Science.gov

Sample records for determining economic viability

  1. Demonstration of a Probabilistic Technique for the Determination of Economic Viability of Very Large Transport Configurations

    NASA Technical Reports Server (NTRS)

    Mavris, Dimitri N.

    1998-01-01

    Over the past few years, modem aircraft design has experienced a paradigm shift from designing for performance to designing for affordability. This report contains a probabilistic approach that will allow traditional deterministic design methods to be extended to account for disciplinary, economic, and technological uncertainty. The probabilistic approach was facilitated by the Fast Probability Integration (FPI) technique; a technique which allows the designer to gather valuable information about the vehicle's behavior in the design space. This technique is efficient for assessing multi-attribute, multi-constraint problems in a more realistic fashion. For implementation purposes, this technique is applied to illustrate how both economic and technological uncertainty associated with a Very Large Transport aircraft concept may be assessed. The assessment is evaluated with the FPI technique to determine the cumulative probability distributions of the design space, as bound by economic objectives and performance constraints. These distributions were compared to established targets for a comparable large capacity aircraft, similar in size to the Boeing 747-400. The conventional baseline configuration design space was determined to be unfeasible and marginally viable, motivating the infusion of advanced technologies, including reductions in drag, specific fuel consumption, wing weight, and Research, Development, Testing, and Evaluation costs. The resulting system design space was qualitatively assessed with technology metric "k" factors. The infusion of technologies shifted the VLT design into regions of feasibility and greater viability. The study also demonstrated a method and relationship by which the impact of new technologies may be assessed in a more system focused approach.

  2. Economic viability of access broadband multiservice networks

    NASA Astrophysics Data System (ADS)

    Castelli, Francesco; Dammicco, Giacinto; Mocci, Ugo

    1995-02-01

    In this paper the economic viability of alternative architectures for optical access networks providing broad band services to different subscriber classes in a metropolitan environment, is investigated by a specific tool, NEVE (Network Economic Viability Evaluator), developed for broad band multiservice network planning, service evolutionary scenarios assessment, evaluation of tariff strategies and other actions taken at stimulating the demand growth. As the viability target can be achieved in different ways, different studies can be carried out by NEVE. In the paper some of them are discussed, particularly the ones addressed: to evaluate the impact on viability of alternative service scenarios; to determine the critical mass of broad band subscribers and the critical joint service adoption cost; to evaluate cross subsidiary policies among different subscriber classes and services; to perform sensitivity analysis with respect to variations of demand parameters and tariffs.

  3. DETERMINATION OF 'GIARDIA' CYST VIABILITY

    EPA Science Inventory

    The principal objective of this research was the development of a sensitive, standardized method of determining whether or not Giardia cysts are viable. The availability of such a method is necessary to determine the effect of chemical and physical agents on the viability of thes...

  4. Economic viability of geriatric hip fracture centers.

    PubMed

    Clement, R Carter; Ahn, Jaimo; Mehta, Samir; Bernstein, Joseph

    2013-12-01

    Management of geriatric hip fractures in a protocol-driven center can improve outcomes and reduce costs. Nonetheless, this approach has not spread as broadly as the effectiveness data would imply. One possible explanation is that operating such a center is not perceived as financially worthwhile. To assess the economic viability of dedicated hip fracture centers, the authors built a financial model to estimate profit as a function of costs, reimbursement, and patient volume in 3 settings: an average US hip fracture program, a highly efficient center, and an academic hospital without a specific hip fracture program. Results were tested with sensitivity analysis. A local market analysis was conducted to assess the feasibility of supporting profitable hip fracture centers. The results demonstrate that hip fracture treatment only becomes profitable when the annual caseload exceeds approximately 72, assuming costs characteristic of a typical US hip fracture program. The threshold of profitability is 49 cases per year for high-efficiency hip fracture centers and 151 for the urban academic hospital under review. The largest determinant of profit is reimbursement, followed by costs and volume. In the authors home market, 168 hospitals offer hip fracture care, yet 85% fall below the 72-case threshold. Hip fracture centers can be highly profitable through low costs and, especially, high revenues. However, most hospitals likely lose money by offering hip fracture care due to inadequate volume. Thus, both large and small facilities would benefit financially from the consolidation of hip fracture care at dedicated hip fracture centers. Typical US cities have adequate volume to support several such centers. PMID:24579222

  5. 30 CFR 203.68 - What pre-application costs will MMS consider in determining economic viability?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., DEPARTMENT OF THE INTERIOR MINERALS REVENUE MANAGEMENT RELIEF OR REDUCTION IN ROYALTY RATES OCS Oil, Gas, and... project can become economic with full relief (see § 203.67). (3) Not include sunk costs How...

  6. Proof of Economic Viability of Blended Learning Business Models

    ERIC Educational Resources Information Center

    Druhmann, Carsten; Hohenberg, Gregor

    2014-01-01

    The discussion on economically sustainable business models with respect to information technology is lacking in many aspects of proven approaches. In the following contribution the economic viability is valued based on a procedural model for design and evaluation of e-learning business models in the form of a case study. As a case study object a…

  7. Economic Viability of Brewery Spent Grain as a Biofuel

    SciTech Connect

    Morrow, Charles

    2016-01-01

    This report summarizes an investigation into the technical feasibility and economic viability of use grain wastes from the beer brewing process as fuel to generate the heat needed in subsequent brewing process. The study finds that while use of spent grain as a biofuel is technically feasible, the economics are not attractive. Economic viability is limited by the underuse of capital equipment. The investment in heating equipment requires a higher utilization that the client brewer currently anticipates. It may be possible in the future that changing factors may swing the decision to a more positive one.

  8. Sperm viability - Determination of sperm viability using fluorescence microscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To determine the percentage of viable sperm in a semen sample using stains that differentiates viable (live) sperm from nonviable (dead) sperm. Viable sperm are detected by SYBR-14, which stains the sperm nuclei green. Nonviable sperm are detected by propidium iodide (PI), which stains the sperm red...

  9. 30 CFR 203.85 - What is in an economic viability and relief justification report?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false What is in an economic viability and relief... Sulfur General § 203.85 What is in an economic viability and relief justification report? This report should show that your project appears economic without royalties and sunk costs using the RSVP model...

  10. 30 CFR 203.85 - What is in an economic viability and relief justification report?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false What is in an economic viability and relief... Sulfur General § 203.85 What is in an economic viability and relief justification report? This report should show that your project appears economic without royalties and sunk costs using the RSVP model...

  11. 30 CFR 203.85 - What is in an economic viability and relief justification report?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... INTERIOR MINERALS REVENUE MANAGEMENT RELIEF OR REDUCTION IN ROYALTY RATES OCS Oil, Gas, and Sulfur General... economic viability and relief justification report must contain the following items for an oil and gas lease. (a) Economic assumptions we provide which include: (1) Starting oil and gas prices; (2)...

  12. An advanced concept that promises ecological and economic viability

    NASA Technical Reports Server (NTRS)

    Wright, B. R.; Sedgwick, T. A.; Urie, D. M.

    1976-01-01

    The actuality of supersonic commercial service being provided by Concorde is demonstrating to the world the advantages offered by supersonic travel for both business and recreation. Public acceptance will gradually and persistently stimulate interest to proceed with a second generation design that meets updated economic and ecological standards. It is estimated that this concept could operate profitably on world-wide routes with a revenue structure based upon economy fares. Airplanes will meet all present day ecological requirements regarding noise and emissions.

  13. 30 CFR 203.85 - What is in an economic viability and relief justification report?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false What is in an economic viability and relief justification report? 203.85 Section 203.85 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR MINERALS REVENUE MANAGEMENT RELIEF OR REDUCTION IN ROYALTY RATES OCS Oil, Gas,...

  14. 30 CFR 203.85 - What is in an economic viability and relief justification report?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What is in an economic viability and relief justification report? 203.85 Section 203.85 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR MINERALS REVENUE MANAGEMENT RELIEF OR REDUCTION IN ROYALTY RATES...

  15. Mitochondrial DNA Assessment to Determine Oocyte and Embryo Viability.

    PubMed

    Fragouli, Elpida; Wells, Dagan

    2015-11-01

    Mitochondria are the key regulators of multiple vital cellular processes, including apoptosis, calcium homeostasis, and the generation of ATP via the metabolic pathway known as oxidative phosphorylation. Unlike other cellular organelles, mitochondria contain one or more copies of their own genome (mtDNA). The mtDNA encodes a total of 13 genes with critical functions in cellular metabolism. The energy required to support the normal progress of preimplantation embryo development is provided in the form of ATP generated by the mitochondria. It has been suggested that cellular bioenergetic capacity and suboptimal levels of mitochondria-generated ATP could contribute to a variety of embryo developmental defects, and therefore adversely affect in vitro fertilization success rates. During this review, we discuss the role of mitochondria and their genome during oogenesis and early embryo development. We also assess whether analysis of mitochondria and their genome could be used as biomarkers to determine oocyte quality and embryo viability. PMID:26565384

  16. Viability of Giardia intestinalis Cysts and Viability and Sporulation State of Cyclospora cayetanensis Oocysts Determined by Electrorotation

    PubMed Central

    Dalton, C.; Goater, A. D.; Pethig, R.; Smith, H. V.

    2001-01-01

    Electrorotation is a noninvasive technique that is capable of detecting changes in the morphology and physicochemical properties of microorganisms. Electrorotation studies are reported for two intestinal parasites, Giardia intestinalis and Cyclospora cayetanensis. It is concluded that viable and nonviable G. intestinalis cysts can be differentiated by this technique, and support for this conclusion was obtained using a fluorogenic vital dye assay and morphological indicators. The viability of C. cayetanensis oocysts (for which no vital dye assay is currently available) can also be determined by electrorotation, as can their sporulation state. Modeling of the electrorotational response of these organisms was used to determine their dielectric properties and to gain an insight into the changes occurring within them. Electrorotation offers a new, simple, and rapid method for determining the viability of parasites in potable water and food products and as such has important healthcare implications. PMID:11157220

  17. The Potential of Energy Storage Systems with Respect to Generation Adequacy and Economic Viability

    NASA Astrophysics Data System (ADS)

    Bradbury, Kyle Joseph

    Intermittent energy resources, including wind and solar power, continue to be rapidly added to the generation fleet domestically and abroad. The variable power of these resources introduces new levels of stochasticity into electric interconnections that must be continuously balanced in order to maintain system reliability. Energy storage systems (ESSs) offer one potential option to compensate for the intermittency of renewables. ESSs for long-term storage (1-hour or greater), aside from a few pumped hydroelectric installations, are not presently in widespread use in the U.S. The deployment of ESSs would be most likely driven by either the potential for a strong internal rate of return (IRR) on investment and through significant benefits to system reliability that independent system operators (ISOs) could incentivize. To assess the potential of ESSs three objectives are addressed. (1) Evaluate the economic viability of energy storage for price arbitrage in real-time energy markets and determine system cost improvements for ESSs to become attractive investments. (2) Estimate the reliability impact of energy storage systems on the large-scale integration of intermittent generation. (3) Analyze the economic, environmental, and reliability tradeoffs associated with using energy storage in conjunction with stochastic generation. First, using real-time energy market price data from seven markets across the U.S. and the physical parameters of fourteen ESS technologies, the maximum potential IRR of each technology from price arbitrage was evaluated in each market, along with the optimal ESS system size. Additionally, the reductions in capital cost needed to achieve a 10% IRR were estimated for each ESS. The results indicate that the profit-maximizing size of an ESS is primarily determined by its technological characteristics (round-trip charge/discharge efficiency and self-discharge) and not market price volatility, which instead increases IRR. This analysis demonstrates that few ESS technologies are likely to be implemented by investors alone. Next, the effects of ESSs on system reliability are quantified. Using historic data for wind, solar, and conventional generation, a correlation-preserving, copula-transform model was implemented in conjunction with Markov chain Monte Carlo framework for estimating system reliability indices. Systems with significant wind and solar penetration (25% or greater), even with added energy storage capacity, resulted in considerable decreases in generation adequacy. Lastly, rather than analyzing the reliability and costs in isolation of one another, system reliability, cost, and emissions were analyzed in 3-space to quantify and visualize the system tradeoffs. The modeling results implied that ESSs perform similarly to natural gas combined cycle (NGCC) systems with respect to generation adequacy and system cost, with the primary difference being that the generation adequacy improvements are less for ESSs than that of NGCC systems and the increase in LCOE is greater for ESSs than NGCC systems. Although ESSs do not appear to offer greater benefits than NGCC systems for managing energy on time intervals of 1-hour or more, we conclude that future research into short-term power balancing applications of ESSs, in particular for frequency regulation, is necessary to understand the full potential of ESSs in modern electric interconnections.

  18. Economic viability of the Saudi Arabian petrochemical industry: methanol as a case study

    SciTech Connect

    Al-Salem, A.M.

    1987-01-01

    In the pursuit of the diversification strategy, Saudi planners invested a sizable amount of oil surplus in export-oriented petrochemical projects at Jubail and Yanbu. For this strategy to be realized, the projects must be economically viable. Economic viability entails the presence of petrochemical plants that are self-sustaining and self-perpetuating in the long run without state subsidies. In view of the projects, heavy reliance on state subsidies along with their location in a remote area, far from the source of demand, it is hypothesized that, barring a significant shift in the development strategy, a dynamic industrial sector focusing on the development of the petrochemical industry is unlikely to emerge in Saudi Arabia and that the export-led growth strategy that accords it a key role in the nation's development is not likely to prove viable. In verifying the hypothesis, a comparative cost analysis was conducted comparing the cost structure at the Ibn-Sina methanol plant to a similar plant in Alberta, Canada. According to the authors forecast of methanol revenues and costs, the Saudi petrochemical industry exemplified by the methanol project emerges to be as a net absorber of rather than contributor to the nation's financial resources and in this regard appears to impede the process of capital formation and economic growth.

  19. Fluorescence Microscopy Methods for Determining the Viability of Bacteria in Association with Mammalian Cells

    PubMed Central

    Johnson, M. Brittany; Criss, Alison K.

    2013-01-01

    Central to the field of bacterial pathogenesis is the ability to define if and how microbes survive after exposure to eukaryotic cells. Current protocols to address these questions include colony count assays, gentamicin protection assays, and electron microscopy. Colony count and gentamicin protection assays only assess the viability of the entire bacterial population and are unable to determine individual bacterial viability. Electron microscopy can be used to determine the viability of individual bacteria and provide information regarding their localization in host cells. However, bacteria often display a range of electron densities, making assessment of viability difficult. This article outlines protocols for the use of fluorescent dyes that reveal the viability of individual bacteria inside and associated with host cells. These assays were developed originally to assess survival of Neisseria gonorrhoeae in primary human neutrophils, but should be applicable to any bacterium-host cell interaction. These protocols combine membrane-permeable fluorescent dyes (SYTO9 and 4',6-diamidino-2-phenylindole [DAPI]), which stain all bacteria, with membrane-impermeable fluorescent dyes (propidium iodide and SYTOX Green), which are only accessible to nonviable bacteria. Prior to eukaryotic cell permeabilization, an antibody or fluorescent reagent is added to identify extracellular bacteria. Thus these assays discriminate the viability of bacteria adherent to and inside eukaryotic cells. A protocol is also provided for using the viability dyes in combination with fluorescent antibodies to eukaryotic cell markers, in order to determine the subcellular localization of individual bacteria. The bacterial viability dyes discussed in this article are a sensitive complement and/or alternative to traditional microbiology techniques to evaluate the viability of individual bacteria and provide information regarding where bacteria survive in host cells. PMID:24056524

  20. Counting and determining the viability of cultured cells.

    PubMed

    Ricardo, Richard; Phelan, Katy

    2008-01-01

    Determining the number of cells in culture is important in standardization of culture conditions and in performing accurate quantitation experiments. A hemacytometer is a thick glass slide with a central area designed as a counting chamber. Cell suspension is applied to a defined area and counted so cell density can be calculated. PMID:19066550

  1. Evaluating the Economic Viability of Universities by Using Price-Level-Adjusted Financial Data. Faculty Working Papers.

    ERIC Educational Resources Information Center

    Chan, James L.; Snyder, Gerald E.

    Ways in which the external financial disclosures by universities may evaluate institutional economic viability are demonstrated. It is argued that the evaluation should take into account the effect of inflation and activity level. The evaluation model requires several years' information about revenues (general operating fund), the impact of…

  2. Determining the viability response of pine pollen to atmospheric conditions during long-distance dispersal.

    PubMed

    Bohrerova, Zuzana; Bohrer, Gil; Cho, Ki Don; Bolch, M Adam; Linden, Karl G

    2009-04-01

    Pollen of forest trees can move on the scales of tens to hundreds of kilometers, but the question of its viability during this long distance dispersal (LDD) has yet to be answered. While empirical studies of pollen viability in forest tree species are rare, controlled and scalable data to outdoor studies of the contribution of UV irradiation on pollen viability are not available. A simple protocol that allows the quantification of the viability response of pollen to UV, temperature, and humidity is developed and described here. Bench-scale conditions that approximate a wide range of atmospheric conditions including different humidity, temperature, and UV irradiation condition are used to determine the independent effects of each abiotic stress factor, and empirical functions are fitted and used to scale these bench-scale experiments to outdoor conditions. As a case study, pollen was sampled from two populations of Pinus taeda during two years and was used to quantify the decrease in viability due to atmospheric conditions during LDD. Contrary to maize pollen, P. taeda pollen viability decreased due to humid and cold conditions. The viability response of pollen to UV-A and UV-B corresponded to a viability reduction of about 10% after a full day of exposure. These laboratory findings were corroborated by an outdoor solar exposure experiment. The Fu-Liou online radiation model and a data set of radiosonde observations were used to estimate the typical conditions that would be encountered by LDD pollen. If initially caught in a strong updraft, dispersing P. taeda pollen could be carried many days and thousands of kilometers in the air. The empirical equations for P. taeda pollen viability reduction due to abiotic stresses predicted that 50% of the pollen would survive 24 hours of LDD under typical external conditions. The viable range of the pollen is, therefore, shorter than the physical dispersal distance. The methods used in our experiments are applicable for determination of dispersing pollen viability, especially when effects of different adverse conditions need to be separated. The empirical viability equations that resulted from our experiments can be used in an atmospheric dispersal model to estimate the viable range of tree pollen. PMID:19425429

  3. Economical Analysis of Different Clinical Approaches in Pre-Viability AmniorrhexisA Case Series

    PubMed Central

    Engemise, Samuel; Thompson, Fiona; Davies, William

    2014-01-01

    Prolonged oligohydramnios following extreme preterm prelabour rupture of membranes (EPPROM) is traditionally associated with a high morbidity and mortality to both the mother and the baby. The clinical maternal evaluation and fetal ultrasound assessment may provide important prognostic information for the clinicians and should be taken into account when counselling the patients so as to provide them with enough information to make decision of continuing or interrupting the pregnancy. Current financial constraints on the National Healthcare Service (NHS) resources make it imperative for clinical decision-makers and budgetary planners to make the right decision of continuing or terminating a second trimester pre-viability amniorrhexis for desperate parents. To assess the economic consequences following EPPROM, the risk of infection to both baby and mother, psychological impact on the parents and associated complications and further disability after delivery on this fragile group of patients to the NHS resources. We review the clinical course, outcome, and the challenges to parents and health care professionals on three pregnancies complicated by EPPROM, occurring before 24 weeks gestation with a membrane rupture to delivery interval (latent period) of 14 days or more. The anticipated birth of an extremely premature infant poses many challenges for parents and health care professionals. As parents are faced with difficult decisions that can have a long-term impact on the infant, family and countrys resources, it is critical to provide the type of information and support that is needed by them. Taking all these into consideration with the period of ventilation and respiratory assistance in Neonatal Intensive Care Unit (NICU) is essential to provide maximum chances for survival, minimizing the risk for long term sequelae of the neonate and provides the parents enough time to decide on making the right decision with the associated guidance of the healthcare provider. PMID:26237250

  4. Comparison of various techniques for determining viability of Paracoccidioides brasiliensis yeast-form cells.

    PubMed Central

    Restrepo, A; Cano, L E; de Bedout, C; Brummer, E; Stevens, D A

    1982-01-01

    The viability of Paracoccidioides brasiliensis yeast-form cells was determined by colony-forming units, direct fluorescent staining, and production of germ tubes in slide culture. The first procedure was unreliable and time consuming; the latter two showed better correlation with hemacytometer total cell counts and required significantly less time. PMID:7107858

  5. Economic viability of phytoremediation of a cadmium contaminated agricultural area using energy maize. Part I: effect on the farmer's income.

    PubMed

    Thewys, T; Witters, N; Van Slycken, S; Ruttens, A; Meers, E; Tack, F M G; Vangronsveld, J

    2010-09-01

    This paper deals with the economic viability of using energy maize as a phytoremediation crop in a vast agricultural area moderately contaminated with metals. The acceptance of phytoremediation as a remediation technology is, besides the extraction rate, determined by its profitability, being the effects it has on the income of the farmer whose land is contaminated. This income can be supported by producing renewable energy through anaerobic digestion of energy maize, a crop that takes up only relatively low amounts of metals, but that can be valorised as a feedstock for energy production. The effect on the income per hectare of growing energy maize instead of fodder maize seems positive, given the most likely values of variables and while keeping the basic income stable, originating from dairy cattle farming activities. We propose growing energy maize aiming at risk-reduction, and generating an alternative income for farmers, yet in the long run also generating a gradual reduction of the pollution levels. In this way, remediation is demoted to a secondary objective with sustainable risk-based land use as primary objective. PMID:21166274

  6. Stressor timing, not cortisol, is an important embryo viability determinant in female rainbow trout Oncorhynchus mykiss.

    PubMed

    Medeiros, L R; Elliott, M; Nagler, J J

    2016-02-01

    The objective of this study was to determine whether the timing of elevated cortisol levels in adult female rainbow trout Oncorhynchus mykiss, achieved by silastic implants within the body cavity, had an effect on embryo viability. Cortisol-implanted fish experienced a significant increase in circulating levels of plasma cortisol compared with sham-implanted fish, and plasma cortisol remained elevated relative to sham-implanted fish for 4 months in each of the three treatment groups (0-4, 4-8 and 8-12 months). There were no significant differences in embryo viability, egg diameters or plasma 17?-oestradiol levels between the cortisol and sham-implanted treatments in any of the groups. There was a significant difference in the number of subfertile females (<80% embryo viability) when the three treatments were compared. The majority of the females (75%) implanted immediately postspawn (0-4 months) produced subfertile eggs, which was significantly higher than those treated 4-8 (33%) or 8-12 (17%) months postspawn. These results imply that silastic implantation can affect oocyte development, independent of plasma cortisol levels, leading to a reduction in embryo viability. PMID:26709244

  7. Escherichia coli viability determination using dynamic light scattering: a comparison with standard methods.

    PubMed

    Loske, Achim M; Tello, Elba M; Vargas, Susana; Rodriguez, Rogelio

    2014-08-01

    To determine the concentration of bacteria in a sample is important in the food industry, medicine and biotechnology. A disadvantage of the plate-counting method is that a microorganism colony could arise from one cell or from many cells. The other standard methodology, known as optical density determination, is based on the turbidity of a suspension and registers all bacteria, dead and alive. In this article, dynamic light scattering is proposed as a fast and reliable method to determine bacterial viability and, consequently, time evolution. Escherichia coli was selected because this microorganism is well known and easy to handle. A correlation between the data from these three techniques was obtained. We were able to calculate the growth rate, usually determined by plate counting or optical density measurement, using dynamic light scattering and to predict bacterial behavior. An analytical relationship between the colony forming units and the light scattered intensity was also deduced. PMID:24853284

  8. A MULTIPLEXED ASSAY FOR DETERMINATION OF NEUROTOXICANT EFFECTS ON SPONTANEOUS NETWORK ACTIVITY AND CELL VIABILITY FROM MICROELECTRODE ARRAYS

    EPA Science Inventory

    AbstractTITLE: A MULTIPLEXED ASSAY FOR DETERMINATION OF NEUROTOXICANT EFFECTS ON SPONTANEOUS NETWORK ACTIVITY AND CELL VIABILITY FROM MICROELECTRODE ARRAYSABSTRACT BODY: Microelectrode array (MEA) recordings are increasingly being used as an in vitro method to detect and characte...

  9. Assessing the Economic Viability of Bio-based Products for Missouri Value-added Crop Production

    SciTech Connect

    Nicholas Kalaitzandonakes

    2005-11-30

    While research and development on biobased products has continued strong over the years, parallel attention on the economics and management of such product innovation has been lacking. With the financial support of the Department of Energy, the Economics and Management of Agrobiotechnology Center at the University of Missouri-Columbia has launched a pilot graduate education program that seeks to fill the gap. Within this context, a multi-disciplinary research and teaching program has been structured with an emphasis on new product and innovation economics and management. More specifically, this pilot graduate education program has the following major objectives: (1) To provide students with a strong background in innovation economics, management, and strategy. (2) To diversify the students academic background with coursework in science and technology. (3) To familiarize the student with biobased policy initiatives through interaction with state and national level organizations and policymakers. (4) To facilitate active collaboration with industry involved in the development and production of biobased products. The pilot education program seeks to develop human capital and research output. Although the research is, initially, focused on issues related to the State of Missouri, the results are expected to have national implications for the economy, producers, consumers and environment.

  10. The future viability of algae-derived biodiesel under economic and technical uncertainties.

    PubMed

    Brownbridge, George; Azadi, Pooya; Smallbone, Andrew; Bhave, Amit; Taylor, Benjamin; Kraft, Markus

    2014-01-01

    This study presents a techno-economic assessment of algae-derived biodiesel under economic and technical uncertainties associated with the development of algal biorefineries. A global sensitivity analysis was performed using a High Dimensional Model Representation (HDMR) method. It was found that, considering reasonable ranges over which each parameter can vary, the sensitivity of the biodiesel production cost to the key input parameters decreases in the following order: algae oil content>algae annual productivity per unit area>plant production capacity>carbon price increase rate. It was also found that the Return on Investment (ROI) is highly sensitive to the algae oil content, and to a lesser extent to the algae annual productivity, crude oil price and price increase rate, plant production capacity, and carbon price increase rate. For a large scale plant (100,000 tonnes of biodiesel per year) the production cost of biodiesel is likely to be 0.8-1.6 per kg. PMID:24220544

  11. Assessment of the efficiency and economic viability of various methods of treatment of sanitary landfill leachate.

    PubMed

    Gupta, S K; Singh, Gurdeep

    2007-12-01

    This study assesses the efficiency of various physico-chemical, biological and other tertiary methods for treating leachate. An evaluation study on the treatability of the leachate from methane phase bed (MPB) reactor indicated that at an optimum hydraulic retention time of 6 days, the efficiency of the reactor in terms of biological oxygen demand (BOD) and chemical oxygen demand (COD) removal was 91.29 and 82.69%, respectively. Recycling of the treated leachate through the municipal solid waste layers in the leachate recycling unit (LRU) resulted in a significant increase in the biodegradation of organics present in the leachate. Optimum BOD and COD removal efficiencies were achieved at the third recycle; additional recycling of the leachate did not produce any significant improvement. Physico-chemical treatment of the leachate demonstrated that alum and lime (Option 2) were more economical than coagulants lime and MgCO(3). A cost analysis of the economics of the various treatments revealed that the alternative treatment consisting of a MPB bed followed by a LRU and aerated lagoon is the most cost-effective treatment. However, the alternative consisting of a MPB followed by the LRU and a soil column, which is slightly more costly, would be the most appropriate treatment when adequate land is readily available. PMID:17505905

  12. Acetone-butanol-ethanol fermentation of corn stover: current production methods, economic viability and commercial use.

    PubMed

    Baral, Nawa R; Slutzky, Lauren; Shah, Ajay; Ezeji, Thaddeus C; Cornish, Katrina; Christy, Ann

    2016-03-01

    Biobutanol is a next-generation liquid biofuel with properties akin to those of gasoline. There is a widespread effort to commercialize biobutanol production from agricultural residues, such as corn stover, which do not compete with human and animal foods. This pursuit is backed by extensive government mandates to expand alternative energy sources. This review provides an overview of research on biobutanol production using corn stover feedstock. Structural composition, pretreatment, sugar yield (following pretreatment and hydrolysis) and generation of lignocellulose-derived microbial inhibitory compounds (LDMICs) from corn stover are discussed. The review also discusses different Clostridium species and strains employed for biobutanol production from corn stover-derived sugars with respect to solvent yields, tolerance to LDMICs and in situ solvent recovery (integrated fermentation). Further, the economics of cellulosic biobutanol production are highlighted and compared to corn starch-derived ethanol and gasoline. As discussed herein, the economic competitiveness of biobutanol production from corn stover largely depends on feedstock processing and fermentation process design. PMID:26872494

  13. Determination of periodontal ligament cell viability in the oral rehydration fluid Gatorade and milks of varying fat content.

    PubMed

    Harkacz, O M; Carnes, D L; Walker, W A

    1997-11-01

    The purpose of this study was twofold: 1) to determine if the oral rehydration fluid Gatorade could serve as a suitable temporary storage medium for maintenance of periodontal ligament (PDL) cell viability on avulsed teeth and 2) to determine if fat content is related to maintenance of cell viability when milk is used as the temporary storage medium. PDL cells were cultured from extracted human teeth then incubated over timed intervals from 15 to 210 min in the oral rehydration fluid Gatorade, milks of varying fat content, and saliva. Dulbeco's Modified Eagles Medium served as the positive control while tap water served as the negative control. Cell viability was determined using a colorimetric assay that used Cell Proliferation Reagent WST-1. Results using Gatorade yielded cell viability data similar to the negative control, tap water, indicating that this oral rehydration fluid was not suitable as a temporary storage medium for the avulsed tooth. However, the fat content of milk was found to have an effect on cell viability, suggesting that milks with lower fat content may be more appropriate for maintaining PDL cell viability than milks with higher fat content. PMID:9587309

  14. Trypan blue dye is an effective and inexpensive way to determine the viability of Batrachochytrium dendrobatidis zoospores.

    PubMed

    McMahon, Taegan A; Rohr, Jason R

    2014-06-01

    Batrachochytrium dendrobatidis (Bd) has been implicated in hundreds of amphibian declines and is the focus of a vast amount of research. Despite this, there is no reported efficient way to assess Bd viability. Discriminating between live and dead Bd would help determine the dose of live Bd zoospores and whether factors have lethal or sublethal effects on Bd. We tested whether trypan blue, a common stain to discriminate live and dead cells, could be used to assess Bd viability. We show that the proportion of live zoospores (zoospores that excluded the trypan blue dye) matched the proportion of known live zoospores added to cultures. In contrast, all of the zoosporangia stages of Bd stained blue. These results demonstrate that trypan blue can be used to determine the viability of Bd zoospores but not zoosporangia. We recommend using trypan blue to report the number of live zoospores to which hosts are exposed. PMID:24519684

  15. Integrated watershed- and farm-scale modeling framework for targeting critical source areas while maintaining farm economic viability.

    PubMed

    Ghebremichael, Lula T; Veith, Tamie L; Hamlett, James M

    2013-01-15

    Quantitative risk assessments of pollution and data related to the effectiveness of mitigating best management practices (BMPs) are important aspects of nonpoint source pollution control efforts, particularly those driven by specific water quality objectives and by measurable improvement goals, such as the total maximum daily load (TMDL) requirements. Targeting critical source areas (CSAs) that generate disproportionately high pollutant loads within a watershed is a crucial step in successfully controlling nonpoint source pollution. The importance of watershed simulation models in assisting with the quantitative assessments of CSAs of pollution (relative to their magnitudes and extents) and of the effectiveness of associated BMPs has been well recognized. However, due to the distinct disconnect between the hydrological scale in which these models conduct their evaluation and the farm scale at which feasible BMPs are actually selected and implemented, and due to the difficulty and uncertainty involved in transferring watershed model data to farm fields, there are limited practical applications of these tools in the current nonpoint source pollution control efforts by conservation specialists for delineating CSAs and planning targeting measures. There are also limited approaches developed that can assess impacts of CSA-targeted BMPs on farm productivity and profitability together with the assessment of water quality improvements expected from applying these measures. This study developed a modeling framework that integrates farm economics and environmental aspects (such as identification and mitigation of CSAs) through joint use of watershed- and farm-scale models in a closed feedback loop. The integration of models in a closed feedback loop provides a way for environmental changes to be evaluated with regard to the impact on the practical aspects of farm management and economics, adjusted or reformulated as necessary, and revaluated with respect to effectiveness of environmental mitigation at the farm- and watershed-levels. This paper also outlines steps needed to extract important CSA-related information from a watershed model to help inform targeting decisions at the farm scale. The modeling framework is demonstrated with two unique case studies in the northeastern United States (New York and Vermont), with supporting data from numerous published, location-specific studies at both the watershed and farm scales. Using the integrated modeling framework, it can be possible to compare the costs (in terms of changes required in farm system components or financial compensations for retiring crop lands) and benefits (in terms of measurable water quality improvement goals) of implementing targeted BMPs. This multi-scale modeling approach can be used in the multi-objective task of mitigating CSAs of pollution to meet water quality goals while maintaining farm-level economic viability. PMID:23195139

  16. Simultaneous determination of bacterial viability and identity in biofilms using ethidium monoazide and fluorescent in situ hybridization.

    PubMed

    Regan, J M; Oldenburg, P S; Park, H D; Harrington, G W; Noguera, D R

    2003-01-01

    A protocol for simultaneously interrogating bacterial viability and identity using in situ, culture-independent methods is described. Viability is assayed using ethidium monoazide (EMA) staining of cells with compromised membranes, and identity is determined using fluorescent in situ hybridization (FISH). Experiments with planktonic cultures were used to demonstrate the compatibility of EMA staining and FISH after covalently bonding EMA to nucleic acids by photoreaction. Applications to biofilm samples showed that diffusion limitations in the biofilm matrix were not problematic and that effective discrimination of viable target cells within a mixed microbial community was possible. PMID:12701916

  17. Feasibility study for a 10 MM GPY fuel ethanol plant, Brady Hot Springs, Nevada. Volume II. Geothermal resource, agricultural feedstock, markets and economic viability

    SciTech Connect

    Not Available

    1980-09-01

    The issues of the geothermal resource at Brady's Hot Springs are dealt with: the prospective supply of feedstocks to the ethanol plant, the markets for the spent grain by-products of the plant, the storage, handling and transshipment requirements for the feedstocks and by-products from a rail siding facility at Fernley, the probable market for fuel ethanol in the region, and an assessment of the economic viability of the entire undertaking.

  18. 7 CFR 400.653 - Determining crops of economic significance.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Determining crops of economic significance. 400.653... Reform, Insurance Implementation § 400.653 Determining crops of economic significance. To be eligible for... of economic significance if the producer does not execute a waiver of any eligibility for...

  19. 7 CFR 400.653 - Determining crops of economic significance.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Determining crops of economic significance. 400.653... Reform, Insurance Implementation § 400.653 Determining crops of economic significance. To be eligible for... of economic significance if the producer does not execute a waiver of any eligibility for...

  20. 7 CFR 400.653 - Determining crops of economic significance.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 6 2014-01-01 2014-01-01 false Determining crops of economic significance. 400.653... Reform, Insurance Implementation § 400.653 Determining crops of economic significance. To be eligible for... of economic significance if the producer does not execute a waiver of any eligibility for...

  1. 7 CFR 400.653 - Determining crops of economic significance.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 6 2012-01-01 2012-01-01 false Determining crops of economic significance. 400.653... Reform, Insurance Implementation § 400.653 Determining crops of economic significance. To be eligible for... of economic significance if the producer does not execute a waiver of any eligibility for...

  2. 7 CFR 400.653 - Determining crops of economic significance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Determining crops of economic significance. 400.653... Reform, Insurance Implementation § 400.653 Determining crops of economic significance. To be eligible for... of economic significance if the producer does not execute a waiver of any eligibility for...

  3. Potential minability and economic viability of the Antaramut-Kurtan-Dzoragukh coal field, north-central Armenia; a prefeasibility study

    USGS Publications Warehouse

    Huber, Douglas W.; Pierce, Brenda S.

    2000-01-01

    The U. S. Geological Survey (USGS) conducted a coal resource assessment of several areas in Armenia from 1997 to 1999. This report, which presents a prefeasibility study of the economic and mining potential of one coal deposit found and studied by the USGS team, was prepared using all data available at the time of the study and the results of the USGS exploratory work, including core drilling, trenching, coal quality analyses, and other ongoing field work. On the basis of information currently available, it is the authors? opinion that a small surface coal mine having about a 20-year life span could be developed in the Antaramut-Kurtan-Dzoragukh coal field, specifically at the Dzoragukh site. The mining organization selected or created to establish the mine will need to conduct necessary development drilling and other work to establish the final feasibility study for the mine. The company will need to be entrepreneurial, profit oriented, and sensitive to the coal consumer; have an analytical management staff; and focus on employee training, safety, and protection of the environment. It is anticipated that any interested parties will be required to submit detailed mining plans to the appropriate Armenian Government agencies. Further development work will be required to reach a final decision regarding the economic feasibility of the mine. However, available information indicates that a small, economic surface mine can be developed at this locality. The small mine suggested is a typical surface-outcropstripping, contour mining operation. In addition, auger mining is strongly suggested, because the recovery of these low-cost mining reserves will help to ensure that the operation will be a viable, economic enterprise. (Auger mining is a system in which large-diameter boreholes are placed horizontally into the coal seam at the final highwall set as the economic limit for the surface mining operation). A special horizontal boring machine, which can be imported from Russia, is required for auger mining. Although auger-mining coal reserves do exist, the necessary development work will further verify the extent of these reserves and all of the other indicated reserves. The following items are based on the detailed study reported in this publication. Initial investment.?Following an investment of US $85,000 over a 12-month period in mine development drilling and other activities, a decision must be taken regarding further investment in an ongoing mining operation. If the new data support the opening of the surface mine, __________________________ 1Consultant, 6024 Morning Dew Drive, Austin, TX 78749. 2 U.S. Geological Survey, 956 National Center, Reston, VA 20192 1 2 MINABILITY AND ECONOMIC VIABILITY, ANTARAMUT-KURTAN-DZORAGUKH COAL FIELD the $85,000 development cost is amortized over the first 10 years of mine production. If the new data do not support the opening of the mine, the $85,000 is considered a business development expense that may be written off against profits from other operations for income or other tax purposes or simply as a business loss. Total capital required.?The equipment costs will reach a total of $900,500 which will be amortized over a 7-year period to establish estimated coal mining costs. Estimated working capital costs are $300,000, which will be borrowed. Surface mining reserves.?Approximately 840,200 metric tonnes of surface minable coal reserves at 9.3 m3 of overburden per metric tonne of minable coal is indicated. Recovery of the minable coal at 85 percent will yield 714,000 recoverable metric tonnes of marketable as-mined coal. Auger mining reserves.?Auger-mining reserves of 576,000 metric tonnes are indicated. Recoverable auger-mining reserves of 202,000 metric tonnes (at 35-percent recovery) can be expected. Auger-mining production will vary according to the hole size being used, but, in either case, augering is a very profitable addition to the mining oper

  4. Measuring the Determinants of Relative Economic Performance of Rural Areas

    ERIC Educational Resources Information Center

    Agarwal, Sheela; Rahman, Sanzidur; Errington, Andrew

    2009-01-01

    This paper examines the determinants of economic performance of 149 English rural Local Authority Districts (LADs). A Three Stage Least Square (3SLS) estimation procedure was employed to jointly determine the influence of a wide range of indicators representing economic, human, cultural and environmental capital, as well as less tangible or "soft"…

  5. Measuring the Determinants of Relative Economic Performance of Rural Areas

    ERIC Educational Resources Information Center

    Agarwal, Sheela; Rahman, Sanzidur; Errington, Andrew

    2009-01-01

    This paper examines the determinants of economic performance of 149 English rural Local Authority Districts (LADs). A Three Stage Least Square (3SLS) estimation procedure was employed to jointly determine the influence of a wide range of indicators representing economic, human, cultural and environmental capital, as well as less tangible or "soft"

  6. Electrical determination of viability in saline-treated mouse myeloma cells

    SciTech Connect

    Matsushita, T.; Brendzel, A.M.; Shotola, M.A.; Groh, K.R.

    1982-07-01

    Suspension of mouse myeloma cells in phosphate buffered saline (PBS) induced a significant amount of cell death. The lethal effects of PBS include an increase in cell lysis, a decreased ability of cells to exclude trypan blue, and a decrease in the colony-forming ability of these cells. Dead cells were also detected on a Coulter counter by the increase in the fraction of cells with a smaller electrical size distribution (ESD). Comparing mixtures of live and dead cells by ESD and trypan-blue exclusion showed a high correlation of electrical size with viability (correlation coefficient = 0.98). Sizing of PBS-treated cells by light microscopy suggested that the altered ESD of the PBS-treated cells was due to a downward shift in the volume distribution. Light-scattering experiments also suggested a decrease in the size of cells after PBS treatment. An increase in permeability of the cell membrane may also contribute to these results. We conclude that electrical sizing is an excellent indicator of physical changes that result from PBS-induced cell death, and is an effective method for distinguishing live and dead mouse myeloma cells after PBS treatment.

  7. Electrical determination of viability in saline-treated mouse myeloma cells.

    PubMed Central

    Matsushita, T; Brendzel, A M; Shotola, M A; Groh, K R

    1982-01-01

    Suspension of mouse myeloma cells in phosphate buffered saline (PBS) induced a significant amount of cell death. The lethal effects of PBS include an increase in cell lysis, a decreased ability of cells to exclude trypan blue, and a decrease in the colony-forming ability of these cells. Dead cells were also detected on a Coulter counter by the increase in the fraction of cells with a smaller electrical size distribution (ESD). Comparing mixtures of live and dead cells by ESD and trypan-blue exclusion showed a high correlation of electrical size with viability (correlation coefficient = 0.98). Sizing of PBS-treated cells by light microscopy suggested that the altered ESD of the PBS-treated cells was due to a downward shift in the volume distribution. Light-scattering experiments also suggested a decrease in the size of cells after PBS treatment. An increase in permeability of the cell membrane may also contribute to these results. We conclude that electrical sizing is an excellent indicator of physical changes that result from PBS-induced cell death, and is an effective method for distinguishing live and dead mouse myeloma cells after PBS treatment. PMID:7104449

  8. Multiple Freezing Points as a Test for Viability of Plant Stems in the Determination of Frost Hardiness 1

    PubMed Central

    McLeester, R. C.; Weiser, C. J.; Hall, T. C.

    1969-01-01

    A technique is presented for a simple, rapid, and reliable means of determining the viability of plant tissue subjected to freezing temperatures. Freezing curves of excised stems of Cornus stolonifera Michx., and several other genera were studied. Tissue temperature was recorded during freezing of plant stem sections. The heat of crystallization deflected the resultant freezing curves at points where tissue froze. Living stem sections of all genera studied revealed 2 freezing points, while dead tissue exhibited only 1. The influence of variables such as moisture content, sample size, thermocouple placement, and cooling rate on freezing curves was analyzed. Stem samples wrapped in moisture-proof film with a thermocouple inserted into the pith were frozen to a predetermined test temperature, thawed, and subjected to a second freezing cycle. The presence or absence of 2 freezing points in the second freezing cycle was used as a criterion for establishing viability. The results were immediately available and identical to results from regrowth tests which took about 20 days. PMID:16657031

  9. The economic viability of smallholder timber production under expanding açaí palm production in the Amazon Estuary

    USGS Publications Warehouse

    Fortini, Lucas; Douglas R. Carter

    2015-01-01

    Relatively little attention has been paid to the economic potentials and limitations of tropical timber production and management at smallholder scales, with the most relevant research focusing on community forestry efforts. As a rare tropical example of long-lasting small-scale timber production, in this study we explore the economics of smallholder vertically integrated timber use to better understand the activity in the context of its primary land use alternative in the Amazon Estuary, açaí palm fruit production. We use data from landowner and firm surveys, participatory monitoring of firms, and detailed forest and sawmill operation monitoring to devise financial returns models of smallholder timber micro firms and açaí palm fruit production. We then compare the economics of the two activities to better understand how differences may shape decisions at the small holder scale that impact current land use shifts in the region.

  10. Real-time direct cell concentration and viability determination using a fully automated microfluidic platform for standalone process monitoring.

    PubMed

    Nunes, P S; Kjaerulff, S; Dufva, M; Mogensen, K B

    2015-06-21

    The industrial production of cells has a large unmet need for greater process monitoring, in addition to the standard temperature, pH and oxygen concentration determination. Monitoring the cell health by a vast range of fluorescence cell-based assays can greatly improve the feedback control and thereby ensure optimal cell production, by prolonging the fermentation cycle and increasing the bioreactor output. In this work, we report on the development of a fully automated microfluidic system capable of extracting samples directly from a bioreactor, diluting the sample, staining the cells, and determining the total cell and dead cells concentrations, within a time frame of 10.3 min. The platform consists of custom made stepper motor actuated peristaltic pumps and valves, fluidic interconnections, sample to waste liquid management and image cytometry-based detection. The total concentration of cells is determined by brightfield microscopy, while fluorescence detection is used to detect propidium iodide stained non-viable cells. This method can be incorporated into facilities with bioreactors to monitor the cell concentration and viability during the cultivation process. Here, we demonstrate the microfluidic system performance by monitoring in real time the cell concentration and viability of yeast extracted directly from an in-house made bioreactor. This is the first demonstration of using the Dean drag force, generated due to the implementation of a curved microchannel geometry in conjunction with high flow rates, to promote passive mixing of cell samples and thus homogenization of the diluted cell plug. The autonomous operation of the fluidics furthermore allows implementation of intelligent protocols for administering air bubbles from the bioreactor in the microfluidic system, so that these will be guided away from the imaging region, thereby significantly improving both the robustness of the system and the quality of the data. PMID:25923294

  11. System dynamic modelling to assess economic viability and risk trade-offs for ecological restoration in South Africa.

    PubMed

    Crookes, D J; Blignaut, J N; de Wit, M P; Esler, K J; Le Maitre, D C; Milton, S J; Mitchell, S A; Cloete, J; de Abreu, P; Fourie nee Vlok, H; Gull, K; Marx, D; Mugido, W; Ndhlovu, T; Nowell, M; Pauw, M; Rebelo, A

    2013-05-15

    Can markets assist by providing support for ecological restoration, and if so, under what conditions? The first step in addressing this question is to develop a consistent methodology for economic evaluation of ecological restoration projects. A risk analysis process was followed in which a system dynamics model was constructed for eight diverse case study sites where ecological restoration is currently being pursued. Restoration costs vary across each of these sites, as do the benefits associated with restored ecosystem functioning. The system dynamics model simulates the ecological, hydrological and economic benefits of ecological restoration and informs a portfolio mapping exercise where payoffs are matched against the likelihood of success of a project, as well as a number of other factors (such as project costs and risk measures). This is the first known application that couples ecological restoration with system dynamics and portfolio mapping. The results suggest an approach that is able to move beyond traditional indicators of project success, since the effect of discounting is virtually eliminated. We conclude that systems dynamic modelling with portfolio mapping can guide decisions on when markets for restoration activities may be feasible. PMID:23524327

  12. Far-red fluorescence gene reporter tomography for determination of placement and viability of cell-based gene therapies

    PubMed Central

    Lu, Yujie; Darne, Chinmay D.; Tan, I-Chih; Zhu, Banghe; Hall, Mary A.; Lazard, ZaWaunyka W.; Davis, Alan R.; Simpson, LaShan; Sevick-Muraca, Eva M.; Olmsted-Davis, Elizabeth A.

    2013-01-01

    Non-invasive injectable cellular therapeutic strategies based on sustained delivery of physiological levels of BMP-2 for spinal fusion are emerging as promising alternatives, which could provide sufficient fusion without the associated surgical risks. However, these injectable therapies are dependent on bone formation occurring only at the specific target region. In this study, we developed and deployed fluorescence gene reporter tomography (FGRT) to provide information on in vivo cell localization and viability. This information is sought to confirm the ideal placement of the materials with respect to the area where early bone reaction is required, ultimately providing three dimensional data about the future fusion. However, because almost all conventional fluorescence gene reporters require visible excitation wavelengths, current in vivo imaging of fluorescent proteins is limited by high tissue absorption and confounding autofluorescence. We previously administered fibroblasts engineered to produce BMP-2, but is difficult to determine 3-D information of placement prior to bone formation. Herein we used the far-red fluorescence gene reporter, IFP1.4 to report the position and viability of fibroblasts and developed 3-D tomography to provide placement information. A custom small animal, far-red fluorescence tomography system integrated into a commercial CT scanner was used to assess IFP1.4 fluorescence and to demark 3-D placement of encapsulated fibroblasts with respect to the vertebrae and early bone formation as assessed from CT. The results from three experiments showed that the placement of the materials within the spine could be detected. This work shows that in vivo fluorescence gene reporter tomography of cell-based gene therapy is feasible and could help guide cell-based therapies in preclinical models. PMID:24104323

  13. Effects of Chemical and Physical Agents on Viability and Infectivity of Encephalitozoon intestinalis Determined by Cell Culture and Flow Cytometry

    PubMed Central

    Santillana-Hayat, Maud; Sarfati, Claudine; Fournier, Sandra; Chau, Franoise; Porcher, Raphal; Molina, Jean-Michel; Derouin, Francis

    2002-01-01

    We combined tissue culture and flow cytometry to assess the activities of various temperatures, chemicals, and disinfectants on the viability and infectivity of spores of Encephalitozoon intestinalis. Surfanios and benzalkonium chloride, disinfectants currently used in the hospital, were remarkably efficient in destroying spore viability and infectivity. PMID:12019139

  14. Effects of chemical and physical agents on viability and infectivity of Encephalitozoon intestinalis determined by cell culture and flow cytometry.

    PubMed

    Santillana-Hayat, Maud; Sarfati, Claudine; Fournier, Sandra; Chau, Franoise; Porcher, Raphal; Molina, Jean-Michel; Derouin, Francis

    2002-06-01

    We combined tissue culture and flow cytometry to assess the activities of various temperatures, chemicals, and disinfectants on the viability and infectivity of spores of Encephalitozoon intestinalis. Surfanios and benzalkonium chloride, disinfectants currently used in the hospital, were remarkably efficient in destroying spore viability and infectivity. PMID:12019139

  15. Determinants of Grades in Maths for Students in Economics

    ERIC Educational Resources Information Center

    Cappellari, Lorenzo; Lucifora, Claudio; Pozzoli, Dario

    2012-01-01

    This paper investigates the determinants of grades achieved in maths by first-year students in economics. We use individual administrative data from 1993 to 2005 to fit an educational production function. Our main findings suggest that good secondary school achievements and the type of school attended are significantly associated with maths

  16. The Empirical Determination of Key Skills from an Economic Perspective

    ERIC Educational Resources Information Center

    Van Loo, Jasper B.; Toolsema, Bert

    2005-01-01

    Notwithstanding an impressive research tradition on key skills, no clear statistical criterion exists that is suitable to determine which skills may be considered key skills. This contribution proposes one possible methodology that can be used to identify key skills. Proposing an economic definition of the key skill concept and disentangling the…

  17. Economic determinants of diet in older adults: systematic review

    PubMed Central

    Conklin, Annalijn I; Maguire, Eva R; Monsivais, Pablo

    2013-01-01

    Background and aims Many economic factors are associated with diet, yet the evidence is generally cross-sectional. Older people are considered especially vulnerable to poor diets from negative changes to varied economic factors. This review extends current knowledge on known correlates to decipher actual economic determinants of diet in older adults. Methods Eight bibliometric databases were searched between May and December 2012, supplemented by hand-searches, with no restrictions on publication date or country. Longitudinal studies, or reviews, were eligible when examining diet as a function of change in an economic factor in non-institutionalised adults ?60?years. Data were extracted using a standardised evidence table and quality assessed before narrative synthesis. Results We found nine original studies for inclusion, of which eight examined change from work to retirement and one evaluated a food price intervention. Designs were generally pre-post without controls and varying in follow-up. Studies reported mixed impact on food spending and/or food intake. Retirement was shown to both reduce and have no impact on food spending and to have either positive and negative, or positive and no impact on food intake. Subgroup differences were observed, especially between men and women. Conclusions Despite ample research on economic correlates of older adults' diets, little is still known about actual economic determinants of diet in this population. Studies of retirement suggest divergent effects in some but not all older people. Robust high-quality longitudinal studies to decipher economic drivers of diet must be prioritised in research and policy as firm conclusions remain elusive. PMID:23761410

  18. Debilitation in conidia of the entomopathogenic fungi Beauveria and Metarhizium anisopliae and implications with respect to viability determinations and mycopesticide quality assessments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Viabilities of entomopathogenic fungal conidia comprising biopesticide products are most commonly determined by suspension of dry conidia from storage in a water/surfactant solution immediately before inoculation onto an agar-based germination substrate; conidia are then incubated at a moderate temp...

  19. Dairy goat kids fed liquid diets in substitution of goat milk and slaughtered at different ages: an economic viability analysis using Monte Carlo techniques.

    PubMed

    Knupp, L S; Veloso, C M; Marcondes, M I; Silveira, T S; Silva, A L; Souza, N O; Knupp, S N R; Cannas, A

    2016-03-01

    The aim of this study was to analyze the economic viability of producing dairy goat kids fed liquid diets in alternative of goat milk and slaughtered at two different ages. Forty-eight male newborn Saanen and Alpine kids were selected and allocated to four groups using a completely randomized factorial design: goat milk (GM), cow milk (CM), commercial milk replacer (CMR) and fermented cow colostrum (FC). Each group was then divided into two groups: slaughter at 60 and 90 days of age. The animals received Tifton hay and concentrate ad libitum. The values of total costs of liquid and solid feed plus labor, income and average gross margin were calculated. The data were then analyzed using the Monte Carlo techniques with the @Risk 5.5 software, with 1000 iterations of the variables being studied through the model. The kids fed GM and CMR generated negative profitability values when slaughtered at 60 days (US$ -16.4 and US$ -2.17, respectively) and also at 90 days (US$ -30.8 and US$ -0.18, respectively). The risk analysis showed that there is a 98% probability that profitability would be negative when GM is used. In this regard, CM and FC presented low risk when the kids were slaughtered at 60 days (8.5% and 21.2%, respectively) and an even lower risk when animals were slaughtered at 90 days (5.2% and 3.8%, respectively). The kids fed CM and slaughtered at 90 days presented the highest average gross income (US$ 67.88) and also average gross margin (US$ 18.43/animal). For the 60-day rearing regime to be economically viable, the CMR cost should not exceed 11.47% of the animal-selling price. This implies that the replacer cannot cost more than US$ 0.39 and 0.43/kg for the 60- and 90-day feeding regimes, respectively. The sensitivity analysis showed that the variables with the greatest impact on the final model's results were animal selling price, liquid diet cost, final weight at slaughter and labor. In conclusion, the production of male dairy goat kids can be economically viable when the kids diet consists mainly of either cow milk or fermented colostrum, especially when kids are slaughtered at 90 days of age. PMID:26584672

  20. 28 CFR 104.43 - Determination of presumed economic loss for decedents.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Determination of presumed economic loss... Determination of presumed economic loss for decedents. In reaching presumed determinations for economic loss for... prior earned income, or who worked only part time outside the home, economic loss may be determined...

  1. 28 CFR 104.43 - Determination of presumed economic loss for decedents.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Determination of presumed economic loss... Determination of presumed economic loss for decedents. In reaching presumed determinations for economic loss for... prior earned income, or who worked only part time outside the home, economic loss may be determined...

  2. NEW METHOD TO DETERMINE 'GIARDIA' CYST VIABILITY: CORRELATION OF FLUORESCEIN DIACETATE AND PROPIDIUM IODIDE STAINING WITH ANIMAL INFECTIVITY

    EPA Science Inventory

    The viability of Giardia muris cysts was studied using the fluorogenic dyes, fluorescein diacetate (FDA) and propidium iodide (PI). Using the mouse model for giardiasis, FDA or PI stained cysts were inoculated into neonatal mice. Feces were examined at days 3, 5, 8, and 11 post-i...

  3. 28 CFR 104.43 - Determination of presumed economic loss for decedents.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 2 2013-07-01 2013-07-01 false Determination of presumed economic loss... of presumed economic loss for decedents. In reaching presumed determinations for economic loss for...-time outside the home, economic loss may be determined with reference to replacement services...

  4. 28 CFR 104.43 - Determination of presumed economic loss for decedents.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Determination of presumed economic loss... of presumed economic loss for decedents. In reaching presumed determinations for economic loss for...-time outside the home, economic loss may be determined with reference to replacement services...

  5. 28 CFR 104.43 - Determination of presumed economic loss for decedents.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Determination of presumed economic loss... of presumed economic loss for decedents. In reaching presumed determinations for economic loss for...-time outside the home, economic loss may be determined with reference to replacement services...

  6. Myocardial viability.

    PubMed Central

    Birnbaum, Y; Kloner, R A

    1996-01-01

    Left ventricular function is a major predictor of outcome in patients with coronary artery disease. Acute ischemia, postischemic dysfunction (stunning), myocardial hibernation, or a combination of these 3 are among the reversible forms of myocardial dysfunction. In myocardial stunning, dysfunction occurs despite normal myocardial perfusion, and function recovers spontaneously over time. In acute ischemia and hibernation, there is regional hypoperfusion. Function improves only after revascularization. Evidence of myocardial viability usually relies on the demonstration of uptake of various metabolic tracers, such as thallium (thallous chloride TI 201) or fludeoxyglucose F 18, by dysfunctional myocardium or by the demonstration of contractile reserve in a dysfunctional region. This can be shown as an augmentation of function during the infusion of various sympathomimetic agents. The response of ventricular segments to increasing doses of dobutamine may indicate the underlying mechanism of dysfunction. Stunned segments that have normal perfusion show dose-dependent augmentation of function. If perfusion is reduced as in hibernating myocardium, however, a biphasic response usually occurs: function improves at low doses of dobutamine, whereas higher doses may induce ischemia and, hence, dysfunction. But in patients with severely impaired perfusion, even low doses may cause ischemia. Myocardial regions with subendocardial infarction or diffuse scarring may also have augmented contractility during catecholamine infusion due to stimulation of the subepicardial layers. In these cases, augmentation of function after revascularization is not expected. Because the underlying mechanism, prognosis, and therapy may differ among these conditions, it is crucial to differentiate among dysfunctional myocardial segments that are nonviable and have no potential to regain function, hibernating or ischemic segments in which recovery of function occurs only after revascularization, and myocardial stunning in which function is expected to recover spontaneously. Because combinations of all of these disorders may occur, even in the same segments, caution should be used in interpreting the imaging results. PMID:9000857

  7. 10 CFR 600.503 - Determining the economic interest of the United States.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Determining the economic interest of the United States... Policy § 600.503 Determining the economic interest of the United States. In determining whether participation of an applicant company in a covered program would be in the economic interest of the...

  8. Mycobacterium avium subsp. paratuberculosis viability determination using F57 quantitative PCR in combination with propidium monoazide treatment.

    PubMed

    Kralik, P; Nocker, A; Pavlik, I

    2010-07-31

    Mycobacterium avium subsp. paratuberculosis (MAP) is known to be a very slow-growing organism. The fact that cells typically need several weeks to form visible colonies severely compromises the suitability of plate counting for assessment of viable cell counts. This problem might be overcome by the application of fast molecular methods containing a viability component. We have evaluated a promising technology combining sample treatment with propidium monoazide (PMA) prior to DNA extraction for selective detection of cells with intact cell membranes with detection of sequence element F57 by quantitative PCR (F57 qPCR). Element F57 is unique for MAP and is not known to exist in any other bacterial species. Conditions of PMA treatment were optimised for MAP isolate 7082 using live and heat-killed cells and comparing different DNA extraction procedures. The subsequent successful application of the optimised protocol to four other MAP isolates of different origins suggested that the optimised protocol might be broadly applicable to different MAP strains. Furthermore, different equations were compared to use the data resulting from this technology to optimally predict the percentage of live MAP cells in mixtures containing both live and dead cells. The presented protocol holds promise to be used routinely for detecting MAP with intact cell membranes in research applications. PMID:20385417

  9. 41 CFR 101-5.104-2 - Basis for determining economic feasibility.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... economic feasibility. 101-5.104-2 Section 101-5.104-2 Public Contracts and Property Management Federal... SERVICES IN FEDERAL BUILDINGS AND COMPLEXES 5.1-General § 101-5.104-2 Basis for determining economic feasibility. (a) Whenever possible, determination of the economic feasibility of a proposed...

  10. 49 CFR 26.67 - What rules determine social and economic disadvantage?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 1 2014-10-01 2014-10-01 false What rules determine social and economic... Standards § 26.67 What rules determine social and economic disadvantage? (a) Presumption of disadvantage. (1... individual's presumption of economic disadvantage is rebutted. You are not required to have a...

  11. 49 CFR 26.67 - What rules determine social and economic disadvantage?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 1 2011-10-01 2011-10-01 false What rules determine social and economic... Standards § 26.67 What rules determine social and economic disadvantage? (a) Presumption of disadvantage. (1... individual's presumption of economic disadvantage is rebutted. You are not required to have a...

  12. 41 CFR 101-5.104-2 - Basis for determining economic feasibility.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... economic feasibility. 101-5.104-2 Section 101-5.104-2 Public Contracts and Property Management Federal... SERVICES IN FEDERAL BUILDINGS AND COMPLEXES 5.1-General § 101-5.104-2 Basis for determining economic feasibility. (a) Whenever possible, determination of the economic feasibility of a proposed...

  13. 41 CFR 101-5.104-2 - Basis for determining economic feasibility.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... economic feasibility. 101-5.104-2 Section 101-5.104-2 Public Contracts and Property Management Federal... SERVICES IN FEDERAL BUILDINGS AND COMPLEXES 5.1-General § 101-5.104-2 Basis for determining economic feasibility. (a) Whenever possible, determination of the economic feasibility of a proposed...

  14. 41 CFR 101-5.104-2 - Basis for determining economic feasibility.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... economic feasibility. 101-5.104-2 Section 101-5.104-2 Public Contracts and Property Management Federal... SERVICES IN FEDERAL BUILDINGS AND COMPLEXES 5.1-General § 101-5.104-2 Basis for determining economic feasibility. (a) Whenever possible, determination of the economic feasibility of a proposed...

  15. 41 CFR 101-5.104-2 - Basis for determining economic feasibility.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... economic feasibility. 101-5.104-2 Section 101-5.104-2 Public Contracts and Property Management Federal... SERVICES IN FEDERAL BUILDINGS AND COMPLEXES 5.1-General § 101-5.104-2 Basis for determining economic feasibility. (a) Whenever possible, determination of the economic feasibility of a proposed...

  16. 49 CFR 26.67 - What rules determine social and economic disadvantage?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false What rules determine social and economic... Standards § 26.67 What rules determine social and economic disadvantage? (a) Presumption of disadvantage. (1... individual's presumption of economic disadvantage is rebutted. You are not required to have a...

  17. Determination of Fares: Pricing Theory and Economic Efficiency

    NASA Technical Reports Server (NTRS)

    Miller, J. C., III

    1972-01-01

    The concept of economic efficiency is described, its application to the pricing of air transport services, and its relevance as a policy objective are outlined. The first two sections discuss economic efficiency in general terms, whereas the third applies this norm to several airline pricing problems. The final section emphasizes the importance of industry behavior as a parameter in policy analysis.

  18. 30 CFR 203.68 - What pre-application costs will MMS consider in determining economic viability?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ROYALTY RATES OCS Oil, Gas, and Sulfur General Royalty Relief for Pre-Act Deep Water Leases and for... include sunk costs How much suspension volume is necessary to make the field, a development project, or...

  19. 30 CFR 203.68 - What pre-application costs will BSEE consider in determining economic viability?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR MINERALS REVENUE MANAGEMENT RELIEF OR REDUCTION IN ROYALTY RATES OCS Oil, Gas, and Sulfur General § 203.68 What pre-application costs will BSEE consider...

  20. 30 CFR 203.68 - What pre-application costs will BSEE consider in determining economic viability?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR MINERALS REVENUE MANAGEMENT RELIEF OR REDUCTION IN ROYALTY RATES OCS Oil, Gas, and Sulfur General § 203.68 What pre-application costs will BSEE consider...

  1. 30 CFR 203.68 - What pre-application costs will BSEE consider in determining economic viability?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR MINERALS REVENUE MANAGEMENT RELIEF OR REDUCTION IN ROYALTY RATES OCS Oil, Gas, and Sulfur General § 203.68 What pre-application costs will BSEE consider...

  2. BALB/c-congenic ANP32B-deficient mice reveal a modifying locus that determines viability.

    PubMed

    Leo, Vonny I; Bunte, Ralph M; Reilly, Patrick T

    2016-02-14

    We previously found that deletion of the multifunctional factor ANP32B (a.k.a. SSP29, APRIL, PAL31, PHAPI2) resulted in a severe but strain-specific defect resulting in perinatal lethality. The difficulty in generating an adult cohort of ANP32B-deficient animals limited our ability to examine adult phenotypes, particularly cancer-related phenotypes. We bred the Anp32b-null allele into the BALB/c and FVB/N genetic background. The BALB/c, but not the FVB/N, background provided sufficient frequency of adult Anp32b-null (Anp32b(-/-)) animals. From these, we found no apparent oncogenic role for this protein in mammary tumorigenesis contrary to what was predicted based on human data. We also found runtism, pathologies in various organ systems, and an unusual clinical chemistry signature in the adult Anp32b(-/-) mice. Intriguingly, genome-wide single-nucleotide polymorphism analysis suggested that our colony retained an unlinked C57BL/6J locus at high frequency. Breeding this locus to homozygosity demonstrated that it had a strong effect on Anp32b(-/-) viability indicating that this locus contains a modifier gene of Anp32b with respect to development. This suggests a functionally important genetic interaction with one of a limited number of candidate genes, foremost among them being the variant histone gene H2afv. Using congenic breeding strategies, we have generated a viable ANP32B-deficient animal in a mostly pure background. We have used this animal to reliably exclude mouse ANP32B as an important oncogene in mammary tumorigenesis. Our further phenotyping strengthens the evidence that ANP32B is a widespread regulator of gene expression. These studies may also impact the choice of subsequent groups with respect to congenic breeding versus de novo zygote targeting strategies for background analyses in mouse genetics. PMID:26558540

  3. BALB/c-congenic ANP32B-deficient mice reveal a modifying locus that determines viability

    PubMed Central

    Leo, Vonny I.; Bunte, Ralph M.; Reilly, Patrick T.

    2015-01-01

    We previously found that deletion of the multifunctional factor ANP32B (a.k.a. SSP29, APRIL, PAL31, PHAPI2) resulted in a severe but strain-specific defect resulting in perinatal lethality. The difficulty in generating an adult cohort of ANP32B-deficient animals limited our ability to examine adult phenotypes, particularly cancer-related phenotypes. We bred the Anp32b-null allele into the BALB/c and FVB/N genetic background. The BALB/c, but not the FVB/N, background provided sufficient frequency of adult Anp32b-null (Anp32b−/−) animals. From these, we found no apparent oncogenic role for this protein in mammary tumorigenesis contrary to what was predicted based on human data. We also found runtism, pathologies in various organ systems, and an unusual clinical chemistry signature in the adult Anp32b−/− mice. Intriguingly, genome-wide single-nucleotide polymorphism analysis suggested that our colony retained an unlinked C57BL/6J locus at high frequency. Breeding this locus to homozygosity demonstrated that it had a strong effect on Anp32b−/− viability indicating that this locus contains a modifier gene of Anp32b with respect to development. This suggests a functionally important genetic interaction with one of a limited number of candidate genes, foremost among them being the variant histone gene H2afv. Using congenic breeding strategies, we have generated a viable ANP32B-deficient animal in a mostly pure background. We have used this animal to reliably exclude mouse ANP32B as an important oncogene in mammary tumorigenesis. Our further phenotyping strengthens the evidence that ANP32B is a widespread regulator of gene expression. These studies may also impact the choice of subsequent groups with respect to congenic breeding versus de novo zygote targeting strategies for background analyses in mouse genetics. PMID:26558540

  4. Comparative assessment of the cytotoxicity of six anti-inflammatory eyedrops in four cultured ocular surface cell lines, as determined by cell viability scores

    PubMed Central

    Ayaki, Masahiko; Iwasawa, Atsuo; Niwano, Yoshimi

    2012-01-01

    Purpose Anti-inflammatory eyedrops are often used in the treatment of corneal epithelial disorders. In the present study, we evaluated the cytotoxicity of six anti-inflammatory eyedrops in four ocular surface cell lines. Methods The cytotoxicity of six commercially available anti-inflammatory ophthalmic solutions (ie, diclofenac, bromfenac, pranoprofen, betamethasone, and fluoromethorone) was assessed in three corneal cell lines and one conjunctival cell line. Cell viability was determined by the 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide and neutral red assays after exposing the cells to 10, 30, and 60 minutes of onefold, twofold, and tenfold dilutions of the drugs. Cytotoxicity was compared using the cell viability score (CVS), an integrated cytotoxic parameter that takes various factors into account, such as dilution by tear fluid or concentration by evaporation, drug exposure time, and ocular surface cell type. Results Based on the CVS scores, the order of the anti-inflammatory eyedrops tested from least to most cytotoxic, with the active ingredient %CVS50, and %CVS40/80 for each solution given in parentheses, was as follows: Rinderon (betamethasone, 100%, 100%) >0.02% Flumethoron (fluoromethorone, 68%, 22%) = 0.1% Flumethoron (fluoromethorone, 76%, 22%) >Bronuck (0.1% bromfenac, 53%, ?8%) = Diclod (0.1% diclofenac, 44%, ?15%) = Niflan (pranoprofen, 50%, ?19%). Rinderon exhibited the least toxicity of all the anti-inflammatory eyedrops tested. Eyedrops containing non-steroidal anti-inflammatory drugs exhibited greater cytotoxicity than those containing steroids with benzalkonium at comparable concentrations. Concentration was the most significant factor affecting cell viability. Conclusion The cytotoxicity of the anti-inflammatory eyedrops evaluated in the present study depended on both the pharmaceutical components and preservatives. The CVS is a concise indicator of drug cytotoxicity. PMID:23185116

  5. Using Economics to Determine the Efficient Curtailment of Wind Energy

    SciTech Connect

    Ela, E.

    2009-02-01

    This paper discusses the potential societal benefits to the energy market by allowing the dispatch of wind generation in times when it may enhance reliability and be economically advantageous to do so.

  6. Using Economics to Determine the Efficient Curtailment of Wind Energy

    SciTech Connect

    Ela, Erik

    2009-02-01

    This paper discusses the potential societal benefits to the energy market of allowing the dispatch of wind generation in times when it may enhance reliability and be economically advantageous to do so.

  7. Determination of Missouri Home Economics Teachers' Training Needs Related to Instruction of Handicapped Students. Final Report.

    ERIC Educational Resources Information Center

    Martin, Betty B.; And Others

    The purpose of this study was to collect data concerning the handicapped students who are enrolled in home economics and to determine the type of training that should be provided for home economics teachers in Missouri. Survey instruments were sent to all home economics teachers in consumer and homemaking programs and occupational programs in

  8. Some Economic Considerations for Determining Additional Educational Expenditures.

    ERIC Educational Resources Information Center

    Goffman, Irving J.

    This conference paper analyzes educational finance from the standpoint of human capital, noting the external economic and social benefits that result from educational expenditures. A case is made for publicly sponsored adjustments to the market mechanism to insure an optimum allocation of educational resources. (LLR)

  9. A multiplexed assay for determination of neurotoxicant effects on spontaneous network activity and viability from microelectrode arrays.

    PubMed

    Wallace, Kathleen; Strickland, Jenna D; Valdivia, Pablo; Mundy, William R; Shafer, Timothy J

    2015-07-01

    Microelectrode array (MEA) recordings are increasingly being used as an in vitro method to detect and characterize the ability of drugs, chemicals and particles to cause neurotoxicity. While compound effects on spontaneous network activity are easily determined by MEA recordings, compound cytotoxicity is not routinely assessed, particularly within the same network from which recordings are collected. With the advent of higher-throughput 48 and 96 well MEA systems, rapid and simple methods to measure compound effects on cell health are required to facilitate efficient compound screening using MEAs. The present experiments sought to develop a multiplexed approach that allows measurement of network activity and cell health in the same MEA well. Primary cultures from rat cortex were exposed to six different compounds (glyphosate, ?-cyfluthrin, domoic acid, tributyltin, lindane and fipronil). Effects of these compounds (0.03-100 ?M) on spontaneous network activity (mean firing rate; MFR), cellular metabolic activity (Cell Titer Blue (CTB) assay) and lactate dehydrogenase (LDH) release were determined in the same well following a 60-min exposure. Glyphosate elicited no effect on MFR, LDH release or CTB reduction. Tributyltin caused concomitant decreases in MFR and CTB reduction and increases LDH release, while domoic acid and ?-cyfluthrin decreased MFR in a concentration-dependent manner without altering either LDH release or CTB reduction. By contrast, lindane and fipronil did not alter LDH release or CTB reduction, but caused biphasic alterations in MFR, with increases in MFR at lower concentrations followed by decreases at higher concentrations. These results demonstrate a simple and rapid method for the simultaneous determination of test compound effects on spontaneous electrical activity and cell health from the same network, and will facilitate rapid screening of compounds for potential neurotoxicity. PMID:26027956

  10. Economics and the determination of Indian reserved water rights

    SciTech Connect

    Brookshire, D.S.; Merrill, J.L.; Watts, G.L.

    1983-10-01

    Economics plays a major role in the historically controversial Indian reserved water rights in which reserved rights differ from appropriated rights because Indian reservations predate other appropriated rights of settlers and miners. Other aspects of Indian reserved rights are their magnitude and their coexistence with the land regardless of use. Court decisions relating to practicably irrigable acres (PIA) are examined in terms of quantification of water rights and ethics. The legal analysis concludes that PIA will probably continue, but needs adjustments to the criteria to make them more strict and more appropriate. 62 references. (DCK)

  11. Clinical utility and economic viability of a 3T MRI in an anti-cancer centre: The experience of the centre Oscar Lambret.

    PubMed

    Taeb, S; Devise, V; Pouliquen, G; Rocourt, N; Faivre-Pierret, M; Brongniart, S; Peugny, P; Ceugnart, L

    2012-07-01

    This paper will try and describe the installation of a 3T MRI in an anti-cancer centre. Functional sequences become indispensable in the assessment of targeted treatments. It is only possible to carry out these treatments on a routine basis in acceptable examination times with 3T. The technical constraints are overcome with third generation MRI and the improvement of the spatial resolution in examination times reduced by 30 to 50% increases patient comfort. Nevertheless, the financial constraints represent a major handicap. It is not possible to obtain an economic balance with rates based on the cost and depreciation of 1.5T imagers that are half the price. PMID:22726637

  12. The Determinants of Child Health in Pakistan: An Economic Analysis

    ERIC Educational Resources Information Center

    Shehzad, Shafqat

    2006-01-01

    This paper estimates linear structural models using LISREL and employs MIMIC models to find out factors determining child health in Pakistan. A distinction has been made in permanent and transitory health states that lend support to Grossman's (1972) stock and flow concepts of health. The paper addresses the issue of health unobservability and

  13. Multiplexing cell viability assays.

    PubMed

    Gerets, Helga H J; Dhalluin, Stéphane; Atienzar, Franck A

    2011-01-01

    Today, obtaining mechanistic insights into biological, toxicological, and pathological processes is of upmost importance. Researchers aim to obtain as many as possible data from one cell sample to understand the biological processes under study. Multiplexing, which is the ability to gather more than one set of data from the same sample, fulfills completely this objective. Obviously, multiplexing has several advantages compared to single plex experiments and probably the most important one is that data on various parameters at exactly the same time point on the same cells or group of cells can be obtained and consequently this may contribute to saving time and effort and a reduction of the costs.In this chapter, different endpoints were measured starting from two-seeded multiwell plates, namely, cell viability, caspase-3/7 activity, lactate dehydrogenase (LDH), adenosine triphosphate (ATP), aspartate aminotransferase (AST), and glutamate dehydrogenase (GLDH) measurements. These -different endpoints were analyzed together to determine the cytotoxic properties of pharmaceutical compounds and/or reference compounds. A 96-well plate was designed to allow appropriate measurement of five doses of a compound in triplicate to determine the effect of the compound on the six different endpoints. The first four endpoints (cell viability, caspase-3/7 activity, LDH, and ATP) are discussed in detail in this chapter. AST and GLDH measurements are not discussed in detail as these are fully automatic measurements and thus behind the scope of this chapter.As an illustrating example, the reference compound tamoxifen was used to evaluate its cytotoxic properties using the hepatocellular carcinoma cell line HepG2 cells. PMID:21468971

  14. The Performance of Economics Graduates over the Entire Curriculum: The Determinants of Success

    ERIC Educational Resources Information Center

    Swope, Kurtis J.; Schmitt, Pamela M.

    2006-01-01

    Most studies of the determinants of understanding in economics focus on performance in a single course or standardized exam. Taking advantage of a large data set available at the U.S. Naval Academy (USNA), the authors examined the performance of economics majors over an entire curriculum. They found that gender was not a significant predictor of

  15. Economics.

    PubMed

    Palley, Paul D; Parcero, Miriam E

    2015-10-01

    A review of literature during calendar year 2014 focused on 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:26420109

  16. Economic Education in the Middle East: Are the Determinants of Success in Introductory Economics Any Different?

    ERIC Educational Resources Information Center

    Kherfi, Samer

    2008-01-01

    The author examines the determinants of success in introductory microeconomics, in the context of a Middle Eastern society but within an American educational setting. The data set is rich and covers over 3,500 students in one regional campus, allowing control for a wide range of student and class characteristics, one of which, nationality, is

  17. 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)

  18. 28 CFR 104.45 - Determination of presumed economic loss for claimants who suffered physical harm.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Determination of presumed economic loss for claimants who suffered physical harm. 104.45 Section 104.45 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) SEPTEMBER 11TH VICTIM COMPENSATION FUND Amount of Compensation for Eligible Claimants § 104.45 Determination of presumed...

  19. LIMITATIONS OF THE FLUORESCENT PROBE VIABILITY ASSAY

    EPA Science Inventory

    Cell viability commonly is determined flow cytometrically by the carboxyfluorescein diacetate (CFDA)/propidium iodide (PI) assay. FDA is taken up by the viable cell and converted via cytoplasmic esterase-catalyzed hydrolysis to carboxyfluorescein (CF). F fluorescence intensity is...

  20. An approach to determining the economic feasibility of refuse-derived fuels and materials recovery processing

    SciTech Connect

    Gershman, H.W.

    1980-06-01

    An approach for determining the economic feasibility of refuse-derived fuel production and the recovery of various materials is demonstrated, using data developed for the metropolitan Washington, D.C., area as input. The processing facility, designed to handle 650 tpd of refuse, is described. Since materials revenues can be predicted with a higher degree of certainty than refuse fuel revenues, it is necessary to determine what revenues the sale of solid waste fuel will have to generate for projected economics to be the same as an alternative disposal practice. (1 diagram, 8 references, 6 tables)

  1. Green analytical chemistry introduction to chloropropanols determination at no economic and analytical performance costs?

    PubMed

    Jędrkiewicz, Renata; Orłowski, Aleksander; Namieśnik, Jacek; Tobiszewski, Marek

    2016-01-15

    In this study we perform ranking of analytical procedures for 3-monochloropropane-1,2-diol determination in soy sauces by PROMETHEE method. Multicriteria decision analysis was performed for three different scenarios - metrological, economic and environmental, by application of different weights to decision making criteria. All three scenarios indicate capillary electrophoresis-based procedure as the most preferable. Apart from that the details of ranking results differ for these three scenarios. The second run of rankings was done for scenarios that include metrological, economic and environmental criteria only, neglecting others. These results show that green analytical chemistry-based selection correlates with economic, while there is no correlation with metrological ones. This is an implication that green analytical chemistry can be brought into laboratories without analytical performance costs and it is even supported by economic reasons. PMID:26592608

  2. Viability of bacteria in peatlands

    NASA Astrophysics Data System (ADS)

    Bogdanova, O. Yu.; Golovchenko, A. V.; Lysak, L. V.; Glukhova, T. V.; Zvyagintsev, D. G.

    2014-04-01

    The viability of bacteria in oligotrofic bogs and fens was determined by the luminescent microscopy method with the help of a two-component fluorescent dye (L7012 LIVE/DEAD). Living bacterial cells were found in the entire peat profiles. Their portion was maximal (up to 60%) in the upper layers and did not exceed 25% in the lower layers. The portion of dead bacterial cells varied from 3 to 19%, and dormant cells constituted 25 to 95% of the total number of bacterial cells. The numbers of dormant cells increased down the profiles irrespectively of the peat type. The portion of nanoforms did not exceed 5% of the total. The cells of the nanoforms, unlike the bacteria of typical sizes, were characterized by their high viability (93-98%).

  3. Socio-economic determinants of life expectancy in Nigeria (1980 - 2011).

    PubMed

    Sede, Peter I; Ohemeng, Williams

    2015-01-01

    Attainment of 70 years life expectancy by 2020 is one of the millennium development goals in Nigeria. This study examined the socio-economic determinants of life expectancy in Nigeria using data from 1980-2011. Judging from the endogeneity feature of the variables, A VAR and VECM frameworks were employed. Socio-economic features were proxy by secondary school enrolment, government expenditure on health, per capita income, unemployment rate and the Naira foreign exchange rate. It was found that, the conventional socio-economic variables such as per capita income, education and government expenditure on health considered to be highly effective in determining life expectancy of developing countries are not significant in the case of Nigeria. The study however suggests that, life expectancy in Nigeria could be improved if attention is given to quality of government health expenditure, unemployment and measures to halt the depreciation of the Nigerian Naira against major foreign currency. PMID:25853000

  4. Understanding School Choice: Location as a Determinant of Charter School Racial, Economic, and Linguistic Segregation

    ERIC Educational Resources Information Center

    Jacobs, Nicholas

    2013-01-01

    The author analyzes the revealed school preferences of parents in the Washington, D.C., and asks, "What is the main determinant of charter school choice and how does it create racial, economic, and linguistic segregation?" The author first establishes a theory of choice, which incorporates past research and adds an additional variable to our

  5. Understanding School Choice: Location as a Determinant of Charter School Racial, Economic, and Linguistic Segregation

    ERIC Educational Resources Information Center

    Jacobs, Nicholas

    2013-01-01

    The author analyzes the revealed school preferences of parents in the Washington, D.C., and asks, "What is the main determinant of charter school choice and how does it create racial, economic, and linguistic segregation?" The author first establishes a theory of choice, which incorporates past research and adds an additional variable to our…

  6. 75 FR 9997 - Determination and Waiver Regarding the Sixth Proviso under the Heading Economic Support Funds...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-04

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Determination and Waiver Regarding the Sixth Proviso under the Heading ``Economic Support Funds'' in the Department of State, Foreign Operations, and Related Programs Appropriations Act, 2009 (Div. H, Pub. L. 111-8) Relating to Assistance for...

  7. 49 CFR Appendix E to Part 26 - Individual Determinations of Social and Economic Disadvantage

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 1 2013-10-01 2013-10-01 false Individual Determinations of Social and Economic Disadvantage E Appendix E to Part 26 Transportation Office of the Secretary of Transportation PARTICIPATION BY DISADVANTAGED BUSINESS ENTERPRISES IN DEPARTMENT OF TRANSPORTATION FINANCIAL ASSISTANCE PROGRAMS Pt. 26, App. E Appendix E to Part...

  8. Viability and Hospital Failure

    PubMed Central

    Cannedy, Lloyd L.; Pointer, Dennis D.; Ruchlin, Hirsch S.

    1973-01-01

    The value and feasibility of utilizing viability as a dependent variable in hospital organizational research are demonstrated in a study of a sample of U.S. hospitals that failed in 1969. The 23 failed study hospitals and a set of matched nonfailed hospitals are compared, on the basis of 14 institutional characteristics for which data are available, in a two-phase multiple-regression analysis, with organizational viability, the dependent variable, specified as a dummy variable. The application to other health services research areas is discussed. PMID:4705215

  9. Non-Economic Determinants of Energy Use in Rural Areas of South Africa

    SciTech Connect

    Annecke, W.

    1999-03-29

    This project will begin to determine the forces and dimensions in rural energy-use patterns and begin to address policy and implementation needs for the future. This entails: Forecasting the social and economic benefits that electrification is assumed to deliver regarding education and women's lives; Assessing negative perceptions of users, which have been established through the slow uptake of electricity; Making recommendations as to how these perceptions could be addressed in policy development and in the continuing electrification program; Making recommendations to policy makers on how to support and make optimal use of current energy-use practices where these are socio-economically sound; Identifying misinformation and wasteful practices; and Other recommendations, which will significantly improve the success of the rural electrification program in a socio-economically sound manner, as identified in the course of the work.

  10. Determination of an economical shipping route considering the effects of sea state for lower fuel consumption

    NASA Astrophysics Data System (ADS)

    Roh, Myung-Il

    2013-06-01

    With increases in international oil prices, the proportion of fuel cost to the operational costs of a ship is currently increasing. To reduce fuel cost, a method for determining an economical route for a ship based on the acquisition of the sea state and the estimation of fuel consumption is proposed. The proposed method consists of three items. The first item is to acquire the sea state information in real time. The second item is to estimate the fuel consumption of a ship according to the sea state. The last item is to find an economical route for minimal fuel consumption based on the previous two items. To evaluate the applicability of the proposed method, it was applied to routing problems in various ocean areas. The result shows that the proposed method can yield economical ship routes that minimize fuel consumption. The results of this study can contribute to energy savings for environmentally friendly ships.

  11. An approach to determining the economic feasibility of refuse-derived fuel and materials recovery processing

    NASA Astrophysics Data System (ADS)

    Gershman, H. W.

    1980-06-01

    An approach for determining the economic feasibility of refuse-derived fuel production and the recovery of materials is presented. This information is based on data developed for the metropolitan Washington, D.C. area as input for the consideration of a regional resource recovery program which would eventually encompass 4000 t/day of municipal solid waste; it is designed to recover refuse-derived fuel (RDF), ferrous and nonferrous metals, flint and color-mixed glass cullet, color-mixed glass fines, and waste newspapers. The planning process requires estimates of recovery product revenues and of process feasibility; since materials revenues can be predicted with a greater degree of certainty than RDF revenues, it becomes necessary to determine what revenues will be required from the sale of RDF so that predicted economics can be the same as the alternative disposal practice. A technique is described which will assist the decisionmaker in evaluating the economic feasibility of the proposed project by determining the RDF 'Indifference Value'.

  12. Financial and economic determinants of collective action: The case of wastewater management

    SciTech Connect

    Brunner, Norbert; Starkl, Markus

    2012-01-15

    Where public environmental funds support development of wastewater infrastructure, funding institutions ensure the economic use of funds, while the beneficiaries minimize their own costs. In rural areas, there is often a choice between decentralized or centralized (multi-village) systems: if the centralized system is most economic, then only this system is eligible for public funding. However, its implementation requires a voluntary cooperation of the concerned communities, who need to organize themselves to develop and run the infrastructure. The paper analyzes the social determinants of collaboration in a generic case study, using the following variables: method of (economic) assessment, modeled by the social discount rate, funding policy, modeled by the funding rate, and users' self-organization, modeled by cost sharing. In a borderline situation, where the centralized system turns out to be most economic, but this assessment is contingent on the assessment method, collective action may fail: the advantages of collective action from funding are too small to outweigh organizational deficiencies. Considering in this situation sanitation as a human right, authors recommend using innovative forms of organization and, if these fail, reassessing either the amount of funding or the eligibility for funding of more acceptable alternatives. - Highlights: Black-Right-Pointing-Pointer A generic case study models collective action and funding in wastewater management. Black-Right-Pointing-Pointer Determinants of success: economic assessment, funding policy and self-organization. Black-Right-Pointing-Pointer Success indicators: conflict rate, funds needed to make cost shares fair. Black-Right-Pointing-Pointer Method for analyzing centralized vs. decentralized disputes. Black-Right-Pointing-Pointer If collective action has less benefits, innovative cost sharing may ensure success.

  13. Pathways of neighbourhood-level socio-economic determinants of adverse birth outcomes

    PubMed Central

    2013-01-01

    Background Although socio-economic factors have been identified as one of the most important groups of neighbourhood-level risks affecting birth outcomes, uncertainties still exist concerning the pathways through which they are transferred to individual risk factors. This poses a challenge for setting priorities and developing appropriate community-oriented public health interventions and planning guidelines to reduce the level of adverse birth outcomes. Method This study examines potential direct and mediated pathways through which neighbourhood-level socio-economic determinants exert their impacts on adverse birth outcomes. Two hypothesized models, namely the materialist and psycho-social models, and their corresponding pathways are tested using a binary-outcome multilevel mediation analysis. Live birth data, including adverse birth outcomes and person-level exposure variables, were obtained from three public health units in the province of Ontario, Canada. Corresponding neighbourhood-level socio-economic, psycho-social and living condition variables were extracted or constructed from the 2001 Canadian Census and the first three cycles (2001, 2003, and 2005) of the Canadian Community Health Surveys. Results Neighbourhood-level socio-economic-related risks are found to have direct effects on low birth weight and preterm birth. In addition, 20-30% of the total effects are contributed by indirect effects mediated through person-level risks. There is evidence of four person-level pathways, namely through individual socio-economic status, psycho-social stress, maternal health, and health behaviours, with all being simultaneously at work. Psycho-social pathways and buffering social capital-related variables are found to have more impact on low birth weight than on preterm birth. Conclusion The evidence supports both the materialist and psycho-social conceptualizations and the pathways that describe them, although the magnitude of the former is greater than the latter. PMID:23786633

  14. Identification and determination of the viability of Giardia lamblia cysts and Cryptosporidium parvum and Cryptosporidium hominis oocysts in human fecal and water supply samples by fluorescent in situ hybridization (FISH) and monoclonal antibodies.

    PubMed

    Lemos, Vanessa; Graczyk, Thaddeus K; Alves, Margarida; Lobo, Maria Lusa; Sousa, Maria C; Antunes, Francisco; Matos, Olga

    2005-12-01

    In the present study, fluorescent in situ hybridization (FISH) and monoclonal antibodies (MAbs) were evaluated for species-specific detection and viability determination of Giardia lamblia, Cryptosporidium parvum, and Cryptosporidium hominis in human fecal and water supply samples. A total of 50 fecal human samples positive for G. lamblia cysts, 38 positive for C. parvum, and 23 positive for C. hominis were studied. Also, 18 water supply samples positive for Giardia spp. and Cryptosporidium spp. by the United States Environmental Protection Agency (USEPA) Method 1623 were studied by FISH and fluorescein isothiocyanate (FITC)-conjugated MAbs. Eighteen percent of the fecal samples parasitologically positive for G. lamblia presented viable and nonviable cysts, and 5% of those positive for Cryptosporidium spp. presented viable and nonviable oocysts. Of the 18 water supply samples analyzed, 6 (33%) presented Giardia spp. viable and nonviable cysts and 2 (11%) presented viable and nonviable Cryptosporidium spp. oocysts. G. lamblia identification was confirmed by polymerase chain reaction (PCR) and sequencing of the beta-giardin gene in the fecal and water samples found positive by FISH and FITC-conjugated MAbs. C. parvum and Cryptosporidium muris were identified, by PCR and sequencing of the small subunit of ribosomal RNA gene, in seven and one water samples, respectively. Our results confirm that this technique enables simultaneous visualization, species-specific identification, and viability determination of the organisms present in human fecal and water supply samples. PMID:16261356

  15. Nutritional status of children in India: household socio-economic condition as the contextual determinant

    PubMed Central

    2010-01-01

    Background Despite recent achievement in economic progress in India, the fruit of development has failed to secure a better nutritional status among all children of the country. Growing evidence suggest there exists a socio-economic gradient of childhood malnutrition in India. The present paper is an attempt to measure the extent of socio-economic inequality in chronic childhood malnutrition across major states of India and to realize the role of household socio-economic status (SES) as the contextual determinant of nutritional status of children. Methods Using National Family Health Survey-3 data, an attempt is made to estimate socio-economic inequality in childhood stunting at the state level through Concentration Index (CI). Multi-level models; random-coefficient and random-slope are employed to study the impact of SES on long-term nutritional status among children, keeping in view the hierarchical nature of data. Main findings Across the states, a disproportionate burden of stunting is observed among the children from poor SES, more so in urban areas. The state having lower prevalence of chronic childhood malnutrition shows much higher burden among the poor. Though a negative correlation (r = -0.603, p < .001) is established between Net State Domestic Product (NSDP) and CI values for stunting; the development indicator is not always linearly correlated with intra-state inequality in malnutrition prevalence. Results from multi-level models however show children from highest SES quintile posses 50 percent better nutritional status than those from the poorest quintile. Conclusion In spite of the declining trend of chronic childhood malnutrition in India, the concerns remain for its disproportionate burden on the poor. The socio-economic gradient of long-term nutritional status among children needs special focus, more so in the states where chronic malnutrition among children apparently demonstrates a lower prevalence. The paper calls for state specific policies which are designed and implemented on a priority basis, keeping in view the nature of inequality in childhood malnutrition in the country and its differential characteristics across the states. PMID:20701758

  16. Assessment of myocardial viability.

    PubMed

    Travin, Mark I; Bergmann, Steven R

    2005-01-01

    The prevalence of left ventricular (LV) dysfunction and resultant congestive heart failure is increasing. Patients with this condition are at high risk for cardiac death and usually have significant limitations in their lifestyles. Although there have been advances in medical therapy resulting in improved survival and well being, the best and most definitive therapy, when appropriate, is revascularization. In the setting of coronary artery disease, accounting for approximately two thirds of cases of congestive heart failure, LV dysfunction often is not the result of irreversible scar but rather caused by impairment in function and energy use of still viable-myocytes, with the opportunity for improved function if coronary blood flow is restored. Patients with LV dysfunction who have viable myocardium are the patients at highest risk because of the potential for ischemia but at the same time benefit most from revascularization. It is important to identify viable myocardium in these patients, and radionuclide myocardial scintigraphy is an excellent tool for this. Single-photon emission computed tomography perfusion scintigraphy, whether using thallium-201, Tc-99m sestamibi, or Tc-99m tetrofosmin, in stress and/or rest protocols, has consistently been shown to be an effective modality for identifying myocardial viability and guiding appropriate management. Metabolic imaging with positron emission tomography radiotracers frequently adds additional information and is a powerful tool for predicting which patients will have an improved outcome from revascularization, including some patients referred instead for cardiac transplantation. Other noninvasive modalities, such as stress echocardiography, also facilitate the assessment of myocardial viability, but there are advantages and disadvantages compared with the nuclear techniques. Nuclear imaging appears to require fewer viable cells for detection, resulting in a higher sensitivity but a lower specificity than stress echocardiography for predicting post-revascularization improvement of ventricular function. Nevertheless, it appears that LV functional improvement may not always be necessary for clinical improvement. Future directions include use of magnetic resonance imaging, as well as larger, multicenter trials of radionuclide techniques. The increasing population of patients with LV dysfunction, and the increased benefit afforded by newer therapies, will make assessment of myocardial viability even more essential for proper patient management. PMID:15645391

  17. Examining Gifted Students Who Are Economically At-Risk to Determine Factors that Influence Their Early Reading Success

    ERIC Educational Resources Information Center

    Bailey, Lora Battle

    2006-01-01

    The aim of this study was to determine whether the "Frequency with which parents read to their children, Preschool Exposure" and the initial "Age" that students "who are economically at-risk" were first exposed to significant literacy activities at home or in a preschool setting affected their reading grades. Students "who are economically

  18. Analysis of economic determinants of fertility in Iran: a multilevel approach

    PubMed Central

    Moeeni, Maryam; Pourreza, Abolghasem; Torabi, Fatemeh; Heydari, Hassan; Mahmoudi, Mahmood

    2014-01-01

    Background: During the last three decades, the Total Fertility Rate (TFR) in Iran has fallen considerably; from 6.5 per woman in 1983 to 1.89 in 2010. This paper analyzes the extent to which economic determinants at the micro and macro levels are associated with the number of children in Iranian households. Methods: Household data from the 2010 Household Expenditure and Income Survey (HEIS) is linked to provincial data from the 2010 Iran Multiple-Indicator Demographic and Health Survey (IrMIDHS), the National Census of Population and Housing conducted in 1986, 1996, 2006 and 2011, and the 1985–2010 Iran statistical year books. Fertility is measured as the number of children in each household. A random intercept multilevel Poisson regression function is specified based on a collective model of intra-household bargaining power to investigate potential determinants of the number of children in Iranian households. Results: Ceteris paribus (other things being equal), probability of having more children drops significantly as either real per capita educational expenditure or real total expenditure of each household increase. Both the low- and the high-income households show probabilities of having more children compared to the middle-income households. Living in provinces with either higher average amount of value added of manufacturing establishments or lower average rate of house rent is associated to higher probability of having larger number of children. Higher levels of gender gap indices, resulting in household’s wife’s limited power over household decision-making, positively affect the probability of having more children. Conclusion: Economic determinants at the micro and macro levels, distribution of intra-household bargaining power between spouses and demographic covariates determined fertility behavior of Iranian households. PMID:25197678

  19. EFFECT OF HALOGENS ON 'GIARDIA' CYST VIABILITY

    EPA Science Inventory

    The objective of this research was to determine the effect of chlorine and other disinfecting agents on Giardia lamblia cyst viability. The agents studied included free residual chlorine and six different methods recommended for emergency disinfection of small quantities of water...

  20. Integration of multiple determinants in the neuronal computation of economic values.

    PubMed

    Raghuraman, Anantha P; Padoa-Schioppa, Camillo

    2014-08-27

    Economic goods may vary on multiple dimensions (determinants). A central conjecture in decision neuroscience is that choices between goods are made by comparing subjective values computed through the integration of all relevant determinants. Previous work identified three groups of neurons in the orbitofrontal cortex (OFC) of monkeys engaged in economic choices: (1) offer value cells, which encode the value of individual offers; (2) chosen value cells, which encode the value of the chosen good; and (3) chosen juice cells, which encode the identity of the chosen good. In principle, these populations could be sufficient to generate a decision. Critically, previous work did not assess whether offer value cells (the putative input to the decision) indeed encode subjective values as opposed to physical properties of the goods, and/or whether offer value cells integrate multiple determinants. To address these issues, we recorded from the OFC while monkeys chose between risky outcomes. Confirming previous observations, three populations of neurons encoded the value of individual offers, the value of the chosen option, and the value-independent choice outcome. The activity of both offer value cells and chosen value cells encoded values defined by the integration of juice quantity and probability. Furthermore, both populations reflected the subjective risk attitude of the animals. We also found additional groups of neurons encoding the risk associated with a particular option, the risky nature of the chosen option, and whether the trial outcome was positive or negative. These results provide substantial support for the conjecture described above and for the involvement of OFC in good-based decisions. PMID:25164656

  1. Social, cultural, and economic determinants of age at birth of first child in Peninsular Malaysia.

    PubMed

    Hirschman, C; Rindfuss, R

    1980-11-01

    Summary In order to unravel the complex set of the determinants of fertility, we suggest that the child-bearing process be separated into a sequence of events and intervals. As the first step in the child-bearing process, age at first birth is a critical variable. Using data from the 1966-67 West Malaysia Family Survey, we formulate and test a model of the cultural, social and economic determinants of the timing of first birth among a sample of mothers, aged 30-44. Social origins, measured by the woman's father's occupation and the woman's birthplace are not important determinants, but education, early work experience, and ethnicity exercise very strong effects on the age at first birth. Age at first marriage mediates much of the effect of background variables, which suggest that there is little use of contraception to plan the first birth interval. The strong effect of ethnicity is consistent with a cultural interpretation, but important qualifications are noted. PMID:22077172

  2. Domestic uranium mining and milling industry, 1990: Viability assessment

    SciTech Connect

    Not Available

    1991-12-19

    This report was prepared by the Energy Information Administration to provide the Secretary of Energy with basic data and analyses for his eighth annual determination of the viability of the domestic uranium mining and milling industry. Topics include: evolution of the US uranium industry, nuclear power requirements and uranium industry projections, and attributes of industry viability.

  3. Viability, Advantages and Design Methodologies of M-Learning Delivery

    ERIC Educational Resources Information Center

    Zabel, Todd W.

    2010-01-01

    The purpose of this study was to examine the viability and principle design methodologies of Mobile Learning models in developing regions. Demographic and market studies were utilized to determine the viability of M-Learning delivery as well as best uses for such technologies and methods given socioeconomic and political conditions within the…

  4. Monitoring cell growth, viability, and apoptosis.

    PubMed

    Butler, Michael; Spearman, Maureen; Braasch, Katrin

    2014-01-01

    The accurate determination of cell growth and viability is pivotal to monitoring a bioprocess. Direct methods to determine the cell growth and/or viability in a bioprocess include microscopic counting, electronic particle counting, image analysis, in situ biomass monitoring, and dieletrophoretic cytometry. These methods work most simply when a fixed volume sample can be taken from a suspension culture. Manual microscopic counting is laborious but affords the advantage of allowing cell viability to be determined if a suitable dye is included. Electronic particle counting is a rapid total cell count method for replicate samples, but some data distortion may occur if the sample has significant cell debris or cell aggregates. Image analysis based on the use of digital camera images acquired through a microscope has advanced rapidly with the availability of several commercially available software packages replacing manual microscopic counting and viability determination. Biomass probes detect cells by their dielectric properties or their internal concentration of NADH and can be used as a continuous monitor of the progress of a culture. While the monitoring of cell growth and viability is an integral part of a bioprocess, the monitoring of apoptosis induction is also becoming more and more important in bioprocess control to increase volumetric productivity by extending bioprocess duration. Different fluorescent assays allow for the detection of apoptotic characteristics in a cell sample.Indirect methods of cell determination involve the chemical analysis of a culture component or a measure of metabolic activity. These methods are most useful when it is difficult to obtain intact cell samples. However, the relationship between these parameters and the cell number may not be linear through the phases of a cell culture. The determination of nucleic acid (DNA) or total protein can be used as an estimate of biomass, while the depletion of glucose from the media can be used as an estimate of cellular activity. The state of cellular viability may be measured by the release of an enzyme such as lactate dehydrogenase or more directly from the intracellular adenylate energy charge from cell lysates. Alternatively, radioactive techniques may be used for an accurate determination of cellular protein synthesis. PMID:24297416

  5. Socio-Economic and Nutritional Determinants of Low Birth Weight in India

    PubMed Central

    Kader, Manzur; Perera, Nirmala K P Perera

    2014-01-01

    Background: Low birth weight (LBW) is an important risk factor for childhood morbidity and mortality, consequently an important public health concern. Aim: This study aims to identify significant socio-economic and nutritional determinants associated with LBW in India. Materials and Methods: Data from 2005 to 2006 National Family Health Survey-3 (NFHS-3) of India was analyzed. A total of 20,946 women (15-49 years) who gave birth at least once 5 years preceding the NFHS-3 were included in this study. Infant's LBW (<2500 grams) as outcome variable was examined in association with all independent predictors as infant's sex, maternal household wealth status, caste, age, education, body mass index (BMI), stature, anemia level, parity, inter-pregnancy interval, antenatal care received, and living place. Results: Almost 20% of the infants were born with LBW. Mother's low education level, BMI <18.5, short stature (height <145 centimeters) and lack of antenatal visits (<4 visits) were significant predictors of LBW. Male gender has a protective effect against LBW. Conclusion: Maternal education, nutritional status and antenatal care received are key determinants that need to be addressed to reduce prevalence of LBW in India. Continue implementation of multifaceted health promotion interventions are needed to address these factors effectively. PMID:25077077

  6. Economic and physical determinants of the global distributions of crop pests and pathogens

    PubMed Central

    Bebber, Daniel P; Holmes, Timothy; Smith, David; Gurr, Sarah J

    2014-01-01

    Crop pests and pathogens pose a significant and growing threat to food security, but their geographical distributions are poorly understood. We present a global analysis of pest and pathogen distributions, to determine the roles of socioeconomic and biophysical factors in determining pest diversity, controlling for variation in observational capacity among countries. Known distributions of 1901 pests and pathogens were obtained from CABI. Linear models were used to partition the variation in pest species per country amongst predictors. Reported pest numbers increased with per capita gross domestic product (GDP), research expenditure and research capacity, and the influence of economics was greater in micro-organisms than in arthropods. Total crop production and crop diversity were the strongest physical predictors of pest numbers per country, but trade and tourism were insignificant once other factors were controlled. Islands reported more pests than mainland countries, but no latitudinal gradient in species richness was evident. Country wealth is likely to be a strong indicator of observational capacity, not just trade flow, as has been interpreted in invasive species studies. If every country had US levels of per capita GDP, then 205 ± 9 additional pests per country would be reported, suggesting that enhanced investment in pest observations will reveal the hidden threat of crop pests and pathogens. PMID:24517626

  7. Determinants of Healthcare Expenditure in Economic Cooperation Organization (ECO) Countries: Evidence from Panel Cointegration Tests

    PubMed Central

    Samadi, Alihussein; Homaie Rad, Enayatollah

    2013-01-01

    Background: Over the last decade there has been an increase in healthcare expenditures while at the same time the inequity in distribution of resources has grown. These two issues have urged the researchers to review the determinants of healthcare expenditures. In this study, we surveyed the determinants of health expenditures in Economic Cooperation Organization (ECO) countries. Methods: We used Panel data econometrics methods for the purpose of this research. For long term analysis, we used Pesaran cross sectional dependency test followed by panel unit root tests to show first whether the variables were stationary or not. Upon confirmation of no stationary variables, we used Westerlund panel cointegration test in order to show whether long term relationships exist between the variables. At the end, we estimated the model with Continuous-Updated Fully Modified (CUP-FM) estimator. For short term analysis also, we used Fixed Effects (FE) estimator to estimate the model. Results: A long term relationship was found between the health expenditures per capita and GDP per capita, the proportion of population below 15 and above 65 years old, number of physicians, and urbanisation. Besides, all the variables had short term relationships with health expenditures, except for the proportion of population above 65 years old. Conclusion: The coefficient of GDP was below 1 in the model. Therefore, health is counted as a necessary good in ECO countries and governments must pay due attention to the equal distribution of health services in all regions of the country. PMID:24596838

  8. Economic and physical determinants of the global distributions of crop pests and pathogens.

    PubMed

    Bebber, Daniel P; Holmes, Timothy; Smith, David; Gurr, Sarah J

    2014-05-01

    Crop pests and pathogens pose a significant and growing threat to food security, but their geographical distributions are poorly understood. We present a global analysis of pest and pathogen distributions, to determine the roles of socioeconomic and biophysical factors in determining pest diversity, controlling for variation in observational capacity among countries. Known distributions of 1901 pests and pathogens were obtained from CABI. Linear models were used to partition the variation in pest species per country amongst predictors. Reported pest numbers increased with per capita gross domestic product (GDP), research expenditure and research capacity, and the influence of economics was greater in micro-organisms than in arthropods. Total crop production and crop diversity were the strongest physical predictors of pest numbers per country, but trade and tourism were insignificant once other factors were controlled. Islands reported more pests than mainland countries, but no latitudinal gradient in species richness was evident. Country wealth is likely to be a strong indicator of observational capacity, not just trade flow, as has been interpreted in invasive species studies. If every country had US levels of per capita GDP, then 205 9 additional pests per country would be reported, suggesting that enhanced investment in pest observations will reveal the hidden threat of crop pests and pathogens. PMID:24517626

  9. Functional Cardiac Magnetic Resonance Imaging (MRI) in the Assessment of Myocardial Viability and Perfusion

    PubMed Central

    2003-01-01

    Executive Summary Objective The objective of this health technology policy assessment was to determine the effectiveness safety and cost-effectiveness of using functional cardiac magnetic resonance imaging (MRI) for the assessment of myocardial viability and perfusion in patients with coronary artery disease and left ventricular dysfunction. Results Functional MRI has become increasingly investigated as a noninvasive method for assessing myocardial viability and perfusion. Most patients in the published literature have mild to moderate impaired LV function. It is possible that the severity of LV dysfunction may be an important factor that can alter the diagnostic accuracy of imaging techniques. There is some evidence of comparable or better performance of functional cardiac MRI for the assessment of myocardial viability and perfusion compared with other imaging techniques. However limitations to most of the studies included: Functional cardiac MRI studies that assess myocardial viability and perfusion have had small sample sizes. Some studies assessed myocardial viability/perfusion in patients who had already undergone revascularization, or excluded patients with a prior MI (Schwitter et al., 2001). Lack of explicit detail of patient recruitment. Patients with LVEF >35%. Interstudy variability in post MI imaging time(including acute or chronic MI), when patients with a prior MI were included. Poor interobserver agreement (kappa statistic) in the interpretation of the results. Traditionally, 0.80 is considered good. Cardiac MRI measurement of myocardial perfusion to as an adjunct tool to help diagnose CAD (prior to a definitive coronary angiography) has also been examined in some studies, with methodological limitations, yielding comparable results. Many studies examining myocardial viability and perfusion report on the accuracy of imaging methods with limited data on long-term patient outcome and management. Kim et al. (2000) revealed that the transmural extent of hyperenhancement was significantly related to the likelihood of improvement in contractility after revascularization. However, the LVEF in the patient population was 43% prior to revascularization. It is important to know whether the technique has the same degree of accuracy in patients who have more severe LV dysfunction and who would most benefit from an assessment of myocardial viability. Substantial viability used as a measure of a patients ability to recover after revascularization has not been definitively reported (how much viability is enough?). Patients with severe LV dysfunction are more likely to have mixtures of surviving myocardium, including normal, infarcted, stunned and hibernating myocardium (Cowley et al., 1999). This may lead to a lack of homogeneity of response to testing and to revascularization and contribute to inter- and intra-study differences. There is a need for a large prospective study with adequate follow-up time for patients with CAD and LV dysfunction (LVEF<35%) comparing MRI and an alternate imaging technique. There is some evidence that MRI has comparable sensitivity, specificity and accuracy to PET for determining myocardial viability. However, there is a lack of evidence comparing the accuracy of these two techniques to predict LV function recovery. In addition, some studies refer to PET as the gold standard for the assessment of myocardial viability. Therefore, PET may be an ideal noninvasive imaging comparator to MRI for a prospective study with follow-up. To date, there is a lack of cost-effectiveness analyses (or any economic analyses) of functional cardiac MRI versus an alternate noninvasive imaging method for the assessment of myocardial viability/perfusion. Conclusion There is some evidence that the accuracy of functional cardiac MRI compares favourably with alternate imaging techniques for the assessment of myocardial viability and perfusion. There is insufficient evidence whether functional cardiac MRI can better select which patients [who have CAD and severe LV dysfuncti

  10. Relative importance of climatic, geographic and socio-economic determinants of malaria in Malawi

    PubMed Central

    2013-01-01

    Background Malaria transmission is influenced by variations in meteorological conditions, which impact the biology of the parasite and its vector, but also socio-economic conditions, such as levels of urbanization, poverty and education, which impact human vulnerability and vector habitat. The many potential drivers of malaria, both extrinsic, such as climate, and intrinsic, such as population immunity are often difficult to disentangle. This presents a challenge for the modelling of malaria risk in space and time. Methods A statistical mixed model framework is proposed to model malaria risk at the district level in Malawi, using an age-stratified spatio-temporal dataset of malaria cases from July 2004 to June 2011. Several climatic, geographic and socio-economic factors thought to influence malaria incidence were tested in an exploratory model. In order to account for the unobserved confounding factors that influence malaria, which are not accounted for using measured covariates, a generalized linear mixed model was adopted, which included structured and unstructured spatial and temporal random effects. A hierarchical Bayesian framework using Markov chain Monte Carlo simulation was used for model fitting and prediction. Results Using a stepwise model selection procedure, several explanatory variables were identified to have significant associations with malaria including climatic, cartographic and socio-economic data. Once intervention variations, unobserved confounding factors and spatial correlation were considered in a Bayesian framework, a final model emerged with statistically significant predictor variables limited to average precipitation (quadratic relation) and average temperature during the three months previous to the month of interest. Conclusions When modelling malaria risk in Malawi it is important to account for spatial and temporal heterogeneity and correlation between districts. Once observed and unobserved confounding factors are allowed for, precipitation and temperature in the months prior to the malaria season of interest are found to significantly determine spatial and temporal variations of malaria incidence. Climate information was found to improve the estimation of malaria relative risk in 41% of the districts in Malawi, particularly at higher altitudes where transmission is irregular. This highlights the potential value of climate-driven seasonal malaria forecasts. PMID:24228784

  11. Spatial variation and socio-economic determinants of Plasmodium falciparum infection in northeastern Tanzania

    PubMed Central

    2011-01-01

    Background Malaria due to Plasmodium falciparum is the leading cause of morbidity and mortality in Tanzania. According to health statistics, malaria accounts for about 30% and 15% of hospital admissions and deaths, respectively. The risk of P. falciparum infection varies across the country. This study describes the spatial variation and socio-economic determinants of P. falciparum infection in northeastern Tanzania. Methods The study was conducted in 14 villages located in highland, lowland and urban areas of Korogwe district. Four cross-sectional malaria surveys involving individuals aged 0-19 years were conducted during short (Nov-Dec) and long (May-Jun) rainy seasons from November 2005 to June 2007. Household socio-economic status (SES) data were collected between Jan-April 2006 and household's geographical positions were collected using hand-held geographical positioning system (GPS) unit. The effects of risk factors were determined using generalized estimating equation and spatial risk of P. falciparum infection was modelled using a kernel (non-parametric) method. Results There was a significant spatial variation of P. falciparum infection, and urban areas were at lower risk. Adjusting for covariates, high risk of P. falciparum infection was identified in rural areas of lowland and highland. Bed net coverage levels were independently associated with reduced risk of P. falciparum by 19.1% (95%CI: 8.9-28.2, p < 0.001) and by 39.3% (95%CI: 28.9-48.2, p < 0.001) in households with low and high coverage, respectively, compared to those without bed nets. Households with moderate and lower SES had risk of infection higher than 60% compared to those with higher SES; while inhabitants of houses built of mud walls were at 15.5% (95%CI: 0.1 - 33.3, p < 0.048) higher risk compared to those living in houses built by bricks. Individuals in houses with thatched roof had an excess risk of 17.3% (95%CI: 4.1 - 32.2, p < 0.009) compared to those living in houses roofed with iron sheet. Conclusions There was high spatial variation of risk of P. falciparum infection and urban area was at the lowest risk. High bed net coverage, better SES and good housing were among the important risk factors associated with low risk of P. falciparum infection. PMID:21612637

  12. Cost and Economics for Advanced Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Whitfield, Jeff

    1998-01-01

    Market sensitivity and weight-based cost estimating relationships are key drivers in determining the financial viability of advanced space launch vehicle designs. Due to decreasing space transportation budgets and increasing foreign competition, it has become essential for financial assessments of prospective launch vehicles to be performed during the conceptual design phase. As part of this financial assessment, it is imperative to understand the relationship between market volatility, the uncertainty of weight estimates, and the economic viability of an advanced space launch vehicle program. This paper reports the results of a study that evaluated the economic risk inherent in market variability and the uncertainty of developing weight estimates for an advanced space launch vehicle program. The purpose of this study was to determine the sensitivity of a business case for advanced space flight design with respect to the changing nature of market conditions and the complexity of determining accurate weight estimations during the conceptual design phase. The expected uncertainty associated with these two factors drives the economic risk of the overall program. The study incorporates Monte Carlo simulation techniques to determine the probability of attaining specific levels of economic performance when the market and weight parameters are allowed to vary. This structured approach toward uncertainties allows for the assessment of risks associated with a launch vehicle program's economic performance. This results in the determination of the value of the additional risk placed on the project by these two factors.

  13. Determinants of Economic and Social Outcomes from a Life-Wide Learning Perspective in Canada.

    ERIC Educational Resources Information Center

    Desjardins, Richard

    2003-01-01

    Measures the relative influence of engaging in various learning activities--spanning the "life-wide" spectrum of learning--on economic and social benefits. Finds that relationship between formal education and economic and social outcomes is complex, with confounding effects, indicating that different types of learning activities taken for

  14. Getting More Bang for the Buck: Determining the Economic Rationale of Vocational Education. A VES Monograph.

    ERIC Educational Resources Information Center

    McElhinney, Kerry R.; Pershing, James A.

    Vocational education in the United States has come under increased scrutiny, and its proponents need the tools to convince the critics of its merits. Many economic conditions have a strong impact on vocational education, and understanding of economics is important in offering a rationale of vocational education. In a time of shrinking revenues,…

  15. Factors Determining Student Retention of Economic Knowledge after Completing the Principles-of-Microeconomics Course.

    ERIC Educational Resources Information Center

    Kohen, Andrew I.; Kipps, Paul H.

    1979-01-01

    Reports results of a study of economics students to test the effect of time and other factors affecting retention, to develop an instrument to measure the rate of depreciation of the student's stock of economic knowledge, and to explore the implications of findings for the student's academic planning. (Author/KC)

  16. Determinants of Human Capital Formation and Economic Growth of African Countries

    ERIC Educational Resources Information Center

    Oketch, Moses O.

    2006-01-01

    Rapid economic growth and improving living standards have benefited almost all regions of the world since the industrial revolution. Africa stands out as one regional exception. While several factors such as civil wars and rampant corruption have been associated with poor economic performance of the African region in the international community,

  17. Determinants of Human Capital Formation and Economic Growth of African Countries

    ERIC Educational Resources Information Center

    Oketch, Moses O.

    2006-01-01

    Rapid economic growth and improving living standards have benefited almost all regions of the world since the industrial revolution. Africa stands out as one regional exception. While several factors such as civil wars and rampant corruption have been associated with poor economic performance of the African region in the international community,…

  18. Motivation and Math Skills as Determinants of First-Year Performance in Economics

    ERIC Educational Resources Information Center

    Arnold, Ivo J. M.; Straten, Jerry T.

    2012-01-01

    The importance of math skills for study success in economics has been widely researched. This article adds to the literature by combining information on students' math skills and their motivation. The authors are thus able to present a rich picture of why students succeed in their study of economics and to confirm previous findings that deficient…

  19. The influence of socio-demographic indicators economic determinants and social recognition on sport participation in Germany.

    PubMed

    Hallmann, Kirstin; Breuer, Christoph

    2014-01-01

    This article analyses sport participation using a demographic-economic model which was extended by the construct 'social recognition'. Social recognition was integrated into the model on the understanding that it is the purpose of each individual to maximise his or her utility. A computer-assisted telephone interview survey was conducted in the city of Rheinberg, Germany, producing an overall sample of n=1934. Regression analyses were performed to estimate the impact of socio-demographic, economic determinants, and social recognition on sport participation. The results suggest that various socio-economic factors and social recognition are important determinants of sport participation on the one hand, and on sport frequency on the other. Social recognition plays a significant yet different role for both sport participation and sport frequency. While friends' involvement with sport influences one's sport participation, parents' involvement with sport influences one's sport frequency. PMID:24444226

  20. Pilot test of Pickliq{reg_sign} process to determine energy and environmental benefits & economic feasibility

    SciTech Connect

    Olsen, D.R.

    1997-07-13

    Green Technology Group (GTG) was awarded Grant No. DE-FG01-96EE 15657 in the amount of $99,904 for a project to advance GTG`s Pickliq{reg_sign} Process in the Copper and Steel Industries. The use of the Pickliq{reg_sign} Process can significantly reduce the production of waste acids containing metal salts. The Pickliq{reg_sign} Process can save energy and eliminate hazardous waste in a typical copper rod or wire mill or a typical steel wire mill. The objective of this pilot project was to determine the magnitude of the economic, energy and environmental benefits of the Pickliq{reg_sign} Process in two applications within the metal processing industry. The effectiveness of the process has already been demonstrated at facilities cleaning iron and steel with sulfuric acid. 9207 companies are reported to use sulfuric and hydrochloric acid in the USA. The USEPA TRI statistics of acid not recycled in the US is 2.4 x 10{sup 9} lbs (net) for Hydrochloric Acid and 2.0 x 10{sup 9} lbs (net) for Sulfuric Acid. The energy cost of not reclaiming acid is 10.7 x 10{sup 6} BTU/ton for Hydrochloric Acid and 21.6 x 10{sup 6} BTU/Ton for Sulfuric Acid. This means that there is a very large market for the application of the Pickliq{reg_sign} Process and the widespread use of the process will bring significant world wide savings of energy to the environment.

  1. Low-level waste vitrification contact maintenance viability study

    SciTech Connect

    Leach, C.E., Westinghouse Hanford

    1996-07-12

    This study investigates the economic viability of contact maintenance in the Low-Level Waste Vitrification Facility, which is part of the Hanford Site Tank Waste Remediation System. This document was prepared by Flour Daniel, Inc., and transmitted to Westinghouse Hanford Company in September 1995.

  2. Assessment of Campus Viability. Report of the Viability Study Group.

    ERIC Educational Resources Information Center

    Pennsylvania State Univ., Allentown.

    This document presents a format for evaluating the viability of individual campuses in the Pennsylvania State University System (PSUS) including criteria and a process to apply them. A viable campus is defined as having a clear mission with a demonstrable agreement among administrative and faculty visions, having adequate resources, involving the

  3. Economic, Social, and Cultural Determinants of Life Satisfaction: Are There Differences between Asia and Europe?

    ERIC Educational Resources Information Center

    Jagodzinski, Wolfgang

    2010-01-01

    This paper investigates the influence of the economic, social, and cultural variables on life satisfaction in Asia and Europe. The second section sets a unifying theoretical framework for all three domains by defining life satisfaction as a function of aspirations and expectations which in turn are affected by micro- and macro-level variables. On

  4. Determining the economic liability of implementing irrigation on small-scale farming systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Small, limited resource farmers are often the primary providers of fresh foods for rural communities. However, they face often insurmountable economic challenges to staying in business. The small and limited resource farmer has declined at an alarming rate. The reasons for the decline or disappearan...

  5. One Generation of Self-Determination: Native American Economic Self-Reliance in New Mexico.

    ERIC Educational Resources Information Center

    Jojola, Theodore S.; Agoyo, Herman

    This paper examines changes in federal policy that have encouraged economic development by American Indian tribes, and presents examples from New Mexico. The Indian Reorganization Act of 1934 guaranteed federal provision of education and other services to the tribes, but the newly reorganized tribal governments were regulated almost exclusively by…

  6. An Approach to Determining the Market for Academic Positions: Application to the Discipline of Agricultural Economics

    ERIC Educational Resources Information Center

    Farrell, Terence; Casavant, Ken; Jessup, Eric

    2007-01-01

    The purpose of this paper is to present issues that are relevant to pursuing an academic career in the chosen discipline of each student. The application will be a general case study of agricultural economics. The analytical model will be used to evaluate options for Ph.D. graduates in a supply and demand context. The first issue presented is a

  7. Financial Viability of Farm Families.

    ERIC Educational Resources Information Center

    Salant, Priscilla; Saupe, William

    1986-01-01

    Survey information from 1,616 farm families in Wisconsin, Mississippi, and Tennessee was used to construct a viability ratio measuring a family's ability to meet its obligations from total income. Coupled with other farm characteristics, the ratio allows policymakers to see why some farms are viable and others are not. (JHZ)

  8. Creating a Sustainability Scorecard as a predictive tool for measuring the complex social, economic and environmental impacts of industries, a case study: assessing the viability and sustainability of the dairy industry.

    PubMed

    Buys, L; Mengersen, K; Johnson, S; van Buuren, N; Chauvin, A

    2014-01-15

    Sustainability is a key driver for decisions in the management and future development of industries. The World Commission on Environment and Development (WCED, 1987) outlined imperatives which need to be met for environmental, economic and social sustainability. Development of strategies for measuring and improving sustainability in and across these domains, however, has been hindered by intense debate between advocates for one approach fearing that efforts by those who advocate for another could have unintended adverse impacts. Studies attempting to compare the sustainability performance of countries and industries have also found ratings of performance quite variable depending on the sustainability indices used. Quantifying and comparing the sustainability of industries across the triple bottom line of economy, environment and social impact continues to be problematic. Using the Australian dairy industry as a case study, a Sustainability Scorecard, developed as a Bayesian network model, is proposed as an adaptable tool to enable informed assessment, dialogue and negotiation of strategies at a global level as well as being suitable for developing local solutions. PMID:24374467

  9. Socio-Economic and Cultural Determinants of Human African Trypanosomiasis at the Kenya Uganda Transboundary

    PubMed Central

    Rutto, Jane Jemeli; Osano, Odipo; Thuranira, Elias Gitonga; Kurgat, Richard Kiptum; Odenyo, Victor Agab Omondi

    2013-01-01

    Background Kenya and Uganda have reported different Human African Trypanosomiasis incidences in the past more than three decades, with the latter recording more cases. This cross-sectional study assessed the demographic characteristics, tsetse and trypanosomiasis control practices, socio-economic and cultural risk factors influencing Trypanosoma brucei rhodesiense (T.b.r.) infection in Teso and Busia Districts, Western Kenya and Tororo and Busia Districts, Southeast Uganda. A conceptual framework was postulated to explain interactions of various socio-economic, cultural and tsetse control factors that predispose individuals and populations to HAT. Methods A cross-sectional household survey was conducted between April and October 2008. Four administrative districts reporting T.b.r and lying adjacent to each other at the international boundary of Kenya and Uganda were purposely selected. Household data collection was carried out in two villages that had experienced HAT and one other village that had no reported HAT case from 1977 to 2008 in each district. A structured questionnaire was administered to 384 randomly selected household heads or their representatives in each country. The percent of respondents giving a specific answer was reported. Secondary data was also obtained on socio-economic and political issues in both countries. Results Inadequate knowledge on the disease cycle and intervention measures contributed considerable barriers to HAT, and more so in Uganda than in Kenya. Gender-associated socio-cultural practices greatly predisposed individuals to HAT. Pesticides-based crop husbandry in the 1970's reportedly reduced vector population while vegetation of coffee and banana's and livestock husbandry directly increased occurrence of HAT. Livestock husbandry practices in the villages were strong predictors of HAT incidence. The residents in Kenya (6.7%) applied chemoprophylaxis and chemotherapeutic controls against trypanosomiasis to a larger extent than Uganda (2.1%). Conclusion Knowledge on tsetse and its control methods, culture, farming practice, demographic and socio-economic variables explained occurrence of HAT better than landscape features. PMID:23638206

  10. Environmental, political, and economic determinants of water quality monitoring in Europe

    NASA Astrophysics Data System (ADS)

    Beck, Lucas; Bernauer, Thomas; Kalbhenn, Anna

    2010-11-01

    Effective monitoring is essential for effective pollution control in national and international water systems. To what extent are countries' monitoring choices driven by environmental criteria, as they should be? And to what extent are they also influenced by other factors, such as political and economic conditions? To address these questions, we describe and explain the evolution of one of the most important international environmental monitoring networks in Europe, the one for water quality, in the time period 1965-2004. We develop a geographic information system that contains information on the location of several thousand active monitoring stations in Europe. Using multivariate statistics, we then examine whether and to what extent the spatial and temporal clustering of monitoring intensity is driven by environmental, political, and economic factors. The results show that monitoring intensity is higher in river basins exposed to greater environmental pressure. However, political and economic factors also play a strong role in monitoring decisions: democracy, income, and peer pressure are conducive to monitoring intensity, and monitoring intensity generally increases over time. Moreover, even though monitoring is more intense in international upstream-downstream settings, we observe only a weak bias toward more monitoring downstream of international borders. In contrast, negative effects of European Union (EU) membership and runup to the EU's Water Framework Directive are potential reasons for concern. Our results strongly suggest that international coordination and standardization of water quality monitoring should be intensified. It will be interesting to apply our analytical approach also to other national and international monitoring networks, for instance, the U.S. National Water-Quality Assessment Program or the European Monitoring and Evaluation Program for air pollution.

  11. Birth, meaningful viability and abortion.

    PubMed

    Jensen, David

    2015-06-01

    What role does birth play in the debate about elective abortion? Does the wrongness of infanticide imply the wrongness of late-term abortion? In this paper, I argue that the same or similar factors that make birth morally significant with regard to abortion make meaningful viability morally significant due to the relatively arbitrary time of birth. I do this by considering the positions of Mary Anne Warren and Jos Luis Bermdez who argue that birth is significant enough that the wrongness of infanticide does not imply the wrongness of late-term abortion. On the basis of the relatively arbitrary timing of birth, I argue that meaningful viability is the point at which elective abortion is prima facie morally wrong. PMID:25012846

  12. The global economic and regulatory determinants of household food waste generation: A cross-country analysis.

    PubMed

    Chalak, Ali; Abou-Daher, Chaza; Chaaban, Jad; Abiad, Mohamad G

    2016-02-01

    Food is generally wasted all along the supply chain, with an estimated loss of 35percent generated at the consumer level. Consequently, household food waste constitutes a sizable proportion of the total waste generated throughout the food supply chain. Yet such wastes vary drastically between developed and developing countries. Using data collected from 44 countries with various income levels, this paper investigates the impact of legislation and economic incentives on household food waste generation. The obtained results indicate that well-defined regulations, policies and strategies are more effective than fiscal measures in mitigating household food waste generation. PMID:26680687

  13. Deaths from alcohol and violence in Moscow: socio-economic determinants.

    PubMed

    Chenet, L; Leon, D; Mckee, M; Vassin, S

    1998-03-01

    The authors "examine the association between accidental, violent and alcohol related adult mortality in the Russian capital and socio-economic status characteristics such as educational status, occupational group and marital status.... The probability of death from alcohol related diseases increased as education level decreased, with those men failing to complete secondary education over two and a half times as likely to die from these causes than men with higher education. Blue collar workers were also much more likely to die from these causes than white collar workers. Marriage had a marked protective effect for both men and women." (EXCERPT) PMID:12293879

  14. Technique to determine contamination exposure routes and the economic efficiency of folded paper-towel dispensing.

    PubMed

    Harrison, Wendy A; Griffith, Christopher J; Michaels, Barry; Ayers, Troy

    2003-04-01

    Handwashing and hand drying are key elements of infection control. Paper towels are generally accepted as the most hygienic means of drying hands and are often distributed from generic dispensers. Effective dispensing of towels is of importance economically and may influence infection control objectives if hands become contaminated during hand drying. In this study, a method to identify potential exposure routes for hand contamination and evaluate the efficiency of paper-towel dispensing is described and applied to 5 different folded paper towels using a generic wall-mounted dispenser. A total of 18 male and female participants of varying heights participated in pull testing of 400 paper towels each, in controlled hand-drying simulations. All events having the potential for hand contamination, including towel jamming, towels falling onto the floor, and incidental contact of paper exits, were monitored and documented. There was considerable variation in dispensing efficiency between different towel brands. One towel (Z) had significantly (P <.05) superior dispensing properties from the generic dispenser. Participants of a shorter height obtained a lower incidence of dispensing malfunctions using all towel products and type. The results indicated likely contamination exposure routes and wastage levels for each towel type. Environmental service managers and infection control practitioners should carefully consider, for economic and infection control reasons, the siting and design of towel dispensers and the types of towel purchased. PMID:12665744

  15. Economic and technical feasibility of utilizing fish waste as organic nutrients for farm/horticultural use. Final report

    SciTech Connect

    Gargasz, R.E.; Pye, E.K.

    1985-01-01

    Results of a study to determine the technical and economic viability of utilizing fish wastes and other organic residues as organic peat nutrients for agriculture/horticulture applications are presented. The project tasks included: (1) Reputable analysis of the waste products to determine the primary plant nutrients, nitrogen, phosphorus, and potash as well as trace elements; (2) Technical feasibility of reducing these organic wastes into nutrients, valuable and assimilable by agricultural or horticultural crops or as a high protein animal feed; and (3) The economic viability of commercializing, manufacturing, and marketing these waste products as a specialty plant growth substance/high protein feed supplement.

  16. Determining economic benefits of satellite data in short-range forecasting

    NASA Technical Reports Server (NTRS)

    Suchman, D.; Auvine, B.; Hinton, B.

    1981-01-01

    The chances of enhanced short term weather predictions and economic benefits from the use of GOES satellite data were examined. Results for a meteorological consulting firm before and after the introduction of GOES data were chosen as the method, and monetary benefits were selected as the measure. Services were provided for use by road and street departments, commodities dealers, and marine clients of the consulting firm. The Man-computer Interactive Data Access Program (McIDAS) was employed to furnish 1/2 hour visual or IR imagery for remote access. The commodities clients reconnected the GOES real-time imagery once the study was completed, while the consulting firm, which was personnel and not equipment intensive, did not. Further development of the flexibility of access to the GOES data and improvements in the projected grids are indicated.

  17. Storage Viability and Optimization Web Service

    SciTech Connect

    Stadler, Michael; Marnay, Christ; Lai, Judy; Siddiqui, Afzal; Limpaitoon, Tanachai; Phan, Trucy; Megel, Olivier; Chang, Jessica; DeForest, Nicholas

    2010-10-11

    Non-residential sectors offer many promising applications for electrical storage (batteries) and photovoltaics (PVs). However, choosing and operating storage under complex tariff structures poses a daunting technical and economic problem that may discourage potential customers and result in lost carbon and economic savings. Equipment vendors are unlikely to provide adequate environmental analysis or unbiased economic results to potential clients, and are even less likely to completely describe the robustness of choices in the face of changing fuel prices and tariffs. Given these considerations, researchers at Lawrence Berkeley National Laboratory (LBNL) have designed the Storage Viability and Optimization Web Service (SVOW): a tool that helps building owners, operators and managers to decide if storage technologies and PVs merit deeper analysis. SVOW is an open access, web-based energy storage and PV analysis calculator, accessible by secure remote login. Upon first login, the user sees an overview of the parameters: load profile, tariff, technologies, and solar radiation location. Each parameter has a pull-down list of possible predefined inputs and users may upload their own as necessary. Since the non-residential sectors encompass a broad range of facilities with fundamentally different characteristics, the tool starts by asking the users to select a load profile from a limited cohort group of example facilities. The example facilities are categorized according to their North American Industry Classification System (NAICS) code. After the load profile selection, users select a predefined tariff or use the widget to create their own. The technologies and solar radiation menus operate in a similar fashion. After these four parameters have been inputted, the users have to select an optimization setting as well as an optimization objective. The analytic engine of SVOW is LBNL?s Distributed Energy Resources Customer Adoption Model (DER-CAM), which is a mixed-integer linear program (MILP) written and executed in the General Algebraic Modeling System (GAMS) optimization software. LBNL has released version 1.2.0.11 of SVOW. Information can be found at http://der.lbl.gov/microgrids-lbnl/current-project-storage-viability-website.

  18. 28 CFR 104.45 - Determination of presumed economic loss for claimants who suffered physical harm.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... JUSTICE (CONTINUED) SEPTEMBER 11TH VICTIM COMPENSATION FUND OF 2001 Amount of Compensation for Eligible... determination of disability made by the Social Security Administration as evidence of disability without...

  19. 28 CFR 104.45 - Determination of presumed economic loss for claimants who suffered physical harm.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... JUSTICE (CONTINUED) SEPTEMBER 11TH VICTIM COMPENSATION FUND OF 2001 Amount of Compensation for Eligible... determination of disability made by the Social Security Administration as evidence of disability without...

  20. 49 CFR Appendix E to Part 26 - Individual Determinations of Social and Economic Disadvantage

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... disadvantage determinations (see 13 CFR 124.103(c) and 124.104). Social Disadvantage I. Socially disadvantaged... disadvantage in American society, not in other countries; and (C) Negative impact on entry into or...

  1. 49 CFR Appendix E to Part 26 - Individual Determinations of Social and Economic Disadvantage

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... disadvantage determinations (see 13 CFR 124.103(c) and 124.104). Social Disadvantage I. Socially disadvantaged... contributed to social disadvantage, such as race, ethnic origin, gender, disability, long-term residence in...

  2. 49 CFR Appendix E to Part 26 - Individual Determinations of Social and Economic Disadvantage

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... disadvantage determinations (see 13 CFR 124.103(c) and 124.104). Social Disadvantage I. Socially disadvantaged... contributed to social disadvantage, such as race, ethnic origin, gender, disability, long-term residence in...

  3. 49 CFR Appendix E to Part 26 - Individual Determinations of Social and Economic Disadvantage

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... disadvantage determinations (see 13 CFR 124.103(c) and 124.104). Social Disadvantage I. Socially disadvantaged... contributed to social disadvantage, such as race, ethnic origin, gender, disability, long-term residence in...

  4. Rapid onsite assessment of spore viability.

    SciTech Connect

    Branda, Steven; Lane, Todd W.; VanderNoot, Victoria A.; Gaucher, Sara P.; Jokerst, Amanda S.

    2005-12-01

    This one year LDRD addresses problems of threat assessment and restoration of facilities following a bioterror incident like the incident that closed down mail facilities in late 2001. Facilities that are contaminated with pathogenic spores such as B. anthracis spores must be shut down while they are treated with a sporicidal agent and the effectiveness of the treatment is ascertained. This process involves measuring the viability of spore test strips, laid out in a grid throughout the facility; the CDC accepted methodologies require transporting the samples to a laboratory and carrying out a 48 hr outgrowth experiment. We proposed developing a technique that will ultimately lead to a fieldable microfluidic device that can rapidly assess (ideally less than 30 min) spore viability and effectiveness of sporicidal treatment, returning facilities to use in hours not days. The proposed method will determine viability of spores by detecting early protein synthesis after chemical germination. During this year, we established the feasibility of this approach and gathered preliminary results that should fuel a future more comprehensive effort. Such a proposal is currently under review with the NIH. Proteomic signatures of Bacillus spores and vegetative cells were assessed by both slab gel electrophoresis as well as microchip based gel electrophoresis employing sensitive laser-induced fluorescence detection. The conditions for germination using a number of chemical germinants were evaluated and optimized and the time course of protein synthesis was ascertained. Microseparations were carried out using both viable spores and spores inactivated by two different methods. A select number of the early synthesis proteins were digested into peptides for analysis by mass spectrometry.

  5. A viability analysis of fishery controlled by investment rate.

    PubMed

    Sanogo, C; Rassi, N; Ben Miled, S; Jerry, C

    2013-09-01

    This work presents a stock/effort model describing both harvested fish population and fishing effort dynamics. The fishing effort dynamic is controlled by investment which corresponds to the revenue proportion generated by the activity. The dynamics are subject to a set of economic and biological state constraints. The analytical study focuses on the compatibility between state constraints and controlled dynamics. By using the mathematical concept of viability kernel, we reveal situations and management options that guarantee a sustainable system. PMID:24002567

  6. Socio-economic and demographic determinants of under-five mortality in rural northern Ghana

    PubMed Central

    2014-01-01

    Background In spite of global decline in under-five mortality, the goal of achieving MDG 4 still remains largely unattained in low and middle income countries as the year 2015 closes-in. To accelerate the pace of mortality decline, proven interventions with high impact need to be implemented to help achieve the goal of drastically reducing childhood mortality. This paper explores the association between socio-economic and demographic factors and under-five mortality in an impoverished region in rural northern Ghana. Methods We used survey data on 3975 women aged 1549 who have ever given birth. First, chi-square test was used to test the association of social, economic and demographic characteristics of mothers with the experience of under-five death. Subsequently, we ran a logistic regression model to estimate the relative association of factors that influence childhood mortality after excluding variables that were not significant at the bivariate level. Results Factors that significantly predict under-five mortality included mothers educational level, presence of co-wives, age and marital status. Mothers who have achieved primary or junior high school education were 45% less likely to experience under-five death than mothers with no formal education at all (OR = 0.55, p < 0.001). Monogamous women were 22% less likely to experience under-five deaths than mothers in polygamous marriages (OR = 0.78, p = 0.01). Similarly, mothers who were between the ages of 35 and 49 were about eleven times more likely to experience under-five deaths than those below the age of 20 years (OR = 11.44, p < 0.001). Also, women who were married had a 27% less likelihood (OR = 0.73, p = 0.01) of experiencing an under-five death than those who were single, divorced or widowed. Conclusion Taken independently, maternal education, age, marital status and presence of co-wives are associated with childhood mortality. The relationship of these indicators with womens autonomy, health seeking behavior, and other factors that affect child survival merit further investigation so that interventions could be designed to foster reductions in child mortality by considering the needs and welfare of women including the need for female education, autonomy and socioeconomic well-being. PMID:25145383

  7. Verification of energy's role as a determinant of US economic activity

    SciTech Connect

    Santini, D.J.

    1987-10-01

    A series of single-equation dynamic regression models are constructed to test the hypotheses that both ''thermodynamic'' and economic-efficiency (t-efficiency and e-efficiency, respectively) configurations of lagged energy variables are statistically informative separately and jointly about subsequent changes in real gross national product (GNP) per capita and in unemployment rate. Separately, t-efficiency is based on quantity of energy used per unit of GNP, while e-efficiency is based on real price of tested energy variables. Used jointly, the two measure real energy cost per unit of real GNP. Tested subperiods are within the 1890-1985 period. Macroeconomic activity is found to be much less informative about energy variables that are energy variables about macroeconomic activity. One-way tests are conducted in which the informativeness of major e-efficiency (wholesale price) variables and budget-share variables about subsequent macroeconomic activity are compared to the informativeness of the e-efficiency energy variable and the combined e- and t-efficiencies energy variable respectively. The energy variables are found to represent the only major category of expenditure whose statistical tests for informativeness about subsequent macroeconomic activity result in coefficient signs that consistently imply a statistically significant negative effect on subsequent macroeconomic activity in the full 1890-1985 period. 64 refs., 14 tabs.

  8. The market viability of nuclear hydrogen technologies.

    SciTech Connect

    Botterud, A.; Conzelmann, G.; Petri, M. C.; Yildiz, B.

    2007-04-06

    The Department of Energy Office of Nuclear Energy is supporting system studies to gain a better understanding of nuclear power's potential role in a hydrogen economy and what hydrogen production technologies show the most promise. This assessment includes identifying commercial hydrogen applications and their requirements, comparing the characteristics of nuclear hydrogen systems to those market requirements, evaluating nuclear hydrogen configuration options within a given market, and identifying the key drivers and thresholds for market viability of nuclear hydrogen options. One of the objectives of the current analysis phase is to determine how nuclear hydrogen technologies could evolve under a number of different futures. The outputs of our work will eventually be used in a larger hydrogen infrastructure and market analysis conducted for DOE-EE using a system-level market simulation tool now underway. This report expands on our previous work by moving beyond simple levelized cost calculations and looking at profitability, risk, and uncertainty from an investor's perspective. We analyze a number of technologies and quantify the value of certain technology and operating characteristics. Our model to assess the profitability of the above technologies is based on Real Options Theory and calculates the discounted profits from investing in each of the production facilities. We use Monte-Carlo simulations to represent the uncertainty in hydrogen and electricity prices. The model computes both the expected value and the distribution of discounted profits from a production plant. We also quantify the value of the option to switch between hydrogen and electricity production in order to maximize investor profits. Uncertainty in electricity and hydrogen prices can be represented with two different stochastic processes: Geometric Brownian Motion (GBM) and Mean Reversion (MR). Our analysis finds that the flexibility to switch between hydrogen and electricity leads to significantly different results in regards to the relative profitability of the different technologies and configurations. This is the case both with a deterministic and a stochastic analysis, as shown in the tables below. The flexibility in output products clearly adds substantial value to the HPE-ALWR and HTE-HTGR plants. In fact, under the GBM assumption for prices, the HTE-HTGR plant becomes more profitable than the SI-HTGR configuration, although SI-HTGR has a much lower levelized cost. For the HTE-HTGR plant it is also profitable to invest in additional electric turbine capacity (Case b) in order to fully utilize the heat from the nuclear reactor for electricity production when this is more profitable than producing hydrogen. The technologies are all at the research and development stage, so there are significant uncertainties regarding the technology cost and performance assumptions used in this analysis. As the technologies advance, the designers need to refine the cost and performance evaluation to provide a more reliable set of input for a more rigorous analysis. In addition, the durability of the catalytic activity of the materials at the hydrogen plant during repetitive price cycling is of prime importance concerning the flexibility of switching from hydrogen to electricity production. However, given the potential significant economic benefit that can be brought from cogeneration with the flexibility to quickly react to market signals, DOE should consider R&D efforts towards developing durable materials and processes that can enable this type of operation. Our future work will focus on analyzing a range of hydrogen production technologies associated with an extension of the financial analysis framework presented here. We are planning to address a variety of additional risks and options, such as the value of modular expansion in addition to the co-generation capability (i.e., a modular increase in the hydrogen production capacity of a plant in a given market with rising hydrogen demand), and contrast that with economies-of-scale of large-unit designs.

  9. Socio-economic determinants of nutritional status of children in rural peninsular Malaysia.

    PubMed

    Marjan, Z M; Taib, M N; Lin, K G; Siong, T E

    1998-12-01

    The data presented is part of the findings from a four-year collaborative research project between Universiti Putra Malaysia, the Institute for Medical Research and the Ministry of Health Malaysia. The project assessed the nutritional status of the major functional groups in Peninsular Malaysia. Mukim Sayong and Pulau Kemiri in the District of Kuala Kangsar, Perak were two of the subdistricts selected to represent small rubber holdings in Peninsular Malaysia. This paper attempts to analyse the socio-economic profile of the households and the nutritional status of children below 9 years of age. A total of 307 households were studied. Approximately 63% of the households were involved in rubber activities and the majority of them were hired tappers. The average monthly income of the households was RM467 and the income ranged between RM30 to RM2120. Based on the per capita poverty line income of RM84.38, it was found that 14.1% of the households earned less than RM42.19, which can be considered as hard-core poor, while 32.7% were poor (monthly per capita income between RM42.19 and RM84.38). Slightly more than half (52.7%) earned income above the poverty line. The average family size was 4.5, ranging from 1 through to 16. The majority of the heads of households (56.6%) had between 3 and 6 years of education, and 14.5% did not receive any formal education. The prevalence of stunting among children 0-5 years of age was 26%, while 31.5% were underweight and 3.8% wasted. Among children aged between 5 and 9 years, almost the same pattern of nutritional status was noted. The overall percentages of stunting, underweight and wasting among these children were 29.2%, 26.1% and 0.62%, respectively. Analysis on nutritional status according to income level showed a noticeable difference in the prevalence of malnutrition in children above and below the poverty line income. The Student's t-test indicated significant differences in weight-for-age and weight-for-height between the two poverty line income for children below 5 years of age. Pearson's correlation coefficient showed a significant correlation between height-for-age with household size (r = -0.26, p<0.05), and monthly per capita income with weight-for-height (r = 0.25, p<0.05). There was a highly significant correlation between acreage of land cultivated and weight-for-height (r = 0.42, p<0.01), and weight-for-age (r = 0.25, p<0.05). The findings indicated the influence of socio-economic factors on the nutritional status of children. PMID:24393689

  10. Economic viability of photovoltaic power for development assistance applications

    NASA Technical Reports Server (NTRS)

    Bifano, W. J.

    1982-01-01

    This paper briefly discusses the development assistance market and examines a number of specific photovoltaic (PV) development assistance field tests, including water pumping/grain grinding (Tangaye, Upper Volta), vaccine refrigerators slated for deployment in 24 countries, rural medical centers to be installed in Ecuador, Guyana, Kenya and Zimbabwe, and remote earth stations to be deployed in the near future. A comparison of levelized energy cost for diesel generators and PV systems covering a range of annual energy consumptions is also included. The analysis does not consider potential societal, environmental or political benefits associated with PV power. PV systems are shown to be competitive with diesel generators, based on life cycle cost considerations, assuming a system price of $20/W(peak), for applications having an annual energy demand of up to 6000 kilowatt-hours per year.

  11. A metasynthesis of qualitative studies regarding opinions and perceptions about barriers and determinants of health services’ accessibility in economic migrants

    PubMed Central

    2012-01-01

    Background Access to health services is an important health determinant. New research in health equity is required, especially amongst economic migrants from developing countries. Studies conducted on the use of health services by migrant populations highlight existing gaps in understanding which factors affect access to these services from a qualitative perspective. We aim to describe the views of the migrants regarding barriers and determinants of access to health services in the international literature (1997–2011). Methods A systematic review was conducted for Qualitative research papers (English/Spanish) published in 13 electronic databases. A selection of articles that accomplished the inclusion criteria and a quality evaluation of the studies were carried out. The findings of the selected studies were synthesised by means of metasynthesis using different analysis categories according to Andersen’s conceptual framework of access and use of health services and by incorporating other emergent categories. Results We located 3,025 titles, 36 studies achieved the inclusion criteria. After quality evaluation, 28 articles were definitively synthesised. 12 studies (46.2%) were carried out in the U.S and 11 studies (42.3%) dealt with primary care services. The participating population varied depending mainly on type of host country. Barriers were described, such as the lack of communication between health services providers and migrants, due to idiomatic difficulties and cultural differences. Other barriers were linked to the economic system, the health service characteristics and the legislation in each country. This situation has consequences for the lack of health control by migrants and their social vulnerability. Conclusions Economic migrants faced individual and structural barriers to the health services in host countries, especially those with undocumented situation and those experimented idiomatic difficulties. Strategies to improve the structures of health systems and social policies are needed. PMID:23245431

  12. On the socio-economic determinants of antenatal care utilization in Azerbaijan: evidence and policy implications for reforms.

    PubMed

    Habibov, Nazim N

    2011-04-01

    Azerbaijan is a country with one of the highest child mortality rates in the regions of Eastern Europe and the former Soviet Union. Drawing on the nationally representative Demographic and Health Survey, this study examines the utilization of antenatal care in Azerbaijan to identify the socio-economic determinants of the usage, and its frequency, timing and quality. Consequently, binomial logit, two ordered logit and negative binomial regression models are specified to estimate the effect of various socio-economic characteristics on the likelihood of utilization. Place of living is an important determinant of antenatal healthcare utilization in Azerbaijan. It is important in determining the likelihood of utilization, its timing and quality of care received, whereas it is not significant in the model predicting the frequency of antenatal utilization. Women's education is also significant in three models out of four. Education is important in explaining the frequency and timing of utilization as well as the quality of services received, but it is not significant in predicting the likelihood of utilization. Wealth gradient is another important determinant of antenatal care utilization in Azerbaijan inasmuch as it is significant in explaining the likelihood of prenatal care utilization and its frequency. In addition, two variables, birth order and desirability of the last child or current pregnancy, are significant only in explaining the likelihood of utilization. Therefore, we confirm the findings of previous studies, which reported that the utilization of prenatal health care is a multistage process in which decisions are sequential. Although the same set of factors may affect decision-making at all stages, the effect of these factors is different at different stages. Implications for reforms in the healthcare sector to improve antenatal care utilization in Azerbaijan are provided and discussed. PMID:20598213

  13. Cultural and economic determinants of geographical mortality patterns in The Netherlands.

    PubMed Central

    Mackenbach, J P; Kunst, A E; Looman, C W

    1991-01-01

    STUDY OBJECTIVE--The geographical pattern of mortality in The Netherlands is dominated by an area of relatively high mortality in the southern part of the country. The aim was to analyse the background of this geographical mortality pattern in the early 1980s, and its evolution over time since the early 1950s. DESIGN--Mortality data by district (n = 39), cause of death (13 large causes, "symptoms and ill defined conditions", all other causes), and time period (1950-54, 1960-64, 1970-74, 1980-84) were available from the Netherlands Central Bureau of Statistics. Standardised mortality ratios were calculated, and the logarithms of these were related to three sociodemographic characteristics using multiple, ordinary least squares regression analysis. SETTING--This study used data for the whole Dutch population. MAIN RESULTS--Although the geographical mortality pattern has been rather stable over the last decades, a clear tendency towards convergence is also apparent. Approximately 90% of the current excess mortality in the southern part of the country is due to cardiovascular diseases. The results of regression analysis show that the excess mortality is primarily related to the high percentage of Roman Catholics in this part of the country, and additionally to a slightly lower average income. In The Netherlands, a higher percentage of Roman Catholics in the population is linked with higher all cause mortality rates, as well as with higher mortality rates for lung cancer, ischaemic heart disease, cerebrovascular disease, arterial disease, and chronic non-specific lung disease. Survey data show that these associations are partly due to a higher prevalence of smoking among Roman Catholics. As in many other countries, a lower average income is linked with high all cause mortality rates in The Netherlands. Cause specific data show negative associations for stomach cancer, ischaemic heart disease, cerebrovascular disease, chronic non-specific lung disease, and traffic accidents. Since the early 1950s the association between geographical mortality patterns and the percentage of Roman Catholics in the population has gradually become less strongly positive. This suggests that the convergence of the mortality rates in the South towards the national average may be related to a gradual lessening of differences in lifestyle between population groups. CONCLUSIONS--Both cultural and economic factors are important in the explanation of geographical mortality patterns in The Netherlands. PMID:1757767

  14. Socio-economic determinants for malaria transmission risk in an endemic primary health centre in Assam, India

    PubMed Central

    2014-01-01

    Background Malaria is a major cause of morbidity and mortality in Northeast India. As there is limited information available on the potential influence of socio-economic variables on malaria risk, the present study was conducted to assess the influence of demographic factors, the socio-economic status, and knowledge, awareness and education on malaria occurrence. Methods Demographics, malaria knowledge and socio-economic variables were collected in four randomly selected health sub-centres of the Orang primary health centre in the Udalguri district, Assam and the association of malaria occurrence with different variables were analysed. The trend of malaria occurrence for different income groups, proximity to health centres and number of mosquito bites per day was also determined using the chi-square test. Relative risk (RR) for gender, house type, knowledge and use of bed nets was determined using Katz approximation. Results Out of the 71 household heads interviewed, 70.4% (50/71) were males. About half (54.9%, 39/71) of the participants had a history of malaria in the last two years, of which 64.1% (25/39) were males, while 35.9% (14/39) were females (?2 = 5.13; p = 0.02; RR = 1.79). Of the total population surveyed, 49.3% lived in bamboo houses and 35.2% lived at a distance of >3 km from the nearest health centre. The number of participants who had a history of malaria decreased with an increasing monthly income (p < 0.0001). Malaria occurrence was higher among the households living in bamboo houses (69.2%), as compared to Kucha houses (20.5%) and Pucca houses (10.3%). No significant association was observed between education level and malaria occurrence (p = 0.93). The participants who did not use bed nets regularly reported a high occurrence of malaria infection as compared to those who used bed nets everyday (p < 0.0001). Conclusions Lower income, house type, distance to health sub-centre, knowledge and awareness about malaria, number of mosquito bites per day and use of bed nets were positively associated with malaria occurrence. Increasing the number of health sub-centres close to rural areas, improving the economic status and increasing awareness about malaria prevention measures will thus help to reduce malaria-associated morbidities. PMID:24991410

  15. Clinical Evaluation of Tuberculosis Viability Microscopy for Assessing Treatment Response

    PubMed Central

    Datta, Sumona; Sherman, Jonathan M.; Bravard, Marjory A.; Valencia, Teresa; Gilman, Robert H.; Evans, Carlton A.

    2015-01-01

    Background.?It is difficult to determine whether early tuberculosis treatment is effective in reducing the infectiousness of patients' sputum, because culture takes weeks and conventional acid-fast sputum microscopy and molecular tests cannot differentiate live from dead tuberculosis. Methods.?To assess treatment response, sputum samples (n = 124) from unselected patients (n = 35) with sputum microscopypositive tuberculosis were tested pretreatment and after 3, 6, and 9 days of empiric first-line therapy. Tuberculosis quantitative viability microscopy with fluorescein diacetate, quantitative culture, and acid-fast auramine microscopy were all performed in triplicate. Results.?Tuberculosis quantitative viability microscopy predicted quantitative culture results such that 76% of results agreed within 1 logarithm (rS = 0.85; P < .0001). In 31 patients with non-multidrug-resistant (MDR) tuberculosis, viability and quantitative culture results approximately halved (both 0.27 log reduction, P < .001) daily. For patients with non-MDR tuberculosis and available data, by treatment day 9 there was a >10-fold reduction in viability in 100% (24/24) of cases and quantitative culture in 95% (19/20) of cases. Four other patients subsequently found to have MDR tuberculosis had no significant changes in viability (P = .4) or quantitative culture (P = .6) results during early treatment. The change in viability and quantitative culture results during early treatment differed significantly between patients with non-MDR tuberculosis and those with MDR tuberculosis (both P < .001). Acid-fast microscopy results changed little during early treatment, and this change was similar for non-MDR tuberculosis vs MDR tuberculosis (P = .6). Conclusions.?Tuberculosis quantitative viability microscopy is a simple test that within 1 hour predicted quantitative culture results that became available weeks later, rapidly indicating whether patients were responding to tuberculosis therapy. PMID:25537870

  16. Comparison of reintroduction and enhancement effects on metapopulation viability

    USGS Publications Warehouse

    Halsey, Samniqueka J; Bell, Timothy J.; McEachern, Kathryn; Pavlovic, Noel B.

    2015-01-01

    Metapopulation viability depends upon a balance of extinction and colonization of local habitats by a species. Mechanisms that can affect this balance include physical characteristics related to natural processes (e.g. succession) as well as anthropogenic actions. Plant restorations can help to produce favorable metapopulation dynamics and consequently increase viability; however, to date no studies confirm this is true. Population viability analysis (PVA) allows for the use of empirical data to generate theoretical future projections in the form of median time to extinction and probability of extinction. In turn, PVAs can inform and aid the development of conservation, recovery, and management plans. Pitcher's thistle (Cirsium pitcheri) is a dune endemic that exhibited metapopulation dynamics. We projected viability of three natural and two restored populations with demographic data spanning 15–23 years to determine the degree the addition of reintroduced population affects metapopulation viability. The models were validated by comparing observed and projected abundances and adjusting parameters associated with demographic and environmental stochasticity to improve model performance. Our chosen model correctly predicted yearly population abundance for 60% of the population-years. Using that model, 50-year projections showed that the addition of reintroductions increases metapopulation viability. The reintroduction that simulated population performance in early-successional habitats had the maximum benefit. In situ enhancements of existing populations proved to be equally effective. This study shows that restorations can facilitate and improve metapopulation viability of species dependent on metapopulation dynamics for survival with long-term persistence of C. pitcheri in Indiana likely to depend on continued active management.

  17. Socio-Economic Status Determines Risk of Receptive Syringe Sharing Behaviors among Iranian Drug Injectors; A National Study

    PubMed Central

    Assari, Shervin; Ahmadi, Khodabakhsh; Rezazade, Majid

    2015-01-01

    Background: Although needle and syringe sharing is one of the main routs of transmission of HIV in several countries in the middle east, very little is known about how socio-economic status of injecting drug users (IDUs) is linked to the receptive syringe sharing behaviors in these countries. Aim: To study socio-economic correlates of receptive needle and syringe sharing among IDUs in Iran. Methods: The study used data from the Unhide Risk Study, a national survey of IDUs. This study sampled 636 IDUs (91% male) via snowball sampling from eight provinces in Iran in 2009. Socio-demographic and drug use characteristics were collected. We used a logistic regression to determine factors associated with receptive needle and syringe sharing during the past 6 months. Results: From 636 IDUs enrolled in this study, 68% (n = 434) reported receptive needle and syringe sharing behaviors in the past 6 months. Odds of receptive needle and syringe sharing in the past 6 months was lower among IDUs who were male [odds ratios (OR) = 0.29, 95% confidence interval (CI) = 0.12–0.70], had higher education (OR = 0.74, 95% CI = 0.64–0.86) but higher among those who were unemployed (OR = 4.05, 95% CI = 1.50–10.94), and were single (OR = 1.47, 95% CI = 1.02–2.11). Conclusion: This study presented factors associated with risk of receptive needle and syringe sharing among Iranian IDUs. This information may be used for HIV prevention and harm reduction purposes. Socio-economic status of Iranian IDUs may be closely linked to high-risk injecting behaviors among them. PMID:25852577

  18. Social and economic determinants of pediatric health inequalities: the model of chronic kidney disease.

    PubMed

    Sereni, Fabio; Edefonti, Alberto; Lepore, Marta; Agostoni, Carlo; Sandoval Diaz, Mabel; Silva Galan, Yajaira; Montini, Giovanni; Tognoni, Gianni

    2016-01-01

    Purpose of this review is to deal with priorities and strategies to significantly tackle inequalities in the management of pediatric diseases in low-middle-income countries. This issue has become a focal point of epidemiological and public health, with special reference to chronic nontransmissible diseases. We will provide our readership with an essential overview of the cultural, institutional, and political events, which have occurred over the last 20 y and which have produced the current general framework for epidemiology and public health. Then the most recent epidemiological data will be evaluated, in order to quantify the interaction between the medical components of the disease profiles and their socioeconomic determinants. Finally, a focus will be added on models of pediatric chronic kidney diseases, which are in our opinion amongst the most sensitive markers of the interplay between health and society. Collaborative, pediatrician-initiated, multicentre projects in these fields should be given priority in calls for grants supported by public agencies. The involvement of a critical mass of those working in the "fringes" of pediatric care is a final, essential mean by which significant results can be produced under the sole responsibility and research interest of centers of excellence. PMID:26466076

  19. Measurement of the viability of Lawsonia intracellularis

    PubMed Central

    2005-01-01

    Abstract The objective of this study was to develop and test both a flow cytometry method (FCM) and a direct count method (DCM) that both use fluorescent stains to determine the viability of Lawsonia intracellularis (LI), an obligate intracellular bacterium and the cause of proliferative enteropathy (PE) in pigs and other animal species. Live LI were passaged in cell culture and harvested from infected McCoy cells. Dead LI were prepared by exposing live LI to 70% isopropyl alcohol for 30 min. Seven samples with dead:live ratios of 0:100 (live control), 10:90, 30:70, 50:50, 70:30, 90:10, and 100:0 (dead control) were prepared for testing by both the FCM and the DCM. For the FCM, TO-PRO-3 iodine was applied to the samples, and viable LI were counted. For the DCM, the samples were stained with LIVE/DEAD BacLight, which contains SYTO 9 and propidium iodine, then filtered through 0.2-μm Nuclepore black polycarbonate filters, viewed, and counted with the use of an epifluorescence microscope. Data were evaluated by estimating 95% limits of agreement and the concordance correlation coefficient (CCC). The limits of agreement between the FCM and the DCM versus the standard ratio of added LI showed mean differences not equal to zero, suggesting that systematic bias was introduced. The CCC showed almost perfect agreement (r = 0.9898). With a specific fluorescent probe, the FCM is useful and as good as the DCM for determining LI viability. PMID:16479724

  20. Local knowledge and socio-economic determinants of traditional medicines' utilization in livestock health management in Southwest Nigeria

    PubMed Central

    2012-01-01

    Smallholder livestock farmers in Nigeria utilize traditional medicines derived from medicinal plants (PMs) for the maintenance of their animals' health. This study was designed to determine the PMs used in the study area and their level of utilization by livestock farmers, compare the level of utilization of PMs across the three states surveyed and identify the socio-economic factors influencing farmer's utilization of PMs. Thirty-five PMs were identified. Farmers had considerable knowledge about the identified PMs but about 80.0% of them used the PMs to poor/moderate extent. There were statistical differences in the utilization level of PMs among the three states. Six socio-economic variables were found to be statistically significant in influencing PMs' utilization. Farmer's age, household size, distance to the nearest veterinary hospital/clinic and extent of travels, had positive effects while negative effects were exhibited by farm income and number of heads of livestock. It was concluded that there was considerable knowledge about PMs and that utilization of PMs varied between the three states. It was recommended that local knowledge of PMs be preserved in the study area through screening and documentation. PMID:22239949

  1. Hierarchical Bayesian Spatio–Temporal Analysis of Climatic and Socio–Economic Determinants of Rocky Mountain Spotted Fever

    PubMed Central

    Raghavan, Ram K.; Goodin, Douglas G.; Neises, Daniel; Anderson, Gary A.; Ganta, Roman R.

    2016-01-01

    This study aims to examine the spatio-temporal dynamics of Rocky Mountain spotted fever (RMSF) prevalence in four contiguous states of Midwestern United States, and to determine the impact of environmental and socio–economic factors associated with this disease. Bayesian hierarchical models were used to quantify space and time only trends and spatio–temporal interaction effect in the case reports submitted to the state health departments in the region. Various socio–economic, environmental and climatic covariates screened a priori in a bivariate procedure were added to a main–effects Bayesian model in progressive steps to evaluate important drivers of RMSF space-time patterns in the region. Our results show a steady increase in RMSF incidence over the study period to newer geographic areas, and the posterior probabilities of county-specific trends indicate clustering of high risk counties in the central and southern parts of the study region. At the spatial scale of a county, the prevalence levels of RMSF is influenced by poverty status, average relative humidity, and average land surface temperature (>35°C) in the region, and the relevance of these factors in the context of climate–change impacts on tick–borne diseases are discussed. PMID:26942604

  2. 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 (676%) of the subjects had poor IQ and most of them (726%) 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 0059; P=0020). Low maternal education was also identified as a significant predictor of low IQ scores (r2 0042; P=0043). With educational achievement, Fe-deficiency anaemia (IDA) was the only variable to show significant association (r2 0025; P=0015). 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. PMID:21492493

  3. Socio-economic & demographic determinants of hypertension & knowledge, practices & risk behaviour of tribals in India

    PubMed Central

    Laxmaiah, A.; Meshram, I.I.; Arlappa, N.; Balakrishna, N.; Rao, K. Mallikharjuna; Reddy, Ch Gal; Ravindranath, M.; Kumar, Sharad; Kumar, Hari; Brahmam, G.N.V.

    2015-01-01

    Background & objectives: An increase in prevalence of hypertension has been observed in all ethnic groups in India. The objective of the present study was to estimate prevalence and determinants of hypertension among tribals and their awareness, treatment practices and risk behaviours in nine States of India. Methods: A community based cross-sectional study adopting multistage random sampling procedure was carried out. About 120 Integrated Tribal Development Authority villages were selected randomly from each State. From each village, 40 households were covered randomly. All men and women ? 20 yr of age in the selected households were included for various investigations. Results: A total of 21141 men and 26260 women participated in the study. The prevalence of hypertension after age adjustment was 27.1 and 26.4 per cent among men and women, respectively. It was higher in the States of Odisha (50-54.4%) and Kerala (36.7-45%) and lowest in Gujarat (7-11.5%). The risk of hypertension was 6-8 times higher in elderly people and 2-3 times in 35-59 yr compared with 20-34 yr. Only <10 per cent of men and women were known hypertensives and more than half on treatment (55-68%). Men with general and abdominal obesity were at 1.69 (CI: 1.43-2.01) and 2.42 (CI: 2.01-2.91) times higher risk of hypertension, respectively, while it was 2.03 (CI=1.77-2.33) and 2.35 (CI 2.12-2.60) times higher in women. Those using tobacco and consuming alcohol were at a higher risk of hypertension compared with the non users. Interpretation & conclusions: The study revealed high prevalence of hypertension among tribals in India. Age, literacy, physical activity, consumption of tobacco, alcohol and obesity were significantly associated with hypertension. Awareness and knowledge about hypertension and health seeking behaviour were low. Appropriate intervention strategies need to be adopted to increase awareness and treatment practices of hypertension among tribals. PMID:26139790

  4. Positron Emission Tomography for the Assessment of Myocardial Viability

    PubMed Central

    2005-01-01

    Executive Summary Objective The objective was to update the 2001 systematic review conducted by the Institute For Clinical Evaluative Sciences (ICES) on the use of positron emission tomography (PET) in assessing myocardial viability. The update consisted of a review and analysis of the research evidence published since the 2001 ICES review to determine the effectiveness and cost-effectiveness of PET in detecting left ventricular (LV) viability and predicting patient outcomes after revascularization in comparison with other noninvasive techniques. Background Left Ventricular Viability Heart failure is a complex syndrome that impairs the contractile ability of the heart to maintain adequate blood circulation, resulting in poor functional capacity and increased risk of morbidity and mortality. It is the leading cause of hospitalization in elderly Canadians. In more than two-thirds of cases, heart failure is secondary to coronary heart disease. It has been shown that dysfunctional myocardium resulting from coronary heart disease (CAD) may recover contractile function (i.e. considered viable). Dysfunctional but viable myocardium may have been stunned by a brief episode of ischemia, followed by restoration of perfusion, and may regain function spontaneously. It is believed that repetitive stunning results in hibernating myocardium that will only regain contractile function upon revascularization. For people with CAD and severe LV dysfunction (left ventricular ejection fraction [LVEF] <35%) refractory to medical therapy, coronary artery bypass and heart transplantation are the only treatment options. The opportunity for a heart transplant is limited by scarcityof donor hearts. Coronary artery bypass in these patients is associated with high perioperative complications; however, there is evidence that revascularization in the presence of dysfunctional but viable myocardium is associated with survival benefits and lower rates of cardiac events. The assessment of left ventricular (LV) viability is, therefore, critical in deciding whether a patient with coronary artery disease and severe LV dysfunction should undergo revascularization, receive a heart transplant, or remain on medical therapy. Assessment of Left Ventricular Viability Techniques for assessing myocardial viability depend on the measurement of a specific characteristic of viable myocytes such as cell membrane integrity, preserved metabolism, mitochondria integrity, and preserved contractile reserve. In Ontario, single photon emission computed tomography (SPECT) using radioactive 201thallium is the most commonly used technique followed by dobutamine echocardiography. Newer techniques include SPECT using technetium tracers, cardiac magnetic resonance imaging, and PET, the subject of this review. Positron Emission Tomography PET is a nuclear imaging technique based on the metabolism of radioactive analogs of normal substrates such as glucose and water. The radiopharmaceutical used most frequently in myocardial viability assessment is F18 fluorodeoxyglucose (FDG), a glucose analog. The procedure involves the intravenous administration of FDG under controlled glycemic conditions, and imaging with a PET scanner. The images are reconstructed using computer software and analyzed visually or semi-quantitatively, often in conjunction with perfusion images. Dysfunctional but stunned myocardium is characterized by normal perfusion and normal FDG uptake; hibernating myocardium exhibits reduced perfusion and normal/enhanced FDG uptake (perfusion/metabolism mismatch), whereas scar tissue is characterized by reduction in both perfusion and FDG uptake (perfusion/metabolism match). Review Strategy The Medical Advisory Secretariat used a search strategy similar to that used in the 2001 ICES review to identify English language reports of health technology assessments and primary studies in selected databases, published from January 1, 2001 to April 20, 2005. Patients of interest were those with CAD and severe ventricular dysfunction being considered for revascularization that had undergone viability assessment using either PET and/or other noninvasive techniques. The outcomes of interest were diagnostic and predictive accuracy with respect to recovery of regional or global LV function, long-term survival and cardiac events, and quality of life. Other outcomes of interest were impact on treatment decision, adverse events, and cost-effectiveness ratios. Of 456 citations, 8 systematic reviews/meta-analyses and 37 reports on primary studies met the selection criteria. The reports were categorized using the Medical Advisory Secretariat levels of evidence system, and the quality of the reports was assessed using the criteria of the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) developed by the Centre for Dissemination of Research (National Health Service, United Kingdom). Analysis of sensitivity, specificity, predictive values and likelihood ratios were conducted for all data as well as stratified by mean left ventricular ejection fraction (LVEF). There were no randomized controlled trials. The included studies compared PET with one or more other noninvasive viability tests on the same group of patients or examined the long-term outcomes of PET viability assessments. The quality assessment showed that about 50% or more of the studies had selection bias, interpreted tests without blinding, excluded uninterpretable segments in the analysis, or did not have clearly stated selection criteria. Data from the above studies were integrated with data from the 2001 ICES review for analysis and interpretation. Summary of Findings The evidence was derived from populations with moderate to severe ischemic LV dysfunction with an overall quality that ranges from moderate to low. PET appears to be a safe technique for assessing myocardial viability. CAD patients with moderate to severe ischemic LV dysfunction and residual viable myocardium had significantly lower 2-year mortality rate (3.2%) and higher event-free survival rates (92% at 3 years) when treated with revascularization than those who were not revascularized but were treated medically (16% mortality at 2-years and 48% 3-year event-free survival). A large meta-analysis and moderate quality studies of diagnostic accuracy consistently showed that compared to other noninvasive diagnostic tests such as thallium SPECT and echocardiography, FDG PET has: Higher sensitivity (median 90%, range 71%100%) and better negative likelihood ratio (median 0.16, range 00.38; ideal <0.1) for predicting regional myocardial function recovery after revascularization. Specificity (median 73%, range 33%91%) that is similar to other radionuclide imaging but lower than that of dobutamine echocardiography Less useful positive likelihood ratio (median 3.1, range 1.4 9.2; ideal>10) for predicting segmental function recovery. Taking positive and negative likelihood ratios together suggests that FDG PET and dobutamine echocardiography may produce small but sometimes important changes in the probability of recovering regional wall motion after revascularization. Given its higher sensitivity, PET is less likely to produce false positive results in myocardial viability. PET, therefore, has the potential to identify some patients who might benefit from revascularization, but who would not have been identified as suitable candidates for revascularization using thallium SPECT or dobutamine echocardiography. PET appears to be superior to other nuclear imaging techniques including SPECT with 201thallium or technetium labelled tracers, although recent studies suggest that FDG SPECT may have comparable diagnostic accuracy as FDG PET for predicting regional and global LV function recovery. No firm conclusion can be reached about the incremental value of PET over other noninvasive techniques for predicting global function improvement or long-term outcomes in the most important target population (patients with severe ischemic LV dysfunction) due to lack of direct comparison. An Ontario-based economic analysis showed that in people with CAD and severe LV dysfunction and who were found to have no viable myocardium or indeterminate results by thallium SPECT, the use of PET as a follow-up assessment would likely result in lower cost and better 5-year survival compared to the use of thallium SPECT alone. The projected annual budget impact of adding PET under the above scenario was estimated to range from $1.5 million to $2.3 million. Conclusion In patients with severe LV dysfunction, that are deemed to have no viable myocardium or indeterminate results in assessments using other noninvasive tests, PET may have a role in further identifying patients who may benefit from revascularization. No firm conclusion can be drawn on the impact of PET viability assessment on long-term clinical outcomes in the most important target population (i.e. patients with severe LV dysfunction). PMID:23074467

  5. Effect of storage time on the viability of cryopreserved bovine spermatozoa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Long term cryopreserved semen viability can impact the National Animal Germplasm Programs (NAGP) sampling strategy and ability to reconstitute livestock populations. Therefore, the purpose of this project was to determine if prolonged storage of cryopreserved sperm impacts cell viability. Cryoprese...

  6. Priorities of Low-Income Urban Residents for Interventions to Address the Socio-Economic Determinants of Health

    PubMed Central

    Danis, Marion; Kotwani, Namrata; Garrett, Joanne; Rivera, Ivonne; Davies-Cole, John; Carter-Nolan, Pamela

    2013-01-01

    Objectives To determine the priorities of low-income urban residents for interventions that address the socio-economic determinants of health. Methods We selected and estimated the cost of 16 interventions related to education, housing, nutrition, employment, health care, healthy behavior, neighborhood improvement, and transportation. Low-income residents of Washington, D.C. (N=431) participated in decision exercises to prioritize these interventions. Results Given a budget valued at approximately twice an estimated cost of medical and dental care ($885), the interventions ultimately prioritized by the greatest percentage of individuals were: health insurance (95%), housing vouchers (82%) dental care (82%), job training (72%), adult education (63%), counseling (68%), healthy behavior incentives (68%), and job placement (67%). The percentages of respondents who received support for housing, adult education, and job training and placement were far less than the percentage who prioritized these interventions. Conclusions Poor and low-income residents’ priorities may usefully inform allocation of social services that affect health. PMID:21099082

  7. Role of Maxillofacial Trauma Scoring Systems in Determining the Economic Burden to Maxillofacial Trauma Patients in India

    PubMed Central

    Ramalingam, Sundar

    2015-01-01

    Background: The objective of this study was to evaluate the association between severity of maxillofacial injuries determined by trauma scoring systems and its economic burden to patients in terms of cost and duration of hospitalization. Materials and Methods: Following ethical approval a retrospective chart review was undertaken at Meenakshi Ammal Dental College and Hospital to identify patients admitted with maxillofacial injuries between January 2006 and December 2008. Patients with incomplete records, associated injuries, debilitating systemic diseases and patients treated under local anesthesia were excluded. Details regarding the nature and severity of injury and treatment were recorded in addition to the total treatment cost and duration of hospitalization. Maxillofacial injury severity was scored using maxillofacial injury severity score (MFISS) and facial injury severity scale (FISS). The MFISS and FISS scores were correlated with two surrogate markers of the economic burden namely cost and duration of hospitalization. Results: A total of 162 patients with maxillofacial injuries were identified (108 males, 54 females; mean age = 32.4 years). Road traffic accidents were the cause of injury in 114 patients (70.4%) and only 29 patients (17.9%) had medical insurance coverage. The mean MFISS and FISS scores were 14.04 (standard deviation [SD] = 9.19; range = 3-42) and 4.40 (SD = 3.17; range = 1-14), respectively. The mean cost and duration of hospitalization of the patients were Indian rupees (INR) 13877.28 (SD = 8252.59; range = INR 5250-42960) and 4.12 days (SD = 1.5; range = 2-8 days) respectively. Pearson’s correlation between the MFISS and FISS scores and the cost and duration of hospitalization, revealed statistically significant correlations (MFISS vs. cost - R = 0.862, P < 0.001; MFISS vs. duration - R = 0.828, P < 0.01; FISS vs. cost - R = 0.845, P < 0.01; FISS vs. duration - R = 0.819, P < 0.01). Conclusion: Based on the results of this study, maxillofacial injury severity measured by MFISS and FISS scores are predictable indicators of the economic burden to the patients. PMID:25954069

  8. Experiments with the Viability of Chicken Eggs

    ERIC Educational Resources Information Center

    Garigliano, Leonard J.

    1975-01-01

    Presents the results of an experiment designed to test two hypotheses: (1) a delay of two weeks at room temperature will have no effect on the viability of fertile chicken eggs and (2) refrigeration will have no effect on the viability of fertile chicken eggs. Experimenters were the author and two ninth-grade students. (PEB)

  9. Effect of Cold Temperatures on the Viability of Chromobacterium violaceum

    PubMed Central

    Efthimion, Mary H.; Corpe, William A.

    1969-01-01

    The effect of low, nonfreezing temperatures on the viability of five strains of Chromobacterium violaceum was studied. The viability of cultures grown at 30 C was determined after exposure to various diluents held at 0 to 2 C. A culture diluted at its growth temperature served as the control. Cells of strain N were most sensitive in the early part of the exponential phase of growth. Cells of strains 252 and 341 were most sensitive in the late exponential, early stationary phase of growth. Cells of strain 9 showed greatest loss of viability during the maximal stationary phase. Strain 69 was completely resistant throughout its growth cycle to cold injury. Cell viability was much greater in buffered salts solution than in distilled water, broth, or physiological saline, whether cultures were diluted at room temperature or in the cold. The proportion of cells surviving after exposure to cold, however, was the same regardless of the composition of the diluent. Loss of viability was progressive at 0 to 2 C and reached a maximum after 2 hr. There was no loss of viability of cells exposed to 20 C, but there was some loss at 12 C. Strain 341 cultivated at 15 C was much less sensitive to 0 to 2 C than when it was cultivated at 30 C. The composition of the growth medium seemed to have no effect on the survival of cells exposed to cold. The polyamines, spermine and trimethylenediamine, as well as erythritol and sucrose, exerted some protective action against the effects of cold but not uniformly for all strains studied. PMID:5774755

  10. A decision-making tool to determine economic feasibility and break-even prices for artisan cheese operations.

    PubMed

    Durham, Catherine A; Bouma, Andrea; Meunier-Goddik, Lisbeth

    2015-12-01

    Artisan cheese makers lack access to valid economic data to help them evaluate business opportunities and make important business decisions such as determining cheese pricing structure. The objective of this study was to utilize an economic model to evaluate the net present value (NPV), internal rate of return, and payback period for artisan cheese production at different annual production volumes. The model was also used to determine the minimum retail price necessary to ensure positive NPV for 5 different cheese types produced at 4 different production volumes. Milk type, cheese yield, and aging time all affected variable costs. However, aged cheeses required additional investment for aging space (which needs to be larger for longer aging times), as did lower yield cheeses (by requiring larger-volume equipment for pasteurization and milk handling). As the volume of milk required increased, switching from vat pasteurization to high-temperature, short-time pasteurization was necessary for low-yield cheeses before being required for high-yield cheeses, which causes an additional increase in investment costs. Because of these differences, high-moisture, fresh cow milk cheeses can be sold for about half the price of hard, aged goat milk cheeses at the largest production volume or for about two-thirds the price at the lowest production volume examined. For example, for the given model assumptions, at an annual production of 13,608kg of cheese (30,000 lb), a fresh cow milk mozzarella should be sold at a minimum retail price of $27.29/kg ($12.38/lb), whereas a goat milk Gouda needs a minimum retail price of $49.54/kg ($22.47/lb). Artisan cheese makers should carefully evaluate annual production volumes. Although larger production volumes decrease average fixed cost and improve production efficiency, production can reach volumes where it becomes necessary to sell through distributors. Because distributors might pay as little as 35% of retail price, the retail price needs to be higher to compensate. An artisan cheese company that has not achieved the recognition needed to achieve a premium price may not find distribution through distributors profitable. PMID:26476951

  11. Bacterial plasmolysis as a physical indicator of viability.

    PubMed Central

    Korber, D R; Choi, A; Wolfaardt, G M; Caldwell, D E

    1996-01-01

    Bacterial plasmolytic response to osmotic stress was evaluated as a physical indicator of membrane integrity and hence cellular viability. Digital image analysis and either low-magnification dark-field, high-magnification phase-contrast, or confocal laser microscopy, in conjunction with pulse application of a 1.5 M NaCl solution, were used as a rapid, growth-independent method for quantifying the viability of attached biofilm bacteria. Bacteria were considered viable if they were capable of plasmolysis, as quantified by changes in cell area or light scattering. When viable Salmonella enteritidis biofilm cells were exposed to 1.5 M NaCl, an approximately 50% reduction in cell protoplast area (as determined by high-magnification phase-contrast microscopy) was observed. In contrast, heat- and formalin-killed S. enteritidis cells were unresponsive to NaCl treatment. Furthermore, the mean dark-field cell area of a viable, sessile population of Pseudomonas fluorescens cells (approximately 1,100 cells) increased by 50% as a result of salt stress, from 1,035 +/- 162 to 1,588 +/- 284 microns2, because of increased light scattering of the condensed, plasmolyzed cell protoplast. Light scattering of ethanol-killed control biofilm cells underwent little change following salt stress. When the results obtained with scanning confocal laser microscopy and a fluorescent viability probe were compared with the accuracy of plasmolysis as a viability indicator, it was found that the two methods were in close agreement. Used alone or in conjunction with fluorochemical probes, physical indicators of membrane integrity provided a rapid, direct, growth-independent method for determining the viability of biofilm bacteria known to undergo plasmolysis, and this method may have value during efficacy testing of biocides and other antimicrobial agents when nondestructive time course analyses are required. PMID:8899980

  12. Bacterial plasmolysis as a physical indicator of viability

    SciTech Connect

    Korber, D.R.; Choi, A.; Wolfaardt, G.M.; Caldwell, D.E.

    1996-11-01

    Bacterial plasmolytic response to osmotic stress was evaluated as a physical indicator of membrane integrity and hence cellular viability. Digital image analysis and either low-magnification dark-field, high-magnification phase-contrast, or confocal laser microscopy, in conjunction with pulse application of a 1.5 NaCl solution, were used as a rapid, growth-independent method for quantifying the viability of attached biofilm bacteria. Bacteria were considered viable if they were capable of plasmolysis, as quantified by changes in cell area or light scattering. When viable Salmonella enteritidis biofilm cells were exposed to 1.5 M NaCl, and {approximately}50% reduction in cell protoplast area (as determined by high-magnification phase-contrast microscopy) was observed. In contrast, heat- and formalin-killed S. enteritidis cells were unresponsive to NaCl treatment. Furthermore, the mean dark-field cell area of a viable, sessile population of Pseudomonas fluorescens cells ({approximately}1,100 cells) increased by 50% as a result of salt stress, from 1,035 {+-} 162 to 1,588 {+-} 284 {mu}m{sup 2}, because of increased light scattering of the condensed, plasmolyzed cell protoplast. Light scattering of ethanol-killed control biofilm cells underwent little change following salt stress. When the results obtained with scanning confocal laser microscopy and a fluorescent viability probe were compared with the accuracy of plasmolysis as a viability indicator, it was found that the two methods were in close agreement. Used alone or in conjunction with fluorochemical probes, physical indicators of membrane integrity provided a rapid, direct, growth-independent method for determining the viability of biofilm bacteria known to undergo plasmolysis, and this method may have value during efficacy testing of biocides and other antimicrobial agents when nondestructive time course analyses and required. 42 refs., 7 figs.

  13. Effect of vinegar on the viability of Giardia duodenalis cysts.

    PubMed

    Costa, Adriana Oliveira; Thomaz-Soccol, Vanete; Paulino, Rosangela Clara; Alcntara de Castro, Edilene

    2009-01-15

    The inactivation of Giardia duodenalis cysts by vinegar was investigated. Experiments were carried out in 100 ml volume of vinegar (acetic acid 4%), undiluted or diluted in distilled water in ratios of 1:1, 1:15.6, and 1:62.5 (vol/vol), which were inoculated with 5x10(5) cysts obtained from human feces. Experiments were performed at room temperature (21+/-1 degrees C) and at 4 degrees C. After contact times of 1.5 min, 10, 30, and 60 min, the cysts were recovered from the treatment fluid and subjected to an in vitro excystation assay to determine their viability. The relative viability, which was calculated in relation to controls (maximum excystation percentage), was significantly affected (p<0.1) by the vinegar concentration, contact time, and temperature. At 21+/-1 degrees C, no cysts remained viable after being treated with undiluted vinegar for 60 min, while the treatment with 1:1, 1:15.6, and 1:62.5 vinegar-water mixtures decreased the relative viability to 1.8%, 19.4%, and 56.4%, respectively. The relative viability after corresponding treatments at 4 degrees C also decreased, but 23.6% to 48.8% remained viable after 60 min, and thus complete inactivation was not obtained with any treatment at that temperature. PMID:18986724

  14. Social and Economic Determinants of the Educational Achievement of Selected Eleventh Grade Students in Rural Kentucky: An Exploratory Study.

    ERIC Educational Resources Information Center

    Bieker, Richard Francis

    Study objectives were (1) to construct a conceptual model to relate incremental educational achievement of individual students during a 2-school-year period to economic inputs of the school, student inputs, and family inputs during that period and (2) to use the model as a basis for generating an economic factor model for the school unit. To test

  15. An efficient and economical MTT assay for determining the antioxidant activity of plant natural product extracts and pure compounds.

    PubMed

    Liu, Yunbao; Nair, Muraleedharan G

    2010-07-23

    Antioxidants scavenge free radicals, singlet oxygen, and electrons in cellular redox reactions. The yellow MTT [3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide] is reduced to a purple formazan by mitochondrial enzymes. NADPH is the basis of established in vitro cell viability assays. An antioxidant assay has been developed utilizing the redox reaction between MTT and selected natural product extracts and purified compounds. This simple, fast, and inexpensive MTT antioxidant assay is comparable with the lipid peroxidation inhibitory assay and can be mechanized to achieve high throughput. PMID:20565070

  16. An Assessment of the Effectiveness and Viability of Various Mitigation Technologies under Different Scenarios Using the PESERA-DESMICE Model

    NASA Astrophysics Data System (ADS)

    Nainggolan, D.; Fleskens, L.; Stringer, L. C.

    2012-04-01

    Scenario analysis of policy options is one of the most valuable ways in which scientific models can be employed to inform decision-making process. This is particularly relevant for land degradation mitigation policies, which are rarely based on this kind of analysis. In this paper we show how the PESERA-DESMICE modelling framework can be used in the assessment of policy options to combat land degradation, illustrating the model analysis of policy options with scenarios for different study sites. The key assumption underlying our analyses is that technologies must be attractive in economic terms, i.e. have the potential to, from a land user perspective, lead to cost reductions, benefit enhancements or both. Trade-off and cost-effectiveness thus form integral parts of the framework. The sequence of options is explored by: (1) Determining which technologies are feasible in which locations. This includes an assessment of economic viability for the land user in each location; we term these the technology scenarios; (2) Determining how policy instruments such as subsidies and credit can have the potential to influence upfront investment requirements and economic viability and how they lead to reduced levels of land degradation on the other; we term these the policy scenarios; (3) Determining how technology adoption affects development issues such as food production and livelihoods; we term these the global scenarios. All types of scenario were found to be useful to policymakers in different ways. Technology scenarios may help focus the portfolio of land degradation mitigation technologies towards areas in need of policy support; policy scenarios further detail the types and levels of support necessary for promoting adoption of the technology; while global scenarios demonstrate how the changes envisaged contribute to the achievement of wider sustainable development goals. Keywords: integrated environmental model, land degradation, mitigation technologies, scenario analysis, policy options

  17. Evolution under Fertility and Viability Selection

    PubMed Central

    Nagylaki, Thomas

    1987-01-01

    Evolution at a single multiallelic locus under arbitrary weak selection on both fertility and viability is investigated. Discrete, nonoverlapping generations are posited for autosomal and X-linked loci in dioecious populations, but monoecious populations are studied in both discrete and continuous time. Mating is random. The results hold after several generations have elapsed. With an error of order s [i.e., O(s)], where s represents the selection intensity, the population evolves in Hardy-Weinberg proportions. Provided the change per generation of the fertilities and viabilities due to their explicit time dependence (if any) is O(s 2), the rate of change of the deviation from Hardy-Weinberg proportions is O(s2). If the change per generation of the viabilities and genotypic fertilities is smaller than second order [i.e., o(s2)], then to O(s 2) the rate of change of the mean fitness is equal to the genic variance. The mean fitness is the product of the mean fertility and the mean viability; in dioecious populations, the latter is the unweighted geometric mean of the mean viabilities of the two sexes. Hence, as long as there is significant gene frequency change, the mean fitness increases. If it is the fertilities of matings that change slowly [at rate o(s 2)], the above conclusions apply to a modified mean fitness, defined as the product of the mean viability and the square root of the mean fertility. PMID:3557116

  18. A New Methodology for Evaluation of Nematode Viability

    PubMed Central

    Ferreira, Sebastio Rodrigo; Mendes, Tiago Antnio Oliveira; Bueno, Lilian Lacerda; de Arajo, Jackson Victor; Bartholomeu, Daniella Castanheira; Fujiwara, Ricardo Toshio

    2015-01-01

    Nematodes infections are responsible for debilitating conditions and economic losses in domestic animals as well as livestock and are considered an important public health problem due to the high prevalence in humans. The nematode resistance for drugs has been reported for livestock, highlighting the importance for development of new anthelmintic compounds. The aim of the current study was to apply and compare fluorimetric techniques using Sytox and propidium iodide for evaluating the viability of C. elegans larvae after treatment with anthelmintic drugs. These fluorescent markers were efficient to stain larvae treated with ivermectin and albendazole sulfoxide. We observed that densitometric values were proportional to the concentration of dead larvae stained with both markers. Furthermore, data on motility test presented an inverse correlation with fluorimetric data when ivermectin was used. Our results showed that lower concentrations of drugs were effective to interfere in the processes of cellular transport while higher drugs concentrations were necessary in order to result in any damage to cell integrity. The methodology described in this work might be useful for studies that aim to evaluate the viability of nematodes, particularly for testing of new anthelminthic compounds using an easy, economic, reproducible, and no time-consuming technique. PMID:25866820

  19. Assessment of skin flap viability using visible diffuse reflectance spectroscopy and auto-fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhu, Caigang; Chen, Shuo; Chui, Christopher Hoe-Kong; Liu, Quan

    2012-12-01

    The accurate assessment of skin flap viability is vitally important in reconstructive surgery. Early identification of vascular compromise increases the change of successful flap salvage. The ability to determine tissue viability intraoperatively is also extremely useful when the reconstructive surgeon must decide how to inset the flap and whether any tissue must be discarded. Visible diffuse reflectance and auto-fluorescence spectroscopy, which yield different sets of biochemical information, have not been used in the characterization of skin flap viability simultaneously to our best knowledge. We performed both diffuse reflectance and fluorescence measurements on a reverse MacFarlane rat dorsal skin flap model to identify the additional value of auto-fluorescence spectroscopy to the assessment of flap viability. Our result suggests that auto-fluorescence spectroscopy appears to be more sensitive to early biochemical changes in a failed flap than diffuse reflectance spectroscopy, which could be a valuable complement to diffuse reflectance spectroscopy for the assessment of flap viability.

  20. Determining the optimal nitrogen rate for summer maize in China by integrating agronomic, economic, and environmental aspects

    NASA Astrophysics Data System (ADS)

    Wang, G. L.; Ye, Y. L.; Chen, X. P.; Cui, Z. L.

    2014-06-01

    The concept of high yield with a goal of minimum environmental cost has become widely accepted. However, the trade-offs and complex linkages among agronomic, economic, and environmental factors are not yet well understood. In this study, reactive nitrogen (Nr) losses were estimated using an empirical model, and an economic indicator and an evaluation model were used to account for the environmental costs of N fertilizer production and use. The minimum N rate to achieve the maximum yield benefit (agronomically optimal N rate), maximum economic benefit (economically optimal N rate: economic benefit was defined as yield benefit minus N fertilizer cost), and maximum net benefit (ecologically optimal N rate: net benefit was defined as yield benefit minus N fertilizer and environmental costs) were estimated based on 91 on-farm experiment sites with five N levels for summer maize production on the North China Plain. Across all experimental sites, the agronomically, economically, and ecologically optimal N rates (Nagr, Neco, and Necl, respectively) averaged 289, 237, and 171 kg N ha-1, respectively. Necl management increased net benefit by 53% with a 46% decrease in total environmental costs, and a 51% decrease in Nr loss intensity from N fertilizer use (47, 65, and 38% for N2O emission, N leaching, and NH3 volatilization, respectively) and maintained grain yield, compared with Nagr management. Compared with Neco management, Necl increased net benefit by 12%, with a 31% decrease in total environmental costs and a 33% decrease in Nr loss intensity from N fertilizer use, and maintained economic benefit and grain yield. No differences in Necl were observed between soil types or years, but significant variation among counties was revealed. Necl increased with the increase in N-derived yield with an R2 of 0.83. In conclusion, Necl was primarily affected by N-derived yield and could enhance profitability as well as reduce Nr losses associated with the maize grain yield.

  1. Determining the optimal nitrogen rate for summer maize in China by integrating agronomic, economic, and environmental aspects

    NASA Astrophysics Data System (ADS)

    Wang, G. L.; Ye, Y. L.; Chen, X. P.; Cui, Z. L.

    2014-02-01

    The concept of high yield with a goal of minimum environmental cost has become widely accepted. However, the trade-offs and complex linkages among agronomic, economic, and environmental factors are not yet well understood. In this study, reactive nitrogen (Nr) losses were estimated using an empirical model, and an economic indicator and an evaluation model were used to account for the environmental costs of different Nr losses after N fertilizer application. The minimum N rate to achieve the maximum yield benefit (agronomically optimal N rate), maximum economic benefit (economically optimal N rate: economic benefit was defined as yield benefit minus N fertilizer cost), and maximum net benefit (ecologically optimal N rate: net benefit was defined as yield benefit minus N fertilizer and environmental costs) were estimated based on 91 on-farm experiment sites with five N levels for summer maize production on the North China Plain. Across all experimental sites, the agronomically, economically, and ecologically optimal N rates (Nagr, Neco, and Necl, respectively) averaged 289, 237, and 186 kg N ha-1, respectively. Necl management increased net benefit by 31% with a 45% decrease in Nr loss intensity (44%, 60%, and 33% for N2O emission, N leaching, and NH3 volatilization, respectively) and maintained grain yield, compared to Nagr management. Compared to Neco management, Necl increased net benefit by 6%, with a 27% decrease in Nr loss intensity, and maintained economic benefit and grain yield. No differences in Necl were observed between soil types or years, but significant variation among counties was revealed. Necl increased with the increase in N-derived yield with an R2 of 0.80. In conclusion, Necl was primarily affected by N-derived yield and could enhance profitability as well as reduce Nr losses associated with the maize grain yield.

  2. The effect of ultrasound-related stimuli on cell viability in microfluidic channels

    PubMed Central

    2013-01-01

    Background In ultrasonic micro-devices, contrast agent micro-bubbles are known to initiate cavitation and streaming local to cells, potentially compromising cell viability. Here we investigate the effects of US alone by omitting contrast agent and monitoring cell viability under moderate-to-extreme ultrasound-related stimuli. Results Suspended H9c2 cardiac myoblasts were exposed to ultrasonic fields within a glass micro-capillary and their viability monitored under different US-related stimuli. An optimal injection flow rate of 2.6 mL/h was identified in which, high viability was maintained (~95%) and no mechanical stress towards cells was evident. This flow rate also allowed sufficient exposure of cells to US in order to induce bioeffects (~5 sec), whilst providing economical sample collection and processing times. Although the transducer temperature increased from ambient 23C to 54C at the maximum experimental voltage (29 Vpp), computational fluid dynamic simulations and controls (absence of US) revealed that the cell medium temperature did not exceed 34C in the pressure nodal plane. Cells exposed to US amplitudes ranging from 029 Vpp, at a fixed frequency sweep period (tsw = 0.05 sec), revealed that viability was minimally affected up to ~15 Vpp. There was a ~17% reduction in viability at 21 Vpp, corresponding to the onset of Rayleigh-like streaming and a ~60% reduction at 29 Vpp, corresponding to increased streaming velocity or the potential onset of cavitation. At a fixed amplitude (29 Vpp) but with varying frequency sweep period (tsw = 0.02-0.50 sec), cell viability remained relatively constant at tsw ? 0.08 sec, whilst viability reduced at tsw < 0.08 sec and minimum viability recorded at tsw = 0.05 sec. Conclusion The absence of CA has enabled us to investigate the effect of US alone on cell viability. Moderate-to-extreme US-related stimuli of cells have allowed us to discriminate between stimuli that maintain high viability and stimuli that significantly reduce cell viability. Results from this study may be of potential interest to researchers in the field of US-induced intracellular drug delivery and ultrasonic manipulation of biological cells. PMID:23809777

  3. Poxvirus Viability and Signatures in Historical Relics

    PubMed Central

    Li, Yu; Wilkins, Kimberly; Karem, Kevin L.; Davidson, Whitni B.; Paddock, Christopher D.; Reynolds, Mary G.; Damon, Inger K.

    2014-01-01

    Although it has been >30 years since the eradication of smallpox, the unearthing of well-preserved tissue material in which the virus may reside has called into question the viability of variola virus decades or centuries after its original occurrence. Experimental data to address the long-term stability and viability of the virus are limited. There are several instances of well-preserved corpses and tissues that have been examined for poxvirus viability and viral DNA. These historical specimens cause concern for potential exposures, and each situation should be approached cautiously and independently with the available information. Nevertheless, these specimens provide information on the history of a major disease and vaccination against it. PMID:24447382

  4. Poxvirus viability and signatures in historical relics.

    PubMed

    McCollum, Andrea M; Li, Yu; Wilkins, Kimberly; Karem, Kevin L; Davidson, Whitni B; Paddock, Christopher D; Reynolds, Mary G; Damon, Inger K

    2014-02-01

    Although it has been >30 years since the eradication of smallpox, the unearthing of well-preserved tissue material in which the virus may reside has called into question the viability of variola virus decades or centuries after its original occurrence. Experimental data to address the long-term stability and viability of the virus are limited. There are several instances of well-preserved corpses and tissues that have been examined for poxvirus viability and viral DNA. These historical specimens cause concern for potential exposures, and each situation should be approached cautiously and independently with the available information. Nevertheless, these specimens provide information on the history of a major disease and vaccination against it. PMID:24447382

  5. Probiotic viability – does it matter?

    PubMed Central

    Lahtinen, Sampo J.

    2012-01-01

    Probiotics are viable by definition, and viability of probiotics is often considered to be a prerequisite for the health benefits. Indeed, the overwhelming majority of clinical studies in the field have been performed with viable probiotics. However, it has also been speculated that some of the mechanisms behind the probiotic health effects may not be dependent on the viability of the cells and, therefore, is also possible that also non-viable probiotics could have some health benefits. The efficacy of non-viable probiotics has been assessed in a limited number of studies, with varying success. While it is clear that viable probiotics are more effective than non-viable probiotics and that, in many cases, viability is indeed a prerequisite for the health benefit, there are also some cases where it appears that non-viable probiotics could also have beneficial effects on human health. PMID:23990833

  6. Economic Time Series Modeling to Determine the Feasibility of Incorporating Drinking Water Treatment in Water Quality Trading

    EPA Science Inventory

    The critical steps required to evaluating the feasiblity of establishing a water quality trading market in a testbed watershed is described. Focus is given toward describing the problem of thin markets as a specifi barrier to successful trading. Economic theory for considering an...

  7. Viability Assays for Cells in Culture

    PubMed Central

    Posimo, Jessica M.; Unnithan, Ajay S.; Gleixner, Amanda M.; Choi, Hailey J.; Jiang, Yiran; Pulugulla, Sree H.; Leak, Rehana K.

    2014-01-01

    Manual cell counts on a microscope are a sensitive means of assessing cellular viability but are time-consuming and therefore expensive. Computerized viability assays are expensive in terms of equipment but can be faster and more objective than manual cell counts. The present report describes the use of three such viability assays. Two of these assays are infrared and one is luminescent. Both infrared assays rely on a 16bit Odyssey Imager. One infrared assay uses the DRAQ5 stain for nuclei combined with the Sapphire stain for cytosol and is visualized in the 700 nm channel. The other infrared assay, an In-Cell Western, uses antibodies against cytoskeletal proteins (?-tubulin or microtubule associated protein 2) and labels them in the 800 nm channel. The third viability assay is a commonly used luminescent assay for ATP, but we use a quarter of the recommended volume to save on cost. These measurements are all linear and correlate with the number of cells plated, but vary in sensitivity. All three assays circumvent time-consuming microscopy and sample the entire well, thereby reducing sampling error. Finally, all of the assays can easily be completed within one day of the end of the experiment, allowing greater numbers of experiments to be performed within short timeframes. However, they all rely on the assumption that cell numbers remain in proportion to signal strength after treatments, an assumption that is sometimes not met, especially for cellular ATP. Furthermore, if cells increase or decrease in size after treatment, this might affect signal strength without affecting cell number. We conclude that all viability assays, including manual counts, suffer from a number of caveats, but that computerized viability assays are well worth the initial investment. Using all three assays together yields a comprehensive view of cellular structure and function. PMID:24472892

  8. Economic Evaluation of Observatory Solar-Energy System

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Long-term economic performance of a commercial solar-energy system was analyzed and used to predict economic performance at four additional sites. Analysis described in report was done to demonstrate viability of design over a broad range of environmental/economic conditions. Topics covered are system description, study approach, economic analysis and system optimization.

  9. Metronidazole decreases viability of DLD-1 colorectal cancer cell line.

    PubMed

    Sadowska, Anna; Kr?towski, Rafa?; Szynaka, Beata; Cechowska-Pasko, Marzanna; Car, Halina

    2013-10-01

    The aim of our study was to evaluate the impact of metronidazole (MTZ) on DLD-1 colorectal cancer cell (CRC) line. Toxicity of MTZ was determined by MTT test. Cells were incubated with MTZ used in different concentrations for 24, 48, and 72 hours. The effect of MTZ on DNA synthesis was measured as [3H]-thymidine incorporation. The morphological changes in human DLD-1 cell line were defined by transmission electron microscope OPTON 900. The influence of MTZ on the apoptosis of DLD-1 cell lines was detected by flow cytometry and fluorescence microscopy, while cell concentration, volume, and diameter were displayed by Scepter Cell Counter from Millipore. Our results show that cell viability was diminished in all experimental groups in comparison with the control, and the differences were statistically significant. We did not find any significant differences in [3H]-thymidine incorporation in all experimental groups and times of observation. Cytofluorimetric assays demonstrated a statistically significant increase of apoptotic rate in MTZ concentrations 10 and 50??g/mL after 24 hours; 0.1, 10, 50, and 250??g/mL after 48 hours; and in all concentrations after 72 hours compared with control groups. In the ultrastructural studies, necrotic or apoptotic cells were occasionally seen. In conclusion, MTZ affects human CRC cell line viability. The reduction of cell viability was consistent with the apoptotic test. PMID:23777253

  10. Metronidazole Decreases Viability of DLD-1 Colorectal Cancer Cell Line

    PubMed Central

    Sadowska, Anna; Kr?towski, Rafa?; Szynaka, Beata; Cechowska-Pasko, Marzanna

    2013-01-01

    Abstract The aim of our study was to evaluate the impact of metronidazole (MTZ) on DLD-1 colorectal cancer cell (CRC) line. Toxicity of MTZ was determined by MTT test. Cells were incubated with MTZ used in different concentrations for 24, 48, and 72 hours. The effect of MTZ on DNA synthesis was measured as [3H]-thymidine incorporation. The morphological changes in human DLD-1 cell line were defined by transmission electron microscope OPTON 900. The influence of MTZ on the apoptosis of DLD-1 cell lines was detected by flow cytometry and fluorescence microscopy, while cell concentration, volume, and diameter were displayed by Scepter Cell Counter from Millipore. Our results show that cell viability was diminished in all experimental groups in comparison with the control, and the differences were statistically significant. We did not find any significant differences in [3H]-thymidine incorporation in all experimental groups and times of observation. Cytofluorimetric assays demonstrated a statistically significant increase of apoptotic rate in MTZ concentrations 10 and 50??g/mL after 24 hours; 0.1, 10, 50, and 250??g/mL after 48 hours; and in all concentrations after 72 hours compared with control groups. In the ultrastructural studies, necrotic or apoptotic cells were occasionally seen. In conclusion, MTZ affects human CRC cell line viability. The reduction of cell viability was consistent with the apoptotic test. PMID:23777253

  11. Sphingosine Kinase Activity Is Not Required for Tumor Cell Viability

    PubMed Central

    Brown, Matthew L.; Carlson, Timothy; Coxon, Angela; Fajardo, Flordeliza; Frank, Brendon; Gustin, Darin; Kamb, Alexander; Kassner, Paul D.; Li, Shyun; Li, Yihong; Morgenstern, Kurt; Plant, Matthew; Quon, Kim; Ruefli-Brasse, Astrid; Schmidt, Joanna; Swearingen, Elissa; Walker, Nigel; Wang, Zhulun; Watson, J. E. Vivienne; Wickramasinghe, Dineli; Wong, Mariwil; Xu, Guifen; Wesche, Holger

    2013-01-01

    Sphingosine kinases (SPHKs) are enzymes that phosphorylate the lipid sphingosine, leading to the formation of sphingosine-1-phosphate (S1P). In addition to the well established role of extracellular S1P as a mitogen and potent chemoattractant, SPHK activity has been postulated to be an important intracellular regulator of apoptosis. According to the proposed rheostat theory, SPHK activity shifts the intracellular balance from the pro-apoptotic sphingolipids ceramide and sphingosine to the mitogenic S1P, thereby determining the susceptibility of a cell to apoptotic stress. Despite numerous publications with supporting evidence, a clear experimental confirmation of the impact of this mechanism on tumor cell viability in vitro and in vivo has been hampered by the lack of suitable tool reagents. Utilizing a structure based design approach, we developed potent and specific SPHK1/2 inhibitors. These compounds completely inhibited intracellular S1P production in human cells and attenuated vascular permeability in mice, but did not lead to reduced tumor cell growth in vitro or in vivo. In addition, siRNA experiments targeting either SPHK1 or SPHK2 in a large panel of cell lines failed to demonstrate any statistically significant effects on cell viability. These results show that the SPHK rheostat does not play a major role in tumor cell viability, and that SPHKs might not be attractive targets for pharmacological intervention in the area of oncology. PMID:23861887

  12. Economics of Distance Education Reconsidered

    ERIC Educational Resources Information Center

    Laaser, Wolfram

    2008-01-01

    According to Gartner a certain hype of e-Learning was followed by a downturn but eLearning will continue to be an important factor in learning scenarios. However the economic viability of e-learning projects will be questioned with more scrutiny than in earlier periods. Therefore it seems to be a good opportunity to see what can be learned from

  13. The socioeconomic determinants of health: economic growth and health in the OECD countries during the last three decades.

    PubMed

    Lpez-Casasnovas, Guillem; Soley-Bori, Marina

    2014-01-01

    In times of economic crisis, most countries face the dual challenge of fighting unemployment while restraining social expenditures and closing budget deficits. The spending cuts and lack of employment affect a large number of decisions that have a direct or indirect impact on health. This impact is likely to be unevenly distributed among different groups within the population, and therefore not only health levels may be at risk, but also their distribution. The main purpose of this paper is to explore links between unemployment, economic growth, inequality, and health. We regress a measure of health, the Health Human Development Index (HHDI), against a set of explanatory variables accounting for the countries' economic performance (GDP growth, unemployment, and income inequality), and some institutional factors related to welfare spending and the nature of the health systems for the past three decades. In addition, we explore the causes for different results obtained using an inequality-adjusted HHDI, vs. the unadjusted HHDI. We describe a panel data model, estimated by random effects, for 32 countries from 1980-2010, in five-year intervals. Our conclusion is that the high economic growth observed in the last decades, together with an increase in the levels of income inequality and/or poverty, explain the observed changes of our index, particularly when this indicator is weighted by health inequality. The remaining institutional variables (the share of social spending, health care expenditure, and the type of health systems) show the expected sign but are not statistically significant. A comment on the methodological pitfalls of the approach completes the analysis. PMID:24406664

  14. The Socioeconomic Determinants of Health: Economic Growth and Health in the OECD Countries during the Last Three Decades

    PubMed Central

    López-Casasnovas, Guillem; Soley-Bori, Marina

    2014-01-01

    In times of economic crisis, most countries face the dual challenge of fighting unemployment while restraining social expenditures and closing budget deficits. The spending cuts and lack of employment affect a large number of decisions that have a direct or indirect impact on health. This impact is likely to be unevenly distributed among different groups within the population, and therefore not only health levels may be at risk, but also their distribution. The main purpose of this paper is to explore links between unemployment, economic growth, inequality, and health. We regress a measure of health, the Health Human Development Index (HHDI), against a set of explanatory variables accounting for the countries’ economic performance (GDP growth, unemployment, and income inequality), and some institutional factors related to welfare spending and the nature of the health systems for the past three decades. In addition, we explore the causes for different results obtained using an inequality-adjusted HHDI, vs. the unadjusted HHDI. We describe a panel data model, estimated by random effects, for 32 countries from 1980–2010, in five-year intervals. Our conclusion is that the high economic growth observed in the last decades, together with an increase in the levels of income inequality and/or poverty, explain the observed changes of our index, particularly when this indicator is weighted by health inequality. The remaining institutional variables (the share of social spending, health care expenditure, and the type of health systems) show the expected sign but are not statistically significant. A comment on the methodological pitfalls of the approach completes the analysis. PMID:24406664

  15. Viability of piping plover Charadrius melodus metapopulations

    USGS Publications Warehouse

    Plissner, Jonathan H.; Haig, Susan M.

    2000-01-01

    The metapopulation viability analysis package, VORTEX, was used to examine viability and recovery objectives for piping plovers Charadrius melodus, an endangered shorebird that breeds in three distinct regions of North America. Baseline models indicate that while Atlantic Coast populations, under current management practices, are at little risk of near-term extinction, Great Plains and Great Lakes populations require 36% higher mean fecundity for a significant probability of persisting for the next 100 years. Metapopulation structure (i.e. the delineation of populations within the metapopulation) and interpopulation dispersal rates had varying effects on model results; however, spatially-structured metapopulations exhibited lower viability than that reported for single-population models. The models were most sensitive to variation in survivorship; hence, additional mortality data will improve their accuracy. With this information, such models become useful tools in identifying successful management objectives; and sensitivity analyses, even in the absence of some data, may indicate which options are likely to be most effective. Metapopulation viability models are best suited for developing conservation strategies for achieving recovery objectives based on maintaining an externally derived, target population size and structure.

  16. Viability of nonminimally coupled f (R) gravity

    NASA Astrophysics Data System (ADS)

    Bertolami, Orfeu; Páramos, Jorge

    2016-03-01

    In this work we explore the viability of nonminimally coupled matter-curvature gravity theories, namely the conditions required for the absence of tachyon instabilities and ghost degrees of freedom. We contrast our finds with recent claims of a pathological behaviour of this class of models, which resorted to, in our view, an incorrect analogy with k-essence.

  17. Optimal optical trap for bacterial viability

    NASA Astrophysics Data System (ADS)

    Mirsaidov, Utkur; Timp, Winston; Timp, Kaethe; Mir, Mustafa; Matsudaira, Paul; Timp, Gregory

    2008-08-01

    Optical trapping is a powerful tool for the micromanipulation of living cellsespecially bacteriabut photodamage induced by the laser beam can adversely affect viability. We have explored optical trapping conditions in the near infrared (840-930nm) that preserve the viability of E. coli, as measured by gene expression of green fluorescent protein. We have found that time-sharing the optical traps, i.e., dwelling only 10?s-1ms on the cell, improves viability relative to continuous wave (CW) exposure for the same exposure time. We have also observed that similar to CW traps the photodamage in a time-shared trap depends weakly on wavelength, but linearly on peak power, implying an effect induced by single photon absorption. Taken altogether, integrating the exposure time and peak power, the data indicate that there is a lethal energy dose of about 5J for E. coli. Thus a single parameterthe energycan be used to describe the limitation on viability.

  18. Observability in strategic models of viability selection.

    PubMed

    Gmez, M; Carreo, R; Ksa, A; Varga, Z

    2003-10-01

    Strategic models of frequency-dependent viability selection, in terms of mathematical systems theory, are considered as a dynamic observation system. Using a general sufficient condition for observability of nonlinear systems with invariant manifold, it is studied whether, observing certain phenotypic characteristics of the population, the development of its genetic state can be recovered, at least near equilibrium. PMID:14563566

  19. Viability of the Matter Bounce Scenario

    NASA Astrophysics Data System (ADS)

    de Haro, Jaume; Amorós, Jaume

    2015-04-01

    It is shown that teleparallel F(T) theories of gravity combined with Loop Quantum Cosmology support a Matter Bounce Scenario which is an alternative to the inflation scenario in the Big Bang paradigm. It is checked that these bouncing models provide theoretical data that fits well with the current observational data, allowing the viability of the Matter Bounce Scenario.

  20. The Viability of "Roe v. Wade."

    ERIC Educational Resources Information Center

    Belson, Nicole

    1989-01-01

    Examines four issues involved in "Webster v. Reproductive Health Services:" (1) the preamble to the 1986 Missouri statute on abortion, (2) prohibiting public employees from performing abortions, (3) public funds for encouraging abortion, and (4) gestational age and viability provision. Focuses on the effects on the continuing vitality of the

  1. Storage and Viability of Hedychium Pollen

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hedychium species generally flower in the summer and fall, but some bloom in winter and spring times. The different flowering times of the species implies that there is a need to find a way for storing and conserving viable pollen. The maintenance of pollen viability depends on several factors, incl...

  2. Viability of mesenchymal stem cells during electrospinning.

    PubMed

    Zanatta, G; Steffens, D; Braghirolli, D I; Fernandes, R A; Netto, C A; Pranke, P

    2012-02-01

    Tissue engineering is a technique by which a live tissue can be re-constructed and one of its main goals is to associate cells with biomaterials. Electrospinning is a technique that facilitates the production of nanofibers and is commonly used to develop fibrous scaffolds to be used in tissue engineering. In the present study, a different approach for cell incorporation into fibrous scaffolds was tested. Mesenchymal stem cells were extracted from the wall of the umbilical cord and mononuclear cells from umbilical cord blood. Cells were re-suspended in a 10% polyvinyl alcohol solution and subjected to electrospinning for 30 min under a voltage of 21 kV. Cell viability was assessed before and after the procedure by exclusion of dead cells using trypan blue staining. Fiber diameter was observed by scanning electron microscopy and the presence of cells within the scaffolds was analyzed by confocal laser scanning microscopy. After electrospinning, the viability of mesenchymal stem cells was reduced from 88 to 19.6% and the viability of mononuclear cells from 99 to 8.38%. The loss of viability was possibly due to the high viscosity of the polymer solution, which reduced the access to nutrients associated with electric and mechanical stress during electrospinning. These results suggest that the incorporation of cells during fiber formation by electrospinning is a viable process that needs more investigation in order to find ways to protect cells from damage. PMID:22183245

  3. Viability of mesenchymal stem cells during electrospinning

    PubMed Central

    Zanatta, G.; Steffens, D.; Braghirolli, D.I.; Fernandes, R.A.; Netto, C.A.; Pranke, P.

    2011-01-01

    Tissue engineering is a technique by which a live tissue can be re-constructed and one of its main goals is to associate cells with biomaterials. Electrospinning is a technique that facilitates the production of nanofibers and is commonly used to develop fibrous scaffolds to be used in tissue engineering. In the present study, a different approach for cell incorporation into fibrous scaffolds was tested. Mesenchymal stem cells were extracted from the wall of the umbilical cord and mononuclear cells from umbilical cord blood. Cells were re-suspended in a 10% polyvinyl alcohol solution and subjected to electrospinning for 30 min under a voltage of 21 kV. Cell viability was assessed before and after the procedure by exclusion of dead cells using trypan blue staining. Fiber diameter was observed by scanning electron microscopy and the presence of cells within the scaffolds was analyzed by confocal laser scanning microscopy. After electrospinning, the viability of mesenchymal stem cells was reduced from 88 to 19.6% and the viability of mononuclear cells from 99 to 8.38%. The loss of viability was possibly due to the high viscosity of the polymer solution, which reduced the access to nutrients associated with electric and mechanical stress during electrospinning. These results suggest that the incorporation of cells during fiber formation by electrospinning is a viable process that needs more investigation in order to find ways to protect cells from damage. PMID:22183245

  4. Viability of bacteria in unused air filter media

    NASA Astrophysics Data System (ADS)

    Maus, R.; Goppelsröder, A.; Umhauer, H.

    Different experimental techniques were applied to determine the effects of different air filter media on the viability of bacteria. Rinse suspensions of unused filter media were employed in standard inhibition tests to determine the effects of filter ingredients on bacterial growth under ideal nutritional conditions. Furthermore, a new test procedure was proposed and validated to determine the survival of viable microorganisms in fibrous air filters as a function of different parameters. Samples of filter media were challenged with microbial aerosols in an experimental set-up designed for measuring the collection efficiencies of fibrous filters. The loaded filter samples were then challenged with clean air under controlled conditions for a definite time span and numbers of viable microorganisms in the filter media were determined as colony forming units. The filter samples were retrieved from unused filter media usually employed in common air conditioning and ventilation systems. Under ideal nutritional and moisture conditions, growth of investigated microorganisms in nutrient broth and on nutrient agar was not inhibited by the inclusion of filter samples or rinse solutions of different filters in the growth medium with one exception. M. luteus and E. coli collected in air filter media and exposed to low air humidity (RH = 30-60%) showed a decline in their viability as a function of time (within 1 h). The decline rate was dependent on the type of bacteria employed and also the filter material itself.

  5. Study of quiet turbofan STOL aircraft for short-haul transportation. Volume 5: Economics

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The economic aspects of the STOL aircraft for short-haul air transportation are discussed. The study emphasized the potential market, the preferred operational concepts, the design characteristics, and the economic viability. Three central issues governing economic viability are as follows: (1) operator economics given the market, (2) the required transportation facilities, and (3) the external economic effects of a set of regional STOL transportation systems.

  6. Fiches pratiques: Le circuit de l'herbe; Journal a plusieurs mains; Comment aborder l'economie d'une facon economique; Des articles d'autrefois aux determinants d'aujourd'hui (Practical Ideas: The Path of Grass; Group Diary; Approaching Economics in an Economical Way; From Yesterday's Articles to Today's Determiners).

    ERIC Educational Resources Information Center

    Vever, Daniel; And Others

    1991-01-01

    Four activities for the French language classroom are described, including a comprehension game based on the cow's digestive system, a group journal exercise using current events, an economics vocabulary development activity, and a grammar exercise focusing on the use of determiners in news articles. (MSE)

  7. Infrared Signatures to Discriminate Viability of Autoclaved Bacillus Spores

    SciTech Connect

    Schneider, Matthew D.; Valentine, Nancy B.; Johnson, Timothy J.

    2011-10-06

    Optical methods can offer good sensitivity for detecting small amounts of chemicals and biologicals, and as these methods mature, are some of the few techniques that can offer true standoff detection. For detection of biological species, determining the viability is clearly important: Certain species of gram-positive bacteria are capable of forming endospores, specialized structures that arise when living conditions become unfavorable or little growth medium is available, being resistant to many chemicals as well as changes in heat or pH. Such spores can remain dormant from months to years until more favorable conditions arise, resulting in germination back to the vegetative state. This persistence characteristic of bacterial spores allows for contamination of a surface (e.g. food or medical equipment) even after the surface has been nominally cleaned. Bacterial spores have also been used as biological weapons, as in the case with B. anthracis. Thus, rapid analysis to determine a spore's viability in a given environment or after attempts to sterilize a given environment is crucial. The increasing availability of portable spectrometers may provide a key to such rapid onsite analysis. The present study was designed to determine whether infrared spectroscopy may be used to differentiate between viable vs. dead B. subtilis and B. atrophaeus spores. Preliminary results show that the reproducible differences in the IR signatures can be used to identify viable vs. autoclaved (dead) B. subtilis and B. atrophaeus bacterial spores.

  8. Infrared signatures to discriminate viability of autoclaved Bacillus spores

    NASA Astrophysics Data System (ADS)

    Schneider, Matthew D. W.; Valentine, Nancy B.; Johnson, Timothy J.

    2011-11-01

    Optical methods can offer good sensitivity for detecting small amounts of chemicals and biologicals, and as these methods mature, are some of the few techniques that can offer true standoff detection. For detection of biological species, determining the viability is clearly important: Certain species of gram-positive bacteria are capable of forming endospores, specialized structures that arise when living conditions become unfavorable or little growth medium is available. Spores are also resistant to many chemicals as well as changes in heat or pH; such spores can remain dormant from months to years until more favorable conditions arise, resulting in germination back to the vegetative state. This persistence characteristic of bacterial spores allows for contamination of a surface (e.g. food or medical equipment) even after the surface has been nominally cleaned. Bacterial spores have also been used as biological weapons, as in the case of B. anthracis. Thus, having rapid analytical methods to determine a spore's viability after attempts to clean a given environment is crucial. The increasing availability of portable spectrometers may provide a key to such rapid onsite analysis. The present study was designed to determine whether infrared spectroscopy may be used to differentiate between viable vs. dead B. subtilis and B. atrophaeus spores. Preliminary results show that the reproducible differences in the IR signatures can be used to identify the viable vs. the autoclaved (dead) spores.

  9. Factors determining the viability of radiation processing in developing countries

    NASA Astrophysics Data System (ADS)

    van der Linde, HJ; Basson, RA

    In the fifteen years since the introduction of radiation processing to South Africa, four commercial irradiation facilities have been established. These are involved in the processing of a large variety of products, from syringes and prostheses to strawberries and sugar yeast. Three of the facilities are devoted mainly to food irradiation and several thousand tonnes are now processed annually. During this period it was repeatedly experienced that the successful introduction of radiation processing in general, and food radurization in particular, on a commercial scale was critically dependent on the following factors: acceptance by the producer, industry and consumer; initial capital expenditure; running costs and overheads in general; and continous throughput. All of these factors contribute to the processing cost which is the ultimate factor in determing the value/price ratio for the potential entrepreneur and customer of this new technology. After a market survey had identified the need for a new food irradiation facility to cope with the growing interest in commercial food radurization in the Western Cape, the above-mentioned factors were of cardinal importance in the design and manufacture of a new irradiator. The resulting batch-pallet facility which was commisioned in August 1986, is rather inefficient as far as energy utilization is concerned but this shortcoming is compensated for by its low cost, versatility and low hold-up. Although the facility has limitations as far as the processing of really large volumes of produce is concerned, it is particularly suitable not only for developing countries, but for developed countries in the introductory phase of commercial food radurization.

  10. A rapid, economical, and accurate method to determining the physical risk of storm marine inundations using sedimentary evidence

    NASA Astrophysics Data System (ADS)

    Nott, Jonathan F.

    2015-04-01

    The majority of physical risk assessments from storm surge inundations are derived from synthetic time series generated from short climate records, which can often result in inaccuracies and are time-consuming and expensive to develop. A new method is presented here for the wet tropics region of northeast Australia. It uses lidar-generated topographic cross sections of beach ridge plains, which have been demonstrated to be deposited by marine inundations generated by tropical cyclones. Extreme value theory statistics are applied to data derived from the cross sections to generate return period plots for a given location. The results suggest that previous methods to estimate return periods using synthetic data sets have underestimated the magnitude/frequency relationship by at least an order of magnitude. The new method promises to be a more rapid, economical, and accurate assessment of the physical risk of these events.

  11. A Search Algorithm for Determination of Economic Order Quantity in a Two-Level Supply Chain System with Transportation Cost

    NASA Astrophysics Data System (ADS)

    Pirayesh Neghab, Mohammadali; Haji, Rasoul

    This study considers a two-level supply chain system consisting of one warehouse and a number of identical retailers. In this system, we incorporate transportation costs into inventory replenishment decisions. The transportation cost contains a fixed cost and a variable cost. We assume that the demand rate at each retailer is known and the demand is confined to a single item. First, we derive the total cost which is the sum of the holding and ordering cost at the warehouse and retailers as well as the transportation cost from the warehouse to retailers. Then, we propose a search algorithm to find the economic order quantities for the warehouse and retailers which minimize the total cost.

  12. Determination of anionactive tensides using cetylpyridinium tetrachlorozincate as titrant. Analytical methods in respect to environmental and economical concern, part 20.

    PubMed

    Hilp, M

    2004-09-01

    Sodium lauryl sulphate (sodium dodecylsulphate) can be determined in aqueous medium using cetylpyridinium tetrachlorozincate as standard solution and methyl orange resp. bromophenol blue as indicator. However, the determination of cetostearyl sulphate is problematic due to its slight solubility in cold water. Therefore, the titration has to be performed in warm solution. As well with methyl orange as with bromophenol blue the change of the indicator has to be titrated to colour shade. A photometric detection is recommended. The visual indication concerning the determination of the content of the technical solutions of the secondary paraffin sulphonates such as Ateban TH liquid and Marlon PS 30 is also critical. PMID:15497747

  13. Thyroid Hormone Signaling and Cone Photoreceptor Viability.

    PubMed

    Ma, Hongwei; Ding, Xi-Qin

    2016-01-01

    Thyroid hormone (TH) signaling regulates cell proliferation, differentiation, and apoptosis. In the retina, TH signaling plays a central role in cone opsin expression. TH signaling inhibits S opsin expression, stimulates M opsin expression, and promotes dorsal-ventral opsin patterning. TH signaling has also been associated with cone photoreceptor viability. Treatment with thyroid hormone triiodothyronine (T3) or induction of high T3 by deleting the hormone-inactivating enzyme type 3 iodothyronine deiodinase (DIO3) causes cone death in mice. This effect is reversed by deletion of the TH receptor (TR) gene. Consistent with the T3 treatment effect, suppressing TH signaling preserves cones in mouse models of retinal degeneration. The regulation of cone survival by TH signaling appears to be independent of its regulatory role in cone opsin expression. The mechanism by which TH signaling regulates cone viability remains to be identified. The current understanding of TH signaling regulation in photoreceptor viability suggests that suppressing TH signaling locally in the retina may represent a novel strategy for retinal degeneration management. PMID:26427466

  14. Routine assessment of viability in split-thickness skin.

    PubMed

    Yang, H; Jia, X M; Acker, J P; Lung, G; McGann, L E

    2000-01-01

    Effective quality control of allograft skin that is cryopreserved for transplantation requires a simple, reproducible technique for the assessment of cell viability. Tetrazolium reduction assays and an oxygen consumption technique have been the two methods of choice to determine the metabolic function of allograft skin after it has been thawed. In this study, we investigated the use of a novel tetrazolium salt, WST-1 (4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzen e disulfonate), that is cleaved to a water-soluble formazan product. Porcine split-thickness skin in minimal essential medium without cryoprotectant was subjected to a graded freezing protocol to generate progressive amounts of cryoinjury. Recovery as determined with WST-1 was compared with measurements made with the use of the oxygen consumption technique. The similarity of the resulting recovery curves indicates that WST-1 is a simple, effective, and convenient technique for the assessment of metabolic function in porcine split-thickness skin. The WST-1 assay is applicable for the routine assessment of tissue viability in cryopreserved allograft skin. PMID:10752741

  15. Low socio-economic environmental determinants of children's physical activity in Coventry, UK: A Qualitative study in parents

    PubMed Central

    Eyre, E.L.J.; Duncan, M.J.; Birch, S.L.; Cox, V.M.

    2014-01-01

    Background Children's physical activity (PA) is affected by socio-economic status (SES) and the environment. Children are not fully autonomous in their decision making; parental decisions thus affect how children utilise their surrounding environments for PA. The aim was to examine environmental influences on children's PA from a qualitative perspective in parents from low SES wards in Coventry, UK. Method 59 parents of children in year 4 (aged 8–9years) completed the ALPHA environmental questionnaire. 16 of these parents took part in focus group discussions examining environmental facilitators and barriers to their child's PA (March–April, 2013). Results Emerging themes related to physical (i.e. poor access, safety and quality of the neighbourhood) and social environment (i.e. ‘rough’ neighbourhood due to crime and anti-social behaviour) influences on the PA behaviour of children. The parents believed these environmental factors resulted in the children engaging in greater sedentary activity (watching TV) indoors. The school environment was perceived as a supportive physical environment for children's PA behaviour. Conclusion Parent's perceptions of an unsupportive physical and social environment restrict children's opportunities to play outside and be physically active and may lead to increased body fat (BF). Schools provide a supportive environment for children from low SES to be physically active in. PMID:26844037

  16. Salinity effects on viability, metabolic activity and proliferation of three Perkinsus species

    USGS Publications Warehouse

    La, Peyre M.; Casas, S.; La, Peyre J.

    2006-01-01

    Little is known regarding the range of conditions in which many Perkinsus species may proliferate, making it difficult to predict conditions favorable for their expansion, to identify conditions inducing mortality, or to identify instances of potential cross-infectivity among sympatric host species. In this study, the effects of salinity on viability, metabolic activity and proliferation of P. marinus, P. olseni and P. chesapeaki were determined. Specifically, this research examined the effects of 5 salinities (7, 11, 15, 25, 35???), (1) without acclimation, on the viability and metabolic activity of 2 isolates of each Perkinsus species, and (2) with acclimation, on the viability, metabolic activity, size and number of 1 isolate of each species. P. chesapeaki showed the widest range of salinity tolerance of the 3 species, with high viability and cell proliferation at all salinities tested. Although P. chesapeaki originated from low salinity areas (i.e. <15???), several measures (i.e. cell number and metabolic activity) indicated that higher salinities (15, 25???) were more favorable for its growth. P. olseni, originating from high salinity areas, had better viability and proliferation at the higher salinities (15, 25, 35???). Distinct differences in acute salinity response of the 2 P. olseni isolates at lower salinities (7, 11???), however, suggest the need for a more expansive comparison of isolates to better define the lower salinity tolerance. Lastly, P. marinus was more tolerant of the lower salinities (7 and 11???) than P. olseni, but exhibited reduced viability at 7???, even after acclimation. ?? Inter-Research 2006.

  17. The role of natural resource and environmental economics in determining the trade-offs in consumption and production of energy inputs: The case of biomass energy crops

    SciTech Connect

    Downing, M.; Graham, R.L.

    1993-12-31

    Natural resource economics issues deal with flows and funds of renewable and nonrenewable resources over time. These issues include topics concerned with management of fisheries, forests, mineral, energy resources, the extinction of species and the irreversibility of development over time. Environmental economics issues deal with regulation of polluting activities and the valuation of environmental amenities. In this study we outline a framework for studying both natural resource and environmental economics issues for any renewable or nonrenewable resource. Valuation from both the cost and benefit sides are addressed as they relate to the valuation of environmental programs or policies. By using this top-down approach to analyze and determine the costs and benefits of using renewable or nonrenewable resources, policy-makers on the global, national and local scales may be better informed as to the probable nonmarket and market ramifications of their natural resource and environmental policy decisions. This general framework for analysis is then focused to address biomass energy crops and their usage as inputs to energy production. As with any energy technology, a complete analysis must include an examination of the entire fuel cycle; specifically both production and consumption sides. From a production standpoint, market valuation issues such as crop management techniques, inputs to production, and community economics issues must be addressed as well as nonmarket valuation issues such as soil erosion, ground water effects and carbon sequestration. On the consumption side, market valuation considerations such as energy fuel efficiency and quality, cost of conversion and employment of labor are important factors while the critical nonmarket valuation factors are ambient air visibility, greenhouse gas release, and disposal of the by-products of conversion and combustion.

  18. 34 CFR 403.114 - How does a State determine the number of economically disadvantaged students attending vocational...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... disadvantaged students attending vocational education programs under the Secondary School Vocational Education... TECHNOLOGY EDUCATION PROGRAM What Kinds of Activities Does the Secretary Assist Under the Basic Programs... School Vocational Education Program? (a) For the purposes of § 403.113, a State may determine the...

  19. Development and validation of a multilateral index to determine economic status in developing countries: the Patient Financial Eligibility Tool (PFET).

    PubMed

    Saba, Joseph; Audureau, Etienne; Bizé, Marion; Koloshuk, Barbara; Ladner, Joël

    2013-04-01

    The objective was to develop and validate a multilateral index to determine patient ability to pay for medication in low- and middle-income countries. Primary data were collected in 2009 from 117 cancer patients in China, India, Thailand, and Malaysia. The initial tool included income, expenditures, and assets-based items using ad hoc determined brackets. Principal components analysis was performed to determine final weights. Agreement (Kappa) was measured between results from the final tool and from an Impact Survey (IS) conducted after beginning drug therapy to quantify a patient's actual ability to pay in terms of number of drug cycles per year. The authors present the step-by-step methodology employed to develop the tool on a country-by-country basis. Overall Cronbach value was 0.84. Agreement between the Patient Financial Eligibility Tool (PFET) and IS was perfect (equal number of drug cycles) for 58.1% of patients, fair (1 cycle difference) for 29.1%, and poor (>1 cycle) for 12.8%. Overall Kappa was 0.76 (P<0.0001). The PFET is an effective tool for determining an individual's ability to pay for medication. Combined with tiered models for patient participation in the cost of medication, it could help to increase access to high-priced products in developing countries. PMID:23276290

  20. Towards "Lisbon Objectives": Economic Determinants of Participation Rates in University Education--An Empirical Analysis in 14 European Countries

    ERIC Educational Resources Information Center

    Agasisti, Tommaso

    2009-01-01

    Participation rates in higher education are an important indicator to pursue one of the main European policy objectives, which is to increase the proportion of population attending higher education. A model used to detect the determinants of participation rates is proposed in this paper, and it is empirically tested for 14 European countries

  1. From Ideas to Development: The Determinants of R&D and Patenting. OECD Economics Department Working Papers, No. 457

    ERIC Educational Resources Information Center

    Jaumotte, Florence; Pain, Nigel

    2005-01-01

    This paper uses panel regressions to investigate the effects of innovation policies and framework factors on business R&D intensity and patenting for a sample of 20 OECD countries over the period 1982- 2001. Both sets of factors are found to matter; the main determinants of innovativeness appear to be the availability of scientists and engineers,

  2. Solar energy system economic evaluation for IBM system 1B, Carlsbad, New Mexico

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The economic performance of an operational test site of a solar energy system is described. The viability of the system was tested over a broad range of environmental and economic conditions. Significant results are reported.

  3. Crop productivity and economics during the transition to alternative cropping systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing economic pressures and continued environmental concerns in agricultural production have heightened the need for more sustainable cropping systems. Research is needed to identify systems that simultaneously improve the economic and social viability of farms and rural communities while prot...

  4. Lactate as a Novel Quantitative Measure of Viability in Schistosoma mansoni Drug Sensitivity Assays

    PubMed Central

    Howe, Stephanie; Zphel, Dorina; Subbaraman, Harini; Unger, Clemens; Held, Jana; Engleitner, Thomas; Hoffmann, Wolfgang H.

    2014-01-01

    Whole-organism compound sensitivity assays are a valuable strategy in infectious diseases to identify active molecules. In schistosomiasis drug discovery, larval-stage Schistosoma allows the use of a certain degree of automation in the screening of compounds. Unfortunately, the throughput is limited, as drug activity is determined by manual assessment of Schistosoma viability by microscopy. To develop a simple and quantifiable surrogate marker for viability, we targeted glucose metabolism, which is central to Schistosoma survival. Lactate is the end product of glycolysis in human Schistosoma stages and can be detected in the supernatant. We assessed lactate as a surrogate marker for viability in Schistosoma drug screening assays. We thoroughly investigated parameters of lactate measurement and performed drug sensitivity assays by applying schistosomula and adult worms to establish a proof of concept. Lactate levels clearly reflected the viability of schistosomula and correlated with schistosomulum numbers. Compounds with reported potencies were tested, and activities were determined by lactate assay and by microscopy. We conclude that lactate is a sensitive and simple surrogate marker to be measured to determine Schistosoma viability in compound screening assays. Low numbers of schistosomula and the commercial availability of lactate assay reagents make the assay particularly attractive to throughput approaches. Furthermore, standardization of procedures and quantitative evaluation of compound activities facilitate interassay comparisons of potencies and, thus, concerted drug discovery approaches. PMID:25487803

  5. Kinetic viability assays using DRAQ7 probe.

    PubMed

    Wlodkowic, Donald; Akagi, Jin; Dobrucki, Jurek; Errington, Rachel; Smith, Paul J; Takeda, Kazuo; Darzynkiewicz, Zbigniew

    2013-07-01

    Cell death within cell populations is a stochastic process where cell-to-cell variation in temporal progression through the various stages of cell death arises from asynchrony of subtle fluctuations in the signaling pathways. Most cell death assays rely on detection of the specific marker of cell demise at the end-point of cell culturing. Such an approach cannot account for the asynchrony and the stochastic nature of cell response to the death-inducing signal. There is a need therefore for rapid and high-throughput bioassays capable of continuously tracking viability of individual cells from the time of encountering a stress signal up to final stages of their demise. In this context, a new anthracycline derivative, DRAQ7, is gaining increasing interest as an easy-to-use marker capable of long-term monitoring of cell death in real-time. This novel probe neither penetrates the plasma membrane of living cells nor does it affect the cells' susceptibility to the death-inducing agents. However, when the membrane integrity is compromised, DRAQ7 enters cells undergoing demise and binds readily to nuclear DNA to report cell death. Here, we provide three sets of protocols for viability assays using DRAQ7 probe. The first protocol describes the innovative use of single-color DRAQ7 real-time assay to dynamically track cell viability. The second protocol outlines a simplified end-point DRAQ7 staining approach. The final protocol highlights the real-time and multiparametric apoptosis assay utilizing DRAQ7 dye concurrently with tetramethylrhodamine methyl ester (TMRM), the mitochondrial trans-membrane electrochemical potential (??m) sensing probe. PMID:23835805

  6. Echinococcus metacestode: in search of viability markers

    PubMed Central

    Gottstein, Bruno; Wang, Junhua; Blagosklonov, Oleg; Grenouillet, Frédéric; Millon, Laurence; Vuitton, Dominique A.; Müller, Norbert

    2014-01-01

    Epidemiological studies have demonstrated that most humans infected with Echinococcus spp. exhibit resistance to disease. When infection leads to disease, the parasite is partially controlled by host immunity: in case of immunocompetence, the normal alveolar echinococcosis (AE) or cystic echinococcosis (CE) situation, the metacestode grows slowly, and first clinical signs appear years after infection; in case of impaired immunity (AIDS; other immunodeficiencies), uncontrolled proliferation of the metacestode leads to rapidly progressing disease. Assessing Echinococcus multilocularis viability in vivo following therapeutic interventions in AE patients may be of tremendous benefit when compared with the invasive procedures used to perform biopsies. Current options are F18-fluorodeoxyglucose-positron emission tomography (FDG-PET), which visualizes periparasitic inflammation due to the metabolic activity of the metacestode, and measurement of antibodies against recEm18, a viability-associated protein, that rapidly regresses upon metacestode inactivation. For Echinococcus granulosus, similar prognosis-associated follow-up parameters are still lacking but a few candidates may be listed. Other possible markers include functional and diffusion-weighted Magnetic Resonance Imaging (MRI), and measurement of products from the parasite (circulating antigens or DNA), and from the host (inflammation markers, cytokines, or chemokines). Even though some of them have been promising in pilot studies, none has been properly validated in an appropriate number of patients until now to be recommended for further use in clinical settings. There is therefore still a need to develop reliable tools for improved viability assessment to provide the sufficient information needed to reliably withdraw anti-parasite benzimidazole chemotherapy, and a basis for the development of new alternative therapeutic tools. PMID:25429386

  7. Quintessence reconstructed: New constraints and tracker viability

    SciTech Connect

    Sahlen, Martin; Liddle, Andrew R.; Parkinson, David

    2007-01-15

    We update and extend our previous work reconstructing the potential of a quintessence field from current observational data. We extend the cosmological data set to include new supernova data, plus information from the cosmic microwave background and from baryon acoustic oscillations. We extend the modeling by considering Pade approximant expansions as well as Taylor series, and by using observations to assess the viability of the tracker hypothesis. We find that parameter constraints have improved by a factor of 2, with a strengthening of the preference of the cosmological constant over evolving quintessence models. Present data show some signs, though inconclusive, of favoring tracker models over nontracker models under our assumptions.

  8. Viability of fungal cultures maintained at -70 degrees C.

    PubMed Central

    Pasarell, L; McGinnis, M R

    1992-01-01

    One thousand four hundred forty-seven clinical and environmental isolates of molds, yeasts, aerobic actinomycetes, and algae belonging to 164 genera (382 taxa) maintained on potato dextrose agar at -70 degrees C for periods ranging from 6 months to 13 years were subcultured and then incubated at 25 degrees C to determine their viabilities. Thirty-three isolates, Alternaria alternata (n = 1), Apophysomyces elegans (n = 1), Bipolaris spicifera (n = 1), Blastomyces dermatitidis (n = 4), Cokeromyces recurvatus (n = 1), Coremiella cubispora (n = 1), Cryptococcus ater (n = 1), Curvularia sp. (n = 1), Exserohilum monoceras (n = 1), Exserohilum pedicillatum (n = 1), Exserohilum rostratum (n = 1), Filobasidium floriforme (n = 1), Madurella mycetomatis (n = 1), Oedocephalum spp. (n = 2), Penicillium marneffei (n = 1), Pseudomicrodochium spp. (n = 4), Saksenaea vasiformis (n = 1), Sporothrix sp. (n = 1), and Mycelia Sterilia (n = 8), did not grow after repeated attempts at subculturing. Neither time in storage nor taxonomic classification was associated with a lack of viability. Storage at low temperature for either short or long periods of time is an excellent method for maintaining most medically important fungi. PMID:1572955

  9. Population Viability Analysis of Riverine Fishes

    SciTech Connect

    Bates, P.; Chandler, J.; Jager, H.I.; Lepla, K.; Van Winkle, W.

    1999-04-12

    Many utilities face conflkts between two goals: cost-efficient hydropower generation and protecting riverine fishes. Research to develop ecological simulation tools that can evaluate alternative mitigation strategies in terms of their benefits to fish populations is vital to informed decision-making. In this paper, we describe our approach to population viability analysis of riverine fishes in general and Snake River white sturgeon in particular. We are finding that the individual-based modeling approach used in previous in-stream flow applications is well suited to addressing questions about the viability of species of concern for several reasons. Chief among these are: (1) the abiIity to represent the effects of individual variation in life history characteristics on predicted population viabili~, (2) the flexibili~ needed to quanti~ the ecological benefits of alternative flow management options by representing spatial and temporal variation in flow and temperaturty and (3) the flexibility needed to quantifi the ecological benefits of non-flow related manipulations (i.e., passage, screening and hatchery supplementation).

  10. A quick, convenient and economical method for the reliable determination of methylglyoxal in millimolar concentrations: the N-acetyl-L-cysteine assay.

    PubMed

    Wild, Rebekka; Ooi, Lezanne; Srikanth, Velandai; Münch, Gerald

    2012-07-01

    The determination of methylglyoxal (MG) concentrations in vivo is gaining increasing importance as high levels of MG are linked to various health impairments including complications of diabetes. In order to standardize the measurements of MG in body fluids, it is necessary to precisely determine the concentration of MG stock solutions used as analytical standards. The "gold standard" method for the determination of MG concentration in the millimolar range is an enzyme-catalyzed endpoint assay based on the glyoxalase I catalyzed formation of S-lactoylglutathione. However, as this assay used purified glyoxalase I enzyme, it is quite expensive. Another method uses a derivation reaction with 2,4-dinitrophenylhydrazine, but this substance is explosive and needs special handling and storage. In addition, precipitation of the product methylglyoxal-bis-2,4-dinitrophenylhydrozone during the reaction limits the reliability of this method. In this study, we have evaluated a new method of MG determination based on the previously published fast reaction between MG and N-acetyl-L-cysteine at room temperature which yields an easily detectable condensation product, N-α-acetyl-S-(1-hydroxy-2-oxo-prop-1-yl)cysteine. When comparing these three different assays for the measurement of MG concentrations, we find that the N-acetyl-L-cysteine assay is the most favorable, providing an economical and robust assay without the need for the use of hazardous or expensive reagents. PMID:22580513

  11. Solar energy system economic evaluation: Fern Tunkhannock, Tunkhannock, Pennsylvania

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The economic performance of an Operational Test Site (OTS) is described. The long term economic performance of the system at its installation site and extrapolation to four additional selected locations to demonstrate the viability of the design over a broad range of environmental and economic conditions is reported. Topics discussed are: system description, study approach, economic analysis and system optimization, and technical and economical results of analysis. Data for the economic analysis are generated through evaluation of the OTS. The simulation is based on the technical results of the seasonal report simulation. In addition localized and standard economic parameters are used for economic analysis.

  12. [Health Impact Assessments (HIA): an intersectoral process for action on the social, economic and environmental determinants of health].

    PubMed

    Saint-Pierre, Louise; Lamarre, Marie-Claude; Simos, Jean

    2014-03-01

    Health Impact Assessment (HIA) is a practice that has grown in popularity worldwide, since the end of the 1990s. Originally used in the framework of Environmental Impact Assessments (EIAs), HIA has become enriched through the addition of knowledge and principles based on the social determinants of health and the tackling of health inequalities, and has been brought to bear on the policy-planning process at all levels of government. HIA has three overlapping objectives: to assess the potential effects of a policy on health, to encourage citizen and stakeholder participation in the impact analysis process, and to inform the decision-making process. This article briefly defines HIA; defines its standardized process in successive steps, which allows users to give structure to their actions and to establish the steps to be followed (detection, framing, analysis, recommendations and evaluation); and offers three examples of HIA in three different situations: the Geneva canton of Switzerland; Rennes, France; and in the Montrgie region of Quebec, Canada. Together, these illustrations show that HIA is a promising strategy to influence local decisions and to integrate health into projects and policies at the local and regional levels. PMID:24737808

  13. Effect of air drying on bacterial viability: A multiparameter viability assessment.

    PubMed

    Nocker, Andreas; Fernández, Priscilla Sossa; Montijn, Roy; Schuren, Frank

    2012-08-01

    The effect of desiccation on the viability of microorganisms is a question of great interest for a variety of public health questions and industrial applications. Although viability is traditionally assessed by plate counts, cultivation-independent methods are increasingly applied with the aim to gain more insight into why cells might not form colonies and to optimize production processes. To evaluate their usefulness, we applied in this study a multiparameter viability assay to selected bacteria (Escherichia coli, Pseudomonas aeruginosa, Enterococcus hirae, and Staphylococcus aureus) subjected to air-drying in the absence or presence of supplements. Tests included growth on solid culture medium and the measurement of membrane integrity, membrane potential, esterase and respiratory activities using fluorescent dyes. All measured parameters were responsive to desiccation stress. Results suggested that extending plate count analysis with cultivation-independent methods can greatly enhance resolution especially for moderate stress conditions, which do not get reflected in plate counts due to cellular recovery. Whereas plate counts reflect the final effect on viability, immediate measurement of cellular functions provides a snapshot picture of the fitness status at a specific point in time. Special emphasis was given to MgCl(2) which in concentrations≥50mM dramatically increased the bacterial susceptibility to desiccation in the case of the gram-negative bacteria and to a lesser extent also for the gram-positive bacteria. The study in addition confirmed a good agreement of results obtained with the recently developed real-time viability (RTV) assay and the BacLight LIVE/DEAD method in combination with a fluorescence plate reader. PMID:22575714

  14. Resilience and vulnerability to a natural hazard: A mathematical framework based on viability theory

    NASA Astrophysics Data System (ADS)

    Rougé, Charles; Mathias, Jean-Denis; Deffuant, Guillaume

    2013-04-01

    This deals with the response of a coupled human and natural system (CHANS) to a natural hazard by using the concepts of resilience and vulnerability within the mathematical framework of viability theory. This theory applies to time-evolving systems such as CHANS and assumes that their desirable properties can be defined as a subset of their state space. Policies can also apply to influence the dynamics of such systems: viability theory aims at finding the policies which keep the properties of a controlled dynamical system for so long as no disturbance hits it. The states of the system such that the properties are guaranteed constitute what is called the viability kernel. This viability framework has been extended to describe the response to a perturbation such as a natural hazard. Resilience describes the capacity of the CHANS to recover by getting back in the viability kernel, where its properties are guaranteed until the onset of the next major event. Defined for a given controlled trajectory that the system may take after the event ends, resilience is (a) whether the system comes back to the viability kernel within a given budget such as a time constraint, but also (b) a decreasing function of vulnerability. Computed for a given trajectory as well, vulnerability is a measure of the consequence of violating a property. We propose a family of functions from which cost functions and other vulnerability indicators can be derived for a certain trajectory. There can be several vulnerability functions, representing for instance social, economic or ecological vulnerability, and each representing the violation of an associated property, but these functions need to be ultimately aggregated as a single indicator. Computing the resilience and vulnerability of a trajectory enables the viability framework to describe the response of both deterministic and stochastic systems to hazards. In the deterministic case, there is only one response trajectory for a given action policy, and methods exist to find the actions which yield the most resilient trajectory, namely the least vulnerable trajectory for which recovery is complete. In the stochastic case however, there is a range of possible trajectories. Statistics can be derived from the probability distribution of the resilience and vulnerability of the trajectories. Dynamic programming methods can then yield either the policies that maximize the probability of being resilient by achieving recovery within a given time horizon, or these which minimize a given vulnerability statistic. These objectives are different and can be in contradiction, so that trade-offs may have to be considered between them. The approach is illustrated in both the deterministic and stochastic cases through a simple model of lake eutrophication, for which the desirable ecological properties of the lake conflict with the economic interest of neighboring farmers.

  15. Ice-Binding Protein Derived from Glaciozyma Can Improve the Viability of Cryopreserved Mammalian Cells.

    PubMed

    Kim, Hak Jun; Shim, Hye Eun; Lee, Jun Hyuck; Kang, Yong-Cheol; Hur, Young Baek

    2015-12-28

    Ice-binding proteins (IBPs) can inhibit ice recrystallization (IR), a major cause of cell death during cryopreservation. IBPs are hypothesized to improve cell viability after cryopreservation by alleviating the cryoinjury caused by IR. In our previous studies, we showed that supplementation of the freezing medium with the recombinant IBP of the Arctic yeast Glaciozyma sp. (designated as LeIBP) could reduce post-thaw hemolysis of human red blood cells and increase the survival of cryopreserved diatoms. Here, we showed that LeIBP could improve the viability of cryopreserved mammalian cells. Human cervical cancer cells (HeLa), mouse fibroblasts (NIH/3T3), human preosteoblasts (MC3T3-E1), Chinese hamster ovary cells (CHO-K1), and human keratinocytes (HaCaT) were evaluated. These mammalian cells were frozen in dimethyl sulfoxide (DMSO)/fetal bovine serum (FBS) solution with or without 0.1 mg/ml LeIBP at a cooling rate of -1°C/min in a -80°C freezer overnight. The minimum effective concentration (0.1 mg/ml) of LeIBP was determined, based on the viability of HeLa cells after treatment with LeIBP during cryopreservation and the IR inhibition assay results. The post-thaw viability of mammalian cells was examined. In all cases, cell viability was significantly enhanced by more than 10% by LeIBP supplementation in 5% DMSO/5% FBS: viability increased by 20% for HeLa cells, 28% for NIH/3T3 cells, 21% for MC3T3-E1, 10% for CHO-K1, and 20% for HaCaT. Furthermore, addition of LeIBP reduced the concentrations of toxic DMSO and FBS down to 5%. Therefore, we demonstrated that LeIBP can increase the viability of cryopreserved mammalian cells by inhibiting IR. PMID:26323271

  16. Lake eutrophication and environmental change: A viability framework for resilience, vulnerability and adaptive capacity

    NASA Astrophysics Data System (ADS)

    Mathias, Jean-Denis; Rougé, Charles; Deffuant, Guillaume

    2013-04-01

    We present a simple stochastic model of lake eutrophication to demonstrate how the mathematical framework of viability theory fosters operational definitions of resilience, vulnerability and adaptive capacity, and then helps understand which response one should bring to environmental changes. The model represents the phosphorus dynamics, given that high concentrations trigger a regime change from oligotrophic to eutrophic, and causes ecological but also economic losses, for instance from tourism. Phosphorus comes from agricultural inputs upstream of the lake, and we will consider a stochastic input. We consider the system made of both the lake and its upstream region, and explore how to maintain the desirable ecological and economic properties of this system. In the viability framework, we translate these desirable properties into state constraints, then examine how, given the dynamics of the model and the available policy options, the properties can be kept. The set of states for which there exists a policy to keep the properties is called the viability kernel. We extend this framework to both major perturbations and long-term environmental changes. In our model, since the phosphorus inputs and outputs from the lake depend on rainfall, we will focus on extreme rainfall events and long-term changes in the rainfall regime. They can be described as changes in the state of the system, and may displace it outside the viability kernel. Its response can then be described using the concepts of resilience, vulnerability and adaptive capacity. Resilience is the capacity to recover by getting back to the viability kernel where the dynamics keep the system safe, and in this work we assume it to be the first objective of management. Computed for a given trajectory, vulnerability is a measure of the consequence of violating a property. We propose a family of functions from which cost functions and other vulnerability indicators can be derived for any trajectory. There can be several vulnerability functions, representing for instance social, economic or ecological vulnerability, and each representing the violation of the associated property, but these functions need to be ultimately aggregated as a single indicator. Due to the stochastic nature of the system, there is a range of possible trajectories. Statistics can be derived from the probability distribution of the vulnerability of the trajectories. Dynamic programming methods can then yield the policies which, among available policies, minimize a given trajectory. Thus, this viability framework gives indication on both the possible consequences of a hazard or an environmental change, and on the policies that can mitigate or avert it. It also enables to assess the benefits of extending the set of available policy options, and we define adaptive capacity as the reduction in a given vulnerability statistic due to the introduction of new policy options.

  17. Extending the viability of acute brain slices

    PubMed Central

    Buskila, Yossi; Breen, Paul P.; Tapson, Jonathan; van Schaik, Andr; Barton, Matthew; Morley, John W.

    2014-01-01

    The lifespan of an acute brain slice is approximately 612?hours, limiting potential experimentation time. We have designed a new recovery incubation system capable of extending their lifespan to more than 36?hours. This system controls the temperature of the incubated artificial cerebral spinal fluid (aCSF) while continuously passing the fluid through a UVC filtration system and simultaneously monitoring temperature and pH. The combination of controlled temperature and UVC filtering maintains bacteria levels in the lag phase and leads to the dramatic extension of the brain slice lifespan. Brain slice viability was validated through electrophysiological recordings as well as live/dead cell assays. This system benefits researchers by monitoring incubation conditions and standardizing this artificial environment. It further provides viable tissue for two experimental days, reducing the time spent preparing brain slices and the number of animals required for research. PMID:24930889

  18. Incorporating evolutionary processes into population viability models.

    PubMed

    Pierson, Jennifer C; Beissinger, Steven R; Bragg, Jason G; Coates, David J; Oostermeijer, J Gerard B; Sunnucks, Paul; Schumaker, Nathan H; Trotter, Meredith V; Young, Andrew G

    2015-06-01

    We examined how ecological and evolutionary (eco-evo) processes in population dynamics could be better integrated into population viability analysis (PVA). Complementary advances in computation and population genomics can be combined into an eco-evo PVA to offer powerful new approaches to understand the influence of evolutionary processes on population persistence. We developed the mechanistic basis of an eco-evo PVA using individual-based models with individual-level genotype tracking and dynamic genotype-phenotype mapping to model emergent population-level effects, such as local adaptation and genetic rescue. We then outline how genomics can allow or improve parameter estimation for PVA models by providing genotypic information at large numbers of loci for neutral and functional genome regions. As climate change and other threatening processes increase in rate and scale, eco-evo PVAs will become essential research tools to evaluate the effects of adaptive potential, evolutionary rescue, and locally adapted traits on persistence. PMID:25494697

  19. Theoretical and Observational Viability of Modified Gravity

    NASA Astrophysics Data System (ADS)

    Andrews, Melinda M.

    The origin of the late-time cosmic acceleration is one of the most intriguing problems of modern physics; the standard theoretical explanation requires extreme fine-tuning to match observations. Resolution of this puzzle may require modifications to either the assumption that all matter has positive pressure or to the theory of gravity itself on cosmological distance scales. In this dissertation we explore the viability of several promising modifications to gravity unified by the presence of a Vainshtein-type screening mechanism suppressing the modifications within the solar system. In order to remain theoretically and observationally viable, a theory of modified gravity must: 1. be free of unphysical degrees of freedom that lead to instabilities, 2. produce a stable phase of cosmic acceleration, 3. allow stable field configurations around astrophysical objects, and 4. be consistent with measured limits on the strength of fifth forces in various environments. We study three models: that of a scalar called the galileon that mediates a gravitational-strength fifth force, a braneworld-inspired theory of multiple galileons, and the theory of a massive graviton coupled to a galileon. We show that the massive graviton -- galileon theory satisfies the first condition for viability but fails the second and that the multi-galileon theory fails the third condition. The theory of a single galileon satisfies the first three conditions; the last is known to be satisfied in the case of an isolated object. We develop a formalism to make more precise predictions regarding the galileon forces in multi-body systems. Finally, we consider the topological defect solutions of more general scalar theories with noncanonical kinetic terms and show that domain walls can mimic the field profile and energy density of a canonical domain wall, though the two are distinguishable by their fluctuation spectra.

  20. Artificial Evolution by Viability Rather than Competition

    PubMed Central

    Maesani, Andrea; Fernando, Pradeep Ruben; Floreano, Dario

    2014-01-01

    Evolutionary algorithms are widespread heuristic methods inspired by natural evolution to solve difficult problems for which analytical approaches are not suitable. In many domains experimenters are not only interested in discovering optimal solutions, but also in finding the largest number of different solutions satisfying minimal requirements. However, the formulation of an effective performance measure describing these requirements, also known as fitness function, represents a major challenge. The difficulty of combining and weighting multiple problem objectives and constraints of possibly varying nature and scale into a single fitness function often leads to unsatisfactory solutions. Furthermore, selective reproduction of the fittest solutions, which is inspired by competition-based selection in nature, leads to loss of diversity within the evolving population and premature convergence of the algorithm, hindering the discovery of many different solutions. Here we present an alternative abstraction of artificial evolution, which does not require the formulation of a composite fitness function. Inspired from viability theory in dynamical systems, natural evolution and ethology, the proposed method puts emphasis on the elimination of individuals that do not meet a set of changing criteria, which are defined on the problem objectives and constraints. Experimental results show that the proposed method maintains higher diversity in the evolving population and generates more unique solutions when compared to classical competition-based evolutionary algorithms. Our findings suggest that incorporating viability principles into evolutionary algorithms can significantly improve the applicability and effectiveness of evolutionary methods to numerous complex problems of science and engineering, ranging from protein structure prediction to aircraft wing design. PMID:24489790

  1. Glufosinate does not affect floral morphology and pollen viability in glufosinate-resistant cotton (Gossypium hirsutum)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies were conducted to determine whether glufosinate treatments to glufosinate-resistant cotton caused changes in floral morphology, pollen viability, and seed set. Four glufosinate treatments were included: (1) glufosinate applied postemergence over the top (POST) at the four-leaf stage, (2) glu...

  2. Dry heat effects on survival of indigenous soil particle microflora and particle viability studies of Kennedy Space Center soil

    NASA Technical Reports Server (NTRS)

    Ruschmeyer, O. R.; Pflug, I. J.; Gove, R.; Heisserer, Y.

    1975-01-01

    Research efforts were concentrated on attempts to obtain data concerning the dry heat resistance of particle microflora in Kennedy Space Center soil samples. The in situ dry heat resistance profiles at selected temperatures for the aggregate microflora on soil particles of certain size ranges were determined. Viability profiles of older soil samples were compared with more recently stored soil samples. The effect of increased particle numbers on viability profiles after dry heat treatment was investigated. These soil particle viability data for various temperatures and times provide information on the soil microflora response to heat treatment and are useful in making selections for spacecraft sterilization cycles.

  3. Use of flow cytometry to assess chondrocyte viability after laser reshaping of cartilage

    NASA Astrophysics Data System (ADS)

    Rasouli, Alexandre; Kim, Charlton C.; Basu, Reshmi; Wong, Brian J.

    2000-05-01

    Lasers have been shown to cause permanent shape change in cartilage via photothermally induced mechanical stress relaxation. While the biophysical properties of cartilage during laser irradiation have been studied, tissue viability following laser irradiation has not been fully characterized. In this study, cell viability staining and flow cytometry were used to determine chondrocyte viability following photothermal stress relaxation. Porcine septal cartilage slabs (10 X 25 X 1.5 mm) were irradiated with light from a Nd:YAG laser ((lambda) equals 1.32 micrometer, 25 W/cm2) while surface temperature, stress relaxation, and diffuse reflectance were recorded. Each slab received one, two, or three laser exposures (respective exposure times of 6.7, 7.2, 10 s), determined from measurements of diffuse reflectance, which correlate with mechanical stress relaxation. Irradiated samples were then divided into two groups analyzed immediately and at five days following laser exposure (the latter group was maintained in culture). Chondrocytes were isolated following serial enzymatic digestion with hyaluronidase, protease, and collagenase II for a total of 17 hours. Chondrocytes were then stained using SYTOR/DEAD RedTM (Molecular Probes; Eugene, OR) wherein live cells stained green (530 nm) and dead cells stained red (630 nm) when excited at 488 nm. A flow cytometer (FACScan, Becton Dickinson, Franklin Lakes, NJ) was then used to detect differential cell fluorescence; size; granularity; and the number of live cells, dead cells, and post irradiation debris in each treatment population. Nearly 60% of chondrocytes from reshaped cartilage samples isolated shortly after irradiation, were viable as determined using flow cytometry while non- irradiated controls were 100 percent viable. Specimens irradiated two or three times with the laser demonstrated increasing amounts of cellular debris along with a reduction in chondrocyte viability: 31 percent following two laser exposures, and 16 percent after three laser exposures. In those samples maintained in culture medium and assayed 5 days after irradiation, viability was reduced by 28 to 88 percent, with the least amount of deterioration in untreated and singly irradiated samples. Functional fluorescent dyes combined with flow cytometric analysis successfully determines the effect of laser irradiation on the viability of reshaped cartilage. The flow cytometric approach to viability is accurate, fast, and can handle large sample numbers and sizes. Most importantly, since the method reveals that a single laser exposure of 6.7 s (sufficient for sustained shape change) causes less than 40 percent acute reduction in viability, photothermal reshaping of cartilage may be further researched as a clinical alternative to conventional techniques.

  4. Thermoforming of Tracheal Cartilage: Viability, Shape Change, and Mechanical Behavior

    PubMed Central

    Chae, Yongseok; Protsenko, Dmitriy; Holden, Paul K.; Chlebicki, Cara; Wong, Brian J.F.

    2014-01-01

    Background and Objectives Trauma, emergent tracheostomy, and prolonged intubation are common causes of severe deformation and narrowing of the trachea. Laser technology may be used to reshape tracheal cartilage using minimally invasive methods. The objectives of this study were to determine: (1) the dependence of tracheal cartilage shape change on temperature and laser dosimetry using heated saline bath immersion and laser irradiation, respectively, (2) the effect of temperature on the mechanical behavior of cartilage, and (3) tissue viability as a function of laser dosimetry. Materials and Methods Ex vivo rabbit trachea cartilage specimens were bent and secured around a cylinder (6 mm), and then immersed in a saline bath (45 and 72°C) for 5– 100 seconds. In separate experiments, tracheal specimens were irradiated with a diode laser (λ = 1.45 μm, 220–400 J/cm2). Mechanical analysis was then used to determine the elastic modulus in tension after irradiation. Fluorescent viability assays combined with laser scanning confocal microscopy (LSCM) were employed to image and identify thermal injury regions. Results Shape change transition zones, between 62 and 66°C in the saline heating bath and above power densities of 350 J/cm2 (peak temperatures 65±10°C) for laser irradiation were identified. Above these zones, the elastic moduli were higher (8.2±4 MPa) than at lower temperatures (4.5±3 MPa). LSCM identified significant loss of viable chondrocytes within the laser-irradiation zones. Conclusion Our results indicate a change in mechanical properties occurs with laser irradiation and further demonstrates that significant thermal damage is concurrent with clinically relevant shape change in the elastic cartilage tissues of the rabbit trachea using the present laser and dosimetry parameters. PMID:18798288

  5. 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. PMID:25247364

  6. Seed viability in declining populations of Caladenia rigida (Orchidaceae): are small populations doomed?

    PubMed

    Faast, R; Facelli, J M; Austin, A D

    2011-01-01

    Despite comparatively good rates of pollination and seed production, some populations of the endangered terrestrial orchid Caladenia rigida continue to decline. To determine whether seed quality may be limiting reproductive potential, we assessed seed viability among declining populations of C.rigida (in the southern part of its distribution) and among populations that are regarded as stable (in the northern part of its distribution). We also compared differences in seed viability to plant traits, population size and habitat characteristics (soil properties, canopy cover, presence of proximate vegetation). Seed capsules from southern populations were significantly smaller, with only 9% of seeds being viable, compared to 36% in capsules from northern populations. Soil phosphorus concentrations differed between regions, but other habitat characteristics did not correlate with seed viability. Using calculations based on seedling recruitment data from other Caladenia species, we predict that seed output is insufficient to ensure the long-term persistence of the smallest C.rigida populations. PMID:21134091

  7. Use of Time-Aggregated Data in Economic Screening Analyses of Combined Heat and Power Systems

    SciTech Connect

    Hudson II, Carl Randy

    2004-09-01

    Combined heat and power (CHP) projects (also known as cogeneration projects) usually undergo a series of assessments and viability checks before any commitment is made. A screening analysis, with electrical and thermal loads characterized on an annual basis, may be performed initially to quickly determine the economic viability of the proposed project. Screening analyses using time-aggregated data do not reflect several critical cost influences, however. Seasonal and diurnal variations in electrical and thermal loads, as well as time-of-use utility pricing structures, can have a dramatic impact on the economics. A more accurate economic assessment requires additional detailed data on electrical and thermal demand (e.g., hourly load data), which may not be readily available for the specific facility under study. Recent developments in CHP evaluation tools, however, can generate the needed hourly data through the use of historical data libraries and building simulation. This article utilizes model-generated hourly load data for four potential CHP applications and compares the calculated cost savings of a CHP system when evaluated on a time-aggregated (i.e., annual) basis to the savings when evaluated on an hour-by-hour basis. It is observed that the simple, aggregated analysis forecasts much greater savings (i.e., greater economic viability) than the more detailed hourly analysis. The findings confirm that the simpler tool produces results with a much more optimistic outlook, which, if taken by itself, might lead to erroneous project decisions. The more rigorous approach, being more reflective of actual requirements and conditions, presents a more accurate economic comparison of the alternatives, which, in turn, leads to better decision risk management.

  8. Recent trends in automobile recycling: An energy and economic assessment

    SciTech Connect

    Curlee, T.R.; Das, S.; Rizy, C.G.; Schexanyder, S.M.

    1994-03-01

    Recent and anticipated trends in the material composition of domestic and imported automobiles and the increasing cost of landfilling the non-recyclable portion of automobiles (automobile shredder residue or ASR) pose questions about the future of automobile recycling. This report documents the findings of a study sponsored by the US Department of Energy`s Office of Environmental Analysis to examine the impacts of these and other relevant trends on the life-cycle energy consumption of automobiles and on the economic viability of the domestic automobile recycling industry. More specifically, the study (1) reviewed the status of the automobile recycling industry in the United States, including the current technologies used to process scrapped automobiles and the challenges facing the automobile recycling industry; (2) examined the current status and future trends of automobile recycling in Europe and Japan, with the objectives of identifying ``lessons learned`` and pinpointing differences between those areas and the United States; (3) developed estimates of the energy system impacts of the recycling status quo and projections of the probable energy impacts of alternative technical and institutional approaches to recycling; and (4) identified the key policy questions that will determine the future economic viability of automobile shredder facilities in the United States.

  9. Sociodemographic and Economic Determinants of Overweight and Obesity for Public-school Children in Geneva State, Switzerland: A Cross-sectional Study

    PubMed Central

    Jeannot, Emilien; Mahler, Per; Elia, Nadia; Cerruti, Bernard; Chastonnay, P.

    2015-01-01

    Background: Obesity among children and adolescents is a growing public health problem. The purpose of this study is to assess the prevalence, socioeconomic and demographic determinants of overweight and obesity in schoolchildren from Geneva. Methods: A cross-sectional study was undertaken at the Public School of Geneva canton in Switzerland. A total of 8544 public school children were collected and analyzed: 2577 were in second grade, 2641 in fifth grade and 3326 in eighth grade. To identify overweight and obesity we used the definition issued by the International Obesity Task Force. Child characteristics included gender, age, socioeconomic status (SES) of father and mother, and school grade. The multivariate logistic regression model was used to examine potential predictors of overweight/obesity. Results: The prevalence of overweight or obese children was 14.4% in second grade, 17.3% in fifth grade and 18.6% in eighth grade. Multivariate logistic regression analyses reveal that children that have a low economic status or certain citizenships are more likely to be overweight or obese. Children of Kosovar origin, have a higher risk of OBO in second grade (adjusted odds ratio [OR] = 2.19; 95% confidence interval [CI]: 1.20–4.00), fifth grade (adjusted OR = 2.36 95% CI: 1.27–4.39) and in eighth grade (adjusted OR = 2.15 95% CI: 1.27–4.39). Association between SES and overweight was high with regards to the father's SES in fifth grade (adjusted OR = 4.21 95% CI: 2.83–6.25). Conclusions: Overweight and obesity is associated to socioeconomic and sociodemographic factors. The analyzes reveals that children with a low economic status and/or from certain countries are more likely to be overweight or obese than Swiss children. There is an urgent need for action to prevent further increase in overweight or obesity among children. PMID:26015862

  10. Novel Sensor-Enabled Ex Vivo Bioreactor: A New Approach towards Physiological Parameters and Porcine Artery Viability

    PubMed Central

    Mundargi, Raghavendra; Venkataraman, Divya; Kumar, Saranya; Mogal, Vishal; Ortiz, Raphael; Loo, Joachim; Venkatraman, Subbu; Steele, Terry

    2015-01-01

    The aim of the present work is to design and construct an ex vivo bioreactor system to assess the real time viability of vascular tissue. Porcine carotid artery as a model tissue was used in the ex vivo bioreactor setup to monitor its viability under physiological conditions such as oxygen, pressure, temperature, and flow. The real time tissue viability was evaluated by monitoring tissue metabolism through a fluorescent indicator “resorufin.” Our ex vivo bioreactor allows real time monitoring of tissue responses along with physiological conditions. These ex vivo parameters were vital in determining the tissue viability in sensor-enabled bioreactor and our initial investigations suggest that, porcine tissue viability is considerably affected by high shear forces and low oxygen levels. Histological evaluations with hematoxylin and eosin and Masson's trichrome staining show intact endothelium with fresh porcine tissue whereas tissues after incubation in ex vivo bioreactor studies indicate denuded endothelium supporting the viability results from real time measurements. Hence, this novel viability sensor-enabled ex vivo bioreactor acts as model to mimic in vivo system and record vascular responses to biopharmaceutical molecules and biomedical devices. PMID:26609536

  11. High speed measurement of corn seed viability using hyperspectral imaging

    NASA Astrophysics Data System (ADS)

    Ambrose, Ashabahebwa; Kandpal, Lalit Mohan; Kim, Moon S.; Lee, Wang-Hee; Cho, Byoung-Kwan

    2016-03-01

    Corn is one of the most cultivated crops all over world as food for humans as well as animals. Optimized agronomic practices and improved technological interventions during planting, harvesting and post-harvest handling are critical to improving the quantity and quality of corn production. Seed germination and vigor are the primary determinants of high yield notwithstanding any other factors that may play during the growth period. Seed viability may be lost during storage due to unfavorable conditions e.g. moisture content and temperatures, or physical damage during mechanical processing e.g. shelling, or over heating during drying. It is therefore vital for seed companies and farmers to test and ascertain seed viability to avoid losses of any kind. This study aimed at investigating the possibility of using hyperspectral imaging (HSI) technique to discriminate viable and nonviable corn seeds. A group of corn samples were heat treated by using microwave process while a group of seeds were kept as control group (untreated). The hyperspectral images of corn seeds of both groups were captured between 400 and 2500 nm wave range. Partial least squares discriminant analysis (PLS-DA) was built for the classification of aged (heat treated) and normal (untreated) corn seeds. The model showed highest classification accuracy of 97.6% (calibration) and 95.6% (prediction) in the SWIR region of the HSI. Furthermore, the PLS-DA and binary images were capable to provide the visual information of treated and untreated corn seeds. The overall results suggest that HSI technique is accurate for classification of viable and non-viable seeds with non-destructive manner.

  12. Economics of residue harvest: Regional partnership evaluation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Economic analyses on the viability of corn (Zea mays, L.) stover harvest for bioenergy production have largely been based on simulation modeling. While some studies have utilized field research data, most field-based analyses have included a limited number of sites and a narrow geographic distributi...

  13. United Nations/World Health Organization Meeting on Socio-Economic Determinants and Consequences of Mortality, Mexico City, 19-25 June 1979.

    PubMed

    1980-01-01

    The objectives of the United Nations/World Health Organization (WHO) Meeting on Socioeconomic Determinants and Consequences of Mortality, held in Mexico City in June 1979, were the following: to review the knowledge of differential mortality and to identify gaps in the understanding of its socioeconomic determinants and consequences; to discuss the methodological and technical problems associated with data collection and analysis; to consider the policy implications of the findings presented and to promote studies on the implications of socioeconomic differentials in mortality on social policy and international development strategies; to formulate recommendations and guidelines for the utilization of the 1980 round of population censuses for in-depth studies of mortality differentials; and to stimulate national and international research on differential mortality. Participants discussed the state of knowledge of socioeconomic differentials and determinants of mortality and described the socioeconomic measures available, the methods of data collection and analysis used, and the findings themselves. A number of characteristics had been employed in the study of differential mortality, and these could be grouped under the following headings: occupation; education; housing; income, wealth; family size; and place of residence. The techniques or methods used to analyze mortality were direct and indirect methods, and these are examined. Inequalities in mortality were found to be closely associated with inequalities in social and economic conditions. Any effort to reduce or remove those inequalities would have to be based on a clear understanding of their causes and interrelationships in order to succeed. Participants indicated a desire to see a resurgence of mortality research, and some research suggestions are outlined. PMID:12262585

  14. Advanced Reservoir Characterization in the Antelope Shale to Establish the Viability of CO2 Enhanced Oil Recovery in California's Monterey Formation Siliceous Shales, Class III

    SciTech Connect

    Perri, Pasquale R.; Cooney, John; Fong, Bill; Julander, Dale; Marasigan, Aleks; Morea, Mike; Piceno, Deborah; Stone, Bill; Emanuele, Mark; Sheffield, Jon; Wells, Jeff; Westbrook, Bill; Karnes, Karl; Pearson, Matt; Heisler, Stuart

    2000-04-24

    The primary objective of this project was to conduct advanced reservoir characterization and modeling studies in the Antelope Shale of the Bureau Vista Hills Field. Work was subdivided into two phases or budget periods. The first phase of the project focused on a variety of advanced reservoir characterization techniques to determine the production characteristics of the Antelope Shale reservoir. Reservoir models based on the results of the characterization work would then be used to evaluate how the reservoir would respond to enhanced oil recovery (EOR) processes such as of CO2 flooding. The second phase of the project would be to implement and evaluate a CO2 in the Buena Vista Hills Field. A successful project would demonstrate the economic viability and widespread applicability of CO2 flooding in siliceous shale reservoirs of the San Joaquin Valley.

  15. Viability and Isolation of Marine Bacteria by Dilution Culture: Theory, Procedures, and Initial Results

    PubMed Central

    Button, D. K.; Schut, Frits; Quang, Pham; Martin, Ravonna; Robertson, Betsy R.

    1993-01-01

    Dilution culture, a method for growing the typical small bacteria from natural aquatic assemblages, has been developed. Each of 11 experimental trials of the technique was successful. Populations are measured, diluted to a small and known number of cells, inoculated into unamended sterilized seawater, and examined three times for the presence of 104 or more cells per ml over a 9-week interval. Mean viability for assemblage members is obtained from the frequency of growth, and many of the cultures produced are pure. Statistical formulations for determining viability and the frequency of pure culture production are derived. Formulations for associated errors are derived as well. Computer simulations of experiments agreed with computed values within the expected error, which verified the formulations. These led to strategies for optimizing viability determinations and pure culture production. Viabilities were usually between 2 and 60% and decreased with >5 mg of amino acids per liter as carbon. In view of difficulties in growing marine oligobacteria, these high values are noteworthy. Significant differences in population characteristics during growth, observed by high-resolution flow cytometry, suggested substantial population diversity. Growth of total populations as well as of cytometry-resolved subpopulations sometimes were truncated at levels of near 104 cells per ml, showing that viable cells could escape detection. Viability is therefore defined as the ability to grow to that population; true viabilities could be even higher. Doubling times, based on whole populations as well as individual subpopulations, were in the 1-day to 1-week range. Data were examined for changes in viability with dilution suggesting cell-cell interactions, but none could be confirmed. The frequency of pure culture production can be adjusted by inoculum size if the viability is known. These apparently pure cultures produced retained the size and apparent DNA-content characteristic of the bulk of the organisms in the parent seawater. Three cultures are now available, two of which have been carried for 3 years. The method is thus seen as a useful step for improving our understanding of typical aquatic organisms. PMID:16348896

  16. Quantifying spore viability of the honey bee pathogen Nosema apis using flow cytometry.

    PubMed

    Peng, Yan; Lee-Pullen, Tracey F; Heel, Kathy; Millar, A Harvey; Baer, Boris

    2014-05-01

    Honey bees are hosts to more than 80 different parasites, some of them being highly virulent and responsible for substantial losses in managed honey bee populations. The study of honey bee pathogens and their interactions with the bees' immune system has therefore become a research area of major interest. Here we developed a fast, accurate and reliable method to quantify the viability of spores of the honey bee gut parasite Nosema apis. To verify this method, a dilution series with 0, 25, 50, 75, and 100% live N. apis was made and SYTO 16 and Propidium Iodide (n = 35) were used to distinguish dead from live spores. The viability of spores in each sample was determined by flow cytometry and compared with the current method based on fluorescence microscopy. Results show that N. apis viability counts using flow cytometry produced very similar results when compared with fluorescence microscopy. However, we found that fluorescence microscopy underestimates N. apis viability in samples with higher percentages of viable spores, the latter typically being what is found in biological samples. A series of experiments were conducted to confirm that flow cytometry allows the use of additional fluorescent dyes such as SYBR 14 and SYTOX Red (used in combination with SYTO 16 or Propidium Iodide) to distinguish dead from live spores. We also show that spore viability quantification with flow cytometry can be undertaken using substantially lower dye concentrations than fluorescence microscopy. In conclusion, our data show flow cytometry to be a fast, reliable method to quantify N. apis spore viabilities, which has a number of advantages compared with existing methods. PMID:24339267

  17. Peripheral blood lymphocytes are able to maintain their viability and basic function in normal urine

    PubMed Central

    Aghamajidi, Azin; Babaie, Hesam; Amirjamshidi, Narges; Abedian, Zeinab; Khorasani, Hamidreza; Mostafazadeh, Amrollah

    2016-01-01

    Background: Similar to inflammatory cells, peripheral blood mononuclear cells (PBMCs) can also infiltrate in to kidney and urinary tracts and subsequently excreted by urine. In this study we determined the viability rate and response to phytohemagglutinin-A (PHA) of human PBMCs in normal urine. Methods: A number of 1106 ficoll-hypaque isolated PBMCs were dispensed in 1 ml normal urine and 6 molar urea and RPMI-1640+FBS10 % were considered as negative and positive control, respectively. After 20, 60 and 120 minutes the viability of these cells was measured by trypan blue dye exclusion assay. 1105 of PBMCs were isolated from urine and cultured as triplicate in RPMI-1640`supplemented with FBS 10% and PHA for 96hr. MTT assay was performed to determine the PBMCs response to PHA. These experiments were repeated three times independently. Results: There was no significant difference between the viability rates of the PBMCs incubated in urine and positive control after 20, 60 and 120 minutes. Overall, there was a significant difference in trends of viability rate across the three groups (p<0.05). Conclusion: Our results showed that not only PBMCs remained remarkably alive in urine after 120 minutes, but can also respond to PHA up to 60 minutes after incubation in urine. These data open a new avenue in the designation for cell culture-based techniques in urine cell analysis.

  18. In Vitro Pollen Viability and Pollen Germination in Cherry Laurel (Prunus laurocerasus L.)

    PubMed Central

    Sulusoglu, Melekber; Cavusoglu, Aysun

    2014-01-01

    Pollen quality is important for growers and breeders. This study was carried out to determine in vitro pollen viability and pollen germination in seven genotypes of cherry laurel (Prunus laurocerasus L.). Two pollen viability tests, TTC (2,3,5-triphenyl tetrazolium chloride) and IKI (iodine potassium iodide), were used. Pollen traits of genotypes were studied using an in vitro medium containing 0%, 5%, 10%, 15%, and 20% sucrose to determine the best sucrose concentrations for germination. In the second step, the germinated pollen was counted 1, 4, 6, 10, 12, 24, and 48 hours later until there was no further germination. The viability rates were different according to genotypes and tests used. The IKI and TTC staining tests and pollen germination had low correlation (r2 = 0.0614 and r2 = 0.0015, resp.). Painted pollen rate was higher and pollen was well-stained with IKI test and pollen viability estimated with TTC staining test was better than that estimated with the IKI staining test. 15% sucrose gave the best germination rates in most of the genotypes. Pollen germination rates were recorded periodically from one hour to 48 hours in 15% sucrose and the results showed that pollen germination rates increased after 6 hours of being placed in culture media. PMID:25405230

  19. 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…

  20. 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

  1. Introducing Economics.

    ERIC Educational Resources Information Center

    Federal Reserve Bank of Boston, MA.

    The booklet outlines and presents examples of basic economics concepts. Objectives are to help elementary and secondary teachers introduce economic concepts in the classroom and to help teachers grasp some of the fundamentals of economics. The document is divided into seven sections. Each section presents concepts, offers three supporting

  2. Microbial engineering strategies to improve cell viability for biochemical production.

    PubMed

    Lo, Tat-Ming; Teo, Wei Suong; Ling, Hua; Chen, Binbin; Kang, Aram; Chang, Matthew Wook

    2013-11-01

    Efficient production of biochemicals using engineered microbes as whole-cell biocatalysts requires robust cell viability. Robust viability leads to high productivity and improved bioprocesses by allowing repeated cell recycling. However, cell viability is negatively affected by a plethora of stresses, namely chemical toxicity and metabolic imbalances, primarily resulting from bio-synthesis pathways. Chemical toxicity is caused by substrates, intermediates, products, and/or by-products, and these compounds often interfere with important metabolic processes and damage cellular infrastructures such as cell membrane, leading to poor cell viability. Further, stresses on engineered cells are accentuated by metabolic imbalances, which are generated by heavy metabolic resource consumption due to enzyme overexpression, redistribution of metabolic fluxes, and impaired intracellular redox state by co-factor imbalance. To address these challenges, herein, we discuss a range of key microbial engineering strategies, substantiated by recent advances, to improve cell viability for commercially sustainable production of biochemicals from renewable resources. PMID:23403071

  3. Assessment of tissue viability by polarization spectroscopy

    NASA Astrophysics Data System (ADS)

    Nilsson, G.; Anderson, C.; Henricson, J.; Leahy, M.; O'Doherty, J.; Sjberg, F.

    2008-09-01

    A new and versatile method for tissue viability imaging based on polarization spectroscopy of blood in superficial tissue structures such as the skin is presented in this paper. Linearly polarized light in the visible wavelength region is partly reflected directly by the skin surface and partly diffusely backscattered from the dermal tissue matrix. Most of the directly reflected light preserves its polarization state while the light returning from the deeper tissue layers is depolarized. By the use of a polarization filter positioned in front of a sensitive CCD-array, the light directly reflected from the tissue surface is blocked, while the depolarized light returning from the deeper tissue layers reaches the detector array. By separating the colour planes of the detected image, spectroscopic information about the amount of red blood cells (RBCs) in the microvascular network of the tissue under investigation can be derived. A theory that utilizes the differences in light absorption of RBCs and bloodless tissue in the red and green wavelength region forms the basis of an algorithm for displaying a colour coded map of the RBC distribution in a tissue. Using a fluid model, a linear relationship (cc. = 0.99) between RBC concentration and the output signal was demonstrated within the physiological range 0-4%. In-vivo evaluation using transepidermal application of acetylcholine by the way of iontophoresis displayed the heterogeneity pattern of the vasodilatation produced by the vasoactive agent. Applications of this novel technology are likely to be found in drug and skin care product development as well as in the assessment of skin irritation and tissue repair processes and even ultimately in a clinic case situation.

  4. The Use of Water Vapor as a Refrigerant: Impact of Cycle Modifications on Commercial Viability

    SciTech Connect

    Brandon F. Lachner, Jr.; Gregory F. Nellis; Douglas T. Reindl

    2004-08-30

    This project investigated the economic viability of using water as the refrigerant in a 1000-ton chiller application. The most attractive water cycle configuration was found to be a flash-intercooled, two-stage cycle using centrifugal compressors and direct contact heat exchangers. Component level models were developed that could be used to predict the size and performance of the compressors and heat exchangers in this cycle as well as in a baseline, R-134a refrigeration cycle consistent with chillers in use today. A survey of several chiller manufacturers provided information that was used to validate and refine these component models. The component models were integrated into cycle models that were subsequently used to investigate the life-cycle costs of both an R-134a and water refrigeration cycle. It was found that the first cost associated with the water as a refrigerant cycle greatly exceeded the savings in operating costs associated with its somewhat higher COP. Therefore, the water refrigeration cycle is not an economically attractive option to today's R-134a refrigeration system. There are a number of other issues, most notably the requirements associated with purging non-condensable gases that accumulate in a direct contact heat exchanger, which will further reduce the economic viability of the water cycle.

  5. Effects of time and socio-economic status on the determinants of oral health-related behaviours of parents of preschool children.

    PubMed

    Van den Branden, S; Van den Broucke, S; Leroy, R; Declerck, D; Hoppenbrouwers, K

    2012-04-01

    The oral health-related beliefs of parents have an important impact on the oral health status of their children; however, they are not stable over time. This study aimed to assess the changes, over time, in the determinants of parental oral health-related behaviour based on the Theory of Planned Behaviour and to investigate socio-economic inequalities. The cohort consisted of the parents - mainly the mothers - of 1,057 children born in 2003 and 2004 in Flanders (Belgium). According to the Theory of Planned Behaviour, validated questionnaires, completed at children's birth and at age 3 and 5 yr, assessed parental attitudes, social norms, perceived behavioural control, and intention towards three behaviours: dietary habits, oral hygiene habits, and dental attendance. Linear mixed-model analyses were applied. Positive parental attitudes towards oral health-related behaviours increased between birth and 3 yr of age, whereas the scores for subjective norms and intentions decreased. Scores remained stable for children between three and 5 yr of age. Highly educated mothers had significantly higher scores for attitudes, perceived behavioural control, and intentions than less-educated mothers. Health promotion campaigns should take these natural changes and inequalities of dental beliefs into account when developing and evaluating interventions. PMID:22409222

  6. Socio-Economic and Health Access Determinants of Breast and Cervical Cancer Screening in Low-Income Countries: Analysis of the World Health Survey

    PubMed Central

    Akinyemiju, Tomi F.

    2012-01-01

    Background Breast and Cervical cancer are the two most common cancers among women in developing countries. Regular screening is the most effective way of ensuring that these cancers are detected at early stages; however few studies have assessed factors that predict cancer screening in developing countries. Purpose To assess the influence of household socio-economic status (SES), healthcare access and country level characteristics on breast and cervical cancer screening among women in developing countries. Methods Women ages 1869 years (cervical cancer screening) and 4069 years (breast cancer screening) from 15 developing countries who participated in the 2003 World Health Survey provided data for this study. Household SES and healthcare access was assessed based on self-reported survey responses. SAS survey procedures (SAS, Version 9.2) were used to assess determinants of breast and cervical cancer screening in separate models. Results 4.1% of women ages 1869 years had received cervical cancer screening in the past three years, while only 2.2% of women ages 4069 years had received breast cancer screening in the past 5 years in developing countries. Cancer screening rates varied by country; cervical cancer screening ranged from 1.1% in Bangladesh to 57.6% in Congo and breast cancer screening ranged from 0% in Mali to 26% in Congo. Significant determinants of cancer screening were household SES, rural residence, country health expenditure (as a percent of GDP) as well as healthcare access. Discussion A lot more needs to be done to improve screening rates for breast and cervical cancer in developing countries, such as increasing health expenditure (especially in rural areas), applying the increased funds towards the provision of more, better educated health providers as well as improved infrastructure. PMID:23155413

  7. Colony Failure Linked to Low Sperm Viability in Honey Bee (Apis mellifera) Queens and an Exploration of Potential Causative Factors.

    PubMed

    Pettis, Jeffery S; Rice, Nathan; Joselow, Katie; vanEngelsdorp, Dennis; Chaimanee, Veeranan

    2016-01-01

    Queen health is closely linked to colony performance in honey bees as a single queen is normally responsible for all egg laying and brood production within the colony. In the U. S. in recent years, queens have been failing at a high rate; with 50% or greater of queens replaced in colonies within 6 months when historically a queen might live one to two years. This high rate of queen failure coincides with the high mortality rates of colonies in the US, some years with >50% of colonies dying. In the current study, surveys of sperm viability in US queens were made to determine if sperm viability plays a role in queen or colony failure. Wide variation was observed in sperm viability from four sets of queens removed from colonies that beekeepers rated as in good health (n = 12; average viability = 92%), were replacing as part of normal management (n = 28; 57%), or where rated as failing (n = 18 and 19; 54% and 55%). Two additional paired set of queens showed a statistically significant difference in viability between colonies rated by the beekeeper as failing or in good health from the same apiaries. Queens removed from colonies rated in good health averaged high viability (ca. 85%) while those rated as failing or in poor health had significantly lower viability (ca. 50%). Thus low sperm viability was indicative of, or linked to, colony performance. To explore the source of low sperm viability, six commercial queen breeders were surveyed and wide variation in viability (range 60-90%) was documented between breeders. This variability could originate from the drones the queens mate with or temperature extremes that queens are exposed to during shipment. The role of shipping temperature as a possible explanation for low sperm viability was explored. We documented that during shipment queens are exposed to temperature spikes (<8 and > 40°C) and these spikes can kill 50% or more of the sperm stored in queen spermathecae in live queens. Clearly low sperm viability is linked to colony performance and laboratory and field data provide evidence that temperature extremes are a potential causative factor. PMID:26863438

  8. Colony Failure Linked to Low Sperm Viability in Honey Bee (Apis mellifera) Queens and an Exploration of Potential Causative Factors

    PubMed Central

    Pettis, Jeffery S.; Rice, Nathan; Joselow, Katie; vanEngelsdorp, Dennis; Chaimanee, Veeranan

    2016-01-01

    Queen health is closely linked to colony performance in honey bees as a single queen is normally responsible for all egg laying and brood production within the colony. In the U. S. in recent years, queens have been failing at a high rate; with 50% or greater of queens replaced in colonies within 6 months when historically a queen might live one to two years. This high rate of queen failure coincides with the high mortality rates of colonies in the US, some years with >50% of colonies dying. In the current study, surveys of sperm viability in US queens were made to determine if sperm viability plays a role in queen or colony failure. Wide variation was observed in sperm viability from four sets of queens removed from colonies that beekeepers rated as in good health (n = 12; average viability = 92%), were replacing as part of normal management (n = 28; 57%), or where rated as failing (n = 18 and 19; 54% and 55%). Two additional paired set of queens showed a statistically significant difference in viability between colonies rated by the beekeeper as failing or in good health from the same apiaries. Queens removed from colonies rated in good health averaged high viability (ca. 85%) while those rated as failing or in poor health had significantly lower viability (ca. 50%). Thus low sperm viability was indicative of, or linked to, colony performance. To explore the source of low sperm viability, six commercial queen breeders were surveyed and wide variation in viability (range 60–90%) was documented between breeders. This variability could originate from the drones the queens mate with or temperature extremes that queens are exposed to during shipment. The role of shipping temperature as a possible explanation for low sperm viability was explored. We documented that during shipment queens are exposed to temperature spikes (<8 and > 40°C) and these spikes can kill 50% or more of the sperm stored in queen spermathecae in live queens. Clearly low sperm viability is linked to colony performance and laboratory and field data provide evidence that temperature extremes are a potential causative factor. PMID:26863438

  9. Common European harmful algal blooms affect the viability and innate immune responses of Mytilus edulis larvae.

    PubMed

    De Rijcke, M; Vandegehuchte, M B; Vanden Bussche, J; Nevejan, N; Vanhaecke, L; De Schamphelaere, K A C; Janssen, C R

    2015-11-01

    Like marine diseases, harmful algal blooms (HABs) are globally increasing in frequency, severity and geographical scale. As a result, bivalves will have to face the combined threat of toxic algae and marine pathogens more frequently in the (near) future. These stressors combined may further affect the recruitment of ecologically and economically important bivalve species as HABs can affect the growth, viability and development of their larvae. To date, little is known on the specific effects of HABs on the innate immune system of bivalve larvae. This study therefore investigates whether two common harmful algae can influence the larval viability, development and immunological resilience of the blue mussel Mytilus edulis. Embryos of this model organism were exposed (48 h) to five densities of Pseudo-nitzschia multiseries or Prorocentrum lima cells. In addition, the effect of six concentrations of their respective toxins: domoic acid (DA) and okadaic acid (OA) were assessed. OA was found to significantly reduce larval protein phosphatase activity (p < 0.001) and larval viability (p < 0.01) at concentrations as low as 37.8 μg l(-1). P. multiseries (1400 cells ml(-1)), P. lima (150 cells ml(-1)) and DA (dosed five times higher than typical environmental conditions i.e. 623.2 μg l(-1)) increased the phenoloxidase (PO) innate immune activity of the mussel larvae. These results suggest that the innate immune response of even the earliest life stages of bivalves is susceptible to the presence of HABs. PMID:26348409

  10. Viability and Virulence of Entomopathogenic Nematodes Exposed to Ultraviolet Radiation

    PubMed Central

    Shapiro-Ilan, David I.; Hazir, Selcuk; Lete, Luis

    2015-01-01

    Entomopathogenic nematodes (EPNs) can be highly effective biocontrol agents, but their efficacy can be reduced due to exposure to environmental stress such as from ultraviolet (UV) radiation. Our objectives were to 1) compare UV tolerance among a broad array of EPN species, and 2) investigate the relationship between reduced nematode viability (after exposure to UV) and virulence. Nematodes exposed to a UV radiation (254 nm) for 10 or 20 min were assessed separately for viability (survival) and virulence to Galleria mellonella. We compared 9 different EPN species and 15 strains: Heterorhabditis bacteriophora (Baine, fl11, Oswego, and Vs strains), H. floridensis (332), H. georgiana (Kesha), H. indica (HOM1), H. megidis (UK211), Steinernema carpocapsae (All, Cxrd, DD136, and Sal strains), S. feltiae (SN), S. rarum (17C&E), and S. riobrave (355). In viability assessments, steinernematids, particularly strains of S. carpocapsae, generally exhibited superior UV tolerance compared with the heterorhabditids. However, some heterorhabditids tended to be more tolerant than others, e.g., H. megidis and H. bacteriophora (Baine) were most susceptible and H. bacteriophora (Vs) was the only heterorhabditid that did not exhibit a significant effect after 10 min of exposure. All heterorhabditids experienced reduced viability after 20 min exposure though several S. carpocapsae strains did not. In total, after 10 or 20 min exposure, the viability of seven nematode strains did not differ from their non-UV exposed controls. In virulence assays, steinernematids (particularly S. carpocapsae strains) also tended to exhibit higher UV tolerance. However, in contrast to the viability measurements, all nematodes experienced a reduction in virulence relative to their controls. Correlation analysis revealed that viability among nematode strains is not necessarily related to virulence. In conclusion, our results indicate that the impact of UV varies substantially among EPNs, and viability alone is not a sufficient measure for potential impact on biocontrol efficacy as other characters such as virulence may be severely affected even when viability remains high. PMID:26527839

  11. Viability and Virulence of Entomopathogenic Nematodes Exposed to Ultraviolet Radiation.

    PubMed

    Shapiro-Ilan, David I; Hazir, Selcuk; Lete, Luis

    2015-09-01

    Entomopathogenic nematodes (EPNs) can be highly effective biocontrol agents, but their efficacy can be reduced due to exposure to environmental stress such as from ultraviolet (UV) radiation. Our objectives were to 1) compare UV tolerance among a broad array of EPN species, and 2) investigate the relationship between reduced nematode viability (after exposure to UV) and virulence. Nematodes exposed to a UV radiation (254 nm) for 10 or 20 min were assessed separately for viability (survival) and virulence to Galleria mellonella. We compared 9 different EPN species and 15 strains: Heterorhabditis bacteriophora (Baine, fl11, Oswego, and Vs strains), H. floridensis (332), H. georgiana (Kesha), H. indica (HOM1), H. megidis (UK211), Steinernema carpocapsae (All, Cxrd, DD136, and Sal strains), S. feltiae (SN), S. rarum (17C&E), and S. riobrave (355). In viability assessments, steinernematids, particularly strains of S. carpocapsae, generally exhibited superior UV tolerance compared with the heterorhabditids. However, some heterorhabditids tended to be more tolerant than others, e.g., H. megidis and H. bacteriophora (Baine) were most susceptible and H. bacteriophora (Vs) was the only heterorhabditid that did not exhibit a significant effect after 10 min of exposure. All heterorhabditids experienced reduced viability after 20 min exposure though several S. carpocapsae strains did not. In total, after 10 or 20 min exposure, the viability of seven nematode strains did not differ from their non-UV exposed controls. In virulence assays, steinernematids (particularly S. carpocapsae strains) also tended to exhibit higher UV tolerance. However, in contrast to the viability measurements, all nematodes experienced a reduction in virulence relative to their controls. Correlation analysis revealed that viability among nematode strains is not necessarily related to virulence. In conclusion, our results indicate that the impact of UV varies substantially among EPNs, and viability alone is not a sufficient measure for potential impact on biocontrol efficacy as other characters such as virulence may be severely affected even when viability remains high. PMID:26527839

  12. The effects of fumonisin B1 on viability and mitogenic response of avian immune cells.

    PubMed

    Keck, B B; Bodine, A B

    2006-06-01

    Fumonisin B1 (FB1) is a mycotoxin produced by the fungus Fusarium verticillioides (formerly Fusarium moniliforme) and is found in diverse crops such as corn, wheat, and barley. Many diseases linked to FB1, such as porcine pulmonary edema, rat hepatic cancer, and equine leukoencephalomalacia, indicate a compromised immune system. The purpose of this study was to determine whether FB1 altered immunological responses in various cell populations of Single Comb White Leghorn chicks. Cells collected for this study were obtained from those immunological organs with well-defined responses (i.e., spleen, thymus, and blood). Cell populations were exposed to 5 to 50 microg/mL FB1 in vitro for 24 to 72 h, and viability and mitogenic response were evaluated. The effects of FB1 on the mitogenic response were evaluated in cell populations from the spleen and blood stimulated with the mitogens, lipopolysaccharide, concanavalin A, and pokeweed mitogen and in thymocytes stimulated with concanavalin A. The 3-(4,5-dimethylthazol-2-yl)-diphenyl-2H-tetrazolium bromide (MTT) reduction assay was used to assess viability and mitogenic response. Fumonisin B1 decreased spleen cell viability and mitogenic response, albeit the degree of decrease varied with mitogen and time of exposure. Fumonisin B1 increased number of viable thymic cells at 50 microg/mL but had no effect on the mitogenic response of thymocytes. Fumonisin B1 had no effect on blood lymphocyte viability or mitogenic response. PMID:16776470

  13. Effect of storage and preservation methods on viability in transplantable human skin allografts.

    PubMed

    Bravo, D; Rigley, T H; Gibran, N; Strong, D M; Newman-Gage, H

    2000-06-01

    This study compared the metabolic activity of fresh skin samples to that of cadaver human skin allografts processed and stored by current tissue banking methods. We chose to use two metabolic assays as surrogate measures for viability in these grafts. Skin allografts stored either in liquid media at 4 degrees C for varying periods of time or stored by cryopreservation were quantitatively assessed for viability by tetrazolium reduction and oxygen consumption assays. These measurements were compared to viability assessments of fresh autograft skin. Human cadaver skin grafts, after procurement and just prior to further tissue bank processing, exhibited approximately 60% of the metabolic activity found in fresh skin samples obtained from living surgical donors. If allowed an overnight (18-24 h) incubation period at 37 degrees C, cadaver samples showed a recovery of their metabolic activity to 95% of that found in the autograft skin samples. When stored in liquid media at 4 degrees C, the cadaver skin declined steadily in cellular metabolic activity, arriving in less than 5 days storage at a measurement below that of cryopreserved skin. The cryopreserved skin was measured both immediately after thawing and dilution of cryoprotectant, as well as after equilibration and overnight incubation. Skin cryopreserved with dimethylsulfoxide Me(2)SO retained higher viability than glycerol cryopreserved skin. Residual concentrations of cryoprotectants were determined following typical recommendations for thawing and diluting skin allografts. The implications of these findings for transplantation and tissue banking are discussed. PMID:10751705

  14. A study of different buffers to maximize viability of an oral Shigella vaccine.

    PubMed

    Chandrasekaran, Lakshmi; Lal, Manjari; Van De Verg, Lillian L; Venkatesan, Malabi M

    2015-11-17

    Live, whole cell killed and subunit vaccines are being developed for diarrheal diseases caused by V. cholerae, Shigella species, ETEC, and Campylobacter. Some of these vaccines can be administered orally since this route best mimics natural infection. Live vaccines administered orally have to be protected from the harsh acidic gastric environment. Milk and bicarbonate solutions have been administered to neutralize the stomach acid. For many Shigella vaccine trials, 100-120 ml of a bicarbonate solution is ingested followed by the live vaccine candidate, which is delivered in 30 ml of bicarbonate, water or saline. It is not clear if maximum bacterial viability is achieved under these conditions. Also, volumes of neutralizing buffer that are optimal for adults may be unsuitable for children and infants. To address these questions, we performed studies to determine the viability and stability of a Shigella sonnei vaccine candidate, WRSS1, in a mixture of different volumes of five different buffer solutions added to hydrochloric acid to simulate gastric acidity. Among the buffers tested, bicarbonate solution, rotavirus buffer and CeraVacx were better at neutralizing acid and maintaining the viability of WRSS1. Also, a much smaller volume of the neutralizing buffer was sufficient to counteract stomach acid while maintaining bacterial viability. PMID:26428454

  15. A method to estimate pollen viability from pollen size variation.

    PubMed

    Kelly, John K; Rasch, Aaron; Kalisz, Susan

    2002-06-01

    The mean diameter of viable pollen grains is approximately 13 ?m greater than the mean diameter of inviable grains in Mimulus guttatus. We show that this difference is large enough to be detected by particle counters and that these machines can be used to obtain a rapid estimate of pollen viability. While requiring a separate calibration, a size-based statistic is also strongly correlated with pollen viability in Collinsia verna. These results suggest that statistics derived from the size distribution of pollen grains may provide an alternative to more labor-intensive methods for estimating pollen viability, particularly in cases where inviability results from inbreeding depression or hybrid failure. PMID:21665702

  16. 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

  17. Assessment of the commercial viability of selected options for on-orbit servicing (OOS)

    NASA Astrophysics Data System (ADS)

    Graham, Andrew Robert; Kingston, Jennifer

    2015-12-01

    The aim of this paper is to determine the commercial viability of on-orbit servicing of communications satellites in geostationary orbit. Previous studies have shown the technical feasibility of servicing as well as the financial viability of some missions, in particular refuelling, therefore this paper analyses these repair missions and life extension missions. A simple parametric model for simulating communications satellite revenue streams is developed and the results are used to determine the maximum possible revenue for a servicing satellite operator. From this, the maximum cost of the servicing satellite as a proportion of the cost of the communications satellite is determined under three profit scenarios representing zero profit, acceptable profit to an operator in a mature industry and acceptable profit to an operator in an emerging industry. The results show that while servicing is financially viable (zero profit scenario), those missions which result in an increase in Comsat life which is a multiple of the mission duration are more likely to be commercially viable. Refuelling is therefore viable in all cases but life extension in most cases is only marginally viable. Repair missions to satellites which are partially operable are also unlikely to deliver sufficient value to justify carrying out servicing. Also the timing of a servicing mission in relation to the expected remaining life expectancy is a major factor in determining the mission's viability.

  18. Morphologic Economics

    NASA Astrophysics Data System (ADS)

    Naitoh, Ken

    2011-11-01

    It has been difficult to predict various classes of boom-and-bust economic cycles and these cyclic catastrophes systematically, because they are related to several biological phenomena. In this report, we will show that our theory on the morphogenetic process and the brain with a rhythm of about seven beats can explain several economic system cycles, because different types of economic cycles are about seven times the length of the fundamental production cycles or durable periods. We will also outline the spatial structure underlying economic systems on the basis of the fluid dynamic theory that describes subatomic systems, biological systems, human network systems, and stars.

  19. Using Bayesian Population Viability Analysis to Define Relevant Conservation Objectives

    PubMed Central

    Green, Adam W.; Bailey, Larissa L.

    2015-01-01

    Adaptive management provides a useful framework for managing natural resources in the face of uncertainty. An important component of adaptive management is identifying clear, measurable conservation objectives that reflect the desired outcomes of stakeholders. A common objective is to have a sustainable population, or metapopulation, but it can be difficult to quantify a threshold above which such a population is likely to persist. We performed a Bayesian metapopulation viability analysis (BMPVA) using a dynamic occupancy model to quantify the characteristics of two wood frog (Lithobates sylvatica) metapopulations resulting in sustainable populations, and we demonstrate how the results could be used to define meaningful objectives that serve as the basis of adaptive management. We explored scenarios involving metapopulations with different numbers of patches (pools) using estimates of breeding occurrence and successful metamorphosis from two study areas to estimate the probability of quasi-extinction and calculate the proportion of vernal pools producing metamorphs. Our results suggest that ≥50 pools are required to ensure long-term persistence with approximately 16% of pools producing metamorphs in stable metapopulations. We demonstrate one way to incorporate the BMPVA results into a utility function that balances the trade-offs between ecological and financial objectives, which can be used in an adaptive management framework to make optimal, transparent decisions. Our approach provides a framework for using a standard method (i.e., PVA) and available information to inform a formal decision process to determine optimal and timely management policies. PMID:26658734

  20. Quantification of cellular viability by automated microscopy and flow cytometry

    PubMed Central

    Sauvat, Allan; Wang, Yidan; Segura, Florian; Spaggiari, Sabrina; Mller, Kevin; Zhou, Heng; Galluzzi, Lrenzo; Kepp, Oliver; Kroemer, Guido

    2015-01-01

    Cellular viability is usually determined by measuring the capacity of cells to exclude vital dyes such as 4?,6-diamidino-2-phenylindole (DAPI), or by assessing nuclear morphology with chromatinophilic plasma membrane-permeant dyes, such as Hoechst 33342. However, a fraction of cells that exclude DAPI or exhibit normal nuclear morphology have already lost mitochondrial functions and/or manifest massive activation of apoptotic caspases, and hence are irremediably committed to death. Here, we developed a protocol for the simultaneous detection of plasma membrane integrity (based on DAPI) or nuclear morphology (based on Hoechst 33342), mitochondrial functions (based on the mitochondrial transmembrane potential probe DiOC6(3)) and caspase activation (based on YO-PRO-3, which can enter cells exclusively upon the caspase-mediated activation of pannexin 1 channels). This method, which allows for the precise quantification of dead, dying and healthy cells, can be implemented on epifluorescence microscopy or flow cytometry platforms and is compatible with a robotized, high-throughput workflow. PMID:25816366

  1. Quantification of cellular viability by automated microscopy and flow cytometry.

    PubMed

    Sauvat, Allan; Wang, Yidan; Segura, Florian; Spaggiari, Sabrina; Mller, Kevin; Zhou, Heng; Galluzzi, Lorenzo; Kepp, Oliver; Kroemer, Guido

    2015-04-20

    Cellular viability is usually determined by measuring the capacity of cells to exclude vital dyes such as 4',6-diamidino-2-phenylindole (DAPI), or by assessing nuclear morphology with chromatinophilic plasma membrane-permeant dyes, such as Hoechst 33342. However, a fraction of cells that exclude DAPI or exhibit normal nuclear morphology have already lost mitochondrial functions and/or manifest massive activation of apoptotic caspases, and hence are irremediably committed to death. Here, we developed a protocol for the simultaneous detection of plasma membrane integrity (based on DAPI) or nuclear morphology (based on Hoechst 33342), mitochondrial functions (based on the mitochondrial transmembrane potential probe DiOC6(3)) and caspase activation (based on YO-PRO-3, which can enter cells exclusively upon the caspase-mediated activation of pannexin 1 channels). This method, which allows for the precise quantification of dead, dying and healthy cells, can be implemented on epifluorescence microscopy or flow cytometry platforms and is compatible with a robotized, high-throughput workflow. PMID:25816366

  2. Decreased winter severity increases viability of a montane frog population.

    PubMed

    McCaffery, Rebecca M; Maxell, Bryce A

    2010-05-11

    Many proximate causes of global amphibian declines have been well documented, but the role that climate change has played and will play in this crisis remains ambiguous for many species. Breeding phenology and disease outbreaks have been associated with warming temperatures, but, to date, few studies have evaluated effects of climate change on individual vital rates and subsequent population dynamics of amphibians. We evaluated relationships among local climate variables, annual survival and fecundity, and population growth rates from a 9-year demographic study of Columbia spotted frogs (Rana luteiventris) in the Bitterroot Mountains of Montana. We documented an increase in survival and breeding probability as severity of winter decreased. Therefore, a warming climate with less severe winters is likely to promote population viability in this montane frog population. More generally, amphibians and other ectotherms inhabiting alpine or boreal habitats at or near their thermal ecological limits may benefit from the milder winters provided by a warming climate as long as suitable habitats remain intact. A more thorough understanding of how climate change is expected to benefit or harm amphibian populations at different latitudes and elevations is essential for determining the best strategies to conserve viable populations and allow for gene flow and shifts in geographic range. PMID:20421473

  3. Tissue viability imaging for quantification of skin erythema and blanching

    NASA Astrophysics Data System (ADS)

    Nilsson, Gert E.; Leahy, Martin J.

    2010-02-01

    Naked eye observation has up to recently been the main method of determining skin erythema (vasodilatation) and blanching (vasoconstriction) in skin testing. Since naked eye observation is a highly subjective and investigatordependent method, it is difficult to attain reproducibility and to compare results reported by different researchers performing their studies at different laboratories. Consequently there is a need for more objective, quantitative and versatile methods in the assessment of alterations in skin erythema and blanching caused by internal and external factors such as the intake of vasoactive drugs, application of agents on the skin surface and by constituents in the environment. Since skin microcirculation is sensitive to applied pressure and heat, such methods should preferably be noninvasive and designed for remote use without touching the skin. As skin microcirculation further possesses substantial spatial variability, imaging techniques are to be preferred before single point measurements. An emerging technology based on polarization digital camera spectroscopy - Tissue Viability Imaging (TiVi) - fulfills these requirements. The principles of TiVi (1) and some of its early applications (2-5) are addressed in this paper.

  4. Decreased winter severity increases viability of a montane frog population

    PubMed Central

    McCaffery, Rebecca M.; Maxell, Bryce A.

    2010-01-01

    Many proximate causes of global amphibian declines have been well documented, but the role that climate change has played and will play in this crisis remains ambiguous for many species. Breeding phenology and disease outbreaks have been associated with warming temperatures, but, to date, few studies have evaluated effects of climate change on individual vital rates and subsequent population dynamics of amphibians. We evaluated relationships among local climate variables, annual survival and fecundity, and population growth rates from a 9-year demographic study of Columbia spotted frogs (Rana luteiventris) in the Bitterroot Mountains of Montana. We documented an increase in survival and breeding probability as severity of winter decreased. Therefore, a warming climate with less severe winters is likely to promote population viability in this montane frog population. More generally, amphibians and other ectotherms inhabiting alpine or boreal habitats at or near their thermal ecological limits may benefit from the milder winters provided by a warming climate as long as suitable habitats remain intact. A more thorough understanding of how climate change is expected to benefit or harm amphibian populations at different latitudes and elevations is essential for determining the best strategies to conserve viable populations and allow for gene flow and shifts in geographic range. PMID:20421473

  5. Using Bayesian Population Viability Analysis to Define Relevant Conservation Objectives.

    PubMed

    Green, Adam W; Bailey, Larissa L

    2015-01-01

    Adaptive management provides a useful framework for managing natural resources in the face of uncertainty. An important component of adaptive management is identifying clear, measurable conservation objectives that reflect the desired outcomes of stakeholders. A common objective is to have a sustainable population, or metapopulation, but it can be difficult to quantify a threshold above which such a population is likely to persist. We performed a Bayesian metapopulation viability analysis (BMPVA) using a dynamic occupancy model to quantify the characteristics of two wood frog (Lithobates sylvatica) metapopulations resulting in sustainable populations, and we demonstrate how the results could be used to define meaningful objectives that serve as the basis of adaptive management. We explored scenarios involving metapopulations with different numbers of patches (pools) using estimates of breeding occurrence and successful metamorphosis from two study areas to estimate the probability of quasi-extinction and calculate the proportion of vernal pools producing metamorphs. Our results suggest that ≥50 pools are required to ensure long-term persistence with approximately 16% of pools producing metamorphs in stable metapopulations. We demonstrate one way to incorporate the BMPVA results into a utility function that balances the trade-offs between ecological and financial objectives, which can be used in an adaptive management framework to make optimal, transparent decisions. Our approach provides a framework for using a standard method (i.e., PVA) and available information to inform a formal decision process to determine optimal and timely management policies. PMID:26658734

  6. Optimizing cell viability in droplet-based cell deposition.

    PubMed

    Hendriks, Jan; Willem Visser, Claas; Henke, Sieger; Leijten, Jeroen; Saris, Daniël B F; Sun, Chao; Lohse, Detlef; Karperien, Marcel

    2015-01-01

    Biofabrication commonly involves the use of liquid droplets to transport cells to the printed structure. However, the viability of the cells after impact is poorly controlled and understood, hampering applications including cell spraying, inkjet bioprinting, and laser-assisted cell transfer. Here, we present an analytical model describing the cell viability after impact as a function of the cell-surrounding droplet characteristics. The model connects (1) the cell survival as a function of cell membrane elongation, (2) the membrane elongation as a function of the cell-containing droplet size and velocity, and (3) the substrate properties. The model is validated by cell viability measurements in cell spraying, which is a method for biofabrication and used for the treatment of burn wounds. The results allow for rational optimization of any droplet-based cell deposition technology, and we include practical suggestions to improve the cell viability in cell spraying. PMID:26065378

  7. Economic Assessment of the Association of Northern California Oncologists Member Practices

    PubMed Central

    Buell, Roberta; Falconer, Patricia; Gonzlez, Jos Luis

    2011-01-01

    In late 2009 and early 2010, the Association of Northern California Oncologists conducted an economic assessment on a volunteer sample (n = 14) of northern California state oncology society member practices to measure key economic factors, diagnose economic viability, and prescribe changes to practice management to enhance practice economic viability. Recommendations for individual member practices as well as for the state oncology society were made as a result of the findings of this study. Results from follow-up interviews conducted with study practices approximately 1 year after the original assessments reveal that most recommendations were implemented and seem to have generally strengthened the economic performance of the practices. PMID:22211125

  8. Effects of ultraviolet radiation on dendritic cell viability and function

    SciTech Connect

    Everson, M.P.; Spalding, D.M.; Koopman, W.J.

    1986-03-01

    Ultraviolet radiation (UVR) has been used by several investigators to successfully abrogate accessory cell function, however its mode of action remains unclear. The findings indicate that dendritic cells (DC) are exquisitely sensitive to UVR and therefore, UVR may provide a good probe to study DC accessory cell function. The authors compared the in vitro effects of UVB and UVC on murine splenic DC viability over a dose range of 0-864 J/m/sup 2/. DC viability as a function of time was not significantly different from control for 108, 432, and 864 J/m/sup 2/ UVB at 0-4 hr post-treatment; however, DC viability decreased significantly in a UVR dose-dependent fashion for the 6-10 h post-treatment period. Fourfold less UVC dosages caused equivalent changes in DC viability indicating that higher frequency radiation is substantially more detrimental than UVB. The authors next compared the effect of UVR on viability to its effect on DC function in oxidative mitogenesis assays. UV exposure induced disproportionate decreases in DC function compared to viability (using 216 J/m/sup 2/ UVB, the viability as a percent of control was 90% and 43% at 10 and 20 h, respectively, while DC function was only 18% of the non-UVR treated control value). Thus, function appears to be more sensitive to UVR than viability and the authors have not been able to restore function with IL-1. Thus, DC are exquisitely sensitive to UVR and better understanding of the defects induced by UVR should increase the knowledge of how DC function in induction of lymphocyte responses.

  9. In vitro radiolabel uptake viability assay for Onchocerca microfilariae

    SciTech Connect

    Callahan, H.L.; Wakeman, J.M.; Crouch, R.K.; James, E.R.

    1989-02-01

    A radiolabel uptake viability assay for Onchocerca cervicalis using (/sup 3/H)2-deoxy-D-glucose in Hanks' balanced salt solution, pH 7.5, at 30 C is described and compared to the traditional visual motility assay. A correlation of r = 0.92 between the assays was found, with the radiolabel uptake method apparently a more sensitive indicator of microfilarial viability.

  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. Economics Pupils

    ERIC Educational Resources Information Center

    Scott, Alexander; Straker-Cook, Dawn

    1976-01-01

    This paper contains survey information relating to the relative performance of economics pupils at"A" level, their feelings about the subject, and the type of teaching to which they are exposed. The primary concern is to stimulate debate about the issues raised. Journal is available from: Economics Association, Room 340, Hamilton House, Mabledon

  12. Economics 301.

    ERIC Educational Resources Information Center

    Manitoba Dept. of Education, Winnipeg.

    The purpose of this one-credit economics course for secondary schools in Manitoba (Canada) is to help students develop skills in business education and to provide them with basic information about how the Canadian economic system affects business, government, and the individual. The course requires 110 to 220 hours of instruction. Students study

  13. Economic evaluation

    NASA Astrophysics Data System (ADS)

    Hoffman, L.

    1981-04-01

    The economic significance of wind energy is assessed on the basis of its potential contribution to Germany's energy supply, its competitiveness vis-a-vis other energy sources, and its social desirability, measured by its contribution to the realization of general socio-economic goals.

  14. Ovarian Fluid Mediates the Temporal Decline in Sperm Viability in a Fish with Sperm Storage

    PubMed Central

    Gasparini, Clelia; Evans, Jonathan P.

    2013-01-01

    A loss of sperm viability and functionality during sperm transfer and storage within the female reproductive tract can have important fitness implications by disrupting fertilization and impairing offspring development and survival. Consequently, mechanisms that mitigate the temporal decline in sperm function are likely to be important targets of selection. In many species, ovarian fluid is known to regulate and maintain sperm quality. In this paper, we use the guppy Poecilia reticulata, a highly polyandrous freshwater fish exhibiting internal fertilization and sperm storage, to determine whether ovarian fluid (OF) influences the decline in sperm viability (the proportion of live sperm in the ejaculate) over time and whether any observed effects depend on male sexual ornamentation. To address these questions we used a paired experimental design in which ejaculates from individual males were tested in vitro both in presence and absence of OF. Our results revealed that the temporal decline in sperm viability was significantly reduced in the presence of OF compared to a saline control. This finding raises the intriguing possibility that OF may play a role in mediating the decline in sperm quality due to the deleterious effects of sperm ageing, although other possible explanations for this observation are discussed. Interestingly, we also show that the age-related decline in sperm viability was contingent on male sexual ornamentation; males with relatively high levels of iridescence (indicating higher sexual attractiveness) exhibited a more pronounced decline in sperm viability over time than their less ornamented counterparts. This latter finding offers possible insights into the functional basis for the previously observed trade-off between these key components of pre- and postcopulatory sexual selection. PMID:23691216

  15. Non-destructive monitoring of viability in an ex vivo organ culture model of osteochondral tissue.

    PubMed

    Elson, K M; Fox, N; Tipper, J L; Kirkham, J; Hall, R M; Fisher, J; Ingham, E

    2015-01-01

    Organ culture is an increasingly important tool in research, with advantages over monolayer cell culture due to the inherent natural environment of tissues. Successful organ cultures must retain cell viability. The aim of this study was to produce viable and non-viable osteochondral organ cultures, to assess the accumulation of soluble markers in the conditioned medium for predicting tissue viability. Porcine femoral osteochondral plugs were cultured for 20 days, with the addition of Triton X-100 on day 6 (to induce necrosis), camptothecin (to induce apoptosis) or no toxic additives. Tissue viability was assessed by the tissue destructive XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxyanilide tetrazolium salt) assay method and LIVE/DEAD staining of the cartilage at days 0, 6 and 20. Tissue structure was assessed by histological evaluation using haematoxylin & eosin and safranin O. Conditioned medium was assessed every 3-4 days for glucose depletion, and levels of lactate dehydrogenase (LDH), alkaline phosphatase (AP), glycosaminoglycans (GAGs), and matrix metalloproteinase (MMP)-2 and MMP-9. Necrotic cultures immediately showed a reduction in glucose consumption, and an immediate increase in LDH, GAG, MMP-2 and MMP-9 levels. Apoptotic cultures showed a delayed reduction in glucose consumption and delayed increase in LDH, a small rise in MMP-2 and MMP-9, but no significant effect on GAGs released into the conditioned medium. The data showed that tissue viability could be monitored by assessing the conditioned medium for the aforementioned markers, negating the need for tissue destructive assays. Physiologically relevant whole- or part-joint organ culture models, necessary for research and pre-clinical assessment of therapies, could be monitored this way, reducing the need to sacrifice tissues to determine viability, and hence reducing the sample numbers necessary. PMID:26122871

  16. Effect of silver nanoparticle geometry on methicillin susceptible and resistant Staphylococcus aureus, and osteoblast viability.

    PubMed

    Actis, Lisa; Srinivasan, Anand; Lopez-Ribot, Jose L; Ramasubramanian, Anand K; Ong, Joo L

    2015-07-01

    Orthopedic implant failure as a result of bacterial infection affects approximately 0.5-5% of patients. These infections are often caused by Staphylococcus aureus which is capable of attaching and subsequently forming a biofilm on the implant surface, making it difficult to eradicate with systemic antibiotics. Further, with the emergence of antibiotic-resistant bacteria, alternative treatments are necessary. Silver nanoparticles have received much attention for their broad spectrum antibacterial activity which has been reported to be both size and shape dependent. The purpose of this study was therefore to evaluate the effect of three different geometries on their effect on microbial susceptibility as well as evaluate their effect on bone cell viability. Silver nanoparticles of spherical, triangular and cuboid shapes were synthesized by chemical reduction methods. The susceptibility of S. aureus and methicillin-resistant S. aureus was evaluated a 24 h period and determined using a colorimetric assay. Further, the viability of human fetal osteoblast (hFOB) cells in the presence of the silver nanoparticles was evaluated over a period of 7 days by AlmarBlue fluorescence assay. hFOB morphology was also evaluated by light microscopy imaging. Results indicated that silver nanoparticle geometry did not have an effect on microbiota susceptibility or hFOB viability. However, high concentrations of silver nanoparticles (0.5 nM) conferred significant susceptibility towards the bacteria and significantly reduced hFOB viability. It was also found that the hFOBs exhibited an increasingly reduced viability to lower silver nanoparticle concentrations with an increase in exposure time. PMID:26194976

  17. Viability of freeze dried microencapsulated human retinal pigment epithelial cells.

    PubMed

    Wikstrm, Jonna; Elomaa, Matti; Nevala, Laura; Rikknen, Johanna; Heljo, Petteri; Urtti, Arto; Yliperttula, Marjo

    2012-09-29

    Encapsulated human retinal pigment epithelial cell line ARPE-19 has been successfully used in experimental cell therapy of retinal degenerations and Parkinson's disease, but the long-term storage of encapsulated cells is still an unresolved question. Reconstitution of viable encapsulated cells from dry form would benefit the development of cell therapy products. We freeze dried and reconstituted microencapsulated ARPE19 and ARPE19-SEAP cells. Cross-linked alginate matrix with polycation (poly-l-lysine, cationic starch) coating was used for microencapsulation. Cell viability was assessed with fluorescence microscopy and oxygen consumption of the cells. Freeze dried and reconstituted cell microcapsules were imaged using scanning electron microscopy (SEM) and environmental scanning electron microscopy (ESEM). We show partial viability of microencapsulated cells after freeze-drying. Unlike poly-l-lysine (PLL) coating, cationic starch supported microcapsule shape and cell viability during freeze-drying. Trehalose pre-treatment augmented cell viability. Likewise, some lyoprotectants (trehalose, glycerol) enabled preservation of cell viability. Upon reconstitution the freeze dried cell microcapsules rapidly regained their original spherical shape. This proof-of-concept study demonstrates that microencapsulated cells can retain their viability during freeze-drying. Therefore, this approach can be further optimized for the benefit of cell therapy product development. PMID:22820032

  18. IDSs reconsider the viability of risk contracting.

    PubMed

    Benoff, M; Harris, J M

    2000-09-01

    As financial success with risk contracting continues to elude many IDSs, some of these organizations have started questioning their overall mission as risk-bearing entities. To determine whether to continue to assume risk, an IDS should consider its market environment, the commitment of its provider constituents to the organization, its core competencies, the likelihood of success with risk contracting, and alternatives. To determine its future course, the IDS should engage in a strategic-planning process that includes all IDS stakeholders. Such a process can help build consensus regarding the IDS's market characteristics and benefits of IDS membership; determine the IDS's appropriate roles, services, and functions; and evaluate resources required to pursue the desired strategy. The process should include planning for various possible future scenarios, and results should be communicated to all IDS provider constituents. PMID:11066386

  19. Influence of adhesion to activated carbon particles on the viability of waterborne pathogenic bacteria under flow.

    PubMed

    van der Mei, Henny C; Atema-Smit, Jelly; Jager, Debbie; Langworthy, Don E; Collias, Dimitris I; Mitchell, Michael D; Busscher, Henk J

    2008-07-01

    In rural areas around the world, people often rely on water filtration plants using activated carbon particles for safe water supply. Depending on the carbon surface, adhering microorganisms die or grow to form a biofilm. Assays to assess the efficacy of activated carbons in bacterial removal do not allow direct observation of bacterial adhesion and the determination of viability. Here we propose to use a parallel plate flow chamber with carbon particles attached to the bottom plate to study bacterial adhesion to individual carbon particles and determine the viability of adhering bacteria. Observation and enumeration is done after live/dead staining in a confocal laser scanning microscope. Escherichiae coli adhered in higher numbers than Raoultella terrigena, except to a coconut-based carbon, which showed low bacterial adhesion compared to other wood-based carbon types. After adhesion, 83-96% of the bacteria adhering to an acidic carbon were dead, while on a basic carbon 54-56% were dead. A positively charged, basic carbon yielded 76-78% bacteria dead, while on a negatively charged coconut-based carbon only 32-37% were killed upon adhesion. The possibility to determine both adhesion as well as the viability of adhering bacteria upon adhesion to carbon particles is most relevant, because if bacteria adhere but remain viable, this still puts the water treatment system at risk, as live bacteria can grow and form a biofilm that can then be shedded to cause contamination. PMID:18351669

  20. [Economic evaluation in healthcare].

    PubMed

    Detournay, Bruno

    2014-05-01

    Economics was only recently considered as a dimension of health technology assessment in France. Yet there are always limits in resources that we collectively agree to devote to health. A comparative "economic" appraisal is therefore needed to guide health choices and contribute to price regulation. Methodologies are based on the determination of incremental cost-effectiveness ratios compared with a reference. The interpretation of these ratios is never isolated from the context of the decision. Health economic evaluation is not involved in healthcare rationing, but it contributes to the rationality of decisions in the interest of the overall population. PMID:24939547

  1. Economic Evaluation of Single-Family-Residence Solar-Energy Installation

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Long-term economic performance of a commercial solar-energy system was analyzed and used to predict economic performance at four additional sites. Analysis described in report was done to demonstrate viability of design over a broad range of environmental/economic conditions. Report contains graphs and tables that present evaluation procedure and results. Also contains appendixes that aid in understanding methods used.

  2. 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.

  3. Swarm Economics

    NASA Astrophysics Data System (ADS)

    Kazadi, Sanza; Lee, John

    The Hamiltonian Method of Swarm Design is applied to the design of an agent based economic system. The method allows the design of a system from the global behaviors to the agent behaviors, with a guarantee that once certain derived agent-level conditions are satisfied, the system behavior becomes the desired behavior. Conditions which must be satisfied by consumer agents in order to bring forth the `invisible hand of the market' are derived and demonstrated in simulation. A discussion of how this method might be extended to other economic systems and non-economic systems is presented.

  4. How to assess intestinal viability during surgery: A review of techniques

    PubMed Central

    Urbanavi?ius, Linas; Pattyn, Piet; Van de Putte, Dirk; Venskutonis, Donatas

    2011-01-01

    Objective and quantitative intraoperative methods of bowel viability assessment are essential in gastrointestinal surgery. Exact determination of the borderline of the viable bowel with the help of an objective test could result in a decrease of postoperative ischemic complications. An accurate, reproducible and cost effective method is desirable in every operating theater dealing with abdominal operations. Numerous techniques assessing various parameters of intestinal viability are described by the studies. However, there is no consensus about their clinical use. To evaluate the available methods, a systematic search of the English literature was performed. Virtues and drawbacks of the techniques and possibilities of clinical application are reviewed. Valuable parameters related to postoperative intestinal anastomotic or stoma complications are analyzed. Important issues in the measurement and interpretation of bowel viability are discussed. To date, only a few methods are applicable in surgical practice. Further studies are needed to determine the limiting values of intestinal tissue oxygenation and flow indicative of ischemic complications and to standardize the methods. PMID:21666808

  5. Comparison of various transport media on human periodontal ligament cell viability.

    PubMed

    Olson, B D; Mailhot, J M; Anderson, R W; Schuster, G S; Weller, R N

    1997-11-01

    The purpose of this study was to determine the ability of various solutions to maintain human periodontal ligament cell (PDL) viability in vitro. PDL cells were obtained from extracted third molars and premolars of healthy individuals. These cells were placed into 24-well culture plates containing milk, Save-A-Tooth, Save-A-Tooth supplemented with platelet-derived growth factor-BB (PDGF), or Gatorade at a concentration of approximately 80,000/well. Cells left dry served as negative controls, and cells placed in Eagles' Minimal Essential Medium served as positive controls. At 1, 2, 4, 8, and 12 h, cell viability was evaluated using an MTS assay and an ELISA plate reader to determine optical density. ANOVA and Student-Newman-Keuls tests indicated that milk and Save-A-Tooth with PDGF are suitable as transport medium for avulsed teeth and that the addition of PDGF to Save-A-Tooth may enhance its ability to maintain PDL cell viability. They also suggests that Gatorade would be unsuitable as a transport medium. PMID:9587306

  6. Viability and growth characteristics of Lactobacillus in soymilk supplemented with B-vitamins.

    PubMed

    Ewe, Joo-Ann; Wan-Abdullah, Wan-Nadiah; Liong, Min-Tze

    2010-02-01

    Ten strains of Lactobacillus were evaluated for their viability in soymilk. Lactobacillus acidophilus ATCC 314, L. acidophilus FTDC 8833, L. acidophilus FTDC 8633 and L. gasseri FTDC 8131 displayed higher viability in soymilk and were thus selected to be evaluated for viability and growth characteristics in soymilk supplemented with B-vitamins. Pour plate analyses showed that the supplementation of all B-vitamins studied promoted the growth of lactobacilli to a viable count exceeding 7 log CFU/ml. alpha-Galactosidase specific activity of lactobacilli as determined spectrophotometrically showed an increase upon supplementation of B-vitamins. High-performance liquid chromatography analyses revealed that this led to increased hydrolysis of soy oligosaccharides and subsequently higher utilization of simple sugars. Production of organic acids as determined via high-performance liquid chromatography also showed an increase, accompanied by a decrease in pH of soymilk. Additionally, the supplementation of B-vitamins also promoted the synthesis of riboflavin and folic acid by lactobacilli in soymilk. Our results indicated that B-vitamin-supplemented soymilk is a good proliferation medium for strains of lactobacilli. PMID:19961357

  7. Optimizing conservation strategies for Mexican freetailed bats: a population viability and ecosystem services approach

    USGS Publications Warehouse

    Wiederholt, Ruscena; Lopez-Hoffman, Laura; Svancara, Colleen; McCracken, Gary; Thogmartin, Wayne E.; Diffendorfer, James E.; Mattson, Brady; Bagstad, Kenneth J.; Cryan, Paul; Amy Russell; Semmens, Darius J.; Rodrigo A. Medellín

    2015-01-01

    Conservation planning can be challenging due to the need to balance biological concerns about population viability with social concerns about the benefits biodiversity provide to society, often while operating under a limited budget. Methods and tools that help prioritize conservation actions are critical for the management of at-risk species. Here, we use a multi-attribute utility function to assess the optimal maternity roosts to conserve for maintaining the population viability and the ecosystem services of a single species, the Mexican free-tailed bat (Tadarida brasiliensis mexicana). Mexican free-tailed bats provide ecosystem services such as insect pest-suppression in agricultural areas and recreational viewing opportunities, and may be threatened by climate change and development of wind energy. We evaluated each roost based on five attributes: the maternity roost’s contribution to population viability, the pest suppression ecosystem services to the surrounding area provided by the bats residing in the roost, the ecotourism value of the roost, the risks posed to each roost structure, and the risks posed to the population of bats residing in each roost. We compared several scenarios that prioritized these attributes differently, hypothesizing that the set of roosts with the highest rankings would vary according to the conservation scenario. Our results indicate that placing higher values on different roost attributes (e.g. population importance over ecosystem service value) altered the roost rankings. We determined that the values placed on various conservation objectives are an important determinant of habitat planning.

  8. Behavioral economics

    PubMed Central

    Hursh, Steven R.

    1984-01-01

    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. PMID:16812401

  9. Polyphenolic extracts of edible flowers incorporated onto atelocollagen matrices and their effect on cell viability.

    PubMed

    Lpez-Garca, Jorge; Kucekov, Zdenka; Humpol?ek, Petr; Ml?ek, Ji?i; Sha, Petr

    2013-01-01

    The phenolic extract of chives flowers (Allium schoenoprasum, Liliaceae), introduced Sage (Salvia pratensis, Lamiaceae), European elderberry (Sambucus nigra, Caprifoliaceae) and common dandelion (Taraxacum officinale, Asteraceae) were characterised by High Performance Liquid Chromatography and incorporated in different concentrations onto atelocollagen thin films. In order to assess the biological impact of these phenolic compounds on cell viability, human immortalised non-tumorigenic keratinocyte cell line was seeded on the thin films and cell proliferation was determined by using an MTT assay. In addition, their antimicrobial activity was estimated by using an agar diffusion test. Data indicated the concomitance between cell viability and concentration of polyphenols. These findings suggest that these phenolic-endowed atelocollagen films might be suitable for tissue engineering applications, on account of the combined activity of polyphenols and collagen. PMID:24177700

  10. Correlation of HSP70 expression and cell viability following thermal stimulation of bovine aortic endothelial cells.

    PubMed

    Rylander, Marissa Nichole; Diller, Kenneth R; Wang, Sihong; Aggarwal, Shanti J

    2005-10-01

    Thermal preconditioning protocols for cardiac cells were identified which produce elevated HSP70 levels while maintaining high cell viability. Bovine aortic endothelial cells were heated with a water bath at temperatures ranging from 44 to 50 degrees C for periods of 1-30 min. Thermal stimulation protocols were determined which induce HSP70 expression levels ranging from 2.3 to 3.6 times the control while maintaining cell viabilities greater than 90%. An Arrhenius injury model fit to the cell damage data yielded values of A = 1.4 X 10(66) s(-1) and Ea = 4.1 X 10(5) J/mol. Knowledge of the injury parameters and HSP70 kinetics will enhance dosimetry guideline development for thermal stimulation of heat shock proteins expression in cardiac tissue. PMID:16248304

  11. The influence of pleiotropy between viability and pollen fates on mating system evolution.

    PubMed

    Jordan, Crispin Y

    2015-02-01

    Floral displays are functionally and genetically integrated structures, so modifications to display will likely affect multiple fitness components (pleiotropy), including pollen export and self-pollination, and therefore selfing rate. Consequently, the great diversities of floral displays and of mating systems found among angiosperms have likely co-evolved. I extend previous models of mating system evolution to determine how pleiotropy that links viability (e.g., probability of survival to reproduction) and the allocation of pollen for export and selfing affects the evolution of selfing, outcrossing, and in particular, mixed mating. I show that the outcome depends on how pollen shifts from being exported, unused, or used for selfing. Furthermore, pleiotropy that affects viability can explain observations not addressed by previous theory, including the evolution of mixed mating despite high inbreeding depression in the absence of pollen-limitation. Therefore, pleiotropy may play a key role in explaining selfing rates for such species that exhibit otherwise enigmatic mating systems. PMID:25448089

  12. Arctic Economics Model

    Energy Science and Technology Software Center (ESTSC)

    1995-03-01

    AEM (Arctic Economics Model) for oil and gas was developed to provide an analytic framework for understanding the arctic area resources. It provides the capacity for integrating the resource and technology information gathered by the arctic research and development (R&D) program, measuring the benefits of alternaive R&D programs, and providing updated estimates of the future oil and gas potential from arctic areas. AEM enables the user to examine field or basin-level oil and gas recovery,more » costs, and economics. It provides a standard set of selected basin-specified input values or allows the user to input their own values. AEM consists of five integrated submodels: geologic/resource submodel, which distributes the arctic resource into 15 master regions, consisting of nine arctic offshore regions, three arctic onshore regions, and three souhtern Alaska (non-arctic) regions; technology submodel, which selects the most appropriate exploration and production structure (platform) for each arctic basin and water depth; oil and gas production submodel, which contains the relationship of per well recovery as a function of field size, production decline curves, and production decline curves by product; engineering costing and field development submodel, which develops the capital and operating costs associated with arctic oil and gas development; and the economics submodel, which captures the engineering costs and development timing and links these to oil and gas prices, corporate taxes and tax credits, depreciation, and timing of investment. AEM provides measures of producible oil and gas, costs, and ecomonic viability under alternative technology or financial conditions.« less

  13. Myocardial viability: what we knew and what is new.

    PubMed

    Shabana, Adel; El-Menyar, Ayman

    2012-01-01

    Some patients with chronic ischemic left ventricular dysfunction have shown significant improvements of contractility with favorable long-term prognosis after revascularization. Several imaging techniques are available for the assessment of viable myocardium, based on the detection of preserved perfusion, preserved glucose metabolism, intact cell membrane and mitochondria, and presence of contractile reserve. Nuclear cardiology techniques, dobutamine echocardiography and positron emission tomography are used to assess myocardial viability. In recent years, new advances have improved methods of detecting myocardial viability. This paper summarizes the pathophysiology, methods, and impact of detection of myocardial viability, concentrating on recent advances in such methods. We reviewed the literature using search engines MIDLINE, SCOUPS, and EMBASE from 1988 to February 2012. We used key words: myocardial viability, hibernation, stunning, and ischemic cardiomyopathy. Recent studies showed that the presence of viable myocardium was associated with a greater likelihood of survival in patients with coronary artery disease and LV dysfunction, but the assessment of myocardial viability did not identify patients with survival benefit from revascularization, as compared with medical therapy alone. This topic is still debatable and needs more evidence. PMID:22988540

  14. Preliminary report on the commercial viability of gas production from natural gas hydrates

    USGS Publications Warehouse

    Walsh, M.R.; Hancock, S.H.; Wilson, S.J.; Patil, S.L.; Moridis, G.J.; Boswell, R.; Collett, T.S.; Koh, C.A.; Sloan, E.D.

    2009-01-01

    Economic studies on simulated gas hydrate reservoirs have been compiled to estimate the price of natural gas that may lead to economically viable production from the most promising gas hydrate accumulations. As a first estimate, $CDN2005 12/Mscf is the lowest gas price that would allow economically viable production from gas hydrates in the absence of associated free gas, while an underlying gas deposit will reduce the viability price estimate to $CDN2005 7.50/Mscf. Results from a recent analysis of the simulated production of natural gas from marine hydrate deposits are also considered in this report; on an IROR basis, it is $US2008 3.50-4.00/Mscf more expensive to produce marine hydrates than conventional marine gas assuming the existence of sufficiently large marine hydrate accumulations. While these prices represent the best available estimates, the economic evaluation of a specific project is highly dependent on the producibility of the target zone, the amount of gas in place, the associated geologic and depositional environment, existing pipeline infrastructure, and local tariffs and taxes. ?? 2009 Elsevier B.V.

  15. Negative effects of temperature and atmospheric depositions on the seed viability of common juniper (Juniperus communis)

    PubMed Central

    Gruwez, R.; De Frenne, P.; De Schrijver, A.; Leroux, O.; Vangansbeke, P.; Verheyen, K.

    2014-01-01

    Background and Aims Environmental change is increasingly impacting ecosystems worldwide. However, our knowledge about the interacting effects of various drivers of global change on sexual reproduction of plants, one of their key mechanisms to cope with change, is limited. This study examines populations of poorly regenerating and threatened common juniper (Juniperus communis) to determine the influence of four drivers of global change (rising temperatures, nitrogen deposition, potentially acidifying deposition and altering precipitation patterns) on two key developmental phases during sexual reproduction, gametogenesis and fertilization (seed phase two, SP2) and embryo development (seed phase three, SP3), and on the ripening time of seeds. Methods In 42 populations throughout the distribution range of common juniper in Europe, 11 943 seeds of two developmental phases were sampled. Seed viability was determined using seed dissection and related to accumulated temperature (expressed as growing degree-days), nitrogen and potentially acidifying deposition (nitrogen plus sulfur), and precipitation data. Key Results Precipitation had no influence on the viability of the seeds or on the ripening time. Increasing temperatures had a negative impact on the viability of SP2 and SP3 seeds and decreased the ripening time. Potentially acidifying depositions negatively influenced SP3 seed viability, while enhanced nitrogen deposition led to lower ripening times. Conclusions Higher temperatures and atmospheric deposition affected SP3 seeds more than SP2 seeds. However, this is possibly a delayed effect as juniper seeds develop practically independently, due to the absence of vascular communication with the parent plant from shortly after fertilization. It is proposed that the failure of natural regeneration in many European juniper populations might be attributed to climate warming as well as enhanced atmospheric deposition of nitrogen and sulfur. PMID:24284814

  16. Exploring the dark side of MTT viability assay of cells cultured onto electrospun PLGA-based composite nanofibrous scaffolding materials.

    PubMed

    Qi, Ruiling; Shen, Mingwu; Cao, Xueyan; Guo, Rui; Tian, Xuejiao; Yu, Jianyong; Shi, Xiangyang

    2011-07-21

    One major method used to evaluate the biocompatibility of porous tissue engineering scaffolding materials is MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The MTT cell viability assay is based on the absorbance of the dissolved MTT formazan crystals formed in living cells, which is proportional to the number of viable cells. Due to the strong dye sorption capability of porous scaffolding materials, we propose that the cell viability determined from the MTT assay is likely to give a false negative result. In this study, we aim to explore the effect of the adsorption of MTT formazan on the accuracy of the viability assay of cells cultured onto porous electrospun poly(lactic-co-glycolic acid) (PLGA) nanofibers, HNTs (halloysite nanotubes)/PLGA, and CNTs (multiwalled carbon nanotubes)/PLGA composite nanofibrous mats. The morphology of electrospun nanofibers and L929 mouse fibroblasts cultured onto the nanofibrous scaffolds were observed using scanning electron microscopy. The viability of cells proliferated for 3 days was evaluated through the MTT assay. In the meantime, the adsorption of MTT formazan onto the same electrospun nanofibers was evaluated and the standard concentration-absorbance curve was obtained in order to quantify the contribution of the adsorbed MTT formazan during the MTT cell viability assay. We show that the PLGA, and the HNTs- or CNTs-doped PLGA nanofibers display appreciable MTT formazan dye sorption, corresponding to 35.6-50.2% deviation from the real cell viability assay data. The better dye sorption capability of the nanofibers leads to further deviation from the real cell viability. Our study gives a general insight into accurate MTT cytotoxicity assessment of various porous tissue engineering scaffolding materials, and may be applicable to other colorimetric assays for analyzing the biological properties of porous scaffolding materials. PMID:21647502

  17. Coiled tubing drilling (CTD) moves to commercial viability

    SciTech Connect

    Romagno, R. ); Walker, R. )

    1994-12-01

    Shell Western E and P, Inc. (SWEPI) California Drilling Operations was interested in coiled tubing (CT) for drilling slimhole steam injectors. A four-well pilot project at South Belridge field, Kern County, Calif., was targeted for immediate CT use. Well programs included completion, a goal not previously attempted on wells drilled from surface with CT. This paper reviews the primary project focus which was to develop slimhole steam injectors and improve injection profiles in lower Tulare formation E and G sands. Feasibility of drilling wells with CT and having CT crews run and cement completion tubulars in place was an issue to be determined. Conventional tubing installation is usually outside the scope of CT operations, so it was not known if this would be technically or economically feasible. Another goal was to refine personnel expertise to further develop CTD services as a successful business line. Other items targeted for investigation were: deviation control; lost circulation solutions; WOB optimization to obtain maximum ROP; potential steam blowout intervals; and high temperature. Finally, economic feasibility of using CTD as a rotary rig alternative for specific applications like slimhole wells on sites where surface location is limited was to be determined.

  18. Solar energy system economic evaluation: Fern Tunkhannock, Tunkhannock, Pennsylvania. Final report

    SciTech Connect

    Not Available

    1980-09-01

    The economic performance of an Operational Test Site (OTS) is described. The long term economic performance of the system at its installation site and extrapolation to four additional selected locations to demonstrate the viability of the design over a broad range of environmental and economic conditions is reported. Topics discussed are: system description, study approach, economic analysis and system optimization, and technical and economical results of analysis. Data for the economic analysis are generated through evaluation of the OTS. The simulation is based on the technical results of the seasonal report simulation. In addition localized and standard economic parameters are used for economic analysis.

  19. COST IMPACT OF ROD CONSOLIDATION ON THE VIABILITY ASSESSMENT DESIGN

    SciTech Connect

    D. Lancaster

    1999-03-29

    The cost impact to the Civilian Radioactive Waste Management System of using rod consolidation is evaluated. Previous work has demonstrated that the fuel rods of two assemblies can be packed into a canister that can fit into the same size space as that used to store a single assembly. The remaining fuel assembly hardware can be compacted into the same size canisters with a ratio of 1 hardware canister per each 6 to 12 assemblies. Transportation casks of the same size as currently available can load twice the number of assemblies by placing the compacted assemblies in the slots currently designed for a single assembly. Waste packages similarly could contain twice the number of assemblies; however, thermal constraints would require considering either a low burnup or cooling. The analysis evaluates the impact of rod consolidation on CRWMS costs for consolidation at prior to transportation and for consolidation at the Monitored Geological Repository surface facility. For this study, no design changes were made to either the transport casks or waste packages. Waste package designs used for the Viability Assessment design were employed but derated to make the thermal limits. A logistics analysis of the waste was performed to determine the number of each waste package with each loading. A review of past rod consolidation experience found cost estimates which range from $10/kgU to $32/kgU. $30/kgU was assumed for rod consolidation costs prior to transportation. Transportation cost savings are about $17/kgU and waste package cost savings are about $21/kgU. The net saving to the system is approximately $500 million if the consolidation is performed prior to transportation. If consolidation were performed at the repository surface facilities, it would cost approximately $15/kgU. No transportation savings would be realized. The net savings for consolidation at the repository site would be about $400 million dollars.

  20. Regional population viability of grassland songbirds: Effects of agricultural management

    USGS Publications Warehouse

    Perlut, N.G.; Strong, A.M.; Donovan, T.M.; Buckley, N.J.

    2008-01-01

    Although population declines of grassland songbirds in North America and Europe are well-documented, the effect of local processes on regional population persistence is unclear. To assess population viability of grassland songbirds at a regional scale (???150,000 ha), we quantified Savannah Sparrow Passerculus sandwichensis and Bobolink Dolichonyx oryzivorus annual productivity, adult apparent survival, habitat selection, and density in the four most (regionally) common grassland treatments. We applied these data to a female-based, stochastic, pre-breeding population model to examine whether current grassland management practices can sustain viable populations of breeding songbirds. Additionally, we evaluated six conservation strategies to determine which would most effectively increase population trends. Given baseline conditions, over 10 years, simulations showed a slightly declining or stable Savannah Sparrow population (mean bootstrap ?? = 0.99; 95% CI = 1.00-0.989) and severely declining Bobolink population (mean bootstrap ?? = 0.75; 95% CI = 0.753-0.747). Savannah Sparrow populations were sensitive to increases in all demographic parameters, particularly adult survival. However for Bobolinks, increasing adult apparent survival, juvenile apparent survival, or preference by changing habitat selection cues for late-hayed fields (highest quality) only slightly decreased the rate of decline. For both species, increasing the amount of high-quality habitat (late- and middle-hayed) marginally slowed population declines; increasing the amount of low-quality habitat (early-hayed and grazed) marginally increased population declines. Both species were most sensitive to low productivity and survival on early-hayed fields, despite the fact that this habitat comprised only 18% of the landscape. Management plans for all agricultural regions should increase quality on both low- and high-quality fields by balancing habitat needs, nesting phenology, and species' response to management. ?? 2008 Elsevier Ltd.

  1. Important population viability analysis parameters for giant pandas (Aliuropoda melanoleuca).

    PubMed

    Gong, Minghao; Song, Yanling; Yang, Zhisong; Lin, Chen

    2012-06-01

    Population viability analysis (PVA) is a tool to evaluate the risk of extinction for endangered species and aid conservation decision-making. The quality of PVA output is dependent on parameters related to population dynamics and life-history; however, it has been difficult to collect this information for the giant panda (Aliuropoda melanoleuca), a rare and endangered mammal native to China, confined to some 30 fragmented habitat patches. Since giant pandas are long-lived, mature late, have lower reproductive rates, and show little sexual dimorphism, obtaining data to perform adequate PVA has been difficult. Here, we develop a parameter sensitivity index by modeling the dynamics of six giant panda populations in the Minshan Mountains, in order to determine the parameters most influential to giant panda populations. Our data shows that the giant panda populations are most sensitive to changes in four female parameters: initial breeding age, reproductive rate, mortality rate between age 0 and 1, and mortality rate of adults. The parameter sensitivity index strongly correlated with initial population size, as smaller populations were more sensitive to changes in these four variables. This model suggests that demographic parameters of females have more influence on the results of PVA, indicating that females may play a more important role in giant panda population dynamics than males. Consequently, reintroduction of female individuals to a small giant panda population should be a high priority for conservation efforts. Our findings form a technical basis for the coming program of giant panda reintroduction, and inform which parameters are crucial to successfully and feasibly monitoring wild giant panda populations. PMID:22653866

  2. Engineered cerium oxide nanoparticles: Effects on bacterial growth and viability

    SciTech Connect

    Pelletier, Dale A; Suresh, Anil K; Holton, Gregory A; McKeown, Catherine K; Wang, Wei; Gu, Baohua; Mortensen, Ninell P; Allison, David P; Joy, David Charles; Allison, Martin R; Brown, Steven D; Phelps, Tommy Joe; Doktycz, Mitchel John

    2010-01-01

    Interest in engineered nanostructures has risen in recent years due to their use in energy conservation strategies and biomedicine. To ensure prudent development and use of nanomaterials, the fate and effects of such engineered structures on the environment should be understood. Interactions of nanomaterials with environmental microorganisms are inevitable, but the general consequences of such interactions remain unclear. Further, standardized methods for assessing such interactions are lacking. Therefore, we have initiated a multianalytical approach to understand the interactions of synthesized nanoparticles with bacterial systems. These efforts are focused initially on cerium oxide nanoparticles and model bacteria in order to evaluate characterization procedures and the possible fate of such materials in the environment. In this study the effects of cerium oxide nanoparticles on the growth and viability of Gram-negative Escherichia coli and Shewanella oneidensis, a metal-reducing bacteria, and Gram-positive Bacillus subtilis were examined relative to particle size, growth media, pH, and dosage. A hydrothermal based synthesis procedure was used to prepare cerium oxide nanoparticles of defined sizes in order to eliminate complications originating from the use of organic solvents and surfactants. Bactericidal effects were determined by minimum inhibitory concentration, colony forming units, disc diffusion tests and Live/Dead assays. In growth inhibition experiments involving E. coli and B. subtilis, a clear strain and size-dependent inhibition was observed. S. oneidensis appeared to be unaffected by the cerium oxide nanoparticles. Transmission electron microscopy along with microarray-based transcriptional profiling have been used to understand the response mechanism of the bacteria. The use of multiple analytical approaches adds confidence to toxicity assessments while the use of different bacterial systems highlights the potential wide-ranging effects of nanomaterial interactions in the environment.

  3. Impedance microflow cytometry for viability studies of microorganisms

    NASA Astrophysics Data System (ADS)

    Di Berardino, Marco; Hebeisen, Monika; Hessler, Thomas; Ziswiler, Adrian; Largiadr, Stephanie; Schade, Grit

    2011-02-01

    Impedance-based Coulter counters and its derivatives are widely used cell analysis tools in many laboratories and use normally DC or low frequency AC to perform these electrical analyses. The emergence of micro-fabrication technologies in the last decade, however, provides a new means of measuring electrical properties of cells. Microfluidic approaches combined with impedance spectroscopy measurements in the radio frequency (RF) range increase sensitivity and information content and thus push single cell analyses beyond simple cell counting and sizing applications towards multiparametric cell characterization. Promising results have been shown already in the fields of cell differentiation and blood analysis. Here we emphasize the potential of this technology by presenting new data obtained from viability studies on microorganisms. Impedance measurements of several yeast and bacteria strains performed at frequencies around 10 MHz enable an easy discrimination between dead and viable cells. Moreover, cytotoxic effects of antibiotics and other reagents, as well as cell starvation can also be monitored easily. Control analyses performed with conventional flow cytometers using various fluorescent dyes (propidium iodide, oxonol) indicate a good correlation and further highlight the capability of this device. The label-free approach makes on the one hand the use of usually expensive fluorochromes obsolete, on the other hand practically eliminates laborious sample preparation procedures. Until now, online cell monitoring was limited to the determination of viable biomass, which provides rather poor information of a cell culture. Impedance microflow cytometry, besides other aspects, proposes a simple solution to these limitations and might become an important tool for bioprocess monitoring applications in the biotech industry.

  4. Detection and Viability of Lactococcus lactis throughout Cheese Ripening

    PubMed Central

    Cocolin, Luca

    2014-01-01

    Recent evidences highlighted the presence of Lactococcus lactis during late cheese ripening. For this reason, the role of this microorganism, well known as dairy starter, should be reconsidered throughout cheese manufacturing and ripening. Thus, the main objective of this study was to develop a RT-qPCR protocol for the detection, quantification and determination of the viability of L. lactis in ripened cheese samples by direct analysis of microbial nucleic acids. Standard curves were constructed for the specific quantification of L. lactis in cheese matrices and good results in terms of selectivity, correlation coefficient and efficiency were obtained. Thirty-three ripened cheeses were analyzed and, on the basis of RNA analysis, twelve samples showed 106 to 108 CFU of L. lactis per gram of product, thirteen from 103 to 105 CFU/g, and in eight cheeses, L. lactis was not detected. Traditional plating on M17 medium led to loads ranging from 105 to 109 CFU/g, including the cheese samples where no L. lactis was found by RT-qPCR. From these cheeses, none of the colonies isolated on M17 medium was identified as L. lactis species. These data could be interpreted as a lack of selectivity of M17 medium where colony growth is not always related to lactococcal species. At the same time, the absence or low abundance of L. lactis isolates on M17 medium from cheese where L. lactis was detected by RT-qPCR support the hypothesis that L. lactis starter populations are mainly present in viable but not culturable state during ripening and, for this reason, culture-dependent methods have to be supplemented with direct analysis of cheese. PMID:25503474

  5. Assessment of losses in honey yield due to the chalkbrood disease, with reference to the determination of its economic injury levels in Egypt.

    TOXLINE Toxicology Bibliographic Information

    Zaghloul OA; Mourad AK; El Kady MB; Nemat FM; Morsy ME

    2005-01-01

    In Egypt, the chalk brood (CHB) disease caused by the fungus, Ascosphaera apis Maassen started again infesting the honeybee, Apis melifera L (Hymenoptera: Apidae) colonies after a cessation pause of seven to nine years. For the first time, an attempt has been made to look into the problem of the CHB disease from the view point of assessing losses in both clover (Trifolium alexandrinum) and chinus (Chinus molus) honey yields. In this regard, two techniques were adopted. Under the natural conditions of the experimental apiary (first technique), loss in clover honey was 18.412 +/- 0.663%, on average, whereas the average loss in chinus honey was 18.332 +/- 1.536%. In the second technique of loss appraisal (artificial infection). The tested honeybee colonies were artificially infected with four sources of A. apis infection, I.e. black mummies, white mummies, pollen grains and water, in addition to controls to create the so-called "different levels of infection". The mean percentages of losses in clover honey were 30.06 +/- 1.807, 27.95 +/- 1.062; 21.13 +/- 0.987; 16.96 +/- 0.672 and 0.00 +/- 0.00 for black mummies, white mummies, pollen grains, water and control, respectively. Taking into account the relationship between number of resulted mummies in each source of infection and % loss in clover honey, it could be concluded that as the resulted mummies increased, the corresponding clover honey yield decreased in each source of infection. It was noticed that the % loss in clover honey differed as the used technique differed. For example, the percentage loss in clover honey produced from colonies exposed to the natural conditions was relatively less than that of the artificially infected ones. This has been discussed in the text. However, the causative pathogen of CHB disease resulted in serious decrease in honey production. Loss appraisal is a perquisite step for the determination of the economic injury levels (EILs). By regressing % loss in clover honey yield against the total number of fallen mummies, the linear equation was worked out to be: Y = 0.242 + 0.040 x (r2 = 0.99, F = 62408.865). Depending on the total costs of controlling CHB disease, the EIL values were 31.875 and 11.250 mummies/colony for cedar oil and thymol granules, subsequently. As to the chinus honey the corresponding EILs were 18.940 and 6.683 mummies/colony for cedar oil and thymol granules, in respect, as a result of adopting the regression formula: Y = -6.762 + 0.101 X. As for the clover honey (artificial infection) the EIL values were 39.844 and 14.063 mummies/ colony in case of using cedar oil and thymol grains, subsequently. These values were worked out using the formula Y = 5.871 + 0.032 X. From the practical point of view, apiarists should not use thymol or cedar oil as fallen mummies don't reach the suggested EILs values to minimize control costs as much as possible.

  6. Influence of Waveform on Cell Viability during Ultrasound Exposure

    NASA Astrophysics Data System (ADS)

    Saliev, Timur; Feril, Loreto B.; McLean, Donald A.; Tachibana, Katsuro; Campbell, Paul A.

    2011-09-01

    We examined the role of ultrasound standing waves, and their travelling wave counterparts, on cell viability in an in-vitro insonation apparatus. Furthermore, the effect of distinct waveforms (sine and top-hat) was also explored, together with the role of microbubble presence. Measurements of cell viability in standing wave scenarios demonstrated a relatively higher rate of lysis (63.1310.89% remaining viable) compared with the travelling wave data, where 96.224.0% remained viable. Significant differences were also seen as a function of waveform, where insonations employing top-hat wave shapes resulted in an average end stage viability of 30.315.71% compared with 61.9414.28% in the sinusoidal counterparts.

  7. Dead or Alive: Molecular Assessment of Microbial Viability

    PubMed Central

    Meschke, John S.

    2014-01-01

    Nucleic acid-based analytical methods, ranging from species-targeted PCRs to metagenomics, have greatly expanded our understanding of microbiological diversity in natural samples. However, these methods provide only limited information on the activities and physiological states of microorganisms in samples. Even the most fundamental physiological state, viability, cannot be assessed cross-sectionally by standard DNA-targeted methods such as PCR. New PCR-based strategies, collectively called molecular viability analyses, have been developed that differentiate nucleic acids associated with viable cells from those associated with inactivated cells. In order to maximize the utility of these methods and to correctly interpret results, it is necessary to consider the physiological diversity of life and death in the microbial world. This article reviews molecular viability analysis in that context and discusses future opportunities for these strategies in genetic, metagenomic, and single-cell microbiology. PMID:25038100

  8. Pilot-scale Production and Viability Analysis of Freeze-Dried Probiotic Bacteria Using Different Protective Agents

    PubMed Central

    Savini, Michele; Cecchini, Cinzia; Verdenelli, Maria Cristina; Silvi, Stefania; Orpianesi, Carla; Cresci, Alberto

    2010-01-01

    The functional food industry requires an improvement of probiotic strain stability during storage, especially when they are stored at room temperature. In this study, the viability of freeze-dried Lactobacillus rhamnosus IMC 501® and Lactobacillus paracasei IMC 502® using different protective agents (i.e., glycerine, mannitol, sorbitol, inulin, dextrin, Crystalean®) was determined and compared with semi skimmed milk (SSM) control. No significant differences were observed between the tested protectants and the control (SSM) during storage at refrigerated conditions. During storage at room temperature, only glycerine was found to stabilize viability better than other tested substances. PMID:22254025

  9. Application of wide-field optical coherence tomography to monitoring of viability of rat brain in vivo

    NASA Astrophysics Data System (ADS)

    Sato, Manabu; Nishidate, Izumi

    2014-05-01

    We investigated the feasibility of OCT in monitoring the viability of the brain. It was confirmed that after an overdose of pentobarbital sodium salt for an euthanasia, the OCT signal intensity increased before cardiac arrest and finally became 2.7 times, and by periodically changing the tissue temperature from 20 to 32 °C in vivo, average correlation coefficients between the ratio of signal intensity (RSI) and temperature were determined to be -0:42 to -0:50. RSI reversibly changed with subsequent variations of temperatures and finally increased rapidly just before cardiac arrest. These results indicate that RSI could correspond to decreases in viability.

  10. Effects of Cartilage Impact with and without Fracture on Chondrocyte Viability and the Release of Inflammatory Markers

    PubMed Central

    Stolberg-Stolberg, Josef A.; Furman, Bridgette D.; Garrigues, N. William; Lee, Jaewoo; Pisetsky, David S.; Stearns, Nancy A; DeFrate, Louis E.; Guilak, Farshid; Olson, Steven A.

    2014-01-01

    Post-traumatic arthritis (PTA) frequently develops after intra-articular fracture of weight bearing joints. Loss of cartilage viability and post-injury inflammation have both been implicated as possible contributing factors to PTA progression. In order to further investigate chondrocyte response to impact and fracture, we have developed a blunt impact model applying 70%, 80% or 90% surface-to-surface compressive strain with or without induction of an articular fracture in a cartilage explant model. Following mechanical loading, chondrocyte viability and apoptosis were assessed. Culture media were evaluated for the release of double-stranded DNA (dsDNA) and immunostimulatory activity via nuclear factor kappa B (NF-?B) activity in Toll-like receptor-expressing Ramos-Blue reporter cells. High compressive strains, with or without articular fracture, resulted in significantly reduced chondrocyte viability. Blunt impact at 70% strain induced a loss in viability over time through a combination of apoptosis and necrosis, whereas blunt impact above 80% strain caused predominantly necrosis. In the fracture model, a high level of primarily necrotic chondrocyte death occurred along the fracture edges. At sites away from the fracture, viability was not significantly different than controls. Interestingly, both dsDNA release and NF-?B activity in Ramos-Blue cells increased with blunt impact, but was only significantly increased in the media from fractured cores. This study indicates that the mechanism of trauma determines the type of chondrocyte death as well as the potential for post-injury inflammation. PMID:23620164

  11. Perceptions of tissue viability nurses of their current roles.

    PubMed

    Fox, C

    This qualitative and quantitative study was undertaken on a national scale. It identifies the perception of the role of the tissue viability nurse by its incumbents through the circulation of postal questionnaires sent to 173 identified tissue viability nurses, of which 87 responded. A constant comparative analysis of the responses identified the repetitive phrases and key words for the qualitative data. The quantitative responses were facilitated through the use of closed questions. The research facilitated four areas of discussion: role overview; perceived levels of education; positive/negative aspects of the role; types of wound contact and reasons. PMID:12146177

  12. Viability of bifidobacteria in commercial dairy products during refrigerated storage.

    PubMed

    Shin, H S; Lee, J H; Pestka, J J; Ustunol, Z

    2000-03-01

    Commercial milk and two brands of yogurt containing bifidobacteria were obtained from retail outlets. All products were evaluated for viability of bifidobacteria and lactic acid bacteria during refrigerated storage at 4 degrees C. Milk was evaluated at 9, 6, and 3 days prior and past its expiration date. The yogurts were evaluated at 3, 2, and 1 week prior and past their expiration. Viability of bifidobacteria and lactic acid bacteria in milk and yogurt remained above 10(6) CFU/ml or g until the expiration date of the respective products. This microbial concentration is the recommended minimum dose to receive the health benefits of these organisms. PMID:10716560

  13. Viability changes: Microbiological analysis of dental casts

    PubMed Central

    ilinskas, Juozas; Junevi?ius, Jonas; Ramonait?, Agn?; Pavilonis, Alvydas; Gleiznys, Alvydas; Sakalauskien?, Jurgina

    2014-01-01

    Background This study evaluated the survival of the most prevalent oral bacteria and fungi (Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, and Candida albicans) in dental casts, and compared changes in the amounts of these microorganisms at different time intervals to determine how long dental casts may pose threat to the health of dental personnel and patients. Material/Methods When manufacturing the casts, regular water was replaced with sterile distilled water, where suspensions of the studied bacteria or the fungus at certain concentrations were prepared. When the dental casts were fully set (solidified), plaster shavings were examined immediately after the contact of the studied microorganism with the plaster, as well as after 1, 2, 24, 48, 72, 96, and 120 hours. Following that, we measured how the amount of the studied bacteria and fungi in 1 gram of the plaster changed within the studied period of time. Results Klebsiella pneumoniae survived in plaster for up to 4 days, and the reduction in the number of these bacteria became statistically significant after 1 day (p<0.05). Staphylococcus aureus remained viable in plaster for up to 4 days, and the number of these bacteria dropped after 1 day (p<0.05). Escherichia coli disappeared after 2 days, and a reduction was already observed after 2 hours (p<0.05). Candida albicans in plaster models died within 2 days, and a reduction in their number was observed after 1 day (p<0.05). Conclusions The microorganisms did not multiply in the gypsum casts and their number significantly dropped instead of increasing. PMID:24902637

  14. Viability study of photo-voltaic systems added to terrestrial electric vehicles

    SciTech Connect

    Rippel, W.E.

    1990-09-01

    The purpose of the following computer study is to determine the set of necessary conditions under which the addition of photo-voltaic (PV) cells to electric vehicles provides a net utility or economic benefit. Economic benefits are given the primary focus and are evaluated in terms of a payback period.

  15. 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.

  16. Population viability analysis: using a modeling tool to assess the viability of tapir populations in fragmented landscapes.

    PubMed

    Medici, Emília Patrícia; Desbiez, Arnaud Leonard Jean

    2012-12-01

    A population viability analysis (PVA) was conducted of the lowland tapir populations in the Atlantic Forest of the Pontal do Paranapanema region, Brazil, including Morro do Diabo State Park (MDSP) and surrounding forest fragments. Results from the model projected that the population of 126 tapirs in MDSP is likely to persist over the next 100 years; however, 200 tapirs would be required to maintain a viable population. Sensitivity analysis showed that sub-adult mortality and adult mortality have the strongest influence on the dynamics of lowland tapir populations. High road-kill has a major impact on the MDSP tapir population and can lead to population extinction. Metapopulation modeling showed that dispersal of tapirs from MDSP to the surrounding fragments can be detrimental to the overall metapopulation, as fragments act as sinks. Nevertheless, the model showed that under certain conditions the maintenance of the metapopulation dynamics might be determinant for the persistence of tapirs in the region, particularly in the smaller fragments. The establishment of corridors connecting MDSP to the forest fragments models resulted in an increase in the stochastic growth rate, making tapirs more resilient to threats and catastrophes, but only if rates of mortality were not increased when using corridors. The PVA showed that the conservation of tapirs in the Pontal region depends on: the effective protection of MDSP; maintenance and, whenever possible, enhancement of the functional connectivity of the landscape, reducing mortality during dispersal and threats in the unprotected forest fragments; and neutralization of all threats affecting tapirs in the smaller forest fragments. PMID:23253367

  17. Some Natural Viability Systems for a Multiallelic Locus: A Theoretical Study

    PubMed Central

    Karlin, Samuel

    1981-01-01

    The maintenance of genetic polymorphism under various natural structured viability regimes vs. general unrestricted fitness assignments are compared. The selection models considered include a generalized dominance fitness system, a generalized viability model based on allelic activity values, viability matrices based on multilocus activity levels, viability matrices defined by partitioned "resource" or "substrate" variables, and circulant-type viability matrices. A number of examples that support these formulations are discussed. Detailed results on the nature of the genotype frequency equilibrium configurations for the specified viability models are presented. An increased likelihood for a globally stable equilibrium is predicted for the more structured viability models. PMID:17249078

  18. Viability Is Associated with Melanin-Based Coloration in the Barn Swallow (Hirundo rustica)

    PubMed Central

    Saino, Nicola; Romano, Maria; Rubolini, Diego; Ambrosini, Roberto; Caprioli, Manuela; Milzani, Aldo; Costanzo, Alessandra; Colombo, Graziano; Canova, Luca; Wakamatsu, Kazumasa

    2013-01-01

    Pigmentation of body surface in animals can have multiple determinants and accomplish diverse functions. Eumelanin and pheomelanin are the main animal pigments, being responsible of yellow, brownish-red and black hues, and have partly common biosynthetic pathways. Many populations of vertebrates show individual variation in melanism, putatively with large heritable component. Genes responsible for eu- or pheomelanogenesis have pleiotropic but contrasting effects on life-history traits, explaining the patterns of covariation observed between melanization and physiology (e.g. immunity and stress response), sexual behavior and other characters in diverse taxa. Yet, very few studies in the wild have investigated if eu- and pheomelanization predict major fitness traits like viability or fecundity. In this correlative study, by contrasting adult barn swallows (Hirundo rustica) matched for age, sex, breeding site, and year and date of sampling, we show that males but not females that survived until the next year had paler, relatively more eu- than pheomelanic pigmentation of ventral body feathers. Better performance of individuals that allocate relatively more to eumelanogenesis was expected based on previous evidence on covariation between eumelanic pigmentation and specific traits related to immunity and susceptibility to stress. However, together with the evidence of no covariation between viability and melanization among females, this finding raises the question of the mechanisms that maintain variation in genes for melanogenesis. We discuss the possibility that eu- and pheomelanization are under contrasting viability and sexual selection, as suggested by larger breeding and sperm competition success of darker males from other barn swallow subspecies. PMID:23573254

  19. Protein and carbohydrate intake influence sperm number and fertility in male cockroaches, but not sperm viability

    PubMed Central

    Bunning, Harriet; Rapkin, James; Belcher, Laurence; Archer, C. Ruth; Jensen, Kim; Hunt, John

    2015-01-01

    It is commonly assumed that because males produce many, tiny sperm, they are cheap to produce. Recent work, however, suggests that sperm production is not cost-free. If sperm are costly to produce, sperm number and/or viability should be influenced by diet, and this has been documented in numerous species. Yet few studies have examined the exact nutrients responsible for mediating these effects. Here, we quantify the effects of protein (P) and carbohydrate (C) intake on sperm number and viability in the cockroach Nauphoeta cinerea, as well as the consequences for male fertility. We found the intake of P and C influenced sperm number, being maximized at a high intake of diets with a P : C ratio of 1 : 2, but not sperm viability. The nutritional landscapes for male fertility and sperm number were closely aligned, suggesting that sperm number is the major determinant of male fertility in N. cinerea. Under dietary choice, males regulate nutrient intake at a P : C ratio of 1 : 4.95, which is midway between the ratios needed to maximize sperm production and pre-copulatory attractiveness in this species. This raises the possibility that males regulate nutrient intake to balance the trade-off between pre- and post-copulatory traits in this species. PMID:25608881

  20. Protein and carbohydrate intake influence sperm number and fertility in male cockroaches, but not sperm viability.

    PubMed

    Bunning, Harriet; Rapkin, James; Belcher, Laurence; Archer, C Ruth; Jensen, Kim; Hunt, John

    2015-03-01

    It is commonly assumed that because males produce many, tiny sperm, they are cheap to produce. Recent work, however, suggests that sperm production is not cost-free. If sperm are costly to produce, sperm number and/or viability should be influenced by diet, and this has been documented in numerous species. Yet few studies have examined the exact nutrients responsible for mediating these effects. Here, we quantify the effects of protein (P) and carbohydrate (C) intake on sperm number and viability in the cockroach Nauphoeta cinerea, as well as the consequences for male fertility. We found the intake of P and C influenced sperm number, being maximized at a high intake of diets with a P : C ratio of 1 : 2, but not sperm viability. The nutritional landscapes for male fertility and sperm number were closely aligned, suggesting that sperm number is the major determinant of male fertility in N. cinerea. Under dietary choice, males regulate nutrient intake at a P : C ratio of 1 : 4.95, which is midway between the ratios needed to maximize sperm production and pre-copulatory attractiveness in this species. This raises the possibility that males regulate nutrient intake to balance the trade-off between pre- and post-copulatory traits in this species. PMID:25608881

  1. Viability of cancer cells exposed to pulsed electric fields: the role of pulse charge.

    PubMed

    Krassowska, Wanda; Nanda, Gurvinder S; Austin, Melissa B; Dev, Sukhendu B; Rabussay, Dietmar P

    2003-01-01

    The goal of this study was to collect a comprehensive set of data that related lethal effects of electric fields to the duration of the pulse. Electric pulses of different strengths and durations were applied to a suspension of HEp-2 cells (epidermoid carcinoma of the human larynx) using a six-needle electrode array connected through an autoswitcher to a square wave generator. Pulse durations varied from 50 micros to 16 ms and the ranges of electric field were adjusted for each duration to capture cell viabilities between 0% and 100%. After pulsation, cells were incubated for 44 h at 37 degrees C, and their viability was measured spectrophotometrically using an XTT assay. For each pulse duration (d), viability data were used to determine the electric field that killed half of the cells (E50). When plotted on logarithmic axes, E50 vs. d was a straight line, leading to a hyperbolic relationship: E50=const/d. This relationship suggests that the total charge delivered by the pulse is the decisive factor in killing HEp-2 cells. PMID:12572658

  2. Proliferation, viability, and metabolism of human tumor and normal cells cultured in microcapsule.

    PubMed

    Zhang, Xulang; Wang, Wei; Xie, Yubing; Zhang, Ying; Wang, Xiuli; Guo, Xin; Ma, Xiaojun

    2006-07-01

    In this study, we investigated the effect of the microenvironment provided by alginate-poly-L-lysine-alginate (APA) microcapsule with liquefied or gelled core on the proliferation, viability, and metabolism of human cells, including anchorage-dependent MCF-7 breast cancer cells and primary fibroblasts, and anchorage-independent K-562 leukemia cells; cells in conventional culture were used as control. The growth pattern of cells in microcapsule was examined by phase-contrast micrography. The cell viability, proliferation, organization, and gene expression were evaluated by 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, hematoxylin and eosin staining, live/dead staining, 5-bromo-20-deoxyuridine labeling, and immunohistochemistry, respectively. Cell metabolism was determined by measuring glucose and lactate concentrations in medium. The results demonstrate that APA microcapsule with liquefied core provides a microenvironment for both anchorage-dependent and anchorage-independent cells to grow into a large cell aggregate and maintain cell viability at a constant level for a period of time. In conclusion, cells in APA microcapsule are alive and have proliferation potential with lower metabolism rate. APA microcapsule may be a useful tool for in vitro tumor cell modeling and anticancer drug screening as well as for cancer gene therapy. In addition, it lays a solid foundation for the use of microencapsulation in cell culture in vitro and cell implantation in vivo. PMID:16891667

  3. Canine adipose-derived stromal cell viability following exposure to synovial fluid from osteoarthritic joints

    PubMed Central

    Kiefer, Kristina M.; O'Brien, Timothy D.; Pluhar, Elizabeth G.; Conzemius, Michael

    2015-01-01

    Introduction Stem cell therapy used in clinical application of osteoarthritis in veterinary medicine typically involves intra-articular injection of the cells, however the effect of an osteoarthritic environment on the fate of the cells has not been investigated. Aims and Objectives Assess the viability of adipose derived stromal cells following exposure to osteoarthritic joint fluid. Materials and Methods Adipose derived stromal cells (ASCs) were derived from falciform adipose tissue of five adult dogs, and osteoarthritic synovial fluid (SF) was obtained from ten patients undergoing surgical intervention on orthopedic diseases with secondary osteoarthritis. Normal synovial fluid was obtained from seven adult dogs from an unrelated study. ASCs were exposed to the following treatment conditions: culture medium, normal SF, osteoarthritic SF, or serial dilutions of 1:1 to 1:10 of osteoarthritic SF with media. Cells were then harvested and assessed for viability using trypan blue dye exclusion. Results There was no significant difference in the viability of cells in culture medium or normal SF. Significant differences were found between cells exposed to any concentration of osteoarthritic SF and normal SF and between cells exposed to undiluted osteoarthritic SF and all serial dilutions. Subsequent dilutions reduced cytotoxicity. Conclusions Osteoarthritic synovial fluid in this ex vivo experiment is cytotoxic to ASCs, when compared with normal synovial fluid. Current practice of direct injection of ASCs into osteoarthritic joints should be re-evaluated to determine if alternative means of administration may be more effective. PMID:26392889

  4. Quantification of lactate-dehydrogenase and cell viability in postmortem human dental pulp.

    PubMed

    Caviedes-Bucheli, Javier; Avendao, Nuvia; Gutierrez, Rhina; Hernndez, Sandra; Moreno, Gloria Cristina; Romero, Mara Consuelo; Muoz, Hugo Roberto

    2006-03-01

    Understanding pulp repair and regeneration requires being familiar with this tissue's behavior under extreme conditions, such as postmortem state where an abrupt interruption of tissue blood supply occurs. The purpose of this study was to quantify cell viability and the amount of lactate-dehydrogenase (LDH) expressed in human pulp tissue 6, 12, and 24 hours postmortem to establish how long dental pulp remains viable after death. Pulp samples were obtained from 14 unidentified corpses of people who had received lethal injuries in car accidents or from gunshot wounds; they had at least three caries- and restoration-free incisors. Half of each sample was used for determining cell viability at three different time intervals. The rest of each sample was used for quantifying LDH expression at the same time intervals. Another 14 pulp samples were obtained from live patients' healthy premolars where extraction was indicated for orthodontic reasons to assess normal LDH value in pulp tissue. The results showed cell viability decreasing from 89 to 68 to 41% measured 6, 12, and 24 hours postmortem, respectively. LDH expression in healthy pulps was 246 U/mg pulp weight. Expression increased after death from 249 U/mg at 6 hours to 337 U/mg at 12 hours. LDH expression decreased to 131 U/mg 24 hours postmortem. These findings are valuable in understanding dental pulp survival capability under extreme conditions that may have important clinical significance in terms of repair and regeneration. PMID:16500222

  5. In vitro assessment of gastrointestinal viability of two photosynthetic bacteria, Rhodopseudomonas palustris and Rhodobacter sphaeroides *

    PubMed Central

    Zhou, Xu-xia; Pan, Yuan-jiang; Wang, Yan-bo; Li, Wei-fen

    2007-01-01

    The objectives of this study were to assess the potential of two photosynthetic bacteria (PSB), Rhodopseudomonas palustris HZ0301 and Rhodobacter sphaeroides HZ0302, as probiotics in aquaculture. The viability of HZ0301 and HZ0302 in simulated gastric transit conditions (pH 2.0, pH 3.0 and pH 4.0 gastric juices) and in simulated small intestinal transit conditions (pH 8.0, with or without 0.3% bile salts) was tested. The effects of HZ0301 and HZ0302 on the viability and permeability of intestinal epithelial cell in primary culture of tilapias, Oreochromis nilotica, were also detected. All the treatments were determined with three replicates. The simulated gastric transit tolerance of HZ0301 and HZ0302 strains was pH-dependent and correspondingly showed lower viability at pH 2.0 after 180 min compared with pH 3.0 and pH 4.0. Both HZ0301 and HZ0302 were tolerant to simulated small intestine transit with or without bile salts in our research. Moreover, there was no significant difference (P>0.05) among three treatments including the control and the groups treated with HZ0301 or HZ0302 both in intestinal epithelial cell viability and membrane permeability, showing no cell damage. In summary, this study demonstrated that HZ0301 and HZ0302 had high capacity of upper gastrointestinal transit tolerance and were relatively safe for intestinal epithelial cells of tilapias. PMID:17726751

  6. Effects of various man-made mineral fibers on cell apoptosis and viability.

    PubMed

    Dika Nguea, Hermine; Rihn, Bertrand; Mahon, Delphine; Bernard, Jean-Luc; De Reydellet, Aymon; Le Faou, Alain

    2005-09-01

    Evaluating the pathogenic potentials of man-made mineral fibers (MMMF) is an important task performed by the European Community. Noting that it has been proposed that the use of laboratory animals for scientific tests should be reduced or phased out, macrophages then become the cells of choice for conducting in vitro studies. We have evaluated the in vitro toxicity of six commercial stonewool fibers (A, B1, B2, C, D, and E) on U-937 cells. The physical interaction between U-937 cells and MMMF was observed using scanning electron microscopy, and the cytotoxicity was evaluated by studying cell viability using MTT assay and cell apoptosis with an ELISA detection kit. Scanning electron microscopy (SEM) analysis has shown that long fibers can be covered by several macrophages, and that a small fiber can be completely engulfed by one cell. With 50 microg/mL of MMMF, a decrease in cell viability appeared after seven days of incubation, whereas 200 microg/mL induced loss of viability and apoptosis after one day. Fiber D, comprising a high proportion of fibers >20 microm in length and a high concentration of MgO, induced the highest loss in viability and the highest rate of apoptosis compared to the other five fibers. Whether this toxic effect is related to either the physical characteristics of the fibers (such as length), or to the high concentration of magnesium is still to be determined. Because the results can be rapidly obtained, the proposed model is suitable for studying the toxicities of mineral components, even if the tested concentrations are far from the ones reached in the lung. PMID:15856181

  7. Automated Quantification of Tumor Viability in a Rabbit Liver Tumor Model after Chemoembolization Using Infrared Imaging.

    PubMed

    D'inca, Hadrien; Namur, Julien; Ghegediban, Saida Homayra; Wassef, Michel; Pascale, Florentina; Laurent, Alexandre; Manfait, Michel

    2015-07-01

    The rabbit VX2 tumor is a fast-growing carcinoma model commonly used to study new therapeutic devices, such as catheter-based therapies for patients with inoperable hepatocellular carcinoma. The evaluation of tumor viability after such locoregional therapies is essential to directing hepatocellular carcinoma management. We used infrared microspectroscopy for the automatic characterization and quantification of the VX2 liver tumor viability after drug-eluting beads transarterial chemoembolization (DEB-TACE). The protocol consisted of K-means clustering followed by principal component analysis (PCA) and linear discriminant analysis (LDA). The K-means clustering was used to classify the spectra from the infrared images of control or treated tumors and to build a database of many tissue spectra. On the basis of this reference library, the PCA-LDA analysis was used to build a predictive model to identify and quantify automatically tumor viability on unknown tissue sections. For the DEB group, the LDA model determined that the surface of tumor necrosis represented 91.6% ± 8.9% (control group: 33.1% ± 19.6%; Mann-Whitney P = 0.0004) and the viable tumor 2.6% ± 4% (control group: 62.2% ± 15.2%; Mann-Whitney P = 0.0004). Tissue quantification measurements correlated well with tumor necrosis (r = 0.827, P < 0.0001) and viable tumor (r = 0.840, P < 0.0001). Infrared imaging and PCA-LDA analysis could be helpful for easily assessing tumor viability. PMID:25979795

  8. Effects of linoleate on cell viability and lipid metabolic homeostasis in goose primary hepatocytes.

    PubMed

    Pan, Zhixiong; Wang, Jiwen; Tang, Hui; Li, Liang; Lv, Jia; Han, Chunchun; Xia, Lu; Xu, Feng

    2011-06-01

    Studies have shown linoleate could not only promote cell viability but also affect lipid metabolism in mammals. However, to what degree these effects are mediated by steatosis in goose primary hepatocytes is unknown. In this study, the effect of linoleate on the lipid metabolic homeostasis pathway was determined. We measured the mRNA levels of genes involved in triglyceride synthesis, lipid deposition, ?-oxidation, and assembly and secretion of VLDL-TGs in goose (Anser cygnoides) primary hepatocytes. Linoleate significantly increased goose hepatocyte viability, and linoleate at 0.125 mM, 0.25 mM, 0.5 mM and 1.0 mM all showed a significant effect on TG accumulation. However, with increasing linoleate concentrations, the extracellular TG concentration and extracellular VLDL gradually decreased. DGAT1, DGAT2, PPAR?, PPAR?, FoxO1, MTP, PLIN and CPT-1 mRNA was detected by real-time PCR. With increasing linoleate concentrations, the changes in DGAT1, DGAT2, PPAR? and CPT-1 gene expression, which regulates hepatic TG synthesis and fatty acid oxidation, first increased and then decreased. Additionally, FoxO1 and MTP gene expression was reduced with increasing linoleate concentrations, and the change in PLIN gene expression was increased at all concentrations, similar to the regulation of intracellular TG accumulation. In conclusion, linoleate regulated TG accumulation and increased hepatocyte viability. The data suggest that linoleate does promote goose hepatocyte viability and steatosis, which may up-regulate TG synthesis-relevant gene expression, suppress assembly and secretion of VLDL-TGs, and increase fatty acid oxidation properly to function of goose primary hepatocytes. PMID:21295151

  9. Viability, Apoptosis, Proliferation, Activation, and Cytokine Secretion of Human Keratoconus Keratocytes after Cross-Linking

    PubMed Central

    Stachon, Tanja; Wang, Jiong; Seitz, Berthold; Szentmáry, Nóra

    2015-01-01

    Purpose. The purpose of this study was to determine the impact of cross-linking (CXL) on viability, apoptosis, proliferation, activation, and cytokine secretion of human keratoconus (KC) keratocytes, in vitro. Methods. Primary KC keratocytes were cultured in DMEM/Ham's F12 medium supplemented with 10% FCS and underwent UVA illumination (370 nm, 2 J/cm2) during exposure to 0.1% riboflavin and 20% Dextran in PBS. Twenty-four hours after CXL, viability was assessed using Alamar blue assay; apoptosis using APO-DIRECT Kit; proliferation using ELISA-BrdU kit; and CD34 and alpha-smooth muscle actin (α-SMA) expression using flow cytometry. Five and 24 hours after CXL, FGFb, HGF, TGFβ1, VEGF, KGF, IL-1β, IL-6, and IL-8 secretion was measured using enzyme-linked-immunoabsorbent assay (ELISA). Results. Following CXL, cell viability and proliferation decreased (P < 0.05; P = 0.009), the percentage of apoptotic keratocytes increased (P < 0.05) significantly, and CD34 and α-SMA expression remained unchanged (P > 0.06). Five hours after CXL, FGFb secretion increased significantly (P = 0.037); however no other cytokine secretion differed significantly from controls after 5 or 24 hours (P > 0.12). Conclusions. Cross-linking decreases viability, triggers apoptosis, and inhibits proliferation, without an impact on multipotent hematopoietic stem cell transformation and myofibroblastic transformation of KC keratocytes. CXL triggers FGFb secretion of KC keratocytes transiently (5 hours), normalizing after 24 hours. PMID:25699261

  10. Fever-Range Hyperthermia vs. Hypothermia Effect on Cancer Cell Viability, Proliferation and HSP90 Expression

    PubMed Central

    Kalamida, Dimitra; Karagounis, Ilias V.; Mitrakas, Achilleas; Kalamida, Sofia; Giatromanolaki, Alexandra; Koukourakis, Michael I.

    2015-01-01

    Purpose The current study examines the effect of fever-range hyperthermia and mild hypothermia on human cancer cells focusing on cell viability, proliferation and HSP90 expression. Materials and Methods A549 and H1299 lung carcinoma, MCF7 breast adenocarcinoma, U87MG and T98G glioblastoma, DU145 and PC3 prostate carcinoma and MRC5 normal fetal lung fibroblasts cell lines were studied. After 3-day exposure to 34C, 37C and 40C, cell viability was determined. Cell proliferation (ki67 index), apoptosis (Caspase 9) and HSP90 expression was studied by confocal microscopy. Results Viability/proliferation experiments demonstrated that MRC5 fibroblasts were extremely sensitive to hyperthermia, while they were the most resistant to hypothermia. T98G and A549 were thermo-tolerant, the remaining being thermo-sensitive to a varying degree. Nonetheless, as a universal effect, hypothermia reduced viability/proliferation in all cell lines. Hyperthermia sharply induced Caspase 9 in the U87MG most thermo-sensitive cell line. In T98G and A549 thermo-tolerant cell lines, the levels of Caspase 9 declined. Moreover, hyperthermia strongly induced the HSP90 levels in T98G, whilst a sharp decrease was recorded in the thermo-sensitive PC3 and U87MG cell lines. Hyperthermia sensitized thermo-sensitive cancer cell lines to cisplatin and temozolomide, whilst its sensitizing effect was diminished in thermo-tolerant cell lines. Conclusions The existence of thermo-tolerant and thermo-sensitive cancer cell lines was confirmed, which further encourages research to classify human tumor thermic predilection for patient stratification in clinical trials. Of interest, mild hypothermia had a universal suppressing effect on cancer cell proliferation, further supporting the radio-sensitization hypothesis through reduction of oxygen and metabolic demands. PMID:25635828

  11. Novel Cell Preservation Technique to Extend Bovine In Vitro White Blood Cell Viability.

    PubMed

    Laurin, Emilie L; McKenna, Shawn L B; Sanchez, Javier; Bach, Horacio; Rodriguez-Lecompte, Juan Carlos; Chaffer, Marcelo; Keefe, Greg P

    2015-01-01

    Although cell-mediated immunity based diagnostics can be integral assays for early detection of various diseases of dairy cows, processing of blood samples for these tests is time-sensitive, often within 24 hours of collection, to maintain white blood cell viability. Therefore, to improve utility and practicality of such assays, the objective of this study was to assess the use of a novel white blood cell preservation technology in whole bovine blood. Blood samples from ten healthy cows were each divided into an unpreserved control sample and a test sample preserved with commercially-available cell transport medium. Samples were maintained at room temperature and stimulated with the mitogens pokeweed and concanavalinA, as well as with interleukin-12 p40. Stimulation was completed on days 1, 5, and 8 post-sampling. Viability of white blood cells was assessed through interferon gamma production determined with a commercial enzyme linked immunosorbent assay. In addition, mononuclear cell viability was assessed with propidium iodide flow cytometry. Greater interferon gamma production was observed on days 5 and 8 post-collection in preserved samples, with both pokeweed and concanavalinA stimulating positive interferon gamma production on day 5 post-collection. A greater proportion of the amount of interferon gamma produced on day 1 continued to be produced on days 5 and 8 post-collection with concanavalinA stimulation (with or without interleukin 12) as compared to pokeweed stimulation. Additionally, viable mononuclear cells were still present at eight days post-collection, with a higher mean proportion detected at days 5 and 8 in all stimulated preserved samples. This practical and simple method to extend in vitro white blood cell viability could benefit the efficient utilization of cell-based blood tests in ruminants. PMID:26447691

  12. Novel Cell Preservation Technique to Extend Bovine In Vitro White Blood Cell Viability

    PubMed Central

    Laurin, Emilie L.; McKenna, Shawn L. B.; Sanchez, Javier; Bach, Horacio; Rodriguez-Lecompte, Juan Carlos; Chaffer, Marcelo; Keefe, Greg P.

    2015-01-01

    Although cell-mediated immunity based diagnostics can be integral assays for early detection of various diseases of dairy cows, processing of blood samples for these tests is time-sensitive, often within 24 hours of collection, to maintain white blood cell viability. Therefore, to improve utility and practicality of such assays, the objective of this study was to assess the use of a novel white blood cell preservation technology in whole bovine blood. Blood samples from ten healthy cows were each divided into an unpreserved control sample and a test sample preserved with commercially-available cell transport medium. Samples were maintained at room temperature and stimulated with the mitogens pokeweed and concanavalinA, as well as with interleukin-12 p40. Stimulation was completed on days 1, 5, and 8 post-sampling. Viability of white blood cells was assessed through interferon gamma production determined with a commercial enzyme linked immunosorbent assay. In addition, mononuclear cell viability was assessed with propidium iodide flow cytometry. Greater interferon gamma production was observed on days 5 and 8 post-collection in preserved samples, with both pokeweed and concanavalinA stimulating positive interferon gamma production on day 5 post-collection. A greater proportion of the amount of interferon gamma produced on day 1 continued to be produced on days 5 and 8 post-collection with concanavalinA stimulation (with or without interleukin 12) as compared to pokeweed stimulation. Additionally, viable mononuclear cells were still present at eight days post-collection, with a higher mean proportion detected at days 5 and 8 in all stimulated preserved samples. This practical and simple method to extend in vitro white blood cell viability could benefit the efficient utilization of cell-based blood tests in ruminants. PMID:26447691

  13. Behavioral economics: Reunifying psychology and economics

    PubMed Central

    Camerer, Colin

    1999-01-01

    Behavioral economics improves the realism of the psychological assumptions underlying economic theory, promising to reunify psychology and economics in the process. Reunification should lead to better predictions about economic behavior and better policy prescriptions. PMID:10485865

  14. Behavioral economics: reunifying psychology and economics.

    PubMed

    Camerer, C

    1999-09-14

    "Behavioral economics" improves the realism of the psychological assumptions underlying economic theory, promising to reunify psychology and economics in the process. Reunification should lead to better predictions about economic behavior and better policy prescriptions. PMID:10485865

  15. Consensus among Economics Teachers from Transition Economies

    ERIC Educational Resources Information Center

    Leet, Don R.; Lang, Nancy A.

    2010-01-01

    The authors analyze the economic opinions of teachers and economists from the former Soviet Union who participated in economic education programs sponsored by the U.S. Department of Education under the auspices of the National Council on Economic Education from 1995-2001. They sought to determine the level of consensus on economic topics among the…

  16. Consensus among Economics Teachers from Transition Economies

    ERIC Educational Resources Information Center

    Leet, Don R.; Lang, Nancy A.

    2010-01-01

    The authors analyze the economic opinions of teachers and economists from the former Soviet Union who participated in economic education programs sponsored by the U.S. Department of Education under the auspices of the National Council on Economic Education from 1995-2001. They sought to determine the level of consensus on economic topics among the

  17. 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.

  18. 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…

  19. 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

  20. 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…

  1. Basketball Economics.

    ERIC Educational Resources Information Center

    Scheinman, Daniel; Scheinman, Ted

    This teaching unit offers five economics lessons related to basketball. Lessons include: (1) "Money, Money, Money in the Basketball Player's World"; (2) "Take Me to the Basketball Game Lesson"; (3) "What Does It Take?"; (4) "Productivity of a Basketball Player"; and (5) "Congratulations! You Just Won the NBA Championships." Most of the lessons

  2. 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

  3. 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

  4. Species-specific viability analysis of Pseudomonas aeruginosa, Burkholderia cepacia and Staphylococcus aureus in mixed culture by flow cytometry

    PubMed Central

    2014-01-01

    Background Bacterial species coexist commonly in mixed communities, for instance those occurring in microbial infections of humans. Interspecies effects contribute to alterations in composition of communities with respect to species and thus, to the course and severity of infection. Therefore, knowledge concerning growth and viability of single species in medically-relevant mixed communities is of high interest to resolve complexity of interspecies dynamics and to support development of treatment strategies. In this study, a flow cytometric method was established to assess the species-specific viability in defined three-species mixed cultures. The method enables the characterization of viability of Pseudomonas aeruginosa, Burkholderia cepacia and Staphylococcus aureus, which are relevant to lung infections of Cystic Fibrosis (CF) patients. The method combines fluorescence detection by antibody and lectin labeling with viability fluorescence staining using SYBR®Green I and propidium iodide. In addition, species-specific cell enumeration analysis using quantitative terminal restriction fragment length polymorphisms (qT-RFLP) was used to monitor the growth dynamics. Finally, to investigate the impact of substrate availability on growth and viability, concentrations of main substrates and metabolites released were determined. Results For each species, the time course of growth and viability during mixed culture cultivations was obtained by using qT-RFLP analysis in combination with flow cytometry. Comparison between mixed and pure cultures revealed for every species differences in growth properties, e.g. enhanced growth of P. aeruginosa in mixed culture. Differences were also observed for B. cepacia and S. aureus in the time course of viability, e.g. an early and drastic reduction of viability of S. aureus in mixed culture. Overall, P. aeruginosa clearly dominated the mixed culture with regard to obtained cell concentrations. Conclusions In combination with qT-RFLP analysis, the methods enabled monitoring of species-specific cell concentrations and viability during co-cultivation of theses strains. Experimental findings suggest that the predominance of P. aeruginosa over B. cepacia and S. aureus in mixed culture under the chosen cultivation conditions is promoted by more efficient substrate consumption of P. aeruginosa, and antagonistic interspecies effects induced by P. aeruginosa. PMID:24606608

  5. [Economic crime].

    PubMed

    Dinitz, S

    1976-01-01

    Economic crime, often also referred to as white collar crime, is one of the most incidious and predatory of offenses. Unlike street crime, for which there may well be some protection, the average citizen is completely at the mercy of the perpetrators of economic crimes. The concept of white collar crime was first identified by Edwin H. Sutherland. He dealt with the problem as a violation of trust involving either or both misrepresentation and duplicity. He argued for the use of criminal sanctions rather than civil remedies as a means of dealing with white collar offenses. Sutherland's views were attacked by the legal profession, by sociologists and criminologists and by public opinion specialists. They contended that an act treated in civil court is not a crime; that criminals are those persons who are defined as such and white collar criminals are neither so defined nor do they define themselves as criminals and, finally, that economic crime is universal. Can anyone be criminal, then, ask the critics? A number of studies by Clinard, Quinney, Black, Ball, Cressey, Newman and others have translated the interest in white collar crime into empirical terms. The last thirty-five years have also witnessed the elaboration and alteration of the theory itself. Geis' work has been particularly important in this respect. His "street" versus "suite" crime is a useful dichotomy. Most important, however, have been the monograph and papers by Herbert Edelhertz who has conceptualized the issues on various levels - from consumer fraud to the illegal activities of the multinational corporation. This article is concerned with the exposition of the theory and research in the field. Most significant, the paper raises serious doubts whether the problem of economic crime can be researched and studied; it raises even more difficult issues concerning the legal and sociological implications of economic crime and of its prevention, management and control. PMID:1030807

  6. Estimating Renewable Energy Economic Potential in the United States. Methodology and Initial Results

    SciTech Connect

    Brown, Austin; Beiter, Philipp; Heimiller, Donna; Davidson, Carolyn; Denholm, Paul; Melius, Jennifer; Lopez, Anthony; Hettinger, Dylan; Mulcahy, David; Porro, Gian

    2015-07-30

    This report describes a geospatial analysis method to estimate the economic potential of several renewable resources available for electricity generation in the United States. Economic potential, one measure of renewable generation potential, may be defined in several ways. For example, one definition might be expected revenues (based on local market prices) minus generation costs, considered over the expected lifetime of the generation asset. Another definition might be generation costs relative to a benchmark (e.g., a natural gas combined cycle plant) using assumptions of fuel prices, capital cost, and plant efficiency. Economic potential in this report is defined as the subset of the available resource technical potential where the cost required to generate the electricity (which determines the minimum revenue requirements for development of the resource) is below the revenue available in terms of displaced energy and displaced capacity. The assessment is conducted at a high geospatial resolution (more than 150,000 technology-specific sites in the continental United States) to capture the significant variation in local resource, costs, and revenue potential. This metric can be a useful screening factor for understanding the economic viability of renewable generation technologies at a specific location. In contrast to many common estimates of renewable energy potential, economic potential does not consider market dynamics, customer demand, or most policy drivers that may incent renewable energy generation.

  7. Growth habit and leaf economics determine gas exchange responses to high elevation in an evergreen tree, a deciduous shrub and a herbaceous annual.

    PubMed

    Shi, Zuomin; Haworth, Matthew; Feng, Qiuhong; Cheng, Ruimei; Centritto, Mauro

    2015-01-01

    Plant growth at high elevations necessitates physiological and morphological plasticity to enable photosynthesis (A) under conditions of reduced temperature, increased radiation and the lower partial pressure of atmospheric gases, in particular carbon dioxide (pCO2). Previous studies have observed a wide range of responses to elevation in plant species depending on their adaptation to temperature, elevational range and growth habit. Here, we investigated the effect of an increase in elevation from 2500 to 3500 m above sea level (a.s.l.) on three montane species with contrasting growth habits and leaf economic strategies. While all of the species showed identical increases in foliar δ(13)C, dark respiration and nitrogen concentration with elevation, contrasting leaf gas exchange and photosynthetic responses were observed between species with different leaf economic strategies. The deciduous shrub Salix atopantha and annual herb Rumex dentatus exhibited increased stomatal (Gs) and mesophyll (Gm) conductance and enhanced photosynthetic capacity at the higher elevation. However, evergreen Quercus spinosa displayed reduced conductance to CO2 that coincided with lower levels of photosynthetic carbon fixation at 3500 m a.s.l. The lower Gs and Gm values of evergreen species at higher elevations currently constrains their rates of A. Future rises in the atmospheric concentration of CO2 ([CO2]) will likely predominantly affect evergreen species with lower specific leaf areas (SLAs) and levels of Gm rather than deciduous species with higher SLA and Gm values. We argue that climate change may affect plant species that compose high-elevation ecosystems differently depending on phenotypic plasticity and adaptive traits affecting leaf economics, as rising [CO2] is likely to benefit evergreen species with thick sclerophyllous leaves. PMID:26433706

  8. Growth habit and leaf economics determine gas exchange responses to high elevation in an evergreen tree, a deciduous shrub and a herbaceous annual

    PubMed Central

    Shi, Zuomin; Haworth, Matthew; Feng, Qiuhong; Cheng, Ruimei; Centritto, Mauro

    2015-01-01

    Plant growth at high elevations necessitates physiological and morphological plasticity to enable photosynthesis (A) under conditions of reduced temperature, increased radiation and the lower partial pressure of atmospheric gases, in particular carbon dioxide (pCO2). Previous studies have observed a wide range of responses to elevation in plant species depending on their adaptation to temperature, elevational range and growth habit. Here, we investigated the effect of an increase in elevation from 2500 to 3500 m above sea level (a.s.l.) on three montane species with contrasting growth habits and leaf economic strategies. While all of the species showed identical increases in foliar δ13C, dark respiration and nitrogen concentration with elevation, contrasting leaf gas exchange and photosynthetic responses were observed between species with different leaf economic strategies. The deciduous shrub Salix atopantha and annual herb Rumex dentatus exhibited increased stomatal (Gs) and mesophyll (Gm) conductance and enhanced photosynthetic capacity at the higher elevation. However, evergreen Quercus spinosa displayed reduced conductance to CO2 that coincided with lower levels of photosynthetic carbon fixation at 3500 m a.s.l. The lower Gs and Gm values of evergreen species at higher elevations currently constrains their rates of A. Future rises in the atmospheric concentration of CO2 ([CO2]) will likely predominantly affect evergreen species with lower specific leaf areas (SLAs) and levels of Gm rather than deciduous species with higher SLA and Gm values. We argue that climate change may affect plant species that compose high-elevation ecosystems differently depending on phenotypic plasticity and adaptive traits affecting leaf economics, as rising [CO2] is likely to benefit evergreen species with thick sclerophyllous leaves. PMID:26433706

  9. EFFECT OF FUMIGATION ON VOLUNTEER POTATO (SOLANUM TUBERSOUM) TUBER VIABILITY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Management of volunteer potato requires an integrated approach and soil fumigation is one tactic known to reduce population densities of certain weeds. The effect of 1,3-D and metham sodium on potato tuber viability were tested in sealed glass jars at various doses, incubation temperatures, and tim...

  10. Evaluating the Viability of Mobile Learning to Enhance Management Training

    ERIC Educational Resources Information Center

    Macdonald, Iain; Chiu, Jason

    2011-01-01

    A qualitative research project was conducted to test the viability of augmenting an e-learning program for workplace learners using mobile content delivered through smart phones. Ten learners taking a six week web-based e-learning course were given smart phones which enabled them to access approximately 70% of the course content, in addition to…

  11. Metam sodium reduces viability and infectivity of Eimeria oocysts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Metam sodium (MS, sodium N-methyldithiocarbamate) is a widely used soil pesticide. Fumigation or chemical sterilization of poultry litter containing infectious oocysts could be an effective strategy to block the transmission of avian coccidia. In the current study the effect of MS on the viability ...

  12. 37 CFR 1.807 - Viability of deposit.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Viability of deposit. 1.807 Section 1.807 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES Biotechnology Invention Disclosures Deposit...

  13. 37 CFR 1.807 - Viability of deposit.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2011-07-01 2011-07-01 false Viability of deposit. 1.807 Section 1.807 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES Biotechnology Invention Disclosures Deposit...

  14. 37 CFR 1.807 - Viability of deposit.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2012-07-01 2012-07-01 false Viability of deposit. 1.807 Section 1.807 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES Biotechnology Invention Disclosures Deposit...

  15. 37 CFR 1.807 - Viability of deposit.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2013-07-01 2013-07-01 false Viability of deposit. 1.807 Section 1.807 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES Biotechnology Invention Disclosures Deposit...

  16. 37 CFR 1.807 - Viability of deposit.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2014-07-01 2014-07-01 false Viability of deposit. 1.807 Section 1.807 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES Biotechnology Invention Disclosures Deposit...

  17. Developing a Predictive Metric to Assess School Viability

    ERIC Educational Resources Information Center

    James, John T.; Tichy, Karen L.; Collins, Alan; Schwob, John

    2008-01-01

    This article examines a wide range of parish school indicators that can be used to predict long-term viability. The study reported in this article explored the relationship between demographic variables, financial variables, and parish grade school closures in the Archdiocese of Saint Louis. Specifically, this study investigated whether…

  18. Dual fluorochrome flow cytometric assessment of yeast viability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A novel staining protocol is reported for the assessment of viability in yeast, specifically the biocontrol yeast, Pichia anomala. Employing both the red fluorescent membrane potential sensitive oxonol stain DiBAC4(5) (Bis-(1,3-dibutylbarbituric acid)pentamethine oxonol), a structural analog of the ...

  19. Viability of stored seed: extension by cathodic protection.

    PubMed

    Pammenter, N W; Adamson, J H; Berjak, P

    1974-12-20

    Placing seeds on a negatively charged conductor extended their viability during artificial aging. Such cathodic protection may reduce free radical attack by providing a source of electrons. The results stupport the hypothesis of free radical damage to cellular components and are consistent with such damage being important in deteriorative senescence changes. PMID:17818626

  20. Effect of Lanthanide Complex Structure on Cell Viability and Association

    PubMed Central

    2015-01-01

    A systematic study of the effect of hydrophobicity and charge on the cell viability and cell association of lanthanide metal complexes is presented. The terbium luminescent probes feature a macrocyclic polyaminocarboxylate ligand (DOTA) in which the hydrophobicity of the antenna and that of the carboxyamide pendant arms are independently varied. Three sensitizing antennas were investigated in terms of their function in vitro: 2-methoxyisophthalamide (IAM(OMe)), 2-hydroxyisophthalamide (IAM), and 6-methylphenanthridine (Phen). Of these complexes, Tb-DOTA-IAM exhibited the highest quantum yield, although the higher cell viability and more facile synthesis of the structurally related Tb-DOTA-IAM(OMe) platform renders it more attractive. Further modification of this latter core structure with carboxyamide arms featuring hydrophobic benzyl, hexyl, and trifluoro groups as well as hydrophilic amino acid based moieties generated a family of complexes that exhibit high cell viability (ED50 > 300 ?M) regardless of the lipophilicity or the overall complex charge. Only the hexyl-substituted complex reduced cell viability to 60% in the presence of 100 ?M complex. Additionally, cellular association was investigated by ICP-MS and fluorescence microscopy. Surprisingly, the hydrophobic moieties did not increase cell association in comparison to the hydrophilic amino acid derivatives. It is thus postulated that the hydrophilic nature of the 2-methoxyisophthalamide antenna (IAM(OMe)) disfavors the cellular association of these complexes. As such, responsive luminescent probes based on this scaffold would be appropriate for the detection of extracellular species. PMID:24901440

  1. Quantitative investigation into methods for evaluating neocortical slice viability

    PubMed Central

    2013-01-01

    Background In cortical and hippocampal brain slice experiments, the viability of processed tissue is usually judged by the amplitude of extracellularly-recorded seizure-like event (SLE) activity. Surprisingly, the suitability of this approach for evaluating slice quality has not been objectively studied. Furthermore, a method for gauging the viability of quiescent tissue, in which SLE activity is intentionally suppressed, has not been documented. In this study we undertook to address both of these matters using the zero-magnesium SLE model in neocortical slices. Methods Using zero-magnesium SLE activity as the output parameter, we investigated: 1) changes in the pattern (amplitude, frequency and length) of SLE activity as slice health either deteriorated; or was compromised by altering the preparation methodology and; 2) in quiescent tissue, whether the triggering of high frequency field activity following electrode insertion predicted subsequent development of SLE activity and hence slice viability. Results SLE amplitude was the single most important variable correlating with slice viability, with a value less than 50?V indicative of tissue unlikely to be able to sustain population activity for more than 3060minutes. In quiescent slices, an increase in high frequency field activity immediately after electrode insertion predicted the development of SLE activity in 100% of cases. Furthermore, the magnitude of the increase in spectral power correlated with the amplitude of succeeding SLE activity (R2 40.9%, p?viability and can be applied independent of the mechanism of tissue activation. PMID:24195598

  2. Low-dose adenosine stress echocardiography: Detection of myocardial viability

    PubMed Central

    Djordjevic-Dikic, Ana; Ostojic, Miodrag; Beleslin, Branko; Nedeljkovic, Ivana; Stepanovic, Jelena; Stojkovic, Sinisa; Petrasinovic, Zorica; Nedeljkovic, Milan; Saponjski, Jovica; Giga, Vojislav

    2003-01-01

    Objective The aim of this study was to evaluate the diagnostic potential of low-dose adenosine stress echocardiography in detection of myocardial viability. Background Vasodilation through low dose dipyridamole infusion may recruit contractile reserve by increasing coronary flow or by increasing levels of endogenous adenosine. Methods Forty-three patients with resting dyssynergy, due to previous myocardial infarction, underwent low-dose adenosine (80, 100, 110 mcg/kg/min in 3 minutes intervals) echocardiography test. Gold standard for myocardial viability was improvement in systolic thickening of dyssinergic segments of ? 1 grade at follow-up. Coronary angiography was done in 41 pts. Twenty-seven patients were revascularized and 16 were medically treated. Echocardiographic follow up data (12 2 months) were available in 24 revascularized patients. Results Wall motion score index improved from rest 1.55 0.30 to 1.33 0.26 at low-dose adenosine (p < 0.001). Of the 257 segments with baseline dyssynergy, adenosine echocardiography identified 122 segments as positive for viability, and 135 as necrotic since no improvement of systolic thickening was observed. Follow-up wall motion score index was 1.31 0.30 (p < 0.001 vs. rest). The sensitivity of adenosine echo test for identification of viable segments was 87%, while specificity was 95%, and diagnostic accuracy 90%. Positive and negative predictive values were 97% and 80%, respectively. Conclusion Low-dose adenosine stress echocardiography test has high diagnostic potential for detection of myocardial viability in the group of patients with left ventricle dysfunction due to previous myocardial infarction. Low dose adenosine stress echocardiography may be adequate alternative to low-dose dobutamine test for evaluation of myocardial viability. PMID:12812523

  3. Impact of thermal effects induced by ultrasound on viability of rat C6 glioma cells.

    PubMed

    Kujawska, T; Secomski, W; Bilmin, K; Nowicki, A; Grieb, P

    2014-07-01

    In order to have consistent and repeatable effects of sonodynamic therapy (SDT) on various cancer cells or tissue lesions we should be able to control a delivered ultrasound energy and thermal effects induced. The objective of this study was to investigate viability of rat C6 glioma cells in vitro depending on the intensity of ultrasound in the region of cells and to determine the exposure time inducing temperature rise above 43 °C, which is known to be toxic for cells. For measurements a planar piezoelectric transducer with a diameter of 20 mm and a resonance frequency of 1.06 MHz was used. The transducer generated tone bursts with 94 μs duration, 0.4 duty-cycle and initial intensity ISATA (spatial averaged, temporal averaged) varied from 0.33 W/cm(2) to 8 W/cm(2) (average acoustic power varied from 1 W to 24 W). The rat C6 glioma cells were cultured on a bottom of wells in 12-well plates, incubated for 24h and then exposed to ultrasound with measured acoustic properties, inducing or causing no thermal effects leading to cell death. Cell viability rate was determined by MTT assay (a standard colorimetric assay for assessing cell viability) as the ratio of the optical densities of the group treated by ultrasound to the control group. Structural cellular changes and apoptosis estimation were observed under a microscope. Quantitative analysis of the obtained results allowed to determine the maximal exposure time that does not lead to the thermal effects above 43 °C in the region of cells for each initial intensity of the tone bursts used as well as the threshold intensity causing cell death after 3 min exposure to ultrasound due to thermal effects. The averaged threshold intensity was found to be about 5.7 W/cm(2). PMID:24589258

  4. 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.

  5. A review of protocols for selecting species at risk in the context of US Forest Service viability assessments

    NASA Astrophysics Data System (ADS)

    Andelman, Sandy J.; Groves, Craig; Regan, Helen M.

    2004-10-01

    In December 2000, the USDA Forest Service (USFS) commissioned a review of their process for conducting viability assessments under the National Forest Management Act (NFMA). The objectives of the USFS review were to establish the scientific basis for geographic and temporal scales used in the assessment of viability, to identify and improve approaches that could be used to assess species viability within the context of NFMA, and to describe the strengths and limitations of the approaches used in the viability assessment process. In this paper, we present one aspect of this overall review: methods available and in use for selection of species at risk for the viability assessment process. A representative group of methods includes threatened and endangered species protocols such as the IUCN protocol, the Heritage ranks, the method devised by Millsap et al. (1990) to identify threatened and endangered species in Florida, as well as protocols for narrower taxonomic and geographic ranges. We provide a description of each of the nine protocols reviewed and compare them in terms of their taxonomic and geographic range, biological attributes, consideration of threats and population trends, data requirements, reliability and robustness, transparency and ability to deal with uncertainty. We found that all threatened and endangered species protocols are useful for classifying species at risk, however, those that explicitly include current and future threats are of most use in determining which species will be adversely affected by proposed management actions. We recommend that Heritage ranks be used to identify an initial set of candidate species for assessment of viability considerations, with further refinement and supplementation based on species distributions, relative to the scale of the planning area.

  6. Impact of release dynamics of laser-irradiated polymer micropallets on the viability of selected adherent cells.

    PubMed

    Ma, Huan; Mismar, Wael; Wang, Yuli; Small, Donald W; Ras, Mat; Allbritton, Nancy L; Sims, Christopher E; Venugopalan, Vasan

    2012-06-01

    We use time-resolved interferometry, fluorescence assays and computational fluid dynamics (CFD) simulations to examine the viability of confluent adherent cell monolayers to selection via laser microbeam release of photoresist polymer micropallets. We demonstrate the importance of laser microbeam pulse energy and focal volume position relative to the glass-pallet interface in governing the threshold energies for pallet release as well as the pallet release dynamics. Measurements using time-resolved interferometry show that increases in laser pulse energy result in increasing pallet release velocities that can approach 10 m s(-1) through aqueous media. CFD simulations reveal that the pallet motion results in cellular exposure to transient hydrodynamic shear stress amplitudes that can exceed 100 kPa on microsecond timescales, and which produces reduced cell viability. Moreover, CFD simulation results show that the maximum shear stress on the pallet surface varies spatially, with the largest shear stresses occurring on the pallet periphery. Cell viability of confluent cell monolayers on the pallet surface confirms that the use of larger pulse energies results in increased rates of necrosis for those cells situated away from the pallet centre, while cells situated at the pallet centre remain viable. Nevertheless, experiments that examine the viability of these cell monolayers following pallet release show that proper choices for laser microbeam pulse energy and focal volume position lead to the routine achievement of cell viability in excess of 90 per cent. These laser microbeam parameters result in maximum pallet release velocities below 6 m s(-1) and cellular exposure of transient hydrodynamic shear stresses below 20 kPa. Collectively, these results provide a mechanistic understanding that relates pallet release dynamics and associated transient shear stresses with subsequent cellular viability. This provides a quantitative, mechanistic basis for determining optimal operating conditions for laser microbeam-based pallet release systems for the isolation and selection of adherent cells. PMID:22158840

  7. Influence of food quality on egg production and viability of the marine planktonic copepod Acartia omorii [review article

    NASA Astrophysics Data System (ADS)

    Shin, Kyoungsoon; Jang, Min-Chul; Jang, Pung-Kuk; Ju, Se-Jong; Lee, Tea-Kyun; Chang, Man

    2003-06-01

    Egg production, egg viability and fecal pellet production were determined for individual Acartia omorii, which were fed diets of two species of diatoms ( Skeletonema costatum and Phaeodactylum tricornutum) and three species of dinoflagellates ( Scrippsiella trochoidea, Heterocapsa triquetra and Cochlodinium polykrikoides). Diets were analyzed for fatty acid content as an indicator of food quality. Depending on the diet, egg production of A. omorii varied over time, diminishing with some diets ( S. trochoidea, C. polykrikoides, P. tricornutum). This rate of reduction was much more rapid for a diet of C. polykrikoides, which caused egg production to decrease to ca. 2.4 eggs f -1 d -1 in only four days. As for all diets, egg viability was high at the beginning but with the C. polykrikoides and P. tricornutum diets, it rapidly decreased with time. Fecal pellet production also varied with time, depending on the diet. Egg production rate was closely correlated with fecal pellet production. There was no direct relationship between egg viability and egg production rate, but both egg production and viability were affected by the nutritional quality of food. Egg viability was also highly dependent on the composition of fatty acids in the eggs. Egg viability showed positive correlation with the ratio of ?3:?6 groups among egg fatty acids, and negative correlation with the ratio of 20:5 ( n-3) : 22:6 ( n-3). While comparing several diets, egg production rate was higher on diets ( H. triquetra and S. trochoidea) containing ample amounts of essential fatty acids such as 18:4 ( n-3) and 22:6 ( n-3). The results suggest that fertility of A. omorii was dependent upon the quality of the food, and dinoflagellate diets, with the exception of C. polykrikoides, were preferable to diatom diets.

  8. Impact of release dynamics of laser-irradiated polymer micropallets on the viability of selected adherent cells

    PubMed Central

    Ma, Huan; Mismar, Wael; Wang, Yuli; Small, Donald W.; Ras, Mat; Allbritton, Nancy L.; Sims, Christopher E.; Venugopalan, Vasan

    2012-01-01

    We use time-resolved interferometry, fluorescence assays and computational fluid dynamics (CFD) simulations to examine the viability of confluent adherent cell monolayers to selection via laser microbeam release of photoresist polymer micropallets. We demonstrate the importance of laser microbeam pulse energy and focal volume position relative to the glasspallet interface in governing the threshold energies for pallet release as well as the pallet release dynamics. Measurements using time-resolved interferometry show that increases in laser pulse energy result in increasing pallet release velocities that can approach 10 m s?1 through aqueous media. CFD simulations reveal that the pallet motion results in cellular exposure to transient hydrodynamic shear stress amplitudes that can exceed 100 kPa on microsecond timescales, and which produces reduced cell viability. Moreover, CFD simulation results show that the maximum shear stress on the pallet surface varies spatially, with the largest shear stresses occurring on the pallet periphery. Cell viability of confluent cell monolayers on the pallet surface confirms that the use of larger pulse energies results in increased rates of necrosis for those cells situated away from the pallet centre, while cells situated at the pallet centre remain viable. Nevertheless, experiments that examine the viability of these cell monolayers following pallet release show that proper choices for laser microbeam pulse energy and focal volume position lead to the routine achievement of cell viability in excess of 90 per cent. These laser microbeam parameters result in maximum pallet release velocities below 6 m s?1 and cellular exposure of transient hydrodynamic shear stresses below 20 kPa. Collectively, these results provide a mechanistic understanding that relates pallet release dynamics and associated transient shear stresses with subsequent cellular viability. This provides a quantitative, mechanistic basis for determining optimal operating conditions for laser microbeam-based pallet release systems for the isolation and selection of adherent cells. PMID:22158840

  9. Satellite power system: Engineering and economic analysis summary

    NASA Technical Reports Server (NTRS)

    1976-01-01

    A system engineering and economic analysis was conducted to establish typical reference baselines for the photovoltaic, solar thermal, and nuclear satellite power systems. Tentative conclusions indicate that feasibility and economic viability are characteristic of the Satellite Power System. Anticipated technology related to manufacturing, construction, and maintenance operations is described. Fuel consumption, environmental effects, and orbital transfer are investigated. Space shuttles, local space transportation, and the heavy lift launch vehicle required are also discussed.

  10. Economic implications of alternative potato cropping systems in Maine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sustainable cropping systems and management practices are needed to improve agricultural viability and rural economic vitality in Maine and the surrounding region. Research is being conducted to 1) identify the constraints to potato system sustainability and 2) develop practices and management strat...

  11. Preliminary technical and economic evaluation of vortex extraction devices

    SciTech Connect

    Kornreich, T. R.; Kottler, Jr., R. J.; Jennings, D. M.

    1980-04-01

    Two innovative vortex extraction devices - the Tornado Wind Energy System (TWES) and the Vortex Augmentor Concept (VAC) - are critically evaluated to provide a preliminary assessment of their technical and economic viability as compared to conventional horizontal axis wind energy systems. This assessment was carried out over a wide range of power output levels and augmentation ratios appropriate to each of the concepts.

  12. ECONOMIC ASSESSMENT OF WASTE WATER AQUACULTURE TREATMENT SYSTEMS

    EPA Science Inventory

    This study attempted to ascertain the economic viability of aquaculture as an alternative to conventional waste water treatment systems for small municipalities in the Southwestern region of the United States. A multiple water quality objective level cost-effectiveness model was ...

  13. Advanced Reservoir Characterization in the Antelope Shale to Establish the Viability of C02 Enhanced Oil Recovery in California's Monterey Formation Siliceous Shales

    SciTech Connect

    Michael F. Morea

    1997-04-25

    The primary objective of this research is to conduct advanced reservoir characterization and modeling studies in the Antelope Shale reservoir. Characterization studies will be used to determine the technical feasibility of implementing a CO2 enhanced oil recovery project in the Antelope Shale in Buena Vista Hills Field. The Buena Vista Hills pilot CO2 project will demonstrate the economic viability and widespread applicability of CO2 flooding in fractured siliceous shale reservoirs of the San Joaquin Valley. The research consists of four primary work processes: Reservoir Matrix and Fluid Characterization; Fracture Characterization; Reservoir Modeling and Simulation; and CO2 Pilot Flood and Evaluation. Work done in these areas is subdivided into two phases or budget periods. The first phase of the project will focus on the application of a variety of advanced reservoir characterization techniques to determine the production characteristics of the Antelope Shale reservoir. Reservoir models based on the results of the characterization work will be used to evaluate how the reservoir will respond to secondary recovery and EOR processes. The second phase of the project will include the implementation and evaluation of an advanced enhanced oil recovery (EOR) pilot in the West Dome of the Buena Vista Hills Field.

  14. Advanced Reservoir Characterization in the Antelope Shale to Establish the Viability of C02 Enhanced Oil Recovery in California's Monterey Formation Siliceous Shales

    SciTech Connect

    Michael F. Morea

    1997-10-24

    The primary objective of this research is to conduct advanced reservoir characterization and modeling studies in the Antelope Shale reservoir. Characterization studies will be used to determine the technical feasibility of implementing a CO2 enhanced oil recovery project in the Antelope Shale in Buena Vista Hills Field. The Buena Vista Hills pilot CO2 project will demonstrate the economic viability and widespread applicability of CO2 flooding in fractured siliceous shale reservoirs of the San Joaquin Valley. The research consists of four primary work processes: Reservoir Matrix and Fluid Characterization; Fracture Characterization; Reservoir Modeling and Simulation; and CO2 Pilot Flood and Evaluation. Work done in these areas is subdivided into two phases or budget periods. The first phase of the project will focus on the application of a variety of advanced reservoir characterization techniques to determine the production characteristics of the Antelope Shale reservoir. Reservoir models based on the results of the characterization work will be used to evaluate how the reservoir will respond to secondary recovery and EOR processes. The second phase of the project will include the implementation and evaluation of an advanced enhanced oil recovery (EOR) pilot in the United Anticline (West Dome) of the Buena Vista Hills Field.

  15. Advanced Reservoir Characterization in the Antelope Shale to Establish the Viability of C02 Enhanced Oil Recovery in California's Monterey Formation Siliceous Shales

    SciTech Connect

    Michael F. Morea

    1998-04-23

    The primary objective of this research is to conduct advanced reservoir characterization and modeling studies in the Antelope Shale reservoir. Characterization studies will be used to determine the technical feasibility of implementing a CO2 enhanced oil recovery project in the Antelope Shale in Buena Vista Hills Field. The Buena Vista Hills pilot CO2 project will demonstrate the economic viability and widespread applicability of CO2 flooding in fractured siliceous shale reservoirs of the San Joaquin Valley. The research consists of four primary work processes: Reservoir Matrix and Fluid Characterization; Fracture Characterization; Reservoir Modeling and Simulation; and CO2 Pilot Flood and Evaluation. Work done in these areas is subdivided into two phases or budget periods. The first phase of the project will focus on the application of a variety of advanced reservoir characterization techniques to determine the production characteristics of the Antelope Shale reservoir. Reservoir models based on the results of the characterization work will be used to evaluate how the reservoir will respond to secondary recovery and EOR processes. The second phase of the project will include the implementation and evaluation of an advanced enhanced oil recovery (EOR) pilot in the United Anticline (West Dome) of the Buena Vista Hills Field.

  16. Advanced Reservoir Characterization in the Antelope Shale to Establish the Viability of CO2 Enhanced Oil Recovery in California's Monterey Formation Siliceous Shales

    SciTech Connect

    Morea, Michael F.

    1999-11-01

    The primary objective of this research is to conduct advanced reservoir characterization and modeling studies in the Antelope Shale reservoir. Characterization studies will be used to determine the technical feasibility of implementing a CO2 enhanced oil recovery project in the Antelope Shale in Buena Vista Hills Field. The Buena Vista Hills pilot CO2 project will demonstrate the economic viability and widespread applicability of CO2 flooding in fractured siliceous shale reservoirs of the San Joaquin Valley. The research consists of four primary work processes: (1) Reservoir Matrix and Fluid Characterization; (2) Fracture characterization; (3) reservoir Modeling and Simulation; and (4) CO2 Pilot Flood and Evaluation. Work done in these areas is subdivided into two phases or budget periods. The first phase of the project will focus on the application of a variety of advanced reservoir characterization techniques to determine the production characteristics of the Antelope Shale reservoir. Reservoir models based on the results of the characterization work will be used to evaluate how the reservoir will respond to secondary recovery and EOR processes. The second phase of the project will include the implementation and evaluation of an advanced enhanced oil recovery (EOR) pilot in the United Anticline (West Dome) of the Buena Vista Hills Field.

  17. Advanced Reservoir Characterization in the Antelope Shale to Establish the Viability of CO2 Enhanced Oil Recovery in California's Monterey Formation Siliceous Shales

    SciTech Connect

    Morea, Michael F.

    1999-11-08

    The primary objective of this research is to conduct advanced reservoir characterization and modeling studies in the Antelope Shale reservoir. Characterization studies will be used to determine the technical feasibility of implementing a CO2 enhanced oil recovery project in the Antelope Shale in Buena Vista Hills Field. The Buena Vista Hills pilot CO2 project will demonstrate the economic viability and widespread applicability of CO2 flooding in fractured siliceous shale reservoirs of the San Joaquin Valley. The research consists of four primary work processes: (1) Reservoir Matrix and Fluid Characterization; (2) Fracture characterization; (3) reservoir Modeling and Simulation; and (4) CO2 Pilot Flood and Evaluation. Work done in these areas is subdivided into two phases or budget periods. The first phase of the project will focus on the application of a variety of advanced reservoir characterization techniques to determine the production characteristics of the Antelope Shale reservoir. Reservoir models based on the results of the characterization work will be used to evaluate how the reservoir will respond to secondary recovery and EOR processes. The second phase of the project will include the implementation and evaluation of an advanced enhanced oil recovery (EOR) pilot in the United Anticline (West Dome) of the Buena Vista Hills Field.

  18. What has happened to suicides during the Greek economic crisis? Findings from an ecological study of suicides and their determinants (2003–2012)

    PubMed Central

    Rachiotis, George; Stuckler, David; McKee, Martin; Hadjichristodoulou, Christos

    2015-01-01

    Objectives There is a controversy about the impact of economic crisis on suicide rates in Greece. We analysed recent suicide data to identify who has been most affected and the relationships to economic and labour market indicators. Setting Greece. Primary and secondary outcome measures Age-specific and sex-specific suicide rates in Greece for the period 2003–2012 were calculated using data provided by the Hellenic Statistical Authority. We performed a join-point analysis to identify discontinuities in suicide trends between 2003 and 2010, prior to austerity, and in 2011–2012, during the period of austerity. Regression models were used to assess relationships between unemployment, Gross Domestic Product (GDP) and suicide rates for the entire period by age and sex. Results The mean suicide rate overall rose by 35% between 2010 and 2012, from 3.37 to 4.56/100 000 population. The suicide mortality rate for men increased from 5.75 (2003–2010) to 7.43/100 000 (2011–2012; p<0.01). Among women, the suicide rate also rose, albeit less markedly, from 1.17 to 1.55 (p=0.03). When differentiated by age group, suicide mortality increased among both sexes in the age groups 20–59 and >60 years. We found that each additional percentage point of unemployment was associated with a 0.19/100 000 population rise in suicides (95% CI 0.11 to 0.26) among working age men. Conclusions We found a clear increase in suicides among persons of working age, coinciding with austerity measures. These findings corroborate concerns that increased suicide risk in Greece is a health hazard associated with austerity measures. PMID:25807950

  19. Viability of Bacillus popilliae after Lyophilization of Liquid Nitrogen Frozen Cells1

    PubMed Central

    Lingg, A. J.; Mcmahon, K. J.; Herzmann, Cheryl

    1967-01-01

    The per cent viability of Bacillus popilliae after lyophilization of liquid nitrogen frozen cells was determined. Lyophilization of 9- to 12-hr cells which had been suspended in 5% sodium glutamate plus 0.5% gum tragacanth, frozen in liquid nitrogen vapor, and dried 4 to 5 hr with the ampoules exposed to room temperature resulted in survival of 64.6% of the original cells. After storage of these lyophilized preparations for 6 months at room temperature, 10.5% of the original cells were still viable. PMID:6031431

  20. The Economic Case for Education

    ERIC Educational Resources Information Center

    Woessmann, Ludger

    2016-01-01

    The case for education can be made from many perspectives. This paper makes the case for education based on economic outcomes. Surveying the most recent empirical evidence, it shows the crucial role of education for individual and societal prosperity. Education is a leading determinant of economic growth, employment, and earnings in modern…

  1. The Economic Case for Education

    ERIC Educational Resources Information Center

    Woessmann, Ludger

    2016-01-01

    The case for education can be made from many perspectives. This paper makes the case for education based on economic outcomes. Surveying the most recent empirical evidence, it shows the crucial role of education for individual and societal prosperity. Education is a leading determinant of economic growth, employment, and earnings in modern

  2. Economic Impact Analysis. Project Report.

    ERIC Educational Resources Information Center

    Literacy Volunteers of America, Inc., Syracuse, NY.

    A study determined the economic impact of each dollar invested in Literacy Volunteers of America, Inc. (LVA). The analysis included 217 interviews, 165 in New York and 52 in Wisconsin; analysis of economic impact; and statistical validation and analysis. For every dollar spent by LVA, the value created (return) to the overall economy was a…

  3. Fetal viability as a threshold to personhood. A legal analysis.

    PubMed

    Peterfy, A

    1995-12-01

    This essay opens with an examination of US laws concerning fetal viability as they apply to induced abortion, to a mother's right to refuse medical treatment necessary to save the life of a fetus, and to the rights to file suit for the wrongful death of unborn children. The history of abortion policies in the US is traced from the common law period of the early 19th century to the restrictive post-Civil War laws and the decisions of the Supreme Court in Roe vs. Wade, which upheld the constitutionality of previability abortions; Webster vs. Reproductive Health Services, in which the Court assigned viability to the 20th week of pregnancy and acknowledged that States could have a compelling previability interest in the fetus; and the Casey decision, which provided tolerance for limits on the availability of abortion before viability as long as the limits did not create an "undue burden" on the woman seeking the abortion. Courts dealing with the issue of compelling a mother to undergo medical treatment to save her fetus have been inconsistent as they balanced the state's interest in the fetus against the mother's rights to privacy. Judges have tended to err on the side of forcing the medical interventions, but the most recent trend is against this sort of judgement. In these cases, fetal viability has also served as a dividing line. The inconsistency of the legal system is illustrated by the fact that, whereas the fetus now has a legal existence, wrongful death actions entered on behalf of a nonviable fetus have often been denied although courts have been more willing to extend protection to fetuses in wrongful death tort cases than in abortion or medical intervention cases. Criminal law has a unique set of rules for dealing with fetuses as some states have broadened their definitions of "homicide" to include fetuses, even nonviable fetuses. Courts, however, are reluctant to enlarge criminal statutes on their own. While the central position given to the role of viability in the Roe vs. Wade decision was intended to apply only to abortion (and is diminishing there), state courts have accepted viability as equating personhood and have used the concept to decide medical treatment, wrongful death, and criminal cases. In order to resolve the inconsistencies exhibited by these decisions, states should be allowed to make all decisions regarding the treatment of fetuses. PMID:8568420

  4. Viability and fertilizing capacity of cryopreserved sperm from three North American acipenseriform species: A retrospective study

    USGS Publications Warehouse

    Horvath, A.; Wayman, W.R.; Dean, J.C.; Urbanyi, B.; Tiersch, T.R.; Mims, S.D.; Johnson, D.; Jenkins, J.A.

    2008-01-01

    Populations of sturgeon across the globe are threatened due to unregulated harvest and habitat loss, and the status varies among species across North America. Ready access to viable and functional sperm would contribute to recovery programmes for these species. In this study, we examined the motility, viability (cell membrane integrity) of cryopreserved sperm from three North American acipenseriform species and fertilizing capacity. Milt samples were collected from captive shortnose sturgeon (Acipenser brevirostrum), wild paddlefish (Polyodon spathula) and pallid sturgeon (Scaphirhynchus albus) and cryopreserved using combinations of Modified Tsvetkova's (MT) extender, Original Tsvetkova's extender, and modified Hanks' balanced salt solution, along with the cryoprotectants methanol (MeOH) or dimethyl sulfoxide (DMSO). A dual-staining technique using the fluorescent stains SYBR-14 and propidium iodide was employed with flow cytometry to determine the percentages of spermatozoa that were viable by virtue of having intact membranes. The percentage of viable spermatozoa ranged from 5% to 12% in shortnose sturgeon, 30-59% in paddlefish, and 44-58% in pallid sturgeon. In the first experiment with shortnose sturgeon sperm, methanol allowed for higher values for dependent variables than did DMSO, and sperm viability generally correlated with post-thaw motility. However, fertilization rate, neurulation, or hatching rates were independent from these factors. In the second experiment with shortnose sturgeon, 5% MeOH combined with MT yielded higher values for all parameters tested than the other combinations: viability was correlated with motility, fertilization rate, and hatching rate. Overall, viability and post-thaw motility was not affected by the use of hyperosmotic extenders (OT) or cryoprotectants (DMSO), but their use decreased fertilization percentages. For paddlefish sperm (experiment 3), MT combined with 10% MeOH was clearly a good choice for cryopreservation; viability and motility results were correlated, but independent of fertilization. For pallid sturgeon sperm (experiment 4), MT with 5-10% MeOH showed significantly higher sperm quality and fertilization parameters. Membrane integrity can be used as a predictor of fertilization by cryopreserved sperm, however additional sperm quality parameters, supplementary to motility and membrane integrity, would be useful in the refining and optimizing cryopreservation protocols with acipenseriform sperm. ?? 2008 Blackwell Verlag, Berlin.

  5. Automated quantification of the spatial extent of perfusion defects and viability on myocardial contrast echocardiography.

    PubMed

    Micari, Antonio; Sklenar, Jiri; Belcik, Todd A; Kaul, Sanjiv; Lindner, Jonathan R

    2006-04-01

    The spatial extent of hypoperfusion or viability is important in the treatment of patients with coronary artery disease. We hypothesized that computerized pixel intensity threshold analysis (PITA) could be used for the automated analysis of perfusion defect size during myocardial contrast echocardiography (MCE). For calibration studies, MCE was performed in 6 dogs undergoing ischemia and reperfusion. Infarct size was determined by PITA, which automatically calculates the percentage of pixels within the myocardium that fail to exceed a predetermined threshold of maximum contrast enhancement. A threshold of 10% of maximum yielded infarct sizes that most closely correlated with those determined by histologic staining. For clinical validation, MCE was performed in 30 patients with acute myocardial infarction before primary percutaneous coronary intervention (PCI) for measurement of risk area; and within 5 days and at 4 weeks after PCI to determine infarct size. The defect size by PITA with a 10% threshold value closely correlated with those measured by expert reader planimetry on background-subtracted color-coded image sets (r = 0.95, P < .001). We conclude that automated analysis of perfusion defect size on MCE is possible by PITA. This technique may be useful for rapid and objective analysis of the extent of ischemia and viability, and for clinical experimentation where accurate and sequential analysis of perfusion defect size is imperative. PMID:16581476

  6. Cosmological viability conditions for f(T) dark energy models

    SciTech Connect

    Setare, M.R.; Mohammadipour, N. E-mail: N.Mohammadipour@uok.ac.ir

    2012-11-01

    Recently f(T) modified teleparallel gravity where T is the torsion scalar has been proposed as the natural gravitational alternative for dark energy. We perform a detailed dynamical analysis of these models and find conditions for the cosmological viability of f(T) dark energy models as geometrical constraints on the derivatives of these models. We show that in the phase space exists two cosmologically viable trajectory which (i) The universe would start from an unstable radiation point, then pass a saddle standard matter point which is followed by accelerated expansion de sitter point. (ii) The universe starts from a saddle radiation epoch, then falls onto the stable matter era and the system can not evolve to the dark energy dominated epoch. Finally, for a number of f(T) dark energy models were proposed in the more literature, the viability conditions are investigated.

  7. Viability of vector-tensor theories of gravity

    SciTech Connect

    Jimenez, Jose Beltran; Maroto, Antonio L. E-mail: maroto@fis.ucm.es

    2009-02-15

    We present a detailed study of the viability of general vector-tensor theories of gravity in the presence of an arbitrary temporal background vector field. We find that there are six different classes of theories which are indistinguishable from General Relativity by means of local gravity experiments. We study the propagation speeds of scalar, vector and tensor perturbations and obtain the conditions for classical stability of those models. We compute the energy density of the different modes and find the conditions for the absence of ghosts in the quantum theory. We conclude that the only theories which can pass all the viability conditions for arbitrary values of the background vector field are not only those of the pure Maxwell type, but also Maxwell theories supplemented with a (Lorentz type) gauge fixing term.

  8. Hybrid Viability and Fertility in Co-occuring Plant Species

    NASA Astrophysics Data System (ADS)

    Hernandez, E.; Garcia, C.; Yost, J.

    2012-12-01

    Similar species of plants can co-exist due to reproductive barriers that keep them from hybridizing. In the case of Lasthenia gracilis and L. californica, certain reproductive barriers allow them to co-exist at Jasper Ridge without hybridization. The two species are locally adapted to different regions of the same hillside, and have slight differences in flowering time but hybrids can be created at low rate in the green house. We tested the viability and fertility of green house produced hybrids to quantify post-zygotic reproductive isolation at Jasper Ridge. We planted 10 hybrid seeds and 10 control seeds from 11 different families. We measured the percent germination, survival to flowering and pollen fertility of the seeds. We expect lower germination, lower survival to flowering, and lower pollen viability of hybrid seeds as compared to control seeds.

  9. Effect of sperm cryopreservation on the European eel sperm viability and spermatozoa morphology.

    PubMed

    Asturiano, J F; Marco-Jiménez, F; Peñaranda, D S; Garzón, D L; Pérez, L; Vicente, J S; Jover, M

    2007-04-01

    The main objective of the present work was to study the effect of cryopreservation of European eel sperm both on the sperm viability and the spermatozoa head morphology. Spermatozoa morphology was evaluated with computer-assisted morphology analysis after collection in fresh samples, after adding the freezing medium containing dimethyl sulfoxide as cryoprotectant and, finally, after the cryopreservation process and thawing. Cell viability was assessed, in both fresh and thawed samples, by Hoechst 33258 staining. Computer-assisted sperm analysis (CASA) was used to determine the percentage of motile cells and to measure motility parameters in sperm samples. A significant decrease of head perimeter (12.56%) and area (17.90%) was detected from spermatozoa in fresh to thawed samples, indicating that cells do not recover the original size after the cryopreservation process. CASA was used to measure the percentage of motile cells (51.9%) and spermatozoa motility parameters such as curvilinear, straight line and angular path velocities, as well as beating cross frequency. This technique was employed in the fresh sperm samples but proteins present at the freezing medium (L-alpha-phosphatidylcholine) made impossible to use this last technique in thawed samples. When sperm viability was assessed by Hoechst staining, a significant decrease of approximately 15% (73.10 vs 58.26%) of alive spermatozoa was registered from fresh to thawed samples. The percentage of motile cells measured by CASA in fresh samples (51.9%) was lower than the percentage of alive cells determined by Hoechst stainning, suggesting the existence of different batches of spermatozoa in different stages of development, even during the eight to tenth weeks of treatment, when the highest sperm quality was found. PMID:17348973

  10. Assessing population viability while accounting for demographic and environmental uncertainty.

    PubMed

    Oppel, Steffen; Hilton, Geoff; Ratcliffe, Norman; Fenton, Calvin; Daley, James; Gray, Gerard; Vickery, Juliet; Gibbons, David

    2014-07-01

    Predicting the future trend and viability of populations is an essential task in ecology. Because many populations respond to changing environments, uncertainty surrounding environmental responses must be incorporated into population assessments. However, understanding the effects of environmental variation on population dynamics requires information on several important demographic parameters that are often difficult to estimate. Integrated population models facilitate the integration of time series data on population size and all existing demographic information from a species, allowing the estimation of demographic parameters for which limited or no empirical data exist. Although these models are ideal for assessments of population viability, they have so far not included environmental uncertainty. We incorporated environmental variation in an integrated population model to account for both demographic and environmental uncertainty in an assessment of population viability. In addition, we used this model to estimate true juvenile survival, an important demographic parameter for population dynamics that is difficult to estimate empirically. We applied this model to assess the past and future population trend of a rare island endemic songbird, the Montserrat Oriole Icterus oberi, which is threatened by volcanic activity. Montserrat Orioles experienced lower survival in years with volcanic ashfall, causing periodic population declines that were compensated by higher seasonal fecundity in years with high pre-breeding season rainfall. Due to the inclusion of both demographic and environmental uncertainty in the model, the estimated population growth rate in the immediate future was highly imprecise (95% credible interval 0.844-1.105), and the probability of extinction after three generations (in the year 2028) was low (2.1%). This projection demonstrates that accounting for both demographic and environmental sources of uncertainty provides a more realistic assessment of the viability of populations under unknown future environmental conditions. PMID:25163115

  11. Fermented red ginseng extract inhibits cancer cell proliferation and viability.

    PubMed

    Oh, Jisun; Jeon, Seong Bin; Lee, Yuri; Lee, Hyeji; Kim, Ju; Kwon, Bo Ra; Yu, Kang-Yeol; Cha, Jeong-Dan; Hwang, Seung-Mi; Choi, Kyung-Min; Jeong, Yong-Seob

    2015-04-01

    Red ginseng (Panax ginseng C.A. Meyer) is the most widely recognized medicinal herb due to its remedial effects in various disorders, such as cancers, diabetes, and heart problems. In this study, we investigated the anticancer effect of fermented red ginseng extract (f-RGE; provided by Jeonju Biomaterials Institute, Jeonju, South Korea) in a parallel comparison with the effect of nonfermented red ginseng extract (nf-RGE; control) on several cancer cell lines--MCF-7 breast cancer cells, HepG2 hepatocellular carcinoma cells, and reprogrammed MCF-7 cells (mimicking cancer stem cells). Cells were cultured at various concentrations of RGE (from 0.5 up to 5?mg/mL) and their viabilities and proliferative properties were examined. Our data demonstrate the following: (1) nf-RGE inhibited cell viability at ?1?mg/mL for MCF-7 cells and ?2?mg/mL for HepG2 cells, (2) in the presence of a carcinogenic agent, 12-O-tetradecanoylphorbol-13-acetate (TPA), nf-RGE treatment in combination with paclitaxel synergistically decreased MCF-7 as well as HepG2 cell viability, (3) f-RGE (which contained a greater level of Rg3 content) more effectively decreased the viability of MCF-7 and HepG2 cells compared to nf-RGE, and (4) f-RGE appeared more potent for inhibiting cancerous differentiation of reprogrammed MCF-7 cells in a synergistic fashion with paclitaxel, especially in the presence of TPA, compared to nf-RGE. These findings suggest that f-RGE treatment may be more effective for decreasing cancer cell survival by inducing apoptotic cell death and also presumably for preventing cancer stem cell differentiation compared to nf-RGE. PMID:25658580

  12. Economic assessment of biodiesel production from waste frying oils.

    TOXLINE Toxicology Bibliographic Information

    Araujo VK; Hamacher S; Scavarda LF

    2010-06-01

    Waste frying oils (WFO) can be a good source for the production of biodiesel because this raw material is not part of the food chain, is low cost and can be used in a way that resolves environmental problems (i.e. WFO is no longer thrown into the sewage network). The goal of this article is to propose a method to evaluate the costs of biodiesel production from WFO to develop an economic assessment of this alternative. This method embraces a logistics perspective, as the cost of collection of oil from commercial producers and its delivery to biodiesel depots or plants can be relevant and is an issue that has been little explored in the academic literature. To determine the logistics cost, a mathematical programming model is proposed to solve the vehicle routing problem (VRP), which was applied in an important urban center in Brazil (Rio de Janeiro), a relevant and potential center for biodiesel production and consumption. Eighty-one biodiesel cost scenarios were compared with information on the commercialization of biodiesel in Brazil. The results obtained demonstrate the economic viability of biodiesel production from WFO in the urban center studied and the relevance of logistics in the total biodiesel production cost.

  13. Economic assessment of biodiesel production from waste frying oils.

    PubMed

    Araujo, Victor Kraemer Wermelinger Sancho; Hamacher, Silvio; Scavarda, Luiz Felipe

    2010-06-01

    Waste frying oils (WFO) can be a good source for the production of biodiesel because this raw material is not part of the food chain, is low cost and can be used in a way that resolves environmental problems (i.e. WFO is no longer thrown into the sewage network). The goal of this article is to propose a method to evaluate the costs of biodiesel production from WFO to develop an economic assessment of this alternative. This method embraces a logistics perspective, as the cost of collection of oil from commercial producers and its delivery to biodiesel depots or plants can be relevant and is an issue that has been little explored in the academic literature. To determine the logistics cost, a mathematical programming model is proposed to solve the vehicle routing problem (VRP), which was applied in an important urban center in Brazil (Rio de Janeiro), a relevant and potential center for biodiesel production and consumption. Eighty-one biodiesel cost scenarios were compared with information on the commercialization of biodiesel in Brazil. The results obtained demonstrate the economic viability of biodiesel production from WFO in the urban center studied and the relevance of logistics in the total biodiesel production cost. PMID:20153167

  14. Seeds of HOPE: a model for addressing social and economic determinants of health in a women's obesity prevention project in two rural communities.

    PubMed

    Benedict, Salli; Campbell, Marci; Doolen, Anne; Rivera, Imana; Negussie, Tezita; Turner-McGrievy, Gabrielle

    2007-10-01

    Socioeconomic status (SES) and income disparity are strong predictors of health, and health promotion interventions that address them are more likely to be meaningful to participants and to sustain positive effects. Seeds of HOPE is an innovative project that is the result of a long-standing collaboration between the University of North Carolina (UNC) Center for Health Promotion and Disease Prevention, a Centers for Disease Control and Prevention (CDC) Prevention Research Center, and communities in rural North Carolina. Initial formative work, including key informant interviews, community surveys, and focus groups, strengthened our understanding of the link between hope and health and the importance of addressing social and economic issues as part of our health promotion interventions. A Seeds of HOPE strategic plan was developed using a community-based participatory process and led to the idea to start Threads of HOPE, an enterprise that will serve as a business laboratory where women will produce and market a unique product and also learn business skills. Threads of HOPE will be a health-enhancing business and will serve as a training program for a new cadre of women entrepreneurs in two rural communities. PMID:17937563

  15. Disruptive viability selection on adult exploratory behaviour in eastern chipmunks.

    PubMed

    Bergeron, P; Montiglio, P-O; Rale, D; Humphries, M M; Gimenez, O; Garant, D

    2013-04-01

    Heterogeneous forces of selection associated with fluctuating environments are recognized as important factors involved in the maintenance of inter-individual phenotypic variance within populations. Consistent behavioural differences over time and across situations (e.g. personality) are increasingly cited as examples of individual variation observed within populations. However, the suggestion that heterogeneous selective pressures target different animal personalities remains largely untested in the wild. In this 5-year study, we investigated the dynamics of viability selection on a personality trait, exploration, in a population of eastern chipmunks (Tamias striatus) experiencing substantial seasonal variations in weather conditions and food availability associated with masting trees. Contrary to our expectations, we found no evidence of fluctuating selection on exploration. Instead, we found strong disruptive viability selection on adult exploration behaviour, independent of seasonal variations. Individuals with either low or high exploration scores were almost twice as likely to survive over a 6-month period compared with individuals with intermediate scores. We found no evidence of viability selection on juvenile exploration. Our results highlight that disruptive selection might play an important role in the maintenance of phenotypic variance of wild populations through its effect on different personality types across temporally varying environmental conditions. PMID:23437956

  16. Drying process strongly affects probiotics viability and functionalities.

    PubMed

    Iaconelli, Cyril; Lemetais, Guillaume; Kechaou, Noura; Chain, Florian; Bermdez-Humarn, Luis G; Langella, Philippe; Gervais, Patrick; Beney, Laurent

    2015-11-20

    Probiotic formulations are widely used and are proposed to have a variety of beneficial effects, depending on the probiotic strains present in the product. The impact of drying processes on the viability of probiotics is well documented. However, the impact of these processes on probiotics functionality remains unclear. In this work, we investigated variations in seven different bacterial markers after various desiccation processes. Markers were composed of four different viability evaluation (combining two growth abilities and two cytometric measurements) and in three in vitro functionalities: stimulation of IL-10 and IL-12 production by PBMCs (immunomodulation) and bacterial adhesion to hexadecane. We measured the impact of three drying processes (air-drying, freeze-drying and spray-drying), without the use of protective agents, on three types of probiotic bacteria: Bifidobacterium bifidum, Lactobacillus plantarum and Lactobacillus zeae. Our results show that the bacteria respond differently to the three different drying processes, in terms of viability and functionality. Drying methods produce important variations in bacterial immunomodulation and hydrophobicity, which are correlated. We also show that adherence can be stimulated (air-drying) or inhibited (spray-drying) by drying processes. Results of a multivariate analysis show no direct correlation between bacterial survival and functionality, but do show a correlation between probiotic responses to desiccation-rewetting and the process used to dry the bacteria. PMID:26325197

  17. Viability of fastidious Phytophthora following different cryopreservation treatments.

    PubMed

    Houseknecht, Janice L; Suh, Sung-Oui; Zhou, Jianlong Jim

    2012-10-01

    Living stock cultures with constant phenotypes and genotypes are required for a wide range of research and industrial applications; however, long-term, stable preservation of fastidious Phytophthora strains has been challenging. In this study, we systematically evaluated different cryopreservation treatments to identify and clarify freezing, thawing, and other conditions appropriate for long-term maintenance. Optimal preservation conditions were largely strain-specific, with robust strains remaining fully viable and the fastidious yielding lower recovery under all test conditions. Nevertheless, several procedures were shown to be generally applicable for effective cryopreservation of most Phytophthora organisms. Fastidious strains retained higher viability following the -1Cmin(-1) freezing protocol (Mr Frosty's) than either of two widely used programmed freezing procedures. Revival was higher when frozen mycelium plugs were thawed at 37C for 2min or 25C for 5min, while lower viability was apparent for fastidious strains thawed at 55C for 1.5min. Among 15 cryoprotective solutions assessed, 5% dimethyl sulfoxide produced the highest viability for all fastidious strains. The effect of prefreeze and postfreeze treatments on revival was mild, if any, and strain-dependent. This study has generated reliable, practical, long-term preservation solutions applicable to a majority of Phytophthora species. It also has revealed a need for in-depth physiological and morphological investigations to further enhance the preservation methods for fastidious strains. PMID:23063187

  18. Viability studies of optically trapped T-cells

    NASA Astrophysics Data System (ADS)

    McAlinden, Niall; Glass, David G.; Millington, Owain; Wright, Amanda J.

    2011-10-01

    We present a viability study of optically trapped live T cell hybridomas. T cells form an important part of the adaptive immune response system which is responsible for fighting particular pathogens or diseases. The cells of interest were directly trapped by a laser operating at a wavelength of 1064 nm and their viability measured as a function of time. Cell death was monitored using an inverted fluorescent microscope to observe the uptake by the cell of the fluorescent dye propidium iodide. Studies were undertaken at various laser powers and beam profiles. There is a growing interest in optically trapping immune cells and this is the first study that investigates the viability of a T cell when trapped using a conventional optical trapping system. In such experiments it is crucial that the T cell remains viable and trapping the cell directly means that any artefacts due to a cell-bead interface are removed. Our motivation behind this experiment is to use optical tweezers to gain a greater understanding of the interaction forces between T cells and antigen presenting cells. Measuring these interactions has become important due to recent theories which indicate that the strength of this interaction may underlie the activation of the T-cell and subsequent immune response.

  19. Nuclear cardiac imaging for the assessment of myocardial viability

    PubMed Central

    Slart, R.H.J.A.; Bax, J.J.; van der Wall, E.E.; van Veldhuisen, D.J.; Jager, P.L.; Dierckx, R.A.

    2005-01-01

    An important aspect of the diagnostic and prognostic work-up of patients with ischaemic cardiomyopathy is the assessment of myocardial viability. Patients with left ventricular dysfunction who have viable myocardium are the patients at highest risk because of the potential for ischaemia but at the same time benefit most from revascularisation. It is important to identify viable myocardium in these patients, and radionuclide myocardial scintigraphy is an excellent tool for this. Single-photon emission computed tomography perfusion scintigraphy (SPECT), whether using 201thallium, 99mTc-sestamibi, or 99mTc- tetrofosmin, in stress and/or rest protocols, has consistently been shown to be an effective modality for identifying myocardial viability and guiding appropriate management. Metabolic and perfusion imaging with positron emission tomography radiotracers frequently adds additional information and is a powerful tool for predicting which patients will have an improved outcome from revascularisation. New techniques in the nuclear cardiology field, such as attenuation corrected SPECT, dual isotope simultaneous acquisition (DISA) SPECT and gated FDG PET are promising and will further improve the detection of myocardial viability. Also the combination of multislice computed tomography scanners with PET opens possibilities of adding coronary calcium scoring and noninvasive coronary angiography to myocardial perfusion imaging and quantification. ImagesFigure 1Figure 2Figure 3 PMID:25696432

  20. Enhancement of cell viability after treatment with polyunsaturated fatty acids.

    PubMed

    Bartl, J; Walitza, S; Grnblatt, E

    2014-01-24

    Attention-deficit/hyperactivity disorder (ADHD) is highly prevalent in children and adolescents and both environmental and genetic factors play major roles. Polyunsaturated fatty acids (PUFAs) are postulated to contribute to the development of the infant brain and an imbalance in these may increase the risk of ADHD. In recent clinical studies, supplementation with PUFAs improved symptoms of ADHD in some cases. Similarly, some beneficial effects were observed with PUFA treatment in neuronal cell cultures. Therefore, in this study, we hypothesized that a specific PUFA combination (available on the market as Equazen [Vifor Pharma, Switzerland]) along with iron, zinc, or vitamin B5 (vitB5) would produce an additive beneficial effect on the viability of rat pheochromocytoma-12 dopaminergic cells. The specific PUFA combination alone, as well as added to each of the three nutrients, was tested in a dose-response manner. The specific PUFAs significantly improved cell viability, starting at very low doses (100pM) from 60h up to 90h; while the combined treatment with vitB5 and minerals did not provide additional benefit. Our results confirmed the beneficial effect of the specific PUFAs on neuronal cell viability; although supplementation with minerals and vitB5 did not enhance this effect. PMID:24269370

  1. Definitions and Basic Concepts of Supply and Demand Analysis Used to Determine Market Equilibrium. Principles of Economics II (Microeconomics), Lesson Plan No. 6.

    ERIC Educational Resources Information Center

    Chiu-Irion, Vicky

    Developed as part of a 37.5-hour microeconomics course, this lesson plan focuses on the concepts of supply and demand analysis used to determine market equilibrium. The objectives of the 50-minute lesson are to enable the student to: (1) explain how a demand schedule is derived from raw data; (2) graph a demand curve from the demand schedule; (3)…

  2. Feasibility of a novel approach for fast, economical determination of radiation damage in nuclear reactor cores. [Annual report, November 1, 1992--October 30, 1993

    SciTech Connect

    Was, G.S.

    1993-07-07

    Progress was made in the following areas: radioinduced segregation (modeling and experiment), deformation of irradiated microstructures, stress corrosion cracking of irradiated microstructures, and development of an apparatus to determine the role of deformation on the radiation microstructure in-situ. Materials used were based on Ni-Cr-Fe and 304L.

  3. Definitions and Basic Concepts of Supply and Demand Analysis Used to Determine Market Equilibrium. Principles of Economics II (Microeconomics), Lesson Plan No. 6.

    ERIC Educational Resources Information Center

    Chiu-Irion, Vicky

    Developed as part of a 37.5-hour microeconomics course, this lesson plan focuses on the concepts of supply and demand analysis used to determine market equilibrium. The objectives of the 50-minute lesson are to enable the student to: (1) explain how a demand schedule is derived from raw data; (2) graph a demand curve from the demand schedule; (3)

  4. Economic evaluation of a solar hot-water system--Palm Beach County, Florida

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Report projects solar-energy costs and savings for residential hot-water system over 20 year period. Evaluation uses technical and economic models with inputs based on working characteristics of installed system. Primary analysis permits calculation of economic viability for four other U.S. sites.

  5. An economic assessment of STOL aircraft potential including terminal area environmental considerations. Volume 2: Appendices

    NASA Technical Reports Server (NTRS)

    Solomon, H. L.; Sokolsky, S.

    1973-01-01

    An economic assessment of short takeoff aircraft for short haul air transportation applications is presented. The economic viability and environmental compatibility of short takeoff aircraft service in high density areas were evaluated. The subjects discussed are: (1) aircraft configurations and performance, (2) airfield and terminal requirements, and (3) direct and indirect operating costs.

  6. The Effect of Tuning Cold Plasma Composition on Glioblastoma Cell Viability

    PubMed Central

    Cheng, Xiaoqian; Sherman, Jonathan; Murphy, William; Ratovitski, Edward; Canady, Jerome; Keidar, Michael

    2014-01-01

    Previous research in cold atmospheric plasma (CAP) and cancer cell interaction has repeatedly proven that the cold plasma induced cell death. It is postulated that the reactive oxygen species (ROS) and reactive nitrogen species (RNS) play a major role in the CAP cancer therapy. In this paper, we seek to determine a mechanism of CAP therapy on glioblastoma cells (U87) through an understanding of the composition of the plasma, including treatment time, voltage, flow-rate and plasma-gas composition. In order to determine the threshold of plasma treatment on U87, normal human astrocytes (E6/E7) were used as the comparison cell line. Our data showed that the 30 sec plasma treatment caused 3-fold cell death in the U87 cells compared to the E6/E7 cells. All the other compositions of cold plasma were performed based on this result: plasma treatment time was maintained at 30 s per well while other plasma characteristics such as voltage, flow rate of source gas, and composition of source gas were changed one at a time to vary the intensity of the reactive species composition in the plasma jet, which may finally have various effect on cells reflected by cell viability. We defined a term “plasma dosage” to summarize the relationship of all the characteristics and cell viability. PMID:24878760

  7. Hydroxyethyl disulfide as an efficient metabolic assay for cell viability in vitro

    PubMed Central

    Li, Jie; Zhang, Donglan; Ward, Kathleen M.; Prendergast, George C.; Ayene, Iraimoudi S.

    2012-01-01

    Cell viability assays have a variety of well known practical and technical limitations. All the available approaches have disadvantages, such as non-linearity, high background and cumbersome protocols. Several commonly used tetrazolium chemicals rely upon generation of a colored formazan product formed by mitochondrial reduction of these compounds via phenazine methosulfate (PMS). However, sensitivity is inherently limited because their reduction relies on mitochondrial bioreduction and cellular transport of PMS, as well as accessibility to tetrazolium chemicals. In this study, we identify hydroxethyldisulfide (HEDS) as an inexpensive probe that can measure cellular metabolic activity without the need of PMS. In tissue culture medium, HEDS accurately quantitated metabolically active live cells in a linear manner superior to tetrazolium based and other assays. Cell toxicity produced by chemotherapeutics (cisplatin, etoposide), oxidants (hydrogen peroxide, acetaminophen), toxins (Phenyl arsine oxide, arsenite) or ionizing radiation was rapidly determined by the HEDS assay. We found that HEDS was superior to other commonly used assays for cell viability determinations in its solubility, membrane permeability, and intracellular conversion to a metabolic reporter that is readily transported into the extracellular medium. Our findings establish the use of HEDS in a simple, rapid and low cost assay to accurately quantify viable cells. PMID:22321380

  8. Population viability impacts of habitat additions and subtractions: A simulation experiment with endangered kangaroo rats

    EPA Science Inventory

    Species viability is influenced by the quality, quantity and configuration of habitat. For species at risk, a principal challenge is to identify landscape configurations that, if realized, would improve a population’s viability or restoration potential. Critical habitat patche...

  9. Population viability impacts of habitat additions and subtractions: A simulation experiment with endangered kangaroo rats

    EPA Science Inventory

    Species viability is influenced by the quality, quantity and configuration of habitat. For species at risk, a principal challenge is to identify landscape configurations that, if realized, would improve a populations viability or restoration potential. Critical habitat patche...

  10. Effects of hypothermic storage of striped bass (Morone saxatilis) sperm on intracellular calcium, reactive oxygen species formation, mitochondrial function, motility, and viability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experiments were conducted to determine the effect of hypothermic 24 h storage of striped bass sperm cells on viability, intracellular Ca2+ ([Ca2+]i), mitochondrial membrane potential (D'm), and reactive oxygen species (ROS) formation (oxidation of hydroethidine to ethidium) as determined by flow cy...

  11. Effects of hypothermic storage of striped bass (Morone saxatilis) sperm on intracellular calcium, reactive oxygen species formation, mitochondrial function, motility, and viability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experiments were conducted to determine the effect of hypothermic 24 h storage of striped bass sperm cells (Morone saxatilis) on viability, intracellular Ca2+ [Ca2+]i, mitochondrial membrane potential (''m), and reactive oxygen species (ROS) formation as determined by flow cytometry; motion activati...

  12. Basic Economic Principles

    NASA Technical Reports Server (NTRS)

    Tideman, T. N.

    1972-01-01

    An economic approach to design efficient transportation systems involves maximizing an objective function that reflects both goals and costs. A demand curve can be derived by finding the quantities of a good that solve the maximization problem as one varies the price of that commodity, holding income and the prices of all other goods constant. A supply curve is derived by applying the idea of profit maximization of firms. The production function determines the relationship between input and output.

  13. Controlling laser-induced jet formation for bioprinting mesenchymal stem cells with high viability and high resolution.

    PubMed

    Ali, Muhammad; Pages, Emeline; Ducom, Alexandre; Fontaine, Aurelien; Guillemot, Fabien

    2014-12-01

    Laser-assisted bioprinting is a versatile, non-contact, nozzle-free printing technique which has demonstrated high potential for cell printing with high resolution. Improving cell viability requires determining printing conditions which minimize shear stress for cells within the jet and cell impact at droplet landing. In this context, this study deals with laser-induced jet dynamics to determine conditions from which jets arise with minimum kinetic energies. The transition from a sub-threshold regime to jetting regime has been associated with a geometrical parameter (vertex angle) which can be harnessed to print mesenchymal stem cells with high viability using slow jet conditions. Finally, hydrodynamic jet stability is also studied for higher laser pulse energies which give rise to supersonic but turbulent jets. PMID:25215452

  14. Economic aspects of production of Caiman crocodilus yacare.

    PubMed

    Carreira, Laura B T; Sabbag, Omar J

    2015-03-01

    The breeding of crocodilians is still a recent activity in Brazil. Its peak was in the 1990's, but it has gaps in its production, as there are no norms for the commercial breeding of these animals in captivity. However, its economic potential is great, and the search for ecological balance and viability of commercial production has become a challenge among farmers of this activity. Therefor, the objective of the study was to economically analyze the production of Caiman crocodilus yacare on a farm located in Caceres, state of Mato Grosso, identifying relevant items of costs in the activity, as well as the parameters related to the profitability and viability of the activity. The economic results for the breeding of this animal were positive, with profitability ratios higher than 70%. PMID:25806993

  15. Criteria for Viability Assessment of Discarded Human Donor Livers during Ex Vivo Normothermic Machine Perfusion

    PubMed Central

    Karimian, Negin; Weeder, Pepijn D.; de Boer, Marieke T.; Wiersema-Buist, Janneke; Gouw, Annette S. H.; Leuvenink, Henri G. D.; Lisman, Ton; Porte, Robert J.

    2014-01-01

    Although normothermic machine perfusion of donor livers may allow assessment of graft viability prior to transplantation, there are currently no data on what would be a good parameter of graft viability. To determine whether bile production is a suitable biomarker that can be used to discriminate viable from non-viable livers we have studied functional performance as well as biochemical and histological evidence of hepatobiliary injury during ex vivo normothermic machine perfusion of human donor livers. After a median duration of cold storage of 6.5 h, twelve extended criteria human donor livers that were declined for transplantation were ex vivo perfused for 6 h at 37C with an oxygenated solution based on red blood cells and plasma, using pressure controlled pulsatile perfusion of the hepatic artery and continuous portal perfusion. During perfusion, two patterns of bile flow were identified: (1) steadily increasing bile production, resulting in a cumulative output of ?30 g after 6 h (high bile output group), and (2) a cumulative bile production <20 g in 6 h (low bile output group). Concentrations of transaminases and potassium in the perfusion fluid were significantly higher in the low bile output group, compared to the high bile output group. Biliary concentrations of bilirubin and bicarbonate were respectively 4 times and 2 times higher in the high bile output group. Livers in the low bile output group displayed more signs of hepatic necrosis and venous congestion, compared to the high bile output group. In conclusion, bile production could be an easily assessable biomarker of hepatic viability during ex vivo machine perfusion of human donor livers. It could potentially be used to identify extended criteria livers that are suitable for transplantation. These ex vivo findings need to be confirmed in a transplant experiment or a clinical trial. PMID:25369327

  16. Ketone supplementation decreases tumor cell viability and prolongs survival of mice with metastatic cancer.

    PubMed

    Poff, A M; Ari, C; Arnold, P; Seyfried, T N; D'Agostino, D P

    2014-10-01

    Cancer cells express an abnormal metabolism characterized by increased glucose consumption owing to genetic mutations and mitochondrial dysfunction. Previous studies indicate that unlike healthy tissues, cancer cells are unable to effectively use ketone bodies for energy. Furthermore, ketones inhibit the proliferation and viability of cultured tumor cells. As the Warburg effect is especially prominent in metastatic cells, we hypothesized that dietary ketone supplementation would inhibit metastatic cancer progression in vivo. Proliferation and viability were measured in the highly metastatic VM-M3 cells cultured in the presence and absence of ?-hydroxybutyrate (?HB). Adult male inbred VM mice were implanted subcutaneously with firefly luciferase-tagged syngeneic VM-M3 cells. Mice were fed a standard diet supplemented with either 1,3-butanediol (BD) or a ketone ester (KE), which are metabolized to the ketone bodies ?HB and acetoacetate. Tumor growth was monitored by in vivo bioluminescent imaging. Survival time, tumor growth rate, blood glucose, blood ?HB and body weight were measured throughout the survival study. Ketone supplementation decreased proliferation and viability of the VM-M3 cells grown in vitro, even in the presence of high glucose. Dietary ketone supplementation with BD and KE prolonged survival in VM-M3 mice with systemic metastatic cancer by 51 and 69%, respectively (p < 0.05). Ketone administration elicited anticancer effects in vitro and in vivo independent of glucose levels or calorie restriction. The use of supplemental ketone precursors as a cancer treatment should be further investigated in animal models to determine potential for future clinical use. PMID:24615175

  17. Bioluminescent, Nonlytic, Real-Time Cell Viability Assay and Use in Inhibitor Screening

    PubMed Central

    Zhou, Wenhui; Meisenheimer, Poncho; Vidugiris, Gediminas; Cali, James J.; Gautam, Prson; Wennerberg, Krister; Vidugiriene, Jolanta

    2015-01-01

    Abstract Real-time continuous monitoring of cellular processes offers distinct advantages over traditional endpoint assays. A comprehensive representation of the changes occurring in live cells over the entire length of an experiment provides information about the biological status of the cell and informs decisions about the timing of treatments or the use of other functional endpoint assays. We describe a homogeneous, nonlytic, bioluminescent assay that measures cell viability in real time. This time-dependent measurement allowed us to monitor cell health for 72?h from the same test samples, distinguish differential cell growth, and investigate drug mechanism of action by analyzing time- and dose-dependent drug effects. The real-time measurements also allowed us to detect cell death immediately (>75% signal decrease within 15?min of digitonin addition), analyze drug potency versus efficacy, and identify cytostatic versus toxic drug effects. We screened an oncology compound library (Z??=?0.7) and identified compounds with varying activity at different time points (1.6% of the library showed activity within 3?h, whereas 35.4% showed a response by 47?h). The assay compared well with orthogonal endpoint cell viability assays and additionally provided data at multiple time points and the opportunity to multiplex assays on the same cells. To test the advantage of time-dependent measurements to direct optimal timing of downstream applications, we used the real-time cell viability assay to determine the ideal time to measure caspase activity by monitoring the onset of cell death and multiplexing a luminescent caspase activation assay on the same test samples. PMID:26383544

  18. Monitoring viability of seeds in gene banks: developing software tools to increase efficiency

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Monitoring the decline of seed viability is essential for effective long term seed storage in ex situ collections. Recent FAO Genebank Standards recommend monitoring intervals at one-third the time predicted for viability to fall to 85% of initial viability. This poster outlines the development of ...

  19. Pollen viability and storage temperature for Southern highbush and Rabbiteye blueberry breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pollen viability, as measured by tetrad germination, has been reported, but these studies focused on freshly collected pollen and did not address viability of pollen stored at different temperatures over time. Moreover, genetic differences in pollen viability have been reported in blueberry genotype...

  20. 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.

  1. Multi-criteria dynamic decision under uncertainty: a stochastic viability analysis and an application to sustainable fishery management.

    PubMed

    De Lara, M; Martinet, V

    2009-02-01

    Managing natural resources in a sustainable way is a hard task, due to uncertainties, dynamics and conflicting objectives (ecological, social, and economical). We propose a stochastic viability approach to address such problems. We consider a discrete-time control dynamical model with uncertainties, representing a bioeconomic system. The sustainability of this system is described by a set of constraints, defined in practice by indicators - namely, state, control and uncertainty functions - together with thresholds. This approach aims at identifying decision rules such that a set of constraints, representing various objectives, is respected with maximal probability. Under appropriate monotonicity properties of dynamics and constraints, having economic and biological content, we characterize an optimal feedback. The connection is made between this approach and the so-called Management Strategy Evaluation for fisheries. A numerical application to sustainable management of Bay of Biscay nephrops-hakes mixed fishery is given. PMID:19084541

  2. Laser viability method for red blood cell-state monitoring

    NASA Astrophysics Data System (ADS)

    Lapotko, Dmitry; Kuchinsky, Georgy; Antonishina, Elena; Scoromnik, Elena

    1996-01-01

    The method for RBC state control is based upon single cell viability control after illumination with laser pulse. Heat shock resulting from absorption of laser energy by a cell is considered as a cell load. This load acts from inside of the cell, is pulsed (10-5) and can be delivered directly to the chosen cells. The result of each illumination as cell survival or damage is controlled optically by monitoring the cells' response on a pulse through photothermal technique. Under fixed laser parameters the percentage of damaged cells is viability index (VI) for a certain cell population. The testing procedure includes consequential illumination of each cell in population and calculation of VI. Experimental set up is based upon optical microscope. Dual laser thermal lens technique is used for cell illumination and monitoring. For cell loading 5 ns pulses, 400 divided by 600 nm with energies up to 20 (mu) J are generated by tunable dye laser. Cell monitoring is realized with cw He-Ne (632.8 nm) laser and photodetector. All data acquisition routines are automated. Up to 3 cell suspensions can be studied in a multisample chamber designed to secure cells. An amount of cell suspension required is 1 (mu) l. One population test at a fixed wavelength takes 2 divided by 3 min. In experiments with rats, treated with LPS E. Coli injection to stimulate fever and a septic stress we found that variation of RBC viability becomes apparent in 20 - 30 min after injection, while the clinical changes (blood pressure, body temperature, skin temperature) become detectable after 1 hour. The results obtained show that the method can reveal additional properties of the cells most abundant for monitoring and diagnostic tasks.

  3. Cell Viability Assessment: Toward Content-Rich Platforms

    PubMed Central

    Ramirez, Christina Nicole; Antczak, Christophe; Djaballah, Hakim

    2013-01-01

    Importance of the field Monitoring cell viability in vitro is critical in many areas of biomedical research, and the ultimate goal in drug discovery is the ability to predict the in vivo toxicology of drug candidates based on their toxicity profile in vitro. Over the last decade, the contribution of high-throughput screening (HTS) toward this goal has been tremendous, providing the ability to screen compounds in parallel against multiple cell types. However, the toxic effects of drug candidates uncovered during clinical trials are by far the main reason for their failure. Over the same period, our understanding of programmed cell death has evolved dramatically with the identification of critical control points in the cell death pathways. As a result, cell viability should no longer be characterized solely on the basis of discrete endpoint measurements such as membrane permeability. Areas covered in this review/What the reader will gain This review summarizes the traditional viability assays currently commercially available, focusing on methods amenable to high density format. Assays categorized into the following classes are discussed: dye exclusion assays, DNA condensation-based assays and assays monitoring a metabolic function. We describe each approach, and using case studies, we emphasize their limitations. Take home message Current low-content methods based on single parameter readouts are prone to error due to the heterogeneity of cell populations and the multi-faceted nature of cell death. High-content approaches based on continuous, multiplexed readouts are becoming increasingly important for monitoring multiple markers of cell death induction simultaneously, on a cell by cell basis. The use of such content-rich platforms is a necessity to predict the toxicology of drug candidates accurately. PMID:22823019

  4. Projecting the success of plant restoration with population viability analysis

    USGS Publications Warehouse

    Bell, T.J.; Bowles, M.L.; McEachern, A.K.

    2003-01-01

    Conserving viable populations of plant species requires that they have high probabilities of long-term persistence within natural habitats, such as a chance of extinction in 100 years of less than 5% (Menges 1991, 1998; Brown 1994; Pavlik 1994; Chap. 1, this Vol.). For endangered and threatened species that have been severely reduces in range and whose habitats have been fragmented, important species conservation strategies may include augmenting existing populations or restoring new viable populations (Bowles and Whelan 1994; Chap. 2, this Vol.). Restoration objectives may include increasing population numbers to reduce extinction probability, deterministic manipulations to develop a staged cohort structure, or more complex restoration of a desired genetic structure to allow outcrossing or increase effective population size (DeMauro 1993, 1994; Bowles et al. 1993, 1998; Pavlik 1994; Knapp and Dyer 1998; Chap. 2, this Vol.). These efforts may require translocation of propagules from existing (in situ) populations, or from ex situ botanic gardens or seed storage facilities (Falk et al. 1996; Guerrant and Pavlik 1998; Chap. 2, this Vol.). Population viability analysis (PVA) can provide a critical foundation for plant restoration, as it models demographic projections used to evaluate the probability of population persistence and links plant life history with restoration strategies. It is unknown how well artificially created populations will meet demographic modeling requirements (e.g., due to artificial cohort transitions) and few, if any, PVAs have been applied to restorations. To guide application of PVA to restored populations and to illustrate potential difficulties, we examine effects of planting different life stages, model initial population sizes needed to achieve population viability, and compare demographic characteristics between natural and restored populations. We develop and compare plant population restoration viability analysis (PRVA) case studies of two plant species listed in the USA for which federal recovery planning calls for population restoration: Cirsium pitcheri, a short-lived semelparous herb, and Asclepias meadii, a long-lived iteroparous herb.

  5. Viability of Cladosporium herbarum spores under 157 nm laser and vacuum ultraviolet irradiation, low temperature (10 K) and vacuum

    NASA Astrophysics Data System (ADS)

    Sarantopoulou, E.; Stefi, A.; Kollia, Z.; Palles, D.; Petrou, P. S.; Bourkoula, A.; Koukouvinos, G.; Velentzas, A. D.; Kakabakos, S.; Cefalas, A. C.

    2014-09-01

    Ultraviolet photons can damage microorganisms, which rarely survive prolonged irradiation. In addition to the need for intact DNA, cell viability is directly linked to the functionality of the cell wall and membrane. In this work, Cladosporium herbarum spore monolayers exhibit high viability (7%) when exposed to 157 nm laser irradiation (412 kJm-2) or vacuum-ultraviolet irradiation (110-180 nm) under standard pressure and temperature in a nitrogen atmosphere. Spore viability can be determined by atomic-force microscopy, nano-indentation, mass, ?-Raman and attenuated reflectance Fourier-transform far-infrared spectroscopies and DNA electrophoresis. Vacuum ultraviolet photons cause molecular damage to the cell wall, but radiation resistance in spores arises from the activation of a photon-triggered signaling reaction, expressed via the exudation of intracellular substances, which, in combination with the low penetration depth of vacuum-ultraviolet photons, shields DNA from radiation. Resistance to phototoxicity under standard conditions was assessed, as was resistance to additional environmental stresses, including exposure in a vacuum, under different rates of change of pressure during pumping time and low (10 K) temperatures. Vacuum conditions were far more destructive to spores than vacuum-ultraviolet irradiation, and UV-B photons were two orders of magnitude more damaging than vacuum-ultraviolet photons. The viability of irradiated spores was also enhanced at 10 K. This work, in addition to contributing to the photonic control of the viability of microorganisms exposed under extreme conditions, including decontamination of biological warfare agents, outlines the basis for identifying bio-signaling in vivo using physical methodologies.

  6. Spore Density and Viability of Entomopathogenic Fungal Isolates from Indonesia, and Their Virulence against Aphis gossypii Glover (Homoptera: Aphididae)

    PubMed Central

    Herlinda, Siti

    2010-01-01

    The focus of this study was on quantifying fitness attributes, such as spore density and viability, and determining the virulence level against aphid (Aphis gossypii) nymphs of isolates from the fungal species Beauveria bassiana and Metarhizium anisopliae. The fungal isolates were obtained from several insects, including Plutella xylostella, Hypothenemus hampei, Bronstispa longissima, A. gossypii, Tenebrio molitor, and Leptocorisa acuta, that were collected from Indonesian islands, such as Sumatera, Java, and Sulawesi. Third instar aphid nymphs were inoculated via topical application of 106 conidia ml−1 of the entomopathogenic fungal isolates. All of the B. bassiana and M. anisopliae isolates could produce very dense spores. The M. anisopliae isolate MaAg, which was obtained from the aphid, had the highest spore density at 6.70 × 108 conidia ml−1. Among the B. bassiana isolates, the highest conidial viability belonged to isolate CPJW8, which was obtained from Chrysodeixis chalcites, with a 39% average viability. Among the M. anisopliae isolates, the highest viabilities belonged to the isolates MaAg and MaLa, which were obtained from L. acuta, with a 33% and 32% average viabilities, respectively. All of the B. bassiana and M. anisopliae isolates were virulent against aphid nymphs, with mortality rates ranging from 64% to 94%. The three most virulent isolates were BBY715 (94%), MPx (92%), and MaTm (92%), and the least virulent isolate was MaLa (64%). BBY715, the most virulent isolate, had the shortest lethal time median (LT50) against aphid nymphs at 2.97 hours, and MaLa had the longest LT50 at 61.81 hours. PMID:24575186

  7. Spore Density and Viability of Entomopathogenic Fungal Isolates from Indonesia, and Their Virulence against Aphis gossypii Glover (Homoptera: Aphididae).

    PubMed

    Herlinda, Siti

    2010-08-01

    The focus of this study was on quantifying fitness attributes, such as spore density and viability, and determining the virulence level against aphid (Aphis gossypii) nymphs of isolates from the fungal species Beauveria bassiana and Metarhizium anisopliae. The fungal isolates were obtained from several insects, including Plutella xylostella, Hypothenemus hampei, Bronstispa longissima, A. gossypii, Tenebrio molitor, and Leptocorisa acuta, that were collected from Indonesian islands, such as Sumatera, Java, and Sulawesi. Third instar aphid nymphs were inoculated via topical application of 10(6) conidia ml(-1) of the entomopathogenic fungal isolates. All of the B. bassiana and M. anisopliae isolates could produce very dense spores. The M. anisopliae isolate MaAg, which was obtained from the aphid, had the highest spore density at 6.70 × 10(8) conidia ml(-1). Among the B. bassiana isolates, the highest conidial viability belonged to isolate CPJW8, which was obtained from Chrysodeixis chalcites, with a 39% average viability. Among the M. anisopliae isolates, the highest viabilities belonged to the isolates MaAg and MaLa, which were obtained from L. acuta, with a 33% and 32% average viabilities, respectively. All of the B. bassiana and M. anisopliae isolates were virulent against aphid nymphs, with mortality rates ranging from 64% to 94%. The three most virulent isolates were BBY715 (94%), MPx (92%), and MaTm (92%), and the least virulent isolate was MaLa (64%). BBY715, the most virulent isolate, had the shortest lethal time median (LT50) against aphid nymphs at 2.97 hours, and MaLa had the longest LT50 at 61.81 hours. PMID:24575186

  8. Viability of Cladosporium herbarum spores under 157 nm laser and vacuum ultraviolet irradiation, low temperature (10 K) and vacuum

    SciTech Connect

    Sarantopoulou, E. Stefi, A.; Kollia, Z.; Palles, D.; Cefalas, A. C.; Petrou, P. S.; Bourkoula, A.; Koukouvinos, G.; Kakabakos, S.; Velentzas, A. D.

    2014-09-14

    Ultraviolet photons can damage microorganisms, which rarely survive prolonged irradiation. In addition to the need for intact DNA, cell viability is directly linked to the functionality of the cell wall and membrane. In this work, Cladosporium herbarum spore monolayers exhibit high viability (7%) when exposed to 157 nm laser irradiation (412 kJm⁻²) or vacuum-ultraviolet irradiation (110–180 nm) under standard pressure and temperature in a nitrogen atmosphere. Spore viability can be determined by atomic-force microscopy, nano-indentation, mass, μ-Raman and attenuated reflectance Fourier-transform far-infrared spectroscopies and DNA electrophoresis. Vacuum ultraviolet photons cause molecular damage to the cell wall, but radiation resistance in spores arises from the activation of a photon-triggered signaling reaction, expressed via the exudation of intracellular substances, which, in combination with the low penetration depth of vacuum-ultraviolet photons, shields DNA from radiation. Resistance to phototoxicity under standard conditions was assessed, as was resistance to additional environmental stresses, including exposure in a vacuum, under different rates of change of pressure during pumping time and low (10 K) temperatures. Vacuum conditions were far more destructive to spores than vacuum-ultraviolet irradiation, and UV-B photons were two orders of magnitude more damaging than vacuum-ultraviolet photons. The viability of irradiated spores was also enhanced at 10 K. This work, in addition to contributing to the photonic control of the viability of microorganisms exposed under extreme conditions, including decontamination of biological warfare agents, outlines the basis for identifying bio-signaling in vivo using physical methodologies.

  9. Effects of trehalose supplementation on cell viability and oxidative stress variables in frozen-thawed bovine calf testicular tissue.

    PubMed

    Zhang, Xiao-Gang; Wang, Yan-Hua; Han, Cong; Hu, Shan; Wang, Li-Qiang; Hu, Jian-Hong

    2015-06-01

    Trehalose is widely used for cryopreservation of various cells and tissues. Until now, the effect of trehalose supplementation on cell viability and antioxidant enzyme activity in frozen-thawed bovine calf testicular tissue remains unexplored. The objective of the present study was to compare the effect of varying doses of trehalose in cryomedia on cell viability and key antioxidant enzymes activities in frozen-thawed bovine calf testicular tissue. Bovine calf testicular tissue samples were collected and cryopreserved in the cryomedias containing varying doses (0, 5, 10, 15, 20 and 25%; v/v) of trehalose, respectively. Cell viability, total antioxidant capacity (T-AOC) activity, catalase (CAT) activity, superoxide dismutase (SOD) activity, glutathione (GSH) content and malondialdehyde (MDA) content were measured and analyzed. The results showed that cell viability, T-AOC activity, SOD activity, CAT activity and GSH content of frozen-thawed bovine calf testicular tissue was decreased compared with that of fresh group (P<0.05). MDA content in frozen-thawed bovine calf testicular tissue was significantly increased compared with that of fresh group (P<0.05). The cryomedia added 15% trehalose exhibited the greatest percentage of cell viability and antioxidant enzyme activity (SOD and CAT) among frozen-thawed groups (P<0.05). Meanwhile, GSH content was the lowest among frozen-thawed groups (P<0.05). However, there were no significance differences in MDA content among the groups added 10, 15 and 20% trehalose (P>0.05). In conclusion, the cryomedia added 15% trehalose reduced the oxidative stress and improved the cryoprotective effect of bovine calf testicular tissue. Further studies are required to obtain more concrete results on the determination of antioxidant capacity of trehalose in frozen-thawed bovine calf testicular tissue. PMID:25818604

  10. 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. PMID:20415136

  11. IDV sources as ICRF sources: viability and benefits

    NASA Astrophysics Data System (ADS)

    Ojha, Roopesh; Fey, Alan L.; Jauncey, David L.; Johnston, Kenneth J.; Lovell, James E.; Kedziora-Chudczer, Lucyna

    2005-01-01

    Radio sources that exhibit rapid variability in their light curves as a result of radio wave propagation through turbulent electron density fluctuations in the interstellar medium are often among the most compact sources in the sky. In particular the most variable weak sources might be the most point-like and thus some of the best candidates for densification of the ICRF and consequent improvement in its accuracy. Further the advent of the MkV VLBI system will make use of weaker sources easier. We will discuss the viability of this idea review existing lists of potential candidates and state the benefits that might flow from this approach.

  12. Methods for isolation and viability assessment of biological organisms

    SciTech Connect

    Letant, Sonia Edith; Baker, Sarah Elyse; Bond, Tiziana; Chang, Allan Shih-Ping

    2015-02-03

    Isolation of biological or chemical organisms can be accomplished using a surface enhanced Raman scattering (SERS) system. The SERS system can be a single or a stacked plurality of photonic crystal membranes with noble-metal lined through pores for flowing analyte potentially containing the biological or chemical organisms. The through pores can be adapted to trap individual biological or chemical organisms and emit SERS spectra, which can then be detected by a detector and further analyzed for viability of the biological or chemical organism.

  13. Applied studies on the viability of El Tor vibrios*

    PubMed Central

    Pesigan, T. P.; Plantilla, J.; Rolda, M.

    1967-01-01

    The viability of El Tor vibrios was tested at various temperatures in foodstuffs, kitchen utensils, and water after these materials had been directly contaminated with stools of cholera patients or carriers from the Philippines, collected in 1963-64. The period of survival of vibrios in foodstuffs was 2-5 days at room temperature (30C-32C) and as long as 9 days under refrigeration (5C-10C). Vibrios survived even longer in refrigerated water. The period of survival was shorter for all materials contaminated with carriers' stools, which contain fewer vibrios. Chlorinated lime was more effective than potassium permanganate as a decontaminant. PMID:4870081

  14. Acoustofluidics 12: Biocompatibility and cell viability in microfluidic acoustic resonators.

    PubMed

    Wiklund, Martin

    2012-05-01

    Manipulation of biological cells by acoustic radiation forces is often motivated by its improved biocompatibility relative to alternative available methods. On the other hand, it is well known that acoustic exposure is capable of causing damage to tissue or cells, primarily due to heating or cavitation effects. Therefore, it is important to define safety guidelines for the design and operation of the utilized devices. This tutorial discusses the biocompatibility of devices designed for acoustic manipulation of mammalian cells, and different methods for quantifying the cell viability in such devices. PMID:22562376

  15. 5 CFR 841.405 - Economic assumptions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 2 2012-01-01 2012-01-01 false Economic assumptions. 841.405 Section 841... (CONTINUED) FEDERAL EMPLOYEES RETIREMENT SYSTEM-GENERAL ADMINISTRATION Government Costs § 841.405 Economic assumptions. The determinations of the normal cost percentage will be based on the economic...

  16. 5 CFR 841.405 - Economic assumptions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 2 2013-01-01 2013-01-01 false Economic assumptions. 841.405 Section 841... (CONTINUED) FEDERAL EMPLOYEES RETIREMENT SYSTEM-GENERAL ADMINISTRATION Government Costs § 841.405 Economic assumptions. The determinations of the normal cost percentage will be based on the economic...

  17. 5 CFR 841.405 - Economic assumptions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 2 2011-01-01 2011-01-01 false Economic assumptions. 841.405 Section 841... (CONTINUED) FEDERAL EMPLOYEES RETIREMENT SYSTEM-GENERAL ADMINISTRATION Government Costs § 841.405 Economic assumptions. The determinations of the normal cost percentage will be based on the economic...

  18. 5 CFR 841.405 - Economic assumptions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 2 2014-01-01 2014-01-01 false Economic assumptions. 841.405 Section 841... (CONTINUED) FEDERAL EMPLOYEES RETIREMENT SYSTEM-GENERAL ADMINISTRATION Government Costs § 841.405 Economic assumptions. The determinations of the normal cost percentage will be based on the economic...

  19. New Directions for Vocational Home Economics.

    ERIC Educational Resources Information Center

    Fane, Xenia F.

    A 2-day conference jointly sponsored by the American Home Economics Association and the American Vocational Association was attended by approximately 400 home economists who sought to determine new directions for vocational home economics. Some presentations were: (1) -The Cooperative Role of AHEA" by D. Hanson, (2) "Vocational Home Economics in

  20. 5 CFR 841.405 - Economic assumptions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Economic assumptions. 841.405 Section 841... (CONTINUED) FEDERAL EMPLOYEES RETIREMENT SYSTEM-GENERAL ADMINISTRATION Government Costs § 841.405 Economic assumptions. The determinations of the normal cost percentage will be based on the economic...

  1. Applications of a rapid endospore viability assay for monitoring UV inactivation and characterizing arctic ice cores.

    PubMed

    Shafaat, Hannah S; Ponce, Adrian

    2006-10-01

    We have developed a rapid endospore viability assay (EVA) in which endospore germination serves as an indicator for viability and applied it to (i) monitor UV inactivation of endospores as a function of dose and (ii) determine the proportion of viable endospores in arctic ice cores (Greenland Ice Sheet Project 2 [GISP2] cores; 94 m). EVA is based on the detection of dipicolinic acid (DPA), which is released from endospores during germination. DPA concentrations were determined using the terbium ion (Tb3+)-DPA luminescence assay, and germination was induced by L-alanine addition. The concentrations of germinable endospores were determined by comparison to a standard curve. Parallel EVA and phase-contrast microscopy experiments to determine the percentage of germinable spores yielded comparable results (54.3% +/- 3.8% and 48.9% +/- 4.5%, respectively), while only 27.8% +/- 7.6% of spores produced CFU. EVA was applied to monitor the inactivation of spore suspensions as a function of UV dose, yielding reproducible correlations between EVA and CFU inactivation data. The 90% inactivation doses were 2,773 J/m2, 3,947 J/m2, and 1,322 J/m2 for EVA, phase-contrast microscopy, and CFU reduction, respectively. Finally, EVA was applied to quantify germinable and total endospore concentrations in two GISP2 ice cores. The first ice core contained 295 +/- 19 germinable spores/ml and 369 +/- 36 total spores/ml (i.e., the percentage of germinable endospores was 79.9% +/- 9.3%), and the second core contained 131 +/- 4 germinable spores/ml and 162 +/- 17 total spores/ml (i.e., the percentage of germinable endospores was 80.9% +/- 8.8%), whereas only 2 CFU/ml were detected by culturing. PMID:17021233

  2. Pressurized liquid extraction of Aglaonema sp. iminosugars: Chemical composition, bioactivity, cell viability and thermal stability.

    PubMed

    Rodríguez-Sánchez, S; Martín-Ortiz, A; Carrero-Carralero, C; Ramos, S; Sanz, M L; Soria, A C

    2016-08-01

    Pressurized liquid extraction of Aglaonema sp. iminosugars has been optimized. A single cycle under optimal conditions (80mg, 100°C, 2min) was enough to extract ⩾96% of most iminosugars. Further incubation with Saccharomyces cerevisiae for 5h removed coextracted interfering low molecular weight carbohydrates from extracts of different Aglaonema cultivars. A complete characterization of these extracts was carried out by gas chromatography-mass spectrometry: three iminosugars were tentatively identified for the first time; α-homonojirimycin and 2,5-dideoxy-2,5-imino-d-mannitol were the major iminosugars determined. α-Glucosidase inhibition activity, cell viability and thermal stability of Aglaonema extracts were also evaluated. Extracts with IC50 for α-glucosidase activity in the 0.010-0.079mgmL(-1) range showed no decrease of Caco-2 cell viability at concentrations lower than 125μgmL(-1) and were stable at 50°C for 30days. These results highlight the potential of Aglaonema extracts as a source of bioactives to be used as functional ingredients. PMID:26988476

  3. Parental age, gametic age, and inbreeding interact to modulate offspring viability in Drosophila melanogaster.

    PubMed

    Tan, Cedric K W; Pizzari, Tommaso; Wigby, Stuart

    2013-10-01

    In principle, parental relatedness, parental age, and the age of parental gametes can all influence offspring fitness through inbreeding depression and the parental effects of organismal and postmeiotic gametic senescence. However, little is known about the extent to which these factors interact and contribute to fitness variation. Here, we show that, in Drosophila melanogaster, offspring viability is strongly affected by a three-way interaction between parental relatedness, parental age, and gametic age at successive developmental stages. Overall egg-to-adult viability was lowest for offspring produced with old gametes of related, young parents. This overall effect was largely determined at the pupa-adult stage, although three-way interactions between parental relatedness, parental age and gametic age also explained variation in egg hatchability and larva-pupa survival. Controlling for the influence of parental and gametic age, we show that inbreeding depression is negligible for egg hatchability but significant at the larva-pupa and pupa-adult stages. At the pupa-adult stage, where offspring could be sexed, parental relatedness, parental age, and gametic age interacted differently in male and female offspring, with daughters suffering higher inbreeding depression than sons. Collectively, our results demonstrate that the architecture of offspring fitness is strongly influenced by a complex interaction between parental effects, inbreeding depression and offspring sex. PMID:24094353

  4. Antigenicity and viability of Anisakis larvae infesting hake heated at different time-temperature conditions.

    PubMed

    Vidacek, Sanja; de las Heras, Cristina; Solas, Maria Teresa; Mendizábal, Angel; Rodriguez-Mahillo, Ana I; Tejada, Margarita

    2010-01-01

    Heat treatments (40 to 94 degrees Celsius, 30 s to 60 min) were applied to different batches of Anisakis simplex L3 larvae isolated from hake ovaries and viscera to study the effect of heat on the viability of the larvae measured as mobility, emission of fluorescence under UV light, and changes in color after staining with specific dyes, and on A. simplex antigenic proteins. The aim was to determine the lowest time-temperature conditions needed to kill the larvae to avoid anisakiasis in consumers, and to evaluate whether high temperature modifies the antigenicity of A. simplex extracts. Heating at 60 degrees Celsius for 10 min (recommended by some authors) was considered unsafe, as differences in viability between batches were found, with some larvae presenting spontaneous movements in one batch. At higher temperatures (> or = 70 degrees Celsius for > or = 1 min), no movement of the larvae was observed. Antigenic protein Ani s 4 and A. simplex crude antigens were detected in the larvae heated at 94 + or - 1 degrees Celsius for 3 min. This indicates that allergic symptoms could be provoked in previously sensitized consumers, even if the larvae were killed by heat treatment. PMID:20051205

  5. Opiates do not violate the viability and proliferative activity of human articular chondrocytes.

    PubMed

    Chechik, Ofir; Arbel, Ron; Salai, Moshe; Gigi, Roy; Beilin, Mark; Flaishon, Ron; Sever, Ronen; Khashan, Morsi; Ben-Tov, Tomer; Gal-Levy, Ronit; Yayon, Avner; Blumenstein, Sara

    2014-09-01

    Articular cartilage injuries present a challenge for the clinician. Autologous chondrocyte implantation embedded in scaffolds are used to treat cartilage defects with favorable outcomes. Autologous serum is often used as a medium for chondrocyte cell culture during the proliferation phase of the process of such products. A previous report showed that opiate analgesics (fentanyl, alfentanil and diamorphine) in the sera have a significant inhibitory effect on chondrocyte proliferation. In order to determine if opiates in serum inhibit chondrocyte proliferation, twenty two patients who underwent knee arthroscopy and were anesthetized with either fentanyl or remifentanil were studied. Blood was drawn before and during opiate administration and up to 2 h after its discontinuation. The sera were used as medium for in vitro proliferation of both cryopreserved and freshly isolated chondrocytes, and the number and viability of cells were measured. There was no difference in the yield or cell viability between the serum samples of patients anesthetized with fentanyl when either fresh or cryopreserved human articular chondrocytes (hACs) were used. Some non-significant reduction in the yield of cells was observed in the serum samples of patients anesthetized with remifentanil when fresh hAC were used. We conclude that Fentanyl in human autologous serum does not inhibit in vitro hAC proliferation. Remifentanil may show minimal inhibitory effect on in vitro fresh hAC proliferation. PMID:24046083

  6. Ischemia-reperfusion model in rat spinal cord: cell viability and apoptosis signaling study

    PubMed Central

    de Lavor, Mrio Srgio Lima; Binda, Nancy Scardua; Fukushima, Fabola Bono; Caldeira, Ftima Maria Caetano; da Silva, Juliana Figueira; Silva, Carla Maria Osrio; de Oliveira, Karen Maciel; Martins, Bernardo de Caro; Torres, Bruno Benetti Junta; Rosado, Isabel Rodrigues; Gomez, Renato Santiago; Gomez, Marcus Vincius; de Melo, Eliane Gonalves

    2015-01-01

    This work aimed at determining the ideal ischemia time in an in vitro ischemia-reperfusion model of spinal cord injury. Rat spinal cord slices were prepared and then exposed or not to oxygen deprivation and low glucose (ODLG) for 30, 45, 60, 75 and 90 minutes. Cell viability was assessed by triphenyltetrazolium (TTC), lactate dehydrogenase (LDH) release, and fluorochrome dyes specific for cell dead (ethidium homodimer) using the apotome system. Glutamate release was enzymatically measured by a fluorescent method. Gene expression of apoptotic factors was assessed by real time RT-PCR. Whereas spinal cord slices exposed to ODLG exhibited mild increase in fluorescence for 30 minutes after the insult, the 45, 60, 75 and 90 minutes caused a 2-fold increase. ODLG exposure for 45, 60, 75 or 90 minutes, glutamate and LDH release were significantly elevated. nNOS mRNA expression was overexpressed for 45 minutes and moderately increased for 60 minutes in ODLG groups. Bax/bcl-xl ratio, caspase 9 and caspase 3 mRNA expressions were significantly increased for 45 minutes of ODLG, but not for 30, 60, 75 and 90 minutes. Results showed that cell viability reduction in the spinal cord was dependent on ischemic time, resulting in glutamate and LDH release. ODLG for 45 minutes was adequate for gene expression evaluation of proteins and proteases involved in apoptosis pathways. PMID:26617703

  7. Study of the competitive viability of minority fuel oil marketers. Final report

    SciTech Connect

    1981-09-30

    Previous studies on the competitive viability of the fuel oil heating market had addressed some of the unique problems facing minority fuel oil marketers (MFMs) within the total market sector (TMS). This study focused on identifying and developing quantitative information on MFMs in the TMS. The specific objective was to determine whether the business problems experienced by MFMs were directly related to their minority status or were characterstic of any firm in the TMS operating under comparable conditions. As an overall conclusion, thorough investigation of the MFMs considered to constitute the universe of minoriy firms within the TMS did not reveal any evidence of overt discrimination affecting the competitive viability of MFMs. Upon analysis, the problems reported by MFMs could not be reasonably ascribed to discrimination on the basis of their minority business status. The study, however, did point up problems unique to MFMs as the result of typical operational and financial characteristics. For example, MFMs, compared to the TMS norm, have not been in the market as long and are smaller in terms of total assets, number of employees, number of trucks, number of accounts and annual volume of oil delivered. Their primary customers are low-income families in urban areas. Financial indicators suggest that the average MFM does not have long-term financial stability. The basis for this overall conclusion, derived by analyses of information from MFMs, as well as many independent sources, is summarized in three parts: (1) MFM industry profile; (2) financial analyses; and (3) problem analyses.

  8. Gallic acid reduces cell viability, proliferation, invasion and angiogenesis in human cervical cancer cells

    PubMed Central

    ZHAO, BING; HU, MENGCAI

    2013-01-01

    Gallic acid is a trihydroxybenzoic acid, also known as 3,4,5-trihydroxybenzoic acid, which is present in plants worldwide, including Chinese medicinal herbs. Gallic acid has been shown to have cytotoxic effects in certain cancer cells, without damaging normal cells. The objective of the present study was to determine whether gallic acid is able to inhibit human cervical cancer cell viability, proliferation and invasion and suppress cervical cancer cell-mediated angiogenesis. Treatment of HeLa and HTB-35 human cancer cells with gallic acid decreased cell viability in a dose-dependent manner. BrdU proliferation and tube formation assays indicated that gallic acid significantly decreased human cervical cancer cell proliferation and tube formation in human umbilical vein endothelial cells, respectively. Additionally, gallic acid decreased HeLa and HTB-35 cell invasion in vitro. Western blot analysis demonstrated that the expression of ADAM17, EGFR, p-Akt and p-Erk was suppressed by gallic acid in the HeLa and HTB-35 cell lines. These data indicate that the suppression of ADAM17 and the downregulation of the EGFR, Akt/p-Akt and Erk/p-Erk signaling pathways may contribute to the suppression of cancer progression by Gallic acid. Gallic acid may be a valuable candidate for the treatment of cervical cancer. PMID:24843386

  9. Effects of borate-based bioactive glass on neuron viability and neurite extension.

    PubMed

    Marquardt, Laura M; Day, Delbert; Sakiyama-Elbert, Shelly E; Harkins, Amy B

    2014-08-01

    Bioactive glasses have recently been shown to promote regeneration of soft tissues by positively influencing tissue remodeling during wound healing. We were interested to determine whether bioactive glasses have the potential for use in the treatment of peripheral nerve injury. In these experiments, degradable bioactive borate glass was fabricated into rods and microfibers. To study the compatibility with neurons, embryonic chick dorsal root ganglia (DRG) were cultured with different forms of bioactive borate glass. Cell viability was measured with no media exchange (static condition) or routine media exchange (transient condition). Neurite extension was measured within fibrin scaffolds with embedded glass microfibers or aligned rod sheets. Mixed cultures of neurons, glia, and fibroblasts growing in static conditions with glass rods and microfibers resulted in decreased cell viability. However, the percentage of neurons compared with all cell types increased by the end of the culture protocol compared with culture without glass. Furthermore, bioactive glass and fibrin composite scaffolds promoted neurite extension similar to that of control fibrin scaffolds, suggesting that glass does not have a significant detrimental effect on neuronal health. Aligned glass scaffolds guided neurite extension in an oriented manner. Together these findings suggest that bioactive glass can provide alignment to support directed axon growth. PMID:24027222

  10. A multi-parametric approach assessing microbial viability and organic matter characteristics during managed aquifer recharge.

    PubMed

    Kim, Hyun-Chul; Noh, Jin Hyung; Chae, So-Ryong; Choi, Jaewon; Lee, Yunho; Maeng, Sung Kyu

    2015-08-15

    Soil column (SC) experiments were conducted to investigate the feasibility of using silver nanoparticles (AgNPs) as microbial inhibitors; the microbial viability affecting the degradation of pharmaceutically active compounds (PhACs) and the characteristics of organic matter during managed aquifer recharge were specifically evaluated. Natural surface water samples treated with AgNPs (0, 2.5, 5, and 10 mg L(-1)) were continually fed into the soil columns for 2 years. The adverse impact of AgNPs on the cell membrane integrity and microbial enzymatic activity was quantitatively determined using flow cytometry and adenosine triphosphate analysis. The increase in AgNP concentration in the feed water (up to 10 mg L(-1)) resulted in a corresponding deterioration in the performance of the managed aquifer recharge (MAR), with respect to the removal of organic carbon, oxidation of nitrogenous compounds, and PhAC attenuation. The fluorescence excitation-emission matrices of feed water and treated water showed the favorable removal of protein-like substances compared to humic-like substances regardless of the AgNP concentrations; however, the extent of removed fractions decreased noticeably when the microbial viability was lowered via AgNP treatment. The biological oxidation of organic nitrogen was almost completely inhibited when 10 mg L(-1) AgNP was added during soil passage. The attenuation of bezafibrate, ketoprofen, diclofenac, clofibric acid, and gemfibrozil was strongly associated with the significant deterioration in biodegradation as a result of AgNP activity. PMID:25897734

  11. Effect of Selenate on Viability and Selenomethionine Accumulation of Chlorella sorokiniana Grown in Batch Culture

    PubMed Central

    Vílchez, Carlos; Torronteras, Rafael; Vigara, Javier; Gómez-Jacinto, Veronica; Janzer, Nora; Gómez-Ariza, José-Luis; Márová, Ivana

    2014-01-01

    The aim of this work was to study the effect of Se(+VI) on viability, cell morphology, and selenomethionine accumulation of the green alga Chlorella sorokiniana grown in batch cultures. Culture exposed to sublethal Se concentrations of 40 mg·L−1 (212 μM) decreased growth rates for about 25% compared to control. A selenate EC50 value of 45 mg·L−1 (238.2 μM) was determined. Results showed that chlorophyll and carotenoids contents were not affected by Se exposure, while oxygen evolution decreased by half. Ultrastructural studies revealed granular stroma, fingerprint-like appearance of thylakoids which did not compromise cell activity. Unlike control cultures, SDS PAGE electrophoresis of crude extracts from selenate-exposed cell cultures revealed appearance of a protein band identified as 53 kDa Rubisco large subunit of Chlorella sorokiniana, suggesting that selenate affects expression of the corresponding chloroplast gene as this subunit is encoded in the chloroplast DNA. Results revealed that the microalga was able to accumulate up to 140 mg·kg−1 of SeMet in 120 h of cultivation. This paper shows that Chlorella sorokiniana biomass can be enriched in the high value aminoacid SeMet in batch cultures, while keeping photochemical viability and carbon dioxide fixation activity intact, if exposed to suitable sublethal concentrations of Se. PMID:24688385

  12. Viability and Effects on Bacterial Proteins by Oral Rinses with Hypochlorous Acid as Active Ingredient.

    PubMed

    Castillo, Diana Marcela; Castillo, Yormaris; Delgadillo, Nathaly Andrea; Neuta, Yineth; Jola, Johana; Caldern, Justo Leonardo; Lafaurie, Gloria Ins

    2015-10-01

    This study investigated the effect of hypochlorous acid (HOCl) rinses and chlorhexidine (CHX) on the bacterial viability of S. mutans, A. israelii, P. gingivalis, A. actinomycetemcomitans, E. corrodens, C. rectus, K. oxytoca, K. pneumoniae and E. cloacae. The percentage of live bacteria was tested by fluorescence method using Live/Dead kit(r) and BacLight (Molecular Probes(r)) and compared between groups by the Kruskal-Wallis and U Mann-Whitney tests with Bonferroni correction (p value<0.012). The effect of HOCl and CHX on total proteins of P. gingivalis and S. mutans was determined by SDS-PAGE. CHX showed a higher efficacy than HOCl against S. mutans, A. israelii, E. corrodens and E. cloacae (p<0.001) while HOCl was more effective than CHX against P. gingivalis, A. actinomycetemcomitans, C. rectus and K. oxytoca (p=0.001). CHX and HOCl had similar efficacy against K. pneumoniae. Proteins of P. gingivalis and S. mutans were affected similarly by HOCl and CHX. HOCl reduced the bacterial viability especially in periodontopathic bacteria, which may support its use in the control of subgingival biofilm in periodontal patients. PMID:26647939

  13. Application of cyclic biamperometry to viability and cytotoxicity assessment in human corneal epithelial cells.

    PubMed

    Rahimi, Mehdi; Youn, Hyun-Yi; McCanna, David J; Sivak, Jacob G; Mikkelsen, Susan R

    2013-05-01

    The application of cyclic biamperometry to viability and cytotoxicity assessments of human corneal epithelial cells has been investigated. Electrochemical measurements have been compared in PBS containing 5.0 mM glucose and minimal essential growth medium. Three different lipophilic mediators including dichlorophenol indophenol, 2-methyl-1,4-naphthoquinone (also called menadione or vitamin K3) and N,N,N',N'-tetramethyl-p-phenylenediamine have been evaluated for shuttling electrons across the cell membrane to the external medium. Transfer of these electrons to ferricyanide in the extra cellular medium results in the accumulation of ferrocyanide. The amount of ferrocyanide is then determined using cyclic biamperometry and is related to the extent of cell metabolic activity and therefore cell viability. To illustrate cytotoxicity assessment of chemicals, hydrogen peroxide, benzalkonium chloride and sodium dodecyl sulfate have been chosen as sample toxins, the cytotoxicities of which have been evaluated and compared to values reported in the literature. Similar values have been reported using colorimetric assays; however, the simplicity of this electrochemical assay can, in principle, open the way to miniaturization onto lab-on-chip devices and its incorporation into tiered-testing approaches for cytotoxicity assessment. PMID:23443523

  14. Cell viability and proteomic analysis in cultured neurons exposed to methylmercury.

    PubMed

    Vendrell, Iolanda; Carrascal, Montserrat; Vilaró, Maria-Teresa; Abián, Joaquín; Rodríguez-Farré, Eduard; Suñol, Cristina

    2007-04-01

    Methylmercury is an environmental contaminant with special selectivity for cerebellar granule cells. The aim of this study was to determine the effect of long-term methylmercury exposure on cell viability and cellular proteome in cultured cerebellar granule cells. Primary cultures of mice cerebellar granule cells were treated with 0-300 nM methylmercury at 2 days in vitro (div) and afterwards the cells were harvested at 12 div. 100 nM methylmercury produced loss of cell viability, reduced intracellular glutamate content and increased lipid peroxidation. Glutamate transport was not modified by methylmercury treatment. Cell death induced by 300 nM methylmercury at 8 div was apoptotic without producing activation of caspase 3. Extracts of total protein were separated by 2D electrophoresis. Around 800 protein spots were visualized by silver staining in SDS-polyacrylamide gels. Gel images were digitized and protein patterns were analysed by image analysis. Several spots were identified through a combination of peptide mass fingerprinting and matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS). The mitochondrial protein 3-ketoacid-coenzyme A transferase I was decreased up to 39% of controls at concentrations of methylmercury that did not produce cytotoxic effects, whereas the cytoplasmic proteins lactate dehydrogenase chain B and actin did not change. PMID:17615107

  15. Effects of lead on viability and intracellular metal content of C6 rat glioma cells

    SciTech Connect

    Tiffany-Castiglioni, E.; Garcia, D.M.; Wu, J.N.; Zmudzki, J.; Bratton, G.R.

    1988-01-01

    Cultured C6 rat glioma cells were exposed to lead (Pb) acetate (0, 1, 10, or 100 ..mu..M) for 3-4 d. Cells were analyzed for changes in viability and intracellular lead, iron, and copper concentrations after Pb treatment was discontinued. The results were compared with previous findings on astroglia and oligodendroglia in culture in order to evaluate C6 cultures as a model for Pb toxicity in glia. Viability was measured by three methods on the day Pb was removed from the cells (designated d 0), and 2 and 9 d after Pb treatment was discontinued (designated d 2 and 9). The methods used were trypan blue dye exclusion, total cell counts, and incorporation of (/sup 3/H)-L-leucine into proteins. With respect to Pb and Fe uptake, C6 cells closely resembled immature astroglia in culture. Unlike C6 cells, however, astroglia showed elevations of intracellular Fe and Cu after treatment. Thus, Pb effects on C6 cells resembled those on cultured oligodendroglia and astroglia in some respects but not in others. C6 cells appear to be an adequate model for selected events in glial toxicosis, such as PB-stimulated protein synthesis in oligodendroglia and Pb uptake in astroglia, but not Pb-induced alterations of intracellular Cu and Fe in astroglia. Their use as a model for glial progenitor cells in Pb toxicity studies remains to be determined.

  16. Effect of cadmium on cellular viability in two species of microalgae (Scenedesmus sp. and Dunaliella viridis).

    PubMed

    Marcano, Letty Beatriz C; Carruyo, Ingrid M; Montiel, Xiomara M; Morales, Carolina B; de Soto, Patricia Moreno

    2009-07-01

    We determined the effect of several concentrations of cadmium (0, 5, 10, and 20 microg/l) on cellular viability in the microalgae Scenedesmus sp. and Dunaliella viridis, by measuring growth at 0, 24, 48, 72, and 96 h and pigment production at 10 days. Algae were obtained from the Nonvascular Plant Laboratory collection, in the Facultad Experimental de Ciencias, Universidad del Zulia, Venezuela. Growth was measured by cellular counting, while pigment content was evaluated using conventional spectrophotometric techniques. Growth of both species decreased in the exposed cultures comparing with the control, but its behavior was similar, because in both control and exposed cultures, its was observed an adaptive phase in the first hours, as well as a growth phase after 72 h. Cadmium concentrations above 10 microg/l produced an adverse effect on pigment production, depending on the concentration and/or exhibition time. However, even though cadmium inhibited growth and pigment production, levels of both parameters indicated cellular viability, demonstrating the adaptability of the algae cultures when they were exposed to the metal. PMID:19172231

  17. A simplified economic filter for open-pit mining and heap-leach recovery of copper in the United States

    USGS Publications Warehouse

    Long, Keith R.; Singer, Donald A.

    2001-01-01

    Determining the economic viability of mineral deposits of various sizes and grades is a critical task in all phases of mineral supply, from land-use management to mine development. This study evaluates two simple tools for estimating the economic viability of porphyry copper deposits mined by open-pit, heap-leach methods when only limited information on these deposits is available. These two methods are useful for evaluating deposits that either (1) are undiscovered deposits predicted by a mineral resource assessment, or (2) have been discovered but for which little data has been collected or released. The first tool uses ordinary least-squared regression analysis of cost and operating data from selected deposits to estimate a predictive relationship between mining rate, itself estimated from deposit size, and capital and operating costs. The second method uses cost models developed by the U.S. Bureau of Mines (Camm, 1991) updated using appropriate cost indices. We find that the cost model method works best for estimating capital costs and the empirical model works best for estimating operating costs for mines to be developed in the United States.

  18. The evolutionary dynamics of haplodiploidy: Genome architecture and haploid viability.

    PubMed

    Blackmon, Heath; Hardy, Nate B; Ross, Laura

    2015-11-01

    Haplodiploid reproduction, in which males are haploid and females are diploid, is widespread among animals, yet we understand little about the forces responsible for its evolution. The current theory is that haplodiploidy has evolved through genetic conflicts, as it provides a transmission advantage to mothers. Male viability is thought to be a major limiting factor; diploid individuals tend to harbor many recessive lethal mutations. This theory predicts that the evolution of haplodiploidy is more likely in male heterogametic lineages with few chromosomes, as genes on the X chromosome are often expressed in a haploid environment, and the fewer the chromosome number, the greater the proportion of the total genome that is X-linked. We test this prediction with comparative phylogenetic analyses of mites, among which haplodiploidy has evolved repeatedly. We recover a negative correlation between chromosome number and haplodiploidy, find evidence that low chromosome number evolved prior to haplodiploidy, and that it is unlikely that diplodiploidy has reevolved from haplodiploid lineages of mites. These results are consistent with the predicted importance of haploid male viability. PMID:26462452

  19. Tau Oligomers Impair Artificial Membrane Integrity and Cellular Viability*

    PubMed Central

    Flach, Katharina; Hilbrich, Isabel; Schiffmann, Andrea; Gärtner, Ulrich; Krüger, Martin; Leonhardt, Marion; Waschipky, Hanka; Wick, Lukas; Arendt, Thomas; Holzer, Max

    2012-01-01

    The microtubule-associated protein Tau is mainly expressed in neurons, where it binds and stabilizes microtubules. In Alzheimer disease and other tauopathies, Tau protein has a reduced affinity toward microtubules. As a consequence, Tau protein detaches from microtubules and eventually aggregates into β-sheet-containing filaments. The fibrillization of monomeric Tau to filaments is a multistep process that involves the formation of various aggregates, including spherical and protofibrillar oligomers. Previous concepts, primarily developed for Aβ and α-synuclein, propose these oligomeric intermediates as the primary cytotoxic species mediating their deleterious effects through membrane permeabilization. In the present study, we thus analyzed whether this concept can also be applied to Tau protein. To this end, viability and membrane integrity were assessed on SH-SY5Y neuroblastoma cells and artificial phospholipid vesicles, treated with Tau monomers, Tau aggregation intermediates, or Tau fibrils. Our findings suggest that oligomeric Tau aggregation intermediates are the most toxic compounds of Tau fibrillogenesis, which effectively decrease cell viability and increase phospholipid vesicle leakage. Our data integrate Tau protein into the class of amyloidogenic proteins and enforce the hypothesis of a common toxicity-mediating mechanism for amyloidogenic proteins. PMID:23129775

  20. Proteus mirabilis viability after lithotripsy of struvite calculi

    NASA Astrophysics Data System (ADS)

    Prabakharan, Sabitha; Teichman, Joel M. H.; Spore, Scott S.; Sabanegh, Edmund; Glickman, Randolph D.; McLean, Robert J. C.

    2000-05-01

    Urinary calculi composed of struvite harbor urease-producing bacteria within the stone. The photothermal mechanism of holmium:YAG lithotripsy is uniquely different than other lithotripsy devices. We postulated that bacterial viability of struvite calculi would be less for calculi fragmented with holmium:YAG irradiation compared to other lithotripsy devices. Human calculi of known struvite composition (greater than 90% magnesium ammonium phosphate hexahydrate) were incubated with Proteus mirabilis. Calculi were fragmented with no lithotripsy (controls), or shock wave, intracorporeal ultrasonic, electrohydraulic, pneumatic, holmium:YAG or pulsed dye laser lithotripsy. After lithotripsy, stone fragments were sonicated and specimens were serially plated for 48 hours at 38 C. Bacterial counts and the rate of bacterial sterilization were compared. Median bacterial counts (colony forming units per ml) were 8 X 106 in controls and 3 X 106 in shock wave, 3 X 107 in ultrasonic, 4 X 105 in electrohydraulic, 8 X 106 in pneumatic, 5 X 104 in holmium:YAG and 1 X 106 in pulsed dye laser lithotripsy, p less than 0.001. The rate of bacterial sterilization was 50% for holmium:YAG lithotripsy treated stones versus 0% for each of the other cohorts, p less than 0.01. P. mirabilis viability is less after holmium:YAG irradiation compared to other lithotripsy devices.