miranda, Vinícius; Jorás, Sergio E; Waga, Ioav; Quartin, Miguel

    2009-06-01

    Several authors have argued that self-consistent f(R) gravity models distinct from the cold dark matter model with a cosmological constant (LambdaCDM) are almost ruled out. Confronting such claims, we present a particular two-parameter f(R) model that (a) is cosmologically viable and distinguishable from LambdaCDM, (b) is compatible with the existence of relativistic stars, (c) is free of singularities of the Ricci scalar during the cosmological evolution, and (d) allows the addition of high-curvature corrections that could be relevant for inflation.

  8. Sonographic diagnosis of a viable abdominal pregnancy with planned delivery after fetal lung maturation.

    PubMed

    Kim, Mi Ju; Bae, Jin Young; Seong, Won Joon; Lee, Yoon Soon

    2013-01-01

    We report a case of a viable abdominal pregnancy with successful outpatient management until fetal lung maturation and planned delivery. Advanced abdominal pregnancy is a very rare extrauterine pregnancy, which results in serious maternal and fetal morbidity. A 28-year-old nullipara was referred from the local clinic to our tertiary center at 18 weeks' gestation. We diagnosed an extrauterine fetus on sonographic examination. The patient had weekly antenatal sonographic examinations. We performed a planned laparotomy at 34 weeks' gestation, and a female baby weighing 2,100 g was delivered. The placenta was completely removed and the uterus was preserved. Both the mother and the baby had no postoperative morbidity.

  9. Using the Malcolm Baldridge criteria: a viable tool for assessing organizational change

    SciTech Connect

    Stack, J.M.

    1998-04-01

    How does understanding and using the Malcolm Baldrige criteria impact library organizational change? In September 1997, the Los Alarnos National Laboratory Research Library used the criteria to apply for a Quality New Mexico Award (QNMA). This paper will provide a fimdamental background on the Malcolm Baldrige criteria and outline the Library project to apply for the award. The Research Library learned from the project and feedback and has started implementing steps to increase its effectiveness providing viable products and services to its customers. This has been a step forward to strengthen our competitive edge to assure our fiture prosperity within the Laboratory.

  10. The Knee Joint Loose Body as a Source of Viable Autologous Human Chondrocytes

    PubMed Central

    Melrose, J.

    2016-01-01

    Loose bodies are fragments of cartilage or bone present in the synovial fluid. In the present study we assessed if loose bodies could be used as a source of autologous human chondrocytes for experimental purposes. Histochemical examination of loose bodies and differential enzymatic digestions were undertaken, the isolated cells were cultured in alginate bead microspheres and immunolocalisations were undertaken for chondrogenic markers such as aggrecan, and type II collagen. Isolated loose body cells had high viability (≥90% viable), expressed chondrogenic markers (aggrecan, type II collagen) but no type I collagen. Loose bodies may be a useful source of autologous chondrocytes of high viability. PMID:27349321

  11. From Homochiral Clusters to Racemate Crystals: Viable Nuclei in 2D Chiral Crystallization.

    PubMed

    Seibel, Johannes; Parschau, Manfred; Ernst, Karl-Heinz

    2015-07-01

    The quest for enantiopure compounds raises the question of which factors favor conglomerate crystallization over racemate crystallization. Studying nucleation and crystal growth at surfaces with submolecular-resolution scanning tunneling microscopy is a suitable approach to better understand intermolecular chiral recognition. Racemic heptahelicene on the Ag(100) surface shows a transition from homochiral nuclei to larger racemic motifs, although the extended homochiral phase exhibits higher density. The homochiral-heterochiral transition is explained by the higher stability of growing nuclei due to a better match of the molecular lattice to the substrate surface. Our observations are direct visual proof of viable nuclei.

  12. Capstone Senior Research Course in Economics

    ERIC Educational Resources Information Center

    Li, Ishuan; Simonson, Robert

    2016-01-01

    In this article, the authors describe the structure and assessment of a capstone course in economics. The outcomes are noteworthy for three reasons. First, among cited evidence to date, this is the only undergraduate economics program from a nonselective public university reporting similar achievements in undergraduate research paper publications.…

  13. Should High School Economics Courses Be Compulsory?

    ERIC Educational Resources Information Center

    Belfield, Clive R.; Levin, Henry M.

    2004-01-01

    This paper estimates the effect of a state-imposed curriculum mandate on the academic achievement of US public school students. By 1998, 14 states across the US had mandates that high school students should take an economics course. For these states, the proportions of public schools students taking high school economics was around twice that of…

  14. Process simulation and economical evaluation of enzymatic biodiesel production plant.

    PubMed

    Sotoft, Lene Fjerbaek; Rong, Ben-Guang; Christensen, Knud V; Norddahl, Birgir

    2010-07-01

    Process simulation and economical evaluation of an enzymatic biodiesel production plant has been carried out. Enzymatic biodiesel production from high quality rapeseed oil and methanol has been investigated for solvent free and cosolvent production processes. Several scenarios have been investigated with different production scales (8 and 200 mio. kg biodiesel/year) and enzyme price. The cosolvent production process is found to be most expensive and is not a viable choice, while the solvent free process is viable for the larger scale production of 200 mio. kg biodiesel/year with the current enzyme price. With the suggested enzyme price of the future, both the small and large scale solvent free production proved viable. The product price was estimated to be 0.73-1.49 euro/kg biodiesel with the current enzyme price and 0.05-0.75 euro/kg with the enzyme price of the future for solvent free process.

  15. Achievement Goals and Achievement Emotions: A Meta-Analysis

    ERIC Educational Resources Information Center

    Huang, Chiungjung

    2011-01-01

    This meta-analysis synthesized 93 independent samples (N = 30,003) in 77 studies that reported in 78 articles examining correlations between achievement goals and achievement emotions. Achievement goals were meaningfully associated with different achievement emotions. The correlations of mastery and mastery approach goals with positive achievement…

  16. Entrepreneur achievement. Liaoning province.

    PubMed

    Zhao, R

    1994-03-01

    This paper reports the successful entrepreneurial endeavors of members of a 20-person women's group in Liaoning Province, China. Jing Yuhong, a member of the Family Planning Association at Shileizi Village, Dalian City, provided the basis for their achievements by first building an entertainment/study room in her home to encourage married women to learn family planning. Once stocked with books, magazines, pamphlets, and other materials on family planning and agricultural technology, dozens of married women in the neighborhood flocked voluntarily to the room. Yuhong also set out to give these women a way to earn their own income as a means of helping then gain greater equality with their husbands and exert greater control over their personal reproductive and social lives. She gave a section of her farming land to the women's group, loaned approximately US$5200 to group members to help them generate income from small business initiatives, built a livestock shed in her garden for the group to raise marmots, and erected an awning behind her house under which mushrooms could be grown. The investment yielded $12,000 in the first year, allowing each woman to keep more than $520 in dividends. Members then soon began going to fairs in the capital and other places to learn about the outside world, and have successfully ventured out on their own to generate individual incomes. Ten out of twenty women engaged in these income-generating activities asked for and got the one-child certificate.

  17. The Caribbean Basin Initiative: Reaction to the CBI I as an Economic Development Model and of Its Impact to the Region.

    ERIC Educational Resources Information Center

    Potoker, Elaine S.

    Begun under President Reagan, the Caribbean Basin Initiative (CBI) was a program of trade, economic assistance, and tax measures designed to generate economic growth in the region through private sector investment and trade. This study proposes to: (1) discuss the reaction to the CBI as a viable economic development model for the region; and (2)…

  18. A Viable Population of the European Red Squirrel in an Urban Park

    PubMed Central

    Rézouki, Célia; Dozières, Anne; Le Cœur, Christie; Thibault, Sophie; Pisanu, Benoît; Chapuis, Jean-Louis; Baudry, Emmanuelle

    2014-01-01

    Whether urban parks can maintain viable and self-sustaining populations over the long term is questionable. In highly urbanized landscapes, urban parks could play a role in biodiversity conservation by providing habitat and resources to native species. However, populations inhabiting urban parks are usually small and isolated, leading to increased demographic stochasticity and genetic drift, with expected negative consequences on their viability. Here, we investigated a European red squirrel population located in an urban park close to Paris, France (Parc de Sceaux; 184 ha) to assess its viability. Using mitochondrial D-loop sequences and 13 microsatellite loci, we showed that the population presented high levels of genetic variation and no evidence of inbreeding. The size of the population was estimated at 100–120 individuals based on the comparison of two census techniques, Distance Sampling and Capture-Mark-Recapture. The estimated heterozygosity level and population size were integrated in a Population Viability Analysis to project the likelihood of the population's persistence over time. Results indicate that the red squirrel population of this urban park can be viable on the long term (i.e. 20 years) for a range of realistic demographic parameters (juvenile survival at least >40%) and immigration rates (at least one immigration event every two years). This study highlights that urban parks can be potential suitable refuges for the red squirrel, a locally threatened species across western European countries, provided that ecological corridors are maintained. PMID:25126848

  19. Viable mononuclear cell stability study for implementation in a proficiency testing program: impact of shipment conditions.

    PubMed

    Kofanova, Olga A; Davis, Kristine; Glazer, Barbara; De Souza, Yvonne; Kessler, Joseph; Betsou, Fotini

    2014-06-01

    The impact of shipping temperatures and preservation media used during transport of either peripheral blood mononuclear cells (PBMCs) or Jurkat cells was assessed, in view of implementing of a proficiency testing scheme on mononuclear cell viability. Samples were analyzed before and after shipment at different temperatures (ambient temperature, dry ice, and liquid nitrogen) and in different preservation media (serum with cryoprotectant, commercial cryopreservation solution, and room temperature transport medium). Sample quality was assessed by viability assays (Trypan Blue dye exclusion, flow cytometry, Cell Analysis System cell counting (CASY)), and by ELISpot functional assay. The liquid nitrogen storage and shipment were found to be the most stable conditions to preserve cell viability and functionality. However, we show that alternative high quality shipment conditions for viable cells are dry ice shipment and commercial cryopreservation solution. These were also cost-efficient shipment conditions, satisfying the requirements of a proficiency testing scheme for viable mononuclear cells. Room temperature transport medium dramatically and adversely affected the integrity of mononuclear cells. PMID:24955735

  20. The determination of viable counts in probiotic cultures microencapsulated by spray-coating.

    PubMed

    Champagne, Claude P; Raymond, Yves; Tompkins, Thomas A

    2010-12-01

    An assessment of various methods to determine viable counts (CFU) in freeze-dried and dried microencapsulated (ME) probiotic cultures was carried out. Microencapsulation was done by spray-coating of dried Lactobacillus rhamnosus R0011 or Bifidobacterium longum ATCC 15708 cultures with fat. Rehydration of the ME powders was incomplete when they were added to water and gently agitated. As a result analytical methods based on vortexing of rehydrated ME cultures and which did not incorporate a high-shear homogenization (HSH) step underestimated the viable counts. The CFU of ME cultures were identical when methods using either blender or generator probes high-shear homogenization (HSH) were carried out. Furthermore HSH reduced the variability of the CFU results of both free-cell and ME cultures by a factor of three. The addition of an emulsifier (Tween 80) in the rehydrating medium to dissolve fat did not improve CFU counts when generator probes were used for HSH. The presence of fat in the ME product, or when added to the rehydration medium, improved CFU counts of B. longum but not of L. rhamnosus.

  1. A viable population of the European red squirrel in an urban park.

    PubMed

    Rézouki, Célia; Dozières, Anne; Le Cœur, Christie; Thibault, Sophie; Pisanu, Benoît; Chapuis, Jean-Louis; Baudry, Emmanuelle

    2014-01-01

    Whether urban parks can maintain viable and self-sustaining populations over the long term is questionable. In highly urbanized landscapes, urban parks could play a role in biodiversity conservation by providing habitat and resources to native species. However, populations inhabiting urban parks are usually small and isolated, leading to increased demographic stochasticity and genetic drift, with expected negative consequences on their viability. Here, we investigated a European red squirrel population located in an urban park close to Paris, France (Parc de Sceaux; 184 ha) to assess its viability. Using mitochondrial D-loop sequences and 13 microsatellite loci, we showed that the population presented high levels of genetic variation and no evidence of inbreeding. The size of the population was estimated at 100-120 individuals based on the comparison of two census techniques, Distance Sampling and Capture-Mark-Recapture. The estimated heterozygosity level and population size were integrated in a Population Viability Analysis to project the likelihood of the population's persistence over time. Results indicate that the red squirrel population of this urban park can be viable on the long term (i.e. 20 years) for a range of realistic demographic parameters (juvenile survival at least >40%) and immigration rates (at least one immigration event every two years). This study highlights that urban parks can be potential suitable refuges for the red squirrel, a locally threatened species across western European countries, provided that ecological corridors are maintained.

  2. Theoretical and observational constraints of viable f (R ) theories of gravity

    NASA Astrophysics Data System (ADS)

    de la Cruz-Dombriz, Álvaro; Dunsby, Peter K. S.; Kandhai, Sulona; Sáez-Gómez, Diego

    2016-04-01

    Modified gravity has attracted much attention over the last few years and remains a potential candidate for dark energy. In particular, the so-called viable f (R ) gravity theories, which are able to both recover general relativity and produce late-time cosmic acceleration, have been widely studied in recent literature. Nevertheless, extended theories of gravity suffer from several shortcomings which compromise their ability to provide realistic alternatives to the standard cosmological Λ CDM Concordance model. We address the existence of cosmological singularities and the conditions that guarantee late-time acceleration, assuming reasonable energy conditions for standard matter in the so-called Hu-Sawicki f (R ) model, currently among the most widely studied modifications to general relativity. Then using the supernovae Ia Union 2.1 catalogue, we further constrain the free parameters of this model. The combined analysis of both theoretical and observational constraints sheds some light on the viable parameter space of these models and the form of the underlying effective theory of gravity.

  3. Personal sampler for monitoring of viable viruses; modelling of outdoor sampling conditions

    NASA Astrophysics Data System (ADS)

    Borodulin, A. I.; Desyatkov, B. M.; Lapteva, N. A.; Sergeev, A. N.; Agranovski, I. E.

    A new personal bioaerosol sampler has recently been developed and verified to be very efficient for monitoring of viable airborne bacteria, fungi and viruses. The device is capable of providing high recovery rates even for microorganisms which are rather sensitive to physical and biological stresses. However, some mathematical procedure is required for realistic calculation of an actual concentration of viable bioaerosols in the air taking into account a rate of inactivation of targeted microorganisms, sampling parameters, and results of microbial analysis of collecting liquid from the sampler. In this paper, we develop such procedure along with the model of aerosol propagation for outdoor conditions. Combining these procedures allows one to determine the optimal sampling locations for the best possible coverage of the area to be monitored. A hypothetical episode concerned with terrorists' attack during music concert in the central square of Novosibirsk, Russia was considered to evaluate possible coverage of the area by sampling equipment to detect bioaerosols at various locations within the square. It was found that, for chosen bioaerosol generation parameters and weather conditions, the new personal sampler would be capable to reliably detect pathogens at all locations occupied by crowd, even at distances of up to 600 m from the source.

  4. The microbiology of selected retail food products with an evaluation of viable counting methods.

    PubMed Central

    Greenwood, M. H.; Coetzee, E. F.; Ford, B. M.; Gill, P.; Hooper, W. L.; Matthews, S. C.; Patrick, S.; Pether, J. V.; Scott, R. J.

    1984-01-01

    In an inter-laboratory survey, the pour plate, surface spread, agar droplet and spiral plate methods were used in parallel with the surface drop method for enumeration of micro-organisms in foods. Good agreement was obtained between all surface methods of enumeration, but there was poor agreement between molten agar methods and the surface drop method. A total of 1143 samples of food that were ready for consumption at the point of retail sale were examined. Eight types of food products were chosen: meat pasties, sausage rolls, real-cream slices, synthetic-cream slices, mayonnaise-based coleslaws, faggots, patés and continental sausages. The results of this survey suggest that the upper limit for an acceptable viable count should vary according to the food product. Salmonellae were not isolated on any occasion. Potentially harmful organisms were not isolated at levels expected to constitute a public health hazard. Information concerning the nature of the product, the total viable count, the presence or absence of pathogenic, toxigenic or indicator organisms, the spectrum of the bacterial flora and the relative predominance of each organism must all be considered when assessing the microbiological acceptability of retail 'ready to eat' products. PMID:6319486

  5. Occurrence of viable, red-pigmented haloarchaea in the plumage of captive flamingoes

    PubMed Central

    Yim, Kyung June; Kwon, Joseph; Cha, In-Tae; Oh, Kyung-Seo; Song, Hye Seon; Lee, Hae-Won; Rhee, Jin-Kyu; Song, Eun-Ji; Rho, Jeong Rae; Seo, Mi Lyu; Choi, Jong-Soon; Choi, Hak-Jong; Lee, Sung-Jae; Nam, Young-Do; Roh, Seong Woon

    2015-01-01

    Flamingoes (Phoenicopterus spp.) whose plumage displays elegant colors, inhabit warm regions close to the ocean throughout the world. The pink or reddish color of their plumage originates from carotenoids ingested from carotenoid-abundant food sources, since flamingoes are unable to synthesize these compounds de novo. In this study, viable red-colored archaeal strains classified as extremely halophilic archaea (i.e., haloarchaea) and belonging to the genera Halococcus and Halogeometricum were isolated from the plumage of flamingoes in captivity. Detailed analysis for haloarchaeal community structure in flamingo feathers based on metagenomic data identified several haloarchaeal genera and unclassified sequences of the class Halobacteria at the genus level. Carotenoid pigment analyses showed that a bacterioruberin precursor carotenoid in haloarchaea was identical to one of the pigments found in flamingo plumage. To the best of our knowledge, this is the first report of viable extremophilic archaea in avian plumage, thus contributing to our understanding of the ecology of haloarchaea. The potential influence of haloarchaea as an environmental factor determining avian plumage coloration should be investigated in further studies. PMID:26553382

  6. Occurrence of viable, red-pigmented haloarchaea in the plumage of captive flamingoes.

    PubMed

    Yim, Kyung June; Kwon, Joseph; Cha, In-Tae; Oh, Kyung-Seo; Song, Hye Seon; Lee, Hae-Won; Rhee, Jin-Kyu; Song, Eun-Ji; Rho, Jeong Rae; Seo, Mi Lyu; Choi, Jong-Soon; Choi, Hak-Jong; Lee, Sung-Jae; Nam, Young-Do; Roh, Seong Woon

    2015-11-10

    Flamingoes (Phoenicopterus spp.) whose plumage displays elegant colors, inhabit warm regions close to the ocean throughout the world. The pink or reddish color of their plumage originates from carotenoids ingested from carotenoid-abundant food sources, since flamingoes are unable to synthesize these compounds de novo. In this study, viable red-colored archaeal strains classified as extremely halophilic archaea (i.e., haloarchaea) and belonging to the genera Halococcus and Halogeometricum were isolated from the plumage of flamingoes in captivity. Detailed analysis for haloarchaeal community structure in flamingo feathers based on metagenomic data identified several haloarchaeal genera and unclassified sequences of the class Halobacteria at the genus level. Carotenoid pigment analyses showed that a bacterioruberin precursor carotenoid in haloarchaea was identical to one of the pigments found in flamingo plumage. To the best of our knowledge, this is the first report of viable extremophilic archaea in avian plumage, thus contributing to our understanding of the ecology of haloarchaea. The potential influence of haloarchaea as an environmental factor determining avian plumage coloration should be investigated in further studies.

  7. The microbiology of selected retail food products with an evaluation of viable counting methods.

    PubMed

    Greenwood, M H; Coetzee, E F; Ford, B M; Gill, P; Hooper, W L; Matthews, S C; Patrick, S; Pether, J V; Scott, R J

    1984-02-01

    In an inter-laboratory survey, the pour plate, surface spread, agar droplet and spiral plate methods were used in parallel with the surface drop method for enumeration of micro-organisms in foods. Good agreement was obtained between all surface methods of enumeration, but there was poor agreement between molten agar methods and the surface drop method. A total of 1143 samples of food that were ready for consumption at the point of retail sale were examined. Eight types of food products were chosen: meat pasties, sausage rolls, real-cream slices, synthetic-cream slices, mayonnaise-based coleslaws, faggots, patés and continental sausages. The results of this survey suggest that the upper limit for an acceptable viable count should vary according to the food product. Salmonellae were not isolated on any occasion. Potentially harmful organisms were not isolated at levels expected to constitute a public health hazard. Information concerning the nature of the product, the total viable count, the presence or absence of pathogenic, toxigenic or indicator organisms, the spectrum of the bacterial flora and the relative predominance of each organism must all be considered when assessing the microbiological acceptability of retail 'ready to eat' products. PMID:6319486

  8. Filter-based pathogen enrichment technology for detection of multiple viable foodborne pathogens in 1 day.

    PubMed

    Murakami, Taku

    2012-09-01

    Conventional foodborne pathogen assays currently used in the food industry often require long culture enrichments to increase pathogen levels so they can be detected. Even using sensitive real-time PCR assays, culture enrichment at least overnight is necessary especially for detection of pathogens with slow growth rates such as Listeria monocytogenes. To eliminate this cumbersome enrichment step and detect minute amounts of pathogens within 1 day, filter-based pathogen enrichment technology was developed utilizing a unique combination of glass fiber depth filter and porous filter aid materials to efficiently separate pathogens from food homogenates and avoid filter clogging by food particles. After pathogen immobilization in depth filters, only viable pathogens were selectively collected in a small volume of growth medium via microbial multiplication and migration; nonviable pathogens remained inside the filters. By assaying viable pathogens using real-time PCRs, multiple species of foodborne pathogens were detected, including L. monocytogenes, Salmonella enterica, and Escherichia coli O157:H7, at around 1 CFU/ml or 1 CFU/g in various food samples. This filter-based pathogen enrichment technology is a unique bacterial enrichment alternative to the conventional culture enrichment step and can significantly shorten the time necessary to obtain assay results.

  9. Occurrence of viable, red-pigmented haloarchaea in the plumage of captive flamingoes.

    PubMed

    Yim, Kyung June; Kwon, Joseph; Cha, In-Tae; Oh, Kyung-Seo; Song, Hye Seon; Lee, Hae-Won; Rhee, Jin-Kyu; Song, Eun-Ji; Rho, Jeong Rae; Seo, Mi Lyu; Choi, Jong-Soon; Choi, Hak-Jong; Lee, Sung-Jae; Nam, Young-Do; Roh, Seong Woon

    2015-01-01

    Flamingoes (Phoenicopterus spp.) whose plumage displays elegant colors, inhabit warm regions close to the ocean throughout the world. The pink or reddish color of their plumage originates from carotenoids ingested from carotenoid-abundant food sources, since flamingoes are unable to synthesize these compounds de novo. In this study, viable red-colored archaeal strains classified as extremely halophilic archaea (i.e., haloarchaea) and belonging to the genera Halococcus and Halogeometricum were isolated from the plumage of flamingoes in captivity. Detailed analysis for haloarchaeal community structure in flamingo feathers based on metagenomic data identified several haloarchaeal genera and unclassified sequences of the class Halobacteria at the genus level. Carotenoid pigment analyses showed that a bacterioruberin precursor carotenoid in haloarchaea was identical to one of the pigments found in flamingo plumage. To the best of our knowledge, this is the first report of viable extremophilic archaea in avian plumage, thus contributing to our understanding of the ecology of haloarchaea. The potential influence of haloarchaea as an environmental factor determining avian plumage coloration should be investigated in further studies. PMID:26553382

  10. Newly designed and validated impedance spectroscopy setup in microtiter plates successfully monitors viable biomass online.

    PubMed

    Luchterhand, Bettina; Nolten, Jannis; Hafizovic, Sadik; Schlepütz, Tino; Wewetzer, Sandra Janine; Pach, Elke; Meier, Kristina; Wandrey, Georg; Büchs, Jochen

    2015-08-01

    In microtiter plates, conventional online monitoring of biomass concentration based on optical measurements is limited to transparent media: It also cannot differentiate between dead or viable biomass or suspended particles. To address this limitation, this study introduces and validates a new online monitoring setup based on impedance spectroscopy for detecting only viable biomass in 48- and 96-well microtiter plates. The setup was first validated electronically and characterized by determining the cell constants of the measuring geometry. Defined cell suspensions of Ustilago maydis, Hansenula polymorpha, Escherichia coli and Bacillus licheniformis were characterized to find, among other parameters, the most suitable frequency range and the characteristic frequency of β-dispersion for each organism. Finally, the setup was exemplarily applied to monitor the growth of Hansenula polymorpha online. As reference, three different parallel cultures were performed in established cultivation systems. This new online monitoring setup based on impedance spectroscopy is robust and enables precise measurements of microbial biomass concentration. It is promising for future high-throughput applications.

  11. Concentration and size distribution of viable bioaerosols during non-haze and haze days in Beijing.

    PubMed

    Gao, Min; Qiu, Tianlei; Jia, Ruizhi; Han, Meilin; Song, Yuan; Wang, Xuming

    2015-03-01

    Accumulation of airborne particulate matter (PM) has profoundly affected the atmospheric environment of Beijing, China. Although studies on health risks have increased, characterization of specific factors that contribute to increased health risks remains an area of needed exploration. Chemical composition studies on PM can readily be found in the literature but researches on biological composition are still limited. In this study, the concentration and size distribution of viable airborne bacteria and fungi were determined in the atmosphere from May to July 2013 in Beijing, China. Samples were collected during non-haze days and haze days based on the value of air quality index (AQI) PM2.5. Multiple linear regression results indicated that concentrations of viable bioaerosol exhibited a negative correlation with PM2.5 (AQI) ranging from 14 to 452. There was a little difference in size distribution of bioaerosol between non-haze and haze days that all airborne bacteria showed skewed trends toward larger sizes and airborne fungi followed a Gaussian distribution. Spearman's correlation analysis showed that a fraction of bioaerosol with fine and coarse particles had negative and positive relations with PM2.5 (AQI), respectively. Moreover, the temporal variation of d g (aerodynamic diameter) of bioaerosol with PM2.5 (AQI) fluctuated from 9:00 to 21:00, which suggested that their deposition pattern would vary during a day. The primary research in this study implied that aerodynamic size variation should be considered in assessing the bioaerosol exposure during haze weather.

  12. Mobilization of Viable Tumor Cells Into the Circulation During Radiation Therapy

    SciTech Connect

    Martin, Olga A.; Anderson, Robin L.; Russell, Prudence A.; Ashley Cox, R.; Ivashkevich, Alesia; Swierczak, Agnieszka; Doherty, Judy P.; Jacobs, Daphne H.M.; Smith, Jai; Siva, Shankar; Daly, Patricia E.; Ball, David L.; and others

    2014-02-01

    Purpose: To determine whether radiation therapy (RT) could mobilize viable tumor cells into the circulation of non-small cell lung cancer (NSCLC) patients. Methods and Materials: We enumerated circulating tumor cells (CTCs) by fluorescence microscopy of blood samples immunostained with conventional CTC markers. We measured their DNA damage levels using γ-H2AX, a biomarker for radiation-induced DNA double-strand breaks, either by fluorescence-activated cell sorting or by immunofluorescence microscopy. Results: Twenty-seven RT-treated NSCLC patients had blood samples analyzed by 1 or more methods. We identified increased CTC numbers after commencement of RT in 7 of 9 patients treated with palliative RT, and in 4 of 8 patients treated with curative-intent RT. Circulating tumor cells were also identified, singly and in clumps in large numbers, during RT by cytopathologic examination (in all 5 cases studied). Elevated γ-H2AX signal in post-RT blood samples signified the presence of CTCs derived from irradiated tumors. Blood taken after the commencement of RT contained tumor cells that proliferated extensively in vitro (in all 6 cases studied). Circulating tumor cells formed γ-H2AX foci in response to ex vivo irradiation, providing further evidence of their viability. Conclusions: Our findings provide a rationale for the development of strategies to reduce the concentration of viable CTCs by modulating RT fractionation or by coadministering systemic therapies.

  13. Short communication: Viable Mycobacterium avium subspecies paratuberculosis in retail artisanal Coalho cheese from Northeastern Brazil.

    PubMed

    Faria, A C S; Schwarz, D G G; Carvalho, I A; Rocha, B B; De Carvalho Castro, K N; Silva, M R; Moreira, M A S

    2014-07-01

    Mycobacterium avium ssp. paratuberculosis (MAP) is the etiologic agent of paratuberculosis and it potentially plays a role in Crohn's disease. In humans, the main route of transmission of MAP might be the intake of contaminated milk and dairy products. Considering that MAP has already been detected in many types of cheese in different counties, and that Coalho cheese is an important dairy product in northeastern Brazil, the aim of this study was to report the first detection of MAP in retail Coalho cheese in Brazil by PCR and culture. Of 30 retail Coalho cheese samples, 3 (10%) amplified fragments of a similar size to that expected (626 bp) were obtained and viable MAP was recovered by culture from 1 (3.3%) sample. The DNA from the positive culture sample was sequenced and showed 99% identity with the insertion sequence IS900 deposited in GenBank. It was possible to identify the presence of MAP-specific DNA in the analyzed samples for the first time in Brazil, and to recover viable cells from retail Coalho cheese.

  14. Enumeration of probiotic strains: Review of culture-dependent and alternative techniques to quantify viable bacteria.

    PubMed

    Davis, Catherine

    2014-08-01

    Probiotics are live microorganisms which, when administered in adequate amounts, confer a health benefit on the host. Standard culture techniques are commonly used to quantify probiotic strains, but cell culture only measures replicating cells. In response to the stresses of processing and formulation, some fraction of the live probiotic microbes may enter a viable but non-culturable state (VBNC) in which they are dormant but metabolically active. These microbes are capable of replicating once acclimated to a more hospitable host environment. An operating definition of live probiotic bacteria that includes this range of metabolic states is needed for reliable enumeration. Alternative methods, such as fluorescent in situ hybridization (FISH), nucleic acid amplification techniques such as real-time quantitative PCR (RT-qPCR or qPCR), reverse transcriptase (RT-PCR), propidium monoazide-PCR, and cell sorting techniques such as flow cytometry (FC)/fluorescent activated cell sorting (FACS) offer the potential to enumerate both culturable and VBNC bacteria. Modern cell sorting techniques have the power to determine probiotic strain abundance and metabolic activity with rapid throughput. Techniques such as visual imaging, cell culture, and cell sorting, could be used in combination to quantify the proportion of viable microbes in various metabolic states. Consensus on an operational definition of viability and systematic efforts to validate these alternative techniques ultimately will strengthen the accuracy and reliability of probiotic strain enumeration.

  15. Biological changes of Enterococcus faecalis in the viable but nonculturable state.

    PubMed

    E, J; Jiang, Y T; Yan, P F; Liang, J P

    2015-11-23

    Enterococcus faecalis may enter a viable but nonculturable (VBNC) state under adverse conditions. E. faecalis, the major bacterial species present in failed root canal treatments, is thought to survive after endodontic treatment by entering a VBNC state. In this study, we characterized the VBNC state of E. faecalis. We designed 3 different protocols to successfully induce the VBNC state. Approximately one-third of bacteria entered a VBNC state after 15-30 days, and all remained viable for at least 2 months. The morphology, glycometabolism, and adhesion capabilities of VBNC cells differed from those of E. faecalis during the exponential growth phase. Specifically, VBNC E. faecalis cells could not decompose lactose, D-mannitol, or D-sorbitol, although they were able to metabolize sucrose. Transmission electron microscopy showed that the morphology of the VBNC E. faecalis cells changed significantly; the cytoplasmic matrix was unevenly condensed and the overall morphology of the cells became irregular, but the cell membranes remained intact. Although the adhesion ability of the bacteria decreased, VBNC E. faecalis could still adhere to collagen fiber type I and tooth dentine. The persistence of this adhesion ability may be important in the virulence of VBNC E. faecalis.

  16. Analysis of total aerobic viable counts in raw fish by high-throughput optical oxygen respirometry.

    PubMed

    Hempel, A; Borchert, N; Walsh, H; Roy Choudhury, K; Kerry, J P; Papkovsky, D B

    2011-05-01

    A simple, miniaturized, and automated screening assay for the determination of total aerobic viable counts in fish samples is presented here. Fish tissue homogenates were prepared in peptone buffered water medium, according to standard method, and aliquots were dispensed into wells of a 96-well plate with the phosphorescent, oxygen-sensing probe GreenLight. Sample wells were covered with mineral oil (barrier for ambient oxygen), and the plate was monitored on a standard fluorescent reader at 30°C. The samples produced characteristic profiles, with a sharp increase in fluorescence above the baseline level at a certain threshold time, which could be correlated with initial microbial load. Five different fish species were analyzed: salmon, cod, plaice, mackerel, and whiting. Using a conventional agar plating method, the relationship between the threshold time and total aerobic viable counts load (in CFU per gram) was established, calibration curve generated, and the test was validated with 169 unknown fish samples. It showed a dynamic range of 10(4) to 10(7) CFU/g, accuracy of ± 1 log(CFU/g), assay time of 2 to 12 h (depending on the level of contamination), ruggedness with respect to the key assay parameters, simplicity (three pipetting steps, no serial dilutions), real-time data output, high sample throughput, and automation. With this test, quality of fish samples, CFU-per-gram levels, and their respective time profiles were determined.

  17. Mycobacterium tuberculosis lacking all mycolic acid cyclopropanation is viable but highly attenuated and hyperinflammatory in mice.

    PubMed

    Barkan, Daniel; Hedhli, Dorsaf; Yan, Han-Guang; Huygen, Kris; Glickman, Michael S

    2012-06-01

    Mycolic acids, the major lipid of the Mycobacterium tuberculosis cell wall, are modified by cyclopropane rings, methyl branches, and oxygenation through the action of eight S-adenosylmethionine (SAM)-dependent mycolic acid methyltransferases (MAMTs), encoded at four genetic loci. Mycolic acid modification has been shown to be important for M. tuberculosis pathogenesis, in part through effects on the inflammatory activity of trehalose dimycolate (cord factor). Studies using the MAMT inhibitor dioctylamine have suggested that the MAMT enzyme class is essential for M. tuberculosis viability. However, it is unknown whether a cyclopropane-deficient strain of M. tuberculosis would be viable and what the effect of cyclopropane deficiency on virulence would be. We addressed these questions by creating and characterizing M. tuberculosis strains lacking all functional MAMTs. Our results show that M. tuberculosis is viable either without cyclopropanation or without cyclopropanation and any oxygenated mycolates. Characterization of these strains revealed that MAMTs are required for acid fastness and resistance to detergent stress. Complete lack of cyclopropanation confers severe attenuation during the first week after aerosol infection of the mouse, whereas complete loss of MAMTs confers attenuation in the second week of infection. Characterization of immune responses to the cyclopropane- and MAMT-deficient strains indicated that the net effect of mycolate cyclopropanation is to dampen host immunity. Taken together, our findings establish the immunomodulatory function of the mycolic acid modification pathway in pathogenesis and buttress this enzyme class as an attractive target for antimycobacterial drug development.

  18. New perspectives on viable microbial communities in low-biomass cleanroom environments.

    PubMed

    Vaishampayan, Parag; Probst, Alexander J; La Duc, Myron T; Bargoma, Emilee; Benardini, James N; Andersen, Gary L; Venkateswaran, Kasthuri

    2013-02-01

    The advent of phylogenetic DNA microarrays and high-throughput pyrosequencing technologies has dramatically increased the resolution and accuracy of detection of distinct microbial lineages in mixed microbial assemblages. Despite an expanding array of approaches for detecting microbes in a given sample, rapid and robust means of assessing the differential viability of these cells, as a function of phylogenetic lineage, remain elusive. In this study, pre-PCR propidium monoazide (PMA) treatment was coupled with downstream pyrosequencing and PhyloChip DNA microarray analyses to better understand the frequency, diversity and distribution of viable bacteria in spacecraft assembly cleanrooms. Sample fractions not treated with PMA, which were indicative of the presence of both live and dead cells, yielded a great abundance of highly diverse bacterial pyrosequences. In contrast, only 1% to 10% of all of the pyrosequencing reads, arising from a few robust bacterial lineages, originated from sample fractions that had been pre-treated with PMA. The results of PhyloChip analyses of PMA-treated and -untreated sample fractions were in agreement with those of pyrosequencing. The viable bacterial population detected in cleanrooms devoid of spacecraft hardware was far more diverse than that observed in cleanrooms that housed mission-critical spacecraft hardware. The latter was dominated by hardy, robust organisms previously reported to survive in oligotrophic cleanroom environments. Presented here are the findings of the first ever comprehensive effort to assess the viability of cells in low-biomass environmental samples, and correlate differential viability with phylogenetic affiliation.

  19. Method for rapid detection of viable Escherichia coli in water using real-time NASBA.

    PubMed

    Heijnen, Leo; Medema, Gertjan

    2009-07-01

    A rapid real-time NASBA method was developed for detection of Escherichia coli in water samples. In this method, a fragment of the clpB-mRNA is amplified and a specific molecular beacon probe is used to detect the amplified mRNA fragment during the NASBA reaction. The method was shown to be specific and sensitive (1 viable E. coli in 100ml) and can be performed within 3-4h. Different inactivation processes (starvation, heat, UV-irradiation and chlorine) were employed to study the relationship between culturability and the ability to detect E. coli using NASBA. Detection of clpB-mRNA correlated with culturability after starvation or chlorine treatment. After UV-irradiation or heat-inactivation, detection of the increase in production of clpB-mRNA in viable E. coli cells after heat-shock induction correlated with culturability. Application of the NASBA method on tap water, treated sewage and surface water samples showed that culture and NASBA yielded comparable results in these different matrices. This study demonstrates that the NASBA method has high potential as a rapid test for microbiological water quality monitoring.

  20. HEPEX - achievements and challenges!

    NASA Astrophysics Data System (ADS)

    Pappenberger, Florian; Ramos, Maria-Helena; Thielen, Jutta; Wood, Andy; Wang, Qj; Duan, Qingyun; Collischonn, Walter; Verkade, Jan; Voisin, Nathalie; Wetterhall, Fredrik; Vuillaume, Jean-Francois Emmanuel; Lucatero Villasenor, Diana; Cloke, Hannah L.; Schaake, John; van Andel, Schalk-Jan

    2014-05-01

    HEPEX is an international initiative bringing together hydrologists, meteorologists, researchers and end-users to develop advanced probabilistic hydrological forecast techniques for improved flood, drought and water management. HEPEX was launched in 2004 as an independent, cooperative international scientific activity. During the first meeting, the overarching goal was defined as: "to develop and test procedures to produce reliable hydrological ensemble forecasts, and to demonstrate their utility in decision making related to the water, environmental and emergency management sectors." The applications of hydrological ensemble predictions span across large spatio-temporal scales, ranging from short-term and localized predictions to global climate change and regional modeling. Within the HEPEX community, information is shared through its blog (www.hepex.org), meetings, testbeds and intercompaison experiments, as well as project reportings. Key questions of HEPEX are: * What adaptations are required for meteorological ensemble systems to be coupled with hydrological ensemble systems? * How should the existing hydrological ensemble prediction systems be modified to account for all sources of uncertainty within a forecast? * What is the best way for the user community to take advantage of ensemble forecasts and to make better decisions based on them? This year HEPEX celebrates its 10th year anniversary and this poster will present a review of the main operational and research achievements and challenges prepared by Hepex contributors on data assimilation, post-processing of hydrologic predictions, forecast verification, communication and use of probabilistic forecasts in decision-making. Additionally, we will present the most recent activities implemented by Hepex and illustrate how everyone can join the community and participate to the development of new approaches in hydrologic ensemble prediction.

  1. The Homogeneity of School Achievement.

    ERIC Educational Resources Information Center

    Cahan, Sorel

    Since the measurement of school achievement involves the administration of achievement tests to various grades on various subjects, both grade level and subject matter contribute to within-school achievement variations. To determine whether achievement test scores vary most among different fields within a grade level, or within fields among…

  2. Leadership, self-efficacy, and student achievement

    NASA Astrophysics Data System (ADS)

    Grayson, Kristin

    This study examined the relationships between teacher leadership, science teacher self-efficacy, and fifth-grade science student achievement in diverse schools in a San Antonio, Texas, metropolitan school district. Teachers completed a modified version of the Leadership Behavior Description Question (LBDQ) Form XII by Stogdill (1969), the Science Efficacy and Belief Expectations for Science Teaching (SEBEST) by Ritter, Boone, and Rubba (2001, January). Students' scores on the Texas Assessment of Knowledge and Skills (TAKS) measured fifth-grade science achievement. At the teacher level of analysis multiple regressions showed the following relationships between teachers' science self-efficacy and teacher classroom leadership behaviors and the various teacher and school demographic variables. Predictors of teacher self efficacy beliefs included teacher's level of education, gender, and leadership initiating structure. The only significant predictor of teacher self-efficacy outcome expectancy was gender. Higher teacher self-efficacy beliefs predicted higher leadership initiating structure. At the school level of analysis, higher school levels of percentage of students from low socio-economic backgrounds and higher percentage of limited English proficient students predicted lower school student mean science achievement. These findings suggest a need for continued research to clarify relationships between teacher classroom leadership, science teacher self-efficacy, and student achievement especially at the teacher level of analysis. Findings also indicate the importance of developing instructional methods to address student demographics and their needs so that all students, despite their backgrounds, will achieve in science.

  3. The Belem Framework for Action: Harnessing the Power and Potential of Adult Learning and Education for a Viable Future

    ERIC Educational Resources Information Center

    Adult Learning, 2012

    2012-01-01

    This article presents the Belem Framework for Action. This framework focuses on harnessing the power and potential of adult learning and education for a viable future. This framework begins with a preamble on adult education and towards lifelong learning.

  4. Multiplex PMA-qPCR Assay with Internal Amplification Control for Simultaneous Detection of Viable Legionella pneumophila, Salmonella typhimurium, and Staphylococcus aureus in Environmental Waters.

    PubMed

    Li, Haiyan; Xin, Hongyi; Li, Sam Fong Yau

    2015-12-15

    Pathogenic microorganisms are responsible for many infectious diseases, and pathogen monitoring is important and necessary for water quality control. This study for the first time explored a multiplex quantitative real-time PCR (qPCR) technique combined with propidium monoazide (PMA) to simultaneously detect viable Legionella pneumophila, Salmonella typhimurium, and Staphylococcus aureus in one reaction from water samples. Sodium lauroyl sarcosinate (sarkosyl) was applied to enhance the dead bacterial permeability of PMA. The sensitivity of the multiplex PMA-qPCR assay achieved two colony-forming units (CFU) per reaction for L. pneumophila and three CFU per reaction for S. typhimurium and S. aureus. No PCR products were amplified from all nontarget control samples. Significantly, with comparable specificity and sensitivity, this newly invented multiplex PMA-qPCR assay took a much shorter time than did conventional culture assays when testing water samples with spiked bacteria and simulated environmental water treatment. The viable multiplex PMA-qPCR assay was further successfully applied to pathogen detection from rivers, canals, and tap water samples after simple water pretreatment. PMID:26512952

  5. Attitude Towards Physics and Additional Mathematics Achievement Towards Physics Achievement

    ERIC Educational Resources Information Center

    Veloo, Arsaythamby; Nor, Rahimah; Khalid, Rozalina

    2015-01-01

    The purpose of this research is to identify the difference in students' attitude towards Physics and Additional Mathematics achievement based on gender and relationship between attitudinal variables towards Physics and Additional Mathematics achievement with achievement in Physics. This research focused on six variables, which is attitude towards…

  6. The Impact of Reading Achievement on Overall Academic Achievement

    ERIC Educational Resources Information Center

    Churchwell, Dawn Earheart

    2009-01-01

    This study examined the relationship between reading achievement and achievement in other subject areas. The purpose of this study was to determine if there was a correlation between reading scores as measured by the Standardized Test for the Assessment of Reading (STAR) and academic achievement in language arts, math, science, and social studies…

  7. Establishment of a viable population of red-cockaded woodpeckers at the Savannah River Site

    SciTech Connect

    Allen, D.H.

    1989-01-01

    In 1985 the Southeastern Forest Experiment Station in cooperation with the Department of Energy (DOE), the Savannah River Forest Station (SRFS) and the Savannah River Ecology Laboratory (SREL) initiated a research/management program to restore a viable population of red-cockaded woodpeckers (RCW) to the Savannah River Site (SRS). The program has progresses in two phases. The first phase (1985-1987) focused on stabilizing the declining RCW population at SRS. The second phase (1988-present) has focused on facilitating population expansion. In 1989 we have focused our efforts on development of techniques for excavating new RCW cavities, identification of old-growth stands with the potential of providing new nesting habitat to support population expansion, continued flying squirrel control, continued translocations of RCW's as needed, and monitoring clan composition and reproduction.

  8. A true cornual pregnancy with placenta percreta resulting in a viable fetus

    PubMed Central

    Rathod, Setu; Samal, Sunil Kumar

    2015-01-01

    Cornual pregnancy is uncommon among ectopic pregnancies. A diagnosis of cornual pregnancy remains challenging, and rupture of a cornual pregnancy causes catastrophic consequence due to massive bleeding. In very rare circumstances, cornual pregnancies can result in a viable fetus. We report a case of a 24-year-old primigravida who presented to us with complaints of decrease fetal movements at 37+5 weeks. Ultrasound revealed a single live intrauterine fetus with anterior low lying placenta with severe oligohydramnios (amniotic fluid index = 1.8). Emergency cesarean section was done and intraoperatively it was diagnosed as a case of placenta percreta with pregnancy in right noncommunicating horn of uterus. Right cornual resection with right salpingectomy done. Uterus, left fallopian tube and bilateral ovary were healthy. Postoperative period was uneventful. PMID:26539372

  9. Is self-sufficiency financially viable and ethically justifiable?--a commercial viewpoint.

    PubMed

    Christie, R B

    1994-12-01

    Manufacturers of blood products have to maintain the highest possible standards for plasma screening and good manufacturing practices to ensure maximum purity and viral safety. The private sector companies have much experience in implementing and complying with national and international regulations. These requirements involve considerable cost in the areas of (1) plasma collection facilities, (2) research and clinical research, (3) manufacture, and (4) quality control. Total self-sufficiency would mean the loss of many existing resources. An alternative would be a collaboration between the public and private sectors to meet the needs of all patients who require plasma derived products. The current definition of self-sufficiency suggests that it is not financially viable.

  10. Drug delivery interfaces in the 21st century: from science fiction ideas to viable technologies.

    PubMed

    Chertok, Beata; Webber, Matthew J; Succi, Marc D; Langer, Robert

    2013-10-01

    Early science fiction envisioned the future of drug delivery as targeted micrometer-scale submarines and "cyborg" body parts. Here we describe the progression of the field toward technologies that are now beginning to capture aspects of this early vision. Specifically, we focus on the two most prominent types of systems in drug delivery: the intravascular micro/nano drug carriers for delivery to the site of pathology and drug-loaded implantable devices that facilitate release with the predefined kinetics or in response to a specific cue. We discuss the unmet clinical needs that inspire these designs, the physiological factors that pose difficult challenges for their realization, and viable technologies that promise robust solutions. We also offer a perspective on where drug delivery may be in the next 50 years based on expected advances in material engineering and in the context of future diagnostics.

  11. Is self-sufficiency financially viable and ethically justifiable?--a commercial viewpoint.

    PubMed

    Christie, R B

    1994-12-01

    Manufacturers of blood products have to maintain the highest possible standards for plasma screening and good manufacturing practices to ensure maximum purity and viral safety. The private sector companies have much experience in implementing and complying with national and international regulations. These requirements involve considerable cost in the areas of (1) plasma collection facilities, (2) research and clinical research, (3) manufacture, and (4) quality control. Total self-sufficiency would mean the loss of many existing resources. An alternative would be a collaboration between the public and private sectors to meet the needs of all patients who require plasma derived products. The current definition of self-sufficiency suggests that it is not financially viable. PMID:7795138

  12. Enrichment of viable bacteria in a micro-volume by free-flow electrophoresis.

    PubMed

    Podszun, Susann; Vulto, Paul; Heinz, Helene; Hakenberg, Sydney; Hermann, Carsten; Hankemeier, Thomas; Urban, Gerald A

    2012-02-01

    Macro- to micro-volume concentration of viable bacteria is performed in a microfluidic chip. The enrichment principle is based on free flow electrophoresis and is demonstrated for Gram positive bacteria. Bacteria from a suspension flow are trapped on a gel interface that separates the trapping location from integrated actuation electrodes in order to enable non-destructive trapping. The microfluidic chip contains integrated electrolytic gas expulsion structures and phaseguides for gel and liquid handling. Trapping efficiency is systematically optimized to reach 25 times the initial concentration from a theoretical maximum of 30. Finally, enrichment from analytically relevant concentrations down to 3 × 10(2) colony forming units per millilitre is demonstrated with a trapping efficiency of 80% which represents the most important parameter in enrichment. PMID:22008897

  13. Semidirect Restorations in Multidisciplinary Treatment: Viable Option for Children and Teenagers.

    PubMed

    Tonetto, Mateus Rodrigues; Frizzera, Fausto; Silva, Monica Barros da; Bhandi, Shilpa H; Kuga, Milton Carlos; Pereira, Kamila Figueiredo; Pinzan-Vercelino, Célia Regina Maio; Bandéca, Matheus Coelho

    2015-04-01

    Due to the esthetic necessity required nowadays, the multidisciplinary treatment became a fundamental step in the restoration success. When the patient exhibits dental agenesis of one or more elements, he can show difficulty in social interactions. The age of the patient is a limiting factor to esthetic procedures, however, it should be evaluated as a real indicative with each case. The utilization of semi-direct restorations is a viable option due the cost, esthetic and improvement of physical and mechanical properties. The purpose of this paper is to present a case detailing the confection and cementation of anterior semi-direct restorations aimed at an anatomic reestablishment associated with integrated treatment with periodontics and orthodontics.

  14. Court reporters: a viable solution for the challenges of focus group data collection?

    PubMed

    Scott, Shannon D; Sharpe, Heather; O'Leary, Kathy; Dehaeck, Ulrike; Hindmarsh, Kathryn; Moore, John Garry; Osmond, Martin H

    2009-01-01

    Focus group interviews are a common approach to data collection in qualitative research projects. They are, however, a method with the potential for methodological and pragmatic difficulties, many of which stem from transcribing focus group data from an audiotape. An alternative to postinterview transcription is the use of a court reporter. Advantages found using court reporters were increased accuracy, timely receipt of transcripts, less distraction for focus group facilitators, guaranteed confidentiality, time saved reviewing transcripts, and convenience. Because court reporters do not traditionally work in health research, there might be issues with medical terminology that require diligence on the part of the researcher to ensure that jargon is appropriately identified and transcribed. Using court reporters in rural areas might be cost-prohibitive because of travel expenses. Court reporters offer a viable and worthwhile approach to data transcription, and in our experience, have provided our research team with rich and accurate data.

  15. Development of a Commercially Viable, Modular Autonomous Robotic Systems for Converting any Vehicle to Autonomous Control

    NASA Technical Reports Server (NTRS)

    Parish, David W.; Grabbe, Robert D.; Marzwell, Neville I.

    1994-01-01

    A Modular Autonomous Robotic System (MARS), consisting of a modular autonomous vehicle control system that can be retrofit on to any vehicle to convert it to autonomous control and support a modular payload for multiple applications is being developed. The MARS design is scalable, reconfigurable, and cost effective due to the use of modern open system architecture design methodologies, including serial control bus technology to simplify system wiring and enhance scalability. The design is augmented with modular, object oriented (C++) software implementing a hierarchy of five levels of control including teleoperated, continuous guidepath following, periodic guidepath following, absolute position autonomous navigation, and relative position autonomous navigation. The present effort is focused on producing a system that is commercially viable for routine autonomous patrolling of known, semistructured environments, like environmental monitoring of chemical and petroleum refineries, exterior physical security and surveillance, perimeter patrolling, and intrafacility transport applications.

  16. A physical and chemical characterization of Martian permafrost as a possible habitat for viable microorganisms.

    PubMed

    Ostroumov, V

    1995-03-01

    Data from experiments with model samples show that ion transfer coefficients in the water-rich permafrost on Mars must be three orders of magnitude less than those of terrestrial permafrost. The effects of low temperatures and of carbon dioxide have been accounted for. Exchange between cells and the environment is impeded in Martian permafrost. The microscopic distributional heterogeneity of concentration, pH, Eh, and other physicochemical parameters may be more pronounced in the permafrost of Mars. We present a classification of unfrozen water types in the permafrost that is based on the structures of unfrozen water films and on their functions with respect to cells. Any viable microorganisms on Mars probably exist with minimum metabolism in compact zones with energy carriers and high transfer coefficients. These zones may be microvolumes of unfrozen water in which cells accumulate.

  17. Drug Delivery Interfaces in the 21st Century: From Science Fiction Ideas to Viable Technologies

    PubMed Central

    Chertok, Beata; Webber, Matthew J.; Succi, Marc D.; Langer, Robert S.

    2013-01-01

    Early science fiction envisioned the future of drug delivery as targeted micron-scale submarines and ‘Cyborg’ body parts. Here we describe the progression of the field toward technologies that are now beginning to capture aspects of this early vision. Specifically, we focus on the two most prominent types of systems in drug delivery – the intravascular micro/nano drug carriers for delivery to the site of pathology and drug-loaded implantable devices that facilitate release with the pre-defined kinetics or in response to a specific cue. We discuss the unmet clinical needs that inspire these designs, the physiological factors that pose difficult challenges for their realization, and viable technologies that promise robust solutions. We also offer a perspective on where drug delivery may be in the next 50 years based on expected advances in material engineering and in the context of future diagnostics. PMID:23915375

  18. [Detection of viable metabolically active yeast cells using a colorimetric assay].

    PubMed

    Růzicka, F; Holá, V

    2008-02-01

    The increasing concern of yeasts able to form biofilm brings about the need for susceptibility testing of both planktonic and biofilm cells. Detection of viability or metabolic activity of yeast cells after exposure to antimicrobials plays a key role in the assessment of susceptibility testing results. Colorimetric assays based on the color change of the medium in the presence of metabolically active cells proved suitable for this purpose. In this study, the usability of a colorimetric assay with the resazurin redox indicator for monitoring the effect of yeast inoculum density on the reduction rate was tested. As correlation between the color change rate and inoculum density was observed, approximate quantification of viable cells was possible. The assay would be of relevance to antifungal susceptibility testing in both planktonic and biofilm yeasts.

  19. Retinal Electrophysiology Is a Viable Preclinical Biomarker for Drug Penetrance into the Central Nervous System

    PubMed Central

    Charng, Jason; He, Zheng; Vingrys, Algis J.; Fish, Rebecca L.; Gurrell, Rachel; Bui, Bang V.; Nguyen, Christine T.

    2016-01-01

    Objective. To examine whether retinal electrophysiology is a useful surrogate marker of drug penetrance into the central nervous system (CNS). Materials and Methods. Brain and retinal electrophysiology were assessed with full-field visually evoked potentials and electroretinograms in conscious and anaesthetised rats following systemic or local administrations of centrally penetrant (muscimol) or nonpenetrant (isoguvacine) compounds. Results. Local injections into the eye/brain bypassed the blood neural barriers and produced changes in retinal/brain responses for both drugs. In conscious animals, systemic administration of muscimol resulted in retinal and brain biopotential changes, whereas systemic delivery of isoguvacine did not. General anaesthesia confounded these outcomes. Conclusions. Retinal electrophysiology, when recorded in conscious animals, shows promise as a viable biomarker of drug penetration into the CNS. In contrast, when conducted under anaesthetised conditions confounds can be induced in both cortical and retinal electrophysiological recordings. PMID:27239335

  20. In vitro maturation of viable islets from partially digested young pig pancreas.

    PubMed

    Lamb, Morgan; Laugenour, Kelly; Liang, Ouwen; Alexander, Michael; Foster, Clarence E; Lakey, Jonathan R T

    2014-03-01

    Isolation of islets from market-sized pigs is costly, with considerable islet losses from fragmentation occurring during isolation and tissue culture. Fetal and neonatal pigs yield insulin unresponsive islet-like cell clusters that become glucose-responsive after extended periods of time. Both issues impact clinical applicability and commercial scale-up. We have focused our efforts on a cost-effective scalable method of isolating viable insulin-responsive islets. Young Yorkshire pigs (mean age 20 days, range 4-30 days) underwent rapid pancreatectomy (<5 min) and partial digestion using low-dose collagenase, followed by in vitro culture at 37°C and 5% CO2 for up to 14 days. Islet viability was assessed using FDA/PI or Newport Green, and function was assessed using a glucose-stimulated insulin release (GSIR) assay. Islet yield was performed using enumeration of dithizone-stained aliquots. The young porcine (YP) islet yield at dissociation was 12.6 ± 2.1 × 10(3) IEQ (mean ± SEM) per organ and increased to 33.3 ± 6.4 × 10(3) IEQ after 7 days of in vitro culture. Viability was 97.3 ± 7% at dissociation and remained over 90% viable after 11 days in tissue culture (n = ns). Glucose responsiveness increased throughout maturation in culture. The stimulation index (SI) of the islets increased from 1.7 ± 2 on culture day 3 to 2.58 ± 0.5 on culture day 7. These results suggest that this method is both efficient and scalable for isolating and maturing insulin-responsive porcine islets in culture. PMID:23394130

  1. Quorum-regulated biofilms enhance the development of conditionally viable, environmental Vibrio cholerae.

    PubMed

    Kamruzzaman, M; Udden, S M Nashir; Cameron, D Ewen; Calderwood, Stephen B; Nair, G Balakrish; Mekalanos, John J; Faruque, Shah M

    2010-01-26

    The factors that enhance the waterborne spread of bacterial epidemics and sustain the pathogens in nature are unclear. The epidemic diarrheal disease cholera caused by Vibrio cholerae spreads through water contaminated with the pathogen. However, the bacteria exist in water mostly as clumps of cells, which resist cultivation by standard techniques but revive into fully virulent form in the intestinal milieu. These conditionally viable environmental cells (CVEC), alternatively called viable but nonculturable cells, presumably play a crucial role in cholera epidemiology. However, the precise mechanism causing the transition of V. cholerae to the CVEC form and this form's significance in the biology of the pathogen are unknown. Here we show that this process involves biofilm formation that is dependent on quorum sensing, a regulatory response that is controlled by cell density. V. cholerae strains carrying mutations in genes required for quorum sensing and biofilm formation displayed altered CVEC formation in environmental water following intestinal infections. Analysis of naturally occurring V. cholerae CVEC showed that organisms that adopt this quiescent physiological state typically exist as clumps of cells that comprise a single clone closely related to isolates causing the most recent local cholera epidemic. These results support a model of cholera transmission in which in vivo-formed biofilms convert to CVEC upon the introduction of cholera stools into environmental water. Our data further suggest that a temporary loss of quorum sensing due to dilution of extracellular autoinducers confers a selective advantage to communities of V. cholerae by blocking quorum-mediated regulatory responses that would break down biofilms and thus interfere with CVEC formation.

  2. Fern spore longevity in saline water: can sea bottom sediments maintain a viable spore bank?

    PubMed

    de Groot, G Arjen; During, Heinjo

    2013-01-01

    Freshwater and marine sediments often harbor reservoirs of plant diaspores, from which germination and establishment may occur whenever the sediment falls dry. Therewith, they form valuable records of historical inter- and intraspecific diversity, and are increasingly exploited to facilitate diversity establishment in new or restored nature areas. Yet, while ferns may constitute a considerable part of a vegetation's diversity and sediments are known to contain fern spores, little is known about their longevity, which may suffer from inundation and--in sea bottoms--salt stress. We tested the potential of ferns to establish from a sea or lake bottom, using experimental studies on spore survival and gametophyte formation, as well as a spore bank analysis on sediments from a former Dutch inland sea. Our experimental results revealed clear differences among species. For Asplenium scolopendrium and Gymnocarpium dryopteris, spore germination was not affected by inundated storage alone, but decreased with rising salt concentrations. In contrast, for Asplenium trichomanes subsp. quadrivalens germination decreased following inundation, but not in response to salt. Germination rates decreased with time of storage in saline water. Smaller and less viable gametophytes were produced when saline storage lasted for a year. Effects on germination and gametophyte development clearly differed among genotypes of A. scolopendrium. Spore bank analyses detected no viable spores in marine sediment layers. Only two very small gametophytes (identified as Thelypteris palustris via DNA barcoding) emerged from freshwater sediments. Both died before maturation. We conclude that marine, and likely even freshwater sediments, will generally be of little value for long-term storage of fern diversity. The development of any fern vegetation on a former sea floor will depend heavily on the deposition of spores onto the drained land by natural or artificial means of dispersal.

  3. Cooperation between Apoptotic and Viable Metacyclics Enhances the Pathogenesis of Leishmaniasis

    PubMed Central

    Wanderley, João Luiz Mendes; Pinto da Silva, Lucia Helena; Deolindo, Poliana; Soong, Lynn; Borges, Valéria Matos; Prates, Deboraci Brito; de Souza, Ana Paula Almeida; Barral, Aldina; de Freitas Balanco, José Mario; do Nascimento, Michelle Tanny Cunha; Saraiva, Elvira Maria; Barcinski, Marcello André

    2009-01-01

    Mimicking mammalian apoptotic cells by exposing phosphatidylserine (PS) is a strategy used by virus and parasitic protozoa to escape host protective inflammatory responses. With Leishmania amazonensis (La), apoptotic mimicry is a prerogative of the intramacrophagic amastigote form of the parasite and is modulated by the host. Now we show that differently from what happens with amastigotes, promastigotes exposing PS are non-viable, non-infective cells, undergoing apoptotic death. As part of the normal metacyclogenic process occurring in axenic cultures and in the gut of sand fly vectors, a sub-population of metacyclic promastigotes exposes PS. Apoptotic death of the purified PS-positive (PSPOS) sub-population was confirmed by TUNEL staining and DNA laddering. Transmission electron microscopy revealed morphological alterations in PSPOS metacyclics such as DNA condensation, cytoplasm degradation and mitochondrion and kinetoplast destruction, both in in vitro cultures and in sand fly guts. TUNELPOS promastigotes were detected only in the anterior midgut to foregut boundary of infected sand flies. Interestingly, caspase inhibitors modulated parasite death and PS exposure, when added to parasite cultures in a specific time window. Efficient in vitro macrophage infections and in vivo lesions only occur when PSPOS and PS-negative (PSNEG) parasites were simultaneously added to the cell culture or inoculated in the mammalian host. The viable PSNEG promastigote was the infective form, as shown by following the fate of fluorescently labeled parasites, while the PSPOS apoptotic sub-population inhibited host macrophage inflammatory response. PS exposure and macrophage inhibition by a subpopulation of promastigotes is a different mechanism than the one previously described with amastigotes, where the entire population exposes PS. Both mechanisms co-exist and play a role in the transmission and development of the disease in case of infection by La. Since both processes confer

  4. Viable Bacteria Associated with Red Blood Cells and Plasma in Freshly Drawn Blood Donations

    PubMed Central

    Damgaard, Christian; Magnussen, Karin; Enevold, Christian; Nilsson, Martin; Tolker-Nielsen, Tim; Holmstrup, Palle; Nielsen, Claus Henrik

    2015-01-01

    Objectives Infection remains a leading cause of post-transfusion mortality and morbidity. Bacterial contamination is, however, detected in less than 0.1% of blood units tested. The aim of the study was to identify viable bacteria in standard blood-pack units, with particular focus on bacteria from the oral cavity, and to determine the distribution of bacteria revealed in plasma and in the red blood cell (RBC)-fraction. Design Cross-sectional study. Blood were separated into plasma and RBC-suspensions, which were incubated anaerobically or aerobically for 7 days on trypticase soy blood agar (TSA) or blue lactose plates. For identification colony PCR was performed using primers targeting 16S rDNA. Setting Blood donors attending Capital Region Blood Bank, Copenhagen University Hospital, Rigshospitalet, Hvidovre, Denmark, October 29th to December 10th 2013. Participants 60 donors (≥50 years old), self-reported medically healthy. Results Bacterial growth was observed on plates inoculated with plasma or RBCs from 62% of the blood donations. Growth was evident in 21 (35%) of 60 RBC-fractions and in 32 (53%) of 60 plasma-fractions versus 8 of 60 negative controls (p = 0.005 and p = 2.6x10-6, respectively). Propionibacterium acnes was found in 23% of the donations, and Staphylococcus epidermidis in 38%. The majority of bacteria identified in the present study were either facultative anaerobic (59.5%) or anaerobic (27.8%) species, which are not likely to be detected during current routine screening. Conclusions Viable bacteria are present in blood from donors self-reported as medically healthy, indicating that conventional test systems employed by blood banks insufficiently detect bacteria in plasma. Further investigation is needed to determine whether routine testing for anaerobic bacteria and testing of RBC-fractions for adherent bacteria should be recommended. PMID:25751254

  5. Enumeration of viable non-culturable Vibrio cholerae using propidium monoazide combined with quantitative PCR.

    PubMed

    Wu, Bin; Liang, Weili; Kan, Biao

    2015-08-01

    The well-known human pathogenic bacterium, Vibrio cholerae, can enter a physiologically viable but non-culturable (VBNC) state under stress conditions. The differentiation of VBNC cells and nonviable cells is essential for both disease prevention and basic research. Among all the methods for detecting viability, propidium monoazide (PMA) combined with real-time PCR is popular because of its specificity, sensitivity, and speed. However, the effect of PMA treatment is not consistent and varies among different species and conditions. In this study, with an initial cell concentration of 1×10(8) CFU/ml, time and dose-effect relationships of different PMA treatments were evaluated via quantitative real-time PCR using live cell suspensions, dead cell suspensions and VBNC cell suspensions of V. cholerae O1 El Tor strain C6706. The results suggested that a PMA treatment of 20 μM PMA for 20 min was optimal under our conditions. This treatment maximized the suppression of the PCR signal from membrane-compromised dead cells but had little effect on the signal from membrane-intact live cells. In addition to the characteristics of PMA treatment itself, the initial concentration of the targeted bacteria showed a significant negative influence on the stability of PMA-PCR assay in this study. We developed a strategy that mimicked a 1×10(8) CFU/ml cell concentration with dead bacteria of a different bacterial species, the DNA of which cannot be amplified using the real time PCR primers. With this strategy, our optimal approach successfully overcame the impact of low cell density and generated stable and reliable results for counting viable cells of V. cholerae in the VBNC state.

  6. Determination of viable legionellae in engineered water systems: Do we find what we are looking for?

    PubMed

    Kirschner, Alexander K T

    2016-04-15

    In developed countries, legionellae are one of the most important water-based bacterial pathogens caused by management failure of engineered water systems. For routine surveillance of legionellae in engineered water systems and outbreak investigations, cultivation-based standard techniques are currently applied. However, in many cases culture-negative results are obtained despite the presence of viable legionellae, and clinical cases of legionellosis cannot be traced back to their respective contaminated water source. Among the various explanations for these discrepancies, the presence of viable but non-culturable (VBNC) Legionella cells has received increased attention in recent discussions and scientific literature. Alternative culture-independent methods to detect and quantify legionellae have been proposed in order to complement or even substitute the culture method in the future. Such methods should detect VBNC Legionella cells and provide a more comprehensive picture of the presence of legionellae in engineered water systems. However, it is still unclear whether and to what extent these VBNC legionellae are hazardous to human health. Current risk assessment models to predict the risk of legionellosis from Legionella concentrations in the investigated water systems contain many uncertainties and are mainly based on culture-based enumeration. If VBNC legionellae should be considered in future standard analysis, quantitative risk assessment models including VBNC legionellae must be proven to result in better estimates of human health risk than models based on cultivation alone. This review critically evaluates current methods to determine legionellae in the VBNC state, their potential to complement the standard culture-based method in the near future, and summarizes current knowledge on the threat that VBNC legionellae may pose to human health.

  7. Bacterial regrowth in water reclamation and distribution systems revealed by viable bacterial detection assays.

    PubMed

    Lin, Yi-wen; Li, Dan; Gu, April Z; Zeng, Si-yu; He, Miao

    2016-02-01

    Microbial regrowth needs to be managed during water reclamation and distribution. The aim of present study was to investigate the removal and regrowth of Escherichia coli (E. coli) and Salmonella in water reclamation and distribution system by using membrane integrity assay (PMA-qPCR), reverse transcriptional activity assay (Q-RT-PCR) and culture-based assay, and also to evaluate the relationships among bacterial regrowth, and environmental factors in the distribution system. The results showed that most of the water reclamation processes potentially induced bacteria into VBNC state. The culturable E. coli and Salmonella regrew 1.8 and 0.7 log10 in distribution system, which included reactivation of bacteria in the viable but non-culturable (VBNC) state and reproduction of culturable bacteria. The regrowth of culturable E. coli and Salmonella in the distribution system mainly depended on the residual chlorine levels, with correlations (R(2)) of -0.598 and -0.660. The abundances of membrane integrity and reverse transcriptional activity bacteria in reclamation effluents had significant correlations with the culturable bacteria at the end point of the distribution system, demonstrating that PMA-qPCR and Q-RT-PCR are sensitive and accurate tools to determine and predict bacterial regrowth in water distribution systems. This study has improved our understanding of microbial removal and regrowth in reclaimed water treatment and distribution systems. And the results also recommended that more processes should be equipped to remove viable bacteria in water reclamation plants for the sake of inhibition microbial regrowth during water distribution and usages.

  8. Fern Spore Longevity in Saline Water: Can Sea Bottom Sediments Maintain a Viable Spore Bank?

    PubMed Central

    de Groot, G. Arjen; During, Heinjo

    2013-01-01

    Freshwater and marine sediments often harbor reservoirs of plant diaspores, from which germination and establishment may occur whenever the sediment falls dry. Therewith, they form valuable records of historical inter- and intraspecific diversity, and are increasingly exploited to facilitate diversity establishment in new or restored nature areas. Yet, while ferns may constitute a considerable part of a vegetation’s diversity and sediments are known to contain fern spores, little is known about their longevity, which may suffer from inundation and - in sea bottoms - salt stress. We tested the potential of ferns to establish from a sea or lake bottom, using experimental studies on spore survival and gametophyte formation, as well as a spore bank analysis on sediments from a former Dutch inland sea. Our experimental results revealed clear differences among species. For Asplenium scolopendrium and Gymnocarpium dryopteris, spore germination was not affected by inundated storage alone, but decreased with rising salt concentrations. In contrast, for Asplenium trichomanes subsp. quadrivalens germination decreased following inundation, but not in response to salt. Germination rates decreased with time of storage in saline water. Smaller and less viable gametophytes were produced when saline storage lasted for a year. Effects on germination and gametophyte development clearly differed among genotypes of A. scolopendrium. Spore bank analyses detected no viable spores in marine sediment layers. Only two very small gametophytes (identified as Thelypteris palustris via DNA barcoding) emerged from freshwater sediments. Both died before maturation. We conclude that marine, and likely even freshwater sediments, will generally be of little value for long-term storage of fern diversity. The development of any fern vegetation on a former sea floor will depend heavily on the deposition of spores onto the drained land by natural or artificial means of dispersal. PMID:24223951

  9. In vivo resuscitation, and virulence towards mice, of viable but nonculturable cells of Vibrio vulnificus.

    PubMed Central

    Oliver, J D; Bockian, R

    1995-01-01

    Vibrio vulnificus is an estuarine bacterium responsible for 95% of all seafood-related deaths in the United States. The bacterium occurs naturally in molluscan shellfish, and ingestion of raw oysters is typically the source of human infection. V. vulnificus is also known to enter a viable but nonculturable (VBNC) state, wherein the cells are no longer culturable on routine plating media but can be shown to remain viable. Whether or not this human pathogen remains virulent when entering the VBNC state has not been definitively demonstrated. In this study, the VBNC state was induced through a temperature downshift to 5 degrees C, with cells becoming nonculturable (< 0.1 CFU/ml) within 7 days. As they became nonculturable, virulence was determined by employing an iron overload mouse model. At the point of nonculturability (7 days), injections of the diluted microcosm population resulted in death when < 0.04 CFU was inoculated, although > 10(5) cells in the VBNC state were present in the inoculum. Culturable cells of V. vulnificus, with identification confirmed through PCR, were recovered from the blood and peritoneal cavities of mice which had died from injections of cells present in the VBNC state for at least 3 days. Thus, our data suggest that cells of V. vulnificus remain virulent, at least for some time, when present in the VBNC state and are capable of causing fatal infections following in vivo resuscitation. Our studies also indicate, however, that virulence decreases significantly as cells enter the VBNC state, which may account, at least to some extent, for the decrease in infections caused by this bacterium during winter months. PMID:7618873

  10. Determination of viable legionellae in engineered water systems: Do we find what we are looking for?

    PubMed Central

    Kirschner, Alexander K.T.

    2016-01-01

    In developed countries, legionellae are one of the most important water-based bacterial pathogens caused by management failure of engineered water systems. For routine surveillance of legionellae in engineered water systems and outbreak investigations, cultivation-based standard techniques are currently applied. However, in many cases culture-negative results are obtained despite the presence of viable legionellae, and clinical cases of legionellosis cannot be traced back to their respective contaminated water source. Among the various explanations for these discrepancies, the presence of viable but non-culturable (VBNC) Legionella cells has received increased attention in recent discussions and scientific literature. Alternative culture-independent methods to detect and quantify legionellae have been proposed in order to complement or even substitute the culture method in the future. Such methods should detect VBNC Legionella cells and provide a more comprehensive picture of the presence of legionellae in engineered water systems. However, it is still unclear whether and to what extent these VBNC legionellae are hazardous to human health. Current risk assessment models to predict the risk of legionellosis from Legionella concentrations in the investigated water systems contain many uncertainties and are mainly based on culture-based enumeration. If VBNC legionellae should be considered in future standard analysis, quantitative risk assessment models including VBNC legionellae must be proven to result in better estimates of human health risk than models based on cultivation alone. This review critically evaluates current methods to determine legionellae in the VBNC state, their potential to complement the standard culture-based method in the near future, and summarizes current knowledge on the threat that VBNC legionellae may pose to human health. PMID:26928563

  11. Rapid detection methods for viable Mycobacterium avium subspecies paratuberculosis in milk and cheese.

    PubMed

    Botsaris, George; Slana, Iva; Liapi, Maria; Dodd, Christine; Economides, Constantinos; Rees, Catherine; Pavlik, Ivo

    2010-07-31

    Mycobacterium avium subsp. paratuberculosis (MAP) may have a role in the development of Crohn's disease in humans via the consumption of contaminated milk and milk products. Detection of MAP from milk and dairy products has been reported from countries on the European continent, Argentina, the UK and Australia. In this study three different methods (quantitative real time PCR, combined phage IS900 PCR and conventional cultivation) were used to detect the presence of MAP in bulk tank milk (BTM) and cheese originating from sheep, goat and mixed milks from farms and products in Cyprus. During the first survey the presence of MAP was detected in 63 (28.6%) of cows' BTM samples by quantitative real time PCR. A second survey of BTM used a new combined phage IS900 PCR assay, and in this case MAP was detected in 50 (22.2%) samples showing a good level of agreement by both methods. None of the herds tested were known to be affected by Johne's disease and the presence of viable MAP was confirmed by conventional culture in only two cases of cows BTM. This suggests that either rapid method used is more sensitive than the conventional culture when testing raw milk samples for MAP. The two isolates recovered from BTM were identified by IS1311 PCR REA as cattle and sheep strains, respectively. In contrast when cheese samples were tested, MAP DNA was detected by quantitative real time PCR in seven (25.0%) samples (n=28). However no viable MAP was detected when either the combined phage IS900 PCR or conventional culture methods were used.

  12. Neutrophil Extracellular Traps Form a Barrier between Necrotic and Viable Areas in Acute Abdominal Inflammation

    PubMed Central

    Bilyy, Rostyslav; Fedorov, Volodymyr; Vovk, Volodymyr; Leppkes, Moritz; Dumych, Tetiana; Chopyak, Valentyna; Schett, Georg; Herrmann, Martin

    2016-01-01

    Neutrophils form neutrophil extracellular traps (NETs) of decondensed DNA and histones that trap and immobilize particulate matter and microbial pathogens like bacteria. NET aggregates reportedly surround and isolate large objects like monosodium urate crystals, which cannot be sufficiently cleared from tissues. In the setting of acute necrotizing pancreatitis, massive tissue necrosis occurs, which is organized as pancreatic pseudocysts (1). In contrast to regular cysts, these pseudocysts are not surrounded by epithelial layers. We hypothesize that, instead, the necrotic areas observed in necrotizing pancreatitis are isolated from the surrounding healthy tissues by aggregated NETs. These may form an alternative, putatively transient barrier, separating necrotic areas from viable tissue. To test this hypothesis, we investigated histological samples from the necropsy material of internal organs of two patients with necrotizing pancreatitis and peritonitis accompanied by multiple organ failure. Tissues including the inflammatory zone were stained with hematoxylin and eosin and evaluated for signs of inflammation. Infiltrating neutrophils and NETs were detected by immunohistochemistry for DNA, neutrophil elastase (NE), and citrullinated histone H3. Interestingly, in severely affected areas of pancreatic necrosis or peritonitis, chromatin stained positive for NE and citrullinated histone H3, and may, therefore, be considered NET-derived. These NET structures formed a layer, which separated the necrotic core from the areas of viable tissue remains. A condensed layer of aggregated NETs, thus, spatially shields and isolates the site of necrosis, thereby limiting the spread of necrosis-associated proinflammatory mediators. We propose that necrotic debris may initiate and/or facilitate the formation of the NET-based surrogate barrier. PMID:27777576

  13. Can Economics Provide Insights into Trust Infrastructure?

    NASA Astrophysics Data System (ADS)

    Vishik, Claire

    Many security technologies require infrastructure for authentication, verification, and other processes. In many cases, viable and innovative security technologies are never adopted on a large scale because the necessary infrastructure is slow to emerge. Analyses of such technologies typically focus on their technical flaws, and research emphasizes innovative approaches to stronger implementation of the core features. However, an observation can be made that in many cases the success of adoption pattern depends on non-technical issues rather than technology-lack of economic incentives, difficulties in finding initial investment, inadequate government support. While a growing body of research is dedicated to economics of security and privacy in general, few theoretical studies in this area have been completed, and even fewer that look at the economics of “trust infrastructure” beyond simple “cost of ownership” models. This exploratory paper takes a look at some approaches in theoretical economics to determine if they can provide useful insights into security infrastructure technologies and architectures that have the best chance to be adopted. We attempt to discover if models used in theoretical economics can help inform technology developers of the optimal business models that offer a better chance for quick infrastructure deployment.

  14. Healthcare information technology and economics

    PubMed Central

    Bates, David W; Berner, Eta S; Bernstam, Elmer V; Covvey, H Dominic; Frisse, Mark E; Graf, Thomas; Greenes, Robert A; Hoffer, Edward P; Kuperman, Gil; Lehmann, Harold P; Liang, Louise; Middleton, Blackford; Omenn, Gilbert S; Ozbolt, Judy

    2013-01-01

    At the 2011 American College of Medical Informatics (ACMI) Winter Symposium we studied the overlap between health IT and economics and what leading healthcare delivery organizations are achieving today using IT that might offer paths for the nation to follow for using health IT in healthcare reform. We recognized that health IT by itself can improve health value, but its main contribution to health value may be that it can make possible new care delivery models to achieve much larger value. Health IT is a critically important enabler to fundamental healthcare system changes that may be a way out of our current, severe problem of rising costs and national deficit. We review the current state of healthcare costs, federal health IT stimulus programs, and experiences of several leading organizations, and offer a model for how health IT fits into our health economic future. PMID:22781191

  15. Healthcare information technology and economics.

    PubMed

    Payne, Thomas H; Bates, David W; Berner, Eta S; Bernstam, Elmer V; Covvey, H Dominic; Frisse, Mark E; Graf, Thomas; Greenes, Robert A; Hoffer, Edward P; Kuperman, Gil; Lehmann, Harold P; Liang, Louise; Middleton, Blackford; Omenn, Gilbert S; Ozbolt, Judy

    2013-01-01

    At the 2011 American College of Medical Informatics (ACMI) Winter Symposium we studied the overlap between health IT and economics and what leading healthcare delivery organizations are achieving today using IT that might offer paths for the nation to follow for using health IT in healthcare reform. We recognized that health IT by itself can improve health value, but its main contribution to health value may be that it can make possible new care delivery models to achieve much larger value. Health IT is a critically important enabler to fundamental healthcare system changes that may be a way out of our current, severe problem of rising costs and national deficit. We review the current state of healthcare costs, federal health IT stimulus programs, and experiences of several leading organizations, and offer a model for how health IT fits into our health economic future.

  16. The New Literacies of Online Research and Comprehension: Rethinking the Reading Achievement Gap

    ERIC Educational Resources Information Center

    Leu, Donald J.; Forzani, Elena; Rhoads, Chris; Maykel, Cheryl; Kennedy, Clint; Timbrell, Nicole

    2015-01-01

    Is there an achievement gap for online reading ability based on income inequality that is separate from the achievement gap in traditional, offline reading? This possibility was examined between students in two pseudonymous school districts: West Town (economically advantaged) and East Town (economically challenged; N = 256). Performance-based…

  17. Cherokee Culture and School Achievement.

    ERIC Educational Resources Information Center

    Brown, Anthony D.

    1980-01-01

    Compares the effect of cooperative and competitive behaviors of Cherokee and Anglo American elementary school students on academic achievement. Suggests changes in teaching techniques and lesson organization that might raise academic achievement while taking into consideration tribal traditions that limit scholastic achievement in an…

  18. Use of sodium lauroyl sarcosinate (sarkosyl) in viable real-time PCR for enumeration of Escherichia coli.

    PubMed

    Wang, Hui; Gill, Colin O; Yang, Xianqin

    2014-03-01

    The cell membranes of inactivated Escherichia coli are not always permeable to propidium monoazide (PMA). This limits the use of PMA real-time PCR (PMA-qPCR) for quantification of DNA from only viable cells for enumeration of E. coli. The aim of this study was to develop PMA-qPCR procedures for E. coli with improved selectivity for viable cells. E. coli inactivated by incubation at 52°C were treated with 12 detergents before PMA treatment, and DNA was quantified by real-time PCR. Treatment with each of the 12 detergents and PMA increased the cycle threshold (Ct) values for heat inactivated E. coli suspensions. The greatest increase, of 10.68 Ct was obtained with sarkosyl. Treatment with sodium deoxycholate (NaDC) increased the Ct value by 8.99 Ct. Treatment with sarkosyl or NaDC of 16 heat treated 5-strain cocktails of verotoxigenic E. coli (VTEC) increased the mean Ct values by 8.15 or 6.82 Ct, respectively. Those mean values were significantly (p<0.05) different. When used to enumerate viable E. coli in suspensions treated with lactic acid or in mixtures of viable E. coli and E. coli inactivated by peroxyacetic acid, the slopes relating the Ct values from sarkosyl treated samples to the numbers of viable E. coli were 2.24 and 2.47, respectively, with regression coefficient values ≥0.85. The findings show that sarkosyl was more effective than NaDC for dissipation of PMA-barrier properties of membranes of inactivated E. coli cells. Viable E. coli in mixtures of viable E. coli and E. coli inactivated by heat, lactic acid or peroxyacetic acid could be reliably enumerated by sarkosyl PMA-qPCR. PMID:24445114

  19. The Economic Value of Higher Teacher Quality. Working Paper 56

    ERIC Educational Resources Information Center

    Hanushek, Eric A.

    2010-01-01

    Most analyses of teacher quality end without any assessment of the economic value of altered teacher quality. This paper combines information about teacher effectiveness with the economic impact of higher achievement. It begins with an overview of what is known about the relationship between teacher quality and student achievement, which provides…

  20. Application of Probabilistic Methods for the Determination of an Economically Robust HSCT Configuration

    NASA Technical Reports Server (NTRS)

    Mavris, Dimitri N.; Bandte, Oliver; Schrage, Daniel P.

    1996-01-01

    This paper outlines an approach for the determination of economically viable robust design solutions using the High Speed Civil Transport (HSCT) as a case study. Furthermore, the paper states the advantages of a probability based aircraft design over the traditional point design approach. It also proposes a new methodology called Robust Design Simulation (RDS) which treats customer satisfaction as the ultimate design objective. RDS is based on a probabilistic approach to aerospace systems design, which views the chosen objective as a distribution function introduced by so called noise or uncertainty variables. Since the designer has no control over these variables, a variability distribution is defined for each one of them. The cumulative effect of all these distributions causes the overall variability of the objective function. For cases where the selected objective function depends heavily on these noise variables, it may be desirable to obtain a design solution that minimizes this dependence. The paper outlines a step by step approach on how to achieve such a solution for the HSCT case study and introduces an evaluation criterion which guarantees the highest customer satisfaction. This customer satisfaction is expressed by the probability of achieving objective function values less than a desired target value.

  1. Students’ Achievement Goals, Learning-Related Emotions and Academic Achievement

    PubMed Central

    Lüftenegger, Marko; Klug, Julia; Harrer, Katharina; Langer, Marie; Spiel, Christiane; Schober, Barbara

    2016-01-01

    In the present research, the recently proposed 3 × 2 model of achievement goals is tested and associations with achievement emotions and their joint influence on academic achievement are investigated. The study was conducted with 388 students using the 3 × 2 Achievement Goal Questionnaire including the six proposed goal constructs (task-approach, task-avoidance, self-approach, self-avoidance, other-approach, other-avoidance) and the enjoyment and boredom scales from the Achievement Emotion Questionnaire. Exam grades were used as an indicator of academic achievement. Findings from CFAs provided strong support for the proposed structure of the 3 × 2 achievement goal model. Self-based goals, other-based goals and task-approach goals predicted enjoyment. Task-approach goals negatively predicted boredom. Task-approach and other-approach predicted achievement. The indirect effects of achievement goals through emotion variables on achievement were assessed using bias-corrected bootstrapping. No mediation effects were found. Implications for educational practice are discussed. PMID:27199836

  2. Evolutionary Systems Theory, Universities, and Endogenous Regional Economic Development

    ERIC Educational Resources Information Center

    Bowen, William M.

    2007-01-01

    Universities today are increasingly being viewed in terms of serving the purpose of economic development. This paper postulates that their chief purpose is to advance knowledge and that in doing so they effectuate regional economic growth and development through processes specified in the endogenous economic growth model. To achieve this purpose…

  3. Thermal-economic analysis of organic Rankine combined cycle cogeneration

    NASA Astrophysics Data System (ADS)

    Porter, R. W.

    1982-12-01

    An evaluation of organic rankine cycles (ORC) as combined with topping incorporating gas turbines or diesel engines, and with subsequent waste heat utilization is presented. It is found that the potential benefit of the proposed organic Rankine combined cycle cogeneration of useful heat and electricity is more flexible in meeting demands for the two products, by varying the mode of operation of the system. A thermal-economic analysis is developed and illustrated with cost and performance data for commercially available equipment, and with general economic parameters reflecting current regulations and market conditions. The performance of the ORC and of the entire combined cycle is described. Equations to evaluate the various thermodynamic and economic parameter, and the resultant case flows are presented. Criteria are developed to assess the addition of an ORC to a cogeneration system without ORC is viable based on rate of return on incremental investment. It is indicated that the proposed system is potentially viable, however, it is not viable under conditions prevailing in Chicago for the selected case studies.

  4. Economic potential of inertial fusion

    SciTech Connect

    Nuckolls, J.H.

    1984-04-01

    Beyond the achievement of scientific feasibility, the key question for fusion energy is: does it have the economic potential to be significantly cheaper than fission and coal energy. If fusion has this high economic potential then there are compelling commercial and geopolitical incentives to accelerate the pace of the fusion program in the near term, and to install a global fusion energy system in the long term. Without this high economic potential, fusion's success depends on the failure of all alternatives, and there is no real incentive to accelerate the program. If my conjectures on the economic potential of inertial fusion are approximately correct, then inertial fusion energy's ultimate costs may be only half to two-thirds those of advanced fission and coal energy systems. Relative cost escalation is not assumed and could increase this advantage. Both magnetic and inertial approaches to fusion potentially have a two-fold economic advantage which derives from two fundamental properties: negligible fuel costs and high quality energy which makes possible more efficient generation of electricity. The wining approach to fusion may excel in three areas: electrical generating efficiency, minimum material costs, and adaptability to manufacture in automated factories. The winning approach must also rate highly in environmental potential, safety, availability factor, lifetime, small 0 and M costs, and no possibility of utility-disabling accidents.

  5. Achievement as Resistance: The Development of a Critical Race Achievement Ideology among Black Achievers

    ERIC Educational Resources Information Center

    Carter, Dorinda J.

    2008-01-01

    In this article, Dorinda Carter examines the embodiment of a critical race achievement ideology in high-achieving black students. She conducted a yearlong qualitative investigation of the adaptive behaviors that nine high-achieving black students developed and employed to navigate the process of schooling at an upper-class, predominantly white,…

  6. Use of real-time PCR with propidium monoazide for enumeration of viable Escherichia coli in anaerobic digestion.

    PubMed

    Ruike, Wataru; Higashimori, Atsushi; Yaguchi, Junichi; Li, Yu-You

    2016-01-01

    A combination of propidium monoazide (PMA) with real-time quantitative polymerase chain reaction (PMA-qPCR) was optimized to enumerate only viable Escherichia coli in anaerobic digestion processes. Repeating the PMA treatment twice and a final concentration of 100 μM resulted in an effective exclusion of DNA from heat-treated E. coli cells. In three anaerobic digestion processes, real-time PCR, PMA-qPCR, and the most probable number method (MPN) were used to estimate the numbers of total, viable, and culturable E. coli cells, respectively. Culturable concentrations of fecal coliforms were also measured by the membrane filter method. For thermophilic digestion, the reductions in total and viable E. coli cells from the digester influent to the effluent were significantly lower than those in culturable cells and fecal coliforms by two to four orders of magnitude. For mesophilic digestion, the differences in the reductions in E. coli and fecal coliforms counts were less than two orders of magnitude. Based on the measurements of viable E. coli determined by the PMA-qPCR method, the microbial quality of digester effluents was discussed for agricultural application, and pasteurization after anaerobic digestion was suggested for the destruction of viable pathogens. PMID:27642844

  7. "Viable motheaten," a new allele at the motheaten locus. I. Pathology.

    PubMed Central

    Shultz, L. D.; Coman, D. R.; Bailey, C. L.; Beamer, W. G.; Sidman, C. L.

    1984-01-01

    A new spontaneous autosomal recessive mutation has recently occurred at the motheaten (me) locus on Chromosome 6 in strain C57BL/6J mice. Homozygotes for the new allele, designated "viable motheaten" (mev), have a mean life span of 61 +/- 2.4 days, compared with only 22 +/- 1.3 days for C57BL/6J-me/me mice. Like the original motheaten mutation, the immediate cause of death in mev/mev mice appears to be severe pneumonitis associated with accumulations of macrophages, granulocytes, and lymphocytes in the lungs. However, because of its longer life span, progression of the disease in mev/mev mice is more amenable to investigation. Eosinophilic crystalline material in alveolar macrophages from mev/mev mice is associated with extravasation of erythrocytes into alveoli. These crystals are morphologically indistinguishable from hematoidin, which results from hemoglobin breakdown following uptake of erythrocytes by macrophages. Severe macrocytic hypochromic anemia with abnormalities in size and shape of erythrocytes develops by 7 weeks. A two-fold increase in peripheral leukocyte count and a five-fold increase in the percentage of neutrophils is seen by 10 weeks. Viable motheaten mice develop focal granulocytic skin lesions by 4 days of age, show depletion of cells from the thymus cortex by 4 weeks, and lack lymphoid follicles in the lymph nodes, spleen, and Peyer's patches. Excessive erythropoiesis and myelopoiesis in the spleen result in marked splenomegaly. Lymph nodes and spleens from mev/mev mice contain increased numbers of plasma cells by 3 weeks; and by 6 weeks, large numbers of atypical plasma cells with Russell bodies are evident. Development of glomerulonephritis by 10 weeks is characterized by granular depositis of immunoglobulin and complement within glomeruli. A twofold increase of blood urea nitrogen levels is present by 15 weeks. Sterility of male mev/mev mice is associated with Leydig cell depletion in the testes, lowered testosterone levels, and impaired

  8. Detection of Only Viable Bacterial Spores Using a Live/Dead Indicator in Mixed Populations

    NASA Technical Reports Server (NTRS)

    Behar, Alberto E.; Stam, Christina N.; Smiley, Ronald

    2013-01-01

    This method uses a photoaffinity label that recognizes DNA and can be used to distinguish populations of bacterial cells from bacterial spores without the use of heat shocking during conventional culture, and live from dead bacterial spores using molecular-based methods. Biological validation of commercial sterility using traditional and alternative technologies remains challenging. Recovery of viable spores is cumbersome, as the process requires substantial incubation time, and the extended time to results limits the ability to quickly evaluate the efficacy of existing technologies. Nucleic acid amplification approaches such as PCR (polymerase chain reaction) have shown promise for improving time to detection for a wide range of applications. Recent real-time PCR methods are particularly promising, as these methods can be made at least semi-quantitative by correspondence to a standard curve. Nonetheless, PCR-based methods are rarely used for process validation, largely because the DNA from dead bacterial cells is highly stable and hence, DNA-based amplification methods fail to discriminate between live and inactivated microorganisms. Currently, no published method has been shown to effectively distinguish between live and dead bacterial spores. This technology uses a DNA binding photoaffinity label that can be used to distinguish between live and dead bacterial spores with detection limits ranging from 109 to 102 spores/mL. An environmental sample suspected of containing a mixture of live and dead vegetative cells and bacterial endospores is treated with a photoaffinity label. This step will eliminate any vegetative cells (live or dead) and dead endospores present in the sample. To further determine the bacterial spore viability, DNA is extracted from the spores and total population is quantified by real-time PCR. The current NASA standard assay takes 72 hours for results. Part of this procedure requires a heat shock step at 80 degC for 15 minutes before the

  9. Primer on Social Economics.

    ERIC Educational Resources Information Center

    Darcy, Robert L.

    An elaboration of the author's booklet entitled "First Steps Toward Economic Understanding," this primer is designed to help the reader develop a functional understanding of the economic process so that he can make wiser decisions on issues of social policy and on matters affecting his economic well-being. The document is not "economics in one…

  10. Competition in Economic Theory.

    ERIC Educational Resources Information Center

    Livesey, F.

    1982-01-01

    Considers two alternative views of competition found in the economics literature. The author demonstrates that these alternative views of competition underlie alternative views in other areas of economics, including welfare economics and micro-economic policy. Implications for college students and teachers are examined. (Author/AM)

  11. Engaging Undergraduates in Economics

    ERIC Educational Resources Information Center

    Gajwani, Kiran; Miron, Jeffrey

    2015-01-01

    Siegfried and Stock (2007) explore the undergraduate training of PhD economists. Their findings show that among U.S. undergraduate economics programs, the Harvard University Economics Department produces many eventual economics PhD recipients. In this article, the authors discuss Harvard's undergraduate economics program and highlight some key…

  12. Finding the economics in economic entomology.

    PubMed

    Onstad, David W; Knolhoff, Lisa M

    2009-02-01

    To recommend new pest management tactics and strategies to farmers and policy makers, economic entomologists must evaluate the economics of biologically reasonable approaches. We collected data to determine how frequently these economic evaluations occur. We discovered from our survey of entomological journals representing the discipline of economic entomology that < 1% of research papers published since 1972 include economic evaluations of pest management tactics. At least 85% of these analyses were performed by entomologists and not economists. Much of the research on economic evaluations is performed without special funds granted by agencies separate from the authors' institutions. In the United States, USDA competitive grants supported 20% of the economic evaluations published since 2000. However, only approximately 12% of the projects funded since 2000 by three sections of the USDA (Crops at Risk, Risk Avoidance and Mitigation Program, and Pest Management Alternatives Program) resulted in publications concerning economic evaluations. If the purpose of economic entomology is to ultimately determine the value of different kinds of tactics, the discipline may need to take steps to enhance the research that supports these evaluations.

  13. The Mechanics of Human Achievement

    PubMed Central

    Duckworth, Angela L.; Eichstaedt, Johannes C.; Ungar, Lyle H.

    2015-01-01

    Countless studies have addressed why some individuals achieve more than others. Nevertheless, the psychology of achievement lacks a unifying conceptual framework for synthesizing these empirical insights. We propose organizing achievement-related traits by two possible mechanisms of action: Traits that determine the rate at which an individual learns a skill are talent variables and can be distinguished conceptually from traits that determine the effort an individual puts forth. This approach takes inspiration from Newtonian mechanics: achievement is akin to distance traveled, effort to time, skill to speed, and talent to acceleration. A novel prediction from this model is that individual differences in effort (but not talent) influence achievement (but not skill) more substantially over longer (rather than shorter) time intervals. Conceptualizing skill as the multiplicative product of talent and effort, and achievement as the multiplicative product of skill and effort, advances similar, but less formal, propositions by several important earlier thinkers. PMID:26236393

  14. Influenza virus survival in aerosols and estimates of viable virus loss resulting from aerosolization and air-sampling.

    PubMed

    Brown, J R; Tang, J W; Pankhurst, L; Klein, N; Gant, V; Lai, K M; McCauley, J; Breuer, J

    2015-11-01

    Using a Collison nebulizer, aerosols of influenza (A/Udorn/307/72 H3N2) were generated within a controlled experimental chamber, from known starting virus concentrations. Air samples collected after variable suspension times were tested quantitatively using both plaque and polymerase chain reaction assays, to compare the proportion of viable virus against the amount of detectable viral RNA. These experiments showed that whereas influenza RNA copies were well preserved, the number of viable viruses decreased by a factor of 10(4)-10(5). This suggests that air-sampling studies for assessing infection control risks that detect only influenza RNA may greatly overestimate the amount of viable virus available to cause infection.

  15. Viable chaotic inflation as a source of neutrino masses and leptogenesis

    NASA Astrophysics Data System (ADS)

    Nakayama, Kazunori; Takahashi, Fuminobu; Yanagida, Tsutomu T.

    2016-06-01

    We show that the seesaw mechanism as well as leptogenesis are natural outcomes of a viable chaotic inflation in supergravity. The inflation model contains two superfields, the inflaton and stabilizer fields, which, being singlets under the standard model gauge symmetry, naturally couple to the lepton and Higgs doublets. The inflaton decays into leptons and Higgs fields, and the reheating temperature is predicted to be of O (1013) GeV, for which thermal leptogenesis is possible. On the other hand, gravitinos are copiously produced, and various solutions to the gravitino problem are discussed. We also argue that, if the shift symmetry of the inflaton is explicitly broken down to a discrete one, neutrino Yukawa couplings are periodic in the inflaton field, and masses of leptons and Higgs do not blow up even if the inflaton takes super-Planckian field values. The inflaton potential is given by a sum of sinusoidal functions with different height and periodicity, the so-called multi-natural inflation. We show that the predicted scalar spectral index and tensor-to-scalar ratio lie in the region favored by the Planck data.

  16. Characterization of viable bacteria from Siberian permafrost by 16S rDNA sequencing

    NASA Technical Reports Server (NTRS)

    Shi, T.; Reeves, R. H.; Gilichinsky, D. A.; Friedmann, E. I.

    1997-01-01

    Viable bacteria were found in permafrost core samples from the Kolyma-Indigirka lowland of northeast Siberia. The samples were obtained at different depths; the deepest was about 3 million years old. The average temperature of the permafrost is -10 degrees C. Twenty-nine bacterial isolates were characterized by 16S rDNA sequencing and phylogenetic analysis, cell morphology, Gram staining, endospore formation, and growth at 30 degrees C. The majority of the bacterial isolates were rod shaped and grew well at 30 degrees C; but two of them did not grow at or above 28 degrees C, and had optimum growth temperatures around 20 degrees C. Thirty percent of the isolates could form endospores. Phylogenetic analysis revealed that the isolates fell into four categories: high-GC Gram-positive bacteria, beta-proteobacteria, gamma-proteobacteria, and low-GC Gram-positive bacteria. Most high-GC Gram-positive bacteria and beta-proteobacteria, and all gamma-proteobacteria, came from samples with an estimated age of 1.8-3.0 million years (Olyor suite). Most low-GC Gram-positive bacteria came from samples with an estimated age of 5,000-8,000 years (Alas suite).

  17. Glass Effect in Inbreeding-Avoidance Systems: Minimum Viable Population for Outbreeders

    NASA Astrophysics Data System (ADS)

    Tainaka, Kei-ichi; Itoh, Yoshiaki

    1996-10-01

    Many animals, birds and plants have evolved mechanisms to avoid inbreeding between close relatives.Such mating systems may have developed several methods for restricting mate choice.If fragmentation of habitats becomes serious, these methods may lead to a lack of acceptable mates. We call this “glass effect”which is a generalization of the so-called Allee effect.We present two inbreeding-avoidance (outbreeding) models.Both models show that outbreeders have a high risk infragmented environments.We thus obtain the minimum viable population (MVP). It is found that the value of MVP amounts to the range from several hundred to several thousand individuals.While this value is much larger than thoseobtained by the previous demographic theories,it is consistent with recent empirical estimations.Moreover, we find that the glass effect is caused bydynamically induced clusters of relatives.This suggests that genetic variation will be decreased by the outbreeding in a highly fragmented environment.

  18. Biosorption of aluminum through the use of non-viable biomass of Pseudomonas putida.

    PubMed

    Boeris, Paola Sabrina; Agustín, María Del Rosario; Acevedo, Diego Fernando; Lucchesi, Gloria Inés

    2016-10-20

    Living and non-living biomass of Pseudomonas putida A (ATCC 12633) was used as biosorbent for the removing of Al(3+) from aqueous solutions. The process was stable with time, efficient at pH 4.3 and between 15°C and 42°C. Two isotherms models were applied to describe the interaction between the biosorbent and Al(3+). Non-living biomass of P. putida A (ATCC 12633) was found to be the most efficient at adsorbing Al(3+) with a maximum sorption capacity of 0.55mg Al(3+)/gr adsorbent and with 36×10(5) binding sites of Al(3+)/microorganisms. Infrared spectroscopy analysis shows that the biosorbent present some vibrational band of functional groups that change in presence of Al(3+): hydroxyl, carboxyl and phosphate. Considering that Al(3+) binds to the phosphate group of phosphatidylcholine, non-viable biomass of P. putida PB01 (mutant lacking phosphatidylcholine) was used. Aluminum adsorption of the parental strain was 30 times higher than values registered in P. putida PB01 (36×10(5) sites/microorganism vs 1.2×10(5) sites/microorganism, respectively). This result evidenced that the absence of phosphatidylcholine significantly affected the availability of the binding sites and consequently the efficiency of the biomass to adsorb Al(3+). PMID:27485814

  19. Gene Expression Profiling in Viable but Nonculturable (VBNC) Cells of Pseudomonas syringae pv. syringae

    PubMed Central

    Postnikova, Olga A.; Shao, Jonathan; Mock, Norton M.; Baker, Con J.; Nemchinov, Lev G.

    2015-01-01

    Pseudomonas syringae infects diverse crop plants and comprises at least 50 different pathovar strains with different host ranges. More information on the physiological and molecular effects of the host inhibitory environment on the pathogen is needed to develop resistant cultivars. Recently, we reported an in vitro model system that mimics the redox pulse associated with the oxidative burst in plant cells inoculated with Pseudomonas syringae pv. syringae. Using this system, we demonstrated that oxidation of acetosyringone, a major extracellular phenolic compound induced in some plants in response to bacteria, rendered Pseudomonas syringae pv. syringae to a “viable but nonculturable” (VBNC) state. Here we performed a large scale transcriptome profiling of P. s. pv. syringae in the VBNC state induced by acetosyringone treatment and identified bacterial genes and pathways presumably associated with this condition. The findings offer insight into what events occur when bacterial pathogens are first encountered and host defense responses are triggered. The acquired knowledge will improve our understanding of the molecular mechanisms of stress tolerance. We believe that this is the first work on global gene expression profiling of VBNC cells in plant pathogenic bacteria. PMID:26733964

  20. Agouti regulation of intracellular calcium: Role in the insulin resistance of viable yellow mice

    SciTech Connect

    Zemel, M.B.; Kim, J.H.; Woychik, R.P.; Michaud, E.J.; Hadwell, S.H.; Patel, I.R.; Wilkison, W.O.

    1995-05-23

    Several dominant mutations at the agouti locus in the mouse cause a syndrome of marked obesity, hyperinsulinemia, and insulin resistance. Although it is known that the agouti gene is expressed in an ectopic manner in these mutants, the precise mechanism by which the agouti gene product mediates these effects is unclear. Since intracellular Ca{sup 2+} is believed to play a role in mediating insulin action and dysregulation of Ca{sup 2+} flux is observed in diabetic animals and humans, we examined the status of intracellular Ca{sup 2+} in mice carrying the dominant agouti allele, viable yellow (A{sup vy}). We show here that in mice carrying this mutation, the intracellular free calcium concentration ([Ca{sup 2+}]{sub i}) is elevated in skeletal muscle, and the degree of elevation is closely correlated with the degree to which the mutant traits are expressed in individual animals. Moreover, we demonstrate that the agouti gene product is capable of inducing increased [Ca{sup 2+}]{sub i} in cultured and freshly isolated skeletal muscle myocytes from wild-type mice. Based on these findings, we present a model in which we propose that the agouti polypeptide promotes insulin resistance in mutant animals through its ability to increase [Ca{sup 2+}]{sub i}. 36 refs., 3 figs., 2 tabs.